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  • 1985-1989  (695)
  • 1975-1979  (1,153)
  • Ultrastructure  (951)
  • Electron microscopy  (906)
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Year
Keywords
  • 1
    Electronic Resource
    Electronic Resource
    Co-localization of islet amyloid polypeptide and insulin in the B cell secretory granules of the human pancreatic islets (1989)
    Springer
    Diabetologia 32 (1989), S. 240-244 
    Details
    ISSN: 1432-0428
    Keywords: Islet amyloid polypeptide ; Pancreatic islets ; B cells ; Ultrastructure ; Immunocytochemistry
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary Islet amyloid polypeptide is a novel 37 amino-acid-residues polypeptide which has been isolated from amyloid deposits in an insulinoma, and in human and cat islets of Langerhans. The molecule has 46% homology with the calcitonin gene-related peptide. Light microscopy examination of the pancreas shows that islet amyloid polypeptide immunoreactivity is restricted to the islet B cells. The present study utilized a rabbit antiserum against a synthetic peptide corresponding to positions 20–29 of islet amyloid polypeptide, a sequence without any amino-acid identity with calcitonin gene-related peptide. By applying the immunogold technique at the ultrastructural level, it was shown that both insulin and islet amyloid polypeptide immunoreactivity occurs in the central granular core of the human B cell secretory granules, while the A cells remain unlabelled. The demonstration that islet amyloid polypeptide is a granular protein of the B cells may indicate that it is released together with insulin. Further studies are necessary to evaluate the functional role of islet amyloid polypeptide.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00285291
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  • 2
    Electronic Resource
    Electronic Resource
    Yolk organelles and their membranes during vitellogenesis ofXenopus oocytes (1989)
    Springer
    Development genes and evolution 198 (1989), S. 92-102 
    Details
    ISSN: 1432-041X
    Keywords: Vitellogenesis ; Xenopus oocyte ; Yolk-platelet membrane ; Ultrastructure
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Summary The yolk platelets ofXenopus laevis have been studied by thin-section and freeze-fracture electron microscopy to characterize the boundary membrane during yolk formation. Throughout vitellogenesis, large yolk platelets are in close contact with smaller nascent yolk organelles. Two types of primordial yolk platelets (I and II) have been discriminated. After membrane fusion these precursors can be completely incorporated into the main body of existing platelets, numerous yolk crystals then merge and form one uniformly stratified core. Lipid droplets are tightly attached to the membrane at all developmental stages of yolk platelets. A direct connection of endoplasmic reticulum to the membranes of yolk platelets was not observed. On freezeetching replicas, yolk-platelet membranes present fracture faces with intramembranous particles (IMP) of various sizes and a heterogeneous distribution of approximately 200–600 IMP/μm2 at the E face, and 1200–2100 IMP/μm2 at the P face. Again, this presentation of the membrane exhibits neither anastomoses to the endoplasmic reticulum, nor caveolae that exclude the uptake of yolk-containing vesicles into these yolk organelles. Proteinaceous yolk platelets tend to fracture along their periphery through the superficial layers.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF02447744
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  • 3
    Electronic Resource
    Electronic Resource
    Ultrastructure of the pineal gland of the monkey, Macaca fascicularis, with special reference to the presence of synaptic junctions on pinealocytes (1989)
    Springer
    Anatomy and embryology 180 (1989), S. 151-158 
    Details
    ISSN: 1432-0568
    Keywords: Monkey ; Ultrastructure ; Pinealocytes ; Axon terminals ; Synapses
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary The present study described the normal ultrastructure of the monkey pineal gland. The gland was composed of the principal pinealocytes, intramural neurons and glial cells. The nucleus of the pinealocytes was deeply infolded with evenly distributed chromatin materials. The abundant cytoplasm was rich in organelles including the well-developed Golgi apparatuses, multivesicular bodies, dense-cored vesicles and widely scattered free and polyribosomes. A variety of axon terminals was observed and the majority of them contained pleomorphic agranular vesicles with a few large dense-cored vesicles. A few terminals showed flattened vesicles or small dense cored vesicles. Some of the axon terminals formed synaptic contacts with the cell bodies of pinealocytes. These synapses were mainly concentrated in the posterior third of the gland. The occasional intramural neurons observed were postsynaptic to axon terminals containing round agranular vesicles. The sources of the nerve fibres and terminals forming synaptic junctions with pinealocytes and intramural neurons were discussed.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00309766
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  • 4
