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  • 2015-2019
  • 1995-1999  (71)
  • 1975-1979  (128)
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  • 1997  (34)
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  • Electron microscopy
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  • 2015-2019
  • 1995-1999  (71)
  • 1975-1979  (128)
  • 1970-1974
  • 1950-1954
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Jahr
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  • 1
    Digitale Medien
    Digitale Medien
    Renewing olfactory receptor neurons in goldfish do not require contact with the olfactory bulb to develop normal chemical responsiveness (1997)
    Springer
    Journal of comparative physiology 181 (1997), S. 425-437 
    Details
    ISSN: 1432-1351
    Schlagwort(e): Key words Olfactory receptor cells ; Olfactory bulbectomy ; Olfactory axotomy ; Electrophysiology ; Electron microscopy
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie , Medizin
    Notizen: Abstract This study investigated whether contact with the olfactory bulb was necessary for developing and renewing olfactory receptor neurons (ORNs) to attain normal odorant responsiveness, and whether the anatomical and functional recoveries of the olfactory epithelium were similar in both bulbectomized (BE) and bilaterally axotomized (AX) preparations. In vivo electrophysiological recordings were obtained in response to amino acids, a bile acid [taurolithocholic acid sulfate(TLCS)] and a pheromonal odorant [17α, 20β,-dihydroxy-4-pregnen-3-one (17,20P)] from sexually immature goldfish. Both transmission and scanning electron microscopy indicated that the olfactory epithelium degenerated in BE and AX goldfish. Within 1–2 weeks subsequent to the respective surgeries, responses to high concentrations (〉0.1 mmol · l−1) of the more stimulatory amino acids remained, whereas responses were no longer obtainable to TLCS and 17,20P. At 4 weeks, responses to amino acid stimuli recovered to control levels, while responses to TLCS and 17,20P were minimal. By 7 weeks post bilateral axotomy, the olfactory epithelium recovered to a condition similar to control sensory epithelium; however, the rate of degeneration and proliferation of receptor neurons in BE preparations appeared to remain in balance, thus blocking further recovery of the olfactory epithelium. At 7 weeks post surgery, odorant responses of AX and BE goldfish to TLCS and 17,20P were still recovering.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/s003590050126
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  • 2
    Digitale Medien
    Digitale Medien
    Cytodifferentiation of atypical adenomatous hyperplasia and bronchioloalveolar lung carcinoma: immunohistochemical and ultrastructural studies (1997)
    Springer
    Virchows Archiv 431 (1997), S. 415-424 
    Details
    ISSN: 1432-2307
    Schlagwort(e): Key words Bronchioloalveolar lung carcinoma ; Atypical adenomatous hyperplasia ; Surfactant apoprotein ; Urine protein 1 ; Electron microscopy
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Medizin
    Notizen: Abstract  We used immunohistochemistry and electron microscopy to evaluate the differentiation of cells comprising atypical adenomatous hyperplasia (AAH; n = 26), early bronchioloalveolar lung carcinoma (BAC; n = 11), and overt BAC (n = 16), which are assumed to constitute a continuous spectrum of developmental steps of BAC. Surfactant apoprotein (SAP), a marker for type 2 alveolar cells, was expressed in cells from all the lesions of AAH, early BAC, and overt BAC. However, the proportion of SAP-positive cells decreased and their distribution became more heterogeneous with advancing lesion grade. Urine protein 1, which is identical to the Clara cell-specific 10 kDa protein, was expressed in 70% of overt BAC, whereas only 20% of early BAC showed weak reactivity and none of AAH lesions showed any reactivity at all. Ultrastructurally, type 2 alveolar cell differentiation was predominant among cells from AAH and early BAC. Our results suggest that precursor cells of BAC differentiate predominantly towards type 2 alveolar cells. Cells comprising overt BAC retain this differentiation phenotype, but to a reduced extent. In contrast, concomitantly with progression, cells with Clara cell differentiation emerge and their proportion increases. Such phenotypic changes may reflect metaplasia occurring in tumour cells during the development of BAC.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/s004280050118
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  • 3
    Digitale Medien
    Digitale Medien
    Adenovirus-induced liver necrosis in a case of AIDS (1997)
    Springer
    Virchows Archiv 431 (1997), S. 469-472 
    Details
    ISSN: 1432-2307
    Schlagwort(e): Key words Adenovirus ; Liver pathology ; Electron microscopy ; AIDS
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Medizin
    Notizen: Abstract  Adenovirus-induced liver necrosis is rare. Before the era of AIDS (acquired immunodeficiency syndrome) this entity was seen predominantly in infants suffering from inborn immunodeficiency syndromes or from iatrogenic immunosuppression because of bone marrow or liver transplantation. Here, we report a case of a 30-year-old woman with AIDS who developed fever and rapidly progressing liver failure. A frozen section from a needle biopsy of the liver allowed a quick diagnosis of viral liver necrosis. The light-microscopic and electron microscopic aspects were typical of adenovirus infection and should be known to the surgical pathologist. The diagnosis was confirmed by immunohistochemistry and DNA hybridization analysis.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/s004280050125
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  • 4
    Digitale Medien
    Digitale Medien
    Argyrophilic tau-positive twisted and non-twisted tubules in astrocytic processes in brains of Alzheimer-type dementia: an electron microscopical study (1997)
    Springer
    Acta neuropathologica 95 (1997), S. 28-39 
    Details
    ISSN: 1432-0533
    Schlagwort(e): Key words Astrocytes ; Alzheimer-type dementia ; Electron microscopy ; Glial fibrillary tangles ; Tau protein
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Medizin
    Notizen: Abstract This report concerns pathological astrocytic tubular structures (astrocytic tubules, As-Tbs) that coexist with glial filaments in astrocytic processes in brains with presenile-onset Alzheimer-type dementia. The formation of As-Tbs appears to be related to the duration of disease and the intensity of Alzheimer histopathology. In three cases in which the disease was of extremely long duration, As-Tbs were found in the frontal and temporal neocortices, the temporal pole and the hippocampus using electron microscopy, whereas they were not found in two cases with a long, but not extremely long, illness duration. As-Tbs were almost exclusively found in the highly devastated neuropil, and we could not find them in regions of moderate neuronal degeneration despite intensive inspection. As reported previously, some As-Tbs was seen adjacent to extracellular neurofibrillary tangles (NFTs) and in perivascular astrocytes. Our novel finding is that they can exist independently from these, in the highly devastated neuropil. Two types of As-Tbs were observed, twisted tubules with periodic constrictions at 50- to 80-nm intervals and non-twisted tubules where no constrictions were seen but which had a 15-nm fuzzy outer contour. They were positively stained by anti-human tau antibody, an antibody that does not recognize extracellular NFTs. Thus, it is most likely that As-Tbs are not the sequestration of extracellular NFTs, and that they are of astrocytic origin. Moreover, As-Tbs showed argyrophilia. As-Tbs appear indistinguishable from dystrophic neurites under the light microscope. The present data suggest that they may be more widely distributed in the damaged cerebral neuropil than previously thought.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/s004010050762
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  • 5
    Digitale Medien
    Digitale Medien
    Scots pine needle injuries at subarctic industrial sites (1997)
    Springer
    Trees 11 (1997), S. 378-387 
    Details
    ISSN: 0931-1890
    Schlagwort(e): Key words Pinus sylvestris (L.) ; Electron microscopy ; Heavy metals ; Multi-stress-symptoms ; SO2
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie , Land- und Forstwirtschaft, Gartenbau, Fischereiwirtschaft, Hauswirtschaft
    Notizen: Abstract  Injuries to needles of Scots pines (Pinus sylvestris L.) growing in nutrient-poor soils on the Kola Peninsula collected in April 1991 were studied on a gradient of increasing distances (10 – 115 km) from the Monchegorsk nickel smelter, Russia, which emits SO2, Ni and Cu. The condition of the mesophyll cells was quantified from needles of the two latest age classes using a light and an electron microscope. The damage to the ultrastructure consisted of multistress symptoms caused by excess sulphur, heavy metals, frost, acidic precipitation and ozone. Injuries were most commonly manifested in the form of dark, irregularly shaped chloroplasts with protrusions and light thylakoids and plastoglobuli. These symptoms gradually disappeared with increasing distance and decreasing deposition rate. Concentrations of sulphur, copper and nickel decreased towards more distant sites where normal levels of the latter two elements were reached. Sulphur concentrations remained above background throughout the distance gradient. In the closest plots to the smelter area, cell collapse under the stomata and epidermis related to acute SO2 and heavy metal effects was found, whereas further away symptoms were more diverse, pointing towards the effects of ozone, acidic deposition and thereby decreased frost tolerance. The additive multistress symptoms were clearly seen in the area up to 40 km from the smelter where needle Cu concentration was above 110 ppm, Ni concentration above 39 ppm and S concentration above 1343 ppm.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/s004680050099
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  • 6
    Digitale Medien
    Digitale Medien
    Phenotypic variability of CADASIL and novel morphologic findings (1997)
    Springer
    Acta neuropathologica 94 (1997), S. 247-254 
    Details
    ISSN: 1432-0533
    Schlagwort(e): Key words CADASIL ; Electron microscopy ; Granular osmiophilic material ; αB crystallin ; Heat ; shock proteins
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Medizin
    Notizen: Abstract Cerebral autosomal dominant arteriopathy with subcortical infarcts and leukoencephalopathy (CADASIL) is a non-arterio-atherosclerotic, non-amyloidotic arteriopathy affecting preferentially the small arteries and arterioles of the brain. The morphologic hallmark is the presence of a characteristic granular alteration of the arterial media that ultrastructurally corresponds to the accumulation of electron-dense material surrounding the smooth muscle cells. Although the presence of this granular osmiophilic material (GOM) was originally described as limited to brain vessels, identical electron microscopic findings have been demonstrated in the media of peripheral tissue arteries, allowing for a pathologic diagnosis of the disease by a simple skin, muscle or nerve biopsy. We report some atypical features identified in our CADASIL patients that broaden the phenotypic expression of this disease. Firstly, we identified a cortical infarct in an otherwise typical CADASIL patient. Secondly, we observed GOM in skin arteries of a 30-year-old man with hemiplegic migraine, the son of a woman who had died with CADASIL. This confirms that it may be possible to diagnose the disease at a preclinical stage by the ultrastructural evaluation of peripheral tissue biopsy material, particularly for individuals for whom there is a supporting family history. Thirdly, ultrastructural examination of the skin, and subcutaneous and striated muscle of an unrelated and apparently sporadic patient with neuropathologic and neuroradiologic evidence of CADASIL in meningeal and cerebral vessels failed to reveal diagnostic lesions in peripheral arteries. Thus, the possibility of a false-negative pathologic diagnosis in patients with a clinicoradiologic diagnosis of CADASIL, if one relies solely on a peripheral tissue biopsy, does exist. Additionally, we have identified heat shock proteins (Hsp70 and αB crystallin) and ubiquitin in the vascular myocytes of affected arteries. αB crystallin also seemed to be deposited extracellularly, which suggests that GOM also might be immunoreactive for αB crystallin.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/s004010050700
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  • 7
    Digitale Medien
    Digitale Medien
    Density and fine structure of peripheral nerves in various skin lesions of atopic dermatitis (1997)
    Springer
    Archives of dermatological research 289 (1997), S. 125-131 
    Details
    ISSN: 1432-069X
    Schlagwort(e): Key words Atopic dermatitis ; Peripheral nerve ;   ; Electron microscopy ; Protein gene product ; Substance P
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Medizin
    Notizen: Abstract The density and fine structure of the peripheral nerve system in various skin lesions of 64 patients with atopic dermatitis (AD) was quantitatively analyzed by immunohistochemical staining with antibodies directed against protein gene product (PGP) and substance P (SP). The density of PGP-positive peripheral nerves was 2.5 × 10 3 μm 2 /Δs (Δs = 0.24 mm 2 selected area) in early acute lesions, 3.8 × 10 3 μm 2 /Δs in subacute lesions, 4.9 × 10 3 μm 2 /Δs in lichenified lesions and 7.1 × 10 3 μm 2 /Δs in prurigo lesions of AD. The density of nerve fibers in subacute, lichenified and prurigo lesions was significantly higher than in uninvolved skin of AD patients (2.0 × 10 3 μm 2 /Δs). Electron microscopically, bulging of axons with many mitochondria and a loss of their surrounding sheath of Schwann cells suggests that the free nerve endings in skin lesions of AD are in an active state of excitation. Many pinocytotic vesicles in the periphery of basal keratinocytes facing nerve endings which contained many neurovesicles suggests reciprocal effects between keratinocytes and nerve endings. The number of SP-positive nerve fibers in AD lesions was far less than one-tenth of the number of PGP-positive nerve fibers.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/s004030050167
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  • 8
    Digitale Medien
    Digitale Medien
    Effects of brefeldin-A and monensin on organelle distribution and morphology in the preimplantation mouse embryo (1997)
    Springer
    Development genes and evolution 206 (1997), S. 503-514 
    Details
    ISSN: 1432-041X
    Schlagwort(e): Key words Preimplantation mouse embryo ; Brefeldin-A ; Monensin ; Golgi ; Electron microscopy
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie
    Notizen: Abstract  The intracellular trafficking of integral membrane and secreted proteins is likely to be a key element involved in the morphogenesis and differentiation of the early mammalian embryo. In this study, we used transmission electron microscopy (TEM) to analyse the effects of brefeldin-A (BFA) and monensin, well known inhibitors of vesicular protein trafficking in somatic cells, on the structure of preimplantation mouse embryos. Both BFA and monensin distinctively altered the morphology of Golgi compartments in the blastomeres of treated morulae. BFA-treated morulae lacked recognizable Golgi complexes but possessed heterogeneous organelle clusters consisting of an abundance of smooth tubular and vesicular membrane compartments in addition to mitochondria, endosomes and lysosomes. Treatment of morulae with monensin was associated with swelling of Golgi compartments in addition to altering the morphology of mitochondria, lysosomes and the plasma membrane. BFA, and to a lesser extent monensin, inhibited cytokinesis as evidenced by the detection of binucleate blastomeres. In addition, BFA induced morulae to decompact. These latter effects have not been reported previously for these agents in mammalian somatic cell lines or other vertebrate or invertebrate embryos. These results provide the first demonstration of the structural effects of BFA and monensin on cells of the early mammalian embryo, some of which are consistent with the known actions of these agents on components of the vesicular protein trafficking system in mammalian somatic cells. This information serves as a foundation for the further use of these agents in studies of vesicular protein trafficking as an agent of preimplantation morphogenesis.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/s004270050081
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  • 9
    Digitale Medien
    Digitale Medien
    Komibinierte neuronale und endokrine Tumoren der Sellaregion (1997)
    Springer
    Der Pathologe 18 (1997), S. 419-424 
    Details
    ISSN: 1432-1963
    Schlagwort(e): Schlüsselwörter Gangliozytom ; Gangliogliom ; Hypophysenadenom ; Immunhistologie ; Ultrastruktur ; Key words Gangliocytoma ; Ganglioglioma ; Pituitary adenoma ; Immunohistochemistry ; Electron microscopy
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Medizin
    Beschreibung / Inhaltsverzeichnis: Summary Gangliocytomas or gangliogliomas of the sellar region are very rare tumors. In a great proportion of those cases an adenoma of the anterior pituitary develops from the cell type that is hyperstimulated by the releasing hormone produced from the gangliocytoma. Five GHRH secreting gangliocytomas are reported. Four of these were localized adjacent to a GH secreting adenoma. In one case, no adenoma tissue was found beside the ganglicytoma. As only the adenomas can secrete GH, the adenomas and not the gangliocytomas are directly responsible for acromegaly so that such an adenoma has to be present in cases of acromegaly. A CRH secreting gangliocytoma was combined with an ACTH cell adenoma that had induced Cushing’s disease. A ganglioglioma of the posterior pituitary had led to an inappropriate secretion of Vasopressin. The morphology of the different tumors is presented.
