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  • 1980-1984  (817)
  • 1981  (417)
  • 1980  (400)
  • Atomic, Molecular and Optical Physics  (568)
  • Ultrastructure  (248)
  • Nuclear reactions
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Years
  • 1980-1984  (817)
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  • 1
    Electronic Resource
    Electronic Resource
    Springer
    Neurosurgical review 4 (1981), S. 17-31 
    ISSN: 1437-2320
    Keywords: Astrocytoma ; Oligodendroglioma ; Ultrastructure ; Astrocytom ; Oligodendrogliom ; Ultrastruktur
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Description / Table of Contents: Zusammenfassung 7 Oligodendrogliome, davon 2 mit uniformem Zell-Typ, 4 mit Zell- oder Gewebs-Unregelmäßigkeit, 1 mit glioblastomatösen Veränderungen wurden elektronenmikroskopisch untersucht. Die Tumorzellen zeigten 2 Haupttypen mit morphologischen Übergängen zwischen beiden auf. Die Hauptformen wurden als Typ 1 (undifferenziert) und 2 (differenziert) definiert, gestützt auf die Anzahl anaplastischer Zellen im jeweiligen Tumor und auf die Beobachtung nicht-neoplastischer Oligodendrocyten nach Mori and Leblond (21). Die meisten Tumorzellen aller Fälle wiesen ähnliche licht- und elektronenmikroskopische Charakteristika auf, einschließlich der Zell-Anordnung und ihrer Tendenz, zytoplasmatische Fortätze zu bilden. Diese Befunde waren auch in den glioblastomähnlichen Tumoren zu erkennen und bestätigen damit deren Oligodendrogliom-Komponente. Außerdem fand man regelmäßig in allen Tumoren eine Zunahme der Größe und Zahl der Mitochondrien, reichlich intrazytoplasmatische Strukturen und Mikrotubuli. Auch Zellen mit zytoplasmatischen Filamenten waren vorhanden, die als reaktive Astrocyten oder als oligodendrogliale Tumorzellen angesehen wurden. Daher scheinen weder zytoplasmatische Filamente noch Mikrotubuli ein spezifisches morphologisches Kriterium für Oligodendroglia oder Astrocyten zu sein. Das Überwiegen einer dieser beiden Strukturen erlaubt jedoch eine zytogenetische Zuordnung. Die zytologischen Charakteristika sind zwar keine spezifischen morphologischen Kriterien; die Feststellung ihrer Anwesenheit gibt jedoch wichtige diagnostische Informationen.
    Notes: Summary Seven Oligodendrogliomas (2 with uniform cell type, 4 with cellular or tissue variability, and 1 with glioblastomatous changes) were examined ultrastructurally. The tumor cells were of two principal types with morphologic transitions between the two main types. The two principal cell types were identified as type 1 (undifferentiated) and type 2 (differentiated) on the basis of the number of anaplastic cells in an individual tumor and on the observations of Mori and Leblond (21) on non-neoplastic oligodendrocytes. Most of the tumor cells in all tumors exhibited similar histologic and ultrastructural characteristics including their arrangement and their tendency to form cytoplasmic processes which sometimes formed short stacks. These features were also recognizable in the glioblastomatous example and confirmed the presence of an oligodendroglial component. In addition to these characteristics, an increase in size and number of mitochondria, abundant intracytoplasmic structures, microtubules were regularly present in virtually all tumor cells. Cells rich in cytoplasmic filaments were present. These were identified as reactive astrocytes or as oligodendroglial tumor cells. Thus neither cytoplasmic filaments nor microtubules appear to be specific morphological markers for oligodendroglia or astrocytes; only the predominance of one of these structures permits cytogenetic identifications. The cytologic characteristics are not specific morphologic markers; however, recognition of their presence provides important diagnostic information.
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  • 2
    Electronic Resource
    Electronic Resource
    Springer
    Calcified tissue international 33 (1981), S. 603-618 
    ISSN: 1432-0827
    Keywords: Preameloblasts ; Tooth germs ; Monkey ; Enamel ; Ultrastructure
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine , Physics
    Notes: Summary Cytodifferentiation of inner enamel epithelium and the adjacent connective tissue from the tip of the cervical loop to the initiation of enamel elaboration in twoMacaca species was examined. Ten- to twelve-month-old specimens were fixed by perfusion and the permanent tooth buds were prepared for transmission electron microscopy. At the cervical loop proper, inner enamel epithelium cells have lobed nuclei, a paucity of cytoplasm, and wide extracellular spaces; the basal lamina facing the dental papilla is straight. With increasing distance from the tip of the cervical loop, the following changes occur gradually: (a) preameloblasts elongate from 15 to 45 µm, and their organelles, particularly mitochondria and profiles of rough endoplasmic reticulum, become more numerous; (b) extracellular spaces decrease between preameloblasts starting at the basal (infranuclear) end; (c) the basement membrane becomes convoluted and associated with aperiodic fibers; (d) preodontoblast projections penetrate the aperiodic fibers; (e) collagen fibers subjacent to the basement membrane increase in density, with particularly thick fibers paralleling the aperiodic fibers. These modifications occur within three-fourths of the distance from the tip of the cervical loop to the mineralization front. The condensation of preodontoblasts is followed immediately by predentin synthesis. Concomitantly, the basement membrane breaks down and the aperiodic fibers are engulfed by preameloblasts. Preameloblast projections penetrate junctional predentin, contact mineralized dentin, and enamel synthesis ensues. At this stage the ameloblast is 45 µm long, the nucleus is central or basal, the Golgi apparatus has migrated apically, but the Tomes' process has not yet formed. The results indicate that odontogenesis inMacaca monkeys more closely resembles human odontogenesis than does that in the murine rodents.
    Type of Medium: Electronic Resource
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  • 3
    ISSN: 1432-1440
    Keywords: Lipids ; Intestinal mucosa ; Diabetes mellitus ; Biochemistry ; Ultrastructure ; Lipide ; Dünndarmschleimhaut ; Diabetes mellitus ; Biochemie ; Ultrastruktur
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Description / Table of Contents: Zusammenfassung Hyperlipidämien sind ein häufiger Befund bei Diabetes mellitus. Da neben der Leber auch die Dünndarmmukosa endogene Lipoproteine synthetisiert, war es von Interesse, bei 11 Erwachsenen mit juvenilem Diabetes und bei 7 Patienten mit Altersdiabetes den Lipidgehalt der Dünndarmmukosa zu bestimmen. Als Kontrolle dienten 11 nicht diabetische Patienten. Nach einer Nüchternperiode von 12–14 h erfolgte zunächst eine Blutabnahme zur Bestimmung von Nüchternblutzucker, Serumlipiden und glykosyliertem Hämoglobin AI, daraufhin wurden mittels einer hydraulischen Biopsiesonde oder endoskopisch mehrere Dünndarmbiopsien entnommen und zur biochemischen, histochemischen und elektronenoptischen Auswertung entsprechend aufgearbeitet. Biochemisch unterschieden sich die Patienten mit juvenilem und mit Altersdiabetes weder hinsichtlich der Serumlipidwerte noch der intestinalen Lipidkonzentrationen von den Kontrollpersonen. Auffallend war allerdings, daß Patienten mit Altersdiabetes eine signifikant höhere intestinale Triglyzeridkonzentration aufwiesen, als Patienten mit juvenilem Diabetes (p〈0,005). Nüchternblutzucker und Hämoglobin AI waren bei beiden Patientengruppen mäßig erhöht. Histochemisch waren sowohl bei den Patienten als auch bei den Kontrollpersonen Lipidpartikel in der Mukosa nachweisbar, allerdings mit großen individuellen Unterschieden. Elektronenoptisch unterschieden sich die Patienten mit Altersdiabetes nicht von den Kontrollen. Nur einer der Patienten mit juvenilem Diabetes zeigte gehäufte Lipidpartikel in den Zisternen des Golgi-Apparates. Somit konnte weder biochemisch, histochemisch, noch elektronenoptisch eine abnorme Lipidakkumulation in der Dünndarmschleimhaut von Patienten mit gut kontrolliertem Diabetes mellitus festgestellt werden.
    Notes: Summary Hyperlipemia is a frequent finding in diabetes mellitus. As not only the liver, but intestinal mucosa as well synthesizes endogenous lipoproteins, we have investigated the small intestinal mucosal lipid content in 11 adult patients with juvenile onset diabetes and in 7 patients with maturity onset diabetes. Eleven non-diabetic patients served as controls. After a fasting period of 12–14 h blood was drawn for determination of glucose, lipids and glycosylated hemoglobin AI. Then several small bowel biopsies were performed by an hydraulic multiple biopsy tube or endoscopically and the specimens were processed immediately for further biochemical, histochemical and electronmicroscopical workup. Patients with juvenile and with maturity onset diabetes did not differ from controls with regard to serum lipids and to intestinal mucosal lipids determined biochemically. Surprisingly, patients with maturity onset diabetes exhibited a significantly (p〈0,005) higher concentration of intestinal mucosal triglycerides than patients with juvenile onset diabetes. Fasting blood glucose and hemoglobin AI levels were slightly elevated in both groups of diabetic patients. Histochemically lipid particles were demonstrable in intestinal mucosa of diabetics and of controls with equal variability. The electronmicroscopical appearance of intestinal mucosa did not differ between diabetic patients and controls. Only in one patient with juvenile onset diabetes an accumulation of lipid particles within the cisternae of the Golgi apparatus was observed. In conclusion, neither biochemically, nor histochemically, nor electronmicroscopically an abnormal accumulation of lipids could be found in the small intestinal mucosa of patients with well controlled diabetes mellitus.
    Type of Medium: Electronic Resource
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  • 4
    ISSN: 1432-2307
    Keywords: Granulocytic sarcoma ; Chloroma ; Meningeal sarcoma ; Ultrastructure ; Myelogenous leukemia
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary An unusual case of meningeal granulocytic sarcoma without evidence of Leukemia is presented. The patient, a 40 year old female, presented with a chronic subdural haematoma. Three months later a large meningeal tumor was discovered adjacent to the previous haematoma and was found to be a granulocytic sarcoma by the use of electron microscopy. The tumor was treated by surgical excision followed by radiotherapy and chemotherapy. The patient remains free of symptoms and without evidence of leukemia in the peripheral blood or bone marrow 9 months after the diagnosis was established. The ultrastructural findings in the tumor and diagnostic difficulties often encountered are emphasized.
    Type of Medium: Electronic Resource
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  • 5
    Electronic Resource
    Electronic Resource
    Springer
    Virchows Archiv 392 (1981), S. 97-104 
    ISSN: 1432-2307
    Keywords: Reducing body myopathy ; Classification ; Ultrastructure
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Description / Table of Contents: Zusammenfassung Die sog. reducing body myopathy, eine sehr seltene progressive muskuläre Krankheit, zeigt neben einer unspezifischen herdförmigen Muskelfaserdegeneration als typisches morphologisches Merkmal Muskelfasereinschlüsse, die reduzierende Eigenschaften aufweisen. Die nosologische Einordnung des Krankheitsbildes blieb bisher ungeklärt. Es wird über ein 15 Jahre altes Mädchen mit einer zunehmenden allgemeinen Muskelschwäche und Muskelatrophie berichtet, bei dem in der Muskelbiopsie neben unterschiedlichen regressiven Veränderungen zahlreiche Fasereinschlüsse beobachtet wurden, die u.a. in der Lage sind, ohne Substrat Tetrazoliumsalze in Gegenwart von Menadione zu reduzieren. Feinstrukturell sind diese Einschlüsse aus Granula von 12–16 nm Durchmesser zusammengesetzt. Eine Schwester der Erkrankten leidet seit vielen Jahren an einer klinisch und morphologisch gleichartigen Krankheit. Die sog. reducing body myopathy muß daher in die Gruppe der congenitalen Myopathien mit strukturellen Besonderheiten eingeordnet werden. Nachdem darüber hinaus bei anderen Muskelkrankheiten ebenfalls Fasereinschlüsse mit reduzierenden Eigenschaften vorkommen können, die jedoch in ihren übrigen strukturellen und histochemischen Eigenschaften keine Übereinstimmung mit den bei der sog. reducing body myopathy nachweisbaren Inclusionen besitzen, sollte das Krankheitsbild nach seinem führenden morphologischen Merkmal, den offenbar nur hier vorkommenden granulären Fasereinschlüssen, benannt werden. Es wird vorgeschlagen, die sog. reducing body myopathy als Granularkörpermyopathie zu bezeichnen.
    Notes: Summary Reducing body myopathy is a very rare progressive muscular disease. Apart from a non-specific circumscribed muscle fiber degeneration it displays muscle fiber inclusions which have reducing properties as a typical morphological feature. The nosological classification of the disease is not settled. A case in a 15 years old girl is reported. She suffered from a progressive muscular weakness and atrophy and in a muscle biopsy regressive changes were obvious. Furthermore, multiple eosinophilic muscle fiber inclusions were also observed, which exhibited reducing properties. They consist of electron dense granules with a diameter of 12–16 nm. Since a sister of the patient has suffered for many years from a clinically and morphologically similar muscle disease, reducing body myopathy apparently belongs to the group of congenital myopathies with structural abnormalities. Muscle fiber inclusions with reducing properties also occur in another myopathy, in which they structural and histochemical differ widely from those found in reducing body myopathy. The reducing body myopathy is better named after its typical morphological property, the granular inclusions. It is proposed to name it “granular body myopathy”.
