Bibliothek

Ihre E-Mail wurde erfolgreich gesendet. Bitte prüfen Sie Ihren Maileingang.

Leider ist ein Fehler beim E-Mail-Versand aufgetreten. Bitte versuchen Sie es erneut.

Vorgang fortführen?

Exportieren
Filter
  • 1995-1999  (304)
  • 1999  (304)
  • Rat  (115)
  • Life and Medical Sciences  (96)
  • MRI  (93)
  • Nuclear reactions
Materialart
Erscheinungszeitraum
  • 1995-1999  (304)
Jahr
Schlagwörter
  • 1
    Digitale Medien
    Digitale Medien
    Springer
    Trauma und Berufskrankheit 1 (1999), S. S92 
    ISSN: 1436-6274
    Schlagwort(e): Schlüsselwörter Wachstumsalter ; MRI ; Beckenfraktur ; Wirbelsäulenfraktur ; Key words Childhood ; Magnetic resonance imaging ; Pelvic fracture ; Spinal injury
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Medizin
    Beschreibung / Inhaltsverzeichnis: Abstract According to the literature, from 1950 to 1995 the overall risk for children of sustaining a fracture of the spinal column or the pelvic ring doubled, the main reason being the increasing incidence of high-energy trauma caused by newly popular sporting activities such as skateboarding, inline skating and mountain biking. Nonetheless, even specialized pediatric level I trauma centers in Europe and the United States of America report an incidence of below 5% for severe spinal injuries and fractures of the pelvis. Although these specific injury patters are seen relatively infrequently, whenever present they are still highly indicative of high-velocity injury mechanisms, frequently revealing a combination of injuries – each of which would be serious in itself – involving the body cavities and the soft tissues of the trunk an extremities. In summary, spinal cord injuries and pelvic ring fractures are rare but can be serious: cervical and spinal cord injuries without radiological abnormality appear to be more frequent than in adults, and the availability of nuclear magnetic imaging technologies has helped in the diagnosis of unsuspected cord injury in children. In addition, retrospective analysis of purely nonoperative management of highly unstable C-type injuries of the spine and the pelvic ring reveal some unsatisfactory results, so that specifically for these injury morphologies the alternative of an operative strategy might be considered. The purpose of this presentation is to discuss various injury patterns in which an operative concept could be considered, particularly for a multiply injured child.
    Notizen: Zusammenfassung Verletzungen des Rückenmarks und Sprengungen des knöchernen Beckenrings liegen im Kindesalter auch im Krankengut spezialisierter Zentren unter 5%. Besonders beachtenswert erscheint hierbei, daß Rückenmark- und besonders Halswirbelsäulenverletzungen v. a. beim Kind häufig keine ossäre Mitbeteiligung der Wirbelsäule zeigen und erst durch kernspintomographische Diagnostik erfaßt werden können. Desgleichen zeigt sich bei der retrospektiven Auswertung, daß ein pauschales, rein konservatives Management aller Verletzungstypen, d. h. v.a. der sog. C-Verletzungstypen an der Wirbelsäule und am Becken, z. T. unbefriedigende Behandlungsergebnisse zeigt und daher zunehmend bei bestimmten, im weiteren näher besprochenen Verletzungskonstellationen ein eher operatives Grundkonzept diskutiert wird. Neue Erkenntnisse zur Diagnostik und Therapie der Wirbelsäulen- und Beckenverletzung beim Kind liegen insofern vor, als 1. neuere epidemiologische Erhebungen heute eine präzisere, d. h. nicht nur empirisch gesicherte Unterscheidung der selten von eher regelmäßig anzutreffenden Verletzungstypen und Frakturmorphologien erlauben, 2. durch vergleichsweise „neue“ Sportarten wie „Scate-boarding“ und „Mountain-biking“ ganz generell eine statistisch belegte Zunahme von Hochrasanztraumen und komplexen Verletzungsmustern beim Kind beobachtet werden kann sowie 3. generell v.a. beim mehrfachverletzten Kind heute eine eher aggressivere Gangart, d. h. ein in bestimmten Einzelaspekten eher operatives Versorgungskonzept angestrebt wird. Gegenstand der vorliegenden Arbeit sind 1. eine Analyse der als besonders bedeutsam erkannten Verletzungsformen sowie 2. eine Darstellung der heute in Veränderung begriffenen Behandlungskonzepte v.a. beim mehrfachverletzten Kind.
    Materialart: Digitale Medien
    Bibliothek Standort Signatur Band/Heft/Jahr Verfügbarkeit
    BibTip Andere fanden auch interessant ...
  • 2
    ISSN: 1436-2023
    Schlagwort(e): Key words: hip ; acetabulum ; labrum ; MRI ; radial-sequence
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Medizin
    Notizen: Abstract: We investigated the usefulness of a radial-sequence magnetic resonance imaging (MRI) technique in the visualization of the acetabular labrum, which surrounds the acetabulum. In 22 hip joints of 12 volunteers, T2-weighted images were obtained on 24 radial planes of the acetabular rim, set at 15°-intervals, using the small tip angle gradient echo method. We examined 7 planes in the weight-bearing portion. The acetabular labrum in the weight-bearing portion was depicted in good contrast to the surrounding tissues. The shape of the labrum differed among individuals and also in the anterior and posterior portions of the labrum. The signal intensity of the labrum was low or partially moderate. There was a high signal intensity band on the base of the acetabular labrum in several portions, which should be carefully interpreted to avoid confusion with abnormality. We concluded that radial-sequence MRI could be a useful technique for evaluation of the condition of the acetabular labrum in the weight-bearing portion.
    Materialart: Digitale Medien
    Bibliothek Standort Signatur Band/Heft/Jahr Verfügbarkeit
    BibTip Andere fanden auch interessant ...
  • 3
    Digitale Medien
    Digitale Medien
    Springer
    Surgical and radiologic anatomy 20 (1999), S. 413-417 
    ISSN: 1279-8517
    Schlagwort(e): Penis ; Ligaments ; MRI ; Erection
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Medizin
    Notizen: Abstract The suspensory system of the penis acquires clinical importance in reparative surgery, traumatology and through its role in erection. The aim of this study was to identify the different anatomic structures constituting the suspensory ligament by dissection and by magnetic resonance imaging (MRI). Ten unembalmed male subjects were used for dissection of the region of the base of the penis. Ten volunteer patients underwent MRI of the penis before and after the injection of prostaglandin (PGE1). The suspensory apparatus consisted of separate ligamentous structures: the fundiform ligament, which is lateral, superficial and not adherent to the tunica albuginea of the corpora cavernosa; the suspensory ligament properly so-called, further back, stretching between the pubis and the tunica albuginea of the corpora cavernosa and consisting of two lateral, circumferential, and one median bundles, which circumscribed the dorsal vein of the penis. These structures were identifiable in MRI and their supporting role was evidenced during tests of erection. The suspensory ligament seemed to maintain the base of the penis in front of the pubis and to behave as a major point of support for the mobile portion of the penis during erection.
    Materialart: Digitale Medien
    Bibliothek Standort Signatur Band/Heft/Jahr Verfügbarkeit
    BibTip Andere fanden auch interessant ...
  • 4
    Digitale Medien
    Digitale Medien
    Springer
    Italian journal of neurological sciences 20 (1999), S. 247-249 
    ISSN: 1126-5442
    Schlagwort(e): Key words Superficial siderosis of the central nervous system ; MRI ; Anticoagulant therapy
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Medizin
    Notizen: Abstract Superficial siderosis of the central nervous system is a rare condition characterized by deposition of haemosiderin in the leptomeninges and in the subpial layers of the brain and spinal cord. With the widespread use of magnetic resonance imaging, an increasing number of cases of superficial siderosis are being discovered, secondary forms being more frequent than idiopathic ones. We report a 78-year-old man in oral anticoagulant therapy, who presented neurosensory hearing loss, gait ataxia and spastic paraparesis. Magnetic resonance imaging suggested the diagnosis of superficial siderosis of the central nervous system, without an evident bleeding source.
    Materialart: Digitale Medien
    Bibliothek Standort Signatur Band/Heft/Jahr Verfügbarkeit
    BibTip Andere fanden auch interessant ...
  • 5
    Digitale Medien
    Digitale Medien
    Springer
    Italian journal of neurological sciences 20 (1999), S. 303-307 
    ISSN: 1126-5442
    Schlagwort(e): Key words Lyme disease ; Chronic neuroborreliosis ; Children ; MRI ; Demyelinating disease
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Medizin
    Notizen: Abstract Lyme disease is a polymorphic and multisystemic disease caused by Borrelia burgdorferi. Neurological manifestations are found in 10%–50% of cases. We present 2 cases followed for 5 and 6 years of chronic relapsing-remitting neuroborreliosis. Diagnosis of neuroborreliosis in these cases was based on serum and cerebrospinal fluid findings. We discuss clinical, neurophysiological, laboratory and instrumental aspects regarding the difficulties of reaching a correct diagnosis. Further studies, especially in the field of immunology, should help identify the mechanisms responsible for the disease becoming chronic. With this knowledge, it may be possible to design immunological therapies for relapses, and to prevent the evolution of the disease.
    Materialart: Digitale Medien
    Bibliothek Standort Signatur Band/Heft/Jahr Verfügbarkeit
    BibTip Andere fanden auch interessant ...
  • 6
    Digitale Medien
    Digitale Medien
    Springer
    Amino acids 17 (1999), S. 139-148 
    ISSN: 1438-2199
    Schlagwort(e): Amino acids ; Polyamine oxidase ; Polyamines ; Gender ; Rat
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Medizin
    Notizen: Summary Variations in level of polyamines and their related enzymes are frequently observed in response to some treatments which affect in a different way male and female. The possibility of a gender-related difference in the oxidation of polyamines was investigated in rats by measuring the activity of polyamine oxidase, a ubiquitous enzyme of vertebrate tissues, which transforms spermine into spermidine and spermidine into putrescine. The study was carried out on thymus, spleen, kidney and liver of young rats of both sexes, and female rats showed a lower polyamine oxidase activity than male rats in all the tissues. We also found higher values of spermidine acetylation in female than male rats in thymus and liver. Owing to these gender-related differences, a higher spermidine N-acetyltransferase/ polyamine oxidase ratio was found in female than in male rats. A second gender-related difference was a higher spermidine/spermine ratio in female than in male, the only exception being the thymus. These basal differences possibly account for the gender-related differences of polyamine metabolic enzyme activities in response to some treatments, including drugs or hormones.
    Materialart: Digitale Medien
    Bibliothek Standort Signatur Band/Heft/Jahr Verfügbarkeit
    BibTip Andere fanden auch interessant ...
  • 7
    ISSN: 1438-2199
    Schlagwort(e): Amino acids ; Taurine ; Osmoregulation ; Rat ; Osmolarity sensor protein ENVZ
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Medizin
    Notizen: Summary Although the involvement of taurine in osmoregulation is well-documented and widely accepted, no detailed mechanism for this function has been reported so far. We used subtractive hybridization to study mRNA steady state levels of genes up- or downregulated by taurine. Rats were fed taurine 100mg/kg body weight per day for a period of three days and hearts (total ventricular tissue) of experimental animals and controls were pooled and used for mRNA extraction. mRNAs from two groups were used for subtractive hybridization. Clones of the subtractive library were sequenced and the obtained sequences were identified by gen bank assignment. Two clones were found to contain sequences which could be assigned to the osmolarity sensor protein envZ, showing homologies of 61 and 65%. EnvZ is an inner membrane protein in bacteria, important for osmosensing and required for porine gene regulation. It undergoes autophosphorylation and subsequently phosphorylates OmpR, which in turn binds to the porin (outer membrane protein) promoters to regulate the expression of OmpF and OmpC, major outer membrane porines. This is the first report of an osmosensing mechanism in the mammalian system, which was described in bacteria only. Furthermore, we are assigning a tentative role for taurine in the osmoregulatory process by modifying the expression of the osmoregulatory sensor protein ENVZ.
    Materialart: Digitale Medien
    Bibliothek Standort Signatur Band/Heft/Jahr Verfügbarkeit
    BibTip Andere fanden auch interessant ...
  • 8
    Digitale Medien
    Digitale Medien
    Springer
    Amino acids 17 (1999), S. 301-313 
    ISSN: 1438-2199
    Schlagwort(e): Amino acids ; Taurine ; Transporter ; Rat ; Brain ; Heart
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Medizin
    Notizen: Summary In pro- and eucaryotic life, cellular and subcellular compartments are separated by membranes and the regulated and selective passage of specific molecules across these membranes is a basic and highly conserved principle. We were interested whether taurine, a naturally occuring amino acid, would be able to induce or suppress expression of transporters with the Rationale that taurine was shown to detoxify a series of endogenous toxins and xenobiotics of various chemically non-related structures. For this purpose we used a gene hunting technique, subtractive hybridization, subtracting mRNAs of taurine-treated rat brain and heart from untreated controls. Subtracted mRNAs were then converted to cDNAs, amplified, sequenced and identified by gene bank data. We found five transporter transcripts, the phosphonate transport ATPase PHNC, multidrug transporter homolog MTH104, protein-exportmembrane protein SECD, oligopeptide transporters oppA and oppD, in the brain and two: ABC-transporter BRAF-2 and cation-transport ATPase PACS, in the heart. Homologies of the sequences found were in any case 〉50% thus permitting the identification of transporters with high probability. The biological meaning could be that a naturally occuring amino acid, taurine, modulates complex transport systems. The most prominent finding is the upregulation of a multidrug transporter transcript, explaining a mechanism for the nonselective detoxifying action of taurine.
    Materialart: Digitale Medien
    Bibliothek Standort Signatur Band/Heft/Jahr Verfügbarkeit
    BibTip Andere fanden auch interessant ...
  • 9
    ISSN: 1432-1912
    Schlagwort(e): Key words Asphyxia ; Nitric oxide ; Electron spin ; resonance ; Adrenocorticotropin ; Resuscitation ; S-Methylisothiourea ; Rat
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Medizin
    Notizen: Abstract Anaesthetized rats, endotracheally intubated and mechanically ventilated with room air, were subjected to a 5-min period of asphyxia by turning off the ventilator. The ventilator was then turned back on and, simultaneously, the animals were treated with either the adrenocorticotropin fragment 1–24 [ACTH-(1–24), 160 µg/kg in a volume of 1 ml/kg i.v.] or an equivalent volume of saline. Nitric oxide (NO)-haemoglobin formation was detected ex vivo in arterial blood by electron spin resonance spectrometry; arterial blood pressure, electrocardiogram (ECG) and electroencephalogram (EEG) were monitored for a 60-min observation period, or until prior death. During asphyxia, there was massive formation of NO (red cell concentrations 40–80 µM), associated with a dramatic fall in mean arterial pressure and pulse pressure, marked bradycardia and ECG signs of ischaemic damage, as well as an isoelectric EEG. Treatment with ACTH-(1–24) produced a prompt (within 15 min) and long-lasting drop in NO blood levels, associated with an almost immediate (within 1 min) restoration of cardiovascular function and with a more gradual recovery of EEG, which became normal after 30–40 min; all parameters remained stable throughout the 60-min observation period. In saline-treated rats, on the other hand, there was a further increase in NO blood levels, as detected 3 min after treatment, and all died within 5–8 min. Moreover, pretreatment and treatment with S-methylisothiourea sulphate (SMT, 3 mg/kg i.v.), a relatively specific inhibitor of inducible NO synthase, inhibited NO formation, but did not affect the mortality rate (100% within 5–8 min). The present results provide the first evidence that prolonged asphyxia is associated with high blood concentrations of NO, and that the life-saving effect of melanocortin peptides in severe hypoxic conditions is associated with a complete normalization of NO blood levels. However, the lack of SMT protection in this experimental model seems to rule out the possibility that the ACTH-(1–24)-induced resuscitation is due to an effect on NO overproduction.
    Materialart: Digitale Medien
    Bibliothek Standort Signatur Band/Heft/Jahr Verfügbarkeit
    BibTip Andere fanden auch interessant ...
  • 10
    Digitale Medien
    Digitale Medien
    Springer
    Naunyn-Schmiedeberg's archives of pharmacology 359 (1999), S. 117-122 
    ISSN: 1432-1912
    Schlagwort(e): Key words Ethanol ; Restraint stress ; NMDA receptor complex ; Memantine ; Drug discrimination ; Rat
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Medizin
    Notizen: Abstract There is a large body of experimental evidence that both stress and N-methyl-d-aspartate (NMDA) receptor antagonists may alter acute behavioural effects of ethanol. Notably, an uncompetitive, low-affinity NMDA receptor antagonist, memantine, has been recently claimed to possess anti-craving properties in rats with a long-term history of ethanol consumption. The aim of the present study was to assess the effects of restraint stress and memantine on the dose-response curve of ethanol discrimination. Rats were trained to discriminate 1 g/kg ethanol from saline in the two-lever drug discrimination procedure. When ethanol discrimination was acquired, the subjects were exposed to 30-min sessions of acute restraint stress, and different doses of ethanol (0.25, 0.5 or 1 g/kg) or saline were administered. In subsequent experiments the effects of memantine (2.25 or 4.5 mg/kg) on the cueing effects of ethanol were tested. Neither the stress sessions nor memantine influenced the ethanol discrimination dose-response curve. Moreover, the stress did not alter the rate of responding. However, both doses of memantine tended to increase the rate of responding when given in combination with lower doses of ethanol (0.25–0.5 g/kg). In contrast, 4.5 mg/kg memantine decreased the response rate when combined with 1 g/kg ethanol. These results suggest that: (1) pre-exposure to acute restraint stress or memantine does not affect the dose-response curve of ethanol discrimination; (2) memantine given in combination with low doses of ethanol may stimulate operant behaviour in the food-reinforced drug discrimination procedure.
    Materialart: Digitale Medien
    Bibliothek Standort Signatur Band/Heft/Jahr Verfügbarkeit
    BibTip Andere fanden auch interessant ...
  • 11
    ISSN: 1433-0407
    Schlagwort(e): Schlüsselwörter Hallervorden-Spatz-Krankheit (HSD) ; präsenile Demenz ; MRT ; paramagnetische Substanzen ; Globus pallidus ; Key words Hallervorden-Spatz-Disease (HSD) ; Early onset dementia ; MRI ; Paramagnetic substances ; Globus pallidus
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Medizin
    Beschreibung / Inhaltsverzeichnis: Summary We report the history of a 38 year old patient who began to develop mental deterioration at the age of 26. After a time of 7 years neurological signs like writing dystonia occured. Hallervorden-Spatz-Desease (HSD) was diagnosed at the age of 36 in vivo with the clinical presentation of severe dystonia, rigidity, dementia, and typical signal loss in the globus-pallidus the reticular part of the substantia nigra, and the nucleus ruber in the T-2 weighted MRI. The „eye-of-the-tiger”-sign, a bilateral hyperintensity in the rostral globus pallidus, was not observed in follow-up examinations. HSD is a rare autosomal-recessive or sporadic disease of unknown etiology. In one third of the patients a dementing process is the first clinical sign of the disorder, and is a rare differential diagnosis of early onset dementia.
    Notizen: Zusammenfassung Wir berichten von einem 38jährigen Patienten, der im Alter von 26 Jahren eine progressive Demenz entwickelte. Erst nach einem Krankheitsverlauf von 7 Jahren kam es zur Manifestation eines rasch progredienten, dystonen Syndroms bis hin zur Immobilität im Alter von 36 Jahren. Die Diagnose der Hallervorden-Spatz-Erkrankung (HSD) wurde aufgrund des klinischen Bildes im Spätstadium der Erkrankung mit schwerster Demenz, Dystonie und Rigidität in Zusammenschau mit den typischen Signalauslöschungen in der T2-gewichteten MRT im Globus pallidus, dem Nucleus ruber und dem retikulären Anteil der Substantia nigra gestellt. Das „Eye-of-the-tiger”-Zeichen, eine bilaterale Signalhyperintensität im rostralen Anteil des Globus pallidus, wurde, auch bei Verlaufsuntersuchungen, nicht gefunden. Die Hallervorden-Spatz-Erkrankung ist ein autosomal-rezessiv oder sporadisch auftretendes Krankheitsbild ungeklärter Ätiologie. Da sich bei einem Drittel der Patienten mnestische Störungen im Kurz- und Langzeitgedächnis als Erstsymptom manifestieren, stellt die HSD eine seltene Differentialdiagnose eines präsenilen Demenzsyndroms dar. In der diagnostischen Beurteilung kommt der Magnetresonanztomographie eine wesentliche Bedeutung zu.
    Materialart: Digitale Medien
    Bibliothek Standort Signatur Band/Heft/Jahr Verfügbarkeit
    BibTip Andere fanden auch interessant ...
  • 12
    Digitale Medien
    Digitale Medien
    Springer
    Der Nervenarzt 70 (1999), S. 276-280 
    ISSN: 1433-0407
    Schlagwort(e): Schlüsselwörter Metachromatische Leukodystrophie ; Totschlag ; Hebephrenie ; MRT ; Diagnose ; Key words Metachromatic leukodystrophy ; Homicide ; Hebephrenia ; MRI ; Diagnosis
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Medizin
    Beschreibung / Inhaltsverzeichnis: Summary We report a patient with metachromatic leukodystrophy (MLD) with a first manifestation of homicide. On admission the patient showed a hebephrenia-like syndrom with inappropriate affect, thought disorder and behavioral changes. Magnetic resonance tomography (MRT) findings suggested a diagnosis of MLD, which was confirmed by a decreased activity of leucocyte arylsulfatase A and an excessive urinary sulfatide excretion.