    Notizen: Zusammenfassung Intraselläre Gangliozytome/Gangliogliome sind sehr seltene Tumoren, die in einem Großteil der Fälle ein Hypophysenadenom aus dem Zelltyp heraus entstehen lassen, der durch das gebildete Releasinghormon überstimuliert wird. Es wird über 5 GHRH-bildende Gangliozytome berichtet, von denen 4 einem STH-bildenden Hypophysenadenom benachbart waren. Ein Fall enthielt keine Adenomanteile. Diese müssen in Anbetracht der klinisch vorhandenen Akromegalie aber vorhanden sein, da nur das jeweilige Adenom, nicht aber die Gangliozytome für die Überfunktion unmittelbar verantwortlich sind. Ein CRH-bildendes Gangliozytom war mit einem zum Morbus Cushing führenden ACTH-Zelladenom kombiniert. Ein Gangliogliom des Hinterlappens hatte zu einer inadäquaten Vasopressinsekretion Anlaß gegeben. Die Morphologie der Tumoren wird dargelegt.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/s002920050236
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  • 10
    Digitale Medien
    Digitale Medien
    Ultrastructural subtypes of glutamate-immunoreactive terminals on rat trigeminal motoneurones and their relationships with GABA-immunoreactive terminals (1997)
    Springer
    Experimental brain research 114 (1997), S. 99-116 
    Details
    ISSN: 1432-1106
    Schlagwort(e): Key words Synapse ; Axo-axonic synaptic contacts ; Trigeminal motor nucleus ; Immunogold ; Electron microscopy ; Rat
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Medizin
    Notizen: Abstract  Electron-microscopic immunolabelling methods were used to study the relationships between glutamate-immunoreactive and γ-aminobutyric acid (GABA)-immunoreactive synapses on trigeminal motoneurones labelled by the retrograde transport of horseradish peroxidase. Serial sections were cut through the motor nucleus, alternate sections were incubated with antibodies to glutamate and GABA, and the immunopositive nerve terminal profiles were recognized using a quantitative, postembedding immunogold method. Boutons exhibiting high levels of glutamate immunoreactivity and GABA-immunoreactive boutons both formed axo-dendritic and axo-somatic synaptic contacts on labelled motoneurones. Boutons strongly immunopositive for glutamate were not immunopositive for GABA, and vice versa. Strongly glutamate immunoreactive boutons received axo-axonic synaptic contacts but did not form such contacts, while GABA-immunoreactive boutons formed axo-axonic synapses but did not receive them. The presynaptic elements at all axo-axonic synapses on to glutamate-immunoreactive boutons sampled were GABA-immunopositive. These data provide ultrastructural evidence in support of the roles of glutamate and GABA as transmitters at synapses on trigeminal motoneurones, and for presynaptic control of transmission at glutamatergic synapses by GABA acting at receptors at axo-axonic synapses. The vast majority (more than 90%) of strongly glutamate immunoreactive boutons contained spherical synaptic vesicles, in contrast to GABA-immunoreactive boutons, which contained pleomorphic vesicles. Most of the glutamate-immunoreactive boutons (67%) formed asymmetrical synaptic active zones, many of which (47% of total) were associated with subsynaptic dense ”Taxi” bodies (T-terminals), while a smaller population of boutons (21%) formed symmetrical synapses, and a few (11%) made synapses associated with subsynaptic cisternae (C-terminals). The heterogeneity of active zone ultrastructure of boutons identified as being glutamatergic on the basis of their high levels of immunolabelling is discussed in relation to possible differences in co-transmitters released, origins of the synaptic input or post-synaptic receptor subtypes activated.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/PL00005627
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  • 11
    Digitale Medien
    Digitale Medien
    Type III Ehlers-Danlos syndrome and pregnancy (1997)
    Springer
    Archives of gynecology and obstetrics 261 (1997), S. 39-43 
    Details
    ISSN: 1432-0711
    Schlagwort(e): Key words: Ehlers-Danlos type III ; Pregnancy ; Electron microscopy ; Prenatal diagnosis ; Premature rupture of membranes
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Medizin
    Notizen: Abstract. We report a case of type III Ehlers-Danlos syndrome with a favourable outcome. We review the literature and do not consider that pregnancy in patients with type III Ehlers-Danlos Syndrome represents a high risk situation.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/s004040050196
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  • 12
    Digitale Medien
    Digitale Medien
    Light and electron microscopic investigation of the process of healing of the naevus of Ota by Q-switched alexandrite laser irradiation (1997)
    Springer
    Virchows Archiv 431 (1997), S. 63-71 
    Details
    ISSN: 1432-2307
    Schlagwort(e): Key words Naevus of Ota ; Q-switched alexandrite laser ; Light microscopy ; Electron microscopy
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Medizin
    Notizen: Abstract  Melanocytes in the naevus of Ota were destroyed by irradiation using the Q-switched alexandrite laser. This laser is highly selective and highly absorbed by melanosomes. Other cells and tissue components of the dermis remained almost intact. Melanosomes were vaporized or fragmented to subelectron microscopical size, or degenerated. If the irradiated energy was sufficient, melanocytes vanished and large vacuoles several times the size of dermal melanocytes formed at the sites. If it was too weak, dermal melanocytes were also vaporized, but vacuoles formed within them. Nuclei were no longer discernible. Following irradiation macrophages infiltrated the irradiated areas and scavenged degenerated melanosomes and cellular debris. Thus, discoloration of the skin was markedly reduced. Although a few melanocytes and melanophages remained, pigmentation cleared to a satisfactory level. Melanocytes and keratinocytes were also injured in the epidermis; however, the epidermis recovered completely. No scarring was observed.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/s004280050070
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  • 13
    Digitale Medien
    Digitale Medien
    Neuropeptide Y-immunoreactive intracardiac neurones, granule-containing cells and nerves associated with ganglia and blood vessels in rat and guinea-pig heart (1997)
    Springer
    Cell & tissue research 289 (1997), S. 445-454 
    Details
    ISSN: 1432-0878
    Schlagwort(e): Key words: Intracardiac neurones ; Innervation ; Heart ; Neuropeptide Y ; Immunocytochemistry ; Electron microscopy ; Rat (Sprague Dawley) ; Guinea-pig (Dunkin Hartley)
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie , Medizin
    Notizen: Abstract. Intrinsic neuropeptide Y-containing neurones in rat and guinea-pig hearts were studied at the ultrastructural level by the pre-embedding peroxidase-antiperoxidase immunocytochemical technique. Intracardiac neuronal cell bodies were often weakly or moderately immunostained, and the labelling was usually pronounced in the Golgi complex, multivesicular bodies, some cisterns of granular endoplasmic reticulum and large granular vesicles. Neuropeptide Y-immunoreactive nerve fibres were also observed in association with intracardiac neurones. A subpopulation of neuropeptide Y-immunoreactive granule-containing cells in the rat heart are described for the first time and were very heavily labelled; other granule-containing cells were non-immunoreactive, but were contacted by neuropeptide Y-containing nerves. Preterminal regions of nerve fibres that were located in nerve bundles were only weakly neuropeptide Y-immunoreactive, in contrast to the heavy labelling observed in varicosities that contained many synaptic vesicles. Many neuropeptide Y-immunoreactive nerve fibres were associated with the coronary vasculature and were particularly prominent in the walls of small arteries and arterioles where labelled nerve varicosities were present close to the smooth muscle cells. Immunoreactive nerves were also seen in the myocardium, usually near to capillaries. In axonal varicosities, the central core of large granular vesicles was immunolabelled, and electron-dense immunoreactive material outlined the membranes of small and large clear vesicles. The significance of neuropeptide Y-immunoreactive intracardiac neurones and granule-containing cells and the origin of associated labelled nerve fibres in the heart are discussed.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/s004410050890
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  • 14
    Digitale Medien
    Digitale Medien
    Immuno-electron microscopy reveals that the excitotoxin quinolinate is associated with the plasma membrane in human peripheral blood monocytes/macrophages (1997)
    Springer
    Cell & tissue research 290 (1997), S. 633-639 
    Details
    ISSN: 1432-0878
    Schlagwort(e): Key words: Quinolinic acid ; Interferon-γ ; Kynurenine ; Electron microscopy ; Immunocytochemistry ; Excitotoxicity ; Human
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie , Medizin
    Notizen: Abstract.  Quinolinate (QUIN), a tryptophan-derived excitotoxin, was localized ultrastructurally in human peripheral blood monocytes/macrophages (MØ) by immuno-electron microscopy. A combined carbodiimide/glutaraldehyde/paraformaldehyde-based fixation procedure was developed for optimal retention of QUIN in the cell as well as minimal loss of ultrastructure; a silver-enhanced colloidal gold detection system was used for electron-microscopic analysis. Gold particles representing QUIN immunoreactivity were associated with the inner side of the plasma membrane in normal MØ. The number of gold particles increased significantly when QUIN levels were elevated by treatment with its precursor kynurenine, but location of the gold particles remained essentially the same under this condition. Treatment with interferon-γ increased the number of Golgi bodies, vacuoles and pseudopodia, reflecting the activated state of the cell. Significantly increased numbers of gold particles representing QUIN were detectable in approximately the same location as in the case of kynurenine treatment. Combined treatment with kynurenine and interferon-γ maximally increased the number of gold particles at the periphery of the cell. The pseudopodia were intensely stained with gold particles, while they were not detectable in the inner part of the cytoplasm or in any other organelle even under this activated condition. The significance of the specific location of QUIN revealed in the present study and its relation to the release and subsequent actions of QUIN are discussed.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/s004410050969
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  • 15
    Digitale Medien
    Digitale Medien
    Synaptic exocytosis of dense-core vesicles in blue crab (Callinectes sapidus) stomach muscles (1997)
    Springer
    Cell & tissue research 289 (1997), S. 517-526 
    Details
    ISSN: 1432-0878
    Schlagwort(e): Key words: Neuromuscular junction ; Synaptic vesicles ; Vesicle fusion ; Electron microscopy ; Callinectes sapidus (Crustacea)
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie , Medizin
    Notizen: Abstract. Neuromuscular terminals of a single motoneuron to four muscles (CPV7a, GM5a, CV2, and CV3) in the stomach of the blue crab Callinectes sapidus showed structural evidence for the exocytotic release of dense-core vesicles exclusively at synapses. The primary evidence was the appearance of dense cores in the synaptic cleft, accompanied by indentations of the presynaptic or postsynaptic membrane. In their simplest form, these consisted of an omega-shaped figure of the presynaptic membrane enclosing one dense core, denoting release of a single dense-core vesicle. A larger indentation of the presynaptic membrane enclosing several dense cores denoted multiple release. A more complex form of multiple release was where the presynaptic membrane was normal, but the postsynaptic membrane elaborated into a sac projecting into the granular sarcoplasm and filled with dense cores. The postsynaptic sac in some instances was compressed into a thin, fingerlike extension, which lacked dense cores and, at its distal end, separated into small cisternae, suggesting a mechanism for membrane recycling. Profiles depicting single and multiple releases of dense-core vesicles were found more frequently at neuromuscular terminals that release relatively large amounts of transmitter with a single stimulus, such as CV2 and CV3, compared to those releasing smaller amounts, such as CPV7a and GM5a. The disparity in release sites among the four muscles of this single motor unit and the fact that many of the multiple-release figures were closely adjacent to the active zones for transmitter release suggest a possible modulatory role for dense-core vesicles in synaptic transmission. Such modulation may be long lasting, as implied by the postsynaptic sacs, which may permit prolonged release of the contents of their dense cores into the synaptic cleft. This is in keeping with the functional role of these stomach muscles, which is to be continuously active for long periods of time.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/s004410050897
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  • 16
    Digitale Medien
    Digitale Medien
    Immunoreactive excitatory amino acids in the parietal eye of lizards, a comparison with the pineal organ and retina (1997)
    Springer
    Cell & tissue research 287 (1997), S. 275-283 
    Details
    ISSN: 1432-0878
    Schlagwort(e): Key words: Parietal eye ; Pineal organ ; Retina ; Glutamate ; Aspartate ; Immunocytochemistry ; Electron microscopy ; Lacerta muralis ; Lacerta agilis ; Lacerta viridis (Lacertilia)
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie , Medizin
    Notizen: Abstract. The fine structure of the organ and the localization of the excitatory amino acids glutamate and aspartate were studied in the parietal eye of lizards by postembedding immunoelectron microscopy. The parietal eye contains cone photoreceptor cells, secondary neurons, and ependymal and lens cells. The photoreceptors form long inner and outer segments, some of them being paired as ”twin-photoreceptors” by zonulae adherentes. Perikarya of neurons bear sensory cilia (containing 9×2+0 pairs of tubules) extending into the intercellular space. No neurohormonal terminals are present in the parietal eye. A higher immunoreactivity to glutamate than to aspartate is found in the photoreceptors and in the secondary neurons of the parietal eye. Glutamate immunogold labeling is more intense in the axonal processes of photoreceptors and neurons and in most of the nerve fibers of the parietal nerve running to the brain stem. Weak aspartate and glutamate immunoreactivity can be detected in the ependymal and lens cells. A similar distribution of immunoreactive amino acids is found in the photoreceptors, secondary neurons, and ependymal glial elements of the pineal organ, and retina of the lateral eye of the same animals. Immunoreactive glutamate accumulates in the axons of photoreceptors and secondary neurons of the parietal eye suggesting that this excitatory amino acid acts as a synaptic mediator in the neural efferentation of the organ. Thus, the efferent light-conducting pathway of the parietal organ is similar to that of the pineal organ and lateral eye retina. As the Mullerian cells of the retina, the ependymal and lens cells of the parietal eye and the ependymal-glial cells of the pineal organ may play a role in the metabolism and/or elimination of excitatory amino acids released by photoreceptors.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/s004410050752
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  • 17
    Digitale Medien
    Digitale Medien
    Expression of basic fibroblast growth factor-like immunoreactivity in the nuclei of regenerating hepatocytes (1997)
    Springer
    Cell & tissue research 288 (1997), S. 517-527 
    Details
    ISSN: 1432-0878
    Schlagwort(e): Key words: Liver ; Subcellular fractions ; Immunohistochemistry ; Electron microscopy ; Rat (Wistar)
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie , Medizin
    Notizen: Abstract. This study, utilizing rats subjected to two-thirds partial hepatectomy or sham operation, was designed (1) to investigate the content of basic fibroblast growth factor (bFGF) in the subcellular fractions of regenerating and sham-operated rat livers by immunoblot experiments and enzyme-linked immunosorbent assay (ELISA), (2) to show that bFGF immunoreactivity and proliferating cell nuclear antigen (PCNA) immunoreactivity are markers for hepatocellular mitosis before and after partial hepatectomy, and (3) to observe the location and fine structure of the bFGF immunoreaction within the regenerating liver with special attention to bFGF immunoreactivity in the nuclei of regenerating hepatocytes. Immunoblot experiments and ELISA showed a transient increase in high-molecular-weight forms of bFGF in the nuclear subcellular fraction of regenerating liver 48 h after partial hepatectomy. By light microscopy, bFGF and PCNA immunoreactivities were detected in the nuclei of regenerating hepatocytes. Electron microscopy demonstrated bFGF-like immunoreactivity mainly in the nuclear euchromatin and rarely in the heterochromatin or nucleoli of regenerating hepatocytes. The transient increase in high-molecular-weight forms of bFGF in the nuclear euchromatin of regenerating hepatocytes, together with the concomitant expression of PCNA in the regenerating liver, suggests an important role of the high-molecular-weight forms of bFGF in hepatocyte proliferation and/or mitosis, although authentic bFGF with a molecular form of 18 kDa is not considered to be involved in hepatic regeneration.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/s004410050837
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  • 18
    Digitale Medien
    Digitale Medien
    Osmoregulatory mutants that affect the function of the contractile vacuole inChlamydomonas reinhardtii (1997)
    Springer
    Protoplasma 200 (1997), S. 99-111 
    Details
    ISSN: 1615-6102
    Schlagwort(e): Chlamydomonas reinhardtii ; Contractile vacuole ; Electron microscopy ; Videomicroscopy ; Osmoregulation ; Osmoregulatory mutants
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie
    Notizen: Summary Four independent osmoregulatory mutants,osml, osm3,osm4, and osm7, were isolated on the basis of their requirement for growth medium of high osmotic strength. In normal low-osmoticstrength medium, in contrast to wild-type cells, the mutants grow poorly or not at all; in distilled water mutant cells are immobilized and eventually swell and burst. The mutants were examined by ordinary brightfield and phase-contrast microscopy, videomicroscopy, and electron microscopy. The four mutants showed different defects in the contractile vacuole (CV) cycle. Timing of various stages of the CV cycle showed thatosm1 was affected primarily in the early stage of the cycle when the CV begins to grow,osm3 primarily in midcycle when vacuoles fuse to form the CV proper,osm7 at a late stage of the cycle at docking and fusion of the CV with the plasma membrane, andosm4 during contraction of the CV. At the electron microscopic level, in dilute medium, mutant cells by comparison with wild-type cells had large autophagosomes, swollen mitochondria, and dilated ER cisternae. Although electron microscopy showed general abnormalities of the contractile vacuoles consistent with the videomicroscopic observations of living cells, no obvious vacuole membrane abnormalities were seen which would explain the mutational defects. The mutations help define the separate processes that contribute to the coordinated CV cycle inChlamydomonas, and open the way to eventual isolation of some of the genes responsible for CV function.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/BF01280738
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  • 19
    Digitale Medien
    Digitale Medien
    Structure and behavior of contractile vacuoles inChlamydomonas reinhardtii (1997)
    Springer
    Protoplasma 198 (1997), S. 73-84 
    Details
    ISSN: 1615-6102
    Schlagwort(e): Chlamydomonas reinhardtii ; Contractile vacuole ; Osmoregulation ; Videomicroscopy ; Electron microscopy
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie
    Notizen: Summary The contractile vacuole (CV) cycle ofChlamydomonas reinhardtii has been investigated by videomicroscopy and electron microscopy. Correlation of the two kinds of observation indicates that the total cycle (15 s under the hypo-osmotic conditions used for videomicroscopy) can be divided into early, middle, and late stages. In the early stage (early diastole, about 3 s long) numerous small vesicles about 70–120 nm in diameter are present. In the middle stage (mid-diastole, about 6 s long), the vesicles appear to fuse with one another to form the contractile vacuole proper. In the late stage (late diastole, also about 6 s long), the CV increases in diameter by the continued fusion of small vesicles with the vacuole, and makes contact with the plasma membrane. The CV then rapidly decreases in size (systole, about 0.2 s). In isosmotic media, CVs do not appear to be functioning; under these conditions, the CV regions contain numerous small vesicles typical of the earliest stage of diastole. Fine structure observations have provided no evidence for a two-component CV system such as has been observed in some other cell types. Electron microscopy of cryofixed and freeze-substituted cells suggests that the irregularity of the profiles of larger vesicles and vacuoles and some other morphological details seen in conventionally fixed cells may be shrinkage artefacts. This study thus defines some of the membrane events in the normal contractile vacuole cycle ofChlamydomonas, and provides a morphological and temporal basis for the study of membrane fusion and fluid transport across membranes in a cell favorable for genetic analysis.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/BF01282133
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  • 20
    Digitale Medien
    Digitale Medien
    Selective UV-induced damage to short-wavelength receptor cells in the butterflyPapilio xuthus (1997)
    Springer
    Protoplasma 200 (1997), S. 112-115 
    Details
    ISSN: 1615-6102
    Schlagwort(e): Electron microscopy ; UV-induced cell damage ; Photoreceptor ; Eye ; Lepidoptera
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie
    Notizen: Summary A technique that allows the specific inactivation of short-wavelength-sensitive photoreceptive cells has been needed for a long time. Such a technique could be useful in studies on the role(s) of UV-receptors in circadian rhythmicity, recognition of floral patterns, homing behaviour, and mate selection in arthropods. We provide ultrastructural evidence that short-wavelength receptor cells can be selectively damaged without affecting other spectral-cell types. Since the method does not require the killing of the experimental animal, the latter can be used in behavioural or other follow-up tests.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/BF01280739
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  • 21
    Digitale Medien
    Digitale Medien
    Electron microscopic and immunomorphological investigations on the mucosa of the human paranasal sinuses (1997)
    Springer
    European archives of oto-rhino-laryngology and head & neck 254 (1997), S. 230-235 
    Details
    ISSN: 1434-4726
    Schlagwort(e): Paranasal sinus mucosa ; Collagen type VII ; Subepithelial connective tissue ; Electron microscopy ; Immunofluorescence microscopy
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Medizin
    Notizen: Abstract The morphology of the mucosa from the human paranasal sinuses was investigated by electron microscopy. A total of 27 specimens was taken from 11 patients following midfacial fractures. All tissue samples were biopsied during surgery after informed consent had been given. In accordance with light microscopic investigations, the mucosa represented a highly prismatic epithelium consisting of kinocilia-carrying and mucus-producing (goblet) cells. Other cell types, such as those occurring in the respiratory epithelium of other areas, could not be demonstrated. Electron microscopic and immunomorphological investigations revealed collagen type VII beneath the lamina densa of the basal lamina. According to findings obtained to date, this collagen type accompanies only a multilayered epithelium. Another peculiarity was the small number of basophils and eosinophils. Pronounced acute reactions of the mucosa in this area cannot be expected, which is in contrast to that of the nasal mucosa.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/BF00874094