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  • 6
    ISSN: 1432-2307
    Keywords: Cyclic hematopoiesis ; Bone marrow ; Ultrastructure ; Nuclearcytoplasmic asynchrony ; Döhle-like bodies
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary The pathogenesis of cyclic hematopoiesis (CH) in the grey collie dog is still unknown. It has been proposed that periodic bursts of necrosis of the bone marrow neutrophils would induce cyclic arrests of the stem cell differentiation. In the present study, the sequential changes undergone by the erythroid and neutrophil series of the bone marrow of CH dogs were evaluated by electron microscopy. Erythroid cells presented quantitative periodic oscillations but the morphologic features of both immature and mature cells were normal. On the contrary, nonspecific necrotic changes were observed to occur in the myeloid series. Those abnormalities, which were more marked between days 9 and 11 of the cycle, mainly involved the immature cells and, to a lesser extent, the mature neutrophils. The number of necrotic cells was variable in different cycles, but always represented a small portion of the myeloid cells. In addition, few bone marrow macrophages displayed signs of phagocytic activity containing cell debris. The ultrastructural changes of the myeloid series were accompanied by an abnormal decrease of peroxidase activity and the permanence of large acid phosphatase-positive Golgi complexes in mature neutrophils, as defined by morphologic criteria. Döhle-like arrays of rough endoplasmic reticulum were present in many cells. Our findings suggest that an asynchronic development of myelocytes occurs as a result of regulatory abnormalities related to the congenital defect of the bone marrow which interferes with the differentiation and maturation of the stem cells. Necrosis in some myeloid cells would be a secondary phenomenon rather than a causal factor for the cyclic arrest of cell maturation as has been previously submitted. Furthermore, the small size of the necrotic cell population could not justify the production of “inhibitors” in sufficient amounts as to block the normal evolution of the bone marrow stem cell pool.
    Type of Medium: Electronic Resource
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  • 7
    Electronic Resource
    Electronic Resource
    Springer
    Virchows Archiv 392 (1981), S. 199-216 
    ISSN: 1432-2307
    Keywords: Aortic media ; Human ; Ultrastructure ; Elastin ; Smooth muscle cell
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary The ultrastructural organization of the adult human aortic media was studied utilizing aortic biopsies from 14 patients, ranging in age from 28 to 67, who underwent cardiac surgery. Apart from solid elastic elements the tissue spaces contained a vast amount of ill-defined thin streaks of elasin, an observation much facilitated by utilizing a selective elastin staining technique. In favorable sections, these streaks were found to be continuous with the solid elastic laminae. Furthermore, most medial smooth muscle cells were in close contact with the thin streaks, but almost none directly with the elastic laminae. The smooth muscle cells had also virtually no connection with collagen fibers. These observations are in contrast with the organization of elastin and with cell-to-stroma connections in the more extensively studied rodent and porcine aortas; they bring into question the role of the smooth muscle cells in the regulation of the viscoelastic properties of the human aortic wall. Other findings were: large number of nexuses connecting the smooth muscle cells, a very small degree of smooth muscle cell degeneration, and the presence of flocculent, fine-granular material investing all formed elements, but especially associated with the thin streaks of elastin.
    Type of Medium: Electronic Resource
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  • 8
    Electronic Resource
    Electronic Resource
    Springer
    Virchows Archiv 393 (1981), S. 103-114 
    ISSN: 1432-2307
    Keywords: Cerebro-hepato-renal (Zellweger-) syndrome ; Morphological diagnosis ; Ultrastructure ; Peroxisomes ; Autopsy ; Catalase
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary A female newborn, the second child of healthy non consanguineous parents, exhibited muscular hypotonia, areflexia, apathy, seizures, hepatomegaly and failure to thrive since birth. The peculiar skull shape was lacking. In the urine pipecolic acid and trihydroxycoprostanoic acid were excreted. At the age of seven weeks she died of bronchopneumonia. Lightmicroscopy revealed malformations and deficiency of myelinisation in the brain, renal cysts and fatty metamorphosis in the enlarged liver, which showed only minimal siderosis. Ultrastructurally no peroxisomes could be found in liver and kidney. No peroxisomes were detected by histochemical demonstration of catalase in frozen liver tissue which was taken immediately after death and stored for three months. Absence of peroxisomes is pathognomonic for the cerebro-hepato-renal syndrome of Zellweger and occurs in the liver irrespective of duration and degree of liver damage. It is best demonstrated by enzymehistochemical electron microscopy. With this method peroxisomes can be visualized even 30 h post mortem. In deep frozen normal liver tissue the activity of catalase remains very stable and enables the identification of peroxisomes even after a 12 months period of storage. In the cerebro-hepato-renal syndrome of Zellweger, frozen liver tissue should be stored for biochemical and diagnostic enzymehistochemical studies.
    Type of Medium: Electronic Resource
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  • 9
    Electronic Resource
    Electronic Resource
    Springer
    Virchows Archiv 393 (1981), S. 133-144 
    ISSN: 1432-2307
    Keywords: Term, normal human placenta ; Fetal arteries ; Ultrastructure ; Specialized processes of smooth muscle cells
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary Fetal stem arteries of the 3rd order of 50 normal placentas obtained at term of unevenful pregnancies were examined by transmission electron microscopy with the aim at providing a base-line information for the assessment of similar arteries in hypertensive disorders of pregnancy. The results showed that the endothelial cells often protruded with a considerable portion of their cellular body into the lumen, and that the intercellular junctions between the neighbouring cells were confined largely to their short basal segments. Numerous myoepithelial junctions were formed between the processes of the endothelial cells and those extending from the smooth muscle cells (SMC) of the adjacent medial layer. At times the “participating” processes of the SMC were entirely enclosed within the endothelial body. Collagen fibrils increased in number between the SMC and the interstitium broadened progressively from the inner to the outer arterial layers. Small cellular processes devoided of a basement membrane and of most cytoplasmic organelles were numerous in the interstitium; these were traced to the main bodies of the medial SMC. It is postulated that the “naked” SMC-processes are susceptible to injury of a nature much more subtle than that affecting the main body of the SMC, since these processes were often swollen and appeared edematous in an otherwise innocuous mural environment.
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  • 10
    ISSN: 1432-2307
    Keywords: Urinary bladder adenocarcinomas ; ABH isoantigens ; Ultrastructure
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary Neoplastic and non-neoplastic tissue specimens from ten patients with primary adenocarcinoma of the urinary bladder were examined. Most of these tumors were associated with either foci of transitional cell carcinoma and/or with glandular metaplasia of the bladder epithelium. The mucin produced by the neoplastic cells was PAS, alcian blue, mucicarmine, PB/KOH/PAS, and RPB/KOH/PAS-positive. ABH isoantigens of these tumors were not always deleted. Ultrastructurally, the neoplastic cells resembled goblet cells. Their plasma membrane had numerous microvilli with prominent glycocalyx. Proliferation and attenuation of tight junctions were noted. The gap junctions were few and small. Two types of desmosomes were found. The ultrastructural features of the neoplastic cells were attributed in part to the malignant transformation and in part to the direction of their differentiation. We have not observed any distinctive morphologic, histochemical, immunologic or ultrastructural features that might be diagnostic for these adenocarcinomas.
    Type of Medium: Electronic Resource
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  • 11
    Electronic Resource
    Electronic Resource
    Springer
    Virchows Archiv 393 (1981), S. 245-250 
    ISSN: 1432-2307
    Keywords: Malignant melanoma of the vagina ; Malignant melanoma of the cervix ; Malignant melanoma ; Ultrastructure
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary This report concerns a very rare case of primary malignant melanoma involving the vagina and cervix uteri occurring in a 45-year-old woman. The clinical, light-microscopic and ultrastructural findings are presented and discussed.
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  • 12
    Electronic Resource
    Electronic Resource
    Springer
    Virchows Archiv 394 (1981), S. 167-176 
    ISSN: 1432-2307
    Keywords: Malignant fibrous histiocytoma ; Sarcoma ; The lung ; Ultrastructure
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary A case of malignant fibrous histiocytoma of the lung is reported. The tumour margin was well circumscribed, showing an expanding border and no capsule. The main part of the tumour was composed of spindle-shaped fibroblast-like cells arranged in broad fascicles with a partially storiform pattern. Other parts of the tumour were arranged in a haphazard pattern, containing many mononucleated and multinucleated giant cells. Ultrastructurally six differnt cell types were encountered. The dominant type was a fibroblast-like cell; also present were many giant cells and some histiocyte-like cells, together with their intermediate forms, and few undifferentiated mesenchymal cells. We consider this tumour to have developed from the peribronchial connective tissue; it has the same cellular composition as the malignant counterpart arising in soft tissues.
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  • 13
    Electronic Resource
    Electronic Resource
    Springer
    Virchows Archiv 391 (1981), S. 33-44 
    ISSN: 1432-2307
    Keywords: Carcinoid heart disease (carcinoid syndrome) ; Endocardial plaque ; Endocardial lesion ; Ultrastructure ; Myofibroblast
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Description / Table of Contents: Zusammenfassung Bei einer 67jährigen Patientin mit einem metastasierenden Dünndarmcarcinoid fanden sich bei der Autopsie die für das Carcinoidsyndrom typischen Endokardveränderungen der rechten Herzhöhlen. Anhand dieses Falles und des Schrifttums wird über die Ultrastruktur der endokardialen Auflagerungen beim Carcinoidsyndrom berichtet. Charakteristisch für diese Auflagerungen ist die Proliferation von glatten Muskelzellen und Myofibroblasten, die von reichlich basalmembranähnlichem Material umgeben sind und vereinzelt durch Maculae adhärentes untereinander verbunden sind. Die Grundsubstanz ist aus sauren Mucopolysacchariden, normalen kollagenen Fibrillen und Mikrofibrillen aufgebaut. Die Verdickungen unterscheiden sich morphologisch von allen anderen Endokardveränderungen, unter anderem durch das Fehlen von amorphem Elastin. Ihre Entstehung im Zusammenhang mit der endokrinen Aktivität der Carcinoide wird diskutiert.
    Notes: Summary In a 67-year-old female patient with metastasising carcinoid of the small intestine there were right-sided endocardial plaques characteristic of the carcinoid syndrome. Ultrastructurally, the lesions showed proliferation of smooth muscle cells and myofibroblasts, which were surrounded by basementmembrane-like material and occasionally showed intercellular connections of the macula adhaerens type. The ground substance consisted of acid mucopolysaccharides, normal collagen fibrils, and microfibrils. The endocardial plaques in the carcinoid syndrome differ morphologically from other endocardial lesions by the lack of amorphous elastin. The formation of plaques and its relation to the endocrine activity of the carcinoid tumors is discussed, and pertinent literature is reviewed.
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  • 14
    Electronic Resource
    Electronic Resource
    Springer
    Urological research 9 (1981), S. 33-44 
    ISSN: 1434-0879
    Keywords: Dog ; Epididymis ; Ultrastructure
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary The ultrastructure of the epididymal duct and ductuli efferentes in the dog has been studied by electron microscopy. The epididymidis can be separated into the classical divisions of caput, corpus and cauda epididymidis on the basis of general morphology and ultrastructure. The ductuli efferentes have a low epithelium with pronounced cilia at the apices of cells and appear to provide primarily a transport role for spermatozoa. In the epididymis proper the caput region is characterized by an extremely large Golgi apparatus with large numbers of lysosomes and nuclear inclusions. Secretory activity appears to be most common in the corpus region. Absorption and secretion are most active in the first two segments while in the cauda epideidymidis the long-term storage of spermatozoa in the lumen is associated with many dense crystalline bodies formed in the epithelial cells within the Golgi apparatus and possibly deriving from absorbed macromolecular material from the lumen. The theory of whole sperm cell resorption by the epididymal duct is not supported by this study.
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  • 15
    Electronic Resource
    Electronic Resource
    Springer
    Anatomy and embryology 161 (1981), S. 329-340 
    ISSN: 1432-0568
    Keywords: Aortic valve ; Smooth muscle cells ; Ultrastructure
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary The location and the spatial arrangement of smooth muscle cells in aortic valves have been assessed by a systematic analysis of serial semithin sections of plastic embedded porcine and human aortic leaflets, combined with an electron microscope study. The investigation showed that smooth muscle cells, either single and arranged in thin bundles, and other cell types such as myofibroblasts are constantly present in the aortic valve leaflets. In addition, it was possible to devise a model of the three dimensional, specific organization of the smooth muscle bundles which can be interpreted as an intrinsic muscle system of the leaflets. As the muscular elements might play an active role in the normal functioning of the valve, their presence should be taken into account in designing (bio) prosthetic leaflets and in the evaluation of valve pathology.
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  • 16
    Electronic Resource
    Electronic Resource
    Springer
    Acta neuropathologica 54 (1981), S. 199-202 
    ISSN: 1432-0533
    Keywords: Hereditary sensory neuropathy ; Sweat glands ; Unmyelinated axons ; Ultrastructure
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary The ultrastructural study of a skin biopsy in a patient afflicted with hereditary sensory neuropathy type IV (congenital insensitivity to pain with anhidrosis) did not reveal any unmyelinated axons or axonal terminals around eccrine sweat glands but only proccsses, partially covered by a basement membrane and therefore resembling Schwann cell processes. The absence of such unmyelinated axons in close proximity to eccrine sweat glands where they normally occur appears to be the morphological equivalent to the anhidrosis and also corresponds to the deficiency of unmyelinated axons in the sural nerve of the same patient, as previously reported.
