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  • 1990-1994
  • 1980-1984
  • 1975-1979  (118)
  • 1975  (118)
  • Ultrastructure  (75)
  • Nuclear reactions
  • Rat
  • 1
    Electronic Resource
    Electronic Resource
    Springer
    Journal of neurology 210 (1975), S. 191-198 
    ISSN: 1432-1459
    Keywords: Pallidumdegeneration ; Bielschowsky bodies ; Lafora bodies ; Corpora amylacea ; Ultrastructure ; Torsion dystonia
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Description / Table of Contents: Zusammenfassung Bei einem 60 Jahre alt gewordenen Mann, mit einer bis in die Kindheit zurückreichenden und extrem langsam progredienten, wahrscheinlich torsionsdystonischen bzw. choreoathetoiden Bewegungsstörung, fand sich eine isolierte Degeneration des äußeren Pallidumgliedes mit intraneuronaler Ablagerung von Bielschowsky-Körperchen und nur geringgradigem Nervenzellausfall. Die Bielschowsky-Körperchen zeigen den gleichen Aufbau wie Corpora amylacea und Lafora-Körperchen. Sie dürften ebenfalls Produkt einer cellulären, vorwiegend den Kohlenhydrat-stoffwechsel treffenden Dysmetabolie sein, die allerdings hier exquisit systembezogen auf die Neurone des äußeren Pallidumgliedes begrenzt ist und erst sehr spät bei fortgeschrittener Stapelung der Metabolite zum Untergang der Nervenzellen führt. Dieser Umstand erklärt den überaus torpiden Verlauf der Erkrankung.
    Notes: Summary In a 60-year-old man with a very slowly progressive motor disturbance probably of torsion dystonic or choreoathetotic type which started in childhood, we found an isolated degeneration of the exterior pallidum with intraneuronal deposition of Bielschowsky bodies and only slight deficit of neurons. The Bielschowsky bodies show the same structure as corpora amylacea and Lafora bodies. They might also be the result of a cellular disturbance mainly concerning the carbohydrate metabolism. In this case they are localised only in the neurons of the exterior part of the pallidum—in contrast to the organogenitically otherwise deriving (from the nuel. entopeduncularis) intact neurons of the pallidum internum—and they induce, after an excessive accumulation of the metabolites, not till extremely late loss of neurons. This circumstance explains the very torpid progress of this disease.
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  • 2
    Electronic Resource
    Electronic Resource
    Springer
    Pflügers Archiv 357 (1975), S. 201-207 
    ISSN: 1432-2013
    Keywords: Allantoin ; Uricase ; Kidney ; Clearance ; Micropuncture ; Rat
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary Renal excretion of allantoin was measured by tracer techniques. After injection of 2-C14 urate and H3 inulin, clearances of allantoin and inulin were measured and both proximal and distal tubules were micropunctured. In confirmation of earlier results 2-C14 urate injected into an intact animal is very rapidly converted to C14 allantoin: after 15 min more than 90% of urinary tracer is present as allantoin. It was further observed that 1) allantoin clearance is essentially identical with inulin clearance over a wide range of urine flows; 2) no net transport of allantoin occurs in either proximal or distal tubules. Clearly allantoin is handled by the rat kidney like inulin. The total excretion of filtered allantoin unlike that of filtered urate provides an easy and effective mechanism for animals possessing the enzyme uricase to dispose of their purine loads.
    Type of Medium: Electronic Resource
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  • 3
    Electronic Resource
    Electronic Resource
    Springer
    Naunyn-Schmiedeberg's archives of pharmacology 287 (1975), S. 1-10 
    ISSN: 1432-1912
    Keywords: Dopamine ; Adrenomedullary Hormones ; Synthesis ; Rat ; Adrenals ; Subcellular Distribution
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary Rats received intravenous injections of3H-tyrosine and were killed at various time intervals thereafter.3H-dopamine (DA) in the adrenals reached a maximum within 1.5 min after the administration of3H-tyrosine. From the 15th min it disappeared with an apparent half life of 90 min.3H-Adrenaline (A) +3H-noradrenaline(NA) increased much more slowly and reached a plateau 120–240 min after the injection. The approximate synthesis rate of adrenal A+NA, calculated from the specific activity curves, ranged from 9.3 to 2.2 nmoles/h per kg b.w. The highest value was noted the first few minutes, the lowest 1–2 hrs after the administration of3H-tyrosine. In some experiments subcellular fractionation of the adrenals was performed. In untreated animals the amount of DA and A+NA recovered from the supernatant fraction was about 10 and 8 per cent, respectively, of the total amount recovered from the supernatant and particulate fractions. In the adrenals of animals receiving3H-tyrosine 3.75 or 60 min beforehand these figures were significantly elevated whereas the DA and A+NA of the particulate fraction did not deviate significantly from control values. The specific activities of3H-DA were the same in the supernatant and particulate fractions within 3.75 min after the injection of3H-tyrosine.
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  • 4
    Electronic Resource
    Electronic Resource
    Springer
    Naunyn-Schmiedeberg's archives of pharmacology 288 (1975), S. 109-121 
    ISSN: 1432-1912
    Keywords: Halothane and Nitrous Oxide Anaesthesia ; 5-HT Turn-Over ; Brain ; Rat
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary The effects of anaesthesia with halothane and nitrous oxide on the turn-over of 5-HT in the rat brain were analysed. The rate of 5-HT synthesis was estimated on the basis of 5-HTP accumulation following 5-HTP decarboxylase inhibition. Inhalation anaesthetics reduced the rate of 5-HT synthesis in the whole brain, this effect being particularly marked in the forebrain. In addition, the reduction of the rate of 5-HT synthesis was still detected after a large tryptophan loading indicating that halothane and nitrous oxide anaesthesia reduced the activity of tryptophan hydroxylase in vivo. The utilization of 5-HT was also delayed during anaesthesia since the rate of 5-HT disappearance following the inhibition of its synthesis at the decarboxylation step was decreased in the whole brain. In spite of this reduced turnover of 5-HT in the brain of rats exposed to inhalation anaesthetics, the 5-HIAA levels were permanently elevated. This was the result of a partial inhibition of the active elimination of the acidic metabolite from the brain during this kind of anaesthesia.
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  • 5
    Electronic Resource
    Electronic Resource
    Springer
    Naunyn-Schmiedeberg's archives of pharmacology 288 (1975), S. 147-153 
    ISSN: 1432-1912
    Keywords: Adenylate Cyclase ; Phosphodiesterase ; cAMP ; Gastric Mucosa ; Rat
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary The effects of starvation, feeding and pentagastrin on gastric mucosal adenylate cyclase (AC) and phosphodiesterase (PDE) activity were studied in the rat. 1. Starvation for 24 hrs and 48 hrs reduced both NaF stimulated and basal AC activities. 2. Feeding of starved rats slowly raised the AC activity up to 430% within 4 hrs after feeding. This effect was more pronounced under basal conditions than with NaF stimulation. 3. A single i.p. injection of pentagastrin (125 μg/kg) caused a stimulation of basal AC lasting 45 min, which was followed by a subsequent decrease in the basal and NaF stimulated enzyme activity. 4. PDE activity was not influenced by starvation and feeding but underwent a transient inhibition by pentagastrin. Accordingly gastric mucosal cAMP levels after starvation, feeding and pentagastrin are regulated by changes in AC and not in PDE activity. The rise in AC activity after feeding appears to be related to functions other than H+ and pepsin secretion.
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  • 6
    Electronic Resource
    Electronic Resource
    Springer
    Journal of neurology 211 (1975), S. 61-68 
    ISSN: 1432-1459
    Keywords: Niemann-Pick ; Liver ; Sural nerve ; Ultrastructure ; Lipids
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Description / Table of Contents: Zusammenfassung Das klinische, biochemische und ultrastrukturelle Bild einer Sphingolipidose vom Typ Niemann-Pick wurde an Hand eines Patienten mit der infantilen Form (A) dargestellt. Die Diagnose wurde klinisch auf Grund einer rasch progredienten psychomotorischen Retardation mit Hepatosplenomegalie sowie typischen Schaumzellen im Knochenmark gestellt und durch den Nachweis von exzessiver Speicherung von Sphingomyelin in einer Leberbiopsie und das Fehlen der Sphingomyelinase bestätigt. Ultrastrukturell konnte eine Anhäufung von präsumptiven Phospholipiden in den Lysosomen von Leber und peripherem Nerv festgestellt werden. Obwohl weder eine axonale Degeneration noch eine Demyelinisierung im biopsierten Nerv gefunden werden konnte, war die Nervenleitgeschwindigkeit in den peripheren Nerven beim Patienten schon bei der Diagnosestellung deutlich herabgesetzt. Die Bedeutung der Befunde wurde diskutiert.
    Notes: Summary A diagnosis of Niemann-Pick disease type A was made in a 6-month-old boy on the grounds of progressive psychomotor retardation, hepatosplenomegaly, typical foam cells in the bone marrow and a deficiency of sphingomyelinase in a liver biopsy. Typical ultrastructural changes in lysosomes were found in hepatocytes and in Schwann cells. In spite of the absence of gross morphological changes in the axons and in the myelin sheath of the peripheral nerve biopsy, the nerve conduction velocity in the patient was greatly reduced. The ultrastructural aspect of the lysosomal inclusion suggested the storage of a phospholipid. Biochemical analysis of the liver biopsy demonstrated an increased content of total phospholipid of which sphingomyelin made up for more than 60%. The significance of these data are discussed.
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  • 7
    ISSN: 1432-1750
    Keywords: Lung fibrosis ; Rat ; Paraquat ; Lungenfibrose ; Ratte ; Paraquatlunge
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Description / Table of Contents: Zusammenfassung Es wird die Erzeugung einer Lungenfibrose bei Spraque-Dawley-Ratten mittels mehrfacher Injektion von Paraquat intraperitoneal beschrieben. Notwendige Dosierungen, Intervalle zwischen den Injektionen sowie der zeitliche Ablauf der histologischen Veränderungen werden dargelegt.
    Notes: Summary An experimental model of lung fibrosis by multiple i.p. injections of the herbicide Paraquat is described. The schedules, intervals between injections and histological changes are described.
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  • 8
    Electronic Resource
    Electronic Resource
    Springer
    Naunyn-Schmiedeberg's archives of pharmacology 288 (1975), S. 185-193 
    ISSN: 1432-1912
    Keywords: Avoidance Acquisition ; Development ; Pimozide ; d-Amphetamine ; Catecholamines ; Rat
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary The acquisition of a conditioned avoidance response (CAR) was investigated in rats of nursing mothers given pimozide 0.5 mg/kg on days 1, 2, 3, 4, 5, 6, and 7 after delivery. Four weeks after birth, the male litter-mates were tested for CAR acquisition in a two-way avoidance situation or for correct CAR acquisition in a brightness discrimination situation. Offspring of mothers treated with pimozide were markedly inferior in the CAR acquisition in both behavioural situations as compared to those of mothers given glucose. The administration of d-amphetamine 15 min prior to the training session specifically counteracted the behavioural impairment obtained in the offspring of pimozide-treated mothers. The results obtained in the present investigation lend further support to the contention that the behavioural deficits in offspring of nursing mothers treated with neuroleptic agents are due to a developmental disturbance in central catecholamine neurones.
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  • 9
    ISSN: 1432-0738
    Keywords: Acrylonitrile ; Phenobarbital ; SKF 525-A ; Dimercaprol (BAL) ; Thiosulfate ; Cyanide-Thiocyanate ; Route of Administration ; Drug Biotransformation ; Rat ; Mouse ; Chinese Hamster ; Acrylonitril ; Phenobarbital ; SKF 525-A ; Dimercaprol (BAL) ; Thiosulfat ; Cyanid ; Thiocyanat ; Applikationsart ; Biotransformation ; Ratte ; Maus ; Chinesischer Hamster
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Description / Table of Contents: Zusammenfassung Wistar Ratten, Standard-Albinomäuse und chinesische Hamster (Weibchen) erhielten eine einmalige Dosis von Acrylonitril, 0,5 oder 0,75 mmol/kg Gewicht. Die Ausscheidung des Thiocyanats, Hauptmetaboliten des Acrylonitrils, wies bei Ratten nach einer oralen (20 %), intraperitonealen und subcutanen (2 bis 5%) und intravenösen (1 %) Applikation einen sinkenden Umwandlungsanteil auf. Auch bei Hamstern und Mäusen rief die orale Verabreichung eine höhere Umwandlung hervor als bei der intraperitonealen Zufuhr. Die Vorbehandlung von Ratten mit Phenobarbital, SKF 525-A, Cystein oder Dimercaptopropanol, hatte keinen signifikanten Einfluß auf die Ausscheidung von Thiocyanat im Harn. Hingegen erhöhte die gleichzeitige Applikation von Thiosulfat bedeutend den Anteil von Thiocyanat, und zwar bei Ratten fast zweifach, bei Mäusen mehr als dreifach. Die Studie bestätigt den ausgeprägten Einfluß der Verteilung (first pass metabolic phenomenon) auf das metabolische Schicksal von Acrylonitril. Anscheinend ist die starke Bindung von Acrylonitril und die Cyanoethylierung für den so markanten Einfluß der Applikationsart verantwortlich. Nach oraler, intraperitonealer und intravenöser Applikation von Acrylonitril wurde dieser bei Mäusen effektiver in Thiocyanat metabolisiert als bei Ratten. Die größere Umwandlung von Acrylonitril in Thiocyanat und die stärkere Senkung seiner akuten Toxicität nach Thiosulfat deuten auf eventuelle Unterschiede im Mechanismus der toxischen Wirkung von Acrylonitril bei Mäusen und Ratten hin. In der Toxicität des Acrylonitrils für Ratten spielt Cyanid anscheinend eine kleine Rolle, wohl aber für Mäuse.
    Notes: Abstract Female Wistar rats, conventional albino mice, and Chinese hamsters were given a single dose of acrylonitrile, 0.5 or 0.75 mM/kg body weight. The elimination in the urine of thiocyanate, which is the main metabolite of acrylonitrile, indicated a decreasing proportion of biotransformation after oral (over 20 %), intraperitoneal, or subcutaneous (2 to 5 %), and intravenous (1 %) administration in rats. Oral administration of acrylonitrile in hamsters and mice was also followed by higher biotransformation than intraperitoneal administration. Pretreatment of rats with phenobarbital, SKF 525 A, cysteine, or dimercaprol did not significantly influence elimination of thiocyanate in the urine after the administration of acrylonitrile, but simultaneous administration of thiosulfate significantly increased the metabolized portion of acrylonitrile given intraperitoneally in rats (almost twice) and mice (more than three times). Acrylonitrile was found to be strongly bound in blood. The study confirmed the marked effect of distribution (first-pass metabolic phenomenon) on the metabolic fate of foreign compounds. The strong acrylonitrile binding and cyanoethylation are apparently responsible for the unusually high influence of the different routes of administration on the metabolic fate of acrylonitrile. Acrylonitrile was more effectively metabolized to thiocyanate in mice than in rats after oral, intraperitoneal, and intravenous administration. A greater response of acrylonitrile to thiocyanate metabolism and a larger decrease in its acute toxicity after thiosulfate in mice than in rats indicate possible differences in the mechanism of acrylonitrile toxicity in these animals. Cyanide apparently plays a minor role in the acrylonitrile toxicity in rats, but may play quite an important one in mice.