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  • 22
    Digitale Medien
    Digitale Medien
    Ultrastructural findings of the macula utriculi in a case of a petrous apex cholesteatoma: a comparison with findings in a patient with an acoustic neuroma (1997)
    Springer
    European archives of oto-rhino-laryngology and head & neck 254 (1997), S. 255-258 
    Details
    ISSN: 1434-4726
    Schlagwort(e): Electron microscopy ; Inner ear ; Utricle ; Cholesteatoma ; Acoustic neuroma
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Medizin
    Notizen: Abstract The morphological characteristics of the vestibular sensory cells of the macula utriculi obtained during surgery in a patient with a petrous apex cholesteatoma were examined using scanning and transmission electron microscopy. Findings were compared to cells studied in a patient with acoustic neuroma. Scanning electron microscopy showed that compared to the apparently normal cells in the acoustic neuroma case, most sensory cells in the cholesteatoma case had large cuticular plates, irregular locations of cilia and no clear polarizations. Supporting cells showed profuse short microvilli on the whole surface. With transmission electron photomicrographs, type I hair cells were not seen and certain morphological changes were observed in type-1I-like cells and supporting cells. We presume that the degenerative changes in the vestibular epithelia were due to circulatory disturbances and/or direct pressure applied to the vestibular nerve at the internal auditory canal, with subsequent involvement of the macula utriculi.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/BF00874100
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  • 23
    Digitale Medien
    Digitale Medien
    Electron microscopic localization of nitric oxide I synthase in the organ of Corti of the guinea pig (1997)
    Springer
    European archives of oto-rhino-laryngology and head & neck 254 (1997), S. 396-400 
    Details
    ISSN: 1434-4726
    Schlagwort(e): Guinea pig hair cells ; Electron microscopy ; Immunocytochemistry ; Nitric oxide synthase ; Sound transduction
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Medizin
    Notizen: Abstract Nitric oxide synthase (NOS) activity has been detected previously in the mammalian cochlea at a light microscopic level. Here we present results of electron microscopic analysis for post-embedding immunoreactivity of neural-type NOS I in the cochlea of the guinea pig. Strong enzyme immunoreactivity was identified in the cytoplasm of inner and outer hair cells. Gold-labeled NOS I antibodies were mainly located in electron-dense areas of the cytoplasm, whereas electron-lucent regions of the receptor cells were nearly free from any immunoreactivity. In both types of hair cells anti-NOS I antibodies were also visible in the cuticular plates, hair bundles and nuclei. Further ultrastructural analysis revealed that the submembranous cisternae of the outer hair cells were nearly free from any reaction product, demonstrating that the whole cytoplasm of this hair cell was not immunoreactive. Other NOS I immunoreactivity was identified in the cuticular plates of the inner and outer pillar cells and in the cytoskeletal elements located in the apical parts of Deiter cells, forming the lamina reticularis or in cytoskeletal-containing regions in basal Deiter cells. Anti-NOS antibodies were visible in the nuclei of various cell types. Our findings suggest that nitric oxide produced by NO I synthase in the organ of Corti may act as a modulator of hair cell physiology during the processes of signal transduction with frequence selectivity.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/BF01642558
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  • 24
    Digitale Medien
    Digitale Medien
    Immunohistochemical and electron microscopical characterization of stromal cells in nasopharyngeal angiofibromas (1997)
    Springer
    European archives of oto-rhino-laryngology and head & neck 254 (1997), S. 196-199 
    Details
    ISSN: 1434-4726
    Schlagwort(e): Nasopharyngeal angiofibroma ; Ultrastructure ; Myofibroblast ; Immunohistochemistry ; Electron microscopy
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Medizin
    Notizen: Abstract Twenty-eight cases of nasopharyngeal angiofibroma were studied immunohistochemically for cytoskeletal phenotyping of stromal cells. Electron microscopy was also used to study the ultrastructure of five of the tumors. All typical stromal cells showed intensive immunostaining for vimentin, but were negative for smooth muscle actin and desmin. Ultrastructurally, most of these cells appeared to be exclusively fibroblasts. However, in some areas stromal cells were seen that morphologically resembled myofibroblasts by their shapes and arrangement, and were characterized by the coexpression of vimentin and smooth muscle actin. Electron microscopy confirmed their myofibroblastic nature. The present study showed that the typical stromal cells in nasopharyngeal angiofibromas were fibroblasts and not myofibroblasts. In these tumors myofibroblasts occurred only focally, in connection with fibrotic areas and exclusively as a vimentin+/actin+ cytoskeletal phenotype. This indicates that myofibroblasts are not primary stromal tumor cells in nasopharyngeal angiofibromas, but occur due to regressive changes.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/BF00879273
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  • 25
    Digitale Medien
    Digitale Medien
    Morphological and cytochemical changes in human mast cells during culture (1997)
    Springer
    Medical molecular morphology 30 (1997), S. 25-30 
    Details
    ISSN: 1860-1499
    Schlagwort(e): Mast cell ; Culture ; Electron microscopy ; Carbohydrate cytochemistry ; Peroxidase
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Medizin
    Notizen: Abstract Mast cells were cultured from human umbilical cord blood CD34-positive cells in the presence of interleukin (IL)-6 and stem cell factor (SCF). Electron microscopically, a particulate or beaded structure, the prominent structure of tryptase-positive mast cell (T mast cell) granules, was frequently observed in 54-day cultures. Straight or coiled lamellae, often observed in the granules of tryptase-and chymase-positive mast cells (TC mast cells), were observed in the granules in 75-day cultures. Cytochemically, the peroxidase activity of the granules was positive but decreased during the term of culture. Glycogen particles were abundant in 54-day cultures, and scarce in 75-day cultures. These findings suggest that the mast cells matured and changed in phenotype during the culture's term.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/BF01458348
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  • 26
    Digitale Medien
    Digitale Medien
    An ultrastructural study of pemphigoid vegetans, characterizing the possible mechanism of vegetation (1997)
    Springer
    Medical molecular morphology 30 (1997), S. 48-54 
    Details
    ISSN: 1860-1499
    Schlagwort(e): Pemphigoid vegetans ; Lamina densa ; Mast cell ; Vegetation ; Electron microscopy
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Medizin
    Notizen: Abstract Ultrastructural changes in the skin lesions of pemphigoid vegetans were observed by transmission electron microscopy. Two significant changes were recognized at the vegetating site: (1) The basal lamina was sometimes interrupted and detached from the basal cells, protruding into the dermis to form folds. In the basal cells, hemidesmosomes were not decreased in number but tonofilament bundles were fewer than normal. Occasionally, basal cell processes extended beyond the basal lamina through its gap. These features resembled the epidermal growth factor-induced morphological changes of cultured skin. It was suspected that the abnormal attachment of the basal lamina to the basal cell was associated with keratinocyte proliferation. (2) Mast cells were encountered in the epidermis abutting on the basal lamina. It is uncommon to find mast cells in the epidermis. Mast cells in the epidermis were reported at the erythematous regions which were adjacent to the bullae of bullous pemphigoid, and were thought to have an important role in forming blisters. It was suggested that early changes in blister formation occur at the vegetating site.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/BF01458352
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  • 27
    Digitale Medien
    Digitale Medien
    Morphological changes of c-Fos-like immunoreactivity in rat cerebral cortex after cerebral ischemia and reperfusion with special reference to vasoactive intestinal polypeptide (1997)
    Springer
    Medical molecular morphology 30 (1997), S. 111-118 
    Details
    ISSN: 1860-1499
    Schlagwort(e): c-Fos ; VIP ; Electron microscopy ; Immunocytochemistry ; Cerebral ischemia
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Medizin
    Notizen: Abstract We investigated morphological changes in neurons with c-Fos-like immunoreactivity (c-Fos-LI) after cerebral ischemia by light and electron microscopic immunocytochemistry. Strong c-Fos-LI was observed in layers II–VI of the cerebral cortex with an especially abundant distribution in the nuclei of layers II, IV, and VI ipsilateral to the lesioned side. Reperfusion after ischemia had a greater effect on the expression of c-Fos-LI than did permanent ischemia. Vasoactive intestinal peptide (VIP)-positive neurons were seen scattered in layers II–V of the cerebral cortex. Some VIP-positive neurons showed c-Fos-LI after ischemia. Electron microscopy revealed c-Fos-LI in euchromatin in the nuclei of c-Fos-positive cells. Dilatation of the cisternae of the rough endoplasmic reticulum and the presence of numerous secondary lysosomes were found in neurons on the lesioned side after 12h of reperfusion. Some VIP-containing neurons revealed c-Fos-LI with reperfusion after ischemia by a double immunostaining method on the same tissue section. These findings suggest that ischemia potentiates c-fos expression in VIP- or other transmitter- or modulator-containing neurons, thereby protecting from neuronal cell death.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/BF01545311
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  • 28
    Digitale Medien
    Digitale Medien
    Morphological changes ofHelicobacter pylori after antibacterial therapy: an electron microscope study (1997)
    Springer
    Medical molecular morphology 30 (1997), S. 131-137 
    Details
    ISSN: 1860-1499
    Schlagwort(e): Helicobacter pylori ; Electron microscopy ; Three-dimensional reconstruction ; Eradication ; 13C-urease breath test ; Coccoid form
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Medizin
    Notizen: Abstract To investigate the effect of morphological change ofHelicobacter pylori on gastric mucosal inflammation,H. pylori was examined by means of an electron microscope and computer-assisted three-dimensional reconstruction before and after antibacterial therapy. The results showed that the bacterium was usually present in different forms and sizes. Most of these variations are helicobacter shaped, 3–5 μm long (43%), or campylobacter shaped, 1–3 μm long (38%); fewer are round or coccoid (19%), and only 0.5–1 μm long. Active inflammation and an abnormal amount of mucus in the epithelial cells are the main changes seen in gastric mucosa withH. pylori infection. In some cases, 6 weeks after antibacterial therapy,H. pylori could still be observed by toludine blue, with slight positive results withH. pylori-antibody-labeled immunostaining. In contrast to the bacteria before antibacterial therapy, in mostH. pylori-positive cases usually only a minute number of bacteria were seen in coccoid form. These surviving coccoid-form bacteria showed thickened walls, and the surrounding periplasmic space was reduced or nonexistent. The epithelial cells were almost normal and13C-text negative. Although neutrophil infiltration was seldom seen, there were still some surviving bulblike cells with excess amounts of mucus in the gastric pits. It is suggested that the coccoid form ofH. pylori may be a static bacterium without urease production. For therapeutic decisions, it may be more important to identify whether there is an active inflammation in the gastric mucosa than to detectH. pylori.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/BF01545314
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  • 29
    Digitale Medien
    Digitale Medien
    Aneurysmal (angiomatoid) fibrous histiocytoma of the skin: an unusual variant of dermatofibroma (1997)
    Springer
    Medical molecular morphology 30 (1997), S. 163-169 
    Details
    ISSN: 1860-1499
    Schlagwort(e): Dermatofibroma ; Aneurysmal ; (angiomatoid) fibrous histiocytoma ; Immunohistochemistry ; Electron microscopy ; Skin
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Medizin
    Notizen: Abstract We present a rare case of aneurysmal (angiomatoid) fibrous histiocytoma (AAFH) of the skin on the back of a 40-year-old Japanese man. Histologically, the tumor was characterized by massive proliferation of fibroblastic and histiocytic cells, prominent aggregation of hemosiderin pigment, and the presence of blood-filled tissue spaces devoid of an endothelial lining within a capillaryrich stroma. Immunohistochemically the tumor cells were immunoreactive for vimentin and for Factor XIIIa or Mac387. Ultrastructural study revealed that the tumor was composed mainly of fibroblast-like cells intermingled with histiocyte-like cells and intermediate cells with combined features of the two types of cells. These findings support the fibrohistiocytic origin of aneurysmal (angiomatoid) fibrous histiocytoma. In addition, ultrastructural examination seems quite useful to differentiate from other cutaneous neoplasms with architectural and cytological similarities to this tumor.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/BF01545318
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  • 30
    Digitale Medien
    Digitale Medien
    Osteoclast-like giant cell tumor of the pancreas: an immunohistochemical and ultrastructural study (1997)
    Springer
    Medical molecular morphology 30 (1997), S. 216-220 
    Details
    ISSN: 1860-1499
    Schlagwort(e): Osteoclast-like giant cell tumor ; Pancreas ; Immunohistochemistry ; Electron microscopy
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Medizin
    Notizen: Abstract We report a rare case of osteoclast-like giant cell tumor of the pancreas in a 70-year-old Japanese woman. The tumor was composed of a proliferation of ovoid to spindle-shaped mononuclear cells admixed with osteoclast-like giant cells. The tumor cells were immunore-active for vimentin, ±1-antitrypsin, and CD68. In ultrastructural examination, the giant cells resembled osteoclasts, and the mononuclear stromal cells had fibroblastic and histiocytic features. No elements of epithelial differentiation were found in this tumor. These findings suggest that this tumor had a derivation similar to giant cell tumor of bone.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/BF01545773
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  • 31
    Digitale Medien
    Digitale Medien
    An electron microscopic and immunohistochemical study of Merkel cell carcinoma (1997)
    Springer
    Medical molecular morphology 30 (1997), S. 209-215 
    Details
    ISSN: 1860-1499
    Schlagwort(e): Merkel cell carcinoma ; Dense core granule ; Chromogranin A ; Electron microscopy ; Immunohistochemistry study
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Medizin
    Notizen: Abstract Two cases of Merkel cell carcinoma (MCC) were examined by electron microscopy and immunohistochemistry. Histologically, tumor cells, which extended from the dermis into the subcutis, showed anastomosing bands with partial trabecular pattern. The ultrastructural study showed tumor cells in case 1 with numerous neurosecretory granules. The number of granules in case 2, however, was smaller compared with that in case 1. Perinuclear bundles of filaments were present in case 2, but few bundles were observed in case 1. By immunohistochemistry, cytokeratin (CK)-8, -18, -19, and -20 and epithelial membrane antigen were stained positively within tumor cells in both cases. It was interesting that staining patterns of chromogranin A and of neuron-specific enolase were different in the two cases. These data indicated that CK-20 is a useful marker for diagnosing MCC and that ultrastructural and immunohistochemical differences in both cases were the result of phenotypic variation.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/BF01545772
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  • 32
    Digitale Medien
    Digitale Medien
    Cervical cord ependymoma with numerous microrosettes (1997)
    Springer
    Brain tumor pathology 14 (1997), S. 145-151 
    Details
    ISSN: 1861-387X
    Schlagwort(e): Microrosette ependymoma ; Spinal cord ependymoma ; Trabecular architecture ; Immunohis-tochemistry ; Electron microscopy
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Medizin
    Notizen: Abstract “Microrosette ependymoma,” which is ependymoma with numerous microrosettes throughout the tumor, has rarely been reported. We describe an autopsy case of cervical cord ependymoma with two unusual features: the presence of numerous microrosettes and the formation of trabecular architecture. The tumor originated in the C2 segment of a man aged 23 years and gradually expanded over the following 15 years and 10 months until the entire cervical cord was involved. Beside the low grade of malignancy, the tumor cells exhibited a strong tendency to form microrosettes and trabecular architecture, which formed many perivascular pseudorosettes. The microrosettes mostly consisted of only two or a few more cells, in the absence of large rosettes. Thus the constituent cells were those forming perivascular pseudorosettes. Electron microscopy and immunohistochemistry characterized the ependymal properties of the microrosettes, whose lumina frequently contained fibril bundles similar to those of the Reissner's fiber fibrils, in addition to cilia and microvilli. The pathogenesis of the occurrence of numerous microrosettes is unknown; however, a defect in the mechanism of regulation of rosette formation and enlargement is the most likely explanation.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/BF02478884
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  • 33
    Digitale Medien
    Digitale Medien
    Gastric carcinoid tumors in a brother-sister occurrence, with special reference to ultrastructural features of endocrine granules (1997)
    Springer
    Medical molecular morphology 30 (1997), S. 228-234 
    Details
    ISSN: 1860-1499
    Schlagwort(e): Gastric carcinoid tumors ; Familial occurrence ; Electron microscopy ; Endocrine granules
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Medizin
    Notizen: Abstract Our report concerns gastric carcinoid tumors in a man and his younger sister who had no endocrine symptoms. The tumors in both cases were multiple, located in the corpus, and showed no significant differences in light microscopic and immunohistochemical examination. In electron microscopic observation, the endocrine granules of tumor cells were roughly classified into four types: granules with fine granular content with low electron density, irregularly striped granules with medium electron density, concentrically laminated or regularly striped granules, or smaller and almost uniformly high electron-dense granules in which it was difficult to recognize the internal structure. From the sequential morphological changes of the granules, we have considered that each type of granule reflects various stages of granulogenesis, although the possibility that they are distinct and contain different hormones or chemical mediators is not absolutely ruled out.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/BF01545775
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  • 34
    Digitale Medien
    Digitale Medien
    Ultrastructure of microvessels and tumor cell processes on central neurocytoma (1997)
    Springer
    Brain tumor pathology 14 (1997), S. 79-83 
    Details
    ISSN: 1861-387X
    Schlagwort(e): Neurocytoma ; Intraventricular tumor ; Electron microscopy ; Blood vessel ; Tumor cell process
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Medizin
    Notizen: Abstract A case of central neurocytoma that was confirmed with ultrastructural and immunohistochemical studies has been reported. Ultrastructurally, thin cytoplasmic processes of tumor cells showed differentiation into neuronal cells containing parallel bundles of microtubules and abortive synapses with dense-core vesicles and/or clear vesicles. It was frequently found that the clusters of tumor cell processes were close to or around the microvessels. Microvessels were composed of endothelial cells without fenestrations and had tight junctions in the endothelial clefts. Neurosecretory granules in thin cell processes appeared close to microvessels and may have been secreted around microvessels.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/BF02478874
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  • 35
    Digitale Medien
    Digitale Medien
    An immunohistochemical and immunoelectron microscopic study of adhesion molecules in synovial pannus formation in rheumatoid arthritis (1996)
    Springer
    Rheumatology international 16 (1996), S. 53-60 
    Details
    ISSN: 1437-160X
    Schlagwort(e): Rheumatoid pannus ; Adhesion molecules ; β1 integrins ; Electron microscopy
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Medizin
    Notizen: Abstract To investigate the mechanism of synovial pannus formation in rheumatoid arthritis, immunohistochemical and immunoelectron microscopic studies with monoclonal antibodies against the adhesion molecules, CD54 (ICAM-1), CD 11a (LFA-1), CDw49a (VLA-1), CDw49b (VLA-2), CDw49c (VLA-3), Cdw49d (VLA-4) and CDw49e (VLA-5), were carried out to determine the pattern of distribution of these molecules at the rheumatoid synovial cartilage junction. Treatment with anti-ICAM-1 resulted in membrane staining of most of the macrophages and fibroblasts infiltrating the synovial tissue and bordering the pannus-cartilage junction, suggesting the possibility that ICAM-1 may function to facilitate the adhesion of synovial type A cells bearing ICAM-1 to type B cells of the pannus. ICAM-1-positive macrophages and fibroblasts were often found to be in contact with lymphoid cells, suggesting also that a cellular immune reaction occurs in the formation of the pannus. In addition, VLA-3, VLA-4 and, particularly, VLA-5 were the predominantβ1 integrins expressed by rheumatoid synovial pannus. Since these three integrins all function as fibronectin receptors, it is possible that the fibronectin-rich environment of the rheumatoid cartilage surface effectively traps pannus cells expressing high levels of these molecules. The VLA-5 molecule was found in a pericellular and interterritorial matrix distribution in the present study, strongly suggesting that a recepfor-ligand interaction between VLA-5 and cartilage matrix may occur at the early stage of pannus formation. Furthermore, an increase inβ1 integrin may be necessary for the growth of the pannus and also for the upregulation of the VLA molecules, leading secondarily to increased attachment.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/BF01816436
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  • 36
    Digitale Medien
    Digitale Medien
    Spinal meningeal melanocytoma. Case report and analysis of diagnostic criteria (1996)
    Springer
    Neurosurgical review 19 (1996), S. 39-42 
    Details
    ISSN: 1437-2320
    Schlagwort(e): Electron microscopy ; immunohistochemistry ; meningeal melanocytoma
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Medizin
    Notizen: Abstract A case of cervical juxtamedullary meningeal melanocytoma is presented along with results of careful neuroradiological and pathological examinations. The authors review the previous literature and discuss the problems related to the intriguing diagnosis of this very rare entity. CT and MRI show variable appearances due to different degrees of melanization and do not reliably allow us to distinguish meningeal melanocytomas from other pigmented tumors. Pathological examination of the tumor is critical for diagnosis, but is absolutely must comprise electron microscopy and immunohistochemistry. Immunohistochemical and ultrastructural criteria are thus proposed to distinguish meningeal melanocytoma from pigmented meningioma or schwannoma and malignant melanoma (primary or secondary).