    Electronic Resource
    Electronic Resource
    Diffusion barrier properties of the perineurium: an in vivo ionic lanthanum tracer study (1989)
    Springer
    Anatomy and embryology 180 (1989), S. 237-242 
    Details
    ISSN: 1432-0568
    Keywords: Perineurium ; Lanthanum ; Diffusion barriers ; In vivo ; Electron microscopy
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary While the perineurium as a diffusion barrier has been extensively investigated by light and electron microscopy, copy, such studies have been largely restricted to the use of protein tracers. In the present study the permeability of the perineurium to a physiologically more relevant ionic tracer has been assessed. In vivo the rat sural or tibial nerve was either microinjected with lanthanum nitrate solution for endoneurial application or bathed in the lanthanum solution for epineurial application. The findings generally demonstrated an effective barrier to the tracer which failed to penetrate the inner layers of the perineurium. Only at the highest lanthanum concentration and longest time intervals employed did trace quantities occasionally penetrate the barrier and then only in the presence of some cytopathological changes to the outermost perineurial cells. The usefulness of the microinjection method was limited by the slight but unavoidable trauma to the perineurium. The findings are related to those of other studies which have used electron dense tracers, also to studies using physiological including electrophysiological techniques and morphological including freeze-fracture methods.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00315882
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  • 5
    Electronic Resource
    Electronic Resource
    Measurements of the DNA amount in mono- and binucleate cells in the celiac superior mesenteric ganglion of the guinea pig (1989)
    Springer
    Anatomy and embryology 179 (1989), S. 587-590 
    Details
    ISSN: 1432-0568
    Keywords: Sympathetic ganglion ; Binucleate cells ; Ultrastructure ; Feulgen staining ; Computerized image analysis ; DNA
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary The relative proportion, ultrastructure and DNA-content of the binucleate cells in the celiac superior mesenteric ganglion of the guinea pig was studied using light and electron microscopy as well as computerized image analysis of Feulgen stained cells. The number of mono — versus binucleate cells was found to vary with stage of development with about 40% of the cells being binucleate in adult animals and 50% in late prenatal stage. No difference in ultrastructure was observed between the nuclei of the two cell types. The binucleate cells contain twice the amount of DNA found in the mononucleate cells.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00315700
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  • 6
    Electronic Resource
    Electronic Resource
    On the presence of reciprocal synapses in the paratympanic organ of the chicken (1989)
    Springer
    Anatomy and embryology 180 (1989), S. 175-178 
    Details
    ISSN: 1432-0568
    Keywords: Paratympanic organ ; Reciprocal synapses ; Ultrastructure
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary The innervation pattern of the paratympanic organ was studied by TEM. The paratympanic organ is a small tapering vesicle, typical of birds, situated in the medial wall of the tympanic cavity; it contains hair cells which are similar to type II receptors of the acoustic-lateral system; these cells are characterised by synapses which are not only afferent and efferent, as previously described, but also reciprocal with efferent fibers. Our observation revealed some efferent nerve fibers which form a relationship with hair cells containing synaptic bodies situated next to the plasma membrane and near the fibers themselves. Since synaptic bodies are commonly considered to be the site where the transmission of the impulse from the receptor to the nerve fiber takes place, our pictures suggest that the efferent fibers and hair cells may be either presynaptic or postsynaptic with respect to each other in the paratympanic organ. The hypothesis is formulated that reciprocal synapses allow interaction between hair cells, thus determining an increase in the contrast of information sent by the paratympanic organ to the CNS.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00309769
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  • 7
    Electronic Resource
    Electronic Resource
    Synaptogenesis in the dorsal lateral geniculate nucleus of the rat (1989)
    Springer
    Anatomy and embryology 180 (1989), S. 243-257 
    Details
    ISSN: 1432-0568
    Keywords: Dorsal lateral geniculate nucleus ; Synapse formation ; Synaptic glomerulus ; Rat ; Electron microscopy