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  • 10
    Electronic Resource
    Electronic Resource
    Springer
    Anatomy and embryology 146 (1975), S. 265-277 
    ISSN: 1432-0568
    Keywords: Granulocytopoiesis ; Perihepatic layer ; Mesothelium ; Amphibia ; Ultrastructure
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Description / Table of Contents: Zusammenfassung Der Peritoneal-Überzug und die subkapsuläre Region der Leber von Xenopus laevis wurden mit dem Elektronenmikroskop untersucht. Dabei wurde festgestellt, daß in der subkapsulären Region eine zwei bis zehn Zellschichten starke perihepatische Schicht vorhanden ist. Die perihepatische Schicht setzt sich zum größten Teil aus granulocytopoetischem Gewebe zusammen. Es wurden jedoch auch Lymphocyten, Pigmentzellen und Fettspeicherzellen gefunden. Das Vorhandensein einer perihepatischen granulocytopoetischen Schicht bei Xenopus laevis steht im Gegensatz zu der bisherigen Auffassung, daß die perihepatische Schicht ein typisches Merkmal der Urodelen sei. Es werden die phylogenetische Bedeutung einer solchen Schicht bei Anuren sowie die Entwicklungsvorgänge der einzelnen Zelltypen der perihepatischen Schicht diskutiert. Außerdem wird auf die mögliche Bedeutung der perihepatischen Schicht für immun-Vorgänge verwiesen.
    Notes: Summary The peritoneal cover and the subcapsular region of the liver of Xenopus laevis were examined with electron microscopy. In the subcapsular region a prominent perihepatic layer two to ten cells wide was found. This perihepatic layer is mainly composed of granulocytopoietic tissue. Other cell types found in the perihepatic layer were lymphocytes, pigment cells and fat storing cells. The presence of a perihepatic granulocytopoietic layer in the liver of Xenopus laevis is in contrast to current opinion that such a layer is a characteristic typical of urodeles. The phylogenetic significance of such a layer in anurans and the developmental processes of the individual cell types of the perihepatic layer are discussed. Furthermore the possible participation of the perihepatic layer in the immune response is considered
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  • 11
    ISSN: 1432-0568
    Keywords: Corticotropin releasing factor ; Neurosecretion ; Hypophysis ; X-irradiation ; Rat
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary In 195 female Wistar rats the influence of adrenalectomy, total body X-irradiation and dexamethasone treatment on the amount of CRF-granules in the external zone of the median eminence and “classical” neurosecretory material (NSM) in the internal zone of the median and in the posterior lobe of the hypophysis has been studied. In the normal rat only very few CRF-granules occur. 15 days after adrenalectomy increased amounts of CRF-granules but normal amounts of “classical” NSM are found. X-irradiation leads to a slight diminishment of “classical” NSM in normal rats. In adrenalectomized animals X-irradiation causes no changes in the amount of “classical” NSM but a marked decrease in the amount of CRF-granules. Application of dexamethasone from the 15th to 18th day after adrenalectomy enhances the augmentation of CRF-granules in irradiated and non-irradiated rats but does not influence the amount of “classical” NSM. The findings show that no correlation exists between the quantitative changes of CRF-granules and “classical” NSM under the experimental conditions used. Therefore it is to be assumed that the release of the two substances is regulated by different control mechanisms and that the substances have a different functional significance. The observations do not exclude the possibility that CRF-granules and “classical” NSM are biochemically identical.
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  • 12
    Electronic Resource
    Electronic Resource
    Springer
    Anatomy and embryology 147 (1975), S. 243-258 
    ISSN: 1432-0568
    Keywords: Fixation ; Foetus ; Liver cells ; Ultrastructure
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary Light and electron microscopic investigations of the ability of various fixatives to preserve foetal pig liver tissue (immersion fixed 5 min, 20 min, and 40 min after the death of the mother) gave the following results: 1) Fixation with 4% formaldehyde gives, in all circumstances, an unacceptable tissue preservation. 2) Fixation with 2.5% glutaraldehyde gives fair tissue preservation in a ca. 130 μ thick zone below the surface. 3) Fixation with a fixative mixture containing 2% formaldehyde and 1.25% glutaraldehyde or 2% formaldehyde, 1% glutaraldehyde and 1% acrolein gives good tissue preservation in a ca. 500 μ thick zone under the surface. 4) The addition of DMSO does not improve tissue preservation. 5) Delayed fixation of liver tissue removed from the foetus after the uterus has been placed in an incubator for 40 min has only a slight effect on tissue preservation.
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  • 13
    Electronic Resource
    Electronic Resource
    Springer
    Anatomy and embryology 148 (1975), S. 47-58 
    ISSN: 1432-0568
    Keywords: Rat ; Endometrium ; Ultrastructure ; Progesterone
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary The effects of various dosages and of various time periods of treatment with progesterone have been studied in the spayed, mature rat. Test objects were the cells of the luminal epithelium and of the endometrial stroma which were examined by qualitative and quantitative electron microscopy. No significant response was observed in epithelial or stromal cells until after 12 hrs of progesterone treatment. The nuclei of both cell types were then more circular than earlier with reduced long diameters. The functional significance of this change in configuration is unclear since only in the stromal cells was it followed by nuclear growth. Further, after 12 hrs of treatment the relative amounts of mitochondria and granular endoplasmic reticulum of stromal cells were reduced while the volume of the stromal cell cytoplasm appeared enlarged. This is taken as evidence that progesterone causes an intracellular oedema probably by decreasing cell membrane permeability. This response is probably not specific for the stroma but also includes the luminal epithelium, although the volume of the epithelial cell cytoplasm could not be determined here. Nucleolar enlargement did occur in stromal cells and was observed after 12 hrs of treatment but was not significant until after 24 hrs. At this point of time the net amount of granular endoplasmic reticulum in stromal and epithelial cells was increased indicating an increased protein synthesis in both cell types. However, only in the stromal cells was this associated with nucleolar enlargement, which supports the idea that progesterone stimulates protein synthesis through different mechanisms in the two cell types. Testing various dosages of progesterone showed that 0.5 mg had an effect similar to 5 mg of progesterone. When 0.05 mg progesterone was injected the only effect observed was an increase in the amount of apical vesicles of the luminal epithelium, showing that the epithelium is more sensitive to progesterone than the stroma.
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  • 14
    Electronic Resource
    Electronic Resource
    Springer
    Anatomy and embryology 148 (1975), S. 89-97 
    ISSN: 1432-0568
    Keywords: Superior cervical ganglion ; Paraganglionic cells ; Rat ; Guanethidine ; Catecholamines
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary Paraganglionic cells in the rat superior cervical ganglion were investigated by fluorescence and electron microscopy following treatment with guanethidine for 5–30 days. Control animals received saline and guanidine. Fluorescence cytophotometric measurements revealed a general decrease in the catecholamine content of paraganglionic cells in guanethidine-treated animals. However a few cell clusters showed focal increases. Similarly by electron microscopy there was a general decrease in the number of dense core vesicles in the majority of paraganglionic cells with a minority of cell clusters showing increases.—guanethidine—as well as guanidine—treated animals showed non-specific cytological alterations such as mitochondrial swelling and increase of cytoplasmic glycogen. However no changes of catecholamine contents and of dense core vesicles were noted in control animals. These results confirm the conception that in rat paraganglionic cells the dense core vesicles are the main storage site of catecholamines. The marked difference in the response of some cell clusters to the experimental treatment can be considered as evidence of functional heterogeneity of this cell population in the rat superior cervical ganglion.
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  • 15
    Electronic Resource
    Electronic Resource
    Springer
    Anatomy and embryology 146 (1975), S. 245-264 
    ISSN: 1432-0568
    Keywords: Hepatocytes ; Amphibia ; Glycogen ; Ultrastructure
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Description / Table of Contents: Zusammenfassung Die Leber von Xenopus laevis wurde mit dem Elektronenmikroskop untersucht. Dabei wurde festgestellt, daß sie in ihrem Bau stark von der Leber der Säuger abweicht, vor allem in Bezug auf die Morphologie des als typisch zu bezeichnenden Hepatocyten. Die Untersuchungen zeigten, daß eine solche Zelle primär Glykogenspeicherungs-Funktion besitzt und nur geringe Bestandteile an Organellen und anderen Inklusionen aufweist. Da dieser Zelltyp in der Leber unbehandelter Tiere am häufigsten auftritt, wurde er als Normalzelle bezeichnet. Bemerkenswert erschien die Tatsache, daß eine Vielzahl von Zelltypen in der Normalleber vorkommen, die sonst vermehrt unter experimentellen Bedingungen zu finden sind, z.B. Zellen mit stark vermehrtem RER, vergrößertem Golgi-Feld, vermehrten Lipidinklusionen etc. Diese hohe Zahl von abweichenden Hepatocyten und die Tatsache, daß alle Zwischenstufen zwischen den einzelnen Extremen vorhanden sind, die nicht durch die lage der Zelle innerhalb der Leber erklärt werden konnten, wurden als der Ausdruck eines zyklischen Durchlaufens der einzelnen Aktivitätsstadien interpretiert. Spezielles Interesse verdient die Tatsache, daß Glykogen in der Leberzelle vermehrt nur während der Vitellogenese abgebaut wird. Akuter und chronischer Hunger, sowie Kälte-adaptation beeinflussen die Morphologie der Normalzelle, besonders in Bezug auf das Glykogen kaum. Die möglichen Ursachen hierfür werden diskutiert.
    Notes: Summary The liver of Xenopus laevis was examined with electron microscopy. Its structure was found to be markedly different from that of mammals, particularly regarding the morphology of the hepatocytes to be classified as typical. It was established that the main function of such a cell is the storage of glycogen, and further that it possesses only scant organelles and other inclusions. Since this type of cell was found most frequently in the liver of untreated animals, it was designated as normal cell. The fact appears noteworthy that in the normal liver of Xenopus laevis an abundance of cell types occur which are otherwise found to be proliferated under experimental conditions, e.g. cells with pronouncedly augmented RER, enlarged Golgi complexes, increased lipid inclusions etc. This high number of divergent hepatocytes and the fact that all intermediate stages between the individual extremes are present and not to be accounted for by the position of the cell within the liver was interpreted as being the expression of a cyclic passage of the various stages of activity. It is of special interest that augmented degradation of glycogen in the liver cell takes place only during vitellogenesis. Acute and chronic hunger, as well as adaptation to cold, hardly affect the morphology of the normal cell, especially as far as the glycogen is concerned. The possible causes for this are discussed.
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  • 16
    Electronic Resource
    Electronic Resource
    Springer
    Anatomy and embryology 148 (1975), S. 73-87 
    ISSN: 1432-0568
    Keywords: Rat ; Temporal cortex ; Synaptogenesis ; Retzius-Cajal cells ; Poly morphous cells
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary The onset of synaptogenesis was studied in the temporal cortex of rat fetuses whose age ranged between 15 and 19 days of gestation. First synapses were found at a surprisingly early stage of cortical development: on day 16. These contacts showed relatively few vesicles and very inconspicuous membrane-thickenings. They were located in the marginal layer, above as well as below the narrow band formed by the newly arrived first neuroblasts of the prospective cortical plate. The postsynaptic structures were probably dendrites of the horizontally or obliquely orientated neurons scattered throughout the marginal layer (such neurons were seen even within the cell-dense band). On day 17, the cortical plate separated the differentiated cells definitely into a superficial and a deep population. As on the following days, synapses were found above and below the cortical plate but not within it. In addition to contacts showing the same features as those described on day 16, there were already synapses with numerous vesicles and clearly asymmetric membrane thickenings. On days 18 and 19 the borders of the cortical plate became more clear-cut. The well-differentiated neurons situated above and below this plate could now be identified as Retzius-Cajal cells of the prospective molecular layer and as polymorphous cells of the layer VI b respectively. The presence of axo-somatic contacts on these neurons provided direct evidence that both cell types are targets for synapses. Desmosome-like junctions were found even in the youngest fetuses studied. Their roughly symmetric membrane thickenings were clearly more conspicuous than those of earliest synapses. Desmosome-like junctions occurred very frequently between structures which subsequently were never seen to become synaptically linked. During the entire period studied, numerous coated vesicles fused with cell membranes were noted. Such “open” vesicles were seen on neurons (sometimes in the immediate vicinity of synapses) but also on non-nervous, extracortical as well as intracortical structures. Thus there does not seem to be a specific relationship between desmosome-like junctions and coated vesicles on the one hand and synapse formation on the other.
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  • 17
    Electronic Resource
    Electronic Resource
    Springer
    Anatomy and embryology 146 (1975), S. 301-311 
    ISSN: 1432-0568
    Keywords: Endocrinology ; Ultrastructure ; Adrenal cortex ; Avian Physiology
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary The ultrastructural characteristics of the interrenal cell were investigated in the quail and the pigeon after fixation by intravascular addominal perfusion. These is no significant fine structural difference between cells belonging to subcapsular and central regions of the gland. The interrenal cell in both species possesses nuclear bodies, polymorphic mitochondria with tubulo-vesicular cristae and tubular crystalline inclusions, considerable amounts of endoplasmic reticulum, ergastoplasm, a well developed Golgi apparatus, coated vesicles, microtubules, filaments, cilia, ribosomes, a profusion of liposomes, dense bodies with varied inner structure, pinocytic invaginations of cell membrane and intercellular attachment devices. The pigoen adrenocortical cell also possesses intranuclear lipidlike inclusions and fibrous bundle (this being never recorded in adrenocortical cell), annulate lamellae, and a variety of cytosomes, probably lipofucsin in nature. The significance and cytophysiological role of various organelles and inclusions have been discussed in the light of earlier data obtained on avian adrenocortical cells.
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  • 18
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    Acta neuropathologica 31 (1975), S. 353-361 
    ISSN: 1432-0533
    Keywords: Intranuclear Inclusions ; Creutzfeldt-Jakob Disease ; Ultrastructure ; Virus-Like Inclusions ; Nuclear Body
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary Two types of intranuclear inclusions were described in a brain biopsy from a patient with Creutzfeldt-Jakob disease. The first type of intranuclear inclusion was papova virus-like and was observed within 20% of the nuclei of all astrocytes and neurons examined. The particles measured 32 nm in diameter and consisted of a dense core surrounded by a multilayered shell. The second type of intranuclear inclusion was a granulo-fibrillar nuclear body found within the nuclei of astrocytes and neurons. The possible significance of these inclusions to the etiology of Creutzfeldt-Jakob disease is discussed.
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  • 19
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    Acta neuropathologica 32 (1975), S. 225-233 
    ISSN: 1432-0533
    Keywords: Tissue Culture ; Ultrastructure ; Chordoma
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Abstract This report concerns an electron microscopic study of a sacrococcygeal chordoma and its in vitro cultured cells. In vitro, the cells that proliferated in the early phase were predominantly non-vacuolated stellate cells, which were later transformed into vacuolated cells. This suggests that various cell types seen in vivo represent variants of the same cell type at different stages of differentiation and cellular activity. The in vitro tumor cells also show the origin of their vacuoles from both rough endoplasmic reticulum and Golgi membranes. The finding of amorphous and granular material and collagen fibrils in the extracellular spaces of cultured cells seems to suggest that chordoma cells have certain synthetic and secretory activity.