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  • 17
    Electronic Resource
    Electronic Resource
    Springer
    Acta neuropathologica 54 (1981), S. 239-246 
    ISSN: 1432-0533
    Keywords: Alzheimer's disease ; Neurofibrillary Tangles ; Senile dementia ; Supranuclear palsy ; Ultrastructure
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary Alzheimer's neurofibrillary tangles were studied by electron microscopy. The study includes four cases of Alzheimer's disease, two cases of atypical senile dementia, and one case of progressive supranuclear palsy. In Alzheimer's disease the tangles were composed of either straight filaments or paired helical filaments. In progressive supranuclear palsy the tangles were composed of 15 nm straight filaments or helical filaments. A few straight filaments were mixed with paired helical filaments. In atypical senile dementia, both straight and paired helical filaments comprised the tangles and one type of filaments appeared to intermingle with the other in the same neurons.
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  • 18
    ISSN: 1432-0533
    Keywords: Human rabies ; Negri bodies ; Ultrastructure
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary Light-and electron-microscopical studies were conducted on necropsy material from six cases of rabies encephalitis including three with the unusual feature of surviving for over 14 days as a result of intensive medical care. This included administration of antiviral agents and interferon inducers and prevention of hypoxia by intermittent positive pressure ventilation. In all these cases, typical Negri bodies were demonstrated. Inflammatory reaction was absent or minimal. Unlike the cases with short survival where Negri bodies were infrequently seen and restricted mostly to the hippocampus, in cases with prolonged survival, they were present in large number, widely distributed throughout the grey matter of the brain. The associated inflammatory reaction in these cases, however, did not keep pace with the increase in number of inclusion bodies. Peripheral neuritis was observed in two of these cases, which also showed myelitis involving the cervical region and inflammation of dorsal root ganglia. One of them showed necrosis and severe inflammation of the lower cervical sympathetic ganglion. An electron-microscopical study conducted in four cases showed three forms of the inclusion body in the cytoplasm of neurons.
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  • 19
    Electronic Resource
    Electronic Resource
    Springer
    Acta neuropathologica 54 (1981), S. 321-324 
    ISSN: 1432-0533
    Keywords: Choroid plexus papilloma (CPP) ; Malignant DCPP ; Choroid plexus endothelium ; Ultrastructure
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary A disseminated choroid plexus papilloma (DCPP) with a malignant change in the cervico-spinal leptomeninges observed 4 years after the removal of choroid plexus papilloma (CPP), originating from the fourth ventricle, was studied under the electron microscope. Although the ultrastructure of intracranial CPP has been reported by several authors, there are just a few reports on DCPP. The present tumor was ultrastructurally very similar to normal choroid plexus, but the lack of the capillary fenestration and of invaginations of the epithelial basal plasmalemmas suggested that the epithelium was deprived of secretory function.
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  • 20
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    Acta neuropathologica 54 (1981), S. 329-330 
    ISSN: 1432-0533
    Keywords: Muscular dystrophy, Duchenne type ; Ultrastructure ; Satellite cell
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary A new organelle found in a case of Duchenne muscular dystrophy is described. It was located at the periphery of a regenerated myofibre close to a satellite cell. It was roughly sperical in shape and 0.30–0.35 μm in diameter. Its internal structure was examined in serial and tilted sections, and consisted of parallel arrays of laminae or, possibly, filaments. The nature of the organelle is briefly discussed.
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  • 21
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    Acta neuropathologica 53 (1981), S. 333-336 
    ISSN: 1432-0533
    Keywords: Amacrine cell ; Tay-Sachs disease ; Ultrastructure ; Biochemistry
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary Ultrastructural study of the retina from a patient with Tay-Sachs disease disclosed that amacrine cells as well as ganglion cells were loaded with numerous membranous cytoplasmic bodies, suggesting an accumulation of GM2 ganglioside, whereas the horizontal cells, bipolar cells, and photoreceptor cells were intact. Chromatography of lipids from the retina showed a prominent spot of GM2 ganglioside. These facts suggest that lipid metabolism in amacrine cells may be different from that in other retinal cells.
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  • 22
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    Acta neuropathologica 54 (1981), S. 113-119 
    ISSN: 1432-0533
    Keywords: Multisystem atrophy ; Neuronal intranuclear ; Hyaline inclusions ; Ultrastructure
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary An 18-year-old girl died following a slowly progressive neurodegenerative disease of nine years duration. At 9 years of age, she developed intellectual deterioration associated with speach difficulty, pseudobulbar palsy and ataxia. The progression included spastic quadriplegia, anarthria, severe dysphagia, ophthalmoplegia, and pes cavus. There was no family history. The brain was uniformly small and the substantia nigra was not pigmented. Neuronal loss and gliosis involving globus pallidus, subthalamic nucleus, thalamic nuclei, brain stem, cerebellum, and spinal cord gave the picture of multisystem atrophy. Intranuclear hyaline inclusions were observed in numerous neurons of the central and peripheral nervous system. These were auto-fluorescent and were made up of intermingled straight filaments (8–9 nm in diameter). Only two previously reported cases showing these same inclusions are known. They are reviewed, compared, and discussed in relation to primary neuronal degenerations.
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  • 23
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    Acta neuropathologica 54 (1981), S. 135-142 
    ISSN: 1432-0533
    Keywords: Cultured Schwann cells ; Ultrastructure ; Cytochemistry
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary Schwann cell cultures were established from sciatic nerve of 3 day-old rats. Described are the ultrastructural, histochemical and ultracytochemical properties of amyelic cultured rat Schwann cells. Ultrastructural characteristics of the cultured Schwann cells are compared to the Schwann cells of 3 day-old and adult rat sciatic nerve. These findings serve as a basis for comparison when studying experimentally induced alterations in the cultured Schwann cells as well as changes due to myelination in vitro.
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  • 24
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    Acta neuropathologica 54 (1981), S. 315-320 
    ISSN: 1432-0533
    Keywords: Myogenesis ; Neoplasms ; Ultrastructure
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary The ultrastructure of myogenic cells occurring in neoplasms was investigated and aspects of differentiation (myofilament interactions and organization, and sarcotubular development) were characterized. The stages of muscle differentiation present were extremely similar to those reported during human fetal development prior to innervation. Exceptions, however, being: (1) the presence of fewer multinucleated cells; (2) the general lack of cell elongation and its apparent effect on myofibril orientation; and (3) evidence of a higher number of myofilaments in mononucleated cells. The findings were compared to those reported in normal human fetal development, human myogenic cells in vitro and the literature on mammalian and avian muscle development and discussed with regard to the influence of tension and innervation. The significance of degenerating myogenic cells found in these neoplasms is also discussed.
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  • 25
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    Acta neuropathologica 55 (1981), S. 199-203 
    ISSN: 1432-0533
    Keywords: Meningioma ; “Pseudopsammoma bodies” ; Ultrastructure ; Intracytoplasmic lumina ; Hyaline inclusions
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary Seven cases of meningiomas with “pseudopsammoma bodies” have previously been described in the literature. Two additional cases are presented. Electron microscopy of the cells surrounding the “pseudopsammoma bodies” reveals an ultrastructure different from that of the meningotheliomatous cells. It is concluded that meningotheliomatous meningiomas with “pseudopsammoma bodies” are mixed tumours, including a non-meningotheliomatous component, the origin and significance of which is uncertain.
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  • 26
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    Anatomy and embryology 163 (1981), S. 43-53 
    ISSN: 1432-0568
    Keywords: Porcine placenta ; Areolae ; Ultrastructure
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary The ultrastructure of the areolae in the porcine placenta is described. The areolae occur on day 30 of pregnancy as a dome-shaped formation over the openings of the uterine glands. The lumen of the areolae is filled with the secretions of the uterine glands, the so-called histiotroph. The areolae lining epithelium is high collumnar, possesing long microvilli, a well-developed apical tubular system and numerous coated vesicles. This indicates that the epithelium has a high absorptive capacity. Our histochemical investigations reveal a high content of glycoproteins within the areolar lumen. The importance of one of the glycoprotein components of the histiotroph, uteroferrin, is discussed in connection with iron transfer from mother to the fetus.
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  • 27
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    Anatomy and embryology 163 (1981), S. 215-222 
    ISSN: 1432-0568
    Keywords: Rat uterus ; Epithelium ; Ultrastructure ; Decidualization
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary Unilateral decidualization was induced in uteri of ovariectomized hormone-injected prepubertal and young adult rats. The antimesometrial luminal epithelia of both the decidualized and contralateral hormone-primed (non-decidual) control uteri were examined and compared by transmission and scanning electron microscopy. Epithelial cells of control uteri were columnar and they had many short microvilli on their luminal surfaces. Nuclei of these cells were round or oval and euchromatic, and other organelles were intact. In decidualized uteri luminal epithelial cells were flat and attenuated, were of greater average widths and possessed fewer microvilli. Some evidence of the degenerative changes which normally follow maximal decidual development in this region of the uterus could be seen within the flattened epithelial cells. The degenerative alterations were nuclear and cytoplasmic. Increase in lipid was observed in epithelial cells of decidualized uteri. This accumulation of intracellular lipid probably resulted from ingestion by the epithelial cells of intraluminally injected sesame oil, according to the protocol for stimulating decidualization.
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  • 28
    ISSN: 1432-0568
    Keywords: Thalamus ; Ultrastructure ; Cat ; Quantitative analysis
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary The ultrastructure of the ventrobasal complex (VB) of the cat thalamus was investigated in order to compare the data with those obtained in other thalamic nuclei. New data are described regarding the identification of Golgi II type neurons and several forms of axo-somatic synapses. By means of a quantitative analysis the number of different profiles, distribution of interprofile contacts, synaptic densities and degree of synaptic input of the two main cell-types were defined. The quantitative data obtained in the VB complex were compared with values for the lateral geniculate body (CGL), nucleus anterior ventralis (AV-non-sensory relay thalamic nucleus) and nucleus lateralis posterior-pulvinar complex (LP-PU-associative thalamic nucleus). The quantitative data reveal that: 1. The occurrence of RL terminals is equal in the two relay nuclei (VB and AV) and three-fold higher than in the LP-PU. 2. The percentage ratio of specific terminals (RL) in the total surface area in the relay nuclei is three-fold higher than in the LP-PU. 3. The RL→D synapses are twice as numerous in the relay nuclei as in the associative nucleus. 4. The density of synaptic RS profiles in VB is half of that found in LP-Pu. 5. In the thalamic relay nuclei the number of synaptic contacts on Golgi II type neurons is one-third of the synaptic supply of relay neurons; in the LP-Pu the amount of synaptic contacts on Golgi II type neuron approaches the synaptic supply of projective neurons.
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  • 29
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    Anatomy and embryology 162 (1981), S. 403-417 
    ISSN: 1432-0568
    Keywords: Muscle ; Ultrastructure ; Differentiation ; Growth and development
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary The differentiation of skeletal muscle was studied by electron microscopy in bovine fetuses from 47 days gestation to neonatal calves 3 days of age. Initally, the muscle was composed of clusters of myotubes with mononucleated myoblasts between them. In 2-month-old fetuses these myoblasts became apposed to the differentiating muscle cells and were enclosed within the rudimentary basal lamina of the myotubes. At this stage the clusters of myotubes consisted of central, larger diameter, more differentiated myotubes and also the mononucleated satellite cells. The differentiated myotubes separated from the clusters accompanied by satellite cells which continued proliferating and fused together to form new generations of satellite myotubes. In this manner new clusters of myotubes were formed. By 4–5 months some of the separating myotubes began to form individual myotubes and independent myofibers were prominent in fetuses of 5–8 months of age. The myofibers in the 8-month-old fetuses showed diversification into fiber types by differences in the thickness of the Z-line, the prominence of the sarcotubular system, the amount of glycogen and lipid droplets and also the number of mitochondria.
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  • 30
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    Archives of dermatological research 271 (1981), S. 55-61 
    ISSN: 1432-069X
    Keywords: Spontaneously regressing plane warts ; Activated Langerhans cells ; Unusual Langerhans cell granule ; Ultrastructure ; Spontan zurückgehende Plattenwarze ; Aktivierte Langerhanssche Zellen ; Ungewöhnliche Körner der Langerhansschen Zellen ; Ultrastruktur
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Description / Table of Contents: Zusammenfassung Es wurden die ultrastrukturellen Veränderungen der Langerhansschen Zellen während der spontanen Involution der Plattenwarze untersucht. In den Gebieten mit aktivierten Makrophagen und epidermischen Zellen zeigten die Langerhansschen Zellen, wie in der Kontaktdermatitis, ein Zeichen erhöhter cellulärer Aktivität mit Vermehrung der cellulären Körner. Ungewöhnlich an der feinen Struktur der Körner der Langerhansschen Zellen war, daß der vesiculäre Teil innen mit einer Membrane umgeben wurde und daß dieser Teil häufig in Gestalt einer Schlinge vorkam.
    Notes: Summary Ultrastructural changes of Langerhans cells during spontaneous involution of plane warts were examined. In areas with activated macrophages and epidermal cell interaction, Langerhans cells showed signs of enhanced cellular activity with an increased number of Langerhans cell granules, as in contact dermatitis. The fine structure of Langerhans cell granules, however, was unusual in that the vesicular portion was surrounded internally by a membrane, and this portion frequently occurred independently taking the shape of a loop.
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  • 31
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    Archives of dermatological research 271 (1981), S. 91-99 
    ISSN: 1432-069X
    Keywords: Cutaneous angioleiomyoma ; Ultrastructure ; Weibel-Palade bodies ; Angioleiomyoma and glomus tumor ; Cutanes Angioleiomyon ; Ultrastruktur ; Weibel-Palade-Körperchen ; Angioleiomyom und Glomustumor
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Description / Table of Contents: Zusammenfassung Die elektronenmikroskopische Untersuchung eines cutanen Angioleiomyoms zeigte, daß die Muskelumhüllungen der Blutgefäße aus typischen glatten Muskelzellen aufgebaut sind. Die Zentralgefäße haben die ultrastrukturellen Charakteristika kleiner Venulen und zeigen neben einem hohen Endothel große Mengen von Weibel-Palade-Körperchen. Abgesehen von sehr spärlichen marklosen Nervenfasern, die kleine Arteriolen begleiten, finden sich keine bedeutenderen nervalen Strukturen. Aufgrund der gravierenden ultrastrukturellen Unterschiede kann eine nähere Beziehung zwischen Angioleiomyom und Glomustumor ausgeschlossen werden.
