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  • 1985-1989  (244)
  • 1980-1984
  • 1987  (244)
  • Chemical Engineering  (119)
  • Engineering  (59)
  • Rat  (56)
  • Magnetic resonance imaging
Materialart
Erscheinungszeitraum
  • 1985-1989  (244)
  • 1980-1984
Jahr
  • 1
    ISSN: 1432-1106
    Schlagwort(e): Spike train analysis ; Spontaneous activity ; Primary culture ; Neuronal development ; Occipital cortex ; Rat
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Medizin
    Notizen: Summary The development of spontaneous bioelectric activity (SBA) was studied in dissociated occipital cortex cultures prepared from 19 day old rat fetuses. All cultures, recorded one per diem from 5 to 33 days in vitro (div), showed SBA. Computer analysis of 76 extracellularly recorded single unit spike trains was carried out after selection on the basis of stationarity criteria. Statistically significant developmental trends were found in (i) interspike interval dependencies and (ii) fluctuations in mean firing rate, on the order of a minute or longer. The highly dependent firing patterns, including stereotyped bursting, were present mostly in the 9–12 div group, whereas minute-to-minute fluctuations in the intensity of firing were considerably more pronounced in the oldest group (22–33 div) than in the younger cultures. In addition, firing categories defined on the basis of factor-analysis revealed that such fluctuations were almost exclusively to be found in neurons which fired in a pronounced ‘burst’, rather than a relatively continuous fashion. Only a few mature appearing synaptic structures were observed electron microscopically prior to 12 div, but increased steadily in number thereafter. No cultures prior to 14 div, but all cultures older than this, stained positively for the presence of glutamic acid decarboxylase. An extensive immunoreactive, putative GABAergic, network was present by three weeks in vitro.
    Materialart: Digitale Medien
    Bibliothek Standort Signatur Band/Heft/Jahr Verfügbarkeit
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  • 2
    Digitale Medien
    Digitale Medien
    Springer
    Psychopharmacology 93 (1987), S. 477-482 
    ISSN: 1432-2072
    Schlagwort(e): Cis-flupentixol ; Reinforced responding ; Motor effects ; Reinforcement efficacy ; Dopamine receptors (D1 and D2) ; Matching law equation ; Variable-interval schedule ; Water reinforcement ; Lever press ; Rat
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Medizin
    Notizen: Abstract We evaluated the effects of cis-flupentixol on reinforced responding. The experimental subjects were rats and the reinforced response was a lever press. The procedure was a five-component multiple schedule that provided five different reinforcement rates. Cis-flupentixol produced dose-dependent decreases in reinforced responding. An equation, the matching law, was fitted to the results. One parameter of this equation represents the estimated response rate asymptote. Cis-flupentixol produced dose-dependent decreases in the asymptotes. A second parameter of the equation represents the rate of reinforcement that maintains a one-half asymptotic response rate. Cis-flupentixol did not appear to affect this measure. There is evidence that the response rate asymptote measures motor components of response rate and that the reinforcement parameter measures the efficacy of the reinforcement maintaining the response. According to these results, cis-flupentixol systematically affected the motor-component of reinforced responding — it slowed down lever pressing — without affecting the subject's sensitivity to the reinforcer maintaining the response. In contrast, other neuroleptics have decreased the subjects' sensitivity to reinforcement, according to the matching law measures.
    Materialart: Digitale Medien
    Bibliothek Standort Signatur Band/Heft/Jahr Verfügbarkeit
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  • 3
    Digitale Medien
    Digitale Medien
    Springer
    Psychopharmacology 92 (1987), S. 215-218 
    ISSN: 1432-2072
    Schlagwort(e): Ethanol ; Naloxone ; Locomotor activity ; Open field ; Active avoidance ; Rat
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Medizin
    Notizen: Abstract The action of naloxone (0.5 and 2 mg/kg IP) on the behavioural effects of a low (2 g/kg PO) and a high dose (4 g/kg PO) of ethanol was studied in rats. Ethanol at the low dose increased spontaneous motility, enhancing open-field external ambulations and reducing shuttle-box latency. All these effects were antagonized by naloxone. Ethanol at the high dose produced hypomotility, decreasing open-field external ambulations and impairing shuttle-box performance. In this case, naloxone also reduced the ethanol effect, but its action was less consistent. Therefore, although mechanisms other than a specific opioid receptor blockade by naloxone must be considered, an involvement of opioid peptides in the effects of ethanol cannot be discounted.