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  • 20
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    Acta neuropathologica 33 (1975), S. 9-21 
    ISSN: 1432-0533
    Keywords: Fabry's Disease ; Glycolipid ; Anhydrosis ; Pain ; Ultrastructure
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary A sural nerve biopsy of a patient with Fabry's disease showed depletion of larger myelinated fibres, but smaller myelinated and unmyelinated fibres were intact. Epineurial and to a lesser degree endoneurial vessels revealed abundant lamellar inclusions in the endothelial and perithelial cells. Larger myelinated nerve fibres contained glycogen granules in the vacuoles caused by splitting of the adaxonal membranes. A skin biopsy revealed abundant inclusions in the secretory cells and myoepithelial cells of the sweat glands. The lumen of the gland was packed with inclusions like those in the vessel walls. The pain and anhydrosis might be caused by accumulation of glycolipid in the vasa nervorum and sweat glands and not by autonomic nerve involvement.
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  • 21
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    Acta neuropathologica 33 (1975), S. 279-284 
    ISSN: 1432-0533
    Keywords: Hemangiopericytoma ; Leiomyoblastic differentiation ; Ultrastructure
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Abstract Two intracranial hemangiopericytomas revealed subcellular features of the neoplastic elements comparable to those observed in normal and neoplastic smooth muscle. These included intracytoplasmic and submembranous fusiform dense bodies associated with bundles of filaments, tapered configuration of cells with grouping of cytoplasmic organelles at nuclear poles and deposition of intercellular basal lamina-like material. These observations are consistent with the pericytic origin but opposed to the ofttimes postulated meningothelial derivation of the neoplasm.
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  • 22
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    Acta neuropathologica 31 (1975), S. 117-127 
    ISSN: 1432-0533
    Keywords: Dark Neurons ; Ultrastructure
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary The lateral vestibular nucleus was studied by light and electron microscopy in normal rats as well as in rats in which the anterior cerebellar vermis was destroyed. Dark neurons were seen in many of the operated rats but were rarely found in normal control animals. The dark neurons were not seen in adjacent nuclei. In additional rats, it was found that anoxia, extra anaesthetic, postmortem rough handling, and sham operations did not increase the frequency of dark neurons. These data indicate that dark neurons might not always be artifactual and that the lateral vestibular nucleus appears to be a focal point for their occurrence.
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  • 23
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    Diabetologia 11 (1975), S. 49-55 
    ISSN: 1432-0428
    Keywords: Rat ; blood glucose ; plasma insulin ; pancreas perfusion ; insulin secretion ; thyroxine ; glucose ; tolbutamide ; pyruvate ; isoprenaline
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary Thyroxine treatment increases blood glucose and plasma insulin levels in the rat. The hypoglycemic effect of tolbutamide is more pronounced in treated animals. The immediate insulin secretory response of the isolated perfused pancreas to maximal, but not to submaximal, glucose stimuli was increased after thyroxine treatment, especially in the lower dose range. However, as thyroxine treatment reduces insulin release during the prolonged late phase, the total amount of insulin released from the pancreas is reduced. Both the early response to tolbutamide and the subsequent basal secretion were increased after thyroxine treatment. When the pancreas of treated rats was exposed to glucose plus pyruvate the inhibition of the late phase was reversed. Isoprenaline did not overcome the inhibitory effect of thyroxine treatment on the late phase of glucose-induced insulin release. Thyroxine induces a selective inhibition of glucose induced insulin release which is reversed by pyruvate; this indicates that thyroxine interferes with the glycolysis in the beta cell.
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  • 24
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    Diabetologia 11 (1975), S. 285-289 
    ISSN: 1432-0428
    Keywords: Ultrastructure ; pregnancy ; B-cell ; granule type ; light (pale) granules ; dark granules
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary The ultramicroscopic appearence of the B-cell of the pregnant rat suggests hyperinsulinism of the individual beta cell. In pregnant rats the B-cell contains an increased volume and an increased number of light granules as well as enlarged mitochondria.
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  • 25
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    Inflammation research 5 (1975), S. 57-61 
    ISSN: 1420-908X
    Keywords: Rat ; Lymphostatic encephalopathy ; Harmine ; Tremor ; Antiphlogistics ; Blood-brain barrier ; Permeability
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Abstract Injection of the tremorigenic alkaloid harmine into lymphostatic encephalopathic rats leads to a longer duration of tremor and higher brain concentrations than in shamoperated controls. In lymphostatic encephalopathic as well as in normal rats different antiphlogistics shorten the tremor duration and decrease harmine concentraion in brain. The antiphlogistics do not influence the plasma concentration of harmine, its protein binding and its tremorend concentration in brain. The effect of antiphlogistics in lymphostatic encephalopathic rats is considered as a consequence of the reduced blood-brain barrier permeability. Obviously in sick animals the blood-brain barrier permeability for harmine is not increased; the prolonged harmine tremor and the increased alkaloid concentration in the brain are consequences of the impaired cerebral lymphatic drainage only.
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  • 26
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    Archives of microbiology 102 (1975), S. 95-101 
    ISSN: 1432-072X
    Keywords: Coelastrum ; Chlorococcales ; Chlorophyta ; Ultrastructure ; Cell Wall ; Tubules ; Bristles ; Polymorphism ; Buoancy ; Taxonomy
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Description / Table of Contents: Résumé La paroi cellulaire de Coelastrum est généralement composée de trois couches. La couche la plus externe a été plus particulièrement étudiée. Elle est composée de tubules dressées, et porte souvent de longues fibrilles dont le rôle serait de stabiliser l'algue dans son milieu. La morphologie de la paroi cellulaire peut se modifier en fonction du milieu.
    Notes: Abstract The cell wall of Coelastrum is usually composed of three layers. The outermost layer was studied most extensively. It consists of erect tubules which often bear long bristles whose function may be to stabilize the algae in its environment. The cell wall can modify its morphology according to the environment.
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  • 27
    ISSN: 1432-072X
    Keywords: Bacillus acidocaldarius ; Spores ; Germination ; Thermophile ; Ultrastructure
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract Spores of the thermophilic, acidophilic, Bacillus acidocaldarius were covered by a thick outer coat and a laminated inner coat (5.5 nm periodicity). Small membranous vesicles were present in the spore core and they disappeared as germination proceeded. After depolymerization of the cortex, and a 30% increase in spore diameter, a localized gap appeared in the laminated inner coat only. This inner coat gap was narrow and could be the whole length of the spore. The germ cell appeared to grow, or to be pushed towards the inner coat gap, at which stage the outer coat disappeared in the same localized area. As the vegetative cell grew out the spore coat fell away, with loose cortical material still attached to it. The young germ cell developed a large spherical electron dense inclusion body in the cytoplasm, at the same time as the ribosomal and nuclear areas became distinct.
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  • 28
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    Archives of microbiology 104 (1975), S. 271-277 
    ISSN: 1432-072X
    Keywords: Protoplasts ; Regeneration ; Wall Structure ; Pullularia ; Ultrastructure ; Membrane Splitting ; Aberrant Tubes
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract During the process of degradation of the cell wall of the yeast form of Pullularia pullulans by the lytic system of Micromonospora chalcea samples were withdrawn at different times and observed under phase contrast and electron microscope. The progressive lysis of the walls reveals a fibrillar component inside the apparently amorphous wall. Freeze etched preparations of cells during the formation and regeneration of protoplasts show that the cellular membrane is split and this method allows the smooth external face of the membrane and other internal face covered by particles to be seen. The fact that the smooth face of the membrane is only visible during the preparation or the regeneration of protoplasts and very rarely when intact cells are fractured, suggests a strong adherence between cell wall and this external layer of the membrane. During the regeneration which takes place as in most of the yeasts and moulds, a special study of the extension of the cell wall is made and a possible mechanism for this extension of the regenerated cell wall is proposed.
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  • 29
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    Archives of toxicology 34 (1975), S. 309-314 
    ISSN: 1432-0738
    Keywords: Glafenine ; Chloroquine ; 4-Amino-7-chloroquinoline ; Rat ; Glafenin ; Chloroquin ; 4-Amino-7-chlorchinolin ; Ratte
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Description / Table of Contents: Zusammenfassung Bei oraler Zufuhr in einer Dosierung von 150 bis 450 mg/kg 2 Tage hintereinander an etwa 100 g schweren Ratten bewirkt Glafenin eine vorübergehende Nephritis mit Steigerung von Blutharnstoff, Hypertrophie der Nebennieren und Veränderungen des Serumproteinogramms. An die 4-Amino-7-chlorochinolin-Struktur scheinen diese toxischen Wirkungen nicht gebunden zu sein, denn die ähnlichen Derivate, Chloroquin und Amodiaquin, rufen sie in äquimolekulären Dosen nicht hervor. Glycerol, ein im Organismus entstehendes Hydrolysisprodukt des Glafenins, zeigte sich auch wirkungslos. Die Toxicität ist wahrscheinlich auf das Glafenin selbst oder sein saures Abbauprodukt 4-(0-carboxyphenylammo-7-chlorochinolin, zurückzuführen.
    Notes: Abstract When given orally in elevated but nonlethal doses (150 to 450 mg/kg, on 2 consecutive days), glafenine induces in rats (body weight 100 g) a transient nephritis with an increase in blood urea, hypertrophy of adrenals, and some changes in the serum proteinogram. These effects do not appear to be due to the 4-amino-7-chloroquinoline structure from which glafenine is derived, as they are not observed with the structural analogue chloroquine given at equimolar doses under the same conditions. Further, they do not appear to be due to glycerol, the by-product of metabolic glafenine hydrolysis. The responsible molecule appears to be either glafenine itself or its acid metabolite 4-(0-carboxyphenylamino) 7-chloroquinoline.
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  • 30
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    Archives of toxicology 34 (1975), S. 213-225 
    ISSN: 1432-0738
    Keywords: Lead ; Chelating agents ; Toxicity ; Rat ; Blei ; Chelatbildner ; Toxicität ; Ratte
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Description / Table of Contents: Zusammenfassung Die intraperitoneale Verabfolgung von Pb-Acetat führt zu einer mäßigen und vorübergehenden hypochromen Anämie, zu einer lang dauernden erhöhten Ausscheidung der δ-Aminolävulinsäure mit dem Urin, während die Ausscheidung der alkalischen Phosphatase überhaupt nicht und die von Lactatdehydrogenase nur geringfügig beeinflußtwird. Es wird gefolgert, daß weder die hamatologische Reaktion noch die angedeutete Nephrotoxicität für die letale Wirkung von Pb verantwortlich sind. Die Chelattherapie begann 3 Tage nach der letzten Pb-Dosis und erstreckte sich auf 7 Wochen, wobei die intraperitoneale Tages-dosis 25, 50 bzw. 100 μmol/kg betrug. Die Wirksamkeit in bezug auf die Erhöhung der Pb-Ausscheidung mit dem Urin nahm in der Reihenfolge ab: Ca-Diäthylentriaminpentaacetat 〉 2,3-Dimercaptopropan-1-sulfonat 〉 Zn-Diäthylentriaminpentaacetat 〉 D-Penicillamin. Das vermehrt ausgeschiedene Pb stammt im wesentlichen aus dem Skelett. Die Chelatbildner erniedrigten ebenfalls die Ausscheidung der δ-Aminolävulinsäure, erwiesen sich aber als unwirksam, die hämatologische Reaktion und die letale Wirkung von Pb günstig zu beeinflussen. Durch diese negativen Ergebnisse wird der Wert der Chelatbehandlung von Fällen akuter Pb-Vergiftung in Frage gestellt.
    Notes: Abstract The intraperitoneal administration of Pb acetate (5 × 20 mg Pb/kg per day) evokes a moderate and transient hypochromic anemia, a long-lasting enhanced urinary excretion of δ-aminolevulinic acid whereas the urinary excretion of alkaline phosphatase is not affected and that of lactic debyhrogenase only marginally. It is concluded that neither the hematologic response nor the slight nephrotoxicity are responsible for the lethal action of Pb. Chelate treatment started 3 days after the last Pb dose and was continued over 7 weeks. The daily intraperitoneal dose was 25, 50, and 100 μmol/kg, respectively. The efficacy in promoting the urinary excretion of Pb decreased in the following order: Ca diethylenetriaminepentaacetate 〉 2,3-dimercaptopropane-1-sulfonate 〉 Zn diethylenetriaminepentaacetate 〉 D-penicillamine. This effect was mainly due to the mobilization of skeletal Pb. The chelating agents also lowered the excretion of δ-aminolevulinic acid but failed to exert a beneficial influence on the anemia and the lethal action of Pb. These negative results raise questions about the usefulness of chelation therapy in cases of acute Pb poisoning.
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  • 31
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    Archives of microbiology 102 (1975), S. 129-137 
    ISSN: 1432-072X
    Keywords: Diazepam ; Benzodiazepines ; Scenedesmus ; Ultrastructure ; Photosynthesis ; Respiration ; Rubidium Uptake
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract Effects of diazepam (Valium) on photosynthesis, chlorophyll/photosynthesis ratios, respiration, uptake of rubidium ions, and ultrastructure of Scenedesmus obliquus synchronized by a light-dark regimen of $$14:\overline {10}$$ hrs were determined. 80 and 160 μM diazepam, added to the nutrient medium at the start of the light-dark change (i.e., start of the cell cycle) gradually reduced rates of photosynthesis below the initial rates from the beginning of the experiment. Contents of chlorophyll, however, remained nearly unaffected. Consequently, the diazepam-treated cells had a higher chlorophyll/photosynthesis ratio—also with regard to respiration in order to calculate the gross photosynthesis. The occurrence of photorespiration cannot be assumed. The net influx or rubidium was slightly reduced by 100 μM diazepam 0.5 and 2.0 hrs after the start of the cell cycle and was strongly inhibited after 5 to 14 hrs. 80 and 160 μM diazepam caused separation of thylakoids, formation of giant mitochondria and enlargement of vacuoles. The results are discussed and it is finally suggested that diazepam acts on different membrane systems. Furthermore an ATP deficiency cannot be excluded.
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  • 32
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    Experimental brain research 22 (1975), S. 13-24 
    ISSN: 1432-1106
    Keywords: Inferior olive ; Spinal afferents ; Ultrastructure
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary Identification of the direct spinal areas (portions of the dorsal and medial accessory nuclei) within the opossum inferior olivary complex was accomplished by mapping the location of the terminal degeneration by the Fink-Heimer technique subsequent to cervical cord lesions. Following similar lesions, sampling of these same regions for electron microscopic study was assured by examination of transversely oriented, 1 μ plastic sections prior to thin sectioning. The first evidence of electron dense axon terminals was found at a survival time of 24 hours. At survival times of 36, 48 and 72 hours, degenerating presynaptic profiles shrink, become irregular in shape and are totally or partially surrounded by glial processes. Spinal terminals average 1–2 μ in their greatest dimension, contain round, clear synaptic vesicles and generally contact small diameter (0.4–1.8 μ) dendritic shafts or occasional spiny appendages. The spiny dendritic appendages make up the central core of the olivary glomeruli and these juxtaposed dendritic processes exhibit gap junctions. At longer survival times (5, 7 and 9 days) many presynaptic profiles with either round or pleomorphic synaptic vesicles remain normal in appearance and contact dendritic shafts or the spiny appendages within glomeruli. Afferents from other sources (possibly including intrinsic neurons) must terminate within the direct spinal portion of the nuclear complex to account for the numerous axon terminals which retain normal morphology after such long survival times.