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/BF00346608
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  • 37
    Digitale Medien
    Digitale Medien
    Morphologische Analyse epiretinaler Membranen bei chirurgisch behandelten idiopathischen Makulaforamina Licht- und elektronenmikroskopische Ergebnisse * (1996)
    Springer
    Der Ophthalmologe 93 (1996), S. 675-679 
    Details
    ISSN: 1433-0423
    Schlagwort(e): Schlüsselwörter Makulaforamen ; Epiretinale Membran ; Elektronenmikroskopie ; Vitrektomie ; Pathogenese ; Key words Macular hole ; Epiretinal membrane ; Electron microscopy ; Vitrectomy ; Pathogenesis
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Medizin
    Beschreibung / Inhaltsverzeichnis: Anteroposterior and tangential traction on the central retina is an important factor in the pathogenesis of idiopathic macular hole formation. Histological studies have shown that macular holes of different stages can be associated with epiretinal membranes. Such membranes can be removed during surgery for macular holes. We investigated such tissue samples of 11 patients with macular holes in stages II – IV. Light microscopially, the tissue consisted of a thin collagen layer mostly covered by a thin layer of cells. Ultrastructural analysis revealed glial cells and macrophages as cellular components. The collagen can be ascribed to vitreous, inner limiting membrane and newly formed collagen. According to the morphological findings a multilayered tissue structure can be assumed. Macrophages were found on the retinal side of the inner limiting membrane and at the vitreal side of the tissue. Therefore, the macrophages probably originate from the retina as well as from the vitreous as so-called resident hyalocytes. Glial cells covered the inner limiting membrane forming pericellular collagen to which outer vitreous collagen fibrils can be attached. The multilayered membrane structure might possibly be the cause for only partial laminar surgical extraction so that contractile or potentially proliferative tissue residues might be one of the reasons for surgical failures after incomplete membrane peeling.
    Notizen: A.-p. und tangentiale Traktionen an der zentralen Netzhaut spielen für die Entstehung idiopathischer Makulaforamina eine wichtige Rolle. Durch histologische Untersuchungen ließen sich bei Makulaforamina unterschiedlicher Stadien epiretinale Membranen nachweisen, die für die tangentiale Traktion auf die Foramenränder verantwortlich gemacht werden. Von 11 Patienten konnten wir derartige, von uns chirurgisch entfernte Membranen licht- und elektronenmikroskopisch untersuchen. Die Membanen bestehen lichtmikroskopisch aus einem azellulären Kollagenband mit einem schmalen, teilweise nur einschichtigen Zellbesatz. Elektronenmikroskopisch lassen sich als zelluläre Komponenten Gliazellen und Makrophagen differenzieren. Die Kollagenanteile sind Glaskörperkollagen, neugebildetem Kollagen und der Lamina limitans interna zuzuordnen. Aus den Befunden läßt sich eine Schichtung der Membranen rekonstruieren mit sublaminären Makrophagen, der Lamina limitans interna und epilaminären Gliazellen und vereinzelten Makrophagen, die am ehesten residenten Hyalozyten entsprechen. Auf der vitrealen Seite können auch Verbindungen der Membran zum äußeren Glaskörperkollagen bestehen. Die Membranen zeigen Charakteristika, die in ihrem Aufbau epiretinalen Proliferationsmembranen entsprechen. Die topographische Schichtung der Membranen könnte zur Folge haben, daß chirurgisch teilweise nur Lamellen und nicht die gesamte Membran abgeschält werden. Kontraktions- oder auch proliferationsfähige Membranreste können dann einer der Faktoren für operative Mißerfolge sein.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/s003470050057
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  • 38
    Digitale Medien
    Digitale Medien
    An in vitro study of silicone migration from intravenous fluid tubing (1996)
    Springer
    Pediatric surgery international 12 (1996), S. 49-53 
    Details
    ISSN: 1437-9813
    Schlagwort(e): Key words Silicone ; Silicon tubing ; Ivac 560 pump ; Energy-dispersive X-ray analysis (EDXA) ; Electron microscopy
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Medizin
    Notizen: Abstract  Migration of particulate matter from plastic tubing and solid plastic implants has been documented in a number of studies, including some with the use of cardiac bypass, haemodialysis, and pump-assisted intravenous infusions. In order to ascertain whether silicone embolisation occurs when children have an Ivac 560 pump-assisted IV infusion, we passed 180 ml of pumped fluid through a microfilter and compared the scanning electron micrographs of those filters with unused filters and with others through which a similar volume had been passed without using the pump. The particles on the filters were analysed for their elemental content using energy-dispersive X-ray analysis. In addition, the appearance of the silicone tubing used in the pump over 3 and 72 h was assessed and compared to that of flow-only and unused tubing. More particles were found on the microfilter when fluid had been delivered via the pump than on those through which non-pumped fluid had passed or that were unused. Elemental silicon-containing particles were only found on the filter when a pump had been attached to the IV line. The flow-only and unused tubing were found to have adherent particles on the inner surface that were not seen once the tubing had been used for 3 h in the Ivac 560 pump. Also, after 72 h use, the silicone tubing had a deformed inner layer. The clinical significance of these findings is yet to be determined, but it does appear that silicone embolisation occurs during pump-assisted infusions in children.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/BF01194802
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  • 39
    Digitale Medien
    Digitale Medien
    An in vitro study of silicone migration from intravenous fluid tubing (1996)
    Springer
    Pediatric surgery international 12 (1996), S. 49-53 
    Details
    ISSN: 1437-9813
    Schlagwort(e): Silicone ; Silicon tubing ; Ivac 560 pump ; Energy-dispersive X-ray analysis (EDXA) ; Electron microscopy
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Medizin
    Notizen: Abstract Migration of particulate matter from plastic tubing and solid plastic implants has been documented in a number of studies, including some with the use of cardiac bypass, haemodialysis, and pump-assisted intravenous infusions. In order to ascertain whether silicone embolisation occurs when children have an Ivac 560 pump-assisted IV infusion, we passed 180 ml of pumped fluid through a microfilter and compared the scanning electron micrographs of those filters with unused filters and with others through which a similar volume had been passed without using the pump. The particles on the filters were analysed for their elemental content using energy-dispersive X-ray analysis. In addition, the appearance of the silicone tubing used in the pump over 3 and 72 h was assessed and compared to that of flow-only and unused tubing. More particles were found on the microfilter when fluid had been delivered via the pump than on those through which nonpumped fluid had passed or that were unused. Elemental silicon-containing particles were only found on the filter when a pump had been attached to the IV line. The flow-only and unused tubing were found to have adherent particles on the inner surface that were not seen once the tubing had been used for 3 h in the Ivac 560 pump. Also, after 72 h use, the silicone tubing had a deformed inner layer. The clinical significance of these findings is yet to be determined, but it does appear that silicone embolisation occurs during pump-assisted infusions in children.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/BF01194802
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  • 40
    Digitale Medien
    Digitale Medien
    Papillary adenoma of type II pneumocytes might have malignant potential (1996)
    Springer
    Virchows Archiv 428 (1996), S. 195-200 
    Details
    ISSN: 1432-2307
    Schlagwort(e): Papillary adenoma of type II pneumocytes ; Immunohistochemistry ; Electron microscopy ; Morphometry ; Multivariate cluster analysis
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Medizin
    Notizen: Abstract Papillary adenoma of type II pneumocytes is a rare tumour. It is considered to be a benign neoplasm and is derived from immature cells in the bronchioloalveolar epithelium, however, its biological nature has not been elucidated. We report a case of an adenomatous tumour; a papillary adenoma of type II pneumocytes, which we regard as possessing malignant potential. Light microscopically, as well circumscribed, papillary tumour of predominantly cuboidal cells resembling type II pneumocytes was found, but Clara type and ciliated cells were also present. Immunohistochemically, the tumour cells reacted positively with antibodies to surfactant apoproteins (A, B), carcinoembryonic antigen, cytochrome P-450 1A1-2 and 2B1-2. Ultrastructurally, many osmiophilic lamellar bodies and electron-dense granules were demonstrated. Semi-serial sections revealed signs of transbronchial dissemination and vascular invasion. Morphometry using 12-dimensional cluster analysis disclosed features of the tumour cells which resembled those of pneumocyte type II adenocarcinoma. These findings suggest that the present case has some malignant characteristics and originates from immature bronchiolar or alveolar cells, with a potential to develop into both type II pneumocyte and Clara cell type adenocarcinomas.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/BF00200662
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  • 41
    Digitale Medien
    Digitale Medien
    Interstitial stroma and carcinogenesis: ultrastructural observations in the rat bladder treated with N-butyl-N-(4-hydroxybutyl)nitrosamine (1996)
    Springer
    Urological research 24 (1996), S. 177-181 
    Details
    ISSN: 1434-0879
    Schlagwort(e): Interstitial stroma ; Carcinogenesis ; Bladder epithelium ; Neovascularization ; Electron microscopy
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Medizin
    Notizen: Abstract This study describes ultrastructural alterations of the interstitial stroma in the rat bladder epithelium during N-butyl-N-(4-hydroxybutyl)nitrosamine (BBN)-induced bladder carcinogenesis using scanning (SEM) and transmission (TEM) electron microscopy with NaOH treatment. The results obtained with SEM demonstrated the occurrence and development of stroma protrusions which exhibited pipe-like structures in the rat bladder epithelium following administration of BBN. Number and size of blood vessel sections also gradually increased both in the stroma and within the layer of the proliferated epithelial cells as examined by light microscopy (LM) and TEM. In this study stroma alterations were not only observed in malignant lesions of rat bladder, but hyperplastic lesions were also accompanied by stroma alterations. It is suggested that: (1) the interstitial stroma of the rat bladder epithelium may exhibit pathological changes in structure and these changes may correlate with the progression of epithelial cell proliferation following administration of BBN and (2) one of the most important alterations in the stroma is the occurrence of neovascularization, which may induce structural modification of the stroma in the processes of bladder tumor growth and development.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/BF00304082
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  • 42
    Digitale Medien
    Digitale Medien
    An ultrastructural study of glomeruli associated with vomeronasal organs transplanted into the rat CNS (1996)
    Springer
    Anatomy and embryology 193 (1996), S. 331-339 
    Details
    ISSN: 1432-0568
    Schlagwort(e): Synapse ; Cell migration ; Olfactory neurons ; Electron microscopy ; Vomeronasal organ
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Medizin
    Notizen: Abstract Rat neonate vomeronasal organs were transplanted into the parietal cortex of littermates to examine their survival and the behavior of axon growth into the surrounding host brain parenchyma. After survival times of 10–100 days the brains were processed for ultrastructural examination. The transplanted vomeronasal organs (VNO) formed several vesicles lined with a sensory epithelium. From these sensory epithelia, VNO neurons leave the epithelium and enter the host brain. Transplant neurons grew axons that fasciculated into bundles surrounded by sheath cell processes and formed one or more fiber plexuses containing distinct globose or spherical-shaped glomeralar-like structures. The glomeruli consisted of nerve terminals between which existed asymmetric synaptic contacts. Rarely did we observe clear reciprocal synapses. The glomeruli also contained terminals that showed signs of degeneration, such as increased density of the terminals, clumping of mitochondria and multivesicular bodies. The glomeruli were not partitioned or subdivided by glial septa; however, glial profiles were interspersed among the sensory terminals. Transplant glomeruli also lacked periglomerular cells and had no definitive glial envelope. These results suggest that glomerular formation is not dependent on dendrite contribution of second order neurons or glial support, but rather on a complementary population of receptor neurons.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/BF00186690
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  • 43
    Digitale Medien
    Digitale Medien
    Ultrastructural characterization of the postnatal development of the thalamic ventrobasal and reticular nuclei in the rat (1996)
    Springer
    Anatomy and embryology 193 (1996), S. 341-353 
    Details
    ISSN: 1432-0568
    Schlagwort(e): Thalamus ; Somatosensory system ; Synaptogenesis ; Nervous system ; Electron microscopy
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Medizin
    Notizen: Abstract Electron microscopy has been employed to analyze the normal maturationai sequence that characterizes the postnatal development of synaptic circuits in the ventrobasal (VB) and reticular (Rt) thalamic nuclei of rats at different ages (from birth to the end of the third postnatal week). Throughout the first postnatal week, similar signs of immaturity are observed in both nuclei, mainly consisting in scarcity of cytoplasmic organelles, presence of wide extracellular spaces, and absence of myelinated fibers. Several synaptic terminals are however present from birth, thus indicating that some of the afferents have already reached and contacted their thalamic target during embryonic life. Most of the terminals are small and contain only a few round, clear vesicles, and therefore their cytological features do not allow the identification of their origin. In particular, in both nuclei, terminals with flat vesicles and symmetric specialization are only rarely observed, and in VB the ascending terminals are not distinguishable from terminals of other sources as they are in adults. During the second postnatal week, progressive maturationai changes in VB and Rt lead to neurons having well-developed cytoplasmic organelles and to an elaborate neuropil containing myelinated fibers and synaptic terminals that are morphologically heterogeneous and resemble the adult ones. The permanence of growth cone-like profiles and of numerous somatic and dendritic protrusions, often contacted by synaptic terminals, indicates that a certain degree of reorganization is still taking place in both nuclei. By the end of the third postnatal week the synaptic organization of VB and Rt is indistinguishable from that observed in adults. This ultrastructural study shows that the appearance of the neuropil of VB and Rt and the morphological complexity of the synaptic arrangements characteristic of the adult rat are not present in neonates, but are gradually acquired during the first three postnatal weeks, and that they result from progressive modifications in circuit organization involving both pre- and postsynaptic elements.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/BF00186691
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  • 44
    Digitale Medien
    Digitale Medien
    Are breaches in the glia limitans the primary cause of the micropolygyria in Fukuyama-type congenital muscular dystrophy (FCMD)? – Pathological study of the cerebral cortex of an FCDM fetus (1996)
    Springer
    Acta neuropathologica 91 (1996), S. 313-321 
    Details
    ISSN: 1432-0533
    Schlagwort(e): Key words Fukuyama-type congential muscular ; dystrophy ; Fetus ; Cerebrocortical pathology ; Breaches in glia limitans ; Electron microscopy
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Medizin
    Notizen: Abstract A light and electron microscopic study of the brain of an 18-week fetus with a prenatal genetic diagnosis of Fukuyama-type congenital muscular dystrophy revealed a widespread mantle of abnormal neurogliomesenchymal tissue that covered a dysplastic cerebral cortex. In this area alone, the glia limitans that adjoined the abnormal mantle via one or two layers of basal lamina had frequent breaches, through which neuroglial elements extruded. In the most severely affected cortical region, which had only a rudimentary and fragmentary glia limitans, the majority of cortical neurons had migrated into the neurogliomesenchymal tissue. The massive overmigrated neurons still maintained a somewhat columnar arrangement, and the marked dysplasia abruptly shifted to a neurogliomesenchymal tissue-free normal cortical structure with an intact glia limitans, thus indicating essentially vertical overmigration of neurons without significant tangential migration of them. Together the above findings imply that breaches in the glia limitans may be the primary cause of the micropolygyria seen in this genetic disorder.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/s004010050431
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  • 45
    Digitale Medien
    Digitale Medien
    Neuronal and glial characteristics of central neurocytoma: electron microscopical analysis of two cases (1996)
    Springer
    Acta neuropathologica 91 (1996), S. 573-577 
    Details
    ISSN: 1432-0533
    Schlagwort(e): Key words Central neurocytoma ; Glial fibrillary acidic protein ; Immunohistochemistry ; Electron microscopy
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Medizin
    Notizen: Abstract We have identified two central neurocytomas which contained cells co-expressing glial fibrillary acidic protein and synaptophysin defined by double-label immunostaining. Dual-positive cells were mostly polygonal in shape and with a morphological appearence similar to that of reactive astrocytes. This distinct morphology could be used to distinguish cells expressing glial fibrillary acidic protein from cells with round and clear cytoplasm which did not express glial fibrillary acidic protein and which composed the majority of the tumor. Samples containing polygonal cells were selected for electron microscopy from toluidine blue-stained semithin sections. Ultrastructural findings were similar in both neurocytomas, with both being composed predominantly of round cells with clear cytoplasm corresponding to the clear cells identified by light microscopy. Dense-core vesicles and clear vesicles were frequently observed in the cell processes. Apart from these clear cells, polygonal cells with electron-dense cytoplasm were noted. Paralleling the results of double immunostaining, these polygonal cells contained both dense-core vesicles and intermediate, presumably glial filaments. Microtubules and lipofuscin granules were also observed. These results suggest that cells expressing glial fibrillary acidic protein in central neurocytoma include tumor cells with both neuronal and glial characteristics.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/s004010050469
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  • 46
    Digitale Medien
    Digitale Medien
    Oxyntic cell differentiation during physiological cell renewal in abomasal mucosa of adult cattle (1996)
    Springer
    Anatomy and embryology 193 (1996), S. 259-269 
    Details
    ISSN: 1432-0568
    Schlagwort(e): Stomach ; Parietal cell lineage ; Heterogeneity ; Electron microscopy ; Cattle
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Medizin
    Notizen: Abstract The origin and differentiation of the oxyntic cell lineage during physiological cell renewal was investigated by light and electron microscopy in the abomasal mucosa of adult cattle. The morphologically heterogeneous oxyntic cell population exhibits various developmental subtypes depending on the position within the oxyntic unit. Pre-oxyntic cells of the isthmus and neck represent the immature precursors. Though heterogeneous with respect to the degree of canalicular and tubulovesicular membrane development, they all contain secretory granules resembling those of either isthmus cells, immature surface mucous cells, neck cells or young chief cells. A secretory granule-free stem cell is not present in the bovine. Downward to the gland base genesis of canalicular as well as tubulovesicular membranes is gradually completed; thus pre-oxyntic cells give rise to mature oxyntic cells. Older degenerative oxyntic cells, primarily located within the gland bottom, are characterized by progressive involution of canalicular and tubulovesicular membranes. Towards the pit, differentiation of pre-oxyntic cells is associated with atypical and incomplete development of canaliculi and tubulovesicles. In consequence, these superficial oxyntic cells have a reduced secretory capacity from a morphological point of view.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/BF00198329
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  • 47
    Digitale Medien
    Digitale Medien
    Hemidesmosome ontogeny in digit skin of the human fetus (1996)
    Springer
    Archives of dermatological research 288 (1996), S. 91-97 
    Details
    ISSN: 1432-069X
    Schlagwort(e): Key words Hemidesmosomes ; Basement membrane ; Fetal skin ; Electron microscopy
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Medizin
    Notizen: Abstract Hemidesmosomes are junctional complexes involved in the attachment of epidermal basal keratinocytes to the basement membrane. To try to understand better the sequence of events in the morphogenesis of hemidesmosomes, we undertook an ultrastructural analysis of hemidesmosome formation in fetal and neonatal digit skin. Hemidesmosomes, defined as membrane-associated densities or plaques, were counted and scored for three morphological characteristics: (1) the presence of a sub-basal dense plate, (2) association with anchoring filaments within the lamina lucida and (3) contacts with intermediate filaments. No hemidesmosomes were evident at 7 weeks’ gestational age. Between 9 and 15 weeks the number of hemidesmosomes increased by about fourfold (from 20.6 ± 3.8 (SD) to 95.5 ± 8.4 per 40 μm of basal cell plasma membrane; P 〈 0.01). The association of hemidesmosomes with intermediate filaments and anchoring filaments also increased after 15 weeks ( P 〈 0.05). Early attachment plaques first appeared as triangular focal densities on the basal plasma membrane with the appearance of sub-basal dense plates, which later became both larger and more electron dense. By 15 weeks, an inner plaque could be distinguished from the outer plaque, which coincided with a closer association with intermediate filaments. Hemidesmosomes appeared fully developed by 15 weeks’ gestation. This study illustrates the structural relationship of hemidesmosomes to both intra- and extracellular filaments, suggesting close functional interactions. The complexity of the hemidesmosome plaque is also revealed early during development.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/s004030050029
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  • 48
    Digitale Medien
    Digitale Medien
    Papillomatosis confluens et reticularis Erfolgreiche Therapie mit Minocyclin* (1996)
    Springer
    Der Hautarzt 47 (1996), S. 209-213 
    Details
    ISSN: 1432-1173
    Schlagwort(e): Schlüsselwörter Papillomatosis confluens et reticularis ; Minocyclin ; Tetracycline ; Elektronenmikroskopie ; Key words Confluent and reticulated papillomatosis ; Minocycline ; Tetracycline ; Electron microscopy
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Medizin
    Beschreibung / Inhaltsverzeichnis: Summary Confluent and reticulated papillomatosis (CRP) is a rare dermatosis of unknown aetiology. Recent electron microscopic studies suggest that CRP is a disorder of keratinisation. In our case we could not confirm the previously reported ultrastructural findings. CRP is generally resistant to therapy. We treated a 19-year-old patient with typical CRP with oral minocycline. Within a few weeks the eruption resolved completely. A mild relapse 7 months later responded promptly to a repeated course of minocycline. Twelve months after discontinuatin of therapy there is no evidence of recurrence. In CRP minocycline should be preferred to systemic retinoid therapy because of its minor side effects.