    Notizen: Zusammenfassung Wir berichten von einem Patienten mit metachromatischer Leukodystrophie (MLD), der im Alter von 16 Jahren ein Kind tötete. Bei der klinischen Untersuchung zeigte er ein hebephrenes Syndrom mit veränderter Affektivität, formalen Denkstörungen und Verhaltensauffälligkeiten. Bei der neuropsychologischen Testung wurde eine starke Beeinträchtigung von Planen und Problemlösen bei insgesamt überdurchschnittlicher Intelligenz nachgewiesen. Die neurologischen und internistischen Befunde waren unauffällig. Anhaltspunkte für eine MLD fanden sich im Magnetresonanztomogramm (MRT) und wurden biochemisch bestätigt.
    Materialart: Digitale Medien
    Bibliothek Standort Signatur Band/Heft/Jahr Verfügbarkeit
    BibTip Andere fanden auch interessant ...
  • 13
    ISSN: 1433-0407
    Schlagwort(e): Schlüsselwörter Septum pellucidum ; Entwicklungs- störungen ; Zerebrale Fehlbildungen ; Schizophrenie ; Magnetresonanztomographie ; Key words Septum pellucidum ; Developmental disorder ; Cerebral malformations ; Schizophrenia ; MRI
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Medizin
    Beschreibung / Inhaltsverzeichnis: Summary Absence of the septum pellucidum is a rare developmental disorder of the human brain. Previous reports focused on the association with other cerebral anomalies. We present MRI scans showing an isolated absence of the septum pellucidum. The patient was suffering from a schizophrenic psychosis. Mental retardation or epileptic seizures, which are often found in more complex developmental brain disorders, were not observed. The septal area is part of the limbic system and aplasia of the septum pellucidum could indicate developmental anomalies of the limbic system. The concept of cerebral maldevelopment and the limbic system in schizophrenic psychosis is discussed.
    Notizen: Zusammenfassung Die isolierte Aplasie des Septum pellucidum gehört zu den seltenen dysplastischen Fehlbildungen des Gehirns. Während in älteren Arbeiten das Fehlen des Septum pellucidum meistens im Zusammenhang mit weiteren zerebralen Fehlbildungen berichtet wird, so zeigen neuere Untersuchungen doch häufiger auch isolierte Aplasien ohne weitere Fehlbildungen des Gehirns. Dabei scheint ein breites Spektrum der Fehlbildungen von komplexen Hirnfehlbildungen bis hin zur einfachen Aplasie des Septum pellucidum zu reichen. Kasuistisch wird über die Aplasie des Septum pellucidum bei einem Patienten berichtet, welche kernspintomographisch im Rahmen der routinemäßig durchgeführten bildgebenden Diagnostik gefunden wurde. Klinisch wurde bei dem Patienten eine hebephrene Psychose diagnostiziert. In der Ätiologie der schizophrenen Psychosen werden dysontongenetische Mechanismen diskutiert, v.a. Migrationsstörungen in limbischen Strukturen. Eine erhöhte Inzidenz von Anomalien des Septum pellucidum, v.a. Septum-pellucidum-Zysten ist von mehreren Autoren bei schizophrenen Patienten berichtet worden. Die Bedeutung des Septum pellucidum und des Septum verum als Bestandteile des limbischen Systems werden erörtert und eine mögliche Relevanz für das Konzept der dysontogenetischen Ätiologie schizophrener Psychosen wird diskutiert.
    Materialart: Digitale Medien
    Bibliothek Standort Signatur Band/Heft/Jahr Verfügbarkeit
    BibTip Andere fanden auch interessant ...
  • 14
    ISSN: 1437-7799
    Schlagwort(e): Key words Desferrioxamine ; Cadmium ; Metallothionein ; Nephrotoxicity ; Rat
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Medizin
    Notizen: Abstract Background. Desferrioxamine (DFO) a chelating agent, is used to treat metal toxicity caused by iron and aluminum in patients on hemodialysis. We hypothesized that DFO could also be used to treat cadrium-induced nephropathy. Animal experiments were therefore performed to explore whether DFO removed cadmium (Cd) from the kidneys of rats with a Cd burden. Methods. Rats received subcutaneous injections of Cd chloride (3 mg Cd/kg per day, days 0–7) followed by DFO (50 mg/kg per day, days 8–14). Levels of Cd were determined in liver, kidneys, and plasma. Enzymes assays and histopathological examination were performed in kidneys. Results. In liver, Cd injections elevated Cd levels; subsequent injections of DFO lowered the Cd levels compared with levels after injections of Cd alone. In kidneys, Cd injections increased levels of total Cd and Cd bound to cellular membranes (Mem-Cd), and decreased leucine aminopeptidase (LAP) activity (a marker of renal injury); subsequent injections of DFO elevated levels of total Cd and Mem-Cd, and lowered LAP activity compared with fundings after the injection of Cd alone. After the injections of Cd alone and DFO following Cd the renal levels of Cd were below the critical concentration required to cause renal injury, since no histopathological changes were observed in the kidney. Conclusion. DFO administration to Cd-burdened rats removed Cd from the liver, but led to accumulation of Cd in the kidneys, particularly in the cellular membranes. These results suggest that if DFO is given long-term to Cd-burdened patients, the Cd level in kidneys, particularly in renal cellular membranes, could reach concentrations that could cause manifest renal injury.
    Materialart: Digitale Medien
    Bibliothek Standort Signatur Band/Heft/Jahr Verfügbarkeit
    BibTip Andere fanden auch interessant ...
  • 15
    ISSN: 1437-9813
    Schlagwort(e): Key words Congenital diaphragmatic hernia ; Rat ; Glucocorticoid ; Antenatal therapy ; Insulin-like growth factor I and II ; Reverse transcription-polymerase chain reaction (RT-PCR)
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Medizin
    Notizen: Abstract There is increasing evidence to suggest that insulin-like growth factors (IGF) I and II play a crucial role in fetal lung development. Expression of IGF-I and II has been demonstrated to be predominant during fetal life and decreases prior to birth. Antenatal glucocorticoids are reported to improve lung immaturity. The aim of this study was to investigate the effect of antenatal glucocorticoid administration on IGF-I and II expression in nitrofen-induced congenital diaphragmatic hernia (CDH) in rats. A CDH model was induced in pregnant rats following administration of 100 mg nitrofen on day 9.5 of gestation (term = 22 days). Dexamethasone (0.25 mg/kg) was given intraperitoneally on days 18.5 and 19.5 of gestation. Cesarean section was performed on day 21. The fetuses were divided into three groups: I, normal controls; II, nitrofen-induced CDH; and III, nitrogen-induced CDH with antenatal dexamethasone treatment. mRNA was extracted from whole lung and a reverse transcription-polymerase chain reaction (RT-PCR) was performed to evaluate the relative amounts of IGF I and II mRNA. Levels of mRNA were expressed as a ratio of the band density divided by that of β-actin, a housekeeping gene known to be expressed at a constant level. Immunohistochemistry using anti-rat IGF I and II antibody was also performed in each group. Levels of IGF I mRNA were significantly increased in group II (0.50 ± 0.08) compared to group I (0.34 ± 0.10) or group III (0.32 ± 0.06) (P 〈 0.05). Levels of IGF II mRNA were also significantly increased in group II (0.95 ± 0.20) compared to group I (0.42 ± 0.07) or group III (0.31 ± 0.09) (P 〈 0.05). Strong IGF I and II expression was observed in the hypoplastic CDH lung (group II), mainly in the bronchiolar epithelium. IGF I and II expression in group I and III lungs was either absent or weak. The finding of significant reductions in IGF I and II mRNA and protein levels in dexamethasone-treated CDH lung suggest that dexamethasone may accelerate the fetal stage of lung development.
    Materialart: Digitale Medien
    Bibliothek Standort Signatur Band/Heft/Jahr Verfügbarkeit
    BibTip Andere fanden auch interessant ...
  • 16
    Digitale Medien
    Digitale Medien
    Springer
    Pediatric surgery international 15 (1999), S. 201-205 
    ISSN: 1437-9813
    Schlagwort(e): Key words Esophagus ; Atresia ; Notochord ; Adriamycin ; Rat
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Medizin
    Notizen: Abstract Esophageal atresia (EA) is often accompanied by vertebral defects and other anomalies. The adriamycin rat model of EA has disclosed the embryology of the malformation and shown that the vertebrae and notochord are also abnormal. This study describes the nature of notochord malformations in rat embryos exposed to adriamycin. Time-mated rats received either 1.75 mg/kg adriamycin or vehicle i.p. on gestational days (E) 6 to 9; E-12, E-12.5, and E-13 embryos were harvested, embedded in paraffin, and serially sectioned at 3 μm in transverse plane from the head to the stomach for subsequent PAS staining. The findings in both groups were compared at the three endpoints. Control embryos had neither tracheoesophageal nor notochord malformations. On day 12, only 11/36 adriamycin embryos were normal; 7/36 had abnormal notochords, 11/36 had EA, and 7/36 had both. The corresponding figures for 12.5 days were 12/27, 0/27, 7/27, and 8/27 and those for the day 13 7/23, 5/23, 3/23, and 8/23. The malformed notochords were thickened, bifurcated, or trifurcated in the sagittal plane. The simultaneous presence of notochord and esophageal malformations suggests a direct link between both defects, but our observation of isolated occurrence of both shows that they reflect two expressions of the profound disturbance of embryonic para-axial organization responsible for the cluster of malformations rather than a cause-effect association.
    Materialart: Digitale Medien
    Bibliothek Standort Signatur Band/Heft/Jahr Verfügbarkeit
    BibTip Andere fanden auch interessant ...
  • 17
    Digitale Medien
    Digitale Medien
    Springer
    Pediatric surgery international 15 (1999), S. 457-460 
    ISSN: 1437-9813
    Schlagwort(e): Key words Blunt testicular injury ; Rat ; DNA flowcytometry ; Antisperm antibodies
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Medizin
    Notizen: Abstract Injury to the testis breaching the tunica albuginea is known to affect fertility. Blunt testicular trauma with an intact tunica albuginea has been reported to have no effect on contralateral testicular histology and Johnsen testicular maturation score. However, sensitive techniques like DNA flowcytometry have not been utilized so far to evaluate contralateral testicular germ-cell changes. Sixty-four male Wistar rats aged 20 days were randomized into groups I (control), II (unilateral blunt testicular trauma, UBTT), III (UBTT and excision of ipsilateral testis at 6 h), and IV (UBTT and cyclosporine for 30 days). Fertility, DNA flowcytometry of contralateral testicular tissue, and anti-sperm antibodies (ASA) were evaluated. Fertility and haploid-cell percentage of the contralateral testis were significantly decreased compared to controls in early adulthood (100 days). Around 150 days of age, as ASA decreased significantly, fertility and contralateral testicular haploid-cell population recovered and were comparable to the controls. Excision of the traumatized testicle around 6 h after injury or administration of cyclosporine for 30 days protected fertility and the contralateral testis. In contrast to group II rats, ELISA for ASA was negative in group III and IV rats. UBTT affects the contralateral testis and fertility. ASA mediate this damage. Orchidectomy performed around 6 h after trauma or short-term cyclosporine therapy prevents the damage.
    Materialart: Digitale Medien
    Bibliothek Standort Signatur Band/Heft/Jahr Verfügbarkeit
    BibTip Andere fanden auch interessant ...
  • 18
    Digitale Medien
    Digitale Medien
    Springer
    Pediatric surgery international 15 (1999), S. 287-289 
    ISSN: 1437-9813
    Schlagwort(e): Key words Soft-tissue tumor ; Myositis ossificans ; MRI
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Medizin
    Notizen: Abstract Two cases on myositis ossificans circumscripta (MOC) in the arm are reported. Plain X-ray films and magnetic resonance imaging (MRI) were performed in both cases. In the first, an intramuscular tumor-like mass without calcifications was found on MRI with soft-tissue edema extension. In the second, MRI disclosed additional bone-marrow edema. The diagnosis of MOC was confirmed by biopsy in one case and by follow-up in the other. MOC is a benign soft-tissue lesion that is rare in children, with an acute course and usually spontaneously favorable evolution. The differential diagnosis from an infection or a malignant tumor remains difficult. The best imaging modalities are conventional radiography and MRI. The MRI patterns of MOC are typical but not pathognomonic; typical MRI findings in conjunction with clinical symptoms during the early phase of MOC permit the postponement of a biopsy or aggressive surgical procedures. Surgery is indicated for cases not showing typical MOC calcifications at a later stage.
    Materialart: Digitale Medien
    Bibliothek Standort Signatur Band/Heft/Jahr Verfügbarkeit
    BibTip Andere fanden auch interessant ...
  • 19
    ISSN: 1437-9813
    Schlagwort(e): Key words Unilateral undescended testis ; Rat ; Testicular injury ; DNA flowcytometry ; Anti-sperm antibody
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Medizin
    Notizen: Abstract This study was designed to evaluate whether creation of a unilateral undescended testis (U/L UDT) in rats by direct fixation of the testis can lead to changes in the contralateral (C/L) descended testis, and if so, whether this inherent problem of the model could be eliminated by anchoring the divided gubernaculum to indirectly fix the testis. Thirty male newborn rats were divided into three groups of 10 each and the procedure done on the 2nd day of life to create U/L UDT according to the group allocated: group I: sham-operated; group II: anchoring the gubernaculum after gubernaculectomy; group III: Direct suture fixation of the testis. Fertility, C/L testicular weight (TW), Johnsen score, seminiferous tubular diameter (STD), DNA flowcytometry, and serum anti-sperm antibodies (ASA) were studied. Fertility, C/L TW, Johnsen score, STD, and haploid cell population were significantly reduced in group III compared to group II, while significantly higher titers of ASA were found in group III. Gubernaculectomy and anchoring the gubernaculum to the anterior abdominal wall is a better technique of creation of experimental UDT, as direct fixation of the testis is potentially detrimental to the C/L normal, descended testis.
    Materialart: Digitale Medien
    Bibliothek Standort Signatur Band/Heft/Jahr Verfügbarkeit
    BibTip Andere fanden auch interessant ...
  • 20
    ISSN: 1432-2161
    Schlagwort(e): Key words Hip joint ; Osteonecrosis ; MRI ; Bone scintigraphy ; Femoral head ; Transtrochanteric rotational osteotomy
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Medizin
    Notizen: Abstract  Objective. To assess the ability of bone scintigraphy and magnetic resonance imaging (MRI) to predict the outcome of transtrochanteric rotational osteotomy (TRO) for osteonecrosis of the femoral head (ONFH). Design. This study was a prospective evaluation of imaging techniques. Patients and methods. MRI and bone scintigraphy were performed on 20 hips in 18 patients at 3 months after TRO. The radiographic findings at 3 months after TRO, and the MRI and bone scintigraphic findings, were compared with the radiographic findings at final follow-up (mean 39 months). Results and conclusions. On MRI a low-intensity area or a low-intensity band in the new weight-bearing area extending over the acetabular edge on T1-weighted images was related to the presence of collapse on the radiographs at final follow-up. In hips with an area of absent activity in the new weight-bearing surface on bone scintigraphy, collapse was seen more frequently on radiographs at final follow-up than in hips without this feature. Bone scintigraphy was no more specific than radiography in predicting the outcome after TRO. We consider MRI to be superior to bone scintigraphy in predicting the occurrence of collapse, which is one of the major short-term problems after TRO.
    Materialart: Digitale Medien
    Bibliothek Standort Signatur Band/Heft/Jahr Verfügbarkeit
    BibTip Andere fanden auch interessant ...
  • 21
    ISSN: 1432-2161
    Schlagwort(e): Key words Lipoma arborescens ; Synovial membrane ; MRI ; Shoulder ; Bursitis
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Medizin
    Notizen: Abstract  A 44-year-old man presented with lipoma arborescens of the right shoulder, associated with a rotator cuff tear. MRI revealed villous proliferations with signal intensity of fat on all pulse sequences. At surgery, this bursa was found to contain moderately yellow cloudy fluid without fat globules. Histological examination of the lesion showed subsynovial accumulation of mature fat cells.
    Materialart: Digitale Medien
    Bibliothek Standort Signatur Band/Heft/Jahr Verfügbarkeit
    BibTip Andere fanden auch interessant ...
  • 22
    Digitale Medien
    Digitale Medien
    Springer
    Skeletal radiology 28 (1999), S. 298-304 
    ISSN: 1432-2161
    Schlagwort(e): Key words Osteosarcoma ; MRI ; Metastases ; skeletal muscle ; Soft tissue neoplasm
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Medizin
    Notizen: Abstract  Two cases of osteogenic sarcoma with skeletal muscle metastases are described. A 40-year-old woman presented with progressive swelling of both calves and a soft tissue back lump. She had been diagnosed with mandibular chondroblastic osteogenic sarcoma 6 years earlier. Radiographs showed calcified masses. MRI scans and bone scintigraphy revealed multiple soft tissue masses in both calves. Bone scintigraphy also showed uptake in the back lump, right thigh and left lung base. Biopsy confirmed metastatic chondroblastic osteogenic sarcoma, which initially responded well to chemotherapy. However, the metastatic disease subsequently progressed rapidly and she died 21 months after presentation. The second case concerns a 20-year-old man who presented with a pathologic fracture of the humerus, which was found to be due to osteoblastic osteogenic sarcoma. He developed cerebral metastases 17 months later, followed by metastases at other sites. Calcified masses were subsequently seen on radiographs of the abdomen and chest. CT scans confirmed the presence of densely calcified muscle metastases in the abdominal wall, erector spinae and gluteal muscles. The patient’s disease progressed rapidly and he died 30 months after presentation.
    Materialart: Digitale Medien
    Bibliothek Standort Signatur Band/Heft/Jahr Verfügbarkeit
    BibTip Andere fanden auch interessant ...
  • 23
    Digitale Medien
    Digitale Medien
    Springer
    Skeletal radiology 28 (1999), S. 342-346 
    ISSN: 1432-2161
    Schlagwort(e): Key words Chordoma ; Notochordal rest ; MRI ; Vertebra
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Medizin
    Notizen: Abstract  Chordomas of the lumbar vertebral bodies are rare. We report an unusual case of an entirely intra-osseous chordoma of the fifth lumbar vertebra treated by vertebrectomy. Conventional radiographs and scintigraphy were normal. The lesion was well visualised by MR imaging, but showed only slight sclerosis on CT. We give our reasons for making a diagnosis of chordoma rather than giant notochordal rest and discuss the problems of management resulting from this diagnostic dilemma.
    Materialart: Digitale Medien
    Bibliothek Standort Signatur Band/Heft/Jahr Verfügbarkeit
    BibTip Andere fanden auch interessant ...
  • 24
    Digitale Medien
    Digitale Medien
    Springer
    Skeletal radiology 28 (1999), S. 347-349 
    ISSN: 1432-2161
    Schlagwort(e): Key words Plasmacytoma ; Plasmacytoma ; amyloid ; Plasmacytoma ; calcified ; Plasmacytoma ; extraosseous ; Plasmacytoma ; thorax ; Plasmacytoma ; MRI
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Medizin
    Notizen: Abstract  We report on a rare, calcified, plasma cell tumor of the spine causing progressive myelopathy. Other unusual features were the lack of an osseous lesion at the site of the mass, considerable calcified amyloid within the mass but no identifiable amyloid elsewhere, and normal serum immunoelectrophoresis.
    Materialart: Digitale Medien
    Bibliothek Standort Signatur Band/Heft/Jahr Verfügbarkeit
    BibTip Andere fanden auch interessant ...
  • 25
    Digitale Medien
    Digitale Medien
    Springer
    Skeletal radiology 28 (1999), S. 33-40 
    ISSN: 1432-2161
    Schlagwort(e): Key words Osteoblastoma ; Spine ; Radiography ; CT ; MRI ; Pathology
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Medizin
    Notizen: Abstract  Objectives. To illustrate the CT and MRI features of spinal osteoblastomas and correlate the imaging with histological findings. Design. In a retrospective review the CT and MRI features of spinal osteoblastomas with respect to mineralisation, signal intensity (SI), adjacent reactive changes, enhancement following gadolinium-DTPA (5 cases) and adjacent soft tissue masses were compared and correlated with the histological findings including the degree of osteoid formation and matrix mineralisation, vascularity and surrounding reactive changes in bone and soft tissue. Patients. Eleven patients (7 males and 4 females; age range 8–43 years, mean age 19.5 years) with 12 osteoblastomas (1 patient suffered a recurrence) were studied. Results. All lesions showed classical features on CT with varying degrees of matrix mineralisation, whereas MRI identified mineralisation in only eight of 12 cases. MRI showed low signal intensity of the lesion on both T1- and T2-weighted sequences in several cases in the absence of heavy mineralisation. In these cases, histological examination revealed diffuse osteoid production by the tumour. All patients given gadolinium showed enhancement within the tumour on MRI. Reactive bone marrow changes were identified on MRI in 10 cases, and in five of these the changes were at multiple levels. An adjacent soft tissue mass was demonstrated in five cases, but extraosseous tumour was present histologically in only two of these. Conclusions. The MRI appearances of spinal osteoblastomas are varied and show no characteristic features. MRI may also overestimate the extent of the lesion due to extensive reactive changes and adjacent soft tissue masses. CT should continue to be the investigation of choice for the characterisation and local staging of suspected spinal osteoblastomas.
    Materialart: Digitale Medien
    Bibliothek Standort Signatur Band/Heft/Jahr Verfügbarkeit
    BibTip Andere fanden auch interessant ...
  • 26
    Digitale Medien
    Digitale Medien
    Springer
    Skeletal radiology 28 (1999), S. 49-51 
    ISSN: 1432-2161
    Schlagwort(e): Key words Cryptococcoma ; sacrum ; Cryptococcoma ; immunocompromised ; MRI ; sacrum ; CT ; sacrum
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Medizin
    Notizen: Abstract  Cryptococcoma of the sacrum was the initial presentation of systemic cryptococcosis in a patient on chronic steroid therapy for autoimmune hepatitis. The bone lesion was the only overt manifestation of systemic cryptococcal disease, which preceded other clinical manifestations and led to the subsequent diagnosis of systemic infection.