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  • 33
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    Experimental brain research 23 (1975), S. 157-166 
    ISSN: 1432-1106
    Keywords: Ventrobasal thalamus complex ; Thermosensitivity ; Burstactivity ; Rat
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary Recordings were made of spike-trains from 163 neurons of the rostral part of the ventrobasal thalamus complex of the rat while the temperature of the scrotal skin was altered. The following results were obtained: 55 neurons were nonthermosensitive, 7 neurons cold-sensitive and 101 neurons warm-sensitive. In the case of the warm-sensitive cells a definite discrimination was possible: 61.4% of the neurons altered their firing behavior during peripheral cooling, changing from relatively even spike frequency to burst firing. This change could be induced repeatedly by altering the temperature. 38.6% of the neurons, on the other hand, reacted to cooling by slowing down their frequency. By way of statistical methods the firing patterns of the two response-types were analyzed more precisely and the differences in response to temperature stimuli more exactly defined. Likewise, the spatial distribution of the two response-types of warm-sensitive cells exhibited differences; whereas the cells devoid of burst activity occured rather uniformly in the region of the thalamus studied, the cells with bursting activity were confined more to the mediocaudal region. These findings are discussed with regard to the phenomenon of peripheral bursts and to the projection of thermoafferent pathways onto the ventrobasal thalamus complex. The functional interpretation of the various cell reactions and their role in the central processing of thermoafferent signals still remains unexplained and requires comparative studies of peripheral and central parts of the thermoafferent system.
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  • 34
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    International archives of occupational and environmental health 34 (1975), S. 167-175 
    ISSN: 1432-1246
    Keywords: N,N-Dimethylformamide ; Embryotoxicity ; Rat ; Inhalation
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary The purpose of this study, which was conducted for industrial toxicological reasons, was to investigate the possible embryotoxic and teratogenic effects after inhalation of dimethylformamide in rats. In a dynamic inhalation apparatus groups of 22–23 rats were subjected to approx. 18 ppm (maximum allowable concentration in the working area, MAC=20 ppm) and 172 ppm in the air for 6 hrs/day on 10 consecutive days, i.e. from the 6th to 15th day of gestation. The dimethylformamide inhalation did not cause any visible impairment to female rats as regards general behaviour, appearance or weight development during the treatment or the entire gestation period. The gestation rate was unchanged. The development of the fetuses was not influenced in any way by the exposure of the pregnant animals to approx. 18 ppm. In contrast the fetuses taken by caesarean section from the dams exposed to 172 ppm weighed significantly less than the fetuses of the control animals. Skeletal development of these fetuses, however, was normal. All other reproduction parameters were within the normal range for this strain. The study showed that the inhalation of dimethylformamide in concentration up to approx. 10 times the MAC had no teratogenic effect on rats.
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  • 35
    ISSN: 1432-1106
    Keywords: Cell cultures ; Fetal ; Hypothalamus ; Ultrastructure
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary Dissociated fetal hypothalamic cells mainly taken from 14 day-old mouse fetuses were grown in vitro for increasing time (9 to 60 days). Soon after inoculation the cells partly reaggregated and attached. The small reaggregates were then interconnected by fibers bundles. After the first week the cultures were composed of a continuous basal monolayer of flat and transparent cells, over which various types of refractile cells were lying in discontinuous areas. The ultra-structural study enabled us to identify these cell types, to describe their spatial relationships, and to follow their evolution with time in culture. The basal cell formed several superimposed layers. With increasing age, they displayed typical features of astrocytes and of ependymal cells. The latter exhibited rhythmic ciliary movements in culture. The overlying cells corresponded to three types which were associated in small clumps: primitive neuro-epithelial cells, maturing as well as mature neurons and typical neurosecretory cells. The latter cells were found as early as 9 days of culture of 14 day-old fetal hypothalamic cells and retained their typical features up to two months. Neuronal processes formed very dense networks at the surface of the cultures and terminated within the basal layers. Axon and dendrites were precociously found and were still present after two months. Within axon terminals dense-core vesicles appeared at the same time as neurosecretory cells. Synaptic vesicles and synaptic junctions were found later on.
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  • 36
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    Experimental brain research 23 (1975), S. 463-470 
    ISSN: 1432-1106
    Keywords: Rat ; Hypoglossal nucleus ; Axotomy ; Horseradish peroxidase
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary The left hypoglossal nuclei of normal rats, and rats which had received left hypoglossal nerve axotomies 7–21 days previously, were studied by electron microscopy after injection of horseradish peroxidase as a marker of extracellular space and pinocytosis. Quantitative analysis showed that the number of pinocytotically-derived structures in presynaptic boutons was significantly increased in rats at 7, 14, and 21 days after axotomy when compared with normal rats. It was suggested that presynaptic boutons which became detached from injured neurones retracted by a membrane cycling mechanism involving pinocytotic uptake of bouton plasmalemma, without compensatory membrane production elsewhere. It was confirmed that the channels in the microglial cells communicated with the extracellular space.
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  • 37
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    Archives of microbiology 106 (1975), S. 209-214 
    ISSN: 1432-072X
    Keywords: Cyanobacteria ; Colonial sheath ; Ultrastructure
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract The colonial sheath of Microcystis marginata has a definite structure as seen by light and electron microscopy, consisting of a relatively smooth inner surface and densely packed, long fibrils on the outer surface. The sheath initially forms around the single cell and expands by continual deposition of sheath material to accomodate the synchronously dividing cells of the colony.
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  • 38
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    Acta neuropathologica 31 (1975), S. 281-296 
    ISSN: 1432-0533
    Keywords: Werdnig-Hoffmann Disease ; Ultrastructure ; Denervation ; Muscle ; Myofibrils ; Centrioles
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary The authors describe in biopsies from 6 cases of Werdnig-Hoffmann disease, including 2 of the more benign type, the ultrastructural typical aspects of denervation. They compare their findings with those of other workers. The striking points are the great variation in the diameter of the muscle fibres and the myofibrils, the disorganisation of the myofibrils, the sarcomeres and the filaments, with persistance of the relations between thick and thin filaments at various levels, the modifications of the Z-band and the triads in chains. The folds and the basement membrane are examined. Centrioles are present in a muscle fibre and in a satellite. Glycogen is very abundant. The nerves seem normal but some Schwann cells contain π granules which are not observed usually at the age of the patient. The end plates and a muscle spindle are normal.
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  • 39
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    Acta neuropathologica 32 (1975), S. 333-339 
    ISSN: 1432-0533
    Keywords: Adult Metachromatic Leukodystrophy ; Polarization Microscopy ; Ultrastructure
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary The findings are described in an adult case of metachromatic leukodystrophy examined by light, polarization and electron microscopy. Symmetrical demyelination was found in the cerebral hemispheres, but was moderate in the cerebellum, brain stem and spinal cord. Early changes in myelin of peripheral nerves have been demonstrated by polarization microscopy. Various metachromatic structures have been described in glial cells and neurons by electron microscopy, indicating disturbances at different metabolic steps of lipid metabolism. There are minor but no essential ultrastructural differences in the disease of different ages.
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  • 40
    ISSN: 1432-0428
    Keywords: Rat ; ammonium infusion ; blood ammonia ; glucose metabolism ; plasma immunoreactive insulin
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary In order to explain the abnormalities of glucose metabolism previously observed in patients with blood ammonia elevation, the effect of a transitory hyperammonemia on I. V. glucose tolerance was investigated in rats. An I. V. glucose tolerance test was performed in 3 groups of 15 rats 60 min after the beginning of a 95 min infusion of either a 2 ml isotonic NaCl solution (control group) or ammonium acetate solutions at low (0.50 μmol/kg/min. NH4+) or high doses (1.70 μmol/kg/min NH4+). The “high” NH4+infusion produced an increase of blood ammonia to levels near 1000 μg/100 ml, a significant decrease in the K coefficient for glucose disappearance (2.53 × 10−2±0.20 compared to 4.92 × 10−2±0.13 in control group) and a suppression of the radioimmunological plasma insulin (I.R.I.) response to glucose. With the “low” NH4 + infusion the hyperammonemia was less pronounced (200–300 μg/100 ml), but the decrease in K(3.02 × 10−2±0.15) and in the first phase of I.R.I, release remained significant. The decrease in glucose disappearance rate could be accounted for by the proportional decrease in insulin secretion. Thus glucose intolerance induced by ammonium acetate infusions may be due to a direct effect of NH4 + on the pancreas. These abnormalities in glucose metabolism depend on the quantity of infused ammonium.
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  • 41
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    Acta neuropathologica 33 (1975), S. 173-177 
    ISSN: 1432-0533
    Keywords: Mesothelioma ; Pleura ; Metastases ; Brain ; Ultrastructure ; Asbestos
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary A malignant fibrous mesothelioma in a 52 year old white man arising from the left parietal pleura associated with lupus erythematosus with metastases to brain and liver is reported. Asbestos bodies were found in digested pulmonary tissue but none in the primary or metastatic lesions. Light microscopic and ultrastructural studies suggest that this tumor contains mesothelial or endothelial cells, some of which revealed fibroblastic features while others disclosed epitheloid characteristics.
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  • 42
    ISSN: 1432-0533
    Keywords: Experimental CNS tumours ; Methylnitrosourea ; Ethylnitrosourea ; Clonal growth ; Serum-free culture ; db cAMP treatment ; Rat
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary Six clones from methylnitrosourea (MNU) or ethylnitrosourea (ENU) induced tumours obtained in the nervous system of the rat were cultured in serum-free medium or treated with dibutyryl cyclic AMP (db cAMP) in vitro. All clones originated from longterm cultures. Three clones forming sarcomas after syngeneic transplantation showed only very slight changes following treatment, whereas the three glioma clones showed striking alterations. They formed long processes or showed rounding of their perikarya. In serum-free medium the cellular shape is intermediate between that seen in normal conditions and that seen in db cAMP treated cultures. The altered cultures resemble the primary cultures of the respective tumours. The relationship of these alterations to tumour types are discussed.
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  • 43
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    Acta neuropathologica 31 (1975), S. 137-150 
    ISSN: 1432-0533
    Keywords: Thiamine Deficiency ; Wernicke's Encephalopathy ; Rhesus Monkey ; Ultrastructure ; Myelin
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary Experimental Wernicke's encephalopathy, induced in rhesus monkeys with a diet lacking thiamine (vitamin B1), is characterized by cavitary necrosis of the striatum as well as a microvacuolar periventricular lesion of the brain stem such as occurs in man. With high resolution light microscopy and electron microscopy, the primary structural alteration in the brain stem lesion, and probably also in the striatum, appears to be that of widespread “blister” formation due to splitting of myelin at the intraperiod line. Microvascular alterations were minimal, even in the most severely affected regions. It is the myelin blisters which give rise to the spongy texture of the neuropil. A similar splitting of myelin has been deseribed in several other experimental encephalopathies, and it is probable that it also occurs in Wernicke's encephalopathy in man.
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  • 44
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    Pflügers Archiv 353 (1975), S. 171-189 
    ISSN: 1432-2013
    Keywords: Enzyme Secretion ; Hormonal Stimulation ; Narcosis ; Pancreas ; Rat
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary 1. A method for collecting duodenal juice and gastric content separately, in conscious rats, is described. Metal cannulas were implanted into the stomach fundus. For the main experiment a double lumen tube was inserted through the cannula via the pylorus into the duodenum. 2. The following secretion patterns were observed: a) In the resting state there was a constant flow rate of duodenal volume, bicarbonate, trypsin and amylase. b) Cholinergic stimuli were capable of increasing enzyme secretion as much as fourfold for a period of 30 to 40 min when administered as a single subcutaneous injection. This effect was annulled by atropine. c) Secretin and cholecystokinin-pancreozymin given together in a single injection s. c. or i. v., elicited a similarly strong response. d) Identical ranges of the secretion maxima were found with a tendency to decrease after the first hour, when the hormones were infused either s. c. or i. v. e) Doses from 0.5 to 25 U/100 g b. w./hr showed identical responses. Doses below 0.2 U/100 g/hr were without effect. 3. Narcosis (pentobarbital) inhibited markedly the resting and stimulated enzyme secretion. 4. The method is suitable for examination of physiological and pharmacological effects on resting and stimulated enzyme secretion of the rat pancreas.
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  • 45
    ISSN: 1432-2072
    Keywords: p-CPA ; Ethanol ; Pentobarbital ; Tolerance ; Brain 5-HT ; Rat
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Abstract Rats were rendered tolerant to ethanol or pentobarbital by daily oral administration. Motor impairments after test doses of ethanol or pentobarbital were measured prior to and at various times during chronic treatment in order to assess the degree of tolerance development. Chronic administration of p-chlorophenylalanine (p-CPA) in a dosage regimen which produced and maintained approximately 95% depletion of brain serotonin (5-HT) did not alter motor impairment after initial acute administration of ethanol or pentobarbital. However, the rate of tolerance development to the motor-impairing effects of both drugs was slowed down in p-CPA-treated rats. p-CPA did not appear to exert this effect by altering the disposition of ethanol or pentobarbital, since blood levels determined 20 min after administration of the test doses were similar in animals treated with p-CPA and in controls. These findings suggest that brain 5-HT may have a role in tolerance development to ethanol and pentobarbital.
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  • 46
    ISSN: 1432-2072
    Keywords: LSD-25 ; UML ; Acute ; Chronic ; Behaviour ; 5-HT ; Brain ; Rat
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Abstract Successive daily injections of LSD-25 and UML (1-methyl-d-lysergic acid butanolamide) caused progressive depression of brain 5-HT levels in the rat. On the fourth day, the decrease was significant with respect to the highly significant fall observed after a single administration, whereas it had been shown earlier that conditioned behaviour is no longer affected by LSD-25 after 3 days and that simultaneous administration of a single dose of LSD-25 and UML is equally ineffective in this respect. Its depression of 5-HT levels, however, has now been shown to be equal to that of LSD-25 alone at doses that influence conditioned behaviour. The findings indicate that changes in such behaviour are not dependent on brain 5-HT levels and that no link exists between such levels and the psychotomimetic effect of LSD-25 in man.
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  • 47
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    Psychopharmacology 41 (1975), S. 301-304 
    ISSN: 1432-2072
    Keywords: Mescaline ; Anti-Drug Antibody ; Hapten ; Immunopharmacology ; Rabbit ; Rat
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Abstract Antibodies with mescaline binding specificity were raised in rabbits by immunization with conjugates of bovine serum albumin with mescaline or its analogue 3,4,5-trimethoxyphenylacetic acid. Immunized rats were given mescaline and their behavior was compared to that of non-immunized controls.
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  • 48
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    Psychopharmacology 42 (1975), S. 147-152 
    ISSN: 1432-2072
    Keywords: Nicotine ; Selection ; Avoidance Conditioning ; Rat ; Latency ; Freezing
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Abstract Rats of both sexes from the genetically selected Roman High Avoidance (RHA), the Roman Low Avoidance (RLA) and the Roman Control (RCA) strains were given one 30-min session of two-way escape-avoidance conditioning (30 trials) in a shuttle box with a buzzer as the conditioned stimulus and shock as the unconditioned stimulus in a factorial design involving three time intervals (0,15 and 30 min) following one subcutaneous injection of saline or of nicotine in five doses (0.05, 0.1, 0.2, 0.4, or 0.8 mg/kg of body weight). Six measures relating to performance were analysed in whole or part. While the number of avoidance responses showed the expected strain differences, no effect of dose or delay interval could be detected. Avoidance and escape latencies and intertriai activity showed some effects of these variables, especially in interaction with sex and strain. Dose determined pre-sessional activity, but its effect was strain dependent. The failure to confirm previous findings is discussed in the context of other instances in the literature, and the results of an operant experiment confirming the continuing sensitivity of the Roman strains to the effects of nicotine are reported.