    Notes: Summary Electron-microscopic examination of a cutaneous angioleiomyoma demonstrated that the muscular coat enveloping the blood vessels is formed of typical smooth muscle cells. The central vessels exhibit the ultrastructural features of small venules with a prominent endothelium and large numbers of Weibel-Palade bodies. Except for scanty unmyelinated nerve fibers accompanying small arterioles, no significant nerval structures were encountered. In view of the evident ultrastructural differences, a relationship of angioleiomyoma and glomus tumor can be ruled out.
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  • 32
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    Archives of dermatological research 271 (1981), S. 237-240 
    ISSN: 1432-069X
    Keywords: Dence-cored filamentous body ; Mycosis fungoides ; Ultrastructure ; Dense-cored filamentous body ; Mycosis fungoides ; Ultrastruktur
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
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  • 33
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    Archives of dermatological research 270 (1981), S. 403-411 
    ISSN: 1432-069X
    Keywords: Spontaneously regressing plane warts ; Activated macrophage ; Lymphocyte ; Ultrastructure ; Spontan zurückgehende Plattenwarze ; aktivierte Makrophage ; Lymphocyte ; Ultrastruktur
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Description / Table of Contents: Zusammenfassung Plane Warzen in der frühesten klinischen Phase der spontanen Involution wurden elektronenmikroskopisch untersucht. Es wurde gezeigt, daß Makrophagen und Lymphocyten in die Epidermis einwandern und daß die Zahl der ersteren die der letzteren überschritt. Die Lymphocyten zeigten Pseudopodien an der Oberfläche und diese drangen zuweilen in die epidermischen Zellen ein. An der Berührungsfläche der Makrophagen und der epidermalen Zellen verschwanden häufig Membranen beider Zellen und gelegentlich wurde ein Teil des Cytoplasmas und auch des Nucleus der Makrophagen von den Zellen der Epidermis aufgenommen. Außerdem wurde ein davon unabhängiger partieller Verlust der Zellmembranen der Makrophagen beobachtet. Diese ultrastrukturellen Verhältnisse zeigen, daß in der spontan zurückgehenden planen Warze eine verringerte Stabilität der Makrophagenmembranen in Gegenwart von Lymphocyten sich entwickelt, wie sie in der durch BCG und anderen Ursachen zerstörten Tumorzelle beobachtet wird, und daß die spontane Involution ein Abstoßungs-Phänomen darstellen kann.
    Notes: Summary Plane warts were examined at the earliest phase of spontaneous involution using an electron microscopy. Macrophages outnumbered lymphocytes in invading the epidermis. Lymphocytes exhibited pseudopods on the surface which occasionally reached into the epidermal cells. The cell membranes of both macrophages and epidermal cells frequently disappeared on the contacting surface and on occasion part of the cytoplasm and even the nucleus of macrophages invaded the epidermal cells. The macrophages showed an independent partial loss of their cell membranes with a subsequent outpour of their contents. This ultrastructural feature indicates that in spontaneously regressing plane warts the depressed membrane stability of macrophages as observed in BCG and other-induced tumor cell destruction also occurs in the presence of lymphocytes. Therefore, the spontaneous involution may represen a rejection phenomenon.
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  • 34
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    Intensive care medicine 7 (1981), S. 115-119 
    ISSN: 1432-1238
    Keywords: Ultrastructure ; Platelets ; Leucocytes ; Microaggregates ; Microfilters ; Microemboli ; Vascular integrity
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Abstract Electron microscopy of citrate-phosphatedextrose (CPD) buffered bank blood performed over 21 days shows that the normal architecture of erythrocytes, platelets and leucocytes disappears and that deformed organelles, leucocyte “ghosts”, cell fragments and microaggregates accumulate. Leucocytes and platelets emerge as the most sensitive indicators of blood deterioration showing profound morphological changes from the first day. Microaggregates which passed through a 20-μm high capacity transfusion filter were identified as platelet conglomerates, leucocyte “ghost” and platelet-leucocyte “ghost” coaggregates with diameters of 6–20, 20–30 and 30–40 μm respectively. of these aggregates present in the filtrate, 62% fell into the size range of 20–40 μm. The composition of microaggregates varies with storage time, the platelet conglomerates appear first during or after Day 1, leucocyte “ghosts” after Day 5 followed by platelet-leucocyte “ghost” coaggregate formation. At this stage the number of intact leucocytes and platelets is reduced and the filtrate shows an abundance of leucocyte debris. Microfiltration would thus appear to reduce but not eliminate the danger of microembolism and damage to capillary endothelium.
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  • 35
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    Experimental brain research 41 (1981), S. 247-255 
    ISSN: 1432-1106
    Keywords: Hippocampal slice ; Ultrastructure ; Mossy fiber synapses
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary 0.2 to 0.4 mm thick slices of guinea pig hippocampus were studied morphologically after varying periods of incubation at 36 ° C in Krebs-Ringer solution. Prior to fixation, the slices were tested for the presence of synaptically driven discharges of CA 3 neurons following mossy fiber (mf) stimulation because tissue preservation was satisfactory only in slices in which electrical responses were obtained. The fine structure of the mf layer in slices was compared with the ultrastructure of this region in hippocampal tissue fixed by transcardial perfusion or immersion of the tissue in the fixative. In the central part of the slices many intact neuronal structures of the mf layer could be seen even after 4 h of incubation. In the outer parts of the slices, neurons were swollen and vacuolated. These alterations were not observed in hippocampal tissue fixed by transcardial perfusion or by immersion. In all parts of the slices dark neurons and processes were found. Since dark neurons were also numerous in tissue blocks immersed in the fixative but were rare in perfused material, these changes were obviously caused by damage to unfixed tissue and fixation by immersion.
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  • 36
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    Experimental brain research 43 (1981), S. 253-260 
    ISSN: 1432-1106
    Keywords: Oculomotricity ; Abducens nucleus ; Vestibular and reticular afferents ; Ultrastructure ; Degeneration
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary The origin of the synaptic boutons in the abducens nucleus was studied following lesions of the contralateral medial vestibular nucleus, the ipsilateral paramedian pontine reticular formation and the contralateral dorsomedial part of the reticular formation caudal to the abducens nucleus. Lesions in the rostral part of the contralateral medial vestibular nucleus resulted in degeneration of boutons located mainly on dendritic processes. On the other hand, lesions in both ipsilateral and contralateral reticular formations provoked degenerating terminals on the somata of the abducens neurones and on proximal dendrites in the abducens nucleus beneath the genu of the facial nerve.
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  • 37
    ISSN: 1432-1920
    Keywords: Metrizamide ; Conray ; Dimer X ; Subacute inflammatory reactions ; Brain edema ; Ultrastructure ; Arachnoid granulation
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary Adult New Zealand rabbits were injected intrathecally with 200 or 300 mgI/ml of metrizamide, meglumine iocarmate or meglumine iothalamate. They were placed in the Trendelenburg position for 20 min and allowed to survive for 1, 2 or 3 weeks. Sacrifice was by intraarterial perfusion of aldehydes under anesthesia followed by preparation of brain and major venous sinuses for light and electron microscopy. Major findings were subpial edema and inflammatory reaction of superficial brain, leptomeninges, subarachnoid space and arachnoid granulations. They were most severe after iothalamate and milder after metrizamide. The severity decreased with time. It is of significance that severe reactions occurred after 300 mg I/ml concentration of metrizamide.
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  • 38
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    Archives of toxicology 49 (1981), S. 85-91 
    ISSN: 1432-0738
    Keywords: Rabbits ; Lead acetate ; Ultrastructure ; Kidney ; Proximal tubule
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Abstract Electron microscopical studies were carried out on the kidneys of rabbits given s.c. injections of 0 (control), 0.25 or 0.50 mg lead acetate/kg b.w. 3 times a week during 14 weeks. At the end of the experimental period the animals had lead blood levels of 60, 500 and 600 μg/1 whole blood respectively. Treatment-related renal changes were found in the proximal tubules; they consisted of a dose-related increase in the amount of lysosomes in epithelial cells of the convoluted part, and of severely damaged cells and loss of brush border in the straight part. There was also an increase in lysosomal tubular inclusions, which are considered characteristic of lysosomes of the proximal tubular cells of the rabbit kidney. The significance of these findings for assessing the risk of occupational exposure to lead is briefly discussed.
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  • 39
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    Archives of toxicology 49 (1981), S. 1-13 
    ISSN: 1432-0738
    Keywords: Chlorinated paraffins ; Liver ; Rat ; Metabolism ; Ultrastructure
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Abstract Short term effects of chlorinated paraffins with different length of the carbon chain and different degree of chlorination were investigated with respect to rat liver cytochrome P-450 mediated metabolism and liver cell morphology. When paraffins were administered by i.p. injection liver weights increased inversely with the length of the carbon chain. The short carbon chain paraffins with a high degree of chlorination increased the concentration of liver microsomal cytochrome P-450, inhibited the metabolism of 7-ethoxyresorufin but increased the metabolism of benzo(a)pyrene, especially the formation of the 4,5-diol metabolite. Short carbon chain paraffins gave rise to a proliferation of the smooth ER, increased the number of cytoplasmic fat droplets as well as the number and size of mitochondria and peroxisomes and finally induced the occurrence of autophagosomes and lysosomes. The fat droplets were preferentially degraded in lysosomes. In all respects the long carbon chain paraffins were less biologically active.
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  • 40
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    Archives of microbiology 128 (1981), S. 384-389 
    ISSN: 1432-072X
    Keywords: Didymium iridis ; Microcyst ; Excystment ; Germination ; Ultrastructure ; Mycetozoa ; Myxomycetes ; Myxamoeba
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract Microcysts of the myxomycete Didymium iridis were induced to excyst by transfer to 5mM potassium phosphate buffer. After 1 h in suspension, 90% of the microcysts had germinated into myxamoebae distinguishable by phase contrast microscopy and staining with Lugol's iodine. Both pH and osmolarity affected the kinetics of excystment. The rate and extent of excystment were decreased by cycloheximide but remained unaffected by actinomycin D, suggesting a requirement for protein synthesis but not RNA synthesis. Initially, the outer wall layers separated from the inner layer, which gradually expanded and loosened. The protoplast rehydrated and reverted to a vegetative morphology. Excysting cells were characterized by nucleolar inclusions, changes in the nuclear envelope and plasma membrane, appearance of ringed cisternal elements and microbodies in the cytoplasm, and formation of a densely fibrous zone adjacent to the site of emergence. Excysting populations have been classified into characteristic stages: mature, initiated, swollen, and pre-emergent microcysts.
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  • 41
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    Archives of microbiology 130 (1981), S. 204-212 
    ISSN: 1432-072X
    Keywords: Agmenellum quadruplicatum ; Nitrogen starvation ; Ultrastructure ; PATO poststain ; Cyanobacteria
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract The effects of nitrogen limitation on the ultrastructure of the unicellular cyanobacterium, Agmenellum quadruplicatum, were studied by thin sectioning transmission electron microscopy. Nitrogen became limiting for growth 14–15 h after transfer to nitrogen-limiting medium, but cultures retained full viability for at least 45 h. The c-phycocyanin: chlorophyll a ratio and cellular nitrogen content of the culture dropped rapidly after 14–15 h, as a progressive deterioration of major cell structures took place. Phycobilisomes were degraded first, followed by ribosomes and, then, thylakoid membranes. These structures were virtually depleted from the cells within 26 h. Intracellular polysaccharide accumulated in place of the normal cell structures throughout this period. Nitrogen limitation did not affect polyphosphate bodies, carboxysomes, lipid granules, the cell envelope, or the extra-cellular glycocalyx. All of the ultrastructural changes resulting from nitrogen limitation were reversed upon addition of nitrate to a starved culture. Most cell structures were restored within 3 h, and restoration was complete within 9 h.
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  • 42
    ISSN: 1432-072X
    Keywords: Arthrobacter ; Facultative methylotroph ; Amine oxidase ; Catalase ; RuMP cycle of formaldehyde fixation ; Ultrastructure
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract A facultative methylotrophic bacterium was isolated from enrichment cultures containing methylamine as the sole carbon source. It was tentatively identified as an Arthrobacter species. Extracts of cells grown on methylamine or ethylamine contained high levels of amine oxidase (E.C. 1.4.3.) activity. Glucose- or choline-grown cells lacked this enzyme. Oxidation of primary amines by the enzyme resulted in the formation of H2O2; as a consequence high levels of catalase were present in methylamine-and ethylamine-grown cells. The significance of catalase in vivo was demonstrated by addition of 20 mM aminotriazole (a catalase inhibitor) to exponentially growing cells. This completely blocked growth on methylamine whereas growth on glucose was hardly affected. Cytochemical studies showed that methylamine-dependent H2O2 production mainly occurred on invaginations of the cytoplasmic membrane. Assimilation of formaldehyde which is generated during methylamine oxidation was by the FBP variant of the RuMP cycle of formaldehyde fixation. The absence of NAD-dependent formaldehyde and formate dehydrogenases indicated the operation of a non-linear oxidation sequence for formal-dehyde via hexulose phosphate synthase. Enzyme profiles of the organism grown on various substrates suggested that the synthesis of amine oxidase, catalase and the enzymes of the RuMP cycle is not under coordinate control.