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary Synapse formation and maturation were examined in the rat dorsal lateral geniculate nucleus (dLGN) from birth to adulthood. Examination of animals, whose ages were closely spaced in time, showed that the maturation of the synaptic organization of the nucleus takes place chiefly during the first 3 weeks of postnatal life. This period of maturation may be divided into 3 broad stages. During the first stage, which spans the first 4 days of life, there are only a few immature synapses scattered throughout the nucleus; occasionally aggregates of 3 or 4 synapses are encountered. Dendrodendritic synapses first appear at the end of this stage. The second stage, which lasts from the end of the first stage through day 8, is characterized by intensive synaptogenesis as well as extensive growth and degeneration. For the first time, large boutons resembling retinal terminals form multiple synaptic contacts with dendrites and dendritic protrusions; these synaptic arrangements are partially covered by glial processes. A feature characteristic of the developing dLGN during the first 2 postnatal weeks, and particularly during the second stage, is the presence of membrane specializations that resemble vacant postsynaptic densities. These specializations, which may be unapposed or opposite another neuronal process, decrease in frequency as the number of synapses increases. It is not known whether these densities are converted to synapses or whether they result from loss of presynaptic elements. The third stage in the process of synaptogenesis, which spans a period between days 10 and 20, is characterized by myelination and by the diminution of growth cones, degenerating profiles and vacant postsynaptic densities. There is also a very significant increase in the number and maturation of synapses including synaptic glomeruli. However, it is not until the end of this stage that synapses appear qualitatively indistinguishable from synaptic arrangements identified in adult animals.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00315883
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  • 8
    Electronic Resource
    Electronic Resource
    Myelin breakdown in the posterior funiculus of the kitten after dorsal rhizotomy (1989)
    Springer
    Anatomy and embryology 180 (1989), S. 273-280 
    Details
    ISSN: 1432-0568
    Keywords: Wallerian degeneration ; Myelin breakdown ; Light microscopy ; Electron microscopy ; Marchi staining
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary Morphological aspects of myelin breakdown in the posterior funiculus during Wallerian degeneration were studied in kittens subjected to lumbosacral dorsal rhizotomies 6–8 days after birth. The first sign of myelin breakdown was characterized by swollen or shrunken nerve fibers. Shortly thereafter there was an increased occurrence of collapsed myelin sheaths and later of rounded myelin bodies. Myelin was clearly seen in microglial cells. Correlative observations on Marchi-stained material indicated the simultaneous and frequent appearance of Marchi-positive bodies (MPB:s) and myelin bodies. Due to the rapidity of the degeneration process in the kitten, the increase in the occurrence of Marchi-positive granules (MPG:s) seemed to start concomitantly with increased occurrence of MPB:s. However, the frequent occurrence of MPG:s outlasted that for MPB:s. The findings indicate that the MPB:s may be the counterpart to myelin bodies and the MPG:s to lipid droplets. Microglial cells may be responsible for the primary uptake of degenerating myelin and the subsequent transformation of myelin bodies to lipid droplets. The much faster breakdown of myelin and elimination of lipid material in the degenerating posteror funiculus of the kitten, as compared to the adult, seemed to be due not only to the lower myelin content in the kitten, but also to a higher density of microglia and a greater efficiency in the myelin breakdown process in the degenerating posterior funiculus of the kitten.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00315885
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  • 9
    Electronic Resource
    Electronic Resource
    Fetal membranes and placenta of the african green monkey (Cercopithecus aethiops) (1989)
    Springer
    Anatomy and embryology 179 (1989), S. 591-604 
    Details
    ISSN: 1432-0568
    Keywords: Fetus ; Membranes ; Placenta ; Green monkey ; Ultrastructure
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary This study examined developmental changes in fetal membranes and placenta of Cercopithecus aethiops from a Carnegie developmental stage 12 embryo to nearterm fetuses. Ultrastructurally, yolk sac cells (endoderm and mesothelium) were similar to comparable stages in other primates. Endodermal cells had few apical microvilli, abundant rough-endoplasmic reticulum, electron dense mitochondria and dense bodies. In contrast, mesothelial cells were squamous with numerous microvilli, small mitochondria and a few short strands of rough endoplasmic reticulum. Amnion cells early in gestation were squamous with few microvilli, large glycogen deposits and poorly developed cytoplasmic components. Tight junctions and desmosomes held adjacent cells together. The basal surface was smooth and the basal lamina was distinct. As development proceeded the amniotic cells became cuboidal and possessed numerous microvilli. Cytoplasmic organelles were better developed and glycogen deposits increased by mid-gestation. A thick layer of microfibrils and collagen fibers was prominent below the basal lamina. Near-term, the glycogen had virtually disappeared and the amount of lipid droplets increased. Basal infoldings and podocytic processes and the extracellular matrix had increased. The smooth chorion consisted of pseudostratified columnar cells. Cells had short microvilli, numerous granules and vesicles of variable size and electron density in early gestation. With increasing age, amounts of granules and vesicles decreased, as the endoplasmic reticulum became prominent. The chorionic trophoblast was a continuous layer in mid-pregnancy and its cells had well-developed organelles and inclusions. Late in gestation, the trophoblastic layer became discontinuous and wide intercellular spaces and channels were present. In the placenta, the trophoblastic elements showed features characteristic of primate placenta.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00315701