    Materialart: Digitale Medien
    Bibliothek Standort Signatur Band/Heft/Jahr Verfügbarkeit
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  • 4
    ISSN: 1432-0878
    Schlagwort(e): 7B2 polypeptide ; Gastro-intestinal tract ; Endocrine cells ; Immunohistochemistry ; Rat
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie , Medizin
    Notizen: Summary Immunoreactivity to the polypeptide designated “7B2” recently isolated from human and porcine pituitary glands, appears to be consistently confined to neuroendocrine and endocrine cells in various tissues. In rat gut, immunoreactive 7B2 was found in endocrine-paracrine cells. Highly labeled cells were found in the antrum of the stomach and, cells with lower concentrations, in the fundus, duodenum, jejunum and ileum. Except for a few cells which were simultaneously positive for 5-hydroxytryptamine, and a few others showing Grimelius's reaction, “7B2” cells do not exhibit argentaffin and/or argyrophil character. The 7B2 polypeptide seems to be distributed amongst several different types of endocrine cells in the gut.
    Materialart: Digitale Medien
    Bibliothek Standort Signatur Band/Heft/Jahr Verfügbarkeit
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  • 5
    ISSN: 1432-0878
    Schlagwort(e): Polypeptide 7B2 ; Adenohypophysis ; Secretion ; Immunocytochemistry ; Rat
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie , Medizin
    Notizen: Summary A highly conserved polypeptide termed “7B2”, isolated from human and porcine pituitaries, has been reported by immunoreactivity to be distributed in various organs. However, the highest concentration has been found in the pituitary as demonstrated by a specific radioimmunoassay. In order to determine the type of cells within the pituitary that contain 7B2 and to analyse its intracellular localization, specific immunocytochemistry techniques (unlabeled antibody, peroxidase-antiperoxidase) were used both for light and electron microscopy. Immunocytochemistry of both expiants and monolayer-cell cultures of the adenohypophysis was studied. Immunoreactivity to 7B2 has been found in 21.9% of the total number of cells. After simultaneous staining of serial sections with appropriate antibodies, 7B2 was found to be colocalized with β-LH/β-FSH in gonadotrophs and with β-TSH in thyrotrophs. In situ immunocytochemistry at the electron-microscopic level showed that immunoreactive 7B2 is compartmentalized within secretory granules. The small (130 to 250 nm) but not the large granules (400 to 700 nm) were labeled in gonadotroph-like cells and small granules (90 to 150 nm) were also labeled in thyrothrophlike cells. Study of the gonadotrophs in cell culture after Zamboni's fixation revealed weak to moderate immunoreaction in rough endoplasmic reticulum. The current findings as well as previous data indicate that 7B2 is synthesized, stored and possibly released from the adenohypophysis similarly to many other secretory products.
    Materialart: Digitale Medien
    Bibliothek Standort Signatur Band/Heft/Jahr Verfügbarkeit
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  • 6
    Digitale Medien
    Digitale Medien
    Hoboken, NJ : Wiley-Blackwell
    AIChE Journal 33 (1987), S. 470-479 
    ISSN: 0001-1541
    Schlagwort(e): Chemistry ; Chemical Engineering
    Quelle: Wiley InterScience Backfile Collection 1832-2000
    Thema: Chemie und Pharmazie , Werkstoffwissenschaften, Fertigungsverfahren, Fertigung
    Notizen: Complete adiabatic fixed-bed adsorption cycles with adsorption, heating, and cooling steps are analyzed using simple wave theory. Solutions consist of simple waves, shocks, combined waves, and wave interactions with patterns established by a mapping between hodograph and physical planes. The system considered is benzene adsorbed on activated carbon with nitrogen as the carrier gas.
    Zusätzliches Material: 11 Ill.
    Materialart: Digitale Medien
    Bibliothek Standort Signatur Band/Heft/Jahr Verfügbarkeit
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  • 7
    Digitale Medien
    Digitale Medien
    Springer
    Anatomy and embryology 176 (1987), S. 367-372 
    ISSN: 1432-0568
    Schlagwort(e): Cajal-Smirnow ansiform fibers ; Mossy fibers ; Axonal guidance ; Cerebellar cortex ; Rat
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Medizin
    Notizen: Summary The present light and electron microscopic study deals with the morphology and organization of Cajal-Smirnow ansiform fibers (AFs) in the molecular layer of the cerebellar cortex. The cerebella of normal adult rats were processed with Cajal's reduced silver method and conventional electron microscopy. With the silver method AFs appear as isolated elements or, more frequently, as small bundles of myelinated fibers, which emerge from the medullary rays, ascend through the granular, Purkinje cell and molecular layers and curve back to reenter the granular layer or cerebellar white matter. They traced an arciform trajectory of variable width and height in the molecular layer. Relatively large bundles of AFs were rarely found. The occurrence of AFs was confirmed in semithin sections as myelinated fibers of variable diameter ranging from 1 to 6 μm. Oligodendrocytes were often observed near AFs. At the ultrastructural level, the most common type of AF is large, with a relatively thin myelin sheath and a moderately dense axoplasm. Nodal or terminal synaptic differentiations were not observed. We suggest that AFs are misoriented cerebellar mossy fibers and their occurrence may be the consequence of a small-scale error in the axonal guidance of growing mossy fibers.