    Notizen: Zusammenfassung Die Papillomatosis confluens et reticularis (PCR) ist eine seltene Erkrankung unklarer Ätiopathogenese. Neuere elektronenmikroskopische Untersuchungen stützen die Vermutung, daß eine Keratinisierungsstörung vorliegt. Anhand unseres Falles konnten wir diese Befunde allerdings nicht bestätigen. Die PCR ist ausgesprochen therapieresistent. Wir behandelten einen 19jährigen Patienten mit klinisch und histologisch typischer PCR systemisch mit Minocyclin. Innerhalb weniger Wochen heilten die Effloreszenzen vollständig ab. Ein 7 Monate später auftretendes leichtes Rezidiv konnte durch einen zweiten Behandlungszyklus schnell und erfolgreich behandelt werden. Der Patient ist jetzt bereits 12 Monate nach Absetzen der Therapie erscheinungsfrei. Zur Behandlung der PCR sollte Minocyclin wegen seiner geringeren Nebenwirkungen systemischen Retinoiden vorgezogen werden.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/s001050050405
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  • 49
    Digitale Medien
    Digitale Medien
    Distribution of glutamate receptor subunit GluR1 and GABA in human cerebral neocortex: a double immunolabelling and electron microscopic study (1996)
    Springer
    Experimental brain research 112 (1996), S. 147-157 
    Details
    ISSN: 1432-1106
    Schlagwort(e): GluR1 ; GABA ; Electron microscopy ; Cerebral neocortex ; Human
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Medizin
    Notizen: Abstract Specimens of human cerebral neocortex were obtained during neurosurgical operations and studied by immunocytochemistry and electron microscopy, using antibodies to the glutamate receptor subunit GluR1 and gamma-aminobutyric acid (GABA). Many GluR1-positive pyramidal neurons and fewer GluR1-positive nonpyramidal neurons were present in the cortex. Non-pyramidal neurons were more heavily labelled for GluR1 than pyramidal neurons. Most GABAergic neurons were labelled for GluR1. The white matter was unstained, except for occasional labelled neurons. This pattern of GluR1 immunostaining is similar to that in rat cerebral cortex, but is different from that in the hippocampus and amygdala, where large numbers of pyramidal or projection neurons, but few non-pyramidal or GABAergic neurons, were labelled for GluR1.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/BF00227188
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  • 50
    Digitale Medien
    Digitale Medien
    A light- and electron-microscopic study of GluR4-positive cells in cerebral cortex, subcortical white matter and corpus callosum of neonatal, immature and adult rats (1996)
    Springer
    Experimental brain research 110 (1996), S. 367-378 
    Details
    ISSN: 1432-1106
    Schlagwort(e): Glutamate receptor ; Cerebral cortex ; White matter ; Electron microscopy ; Development ; Rat
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Medizin
    Notizen: Abstract The distribution of the [3H]alpha-amino-3-hydroxy-5-methylisoxzalepropionic acid (AMPA) receptor subunit GluR4 was studied in frontal, parietal and temporal cerebral cortex, subcortical white matter and corpus callosum of neonatal, immature and mature rats. In 1-to 2-day-old rats, a few oligodendrocyte progenitors and amoeboid microglia in the supraventricular part of the corpus callosum were immunolabelled for GluR4. At 7 to 10 days, the number of amoeboid microglia and oligodendrocyte progenitors in white matter increased; many neurons in cortex, including pyramidal neurons, were also moderately labelled for GluR4. The pattern of GluR4 immunostaining in 14-day-old rats was different from that in 7-to 10-day-old rats, but similar to the adult, in that there was no immunoreactivity in microglia and oligodendrocyte progenitors in subcortical white matter. A proportion of non-pyramidal neurons in cortex were moderately labelled, while some pyramidal neurons were lightly labelled. A population of small glial cells with features of oligodendrocyte progenitors were densely labelled in cortex.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/BF00229137
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  • 51
    Digitale Medien
    Digitale Medien
    Liver glycogen synthase deficiency: a rarely diagnosed entity (1996)
    Springer
    European journal of pediatrics 155 (1996), S. 561-567 
    Details
    ISSN: 1432-1076
    Schlagwort(e): Key words Glycogen deficiency ; Glycogen synthase ; Ketotic ; hypoglycaemia ; Corn (maize) ; starch ; Electron microscopy
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Medizin
    Notizen: Abstract Three children from two German families are described and the observations compared with the previously published three families comprising eight patients. The two index cases presented with morning fatigue, had ketotic hypoglycaemia when fasting which rapidly disappeared after eating, and hepatic glycogen deficiency and absent or very low hepatic glycogen synthase activity. Metabolic profiles comprising glucose, lactate, alanine, and ketones in blood were typical for hepatic glycogen synthase deficiency. Symptoms were rapidly relieved and chemical signs corrected by introducing frequent protein-rich meals and night-time feedings of suspensions of uncooked corn (maize) starch. The discovery of oligosymptomatic and asymptomatic siblings suggests that there are more persons with undiagnosed hepatic glycogen synthase deficiency. Conclusion Liver glycogen synthase deficiency is likely to be more common than is believed today. It should be sought in children who, before the first meal of the day, present with drowsiness, lack of attention, pallor, uncoordinated eye movements, disorientation or convulsions and who have hypoglycaemia and acetone in urine.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/BF01957905
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  • 52
    Digitale Medien
    Digitale Medien
    Liver glycogen synthase deficiency: A rarely diagnosed entity (1996)
    Springer
    European journal of pediatrics 155 (1996), S. 561-567 
    Details
    ISSN: 1432-1076
    Schlagwort(e): Glycogen deficiency ; Glycogen synthase ; Ketotic hypoglycaemia ; Corn (maize) starch ; Electron microscopy
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Medizin
    Notizen: Abstract Three children from two German families are described and the observations compared with the previously published three families comprising eight patients. The two index cases presented with morning fatigue, had ketotic hypoglycaemia when fasting which rapidly disappeared after eating, and hepatic glycogen deficiency and absent or very low hepatic glycogen synthase activity. Metabolic profiles comprising glucose, lactate, alanine, and ketones in blood were typical for hepatic glycogen synthase deficiency. Symptoms were rapidly relieved and chemical signs corrected by introducing frequent protein-rich meals and night-time feedings of suspensions of uncooked corn (maize) starch. The discovery of oligosymptomatic and asymptomatic siblings suggests that there are more persons with undiagnosed hepatic glycogen synthase deficiency.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/BF01957905
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  • 53
    Digitale Medien
    Digitale Medien
    Bimodal solubilization of phospholipid-cholesterol vesicles in 3-[(3-cholamidopropyl)dimethylammonio]-1-propanesulfonate (CHAPS) solutions. Formation of filamentous and helical microstructures depends on negatively charged lipids (1996)
    Springer
    European biophysics journal 25 (1996), S. 67-73 
    Details
    ISSN: 1432-1017
    Schlagwort(e): Key words Gallstone ; Cholesterol monohydrate crystals ; Phase separation ; Light scattering ; Electron microscopy
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie , Physik
    Notizen: Abstract Phospholipid/cholesterol vesicles were solu-bilized by 3-[(3-cholamidopropyl)dimethylammonio]-1-propanesulfonate (CHAPS). Above 30 mol% cholesterol (Ch) in the lipid vesicles several remarkable changes of the solubilization process were observed. (i) Two modes of solubilization: The effective detergent to lipid ratio Rc(M) for the formation of mixed micelles decreased from Rc(M) = 43 ± 3 at low lipid concentrations, [L]≤ 0.15 mm, to Rc(M) = 2.4 ± 0.3 above [L] = 0.5 mm (40 mol% Ch, T = 20 °C). (ii) At subsolubilizing CHAPS concentrations, filamentous and helical microstructures were formed, similar to those which were observed in native and model bile. (iii) The number of observed fibers was about two orders of magnitude higher in the presence of the negatively charged lipids phosphatidylglycerol (PG) and phosphatidic acid (PA) compared to the zwitterionic phosphatidylcholine (PC). Fiber formation began after 16–18 h using PG and PA compared to 3–4 days in the presence of PC. Screening of the charged lipids by NaCl effectively reduced the formation of fibers. Assuming binding of Na+ to the charged lipid aggregates, an intrinsic binding constant Kint = 0.6 M–1 was determined by applying the Gouy-Chapman theory. After the addition of CHAPS to PG/Ch vesicles, a fast initial solubilization of the vesicles (〈1 min) to mixed micelles (rh = 2.3 ± 0.2 nm) and small vesicles (rh = 23 ± 1 nm) was observed, followed by an intermediate period of 2 h, after which the formation of fibers occurred (〉15 h). The microstructures are visualized by darkfield and electron microscopy. The method of vesicle solubilization is compared to the dilution of concentrated micellar solutions, which is usually applied to model bile systems.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/s002490050019
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  • 54
    Digitale Medien
    Digitale Medien
    Endophytic establishment of Azorhizobium caulinodans through auxin-induced root tumors of rice (Oryza sativa L.) (1996)
    Springer
    Biology and fertility of soils 21 (1996), S. 293-302 
    Details
    ISSN: 1432-0789
    Schlagwort(e): Key words Ammonium excretion ; Azorhizobium caulinodans ; Auxine ; 2 ; 4-Dichlor-phenoxy-acetic acid ; Nitrogen fixation ; Paranodulation ; Rice ; Electron microscopy
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie , Geologie und Paläontologie , Land- und Forstwirtschaft, Gartenbau, Fischereiwirtschaft, Hauswirtschaft
    Notizen: Abstract Rice seedlings developed nodule-like tumors (para-nodules) along primary and secondary roots when treated with the auxin 2,4-dichlor-phenoxy-acetic acid (2,4-D). Histologically, these tumors appeared as cancerous out-grown lateral-root primordes and were thus comparable with stem nodules of the legume Sesbania rostrata. Azorhizobium caulinodans (a diazotroph known as a specific endophyte of Sesbania rostrata) was introduced and became established inside rice para-nodules and in root tissues around tumor bases. The infection with A. caulinodans followed a typical “crack-entry” invasion at places where para-nodule tumors had emerged through the root cortex and epidermis. The bacteria settled with high cell densities in intercellular spaces of the induced tumors and betwen root cortical cells. Infection of plant cells took place both in the epidermis and in cortical tissue. Intracellularly established A. caulinodans was found inside the cytoplasm, surrounded by membrane-like structures. N2 fixation by tumor-inhabiting Azorhizobium sp. was increased at low O2 tensions (1.5–3 kPa) compared with an untreated control. Only a little activity remained at O2 tensions of 5 kPa and above. The present results confirm that root-tumor induction offers a suitable method of establishing diazotrophs endophytically in the roots of gramineous crops.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/BF00334906
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  • 55
    Digitale Medien
    Digitale Medien
    Endophytic establishment of Azorhizobium caulinodans through auxin-induced root tumors of rice (Oryza sativa L.) (1996)
    Springer
    Biology and fertility of soils 21 (1996), S. 293-302 
    Details
    ISSN: 1432-0789
    Schlagwort(e): Ammonium excretion ; Azorhizobium caulinodans ; Auxine 2.4-Dichlor-phenoxy-acetic acid ; Nitrogen fixation ; Paranodulation ; Rice ; Electron microscopy
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie , Geologie und Paläontologie , Land- und Forstwirtschaft, Gartenbau, Fischereiwirtschaft, Hauswirtschaft
    Notizen: Abstract Rice seedlings developed nodule-like tumors (para-nodules) along primary and secondary roots when treated with the auxin 2,4-dichlor-phenoxy-acetic acid (2,4-D). Histologically, these tumors appeared as cancerous out-grown lateral-root primordes and were thus comparable with stem nodules of the legume Sesbania rostrata. Azorhizobium caulinodans (a diazotroph known as a specific endophyte of Sesbania rostrata) was introduced and became established inside rice para-nodules and in root tissues around tumor bases. The infection with A. caulinodans followed a typical “crack-entry” invasion at places where paranodule tumors had emerged through the root cortex and epidermis. The bacteria settled with high cell densities in intercellular spaces of the induced tumors and between root cortical cells. Infection of plant cells took place both in the epidermis and in cortical tissue. Intracellularly established A. caulinodans was found inside the cytoplasm, surrounded by membrane-like structures. N2 fixation by tumor-inhabiting Azorhizobium sp. was increased at low O2 tensions (1.5–3 kPa) compared with an untreated control. Only a little activity remained at O2 tensions of 5 kPa and above. The present results confirm that root-tumor induction offers a suitable method of establishing diazotrophs endophytically in the roots of gramineous crops.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/BF00334906
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  • 56
    Digitale Medien
    Digitale Medien
    Isolated dihydroxyacetonephosphate- acyl-transferase deficiency in rhizomelic chondrodysplasia punctata: clinical presentation, metabolic and histological findings (1996)
    Springer
    European journal of pediatrics 155 (1996), S. 1035-1039 
    Details
    ISSN: 1432-1076
    Schlagwort(e): Key words Rhizomelic ; chondrodysplasia punctata ; Dihydroxyacetonephosphate-acyl-transferase ; Electron microscopy ; Peroxisomes ; Morphometry
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Medizin
    Notizen: Abstract Rhizomelic chondrodysplasia punctata (RCDP) is clinically characterized by symmetrical shortening of the proximal limbs, contractures of joints, a characteristic dysmorphic face, and cataracts. In the classical form an impairment of several peroxisomal functions and enzymes (plasmalogen synthesis, phytanic acid oxidation, 3-oxoacyl-CoA thiolase) has been repeatedly shown. Recently a variant involving only the peroxisomal dihydroxyacetonephosphate acyltransferase (DHAP-AT) has been described. We present a patient with isolated DHAP-AT deficiency and all clinical, radiological, and pathological features of classical RCDP. For the first time, microscopy and immunocytochemistry of hepatocytes could be performed. Conclusion In contrast to studies on classical rhizomelic chondrodysplasia punctata which have shown enlarged peroxisomes in numbers varying from hepatocyte to hepatocyte, the peroxisomes in our patient seem to be normal in size, number and shape.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/s004310050529
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  • 57
    Digitale Medien
    Digitale Medien
    Fine surface structure of enterotoxemic Escherichia coli O139:K12 strains associated with swine edema disease (1996)
    Springer
    Archives of microbiology 166 (1996), S. 357-360 
    Details
    ISSN: 1432-072X
    Schlagwort(e): Key wordsEscherichia coli ; Capsule ; Serotype ; Edema disease ; Electron microscopy ; Cell adhesion
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie
    Notizen: Abstract The fine structure of the cell surface of seven enterotoxemic Escherichia coli (ETEEC) O139:K12 strains isolated from piglets with edema disease were examined electron microscopically using both the negative-staining method and the freeze-substitution fixation method. Densely packed, fine fibers were observed; they consisted of a capsule layer approximately 25 nm thick around the cell surfaces of strains 107/86, IW-2, ED-3, ED-43, and ED-61, all of which have a capacity to adhere strongly to HEp-2 cells. In contrast, no such structure was observed on the surface of strains RK-O139 or ED-1, both of which adhere only weakly to HEp-2 cells. These results suggest that the capsule structure might be associated with the ability to adhere to HEp-2 cells and, as a result, also potentially play some role in ETEEC infection.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/s002030050395
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  • 58
    Digitale Medien
    Digitale Medien
    A current assessment of photosystem II structure (1996)
    Springer
    Bioscience reports 16 (1996), S. 159-187 
    Details
    ISSN: 1573-4935
    Schlagwort(e): Electron microscopy ; photosystem II ; thylakoid membrane
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie , Chemie und Pharmazie
    Notizen: Abstract This review covers the recent progress in the elucidation of the structure of photosystem II (PSII). Because much of the structural information for this membrane protein complex has been revealed by electron microscopy (EM), the review will also consider the specific technical and interpretation problems that arise with EM where they are of particular relevance to the structural data. Most recent reviews of photosystem II structure have concentrated on molecular studies of the PSII genes and on the likely roles of the subunits that they encode or they were mainly concerned with the biophysical data and fast absorption spectroscopy largely relating to electron transfer in various purified PSII preparations. In this review, we will focus on the approaches to the three-dimensional architecture of the complex and the lipid bilayer in which it is located (the thylakoid membrane) with special emphasis placed upon electron microscopical studies of PSII-containing thylakoid membranes. There are a few reports of 3D crystals of PSII and of associated X-ray diffraction measurements and although little structural information has so far been obtained from such studies (because of the lack of 3D crystals of sufficient quality), the prospects for such studies are also assessed.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/BF01206204
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  • 59
    Digitale Medien
    Digitale Medien
    Fibrillary inclusions in neoplastic and fetal acinar cells of the pancreas (1996)
    Springer
    Virchows Archiv 428 (1996), S. 261-266 
    Details
    ISSN: 1432-2307
    Schlagwort(e): Acinar cell carcinoma ; Fetal pancreas ; Electron microscopy ; Fibrillary inclusion ; Rough endoplasmic reticulum
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Medizin
