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  • Electronic Resource  (7,922)
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  • 1980-1984
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  • 1
    Electronic Resource
    Electronic Resource
    Maligne Entartung der Colitis ulcerosa im Experiment (1976)
    Springer
    Langenbeck's archives of surgery 343 (1976), S. 307-311 
    Details
    ISSN: 1435-2451
    Keywords: Ulcerative colitis ; Carrageenan ; 1,2-Dimethylhydrazine ; Adenocarcinoma ; Rat
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Description / Table of Contents: Zusammenfassung Im Tierversuch wurde die Frage geprüft, ob der Dickdarm bei bestehender Colitis zur malignen Entartung disponiert ist. Männliche Wistarratten erhielten nach Induktion einer Colitis ulcerosa (durch Verabreichung von 4%igem Carrageenan im Trinkwasser) das dickdarmspezifische Karzinogen 1,2-Dimethylhydrazin (DMH; Gesamtdosis 132 mg/kg Körpergewicht subcutan während 7 Wochen). 17 von 18 Tieren entwickelten 15 Wochen nach der letzten Injektion des Karzinogens multiple Adenocarcinome im distalen Colon; dieser Dickdarmabschnitt war auch der bevorzugte Ort der Carrageenan-induzierten Colitis. In einem Kollektiv von Kontrolltieren (n = 18), welche nur DMH erhalten halten, erkrankten im gleichen Zeitraum lediglich 3 Ratten an einem Coloncarcinom. Der Unterschied ist statistisch signifikant (P 〉 0,01). Carrageenan allein wirkte nicht als Karzinogen. Die Ergebnisse unserer Untersuchungen zeigen, daß die Colitis ulcerosa auch im Tierversuch als Krebsrisikokrankheit aufzufassen ist.
    Notes: Summary Animal experiments were performed to answer the question whether ulcerative colitis is predisposed to malignant degeneration.-Male Wistar rats were given aqueous solutions of degraded Carrageenan (4%; w/v). After induction of ulcerative colitis, 1,2-Dimethylhydrazine (DMH; 132 mg/kg body weight) was applicated during a period of 7 weeks. 17 of 18 rats developed multiple adenocarcinomas in the distal colon 15 weeks after the last injection of DMH. The Carrageenan induced colitis was localized predominantly in the distal part of the large bowel. Only 3 rats of a control group of 18 animals exposed to DMH only showed carcinomas of the colon. The difference is proven significant (P 〈 0.01). Carrageenan for itself caused no malignancy.-The results of the experiments demonstrate that, during ulcerative colitis, the colon of the rat is more susceptible to induction of cancer than the intact one.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF01300577
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  • 2
    Electronic Resource
    Electronic Resource
    Autoradiographische und elektronenmikroskopische Untersuchungen an der Rattenleber nach experimenteller Blockade des Ductus thoracicus in Höhe des linken Venenwinkels (1976)
    Springer
    Research in experimental medicine 168 (1976), S. 173-186 
    Details
    ISSN: 1433-8580
    Keywords: Rat ; liver damage ; thoracic duct ; thermocoagulation ; lymphedema ; 3H-thymidine ; autoradiography ; electron microscopy ; Ductus-thoracicus-Blockade ; Rattenleber ; 3H-Thymidin ; Elektronenmikroskopie
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Description / Table of Contents: Zusammenfassung Bei 90 männlichen und weiblichen, weißen Sprague Dawley Ratten wurden autoradiographische Untersuchungen mit3H-Thymidin nach experimenteller Blockade des Ductus thoracicus unternommen. Dabei zeigte sich im akuten Versuch kein nennenswerter Einfluß der intrahepatischen Lymphstase auf den DNS-Einbau in die Kerne der Hepatozyten bzw. Sternzellen. Bei den Langzeittieren (20–360 Tage) lagen die Markierungsindices der Hepatozyten geringfügig über denjenigen gleich alter, gesunder Kontrolltiere. Bei 14 männlichen und weiblichen, weißen Sprague Dawley Ratten führten wir zusätzlich elektronenmikroskopische Untersuchungen in der Leber durch. Dabei fanden sich im akuten Versuch ein intra- und extra-zelluläres Ödem sowie Schädigungen läppchenperipherer Hepatozyten. Nach 12–15 Tagen haben sich diese Veränderungen weitgehend zurückgebildet. Somit scheint eine intrahepatische Lymphstase keinen nachhaltigen Einfluß auf das Regenerationsverhalten der Leberzellen auszuüben.
    Notes: Summary Autoradiographic studies with3H-thymidine were done in 90 male and female white Sprague Dawley rats following thermocoagulation of the thoracic duct at the base of the neck. In the acute stages of these experiments we were unable to find any significant influence of a lymphedema on the hepatocytes and Kupffer cells. In the longterm experiments the labelling indices of the hepatocytes were slightly above those of healthy controls of the same age. In another 14 male and female white Sprague Dawley rats we did electron microscopical investigations of the liver. In the acute phase of the experiment we found an intra- and extrahepatic edema as well as damages of the hepatocytes at the periphery of the liver acini. After 12–15 days these findings have regressed. It seems therefore that an intrahepatic lymphedema does not influence the regenerative capacity of the liver to a marked extend.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF01851315
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  • 3
    Electronic Resource
    Electronic Resource
    Time sequence and site of fluid accumulation in experimental neurogenic pulmonary edema (1976)
    Springer
    Research in experimental medicine 168 (1976), S. 219-227 
    Details
    ISSN: 1433-8580
    Keywords: Initial phase of neurogenic pulmonary edema ; Perfusion fixation ; HRP ; Electron microscopy
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary The initial phase of pulmonary edema development following intracranial pressure elevation was studied by means of transmission electron microscopy. Using perfusion fixation and application of a blood tracer (HRP horseradish peroxidase) the time sequence and site of fluid leakage out of pulmonary vessels was demonstrated: - passage of edema fluid through intercellular clefts of alveolar capillary endothelium - edema accumulation in alveolar interstitial tissue - draining of edema fluid from the alveolar septum to the interstitium of terminal bronchioli and to lymphatic vessels. An early interepithelial fluid leakage out of the alveolar wall remains questionable.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF01851320
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  • 4
    Electronic Resource
    Electronic Resource
    Metabolism and ultrastructure in ovaries of alloxan-diabetic juvenile rats (1976)
    Springer
    Archives of gynecology and obstetrics 220 (1976), S. 199-208 
    Details
    ISSN: 1432-0711
    Keywords: Rat ovaries ; Diabetes mellitus ; Alloxan ; ATP/ADP ; Lactate/pyruvate ; NADP/NADPH ; Glucose ; Protein content ; Hydrogen-coveying enzymes ; alkal. phosphatase ; Electron microscopy
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Description / Table of Contents: Zusammenfassung Es wurde der Einfluß eines alloxan-induzierten Diabetes mellitus auf den Stoffwechsel und die Ultrastruktur juveniler Rattenovarien untersucht. Der Diabetes mellitus bewirkte folgende Änderungen imStoffwechsel: Abfall der Konzentration von ATP und NADPH, Anstieg des Lactat/Pyruvat-Quotienten über 40, Abfall des ATP/ADP-Quotienten unter 1, Aktivitätsminderung der wasserstoffübertragenden Enzyme G-6-DH, Isocitrat-DH, Malat-DH, Aktivitätszunahme der alkalischen Phosphatase, Erniedrigung des Proteingehaltes.Ultrastruktur: Nahezu vollständiges Verschwinden des rauhen endoplasmatischen Reticulums, Schrumpfung der Mitochondrien, Reduktion der cristae und Kondensation der Matrix. Das glatte endoplasmatische Reticulum bleibt unverändert, der Golgi-Komplex ist in seiner Ausdehnung reduziert. Leichte Extrahierbarkeit der Lipiddepots. Die Befunde sprechen für eine Hemmung der oxydativen Phosphorylierung sowie für eine Beeinträchtigung des Steroid- und Proteinstoffwechsels.
    Notes: Summary Tests were carried out on the influence of alloxan-induced diabetes mellitus on the metabolism and the ultrastructure of ovaries of juvenile rats. The diabetes mellitus caused the following changes in themetabolism: reduction in the concentration of ATP and NADPH, increase in the lactate/pyruvate quotient to above 40, reduction in the ATP/ADP quotient to below 1, reduction in the level of activity of the hydrogen-conveying enzymes G-6-P-dehydrogenase, isocitrate dehydrogenase and malate dehydrogenase, increase in the level of activity of the alkaline phosphatase, reduction of the protein content. Ultrastructure almost complete disappearance of the rough endoplasmic reticulum, shrinkage of the mitochondria, reduction of the cristae and condensation of the matrix. The smooth endoplasmic reticulum remains unchanged, the extent of the Golgi-complex is reduced. Easy removal of the lipid deposits.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00667748
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  • 5
    Electronic Resource
    Electronic Resource
    Ultrastructural study of testis in testicular feminization (1976)
    Springer
    Archives of gynecology and obstetrics 221 (1976), S. 277-287 
    Details
    ISSN: 1432-0711
    Keywords: Electron microscopy ; Endocrinology ; Pathology ; Testicular feminization ; Testis
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary Testicular tissue was investigated by electron microscopy in a case of testicular feminization. The seminiferous tubules were lined by spermatogonia and by Sertoli cells. Spermatocytic maturation was not observed. Leydig cells were numerous and contained well developed, abundant vesicular smooth-surfaced endoplasmic reticulum and large mitochondria with tubulovesicular cristae. Reinke crystalloids were absent. The ultrastructural findings were consistent with the assumption that Leydig cells were under adequate stimulation and were in a stage of active secretion. Hence, the results seem to indicate that testicular endocrine function was maintained in the studied case.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00667021
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  • 6
    Electronic Resource
    Electronic Resource
    Effect of peripheral axotomy on the fine structure and histochemistry of the Rolando substance: Degenerative atrophy of central processes of pseudounipolar cells (1976)
    Springer
    Experimental brain research 26 (1976), S. 73-87 
    Details
    ISSN: 1432-1106
    Keywords: Rolando substance ; Degeneration ; Atrophy ; Axotomy ; Histochemistry ; Electron microscopy
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary Disappearence of fluorid-resistant acid phosphatase activity from the ipsilateral Rolando substance after transection of the peripheral nerve, is shown to be due to the cessation of enzyme supply from dorsal root ganglion cells to their central terminals. This is accompanied by (or ensues in consequence of) a fine structural derangement of these terminals (“degenerative atrophy”). Fine structural alterations of axon terminals undergoing degenerative atrophy, though similar to some extent to those seen during early phases of a Wallerian degeneration, are markedly different. Also myelinated nerve fibers, both in the dorsal horn and in dorsal columns, are affected by degenerative atrophy. This important, new trophical feature of sensory ganglion cells suggests a delicate metabolic balance between peripheral and central axonal branches of bipolar (pseudounipolar) cells. Degenerative atrophy raises serious implications in evaluating hodological experiments based upon Wallerian degeneration and offers new perspectives for theoretical and clinical neurology.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00235250
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  • 7
    Electronic Resource
    Electronic Resource
    Quantitative ultrastructural observations on the inhibited recovery of the hypoglossal nucleus from the axotomy response when regeneration of the hypoglossal nerve is prevented (1976)
    Springer
    Experimental brain research 26 (1976), S. 141-150 
    Details
    ISSN: 1432-1106
    Keywords: Rat ; Hypoglossal nucleus ; Inhibited regeneration ; Ultrastructure
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary Electron micrographs of the left hypoglossal nucleus were quantitatively analyzed in adult rats 52 to 98 days after transection of the left hypoglossal nerve and implantation of the proximal stump into the already innervated ipsilateral sternomastoid muscle, a procedure which prevented the transected nerve from regenerating. Many presynaptic boutons with clear spherical synaptic vesicles and symmetrical synapses were lost from the injured perikarya and dendrites. Some perikarya and dendrites (and, rarely, boutons) became electron dense, and astrocyte or microglial sheaths partly surrounded them. Numbers of dendrite profiles in the neuropil decreased. These statistically significant effects persisted throughout the postoperative period, whereas after axotomy with unimpeded nerve regeneration, these features would have returned to normal by 84 days postoperatively. It was therefore suggested that their recovery depended upon successful regeneration and reconnection of the hypoglossal nerve with the tongue. Subsurface cisterns, and profiles containing unusual inclusions, were numerically normal 52 to 98 days postoperatively, so it was suggested that their early response and recovery after simple axotomy might be entirely dependent on nerve disconnection and not on nerve reconnection.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00238278
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  • 8
    Electronic Resource
    Electronic Resource
    Input from trigeminal cutaneous afferents to neurones of the inferior olive in rats (1976)
    Springer
    Experimental brain research 26 (1976), S. 193-202 
    Details
    ISSN: 1432-1106
    Keywords: Inferior olive ; Trigeminal nerve ; Rat
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary Extracellular recordings were obtained from inferior olivary neurones of the rat. The responses of fifty neurones evoked by electrical stimulation of a branch of the trigeminal nerve were recorded. Maxillary nerve stimulation was most effective. The response was characterized by an early discharge (single spike and wave, typically with latencies between 16 and 30 msec) and a weak late discharge which followed a period of inhibition of about 100 msec. Half of the neurones responded to one branch of the trigeminal nerve only whereas the other neurones displayed a varying degree of convergence, including sometimes a convergence from limb nerves. Forty-nine olivary neurones were tested for cutaneous receptive fields. Ten out of these had small receptive fields (〈20% of the contralateral face) and a low threshold to mechanical stimuli. Twenty neurones which had larger receptive fields responded also to low-threshold or to medium-threshold (i.e. non-nociceptive) mechanical stimuli. None of the neurones displayed receptive fields more extensive than half of the contralateral face and some of the larger fields had a small, low-threshold focus. Olivary neurones responding to electrical stimulation of trigeminal nerves or mechanical stimulation of the face were located in the medial segment of the olivary complex (dorsal accessory and principal olive). A few cells only were located in the lateral segment. It is concluded that neurones of the inferior olive receive a substantial input from trigeminal afferents and are capable of transmitting precise somatotopical information to the cerebellum.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00238283
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  • 9
    Electronic Resource
    Electronic Resource
    Zur Histogenese des Sarcoma idiopathicum multiplex haemorrhagicum (Morbus Kaposi) (1976)
    Springer
    Virchows Archiv 369 (1976), S. 215-227 
    Details
    ISSN: 1432-2307
    Keywords: Kaposi's sarcoma ; Endothelial cells ; Ultrastructure
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Description / Table of Contents: Zusammenfassung 1. Das wesentliche histologische Substrat des M.K. ist charakterisiert durch eine Proliferation von Zügen spindelförmiger Zellen, durch zellig begrenzte Gefäßspalten und durch eine geringfügige zellulär-entzündliche Begleitreaktion. 2. Die Zellen, welche die Gefäßspalten begrenzen, vehalten sich wie Capillarendothelzellen. Sie zeigen eine starke alkalische Phosphatase-Reaktivität und eine deutliche Leucinaminopeptidase-Aktivität; sie enthalten typische Weibel-Palade Granula. 3. Die ultrastrukturelle Analyse der Tumorzellen läßt ferner gefäßsprossenartige Formationen mit und ohne Lumen erkennen, an deren Ausbildung in der Hauptsache wenig ausdifferenzierte Endothelzellen beteiligt sind. Daneben erscheinen fibroblastoide Tumorzellen die sich möglicherweise von den Perithelzellen herleiten lassen. 4. Typisch für M.K. sind Extravasation und Phagocytose von Erythrocyten mit intracytoplasmatischem Abbau und Einlagerung myelinartiger, an Schwannzellen erinnernde Figuren. 5. Folgerung: Der M.K. ist gekennzeichnet durch eine multifokale Neubildung kapillarartiger Strukturen mit einer progressiven sarkomatösen Entwicklung.
    Notes: Summary 1. Histologically, Morbus Kaposi is primarily characterized by a proliferation of streams composed of spindle-shaped cells, by vascular slits lined by cells, and by a minor cellular inflammatory reaction. 2. The cells lining the vascular slits resemble endothelial cells and exhibit strong alkaline phosphatase activity and a clear leucinaminopeptidase activity. They contain Weibel-Palade bodies. 3. The ultrastructural analysis of the tumor cells shows a proliferative formation resembling capillary sprouts with and without lumina. The lumina are composed primarily of poorly differentiated endothelial cells. A second typical cellular component are fibroblast-like tumor cells possibly derived from perithelial cells. 4. Indicative of M.K. are also extravasation and phagocytosis of erythrocytes with intracytoplasmic decomposition, and storage of myelinlike structures somewhat resembling Schwannian-cells. 5. Conclusion: M.K. is characterized by a multifocal neoplasia of capillary like structures and by a progressive sarcomatous development.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00427710
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  • 10
    Electronic Resource
    Electronic Resource
    An electron microscopic study of plasmatic arterionecrosis in the human cerebral arteries (1976)
    Springer
    Virchows Archiv 369 (1976), S. 181-190 
    Details
    ISSN: 1432-2307
    Keywords: Cerebral hemorrhage ; Cerebral artery disease ; Plasmatic arterionecrosis ; Electron microscopy
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary An electron microscopic study of the intracerebral arteries from 9 hypertensive cases was performed in order to elucidate the morphogenesis of the plasmatic arterionecrosis which was considered to be the direct cause of hypertensive intracerebral hemorrhage. In the preceding stage of the arterial lesions, marked necrosis of medial smooth muscle cells and increase of basement membrane-like substance in the intima and media were observed. The lumina of these arteries were slightly dilated. The dilatation and hemodynamic factors were supposed to cause endothelial injury resulting in blood plasma insudation into the intima through the opened spaces between endothelial cells. The insudated blood plasma dispersed and dissolved the basement membrane-like substance, collagen and elastic fibers in the arterial wall, leading to the development of the plasmatic arterionecrosis.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00427707
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  • 11
    Electronic Resource
    Electronic Resource
    Abnormal cilia in the bronchial mucosa (1976)
    Springer
    Virchows Archiv 371 (1976), S. 121-129 
    Details
    ISSN: 1432-2307
    Keywords: Compound cilia ; Axial filament complex ; Bronchitis ; Ultrastructure
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary Atypical cilia in the bronchial mucosa of non-smoking women and in guinea-pig lungs were studied by the electron microscope. In human cases, numerous compound cilia were observed in the main bronchi. The largest one contained about 40 axial filament complexes in a ciliary shaft. Occasionally, atypical basal bodies were also seen. In the experimental model in guinea-pigs, 50% oxygen at one atmospheric pressure damaged the bronchial surface and resulted in degeneration and reduction of cilia and pellicular structures. The injury was not sufficiently severe to initiate adaptation and reparative mechanisms in the bronchial mucosa, and rapid renewal of the surface structures was found. The human cases were associated with bronchogenic carcinoma but the experimental model suggested that atypical cilia were not always related to pulmonary carcinogenesis.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00444928
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  • 12
    Electronic Resource
    Electronic Resource
    Surface features of cirrhotic liver (1976)
    Springer
    Virchows Archiv 372 (1976), S. 97-108 
    Details
    ISSN: 1432-2307
    Keywords: Scanning electron microscopy ; Cirrhosis ; Liver ; Rat
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary The surface features of single cells and of multicellular tissue units in cirrhotic rat livers have been studied by scanning electron microscopy (SEM). Cirrhosis of the liver was produced in rats by simultaneously treating them with carbon tetrachloride and sodium phenobarbital. Connective tissue septa consisted of a loose mesh-work of fibers in which fibroblasts were embedded. The arrangement and surface features of hepatocytes in cirrhotic nodules differed from those found in parenchyma of normal livers. Hepatocytes in cirrhotic nodules universally formed plates two cells thick. The portion of the hepatocyte surface covered by microvilli was greatly increased in cells from cirrhotic livers, and this was reflected in a corresponding reduction in the area occupied by the smooth-surfaced narrow intercellular space. Canaliculi between hepatocytes in cirrhotic livers were reduplicated and frequently branched. Hepatocyte surfaces covered by microplicae and flattened microvilli, typical of connective tissue-facing surfaces in normal livers, were greatly increased in cirrhotic livers corresponding to the increase in connective tissue. Where hepatocytes directly contacted fibroblasts (and not fibers), their surfaces were entirely smooth. Sinusoidal endothelial cells in cirrhotic livers contained only isolated, relatively sparse pores, and they lacked both sieve plates (pore complexes) and large fenestrations.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00427085
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  • 13
    Electronic Resource
    Electronic Resource
    Das zentrale Riesenzellgranulom (1976)
    Springer
    Virchows Archiv 371 (1976), S. 161-170 
    Details
    ISSN: 1432-2307
    Keywords: Giant cell granuloma ; Histochemistry ; Ultrastructure ; Cell function ; Osteoclasts
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Description / Table of Contents: Zusammenfassung Die mehrkernigen Riesenzellen des zentralen Riesenzellgranuloms entstehen durch Zellfusion aus den Pericyten der Kapillaren. In der vorliegenden Studie werden die Funktionsmerkmale der Riesenzellen durch Kombination histologischer, histochemischer und elektronenmikroskopischer Methoden untersucht. In den mehrkernigen Riesenzellen ließen sich in Übereinstimmung mit älteren Untersuchungen die lysosomalen Enzyme saure Phosphatase und Aminopeptidase nachweisen. Das lysosomale System der Riesenzellen befähigt diese zur aktiven Phagocytoseleistung. Darüber hinaus können sich die Riesenzellen neugebildeten Geflechtknochenbälkchen anlagern und osteoclastäre Funktionen übernehmen. Die enzymhistochemische und funktioneile Ähnlichkeit mit den mehrkernigen Osteoclasten wirft die Frage nach einer vergleichbaren Cytogenese beider Zellformen auf.