    Materialart: Digitale Medien
    Bibliothek Standort Signatur Band/Heft/Jahr Verfügbarkeit
    BibTip Andere fanden auch interessant ...
  • 27
    Digitale Medien
    Digitale Medien
    Springer
    Skeletal radiology 28 (1999), S. 545-560 
    ISSN: 1432-2161
    Schlagwort(e): Key words Trauma ; Joints ; injuries ; Joints ; radiography ; Joints ; MRI ; Cartilage ; Bones ; fractures
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Medizin
    Notizen: Abstract  Fractures involving the articulating surfaces of bone are a common cause of chronic disability after joint injury. Acute fractures of the articular surface typically run parallel to the surface and are confined to the cartilage and/or the immediate subchondral cancellous bone. They should be distinguished from vertical or oblique bone fractures with intra-articular extension. This article reviews the mechanism of acute articular surface injuries, as well as their incidence, clinical presentation, radiologic appearance and treatment. A classification is presented based on direct inspection (arthroscopy) and imaging (especially MRI), emphasizing the distinction between lesions with intact (subchondral impaction and subchondral bone bruises) and disrupted (chondral, osteochondral lesions) cartilage. Hyaline cartilage, subchondral bone plate and subchondral cancellous bone are to be considered an anatomic unit. Subchondral articular surface lesions, osteochondral fractures and solely chondral fractures are different manifestations of impaction injuries that affect the articulating surface. Of the noninvasive imaging modalities, conventional radiography and MRI provide the most relevant information. The appropriate use of short tau inversion recovery, T1-weighted and T2-weighted (turbo) spin-echo as well as gradient-echo sequences, enables MRI to classify the various acute articular surface lesions with great accuracy and provides therapeutic guidance.
    Materialart: Digitale Medien
    Bibliothek Standort Signatur Band/Heft/Jahr Verfügbarkeit
    BibTip Andere fanden auch interessant ...
  • 28
    Digitale Medien
    Digitale Medien
    Springer
    Skeletal radiology 28 (1999), S. 658-660 
    ISSN: 1432-2161
    Schlagwort(e): Key words Medial collateral ligament ; tear ; interposition ; Knee ; MRI ; Posterolateral dislocation
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Medizin
    Notizen: Abstract  Displacement of the medial collateral ligament (MCL) into the medial knee joint is an extremely rare finding associated with MCL tears, and is easily diagnosed on magnetic resonance imaging. A case of intra-articular interposition of the MCL during a severe knee injury is presented. A radiolucent ”fat stripe” sign and adjacent skin dimpling on radiographs may be relatively specific indicators of this injury.
    Materialart: Digitale Medien
    Bibliothek Standort Signatur Band/Heft/Jahr Verfügbarkeit
    BibTip Andere fanden auch interessant ...
  • 29
    ISSN: 1432-2161
    Schlagwort(e): Key words Shoulder ; arthrography ; Shoulder ; comparative studies ; Shoulder ; injury ; Shoulder ; MRI
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Medizin
    Notizen: Abstract  Purpose. In a patient with internal derangement of the shoulder, the diagnostic method of choice is controversial. Conventional arthrography can diagnose most rotator cuff tears accurately; however, in many institutions MR arthrography is usually necessary to diagnose labral tears. We utilized decision tree methodology to compare the cost- effectiveness of conventional arthrography and conventional MRI with a hypothetical algorithm in which a patient underwent arthrography, performed with admixed gadolinium, which if negative, was followed by MRI. Design. The use of double-contrast arthrography alone, conventional MRI alone, and gadolinium-enhanced MRI used as an adjunct to conventional arthrography were modeled for the diagnosis of full-thickness rotator cuff tears (RCT), partial RCTs, labral tears, and the absence of cuff/labral tears using decision analysis methodology. English language medical publications were searched to determine the base probabilities for the accuracy of the diagnostic tests. The outcome utilities ranged from –1 to +1 to reflect the value of correct diagnostic evaluation. Charges for diagnostic tests and appropriate surgical treatments were based on 1997 Medicare reimbursement rates for professional fees and hospital charges in an outpatient setting. Sensitivity analyses were performed to evaluate the effects of uncertainty regarding the prevalence of each disease state and the accuracy of several diagnostic tests. Results. In the base-case analysis, the average effectiveness of double-contrast arthrography alone, MRI alone and arthrography selectively followed by MRI were 0.6610, 0.6715, and 0.7204, respectively. The average costs for each of these strategies were $1090, $2033, and $2339, respectively. Conclusion. Arthrography performed with admixed diluted gadolinium, which if negative is immediately followed by MRI, was somewhat more expensive than conventional MRI. However, because of much greater effectiveness, cost-effectiveness was significantly higher for our proposed algorithm. Conventional arthrography without gadolinium, although less expensive, had severely limited effectiveness.
    Materialart: Digitale Medien
    Bibliothek Standort Signatur Band/Heft/Jahr Verfügbarkeit
    BibTip Andere fanden auch interessant ...
  • 30
    Digitale Medien
    Digitale Medien
    Springer
    Skeletal radiology 28 (1999), S. 61-74 
    ISSN: 1432-2161
    Schlagwort(e): Key words Ligament ; Ligament injury ; MRI ; Soft tissue injury ; Soft tissue trauma
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Medizin
    Notizen: Abstract  Magnetic resonance imaging has had a dramatic effect on the means by which we diagnose ligament injuries. Tears resulting from either acute trauma or overuse can be detected noninvasively, directing appropriate therapy be it conservative or surgical. For the elite athlete, earlier diagnosis leads to earlier intervention, or alternatively, a normal MRI examination can result in an earlier return to play. While MRI is accepted for the diagnosis of certain injuries such as complete tears of the cruciate ligaments of the knee, other injuries, such as partial cruciate ligament tears or tears of the intercarpal ligaments of the wrist, remain controversial.
    Materialart: Digitale Medien
    Bibliothek Standort Signatur Band/Heft/Jahr Verfügbarkeit
    BibTip Andere fanden auch interessant ...
  • 31
    Digitale Medien
    Digitale Medien
    Springer
    Skeletal radiology 28 (1999), S. 717-722 
    ISSN: 1432-2161
    Schlagwort(e): Key words Sarcoid ; vertebrae ; Sarcoid ; rib ; Sarcoid ; calvarium ; Osteolytic ; CT ; MRI ; Surgical fusion
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Medizin
    Notizen: Abstract  Skeletal sarcoidosis is rare. This report describes a 31-year-old African American man who presented with a destructive osteolytic lesion of C2 and another lesion in a rib. The lesion at C2 was treated with corpectomy and bone graft. Four months later the lesion recurred and a new lesion was discovered in the cervical vertebral column. The patient declined surgery for instability for another 3 months, choosing to remain in a halo. Seven months following the initial operation, a technetium bone scan showed spread of the disease to the calvarium and thoracic and lumbar vertebrae. The patient had no symptoms referable to these sites. The patient agreed to have his neck fused at this point. For the next 10 months, the patient was on steroids and a further new lesion appeared at L5 without localizing signs or symptoms. The patient declined further evaluation over the next 12 months and is now considered lost to follow-up.
    Materialart: Digitale Medien
    Bibliothek Standort Signatur Band/Heft/Jahr Verfügbarkeit
    BibTip Andere fanden auch interessant ...
  • 32
    Digitale Medien
    Digitale Medien
    Springer
    Skeletal radiology 28 (1999), S. 52-56 
    ISSN: 1432-2161
    Schlagwort(e): Key words Intraneural ganglion ; Peroneal nerve palsy ; Drop foot ; MRI
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Medizin
    Notizen: Abstract  A case of peroneal nerve palsy caused by an intraneural ganglion is presented. The cystic mass was located posterolateral to the lateral femoral condyle and extended along the common peroneal nerve distal to the origin of the peroneus longus muscle. The nerve was compressed in the narrow fibro-osseous tunnel against the fibula neck and the tight origin of the peroneus longus muscle. The nerve was decompressed by complete tumor excision and transection of the origin of the peroneus longus muscle. Full recovery of nerve function was obtained in 6 months.
    Materialart: Digitale Medien
    Bibliothek Standort Signatur Band/Heft/Jahr Verfügbarkeit
    BibTip Andere fanden auch interessant ...
  • 33
    Digitale Medien
    Digitale Medien
    Springer
    Skeletal radiology 28 (1999), S. 594-598 
    ISSN: 1432-2161
    Schlagwort(e): Key words Osteochondroma ; Chondroma ; Extraskeletal tumor ; Soft tissue tumor ; Foot ; CT ; MRI
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Medizin
    Notizen: Abstract  A case of pathologically proven extraskeletal osteochondroma is presented with magnetic resonance imaging (MRI), computed tomography (CT), bone scan and radiographic findings. The diagnosis of extraskeletal osteochondroma should be considered when a discrete, ossified mass is localized in the soft tissues of the distal extremities. Nomenclature surrounding this entity is controversial and is discussed.
    Materialart: Digitale Medien
    Bibliothek Standort Signatur Band/Heft/Jahr Verfügbarkeit
    BibTip Andere fanden auch interessant ...
  • 34
    Digitale Medien
    Digitale Medien
    Springer
    Skeletal radiology 28 (1999), S. 616-620 
    ISSN: 1432-2161
    Schlagwort(e): Key words Joint ; MRI ; Infectious arthritis ; Septic joint ; Inflammation
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Medizin
    Notizen: Abstract  Objective. To differentiate the MR features of septic versus nonseptic inflamed joints. Design and patients. Thirty patients were referred for MRI with inflamed joints (19 were subsequently found to be septic and 11 nonseptic). At 1.5 T enhanced MRI five groups of signs related to joint space, synovium, cartilage, bone and peri-articular soft tissue respectively were assessed and compared between the septic and nonseptic groups. Results. The prevalence of MRI findings in septic versus nonseptic joints (respectively) was as follows: effusion (79% vs 82%), fluid outpouching (79% vs 73%), fluid heterogeneity (21% vs 27%), synovial thickening (68% vs 55%), synovial periedema (63% vs 55%), synovial enhancement (94% vs 88%), cartilage loss (53% vs 30%), bone erosions (79% vs 38%), bone erosions enhancement (77% vs 43%), bone marrow edema (74% vs 38%), bone marrow enhancement (67% vs 50%), soft tissue edema (63% vs 78%), soft tissue enhancement (67% vs 71%), periosteal edema (11% vs. 10%). The presence of bone erosions appeared to be an indicator for an infected joint (P=0.072); coexistence of bone marrow edema slightly improves the significance (0.068). A similar trend was obtained when combining bone erosions with either synovial thickening, synovial periedema, bone marrow enhancement or soft tissue edema (P=0.075). Conclusions. The combination of bone erosions with marrow edema is highly suggestive for a septic articulation; the additional coexistence of synovial thickening, synovial edema, soft tissue edema or bone marrow enhancement increases the above level of confidence. Similar to conventional radiography, the single sign that appeared to show a significant trend was the presence of bone erosions. However, no single sign or combination could either be considered pathognomonic or exclude the presence of a joint infection.
    Materialart: Digitale Medien
    Bibliothek Standort Signatur Band/Heft/Jahr Verfügbarkeit
    BibTip Andere fanden auch interessant ...
  • 35
    Digitale Medien
    Digitale Medien
    Springer
    Skeletal radiology 28 (1999), S. 655-657 
    ISSN: 1432-2161
    Schlagwort(e): Key words Acromegaly ; Locking ; Metacarpophalangeal joint ; Osteophyte ; Volar plate hypertrophy ; Radiography ; MRI
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Medizin
    Notizen: Abstract  A 39-year-old man with acromegaly exhibited locking of metacarpophalangeal (MCP) joints of both index fingers. Large osteophytes were found at the metacarpal heads by radiography and computerized tomography (CT). Magnetic resonance (MR) images revealed hypertrophy of volar plates. We suggest that these characteristic acromegalic features caused locking of MCP joints. Surgery was required on one of the joints to release the locking.
    Materialart: Digitale Medien
    Bibliothek Standort Signatur Band/Heft/Jahr Verfügbarkeit
    BibTip Andere fanden auch interessant ...
  • 36
    Digitale Medien
    Digitale Medien
    Springer
    Skeletal radiology 28 (1999), S. 703-709 
    ISSN: 1432-2161
    Schlagwort(e): Key words Proliferative myositis ; Childhood ; Lumbar muscles ; Ossification ; X-ray ; CT ; MRI ; PET
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Medizin
    Notizen: Abstract  A case of proliferative myositis in the lumbar paraspinal muscles in a 14-year-old boy is presented. Imaging investigations including plain radiograph, ultrasound, computed tomography (CT), magnetic resonance imaging (MRI), bone scan and positron emission tomography (PET) were suggestive of an inflammatory process such as myositis ossificans. The diagnosis was made by incisional biopsy. More pronounced edema, more muscle fiber necrosis and a higher cellularity were found compared to adult cases. The karyotype of the lesion was normal. Clinically, the mass disappeared spontaneously. After 24 months, asymptomatic bridging ossification between the third and fourth lumbar vertebrae was noted.
    Materialart: Digitale Medien
    Bibliothek Standort Signatur Band/Heft/Jahr Verfügbarkeit
    BibTip Andere fanden auch interessant ...
  • 37
    ISSN: 1432-2161
    Schlagwort(e): Key words Shoulder ; Biceps tendon ; Anomaly ; Arthroscopy ; MRI
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Medizin
    Notizen: Abstract  A developmental anomaly of the long head of the biceps tendon was found in a cadaveric shoulder. Findings on arthroscopy, routine MR imaging, and MR arthrography were compared and correlated with results of anatomic dissection. MR arthrography appears to be a very good diagnostic imaging method for depicting this anomaly prior to arthroscopy.
    Materialart: Digitale Medien
    Bibliothek Standort Signatur Band/Heft/Jahr Verfügbarkeit
    BibTip Andere fanden auch interessant ...
  • 38
    ISSN: 1432-2307
    Schlagwort(e): Key words Pyruvate kinase isoenzymes ; N-Nitrosomorpholine ; Rat
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Medizin
    Notizen: Abstract  The expression of the pyruvate kinase (PK) isoenzymes L and M2 was analysed in the livers of rats treated with the hepatocarcinogenic agent N-nitrosomorpholine (NNM) in the drinking water. In control animals L-PK expression was restricted to liver parenchymal cells, whereas M2-PK was detected in bile duct epithelial, blood vessel wall, endothelial and Kupffer cells. In rats treated with NNM proliferating oval cells were consistently L-PK negative and M2-PK positive, while the ductal cells of cholangiofibroses were clearly L-PK positive and coexpressed M2-PK. However, no morphological differentiation of ductal cells into hepatocyte-like cells was observed. In the clear and acidophilic cell foci storing glycogen in excess strong staining for L-PK was observed. In glycogen-poor foci induced by NNM a shift from L-PK to M2-PK expression takes place.
    Materialart: Digitale Medien
    Bibliothek Standort Signatur Band/Heft/Jahr Verfügbarkeit
    BibTip Andere fanden auch interessant ...
  • 39
    ISSN: 1432-2307
    Schlagwort(e): Key words Medullary thyroid carcinoma ; Basement membrane ; Laminin ; Rat
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Medizin
    Notizen: Abstract  Medullary thyroid carcinoma (MTC) originates from C cells, which secrete calcitonin (CT), their specific marker. C cells are located in contact with the basement membrane (BM) of the thyroid follicles, which is partly made up of the laminin-2 isoform synthesized by thyrocytes. During oncogenesis, proliferation of the C cells, invading the centre of the follicles, leads to a break in their normal contact with the BM. As specific interactions of cells with BM components, especially laminins, are important for proliferation and differentiation, we investigated the relationships of normal and neoplastic C cells with laminin in the Wag/Rij rat model of human MTC. Immunocytochemical studies showed a progressive loss of the laminin layer underlying the hyperplastic C cell nodules around the large dedifferentiated tumours. The α2, β1 and γ1 chains of the laminin-2 isoform were synthesized and secreted by rat MTC 6–23 cell cultures and the tumours induced by subcutaneous injection of these cells. In situ hybridization combined with anti-CT immunocytochemistry showed a low expression of α2 mRNA on differentiated C cells and thyrocytes, but an overexpression on immunonegative spontaneous MTC and induced intrathyroid tumours. The high level of α2 gene expression, together with tumour dedifferentiation, suggests a relationship with malignancy.
    Materialart: Digitale Medien
    Bibliothek Standort Signatur Band/Heft/Jahr Verfügbarkeit
    BibTip Andere fanden auch interessant ...
  • 40
    Digitale Medien
    Digitale Medien
    Springer
    Urological research 27 (1999), S. 41-47 
    ISSN: 1434-0879
    Schlagwort(e): Key words Ureter ; Histology ; Polyuria ; Diabetes mellitus ; Nephrectomy ; Rat
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Medizin
    Notizen: Abstract The influence of increased functional load on the macroscopical and histological appearance of the ureter was investigated. Sixty rats were divided into five groups: (1) sucrose-fed rats with non-osmotic polyuria; (2) diabetic rats with osmotic polyuria; (3) uninephrectomized rats; (4) sham-operated control rats; and (5) control rats. The 24-hour urinary volume was measured on days 7, 14 and 21. Growth of the kidney, ureter and bladder was investigated and the histological appearance of the ureter was further evaluated. Diabetic and sucrose-fed rats had comparable polyuria with a seven-fold increase in urinary output. The urinary volume for the remaining kidney was doubled in uninephrectomized rats. After 3 weeks, diabetic rats had increased weight of the kidney, ureter and bladder, sucrose-fed rats had increased weight of the bladder, whereas uninephrectomized rats had increased weight of the kidney and ureter. The cross-sectional area (CSA) of the ureter wall from control rats increased from the proximal to the distal portion. The size of the whole ureter from diabetic rats was dramatically increased, the CSA of the wall of the distal ureter portion being four times that of the controls. The CSA of the ureter wall from sucrose-fed rats was increased only in the distal portion, whereas the ureter from uninephrectomized rats was increased only in the proximal portion. The results demonstrate the importance of differentiating between different portions of the rat ureter when examining histological sections of this organ. Moreover, polyuria per se is shown to induce growth of the bladder and of the adjacent distal part of the ureter, whereas uninephrectomy and diabetes caused growth of the kidney and the upper parts of the ureter, in addition to the growth induced by polyuria.
    Materialart: Digitale Medien
    Bibliothek Standort Signatur Band/Heft/Jahr Verfügbarkeit
    BibTip Andere fanden auch interessant ...
  • 41
    ISSN: 1434-0879
    Schlagwort(e): Key words Nonbacterial prostatitis ; Animal model ; Partial urethral obstruction ; Rat
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Medizin
    Notizen: Abstract The pathogenesis of nonbacterial prostatitis (NBP) is not understood mainly due to the lack of appropriate experimental models. We developed a new experimental model of NBP by inducing a partial obstruction of the urethra (PUO) in the rat. Male Wistar rats aged 12 weeks were used. PUO was produced by a nylon ligature on the urethra over a rubber tube. The tube was slipped out after the ligature had been tied. Two rats were examined histologically 6 h, 1 day, 3 days and 7 days after PUO. In another group, two rats were killed at 1, 3 and 7 days after the release of the PUO that had been left in place for 3 days. On day 3, another eight rats with PUO and eight control rats had 2 ml of urine in the bladder replaced by the same volume of lucifer yellow (LY; 10 μg/ml, MW 500), microperoxidase (MP; 20 μg/ml, MW 1900), horseradish peroxidase (HRP; 10 μg/ml, MW 40 000), or saline as control, respectively. Lymphocytic infiltration and interstitial edema were noted in the prostate following PUO, being most prominent on day 3. After the release of the PUO, these inflammatory changes gradually disappeared. Only LY was noted within the prostatic stroma of the rats 2 h after bladder instillation. Intraprostatic urinary reflux may be an etiologic factor in NBP. The present study showed that lower urinary tract obstruction caused NBP in the rat. Penetration of prostatic tissue by low-molecular-weight substances in the urine may trigger NBP.
    Materialart: Digitale Medien
    Bibliothek Standort Signatur Band/Heft/Jahr Verfügbarkeit
    BibTip Andere fanden auch interessant ...
  • 42
    Digitale Medien
    Digitale Medien
    Springer
    Urological research 27 (1999), S. 476-482 
    ISSN: 1434-0879
    Schlagwort(e): Key words Urinary bladder ; Enterocystoplasty ; Cecocystoplasty ; Innervation ; Nerve growth ; Rat
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Medizin
    Notizen: Abstract Incorporation of bowel into the bladder (enterocystoplasty) has been widely used to increase bladder capacity. It has been reported by others that the response of smooth muscle from the cystoplastic segment of the intestine shifts from that of the intestine (relaxation to α-agonists and ATP) to that of the bladder (contraction to α-agonists and ATP). This suggests a functional integration of the intestinal muscle into the bladder; the mechanisms are unknown. The aims of the present study were (1) to elucidate if there are signs of bladder nerves sprouting across the anastomosis into the intestinal segment, and (2) to study what happens with the intrinsic innervation of the intestinal segment. As a model, we used cecocystoplasty in rats. The bladder was opened and a patch of cecum with intact vascular supply was anastomosed to the bladder. After two to 11 months the rats were sacrificed and the bladders mounted as wholemounts and stained for acetylcholinesterase-containing nerves, or embedded in paraffin for histology. A pronounced degeneration of the myenteric plexus was found in the cecal segments. In some areas, this had proceeded to the extent that the ganglia were isolated ovoid lumps of cells with no apparent connection to other ganglia. Areas lacking ganglia and nerve trunks but still with muscle could be found in all specimens. Abundant axon bundles were demonstrated sprouting from the cut bladder nerves close to the anastomosis. The bundles spread out in a fan-like pattern or were organized as fewer thicker nerves. There were many nerve bundles entering the cecal segment where they branched and the diameter decreased till they no longer became visible. Some nerves reached surviving lumps of myenteric ganglion cells. The results show that the bladder nerves sprout into the anastomosed cecal segment. It is reasonable to assume that these nerves are responsible for the changes in receptor pharmacological properties of the cecal smooth muscle towards that of bladder muscle.