    Notizen: Abstract We report a case of pancreatic acinar cell carcinoma which contained a large number of pleomorphic inclusions with fibrillary internal structures and mature zymogen granules. To clarify the significance of fibrillary inclusions in the differentiation of acinar cells of the pancreas, we further investigated fetal pancreases (gestational weeks 16, 17, 19, 20 and 28). We found two types of inclusions: type A, corresponding to fibrillary inclusion of neoplastic acinar cells, was observed only in a 19-week fetus; type B showed a homogeneous density similar to that of zymogen granules. Type B was observed in all the fetuses after the 17th gestational week. Although the type A inclusion might be generated throught a different mechanism than the type B inclusion, the appearance of a large number of fibrillary inclusions in neoplastic acinar cells may represent a transient form of zymogen granule.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/BF00196699
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  • 60
    Digitale Medien
    Digitale Medien
    Alveolar adenoma of the lung: further characterization of this uncommon tumour (1996)
    Springer
    Virchows Archiv 429 (1996), S. 101-108 
    Details
    ISSN: 1432-2307
    Schlagwort(e): Alveolar adenoma ; Lung neoplasms ; Flow cytometry ; Electron microscopy ; Proliferating cell nuclear antigen
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Medizin
    Notizen: Abstract Alveolar adenoma of the lung is a poorly characterized, uncommon pulmonary lesion with proliferation of alveolar epithelium and septal mesenchyme. We describe the electron microscopy, immunohistochemistry and DNA flow cytometry in a case of alveolar adenoma in a 55-year-old woman. Alveolar adenoma appears to be a distinct benign neoplasm of the alveolar structures. Our findings further suggest that it is not a precursor of bronchioloalveolar carcinoma or other type II pneumocyte lesions of presumed malignant potential.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/BF00192432
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  • 61
    Digitale Medien
    Digitale Medien
    Desmin filaments in the electrocytes of the electric organ of the electric eel Electrophorus electricus (1996)
    Springer
    Cell & tissue research 285 (1996), S. 387-393 
    Details
    ISSN: 1432-0878
    Schlagwort(e): Key words: Electrocyte ; Intermediate filaments ; Desmin ; Cytoskeleton ; Electron microscopy ; Electrophorus electricus (Teleostei)
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie , Medizin
    Notizen: Abstract. Desmin protein is an abundant constituent of the intermediate filaments in the electrocytes of the electric organ of the electric eel Electrophorus electricus. Polyclonal antibodies were raised against purified desmin from the electric organ and used for immunolabeling of the protein in reconstituted filaments. In thick sections of the main electric organ that has been stained with fluorescein-labeled desmin-specific antibodies, light microscope revealed a diffuse meshwork of desmin filaments dispersed in the cytoplasm of electrocytes. In the region under the membrane, the immunostaining was slightly more intense than elsewhere. The meshwork of intermediate filaments composed of desmin was examined by electron microscopy of the main electric organ. Immuno-gold labeling demonstrated a widespread meshwork of desmin filaments in the cytoplasm and in close association with the plasma membrane. These observations suggest that intermediate filaments play a role in the maintenance of the morphology of electrocytes and, as an intracellular meshwork spanning the width of the cell, they may contribute to the organization of the intracellular compartments.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/s004410050654
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  • 62
    Digitale Medien
    Digitale Medien
    Nitric oxide synthase-containing neurones and nerve fibres within cardiac ganglia of rat and guinea-pig: an electron-microscopic immunocytochemical study (1996)
    Springer
    Cell & tissue research 284 (1996), S. 19-28 
    Details
    ISSN: 1432-0878
    Schlagwort(e): Key words: Innervation ; Heart ; Intracardiac neurone ; Nitric oxide ; Immunocytochemistry ; Electron microscopy ; Rat (Sprague Dawley) ; Guinea-pig (Dunkin Hartley)
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie , Medizin
    Notizen: Abstract. The nitric oxide synthase-immunoreactivity and NADPH-diaphorase activity of intracardiac neurones in the rat and guinea-pig was studied at the ultrastructural level. While some nitric oxide synthase-containing intracardiac neurones were very heavily labelled, with electron-dense immunoprecipitate distributed throughout the neuronal cell bodies and their processes, most of the labelled neurones exhibited a lighter and more patchy distribution of nitric oxide synthase-immunoreactive material. Synapses made by nitric oxide synthase-negative nerve fibres with labelled intracardiac neurones were seen. Conversely, many nitric oxide synthase-containing nerve fibres that made synaptic contacts with unlabelled intracardiac neurones were also observed. Some small granule-containing cells were nitric oxide synthase-immunoreactive and were associated with unlabelled nerve terminals, while non-immunoreactive small granule-containing cells that were innervated by nitric oxide synthase-immunoreactive nerves were also seen. Small patches of osmiophilic electron-dense material were observed in the cytoplasm of NADPH-diaphorase-positive intracardiac neurones. This is the first description of the ultrastructural distribution of nitric oxide synthase-immunoreactivity and NADPH-diaphorase activity in a subpopulation of intracardiac neurones of rat and guinea-pig heart and provides further evidence in support of a role for nitric oxide in the local control of the heart by intrinsic neurones.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/s004410050563
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  • 63
    Digitale Medien
    Digitale Medien
    Studies on the structure of ocellar photoreceptor cells of Drosophila melanogaster with special reference to subrhabdomeric cisternae (1996)
    Springer
    Cell & tissue research 284 (1996), S. 77-85 
    Details
    ISSN: 1432-0878
    Schlagwort(e): Key words: Ocellus ; Photoreceptor cells ; Retinal degeneration ; Subrhabdomeric cisternae ; Electron microscopy ; Immuno-electron microscopy ; Phosphatidylinositol transfer protein ; Drosophila melanogaster (Insecta)
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie , Medizin
    Notizen: Abstract. We studied the structure of ocellar photoreceptor cells of Drosophila melanogaster, particularly the subrhabdomeric cisternae which our previous studies have shown to be essential structures for turnover of photoreceptive membranes in compound eyes. Each ocellus contained elongated photoreceptor cells with rhabdomeres positioned distally. In the subrhabdomeric regions, endocytotic invaginations were frequently observed, suggesting active turnover of photoreceptive membranes. In the vicinity of the photoreceptive microvilli, membranous structures similar to the subrhabdomeric cisternae in compound eyes were observed. These membranous structures were immunopositive for the rdgB protein, a phosphatidylinositol transfer protein that is localized to the subrhabdomeric cisternae in compound eyes. The ocellar photoreceptor cells of the retinal degeneration mutants (rdgA,B) were also studied. In these mutants, retinal degeneration has been reported to start, in compound eyes, with the disappearance of the subrhabdomeric cisternae. We found that the ocellar subrhabdomeric cisternae also disappear during the initial stage of retinal degeneration. From these observations, we conclude that the mechanism of photoreceptive membrane turnover in ocellar photoreceptor cells involves the rdgB and probably the rdgA proteins which are associated with subrhabdomeric cisternae, as is the case for photoreceptive membrane turnover in compound eyes.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/s004410050568
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  • 64
    Digitale Medien
    Digitale Medien
    Chordotonal sensilla embedded in the epidermis of the soft integument of the cricket, Teleogryllus commodus (1996)
    Springer
    Cell & tissue research 284 (1996), S. 125-142 
    Details
    ISSN: 1432-0878
    Schlagwort(e): Key words: Chordotonal organ ; Scolopidium ; Mechanoreceptor ; Sensilla ; Electron microscopy ; Phylogenesis ; Teleogryllus commodus (Insecta)
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie , Medizin
    Notizen: Abstract. More than 50 chordotonal sensilla, or scolopidia, embedded entirely in the integument were found in each side of the genital chamber wall in the female cricket, Teleogryllus commodus. Their cell bodies lie among the epidermal cells, and the tips of their dendrites terminate in the cuticle. About half of them contain two sensory cells (two-cell scolopidium), the others only one (one-cell scolopidium). The sensory cell in the one-cell scolopidium is the type-1 cell. In the two-cell scolopidium one is type-1 and the other type-2. Regardless of the number of sensory cells, they are all amphinematic. In the two-cell scolopidium only the type-2 dendrite, rich in microtubules, penetrates into the cuticle, bifurcates and terminates in the tube enclosed by an attachment cell; the type-1 never extends into the cuticle. On the other hand, the type-1 cell in the one-cell scolopidium projects its apex into the cuticle. The unique topography and structure of these scolopidia lead to the following hypothesis about the phylogenetic relationship between the scolopidia and other kinds of sensilla: the type-1 scolopidial sensory cell buried in the integument may be the original model, which through the loss of the long regular axoneme has given rise to type-2 cells. Modification of the apical region, the tubular body or ramification, may have lead to the cuticular sensilla corresponding to the development of the cuticular apparatus, and the scolopidia may have been withdrawn into the body cavity to form ordinary chordotonal organs.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/s004410050573
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  • 65
    Digitale Medien
    Digitale Medien
    Transmission electron microscopy procedure for endothelial cell cultures with angiogenesis (1996)
    Springer
    Methods in cell science 18 (1996), S. 15-18 
    Details
    ISSN: 1573-0603
    Schlagwort(e): Angiogenesis ; Endothelial cells ; Angiogenesis analysis ; Electron microscopy ; Cell culture
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie
    Notizen: Abstract Determination of the structural characteristics of angiogenesis requires a procedure protective of the forming vascular fibers and the endothelial cell monolayer exhibiting cord formation. This report describes in situ fixation of angiogenic cultures in 96-well plates and the subsequent double embedding processing for electron microscopy. Cross sections of the monolayer are obtained without damage of the incipient capillaries.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/BF00123518
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  • 66
    Digitale Medien
    Digitale Medien
    A comparison of morphological effects on the rabbit nasal and sinus mucosa after surgical denervation and topical capsaicin application (1996)
    Springer
    European archives of oto-rhino-laryngology and head & neck 253 (1996), S. 205-213 
    Details
    ISSN: 1434-4726
    Schlagwort(e): Nasal neuropeptides ; Perennial rhinitis ; Mucosal glands ; Immunofluorescence ; Electron microscopy
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Medizin
    Notizen: Abstract In order to study morphological effects on the nasal and sinus mucosa, New Zealand White rabbits underwent either unselective, regional sectioning of sensory and parasympathetic nerve branches or topical treatment of the mucosa with capsaicin. Ten days after treatment, mucosal specimens were analyzed by light and electron microscopy. Immunohistochemistry was used to evaluate neuropeptides present, in particular substance P, calcitonin gene-related peptide, vasoactive intestinal peptide and neuropeptide Y. In surgically denervated rabbits, mucosal glands were found to be enlarged and contained an increased number of zymogen granules having a bipartite substructure. Topical capsaicin application caused localized epithelial changes in the sinus mucosa and maxilloturbinal region of the nose, including clotting of cilia and an increased number of goblet cells. Reduced amounts of all neuropeptides investigated were found in the surgically denervated animals, while topical capsaicin treatment had only marginal effects on the mucosal neuropeptide content. The morphological changes observed after surgical denervation suggest an imbalance between neural stimulation and secretory capacity of the mucosal glands. These findings could explain the difference in clinical effect noted between sectioning of the vidian nerve and topical treatment with capsaicin in patients with perennial rhinitis.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/BF00171129
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  • 67
    Digitale Medien
    Digitale Medien
    Lipid-rich keratin spherules containing cholesterol crystals in an epidermal cyst (1996)
    Springer
    Medical molecular morphology 29 (1996), S. 7-12 
    Details
    ISSN: 1860-1499
    Schlagwort(e): Keratin spherules ; Cholesterol crystals ; Epidermal cyst ; Electron microscopy
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Medizin
    Notizen: Abstract Numerous, small spherical inclusions with laminated horn-like material were observed in an epidermal cyst from the left earlobe of a 52-year-old Japanese man. They were examined by light and electron microscopy. Positive reactions obtained by staining with both oil red-O and anti-pankeratin antibody led to the conclusion that the inclusions consisted of lipid-rich keratin spherules. These were thought to have been formed in the hydrophobic regions of keratin proteins and non-polar lipids in the hydrophilic milieu of the cyst. Electron microscopy revealed cholesterol crystals within the spherules, suggesting that cholesterol had been slowly isolated from the lipoproteins and the membrane components of the cornified cells included in the lipid-rich keratin spherules, and had gradually become concentrated, finally appearing in the spherules as cholesterol crystals. With further study, a more detailed understanding of this process may throw some light on the development of gallstones and atheroembolism.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/BF02348071
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  • 68
    Digitale Medien
    Digitale Medien
    pathological findings in the facial nerve sheath in Melkersson-Rosenthal syndrome (1996)
    Springer
    Medical molecular morphology 29 (1996), S. 37-42 
    Details
    ISSN: 1860-1499
    Schlagwort(e): Melkersson-Rosenthal syndrome ; Facial nerve sheath ; Electron microscopy ; Collagen
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Medizin
    Notizen: Abstract To our knowledge, this is the first report of electron microscopic findings in the facial nerve sheath in Melkersson-Rosenthal syndrome. We performed decompression of the right facial nerve on a patient with Melkersson-Rosenthal syndrome. A part from the facial nerve sheath was obtained and observed with a transmission electron microscope. There were some fibers 180 to 200 nm in diameter which had obscure cross bandings, and also accumulations of these degenerated fibers among normal collagen fibers.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/BF02348075
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  • 69
    Digitale Medien
    Digitale Medien
    A case of a placental site trophoblastic tumor (1996)
    Springer
    Medical molecular morphology 29 (1996), S. 48-51 
    Details
    ISSN: 1860-1499
    Schlagwort(e): Placental site trophoblastic tumor ; Intermediate trophoblast ; Immunohistochemistry ; Electron microscopy
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Medizin
    Notizen: Abstract A rare placental site trophoblastic tumor (PSTT) in a 39-year-old female was studied. This tumor, protruding into the uterine cavity, was histologically similar to tumors in previously reported cases of PSTT. Ultrastructurally, the characteristic finding was the presence of perinuclear filaments. Also, the tumor cells were strongly positive for hPL by immunohistochemical method. These findings suggest that this was a tumor caused by neoplastic proliferation of the extravillous intermediate trophoblast.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/BF02348077
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  • 70
    Digitale Medien
    Digitale Medien
    Occurrence of long-spacing collagen in the intramuscular nerves of biopsied muscle tissues (1996)
    Springer
    Medical molecular morphology 29 (1996), S. 124-128 
    Details
    ISSN: 1860-1499
    Schlagwort(e): Long-spacing collagen ; Intramuscular nerves ; Neuromuscular diseases ; Electron microscopy
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Medizin
    Notizen: Abstract We examined the incidence and morphological features of long-spacing collagen (LSC) in the intramuscular nerves of biopsied muscle tissues from patients with various neuromuscular diseases. LSC was found in 12 of 55 cases (21.8%). The muscles in all cases with LSC showed typical neurogenic changes at the light microscopic level. At the electron microscopic level, LSC was seen either in the vicinity of the basement membranes of the perineurium or Schwann cells, or running among the collagen fibrils. A close relationship between the form (compact or solitary type) and the periodicity of collagen was not confirmed.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/BF02348065
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  • 71
    Digitale Medien
    Digitale Medien
    Use of excluded volume to increase the heterogeneity of pore size in agarose gels (1996)
    Weinheim : Wiley-Blackwell
    Electrophoresis 17 (1996), S. 971-976 
    Details
    ISSN: 0173-0835
    Schlagwort(e): Biological systems ; Electron microscopy ; Agarose gel electrophoresis ; Image processing ; Light scattering ; Chemistry ; Biochemistry and Biotechnology
    Quelle: Wiley InterScience Backfile Collection 1832-2000
    Thema: Biologie , Chemie und Pharmazie
    Notizen: When testing theoretical models that quantitatively describe the sieving of macromolecules during gel electrophoresis, investigators have been limited by absence of control of the heterogeneity of the size of pores in the gel. In a recent study performed by electron microscopy of thin sections (G. A. Griess et al., J. Struct. Biol. 1993, 111, 39-47), pore size heterogeneity has been increased for agarose gels by a combination of both derivatization and molecular weight reduction of the polysaccharide chains of agarose. In the present study, pore size heterogeneity is increased by a mechanism that appears to have an origin different from the origin of this previously observed increase in heterogeneity: Pore size heterogeneity is increased by addition of a polyethylene glycol (PEG) of high molecular weight (18 500) to molten agarose before gelation. In contrast, the use of a lower molecular weight PEG (either 4 000 or 7 500) causes the formation of micron-sized precipitates within a gelled network of agarose fibers. Thus far, the PEG-induced heterogeneity of pore size occurs primarily in 100-1000 μm scale zones separated from each other by interzone regions of decreased agarose fiber density. More uniform gels are needed for the study of sieving.