    Notes: Summary Multinucleated giant cells in giant cell granuloma are formed by cell fusion of capillary pericytes. In our present study we tried to analyze cell function and activity by histologic, histochemical, and electronmicroscopic examination of giant cells. Lysosomal enzymes such as acid phosphatase and amino-peptidase were found in giant cells which is in agreement with former work. By their lysosomal system giant cells are proved phagocytic. In addition, giant cells being localized at trabecular surfaces of newly formed woven bone may develop osteoclastic functions. The enzymatic and functional resemblance of giant cells and multinucleated osteoclasts points to the possibility of a similar cytogenesis of both cell types.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00444932
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  • 14
    Electronic Resource
    Electronic Resource
    Über die Feinstruktur von Mammamischtumoren der Hündin (1976)
    Springer
    Virchows Archiv 371 (1976), S. 219-226 
    Details
    ISSN: 1432-2307
    Keywords: Canine mammary gland ; Mixed tumor ; Myoepithelial cells ; Ultrastructure
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Description / Table of Contents: Zusammenfassung Es wurden licht- und elektronenmikroskopisch Spindelzellen fischzugartiger Verbände in 19 Mammamisehtumoren von Hündinnen untersucht. Die elektronenmikroskopischen Befunde sprechen dafür, daß es sich bei den spindeligen Tumorzellen meist um Zellen myothelialen Ursprungs handelt. Es wurden jedoch auch spindelzellige Verbände gefunden, die aus Fibroblasten bzw. Pibrocyten bestehen. Im lichtmikroskopischen Bereich ist eine sichere Unterscheidung nicht in jedem Fall möglich.
    Notes: Summary Spindle cells of myomatous formations of 19 canine mixed mammary tumors were studied by light and electron microscopy. The EM findings indicate that the spindleshaped tumor cells are mostly of myoepithelial origin. However there were also formations of spindle cells which consisted of fibroblasts or fibrocytes. By light microscopy they are not always clearly distinguishable.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00433069
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  • 15
    Electronic Resource
    Electronic Resource
    Stereology of liver biopsies from healthy volunteers (1976)
    Springer
    Virchows Archiv 371 (1976), S. 251-263 
    Details
    ISSN: 1432-2307
    Keywords: Human liver ; Electron microscopy ; Stereology
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary The stereologioal model and the base-line data of normal human liver needle biopsy-specimens are presented. Four reference systems were introduced: 1 cm3 of liver tissue, 1 cm3 of hepatoeyte, 1 cm3 of hepatocytic cytoplasm and the volume of an average “mononuclear” hepatocyte. The sampling was done at three levels of magnification (1,000 ×, 5,000 × and 10,000 ×). A lobular differentiation was not considered. The baseline data show strikingly small variations (s.e. less than 10%) within the individual biopsy specimen and within the group of four biopsies. There is no principal difference between human beings presented here, rats, mice and dogs. Only the mean individual volume of human hepatocytes is clearly larger than in rodents. The problems and limitations of stereological work on liver biopsy specimens are discussed.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00433072
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  • 16
    Electronic Resource
    Electronic Resource
    Hairy cell leukemia (1976)
    Springer
    Virchows Archiv 370 (1976), S. 273-289 
    Details
    ISSN: 1432-2307
    Keywords: Bone marrow biopsy ; Hairy cell leukemia ; Differential diagnosis ; Myelofibrosis ; Electron microscopy
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary In 24 patients with hairy cell leukemia, histological and fine structural findings from biopsies of the bone marrow are reported and their validity is compared with other diagnostic procedures available. Diagnosis by light microscopy of anterior iliac crest biopsies obtained by the method of myelotomy is possible with a high degree of accuracy. The differentiation of hairy cell leukemia from other myelo- or lymphoproliferative disorders based on cytomorphology as well as patterns of growth is emphasized. Morphological differences between fibrosis in this entity and other lesions such as malignant lymphomas, Hodgkin's disease, osteomyelofibrosis and -sclerosis are emphasized. Electron microscopy of the bone marrow shows single fibroblastic cells with numerous slender cytoplasmic processes randomly dispersed among the hairy cells. These fibroblasts are probably responsible for the synthesis of the reticulin and collagen fibres in their surroundings. Moreover fine structure of the hairy cells demonstrates pinocytic activity but no apparent phagocytosis in contrast to the phagocytic reticulum cells (histiocytes, macrophages). In the bone marrow the precursor cells and the many immature forms of hairy cells exhibit an overall lymphocytoid appearance during their maturation, suggesting a lymphocytic origin.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00445773
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  • 17
    Electronic Resource
    Electronic Resource
    Comparative ultrastructure of thyroid, tongue and eyelid lesions in the neuroma phenotype of medullary carcinoma of the thyroid (1976)
    Springer
    Virchows Archiv 369 (1976), S. 249-258 
    Details
    ISSN: 1432-2307
    Keywords: Ultrastructure ; Thyroid ; Mucosal neuromas
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary Electron-microscopic and histochemical studies of thyroid tumor, tongue neuromas and eyelid neuromas from the lesions of a patient with medullary thyroid carcinoma were compared. In the thyroid tumor, a significant number of the C cells showed heterogeneity of granule types; no C cells, however, were identified in the tongue and eyelid neuromas. Amyloid was clearly shown by Congo red staining in the thyroid neoplasm and in the tongue neuromas. In all tissues, amyloid fibrils were found to be ultrastructurally closely associated with fibroblasts. These fingings suggest that the fibroblast rather than the C cell may have played the important role in the deposition of amyloid in this patient's thyroid carcinoma.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00427713
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  • 18
    Electronic Resource
    Electronic Resource
    Experimentell induzierte Herzmuskelfasernekrosen nach Praemedikation mit Strophanthin (1976)
    Springer
    Virchows Archiv 370 (1976), S. 141-150 
    Details
    ISSN: 1432-2307
    Keywords: Angiotensin ; Catecholamine ; Strophanthin ; Rat heart ; Myocardial necroses ; Optical microscopy ; Electron microscopy
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Description / Table of Contents: Zusammenfassung Bei der Ratte nehmen die durch Angiotensin induzierten Herzmuskelfasernekrosen (75 mg/kg s.c. und i.p.) unter Strophanthin-Praemedikation (2 × 10−2 mg/kg i.p.) an Zahl und Ausmaß ab. Darüberhinaus ändert sich der elektronenmikroskopische Befund: Die alleinige Gabe von Angiotensin bewirkt eine Vakuolisation der Mitochondrion und eine Dilatation des endoplasmatischen Reticulum ohne Alteration der Myofibrillen. Die kombinierte Gabe von Strophanthin und Angiotensin führt zu einer primären Zerstörung der Myofibrillen, ohne daß Mitochondrien und tubuläres System sichtbar verändert werden. Der Schutzmechanismus des Strophanthin wird im Sinne einer Ökonomisierung des Zellstoffwechsels bei relativer coronarieller Insuffizienz diskutiert, welche durch die starke vasokonstriktorische Wirkung des Angiotensin ausgelöst wird.
    Notes: Summary Number and degree of angiotensin-induced heart muscle necroses in the rat (75 mg/kg body weight) are diminuished by premedication with strophanthin (2 × 10−2 mg/kg body weight). The electron-microscopic findings are also changed: the application of angiotensin only results in vacuolization of mitochondria and a dilatation of the endoplasmatic reticulum while myofibrils are unaltered. Angiotensin in combination with strophanthin has a direct destructive effect on the myofibrils without evident changes of the mitochondria and the tubular system of the heart. The protective action of Strophanthin on the heart muscle cell is discussed in the sense of an economization of the cellular metabolism under conditions of relative coronary insufficiency, induced by the vasoconstructive effect of angiotensin.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00430810
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  • 19
    Electronic Resource
    Electronic Resource
    Das zentrale Riesenzellgranulom (1976)
    Springer
    Virchows Archiv 370 (1976), S. 163-175 
    Details
    ISSN: 1432-2307
    Keywords: Central giant cell granuloma ; Histogenesis ; Histochemistry ; Ultrastructure
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Description / Table of Contents: Zusammenfassung Bisherige Untersuchungen an zentralen Riesenzellgranulomen des Gesichts-Kieferbereiches haben die Histogenese dieser tumorähnlichen Knochenerkrankung nicht klären können. Wir untersuchten daher zwei bioptisch gesicherte zentrale Riesenzellgranulome unter dieser Fragestellung histochemisch und elektronenmikroskopisch. Histochemisch findet sich eine enge Enzymverwandtschaft zwischen den mehrkernigen Riesenzellen und den Pericyten der Kapillaren, die das Granulom dicht durchsetzen. Elektronenmikroskopisch zeigen sich typische Membranphänomene der Zellfusion zwischen den mehrkernigen Riesenzellen und den Pericyten. Die für das Granulom charakteristischen mehrkernigen Riesenzellen entstehen daher durch Zellfusion aus den Pericyten, die als ihre Stammzellen angesehen werden müssen. Da die Pericyten das Granulom auch in Form zahlreicher blinder Kapillarsprossen durchsetzen, erklärt sich die Entwicklung einer Vielzahl von Riesenzellen. Die Ursachen, die diesem Verhalten der Pericyten aetiologisch zugrunde liegen, sind unbekannt. Ob die Cytogenese der Riesenzellen des zentralen Riesenzellgranuloms Modellcharakter hat und analog auch für die Entwicklung von Riesenzellen in anderen Gewebsneubildungen oder für die Enstehung der mehrkernigen Osteoclasten gilt, muß weiteren Untersuchungen vorbehalten bleiben.
    Notes: Summary Until now numerous studies on central giant cell granuloma of jawbones have not been able to reveal the histogenesis of this tumourlike lesion. The aim of the present investigation in two surgically proven cases was to study this question by means of histochemical and electron-microscopic methods. Rather similar histochemieal properties were shown in giant cells and pericytes of capillary sprouts penetrating the granuloma. Cell fusion occurred between both cell types as was observed by electron microscopy. The process of cell fusion is defined by characteristic interdigitations of cell membranes. Therefore pericytes are believed to be the stem cells of multinucleated giant cells in giant cell granuloma. The abundance of giant cells usually occurring in the granuloma might be explained by plenty of capillary sprouts made up by clusters of pericytes. The factors inducing the pericytic cell fusion process are still unknown. The question arises whether cytogenesis of giant cells in giant cell granuloma might be similar in other giant cell lesions or even in the development of multinucleated osteoclasts.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00430812
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  • 20
    Electronic Resource
    Electronic Resource
    The fine structure of the normal, resting terminal ductal-lobular unit of the female breast (1976)
    Springer
    Virchows Archiv 372 (1976), S. 205-226 
    Details
    ISSN: 1432-2307
    Keywords: Breast ; Ultrastructure
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary The fine structure of the terminal ductal-lobular unit (TDLU) of the normal, resting female breast is described. Tissue used conformed to strict criteria for normal. 4 distinct cell types, were observed, epithelium, myoepithelium, macrophages and lymphocytes. A gradation in structure, especially of myoepithelium, was found between the ductule tip and intralobular duct, apparently reflecting the age and function of each region. Cilia originating from the myoepithelial cells are possibly sensory in function. Epithelial vesicular inclusions may represent minimal secretory activity, transport of material across the cell, or be lysosomal in nature. The capillaries in close contact with the delimiting fibroblasts of the epithelial-stromal junction (ESJ) are described and the zone designated the capillary-fibroblast junction (CFJ). The CFJ is conceived as a regulatory unit similar to the ESJ, and may contribute to dysplasia due to biochemical or functional alterations, or to disruption of the microvascular geometry.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00433280
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  • 21
    Electronic Resource
    Electronic Resource
    The ultrastructure of the zygospore in Endogone flammicorona Trappe & Gerdemann (1976)
    Springer
    Mycopathologia 59 (1976), S. 117-123 
    Details
    ISSN: 1573-0832
    Keywords: Ultrastructure ; Zygospore ; Mycorrhizal fungus ; Flaming crown
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Abstract The ultrastructural organization of the spores of the sporocarp of Endogone flammicorona was studied. Two types of organization are described. Initially the spore possessed a vacuolate protoplasm and was bound by two cell wall layers. The spore was surrounded by a hyphal mantle formed of a sheet of vacuolized hyphae with uniformly thin walls. Secondly, although the ultrastructural features of the spore appeared the same, it was now surrounded by a hyphal mantle with unevenly thickened walls (i. e., the so-called flaming crown) due to the gradual and irregular deposition of granules and lamellae. This crown gives the spore its most commonly observed morphological feature and is the preminent character employed taxonomically to speciate Endogone flammicorona Trappe & Gerdemann.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00493564
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  • 22
    Electronic Resource
    Electronic Resource
    On the fungitoxicity of some new thiocyanatopyrazole derivatives: Electron microscopical study in trichophyton mentagrophytes (1976)
    Springer
    Mycopathologia 58 (1976), S. 39-47 
    Details
    ISSN: 1573-0832
    Keywords: Trichophyton mentagrophytes ; Thiocyanatopyrazole derivatives ; Electron microscopy
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Abstract Four thiocyanatopyrazole derivatives were synthesized and their fungistatic activity was demonstrated in vitro against a number of dermatophytic fungi. In Trichophyton mentagrophytes, the most active compound induced an unusual increase of the plasma membrane with production of intra and extracytoplasmic complexes, a deterioration of nuclear and mitochondrial membranes and a formation of autophagic-like vacuoles. Plasmolysis, accompanied by an almost complete disorganization of cytoplasmic structures, seemed to be the final event. A possible mechanism of action of the compounds was discussed.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00493592
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  • 23
    Electronic Resource
    Electronic Resource
    Ultrastructure of the labyrinth in the rat full-term placenta (1976)
    Springer
    Anatomy and embryology 149 (1976), S. 123-148 
    Details
    ISSN: 1432-0568
    Keywords: Rat-placenta ; Gap junctions ; Electron microscopy ; Freeze-fracturing
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary The placental labyrinth of the chorioallantoic placenta of the rat was studied with transmission and scanning electron microscopy. Full-term placentas were investigated after perfusion fixation from the maternal and fetal circulation, including thin-sectioning and freeze-fracturing. The labyrinthal three-dimensional structure was found not to be trabecular but spongious lamellar. We propose a division of the lamellae into three groups—the first, second, and third order. The trophoblastic layers are described in detail, showing a cellular layer I and two syncytial layers II and III. Layer I is found to be fenestrated and highly permeable. Layers II and III are connected by extended gap junction areas. It is suggested that the gap junctions function as a molecular sieve and represent the limiting barrier in diaplacental transport of the choriollantoic placenta. Fetal capillaries are fenestrated and endothelial cells are connected by tight junctions. The functional significance of the morphologic findings is discussed.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00317893
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  • 24
    Electronic Resource
    Electronic Resource
    Influence of sodium chloride on the amount of CRF-granules and “classical” neurosecretory material (NSM) in the neurohypophysis of bilaterally adrenalectomized rats (1976)
    Springer
    Anatomy and embryology 149 (1976), S. 307-313 
    Details
    ISSN: 1432-0568
    Keywords: CRF-granules ; Sodium chloride ; Adrenalectomy ; Rat ; Histology
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary Bilaterally adrenalectomized female SPF Wistar rats were given tap water containing various concentrations of sodium chloride to drink ad lib. After a survival period of 14 days the animals were killed by perfusion-fixation. Their brains were removed, fixed in pieric acid formalin solution and embedded in Paraplast. Serial sections of median eminence and hypophysial posterior lobe were cut and stained with crotonaldehyde-fuchsine. In the stained sections the amount of CRF-granules visible in the external zone of the median eminence, and the amount of “classical” neurosecretory material (NSM) occuring in the internal zone of the median eminence and in the posterior lobe of the hypophysis were estimated. After administration of drinking solutions to which 0%–1% sodium chloride were added, the amount of CRF-granules increased with increasing NaCl uptake, whereas the amount of “classical” NSM was not changed. Application of tap water containing 2% NaCl led to a marked decrease in the amount of “classical” NSM but did only slightly impair the amount of CRF-granules. From the findings it is concluded that 1. following bilateral adrenalectomy administration of sodium chloride inhibits the secretion of CRF-granules; 2. CRF-granules and “classical” NSM, although histochemical identical, have different functional significances; 3. the mechanisms regulating the secretion of CRF-granules are different from those controlling the release of “classical” NSM.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00315446
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  • 25
    Electronic Resource
    Electronic Resource
    The ultrastructure of the nucleus of the oculomotor nerve (somatic efferent portion) of the cat (1976)
    Springer
    Anatomy and embryology 149 (1976), S. 323-346 
    Details
    ISSN: 1432-0568
    Keywords: Oculomotor nucleus ; Ultrastructure ; Synapses ; Membrane apposition ; Motoneurons
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary The ultrastructure, of the somatic efferent portion of the nucleus of the oculomotor nerve was studied in four adult cats. The neuronal population is composed of neurons of variable size. A continuous pattern of morphological aspects is evident between the large neurons, which show abundant cytoplasm with well developed organelles and the small neurons which have a reduced amount of cytoplasm. The dendrites are generally smooth, with few short spines. Axo-somatic and axo-dendritic synapses are numerous. Synaptic boutons are also present on the axon hillock. The neuropil is characterized by the occurrence of small groups of dendrites which may be in direct touch with their membranes. Direct membrane appositions may also occur between neighbouring neurons and between the cell somata and tangentially running dendrites. Generally beneath the site of apposition there is accumulation of mitochondria, multivesicular bodies, coated vesicles and moderately dense amorphous material. The morphological features suggest the possibility of cellular interchanges at the sites of direct membrane apposition. Five types of synaptic boutons were recognized on the basis of their vesicular content, the presence of abundant filaments in the pre-synaptic bag, the occurrence of post-synaptic specializations. The, different synaptic types and their distribution are similar to those reported in the spinal motor nuclei. Many of the synapses make synaptic contacts with two or more post-synaptic elements. Axo-axonic synapses were also observed.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00315448
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  • 26
    Electronic Resource
    Electronic Resource
    Simultaneous changes of the perivascular contact area and HIMOT activity in the pineal organ after bilateral adrenalectomy in the rat (1976)
    Springer
    Anatomy and embryology 149 (1976), S. 297-305 
    Details
    ISSN: 1432-0568
    Keywords: Pineal organ ; Perivascular contact ; HIOMT ; Median eminence ; Adrenal cortex ; Rat