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  • 49
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    Psychopharmacology 44 (1975), S. 287-289 
    ISSN: 1432-2072
    Keywords: Delta-9-tetrahydrocannabinol ; Social behaviour ; Mouse ; Rat
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Abstract The behavioural effects of delta-9-tetrahydrocannabinol in mice and rats have been studied by an ethological analysis of encounters between animals injected with the drug and partners injected with the solvent (Tween-saline). In both species, Immobility was increased and Non-Social Activity reduced after injections of 5 mg/kg of delta-9-tetrahydrocannabinol. Flight was increased in treated mice but not in treated rats. Aggression was not significantly altered in either species. Thus, in the mouse, the qualitative behavioural effects of delta-9-tetrahydrocannabinol were similar to those previously reported for crude cannabis resin. Comparison of the dose-response data indicated that some other constituents of cannabis may reduce the Flight reaction from delta-9-tetrahydrocannabinol although not interfering with Immobility.
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  • 50
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    Psychopharmacology 42 (1975), S. 231-234 
    ISSN: 1432-2072
    Keywords: Heroin ; Self-Stimulation ; Water Intake ; Food Intake ; Rat
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Abstract Male rats maintained with continuous access to levers for intracranial self-stimulation (ICSS), water, and food were subjected to five consecutive daily injections of heroin (5 mg/kg). Rates of lever pressing for ICSS were increased in 8 rats, 2–6 hrs after administration of heroin. Rates of lever pressing for water and food were not significantly changed during this period. Naloxone (5 mg/kg) pretreatment attenuated by 82% the facilitative effect of heroin on ICSS. A second group of 8 rats maintained at reduced ICSS rates failed to show an increase in lever pressing for ICSS with heroin. The facilitative effect of heroin described in this study is consistent with previously reported studies describing the effects of morphine on ICSS.
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  • 51
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    Psychopharmacology 42 (1975), S. 255-261 
    ISSN: 1432-2072
    Keywords: Methadone ; Mode of Withdrawal ; Body Weight ; Relapse ; Rat
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Abstract Physical dependence on methadone was induced in rats by an initial “forced drinking” procedure and subsequently by i.p. administration of the drug. In a subsequent Experimental Phase of the study the physical dependence of one group was sustained by a “methadone maintenance” treatment, while two other groups were withdrawn from the drug, one gradually and one abruptly. When relapse trials were carried out during a Readdiction Phase it was found that the maintained group voluntarily consumed significantly greater amounts of methadone than did the two withdrawal groups. These groups did not differ between themselves but did in turn ingest significantly more methadone than a control group with no prior exposure to the drug. The characteristic loss of body weight reliably found during withdrawal from morphine was not demonstrated. This may have been due to the unexpected weight loss which occurred during the last stage of the initial Addiction Phase. The dependent variables of amount of methadone solution and the percentage of fluid consumed as methadone solution correlated highly. However the amount of methadone solution ingested was a better indicator of addiction liability as it was not influenced by fluctuations in the amount of water consumed by the animals.
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  • 52
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    Pflügers Archiv 353 (1975), S. 215-225 
    ISSN: 1432-2013
    Keywords: Muscle Regeneration ; Muscle Transplantation ; Contractile Properties of Muscle Transplants ; Denervation of Muscle ; Rat
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary The soleus or extensor digitorum longus muscles of young rats were freely grafted into the bed of the corresponding contralateral muscle. The grafts were of normal muscle or muscles which had been denervated for 14 days. Grafts of normal muscle were characterized by little or no contractile activity for the first 2–4 days after transplantation. In contrast, denervated grafts contracted weakly, but consistently, throughout this early period. The patterns of contraction were complex. In early transplants, the contractions were due entirely to surviving muscle fibers in the graft, and the contractile characteristics were those of denervated muscle fibers. After the first week, contractions of newly regenerating muscle fibers within the grafts were superimposed upon and later took over those from the fibers that survived the original transplantation. The contraction time approached those of the normal soleus or extensor muscles during the second month after grafting, and the grafts contracted like fast or slow muscles.
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  • 53
    ISSN: 1432-2013
    Keywords: High Altitude ; Coronary Blood Flow ; Cardiac Output ; Cardiac Hypertrophy ; Rat ; TissueP O 2
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary In rats exposed to a simulated high altitude of 3500 m for their whole prenatal and postnatal life a severe cardiac hypertrophy develops. In rats born and first staying 5 weeks at sea level and then being exposed to simulated high altitude, only a unilateral right cardiac hypertrophy occurs. In both groups nutritional coronary blood flow was estimated in left ventricle, right ventricle, and septum and was compared with control animals of similar age. Coronary blood flow was measured at hypoxia in all groups. At first cardiac output was determined by the Fick principle, then86Rb was applied and the animals were killed after 55 sec. Activity of86Rb was measured in both cardiac ventricles and septum and the fractional uptake was calculated. According to Sapirstein (1956, 1958) the distribution of86Rb follows the distribution of cardiac output and from both these data the nutritional blood flow to the parts of the heart may be estimated. Cardiac output was similar in rats exposed to simulated high altitude later in life (“newcomers”) and in control animals, but it was significantly lower in rats born in the low pressure chamber (“natives”). Fractions of cardiac output supplying cardiac ventricles and septum in rats from both hypoxic groups were significantly higher than in control animals. In the “natives” they were significantly higher than in the “newcomers”. The fractions of cardiac output in both “newcomers” and “natives” remained significantly higher than those of the control animals, also when calculated per gram of heart tissue. Nutritional coronary blood flow (in ml/min) was higher in both ventricles and septum of the “newcomers” and in the right ventricle of the “natives”, and lower in the septum of the “natives”, when compared with control animals. Coronary blood flow per gram of heart tissue (in ml/min·g) was significantly higher in all cardiac parts of the “newcomers”, but it was about the same in all cardiac parts of the “natives” when compared with controls. The importance of observed changes concerning myocardial tissue oxygenation is analyzed by using Krogh's cylindrical tissue model.
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  • 54
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    Pflügers Archiv 360 (1975), S. 121-134 
    ISSN: 1432-2013
    Keywords: Muscle cross ; Myosin ATPase ; Ultrastructure ; Fibre types ; Light chains of myosin
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary The slow anterior latissimus dorsi (ALD) muscles of newly hatched chiekens were transposed and cross-innervated by the mixed, predominantly fast superior brachialis nerve, and investigated 2 to 15 months after the operation. Two months after the operation, myosin ATPase activity of the cross-innervated ALD muscles was still as low as in the control ALD, although the ultrastructure and the histochemical ATPase activity already showed a mixed fibre-type pattern with a predominance of fast-type fibres around the site of nerve implantation. The change of myosin properties of the whole cross-innervated ALD did not occur until the third month after the operation. At that time, the myosin ATPase activity increased about 2.5 times and light chains of myosin of the fast type appeared in the electrophoretic pattern. The myosin ATPase activity attained 62% of the activity found in the control fast posterior latissimus dorsi muscles at three months; subsequently it remained at about this level reaching 68% 18 months after the operation. The results indicate that approximately two thirds of the corss-innervated ALD muscle fibres became changed towards the fast type under neural influence, whereas about one third remained slow, being re-innervated by the slow-type motor fibres of the implanted nerve.
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  • 55
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    Mycopathologia 55 (1975), S. 53-55 
    ISSN: 1573-0832
    Keywords: Rubratoxine B ; Mitochondria ; Rat
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Abstract The in vitro effect of rubratoxin B on the electron transport system of rat liver mitochondria was investigated. This mycotoxin depressed oxygen consumption in ADP-lacking mitochondria and in ADP-coupled mitochondria, using succinate or β-hydroxybutyrate as substrats. Rubratoxin B is neither an oxidative-phosphorylation inhibitor nor uncoupling agent. Its effect is compared with aflatoxin B1.
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  • 56
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    Experimental brain research 22 (1975), S. 525-540 
    ISSN: 1432-1106
    Keywords: Supraoptic nucleus ; Quantitative electron microscopy ; Afferent fiber connections ; Rat
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary A quantitative electron microscopic study of synaptic terminal degeneration was performed in the supraoptic nucleus (NSO) after a variety of major transections or ablations, destroying or interrupting in different combinations the afferent pathways known from earlier and own light microscopic degeneration studies. Solutions of a set of equations, expressing the percentage degenerations in synaptic profiles after different combinations in which the several pathways are interrupted by the various interferences, enabled the authors to give the following percentage numbers for afferent synapses from different sources. 32.7% of supraoptic afferents originate from the brain stem probably representing the monoaminergic innervation of this nucleus. The medial basal hypothalamus (21.0%), amygdala (13.5%), septum (13.5%), hippocampus (8.5%) and olfactory tubercle and further rostral cortical region (17.0%) are the other main sites of origin of supraoptic nucleus afferents. There are no supraoptic afferents from the optic nerve, superior cervical ganglion or fimbria hippocampi.
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  • 57
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    Experimental brain research 22 (1975), S. 175-183 
    ISSN: 1432-1106
    Keywords: Rat ; Hypoglossal nucleus ; Axotomy ; Subsurface cisterns
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary A quantitative ultrastructural survey was made of subsurface cisterns and their association with overlying structures in the left hypoglossal nucleus of normal rats, and rats which had received left hypoglossal axotomies 7–84 days previously. Subsurface cisterns in normal rats occurred in some hypoglossal neurones, and, sporadically, in proximal dendrites. They were mostly subsynaptic, and often associated with Nissl substance. From 7–14 days postoperatively, when many somatic boutons temporarily lost contact with the perikaryal surface, and were replaced by a microglial sheath, the percentage of perikaryon with underlying cistern was significantly reduced. The Nissl substance was also dispersed at this stage, and not restored until 28 days postoperatively. At 21 days normal percentages of subsurface cistern were restored, but the cisterns were now mostly subastrocytic, an astrocytic sheath having replaced the microglial sheath. From 63 days onwards the cisterns were mostly subsynaptic again as boutons returned to the regenerating perikarya and the temporary astrocytic sheath disappeared. It is suggested that subsurface cisterns might alter the overlying perikaryal surface in some way during neuronal regeneration, causing certain boutons to adhere there.
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  • 58
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    Research in experimental medicine 165 (1975), S. 213-217 
    ISSN: 1433-8580
    Keywords: Rat ; Lymph nodes ; lymphography
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary Most the lymphatic system in the rat was directly observed in our experiment by radiological means. The lymphatics of the limbs were firstly revealed by subcutaneous injection of Patent Blue V. Lipiodol was used as radio-opaque compound injected by a micro-technique fully described by the authors.
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  • 59
    ISSN: 1432-2307
    Keywords: Lathyrism ; Capillaries ; Rat ; Ultrastructure ; Flavonoids
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary The ultrastructure of rat myocardial capillaries was studied in the course of experimental lathyrism. Endothelial cells were hypertrophic, with a sinuous profile of the plasma membrane facing the lumen and with a consistent increase of pinocytotic vesicles; the nuclei were irregular in shape; ATPase activity was no more demonstrable. Therefore, various and well distinct structural endothelial mechanisms seem to be primarily involved, causing an alteration of the dynamics of transcellular exchanges and of the permeability of the vascular wall. Simultaneous treatment with certain flavonoids, (O-(β-hydroxyethyl)-rutosides and Na(+)-epicatechin-2-sulfonate), resulted in a less pronounced alteration and a more rapid recovery. The possibility of the existence of a common site of action of lathyrogens and flavonoids is raised in the discussion.
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  • 60
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    Cell & tissue research 163 (1975), S. 169-174 
    ISSN: 1432-0878
    Keywords: Muscles ; Blood supply ; Capillaries ; Lymphatic system ; Ultrastructure
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary Capillary fenestrae occur in one of about 60 cross-sectioned blood capillaries in normal adult rat skeletal muscles. The fenestrae occur singly or in groups. Fenestrated capillaries are found close to muscle fibers as well as in the perimysial and perineurial connective tissue. Small numbers of lymphatic capillaries are also present, mostly in the perimysial connective tissue.
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  • 61
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    Cell & tissue research 163 (1975), S. 199-214 
    ISSN: 1432-0878
    Keywords: Smooth muscle ; Intestine ; Hypertrophy ; Ultrastructure
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary Proximal to an experimental stenosis of the small intestine of rats and guinea-pigs a remarkable hypertrophy of the muscle coat develops 3–5 weeks after the operation. There is no increase in the length of the intestine but an overall increase in volume of the muscularis externa up to 10 times. This increase is accounted for by an increase in size and in number (by mitosis) of smooth muscle cells of both the longitudinal and circular layers. Bundles of newly-formed smooth cells appear in the serosa and are circularly arranged. In the hypertrophic smooth muscle cells of the circular layer the ratio of surface to volume is 0.80 (0.80 μm2 of cell surface for every μm3 of cell volume) as against 1.4 in the control muscle. The hypertrophic muscle cells have a highly developed sarcoplasmic reticulum and show a large number of nexuses. The density of innervation (number of axons per given number of smooth muscle cells) is smaller than in controls. Few collagen fibrils are visible in the extracellular space.
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  • 62
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    Cell & tissue research 156 (1975), S. 377-380 
    ISSN: 1432-0878
    Keywords: Vasopressin-neurophysin neurons ; Suprachiasmatic nuclei ; Immunoenzyme histochemistry ; Rat
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary Immuno-enzyme histochemical investigations on the hypothalamus of the normal rat showed (1) that the Suprachiasmatic nuclei produce vasopressin; (2) that it is highly probable that these nuclei do not produce oxytocin. From the present and previous investigations it may be concluded that the Suprachiasmatic neurons produce a vasopressin-neurophysin complex.
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  • 63
    ISSN: 1432-0878
    Keywords: Adenohypophysis ; Rat ; L-dopa ; Fluorescence histochemistry
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary The uptake of L-dopa into the cells of the adenohypophysis of the rat was studied during the postnatal development and at adult age using the formaldehyde-induced fluorescence method (FIF). The cells taking up L-dopa were classified by Alcian blue-PAS-Orange G staining. The correlation between the cells taking up L-dopa and those containing tryptophyl-peptide was estimated during the postnatal period and in adult rats. The cells containing tryptophyl-peptide were demonstrated using fluorescence induced by treatment with combined formaldehyde and acetyl chloride vapour. The following observations were made: 1) Great majority of the cells taking up L-dopa did not contain tryptophyl-peptide. Thus the accumulation of L-dopa into the cells of pars distalis is not due to accumulation of L-dopa into the cells by the same transport mechanism as the amino acids for tryptophyl-peptide. 2) Of the cells taking up L-dopa in the adult rats 96% were chromophobes, 2.0% acidophilic cells (somatotrophs and cells producing prolactin), 0.9% R-mucoid cells (corticotrophs), and 1.2% S1- and S2-mucoid cells (gonadotrophs and thyrotrophs). At 10 and 25 days' age the relative numbers of the cells taking up L-dopa were about the same. 3) Pretreatment with nialamide caused only a slight increase in the number of the cells taking up L-dopa. The decrease in the number of the cells uptaking L-dopa of the pars distalis, which takes place after 5 weeks' age is thus not caused by the increased MAO-activity. 4) Strongly chromophilic cells did not take up L-dopa. At the light of our results it seems evident that L-dopa is taken up by the chromophobic cells when these differentiate into chromophilic cells. The accumulation of L-dopa may be a sign of an active transport of amino acids into the cells. The accumulation of L-dopa into the chromophobic stellate and follicular cells may reflect their metabolic activity. These cells probably have an important role in the production of the hormones of the pars distalis.