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  • 43
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    Journal of cancer research and clinical oncology 101 (1981), S. 149-164 
    ISSN: 1432-1335
    Keywords: Lymphoid tissue ; Reticulum cells ; Histochemistry ; Ultrastructure
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary Fibroblastic reticulum cells of different lymphoid organs were investigated to clarify their relationship to other stationary cells of the lymphoid tissue and to fibroblasts of the connective tissue. Fibroblastic reticulum cells have many ultrastructural characteristics of fibroblasts but differ from them in containing prominent bundles of microfilaments and in reacting strongly with antibodies to smooth muscle type myosin and actin. The fibroblastic reticulum cell may be thus classified as a myofibroblast. Enzyme-histochemical studies showed that fibroblastic reticulum cells contain a definite alkaline phosphatase isoenzyme. During ontogeny fibroblastic and dendritic reticulum cells are derived from the local mesenchyme and may be considered as primary stationary reticulum cells. During the formation of the follicle in the splenic white pulp in young rats fibroblastic and dendritic reticulum cells show a different turnover which speaks in favor of a proliferation of dendritic reticulum cells or their precursors in follicle formation.
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  • 44
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    Journal of cancer research and clinical oncology 101 (1981), S. 135-148 
    ISSN: 1432-1335
    Keywords: Hodgkin's disease ; Ultrastructure ; Reticulum cells ; Hodgkin's cells ; Sternberg-Reed cells
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary Lymph nodes from patients with Hodgkin's disease of the nodular sclerosis or mixed cellularity type were examined by electron microscopy to classify all the cells that occur in these types of lymphoma. Most of the cells showed morphological features that were the same, or nearly the same as those of cells of normal lymphoid tissue. These included typical interdigitating reticulum cells (IDC), histiocytic reticulum cells, so-called dark reticulum cells, and sinus macrophages. There were also small and medium-sized lymphocytes, immunoblasts, plasma cells, and plasma cell precursors resembling those seen in non-specific lymphadenitis. Germinal center cells, on the other hand, were present in negligible numbers. Special attention was paid to Hodgkin's (H) and Sternberg-Reed (SR) cells. This group of cells proved to be heterogeneous. The only common features were a large cell size, large nuclei, and a prominent nucleolus. Some of the H and SR cells resembled immunoblasts of normal lymphoid tissue. The cytoplasm of these cells contained numerous polyribosomes, and their heterochromatin was coarsely condensed at the nuclear membrane. Other H and SR cells were more similar to histiocytic cells or reticulum cells because of the large number of cell organelles (e.g., lysosome-like granules) and diffuse heterochromatin. Finally, cases of the nodular sclerosis type of Hodgkin's disease showed another cell type with some resemblance to IDC. The cells of this type are called lacunar cells because of their special light-microscopic appearance.
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  • 45
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    Journal of cancer research and clinical oncology 101 (1981), S. 191-202 
    ISSN: 1432-1335
    Keywords: Bone tumor ; Fibrous histiocytoma ; Ultrastructure
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary Case report of a patient with an unusual, rapidly growing bone tumor in the third and fourth cervical vertebrae. Histological and electron-microscopic investigations reveal a tumor composed of histiocytic cells, xanthomatous cells, giant cells of Touton type, and fibroblastic cells. No cellular features of malignancy are observed. From its cytologic appearance the tumor has to be classified as a benign fibrous histiocytoma. Regarding its ultrastructural features, the tumor may not be distinguished from non-ossifying fibroma of bone, but its clinical pattern shows obvious differences of localization and growth potential. The term “benign fibrous histiocytoma of bone” is proposed for these tumors which must be differentiated from non-ossifying fibroma.
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  • 46
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    Journal of cancer research and clinical oncology 101 (1981), S. 219-226 
    ISSN: 1432-1335
    Keywords: Giant-cell reaction ; Small tubular bone ; Ultrastructure
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary Light- and electron-microscopic investigations were performed in a case of cystic soap-bubble-like expansion of the shaft region of the second metatarsal bone. Morphologically, strongly cellular tissue with a closely packed net of osteoid trabeculae containing osteoblasts and a whorl-shaped spindle cell stroma with fibroblasts, fibrocytes, and irregularly scattered multinucleated giant cells of the osteoclast type were observed. After clinical and morphological exclusion of osteosarcoma, enchondroma, non-ossifying fibroma, osteoblastoma, osteoclastoma, and bone cysts the final diagnosis was giant-cell reaction of small tubular bone with unusual marked osteoid formation. As recurrences are possible, block resection appears more appropriate than curettage.
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  • 47
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    International orthopaedics 5 (1981), S. 47-52 
    ISSN: 1432-5195
    Keywords: Osteoarthritis ; Collagen framework ; Ultrastructure
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Description / Table of Contents: Résumé Des prélèvements obtenus à partir de genoux humains arthrosiques et de genoux de chien porteurs de lésions arthrosiques expérimentales ont permis l'étude de la charpente de collagène du cartilage articulaire et de l'os sous-chondral, par microscopie conventionnelle et par microscopie électronique. Dans les lésions dégénératives, les fibrilles de collagène du cartilage ont une orientation radiale, alors qu'elles sont habituellement groupées en faisceaux. En cas de lésions étendues, le cartilage présente souvent des clivages ou des fissures menant jusqu'aux couches calcifiées. Les fibrilles de collagène du cartilage arthrosique se fondent dans la plaque osseuse souschondrale, rendant la jonction ostéo-cartilagineuse irrégulière ou mal définie. L'orientation trabéculaire de l'os sous-chondral se modifie en fonction de l'altération du cartilage articulaire. Ces modifications réactionnelles montrent que, même au niveau ultrastructural, l'architecture de l'os sous-chondral reflète la dégénérescence cartilagineuse.
    Notes: Summary Specimens obtained from human osteoarthritic knee joints and dog knees with experimentally induced osteoarthritis were used to study the collagenous framework of articular cartilage and subchondral bone in relation to osteoarthritic changes using scanning electron microscopy and light microscopy. Degenerative articular cartilage in osteoarthritic joints showed radial orientation of the collagen fibrils, which were usually discernible as fibrillar bundle formations. Cartilage with extensive lesions often showed cleavages or fissures down to the calcified layer. The cartilagenous collagen fibrils in osteoarthritic specimens merged into the subchondral bone plate making the tidemark and the osteochondral junction irregular or obscure. The trabecular orientation of subchondral bone changed with alteration in the articular cartilage and with reactive changes in the subchondral bone, showing the effect of cartilaginous degeneration on its ultrastructure.
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  • 48
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    Virchows Archiv 390 (1981), S. 181-191 
    ISSN: 1432-2307
    Keywords: Experimental islet cell tumour ; Streptozotocin ; Immunohistochemistry ; Ultrastructure ; Cellular dedifferentation
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary Fourteen rat islet tumours induced by Streptozotocin and nicotinamide were examined by light microscopy with indirect immunoperoxidase staining and by electron microscopy. Most tumours consisted predominantly of B cells, but over a half of the tumours examined showed mixed cellularity with considerable numbers of A cells and small numbers of D or PP cells. Only 4 tumours consisted exclusively of B cells. There was no positive reaction for any kind of specific islet hormone antibodies in 2 tumours. Ultrastructurally, most tumours were composed of cells containing numerous secretory granules with B cell properties, with great variation in size, shape and number. We often encountered enterochromaffin-like cells or atypical granular cells or cells containing non-beta secretory granules. We could not identify, however, the ultrastructural counterparts of A or D cells. The results suggested that the multiplicity of the endocrine cells of rat islet cell tumours might be an expression of the cellular dedifferentiation of tumour cells which could re-differentiate into the whole range of components of the endocrine pancreas.
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  • 49
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    Virchows Archiv 391 (1981), S. 363-369 
    ISSN: 1432-2307
    Keywords: Tuberous sclerosis ; Spleen ; Ultrastructure ; Glial fibrillary acidic protein (GFAP)
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary Three cases of tuberous sclerosis in neonates were found to have focal, frequently perivascular, collections of large cells with abundant eosinophilic cytoplasm. These cells resembled those found in brain lesions of tuberous sclerosis but did not stain for acidic protein. Ultrastructurally, they were characterized by many membrane bound cytoplasmic bodies, 90 to 270 nm in diameter, with amorphous contents. Filaments were not demonstrated. Their appearance is considered most consistent with histiocytic origin. Large cells with a histiocytic appearance and a superficial resemblance to those seen in the brain in tuberous sclerosis, but a different ultrastructure and reaction to GFAP staining, may be found in the spleen of neonates with this disease.
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  • 50
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    Virchows Archiv 393 (1981), S. 233-244 
    ISSN: 1432-2307
    Keywords: Adamantinoma of long bone ; Ultrastructure ; Histogenesis ; Mesodermal or mesectodermal origin
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary Electron microscopic examination of three adamantinomas of long bones revealed structures usually observed in both mesenchymal and epithelial tumours. Tumour cells showing high alkaline phosphatase activity frequently tended to line clefts in connective tissue, resembling endothelial cells. The long processes of such cells showed fenestration. In areas showing fibre production the tumour cells were in close relationship to collagen fibrils. The latter were found, together with microfibrils, between the processes and above the basement membranes. The tumour cells were interconnected by desmosomes with tonofilaments and contained numerous bundles of microfilaments. All three cases revealed tiny intracytoplasmic inclusions resembling Weibel-Palade endothelial bodies. In addition, some of the structures in the lumena contained definite acid mucosubstances. A squamous cell pattern was present in only one of the three specimens. The coincidence of divergent structures in a single specimen has led us to the conclusion that the so-called adamantinoma of long bone might be possibly related to tumours of mesodermal or mesectodermal origin.
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  • 51
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    Cell & tissue research 216 (1981), S. 253-271 
    ISSN: 1432-0878
    Keywords: Pinealocytes ; Cell populations ; Bat ; Ultrastructure
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary In the pineal gland of the pipistrelle bat two different populations of pinealocytes and glial cells were observed electron microscopically. The pinealocytes of populations I and II differ in their content of metabolically active cell organelles. In the pinealocytes of population I, granular vesicles originating from the Golgi apparatus were found in the perikaryon and especially in the endings of the pinealocyte processes. Granular vesicles appeared to be more numerous in hibernating nulliparous females. The pinealocytes of population II are characterized by the presence of small cytoplasmic vacuoles, probably originating from cisternae of the granular endoplasmic reticulum and containing flocculent material of moderate electron density. The classification of the pinealocytes belonging to population II is discussed.
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  • 52
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    Cell & tissue research 216 (1981), S. 333-347 
    ISSN: 1432-0878
    Keywords: Insect eye ; Retina ; Ultrastructure ; Moth ; Spodoptera exempta
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary The morphology of the compound eye of the noctuid moth Spodoptera exempta was investigated by electron microscopy. This eucone superposition eye is composed of about 8000 ommatidia. Each ommatidium is surrounded by six secondary pigment cells showing pigment movement according to the state of adaptation. It contains four crystalline cone cells forming together a crystalline cone and tract, two primary pigment cells, which encompass the crystalline cone, and usually eight retinula cells. On the basis of their rhabdomeric structure, three types of retinula cells can be distinguished. According to the structure of the rhabdom, two types of ommatidia are found in different regions of the eye. The rhabdom of the lobed type, providing more than 80% of ommatidia, is composed of V-shaped rhabdomeres with fanwise arranged microvilli. The rhabdom of the square type, found in a small area in the dorsal region of the eye, consists of triangular rhabdomeres with parallel microvilli. The functional significance of this difference is discussed.
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  • 53
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    Cell & tissue research 216 (1981), S. 293-312 
    ISSN: 1432-0878
    Keywords: Ascidians ; Metamorphosis ; Attachment organs ; Ultrastructure ; Rhythmic contractions
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary The ampullae of Molgula occidentalis are hollow, tubular extensions of the epidermis. They are ensheathed by a secreted tunic. When they grow out shortly after settlement, the ampullae spread the tunic over the substratum to form a firm attachment for the sessile juvenile. A simple squamous epithelium forms the thin ampullar walls. A glandular, simple columnar epithelium forms the distal tip of each ampulla. The glandular cells probably secrete the adhesive that attaches the tunic to the substratum. Repetitive, peristaltic contractions pass from the base to the distal end of each ampulla. Microsurgery, time-lapse cinemicrography and TEM have been used to analyze this phenomenon. The contractions are mediated by a layer of 4–8 nm microfilaments in the base of the ampullar epithelium. Each juvenile has 7–9 ampullae which contract at different frequencies. Isolated ampullae continue to contract normally for several days. Thus each ampulla has an intrinsic rhythm. Microsurgical experiments suggest that there is no specific region within an ampulla with unique pacemaker properties. It is proposed that communication via gap junctions allows the coordination of ampullar cells into a well organized peristaltic wave.
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  • 54
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    Cell & tissue research 216 (1981), S. 131-141 
    ISSN: 1432-0878
    Keywords: Synovial membrane ; Secretory granules ; Ultrastructure ; Cytochemistry
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary Ultrastructural and cytochemical studies have been made on secretory granules of B-cells (fibroblast-like cells) in the knee-joint synovium. The secretory granules were membrane-bounded spherical or slightly elongated bodies, 150 to 350 nm (average 230 nm) in diameter and had a homogenous matrix with several cores. These granules were found in B-cells of all animal species examined; they were numerous in mice and rats, and few in guinea pigs, rabbits and man. Ultrastructural and cytochemical examinations revealed that the Golgi apparatus was involved in the formation of the secretory granules. Unlike lysosomes, they showed no acid phosphatase activity. The granule matrix was positively stained by Thiéiy's periodic acid-thiocarbohydrazidesilver proteinate technique, and the cores were digested by protease. These findings suggest that the granule matrix contains mucopolysaccharide(s) and/or glycoprotein(s) and the core material is largely proteinaceous in nature.