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary In the pineal organ of the female rat, proportional changes in the area of contact of pinealocyte processes and glial processes with the perivascular space were found after bilateral adrenalectomy. The contact area was evaluated by measuring the length of pinealocyte and glial cell membranes directly abutting on the basal lamina. In the normal female rat, 40% of the contact area is occupied by pinealocyte and 60% by glial cell processes. Fourteen days after bilateral adrenalectomy, this proportion is reversed. In addition, cell counts demonstrate that more pinealocytes gain access to the pericapillary space due to the experimental conditions. In order to prove whether or not these results indicate an increase of pineal endocrine activity, the melatonin-forming enzyme hydroxyindole-O-methyltransferase (HIOMT, E.C. 2.1.1.4) was assayed. After bilateral adrenalectomy the HIOMT activity was found to significantly increase.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00315445
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  • 27
    Electronic Resource
    Electronic Resource
    Ultrastructure of the surface principal cells of the large intestine in postnatal developing rats (1976)
    Springer
    Anatomy and embryology 149 (1976), S. 155-171 
    Details
    ISSN: 1432-0568
    Keywords: Large intestinal epithelium ; Postnatal development ; Rat ; Ultrastructure
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary The principal cells of the surface of the cecum, the ascending colon, and the descending colon in postnatal developing rats were investigated using both light and electron microscopy. In rats 1 to 14 days old the ultrastructure of the surface principal cells in the cecum and ascending colon were characterized by apical tubulo-vacuolar systems and large supranuclear vacuoles similar to those in the absorbing cells of the neo-natal ileum as reported by Clark, 1959, and others. After about the 16th day, the special membrane system disappears from the principal cells of the proximal large intestine. On the other hand, in the descending colon, this special membrane system was absent from the cytoplasmic matrix of the epithelium. It is thought that the proximal portion of the large intestine together with the distal part of the small intestine actively participate in the absorption of protein molecules at least during the early postnatal period.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00317895
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  • 28
    Electronic Resource
    Electronic Resource
    Ultrastructure of Lewy bodies in the stellate ganglion (1976)
    Springer
    Acta neuropathologica 34 (1976), S. 183-197 
    Details
    ISSN: 1432-0533
    Keywords: Lewy body ; Electron microscopy ; Parkinsonism ; Dense core vesicles ; Catecholamines ; Mitochondrial inclusions
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary The Lewy body, a characteristic nerve cell inclusion in idiopathic parkinsonism, was examined by electron microscopy in the stellate ganglion, obtained from 9 patients at autopsy. Three main forms of Lewy bodies or Lewy body-related structures were demonstrated: A. Rare filamentous Lewy bodies, similar to Lewy bodies in the central nervous system. B. Granular Lewy bodies in nerve cell processes. C. Abnormal nerve cell processes, filled with heterogenous material. Large dense core vesicles were prominent in the last 2 forms. None of these abnormalities were found in 2 control groups consisting of 9 parkinsonism cases without central nervous system Lewy bodies, and 17 cases without parkinsonism. The filamentous Lewy body (type A) was found in the perikaryon and was surrounded by neuromelanin, whereas the other forms (type B and C) were seen in nerve cell processes. Mitochondrial inclusions, present mainly, but not exclusively, in neuromelanin-containing cells, were not related to Lewy body formation or to parkinsonism.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00688674
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  • 29
    Electronic Resource
    Electronic Resource
    Damage of skeletal muscle in rats by immunoglobulins (1976)
    Springer
    Acta neuropathologica 34 (1976), S. 207-218 
    Details
    ISSN: 1432-0533
    Keywords: Immunomyopathy ; Muscle disease ; Electron microscopy ; Experimental muscle pathology
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary An experimental model of the autoimmune process was developed to study the ultrastructural aspects of immunomyopathies. Every type of muscle fibre organelle was affected and the severity of injury increased in direct proportion to time following immunization. It is suggested that ultrastructural methods are useful in studies concerned with the analysis of structural aspects of experimental immunomyopathies.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00688676
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  • 30
    Electronic Resource
    Electronic Resource
    In vitro characteristics of a sacrococcygeal chordoma maintained in tissue and organ culture systems (1976)
    Springer
    Acta neuropathologica 35 (1976), S. 13-25 
    Details
    ISSN: 1432-0533
    Keywords: Chordoma ; Tissue and organ culture ; Electron microscopy
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary Explants of a human sacral chordoma were successfully maintained on collagen-coated coverslips, gelfoam sponge matrices, and Millipore filter platforms for up to 30 days. Tumor cells cultured on collagen-coated coverslips became increasingly vacuolated whereas those maintained in organ culture were entirely free of vacuoles after 22 days in vitro. A single basic tumor cell, small and polygonal with a large central spherical nucleus and abundant endoplasmic reticulum and Golgi apparatus, was recognized. Vacuoles were formed as the result of the progressive expansion of smooth endoplasmic reticulum. Coalescence of these vacuoles produced the physaliferous cell of light microscopy.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00688940
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  • 31
    Electronic Resource
    Electronic Resource
    Esthésioneurocytome olfactif (1976)
    Springer
    Acta neuropathologica 35 (1976), S. 139-150 
    Details
    ISSN: 1432-0533
    Keywords: Electron microscopy ; Olfactory esthesioneurocytoma ; Neurosecretory granules ; Microtubules ; Dystrophic axons
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary One case of malignant tumour of the left nasal cavity is reported in a woman 56 year old, affected by the disease 24 years. Numerous recurrences appeared and various histological diagnoses were performed. At the last surgery, the tumour invaded the ethmoïd and was a typical olfactory esthesio-neurocytoma. By electron microscopy, mature ganglion cells with dense cored vesicles (neurosecretory granules) were densely packed. Neuritic processes with microtubules were rarely normal in size and their content was most often abnormal; furthermore dystrophic axons were noted in great number.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00690560
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  • 32
    Electronic Resource
    Electronic Resource
    Light and electron microscopic investigations on a transplantable tumour of the rat, induced by transplacental administration of ENU (ethylnitrosourea) (1976)
    Springer
    Acta neuropathologica 36 (1976), S. 177-184 
    Details
    ISSN: 1432-0533
    Keywords: Neurinoma ; ENU ; Prenatal carcinogenesis ; Transplantability ; Metastases ; Electron microscopy
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary With a single dose of 80 mg/kg ENU, a tumour originating from the trigeminal nerve was induced transplacentally in the offspring of a Sprague-Dawley rat. The neoplasm diagnosed as a neurinoma, was transplanted over 20 passages to 5 six-month-old Sprague-Dawley rats in each case. During this time, the biological behaviour of the tumour as well as its histological appearance were followed. Ultrastructural observations were made of the 20th passage. The tumour caused multiple metastases in the lung and in the lymph nodes of the neck in 30 animals. Recurrences were formed within a week, metastases of the lung appeared from then on in all cases. During the time of transplantation, the neurinoma dedifferentiated histologically so markedly that it was no longer possible to classify the neoplasm as a neurogenous tumour after 20 passages. Ultrastructurally, poorly differentiated Schwann cells could nervetheless be recognized.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00685279
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  • 33
    Electronic Resource
    Electronic Resource
    “PKU Bodies”: Characteristic inclusions in the brain in phenylketonuria (1976)
    Springer
    Acta neuropathologica 36 (1976), S. 295-305 
    Details
    ISSN: 1432-0533
    Keywords: PKU bodies ; Demyelination ; Dysmyelination ; Neuroglia ; Inborn errors of metabolism ; Phenylketonuria ; Electron microscopy
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary The ultrastructure of various inclusions within oligodendroglial cells in the brains from two phenylketonuric patients was studied. Characteristic lamellar, oval, slightly irregular inclusions measured between 0.5 and 2 micra in diameter and were bounded by a single membrane. The longitudinal and transverse lamellae of these inclusions had a distinct pattern. In analogy to lamellated but different inclusions of other diseases, these structures were termed “PKU bodies”. Various possibilities that would explain the morphogenesis of the PKU bodies and other inclusions in the oligodendroglial cells, and the significance of these findings, are discussed.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00699635
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  • 34
    Electronic Resource
    Electronic Resource
    Sequence of morphological alterations in the nervous system of metachromatic leucodystrophy (1976)
    Springer
    Acta neuropathologica 36 (1976), S. 369-379 
    Details
    ISSN: 1432-0533
    Keywords: Leukodystrophy, metachromatic ; Prenatal diagnosis ; Sulphatide accumulation ; Myelination, central, peripheral ; Electron microscopy
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary Light and electronmicroscopic findings are reported in a case of metachromatic leukodystrophy diagnosed prenatally who died after iatrogenic abortion during the 23th week of gestation. The brain of this foetus was not yet myelinated while the spinal cord showed early, and the peripheral nerves advanced myelination. The onset and the degree of myelination were similar as in a normal foetus of the same age. Ultrastructurally there was evidence of sulphatide storage before the beginning of myelination. During myelination lysosomal storage material, staining metachromatically in acid cresyl violet preparations, appeared in oligodendrocytes and Schwann cells. Besides sulphatide storage material, prominent amounts of neutral lipids were found in oligodendrocytes. Myelin breakdown was encountered very seldom.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00699642
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  • 35
    Electronic Resource
    Electronic Resource
    Development of onion bulb neuropathy in the Trembler mouse (1976)
    Springer
    Acta neuropathologica 36 (1976), S. 137-152 
    Details
    ISSN: 1432-0533
    Keywords: Trembler mouse ; Peripheral neuropathy ; Electron microscopy ; Morphometry
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary The Trembler mouse is a neurological mutant showing dominant inheritance. The peripheral nerves show a delay in myelination, segmental demyelination and the development of an onion bulb neuropathy. Using electron microscopy a comparative morphometric study of nerve fibres in the sciatic nerve in normal and Trembler mice was made. The animals ranged in age from 3 days to adult. The following features were noted: 1. Mean axon diameters of the Trembler mice were smaller than normal at all ages. 2. Myelination was delayed and myelin was thinner than normal in the Trembler mice. 3. The ratio of myelin thickness to axon diameter was reduced in Trembler mice. 4. There were no significant quantitative or qualitative differences observed between middle and distal levels of Trembler nerves. The balance of evidence from these findings and the previous morphological studies is in keeping with the suggestion that the primary lesion resides in the Schwann cell.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00685276
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  • 36
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    The protracted form of juvenile neuronal ceroid-lipofuscinosis (1976)
    Springer
    Acta neuropathologica 36 (1976), S. 393-396 
    Details
    ISSN: 1432-0533
    Keywords: Ceroid lipofuscinosis ; Juvenile or adult ; Protracted form ; Lipopigments ; Ultrastructure
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary Clinical and ultrastructural findings consisting of curvilinear and fingerprint residual bodies, in a protracted juvenile form of NCL are reported from a woman who died at the age of 35 years. Homochrony and homotypy of her brother's illness emphasize intrafamilial similarities within subgroups of lysosomal disorders.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00699645
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  • 37
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    Electronic Resource
    The target phenomenon in human muscle (1976)
    Springer
    Acta neuropathologica 34 (1976), S. 329-338 
    Details
    ISSN: 1432-0533
    Keywords: Muscle pathology ; Target muscle fibre ; Targetoid muscle fibre ; Histochemistry ; Electron microscopy
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary A large number of target fibres is observed in a muscle biopsy from a patient with an acute flaccid paraplegia of the lower limbs due to a polyneuroradiculopathy of unknown origin. With the electron microscope up to 4 structural zones are seen in the target fibers. The histochemical and ultrastructural observations in this case, suggest that the “target fibre” phenomenon is due to a disturbed trophic influence of the nervous system.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00696562
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  • 38
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    Electronic Resource
    Extraocular muscles light microscopy and ultrastructural features (1976)
    Springer
    Acta neuropathologica 34 (1976), S. 237-253 
    Details
    ISSN: 1432-0533
    Keywords: Strabismus ; Extraocular muscles ; Hirano bodies ; Ultrastructure ; Luse bodies ; Leptomeres
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary Thirty extraocular muscles (EOM) from 20 patients were evaluated by light microscopy (LM), electron microscopy (EM), and enzyme histochemistry (EZH). Twenty-one EOM were obtained from 13 patients with strabismus, 9 EOM from 4 patients undergoing eye surgery for other reasons and from 3 autopsy cases. One μm thick sections revealed marked variation in muscle fibre shape and size and in myofibrillar structure; also noted were small, hypertrophied, whorled, and ringbinden fibres. Dense and granular material in the central portion of some fibres and sarcomere disruption in 2–3 μm sections was observed. EZH revealed the absence of the classical mosaic pattern usually found in skeletal muscles. ATPase studies were inconsistent and did not correlate with the expected reciprocal activity of NAD-H diaphorase, particularly on the large fibres. Ultrastructural features consisted of vacuoles within myofilament bundles, “smearing” of Z bands, and “nemaline rods”. Occasional myelin figures and lipid-like droplets were observed in subsarcolemmal spaces, associated with scattered clusters of glycogen granules. Abnormal mitochondria and subsarcolemmal inclusions of dense and granular material were conspicuous. “Leptomeric” profiles, “Zebra bodies”, or “striated bodies” were noted in 8 EOM's, and an Hirano body was found in 1. The intramuscular nerves contained structures resembling “Luse bodies” in 7 cases. These observations suggest that EOM from individuals with and without strabismus possess unique structural characteristics suggestive of developmental and morphological disarrangement of contractile elements. Some of these changes might play a role in the pathogenesis of strabismus and in the development of clinical symptoms. These features are significantly different from striated skeletal muscle. Therefore the criteria used in the pathological evaluation and diagnosis of skeletal muscle disorders cannot be unequivocally applied to EOM investigations. These data establish the necessity to determine histological norms, ultrastructural patterns, and develop new enzyme histochemistry criteria for the evaluation of EOM. Only then can an acceptable comparison of EOM and skeletal muscle be made.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00688678
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  • 39
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    Morphological differences between the atrophied small muscle fibres in amyotrophic lateral sclerosis and Werdnig-Hoffmann disease (1976)
    Springer
    Acta neuropathologica 34 (1976), S. 321-327 
    Details
    ISSN: 1432-0533
    Keywords: Muscle fibres ; Amyotrophic lateral sclerosis ; Werdnig-Hoffmann disease ; Electron microscopy
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary Muscle biopsies from 5 cases of Werdnig-Hoffmann disease and 4 cases of ALS were investigated by histology and electronmicroscopy. The differences in morphology found in the atrophic muscle fibres in ALS and in W.H. diesease consisted mainly in the shape and structure of their cells and the number of the nuclei. Atrophic muscle fibres irregular in shape and size with degenerative changes and accumulated nuclei observed in ALS were markedly different from the picture of the fibres in W.H. disease. The presence of small muscle cells uniform diameter with well preserved architecture and single nuclei and numerous myotube-like cells seem to indicate a foetal defect in children with W.H. disease.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00696561
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  • 40
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    Electronic Resource
    Renflement fusiforme d'origine mécanique d'un nerf périphérique. Étude anatomique (1976)
    Springer
    Acta neuropathologica 35 (1976), S. 47-54 
    Details
    ISSN: 1432-0533
    Keywords: Entrapment neuropathy ; Fusiform nerve enlargement ; Segmental demyelination ; Axonal changes ; Electron microscopy
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary This paper reports on the study of a symptomless fusiform enlargement of the superficial peroneal nerve. The swelling was located in the part of the nerve passing through the aponevrosis. On incision of the epineurium small swellings were seen in the nerve fascicles. A fascicular biopsy was done and the fascicles studied by teasing and by optic and electron microscopy. Isolated nerve fiber study gave evidence of segmental demyelinisation with subsequent remyelinisation in almost all the myelinated fibers. These abnormalities were only encountered in the swollen part of the fascicle. A striking proliferation of cells was demonstrated in isolated fibers by counter-staining with hematoxylin. Electron microscopy showed primary demyelinsation and cellular proliferation affecting Schwann-cells (without onion bulb formations), fibroblasts and giant-vacuolated histiocytes. There was also a massive increase of endoneurial fluid. A few Büngner bands were seen. These rare abnormalities appear to be caused by chronic irritation of the nerve in its passage through the aponebrosis.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00688942
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  • 41
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    Electronic Resource
    Studies on experimental malignant nerve sheath tumors maintained in tissue and organ culture systems (1976)
    Springer
    Acta neuropathologica 35 (1976), S. 27-45 
    Details
    ISSN: 1432-0533
    Keywords: Experimental malignant Schwannomas ; Melanin and melanogenesis ; Tissue and organ culture ; Electron microscopy ; Pigmented nerve sheath tumors
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary Four melanin pigment-containing intracranial tumors were found in three Long-Evans rats in the course of experimental oncogenesis by transplacental ethylnitrosourea (ENU). One of them was a leptomeningeal melanoma. Aside from the presence of scattered melanin-pigmented cells, the other three had the typical histological features of ENU-induced malignant nerve sheath tumors. Two of the three tumors were studied by electron microscopy and in tissue and organ culture systems. One of them demonstrated progressive melanogenesis in vitro; the other failed to produce more melanin and showed increasing differentiation, with a Schwannoma-like pattern by light microscopy. Melanosomes and premelanosomes were identified in both tumors by electron microscopy; the other fine structural features were those of malignant Schwannomas. These observations are relevant to the controversy on the histogenesis of pigmented nerve sheath tumors occasionally encountered in man and on the relationship of these tumors to pigmented nevi. The findings in the present study support the view of Masson that neoplastic nerve sheath cells are capable of melanogenesis.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00688941
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  • 42
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    Electronic Resource
    Ultrastructure of the Gunn rat substantia nigra I. Cytoplasmic changes (1976)
    Springer
    Acta neuropathologica 35 (1976), S. 93-107 
    Details
    ISSN: 1432-0533
    Keywords: Substantia nigra ; Gunn rat ; Complex membranous bodies ; Bilirubin ; Electron microscopy