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  • 64
    ISSN: 1432-0878
    Keywords: Gonadotrophins ; Testis ; Hypophysectomy ; Ultrastructure ; Japanese quail (Coturnix coturnix japonica)
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary Five-week old Japanese quail held under short daylengths (8L/16D) were injected daily for two weeks with 20 μg/day of purified chicken luteinizing hormone (LH) or with one of two chicken follicle-stimulating hormone (FSH) fractions. Both intact and hypophysectomized birds were used. After killing, the testes were weighed and fixed for light- and electron-microscopy. Following hypophysectomy testicular weights fell significantly below those of saline-injected controls, indicating that short day conditions are not equivalent to “physiological hypophysectomy”, the pituitary-gonadal axis continuing to function at a low level. Chicken LH stimulated differentiation of the interstitium, producing mature Leydig cells containing the full complement of organelles typical of steroid-secretion. In addition it induced some testicular growth caused by spermatogonial division and partial differentiation of the Sertoli cells. This effect was assumed to be a secondary response to androgen secretion but a direct action of chicken LH on the tubules is not dismissed. LH given to intact quail caused greater testicular growth, presumably due to synergism with endogenous hormones. Both chicken FSH fractions induced testicular growth and development; in intact birds the effects were similar to those observed in intact LH-treated birds. In hypophysectomized quail given FSH the testicular weights were greater than in hypophysectomized LH-treated birds and the seminiferous tubules were larger. Sertoli cells were stimulated and pachytene spermatocytes were numerous. Leydig cell differentiation was minimal in all FSH-treated birds, being less pronounced in hypophysectomized than in intact birds.
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  • 65
    ISSN: 1432-0878
    Keywords: Milk ; Fat globule membrane ; Carbohydrates ; Chemistry ; Ruthenium red ; Ultrastructure
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary The fat globules of the cream fractions of human and rat milk were stained with ruthenium red. Under the electron microscope, discrete granules and an amorphous coat of lesser density are seen at the surface of the milk fat globules. Since ruthenium red binds anionic groups selectively, it is probable that the granules containe the greatest concentration of these groups. The cream fraction of rat milk contains hexoses, hexosamines, methylpentoses and sialic acid. Methylpentoses and hexosamines are significantly enriched in the cream fraction. It is concluded that the finding of a surface coat in milk fat globules is in keeping with the Bargmann-Knoop model and suggests a distinct mechanism for carrying certain complex carbohydrates in milk. The role of the negative charges at the outer surface of the membrane coat in maintaining fat globules in suspension and in binding certain cations such as calcium is suggested.
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  • 66
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    Cell & tissue research 157 (1975), S. 25-51 
    ISSN: 1432-0878
    Keywords: Pineal gland (Rabbit) ; Autonomic innervation ; Ultrastructure
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary In the rabbit pineal gland two types of postganglionic nerve endings were found which are characterized by the presence of small dense-core vesicles or small clear vesicles. Pharmacological and cytochemical experiments showed them to be noradrenergic and cholinergic, respectively. Both types were often present in the same nerve bundle, occasionally in close apposition. Intrapineal neurons were only rarely observed. They showed cholinergic synapses on their perikaryon and dendrites as well as noradrenergic axo-dendritic close eontacts. Bilateral extirpation of the superior cervical ganglia revealed the postganglionic sympathetic origin of the pineal noradrenergic nerve fibres. Moreover, it appeared that these ganglia are hardly, if at all, involved in the pathway of pineal cholinergic innervation. The results obtained from lesions of both facial nerves, taken together with the results reported in the literature, led to the conclusion that the postganglionic cholinergic nerve fibres in the pineal are of parasympathetic origin. A model for the sympathetic and parasympathetic pineal innervation is proposed.
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  • 67
    ISSN: 1432-0878
    Keywords: Golgi complex ; GERL ; Sertoli cell ; Ultrastructure ; Phosphatase cytochemistry
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary The Golgi complex in the Sertoli cell of the Syrian hamster is well developed and consists of stacks of cisternae and associated vesicles. The inner-and outermost cisternae of the Golgi stacks are usually moderately dilated and exhibit numerous fenestrations. The middle portions of the intermediate cisternae are greatly flattened and not fenestrated, but toward the periphery these cisternae gradually become dilated and show a few fenestrations. On the inner aspect of the Golgi stacks the following structures are seen frequently: (1) one or two series of linearly arrayed circular profiles some of which are interconnected by tubules; (2) networks of anastomosing tubules with circular or oval meshes (800 to 1200 Å in diameter); and/or (3) irregularly disposed tubules. The circular profiles and tubules are approximately 450 Å in diameter. Acid phosphatase activity was localized in these anastomosing tubules when the tissues were incubated for more than one hour in a modified Gomori's medium (Barka and Anderson, 1963). Strong thiamine pyrophosphatase activity was demonstrated in the inner one to three cisternae of the Golgi stacks but not in the associated tubules. The system of the Golgi associated tubules is morphologically and histochemioally distinct from the Golgi stacks and is probably equivalent to the Golgi-endoplasmic reticulum-lysosome system (GERL) in other cell types. The three dimensional aspects of the GERL-equivalent system are discussed.
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  • 68
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    Cell & tissue research 158 (1975), S. 281-283 
    ISSN: 1432-0878
    Keywords: Glycocalyx ; Urinary bladder ; Ruthenium red ; Rat
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary Earlier statements to the contrary, the present study demonstrates the presence of a cell surface coat (glycocalyx) on the luminal plasma membrane of the super ficial transitional epithelial cells lining the urinary bladder of male Buffalo rats. This coat was demonstrated with ruthenium red, an electron dense stain, which revealed a surface layer, 60–80 Å thick, separated from the outer leaflet of the plasma membrane by an electron lucent layer, approximately 30 Å thick. The structure of the glycocalyx was not affected by 12 weeks of treatment with dibutylnitrosamine, a known bladder carcinogen.
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  • 69
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    Cell & tissue research 159 (1975), S. 399-412 
    ISSN: 1432-0878
    Keywords: Porcellidium (copepode) ; Ultrastructure
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Description / Table of Contents: Résumé Deux espèces de Porcellidium ont été examinées en microscopic à balayage et sur coupe avec les techniques habituelles (P. viride provenant de Banyuls-sur-mer, Méditerranée et P. fimbriatum de Roscoff, Manche; ces deux espèces vivent sur les Algues vertes du genre Ulva). Nous avons retrouvé les ultrastructures classiques de la cuticule, observées dans les principaux groupes de Copépodes. Quatre caractères nouveaux distinguent la cuticule dorsale des Porcellidium: 1. Différenciation d'un système de microvillosités externes, avec un niveau dense aux électrons, très contrasté par rapport aux extrémités d'où semblent partir de fins filaments englobant une population assez dense de Bactéries. 2. Cette plage de microvillosités recouvre un relief assez particulier de la procuticule, évoquant par ses cratères un paysage lunaire. 3. Présence de canaux cytoplasmiques ramifiés et terminés par une expansion arrondie, sous l'épicuticule. 4. Existence d'un système de vésicules reliant la base des microvillosités aux extrémités renflées des canaux cytoplasmiques. L'association des Bactéries est régulière et une grande proportion de celles-ci est en cours de cytolyse. La système de microvillosités et de canaux ne nous parait pas étranger à la présence de cette population bactérienne.
    Notes: Summary Two species of Porcellidium have been studied by scanning and transmission electron microscopy: P. viride from Banyuls-sur-mer, Mediterranian Sea and P. fimbriatum from Roscoff, English Channel. Both species live on green Algae of the genus Ulva. We confirmed previous descriptions of the cuticular ultrastructure in the main groups of Copepods. Four new characteristics however were shown to occur in the backcuticle of Porcellidium: 1. The presence of a system of highly differentiated external microvilli showing electron dense basal portions and less electron dense tips, from which thin filaments project towards a large population of Bacteria associated with the Copepod. 2. The surface of the cuticle resembles a lunar landscape with craters. The sheet of microvilli closely follows the contour of the cuticle. 3. The presence of branched cytoplasmic canals with swollen extremities (beneath the epicuticle) extending from the epidermal cells. 4. Systems of vesicles lying between the bases of the microvilli and the expansions (ampullae) at the tip of the cytoplasmic canals. The association of Bacteria with the cuticle is constant and many of these are apparently undergoing cytolysis. The system of microvilli and of cytoplasmic canals are apparently related to the presence of the bacterial microflora.
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  • 70
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    Cell & tissue research 159 (1975), S. 541-550 
    ISSN: 1432-0878
    Keywords: Testis ; Budgerigar ; Photoperiod ; Ultrastructure
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary Spermatogenesis in the Budgerigar can be arrested by reducing the birds' photoperiod to 8 hours of daylight or less. When this occurs, Sertoli cell cytoplasm shows a great increase in the size and number of residual bodies, while the smooth endoplasmic reticulum is reduced. If the bird is kept at 8 hours of daylight for some weeks large lipid droplets are seen in Sertoli cytoplasm, and degenerated spermatids are apparently phagocytosed. The interstitium shows fewer active Leydig cells, a paucity of lipids and occasional ovoid mitochondria. The basal lamellae of the tubule which are thick and convoluted before and during spermatogenesis become thinner and straighter. It is thought that these morphological changes reflect changes in metabolic activity.
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  • 71
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    Cell & tissue research 159 (1975), S. 551-561 
    ISSN: 1432-0878
    Keywords: Neurohypophysis, rat ; Exocytosis ; Blood vessels ; Ultrastructure
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary Neural lobes of rats subjected to dehydration by drinking 2% saline for four days were examined electron microscopically and compared to untreated controls. The ultrastructure of the blood vessels and the tissues surrounding them were examined and it was found that, although few exocytotic figures could be seen in either group of animals, a significantly larger (P〈0.01) number of small vesicles were found in nerve endings adjacent to the perivascular space in the saline treated group when compared to nerve endings not closely associated with blood vessels. No differences were found in the control group of animals, which supports the suggestion that the vesicles could arise from a membrane recapture process.
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  • 72
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    Cell & tissue research 160 (1975), S. 81-98 
    ISSN: 1432-0878
    Keywords: Sensillae ; Isoptera ; Schedorhinotermes ; Labrum ; Ultrastructure
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Description / Table of Contents: Résumé L'étude du labre du petit soldat de Schedorhinotermes, en microscopie photonique et électronique (balayage et transmission), a permis de préciser la distribution, les types et la structure des organes sensoriels présents sur celui-ci. Trois types de sensilles ont été observés: de nombreux sensilles campaniformes situés dans les régions antéro-latérales et deux types de sensilles trichoïdes: de petites soies (5 μ de longueur) réparties sur toute la surface du labre et quelques grandes soies (50 à 100 μ de longueur) localisées sur le bord antérieur du labre. Ces deux types de soies assurent à la fois une fonction mécanoréceptrice et chimioréceptrice. De nombreux orifices de glandes épidermiques débouchent également sur le labre qui porte à son apex une brosse formée de nombreuses écailles cuticulaires aplaties et non innervées. Une interprétation fonctionnelle est avancée, elle est basée sur les résultats ultrastructuraux obtenus et sur ce que l'on connait du comportement défensif du soldat.
    Notes: Summary The labrum of Schedorhinotermes minor soldier was examined to determine the distribution, types and structures of sense organs present with both light microscopy and scanning and transmission electron microscopy. Three types of sensilla were recognized: campaniform sensillae and two types of sensilla trichodea, the short bristles and the long bristles. The campaniform sensillae are singly-innervated receptors distributed in large numbers on the anterolateral margins of the labrum. The short and long bristles are multiinnervated; the former are found all over the surface, the latter are much more scarce and are found only at the front of the labrum. Both are at the same time chemo-and mechanoreceptors. The labrum is strewn with many glandular pits and exhibits at its apex a brush of cuticular not innervated spines. On the basis of ultrastructural evidence and of what we know of the defence mechanisms of the soldier, a functional interpretation is attempted.
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  • 73
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    Cell & tissue research 160 (1975), S. 125-138 
    ISSN: 1432-0878
    Keywords: Avian intestine ; Duodenum ; Ultrastructure ; Crypt cells ; Paneth cells
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary The fine structure of the development and maturation of intestinal chief cells from the duodenal crypts of the fowl has been described in detail. Three areas within the crypt can be recognised: (1) the crypt base where cell division is frequent but cell development is minimal; (2) the mid-crypt region where rapid growth and development of the cells takes place; and (3) the zone of differentiation where final development and functional maturation occurs. The structure of the fowl's intestinal crypt is very similar to that described for the mammal. The results are discussed in relation to previous histochemical studies.
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  • 74
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    Cell & tissue research 161 (1975), S. 47-53 
    ISSN: 1432-0878
    Keywords: Acrosome ; Centriolar complex ; Ultrastructure ; Sabella penicillum (Polychaeta)
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary The acrosomal vesicle of Sabella penicillum spermatids consists of an electrondense core and a more transparent surrounding zone. During subsequent differentiation the vesicle membrane forms several invaginations in the juxtanuclear area. These invaginations later establish contact with the core. In the mature spermatozoon the spaces between the invaginations appear as electron-dense “tubules”; this is probably due to a shift of material from core to periphery. The ultrastructure of the centriolar complex is described in detail.
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  • 75
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    Cell & tissue research 161 (1975), S. 183-191 
    ISSN: 1432-0878
    Keywords: Hypothalamus ; Pituitary ; Rat ; Localization of 3H-dexamethasone ; Radioautography
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary The central nervous system and the pituitary of adrenalectomized male rats injected with 3H-dexamethasone were examined by radioautography. At 1 hr after the injection, radioactivity concentration was high in the medial basal hypothalamus, the pituitary and the pineal gland. In the hypothalamus, radioactive material was found to be selectively concentrated in neurons in the ventral part of nucleus arcuatus and in the infundibular region. In the anterior pituitary, a large proportion of cells showed silver grains both in the cytoplasm and over the cell nuclei. However, in a small number of cells, the radioactive material was associated with the cell nuclei. Less radioactivity was present in the intermediate and posterior lobes. The pineal gland contained more silver grains than did other regions of the brain. The results obtained in the present study suggest essentially an action of dexamethasone in the medial basal hypothalamus and at the level of the pituitary.
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  • 76
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    Cell & tissue research 161 (1975), S. 167-176 
    ISSN: 1432-0878
    Keywords: Sphincter Oddi (Dog) ; Innervation ; Ultrastructure
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary The ultrastructure and acetylcholinesterase activity of the intrinsic innervation of the sphincter of Oddi of eight adult dogs was studied by electron microscopy. A rich distribution of unmyelinated axons embedded individually or as groups within Schwann cell cytoplasm (“innervation fasciculée”), is to be observed. A few myelinated fibres were also observed. Many of the axons are acetylcholinesterase-positive. Three main types of nerve terminals are distinguished according to their vesicle populations. Individual nerve cells or small groups of nerve cells were scattered between the smooth muscle bundles and in the lamina glandularis mucosae. The cytoplasm of some neurons contains many electron dense spherical bodies resembling “myeloid bodies”, and many lysosomes. Nerve terminals synapse onto both neuronal perikarya and their dendrites. Within the nerve fascicles, close appositions between the terminals occur frequently probably representing the most peripheral inter-neuronal integrative link in the neural regulation of the function of the sphincter of Oddi. — The gap between nerve terminals and smooth muscle cells usually measures several thousands of Å. Closer appositions are seldom seen, and no synaptic complexes can be observed.