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  • 10
    Electronic Resource
    Electronic Resource
    A comparative ultrastructural study of in vivo versus in vitro fertilization of bovine oocytes (1989)
    Springer
    Anatomy and embryology 179 (1989), S. 435-442 
    Details
    ISSN: 1432-0568
    Keywords: Ultrastructure ; In vitro fertilization ; Bovine ; Ova ; Cortical granules
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary Heifers were superovulated by PMSG or FSH, and oestrus was induced by prostaglandin. One group of animals was ovariectomized 19–26 h after the LH peak, the content of preovulatory follicles aspirated, and the oocytes processed for in vitro fertilization. Another group was inseminated and ova were collected from the oviducts for study of in vivo fertilization. All ova were examined ultrastructurally. The developmental rate following in vitro fertilization was delayed compared to fertilization in vivo. A high proportion of the in vitro fertilized ova showed polyspermic penetration of the zona pellucida, and supernumerary spermatozoa were found in the ooplasm of some ova. In vivo fertilization was associated with release and subsequent dispersal of the cortical granule content in the perivitelline space. In contrast to this the released granule content of the in vitro fertilized ova remained undispersed close to the oolemma. This feature may account for the high incidence of polyspermic penetration of the zona pellucida. In addition, the study provided an ultrastructural visualization of the initial contact between the equatorial segment of the spermatozoon and the microvilli of the oocyte, and the subsequent internalization of the sperm head.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00319585
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  • 11
    Electronic Resource
    Electronic Resource
    Effects of continuous light on rat parotid gland structure and reactivity (1989)
    Springer
    Anatomy and embryology 179 (1989), S. 497-501 
    Details
    ISSN: 1432-0568
    Keywords: Parotid gland ; Ultrastructure ; Amylase ; Secretion ; Isoproterenol
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary The effects of continuous light on ultrastructural organization and sympathetic secretory responses of the rat parotid gland are reported. After 50 days of continuous light exposure, the fine structure of the parotid gland exhibited features of enhanced secretory activity as judged by the striking development of rough endoplasmic reticulum and Golgi complexes, the depletion of secretory granules and the increased turnover of secretory cells. The secretory responses of parotid gland to isoproterenol revealed that continuous light induced a 30% increase in amylase release. This secretory hyperactivity appears to be related to a postsynaptic supersensitivity of sympathetic fibers of the autonomic nervous system.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00319593
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  • 12
    Electronic Resource
    Electronic Resource
    Ultrastructural study of the endocrine cells of the gut of Testudo graeca (Chelonia) (1989)
    Springer
    Anatomy and embryology 180 (1989), S. 103-108 
    Details
    ISSN: 1432-0568
    Keywords: Ultrastructure ; Gut ; Endocrine cells ; Testudo graeca ; Chelonia
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary The digestive tract of Testudo graeca (Chelonia) was investigated by means of electron microscopy using both conventional and immunocytochemical techniques. EC-, L-, D-, G-, B-, N- and EC-L-cells were detected. These cells share several common ultrastructural characteristics with the endocrine cells of mammals (i.e. clear cytoplasm, prominent Golgi apparatus, secretory granules etc.). EC and D1 cells have so far not been described in the esophagus of any animal species; in the present study these cells have been observed in the esophagus of T. graeca. Of special interest was the presence of B-cells in the intestine, suggesting that the migration of B-cells from the gut to the pancreas to constitute pancreatic islets is not concluded in T. graeca. The present study demonstrates that the gut endocrine system of T. graeca is a complex structure containing a large variety of endocrine cell types similar in morphology to those found in higher vertebrates.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00321906
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  • 13
    Electronic Resource
    Electronic Resource