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary The substantia nigra of various aged hyperbilirubinemic (Gunn) rats was studied by means of electron microscopy. The cytological features observed in the neuronal somata were the presence of (1) complex membranous bodies (CMBs), (2) dilated cisternae of granular endoplasmic reticulum, (3) single membrane bound vacuoles and (4) enlarged mitochondria. Nearly every neuronal soma studied in two week old Gunn rats contained CMBs, which consisted of several layers of membrane that usually, but not always, surrounded small islands of cytoplasm. On occasion CMBs were seen to be directly connected with granular endoplasmic reticulum and, in a few instances, they were located within a cistern of endoplasmic reticulum. There were significantly fewer CMBs in the neuronal somata of adult Gunn rats. They were located peripherally in the somata or in the proximal portions of dendrites. Furthermore, in these animals the cytoplasm appeared normal and did not exhibit the features commonly seen in younger animals. Only a few hyperchromatic neurons were observed and no pronounced gliosis was evident. Therefore it is assumed that the majority of substantia nigra neurons recovered from the toxic effect of bilirubin or that the concentration of bilirubin deposited in the substantia nigra is not sufficient to be lethal. The hypothesis that is considered is that CMBs represent autophagic activity which results from exposure of neurons to bilirubin. The adjacent neurites and glia did not demonstrate the cytoplasmic changes that were characteristic of the neuronal somata.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00690556
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  • 43
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    Electronic Resource
    Whipple's disease of the central nervous system (1976)
    Springer
    Acta neuropathologica 36 (1976), S. 31-38 
    Details
    ISSN: 1432-0533
    Keywords: Whipple's disease ; Central nervous system ; Granulomatous infiltration ; Electron microscopy ; Bacillary bodies
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary Whipple's disease presenting as a neurological disease without gastrointestinal symptoms is an unusual occurrence. A 40 year old man suffered hypersomnia, memory loss and progressive ophthalmoplegia for 6 months prior to death. The nature of his disease was not established during life. Extensive granulomatous inflammation affecting the hypothalamus, hippocampus and periaqueductal gray matter of the brain was found to represent Whipple's disease by electron microscopy. Characteristic lesions were also present in spleen, mesenteric lymph nodes, small intestine and myocardium. Bacillary bodies and membranous inclusions similar to those seen in visceral lesions of Whipple's disease were present in macrophages. The findings supported the theory of direct involvement of the central nervous system by bacilli rather than a metabolic origin for the lesions.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00685145
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  • 44
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    Electronic Resource
    Studies on experimental malignant nerve sheath tumors maintained in tissue and organ culture systems II. Electron microscopy observations (1976)
    Springer
    Acta neuropathologica 34 (1976), S. 293-310 
    Details
    ISSN: 1432-0533
    Keywords: Experimental malignant Schwannomas ; Organ culture ; Electron microscopy ; Differentiation ; Microtubules ; Basal lamina ; Perineurial fibroblasts
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary The sequential electron microscopic features of six malignant nerve sheath tumors (three cranial and three spinal) induced in rats by transplacental ethylnitrosourea and maintained in organ culture systems were compared with those of a human acoustic Schwannoma similarly cultured. After 4 weeks in vitro, the malignant tumor cells often showed progressive elongation of their processes, with the development of an interdigitating pattern resembling that seen in well-differentiated Schwannomas. This was accompanied by an increase of microtubules. Basal lamina formation, less well-developed and less complete than in the benign Schwannoma in this study, was maintained in culture. Some explants demonstrated an increase in number and width of collagen fibrils, accompanied by a relative concomitant decrease of intercellular basement membrane material. The malignant tumor cells also showed numerous micropinocytotic vesicles and various junctional complexes, which are characteristic of perineurial cells. Since the origin of the experimental tumors from adult Schwann cells seems well established, this apparent contradiction is best resolved by the concept that Schwann cells and perineurial fibroblasts are functional variants of the same cell type.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00696559
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  • 45
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    Electronic Resource
    Le cortex cérébral des malades atteints d'hydrocéphalie à pression normale (1976)
    Springer
    Acta neuropathologica 34 (1976), S. 353-357 
    Details
    ISSN: 1432-0533
    Keywords: Normal pressure hydrocephalus ; Human cerebral cortex ; Ultrastructure ; Extracellular space
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary A cortical biopsy was taken at the time when ventricular pressure was measured, or a ventriculo-atrial shunt placed, in 11 patients with Normal Pressure Hyprocephalus (N.P.H.), and was studied with the electron microscope. In 9 cases, a rather typical electron microscopic picture with marked increase of extracellular space in an otherwise normal cortical neuropil was observed. 2 patients did not exhibit this pattern and, coincendentally, did not benefit from the placing of the shunt. As a control, about 600 cortical biopsies that had been taken for other reasons were reviewed. In the group, there were only 3 cortices that had a pattern of increased extracellular space similar to the described in N.P.H. On review of the clinico-pathologic data of these cases, it was felt that all 3 probably represented cases of normal pressure hydrocephalus. It is concluded that the ultrastructure of the cerebral cortex is of at least nosological interest in the study of N.P.H.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00696564
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  • 46
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    Electronic Resource
    Vacuolation of oligodendroglia in neoplastic perifocal edema (1976)
    Springer
    Acta neuropathologica 35 (1976), S. 1-12 
    Details
    ISSN: 1432-0533
    Keywords: Cytoplasmic vacuole ; Oligodendroglia ; Brain edema ; Metastatic carcinoma ; Glioma ; Electron microscopy
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary Vacuolation of oligodendroglia, a new type of cytopathological change, has been described. The change is observed frequently at the perifocally edematous cerebral white matter adjacent to the metastatic lesions of carcinoma from the lung in all three cases examined. It is also present occasionally in association with astrocytoma. This condition is characterized by swelling of oligodendroglias due to numerous cytoplasmic vacuolations which contain the material identical with that of the extracellular edema fluid. In such cells, the nucleus is displaced and deformed by vacuoles but the nuclear chromatin and envelopes are arranged normally. By occupation of numerous large vacuoles the cytoplasm is divided into small areas, but the individual organelles are only minimally altered. The oligodendroglial vacuolation seems to be a phagocytic response to the edema fluid which contains proteinous macromolecules derived from blood-borne protein and necrotic material of brain tissue and neoplastic cells. The vacuolation may result in some oligodendroglial dysfunction in maintenance of myelin and probably be related with diffuse loss of myelin sheath in the longstanding brain edema secondary to neoplastic invasion. The vacuolated cells can be identified with light and electron microscopes in Epon-embedded sections of surgically removed tissue but not in paraffin sections.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00688939
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  • 47
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    Electronic Resource
    Dense core mitochondria in peripheral ganglia of man (1976)
    Springer
    Acta neuropathologica 36 (1976), S. 85-90 
    Details
    ISSN: 1432-0533
    Keywords: Mitochondrial inclusions ; Mitochondria ; Peripheral ganglia ; Ultrastructure
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary Neuronal perikarya of peripheral ganglia contained unusual dense core mitochondria that were not seen in other cell types or tissues of the same individual. They were found in several patients autopsied with GM1-gangliosidosis and neuronal ceroid-lipofuscinosis. Previous observations on human sympathetic ganglia, obtained by biopsy, and our findings suggest that these dense core mitochondria might represent a rare but regular feature of neuronal perikarya in peripheral ganglia of man.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00685151
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  • 48
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    Electronic Resource
    Ultrastructural changes in blood vessels of peripheral nerves in leprosy neuropathy (1976)
    Springer
    Acta neuropathologica 35 (1976), S. 159-181 
    Details
    ISSN: 1432-0533
    Keywords: Leprosy neuropathy ; Ultrastructure ; Angiopathy ; Basement membrane ; “Blood-nerve barrier”
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary Radial or superficial peroneal nerve biopsies of 6 patients with tuberculoid or borderline-tuberculoid leprosy and 6 control nerve biopsies were examined by electron microscopy. Endoneurial blood vessels showed histopathology in all the leprosy patients. Changes, in particular, involved the basement membrane in postcapillary venules and venules. Multilayered parellel basement membranes, with collagen and ground substance, formed a thick coat (“hyaline zone”) around the vessels. It is suggested that the zone inhibits passage of nutrients and metabolites and, thus, contributes to or is the main cause of the local destruction of (unmyelinated) nerve fibres and the lack of nerve fibre regeneration observed in this type of leprosy. The perivascular zone, presumably, is produced by pericytes in response to defects in the “blood-nerve barrier” of endoneurial vessels. In granulomata of leprosy skin lesions, a perivascular zone was not present. The endothelium of endoneurial vessels, in affected nerves, generallywas normal. Occasionally, however, gaps and fenestrations were seen and there were histological indications that leakage of blood plasma had occurred through the gaps and through the basement membrane of the endothelium. Occlusion of endoneurial vessels was found only in the oldest patient and the degeneration of nerve fibres generally observed thus is considered not to be caused by ischaemia. Histopathology in epi-and perineurial vessels was definitely less pronounced than in endoneurial vessels.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00690562
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  • 49
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    Tissue distribution of 14C-heteronium bromide: Radioactivity levels at different time intervals after oral administration in the rat (1976)
    Springer
    Naunyn-Schmiedeberg's archives of pharmacology 294 (1976), S. 109-113 
    Details
    ISSN: 1432-1912
    Keywords: 14C-Heteronium bromide ; Drug distribution ; Rat ; Anticholinergic agent
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary The tissue distribution of radioactivity after oral administration to rats of 14C-heteronium bromide is measured by liquid scintillation counting and the results expressed as specific activity and percentage of administered radioactivity. From the data obtained in blood, liver, kidney, stomach, duodenum, cecum, large intestine and stool some conclusions can be drawn. Heteronium bromide undergoes a rapid systemic absorption, the radioactivity being present as early as 15 min from the administration, in all the tested organs. The blood levels show two peaks: one at 120 min and a second at 360 min. This diphasic behaviour can be explained either by the presence of an active enterohepatic circulation, as indirectly indicated by the data from liver and duodenum, or by a transient shift of the molecule from blood to other tissues, rich in polysulfuronic acids. The principal route of excretion is represented by the kidney, where consistent levels are reached at 120 min, while the intestinal route becomes evident at 240 min and reaches its maximum at 720 min. The complete metabolic cycle of the compound is long lasting, since in all the tested tissues, marked radioactivity levels are still present after 720 min. The pharmacokinetic profile obtained, suggesting a long persistence of the drug and/or of its metabolites in the organism, is in agreement with previous pharmacodynamic data showing a long lasting action for heteronium bromide.
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    URL: http://dx.doi.org/10.1007/BF00507842
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  • 50
    Electronic Resource
    Electronic Resource
    Effects of acetylcholine and atropine on the bile flow and biliary excretion of digoxin in the isolated perfused rat liver (1976)
    Springer
    Naunyn-Schmiedeberg's archives of pharmacology 295 (1976), S. 165-169 
    Details
    ISSN: 1432-1912
    Keywords: Digoxin ; Bile flow ; Biliary excretion ; Acetylcholine ; Atropine ; Rat
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary The effects of acetylcholine (ACh), physostigmine, and atropine on bile flow and biliary elimination of digoxin were investigated using isolated rat liver perfusion. 1. ACh in the presence of physostigmine caused a temporary reduction in the bile secretion, while physostigmine alone had no effect on the bile flow. 2. The biliary concentration of radioactivity derived from 3H-digoxin was slightly decreased after an addition of physostigmine alone. This effect of physostigmine was not potentiated by ACh. 3. The addition of ACh decreased transiently the biliary elimination of digoxin, as a result of the reduced bile flow. 4. Atropine in the concentration range of 10−6–10−5 M in the perfusion medium did not affect bile flow or biliary excretion of digoxin; repeated addition of atropine (2×2×10−4 M) caused a choleresis lasting over the perfusion period. 5. This choleresis induced by atropine was associated with decreased concentration of tritium in the bile but slightly increased biliary elimination of total radioactivity. 6. The results allow us to draw the conclusion that ACh in the presence of physostigmine has an inhibitory action on bile flow and biliary elimination of digoxin in the isolated perfused rat liver.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00499450
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  • 51
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    Differential effects of chlordiazepoxide on simultaneous and successive brightness discrimination learning in rats (1976)
    Springer
    Psychopharmacology 48 (1976), S. 75-78 
    Details
    ISSN: 1432-2072
    Keywords: Chlordiazepoxide ; Rat ; Simultaneous discrimination ; Successive discrimination
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Abstract Chlordiazepoxide (CDP) at a dose of 20 mg/kg, i.p. was found to exert a marked disruptive effect on black-white successive discrimination learning in rats, while this effect failed to be obtained on black-gray simultaneous discrimination. Since trials to the learning criterion were found almost equal for saline rats on both successive and simultaneous discrimination tasks, the differential inhibitory effects of CDP could not be accounted for in terms of differences in difficulties of the two tasks. It is suggested that present results might be interpreted in terms of the hypotheses (a) that CDP produces a deficit in the integration of relevant stimulus cues when they were presented across trials or (b) that CDP has a dis-inhibitory effect in that inhibition of dominant response (positional preference) patterns is weakened by the drug, in a manner similar to effects observed in hippocampectomized animals.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00423309
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  • 52
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    Eine Apparatur zur Messung motorischer Funktionsstörungen bei Ratten (1976)
    Springer
    Psychopharmacology 50 (1976), S. 281-283 
    Details
    ISSN: 1432-2072
    Keywords: Motor incoordination ; Runway test ; Diazepam ; Phenobarbital ; Chlorpromazine ; Rat
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Abstract A runway apparatus for rats has been developed for measuring motor incoordination and running time. Animals were trained to run along an elevated narrow pathway. Frequency and severity of slipping off and running time were automatically counted. Rats were given diazepam, phenobarbital or chlorpromazine orally and tested 1 h later. Diazepam, 8–64 mg/kg p.o., caused slipping off in a dose-dependent manner. Phenobarbital had a similar effect with 64 mg/kg p.o. Chloropromazine, 32 and 64 mg/kg p.o., caused other signs of motor deficit.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00426845
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  • 53
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    Electronic Resource
    Differential effects of para-chlorophenylalanine on self-stimulation in caudate-putamen and lateral hypothalamus (1976)
    Springer
    Psychopharmacology 49 (1976), S. 23-27 
    Details
    ISSN: 1432-2072
    Keywords: Intracranial self-stimulation ; Caudateputamen ; Hypothalamus ; Serotonin ; Dopamine ; Para-chlorophenylalanine ; Rat
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Abstract Rats were prepared with chronic bipolar electrodes aimed at either the caudate-putamen or lateral hypothalamus and those displaying consistent self-stimulation were given additional training at half-maximal current intensities. All subjects received an intragastric injection of para-chlorophenylalanine (400 mg/kg) and self-stimulation tests continued until pre-injection rates were re-established. Responding in both brain areas was suppressed 24 h after drug treatment. The next day, self-stimulation rates in the hypothalamus increased to 115% of pre-drug levels reaching a level of 180% by the third day of post-drug testing. In contrast, self-stimulation of sites in the neostriatum continued to decline, with minimal levels reaching 48% of control on the fourth post-drug day. Self-stimulation rates in both groups had returned to control levels by post-drug day 6. These data indicate that the role of serotonergic mechanisms in brain stimulation is locus specific, and that the specific nature of this role may be determined by interaction with other neurochemical systems. The possible interaction between dopaminergic and serotinergic mechanisms in the neostriatum is discussed as a model of self-stimulation in this region of the brain.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00427466
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  • 54
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    A comparison of the central actions of prostaglandins A1, E1, E2, F1α, and F2α in the rat (1976)
    Springer
    Psychopharmacology 50 (1976), S. 89-94 
    Details
    ISSN: 1432-2072
    Keywords: Prostaglandins A1, E1, E2, F1α, F2α ; Intraventricular administration ; Rat ; Behavior
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Abstract The effect of prostaglandins (PGs) A1, E1, E2, F1α, and F2α administered intraventricularly at doses of 0.02–4.0 μg/rat were studied in some behavioral, antinociceptive and anticonvulsant tests in rats. Exploratory and locomotor activity were decreased by all PGs except A1 and F2α which had no effect on locomotor activity. All PGs studied, except A1, induced hyperthermia and afforded protection in the ‘hot-plate’ analgesic test and against maximal electroshock seizures.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00634161
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  • 55
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    Effect of unit dose and route of administration on self-administration of morphine (1976)
    Springer
    Psychopharmacology 50 (1976), S. 103-105 
    Details
    ISSN: 1432-2072
    Keywords: Intravenous ; Intragastric ; Self-Administration ; Unit dose ; Route of administration ; Rat
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Abstract Rats were implanted with intravenous or intragastric cannulas and allowed to self-administer morphine sulfate in doses of 0 (saline), 0.03, 0.1, 0.3, 1.0, 3.0, and 10.0 mg/kg/infusion. For the intravenous route the number of infusions decreased with increasing unit dose, while the amount self-administered was directly related to unit dose. However, for the intragastric route the number of infusions first increased and then decreased as unit dose was elevated, while the amount self-administered again increased with unit dose. Comparisons between routes showed that for intragastric subjects the number of infusions and amount self-administered both were lower at the two lowest doses but higher for all other doses. These results support the expectation that intravenous injection should produce more potent reinforcing effects than intragastric administration.