    Materialart: Digitale Medien
    Bibliothek Standort Signatur Band/Heft/Jahr Verfügbarkeit
    BibTip Andere fanden auch interessant ...
  • 43
    Digitale Medien
    Digitale Medien
    Springer
    Urological research 27 (1999), S. 174-179 
    ISSN: 1434-0879
    Schlagwort(e): Key words Apoptosis ; Ischemia-reperfusion ; Blood flow ; Ischemia ; Prostate ; Rat
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Medizin
    Notizen: Abstract The mechanisms involved in the castration-induced involution of the ventral prostate (VP) are not fully understood. It was recently reported that castration decreases blood flow in the VP in rats and that this occurs before the apoptotic involution of the organ. However, it is unknown whether a decrease in blood flow may trigger apoptosis in the VP, and this was therefore examined in this study. The right iliac artery was clamped for 1 h in adult male rats. After 24 h of reperfusion, the VPs were frozen or fixed. In situ end-labeling (ISEL) was used to identify apoptotic cells, and testosterone repressed prostatic message-2 (TRPM-2) was measured. Proliferating cell nuclear antigen (PCNA) immunohistochemistry was used to identify proliferating cells. Clamping the right iliac artery reduced blood flow in the right VP to 0.17 of that in the contralateral lobe. This relative ischemia resulted in a threefold increase in the volume density of apoptotic epithelial cells on the treated side, but left cell proliferation unaffected. Testosterone substitution did not change this pattern. This study suggests that a transient period of relative ischemia may induce apoptosis in the rat ventral prostate. This may be of importance for the understanding of castration-induced prostatic involution.
    Materialart: Digitale Medien
    Bibliothek Standort Signatur Band/Heft/Jahr Verfügbarkeit
    BibTip Andere fanden auch interessant ...
  • 44
    Digitale Medien
    Digitale Medien
    Springer
    Anatomy and embryology 199 (1999), S. 265-280 
    ISSN: 1432-0568
    Schlagwort(e): Key words Cat ; Rat ; Immunocytochemistry ; NADPH-diaphorase ; Thalamus
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Medizin
    Notizen: Abstract  To gain insight into the cellular organisation of the zona incerta, we have examined the chemoarchitectonic properties of this ”uncertain zone”. The brains of Sprague-Dawley rats and common cats were processed for immunocytochemistry or NADPH-diaphorase histochemistry using standard methods. For the immunocytochemistry, antibodies to γ-aminobutyric acid (GABA), glutamic acid decarboxylase (GAD), parvalbumin, calbindin, tyrosine hydroxylase, somatostatin, serotonin and glutamate were used. Two general patterns of distribution in the zona incerta were seen. First, labelled cells were restricted largely to one of the cytoarchitectonically defined sectors of the zona incerta. For instance, GABA, GAD and parvalbumin-immunoreactive cells were found principally within the ventral sector, NADPH-diaphorase and glutamate-immunoreactive cells within the dorsal sector and tyrosine hydroxylase- and somatostatin-immunoreactive cells within the rostral sector. Second, labelled cells were scattered somewhat across all incertal sectors, with no clear region of concentration. This pattern included the calbindin- and serotonin-immunoreactive cell groups. These results indicate that the zona incerta is made up of many neurochemically distinct cell groups, some of which respect the well-defined cytoarchitectonic boundaries of the nucleus, whilst others do not. This rich neurochemical diversity in the zona incerta suggests that this nucleus may have differential effects on the different structures that it projects to.
    Materialart: Digitale Medien
    Bibliothek Standort Signatur Band/Heft/Jahr Verfügbarkeit
    BibTip Andere fanden auch interessant ...
  • 45
    Digitale Medien
    Digitale Medien
    Springer
    Anatomy and embryology 200 (1999), S. 521-531 
    ISSN: 1432-0568
    Schlagwort(e): Key words Development ; Internal capsule ; Nucleus basalis ; Rat ; Thalamus
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Medizin
    Notizen: Abstract  This study defines several features of the early connections of the developmentally transient perireticular thalamic nucleus of rats. The neocortex of developing rats was injected with either DiI, biotinylated dextran, WGA-HRP (wheatgerm agglutinin conjugated-horseradish peroxidase), fluorescent latex beads or cholera toxin subunit B (CTB) and their brains were processed for tracer detection with standard methods. In general, tracer injections into various regions of the developing neocortex revealed no labelled neurones within the perireticular nucleus, although some of these tracers (WGA-HRP, dextran) labelled many of the amoeboid microglial cells that are found within this nucleus. There were, however, many retrogradely labelled neurones in a region adjacent to the perireticular nucleus, within the nucleus basalis of the basal forebrain (medial edge of globus pallidus). Their identity was confirmed as neurones of the nucleus basalis since they were all were similar in morphology and somal size to neurones that were immunoreactive to NGFr (nerve growth factor receptor), an antigen found only among neurones of the nucleus basalis and basal forebrain. Moreover, double labelling experiments revealed that most, if not all, of the cortically labelled neurones were NGFr-immunoreactive also. Thus, in conclusion, our results suggest that the perireticular nucleus does not project to the neocortex; the only neurones in the general vicinity of the perireticular nucleus that have a cortical projection form part of the nucleus basalis.
    Materialart: Digitale Medien
    Bibliothek Standort Signatur Band/Heft/Jahr Verfügbarkeit
    BibTip Andere fanden auch interessant ...
  • 46
    Digitale Medien
    Digitale Medien
    Springer
    Anatomy and embryology 200 (1999), S. 533-540 
    ISSN: 1432-0568
    Schlagwort(e): Key words Coronary vasculogenesis ; Angiogenesis ; Coronary artery ; Development ; Rat ; Embryonic heart
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Medizin
    Notizen: Abstract  The aim of this work was to address spatiotemporal and morphologic patterns of coronary artery development in rats, based on immunohistochemical and ultrastructural studies of hearts at different stages of prenatal development. Griffonia simplicifolia I lectin and α-smooth muscle antibody were used to demonstrate endothelial cells and/or their precursors and smooth muscle cells, respectively. Ultrastructural examination was performed on ED14–16 hearts to study the morphology of the developing coronary arteries in different regions of the truncus arteriosus and adjacent myocardium. On ED14 endothelial-like cells present within the mesenchyme surrounding the outflow tract penetrated the aortic wall and the truncoconal proximal myocardium. On ED15 these penetrating cells formed vascular clusters, which were the first signs of presumptive vascular channels. Development of the coronary artery proceeded by coalescence of discontinous vascular clusters, formation of the lumen (vascular channels) and establishing a connection of the proximal part with the aorta. The second layer of cells around vascular channels (embryonic media) consisted of mesenchymal cells that were attracted to the immature vessel and were first seen on ED15. At this time no lumenized connection of the coronary artery with the aorta has been seen. After the lumenized connection of the coronary artery with the aorta had been established perivascular cells of the media started to differentiate into vascular smooth muscle, as was shown by α-smooth muscle actin-staining. Further development and differentiation of the media and adventitia proceeded distally (towards the apex).
    Materialart: Digitale Medien
    Bibliothek Standort Signatur Band/Heft/Jahr Verfügbarkeit
    BibTip Andere fanden auch interessant ...
  • 47
    ISSN: 1432-0568
    Schlagwort(e): Key words Morphogenesis ; Histochemistry ; Lectins ; Carbohydrates ; Salivary glands ; Rat
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Medizin
    Notizen: Abstract  The developmental expression of salivary glycoconjugates was investigated in the rat submandibular and sublingual glands by conventional and lectin histochemistry. By the time of the first differentiation of secretory structures, in spite of similar morphological features, a different histochemical reactivity was detected, accounting for a relevant content of neutral glycoconjugates in the submandibular gland and the occurrence of both neutral and acidic glycoconjugates in the sublingual one. The use of lectins allowed the main changes of secretory components to be noted around gestational day 18. DBA and WGA lectins seemed to act as pre- and post-natal development markers while Con A lectin was indicative of post-natal differentiation. Taken together, data from lectin histochemistry indicated the transitional occurrence of glycoconjugates, probably involved in temporally restricted functions, as well as the co-existence of different secretory components that might also reflect maturational changes of single products.
    Materialart: Digitale Medien
    Bibliothek Standort Signatur Band/Heft/Jahr Verfügbarkeit
    BibTip Andere fanden auch interessant ...
  • 48
    ISSN: 1432-0533
    Schlagwort(e): Key words Clomethiazole ; Rat ; Spinal cord-injury ; Neuroprotection
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Medizin
    Notizen: Abstract Clomethiazole (CMZ) has a neuroprotective effect in experimental focal and global forebrain ischemia. This neuroprotective effect may depend on its ability to enhance GABA receptor activity. We have studied the effect of pretreatment with CMZ on motor function recovery and nerve cell damage after spinal cord injury (SCI). Rats were randomized and 30 min before SCI they received a single intraperitoneal dose of CMZ (150 mg/kg) or saline. The spinal cord was injured with a 50 g (4.5 g/mm2) load, applied over the exposed dura, through a curved rectangular plate (2.2 × 5.0 mm) for 5 min at T8–9. The animals became paraplegic 1 day after injury. The rats were evaluated for recovery of hind limb motor function. All animals recovered to some extent over the observation period of 12 weeks. However, hind limb motor function was significantly better in the animals pretreated with CMZ. At 12 weeks the rats were killed and perfused/fixed for morphological investigations. Microtubule-associated protein 2 (MAP2) immunostaining was used to stain neurons and dendrites and Luxol-fast blue to stain myelinated tracts of the white matter. The injured segment of the spinal cord showed severe atrophy, distortion, cavitation and necrosis of grey and white matter. Compared to uninjured controls the transverse sectional area was reduced to 32.7 ± 4% in untreated animals but only to 38.5% ± 4.1 in CMZ-treated animals. MAP2 staining showed that, compared to uninjured controls, grey matter was reduced to 7.4 ± 2.7% in saline-treated injured animals and to 22.7 ± 5.4% in CMZ-treated rats. Our results thus show that in this model CMZ improves hind limb motor function and attenuates the morphological damage to the spinal cord.
    Materialart: Digitale Medien
    Bibliothek Standort Signatur Band/Heft/Jahr Verfügbarkeit
    BibTip Andere fanden auch interessant ...
  • 49
    Digitale Medien
    Digitale Medien
    Springer
    Anatomy and embryology 200 (1999), S. 413-417 
    ISSN: 1432-0568
    Schlagwort(e): Key words Receptor cell ; Axon ; Vomeronasal organ ; Regeneration ; Rat ; HRP-WGA
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Medizin
    Notizen: Abstract  Chemosensory neurons in the vomeronasal epithelium (vomeronasal neurons) regenerate following experimentally induced degeneration. Transection of the vomeronasal nerves leads to retrograde degeneration of vomeronasal neurons followed by replacement of the cell population. The projection of the axons of regenerated vomeronasal neurons was examined by horseradish peroxidase(HRP) histochemistry and electron microscopy. HRP-wheat germ agglutinin (WGA) was placed on the surface of the vomeronasal organ of the rat. Dense distribution of HRP-labeled fibers was observed in the vomeronasal nerve and glomerular layers in the accessory olfactory bulb (AOB) of the intact rat. At one week after transection, HRP-labeled fibers were not found in the AOB, and no labeled fibers could be observed on the medial surface of the olfactory bulb where the vomeronasal nerve traversed. Three weeks after transection, labeled fiber bundles were observed on the medial surface of the olfactory bulb in all animals. No labeled fibers were detected in the AOB. From 12 to 32 weeks after transection, projection of HRP-labeled fibers was identified in the AOB in 8 out of 26 rats (the incidence of projection was 30%). But the number of projection fibers on the operated side was much smaller than on the control side. Electron microscopy confirmed that the HRP-labeled terminals make synaptic contacts with neurons in the AOB.
    Materialart: Digitale Medien
    Bibliothek Standort Signatur Band/Heft/Jahr Verfügbarkeit
    BibTip Andere fanden auch interessant ...
  • 50
    ISSN: 1279-8517
    Schlagwort(e): Anterior cruciate ligament ; Kinematics ; Knee ; MRI
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Medizin
    Beschreibung / Inhaltsverzeichnis: Résumé Ce travail a pour but de proposer à l'aide d'un modèle informatique 3D du genou chez un sujet vivant une étude anatomique des modifications de longueur du ligament croisé antérieur (LCA) et de ses faisceaux au cours de la flexion. La méthode d'évaluation proposée est une reconstruction informatique 3D, à partir de coupes IRM, reproduisant le mouvement de flexion du genou de 0 à 75°. Vingt-et-une coupes ont été réalisées pour chacune des 13 positions de flexion. La reconstruction de Delaunay et le recalage de chaque position permettent d'obtenir un modèle 3D. Ce modèle permet le suivi d'un point osseux lors du mouvement. En connaissant le déplacement relatif des insertions ligamentaires, il est possible de préciser la biométrie du ligament en calculant la longueur des faisceaux du LCA à chaque position, de mettre en évidence les variations de longueur au cours du mouvement. La longueur moyenne du ligament était de 34 mm. Le faisceau antéro-médial était plus long de 30 % par rapport aux deux autres faisceaux. Lors de la flexion, le faisceau antéro-médial était peu modifié (cette caractéristique semblait en faire une position de référence pour une ligamentoplastie), le faisceau postéro-latéral se tendait à partir de 30°, le faisceau intermédiaire se détendait dès le début du mouvement. En retrouvant les données de la littérature, cette méthode permet une approche anatomique du LCA faisceau par faisceau lors du mouvement de flexion.
    Notizen: Summary The aim of this study is to suggest an anatomic study of the modifications of the length of the anterior cruciate ligament (ACL) and its bundles during flexion with the aid of a 3D computerized model of the knee in a living subject. The method of evaluation suggested is a 3D computerized reconstruction based on MRI sections, reproducing the movement of flexion of the knee from 0 to 75°. Twenty-one sections were made for each of the 13 positions of flexion. The reconstruction of Delaunay and the realignment of each position provided a 3D model which allowed monitoring of a bony point during the movement. By knowing the relative displacement of the ligamentous attachments it was possible to define the biometry of the ligament by calculating the length of the bundles of the ACL in each position and to demonstrate the variations in length during the movement. The mean length of the ligament was 3.4 mm. The anteromedial bundle was longer by 30% compared with the other two bundles. During flexion the anteromedial bundle was not much modified (this feature seems to provide a reference position for a ligamentoplasty), the posterolateral bundle became taut after 30°, and the intermediate bundle relaxed from the beginning of movement. Based on the data from the literature, this method allows an anatomic approach to the ACL, bundle by bundle, during flexion movement.
    Materialart: Digitale Medien
    Bibliothek Standort Signatur Band/Heft/Jahr Verfügbarkeit
    BibTip Andere fanden auch interessant ...
  • 51
    Digitale Medien
    Digitale Medien
    Springer
    Zeitschrift für Lebensmittel-Untersuchung und -Forschung 208 (1999), S. 183-188 
    ISSN: 1431-4630
    Schlagwort(e): Key words Sulphadimidine ; Fermented sausage ; Carbon-14-labelling ; Rat ; Bound residues
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Werkstoffwissenschaften, Fertigungsverfahren, Fertigung
    Notizen: Abstract  Sulphadimidine (SDM), a drug frequently administered to pigs, is partially converted into other compounds by processing meat to produce raw, fermented sausage. With the aid of 14C-labelled SDM, evidence was obtained that part of the radioactive matter was covalently bound to the matrix. Part of these bound residues could be released in vitro by 4 M HCl at 21  °C or by 0.024 M HCl at 37  °C. Female rats were also able to release bound SDM residues and to excrete these in their urine, in amounts approaching those obtained by treatment with 4 M HCl. Both the parent compound and its main metabolite, N 4-acetyl-SDM, were observed in the urine of rats.
    Materialart: Digitale Medien
    Bibliothek Standort Signatur Band/Heft/Jahr Verfügbarkeit
    BibTip Andere fanden auch interessant ...
  • 52
    ISSN: 1432-1211
    Schlagwort(e): Key words Class II MHC sequence ; Rat ; Cloning ; RT-PCR ; Polymorphism
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie , Medizin
    Materialart: Digitale Medien
    Bibliothek Standort Signatur Band/Heft/Jahr Verfügbarkeit
    BibTip Andere fanden auch interessant ...
  • 53
    Digitale Medien
    Digitale Medien
    Springer
    European radiology 9 (1999), S. 336-343 
    ISSN: 1432-1084
    Schlagwort(e): Key words: Cryptorchidism ; Scrotum ; US ; CT ; MRI ; Testis
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Medizin
    Notizen: Abstract. Imaging evaluation of the patient with a non-palpable testis has evolved over recent decades. The rational explanation of imaging in these patients requires a clear understanding of the various causes of a non-palpable testis, and an appreciation of the utility and limitations of the available imaging modalities. This review describes the classification of non-palpable testis and discusses the role of modern imaging in evaluation. In particular, the relative accuracies of ultrasound, CT and MRI is reviewed.
    Materialart: Digitale Medien
    Bibliothek Standort Signatur Band/Heft/Jahr Verfügbarkeit
    BibTip Andere fanden auch interessant ...
  • 54
    ISSN: 1432-1106
    Schlagwort(e): Key words Coherence ; Entorhinal cortex ; Cortex ; Hippocampus ; Amygdala ; 192 IgG-saporin ; Rat
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Medizin
    Notizen: Abstract  Changes in brain electrical activity in response to cholinergic agonists, antagonists, or excitotoxic lesions of the basal forebrain may not be reflective entirely of changes in cholinergic tone, in so far as these interventions also involve noncholinergic neurons. We examined electrocortical activity in rats following bilateral intracerebroventricular administration of 192 IgG-saporin (1.8 µg/ventricle), a selective cholinergic immunotoxin directed to the low-affinity nerve growth factor receptor p75. The immunotoxin resulted in extensive loss of choline acetyl transferase (ChAT) activity in neocortex (80%–84%) and hippocampus (93%), with relative sparing of entorhinal-piriform cortex (42%) and amygdala (28%). Electrocortical activity demonstrated modest increases in 1- to 4-Hz power, decreases in 20- to 44-Hz power, and decreases in 4- to 8-Hz intra- and interhemispheric coherence. Rhythmic slow activity (RSA) occurred robustly in toxin-treated animals during voluntary movement and in response to physostigmine, with no significant differences seen in power and peak frequency in comparison with controls. Physostigmine significantly increased intrahemispheric coherence in lesioned and intact animals, with minor increases seen in interhemispheric coherence. Our study suggests that: (1) electrocortical changes in response to selective cholinergic deafferentation are more modest than those previously reported following excitotoxic lesions; (2) changes in cholinergic tone affect primarily brain electrical transmission within, in contrast to between hemispheres; and (3) a substantial cholinergic reserve remains following administration of 192 IgG-saporin, despite dramatic losses of ChAT in cortex and hippocampus. Persistence of a cholinergically modulated RSA suggests that such activity may be mediated through cholinergic neurons which, because they lack the p75 receptor, remain unaffected by the immunotoxin.
    Materialart: Digitale Medien
    Bibliothek Standort Signatur Band/Heft/Jahr Verfügbarkeit
    BibTip Andere fanden auch interessant ...
  • 55
    ISSN: 1432-1106
    Schlagwort(e): Key words Spatial function ; Water maze ; Procedural learning ; Cerebellum ; Rat
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Medizin
    Notizen: Abstract  Recently, we demonstrated the prevalent role of cerebellar networks in the acquisition of the procedural components of spatial information by testing hemicerebellectomized (HCbed) rats in a classical spatial task, the Morris water maze (MWM). As procedures used in the water maze are a mixture of different components (that is, general procedures, exploration procedures, direct reaching procedures), for optimally solving a spatial task all procedural components must be opportunely managed. Thus, severely impaired procedural learning of cerebellar origin can be better comprehended by fractionating the procedural facets. To this aim, a two-step water-maze paradigm was employed. Normal rats were first trained to search for a hidden platform moved to a different position in each trial, utilizing a water maze setting in which visual cues were abolished by heavy black curtains surrounding the tank. In this paradigm, normal animals solved the task by using general and exploration procedures, but they could not use direct reaching skills. A subgroup of these pretrained animals was then HCbed and, after recovery from cerebellar lesion, was tested in a water maze with normal environmental cues available, a paradigm in which normal animals develop abilities for reaching the target with very direct trajectories. Pretrained HCbed animals, however, did not display the typical spatial deficits of naive HCbed rats, persisted in exhibiting the scanning strategy learned during pretraining, and never displayed direct reaching skills. In conclusion, cerebellar networks appear to be involved in the acquisition of all procedural facets necessary for shifting behavior within the maze until direct reaching of the platform. The lack of flexibility in changing exploration strategies displayed by pretrained HCbed rats is interpreted by taking into account the well-known cerebellar frontal interplay sculpting a specific cerebellar role in the acquisition of spatial procedural steps.
    Materialart: Digitale Medien
    Bibliothek Standort Signatur Band/Heft/Jahr Verfügbarkeit
    BibTip Andere fanden auch interessant ...