    Influence of conventionalization on cecal wall structure of germ-free Wistar rats: quantitative light and qualitative electron microscopic observations (1989)
    Springer
    Anatomy and embryology 180 (1989), S. 191-198 
    Details
    ISSN: 1432-0568
    Keywords: Cecum ; Germ-free rat ; Microflora inoculation ; Morphometry ; Ultrastructure
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary The structural changes of the cecal wall in germfree rats were observed at regular intervals after the inoculation of fecal microflora from conventional rats. Quantitative light microscopy showed that most of the elements in the cecal wall increased at 12 or 24 h and reached peak values at 4 days after inoculation. On the 7th day, they decreased approximately to the values for conventional rats. The crypts were bent or widely open till 24 h but were not after the 4th day. Hyperplasia of the crypt epithelial cells including mucous-type cells was observed following microbial inoculation. Electron microscopy revealed that most of the epithelial cells lining the mucosa were typical columnar cells. Desquamation of the epithelial cells and contraction of the muscle fibers were often seen on 4th day. The mucous-type cells were divided into two types, goblet and non-goblet mucous-type cells. Reduction of cecal volume after microbial inoculation may be mainly caused by muscle contraction in the early period and hyperplasia and desquamation of the epithelial cells may suggest their role as the first and non-specific defense line prior to operation of the specific immune system.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00309771
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  • 14
    Electronic Resource
    Electronic Resource
    Hypomyelination in the neonatal rat central and peripheral nervous systems following tellurium intoxication (1989)
    Springer
    Acta neuropathologica 78 (1989), S. 301-309 
    Details
    ISSN: 1432-0533
    Keywords: Schwann cell ; Oligodendrocyte ; Electron microscopy ; Myelin ; Optic nerve
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary Neonatal rats were exposed to Tellurium (Te), via the mother's milk, from the day of birth until sacrifice at 7, 14, 21, and 28 days of age. Light and electron microscopy revealed Schwann cell and myelin degeneration in the sciatic nerves at each age studied. These changes were similar to those described in weanling rats as a result of Te intoxication. In the CNS, hypomyelination of the optic nerves was convincingly demonstrated at 14, 21, and 28 days of age, accompanied by some evidence of myelin degeneration. These changes were also seen in the ventral columns of the cervical spinal cords, although less markedly, and were confirmed by quantitative methods. There was little evidence of oligodendrocyte pathology in the CNS, and it appears that degeneration of these cells is not the primary cause of the CNS hypomyelination, in contrast to the PNS where Schwann cell degeneration has been shown to precede the myelin pathology.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00687760
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  • 15
    Electronic Resource
    Electronic Resource
    Reappraisal of neurofibrillary tangles (1989)
    Springer
    Acta neuropathologica 77 (1989), S. 258-266 
    Details
    ISSN: 1432-0533
    Keywords: Neurofibrillary tangles ; Alzheimer's disease ; Pick bodies ; Immunohistochemistry ; Ultrastructure
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary We have studied the immunohistochemical reactivity and ultrastructure of both neurofibrillary tangles (NFTs) occurring with severe neurofibrillary diseases, and Pick bodies (PBs) associated with Pick's disease. The NFTs and PBs did not react immunohistochemically with the anti-nonphosphorylated neurofilament monoclonal antibody irrespective of whether they were pretreated with alkaline phosphatase. In granular neurons of the dentate fascia of Ammon's horn in cases of dementia of the Alzheimer type (DAT), NFTs either resembled PB-like inclusion bodies (Horoupian's inclusion bodies) in form, or had a perinuclear structure. Immunohistochemically and ultrastructurally, the NFTs in the dentate fascia in cases of DAT, including Horoupian's inclusion bodies, were similar to the NFTs in the pyramidal neurons of Ammon's horn, which are found most frequently in association with severe neurofibrillary diseases. Under a light microscope, Horoupian's inclusion bodies and PBs could not be differentiated and appeared to be argyrophilic round cytoplasmic inclusions in granular neurons of the dentate fascia. There were, however, ultrastructural differences. Horoupian's inclusion bodies consisted of bundles made up of straight tubules (STs), each about 15 nm in diameter. These bundles were intermixed with a few paired helical filaments which occurred at intervals of about 80 nm. On the other hand, PBs were composed of randomly distributed 15-nm-wide STs, intermixed with a very few fibrillary structures. These fibrils had a periodicity of about 160 nm, and ranged in width from about 15 nm to 30 nm. Horoupian's inclusion bodies associated with DAT and PBs associated with Pick's disease are different in this neuropathological aspect. The NFTs, including Horoupian's inclusion bodies in the dentate fascia in cases of DAT, are considered to be a manifestation of neurofibrillary degeneration.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00687577