    Type of Medium: Electronic Resource
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    Changes of plasma volume and plasma composition in water-deprived rats (1976)
    Springer
    Pflügers Archiv 365 (1976), S. 191-196 
    Details
    ISSN: 1432-2013
    Keywords: Plasma volume ; Protein ; Electrolytes ; Dehydration ; Rat
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary Plasma volume, hematocrit, protein and electrolyte concentrations in plasma were measured in control and water-deprived rats every three days after starting the experiment until the 15th day. Plasma volume variations, as related to body weight, suggest that water loss from plasma was proportional to total body water at three days and after 9 days of water deprivation. Greater plasma water than body water loss was found during the period between 3 and 9 days. Plasma protein and electrolyte variations suggest that during water deprivation there is a loss of protein, sodium and potassium from plasma, which is proportionally less than that of plasma water. Potassium, calcium and inorganic phosphorus were lost proportionally to plasma water. The variations in plasma volume changes were partially explained as due to variations in plasma protein and electrolyte concentrations.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF01067018
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  • 57
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    Functional and anatomical characteristics of the nerve-brown adipose interaction in the rat (1976)
    Springer
    Pflügers Archiv 365 (1976), S. 9-14 
    Details
    ISSN: 1432-2013
    Keywords: Brown adipose tissue ; Adipose innervation ; Rat ; Nonshivering heat production
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary Two aspects of the coupling of neural information to brown fat thermogenesis were examined—namely, the thermal responses to increasing neural stimulation and the anatomical nature of the brown fat innervation. Upon stimulation of the nerves to the interscapular brown fat pad, there ensued a biphasic response. This response was manifested by an initial, but transient temperature decrease, followed by a rise in brown fat temperature. The magnitude of both components of this response increased with increasing stimulus strength, thereby demonstrating the ability of the tissue to respond in a graded manner—a feature which may underlie the controlled thermogenic response of brown fat observed in the cold-exposed intact animal. No anatomically unique fiber types appeared to be specifically associated with innervation to the brown adipocytes or to the vessels within the fat pad. On the other hand, the nerves entering the interscapular fat pad were morphologically dissimilar, a finding consonent with their functional dissimilarity (i.e., innervation of adipocytes, innervation of blood vessels in the fat pad, and innervation of areas in the overlying skin).
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    URL: http://dx.doi.org/10.1007/BF00583622
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    Rythmes circadiens des températures internes et ambiance thermique chez le rat (1976)
    Springer
    Pflügers Archiv 365 (1976), S. 183-189 
    Details
    ISSN: 1432-2013
    Keywords: Temperature regulation ; Circadian rhythms ; Ambiant temperature ; Rat
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Description / Table of Contents: Résumé L'enregistrement chronique des températures cérébelleuses et sous-cutanées par thermistance a été réalisé chez le rat soumis à différentes températures ambiantes et à une alternance lumière-obscurité de 12 h (lumière de 7 à 19 h). La période du rythme des températures cérébelleuses et sous-cutanées est de 24 h avec acrophase nocturne (1 h) et amplitude de 0,75° C. L'amplitude et l'acrophase ne sont pas modifiées au cours des expositions à différentes températures ambiantes (20-25-30-34-35° C). Chaque augmentation d'ambiance se traduit par une élévation du niveau moyen de la température interne. Cette augmentation, peu perceptible entre 25 et 30° C, atteint 0,5° C entre 20 et 25° C et 1° C entre 30 et 34° C. Elle se maintient tout au long des 10 jours d'observation. Ces résultats soulèvent au moins 3 questions: le degré de liaison entre les rythmes d'activité (éveil) et de température, la labilité de la température interne qui varie avec l'ambiance alors que l'amplitude du rythme circadien reste constante, l'absence de diminution de la température interne après plusieurs jours en ambiance chaude alors qu'activité et métabolisme sont diminués dès le 2ème jour d'exposition.
    Notes: Summary Chronic recording of cerebellar and subcutaneous temperatures were carried out in rats maintained at different ambient temperatures in a 12 h light-dark cycle (light from 7 to 19 h). Cerebellar and subcutaneous temperatures followed a rhythm with a period of 24 h with acrophase at 1 h and an amplitude of 0.75° C. The amplitude and acrophase were not altered by modification of the ambient temperature (20-25-30-34 or 35° C), but each elevation of ambient temperature produced a rise in the mean internal temperature of the rat. This rise, hardly perceptible at ambient temperatures, of 25 and 30° C, reaches 0.5° C between 20 and 25° C and 1° C between 30 and 34° C. This elevation of temperature was maintained for the duration of the 10 days of observation. These results pose at least three questions: the degree of liaison between the rhythms of activity (waking) and temperature; the lability of the mean internal temperature, which alter with ambient temperature while the amplitude of the circadian rhythm is unaltered and the absence of reduction of mean internal temperature several days exposure to a raised ambient temperature, even when activity and metabolism are reduced by the second day of exposure.
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    URL: http://dx.doi.org/10.1007/BF01067017
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    Early embryogenesis in Tropaeolum majus L.: Diversification of plastids (1976)
    Springer
    Planta 133 (1976), S. 15-19 
    Details
    ISSN: 1432-2048
    Keywords: Tropaeolum, Embryogenesis ; Differentiation ; Plastids ; Ultrastructure
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract Embryogeny in the nasturtium is characterized by the development of a large, tripartite suspensor and storing cotyledons. A light and electron microscopic study revealed an early diversification of the plastids in the various regions of the suspensor and the embryo proper. Amyloplasts are found in the developing cotyledons of the heart-like embryo, while chloroplasts occur within the meristematic part of the embryo and the adjacent portion of the suspensor. The cells between the meristem and the storing cotyledons display undifferentiated leukoplasts, whereas leukoplasts with an electron-dense matrix occur in the basal cell mass of the embryo-suspensor. Etioplasts develop in several cells of the placental haustorium of the suspensor. The carpel haustorium shows rather undifferentiated leukoplasts, which are transformed into electron-dense plastids during autolysis of the suspensor. This early plastidal differentiation in discussed with respect to its control and functional significance.
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    URL: http://dx.doi.org/10.1007/BF00386000
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  • 60
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    Circadian rhythm of the renin-angiotensin-aldosterone system in the rat (1976)
    Springer
    Archives of toxicology 36 (1976), S. 305-316 
    Details
    ISSN: 1432-0738
    Keywords: Circadian rhythm ; Renin ; Aldosterone ; Corticosterone ; Rat
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Description / Table of Contents: Zusammenfassung Der 24 Std-Verlauf der Plasma-Renin-Aktivität (PRA), der Plasma-Aldosteron-Konzentration (PAC), der Plasma-Corticosteron-Konzentration (PCC) sowie der Urinexkretion von Natrium, Kalium und Aldosteron wurde an männlichen Sprague-Dawley-Ratten unter verschiedenen experimentellen Bedingungen untersucht. Die Ergebnisse lassen sich wie folgt zusammenfassen: 1. Das Renin-Angiotensin-Aldosteron-System (RAAS) der Ratte weist einen zirkadianen Rhythmus auf, der dem gut bekannten Rhythmus des Hypophysen Nebennierenrinden-Systems parallel läuft. Dieser Rhythmus läßt sich durch Messung der PRA, der PAC und der Exkretionsrate von Aldosteron im Urin nachweisen. Der Rhythmus der Elektrolytausscheidung im Urin scheint nicht durch den Rhythmus der Aldosteronsekretion bedingt zu sein. 2. Der Licht-Dunkel-Zyklus ist der Zeitgeber für diese Rhythmen: Eine Umkehr des Licht-Dunkel-Zyklus für 5 Wochen bewirkt eine komplette Umkehr der Rhythmen aller genannten Parameter. 3. Unter Natrium-Restriktion oder Dexamethason-Behandlung wird eine Dissoziation des Rhythmus der PRA von dem der PAC beobachtet, während der Rhythmus der PAC unter allen Versuchsbedingungen mit dem der PCC parallel geht. Diese Beobachtung legt den Schluß nahe, daß das ACTH an der Steuerung des Rhythmus der Aldosteronsekretion beteiligt ist. 4. Der Grad der Stimulierbarkeit bzw. Supprimierbarkeit des RAAS unterliegt tageszeitlichen Schwankungen. 5. Es wird daher empfohlen, bei Untersuchungen über das RAAS der Ratte die Experimente nicht nur während der Inaktivitätsperiode (Lichtphase), sondern auch während der Aktivitätsperiode (Dunkelphase) dieser Tiere durchzuführen. Dies läßt sich durch Benutzung eines Tierstalls mit umgekehrtem Licht-DunkelZyklus vereinfachen.
    Notes: Abstract The 24 h-course of plasma renin activity (PRA), plasma aldosterone concentration (PAC), plasma corticosterone concentration (PCC) and of the urinary excretion of sodium, potassium and aldosterone was investigated in male Sprague-Dawley rats under different experimental conditions. The data obtained can be summarized as follows: 1. The renin-angiotensin-aldosterone system (RAAS) of the rat is subject to a circadian rhythm which is largely in phase with the well-known rhythm of the pituitary-adrenal axis. This rhythm can be demonstrated in PRA as well as in plasma concentrations and urinary excretion rates of aldosterone. The rhythm of urinary excretion of electrolytes is unlikely to be due to the rhythm of aldosterone secretion. 2. The light-dark cycle is the main synchronizer for these rhythms: inverting the light-dark cycle for 5 weeks entirely inverts the rhythms of all the parameters cited. 3. A dissociation of the rhythms of PRA and PAC can be observed following sodium restriction or dexamethasone treatment. A role of ACTH in regulating the rhythmic pattern of aldosterone secretion is suggested by the finding that PAC and PCC follow the same pattern of circadian variations under every experimental condition tested. 4. The responsiveness of the RAAS to stimulation or suppression varies with the time of day. 5. It is suggested that experiments ought to be performed not only during the inactive (light hours) but also during the active (dark hours) phase when investigating the RAAS in the rat. This can conveniently be achieved by the use of an animal room with a reversed lighting regime.
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    The excretion and distribution of inorganic mercury in the rat as influenced by several chelating agents (1976)
    Springer
    Archives of toxicology 35 (1976), S. 15-24 
    Details
    ISSN: 1432-0738
    Keywords: Inorganic mercury ; Chelating agents ; Excretion ; Distribution ; Rat ; Anorganisches Quecksilber ; Chelatbildner ; Ausscheidung ; Verteilung ; Ratte
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Description / Table of Contents: Zusammenfassung Unter 15 untersuchten Chelatbildnern wurden die Ausscheidung und Organ-verteilung von Hg nur durch Natrium-2,3-Dimercaptopropan-1-sulfonat (DMPS), 2,3-Dimercaptopropanol (BAL), Natrium-Mercaptoäthyliminodiacetat (MEIDA) und D-Penicillamin (PA) beeinflußt. Das Ausscheidungsmuster ist jedoch bei diesen Substanzen unterschiedlich, und einen praktisch günstigen Effekt zeigt nur DMPS, das die renale Ausscheidungsrate erhöht und die Hg-Konzentration in allen Organen senkt.
    Notes: Abstract Among 15 chelating agents tested, sodium-2,3-dimercaptopropane-1-sulfonate (DMPS), 2,3-dimercaptopropanol (BAL), sodium-mercaptoethyliminodiacetate (MEIDA), and D-penicillamine (PA) exerted an influence on the excretion of Hg and its distribution in the organs. The excretion pattern, however, is different for these compounds, and, from the practical point of view, a favourable effect is exhibited only by DMPS which enhances the urinary excretion rate and lowers the Hg-concentration in all organs.
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    URL: http://dx.doi.org/10.1007/BF00333982
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    Dichlorvos — a 2-year inhalation carcinogenesis study in rats (1976)
    Springer
    Archives of toxicology 35 (1976), S. 281-294 
    Details
    ISSN: 1432-0738
    Keywords: Dichlorvos ; Inhalation toxicity ; Rat ; Carcinogenesis ; Dichlorvos ; Inhalation-Toxizität ; Ratte ; Karzinogenese
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Description / Table of Contents: Zusammenfassung In den vorliegenden Untersuchungen wurde der Effekt von Dichlorvos-Inhalation in Beziehung zur Krebserzeugung bei Ratten (5 Wochen alte Carworth Farm E, 94–150 g) langfristig (2 Jahre) in Konzentrationen von 0, 0,05, 0,5 und 5 mg/m3 geprüft. Das Wachstum aller geprüften Tiere, im besonderen der männlichen, war verzögert. Bei Exposition in 5 mg/m3 war die Überlebensrate von Ratten erhöht. Die verschiedenen Gruppen zeigten keinen Unterschied in Futteraufnahme, Organgewichten, hämatologischen oder chemischen Bestimmungen, mit Ausnahme der Cholinesterase-Aktivität. Nach einer 2jährigen Inhalation wurden keine Unterschiede des Gehaltes an Acetylcholin und Cholin in einer kleineren Zahl weiblicher Tiere gefunden. Makro- oder mikroskopische Veränderungen in den Rattengeweben, die auf Dichlorvos zurückzuführen wären, wurden nicht beobachtet. Auch die Ultrastruktur der Lungengewebe von Kontrollratten und der Ratten in 5 mg/m3 zeigte keine Veränderungen, die von Dichlorvos abhängig waren. Die Ergebnisse einer “relative risk analysis” der vorliegenden Tumorversuchsreihe haben keine dosisabhängige Erhöhung des Tumorrisikos für Ratten beider Geschlechter gezeigt. Die Befunde sind in Übereinstimmung mit früheren und sprechen für die Unbedenklichkeit des Gebrauchs von Dichlorvos als Insektizid.
    Notes: Summary To determine the effects of dichlorvos vapour on the tumour incidence in rats, 5 week old Carworth Farm E strain rats weighing between 94 and 150 g were exposed to 0, 0.05, 0.5 and 5.0 mg/m3 in a 2-year inhalation study. The growth rate of all treated rats was depressed, particularly in the males. There was increased survival of the rats exposed to 5 mg/m3. There were no consistent differences in food intakes, organ weights, haematological or blood chemistry estimations, except in cholinesterase activities, amongst the various groups of rats. No compound-related differences were seen in acetylcholine and choline estimations carried out on a small number of female rats' brain tissues after two years' exposure. There were no gross or microscopical compound-related changes in the rats' tissues. Ultrastructural examination of the respiratory tissues of the rats from the control and 5 mg/m3 group showed no changes attributable to dichlorvos. The results of a relative risk analysis of the tumour data showed that no dose-related increase in tumour risk was established for rats of either sex. These data confirm the results of earlier studies supporting the safety of insecticidal uses of dichlorvos.
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    URL: http://dx.doi.org/10.1007/BF00570270
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    Effects of cadmium on carbonic anhydrase activity and hemoglobin content of rat testes (1976)
    Springer
    Archives of toxicology 37 (1976), S. 39-46 
    Details
    ISSN: 1432-0738
    Keywords: Cadmium ; Carbonic anhydrase ; Hemoglobin ; Blood ; Testes ; Rat
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Description / Table of Contents: Zusammenfassung Die bei Säugetieren durch Cadmium (Cd) hervorgerufenen Hodenschäden beruhen angeblich auf einer Hemmung der Carboanhydratase (CAH). Da Cd dosisabhängig die Hodendurchblutung beeinflußt, könnte jedoch durch eine Verminderung der Zahl CAH-reicher Erythrocyten eine Hemmung der CAH im Hoden vorgetäuscht werden. Wir bestimmten deshalb CAH-Aktivitäten und Hämoglobin (Hb)-Gehalt im Blut und im Hoden von unbehandelten und Cd-behandelten Sprague-Dawley-Ratten. Entsprechende Untersuchungen wurden an Ratten-Hoden durchgeführt, die vorher über die a. testicularis perfundiert worden waren. Die Ratten erhielten Cd intraperitoneal als CdCl2 jeweils in Einzeldosen von 1,5, 3,0 und 5,0 mg Cd2+/kg Körpergewicht. 1. Die Untersuchungen an perfundierten Hoden zeigten deutlich, daß die im Hodengewebe bestimmten CAH-Aktivitäten nicht einer Hoden-CAH sondern vielmehr der Erythrocyten-CAH zuzuordnen sind. 2. Bei den Cd-behandelten Ratten beobachteten wir kurze Zeit (0,25–1,0 h) nach der Cd-Zufuhr zunächst reversible Durchblutungsänderungen. Sie bestanden in Abhängigkeit von der Cd-Dosis sowohl in einer vorübergehenden Abnahme (1,5 mg Cd2+/kg) als auch in einer Zunahme (3,0 bzw. 5,0 mg Cd2+/kg) des Hb-Gehaltes im Hoden. 3. Unabhängig von diesen geringfügigen Durchblutungsänderungen kam es später (14–24 h nach 1,5 mg Cd2+/kg, 7–14 h nach 3,0 mg Cd2+/kg und 1–3 h nach 5,0 mg Cd2+/kg) zu den bekannten hämorrhagischen Hodenveränderungen mit einer starken Zunahme des Hb-Gehaltes und der CAH-Aktivität. 4. Anhand der Korrelationen zwischen CAH-Aktivität und Hb-Gehalt im Blut und im Hoden konnte eine Hemmung der CAH als primäre Ursache der Cd induzierten Hodenschäden ausgeschlossen werden.
    Notes: Abstract The cadmium-induced (Cd) damage of mammalian testes is thought to be correlated with an inhibition of carbonic anhydrase (CAH) by Cd. Since Cd causes dose-dependent changes in blood flow of the testes, an inhibition of CAH in the testes could be simulated by a decrease of CAH-rich erythrocytes. Therefore, CAH activities and hemoglobin (Hb) content were determined in blood and testes of untreated and Cd-treated Sprague-Dawley rats as well as in testes perfused via the testicular artery. Cd was intraperitoneally applied as CdCl2 in single doses of 1.5, 3.0, and 5.0 mg Cd2+/kg b.w., respectively. 1. The experiments on perfused testes clearly demonstrated that the CAH activities originate from erythrocytes rather than from a tissue located enzyme. 2. The alterations in blood circulation occurring shortly (0.25–1.0 h) after the Cd administration were characterized by a dose-dependent, transient decrease (1.5 mg Cd2+/kg) as well as an increase (3.0 and 5.0 mg Cd2+, respectively) of the Hb content in the testes. 3. Independent of these minor alterations in a later state (14–24 h after 1.5 mg Cd2+/kg, 7–14 h after 3.0 mg Cd2+/kg, and 1–3 after 5.0 mg Cd2+/kg), Cd induced the well known hemorrhagic alterations of the testes with a high increase of Hb content and CAH activity. 4. By means of the correlations between CAH activities and Hb content in blood and testes an inhibition of the CAH by Cd as the primary cause for the tissue damage of the testes could largely be excluded.
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    Prevention by steroids of cerium hepatotoxicity (1976)
    Springer
    Archives of toxicology 35 (1976), S. 115-125 
    Details
    ISSN: 1432-0738
    Keywords: Cerium ; Microsomal enzyme inducers ; Pregnenolone-16α-car-bonitrile ; Estradiol ; Fatty liver ; Ultrastructure ; Triglycerides ; Cerium ; Arzneimittelmetabolisierende Enzyme ; Pregneno-lon-16α-carbonitril „PCN“ ; Oestradiol ; Leberverfettung ; Elektronenmi-kroskopie ; Triglyceride
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Description / Table of Contents: Zusammenfassung Nach Vorbehandlung mit Steroiden und mit nicht steroidartigen Substanzen (Pregnenolon-16α-carbonitril „PCN“, Dexamethason, Spironolacton, Phenobarbital), welche die arzneimittelmetabolisierenden Enzyme der Leber stimulieren, und nach Oestradiol, wurde die Sterblichkeit und die Lebertoxicität der weiblichen Ratte erheblich verändert. PCN, Oestradiol, Dexamethason senken die hepatischen Triglyceride wesentlich, jedoch erhöht Dexamethason die Sensitivität der Tiere für CeCl3 bedeutend. Spironolacton und Phenobarbital üben keine große Wirkung auf die Triglyceride aus. Licht- und Elektronenmikroskopie zeigten, daß die durch CeCl3 hervorgerufenen hepatocellulären Veränderungen durch PCN, Oestradiol und Dexamethason bedeutend verringert wurden. Die Steroide dürften die Verteilung und die Bindung des Metalles an das endoplasmatische Reticulum verändern, und somit diese Membranen vor Cerium schützen.