  • 56
    Digitale Medien
    Digitale Medien
    Springer
    Experimental brain research 126 (1999), S. 307-314 
    ISSN: 1432-1106
    Schlagwort(e): Key words Striatal dopamine depletion ; Rat ; Locomotion ; Ground reaction forces ; Gait ; Unilateral ; Kinetic ; Centre of mass
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Medizin
    Notizen: Abstract  Hemi-parkinsonian rats have preserved postural reflexes but are impaired in initiation of voluntary movements. Surprisingly, these rats can walk and run, suggesting that they can access some compensatory strategy to overcome the rigidity in their impaired limbs. The purpose of the present experiment was to investigate the locomotor compensations made by hemi-parkinsonian rats by measuring the forces exerted by the limbs on the ground throughout the stride during trotting. Rats with unilateral dopamine depletion produced by injection of 6-hydroxydopamine into the nigrostriatal bundle were trained to run back and forth in an alley for food reinforcement. Ground reaction forces were measured in three orthogonal directions using a force plate embedded in the runway. Rats were also videotaped so that limb movements were synchronized with force recordings. Although locomotion was obviously impaired, the affected limbs could support weight and provide some braking forces. In addition, the impaired hindlimb provided significant propulsive force, and a relatively large laterally directed force. Analysis of vertical movement of the centre of mass suggested that the impaired hindlimb was being used partly as a spring. The most significant abnormalities were seen during the diagonal couplet of the impaired forelimb and the unimpaired hindlimb, partly reflecting the important compensatory role of the unimpaired hindlimb. These results demonstrate that this method is useful in the analysis of hemi-parkinsonian gait and provide insights as to how rats can use an impaired limb to produce weight support and propulsion.
    Materialart: Digitale Medien
    Bibliothek Standort Signatur Band/Heft/Jahr Verfügbarkeit
    BibTip Andere fanden auch interessant ...
  • 57
    Digitale Medien
    Digitale Medien
    Springer
    Experimental brain research 126 (1999), S. 351-358 
    ISSN: 1432-1106
    Schlagwort(e): Key words Tooth pulp ; Phrenic nerve ; Electrical stimulation ; C1 spinal neuron ; Digastric electromyogram ; Somatic receptive field ; Rat
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Medizin
    Notizen: Abstract  Effects of electrical stimulation of the ipsilateral tooth pulp (TP) on C1 spinal neurons were determined in 33 anesthetized rats. One hundred and seven neurons responded to TP stimulation. In 10 rats, the activity of 18 C1 spinal neurons and the amplitude of a digastric electromyogram (dEMG, n=10) increased proportionally during the TP stimulation at an intensity of 1–3 times the threshold for jaw-opening reflex (JOR). Excitatory receptive somatic fields were examined in 61 neurons. Somatic field locations of many neurons (67.2%) involved the ipsilateral face, neck, and jaw. The activity of 45 neurons was increased by both noxious pinch and brushing hair. Of the 107 C1 spinal neurons responding to TP stimulation, 55 were tested to determine the effects of electrical stimulation of the ipsilateral phrenic nerve (PN) above the heart. Twenty-eight of 55 neurons tested were excited; no change in activity was seen for the remaining 27 neurons. The activity of six neurons increased as the intensity of PN stimulation was increased. Excitatory receptive somatic fields were determined in 28 neurons, and somatic field locations of 17 neurons (60.7%) included the ipsilateral face, neck, and jaw. Both noxious pinch and brushing hair excited all 28 neurons. These results suggest that there may be the convergence of face, neck, jaw, TP, and PN afferents on the same C1 spinal neurons in the rat.
    Materialart: Digitale Medien
    Bibliothek Standort Signatur Band/Heft/Jahr Verfügbarkeit
    BibTip Andere fanden auch interessant ...
  • 58
    ISSN: 1432-1106
    Schlagwort(e): Key words Acetylcholine ; Brain slices ; Cerebral cortex ; Long-term depression ; Rat ; Synaptic plasticity
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Medizin
    Notizen: Abstract  The ability of layer I activation to facilitate the induction of long-term potentiation (LTP) in layer II/III horizontal connections of motor cortex (MI) was examined in rat brain slice preparations. Field potentials evoked in layer I and layer II/III horizontal pathways were recorded from radially aligned MI sites. While theta burst stimulation (TBS) of layer II/III pathways alone failed to induce LTP, simultaneous TBS of layer I and layer II/III inputs on alternate sides of the recording electrodes induced LTP in the layer II/III input in 8 out of 13 slices (mean change +20±6%; N=13). In the same cases, the layer I connections showed mixed effects: LTP in three cases, LTD in five cases, and no modification in five slices. Despite the facilitatory effect of layer I activation on layer II/III LTP induction, we found that the critical circuitry for this effect was outside layer I. Cutting the layer I fibers selectively in the slice did not prevent layer II/III LTP induction, while cuts preserving only layer I blocked layer II/III LTP after conjoint I+II/III TBS. Cholinergic fibers were evaluated as candidates for the facilitatory effect because they branch widely in both layers and they are thought to participate in synaptic modification. The cholinergic contribution to layer II/III LTP facilitation was investigated using bath application of muscarinic antagonists. Muscarinic blockade prevented facilitation of layer II/III LTP by layer I coactivation. Instead, conjoint stimulation in 10 µM atropine produced long-term depression (LTD) of layer II/III (–18±9%; N=11) as well as of layer I (–21±6%; N=11) horizontal responses. These results indicate that connections formed within layer I are ineffective in promoting LTP in the deeper-lying horizontal connections; the critical route by which layer I stimulation influenced LTP induction required the circuitry in the deeper layers, particularly the cholinergic system. Thus, it appears that diffuse cholinergic afferents provide an additional route to regulate activity-dependent synaptic modificaton in horizontal cortical connections.
    Materialart: Digitale Medien
    Bibliothek Standort Signatur Band/Heft/Jahr Verfügbarkeit
    BibTip Andere fanden auch interessant ...
  • 59
    Digitale Medien
    Digitale Medien
    Springer
    Experimental brain research 127 (1999), S. 298-306 
    ISSN: 1432-1106
    Schlagwort(e): Key words Motor unit ; Contraction ; Stimulation pattern ; Rat ; Medial gastrocnemius
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Medizin
    Notizen: Abstract  The effects of irregularity in the pattern of stimulation on the tension produced by motor units in the rat medial gastrocnemius muscle were investigated. The effects of decreasing as well as increasing the interpulse intervals were observed for each motor unit in tetani fused to different degrees. For each motor-unit type, it was found that the effects of these changes depended on the extent of tetanic fusion. Decreasing the interpulse interval produced an increase in tension during the tetanus: the more fused the profile of tetanus, the smaller the tension increase. Increasing the interpulse interval resulted in a decrease in tetanic tension. This effect was most prominent when the tetanic fusion index was approximately 0.75. This phenomenon resulted from the prolongation in relaxation when tetanic fusion increased, thereby preventing a decrease in tension when the interpulse interval increased. We also investigated the effects of introducing a short interpulse interval (”doublet”) at the beginning of the stimulation. The doublets produced increased tetanic tension with a more fused profile. However, the doublet enhanced the sensitivity of the tetanus to increases in interpulse interval and decreased its sensitivity to decreases in interpulse intervals. Slow-twitch motor units appeared to be significantly less sensitive to both increases and decreases in interpulse interval than fast-twitch units. This suggests that slow-twitch units are better suited for producing long-lasting contractions with a constant tension level. Conversely, the high sensibility of fast-twitch units to changes in stimulation frequency enhances their participation in regulation of tension of the muscular contraction.
    Materialart: Digitale Medien
    Bibliothek Standort Signatur Band/Heft/Jahr Verfügbarkeit
    BibTip Andere fanden auch interessant ...
  • 60
    ISSN: 1432-1106
    Schlagwort(e): Key words Thyroid hormone ; RT-PCR ; p75 receptor ; trkA ; trkB ; trkC ; Septum ; Hippocampus ; Rat
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Medizin
    Notizen: Abstract  Early postnatal application of thyroid hormones to rats results in morphological changes of the septo-hippocampal cholinergic and the hippocampal mossy fiber systems. Modulation in the expression of either neurotrophins and/or their receptors is postulated to be involved in these effects. In a recent study, we showed that, after thyroxine application, the mRNA expression of neurotrophins of the nerve-growth-factor (NGF) family is significantly upregulated both in septum and hippocampus. To test whether the neurotrophin receptors (the low-affinity neurotrophin receptor p75 and the specific high-affinity receptors trkA, trkB, and trkC) were also affected by hormone administration, newborn rats were treated daily with subcutaneous injections of thyroxine until postnatal day 12 (P12) at latest. Control animals received corresponding injections of saline. The pups were sacrificed at defined intervals from P9 to P14. The septal areas and the hippocampi were analyzed using the reverse-transcription polymerase chain reaction (RT-PCR) method for quantification of p75, trkA, trkB, and trkC mRNA levels. Analysis of variance over the total investigation period revealed no significant general increases of the gene expressions of either neurotrophin receptor, neither in the septum nor in the hippocampus, although previous results have shown marked changes in neurotrophin levels. On particular postnatal days, significant upregulation could be observed in hippocampus for trkB and trkC. From these and recent data, we conclude that modulation of neurotrophin expression rather than neurotrophin-receptor expression contributes to the morphological modifications within the hippocampal mossy fiber system and the septo-hippocampal cholinergic system.
    Materialart: Digitale Medien
    Bibliothek Standort Signatur Band/Heft/Jahr Verfügbarkeit
    BibTip Andere fanden auch interessant ...
  • 61
    Digitale Medien
    Digitale Medien
    Springer
    Experimental brain research 128 (1999), S. 309-314 
    ISSN: 1432-1106
    Schlagwort(e): Key words GABA ; Bromodeoxyuridine ; Proliferation ; Immunohistochemistry ; Retina ; Rat
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Medizin
    Notizen: Abstract  The birthdates of GABAergic amacrine cells in the rat retina were investigated by immunocytochemistry using anti-GABA and anti-bromodeoxyuridine (BrdU) antisera. The ratio of co-localization of GABA to BrdU increased gradually from embryonic-day 13 (E13) and showed a peak value on E18 in the central retina and on E20 in the periphery. After birth, until postnatal-day 3 (P3), a few co-localized cells were observed in the inner nuclear layer (INL). However, in the peripheral retina, co-localized cells were observed in the INL and ganglion cell layer until P5. Our results suggest that the birthdates of GABA-immunoreactive cells vary, depending on cell-type and that there is a temporal lag in the GABA-immunoreactive cell production in the peripheral retina relative to the central retina.
    Materialart: Digitale Medien
    Bibliothek Standort Signatur Band/Heft/Jahr Verfügbarkeit
    BibTip Andere fanden auch interessant ...
  • 62
    Digitale Medien
    Digitale Medien
    Springer
    Naunyn-Schmiedeberg's archives of pharmacology 359 (1999), S. 322-330 
    ISSN: 1432-1912
    Schlagwort(e): Key words Blood pressure ; Endothelium ; Human ; Mesenteric artery ; Rat ; Smooth muscle
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Medizin
    Notizen: Abstract The majority of the findings concerning arterial physiology and pathophysiology originate from studies with experimental animals, while only limited information exists about the functional characteristics of human arteries. Therefore, the aim of the present work was to compare the control of vascular tone in vitro in mesenteric arterial rings of corresponding size (outer diameter 0.75–1 mm) from humans and Wistar-Kyoto rats. The relaxations to acetylcholine (ACh) were clearly less marked in the mesenteric arteries of humans when compared with rats. How-ever, when calcium ionophore A23187 was used as the vasodilator, the endothelium-mediated relaxations did not significantly differ between these species. The NO synthase inhibitor N G-nitro-l-arginine methyl ester (l-NAME) attenuated the relaxations to ACh and A23187 in both groups. The endothelium-independent relaxations to the β-adrenoceptor agonist isoprenaline and the nitric oxide (NO)-donor nitroprusside were somewhat lower in human arteries, while vasodilation induced by the K+ channel opener cromakalim was similar between humans and rats. Arterial contractile sensitivity to noradrenaline and serotonin was slightly lower in human vessels, whereas contractile sensitivity to KCl was similar between these species. The contractions induced by cumulative addition of Ca2+ with noradrenaline as the agonist were effectively inhibited in both groups by the calcium channel blocker nifedipine, the effect of which was clearly more pronounced in human arteries. In conclusion, the control of vascular tone of isolated arteries of corresponding size from humans and rats appeared to be rather similar. The most marked differences between these species were the impaired endothelium-mediated dilation to ACh and the more pronounced effect of nifedipine on the Ca2+-induced contractions in human arteries.
    Materialart: Digitale Medien
    Bibliothek Standort Signatur Band/Heft/Jahr Verfügbarkeit
    BibTip Andere fanden auch interessant ...
  • 63
    ISSN: 1432-198X
    Schlagwort(e): Key words Hypercalciuria ; Idiopathic hypercalciuria ; Bone mineral content ; 1 ; 25-Dihydroxyvitamin D ; Furosemide ; Ammonium chloride ; Rat
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Medizin
    Notizen: Abstract  The relationship between bone mineral status and hypercalciuria is controversial. The effect on bone composition of different forms of hypercalciuria was studied in female rats made hypercalciuric by 7-week administration of oral furosemide (F, n=12), intraperitoneal 1,25-dihydroxy vitamin D (VD, n=11), or oral ammonium chloride (AC, n=12). Seven untreated rats served as controls (C). Hypercalciuria (mg/100 g per 24 h, mean ±SEM) of F (4.3±0.2), VD (4.1±0.4), and AC (3.9±0.3) groups was of similar intensity (C rats 1.3±0.1, P〈0.01). Weight and length gains and serum CO2, sodium, potassium, calcium, and phosphate were no different among the four groups. Bone was studied by dual-energy X-ray absorptiometry of left tibiae. AC rats had significantly less bone area (1.505±0.018 cm2) than VD and C (1.602±0.020 and 1.587±0.019 cm2). Bone mineral content was decreased in F (0.357±0.007 g) and AC (0.362±0.006 g) compared with VD (0.407±0.008 g) and C (0.389±0.009 g) groups. Bone mineral density was different between F (0.231±0.002 g/cm2) and VD and C rats (0.254±0.004 and 0.245±0.003 g/cm2), and also between AC (0.240±0.003 cm2) and VD rats. In these rat models, hypercalciuria of renal origin (F) and hypercalciuria caused by acid load (AC) adversely impaired bone mass.
    Materialart: Digitale Medien
    Bibliothek Standort Signatur Band/Heft/Jahr Verfügbarkeit
    BibTip Andere fanden auch interessant ...
  • 64
    Digitale Medien
    Digitale Medien
    Springer
    Pediatric nephrology 13 (1999), S. 800-805 
    ISSN: 1432-198X
    Schlagwort(e): Key words In situ hybridization ; Kidney development ; Nephrogenesis ; Phosphatase activity ; Serine/threonine protein phosphatase 2A ; Protein phosphorylation ; Rat
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Medizin
    Notizen: Abstract  Several lines of evidence suggest that the serine/threonine protein phosphatase (PP)2A is of vital importance for cell cycle regulation, cell differentiation, and signal transduction. This prompted us to study the expression of the mRNA for PP2A catalytic isoforms α and β in the developing rat kidney using in situ hybridization histochemistry. The expression patterns of the two isoforms were strikingly similar. Both were ubiquitously expressed in early metanephric kidneys. Later in gestation they were expressed in the nephrogenic zone. Strong expression was observed on postnatal day (PN) 10. This was followed by a downregulation at PN20, i.e., when nephrogenesis is completed. The expression in the adult kidney was very weak and mainly confined to the medulla. In a phosphatase activity assay, PP2A accounted for 78% of the total serine/threonine phosphatase activity in embryonic day 15 rat kidneys. PP1 was the main contributor to the remaining activity. In conclusion, PP2A is the major serine/threonine phosphatase in fetal kidneys. The age-dependent expression pattern supports the concept that this enzyme is of particular importance during renal morphogenesis and development.
    Materialart: Digitale Medien
    Bibliothek Standort Signatur Band/Heft/Jahr Verfügbarkeit
    BibTip Andere fanden auch interessant ...
  • 65
    Digitale Medien
    Digitale Medien
    Springer
    Pediatric nephrology 13 (1999), S. 812-815 
    ISSN: 1432-198X
    Schlagwort(e): Key words Cystinosis ; Cysteamine ; Renal function ; Rat ; Prenatal
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Medizin
    Notizen: Abstract  The safety of cysteamine after renal transplantation and during pregnancy is an important issue, since girls with cystinosis are in better health on cysteamine therapy and thus more likely to become pregnant. In the first study, cysteamine was given to pregnant rats on days 6.5–18.5 post conception in oral doses of 0, 37.5, 75, 100, and 150 mg/kg per day. The dams were sacrificed on day 20.5, the fetal kidneys removed and prepared for histological examination. In the second study, cysteamine was given to dams on days 6.5–19.5 post conception in oral doses of 0, 37.5, 50, and 75 mg/kg per day. Dams were allowed to give birth naturally and pups were given cysteamine on days 4–21 to yield the same oral doses of cysteamine given to the dam. Renal function was evaluated on day 35. Histological examination of fetal kidneys revealed no changes even in kidneys from fetuses with growth retardation and malformations. Furthermore, there were no alterations in renal function in offspring on day 35. These findings demonstrate that cysteamine therapy does not affect renal development in the rat. Further investigations will be required to prove whether cysteamine therapy has the potential to affect renal development in the human.
    Materialart: Digitale Medien
    Bibliothek Standort Signatur Band/Heft/Jahr Verfügbarkeit
    BibTip Andere fanden auch interessant ...
  • 66
    Digitale Medien
    Digitale Medien
    Springer
    Der Radiologe 39 (1999), S. 876-881 
    ISSN: 1432-2102
    Schlagwort(e): Schlüsselwörter Kraniale arteriovenöse Duratisteln ; MRA ; DSA-Interventionelle Neuroradiologie ; Endovaskulärer Verschluß ; Key words Dural arterio-venous fistula ; MRI ; DSA ; Interventional Neuroradiology ; Venous occlusion
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Medizin
    Beschreibung / Inhaltsverzeichnis: Summary DAVF are difficult to recognize with CT- or MR-imaging. Diagnosis is often possible by arterial MRA. The type of the venous drainage as demonstrated by DSA is relevant for the clinical decision. Most often the endovascular occlusion of the affected venous segment a suitable therpeutical approach.
    Notizen: Zusammenfassung Kraniale arteriovenöse Durafisteln (DAVF) sind in der Schnittbilddiagnostik schwierig, am besten mittels der arteriellen MRA erkennbar. Klinisch ist die Einteilung nach dem in der DSA ermittelten venösen Drainagetyp relevant. Therapeutisch kommt in erster Linie der transvenöse endovasculäre Verschluss in Betracht.
    Materialart: Digitale Medien
    Bibliothek Standort Signatur Band/Heft/Jahr Verfügbarkeit
    BibTip Andere fanden auch interessant ...
  • 67
    ISSN: 1432-2102
    Schlagwort(e): Schlüsselwörter Retrocochleäre Taubheit ; CISS-3D-Sequenz ; MRT ; N. cholearis ; Aplasie ; Atrophie ; Key words Retrocochlear deafness ; Retrocochlear anakusis ; Cochlear nerve aplasia ; Cochlear nerve atrophy ; MRI ; CISS-3D-sequence
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Medizin
    Beschreibung / Inhaltsverzeichnis: Summary MRI gains greater importance in the differential diagnosis of retrocochlear hearing loss. Retrocochlear anakusis is rarely caused by aplasia or atrophia of the cochlear nerv. In the following we report about a five year old boy suffering from unilateral deafness, where a strongly T2-weighted CISS-3D MRI sequence demonstrates a missing of the cochlear nerv on the deaf side.
    Notizen: Zusammenfassung Die Kernspintomographie gewinnt eine immer größere Bedeutung in der Differentialdiagnostik retrocochleärer Hörstörungen. Äußerst selten handelt es sich dabei um eine Aplasie oder Atrophie des N. cochlearis. Im folgenden wird über einen 5jährigen Jungen mit einer einseitigen Anakusis berichtet, bei dem kernspintomographisch mit einer stark T2-gewichteten CISS-3D-Sequenz (CISS: constructive interference of steady state) das Fehlen des N. cochlearis auf der tauben Seite nachgewiesen werden konnte.
    Materialart: Digitale Medien
    Bibliothek Standort Signatur Band/Heft/Jahr Verfügbarkeit
    BibTip Andere fanden auch interessant ...
  • 68
    ISSN: 1432-2102
    Schlagwort(e): Schlüsselwörter PACS ; Filmlos ; MR ; Key words PACS ; Filmless ; MRI
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Medizin
    Beschreibung / Inhaltsverzeichnis: Summary At our hospital, an average MRI examination comprises 170 images. These examinations were evaluated exclusively on digital reporting systems with two high-resolution monitors for a period of 1 year. A retrospective analysis of this reporting method in comparison with films on a conventional viewing wall was performed with subjective and objective data. Radiologists and technicians were requested to evaluate the system on a subjective scale from 1 to 5 for seven topics (image analysis, inspection, time for reporting, handling, comparison with previous reports, quality of PC laser prints, training period). Moreover, personal interviews were conducted and protocols taken. Patient and image frequency, film costs, data transfer time and amount of system failures were evaluated as objective data. The most important results were: Two thirds of the film checking radiologists prefer the conventional viewing walls over the computer monitors. However, 70% of the residents prefer using the computer monitor for reporting. Seventy percent of the interviewed radiologists considered comparison with former examinations on film very difficult. Digitizing of former MRI examinations was not a convincing method; printing on a standard PC laser printer was considered to yield insufficient quality. The different acceptance between radiologists and residents seems to be related to different experiences. The reduction in film costs (48.6%) will improve further with complete PACS installation in the whole hospital. Data transfer rates are still poor; further improvement of network performance is necessary for convenient work. One whole MRI examination and report could be stored on CD-ROM for a cost of less than 2 euros. This could be a future means of cheap archiving and documentation suitable for viewing on any PC with DICOM III viewer. Images and reports could stay with the patient as in the past.