    Materialart: Digitale Medien
    Bibliothek Standort Signatur Band/Heft/Jahr Verfügbarkeit
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  • 8
    Digitale Medien
    Digitale Medien
    Springer
    Surgical and radiologic anatomy 9 (1987), S. 141-149 
    ISSN: 1279-8517
    Schlagwort(e): Magnetic resonance imaging ; Thoracic aorta ; Gated acquisition ; Oblique slices ; Flow Phenomena
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Medizin
    Beschreibung / Inhaltsverzeichnis: Résumé Les auteurs présentent les résultats d'une investigation concernant l'imagerie par résonance magnétique de l'aorte thoracique d'après l'étude de huit volontaires et d'un patient suspect de maladie de Takayasu mais ayant une aorte morphologiquement normale. Des coupes axiales, frontales, sagittales et obliques ont été réalisées et les résultats morphologiques sont présentés. De plus, les principaux phénomènes de flux sont expliqués et des exemples de chacun sont montrés.
    Notizen: Summary The authors present the results of magnetic resonance imaging (MRI) in the investigation of the anatomy of the thoracic aorta in a group of eight volunteers and in one patient with presumptive Takayasu's disease but with normal aorta. Transaxial, coronal, sagittal and oblique slices were made and the morphologic results are presented. Major flow phenomena are also discussed and some examples given.
    Materialart: Digitale Medien
    Bibliothek Standort Signatur Band/Heft/Jahr Verfügbarkeit
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  • 9
    ISSN: 1432-1106
    Schlagwort(e): Carrageenin hyperalgesia ; Rat ; Ventro-basal thalamic neurones ; Responses to mechanical stimuli
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Medizin
    Notizen: Summary Neuronal response thresholds and the encoding of mechanical stimulus intensity in the ventro-basal (VB) thalamus was analyzed in anaesthetized rats before and during the first two hours following induction of hyperalgesic inflammation. This inflammation was induced by the intra-plantar injection of carrageenin in the hindpaw contralateral to the recorded neurones. Only neurones exclusively driven by noxious stimuli and with a receptiv field on or including the injected paw were considered. In this early phase of the inflammatory process, there was no significant modification of the response threshold to the mechanical stimulus (indentation of about 300μm). This suggests the involvement of additional neuronal population(s) to account for the decrease in the vocalisation threshold to pressure observed in the freely moving animal at this time of the inflammation, A liner encoding of the indentation depth was observed before and after the carrageenin injection although the slope of the stimulus response-curve was steeper after the injection. The data emphasize that the carrageenin-sensitization acts differentially on the liminal and supra-liminal responses of the same neurone to a skin indentation, since in the first hour following the initiation of the inflammation the sensitization is essentially observed for responses obtained with stimulus intensity largely above the threshold value. With regard to previous observations using thermal stimulation, the results also illustrate that the carrageenin induced sensitization of responses differs depending on the stimulus intensity and modality used.
    Materialart: Digitale Medien
    Bibliothek Standort Signatur Band/Heft/Jahr Verfügbarkeit
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  • 10
    ISSN: 1432-1920
    Schlagwort(e): Multiple scleosis, diagnosis of ; Magnetic resonance imaging ; Vascular brain disease
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Medizin
    Notizen: Summary Disseminated lesions in the white matter of the cerebral hemispheres and confluent lesions at the borders of the lateral ventricles as seen on MRI are both considered acceptable paraclinical evidence for the diagnosis of multiple sclerosis. Similar changes are, however, also found in vascular diseases of the brain. We therefore aimed at identifying those additional traits in the infratentorial region, which in our experience are not frequently found in cerebrovascular pathology. We evaluated MR brain scans of 68 patients and found pontine lesions in 71% of cases with a clinically definite diagnosis (17 out of 24) and in 33% of cases with a probable diagnosis (14 out of 43). Lesions in the medulla oblongata were present in 50% and 16%, respectively, and in the midbrain in 25% and 7%, respectively. With rare exceptions all brainstem lesions were contiguous with the cisternal or ventricular cerebrospinal fluid spaces. In keeping with post-mortem reports the morphological spectrum ranged from large confluent patches to solitary, well delineated paramedian lesions or discrete linings of the cerebrospinal fluid border zones and were most clearly depicted from horizontal and sagittal T2 weighted SE-sequences. If there is a predilection for the outer or inner surfaces of the brainstem, such lesions can be considered an additional typical feature of multiple sclerosis and can be more reliably weighted as paraclinical evidence for a definite diagnosis.
    Materialart: Digitale Medien
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