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  • 16
    Electronic Resource
    Electronic Resource
    Pick bodies in the locus ceruleus (1989)
    Springer
    Acta neuropathologica 79 (1989), S. 10-17 
    Details
    ISSN: 1432-0533
    Keywords: Locus ceruleus ; Pick bodies ; Lewy bodies ; Immunocytochemistry ; Electron microscopy
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary In classical Pick's disease with typical Pick bodies, inclusions resembling those present in the cerebral cortex are frequently found in the locus ceruleus. In three such cases Pick bodies were studied by light and electron microscopy and compared with Lewy bodies, inclusions more commonly found in this location. In contrast to the situation in the cerebral cortex, nerve cells with multiple Pick bodies were often found in the locus ceruleus, but in other respects definite light and electron microscopic differences between Pick bodies and Lewy bodies were present. Pick bodies were slightly basophilic and never had a central core or a peripheral halo. They were intensely argyrophilic. Differences in immunocytochemical reactions were especially marked with antibodies to tau and to paired helical filaments. Pick bodies displayed an intense reaction with these two antibodies, contrasting with that of Lewy bodies, which either lacked reactivity or reacted in a peripheral band. By electron microscopy the Pick bodies were composed of random filaments with smooth contour, whereas typical Lewy bodies had fuzzy deposits on filaments that radiated from a central core. Pick bodies in the locus ceruleus therefore maintained their immunocytochemical and electron microscopic characteristics and did not take on the character of Lewy bodies. Such differences point to a different pathogenesis and perhaps etiology of these two types of inclusions and attest to the marked difference clinically and pathologically between Pick's and Parkinson's diseases.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00308950
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  • 17
    Electronic Resource
    Electronic Resource
    Malignant melanotic neuroectodermal tumor arising from the pineal body (1989)
    Springer
    Acta neuropathologica 77 (1989), S. 654-658 
    Details
    ISSN: 1432-0533
    Keywords: Melanotic neuroectodermal tumor ; Immunohistochemistry ; Ultrastructure ; Pineal origin
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary A case of a melanotic neuroectodermal tumor arising from pineal region of a 4-year-old girl is presented. The tumor had spread diffusely to the meninges, consistent with malignant behavior. Histologically, the tumor consisted primarily of epithelial elements arranged in tubules, cords and nests separated by fibrous vascular tissue in addition to a small neuroblastomatous focus. Melanin pigment was frequently observed in the epithelial tumor cells, and melanin-laden macrophages were also often observed. No teratoid elements were found. Immunohistochemically, tumor cells were positive for neuron-specific enolase but were nonreactive for S-100 protein, epithelial membrane antigen, glial fibrillary acidic protein, vimentin, α-fetoprotein and human chorionic gonadotrophin. Ultrastructurally, the epithelial nature of the tumor cells could be easily demonstrated. In addition, melanosomes in various stages in maturation were observed, indicating melanogenesis of the tumor. On the basis of the tumor location and the histological similarities previously observed for the fetal pineal body, it is very likely that this melanotic epithelial tumor could have originated from the fetal pineal gland.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00687894
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  • 18
    Electronic Resource
    Electronic Resource
    Electron microscopic and Golgi study in a case of hemimegalencephaly (1989)
    Springer
    Acta neuropathologica 77 (1989), S. 664-666 
    Details
    ISSN: 1432-0533
    Keywords: Hemimegalencephaly ; Golgi study ; Electron microscopy
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary Pathological findings in a case of hemimegalencephaly are presented. Hemispherectomy, performed because of intractable seizures, allowed an electron microscopic and Golgi study. Glial abnormalities consisted of hyperplasia of glia cells with giant astrocytes often containing several nuclei and proliferation of numerous Rosenthal fibers. Golgi stain showed many giant neurons with a perikaryon covered by perisomatic processes, and a complex dendritic tree. Glial abnormalities could be correlated with the firmness of the hemisphere and intense hypersignal on magnetic resonance imaging. Giant neurons were associated with an increase in size of the perikaryon and dendritic tree; this pattern suggests a polyploidy.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00687896
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  • 19
    Electronic Resource
    Electronic Resource
    Melanotic paraganglioma of the orbit: a case report (1989)
    Springer