    Notizen: Zusammenfassung Im Durchschnitt werden pro Tag 14,05 Patienten mit durchschnittlich 170 Schichtbildern pro Patient an unserer MRT-Anlage untersucht. Die Befundung dieser Bilder erfolgte über ein Jahr ausschließlich auf digitalen Befundungsstationen, bestehend aus zwei hochauflösenden Monitoren und einer Graphikworkstation. Ein Bildausdruck erfolgte zusätzlich auf einem hochauflösenden Laserpapierdrucker. Auf Grund von subjektiv und objektiv erhobenen Daten wurde ein retrospektiver Vergleich zwischen digitaler Bildschirmbefundung und Filmbefundung am Leuchtkasten durchgeführt. Material und Methode: Befragt wurde aufgrund einer subjektiven Bewertungsskala von 1 bis 5 nach 7 Kriterien. Weiters wurden in Interviews die subjektiven Erfahrungen protokolliert. Objektiv wurde überdies Anzahl und Zeit der Systemausfälle, Filmverbrauch, Untersuchungsfrequenzen, Bildmenge pro Tag sowie Zeitmessungen für Datentransfers gemessen. Ergebnisse: Zwei Drittel der Oberärzte bevorzugten die Leuchtkastenbefundung, 70% der Ärzte in Ausbildung zogen die Befundung auf Bildschirmen vor. 70% der befragten Ärzte sahen als eindeutiger Schwachpunkt des digitalen Befundungssystems den Vorbildvergleich an. Alle befragten Ärzte (n=13) bewerteten die Arbeit mit (auswärtigen) konventionellen MRT-Untersuchungen auf Film und der gleichzeitigen Bildschirmbefundung als besonders mühsam. Das Einscannen von Voruntersuchungen mit Betrachtung am Bildschirm erwies sich als nicht Praxis tauglich, die Dokumentation auf Papierbildern durch PC-Laserausdruck erwies sich als unbrauchbar. Diskussion: Der deutliche Akzeptanzunterschied zwischen Fachärzten und in Ausbildung befindlichen Ärzten ist vermutlich auf die unterschiedliche Vorerfahrung (Vorprägung) zurückzuführen. Die nur 48,6% Reduktion Filmverbrauch werden vermutlich nach einer stärkeren Verbreitung von digitalen Bilddaten verbessert werden. Die tatsächlich erzielten Bildtransferraten liegen derzeit zeitlich weit über den technisch möglichen. Die Optimierungen von Netzwerken und beteiligten Rechnern sind daher dringend erforderlich. Als alternatives Dokumentations- und Ausgabemedium könnte auch die äußerst preiswerte CD-ROM dienen. Sie sind auf jedem gängigen PC-System verwendbar. Das Prinzip, daß Befund und Bilder beim Patienten verbleiben, wäre damit leicht aufrecht zu erhalten.
    Materialart: Digitale Medien
    Bibliothek Standort Signatur Band/Heft/Jahr Verfügbarkeit
    BibTip Andere fanden auch interessant ...
  • 69
    Digitale Medien
    Digitale Medien
    Springer
    Der Radiologe 39 (1999), S. 16-24 
    ISSN: 1432-2102
    Schlagwort(e): Schlüsselwörter Sprunggelenk ; Sprunggelenksverletzung ; Bandverletzung ; Streßradiographie ; MRT ; Key words Ankle ; Ankle injuries ; Ligament injuries ; Stress X-ray ; MRI
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Medizin
    Beschreibung / Inhaltsverzeichnis: Summary The diagnosis of lateral collateral ankle ligament trauma is based on patient history, clinical examination, and clinical stress tests. If the clinical stress test is positive, stress radiography could be performed. There is no consensus about the usefulness of stress radiography in acute ankle sprain, particularly about the cut-off talar tilt angle beyond which a two-ligament rupture would be certain, ranging from 5° to 30°. Today MRI is not used for this indication, although it allows, with controlled positioning of the foot and with defined sections, visualization of injured lateral collateral ankle ligaments. In ankle injuries, plain radiographs form the established basis of diagnostic imaging and can provide definitive answers in most cases. CT is used in complex fractures for complete visualization. MRI is the method of choice for several diagnostic problem cases, including occult fractures and post-traumatic avascular necrosis. In tendon injuries, MRI is important if ultrasound is not diagnostic. Generally, for the evaluation of acute ankle injuries, MRI is the most important second-step procedure when radiographs are nondiagnostic.
    Notizen: Zusammenfassung Die Diagnose einer lateralen Bandverletzung beim frischen Sprunggelenkstrauma fußt auf der Anamnese, der klinischen Untersuchung und klinischen Streßtests. Bei positiven klinischen Streßtests kann eine Streßradiographie durchgeführt werden. Es gibt keine Übereinstimmung für den Wert der Streßradiographie beim frischen Supinationstrauma des Sprunggelenks, insbesonders für den Winkel der Aufklappbarkeit bei einer Zweibandverletzung, der von 5°–30° reicht. Die MRT wird zur Zeit bei dieser Indikation nur in Einzelfällen benutzt, obwohl sie mit definierter Fußpositionierung und Ausrichtung der Untersuchungsebene eine ausgezeichnete Beurteilung der Sprunggelenksbänder erlaubt. Bei knöchernen Sprunggelenksverletzungen ist die Verwendung des konventionellen Röntgen die etablierte Methode und meist diagnostisch. Die CT kommt bei komplexen Frakturen zum Einsatz, um das gesamte Frakturausmaß darzustellen. Die MRT ist die Methode der Wahl bei verschiedenen Problemfällen wie okkulter Fraktur oder posttraumatischer Osteonekrose. Bei Sehnenverletzungen ist die MRT wichtig, falls eine Ultraschalluntersuchung nicht zur Diagnose führt. Allgemein entwickelt sich bei der Untersuchung der frischen Sprunggelenksverletzung die MRT zur zweitwichtigsten bildgebenden Methode, falls das konventionelle Röntgen zu keiner ausreichenden Diagnose kommt.
    Materialart: Digitale Medien
    Bibliothek Standort Signatur Band/Heft/Jahr Verfügbarkeit
    BibTip Andere fanden auch interessant ...
  • 70
    ISSN: 1432-2102
    Schlagwort(e): Schlüsselwörter Fokale Leberläsionen ; Spiral-CT ; MRT ; Kontrastmittel ; SPIO ; Key words Focal liver lesions ; Spiral CT ; MRI ; Ferumoxides
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Medizin
    Beschreibung / Inhaltsverzeichnis: Summary Purpose: Evaluation of the diagnostic efficacy of contrast-enhanced, dual-phase spiral CT and MRI before and after administration of SPIO particles in focal hepatic disease with previously uncertain diagnosis. Material and methods: In 46 patients in whom primary or secondary hepatic malignancy was suspected, dual-phase spiral CECT and breath-held T1-weighted gradient-echo and T2-weighted fast spin-echo MRI (1.5 T, body-phased-array coil) before and after SPIO administration were compared. The indications for the subsequent MRI studies were based on ambiguous findings on CECT. The number of hepatic lesions, the overall lesion detection and characterization was evaluated by consensus and compared to the gold standard (histological proof in 30/46 of the cases, long-term follow-up in 16/46 of the cases). Results: In 34 of 46 cases the correct diagnoses were established by CECT (sensitivity 96%, specificity 48%) revealing significantly less lesions than MRI. Unenhanced MRI had sensitivity of 93% and specificity of 71%, whereas SPIO-enhanced MRI had sensitivity of 97% and specificity of 88%. The differences between the modalities were even more pronounced in the detection of lesions smaller than 10 mm with SPIO-MRI as the most sensitive method. Conclusions: In this problem-oriented scenario, SPIO-enhanced MRI was superior to spiral CT and unenhanced MRI regarding the diagnostic efficacy in the pre-operative work-up of focal liver lesions. SPIO-enhanced MRI can be recommended as a problem-solving tool for the clinical routine.
    Notizen: Zusammenfassung Fragestellung: Analyse der diagnostischen Wertigkeit der kontrastmittelverstärkten, biphasischen Spiral-CT im Vergleich zu nativer und SPIO-verstärkter MRT bei Patienten mit V.a. fokale Leberläsionen vor eventueller Leber-OP. Material und Methode: 46 Patienten mit V.a. sekundäre oder primäre Lebertumoren wurden nach i.v.-Kontrastmittelgabe an einem Spiral-CT und an einem 1,5 Tesla-Magneten (Atemstillstand-Sequenzen, Körper-Array-Spule) vor und nach i.v.-Infusion von superparamagnetischen Eisenoxydpartikeln untersucht. Die CT- und MRT-Untersuchungen wurden hinsichtlich Läsionsanzahl, -detektion und -charakterisierung qualitativ beurteilt und mit dem Goldstandard (Histologie in 30/46, follow-up in 16/46 der Fälle) verglichen. Ergebnisse: Die Spiral-CT erbrachte in 34/46 Fällen eine korrekte Diagnose, wobei sie signifikant weniger Läsionen in der Leber zeigte als die MRT. Die native MRT war der Spiral-CT hinsichtlich Läsionsdetektion und diagnostischer Effizienz überlegen und wurde noch von der SPIO-verstärkten MRT übertroffen. Der Unterschied zwischen den Modalitäten war bei Läsionen kleiner 10 mm noch deutlicher, von denen die Spiral-CT lediglich 6/13 Läsionen detektierte. Schlußfolgerungen: Die SPIO-MRT ist der biphasischen Spiral-CT und der nativen MRT im Nachweis und bei der Charakterisierung fokaler Leberläsionen überlegen und kann in problematischen Fällen allgemein empfohlen werden.
    Materialart: Digitale Medien
    Bibliothek Standort Signatur Band/Heft/Jahr Verfügbarkeit
    BibTip Andere fanden auch interessant ...
  • 71
    ISSN: 1432-2072
    Schlagwort(e): Key words Nicotine ; Mecamylamine ; Tolerance ; Rat
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Medizin
    Notizen: Abstract  Chronic injections of nicotine in rats produce upregulation of nicotinic cholinergic receptors. It has been proposed that this upregulation is a reflection of receptor desensitization and is the basis of functional tolerance. Mecamylamine, a non-competitive antagonist that blocks activation of nicotinic receptors, does not prevent upregulation produced by nicotine injections. This suggests that receptor activation is not a prerequisite for nicotine-induced receptor upregulation. Therefore, the present experiments tested whether mecamylamine would also fail to prevent the development of tolerance to nicotine. Six daily pairings of mecamylamine (1 mg/kg SC) with nicotine did block the development of tolerance to nicotine-induced antinociception (0.35 mg/kg) and to the ability of nicotine to suppress milk intake (0.66 mg/kg). In another experiment, six daily injections of mecamylamine, when given alone, did not alter the effects of a subsequent, acute injection of nicotine (0.35 mg/kg) in inducing antinociception in rats. There was no evidence that after six pairings of mecamylamine with nicotine, the cues associated with mecamylamine delivery took on conditioned antagonistic properties. These findings suggest that, unlike the receptor upregulation that results from either continuous or repeated nicotine administration, the tolerance following a short series of intermittent nicotine injections is dependent on receptor activation.
    Materialart: Digitale Medien
    Bibliothek Standort Signatur Band/Heft/Jahr Verfügbarkeit
    BibTip Andere fanden auch interessant ...
  • 72
    Digitale Medien
    Digitale Medien
    Springer
    Psychopharmacology 141 (1999), S. 351-361 
    ISSN: 1432-2072
    Schlagwort(e): Key words Amphetamine ; Behavioral sensitization ; MK-801 ; NMDA receptor ; State-dependency ; Rat
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Medizin
    Notizen: Abstract  Many laboratories have reported that coadministration of N-methyl-d-aspartate (NMDA) receptor antagonists with psychomotor stimulants prevents the development of behavioral sensitization and therefore concluded that NMDA receptor transmission is necessary for sensitization. According to an alternative ”state-dependency” interpretation, NMDA receptor antagonists do not prevent sensitization. Rather, they become a conditioned stimulus for the sensitized response, i.e., it is only elicited in response to combined administration of the NMDA receptor antagonist and the stimulant. This hypothesis is supported by progressive augmentation of the locomotor response to the drug combination during the induction phase, and expression of sensitization when challenged with the combination but not the stimulant alone. To test this hypothesis, rats were treated during a 6-day induction phase with amphetamine (Amph) alone or in combination with the competitive NMDA receptor antagonist CGS 19755 (10 mg/kg) or the non-competitive NMDA receptor antagonist MK-801 (0.05, 0.1 and 0.25 mg/kg). When CGS 19755 was coadministered with Amph, there was no progressive augmentation of response to the drug combination. When challenged with Amph alone, rats did not exhibit the biphasic pattern of locomotor activity characteristic of Amph sensitization. No sensitization of stereotyped behaviors was evident, although the ambulatory response was greater than that exhibited by naive rats. Results with MK-801 were complex, but progressive augmentation of response to the drug combination appeared to in part reflect sensitization to MK-801 and could be dissociated from the ability of MK-801 to prevent the development of sensitization as assessed by response to challenge with Amph alone. Many of these findings are inconsistent with predictions of the ”state-dependency” hypothesis. Moreover, the ability of NMDA receptor antagonists to prevent biochemical and electrophysiological correlates of sensitization is difficult to reconcile with the idea that sensitization develops in the presence of NMDA receptor blockade but cannot be expressed. Together, these findings suggest that the ability of NMDA receptor antagonists to prevent Amph sensitization reflects a requirement for NMDA receptor transmission during its induction.
    Materialart: Digitale Medien
    Bibliothek Standort Signatur Band/Heft/Jahr Verfügbarkeit
    BibTip Andere fanden auch interessant ...
  • 73
    ISSN: 1432-2072
    Schlagwort(e): Key words SSRI ; Cytochrome P450 ; Serotonin ; Microdialysis ; Norfluoxetine ; Locomotor activity ; Rat
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Medizin
    Notizen: Abstract Amphetamine stimulates locomotor activity, in large part by activating central dopaminergic systems. Serotonin shares on overlapping distribution with dopamine and has been shown to modulate dopaminergic function and dopamine-mediated behaviors. The present study examined whether increasing serotonergic function, via the selective serotonin reuptake inhibitor fluoxetine, would alter the stimulatory effects of amphetamine on locomotor activity and dopamine overflow in the nucleus accumbens. In addition, the present study determined whether fluoxetine treatment would alter the metabolism of amphetamine. Results show that 5.0 mg/kg fluoxetine potentiated the locomotor activity induced by amphetamine (0.5–1.0 mg/ kg), and enhanced the increased dopamine overflow in the nucleus accumbens induced by amphetamine. Fluoxetine treatment also resulted in a higher concentration of amphetamine in the CNS. Together, these findings indicate that acute fluoxetine treatment potentiates the locomotor stimulating and dopamine activating effects of amphetamine. Further, the results indicate that fluoxetine potentiates the effects of amphetamine by decreasing the metabolism of amphetamine, probably through inhibition of cytochrome P450 isozymes.
    Materialart: Digitale Medien
    Bibliothek Standort Signatur Band/Heft/Jahr Verfügbarkeit
    BibTip Andere fanden auch interessant ...
  • 74
    ISSN: 1432-2072
    Schlagwort(e): Key words NMDA (N-methyl-D-aspartate) ; Schizophrenia ; Prepulse inhibition (PPI) ; Sensory gating ; P50 ; Auditory evoked potentials (AEP) ; Ketamine ; d-Amphetamine ; Rat
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Medizin
    Notizen: Abstract Schizophrenic patients suffer from deficits in information processing. Patients show both a decrease in P50 gating [assessed in the conditioning-testing (C-T) paradigm] and prepulse inhibition (PPI), two paradigms that assess gating. These two paradigms might have a related underlying neural substrate. Gating, as measured in both the C-T paradigm (the gating of a component of the auditory evoked potential (AEP)], and PPI can easily be measured in animals as well as in humans. This offers the opportunity to model these information processing paradigms in animals in order to investigate the effects of neurotransmitter manipulations in the brain. In order to validate the animal model for disturbances in AEP gating, d-amphetamine (0.5 and 1 mg/kg, IP) was administered. Gating of an AEP component was changed due to injection of d-amphetamine (1 mg/kg) in the same way as seen in schizophrenic patients: both the amplitude to the conditioning click and the gating were significantly reduced. Next, the effect of the N-methyl-D-aspartate (NMDA) antagonist ketamine (2.5 and 10 mg/kg, IP) was investigated to assess its effects in the two gating paradigms. It was found that ketamine (10 mg/kg) did not affect gating as measured with components of the AEP. However, ketamine (10 mg/kg) disrupted PPI of the startle response to the extent that prepulse facilitation occurred. Firstly, it is concluded that AEP gating was disrupted by d-amphetamine and not by ketamine. Secondly, PPI and the C-T paradigm reflect distinct inhibitory sensory processes, since both paradigms are differentially influenced by ketamine.
    Materialart: Digitale Medien
    Bibliothek Standort Signatur Band/Heft/Jahr Verfügbarkeit
    BibTip Andere fanden auch interessant ...
  • 75
    ISSN: 1432-2072
    Schlagwort(e): Key words Alcoholism ; Alcohol drinking ; Alcohol intake ; Calcium channells ; Genetic model of alcoholism ; Pharmacotherapy ; Rat
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Medizin
    Notizen: Abstract Drugs which possess selective actions on a given voltage operated calcium (Ca2+) channel (VOCC) are reportedly involved in the pharmacological actions of alcohol. Recently it was shown that the 1,4-dihydropyridine (−)-BAY k 8644, an L-type VOCC agonist, reduces alcohol intake relatively selectively in the genetic drinking AA rat. This study determined whether (−)-BAY k 8644 would alter volitional alcohol drinking in two other genetic models of alcoholism, male P rats and a new strain of male and female high ethanol preferring (HEP) rats. By use of a standard 10-day preference test for water versus 3 to 30% alcohol, the maximally preferred concentration of alcohol was first determined for each rat individually, i.e. 9%, 13% or 15%. Then the rats were allowed free access over 24 h or limited access to alcohol for only 2 h, during which time the intakes of water and preferred solution of alcohol were recorded. After the drinking patterns stabilized for 4 days, saline, a solutol vehicle solution or (−)-BAY k 8644 was administered: (1) in a dose of 0.125, 0.25 or 0.5 mg/kg given intraperitoneally twice daily for 4 days during free access to alcohol; and (2) for 3 days in a dose of 0.125 or 0.25 mg/kg given subcutaneously 30 min prior to 2 h of limited access to alcohol. Fluid intakes were recorded for either 4 or 8 days after limited and free access conditions, respectively. Whereas the control solutions were without effect during 24 h access, (−)-BAY k 8644 caused a significant dose-dependent suppression of up to 80% in absolute g/kg and proportion of alcohol to total fluid consumed; this decline persisted in the post drug period. During the limited access paradigm, (−)-BAY k 8644 similarly reduced alcohol drinking maximally within the first 15 min of presentation of alcohol; again, this reduction persisted over the remaining 105 min of alcohol access. Also, individual levels of blood alcohol declined concurrently with the suppression of drinking. These results demonstrate that (−)-BAY k 8644 possesses a short latency of action on alcohol intake and that its salutary effects on drinking persist after the drug is terminated. Finally, the hypothesis that L-type calcium channel agonists may be useful as a therapeutic adjunct in the treatment of alcoholism is extended.
    Materialart: Digitale Medien
    Bibliothek Standort Signatur Band/Heft/Jahr Verfügbarkeit
    BibTip Andere fanden auch interessant ...
  • 76
    Digitale Medien
    Digitale Medien
    Springer
    Psychopharmacology 142 (1999), S. 302-308 
    ISSN: 1432-2072
    Schlagwort(e): Key words Alcohol ; Beer ; Craving ; Rat ; Naloxone ; SR 141716 ; Ritanserin
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Medizin
    Notizen: Abstract Rats were given two weeks of home cage access to either “near-beer” (a beverage that tastes like beer but contains 〈0.5% ethanol v/v) or near-beer with added ethanol (4.5% v/v), which is simply referred to as “beer”. The two groups of rats (near-beer and beer) were then trained on a “lick-based progressive ratio paradigm” in operant chambers in which an ever increasing number of licks had to be emitted for each successive fixed unit of near-beer or beer delivered. Break points (the ratio at which responding ceased) for near-beer and beer were approximately equal under baseline conditions. Rats were then tested for the effects of the 5HT2A/2C receptor antagonist ritanserin (0.625, 2.5 or 10 mg/kg), the opioid receptor antagonist naloxone (0.625, 2.5 or 10 mg/kg) or the cannabinoid CB1 receptor antagonist SR 141716 (0.3, 1 or 3 mg/kg). All three drugs caused a dose-dependent reduction of break-points and locomotor activity in both the beer and near-beer groups. However, the effects of SR 141716 and naloxone, but not ritanserin, on break-points were significantly more pronounced on rats drinking beer compared to those drinking near-beer. There were no such differential effects of any of the drugs on locomotor activity across the two groups. These results suggest that both SR 141716 and naloxone differentially affect the motivation to consume alcoholic beverages and may thus have potential as drugs for the treatment of alcohol craving.
    Materialart: Digitale Medien
    Bibliothek Standort Signatur Band/Heft/Jahr Verfügbarkeit
    BibTip Andere fanden auch interessant ...