    Notes: Abstract In female rats, the lethality and hepatotoxicity of cerous chloride (CeCl3) were significantly altered by pretreatment with steroidal and nonsteroidal compounds (pregnenolone-16α-carbonitrile “PCN”, dexamethasone, spironolactone, phenobarbital) that stimulate hepatic drug-metabolizing enzyme activity and by estradiol. PCN, estradiol, and dexamethasone considerably decreased hepatic triglycerides, but the latter steroid also greatly sensitized the animals to CeCl3 lethality. Spironolactone and phenobarbital similarly lowered the triglyceride level but not significantly. Light and electron microscopy indicated that the hepatocytic damage elicited by CeCl3 was decreased significantly by PCN, estradiol, and dexamethasone. The steroids may have altered the distribution and binding of the metal to the endoplasmic reticulum (ER) thus protecting these membranes against the effect of cerium.
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    URL: http://dx.doi.org/10.1007/BF00372765
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    Zur Toxikologie von Carbromal (1976)
    Springer
    Archives of toxicology 36 (1976), S. 31-42 
    Details
    ISSN: 1432-0738
    Keywords: Carbromal ; Bromoethylbutyramide ; Ethylbutyrylurea ; Bromide ; Rat ; Humans ; Gaschromatography ; Carbromal ; Carbromid ; Äthylbutyrylharnstoff ; Gesamtbromid ; Ratte ; Mensch ; Gaschromatographie
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Description / Table of Contents: Zusammenfassung Die Interpretation toxischer Effekte von Carbromal erforderte Daten über die im Organismus wirksamen Substanzen. Diese Information kann mit einem einfachen gaschromatographischen Verfahren erhalten werden, mit dem Carbromal und seine sedierend wirksamen Metabolite Carbromid und Äthylbutyrylharnstoff spezifisch, quantitativ und sehr empfindlich in Geweben erfaßt werden können. Bei Einsatz verschiedener Detektorsysteme (Flammenionisations- bzw. Elektroneneinfangdetektor) liegt die untere Nachweisgrenze bei 2–3 nMol der genannten Stoffe je Gramm Gewebe. Die Methode wird in Versuchen an der Ratte demonstriert, bei denen in Serum und Gehirn die Resorption und Elimination von Carbromal einschließlich seiner Biotransformation zu Carbromid und Äthylbutyrylharnstoff verfolgt wurden. Es traten nennenswerte Mengen der Metabolite Carbromid und Äthylbutyrylharnstoffe auf, die sich wie Carbromal gleichmäßig zwischen Serum und Gehirn verteilen, jedoch länger im Organismus nachweisbar waren als Carbromal. Nach Aufnahme einer therapeutischen Carbromaldosis (1 g = 4,22 mMol) durch vier gesunde Versuchspersonen traten 30 min nach Ingestion die höchsten Carbromalkonzentrationen im Serum auf (bis 30 nMol/ml). Sie fielen rasch ab, in 24 Std auf 3–4 % der Höchstwerte. Neben Carbromal fanden sich im Serum 4–5 Std nach Aufnahme erhebliche Mengen von Carbromid (bis 20 nMol/ml), aber nur geringe Mengen an Äthylbutyrylharnstoff (2–3 nMol/ml). Beide Metabolite konnten wie bei der Ratte länger im Serum gemessen werden als unverändertes Carbromal. Parallelbestimmungen des Gesamtbromidgehaltes in Serum und Gehirn der Ratte und im Serum des Menschen zeigten, daß die Konzentrationen der hypnotisch aktiven Substanzen rasch abfielen, während anorganisches Bromid wesentlich langsamer ausgeschieden wurde.
    Notes: Abstract To analyze the toxic effects of carbromal it was necessary to have information on the concentrations of carbromal and of its metabolites in the organism. This information can be obtained by a simple method based on gaschromatography that allows rapid, specific, sensitive and quantitative estimation of carbromal and of its hypnotically active metabolites bromoethylbutyramide and ethylbutyrylurea. Employing different detectors (flame ionisation or electron capture detector) the limit of detection for carbromal and of its two metabolites was 2–3 nmoles/g of tissue. The method was used to study in rats the absoption and elimination of carbromal including biotransformation of carbromal to bromoethylbutyramide and ethylbutyrylurea. Both metabolites, significant amounts of which were found in serum and brain, distribute evenly between serum and brain as does carbromal. Both metabolites were detectable in the organism for a longer time than carbromal. Carbromal was given orally to 4 healthy volunteers at a dose of l g (4.2 mmoles). Highest serum concentrations (30 nmoles/ml) were found 30 min after ingestion. Serum concentrations declined rapidly. Twenty-four hours later 3–4% of the values were present in the serum. Beside carbromal considerable amounts (up to 20 nmoles/ml) of bromoethylbutyramide were detected but only small amounts (2–3 nmoles/ml) of ethylbutyrylurea. Peak concentrations of these metabolites were recorded 4–5 h after ingestion of carbromal. As was the case in rats both metabolites were present in the organism for a longer time than carbromal. Carbromal was given orally to 4 healthy volunteers at a dose of l g (4.2 mmoles). Highest serum concentrations (30 nmoles/ml) were found 30 min after ingestion. Serum concentrations declined rapidly. Twenty-four hours later 3–4% of the values were present in the serum. Beside carbromal considerable amounts (up to 20 nmoles/ml) of bromoethylbutyramide were detected but only small amounts (2–3 nmoles/ml) of ethylbutyrylurea. Peak concentrations of hese metabolites were recorded 4–5 h after ingestion of carbromal. As was the case in rats both metabolites were present in the organism for a longer time than carbromal. Parallel determination of total bromide in rat tissues and in human serum showed that the concentrations of the hypnotically active compounds declined rapidly while inorganic bromide was eliminated much more slowly.
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    Ultrastructural investigations of peripheral nerves in neuronal ceroid-lipofuscinoses (NCL) (1976)
    Springer
    Journal of neurology 213 (1976), S. 295-303 
    Details
    ISSN: 1432-1459
    Keywords: Neuronal ceroid lipofuscinosis ; Lipopigments ; Ultrastructure ; π-granules
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Description / Table of Contents: Zusammenfassung Bei einem Patienten mit spätinfantiler und 3 mit juveniler NCL wurden periphere Nerven verschiedener Herkunft (Armplexus, N. suralis und 2 Hirnnerven) elektronenmikroskopisch untersucht. Im Lichtmikroskop wurden keine signifikanten histologischen Veränderungen gefunden. Kurvilineäre und/oder Fingerabdruck-Einschlüsse konnten ultrastrukturell in jedem Fall festgestellt werden, und zwar hauptsächlich in Schwannschen Zellen. Außerdem fanden sich lamelläre π-granulaähnliche Cytosomen. Sie kamen in den juvenilen Fällen gewöhnlich gar nicht und in dem spätinfantilen Fall lediglich vereinzelt mit kurvilineären/Fingerabdruck-Profilen gemeinsam vor. Bei spärlichen Veränderungen an Axonen und Myelinscheiden könnten diese Cytosomen Zeichen einer chronischen Schädigung der Schwannschen zellen sein und die spezifische morphologische Ausprägung eines „cellulären Verschleißprozesses“ darstellen, wie er im Alter und bei der NCL diskutiert wird. Biopsien aus peripheren Nerven eignen sich aufgrund der zahlreichen π-Granula und ihrer Varianten weniger zur Diagnose der NCL als beispielsweise solche der Haut, der Skeletmuskulatur und des Rectums.
    Notes: Summary Specimens of brachial plexus, sural nerve and two cranial nerves of one patient with the Jansky-Bielschowsky type and 3 patients with the Spielmeyer-Sjögren type of NCL were studied by electron microscopy. Significant light microscopic changes were absent in all specimens. Ultrastructurally, curvilinear and/or fingerprint inclusions were present in each case, located chiefly in Schwann cells. These diagnostic findings were, however, overshadowed by masses of lamellar π-granule-like cytosomes, usually not mixed with curvilinear or finger-print profiles in the juvenile cases and only rarely associated with curvilinear profiles in the late infantile case. Since secondary changes of axons and myelin sheaths were mild, these lamellar cytosomes might indicate chronic damage to Schwann cells, perhaps by “wear and tear” as seen in aging as well as NCL. On account of the abundance of π-granules in NCL, peripheral nerve biopsy appears less suitable for confirming this diagnosis than biopsy of skin, striated muscle and rectal tissue.
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    URL: http://dx.doi.org/10.1007/BF00316269
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    Dynamic aspects of peripheral nerve changes in progressive neural muscular atrophy (1976)
    Springer
    Journal of neurology 211 (1976), S. 111-124 
    Details
    ISSN: 1432-1459
    Keywords: Peripheral nerve ; Peroneal muscular atrophy ; Nerve biopsy ; Electron microscopy
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Description / Table of Contents: Zusammenfassung Bei 2 Patienten mit progressiver neuraler Muskelatrophie wurden Nervenbiopsien jeweils in einem frühen und in einem fortgeschrittenerem Stadium der Erkrankung entnommen und verglichen. In beiden Fällen zeigten bereits die frühen Biopsien ein völliges Fehlen der großkalibrigen, dickbemarkten Axone. Ebenfalls als frühe Veränderung wurde eine Erweiterung des endoneuralen Interstitiums festgestellt. Eine geringe Anzahl der vorhandenen bemarkten und unbemarkten Axone in allen Biopsien wies degenerative Veränderungen auf. Die für die progressive neurale Muskelatrophie typische Zwiebelschalenbildung der Schwannschen Zellen — möglicherweise eine Reaktion auf wiederholte De-und Remyelinisierungsvorgänge um dystrophische Axone — trat erst in den späteren Biopsien deutlicher hervor. Hinsichtlich der formalen Genese der hypertrophischen Neuropathie bei neuraler Muskelatrophie sind nach diesen Beobachtungen axonale Dystrophie und interstitielle Veränderungen des Endoneuriums als primäre Entmarkung und Zwiebelschalenbildung als sekundäre Phänomene zu betrachten. Die Möglichkeit einer kausalen Beziehung zwischen axonaler Dystrophie und interstitiellen Veränderungen wird an Hand der vorliegenden Befunde und Literatur diskutiert.
    Notes: Summary Serial nerve biopsies were performed at an early, and at an advanced stage of the disease in 2 patients with progressive neural muscular atrophy. The early biopsy showed a complete loss of the large diameter and thickly myelinated fibres, as well as an expansion of the endoneurial interstitium in both cases. Myelinated and unmyelinated fibres exhibited axonal degeneration in all biopsies occasionally. “Onion bulb” formation, a typical feature of peripheral neuropathy in neural muscular atrophy, was found to be prominent only in the latter biopsies. As regards the formal pathogenesis of hypertrophic neuropathy in neural muscular atrophy, axonal dystrophy and interstitial changes of the endoneurium were regarded as primary phenomena, demyelination and “onion bulb” formation as secondary. A possible causal relation between axonal dystrophy and interstitial changes, observed in these cases, is discussed in the light of the present literature.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00313355
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  • 68
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    Unusual cell structures in tumor-like formations of Gracilaria (Rhodophyta) (1976)
    Springer
    Archives of microbiology 108 (1976), S. 167-174 
    Details
    ISSN: 1432-072X
    Keywords: Red algae ; Gracilaria verrucosa ; Tumor-like formations ; Ultrastructure ; Viruses ; Endoplasmic reticulum ; Plastids
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract This paper deals with electron microscopic observations on cultivated plants of the marine red alga Gracilaria verrucosa which developed simple galls; also sea collected material, without galls, had been studied. The galls showed unusual but characteristic cell structures, caterpillar-like bodies, containing rows of fusiform bodies. These were found mostly in the cytoplasm near the plastids, in one case connected with the endoplasmic reticulum, occasionally even inside the nucleus, and are described here, as far as we know, for the first time. It does not seem probable that the caterpillar-like bodies represent mitochondria or bacteria, but the hypothesis that fusiform bodies are related to virus-like structures is discussed. The normal tissues as well as the gall tissue of the laboratory plants contained, besides plastids typical for the red algae, another type of plastids characterized by tubular thylakoids.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00428947
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  • 69
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    Purification, some properties and quaternary structure of thed-ribulose 1,5-diphosphate carboxylase ofAlcaligenes eutrophus (1976)
    Springer
    Archives of microbiology 110 (1976), S. 157-166 
    Details
    ISSN: 1432-072X
    Keywords: d-Ribulose 1,5-diphosphate carboxylase ; Oxygenase activity ; Quaternary structure ; Electron microscopy ; Alcaligenes eutrophus
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract d-Ribulose 1,5-diphosphate carboxylase has been purified from autotrophically grown cells of the facultative chemolithotrophic hydrogen bacteriumAlcaligenes eutrophus. The enzyme was homogeneous by the criteria of polyacrylamide gel electrophoresis. The molecular weight of the enzyme was 505000 determined by gel filtration and sucrose density gradient centrifugation, and a sedimentation coefficient of 18.2 S was obtained. It was demonstrated by sodium dodecyl sulphate-polyacrylamide gel electrophoresis that the enzyme consists of two types of subunits of molecular weight 52000 and 13000. Electron microscopy on the intact and the partially dissociated enzyme lead to the construction of a model for the quaternary structure of the enzyme which is composed of 8 large and 8 small subunits. The most probable symmetry of the enzyme molecule is 4:2:2. Michaelis constant (K m ) values for ribulose 1,5-diphosphate, Mg2-, and CO2 were 0.59 mM, 0.33 mM, and 0.066 mM measured under air. Oxygen was a competitive inhibitor with respect to CO2 suggesting that the enzyme also exhibits an oxygenase activity. The oxygenolytic cleavage of ribulose 1,5-diphosphate was shown and a 1:1 stoichiometry between oxygen consumption and 3-phosphoglycerate formation observed.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00690223
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  • 70
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    Physiology and fine structure of sporangiospore germination in Piptocephalis unispora prior to infection (1976)
    Springer
    Archives of microbiology 107 (1976), S. 99-107 
    Details
    ISSN: 1432-072X
    Keywords: Piptocephalis unispora ; Mucorales ; Kickxellaceae ; Electron microscopy ; Germination ; Spore swelling ; Sporangiospore
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract Germination of the sporangiospore of Piptocephalis unispora Benjamin, observed by means of light and electron microscopy, involved the formation of a new inner wall which became continous with the inner layer of the wall of the germ tube. The outer wall layer of the germ tube was continous with the original inner wall layer of the dormant spore. Preliminary details of appressorium structure were noted. Nutritional experiments indicated that sporangiospores required external sources of utilisable nitrogen and carbon compounds for maximal swelling and germ tube production. Limited development occurred when either nutrient was supplied singly. Comparison of germination of the asexual spore with that in other Mucorales, especially the Kickxellaceae, has been made, and the merosporangial status in P. unispora discussed.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00427874
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  • 71
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    Microfilament bundles in antheridial nuclei of Achlya ambisexualis E 87 (1976)
    Springer
    Archives of microbiology 107 (1976), S. 113-114 
    Details
    ISSN: 1432-072X
    Keywords: Achlya ; Electron microscopy ; Nuclear microfilaments ; Antheridia ; Mycology
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract This is the first report of intranuclear microfilaments within gametangial nuclei of oömycetous fungi. Longitudinal sections of four to six microfilaments were frequently observed in meiotic antheridial nuclei of Achlya ambisexualis. Each microfilament measured approximately 7–10 nm in diameter. Spindle tubules (25 nm in diameter) were also observed within some of the nuclei possessing microfilaments.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00427876
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  • 72
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    An ammonia-oxidizing bacterium, Nitrosovibrio tenuis nov. gen. nov. sp. (1976)
    Springer
    Archives of microbiology 108 (1976), S. 105-111 
    Details
    ISSN: 1432-072X
    Keywords: Ammonia oxidizing bacterium ; Nitrosovibrio tenuis ; Isolation ; Morphology ; Ultrastructure ; Physiology ; Taxonomy
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract An ammonia-oxidizing, autotroph growing, slender, curved rod was isolated from the soil of Hawaii. It is well distinguishable from any other nitrifying bacteria thus far described by their morphology. The cells are 1.1–3.0 μm long and 0.3–0.4 μm wide. They are motile by means of 1–4 subpolar to lateral flagella. In contrast to most of the ammonia-oxidizing bacteria the isolated vibrio is void of an extensive cytomembrane system. To categorize this not yet described species we propose to create the new genus Nitrosovibrio and to classify the isolated strain as Nitrosovibrio tenuis.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00425099
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  • 73
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    Electron microscopy of isolated cell walls of Bacillus subtilis var. niger (1976)
    Springer
    Archives of microbiology 109 (1976), S. 195-197 
    Details
    ISSN: 1432-072X
    Keywords: Cell wall ; Peptidoglycan ; Electron microscopy ; Bacillus subtilis
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract Isolated cell walls of Bacillus subtilis have a striated appearance in the electron microscope. The structure persists when teichoic acids are removed. It is inferred that the structure bears on the arrangement of the peptidoglycan chains.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00425135
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  • 74
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    Penetration of Phytophthora cinnamomi into disease tolerant and susceptible eucalypts (1976)
    Springer
    Archives of microbiology 108 (1976), S. 231-242 
    Details
    ISSN: 1432-072X
    Keywords: Phytophthora ; Penetration ; Eucalypts ; Roots ; Electron microscopy ; Appressoria ; Plugs
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract The mechanisms of penetration of Phytophthora cinnamomi Rands into seedling eucalypt roots were studied by light and electron microscopy. Culture grown seedlings of root-rot tolerant Eucalyptus st johnii and root-rot susceptible Eucalyptus obliqua were inoculated with both zoospores and mycelium. Zoospores encysted on roots of both species and the germ tubes penetrated without the formation of appressoria. Swellings, previously described as appressoria, were formed when the germ tube was slow to enter the host by intracellular penetration. Vegetative hyphae penetrated both inter- and intracellularly into the zones of root elongation and differentiation, often through root hairs. Evidence of hydrolysis of the host cell-wall at the point of penetration was observed in electron micrographs. Several hours after the germ tube penetrated the epidermis, a thick plug of amorphous material formed in the germ tube slightly below the level of the outer walls of the epidermal cells, sealing off the hypha within the root. Behaviour of zoospores and germ tubes and the mechanism of penetration were similar on both hosts. Micrographs do not suggest any kind of a hypersensitive reaction by the host cells during the early stages of infection.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00454847
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  • 75
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    Ultrastructure of infection of Cokeromyces recurvatus by Piptocephalis unispora (Mucorales) (1976)
    Springer
    Archives of microbiology 109 (1976), S. 277-288 
    Details
    ISSN: 1432-072X
    Keywords: Ultrastructure ; Mucorales ; Piptocephalis ; Mycoparasitism ; Cokeromyces ; Yeastphase ; Appressorium ; Infection peg ; Penetration ; Haustorium
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract Infection of the mucoraceous host Cokeromyces recurvatus by Piptocephalis unispora was studied ultrastructurally, using a new technique involving yeast-phase cells of the host to obtain large numbers of infection sites for thin-sectioning. Morphologically, the haustorial apparatus was similar to that of fungi parasitic on higher plants, and comprised an appressorium, a neck region with a collar and a neck ring, and a lobed region surrounded by a sheath matrix enclosed in an extra-haustorial membrane. Penetration of the host by the infection peg probably involved both enzymatic degradation and physical pressure. Reaction of the host to infection is described and the results related to the theory of host infection by haustorial fungal parasites.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00446639
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  • 76
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    Isolation of a moderate halophilic ammonia-oxidizing bacterium, Nitrosococcus mobilis nov. sp. (1976)
    Springer
    Archives of microbiology 107 (1976), S. 277-282 
    Details
    ISSN: 1432-072X
    Keywords: Nitrosococcus mobilis ; Ammonia oxidizing bacterium ; Morphology ; Ultrastructure ; Physiology
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract An ammonia-oxidizing bacterium was isolated from a sample of brackish water (North Sea, Harbour of Husum). It is a motile large coccus 1.5–1.7 μm in diameter. The extensive cytomembrane system occurring as flattened vesicles in the peripheral region of the cytoplasm and as intrusions into the center of the cytoplasm is to be emphasized as a characteristic mark of identification. The lithoauto-trophically growing bacterium turned out to be an obligate halophile. Because of its physiological and morphological properties, we assigned it to the genus Nitrosoccus and propose the name Nitrosococcus mobilis.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00425339
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  • 77
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    Origin of sclerotia-like cells in submerged Claviceps purpurea producing clavine alkaloids (1976)
    Springer
    Archives of microbiology 107 (1976), S. 321-327 
    Details
    ISSN: 1432-072X
    Keywords: Claviceps purpurea ; Saprophytic ; Clavine alkaloids ; Ultrastructure ; Extended hyphae ; Blastospores
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract Ultrathin sectioning of submerged mycelium of Claviceps purpurea Tul. producing clavine alkaloids revealed yeast-like budding resulting in asexual sporesblastospores. These deciduous spores were born by extended hyphal cells and retained the same ultrastructure of cell organelles. Both the extended hyphae and the blastospores resembled the cells of ergot sclerotial tissue. A surface culture of C. purpurea Tul. producing no alkaloids was used as a reference.