    Zusätzliches Material: 6 Ill.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1002/elps.1150170603
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  • 72
    Digitale Medien
    Digitale Medien
    Time sequence and site of fluid accumulation in experimental neurogenic pulmonary edema (1976)
    Springer
    Research in experimental medicine 168 (1976), S. 219-227 
    Details
    ISSN: 1433-8580
    Schlagwort(e): Initial phase of neurogenic pulmonary edema ; Perfusion fixation ; HRP ; Electron microscopy
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Medizin
    Notizen: Summary The initial phase of pulmonary edema development following intracranial pressure elevation was studied by means of transmission electron microscopy. Using perfusion fixation and application of a blood tracer (HRP horseradish peroxidase) the time sequence and site of fluid leakage out of pulmonary vessels was demonstrated: - passage of edema fluid through intercellular clefts of alveolar capillary endothelium - edema accumulation in alveolar interstitial tissue - draining of edema fluid from the alveolar septum to the interstitium of terminal bronchioli and to lymphatic vessels. An early interepithelial fluid leakage out of the alveolar wall remains questionable.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/BF01851320
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  • 73
    Digitale Medien
    Digitale Medien
    Metabolism and ultrastructure in ovaries of alloxan-diabetic juvenile rats (1976)
    Springer
    Archives of gynecology and obstetrics 220 (1976), S. 199-208 
    Details
    ISSN: 1432-0711
    Schlagwort(e): Rat ovaries ; Diabetes mellitus ; Alloxan ; ATP/ADP ; Lactate/pyruvate ; NADP/NADPH ; Glucose ; Protein content ; Hydrogen-coveying enzymes ; alkal. phosphatase ; Electron microscopy
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Medizin
    Beschreibung / Inhaltsverzeichnis: Zusammenfassung Es wurde der Einfluß eines alloxan-induzierten Diabetes mellitus auf den Stoffwechsel und die Ultrastruktur juveniler Rattenovarien untersucht. Der Diabetes mellitus bewirkte folgende Änderungen imStoffwechsel: Abfall der Konzentration von ATP und NADPH, Anstieg des Lactat/Pyruvat-Quotienten über 40, Abfall des ATP/ADP-Quotienten unter 1, Aktivitätsminderung der wasserstoffübertragenden Enzyme G-6-DH, Isocitrat-DH, Malat-DH, Aktivitätszunahme der alkalischen Phosphatase, Erniedrigung des Proteingehaltes.Ultrastruktur: Nahezu vollständiges Verschwinden des rauhen endoplasmatischen Reticulums, Schrumpfung der Mitochondrien, Reduktion der cristae und Kondensation der Matrix. Das glatte endoplasmatische Reticulum bleibt unverändert, der Golgi-Komplex ist in seiner Ausdehnung reduziert. Leichte Extrahierbarkeit der Lipiddepots. Die Befunde sprechen für eine Hemmung der oxydativen Phosphorylierung sowie für eine Beeinträchtigung des Steroid- und Proteinstoffwechsels.
    Notizen: Summary Tests were carried out on the influence of alloxan-induced diabetes mellitus on the metabolism and the ultrastructure of ovaries of juvenile rats. The diabetes mellitus caused the following changes in themetabolism: reduction in the concentration of ATP and NADPH, increase in the lactate/pyruvate quotient to above 40, reduction in the ATP/ADP quotient to below 1, reduction in the level of activity of the hydrogen-conveying enzymes G-6-P-dehydrogenase, isocitrate dehydrogenase and malate dehydrogenase, increase in the level of activity of the alkaline phosphatase, reduction of the protein content. Ultrastructure almost complete disappearance of the rough endoplasmic reticulum, shrinkage of the mitochondria, reduction of the cristae and condensation of the matrix. The smooth endoplasmic reticulum remains unchanged, the extent of the Golgi-complex is reduced. Easy removal of the lipid deposits.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/BF00667748
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  • 74
    Digitale Medien
    Digitale Medien
    Ultrastructural study of testis in testicular feminization (1976)
    Springer
    Archives of gynecology and obstetrics 221 (1976), S. 277-287 
    Details
    ISSN: 1432-0711
    Schlagwort(e): Electron microscopy ; Endocrinology ; Pathology ; Testicular feminization ; Testis
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Medizin
    Notizen: Summary Testicular tissue was investigated by electron microscopy in a case of testicular feminization. The seminiferous tubules were lined by spermatogonia and by Sertoli cells. Spermatocytic maturation was not observed. Leydig cells were numerous and contained well developed, abundant vesicular smooth-surfaced endoplasmic reticulum and large mitochondria with tubulovesicular cristae. Reinke crystalloids were absent. The ultrastructural findings were consistent with the assumption that Leydig cells were under adequate stimulation and were in a stage of active secretion. Hence, the results seem to indicate that testicular endocrine function was maintained in the studied case.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/BF00667021
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  • 75
    Digitale Medien
    Digitale Medien
    Effect of peripheral axotomy on the fine structure and histochemistry of the Rolando substance: Degenerative atrophy of central processes of pseudounipolar cells (1976)
    Springer
    Experimental brain research 26 (1976), S. 73-87 
    Details
    ISSN: 1432-1106
    Schlagwort(e): Rolando substance ; Degeneration ; Atrophy ; Axotomy ; Histochemistry ; Electron microscopy
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Medizin
    Notizen: Summary Disappearence of fluorid-resistant acid phosphatase activity from the ipsilateral Rolando substance after transection of the peripheral nerve, is shown to be due to the cessation of enzyme supply from dorsal root ganglion cells to their central terminals. This is accompanied by (or ensues in consequence of) a fine structural derangement of these terminals (“degenerative atrophy”). Fine structural alterations of axon terminals undergoing degenerative atrophy, though similar to some extent to those seen during early phases of a Wallerian degeneration, are markedly different. Also myelinated nerve fibers, both in the dorsal horn and in dorsal columns, are affected by degenerative atrophy. This important, new trophical feature of sensory ganglion cells suggests a delicate metabolic balance between peripheral and central axonal branches of bipolar (pseudounipolar) cells. Degenerative atrophy raises serious implications in evaluating hodological experiments based upon Wallerian degeneration and offers new perspectives for theoretical and clinical neurology.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/BF00235250
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  • 76
    Digitale Medien
    Digitale Medien
    An electron microscopic study of plasmatic arterionecrosis in the human cerebral arteries (1976)
    Springer
    Virchows Archiv 369 (1976), S. 181-190 
    Details
    ISSN: 1432-2307
    Schlagwort(e): Cerebral hemorrhage ; Cerebral artery disease ; Plasmatic arterionecrosis ; Electron microscopy
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Medizin
    Notizen: Summary An electron microscopic study of the intracerebral arteries from 9 hypertensive cases was performed in order to elucidate the morphogenesis of the plasmatic arterionecrosis which was considered to be the direct cause of hypertensive intracerebral hemorrhage. In the preceding stage of the arterial lesions, marked necrosis of medial smooth muscle cells and increase of basement membrane-like substance in the intima and media were observed. The lumina of these arteries were slightly dilated. The dilatation and hemodynamic factors were supposed to cause endothelial injury resulting in blood plasma insudation into the intima through the opened spaces between endothelial cells. The insudated blood plasma dispersed and dissolved the basement membrane-like substance, collagen and elastic fibers in the arterial wall, leading to the development of the plasmatic arterionecrosis.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/BF00427707
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  • 77
    Digitale Medien
    Digitale Medien
    Stereology of liver biopsies from healthy volunteers (1976)
    Springer
    Virchows Archiv 371 (1976), S. 251-263 
    Details
    ISSN: 1432-2307
    Schlagwort(e): Human liver ; Electron microscopy ; Stereology
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Medizin
    Notizen: Summary The stereologioal model and the base-line data of normal human liver needle biopsy-specimens are presented. Four reference systems were introduced: 1 cm3 of liver tissue, 1 cm3 of hepatoeyte, 1 cm3 of hepatocytic cytoplasm and the volume of an average “mononuclear” hepatocyte. The sampling was done at three levels of magnification (1,000 ×, 5,000 × and 10,000 ×). A lobular differentiation was not considered. The baseline data show strikingly small variations (s.e. less than 10%) within the individual biopsy specimen and within the group of four biopsies. There is no principal difference between human beings presented here, rats, mice and dogs. Only the mean individual volume of human hepatocytes is clearly larger than in rodents. The problems and limitations of stereological work on liver biopsy specimens are discussed.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/BF00433072
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  • 78
    Digitale Medien
    Digitale Medien
    Hairy cell leukemia (1976)
    Springer
    Virchows Archiv 370 (1976), S. 273-289 
    Details
    ISSN: 1432-2307
    Schlagwort(e): Bone marrow biopsy ; Hairy cell leukemia ; Differential diagnosis ; Myelofibrosis ; Electron microscopy
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Medizin
    Notizen: Summary In 24 patients with hairy cell leukemia, histological and fine structural findings from biopsies of the bone marrow are reported and their validity is compared with other diagnostic procedures available. Diagnosis by light microscopy of anterior iliac crest biopsies obtained by the method of myelotomy is possible with a high degree of accuracy. The differentiation of hairy cell leukemia from other myelo- or lymphoproliferative disorders based on cytomorphology as well as patterns of growth is emphasized. Morphological differences between fibrosis in this entity and other lesions such as malignant lymphomas, Hodgkin's disease, osteomyelofibrosis and -sclerosis are emphasized. Electron microscopy of the bone marrow shows single fibroblastic cells with numerous slender cytoplasmic processes randomly dispersed among the hairy cells. These fibroblasts are probably responsible for the synthesis of the reticulin and collagen fibres in their surroundings. Moreover fine structure of the hairy cells demonstrates pinocytic activity but no apparent phagocytosis in contrast to the phagocytic reticulum cells (histiocytes, macrophages). In the bone marrow the precursor cells and the many immature forms of hairy cells exhibit an overall lymphocytoid appearance during their maturation, suggesting a lymphocytic origin.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/BF00445773
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  • 79
    Digitale Medien
    Digitale Medien
    Experimentell induzierte Herzmuskelfasernekrosen nach Praemedikation mit Strophanthin (1976)
    Springer
    Virchows Archiv 370 (1976), S. 141-150 
    Details
    ISSN: 1432-2307
    Schlagwort(e): Angiotensin ; Catecholamine ; Strophanthin ; Rat heart ; Myocardial necroses ; Optical microscopy ; Electron microscopy
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Medizin
    Beschreibung / Inhaltsverzeichnis: Zusammenfassung Bei der Ratte nehmen die durch Angiotensin induzierten Herzmuskelfasernekrosen (75 mg/kg s.c. und i.p.) unter Strophanthin-Praemedikation (2 × 10−2 mg/kg i.p.) an Zahl und Ausmaß ab. Darüberhinaus ändert sich der elektronenmikroskopische Befund: Die alleinige Gabe von Angiotensin bewirkt eine Vakuolisation der Mitochondrion und eine Dilatation des endoplasmatischen Reticulum ohne Alteration der Myofibrillen. Die kombinierte Gabe von Strophanthin und Angiotensin führt zu einer primären Zerstörung der Myofibrillen, ohne daß Mitochondrien und tubuläres System sichtbar verändert werden. Der Schutzmechanismus des Strophanthin wird im Sinne einer Ökonomisierung des Zellstoffwechsels bei relativer coronarieller Insuffizienz diskutiert, welche durch die starke vasokonstriktorische Wirkung des Angiotensin ausgelöst wird.
    Notizen: Summary Number and degree of angiotensin-induced heart muscle necroses in the rat (75 mg/kg body weight) are diminuished by premedication with strophanthin (2 × 10−2 mg/kg body weight). The electron-microscopic findings are also changed: the application of angiotensin only results in vacuolization of mitochondria and a dilatation of the endoplasmatic reticulum while myofibrils are unaltered. Angiotensin in combination with strophanthin has a direct destructive effect on the myofibrils without evident changes of the mitochondria and the tubular system of the heart. The protective action of Strophanthin on the heart muscle cell is discussed in the sense of an economization of the cellular metabolism under conditions of relative coronary insufficiency, induced by the vasoconstructive effect of angiotensin.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/BF00430810
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  • 80
    Digitale Medien
    Digitale Medien
    On the fungitoxicity of some new thiocyanatopyrazole derivatives: Electron microscopical study in trichophyton mentagrophytes (1976)
    Springer
    Mycopathologia 58 (1976), S. 39-47 
    Details
    ISSN: 1573-0832
    Schlagwort(e): Trichophyton mentagrophytes ; Thiocyanatopyrazole derivatives ; Electron microscopy
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie , Medizin
    Notizen: Abstract Four thiocyanatopyrazole derivatives were synthesized and their fungistatic activity was demonstrated in vitro against a number of dermatophytic fungi. In Trichophyton mentagrophytes, the most active compound induced an unusual increase of the plasma membrane with production of intra and extracytoplasmic complexes, a deterioration of nuclear and mitochondrial membranes and a formation of autophagic-like vacuoles. Plasmolysis, accompanied by an almost complete disorganization of cytoplasmic structures, seemed to be the final event. A possible mechanism of action of the compounds was discussed.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/BF00493592
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  • 81
    Digitale Medien
    Digitale Medien
    Ultrastructure of the labyrinth in the rat full-term placenta (1976)
    Springer
    Anatomy and embryology 149 (1976), S. 123-148 
    Details
    ISSN: 1432-0568
    Schlagwort(e): Rat-placenta ; Gap junctions ; Electron microscopy ; Freeze-fracturing
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Medizin
    Notizen: Summary The placental labyrinth of the chorioallantoic placenta of the rat was studied with transmission and scanning electron microscopy. Full-term placentas were investigated after perfusion fixation from the maternal and fetal circulation, including thin-sectioning and freeze-fracturing. The labyrinthal three-dimensional structure was found not to be trabecular but spongious lamellar. We propose a division of the lamellae into three groups—the first, second, and third order. The trophoblastic layers are described in detail, showing a cellular layer I and two syncytial layers II and III. Layer I is found to be fenestrated and highly permeable. Layers II and III are connected by extended gap junction areas. It is suggested that the gap junctions function as a molecular sieve and represent the limiting barrier in diaplacental transport of the choriollantoic placenta. Fetal capillaries are fenestrated and endothelial cells are connected by tight junctions. The functional significance of the morphologic findings is discussed.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/BF00317893
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  • 82
    Digitale Medien
    Digitale Medien
    Ultrastructure of Lewy bodies in the stellate ganglion (1976)
    Springer
    Acta neuropathologica 34 (1976), S. 183-197 
    Details
    ISSN: 1432-0533
    Schlagwort(e): Lewy body ; Electron microscopy ; Parkinsonism ; Dense core vesicles ; Catecholamines ; Mitochondrial inclusions
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Medizin
    Notizen: Summary The Lewy body, a characteristic nerve cell inclusion in idiopathic parkinsonism, was examined by electron microscopy in the stellate ganglion, obtained from 9 patients at autopsy. Three main forms of Lewy bodies or Lewy body-related structures were demonstrated: A. Rare filamentous Lewy bodies, similar to Lewy bodies in the central nervous system. B. Granular Lewy bodies in nerve cell processes. C. Abnormal nerve cell processes, filled with heterogenous material. Large dense core vesicles were prominent in the last 2 forms. None of these abnormalities were found in 2 control groups consisting of 9 parkinsonism cases without central nervous system Lewy bodies, and 17 cases without parkinsonism. The filamentous Lewy body (type A) was found in the perikaryon and was surrounded by neuromelanin, whereas the other forms (type B and C) were seen in nerve cell processes. Mitochondrial inclusions, present mainly, but not exclusively, in neuromelanin-containing cells, were not related to Lewy body formation or to parkinsonism.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/BF00688674
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  • 83
    Digitale Medien
    Digitale Medien
    Damage of skeletal muscle in rats by immunoglobulins (1976)
    Springer
    Acta neuropathologica 34 (1976), S. 207-218 
    Details
    ISSN: 1432-0533
    Schlagwort(e): Immunomyopathy ; Muscle disease ; Electron microscopy ; Experimental muscle pathology
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Medizin
    Notizen: Summary An experimental model of the autoimmune process was developed to study the ultrastructural aspects of immunomyopathies. Every type of muscle fibre organelle was affected and the severity of injury increased in direct proportion to time following immunization. It is suggested that ultrastructural methods are useful in studies concerned with the analysis of structural aspects of experimental immunomyopathies.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/BF00688676
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  • 84
    Digitale Medien
    Digitale Medien
    In vitro characteristics of a sacrococcygeal chordoma maintained in tissue and organ culture systems (1976)
    Springer
    Acta neuropathologica 35 (1976), S. 13-25 
    Details
    ISSN: 1432-0533
    Schlagwort(e): Chordoma ; Tissue and organ culture ; Electron microscopy
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Medizin
    Notizen: Summary Explants of a human sacral chordoma were successfully maintained on collagen-coated coverslips, gelfoam sponge matrices, and Millipore filter platforms for up to 30 days. Tumor cells cultured on collagen-coated coverslips became increasingly vacuolated whereas those maintained in organ culture were entirely free of vacuoles after 22 days in vitro. A single basic tumor cell, small and polygonal with a large central spherical nucleus and abundant endoplasmic reticulum and Golgi apparatus, was recognized. Vacuoles were formed as the result of the progressive expansion of smooth endoplasmic reticulum. Coalescence of these vacuoles produced the physaliferous cell of light microscopy.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/BF00688940
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  • 85
    Digitale Medien
    Digitale Medien
    Esthésioneurocytome olfactif (1976)
    Springer
    Acta neuropathologica 35 (1976), S. 139-150 
    Details
    ISSN: 1432-0533
    Schlagwort(e): Electron microscopy ; Olfactory esthesioneurocytoma ; Neurosecretory granules ; Microtubules ; Dystrophic axons
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Medizin
    Notizen: Summary One case of malignant tumour of the left nasal cavity is reported in a woman 56 year old, affected by the disease 24 years. Numerous recurrences appeared and various histological diagnoses were performed. At the last surgery, the tumour invaded the ethmoïd and was a typical olfactory esthesio-neurocytoma. By electron microscopy, mature ganglion cells with dense cored vesicles (neurosecretory granules) were densely packed. Neuritic processes with microtubules were rarely normal in size and their content was most often abnormal; furthermore dystrophic axons were noted in great number.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/BF00690560
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  • 86
    Digitale Medien
    Digitale Medien
    Light and electron microscopic investigations on a transplantable tumour of the rat, induced by transplacental administration of ENU (ethylnitrosourea) (1976)
    Springer
    Acta neuropathologica 36 (1976), S. 177-184 
    Details
    ISSN: 1432-0533
    Schlagwort(e): Neurinoma ; ENU ; Prenatal carcinogenesis ; Transplantability ; Metastases ; Electron microscopy
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Medizin
    Notizen: Summary With a single dose of 80 mg/kg ENU, a tumour originating from the trigeminal nerve was induced transplacentally in the offspring of a Sprague-Dawley rat. The neoplasm diagnosed as a neurinoma, was transplanted over 20 passages to 5 six-month-old Sprague-Dawley rats in each case. During this time, the biological behaviour of the tumour as well as its histological appearance were followed. Ultrastructural observations were made of the 20th passage. The tumour caused multiple metastases in the lung and in the lymph nodes of the neck in 30 animals. Recurrences were formed within a week, metastases of the lung appeared from then on in all cases. During the time of transplantation, the neurinoma dedifferentiated histologically so markedly that it was no longer possible to classify the neoplasm as a neurogenous tumour after 20 passages. Ultrastructurally, poorly differentiated Schwann cells could nervetheless be recognized.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/BF00685279
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  • 87
    Digitale Medien
    Digitale Medien
    “PKU Bodies”: Characteristic inclusions in the brain in phenylketonuria (1976)
    Springer
    Acta neuropathologica 36 (1976), S. 295-305 
    Details