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  • 55
    ISSN: 1432-0878
    Keywords: Pineal gland ; Monolayer culture ; N-acetyl transferase ; Ultrastructure ; Rat
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary To determine how neural influences control the function of the pineal gland, morphological and biochemical relationships after pharmacological treatment have been studied in rat pineal cells in monolayer cultures. Norepinephrine (NE) and dibutyryl cyclic 3′,5′-adenosine monophosphate (dBcAMP) treatment of cells that had been in culture for 5 and 21 days produced a stimulation in the enzyme activity of serotonin N-acetyl transferase, an enzyme important in indole synthesis. NE and dBcAMP also produced morphological changes which were dependent on the time of cells in culture. When 5 day-cultures were treated with NE and dBcAMP, light and dark cells were noted and endoplasmic reticulum increased and became more organized. Only dBcAMP treatment at 5 days produced an increase in dense granules and an elongation of cytoplasmic processes. Treatment of 21 day-cultures with dBcAMP also produced an increase in cytoplasmic processes while treatment with NE produced an increase in the synaptic ribbons and clear vesicles within the processes.
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  • 56
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    Cell & tissue research 216 (1981), S. 615-624 
    ISSN: 1432-0878
    Keywords: Rat ; Preovulatory follicle ; Ultrastructure ; Estrogen ; Androgen
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary The effects of Nitromifene citrate (CI 628), an antiestrogen, and Flutamide, an antiandrogen, on the ultrastructure and viability of the preovulatory follicle and granulosa cells were examined both in vivo and in vitro. In vivo administration of either antihormone induced degeneration within the granulosa cells. In some of the affected granulosa cells, the nuclear material was condensed while the cytoplasm and associated organelles were unaltered. In others, the density of the cytoplasm was reduced, the smooth endoplasmic reticulum was dilated but the nucleus remained unaltered. In vitro, either antihormone reduced granulosa-cell viability but the granulosa cells were twenty times more sensitive to CI 628 than to Flutamide. In addition, exposure to CI 628 induced nuclear condensation without affecting the cytoplasm, while Flutamide induced the deterioration of the cytoplasm without altering the nucleus. These observations suggest that: (1) both estrogen and androgens control the viability of the granulosa cells and thereby the follicle, (2) the action of estrogen and androgen is mediated through receptors within the granulosa cells since these antihormones prevent the nuclear uptake of their respective hormone, (3) the granulosa cells of preovulatory follicles appear to be more dependent on estrogen than on androgen, and (4) each steroid appears to have a specific role in maintaining the granulosa cell; estrogens control the integrity of the nucleus while androgens preserve the cytoplasmic organization of the granulosa cell.
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  • 57
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    Cell & tissue research 216 (1981), S. 655-659 
    ISSN: 1432-0878
    Keywords: Eye ; Neuroeffector junction ; Octopamine ; Circadian rhythm ; Ultrastructure
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary Efferent fibers to the compound eye of the horseshoe crab, Limulus polyphemus, not only innervate the various pigment cells, but also invade the eccentric cell dendrite and the retinula cells. This finding provides a structural basis for the coupling of circadian rhythm between the efferents and the receptor cells.
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  • 58
    ISSN: 1432-0878
    Keywords: Vascular smooth muscle ; Spontaneously hypertensive rat ; Reaggregate cultures ; Ultrastructure ; Collagen synthesis
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary Vascular smooth muscle cells were taken from the aortae of the WKY (normotensive) and SHR (spontaneously hypertensive) strains of rat by enzymatic dispersion and put into reaggregate culture. Initially the cells became individual spheroids having average diameters of 10 μm and surfaces that were either rough or smooth. The cells were far more complex than they appeared on their surfaces; after one day in culture, there was considerable internal variation in these cells. All the cells, whether WKY or SHR, lost the bulk of their cytoplasmic contents (including myofilaments, many mitochondria, and vesicular structures) in the early stages of culture and eventually became flattened. After 14 days in culture, these modified cells collected to form reaggregates that were commonly roughly spherical and several hundred μm in diameter. These reaggregates consisted of peripheral regions made up of several layers of flattened cells overlying cores formed by glia-like networks of cells similar in cytological appearance to the cells at the periphery. The meshes formed in this way contained cellular debris derived from dead cells or extrusion of cellular contents. It appears that SHR cells are quicker to form reaggregates than are WKY cells. Yet the SHR cells retained a rounded conformation after five days, whereas the WKY cells were more flattened and formed a more discrete aggregate at this stage of culture. However, by the fourteenth day of culture, differences between the two cell strains were not so pronounced, as far as could be judged by observations made with scanning and transmission electron microscopy. Both WKY and SHR cells at 14 days appeared highly secretory, possessing large Golgi systems as well as numerous ER cisternae and mitochondria. SHR cells produced greater amounts of connective tissue at all stages of culture than did WKY cells, indicating that a similar difference may contribute to the hypertension which develops naturally in situ in SHR animals.
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  • 59
    ISSN: 1432-0878
    Keywords: Paraventricular neurones ; Alcian-blue labelling ; Ultrastructure ; Electrophysiology ; Rat
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary The ultrastructural characterization of electrophysiologically identified neurones of the rat paraventricular hypothalamic nucleus was performed with extracellular labelling technique. The extracellularly recorded neurones are labelled with an electrophoretic deposit of alcian blue contained in the recording micropipette. The neurone thus labelled takes on a dark and shrunken appearance which enables its detection among neighbouring cells without, however, concealing its main morphological characteristics. 1) Spontaneously firing neurones, invaded by an antidromic action potential elicited by electrical stimulation of the neurohypophysis, were identified as magnocellular cells containing dense-cored vesicles of 200–250 nm in diameter. Dense-cored vesicles were not found in the antidromically activated neurones devoid of spontaneous activity. 2) Trans-synaptically activated neurones in the PVN or in its dorso-lateral edge were small cells devoid of dense secretory vesicles. 3) PV neurones in which neurohypophysial stimulation evoked no response, contained small, dense vesicles (100 nm in diameter) comparable with those found in parvocellular peptidergic neurones.
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  • 60
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    Cell & tissue research 216 (1981), S. 491-501 
    ISSN: 1432-0878
    Keywords: Ultrastructure ; Cornea ; Compound eye ; Honey bee (Apis mellifera)
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary The fine structure of the cornea in an anatomically and functionally specialized part of the honey bee's compound eye (dorsal rim area) was examined by light microscopy, transmission electron and scanning electron microscopy. Under incident illumination the cornea appears grey and cloudy, leaving only the centers of the corneal lenses clear. This is due to numerous pore canals that penetrate the cornea from the inside, ending a few μm below the outer surface. They consist of (1) a small cylindrical cellular evagination of a pigment cell (proximal), and (2) a rugged-walled, pinetree-shaped extracellular part (distal). The functional significance of these pore canals is discussed. It is concluded that their light scattering properties cause the wide visual fields of the photoreceptor cells measured electrophysiologically in the dorsal rim area, and that this is related to the way this eye region detects polarization in skylight.
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    Cell & tissue research 216 (1981), S. 525-543 
    ISSN: 1432-0878
    Keywords: Hygroreceptor ; Thermoreceptor ; Sensillum capitulum ; Cockroach ; Ultrastructure
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary The sensillum capitulum, a hygro- and thermoreceptive sensillum of the cockroach Periplaneta americana L. is comprised of four receptor cells, one glial cell, two gland cells and four enveloping cells. Each receptor cell sends a single axon to the CNS, and has a single dendrite which extends distally. The perikarya of three receptor cells are enclosed by one of the enveloping cells (number one) and the fourth by a gland cell. The dendrites of all four receptor cells are enclosed by the same enveloping cell. The dendrites contain rootlets and many microtubules. The sensory cilia arise at the end of the dendrites at the level of the inner cavity, expand from the connecting cilium in a manner similar to those of the amphinematic scolopidia, and have numerous microtubules. The 1st enveloping cell contains scolopale rod-like structures. The sensory cilia are surrounded distally by a cuticular sheath formed within the 1st enveloping cell. One of the sensory cilia disappears distally, and the remaining ones enter the sensillum cone. Of these, one branches and the other two do not. The distal ends of the unbranched cilia are differentiated into tubular structures. The sensillum cone is comprised of an inner stem and a guard wall, neither of which is perforated. The outer cavity is enclosed by the 2nd, 3rd, and 4th enveloping cells, and distally in the antenna is closely apposed to the cuticular wall. This cavity contains lipid deposits. These structural features are discussed with regard to the mechanism of hygroreception in P. americana.
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    Cell & tissue research 217 (1981), S. 11-21 
    ISSN: 1432-0878
    Keywords: Intestinal mucosa ; Small intestinal epithelium ; Ultrastructure ; Duodenum ; Jejunum ; Stereology ; Rats
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary Quantitative macroscopic, light-microscopic and electron-microscopic studies were performed on the small intestine of fasted and non-fasted adult, male Sprague-Dawley rats. In non-fasted rats the small intestine was longer than in fasted rats. Due to the presence of villi the surface area in the duodenum and the jejunum was enlarged about six times. The microvilli on the villous crests caused a surface enlargement by 13 times in the duodenum (value corrected for overestimation due to section thickness), and 19 times in the jejunum of the fasted rats. At the base of the villi these values were about 50% lower. It was calculated that, in the fasted rats, the total enlargement of the luminal surface area — due to villi and microvilli — was 63 times in the duodenum and 81 times in the jejunum (corrected for section thickness). Differences between the villous crest epithelium and the villous base epithelium were also found with regard to the mean cell height, and the volume densities of the absorptive cell nuclei, the mitochondria, and the paracellular channels.
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  • 63
    ISSN: 1615-6102
    Keywords: Acid phosphatase ; Capsella ; Female meiocyte ; Ovule ; Ultrastructure
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Summary Pre-meiotic and prophase I ovules ofCapsella bursa-pastoris (L.) Medic.(monosporic,Polygonum type of gametophyte development) were fixed routinely or incubated in a modified Gomori medium containing β-glycerophosphate as a substrate. Prior to the beginning of meiosis the potential meiocyte is ultrastructurally similar to the other cells of the nucellus and is distinguished only by its size and position. At the initiation of prophase I dramatic ultrastructural and ultracytochemical changes take place in the female meiocyte. These include the sudden appearance of cytoplasmic structures composed of single and multiple concentric cisternae, distinctive changes in plastids and mitochondria, and the blebbing of 0.3 μm double-membraned vesicles from the nuclear envelope. The concentric cisternae encapsulate portions of cytoplasm containing ribosomes, plastids, mitochondria, ER fragments and vesicles. Both single and multiple concentric cisternae localize high levels of acid phosphatase and function as autophagic vesicles (AVs) that sequester ribosomes and organelles for destruction during meiosis. Plastids stop dividing and become more spherical during prophase I. Some plastids localize acid phosphatase and many show continuities between the outer membrane and the plastid envelope and acid phosphatase-rich RER cisternae. Mitochondria appear as dense, contracted spheres or rods. Some mitochondria localize acid phosphatase but they do not show membrane confluencies with the ER. Some of the plastids and mitochondria that are segregated into the functional megaspore at meiosis II are destroyed but others apparantly survive meiosis and give rise to the plastid and mitochondrial populations of the young gametophyte (Schulz andJensen, unpublished). The lateral and end walls of the meiocyte show patches of intense aniline blue fluorescence and the chalazal end wall of the cell is perforated with large numbers of plasmodesmata.
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    Protoplasma 107 (1981), S. 85-107 
    ISSN: 1615-6102
    Keywords: Male cytoplasmic inheritance ; Plumbago ; Pollen grain ; Pollen tube ; Sperm ; Ultrastructure
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Summary Male gametes ofPlumbago zeylanica were examined in pollen grains and tubes using light and electron microscopy of chemically and physically fixed tissues, and Nomarski interference microscopy of isolated, living sperm cells. Male gametes are elongate, spindleshaped cells containing a nucleus, mitochondria, ER, ribosomes, vesicles, dictyosomes, probable microfilaments, and a variable number of plastids. In mature pollen grains ofP. zeylanica, the two sperm cells are directly linked; they share a transverse cell wall with plasmodesmata and are enclosed together by the inner vegetative cell plasma membrane. One of these two sperms is also associated with the vegetative nucleus as a consistent feature of pollen grain organization. The basis of this association appears to be a long, narrow projection of the sperm cell (averaging 〈 1 μm wide and about 30 μm long) which wraps around the periphery of the vegetative nucleus and occupies embayments of that nucleus. This association is maintained throughout pollen tube growth but becomes less extensive near the completion of tube growth and is severed following tube discharge. The consistent occurrence of the sperm-vegetative nucleus association in pollen grains, tubes and isolated pollen cytoplasm suggests that the two structures may be directly connected, but attempts to visualize this type of connection were unsuccessful. Possibly, the entwining nature and extent of complementary interfaces between vegetative nucleus and sperm may have a role in stabilizing their association. Functionally, the two sperms and vegetative nucleus appear to travel as a linked unit within the pollen tube, possibly increasing the effectiveness of gamete delivery and helping to ensure nearly simultaneous transmission of sperms into the receptive megagametophyte.