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    URL: http://dx.doi.org/10.1007/BF00425347
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  • 78
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    The fine structure of Micrococcus radiophilus and Micrococcus radioproteolyticus (1976)
    Springer
    Archives of microbiology 107 (1976), S. 313-320 
    Details
    ISSN: 1432-072X
    Keywords: Micrococcus radiophilus ; Micrococcus radioproteolyticus ; Bacterial cell walls ; Fine structure ; Electron microscopy ; Taxonomy
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract The radiation resistant bacteria Micrococcus radiophilus and M. radioproteolyticus were studied by thin sectioning and freeze-etching techniques and the two species were found to be similar in the fine structure. The only significant difference was in the appearance of the surfaces of the cell walls in freeze-etched preparations. Since the two species, together with M. radiodurans, possess a unique cell wall structure and a cell wall peptidoglycan, which is different from that of other micrococci and Gram-positive cocci, it is recommended that they be reclassified into a new genus.
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    URL: http://dx.doi.org/10.1007/BF00425346
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  • 79
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    Alterations in the cell wall of Spirillum serpens VHL early in its association with Bdellovibrio bacteriovorus 109D (1976)
    Springer
    Archives of microbiology 108 (1976), S. 55-64 
    Details
    ISSN: 1432-072X
    Keywords: Bdellovibrio ; Spirillum ; Cell wall ; Bdelloplast ; Lipoprotein ; Peptidoglycan ; Electron microscopy
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract In both freeze-etched and critical-point dried preparations examined by transmission and scanning electron microscopy, respectively, the outer surfaces of the cells of Spirillum serpens VHL assume a wrinkled appearance 10–15 min after challenge by Bdellovibrion bacteriovorus 109D. This wrinkling effect is believed (on circumstantial evidence) to be caused by the bdellovibrio's disruption of the cell wall lipoprotein of the Spirillum. With the exception of those topological changes caused by wrinkling, the outer membrane of the Spirillum cell wall retains a normal appearance as viewed in freeze-etched preparations, even after the Spirillum cell has been converted into a bdelloplast. Although the peptidoglycan layer of the Spirillum cell presumably is weakened somewhat by the invading Bdellovibrio, evidence obtained from freeze-fractured preparations of Spirillum bdelloplasts suggests that the peptidoglycan remains as a discrete cell wall layer, even though the Spirillum cell wall apparently has lost much of its rigidity. That the peptidoglycan backbone remains essentially intact, even after the Spirillum cell has been entered by the Bdellovibrio, is supported by the observation that the soluble amino sugar content of the culture medium, as determined by chemical analysis, does not rise even 5.0 h after the association of the Bdellovibrio with the Spirillum has begun.
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    URL: http://dx.doi.org/10.1007/BF00425093
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  • 80
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    The cytology of the gametes and fertilization of Allomyces macrogynus (1976)
    Springer
    Archives of microbiology 109 (1976), S. 21-30 
    Details
    ISSN: 1432-072X
    Keywords: Electron microscopy ; Allomyces ; Gametes ; Fertilization ; Membrane fusion
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract The gametes and the process of fertilization were examined by light and electron microscopy in the lower eukaryote Allomyces macrogynus. Differences in gamete morphology included the overall larger size and the presence of a larger nuclear apparatus, along with the association of a side-body complex and many more mitochondria in the female gamete. In this species of Allomyces, fertilization was initiated by contact and fusion of specialized regions of the gamete plasma membranes resulting in a binucleate fusion cell surrounded by plasma membrane contributed by both partners. Following plasmogamy, nuclear fusion was initiated by multiple nuclear membrane contacts between adjacent outer membranes. Following inner membrane fusion, small nucleoplasmic bridges were observed which presumably fused with one another and resulted in a single bridge which widened, forming the mature diploid nucleus. After karyogamy, fusion of the nuclear caps did not always occur and zygotes with and without fused caps were observed. Coalescence of the nucleoli completed the events of fertilization, forming a zygote with a single nuclear apparatus (sometimes with two caps) and two flagella. These observations are discussed in relation to fertilization mechanisms and compared to fertilization in other organisms.
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    URL: http://dx.doi.org/10.1007/BF00425108
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  • 81
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    Growth of Nitrobacter in the presence of organic matter (1976)
    Springer
    Archives of microbiology 108 (1976), S. 305-312 
    Details
    ISSN: 1432-072X
    Keywords: Nitrobacter agilis ; Chemoorganotrophic growth ; Acetate ; Formate ; Pyruvate ; Yeast extract-peptone ; Ultrastructure
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract 1. After a resting period of up to 6 months cells of Nitrobacter agilis grow with acetate, formate, and pyruvate as carbon and energy source. Yeast extract and peptone were added to supply the organism with nitrogen and to meet possible vitamin requirements. 2. The length of the growth period depends on the substrate; it increases according to the following sequence: pyruvate, formate, acetate. The highest growth yield is observed with pyruvate, the lowest with formate. 3. O2 consumption is increased in the presence of substrates as compared to endogenous respiration. With pyruvate and acetate twice as much O2 is consumed, with formate 7 times, with yeast extractpeptone 10 times as much. 4. The ability of nitrite oxidation is largely preserved, except in cells grown with acetate or pyruvate in the presence of 0.015% yeast extract and peptone. Such cells have nearly no cytochrome a 1. Accordingly, the cytochrome spectra of nitrite oxidizers grown under chemoorganotrophic and lithoautotrophic conditions coincide qualitatively. 5. The nitrite oxidizing system is inducible. It is induced by nitrite but also by substances present in yeast extract and peptone. Cells grown on acetate and yeast extract and peptone (0.015%) require 3–4 weeks before they regain the ability to grow with nitrite. Cells grown chemoorganotrophically with the same substrates and yeast extract and peptone (0.15%) start growing with nitrite as energy source without a lag. 6. Cell size and form, distribution of storage materials, order and fine structure of double membranes are correlated with growth conditions.
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    URL: http://dx.doi.org/10.1007/BF00454857
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  • 82
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    Structure and composition of intracytoplasmic membranes of Ectothiorhodospira mobilis (1976)
    Springer
    Archives of microbiology 107 (1976), S. 167-182 
    Details
    ISSN: 1432-072X
    Keywords: Ectothiorhodospira mobilis ; Photosynthetic membranes ; Electron microscopy ; Isolation of membranes ; Structure of membranes ; Composition of membranes
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract The lamellar membrane stacks of Ectothiorhodospira mobilis were isolated and purified by a combination of lysozyme and osmotic shock treatment, followed by differential and density gradient centrifugation. Preparations of lamellar membranes were enriched at least 2.4-fold in the ratio of bacteriochlorophyll a to protein. Thin-sectioning, negative staining, platinumcarbon shadowing and freeze-etching were used to study the architecture of the membrane units. Both platinum-carbon shadowing and freeze-etching showed the outer surfaces of the isolated lamellar membrane stacks to be relatively smooth. Particles averaging 7 nm in diameter were seen on several faces following freeze-ctching. Non-polar amino acids amounted to 60% of the total amino acid composition. Lipids constituted 32% of the membrane dry weight. Phosphatidyl ethanolamine and diphosphatidyl glycerol were the major phospholipids. Fatty acids of 10–15 carbons represented a small fraction of both membrane and whole cell fatty acids. Monoenes constituted 36% of the total membrane fatty acids and 38.4% of the total whole cell fatty acids. The major fatty acids of both whole cells and purified membranes were C16:0, C18:1 and cyclopropane C19:0.
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    URL: http://dx.doi.org/10.1007/BF00446836
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  • 83
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    Intracelluläre Organisation phagenschwanz-ähnlicher Bacteriocine der Gruppe A in Serratia marcescens (1976)
    Springer
    Archives of microbiology 111 (1976), S. 175-183 
    Details
    ISSN: 1432-072X
    Keywords: Serratia marcescens ; (Phage tail) bacteriocin ; Electron microscopy
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Description / Table of Contents: Zusammenfassung Die Genese eines phagenschwanzähnlichen Bacteriocins in Zellen des Gruppe A-bacteriocinogenen (bA+) Serratia marcescens-Stammer Nr. 16 wurde nach Mitomycin C (MC) Induktion elektronenoptisch untersucht. Dieses Bacteriocin (Gesamtlänge 117 nm) besteht aus einem hohlen Stift mit kontraktiler Scheide. Nach 60 min Induktion wurden in Dünnschnitten stäbchenförmige Bacteriocine identifiziert. Sie erscheinen in drei Aggregationsformen: 1. als hexagonale Einschlüsse, 2. als Bänder dicht nebeneinanderliegender Bacteriocine und 3. als Stapel von übereinanderliegenden Bacteriocinschichten, wenn nach 120 min Induktion ein Maximum von ca. 450 Bacteriocinen pro Zelle erreicht wird. Bacteriocine konnten nach der gleichen Induktionszeit von 60 min auch mit der “in situ lysis technique” nachgewiesen werden. Neben Bacteriocinen traten relativ selten und unregelmäßig auch Phagenköpfe auf. Die Stäbchenform teilungsfähiger Zellen blieb bis zum Auftreten von intracellulären Bacteriocinen erhalten. Ihre Umwandlung in geblähte, sphäroplastenähnliche Zellformen, die nach 120 min Induktion lysierten, war zeitlich korreliert mit Feinstrukturveränderungen der Zellwand.
    Notes: Abstract The biosynthesis of a phage tail-like Bacteriocin by cells of the group A-bacteriocinogenic (bA+ Serratia marcescens strain no. 16 after induction with mitomycin C (MC) was examined electronmicroscopically. This bacteriocin (total length 117 nm) consists of a hollow core and a contractile sheath. At 60 min following induction, rod-like bacteriocin-partieles were identifiable in ultrathin sections. The particles were found to comprise three morphologically different forms of aggregation: 1. hexagonal inclusions, 2. contiguous, bank-like particles, and 3. staples of superimposed layers of bacteriocin particles. At 120 min after induction bA+ cells revealed maximally 450 bacteriocin particles. Similarly, the phage tail particles could be demonstrated with the “in situ lysis technique” at 60 min following induction. Occasionally, phage heads were demonstrable, but in no instance were complete phage particles discernible. Dividing cells of the bA+ strain of S. marcescens maintained their rod-form following induction with MC until intracellular phage tail bacteriocin particles were seen. However, at 120 min after induction, the swollen, sphaeroplast-like cells lysed, an event that could be correlated with fine structural alterations of the cell wall.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00446566
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    Oral taurine effects on inhibitory behavior: Response transients to step-like schedule changes (1976)
    Springer
    Psychopharmacology 49 (1976), S. 249-252 
    Details
    ISSN: 1432-2072
    Keywords: Response inhibition ; Taurine ; DRL schedule ; Rat ; Response transients ; Defecation ; Frustration ; Temporal discrimination ; Sudden reinforcement schedule changes
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Abstract Rats habituated to DRL 6-s schedules that required response inhibition in order to obtain reward did not alter their total responses or efficiency ratios (response/reinforcement) when placed ad libitum (orally) on 0.9% taurine (1.1±0.4 g/kg/24-h) relative to controls. In three separate experiments, taurine-administered rats did show significantly poorer adjustment profiles (higher response/reinforcement ratios) during the 15 min immediately following step-like increases in inhibition time demand to DRL 12 s. The effect was transient and was not significant in subsequent sessions. Taurine rats had been habituated to a DRL schedule intended to induce ‘frustration’ before the step-change did not differ from the taurine group maintained on the normal DRL schedule. No significant differences were noted between taurine and control groups, either before or after taurine administration or before or after the step-change in inhibition demand, with respect to defecation in the test chamber, daily fluid consumption, body weight or total responses. We concluded that oral taurine may inhibit learning during labile periods of adjustment following sudden changes of input demand but does not influence a well learned or established response pattern. These results imply taurine's role in the brain as a ‘stabilizer’ against short-term input fluctuations.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00426824
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  • 85
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    A comparison of the central actions of prostaglandins A1, E1, E2, F1α, and F2α in the rat (1976)
    Springer
    Psychopharmacology 50 (1976), S. 95-102 
    Details
    ISSN: 1432-2072
    Keywords: Prostaglandins A1, E1, E2, F1α, F2α ; Intraventricular administration ; Rat ; Narcosis ; Catalepsy ; Amphetamine ; α ; MT ; PCPA ; Biogenic amines ; Turnover
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Abstract Prostaglandins (PGs) injected into the right lateral brain ventricle (i.v.c.) of the rat increased the sleeping time induced by hexobarbital, chloral hydrate, and ethanol. PGE1 and PGE2 intensified chlorpromazine-induced catalepsy, inhibited amphetamine hyperactivity, and significantly depressed the amphetamine-induced stereotypy. NA concentrations were decreased by PGE1 and PGE2 and were increased by PGF2α. PGF2α increased both 5-HT and 5-HIAA levels in rat brain. “Total” ACh concentrations were increased by PGF1α and PGF2α. PGE1, PGE2, and PGF2α enhanced the turnover of NA, DA, and 5-HT. PGE2 counteracted the decreased activity induced by α-MT and abolished the hypothermic action of α-MT. PGF2α had little effect on the activity of PCPA pretreated rats, whereas the higher doses of PGF2α increased body temperature in these animals.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00634162
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  • 86
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    Acquisition and loss of behaviorally augmented tolerance to ethanol in the rat (1976)
    Springer
    Psychopharmacology 48 (1976), S. 153-158 
    Details
    ISSN: 1432-2072
    Keywords: Ethanol ; Tolerance ; Rat ; Behavioral augmentation ; Rate
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Abstract The phenomenon of behavioral augmentation of tolerance (BAT) to ethanol (EtOH) in the rat was replicated in studies using the moving belt test of intoxication. Rats performing the test daily under the influence of EtOH (2.2 or 2.5 g/kg i.p.) developed tolerance more rapidly than those receiving the same dose after each daily session on the belt. However, both groups reached the same maximum level of tolerance. Acceleration of tolerance by BAT was proportional to the frequency of performance under the influence of EtOH when total exposure to EtOH was held constant. The degree of tolerance produced by BAT could not be increased by daily gavage with a large dose (6 g/kg) of EtOH. After termination of EtOH administration, tolerance produced by BAT was lost at the same rate, whether or not daily alcohol-free sessions on the belt test were given. These findings are consistent with the hypothesis that BAT and conventionally produced tolerance differ only in rate.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00423254
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  • 87
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    Specificity of innervation of iris musculature by sympathetic nerve fibres in tissue culture (1976)
    Springer
    Pflügers Archiv 361 (1976), S. 127-134 
    Details
    ISSN: 1432-2013
    Keywords: Tissue culture ; Fluorescence histochemistry ; Electrophysiology ; Electron microscopy
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary Irides from 3–5 day old rats have been grown 1–3 mm from superior cervical or lumbar paravertebral sympathetic ganglia in modified Rose chambers. The two muscles of the iris received distinctly different innervation patternsin vitro, and these were similar to those seenin vivo. Varicose, adrenergic fibres were consistently associated with the dilator pupillae rather than with the sphincter pupillae while excitatory, cholinergic junctions developed between the nerve fibres and the muscle cells of the sphincter but not the dilator. There was a lack of specificity shown by the sympathetic neurons during this innervation. Fibres from lumbar ganglia formed plexuses within the dilator similar to those formed by superior cervical fibres, and sympathetic, cholinergic fibres were able to substitute for the normal parasympathetic, cholinergic fibres in the sphincter.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00583456
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  • 88
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    Ontogenetic development of locomotor activity and rate of tyrosine hydroxylation (1976)
    Springer
    Psychopharmacology 49 (1976), S. 119-123 
    Details
    ISSN: 1432-2072
    Keywords: Locomotor activity ; Tyrosine hydroxylation ; Catecholamines ; Ontogenesis ; Rat
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Abstract A combined biochemical and behavioral study was performed postnatally on albino rats. An almost linear increase in total motor activity was observed from 1 to 15 days of age followed by a pronounced decrease in motor activity between days 15 and 18. The in vivo rate of tyrosine hydroxylase activity in whole brain was estimated by means of measuring accumulation of L-3,4-dihydroxyphenylalanine (Dopa) after administration of an inhibitor of aromatic amino acid decarboxylase NSD 1015. Additionally, Dopa accumulation was studied in regional brain areas in 10 and 14-day-old animals. A slight gradual increase in the amount of Dopa accumulation in whole brain was observed from 1 to 10 days of age, followed by a pronounced increase between 10 and 14 days. Regional studies revealed that the increase in Dopa accumulation was primarily located to striatum. The data suggest an involvement of central catecholamine neurons possibly dopaminergic, terminating in striatum. The decrease in motor activity observed after 15 days of age is interpreted as involvement of maturing inhibitory pathways of noncatecholaminergic origin.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00427279
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  • 89
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    Effect of clozapine on the metabolism of serotonin in rat brain (1976)
    Springer
    Psychopharmacology 46 (1976), S. 103-109 
    Details
    ISSN: 1432-2072
    Keywords: Clozapine ; Rat ; Brain ; Tryptophan ; Serotonin ; Neuroleptic drugs
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Abstract Clozapine, but not chlorpromazine, haloperidol, thioridazine, or loxapine, increases the concentrations of tryptophan, serotonin, and 5-hydroxyindoleacetic acid in the brain of the rat. This effect of clozapine is due to an increased serotonin synthesis as demonstrated by an enhanced accumulation of 3H-serotonin in the brain after i.v. infusion of 3H-tryptophan. Clozapine also elevates the plasma concentration of free tryptophan, and reduces the plasma concentration of total tryptophan. Therefore, clozapine may increase the brain serotonin concentration by enhancing the availability of tryptophan in the brain, thereby promoting serotonin synthesis. Measurement of the rate of disappearance from the brain of 3H-serotonin or of endogenous serotonin after synthesis inhibition with 6-fluorotryptophan shows that clozapine has no direct effect on the release and degradation of serotonin. The effect of clozapine on brain serotonergic systems may possibly be related to the pronounced sedative and sleepinducing properties of this drug.