    ISSN: 1432-0533
    Schlagwort(e): PKU bodies ; Demyelination ; Dysmyelination ; Neuroglia ; Inborn errors of metabolism ; Phenylketonuria ; Electron microscopy
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Medizin
    Notizen: Summary The ultrastructure of various inclusions within oligodendroglial cells in the brains from two phenylketonuric patients was studied. Characteristic lamellar, oval, slightly irregular inclusions measured between 0.5 and 2 micra in diameter and were bounded by a single membrane. The longitudinal and transverse lamellae of these inclusions had a distinct pattern. In analogy to lamellated but different inclusions of other diseases, these structures were termed “PKU bodies”. Various possibilities that would explain the morphogenesis of the PKU bodies and other inclusions in the oligodendroglial cells, and the significance of these findings, are discussed.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/BF00699635
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  • 88
    Digitale Medien
    Digitale Medien
    Sequence of morphological alterations in the nervous system of metachromatic leucodystrophy (1976)
    Springer
    Acta neuropathologica 36 (1976), S. 369-379 
    Details
    ISSN: 1432-0533
    Schlagwort(e): Leukodystrophy, metachromatic ; Prenatal diagnosis ; Sulphatide accumulation ; Myelination, central, peripheral ; Electron microscopy
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Medizin
    Notizen: Summary Light and electronmicroscopic findings are reported in a case of metachromatic leukodystrophy diagnosed prenatally who died after iatrogenic abortion during the 23th week of gestation. The brain of this foetus was not yet myelinated while the spinal cord showed early, and the peripheral nerves advanced myelination. The onset and the degree of myelination were similar as in a normal foetus of the same age. Ultrastructurally there was evidence of sulphatide storage before the beginning of myelination. During myelination lysosomal storage material, staining metachromatically in acid cresyl violet preparations, appeared in oligodendrocytes and Schwann cells. Besides sulphatide storage material, prominent amounts of neutral lipids were found in oligodendrocytes. Myelin breakdown was encountered very seldom.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/BF00699642
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  • 89
    Digitale Medien
    Digitale Medien
    Development of onion bulb neuropathy in the Trembler mouse (1976)
    Springer
    Acta neuropathologica 36 (1976), S. 137-152 
    Details
    ISSN: 1432-0533
    Schlagwort(e): Trembler mouse ; Peripheral neuropathy ; Electron microscopy ; Morphometry
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Medizin
    Notizen: Summary The Trembler mouse is a neurological mutant showing dominant inheritance. The peripheral nerves show a delay in myelination, segmental demyelination and the development of an onion bulb neuropathy. Using electron microscopy a comparative morphometric study of nerve fibres in the sciatic nerve in normal and Trembler mice was made. The animals ranged in age from 3 days to adult. The following features were noted: 1. Mean axon diameters of the Trembler mice were smaller than normal at all ages. 2. Myelination was delayed and myelin was thinner than normal in the Trembler mice. 3. The ratio of myelin thickness to axon diameter was reduced in Trembler mice. 4. There were no significant quantitative or qualitative differences observed between middle and distal levels of Trembler nerves. The balance of evidence from these findings and the previous morphological studies is in keeping with the suggestion that the primary lesion resides in the Schwann cell.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/BF00685276
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  • 90
    Digitale Medien
    Digitale Medien
    The target phenomenon in human muscle (1976)
    Springer
    Acta neuropathologica 34 (1976), S. 329-338 
    Details
    ISSN: 1432-0533
    Schlagwort(e): Muscle pathology ; Target muscle fibre ; Targetoid muscle fibre ; Histochemistry ; Electron microscopy
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Medizin
    Notizen: Summary A large number of target fibres is observed in a muscle biopsy from a patient with an acute flaccid paraplegia of the lower limbs due to a polyneuroradiculopathy of unknown origin. With the electron microscope up to 4 structural zones are seen in the target fibers. The histochemical and ultrastructural observations in this case, suggest that the “target fibre” phenomenon is due to a disturbed trophic influence of the nervous system.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/BF00696562
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  • 91
    Digitale Medien
    Digitale Medien
    Morphological differences between the atrophied small muscle fibres in amyotrophic lateral sclerosis and Werdnig-Hoffmann disease (1976)
    Springer
    Acta neuropathologica 34 (1976), S. 321-327 
    Details
    ISSN: 1432-0533
    Schlagwort(e): Muscle fibres ; Amyotrophic lateral sclerosis ; Werdnig-Hoffmann disease ; Electron microscopy
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Medizin
    Notizen: Summary Muscle biopsies from 5 cases of Werdnig-Hoffmann disease and 4 cases of ALS were investigated by histology and electronmicroscopy. The differences in morphology found in the atrophic muscle fibres in ALS and in W.H. diesease consisted mainly in the shape and structure of their cells and the number of the nuclei. Atrophic muscle fibres irregular in shape and size with degenerative changes and accumulated nuclei observed in ALS were markedly different from the picture of the fibres in W.H. disease. The presence of small muscle cells uniform diameter with well preserved architecture and single nuclei and numerous myotube-like cells seem to indicate a foetal defect in children with W.H. disease.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/BF00696561
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  • 92
    Digitale Medien
    Digitale Medien
    Renflement fusiforme d'origine mécanique d'un nerf périphérique. Étude anatomique (1976)
    Springer
    Acta neuropathologica 35 (1976), S. 47-54 
    Details
    ISSN: 1432-0533
    Schlagwort(e): Entrapment neuropathy ; Fusiform nerve enlargement ; Segmental demyelination ; Axonal changes ; Electron microscopy
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Medizin
    Notizen: Summary This paper reports on the study of a symptomless fusiform enlargement of the superficial peroneal nerve. The swelling was located in the part of the nerve passing through the aponevrosis. On incision of the epineurium small swellings were seen in the nerve fascicles. A fascicular biopsy was done and the fascicles studied by teasing and by optic and electron microscopy. Isolated nerve fiber study gave evidence of segmental demyelinisation with subsequent remyelinisation in almost all the myelinated fibers. These abnormalities were only encountered in the swollen part of the fascicle. A striking proliferation of cells was demonstrated in isolated fibers by counter-staining with hematoxylin. Electron microscopy showed primary demyelinsation and cellular proliferation affecting Schwann-cells (without onion bulb formations), fibroblasts and giant-vacuolated histiocytes. There was also a massive increase of endoneurial fluid. A few Büngner bands were seen. These rare abnormalities appear to be caused by chronic irritation of the nerve in its passage through the aponebrosis.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/BF00688942
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  • 93
    Digitale Medien
    Digitale Medien
    Studies on experimental malignant nerve sheath tumors maintained in tissue and organ culture systems (1976)
    Springer
    Acta neuropathologica 35 (1976), S. 27-45 
    Details
    ISSN: 1432-0533
    Schlagwort(e): Experimental malignant Schwannomas ; Melanin and melanogenesis ; Tissue and organ culture ; Electron microscopy ; Pigmented nerve sheath tumors
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Medizin
    Notizen: Summary Four melanin pigment-containing intracranial tumors were found in three Long-Evans rats in the course of experimental oncogenesis by transplacental ethylnitrosourea (ENU). One of them was a leptomeningeal melanoma. Aside from the presence of scattered melanin-pigmented cells, the other three had the typical histological features of ENU-induced malignant nerve sheath tumors. Two of the three tumors were studied by electron microscopy and in tissue and organ culture systems. One of them demonstrated progressive melanogenesis in vitro; the other failed to produce more melanin and showed increasing differentiation, with a Schwannoma-like pattern by light microscopy. Melanosomes and premelanosomes were identified in both tumors by electron microscopy; the other fine structural features were those of malignant Schwannomas. These observations are relevant to the controversy on the histogenesis of pigmented nerve sheath tumors occasionally encountered in man and on the relationship of these tumors to pigmented nevi. The findings in the present study support the view of Masson that neoplastic nerve sheath cells are capable of melanogenesis.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/BF00688941
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  • 94
    Digitale Medien
    Digitale Medien
    Ultrastructure of the Gunn rat substantia nigra I. Cytoplasmic changes (1976)
    Springer
    Acta neuropathologica 35 (1976), S. 93-107 
    Details
    ISSN: 1432-0533
    Schlagwort(e): Substantia nigra ; Gunn rat ; Complex membranous bodies ; Bilirubin ; Electron microscopy
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Medizin
    Notizen: Summary The substantia nigra of various aged hyperbilirubinemic (Gunn) rats was studied by means of electron microscopy. The cytological features observed in the neuronal somata were the presence of (1) complex membranous bodies (CMBs), (2) dilated cisternae of granular endoplasmic reticulum, (3) single membrane bound vacuoles and (4) enlarged mitochondria. Nearly every neuronal soma studied in two week old Gunn rats contained CMBs, which consisted of several layers of membrane that usually, but not always, surrounded small islands of cytoplasm. On occasion CMBs were seen to be directly connected with granular endoplasmic reticulum and, in a few instances, they were located within a cistern of endoplasmic reticulum. There were significantly fewer CMBs in the neuronal somata of adult Gunn rats. They were located peripherally in the somata or in the proximal portions of dendrites. Furthermore, in these animals the cytoplasm appeared normal and did not exhibit the features commonly seen in younger animals. Only a few hyperchromatic neurons were observed and no pronounced gliosis was evident. Therefore it is assumed that the majority of substantia nigra neurons recovered from the toxic effect of bilirubin or that the concentration of bilirubin deposited in the substantia nigra is not sufficient to be lethal. The hypothesis that is considered is that CMBs represent autophagic activity which results from exposure of neurons to bilirubin. The adjacent neurites and glia did not demonstrate the cytoplasmic changes that were characteristic of the neuronal somata.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/BF00690556
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  • 95
    Digitale Medien
    Digitale Medien
    Whipple's disease of the central nervous system (1976)
    Springer
    Acta neuropathologica 36 (1976), S. 31-38 
    Details
    ISSN: 1432-0533
    Schlagwort(e): Whipple's disease ; Central nervous system ; Granulomatous infiltration ; Electron microscopy ; Bacillary bodies
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Medizin
    Notizen: Summary Whipple's disease presenting as a neurological disease without gastrointestinal symptoms is an unusual occurrence. A 40 year old man suffered hypersomnia, memory loss and progressive ophthalmoplegia for 6 months prior to death. The nature of his disease was not established during life. Extensive granulomatous inflammation affecting the hypothalamus, hippocampus and periaqueductal gray matter of the brain was found to represent Whipple's disease by electron microscopy. Characteristic lesions were also present in spleen, mesenteric lymph nodes, small intestine and myocardium. Bacillary bodies and membranous inclusions similar to those seen in visceral lesions of Whipple's disease were present in macrophages. The findings supported the theory of direct involvement of the central nervous system by bacilli rather than a metabolic origin for the lesions.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/BF00685145
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  • 96
    Digitale Medien
    Digitale Medien
    Studies on experimental malignant nerve sheath tumors maintained in tissue and organ culture systems II. Electron microscopy observations (1976)
    Springer
    Acta neuropathologica 34 (1976), S. 293-310 
    Details
    ISSN: 1432-0533
    Schlagwort(e): Experimental malignant Schwannomas ; Organ culture ; Electron microscopy ; Differentiation ; Microtubules ; Basal lamina ; Perineurial fibroblasts
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Medizin
    Notizen: Summary The sequential electron microscopic features of six malignant nerve sheath tumors (three cranial and three spinal) induced in rats by transplacental ethylnitrosourea and maintained in organ culture systems were compared with those of a human acoustic Schwannoma similarly cultured. After 4 weeks in vitro, the malignant tumor cells often showed progressive elongation of their processes, with the development of an interdigitating pattern resembling that seen in well-differentiated Schwannomas. This was accompanied by an increase of microtubules. Basal lamina formation, less well-developed and less complete than in the benign Schwannoma in this study, was maintained in culture. Some explants demonstrated an increase in number and width of collagen fibrils, accompanied by a relative concomitant decrease of intercellular basement membrane material. The malignant tumor cells also showed numerous micropinocytotic vesicles and various junctional complexes, which are characteristic of perineurial cells. Since the origin of the experimental tumors from adult Schwann cells seems well established, this apparent contradiction is best resolved by the concept that Schwann cells and perineurial fibroblasts are functional variants of the same cell type.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/BF00696559
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  • 97
    Digitale Medien
    Digitale Medien
    Vacuolation of oligodendroglia in neoplastic perifocal edema (1976)
    Springer
    Acta neuropathologica 35 (1976), S. 1-12 
    Details
    ISSN: 1432-0533
    Schlagwort(e): Cytoplasmic vacuole ; Oligodendroglia ; Brain edema ; Metastatic carcinoma ; Glioma ; Electron microscopy
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Medizin
    Notizen: Summary Vacuolation of oligodendroglia, a new type of cytopathological change, has been described. The change is observed frequently at the perifocally edematous cerebral white matter adjacent to the metastatic lesions of carcinoma from the lung in all three cases examined. It is also present occasionally in association with astrocytoma. This condition is characterized by swelling of oligodendroglias due to numerous cytoplasmic vacuolations which contain the material identical with that of the extracellular edema fluid. In such cells, the nucleus is displaced and deformed by vacuoles but the nuclear chromatin and envelopes are arranged normally. By occupation of numerous large vacuoles the cytoplasm is divided into small areas, but the individual organelles are only minimally altered. The oligodendroglial vacuolation seems to be a phagocytic response to the edema fluid which contains proteinous macromolecules derived from blood-borne protein and necrotic material of brain tissue and neoplastic cells. The vacuolation may result in some oligodendroglial dysfunction in maintenance of myelin and probably be related with diffuse loss of myelin sheath in the longstanding brain edema secondary to neoplastic invasion. The vacuolated cells can be identified with light and electron microscopes in Epon-embedded sections of surgically removed tissue but not in paraffin sections.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/BF00688939
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  • 98
    Digitale Medien
    Digitale Medien
    Dynamic aspects of peripheral nerve changes in progressive neural muscular atrophy (1976)
    Springer
    Journal of neurology 211 (1976), S. 111-124 
    Details
    ISSN: 1432-1459
    Schlagwort(e): Peripheral nerve ; Peroneal muscular atrophy ; Nerve biopsy ; Electron microscopy
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Medizin
    Beschreibung / Inhaltsverzeichnis: Zusammenfassung Bei 2 Patienten mit progressiver neuraler Muskelatrophie wurden Nervenbiopsien jeweils in einem frühen und in einem fortgeschrittenerem Stadium der Erkrankung entnommen und verglichen. In beiden Fällen zeigten bereits die frühen Biopsien ein völliges Fehlen der großkalibrigen, dickbemarkten Axone. Ebenfalls als frühe Veränderung wurde eine Erweiterung des endoneuralen Interstitiums festgestellt. Eine geringe Anzahl der vorhandenen bemarkten und unbemarkten Axone in allen Biopsien wies degenerative Veränderungen auf. Die für die progressive neurale Muskelatrophie typische Zwiebelschalenbildung der Schwannschen Zellen — möglicherweise eine Reaktion auf wiederholte De-und Remyelinisierungsvorgänge um dystrophische Axone — trat erst in den späteren Biopsien deutlicher hervor. Hinsichtlich der formalen Genese der hypertrophischen Neuropathie bei neuraler Muskelatrophie sind nach diesen Beobachtungen axonale Dystrophie und interstitielle Veränderungen des Endoneuriums als primäre Entmarkung und Zwiebelschalenbildung als sekundäre Phänomene zu betrachten. Die Möglichkeit einer kausalen Beziehung zwischen axonaler Dystrophie und interstitiellen Veränderungen wird an Hand der vorliegenden Befunde und Literatur diskutiert.
    Notizen: Summary Serial nerve biopsies were performed at an early, and at an advanced stage of the disease in 2 patients with progressive neural muscular atrophy. The early biopsy showed a complete loss of the large diameter and thickly myelinated fibres, as well as an expansion of the endoneurial interstitium in both cases. Myelinated and unmyelinated fibres exhibited axonal degeneration in all biopsies occasionally. “Onion bulb” formation, a typical feature of peripheral neuropathy in neural muscular atrophy, was found to be prominent only in the latter biopsies. As regards the formal pathogenesis of hypertrophic neuropathy in neural muscular atrophy, axonal dystrophy and interstitial changes of the endoneurium were regarded as primary phenomena, demyelination and “onion bulb” formation as secondary. A possible causal relation between axonal dystrophy and interstitial changes, observed in these cases, is discussed in the light of the present literature.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/BF00313355
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  • 99
    Digitale Medien
    Digitale Medien
    Purification, some properties and quaternary structure of thed-ribulose 1,5-diphosphate carboxylase ofAlcaligenes eutrophus (1976)
    Springer
    Archives of microbiology 110 (1976), S. 157-166 
    Details
    ISSN: 1432-072X
    Schlagwort(e): d-Ribulose 1,5-diphosphate carboxylase ; Oxygenase activity ; Quaternary structure ; Electron microscopy ; Alcaligenes eutrophus
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie
    Notizen: Abstract d-Ribulose 1,5-diphosphate carboxylase has been purified from autotrophically grown cells of the facultative chemolithotrophic hydrogen bacteriumAlcaligenes eutrophus. The enzyme was homogeneous by the criteria of polyacrylamide gel electrophoresis. The molecular weight of the enzyme was 505000 determined by gel filtration and sucrose density gradient centrifugation, and a sedimentation coefficient of 18.2 S was obtained. It was demonstrated by sodium dodecyl sulphate-polyacrylamide gel electrophoresis that the enzyme consists of two types of subunits of molecular weight 52000 and 13000. Electron microscopy on the intact and the partially dissociated enzyme lead to the construction of a model for the quaternary structure of the enzyme which is composed of 8 large and 8 small subunits. The most probable symmetry of the enzyme molecule is 4:2:2. Michaelis constant (K m ) values for ribulose 1,5-diphosphate, Mg2-, and CO2 were 0.59 mM, 0.33 mM, and 0.066 mM measured under air. Oxygen was a competitive inhibitor with respect to CO2 suggesting that the enzyme also exhibits an oxygenase activity. The oxygenolytic cleavage of ribulose 1,5-diphosphate was shown and a 1:1 stoichiometry between oxygen consumption and 3-phosphoglycerate formation observed.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/BF00690223
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  • 100
    Digitale Medien
    Digitale Medien
    Physiology and fine structure of sporangiospore germination in Piptocephalis unispora prior to infection (1976)
    Springer
    Archives of microbiology 107 (1976), S. 99-107 
    Details
    ISSN: 1432-072X
    Schlagwort(e): Piptocephalis unispora ; Mucorales ; Kickxellaceae ; Electron microscopy ; Germination ; Spore swelling ; Sporangiospore
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie
    Notizen: Abstract Germination of the sporangiospore of Piptocephalis unispora Benjamin, observed by means of light and electron microscopy, involved the formation of a new inner wall which became continous with the inner layer of the wall of the germ tube. The outer wall layer of the germ tube was continous with the original inner wall layer of the dormant spore. Preliminary details of appressorium structure were noted. Nutritional experiments indicated that sporangiospores required external sources of utilisable nitrogen and carbon compounds for maximal swelling and germ tube production. Limited development occurred when either nutrient was supplied singly. Comparison of germination of the asexual spore with that in other Mucorales, especially the Kickxellaceae, has been made, and the merosporangial status in P. unispora discussed.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/BF00427874
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