  • 77
    Digitale Medien
    Digitale Medien
    Springer
    Psychopharmacology 143 (1999), S. 54-63 
    ISSN: 1432-2072
    Schlagwort(e): Key words Nicotine ; Midazolam ; Caffeine ; Cocaine ; Amphetamine ; Pentobarbitone ; Ethanol ; Drug discrimination ; Rat
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Medizin
    Notizen: Abstract Rationale: Studies of the discriminative stimulus effects of drug mixtures provide an approach to polydrug abuse and studies on single drugs with multiple effects. Objective: This study was designed to investigate whether the use of the AND-OR procedure increases the specificity of drug mixture discriminations. Methods: Rats were trained to discriminate a mixture of amphetamine (0.4 mg/kg) plus pentobarbitone (10 mg/kg) from saline (AND-discrimination, n = 8) or to discriminate the same mixture from its component drugs alone (AND–OR discrimination, n = 9). The studies used two-lever operant procedures with a tandem variable interval 1-min fixed ratio 10 schedule of food reinforcement. Results: Under AND-discrimination conditions, there was partial generalization to nicotine and midazolam when each drug was administered singly, and there was no generalization to cocaine, caffeine or ethanol. With the AND-OR discrimination, there was no generalization to any of the preceding drugs administered singly. In “single substitution” tests, nicotine or midazolam was co-administered with the training doses of pentobarbitone and amphetamine, respectively; there was full generalization in the AND-discrimination and partial generalization under AND-OR conditions. Cocaine co-administered with pentobarbitone generalized fully under both procedures, but the dose of cocaine needed was much larger in the AND-OR than in the AND-discrimination. In “dual substitution” tests, mixtures of two novel substances were tested. Mixtures of either nicotine plus midazolam or caffeine plus ethanol produced very marked generalization under AND-discrimination conditions, but were without significant effect in the AND-OR procedure. Throughout the studies, in every instance where comparisons were made, generalization was greater or occurred at lower doses under AND- than under the AND-OR discrimination. Conclusions: The study yielded extensive evidence supporting the hypothesis that the AND-OR discrimination procedure increases the specificity of discriminations based on drug mixtures.
    Materialart: Digitale Medien
    Bibliothek Standort Signatur Band/Heft/Jahr Verfügbarkeit
    BibTip Andere fanden auch interessant ...
  • 78
    ISSN: 1432-2072
    Schlagwort(e): Key words BC264 ; Cholecystokinin ; CCKB receptor ; Memory ; Ageing ; Rat
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Medizin
    Notizen: Abstract Rationale: The implication of CCKB receptors in cognitive processes is far from fully understood. Objective: The present study investigated the effect of propionyl-BC264, a selective agonist of CCKB receptors, in young and old rats. Methods: Cognitive functions were studied in a two-trial recognition memory task developed in our laboratory. Results: It was shown that propionyl-BC264 enhanced information processing in young as well as in old rats when injected (10 μg/kg; IP) immediately after the acquisition phase and before the retrieval trial but not before the acquisition trial. This cognitive enhancing effect was blocked by prior administration of L 365,260, a selective CCKB receptor antagonist. Conclusions: In view of the fact that BC264 is devoid of anxiogenic effects, it could be of value in the treatment of cognitive impairments associated with both normal and pathological ageing.
    Materialart: Digitale Medien
    Bibliothek Standort Signatur Band/Heft/Jahr Verfügbarkeit
    BibTip Andere fanden auch interessant ...
  • 79
    Digitale Medien
    Digitale Medien
    Springer
    Psychopharmacology 145 (1999), S. 153-161 
    ISSN: 1432-2072
    Schlagwort(e): Key words Cocaethylene ; Cocaine ; Alcohol ; Interaction ; Schedule-controlled responding ; Rat
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Medizin
    Notizen: Abstract  Rationale: Cocaethylene is a unique metabolite of cocaine, produced only in the presence of alcohol. This metabolite is pharmacologically, physiologically and behaviorally active. Further, it has been reported to interact pharmacokinetically with both cocaine and alcohol, an interaction that may mediate, in part, the interaction of cocaine and alcohol. Although cocaethylene has been shown to interact with both cocaine and alcohol, behavioral assessments of these interactions are limited. Objectives: To examine directly the behavioral interactions between cocaethylene and cocaine and between cocaethylene and alcohol, the present study assessed the effects produced by these combinations on schedule-controlled responding. Methods: Rats were first administered cumulative doses of cocaethylene, cocaine and alcohol to assess their effects alone on responding. Following this, doses of cocaethylene were combined with cumulative doses of cocaine or alcohol. Additionally, doses of cocaine or alcohol were given in combination with cumulative doses of cocaethylene. Results: When administered alone, cocaethylene, cocaine and alcohol produced dose-related decreases in responding. Further, cocaethylene shifted the dose–response functions for both cocaine and alcohol to the left and down, while cocaine and alcohol shifted the dose–response function for cocaethylene to the left and down. An isobolographic analysis revealed that these interactions were additive in nature. Conclusions: The present study suggests behavioral interactions between cocaethylene and cocaine and between cocaethylene and alcohol. The contribution of cocaethylene to the enhanced effects produced by the co-administration of cocaine and alcohol was discussed.
    Materialart: Digitale Medien
    Bibliothek Standort Signatur Band/Heft/Jahr Verfügbarkeit
    BibTip Andere fanden auch interessant ...
  • 80
    ISSN: 1432-2072
    Schlagwort(e): Key words Ibogaine ; Cocaine ; Dose-response ; Locomotor activity ; Sensitization ; Rat
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Medizin
    Notizen: Abstract  Rationale: Results of single-dose studies suggest that the effects of pretreatment with the putative anti-addictive compound, ibogaine, on drug-induced locomotor behavior depends on the previous drug history of the animal. Objectives: To compare the effects of ibogaine pretreatment on the dose-locomotor response function for cocaine in rats treated chronically with either saline or cocaine. Methods: Rats were chronically treated with either cocaine (15 mg/kg, IP, once daily for 5 days, followed by 2 week withdrawal) or saline. Ibogaine (40 mg/kg, IP) or vehicle was administered and 19 h later, a cocaine dose-locomotor response test was conducted (0, 5, 10, 20 and 40 mg/kg, IP). Results: Chronic cocaine administration augmented the locomotor response to cocaine in chronic cocaine-treated rats, compared to acutely treated controls. Ibogaine pretreatment enhanced the locomotor effects of cocaine in both chronic and acute cocaine groups. Furthermore, due to the shape of the dose-response curve, in chronic cocaine but not in acute cocaine rats, ibogaine pretreatment enhanced the locomotor response to 5 and 10 mg/kg cocaine while decreasing the locomotor response to 40 mg/kg cocaine. Conclusions: These data demonstrate definitively that ibogaine can enhance sensitivity to the locomotor stimulant effects of cocaine, an effect which depends, in part, on the previous cocaine history of the animal.
    Materialart: Digitale Medien
    Bibliothek Standort Signatur Band/Heft/Jahr Verfügbarkeit
    BibTip Andere fanden auch interessant ...
  • 81
    ISSN: 1432-2072
    Schlagwort(e): Key words Dextromethorphan ; Dextrorphan ; Phencyclidine ; Self-administration ; Drug discrimination ; Monkey ; Rat
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Medizin
    Notizen: Abstract  Rationale: Dextromethorphan (DXM) and its metabolite, dextrorphan (DXO) have neuroprotective and anticonvulsant properties through their activity as N-methyl-d-aspartate (NMDA) receptor channel blockers. Based on this receptor activity, coupled with reports of DXM abuse, both were evaluated for abuse potential and phencyclidine (PCP)-like behavioral effects in two animal models. Objectives and methods: The discriminative stimulus properties of DXO and DXM were tested in rats (3–56 mg/kg DXM, i.p. and 2.2–40.9 mg/kg DXO, i.p.) and rhesus monkeys (0.3–10 mg/kg DXM, i.m. and 0.25–8.0 mg/kg DXO, i.m.) trained to discriminate PCP from saline using a standard two-lever drug-discrimination paradigm under a fixed-ratio (FR) schedule of food reinforcement. In a second set of experiments, i.v. self-administration of DXO (10–100 µg/kg/infusion) and DXM (10–1000 µg/kg/infusion) were tested under a FR schedule of reinforcement in monkeys trained to lever press for infusions of PCP during daily 1-h sessions. Results: In rats, both DXM and DXO produced a dose-dependent substitution for PCP. When tested in monkeys, DXM yielded partial (1 monkey) and full (2 monkeys) substitution for PCP, while DXO substituted fully for PCP in all four subjects tested. In the self-administration study, in five of the six subjects, at least one dose of DXM served as a positive reinforcer, maintaining infusion rates above those for saline. For DXO, at least one dose maintained infusion numbers well above mean saline infusion numbers in all subjects. Conclusions: Taken together, these data show that DXM has some PCP-like effects in rats and monkeys, but that they are more reliably produced by its metabolite, DXO. Thus, high doses of DXM may have some PCP-like abuse potential in humans but this potential may be associated with, or enhanced by, metabolism of DXM to DXO.
    Materialart: Digitale Medien
    Bibliothek Standort Signatur Band/Heft/Jahr Verfügbarkeit
    BibTip Andere fanden auch interessant ...
  • 82
    ISSN: 1432-2072
    Schlagwort(e): Key words Nicotinic receptor ; Dorsal hippocampus ; Anxiety ; Phobia ; Elevated plus-maze ; Rat
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Medizin
    Notizen: Abstract   Rationale: The elevated plus-maze provides a test situation in which distinctive states of anxiety are elicited on trials 1 and 2 and the dorsal hippocampus has previously been shown to mediate the anxiogenic effects of (–)-nicotine in the social interaction test. Objective: To determine the effects of a wide dose range of (–)-nicotine on trial 1 and 2 in the plus-maze after systemic administration and whether the dorsal hippocampus is a site mediating the anxiogenic effect of nicotine. Methods: (–)-Nicotine (0.001, 0.005, 0.01, 0.05, 0.1, 0.5 and 1 mg/kg) was injected IP 30 min before testing for 5 min in the plus-maze. Rats receiving dorsal hippocampal infusions received bilateral infusions of 0.5 μl of artificial CSF or (–)-nicotine (0.1, 1, 4 or 8 μg). The needle was left in place for 50 s after injection and testing took place 3 min later. Rats tested on trial 1 were naive to the plus-maze, those tested on trial 2 had received a previous 5-min undrugged exposure to the maze 48 h earlier. Results: Low doses of (–)-nicotine (0.001, 0.005, 0.01, 0.05 and 0.1 mg/kg, IP) were without effect on either trial, but higher doses (0.5 and 1 mg/kg, IP) had anxiogenic effects on both trials, as shown by decreases in percentage time spent and percentage entries onto the open arms. Infusion of (–)-nicotine (0.1, 1, 4 and 8 μg) bilaterally into the dorsal hippocampus was without effect on trial 1, but 1 μg had an anxiolytic effect on trial 2, shown by an increased percentage time spent on the open arms. Conclusions: The results on both trials in the plus-maze after systemic administration of nicotine add to previous reports from the social interaction test that high doses of nicotine have anxiogenic effects. However, the effects of nicotine in the dorsal hippocampus are different in all three anxiety tests (anxiogenic in social interaction, ineffective on trial 1, anxiolytic on trial 2) showing that nicotinic cholinergic control in this brain region may vary depending on the state and/or type of anxiety generated by the test. The brain region(s) underlying the anxiogenic effects of IP nicotine on both trials in the plus-maze remain to be identified.
    Materialart: Digitale Medien
    Bibliothek Standort Signatur Band/Heft/Jahr Verfügbarkeit
    BibTip Andere fanden auch interessant ...
  • 83
    Digitale Medien
    Digitale Medien
    Springer
    Psychopharmacology 144 (1999), S. 77-82 
    ISSN: 1432-2072
    Schlagwort(e): Key words Acquisition ; Cocaine ; Heroin ; Rat ; Self-administration ; Sex difference
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Medizin
    Notizen: Abstract   Rationale: Despite numerous reports that male and female animals differ in behavioral responses to drugs, few studies have investigated sex differences in drug-reinforced behavior. Objectives: Acquisition of IV cocaine and heroin self-administration was compared in 20 female and 22 male Wistar rats. Methods: An autoshaping procedure was used to train rats to press a lever that resulted in either a 0.2 mg/kg infusion of cocaine or a 0.015 mg/kg infusion of heroin under a fixed-ratio 1 (FR 1) schedule. Daily sessions consisted of six 1-h autoshaping components followed by a 6-h self-administration component. During each autoshaping component, a retractable lever briefly (15 s) extended into the test chamber on a random interval schedule with a mean of either 90 s (cocaine groups) or 480 s (heroin groups) and either ten (cocaine groups) or five (heroin groups) computer-automated infusions were delivered each hour. During each 6-h self-administration component, the lever remained extended and each response on the lever resulted in an infusion of either cocaine (0.2 mg/kg) or heroin (0.015 mg/kg). The criterion for acquisition of cocaine self-administration was a mean of at least 100 infusions and the criterion for heroin self-administration was a mean of at least 20 infusions during the self-administration component over five consecutive sessions. Results: Female rats acquired both cocaine and heroin self-administration more rapidly than males. Acquisition of cocaine self-administration occurred in a greater percentage of female rats compared to males. Female rats self-administered more cocaine than males after acquisition criteria had been met. Conclusions: These findings indicate that female rats were more vulnerable than males to the acquisition of cocaine and heroin self-administration under the conditions of the present experiment.
    Materialart: Digitale Medien
    Bibliothek Standort Signatur Band/Heft/Jahr Verfügbarkeit
    BibTip Andere fanden auch interessant ...
  • 84
    ISSN: 1432-2072
    Schlagwort(e): Key words Nicotinic acetylcholine receptor ; ABT-418 ; Methylphenidate ; Basal forebrain ; 192 IgG-saporin ; Sustained attention ; Rat
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Medizin
    Notizen: Abstract   Rationale: Loss of telencephalic cholinergic projections has been postulated to contribute significantly to the cognitive decline associated with aging and dementia. Objective: The effects of the nicotinic acetylcholine receptor agonist ABT-418, a potential therapeutic drug for the treatment of the age- and dementia-associated cognitive disorders, were tested in an animal model of the cortical cholinergic deafferentation-induced impairments in sustained attention. Methods: Animals were trained in an operant task designed to test sustained attention performance. A partial loss of cortical cholinergic inputs was produced by infusions of 192 IgG-saporin into the basal forebrain. The effects of the systemic administration of ABT-418 (0.04, 0.13, 0.39 mg/kg) and the psychostimulant methylphenidate (0.2, 0.4, 0.8 mg/kg) were assessed. Results: Compared with sham-lesioned animals, this lesion resulted in a decrease in the relative number of hits while the relative number of correct rejections remained unaffected. Administration of ABT-418 significantly improved the relative number of hits. Furthermore, this effect of ABT-418 interacted with the effects of the lesion. Unexpectedly, this interaction was based on a significant enhancement of the performance of sham-lesioned animals while no effects were found in 192 IgG-saporin-lesioned animals. Administration of methylphenidate did not affect performance. Conclusions: While these data do not support the hypothesis that administration of ABT-418 attenuates the impairments in attentional performance that result from loss of cortical cholinergic inputs, they support previous notions about this drug’s ability to enhance cognitive processes in intact subjects.
    Materialart: Digitale Medien
    Bibliothek Standort Signatur Band/Heft/Jahr Verfügbarkeit
    BibTip Andere fanden auch interessant ...
  • 85
    Digitale Medien
    Digitale Medien
    Springer
    Psychopharmacology 147 (1999), S. 274-279 
    ISSN: 1432-2072
    Schlagwort(e): Key words Ethanol ; Initiation ; Sucrose-substitution ; Appetitive-consummatory ; Rat
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Medizin
    Notizen: Abstract  Rationale: The concepts of appetitive and consummatory behaviors provide a framework for examining ethanol-drinking behavior. However, traditional studies of ethanol self-administration using dipper procedures make separating the appetitive from the consummatory components difficult. Objective: This study compared the ability to initiate ethanol self-administration using a new sipper-tube self-administration procedure with the older established sucrose-substitution initiation model that employed dipper presented reinforcement. The new model was developed to allow for an assessment of the appetitive and consummatory components in ethanol self-administration. Methods: For the sipper-tube procedure, the rats were initiated to self-administer ethanol using a sucrose-substitution procedure that provided limited access to a sipper tube containing ethanol. This procedure required the completion of a fixed ratio requirement (FR4) in order to gain access to a sipper tube for 20 min. Initially, a 20% sucrose solution with no ethanol was provided in the sipper tube. Over sessions, the concentration of sucrose was reduced and the ethanol concentration increased, until 10% ethanol in water was the solution presented. A second group of animals was initiated to self-administer ethanol using the dipper-presentation procedure employed in our laboratory for many years. This group was used for comparison of the effectiveness of initiation in the sipper-tube procedure. Results: Following initiation, the sipper-tube rats self-administered 10% ethanol in water with intakes averaging 0.75 g/kg during the 20-min drinking period. Increasing the ethanol concentrations as high as 20%, increased intakes as high as 1.5 g/kg. The ethanol intakes observed were similar to those obtained with the dipper initiation procedure but occurred in one-third of the time. Conclusions: The sipper-tube procedure employed here results in similar ethanol self-administration behavior as has been found with a dipper presentation procedure. More importantly, however, it allows for a separation of the appetitive and consummatory components of ethanol self-administration. This separation may prove useful for examining the strength of ethanol-seeking behaviors without the confound of increasing levels of ethanol interacting with the appetitive seeking behaviors.
    Materialart: Digitale Medien
    Bibliothek Standort Signatur Band/Heft/Jahr Verfügbarkeit
    BibTip Andere fanden auch interessant ...
  • 86
    Digitale Medien
    Digitale Medien
    Springer
    Psychopharmacology 144 (1999), S. 311-315 
    ISSN: 1432-2072
    Schlagwort(e): Key words Anxiety ; ACTH ; Corticosterone ; GH ; Stress ; Anxiolytic ; Chlordiazepoxide ; Rat
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Medizin
    Notizen: Abstract   Rationale: Social isolation is anxiogenic and may change the effects of anxiolytic drugs. These effects are generally attributed to ”isolation stress”. However, isolation does not affect basal corticosterone levels; thus, it cannot be considered stressful. On the contrary, isolation deprives animals of mild daily stressors that are inherent to social life. Since mild stressors were shown to be anxiolytic in rats, it was postulated that short-term, repeated stressors may abolish the effects of isolation. Objectives: The aim of the present study was to investigate whether short-term, repeated, mild social stress can abolish the consequences of isolation on anxiety and on the effects of chlordiazepoxide. Methods: Rats were housed in groups or in individual cages for 5 days (isolates). Half of isolates were daily submitted to the attacks of a resident rat for 30 min per day, on 4 consecutive days (stressed isolates). On day 5, rats were treated either with vehicle or with chlordiazepoxide and submitted to the elevated plus-maze test. Endocrinological consequences of experimental manipulations were assessed in a different set of rats. Results: Plasma ACTH and corticosterone levels were similar in the three groups. Weight gain was higher, while plasma growth hormone was lower in stressed isolates, both effects being consistent with a mild stress. Isolation had a clear anxiogenic effect. This effect was completely abolished by the daily experience of social stress. Chlordiazepoxide had a significant anxiolytic effect in all three groups. Its effects on classical plus-maze variables did not differentiate the three groups. However, chlordiazepoxide decreased risk assessment activity only in isolates. Conclusions: The lack of appropriate endocrinological changes challenges the concept of ”isolation stress”. However, isolation was anxiogenic in our study and it also induced subtle changes in the effects of chlordiazepoxide. It appears that mild daily stressors have a protective effect against the effects of isolation.
    Materialart: Digitale Medien
    Bibliothek Standort Signatur Band/Heft/Jahr Verfügbarkeit
    BibTip Andere fanden auch interessant ...
  • 87
    ISSN: 1432-2072
    Schlagwort(e): Key words Hippocampus ; Lesion ; Glutamate receptor and release ; Dopamine receptor ; Locomotor activity ; Schizophrenia ; Rat
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Medizin
    Notizen: Abstract In 6-week and 8-week-old rats (pre- and postpubertally) with neonatal excitotoxic lesions of the ventral hippocampus with ibotenic acid (IBO), we have studied apomorphine-induced motor activity and glutamate and dopamine D1 and D2 binding sites in the hippocampus, striatum, nc. accumbens and frontal cortex as well as K+-stimulated (3H)-D-aspartate release from hippocampal and frontal cortical slices. Specific glutamate binding was enhanced in the frontal cortex of 8-week-old IBO-treated animals, whereas that in other brain regions remained unchanged. Both D1 and D2 binding sites were downregulated in the striatum without changes in other brain structures. In 6-week-old rats, neither the glutamate nor the dopamine binding sites were altered. The amino acid release from hippocampal and frontal cortical slices of adult IBO treated rats was significantly decreased in comparison to controls, whereas in 6-week-old rats, no significant alterations were detectable. The additionally monitored motor activity was enhanced only in adult IBO-lesioned rats after apomorphine pretreatment. The present data are in agreement with the hypothesis of hyperactive dopamine and hypoactive glutamate systems in schizophrenia and are discussed in the light of schizophrenia-like behavioral changes in rats after postnatal hippocampal IBO lesion.
    Materialart: Digitale Medien
    Bibliothek Standort Signatur Band/Heft/Jahr Verfügbarkeit
    BibTip Andere fanden auch interessant ...