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    URL: http://dx.doi.org/10.1007/BF00421556
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  • 90
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    Zur Ultrastruktur und formalen Pathogenese des embryonalen Rhabdomyosarkoms (1976)
    Springer
    Journal of cancer research and clinical oncology 86 (1976), S. 55-68 
    Details
    ISSN: 1432-1335
    Keywords: Rhabdomyosarcoma ; Rhabdomyoblast ; Cellular Differentiation ; Ultrastructure
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Description / Table of Contents: Zusammenfassung In der vorliegenden Untersuchung werden die cytomorphologischen Merkmale eines embryonalen Rhabdomyosarkoms des Nasenrachenraumes bei einem 10 jährigen Jungen aufgezeigt. Aufgrund der Ultrastruktur lassen sich im Tumor 4 Zelltypen darstellen: 1. Undifferenzierte mesenchymale Tumorzellen mit großem, euchromatischem Zellkern und schmalem, organellenarmem Cytoplasma; 2. undifferenzierte Tumorzellen mit einem Netzwerk von Intermediärfilamenten (Durchmesser etwa 100 Å) im breiten Cytoplasma; 3. unreife Rhabdomyoblasten mit zunehmender Entwicklung spezifische Myofilamente (Myosin: 180–210 Å, Actin: 68–80 Å Durchmesser); 4. reife Rhabdomyoblasten mit Myofibrillen in sarkomerischer Gliederung (Sarkomerlänge: 1,8 μ). Die starken Glykogenablagerungen in einigen cytoplasmareichen Tumorzellen werden als Zeichen eines Degenerationsprozesses gedeutet. Die cellulären Entwicklungsstadien des embryonalen Rhabdomyosarkoms sind identisch mit dem Ablauf der Embryogenese sowie der Regeneration normaler quergestreifter Muskulatur. Daher bieten sich für die Entstehung des embryonalen Rhabdomyosarkoms zwei Denkmodelle an: 1. Entstehung des Tumors aus einer undifferenzierten mesenchymalen Tumorstammzelle und 2. Atypische Regeneration nach Schädigung der quergestreiften Muskulatur mit Übergang in ein autonomes Tumorwachstum. Die zweite Hypothese ist jedoch wenig wahrscheinlich, da bis heute weder morphologisch noch experimentell eine derartige Tumorentstehung nachgewiesen werden konnte und zudem ätiologisch gesicherte Faktoren zur Induktion von Rhabdomyosarkomen beim Menschen fehlen.
    Notes: Summary An embryonal rhabdomyosarcoma of the nasopharynx of a 10 year old boy is analysed with light and electron microscopy. With regard to cell shape and cytoplasmic features the following four tumour cell types could be distinguished: 1. Undifferentiated mesenchymal cells with a big loosely packed nucleus and a small cytoplasmic rim with only few cell organelles; 2. Undifferentiated tumour cells with a broad cytoplasmic body which contains a dense network of nonspecific intermediate filaments with a diameter of about 100 Å; 3. Immature rhabdomyoblasts with randomly orientated specific myofilaments; 4. Fully differentiated rhabdomyoblasts with well developed myofibrils often showing a sarcomeric pattern. Glycogen deposits which were seen in great masses in many tumour cells were regarded to result from degenerative processes within the tumour. The cellular stages in the development of rhabdomyoblasts are basically identical to those known from the embryogenesis and regeneration of striated muscle. From these observations the two following developmental pathways are suggested: 1. Origin of the tumour from an undifferentiated mesenchymal cell; 2. Atypical regeneration of striated muscle which terminates in malignant progressive tumour growth. At present, the body of information about rhabdomyosarcomas supports the assumption of an origin from immature mesenchymal cells. Nevertheless, the second theory cannot be totally excluded.
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    URL: http://dx.doi.org/10.1007/BF00304934
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    The effect of some glucocorticoids on hepatic microsomal hydroxylation in the rat and hamster (1976)
    Springer
    Naunyn-Schmiedeberg's archives of pharmacology 292 (1976), S. 267-270 
    Details
    ISSN: 1432-1912
    Keywords: Rat ; Hamster ; Hepatic microsomal drug metabolism ; Glucocorticoid interaction
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary The effect of some glucocorticoids on hepatic microsomal biphenyl and aniline hydroxylations were investigated in rat and hamster. Steroids were either added to the standard incubation mixture or given as a single dose intraperitoneally before preparation of the liver microsomes for enzyme determination. The addition of steroids in vitro enhanced biphenyl-2-hydroxylation activity in hepatic microsomes of rat but not of hamster and the most pronounced effect was obtained with betamethasone. A similar species difference in the effects of betamethasone on this enzyme was also observed after administration of a single dose of the steroid in vivo.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00517388
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  • 92
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    Factors responsible for reduced pharmacological activity in rats of pentetrazol administered orally (1976)
    Springer
    Naunyn-Schmiedeberg's archives of pharmacology 293 (1976), S. 277-283 
    Details
    ISSN: 1432-1912
    Keywords: Pentetrazol ; Rat ; Pharmacokinetics ; Food ; Smooth muscle
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary It was the aim of this investigation to find out why pentetrazol (PTZ) administered orally to rats has considerably lower convulsive effectiveness than PTZ injected parenterally. It could be demonstrated that PTZ is distributed to and eliminated from all organs analyzed, without any sign of storage or of redistribution. Biological halftime was found to be about 3.5 h after subcutaneous injection. PTZ is absorbed slowly from the gastrointestinal tract because PTZ given orally is retained in the stomach for many hours. PTZ absorption is slow from the stomach while it is rapid from the small intestine. Food taken in before and after PTZ administration decreases the rate of PTZ absorption. Retention in the stomach of PTZ given orally is probably due to delayed gastric emptying since PTZ is able to reduce the basal tone and the acetylcholine-induced contractions of isolated preparations of the fundus of the stomach.
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    URL: http://dx.doi.org/10.1007/BF00507350
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  • 93
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    Giant cell tumor of soft parts (1976)
    Springer
    Virchows Archiv 371 (1976), S. 199-217 
    Details
    ISSN: 1432-2307
    Keywords: Giant cell tumor of soft parts ; Histopathology ; Ultrastructure
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary The light-microscopic and ultrastructural findings in a case of so-called giant cell tumor of soft parts, localized at the dorsal side of the left foot of a 23-years-old male are described. An amputation of the lower extremity was performed and subsequently chemotherapy with adriamycin was given for 3 months. Despite the histology and cytologic malignant appearance and the evident vascular invasion, already present at the time of the first excision, the last known status 2 years later seems favorable. There are no pathologic lymph nodes in the groins and no signs of metastases on chest X-rays. From the electron-microscopic study no definite conclusion can be drawn as regards the histogenesis of this tumor. We feel, as do others, that many of the principal mononuclear tumor cells are poorly differentiated mesenchymal cells. Some of the neoplastic cells, however, show ultrastructural features suggestive of chondro- or osteoblasts (a well-developed r.e.r. containing electron-dense material; multiple Golgi complexes; masses of glycogen; interdigitating cell membrane villi; cytoplasmic filaments; an extracellular amorphous matrix). Some of the larger tumor cells have the submicroscopic aspects of histiocytes as described in osseous, cutaneous, or pulmonary lesions of the histiocytosis X group. As yet undetermined cytoplasmic inclusion bodies constitute another rare observation in our material.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00433068
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  • 94
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    Cellular differentiations and structural characteristics in nasopharyngeal angiofibromas (1976)
    Springer
    Virchows Archiv 371 (1976), S. 273-282 
    Details
    ISSN: 1432-2307
    Keywords: Nasopharyngeal angiofibroma ; Fibroblast ; Vascular cells ; Fibromatosis ; Electron microscopy
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary An electron-microscopic study of 9 nasopharyngeal angiofibromas was performed in order to elucidate the ultrastructural characteristics. Stromal fibroblasts and proliferating cells of the microvasculature were found. The stromal fibroblasts were subdivided into 3 different groups: (1) “classical” fibroblasts, (2) fibroblasts with histiocytelike features, and (3) fibroblasts with myoid features. By proliferation the cells of the capillary vessels change into stromal cells. A particular pattern of nuclei and dense intranuclear granules is only found in stromal fibroblasts. Consequently fibroblasts as well as cells of the microvasculature contribute to the pool of tumor cells.
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    URL: http://dx.doi.org/10.1007/BF00433074
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  • 95
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    Fluorescence histochemical and electron-microscopical observations on the innervation of the atrial myocardium of the adult human heart (1976)
    Springer
    Virchows Archiv 371 (1976), S. 101-119 
    Details
    ISSN: 1432-2307
    Keywords: Human heart ; Innervation ; Fluorescence histochemistry ; Electron microscopy ; Catecholamines
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary The existence of both adrenergic and cholinergic innervation of the atrial myocardium of the adult human heart was demonstrated by means of fluorescence induced by formaldehyde or glyoxylic acid and by electron microscopy. The adrenergic fluorescing axons (1) followed the course of blood vessels as typical perivascular nerve plexuses, and (2) formed a three-dimensional fairly dense nerve net obviously not related to the blood vessels. The varicosities frequently came into close apposition on myocardial cells. Several types of nerve terminals were differentiated at electron microscopy: (1) an “adrenergic” type containing small (diameter 450–700 Å) dense-cored vesicles and usually (in various proportions) small “empty” and/or large (900–1500 Å) dense-cored vesicles, (2) a “cholinergic” type containing small (ca. 500 Å) “empty” vesicles and occasionally also some large (mean diameter ca. 1200 Å) dense-cored vesicles, (3) a “pale” type containing only a few or no vesicles, (4) a “disintegrated” type containing degenerated mitochondria, autophagic vacuoles, and occasional normal-looking mitochondria, (5) nerve terminals containing a large number of mitochondria in addition to varying vesicle populations, and (6) a (possibly baroreceptive type of) nerve terminal containing myelinlike lamellated structures. The “disintegrated” and the “pale” types of nerve terminals possibly represent different stages of axonal degeneration, or may correspond to diminution in the transmitter substance concentration under certain pathophysiologic conditions, respectively. Nerve terminals crowded with mitochondria may be sensory and involved in mechano-or chemoreceptive functions. In preliminary experiments convincing evidence was obtained that the glyoxylic acid-induced fluorescence histochemical method will be suitable for comparative studies on (human) clinical specimens, e.g., for analyzing the degree of the functional activity of the intrinsic adrenergic innervation of the myocardium under various pathophysiologic conditions. The modification which appeared most appropriate for such studies is described in detail, and is proposed for use as a standard method in other similar or related studies on human clinical series. The essential criteria for analyzing the specimens at fluorescence microscopy are suggested as well.
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    URL: http://dx.doi.org/10.1007/BF00444927
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  • 96
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    Fine structure of baroreceptor terminals in the carotid sinus of guinea pigs and mice (1976)
    Springer
    Cell & tissue research 170 (1976), S. 95-112 
    Details
    ISSN: 1432-0878
    Keywords: Baroreceptors ; Carotid sinus ; Mechanoreceptors ; Electron microscopy ; Fluorescence histochemistry ; Guinea pig, mouse
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary A light and electron microscopic study was undertaken on the baroreceptor axon terminals in the carotid sinus of guinea pigs and mice, using serial semithin and thin sections. Together with their enveloping Schwann cells, numerous lanceolate axon terminals are organized into a well-defined discoid end organ, referred to as the ‘baroreceptor unit’. Baroreceptor units measure 100 to 150 μm in diameter and are arranged in a hexagonal pattern. These end organs represent free branched lanceolate mechanoreceptors of complex type (Andres and von Düring, 1973) which belong to the main group of stretch receptors. In the guinea pig the lanceolate terminals enter the media and approach the innermost layers near the intima. In the mouse the terminals are seen to spread in the adventitia and along the medio-adventitial border. Only a few of them penetrate the external elastic layer. Species differences concerning the localization and extent of these visceral mechanoreceptors are discussed, as well as the modified architecture of the sinus wall in the receptor area (‘elastic segment’). Lanceolate terminals form beaded varicosities which are equipped with finger-like or lamellar axoplasmic protrusions. These projections contain a well-differentiated receptor matrix. They are attached to collagen and elastic fibers. The varicosities include densely packed mitochondria, neurotubules, profiles of axoplasmic reticulum, clear and granular vesicles, and striking accumulations of glycogen particles, lamellated bodies and lysosomes. Four types of varicosities are discerned according to their main axoplasmic components. Various types of these varicosities occur within an individual lanceolate terminal. The adrenergic innervation of the carotid sinus was studied by fluorescence histochemistry. In guinea pigs a multilayered wide-meshed plexus of fluorescent fibers occurs in the adventitia where it is closely related to baroreceptor stem fibers. However, adrenergic axons do not enter the media. In mice fluorescent fibers are extremely rare in the adventitia of the carotid sinus.
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    URL: http://dx.doi.org/10.1007/BF00220113
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  • 97
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    Quantitative morphological study of smooth muscle cells of the guinea-pig taenia coli (1976)
    Springer
    Cell & tissue research 170 (1976), S. 161-186 
    Details
    ISSN: 1432-0878
    Keywords: Smooth muscle ; Intestine ; Ultrastructure ; Morphometry
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary A quantitative study of muscle cells of the guinea-pig taenia coli is reported. Stereological methods were used on electron micrographs and phase contrast micrographs. Smooth muscle cells of taeniae fixed under 1 gram load were about 515 μm long. Muscle cell volume was about 3,500 μm3 and cell surface 5,300 μm2. About 168,000 caveolae were found at the surface of each muscle cell, covering about 29 percent of its surface. They produced a 73 percent increase of the cell membrane compared to a smooth-surfaced cell. The ratio surface-to-volume is about 1∶0.67 if the geometrical surface is considered, or 1∶0.39 if the total surface of the cell membrane (including the caveolae) is considered. Mitochondria constituted 3.5–4 percent of the cell volume. A few nexuses were observed, both between two muscle cells and between a muscle cell and an interstitial cell. In serial sections septa of connective tissue and groups of muscle cells were found to disappear within few tens of microns or to merge with other septa, and the taenia did not appear to be divided into clear-cut muscle cell bundles. Bundles of smooth muscle cells were seen passing from the taenia to the underlying circular muscle. The transverse sectional area of the taenia ranged between 0.14 and 0.39 mm2; it showed about 526 blood vessels · mm-2.
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    URL: http://dx.doi.org/10.1007/BF00224297
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  • 98
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    Structural changes in smooth muscle cells during isotonic contraction (1976)
    Springer
    Cell & tissue research 170 (1976), S. 187-201 
    Details
    ISSN: 1432-0878
    Keywords: Smooth muscle ; Contraction ; Taenia coli ; Ultrastructure ; Collagen
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary Smooth muscle cells of the guinea-pig taenia coli were studied in light and electron microscopy, in condition of mild stretch or of isotonic contraction. During contraction the cells increase in transverse sectional area and their packing density passes from 94,000 · mm-2 to 18,000 · mm-2. The percentage increase in transverse sectional area of the taenia is approximately the same as the percentage decrease in length. Measurements of cell transverse sectional area suggest that the individual cells shorten and fatten more than the taenia as a whole. Whereas stretched muscle cells run parallel to each other and show a fairly smooth surface, isotonically contracted cells are twisted and entwine around each other. Their surfaces are covered with myriad processes and folds. Longitudinal, transverse or oblique stripes are seen in light microscopy in the contracted muscle cells and it is suggested that they are related to the characteristics of the cell surface. In electron microscopy a complex pattern of interdigitating finger-like and laminar processes is observed. Caveolae are mainly found on the evaginated parts of the cell surface, dense patches are mainly (but not always) found on the invaginated parts. Desmosome-like attachments between contracted cells are frequent. The collagen fibrils run approximately parallel to the stretched muscle cells; on the other hand, they run obliquely and transversely around the isotonically contracted cells.
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    URL: http://dx.doi.org/10.1007/BF00224298
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  • 99
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    Structure and regeneration of the eyes of strombid gastropods (1976)
    Springer
    Cell & tissue research 171 (1976), S. 259-271 
    Details
    ISSN: 1432-0878
    Keywords: Eyes ; Strombus ; Regeneration ; Ultrastructure
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary The tips of the eyestalks of three species of strombid gastropods were amputated and the structure of the fully developed eye investigated. The retina contains at least two types of cell: sensory cells bearing long tufts of microvilli with a central cytoplasmic core, and pigment cells with short microvilli. New eyes became visible at the tips of the eyestalk stump 5–16 days after amputation. When the regenerated eyes first appear, they consist of hollow balls of cells with a pigment lined cavity; two types of retinal cells are already distinguishable but their microvilli and cilia are small and sparse. The microvillous tufts and sensory cell contents develop quickly and about 14 days after their first appearance, the eye is a fully formed but miniature organ.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00219410
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    Electronic Resource
    Gap junctions in hemodichorial and hemotrichorial placentae (1976)
    Springer
    Cell & tissue research 171 (1976), S. 305-315 
    Details
    ISSN: 1432-0878
    Keywords: Chorioallantoic placenta ; Gap junctions ; Diaplacental transport ; Ultrastructure ; Freeze-fracturing
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary Gap junctions were found to be a constant feature of chorioallantoic placentae with two or three trophoblastic layers. The gap junctions connect layers I and II in hemodichorial and layers II and III in hemotrichorial placentae. Although the gap junctions vary in form and in the packing density of membrane-associated particles, they cover an extensive surface area in all species examined. The gap junctions always connect adjacent membranes of two trophoblastic layers, which show no evidence of micropinocytotic activity; at least one of these trophoblastic layers is syncytial. It is therefore concluded that the gap junctions play an important role in diaplacental transport. We consider that gap junctions act as molecular sieves, resulting in limitations in the transport of large molecules. The passage of small molecules, on the contrary, would be facilitated by the gap junctions.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00224656
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