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  • 77
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    Cell & tissue research 161 (1975), S. 413-419 
    ISSN: 1432-0878
    Keywords: Rectal papilla ; Insects ; Hymenoptera ; Cell Types ; Ultrastructure
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary The ultrastructure of the rectal papillae of the parasitoid hymenopteran, Nasonia vitripennis (Walk), is described. These organs in this insect consist of four distinct cell types arranged as a closed, hollow cone. The majority of the cells are present in the raised cone, and are characterised by large numbers of mitochondria arranged in a membranous labyrinth. A series of cells form a collar around the base of the cone. Junction cells have been identified which are present at the point of insertion of the cone into the rectal epithelium. The base of the cone consists of cells with elaborately folded plasma membranes facing both the central cavity of the cone, and the haemolymph. The structure of this rectal papilla is compared with those found in other insects.
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    Cell & tissue research 162 (1975), S. 253-269 
    ISSN: 1432-0878
    Keywords: Spermatheca ; Ultrastructure ; Cuticle ; Secretory cells ; Sperm storage ; Exocrine glands ; Insect
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary The spermatheca of the female mealworm beetle is an inflorescence of branching cuticular ducts which is connected to the bursa copulatrix via a cuticular neck surrounded by a muscular coat. The infolded bursal cuticle consists of a distinct outer epicuticle, inner epicuticle, procuticle, and a subcuticular zone; the latter is rich in mucopolysaccharides. The cuticle of the neck lacks a distinct procuticle. The cuticle of the spermatheca itself is mostly inner epicuticle with two thin underlying lamellae of procuticle. The cells of the bursa are loosely coupled to the procuticle, whereas cuticular projections bind the epithelia of the “neck” and the spermatheca proper to the underlying epithelia. The apical plasma membranes of the spermathecal epithelium are sinuous and much infolded; we believe that this epithelium controls the micro-environment within the cuticular ducts.
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    Cell & tissue research 162 (1975), S. 459-473 
    ISSN: 1432-0878
    Keywords: Carotid body ; Domestic fowl ; Reciprocal synapses ; Afferent axons ; Ultrastructure
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary Efferent and reciprocal synapses have been demonstrated in the carotid body of the domestic fowl (Gallus gallus domesticus). Synapses were also found with purely afferent morphology, but were probably components of reciprocal synapses. The general morphology of the endings suggested the presence of two types of axon, afferent axons making reciprocal and perhaps afferent synapses with Type I cells, and efferent axons making efferent synapses with Type I cells. A few axo-dendritic synapses were also found. The dense-cored vesicles associated with the afferent components of reciprocal synapses and with the possible true afferent synapses varied in diameter and core but could belong to one population of presynaptic vesicles. These observations are consistent with a new theory for the carotid body receptor mechanism. This proposes a spontaneously discharging afferent axon inhibited by an inhibitory transmitter substance released by the Type I cell via the “afferent” component of its reciprocal synapse, the “efferent” component inhibiting this release. Besides this chemoreceptor modulation of its afferent axon, the Type I cell may also have a general secretory function.
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    Cell & tissue research 162 (1975), S. 475-481 
    ISSN: 1432-0878
    Keywords: Annulate lamellae ; Parthenogenone ; Ultrastructure ; Rabbit
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary Previously it has been shown that, in the rabbit, although annulate lamellae (AL) are absent in the follicular oocytes, they appear in the fertilized eggs after the formation of the pronuclei. Furthermore, neither pronuclei nor AL appear when unfertilized eggs are aged in vivo or in vitro. This study was undertaken to determine whether AL formation requires presence of an intact nucleus, or whether the sperm alone contains the stimulatory factors essential to AL synthesis. Rabbit eggs were exposed to 10°C, then incubated for 24 hours. Control eggs were incubated without cold-treatment. Electron microscopic observations indicated that two-thirds of the eggs formed one or two ‘pronuclei,’ or subnuclei. The remainder one-third of the cold-treated eggs and the control eggs failed to form ‘pronuclei.’ AL were present in large amounts only in those activated eggs (parthenogenones) which formed ‘pronuclei.’ AL were absent in the control and the non-activated experimental eggs, both of which failed to form a ‘pronucleus.’ A few small AL were observed in eggs with subnuclei. Condensed fine textured nucleoli appeared precociously during cold-treatment in some eggs and they were present in the ‘pronuclei’ of activated eggs. It was concluded that the sperm is not necessary for AL formation, but the presence of an intact nucleus is mandatory.
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    Cell & tissue research 164 (1975), S. 11-26 
    ISSN: 1432-0878
    Keywords: Intermediate lobe ; Mouse ; Growth and development ; Ultrastructure
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary The development of the intermediate lobe of the hypophysis was studied in the embryonic C3H mouse; at least four glands from embryos of every gestational day from 15 to 19 were examined. In the 16 day-old embryo prospective secretory cells proliferate at the centre of the intermediate lobe anlage. At the same stage cylindrical cells bordering the hypophyseal cleft begin to reorganize into marginal cells. By the end of fetal life marginal cells are well differentiated. In the 17 day-old embryo a few granular inclusions appear in some centrally located cells. Secretory cells increase in number during the following two embryonic days. Some of these cells contain polymorphic populations of granular and vesicular inclusions by gestational day 19. The possibility of a dual formation of secretory inclusions is discussed. The result implies that the onset of granule-formation by these cells is not contemporaneous with the start of production of melanophore-expanding substances, the presence of which has been detected by earlier biological assays.
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    Cell & tissue research 164 (1975), S. 215-232 
    ISSN: 1432-0878
    Keywords: Ultimobranchial glands ; Anuran larvae ; Metamorphosis ; Ultrastructure
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary A comparative optical microscopic and ultrastructural study on the ultimobranchial (UB) glands of three common species of Israeli anurans: Bufo viridis, Hyla arborea, and Rana ridibunda during metamorphosis is presented. The UB glands typically consist of a single follicle with a central lumen, though occasionally secondary follicles are present in Hyla and Rana. A single UB cell type is found which appears either in a very electrondense “dark” form or as a less dense “light” form, though the ratio of dark: light cells from gland to gland at any one stage of metamorphic development is quite variable. By the end of metamorphosis in Bufo and Hyla all the UB cells are usually of the light variety, whereas in Rana the dark cells persist. The organelles of these secretory cells including secretory granules, granular endoplasmic reticulum, free ribosomes, tonofilaments, microtubules, Golgi bodies, and lipid droplets, their distribution, abundance, and possible functions in relation to metamorphosis are described. Apocrine secretion into the central lumen of the gland is also described and discussed.
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  • 83
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    Keywords: Flight muscle ; Denervation ; Peripheral Wallerian degeneration ; Metamorphic axon degeneration ; Antheraea (Lepidoptera) ; Trophic action ; Ultrastructure
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary In the moth Antheraea polyphemus the innervation of the anlage of the dorsolongitudinal flight muscle (dlm) was transected at the onset of adult development. The subsequent breakdown of the isolated motor stumps during early adult development was studied at the ultrastructural level. First reactions are seen on the second day of development when axonal mitochondria shrink. Later, elongated vesicles similar in structure to channels of smooth ER, appear in large numbers in the axoplasm. Their nature as well as the functional aspects of early axonal changes are discussed. From the 7th day onward two types of axonal breakdown become prominent. The first is characterized by swelling axon profiles, distorted vesicles and strongly shrunken mitochondria, while shrinking axon profiles containing tightly packed mitochondria and unaltered vesicles are typical of the second. Both types presumably take place independently of each other in different axon terminals. Axons and the contents of at least the first type are finally removed by transformation into lamellar bodies. Glial processes obviously behave independently of degenerating terminals; they loose any contact with them and never act as phagocytes for axon remnants. During the whole period of breakdown undifferentiated contacts between nerve fibers and muscle anlagen are present but synaptic structures as in normal developing dlm have never been observed. This fact, in comparison with earlier studies, suggests a lack of trophic nervous activity on the muscle anlagen tissue. A short time after removal of the isolated stumps new nerve tracts appear between dlm-fibers (which are, of course, strongly retarded in development). They are presumably sensory wing nerves which lack a guide structure to the central target, due to axotomy. Neuromuscular contacts or even junctions formed by axons of these nerves have occasionally been detected on the dlm. Their nature is discussed. Wallerian axon degeneration is compared to the normal, metamorphic breakdown of the innervation of the larval dlm-precursor. In contrast to the former, glial processes here remain in contact with the terminals. Glia and axons first swell. Then most glial processes are transformed into lamellar bodies whereas neuntes shrink and become electron-dense. Axonal organelles remain intact for a long period.
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    Cell & tissue research 164 (1975), S. 447-456 
    ISSN: 1432-0878
    Keywords: Protein secretion ; Protein synthesis ; Salivary glands ; Rat
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary The effect of pilocarpine and food uptake on the rate of incorporation of [3H]-leucine in vivo was measured by means of quantitative radioautography in three exocrine cells of the rat: the acinar and the granular duct cells of the submandibular and the acinar cells of the parotid gland. The three cell types react differently. The submandibular acinar cells showed a decrease in incorporation rate after pilocarpine administration but not after feeding. The incorporation rate of the granular duct cells of the submandibular gland remains constant after both stimulations. The acinar cells of the parotid gland show an increase in incorporation rate of [3H]-leucine in response to both. The contrast between the submandibular and the parotid gland could also be demonstrated radiobiochemically, the results reflecting the incorporation rates of the acinar cells of both glands, giving no information on the contribution of other cell types. The decrease in incorporation rate of the submandibular gland acinar cells is accompanied by a shift of polyribosomes towards monomers.
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    Cell & tissue research 164 (1975), S. 457-466 
    ISSN: 1432-0878
    Keywords: Protein secretion ; Protein synthesis ; Salivary glands ; Rat
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary After stimulation of the protein secretion by pilocarpine or feeding the rate of incorporation of [3H]-leucine increases in the acinar cells of the parotid gland of the rat while the secretory cells of the submandibular gland show a moderate decrease (Kuijper et al., 1975b). Since the rate of labelled amino acid incorporation depends on the specific radioactivity of the amino acid used, which is not easy to determine in vivo, experiments in vitro were performed to get an idea of the influence of this factor on the measured changes in [3H]-leucine incorporation. In vitro both cell types showed a more pronounced but essentially identical reaction as in vivo. Since in these experiments the specific radioactivity of the extracellular leucine is the same whether fragments of stimulated or unstimulated glands incorporate the radioactive amino acid, the increase of incorporation in the parotid and the decrease in the submandibular cells cannot be ascribed to differences in specific radioactivity of leucine, unless the intracellular leucine pool should show great differences between secreting and non-secreting cells. However, in vitro the submandibular gland cells under both conditions appear to use the extracellular leucine for their protein synthesis (or a small compartmentalized pool in rapid exchange with the extracellular pool). In the parotid cells the whole intracellular pool showed such a rapid exchange with the extracellular one that for practical reasons one may say that these cells, too, rely on the extracellular specific radioactivity of leucine in their protein synthesis. We conclude that the rat parotid gland cells show a rapid and substantial increase of protein synthesis after stimulation of their enzyme secretion, while the submandibular gland cells do not.
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    Cell & tissue research 164 (1975), S. 503-517 
    ISSN: 1432-0878
    Keywords: Optic system ; Ouabain ; Axoplasmic flow ; Wallerian degeneration ; Ultrastructure
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary The cardiac glycoside ouabain was injected into the eye-bulb of the teleost fish, Carassius carassius. Three doses of ouabain were used: 10-4 M, 10-5 M, 10-6 M. The final concentrations in the vitreous body of the eye were approximately 3 · 10-5 M, 3 · 10-6 M and 3 · 10-7 M, respectively. After 8 hrs, 1,2,4,6 and 8 days the ultrastructural alterations of retinal ganglion cells, the optic axons near the bulb and the terminal segments in the optic tectum were studied. The high doses of ouabain induced an early necrobiosis of the cell bodies in the retina followed by degeneration in the nerve. This is characterized as a protracted form of Wallerian degeneration. The significance of the inhibition of Na+-K+-activated ATPase at the perikaryal level for both the integrity of axonal morphology and the axonal flow is discussed.
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  • 87
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    Cell & tissue research 165 (1975), S. 135-139 
    ISSN: 1432-0878
    Keywords: Adrenal cortex ; Gerbils ; Castration ; Steroids ; Ultrastructure
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary The effect of ovariectomy on the adrenal gland was studied in the Mongolian gerbil. Castration stimulated cells in the zona fasciculata as well as those in the region between the zona fasciculata and zona reticularis. No alterations occurred in the zona reticularis. The width of the intermediate region was enlarged, the cells were hypertrophic and contained an increased number of concentric whorls of rough endoplasmic reticulum. Smooth endoplasmic reticulum was hypertrophie in cells of the zona fasciculata and intermediate region. Many mitochondria in cells of the intermediate region were larger than those in controls. Stimulation of cellular ultrastructure is directly correlated with a significant elevation in plasma cortisol in ovariectomized gerbils.
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  • 88
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    Cell & tissue research 157 (1975), S. 283-305 
    ISSN: 1432-0878
    Keywords: Microbodies ; Kidney ; Proximal tubule ; Ultrastructure ; Cytochemistry
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary The present study was undertaken to provide a detailed morphological and cytochemical characterization of the microbodies of the rat renal proximal tubule following perfusion fixation. The following observations were made: 1) Two basic types of microbodies (Mb-I and Mb-II) can be identified. Mb-I have both circular and tubular profiles which are located peripherally within the granular matrix of these microbodies. Mb-II have marginal plates and crystalloid inclusion in addition to circular and tubular profiles. 2) Circular and tubular profiles, 100 nm in diameter, described by previous investigators as being infrequent in occurrence, are the most consistent morphological characteristic of rat renal microbodies after perfusion fixation. These profiles have a homogeneous center surrounded by a double or single ring of granules. The uniform size and spacing of these granules within profiles establish a basic 100 Å periodicity found in both types of microbodies. 3) Evidence is presented which suggests that both “nucleoids” and “tubular protrusion rods” as described by other investigators of the rat renal microbodies may result from poor fixation and/or osmotic stress. 4) The density of the matrix of Mb-I is, in contrast to previous reports, greater than the density of adjacent mitochondria. 5) Marginal plates or crystalloid inclusions were demonstrated in some microbodies (Mb-II) of all the rats studied; periodicities of 100, 200, and 300 Å were identified within these structures. 6) Both types of microbodies were positive for catalase activity, but were negative for acid phosphatase activity. On the basis of both morphological and cytochemical criteria, it seems plausible that these two populations of renal microbodies (Mb-I and Mb-II) represent a morphological and functional continuum.