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  • 65
    ISSN: 1615-6102
    Keywords: C4 Photosynthesis ; C4 Types ; Leaf blades ; Poaceae ; Suberized lamella ; Ultrastructure
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Summary Leaf blades of 42 grasses (Poaceae) have been examined ultrastructurally for the occurrence of a suberized lamella in walls of parenchymatous bundle sheaths and PCR (= “Kranz”) sheaths in both large and small vascular bundles. The sample includes species from a range of major grass taxa, and represents all photosynthetic types found in the grasses. Three grasses with unusual C4 leaf anatomy were also included:Alloteropsis semialata, Aristida biglandulosa, Arundinella nepalensis. The presence of a suberized lamella in PCR cell walls was perfectly correlated with photosynthetic type. All PEP-carboxykinase type and NADP-malic enzyme type C4 species examined possessed a suberized lamella in outer tangential and radial walls, but with variable presence in inner tangential walls. PCR cells of bothAlloteropsis semialata andArundinella nepalensis also possessed a suberized lamella. A lamella was totally absent from parenchymatous bundle sheath cells of the C3 species examined (5 spp.) and ofPanicum milioides, a C3-C4 intermediate. It was also absent from PCR cells of NAD-malic enzyme type C4 species (14 spp.) andAristida biglandulosa. The results are discussed in relation to the leakage of CO2 from PCR cells, and to differences between C4 types in δ13C values, chloroplast position in PCR cells, and other anatomical characteristics.
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  • 66
    ISSN: 1615-6102
    Keywords: Dasya ; Mitosis ; Rhodophyta ; Spermatangia ; Ultrastructure
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Summary Mitosis in the marine red algaDasya baillouviana (Ceramiales, Florideophyceae) was observed with the electron microscope. Most details of the process are quite similar to those observed in the other macroscopic red algae studied to date. However, some minor variations were noted. At late prophase a very small nuclear envelope protrusion (NEP) is formed at each division pole subjacent to the “nucleus associated organelle” known as the polar ring (PR) and 2–3 cisternae of perinuclear endoplasmic reticulum (PER) are commonly present during metaphase-anaphase. In contrast, in the other florideophycean algae where mitosis has been reported, a prominent NEP is present at late prophase (McDonald personal communication,Scott et al. 1980) and only a single cisterna of PER is observed. Additionally, during mid-late interphase and in mitotically-quiescent cells ofDasya, a single cisterna of smooth-surfaced ER is always juxtaposed with each PR. The possible significance of PER in theFlorideophyceae and other multinucleate organisms is discussed as well as the likely functions of spindle-associated smooth ER. It is suggested that ultrastructural features of mitosis should be useful as criteria to aid in the interpretation of the phylogeny of red algae.
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  • 67
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    European archives of oto-rhino-laryngology and head & neck 230 (1981), S. 121-132 
    ISSN: 1434-4726
    Keywords: Cholesteatom ; Histochemie ; Ultrastruktur ; Lysosomen ; Oxytalanfaser ; Cholesteatoma ; Histochemistry ; Ultrastructure ; Lysosomes ; Oxytalan fibres
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Description / Table of Contents: Summary In a histochemical and ultrastructural study the pathogenesis of cholesteatoma ostitis is analysed on human tissue. In the subepithelial layer there is evidence of an inflammatory reaction leading to proliferation of granulation tissue with bony invasion. Bony destruction is initiated by osteocytic osteolysis. In the case of cholesteatoma there is a combined action of extraosseous and osseous lysosomal enzymes. The pathological changes of the fibrillar elements suggest that the self-perpetuation of degeneration is maintained by a disturbance of fibrillogenesis. The causal pathogenesis of cholesteatoma formation is discussed as a function of a disturbance between cellular activity, extracellular matrix, and cellular surface.
    Notes: Zusammenfassung In einer histochemischen und ultrastrukturellen Untersuchung wird die Pathogenese des Cholesteatoms analysiert. Charakteristikum des subepithelialen Gewebes ist die Ausbildung einer entzündlichen Reaktion mit anschließender Formation eines in den Knochen proliferierenden Granulationsgewebes. Der Knochenabbau wird durch osteozytäre Osteolyse eingeleitet. Dadurch kommt es bei der Erkrankung zu einem Zusammenwirken ossär lysosomaler und extraossär lysosomaler Enzyme. Die pathologischen Befunde im Bereich der Faserelemente deuten an, daß der Selbsterhaltungsprozeß der degenerativen Veränderungen durch eine Störung der Fibrillogenese verstärkt wird. Die kausale Genese des Cholesteatoms wird unter Berücksichtigung der gestörten Interaktion zwischen Zellaktivität, Extrazellularmatrix und Zelloberfläche diskutiert.
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  • 68
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    European archives of oto-rhino-laryngology and head & neck 230 (1981), S. 181-188 
    ISSN: 1434-4726
    Keywords: M. vocalis ; Histologie ; Ultrastruktur ; Muskuläre Dystrophie ; Vocal muscle ; Histology ; Ultrastructure ; Musculardystrophy
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Description / Table of Contents: Summary Biopsy material from the vocal muscle of patients suffering from Steinert's muscular dystrophy, Duchenne's muscular dystrophy, oculopharyngeal progressive muscular dystrophy, and paraneoplastic myopathy was examined under the light and electron microscope. The histological findings were compatible with the muscular changes seen in the skeletal muscles of the extremities of the same patients. Slight differences in the severity of the pathologic process were noticed in correlation with the muscles of the extremities which were always more seriously affected than the vocal muscles. The ultrastructural study revealed a moderate to very porminent dilatation of the sarcotubular system, involving the T-tubules and the cisternae of the smooth endoplasmic reticulum as well. From the clinical point of view, the vocal muscle biopsy was beneficial to the patients suffering from Steinert's myotonic muscular dystrophy, whereas it did not affect the clinical condition of the others.
    Notes: Zusammenfassung Biopsiematerial aus den Stimmuskeln von Patienten, die an einer Steinertschen Myodystrophie, einer Myodystrophie von Duchenne, einer progressiven occulopharyngealen Myodystrophie oder einer paraneoplastischen Myopathie litten, wurde licht- und elektronenmikroskopisch untersucht. Die histologischen Befunde sind mit den Veränderungen vergleichbar, die auch an der Skelettmuskulatur derselben Patienten gefunden wurde. Die feingewebliche Untersuchung zeigte eine mäßige bis stärkere Erweiterung des sarcotubulären Systems mit Befall der Tubuli und der Cysternen des endoplasmatischen Reticulums. Klinisch zeigte der Patient, der an einer Steinertschen Myodystrophie litt, nach der Biopsie eine Besserung der Stimme.
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  • 69
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    International Journal of Quantum Chemistry 19 (1981), S. 25-31 
    ISSN: 0020-7608
    Keywords: Computational Chemistry and Molecular Modeling ; Atomic, Molecular and Optical Physics
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: As an alternative to the density functional approach to estimating total molecular correlation energies, the equation Ecorr=-0.06593 ∑i=1M Ri-0.3916, where Ri=〈r2〉i½ and i runs over the localized molecular orbitals was fitted to 25 STO-3G data points with a root-mean-square error of 0.025 hartree. Other more general equations were tried but no significant improvement was observed in the fit.
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  • 70
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    International Journal of Quantum Chemistry 19 (1981), S. 105-112 
    ISSN: 0020-7608
    Keywords: Computational Chemistry and Molecular Modeling ; Atomic, Molecular and Optical Physics
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: Quantum mechanical calculations have been made of vibrational transition probabilities in the collinear collision of an inert gas atom with either CO2 or OCS. The dependence of the transition probability on the relative translational energy and the reduced mass is similar to that found for atom-diatom collisions. The transition P00 → 10 (excitation of the first stretching mode) is much greater than P00 → 01 (the second stretching mode). This is largely due to the difference in frequencies but it has been shown that there is an independent mass factor responsible for this difference.
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  • 71
    ISSN: 0020-7608
    Keywords: Computational Chemistry and Molecular Modeling ; Atomic, Molecular and Optical Physics
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: While the concept of the graph center is unambiguous (and quite old) in the case of acyclic graphs, an attempt has been made recently to extend the concept to polycyclic structures using the distance matrix of a graph as the basis. In this work we continue exploring such generalizations considering in addition to the distance matrix, self-avoiding walks or paths as graph invariants of potential interest for discriminating distinctive vertex environments in a graph of polycyclic structures. A hierachy of criteria is suggested that offers a systematic approach to the vertex discrimination and eventually establishes in most cases the graph center as a single vertex, a single bond (edge), or a single group of equivalent vertices. Some applications and the significance of the concept of the graph center are presented.
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  • 72
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    International Journal of Quantum Chemistry 19 (1981), S. 251-257 
    ISSN: 0020-7608
    Keywords: Computational Chemistry and Molecular Modeling ; Atomic, Molecular and Optical Physics
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: In this paper we define the algebraic structure of a reduced fermion density matrix. We relate the algebraic structure to certain symmetry properties of the reduced density matrix.
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  • 73
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    International Journal of Quantum Chemistry 19 (1981), S. 259-269 
    ISSN: 0020-7608
    Keywords: Computational Chemistry and Molecular Modeling ; Atomic, Molecular and Optical Physics
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: A method of expansion of molecular orbital wave functions into valence bond (VB) functions is extended to molecular fragments. The wave function is projected onto a basis of mixed determinants, involving molecular orbitals as well as fragment atomic orbitals, and is further expressed as a linear combination of VB functions, characteristic of structural formulas of the fragment but whose remaining bonds are frozen. Structural weights for the fragment are deduced from this expression. Delocalized molecular orbitals are used as a startpoint, as they are after an ordinary SCF calculation. Wave functions of medium-sized molecules may be analyzed with reasonable storage requirements in a computer.
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  • 74
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    International Journal of Quantum Chemistry 19 (1981), S. 413-426 
    ISSN: 0020-7608
    Keywords: Computational Chemistry and Molecular Modeling ; Atomic, Molecular and Optical Physics
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: The generalized branching diagram (GBD) spin representation is defined as the method of sequentially coupling together a number of subsystem spin eigenfunctions using the general rules of angular momentum coupling. It is shown that any GBD representation may also be obtained by Schmidt orthogonalizing a set of cannonical spin-paired (SP) functions, provided the SP basis is suitably ordered. The ordering procedure used is well suited to computer implementation. This is a generalization of results known in the literature for the Yamanouchi-Kotani and for the Serber spin representations.
    Additional Material: 4 Ill.
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  • 75
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    International Journal of Quantum Chemistry 19 (1981), S. 383-399 
    ISSN: 0020-7608
    Keywords: Computational Chemistry and Molecular Modeling ; Atomic, Molecular and Optical Physics
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: The molecule-in-molecule method of computation has been applied in a SCF study of the electronic absorption spectra of 2- and 3-phenylfurans and 2,2′- and 3,3′-bifurans. The computed values for the transition energies and band intensities differ for the different isomers and help one to assign the preferred conformer of the studied molecules. Computations were performed on planar as well as nonplanar conformers. The calculated parameters as well as the interaction energy suggest all-planar configuration for the studied molecules. A model potential for the sigma framework for the ortho-hydrogens is considered. The calculated steric repulsion energy is negligible compared to the π delocalization. The height of the rotational barrier was larger for 2-phenylfuran than for 3-phenylfuran, and larger for 2,2′-bifuran than for 3,3′-bifuran. This result is in accord with predictions based on the extent of “π” conjugation in these molecules.
    Additional Material: 4 Ill.
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  • 76
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    International Journal of Quantum Chemistry 19 (1981), S. 451-461 
    ISSN: 0020-7608
    Keywords: Computational Chemistry and Molecular Modeling ; Atomic, Molecular and Optical Physics
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: Ab initio LCAO SCF MO calculations are carried out on the ground state and d-d transition states of CoF64-, CoF63-, and CoF62- complexes with a basis set of more than double-zeta quality. To obtain a better description for the excitation energy of d-d transition states, a ligand field configuration interaction calculation is performed. The calculation is improved further by taking into account the correlation energy in the central metal atom and it gives good results for the observed excitation energies. Especially, the excitation energies for the states which have the same configuration as the ground state agree with observed ones within about 1 kK. The excitation energies of several charge transfer states in the CoF62- complex are also computed at the level of SCF MO calculation and the assignments are made for the four strong bands observed in the energy region higher than the weak d-d bands.
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  • 77
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    International Journal of Quantum Chemistry 19 (1981), S. 483-484 
    ISSN: 0020-7608
    Keywords: Computational Chemistry and Molecular Modeling ; Atomic, Molecular and Optical Physics
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Additional Material: 1 Tab.
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  • 78
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    International Journal of Quantum Chemistry 19 (1981), S. 505-514 
    ISSN: 0020-7608
    Keywords: Computational Chemistry and Molecular Modeling ; Atomic, Molecular and Optical Physics
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: The properties of the algebraic structure of fermion density matrices are studied. The algebraic structure of a density matrix leads to a more varied and detailed classification scheme than that offered by the usual shell structure approach. Investigation of the algebraic structure of fermion density matrices by the methods of algebraic topology leads to a classification scheme based on Betti numbers.
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  • 79
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    International Journal of Quantum Chemistry 20 (1981) 
    ISSN: 0020-7608
    Keywords: Computational Chemistry and Molecular Modeling ; Atomic, Molecular and Optical Physics
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
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  • 80
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    International Journal of Quantum Chemistry 20 (1981), S. 41-48 
    ISSN: 0020-7608
    Keywords: Computational Chemistry and Molecular Modeling ; Atomic, Molecular and Optical Physics
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: Synchrotron radiation has been used to determine the fluorescence decay parameters of a tryptophan-containing oligopeptide, Lys-Trp-Lys, bound to nucleic acids. All fluorescence decay curves can be fitted by a sum of two exponentials. The two lifetimes very likely correspond to two conformational states of the oligopeptide. The mean fluorescence lifetime of the peptide is not markedly affected upon binding to nucleic acids even though the fluorescence quantum yield is strongly reduced. A model is presented that accounts for the existing fluorescence data: two consecutive complexes are formed both involving electrostatic interactions. In one of the complexes the tryptophyl ring is stacked with the nucleic acid bases and its fluorescence is completely quenched. The other complex emits a fluorescence having characteristics which are similar to those of the free peptide.