  • 88
    ISSN: 1432-2072
    Schlagwort(e): Key words Amphetamine ; Fluoxetine ; Intracranial self-stimulation thresholds ; Withdrawal ; Depression ; Selective serotonin reuptake inhibitors ; Psychostimulant ; Reward ; Rat
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Medizin
    Notizen: Abstract  Rationale: Withdrawal from chronic amphetamine administration is characterized by deficits in reward that resemble some symptoms of depression. Nevertheless, the effects of long-term administration and withdrawal from other drugs, such as fluoxetine, that have the potential to elevate mood in depressed individuals have not been characterized. Objectives: The purpose of this study was to characterize the effects of withdrawal from chronic amphetamine or fluoxetine administration on central reward function. Furthermore, the effects of acute or chronic pretreatment with fluoxetine on responsiveness to an acute amphetamine challenge were examined to identify potential interactions between the two drugs. Methods: A rate-independent discrete-trial threshold procedure was used to characterize self-stimulation behavior in rats prepared with bipolar electrodes in the medial forebrain bundle. Results: Elevations in intracranial self-stimulation (ICSS) thresholds, reflecting a decrease in the reward value of the stimulation, were associated with withdrawal from various chronic amphetamine treatment regimens (1–5 mg/kg, three injections per day for 1, 2, 4 or 6 days). The magnitude and duration of threshold elevations were proportional to the duration and dose of amphetamine treatment prior to withdrawal. In contrast, no alterations in ICSS thresholds were associated with withdrawal from chronic fluoxetine treatment (5 mg/kg/day for 15 days). While neither acute nor chronic administration of fluoxetine alone altered ICSS thresholds, chronic pretreatment with fluoxetine blocked the threshold-lowering effect of acute amphetamine administration (4 mg/kg), but acute pretreatment did not. Amphetamine-induced decreases in response latency, a measure of motor performance, were not affected by either chronic or acute fluoxetine pretreatment. Conclusions: The results of these experiments suggest that chronic fluoxetine treatment may induce adaptive changes in serotonergic transmission that, in themselves, do not alter the function of central reward processes, but may alter the ability of amphetamine to potentiate ICSS reward. In addition, the lack of change in ICSS thresholds during withdrawal from the chronic fluoxetine treatment regimen used suggests that withdrawal from all mood-altering drugs may not necessarily produce changes in central reward functions.
    Materialart: Digitale Medien
    Bibliothek Standort Signatur Band/Heft/Jahr Verfügbarkeit
    BibTip Andere fanden auch interessant ...
  • 89
    ISSN: 1432-2072
    Schlagwort(e): Key words Nicotine ; Nornicotine ; Behavioral sensitization ; Locomotor activity ; Rat
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Medizin
    Notizen: Abstract  Rationale: Nicotine, a tobacco alkaloid, is known to be important in the acquisition and maintenance of tobacco smoking. Nornicotine, an active nicotine metabolite, stimulates nicotinic receptors and may produce psychomotor effects similar to nicotine. Objective: The present study determined the effects of acute and repeated administration of nornicotine on locomotor activity and compared its effects with those of nicotine. Methods: R(+)-Nornicotine (0.3–10 mg/kg), S(–)-nornicotine (0.3–10 mg/kg), S(–)-nicotine (0.1–1 mg/kg) or saline was administered s.c. to rats acutely or repeatedly (eight injections at 48-h intervals). Activity was recorded for 50 min immediately after each injection. Results: S(–)-Nicotine produced transient hypoactivity, followed by dose-related hyperactivity. Repeated S(–)-nicotine administration resulted in tolerance to the hypoactivity and sensitization to the hyperactivity. Subsequent testing following a saline injection revealed evidence of conditioned hyperactivity. Acute administration of 0.3 mg/kg or 1 mg/kg R(+)- or S(–)-nornicotine produced no effect. Transient hypoactivity was observed at 3 mg/kg and 10 mg/kg R(+)-nornicotine and at 10 mg/kg S(–)-nornicotine. However, rebound hyperactivity was not observed following acute administration of either nornicotine enantiomer, suggesting that nornicotine-induced psychomotor effects differ qualitatively from those of S(–)-nicotine. Repeated R(+)-nornicotine resulted in tolerance to the transient hypoactivity, however hyperactivity was not observed. Repeated S(–)-nornicotine resulted in tolerance to the hypoactivity and the appearance of hyperactivity. Repeated administration of either nornicotine enantiomer resulted in a dose-dependent alteration in response to a 1 mg/kg S(–)-nicotine challenge, suggesting some commonalities in the mechanism of action. Conclusion: Nornicotine likely contributes to the neuropharmacological effects of nicotine and tobacco use.
    Materialart: Digitale Medien
    Bibliothek Standort Signatur Band/Heft/Jahr Verfügbarkeit
    BibTip Andere fanden auch interessant ...
  • 90
    Digitale Medien
    Digitale Medien
    Springer
    Psychopharmacology 146 (1999), S. 19-23 
    ISSN: 1432-2072
    Schlagwort(e): Key words Serotonin ; Sensitization ; Rat ; Dopamine opiate ; Movement disorder
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Medizin
    Notizen: Abstract   Rationale: Repeated high doses of morphine in the rat cause stereotypic gnawing behavior that can be re-expressed by a low dose of morphine weeks and even months after the initial treatment. The determination of the role of serotonin in this sensitized morphine-induced behavior has both empirical and theoretical relevance. Objectives: To determine whether the serotonin-reuptake blocker fluoxetine will block the development and/or the expression of this opiate-induced stereotypy. Methods: Rats were given four 10-mg/kg injections of morphine alone or with 5.0 mg/kg fluoxetine over a 36-h period. At weekly intervals for 6 weeks after the last of the sensitizing morphine doses, all rats were challenged with 4.0 mg/kg morphine. At week 2 and week 4, however, the morphine was co-administered with fluoxetine. Results: Fluoxetine completely blocked the expression of the morphine-induced stereotypy; however, when the morphine/fluoxetine-treated rats were challenged with morphine alone, they expressed similar degrees of stereotypy as the rats that initially only received morphine. Conclusions: The results indicate that increasing synaptic serotonin will block the expression but not the development of sensitization to the oral stereotypic effects of repeated high doses of morphine. Also, despite the complete blocking of the morphine effect by fluoxetine during the sensitization phase, the presence of significant biting by these rats during the challenge with morphine alone argues that conditioning factors are not a necessary component for the morphine sensitization to develop.
    Materialart: Digitale Medien
    Bibliothek Standort Signatur Band/Heft/Jahr Verfügbarkeit
    BibTip Andere fanden auch interessant ...
  • 91
    ISSN: 1432-2072
    Schlagwort(e): Key words Delayed non-matching to position task ; Scopolamine ; ENA 713 ; Exelon ; Working memory ; Rat
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Medizin
    Notizen: Abstract   Rationale: The disruption of working memory in the delayed non-matching to position (DNMTP) task by the muscarinic antagonist, scopolamine, is considered to be a model of the spatial working memory deficit in Alzheimer’s disease (AD) patients. Objective: To investigate whether ENA 713 (Exelon) (0.1, 0.5 mg/kg, IP), an acetylcholinesterase inhibitor, would reverse the effects of scopolamine in the DNMTP task. Methods: Male Lister Hooded rats were trained to criterion in an operant DNMTP task (0- to 16-s delay intervals) before receiving vehicle, scopolamine (0.05 mg/kg, SC) alone, ENA 713 (0.1, 0.5 mg/kg, IP) alone, or combinations of scopolamine and ENA 713, in two variations of the task – with and without barriers inserted between the food magazine and the two levers. Barriers were inserted to prevent the use of positional strategies to perform the task, since this behaviour may confound the conclusions of the effect of drugs on working memory. Results: It was found that: (i) scopolamine significantly reduced choice accuracy delay-dependently in both test situations while modifying non-mnemonic measures of task performance delay-independently, indicating an impairment of working memory; (ii) ENA 713 (0.5 mg/kg) significantly attenuated the scopolamine-induced impairment of working memory and significantly reduced the scopolamine-induced changes in some non-mnemonic measures of task performance; (iii) the presence of barriers did not alter the effects of scopolamine and ENA 713 on working memory. Conclusion: ENA 713 reversed the working memory deficit induced by scopolamine. These results are consistent with the attenuation of learning and memory disruptions due to cholinergic dysfunction by ENA 713 in other preclinical assays, and predict a drug-induced improvement in working memory in AD patients.
    Materialart: Digitale Medien
    Bibliothek Standort Signatur Band/Heft/Jahr Verfügbarkeit
    BibTip Andere fanden auch interessant ...
  • 92
    ISSN: 1432-2072
    Schlagwort(e): Key words Compulsion ; Addiction ; Cocaine ; Amphetamine ; Cannabis ; Phencyclidine ; Nucleus accumbens ; Amygdala ; Frontal cortex ; Limbic ; Stimulus-reward association ; Conditioned reward ; Sensitization ; Drug-seeking ; Inhibitory control ; Cognition ; Conditioned stimulus ; Incentive motivational ; Dopamine ; Rat ; Monkey
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Medizin
    Notizen: Abstract  Drug abuse and dependence define behavioral states involving increased allocation of behavior towards drug seeking and taking at the expense of more appropriate behavioral patterns. As such, addiction can be viewed as increased control of behavior by the desired drug (due to its unconditioned, rewarding properties). It is also clear that drug-associated (conditioned) stimuli acquire heightened abilities to control behaviors. These phenomena have been linked with dopamine function within the ventral striatum and amygdala and have been described specifically in terms of motivational and incentive learning processes. New data are emerging that suggest that regions of the frontal cortex involved in inhibitory response control are directly affected by long-term exposure to drugs of abuse. The result of chronic drug use may be frontal cortical cognitive dysfunction, resulting in an inability to inhibit inappropriate unconditioned or conditioned responses elicited by drugs, by related stimuli or by internal drive states. Drug-seeking behavior may thus be due to two related phenomena: (1) augmented incentive motivational qualities of the drug and associated stimuli (due to limbic/amygdalar dysfunction) and (2) impaired inhibitory control (due to frontal cortical dysfunction). In this review, we consider the neuro-anatomical and neurochemical substrates subserving inhibitory control and motivational processes in the rodent and primate brain and their putative impact on drug seeking. The evidence for cognitive impulsivity in drug abuse associated with dysfunction of the frontostriatal system will be discussed, and an integrative hypothesis for compulsive reward-seeking in drug abuse will be presented.
    Materialart: Digitale Medien
    Bibliothek Standort Signatur Band/Heft/Jahr Verfügbarkeit
    BibTip Andere fanden auch interessant ...
  • 93
    ISSN: 1432-2072
    Schlagwort(e): Key words Schizophrenia ; Extrapyramidal side-effect ; Neuroleptic ; Antipsychotic ; Dopamine D2 receptor ; Serotonin 5-HT1A receptor ; Intrinsic activity ; Paw test ; Catalepsy ; Rat
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Medizin
    Notizen: Abstract Rationale: Combining neuroleptics with 5-HT1A ligands is thought to improve the preclinical profile of neuroleptics and may be of interest in the development of new compounds that have greater therapeutic potential and/or are better tolerated. Objective: To examine 1) the ability of 5-HT1A ligands to alter the effects of neuroleptics in preclinical models for antipsychotic potential (hindlimb retraction time in the paw test) and extrapyramidal side-effects (forelimb retraction time in the paw test; catalepsy tests), 2) the role of intrinsic activity at 5-HT1A receptors in the modulatory effects of 5-HT1A ligands, and 3) the generality of the interactions across neuroleptics. Methods: The effects of different doses of 5-HT1A ligands with intrinsic activity ranging from high (e.g., 8-OH-DPAT) to low (e.g., WAY 100135) administered together with a fixed, high dose of the neuroleptics haloperidol, risperidone, and tropapride were examined in the paw test and on catalepsy. Results: Firstly, the 5-HT1A agonists 8-OH-DPAT and ipsapirone attenuated the extrapyramidal-like effects of haloperidol and risperidone more than their therapeutic-like effects; this was not observed for tropapride, where all of its effects were markedly attenuated. Secondly, neither the weak 5-HT1A agonist WAY 100135 nor the silent antagonist WAY 100635 attenuated the effects of neuroleptics. Thirdly, neuroleptics apparently differed in their sensitivity to interactions with 5-HT1A agonists inasmuch as 8-OH-DPAT and ipsapirone attenuated the effects of tropapride on hindlimb retraction times more than those of haloperidol or risperidone. Conclusions: The present data suggest that 5-HT1A agonists with intermediate or high, but not low, intrinsic activity may abolish the extrapyramidal effects of neuroleptics. Together with results of previous studies, it appears that 5-HT1A agonists alter the antipsychotic-like effects of neuroleptics, although this may depend on the neuroleptic studied.
    Materialart: Digitale Medien
    Bibliothek Standort Signatur Band/Heft/Jahr Verfügbarkeit
    BibTip Andere fanden auch interessant ...
  • 94
    Digitale Medien
    Digitale Medien
    Springer
    Psychopharmacology 147 (1999), S. 250-256 
    ISSN: 1432-2072
    Schlagwort(e): Key words Locomotion ; Activity ; Dose-response ; Time-course ; Anticholinergic drug ; Rat
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Medizin
    Notizen: Abstract  Rationale: In order to facilitate direct comparisons of anticholinergic drug effects on activity, nine drugs were tested in one laboratory using a standardized procedure. Objective: The present study compared the effects of aprophen hydrochloride, atropine sulfate, azaprophen hydrochloride, benactyzine hydrochloride, biperiden hydrochloride, diazepam, procyclidine hydrochloride, scopolamine hydrobromide, and trihexyphenidyl hydrochloride on activity levels in rats. Methods: Both fine motor activity (reflecting smaller movements) and ambulatory activity (reflecting larger movements) were recorded for 23 h following drug administration in food-restricted rats. All drugs were administered during the light period of the photocycle. Results: Atropine, azaprophen, biperiden, scopolamine, and trihexyphenidyl increased both ambulations and fine motor activity significantly during the first hour post-injection, but the increased activity levels returned to vehicle control levels within 2–6 h post-injection. Benactyzine and procyclidine only increased fine motor activity significantly above vehicle control levels and activity levels returned to vehicle control levels within 2–3 h. Finally, aprophen and diazepam generally did not increase measures of activity significantly above vehicle controls at the dose ranges examined. Conclusions: Based on potencies relative to scopolamine, the potency of the drugs could be ranked as follows: scopolamine 〉 trihexyphenidyl 〉 biperiden 〉 azaprophen 〉 procyclidine 〉 benactyzine 〉 atropine 〉 aprophen. The comparison of drug effects on activity may be useful in selecting anticholinergic drug therapies with a minimal range of side effects. In addition, these data may reduce the number of anticholinergic drugs that need to be tested in comparison studies involving more complex behavioral tests.
    Materialart: Digitale Medien
    Bibliothek Standort Signatur Band/Heft/Jahr Verfügbarkeit
    BibTip Andere fanden auch interessant ...
  • 95
    ISSN: 1432-2013
    Schlagwort(e): Key words AMPA receptor-mediated EPSCs ; Cyclothiazide ; Hippocampus ; Kinetics ; Long-term potentiation (LTP) ; Rat
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Medizin
    Notizen: Abstract  We have analysed whether the expression of long-term potentiation (LTP) in rat hippocampal CA1 neurons involves a change in the kinetics of (S)-α-amino-3-hydroxy-5-methyl-4-isoxazolepropionic acid (AMPA) receptor-mediated excitatory postsynaptic currents (EPSCs) (AMPA-EPSCs) or their susceptibility to the AMPA receptor modulator cyclothiazide. AMPA-EPSCs in the CA1 region were evoked by alternate stimulation of two independent Schaffer collateral-commissural inputs of slices of adult rat hippocampus. In the current-clamp mode a strong tetanus (100 Hz, 1 s) applied to one input (input I) induced stable LTP of AMPA-EPSCs in this input, while the control input (input II) remained unaffected. For neither input were EPSC rise time and decay kinetics significantly changed. The application of cyclothiazide prolonged the rise time and the decay time constants of the AMPA-EPSCs in both control and potentiated inputs to the same extent (Input I–rise time: 198±8%, decay: 148±12%; input II–rise time: 212±14%, decay: 144±19%; n=8). Furthermore, when present during tetanization cyclothiazide did not occlude LTP, suggesting that cyclothiazide and tetanic stimulation enhance AMPA-EPSCs via independent mechanisms. Our findings argue against changes in (de-)activation or desensitization of AMPA receptors as the molecular basis for the expression of LTP.
    Materialart: Digitale Medien
    Bibliothek Standort Signatur Band/Heft/Jahr Verfügbarkeit
    BibTip Andere fanden auch interessant ...
  • 96
    Digitale Medien
    Digitale Medien
    Springer
    Pflügers Archiv 437 (1999), S. 910-916 
    ISSN: 1432-2013
    Schlagwort(e): Key words Cardiorespiratory system ; Anaesthesia ; Rat ; Rabbit ; Guinea-pig
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Medizin
    Notizen: Abstract  Cardioventilatory coupling is a temporal coherence of respiratory and cardiac rhythms, seen in humans at rest, and during sleep and anaesthesia. In this study we compared the cardioventilatory coupling of anaesthetised rabbits, rats and guinea-pigs. Breathing two successive anaesthetic concentrations (1 or 2% isoflurane) we compared the effect of anaesthetic depth and species on (1) heart rate, (2) heart rate variability, (3) ventilatory rate (f), (4) ventilatory variability, (5) ratio HR/f, (6) degree of coupling (Shannon entropy of the distribution of intervals between inspiration and the preceding electrocardiographic R wave – the RI interval) and (7) coupling pattern, classified into four sub-patterns (I-IV) based upon inspection of the RI interval time series. Rabbits exhibited significantly less ventilatory variability and coupling than rats or guinea-pigs. The sub-pattern of coupling also differed between the three species. Rabbits showed coupling only when HR and f were close to integer ratios whereas other species coupled at non-integer ratios. Ventilatory variability in the rat and guinea-pig differed according to the pattern of coupling observed. Of the three species studied, the rat and guinea-pig demonstrated coupling most similar to that of anaesthetised human subjects. Anaesthetic concentration did not influence the pattern or degree of coupling.
    Materialart: Digitale Medien
    Bibliothek Standort Signatur Band/Heft/Jahr Verfügbarkeit
    BibTip Andere fanden auch interessant ...
  • 97
    Digitale Medien
    Digitale Medien
    Springer
    European radiology 9 (1999), S. 192-200 
    ISSN: 1432-1084
    Schlagwort(e): Key words: Sarcoma ; Metastasis ; MRI
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Medizin
    Notizen: Abstract. Both the prognosis and the morbidity of a patient with a primary malignant musculoskeletal tumour have improved over the past 25 years due to the advent of adjuvant chemotherapy and limb-sparing surgery. This has important implications for the role of imaging at the time of initial diagnosis and during follow-up. This pictorial essay reviews the imaging and pitfalls in the interpretation of musculoskeletal sarcoma metastases using a variety of radiological techniques. The optimal imaging strategy will be stressed.
    Materialart: Digitale Medien
    Bibliothek Standort Signatur Band/Heft/Jahr Verfügbarkeit
    BibTip Andere fanden auch interessant ...
  • 98
    ISSN: 1432-1084
    Schlagwort(e): Key words: Lumbar spine ; MRI ; MR myelography
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Medizin
    Notizen: Abstract. The purpose of our study was to evaluate the accuracy of MR myelography in depicting disc herniation in the lumbar spine when compared with conventional MRI in patients presenting with clinical evidence of disc herniation. One hundred patients referred for conventional MR imaging of the lumbar spine also had coronal MR (TR 9000 ms, TE 272 ms eff, NEX 3, echo train length 32) myelography performed. Three experienced observers compared magnetic resonance myelography (MRM) with conventional lumbar spine MR using the following variables: visibility of thecal sac and nerve roots, and the presence, location and severity of disc herniation. Disc protrusions were seen at 110 disc space levels on conventional MR images as opposed to 93 on MRM. However, only 72 % of lesions seen on conventional MR were diagnosed by MRM. Similarly, only 63.8 % of nerve root compression abnormalities seen at conventional MR were visualized when compared with conventional MRM. The sensitivity, specificity and accuracy of MRM when compared with conventional MR was 72, 93 and 85 %, respectively. The MRM technique yields images that resemble conventional myelography and may be used to help confirm abnormalities seen on conventional MR in selected cases; however, the large number of false-positive and false-negative examinations indicates that caution should be used in interpreting MRM images.
    Materialart: Digitale Medien
    Bibliothek Standort Signatur Band/Heft/Jahr Verfügbarkeit
    BibTip Andere fanden auch interessant ...
  • 99
    Digitale Medien
    Digitale Medien
    Springer
    European radiology 9 (1999), S. 1098-1100 
    ISSN: 1432-1084
    Schlagwort(e): Key words: Osteoid osteoma ; Carpal bones ; Capitate ; MRI
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Medizin
    Notizen: Abstract. A case of osteoid osteoma of the capitate in a 29-year-old male is reported. The patient suffered from unspecific clinical findings and a 3-year history of uncharacteristic wrist pain. Conventional radiographs of the wrist revealed a circumscribed sclerosis in the proximal part of the capitate bone beside a diffuse demineralisation of the carpal bones. Magnetic resonance imaging demonstrated a circumscribed, tumorous lesion with marked enhancement after IV administration of contrast agent and a highly calcified nidus, which was sharply demarcated by a small rim of granulation tissue from the surrounding spongious bone. Based on MRI findings, the diagnosis of an osteoid osteoma was established and confirmed after operation and histologic analysis.
    Materialart: Digitale Medien
    Bibliothek Standort Signatur Band/Heft/Jahr Verfügbarkeit
    BibTip Andere fanden auch interessant ...
  • 100
    Digitale Medien
    Digitale Medien
    Springer
    European radiology 9 (1999), S. 1101-1103 
    ISSN: 1432-1084
    Schlagwort(e): Key words: Echinococcosis ; Soft tissues ; MRI ; Hydatid disease
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Medizin
    Notizen: Abstract. Hydatid disease of the soft tissues forms a rare mass lesion of the extremities. Two cases of primary hydatid disease in soft tissues are presented with MR imaging findings. A cystic mass with multiloculated or multicystic appearance was identified on MR images in both cases. The lesions were surrounded by a rim with two layers representing a collageneous and a vascularized pericyst. The contrast-enhanced images demonstrated the vascularized component of the wall clearly in the first case. In diagnosis of hydatid disease and in its differentiation from other cystic lesions of the extremities, we think that the described MR appearances can be used confidently.
    Materialart: Digitale Medien
    Bibliothek Standort Signatur Band/Heft/Jahr Verfügbarkeit
    BibTip Andere fanden auch interessant ...
Schließen ⊗
Diese Webseite nutzt Cookies und das Analyse-Tool Matomo. Weitere Informationen finden Sie hier...