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  • 89
    ISSN: 1432-0878
    Keywords: Sympathetic ganglia ; Nerve growth factor ; Enzyme induction ; Ultrastructure ; Morphometry
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary Nerve cells of the superior cervical ganglion of young rats (20 g body weight) were investigated electron microscopically 6 h, 24 h, 48 h and 5 days after subcutaneous injection of nerve growth factor (10 μ/g body weight every 24 h). By means of a planimetric method with high accuracy significant changes of the Nissl substance and the Golgi apparatus could be demonstrated as early as 6 h after injection. Within the Nissl bodies both the density of bound ribosomes on the cisternae of the rough endoplasmic reticulum and the density of free ribosomes and polysomes decreased in a given field. This finding reflects a rearrangement of the Nissl substance and a spreading over larger areas of the cytoplasm, indicating an activation of the ribosomal system. The Golgi apparatus, in particular its outer part, increases in volume with time of nerve growth factor treatment. On the other hand, the total cell volume does not show significant changes before 48 h of nerve growth factor treatment. At this time an increase in the cytoplasmic volume can be seen, whereas the nuclear volume remains unchanged. The possibility of correlations of the present findings with data from biochemical studies done under similar experimental conditions is discussed.
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  • 90
    ISSN: 1432-0878
    Keywords: Median eminence ; Agranular and granular vesicles ; Horseradish peroxidase ; Castration ; Ultrastructure
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary In the median eminence of male rats, nerve profiles in the immediate vicinity of portal capillaries have been divided into 4 categories on the basis of their vesicular content: profiles a with agranular “synaptic” vesicles of about 50 nm, b with similar agranular vesicles and also with granular vesicles of mainly 60–140 nm, c with granular vesicles alone and d without vesicles. Twenty-four hours after castration, the percentage of profiles of category a was significantly increased when compared with sham-operated animals, whereas the percentage of profiles of category b was significantly decreased. After intravenous injection of exogenous peroxidase, especially the nerve profiles located in direct contact with the outer basement membrane of the portal capillaries contained peroxidase positive “synaptic” vesicles. Injection off peroxidase after castration resulted in a significant increase in the percentage of nerve profiles containing both peroxidase positive and peroxidase negative “synaptic” vesicles (category a). It is suggested that, in certain nerve terminals, castration may lead to release off the content of granular vesicles, which may contain gonadotropin releasing factor. This release then may cause that nerve terminals with both agranular vesicles and granular vesicles (category b) change in their vesicular content and are therefore classified as terminals with only agranular vesicles (category a). An increased turnover rate in the ultrastructurally affected terminals may be reflected in increased uptake of exogenous peroxidase. The observations imply that certain neurones projecting to portal capillaries in the median eminence are, directly or indirectly, sensitive to changes in the level of gonadal steroids.
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  • 91
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    Cell & tissue research 159 (1975), S. 49-62 
    ISSN: 1432-0878
    Keywords: Autonomic ganglia ; Pelvic plexus ; SIF cells ; Rat
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary To further evaluate the role of autonomic ganglia in the regulation of pelvic visceral activity, the neural elements in the major pelvic ganglion of the male rat have been studied with histochemical and electron microscopic techniques. The principal findings are that the ganglion is composed of cholinergic and adrenergic ganglion cells as well as small intensely fluorescent (SIF) cells. Polarity in the ganglion is indicated by clustering of small ganglion cells which stain intensely for acetylcholinesterase (AChE) along the pelvic nerve while larger cells, with weak to moderate AChE activity, collect near small branches of the hypogastric nerve. Some cholinergic ganglion cells are enclosed by a plexus of adrenergic terminals. SIF cells appear to be in contact with both cholinergic and adrenergic cells, although many of the fluorescent beads around adrenergic neurons may be short dendrites of ganglion cells, rather than processes of SIF cells. Two types of SIF cells may be distinguished on the basis of size and morphology of their granulated vesicles. Afferent synapses of the cholinergic type were common on SIF cells of the large granule and small granule type. Portions of SIF cells with large granules occur within the capsule of ganglion cells. Contacts seen here were interpreted as efferent synapses from SIF cells to the dendrites of ganglion cells.
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  • 92
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    Cell & tissue research 159 (1975), S. 287-290 
    ISSN: 1432-0878
    Keywords: Stannius bodies ; Euryhaline teleosts ; Calcium regulation ; Ultrastructure
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary In the corpuscles of Stannius of sticklebacks and eels two cell types are described of presumably endocrine nature. The predominating type, comparable to the cells observed in other species, responds to variation in calcium content of the medium and possibly produces a hypocalcemic hormone. The second cell type is unreactive to calcium. Since it is more active in freshwater than in seawater specimens, this cell type is possibly involved in ionic regulation. It was not found in two seawater teleost species.
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  • 93
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    Cell & tissue research 159 (1975), S. 369-378 
    ISSN: 1432-0878
    Keywords: Crab muscle ; Excitation-contraction coupling ; Glycerol treatment ; Horseradish peroxidase ; Ultrastructure
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary The ultrastructure of normal and glycerol treated fibers of the closer muscle of the ghost crab, Ocypode cursor, was studied. The muscle is composed of presumably phasic (short sarcomeres) and tonic (long sarcomeres) fibers, the latter greatly predominating. Horseradish peroxidase (HRP) was used as an extracellular tracer to delineate the tubular system (TS), and to determine to what extent this system becomes detached from the extracellular space as a result of glycerol treatment. Sarcolemmal clefts invade deeply into the muscle at Z-lines and I-bands; tubules invaginate into the muscle from the clefts and from the surface sarcolemma at the Z-lines, A-I overlaps and A-bands. A tubules are in frequent diadic or tetradic contact with the sarcoplasmic reticulum (SR), whereas Z tubules appear to be randomly associated with SR, terminal cisterns (TC) and Z-line fibrils. When HRP was administered to normal muscle, black reaction product was found adjacent to the outer surface of the sarcolemma, within the clefts and within profiles of the TS throughout the tissue. In glycerol treated muscle peripheral vacuolation frequently occurred; black reaction product penetrated only as far as the vacuoles and into dilated Z-line tubules, but was virtually absent from the rest of the TS. This lack of continuity between the extracellular space and the A tubules indicated disruption or constriction of the A tubules as a result of glycerol treatment, although Z tubule contact with the extracellular space appeared unimpaired. These findings provide ultrastructural correlates of the electrophysiological changes produced by glycerol treatment of the closer muscle of the ghost crab (Papir, 1973), namely, interference with excitation-contraction (e-c) coupling. The random association of the Z tubules with SR and TC, and their resistance to disruption by glycerol treatment, tend to endorse the claims that the Z tubules in crustacean muscle are not directly involved in e-c coupling (Brandt et al., 1965; Peachey, 1967; Selverston, 1967).
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  • 94
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    Cell & tissue research 160 (1975), S. 99-112 
    ISSN: 1432-0878
    Keywords: Pineal organ ; Blind cave fish (Astyanax mexicanus) ; Continuous illumination and darkness ; Ultrastructure ; Degeneration, photoreceptor outer segment
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary Ultrastructural changes of the pineal organ were investigated in the blind cave fish, Astyanax mexicanus, kept under continuous artificial light (5000 lux), in continuous darkness, and under natural light conditions. The pineal end-vesicle of the fish kept under natural photoperiod consisted of photoreceptor cells and supporting cells mixed with a few ganglion cells. The photoreceptor cells possessed well-developed outer segments with regularly arranged lamellar membranes. The supporting cells contained a number of lipid droplets and large globular cisternae filled with fine granules. In the fish kept under continuous light or in darkness, the pineal end-vesicle displayed a dilated lumen, and the outer segments of the receptors showed signs of degeneration. Furthermore, alterations of cell organelles were observed in the photoreceptor and supporting cells.
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  • 95
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    Cell & tissue research 161 (1975), S. 225-237 
    ISSN: 1432-0878
    Keywords: Muscle adaptation to isometric training (Rat) ; Muscle fiber types ; Ultrastructure
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary The soleus, reetus femoris, and gastrocnemius muscles of young rats trained isometrically for 4 weeks were studied by light and electron microscopy.—The percentage of fast-twitch oxidative muscle fibers decreased at the cost of the fast-twitch glycolytic fibers in the rectus femoris muscle. The percentages of the slow-twitch oxidative fibers did not change significantly in any of the muscles studied. The changes in the areas of the muscle fibers were specific for the muscle and the fiber type and indicate geometrical rearrangements of the fibers in the trained muscles. The Z and M lines were broader in the soleus (containing about 85% slow-twitch oxidative fibers) than in the rectus femoris muscle (containing about 90% fast-twitch glycolytic fibers), while the sarcomere length and the pseudo-H zone were similar. The length of the myosin filaments appeared to be slightly shorter in the fast rectus femoris than in the slow soleus muscle.—The hypothesis on the temporal progress of muscle adaptation to training (Müller, 1974) was substantiated. Correlations between biochemical (Exner et al., 1973a) and histochemical parameters measuring the oxidative capacity were preserved during adaptation to training. The comparison of the histochemical results with the physiological data on similar animals (Exner et al., 1973a) suggests a complex relationship between the contraction time and the percentage of fast-twitch muscle fibers.
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  • 96
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    Cell & tissue research 161 (1975), S. 239-261 
    ISSN: 1432-0878
    Keywords: Adenohypophysis ; Teleosts (Poecilia, latipinna) ; Cell types ; Ultrastructure
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary In the sailfin molly, Poecilia latipinna, seven morphological endocrine celltypes could be distinguished with the electron microscope. Each of these was identified with one of the seven cell-types distinguished with the light microscope, to most of which endocrine functions have previously been allocated. Corticotrophs and prolactin cells form the rostral pars distalis, and the proximal pars distalis consists of an outer layer of gonadotrophs and an inner zone containing growth hormone cells and thyrotrophs. The pars intermedia contains two cell-types, of uncertain function. Stellate cells (interstitial cells) occur throughout the adenohypophysis, but are most numerous and prominent in the rostral pars distalis. The inner proximal pars distalis contains a cell-type not previously distinguished in this species with the light microscope, the Z-cell, which could be aminergic. The ultrastructural features of each cell-type are described in detail, and discussed in comparisons with the homologous cells described in other teleosts. There is good agreement for different teleosts in the ultrastructural details of each cell type.
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  • 97
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    Cell & tissue research 162 (1975), S. 395-410 
    ISSN: 1432-0878
    Keywords: Larval corpus allatum ; Activity cycles ; Lepidoptera ; Ultrastructure
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary The corpora allata of the three last larval instars were studied in newly molted animals, at the beginning, middle, and end of the feeding period, and during the molt period. They were found to consist of uniform gland cells, whose ultrastructure changes in the course of the instars. In gland cells considered to be resting, the outer and inner nuclear membranes run in parallel without forming a dilated perinuclear space. Mitochondria are small, polymorphic, with an electron-dense matrix. The smooth endoplasmic reticulum (SER) appears as stacks of parallel cisternae near the nuclear envelope and in the rest of the cytoplasm, and as accumulations of twisted profiles. Occasionally, the SER takes the form of paracrystalline bodies. There are few small smooth-surfaced vesicles in the cytoplasm. In cells considered as active, a dilated perinuclear space occurs. The peripheral ends of profiles forming the SER are swollen, and numerous vesicles and vacuoles bud off from them to fill the cytoplasm. Mitochondria are large, with a more transparent matrix. The plasma membrane of gland cells located just beneath the connective tissue sheath forms numerous small invaginations. The corpora allata consist of resting cells during the molt periods. At the beginning of each instar, few active gland cells appear. In the middle of the second to last and the third to last instars, the bulk of the gland cells is active. At the end of these instars, there are both active and inactive cells. In the middle of the last instar, the gland cells are inactive or subactive, and at its end, all gland cells are completely inactive.
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  • 98
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    Cell & tissue research 162 (1975), S. 483-497 
    ISSN: 1432-0878
    Keywords: Carotid body ; Domestic fowl ; Ultrastructure
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary Electron microscopic studies of the carotid body of the domestic fowl (Gallus gallus domesticus) have shown Type I and Type II cells combined with axons into compact groups. The many Type I cells in the depths of the organ had a body, containing the nucleus, and an elongated, flared process. Some of the Type I cells in the superficial regions tended to be spindle-shaped. Type I cells were characterised by membrane-bound, dense-cored vesicles about 120 nm in diameter. Type II cells invested the Type I cells and had axons embedded in them as in Schwann cells. The fine structure of the carotid body in the domestic fowl resembles that of the Lovebird (Uroloncha domestica) and of various amphibia and mammals. The possibility is discussed that the Type I cells may have a chemoreceptor or a general secretory function, or even both pathway for functions together. The main role of the Type II cells seems to be to provide a of these axons leading to or from Type I cells.
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  • 99
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    Cell & tissue research 164 (1975), S. 85-104 
    ISSN: 1432-0878
    Keywords: Swimbladder ; Opsanus tau ; Physoclist ; Ultrastructure
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary The anterior chamber of the swimbladder of the toadfish Opsanus tau L. is lined by a single layer of columnar gas gland cells, cuboidal cells that resemble gas gland cells but are located outside of the gas gland region, and squamous cells. Multilamellar bodies are numerous in the gas gland cells and the cuboidal cells and are present in smaller numbers in the squamous cells. Capillaries lie in the lamina propria directly below the epithelial lining. A thick continuous muscularis mucosae and a submucosa consisting of tightly packed cells, cell processes, and connective tissue may contribute to the impermeability to gases of the wall of the anterior chamber. The posterior chamber of the swimbladder is lined by a single type of squamous epithelial cell. Multilamellar bodies were occasionally observed in these cells also. Other types of cells frequently form a partial second layer between the epithelial lining and the basement lamina. A thin muscularis mucosae lies directly below the basement lamina and the capillaries of the posterior chamber are located in the submucosa. The tunica externa is a layer of dense connective tissue that surrounds both the anterior and posterior chambers. Collagen fibrils in the form of tactoids are present in this layer.
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  • 100
    ISSN: 1432-0878
    Keywords: Granulosa lutein cells ; Western spotted skunk ; Ultrastructure ; Progesterone levels ; Implantation
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary The ultrastructure of corpora lutea obtained during the preimplantation, implantation and early postimplantation periods has been studied in 20 western spotted skunks. Fine structure of granulosa lutein cells was correlated with progesterone levels. The corpus luteum of the prolonged (7 month) preimplantation period contained undifferentiated small granulosa cells and differentiated large granulosa lutein cells. The former ranged in size between 12 and 20 μ and the latter between 20 and 45 μ. The ratio of small and large cells was about equal in an animal 2 days prior to nidation whereas only few small cells and numerous large cells were observed in an animal estimated to be 8 to 12 hours from nidation. Occasionally small cells were observed amidst large ones during the 24 hour nidation period, i.e. adhesion of trophoblast with the luminal uterine epithelium, but small cells were absent in animals after this period. Small cells had some smooth and rough endoplasmic reticulum, rod-shaped mitochondria with platelike cristae, small Golgi complex, and relatively smooth plasma membranes. Large lutein cells had abundant smooth endoplasmic reticulum, membranous whorls of smooth endoplasmic reticulum, usually round mitochondria with tubular and lamellar cristae, a well developed Golgi complex, variable amounts of lipid droplets, and highly plicated and ruffled plasma membranes. Peripheral plasma progesterone levels during the prolonged preimplantation period ranged between 1.1 and 7.9 ng/ml, but during implantation it was between 8 and 16.6 ng/ml. It is suggested that plasma progesterone levels fluctuate during the time of implantation and should not be regarded as a basis to predict actual nidation in the western spotted skunk.
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