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  • 81
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    International Journal of Quantum Chemistry 19 (1981), S. 1099-1103 
    ISSN: 0020-7608
    Keywords: Computational Chemistry and Molecular Modeling ; Atomic, Molecular and Optical Physics
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: After emphasizing the importance of absorption spectra of metal clusters, with special reference to alkali halide IR absorption, the equilibrium configurations and the binding energies of alkali halide clusters are discussed in terms of a very simple two-body interaction.
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  • 82
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    International Journal of Quantum Chemistry 19 (1981), S. 1133-1135 
    ISSN: 0020-7608
    Keywords: Computational Chemistry and Molecular Modeling ; Atomic, Molecular and Optical Physics
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
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  • 83
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    International Journal of Quantum Chemistry 20 (1981), S. 167-178 
    ISSN: 0020-7608
    Keywords: Computational Chemistry and Molecular Modeling ; Atomic, Molecular and Optical Physics
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: The paper reports comparison of electrostatic charge and energy distribution on the basis of the CNDO/2 method for six forms of prostaglandins-PGF2α, PGF1β, PGE1, PGE2, PGB1, and PGA1-having diverse physiological action. The isopotential mapping done in three dimension showed that the lower value of electrostatic potential and proximity of the two low energy regions around O9 and O11 in PGE2 and PGF2α is probably responsible for their higher abortificient activity. We also compare here the variation of the long- and short-range interaction between ring-chain and chain-chain portion of different forms and compared them with the variation in their action.
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  • 84
    ISSN: 0020-7608
    Keywords: Computational Chemistry and Molecular Modeling ; Atomic, Molecular and Optical Physics
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: We performed ab initio pseudopotential and CNDO calculations on γ-aminobutyric acid (GABA) and its Ca2+ and Mg2+ clathrates. We were particularly interested in the rotational barrier existing between two extreme conformers of GABA and its modification upon metal complexing. We found that the pseudopotential method predicts a coordination of the ions to GABA and that this coordination inverts the rotational barrier observed for the isolated molecule. We also looked into the adequacy of CNDO for the study of this type of coordination and found several shortcomings in its predictions. The biological implications of these findings are discussed and a hypothesis on the role of a GABA-Ca2+ complex is presented.
    Additional Material: 3 Ill.
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  • 85
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    International Journal of Quantum Chemistry 19 (1981) 
    ISSN: 0020-7608
    Keywords: Computational Chemistry and Molecular Modeling ; Atomic, Molecular and Optical Physics
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
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  • 86
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    International Journal of Quantum Chemistry 19 (1981), S. 493-500 
    ISSN: 0020-7608
    Keywords: Computational Chemistry and Molecular Modeling ; Atomic, Molecular and Optical Physics
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: In the frame of direct minimization of MC-SCF energy by an orthogonal transformation of the basis, a new procedure for iteratively solving the orbital equations is presented, in which the orthogonal matrix is calculated by the singular value and vector decomposition of a nonsymmetric matrix. The procedure is applied to the self-consistent electron pair theory and tested on LiH molecule. Convergence rate and numerical stability are found to be satisfactory.
    Additional Material: 1 Tab.
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  • 87
    ISSN: 0020-7608
    Keywords: Computational Chemistry and Molecular Modeling ; Atomic, Molecular and Optical Physics
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: A method for basis set generation for SCF calculations is proposed. Using SCF orbitals and orbital energies obtained in the extended basis set the Fock operator can be expressed as its spectral resolution. The sum of differences between occupied orbital energies and corresponding eigenvalues obtained by the diagonalization of this operator in the new smaller basis set is a criterion of the quality of this new set. The present method consists of the minimization of this sum by changing the parameters that determine the new basis functions. An example of the optimization of the different Gaussian basis sets for the LiH molecule is described.
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  • 88
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    International Journal of Quantum Chemistry 19 (1981), S. 637-648 
    ISSN: 0020-7608
    Keywords: Computational Chemistry and Molecular Modeling ; Atomic, Molecular and Optical Physics
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: An SCF LCAO MO calculation on the methane-methane-methane system is presented, in order to analyze the deviation from pairwise additivity of the interaction energy. Three-body terms are shown to be remarkably similar to those of noble gas trimers both in magnitude and in their dependence on the geometrical arrangements of the three molecules.
    Additional Material: 5 Ill.
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  • 89
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    International Journal of Quantum Chemistry 19 (1981), S. 673-679 
    ISSN: 0020-7608
    Keywords: Computational Chemistry and Molecular Modeling ; Atomic, Molecular and Optical Physics
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: Making use of different information measures, the Pauli exclusion principle and the first Hund rule were found to be related to a trend toward acquiring a maximum information content of the atoms and molecules, and more generally, for any fermion system. The bosons conversely always have a minimum (zero) information content with respect to the permutation symmetry of their wave functions. Some new interpretations of the Pauli principle are presented.
    Additional Material: 1 Tab.
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  • 90
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    International Journal of Quantum Chemistry 19 (1981), S. 681-691 
    ISSN: 0020-7608
    Keywords: Computational Chemistry and Molecular Modeling ; Atomic, Molecular and Optical Physics
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: A first principles method based on an APW-k · p band structure calculation is derived in order to obtain the self-consistent eigenenergies, crystal potential, and electronic density. The simplicity and extensions of the method are discussed, including comparison with the results obtained by the use of the Chadi and Cohen special points technique.
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  • 91
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    International Journal of Quantum Chemistry 19 (1981), S. 719-720 
    ISSN: 0020-7608
    Keywords: Computational Chemistry and Molecular Modeling ; Atomic, Molecular and Optical Physics
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Additional Material: 1 Ill.
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  • 92
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    International Journal of Quantum Chemistry 19 (1981), S. 729-734 
    ISSN: 0020-7608
    Keywords: Computational Chemistry and Molecular Modeling ; Atomic, Molecular and Optical Physics
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: An analytic atomic active electron model potential adjusted to experimental single-particle energy levels is used to generate wave functions for the valence and excited states of O1+, F2+, Ne3+, Na4+, and Mg5+. Using these wave functions in conjunction with the Born approximation and the LS-coupling scheme, we calculate optical oscillator strengths for excitations from the 1s22s22p3(4S3/2) ground state. The results are compared to experimental data and other calculations. Systematic trends along the isoelectronic sequence are discussed.
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  • 93
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    International Journal of Quantum Chemistry 19 (1981), S. 763-769 
    ISSN: 0020-7608
    Keywords: Computational Chemistry and Molecular Modeling ; Atomic, Molecular and Optical Physics
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: A coupled perturbation theory for the antisymmetrized product of separated geminals (APSG) approximation is derived. The variational principle for the APSG wave function in an external oscillating field is employed and a set of equations of the form analogous to the normal RPA is obtained. At this level the reduced resolvent in the form of a spectral expansion is written and it is used for the evaluation of the second-order properties.
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  • 94
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    International Journal of Quantum Chemistry 19 (1981), S. 805-819 
    ISSN: 0020-7608
    Keywords: Computational Chemistry and Molecular Modeling ; Atomic, Molecular and Optical Physics
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: A charge density distribution study, based on ab initio SCF-6-31G wave functions, on the optimized geometry of 1,2-dioxethane indicates its high instability which results from (i) the high ring strain, (ii) the large amount of charge contained on the nonbonded sides of the oxygen nuclei, and (iii) the weak binding character of the charge density in the O—O bond region. The redistribution of the charge density when 1,2-dioxethane undergoes change in its nuclear configuration has been discussed. This redistribution of charge along the reaction path (the dissociation of 1,2-dioxethane to formaldehyde products) shows clearly the preceding nature of the electron cloud. The characteristic features of the charge density distribution of the two Hartree-Fock solutions to which the SCF procedure converges have been analyzed and discussed.
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  • 95
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    International Journal of Quantum Chemistry 19 (1981), S. 859-871 
    ISSN: 0020-7608
    Keywords: Computational Chemistry and Molecular Modeling ; Atomic, Molecular and Optical Physics
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: By applying the projection operator method it is shown that the complicated Hamiltonian of a E ⊗ ∊ JT system with nonlinear coupling coefficients can be written in terms of two Hamiltonians which are simple to handle and transform according to irreducible representations E, A1, and A2 of C3v point group. A variational approach is then used to calculate the ground state energy, using the Hamiltonian that transforms according to E, as an explicit function of the linear and nonlinear coupling parameters. The energies calculated in the strong coupling limit are finally compared with the corresponding previously calculated energies.
    Additional Material: 1 Ill.
    Type of Medium: Electronic Resource
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  • 96
    Electronic Resource
    Electronic Resource
    New York, NY : Wiley-Blackwell
    International Journal of Quantum Chemistry 19 (1981), S. 901-906 
    ISSN: 0020-7608
    Keywords: Computational Chemistry and Molecular Modeling ; Atomic, Molecular and Optical Physics
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: A coupled channel formulation for the static Stark effect on the hydrogen atom is used to obtain directly the complex resonance energies through an iterative matching procedure. The formulation makes use of a complex coordinate. This solves the initialization problem in a very simple way, since the boundary conditions can be those used for bound states. A comparison is made with the results of Reinhardt and collaborators who expand the complex rotated resonance wave function in a basis of integrable functions.
    Additional Material: 3 Tab.
    Type of Medium: Electronic Resource
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  • 97
    Electronic Resource
    Electronic Resource
    New York, NY : Wiley-Blackwell
    International Journal of Quantum Chemistry 20 (1981), S. 347-356 
    ISSN: 0020-7608
    Keywords: Computational Chemistry and Molecular Modeling ; Atomic, Molecular and Optical Physics
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: Single chain and packing energy calculations have been made on polyglycine (threefold and fourfold helical structures) with interchain NH…O hydrogen bonds. In conformation A of polyglycine, in which the NH groups point away from the helix axis and the CO groups are nearer to the helix axis, the conformational energy is nearly the same for threefold and fourfold structures. However, the minimum energy conformation corresponds to a threefold structure of polyglycine with peptide configurations in conformation B in which the CO groups point away from the helix axis and NH groups are nearer to the helix axis. This structure is consistent with the polyglycine II x-ray diffraction data.
    Additional Material: 4 Ill.
    Type of Medium: Electronic Resource
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  • 98
    Electronic Resource
    Electronic Resource
    New York, NY : Wiley-Blackwell
    International Journal of Quantum Chemistry 20 (1981), S. 393-406 
    ISSN: 0020-7608
    Keywords: Computational Chemistry and Molecular Modeling ; Atomic, Molecular and Optical Physics
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: The ab initio MO and semiempirical multireference (MR) CI calculations were carried out to elucidate the energy differences between peroxy 1,4-diradical (DR) and 1,4-zwitterionic (ZWI) intermediates, which play crucial roles in photo-oxygenation reactions of nitrogen-activated C—C double bonds of enamines, indoles, and tryptamines. It is found that ZWI is more stable than DR in the case of electron-rich enamines. Protic solvents such as methanol are highly effective for the stabilization of ZWI by hydrogen bondings. From the present theoretical results, it is concluded that tryptophane undergoes the photooxidative cleavage reaction to give formylkynurenine under a specific condition, where polar solvents or catalysts sufficiently stabilize the ZWI state for the species.
    Additional Material: 3 Ill.
    Type of Medium: Electronic Resource
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  • 99
    Electronic Resource
    Electronic Resource
    New York, NY : Wiley-Blackwell
    International Journal of Quantum Chemistry 20 (1981), S. 461-478 
    ISSN: 0020-7608
    Keywords: Computational Chemistry and Molecular Modeling ; Atomic, Molecular and Optical Physics
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: The present state in the chemistry of peptides and proteins capable of transporting ions across biological and model membranes have been reviewed. The mechanisms of action of peptide ionophores valinomycin and enniatin and also the channel-forming peptide gramicidin-A have been discussed on the basis of spatial structure and dynamic conformational properties of the compounds. Recent progress in the studies of bacteriorhodopsin, cholinergic receptor from postsynaptic membrane, and sodium channel from the excitable nerve membrane, the integral membrane proteins acting as proton or metal ion channel formers is also discussed.
    Additional Material: 13 Ill.
    Type of Medium: Electronic Resource
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  • 100
    Electronic Resource
    Electronic Resource
    New York, NY : Wiley-Blackwell
    International Journal of Quantum Chemistry 20 (1981), S. 495-504 
    ISSN: 0020-7608
    Keywords: Computational Chemistry and Molecular Modeling ; Atomic, Molecular and Optical Physics
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: The role of water structure around model membrane systems (e.g., liposomes) on phase transition of the lipid dipalmitoyl phosphatidylcholine was investigated. Water structure was altered by changing pH and by addition of solutes which are known breakers and makers of water structure. The structure makers broadened the zone of transition and changed the overall phase transition profile, while the main effect of structure breakers was to cause a shift in the transition temperature. The observed variation of Chapman transition temperature and broadening of zone of transition with varying pH is discussed in terms of altered water structure around the membrane-aqueous interface. Binding studies with the dye 1-anilino-8-napthalene sulfonate showed that structure makers or breakers did not bind to the liposome surface directly. Thus the structure makers and breakers act on the membranes perhaps by altering the water structure differentially. Possible associated mechanisms of action are discussed.
    Additional Material: 2 Ill.
    Type of Medium: Electronic Resource
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