    Acta neuropathologica 79 (1989), S. 340-346 
    Details
    ISSN: 1432-0533
    Keywords: Paraganglioma ; Melanin ; Orbit ; Immunocytochemistry ; Electron microscopy
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary A paraganglioma of the orbit in a 21-year-old woman is presented, containing oculo-cutaneous melanin in many tumor cells, occasionally adjacent to neurosecretory granules, and in macrophages. This tumor expands the list of neuroectodermal tumors with potential melaninization.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00294673
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    Electronic Resource
    Electronic Resource
    The astroblastoma and its possible cytogenic relationship to the tanycyte (1989)
    Springer
    Acta neuropathologica 78 (1989), S. 472-483 
    Details
    ISSN: 1432-0533
    Keywords: Astroblastoma ; Electron microscopy ; Immunohistochemistry ; Organ culture ; Tanycytes
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary Two examples of cerebral astroblastoma have been studied by electron microscopy and immunohistochemistry, one of them having been maintained in vitro in an organ-culture matrix system for 8 months and the explants studied by light and electron microscopy at different time intervals. The fine structural characteristics were those of a glial cell type with features intermediary between those of astrocytes and ependymocytes. They recapitulated the structure of the tanycyte, a glial precursor cell which is normally found scattered along the ependymal lining of the embryonal and neonatal mammalian brain, but is distinct from epithelial ependymocytes. The possible origin of some astroblastomas from such a cell would account for a number of characteristics in this enigmatic type of glioma.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00687708
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  • 21
    Electronic Resource
    Electronic Resource
    Sporadic motor neuron disease with Lewy body-like hyaline inclusions (1989)
    Springer
    Acta neuropathologica 78 (1989), S. 555-560 
    Details
    ISSN: 1432-0533
    Keywords: Sporadic motor neuron disease ; Lewy body-like hyaline inclusions ; Immunocytochemistry ; Electron microscopy
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary Lewy body-like hyaline inclusions were immunocytochemically and electron microscopically investigated in a patient with sporadic motor neuron disease. The hyaline inclusions were chiefly observed within the perikarya of both normal-looking and chromatolytic anterior horn cells in the lumbar spinal cord, but some were detected in the axons and dendrites. Usually, a single inclusion was found in the perikaryon, but in rare cases two or more were observed. Immunocytochemically, these inclusions were intensely immunostained with anti-ubiquitin anti-body. Ultrastructurally, the hyaline inclusions were chiefly composed of randomly arranged linear structures associated with ribosome-like granules, varying from compactly arranged linear densities to more loosely packed ones. They contained scattered vesicles of various sizes and occasionally a focal accumulation of randomly arranged 10-nm neurofilaments or 13–25-nm filamentous structures.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00687719
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  • 22
    Electronic Resource
    Electronic Resource
    Membranous changes in primary malignant CNS lymphomas (1989)
    Springer
    Acta neuropathologica 79 (1989), S. 86-93 
    Details
    ISSN: 1432-0533
    Keywords: Primary malignant CNS lymphoma ; Ultrastructure ; Intracytoplasmic tubuloreticular, membranous structures ; Intranuclear inclusions
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary Ultrastructural studies of 17 primary malignant CNS lymphomas revealed 6 tumors with abnormal intracytoplasmic and/or intranuclear membranous structures, most frequently, associated with the endoplasmic reticulum or perinuclear envelope. In most cases, tubuloreticular inclusions and paired cisternae were present. Less frequent were accumulation of mictotubules, concentric lamellar bodies, and rod-like or paracrystalline intranuclear inclusions. The specificity and significance of these membranous structures remain questionable because of their frequent occurrence in a variety of normal and pathological conditions. Some of these changes may be considered as cellular reactions to viral infections, others may indicate cellular activity or degeneration.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00308962
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  • 23
    Electronic Resource
    Electronic Resource
    Dithiobiuret neurotoxicity: an ultrastructural investigation of the lesion in preterminal axons and motor endplates in the rat lumbrical muscle (1989)
    Springer
    Acta neuropathologica 78 (1989), S. 72-85 
    Details
    ISSN: 1432-0533
    Keywords: 2,4-Dithiobiuret ; Thioimidodicarbonic diamide ; Motor endplate ; Neuromuscular junction ; Ultrastructure
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary 2,4-Dithiobiuret was given i.p. to rats for 4 days at a daily dosage of 1 mg/kg and the development of the lesion associated with neuromuscular dysfunction studied in hindlimb lumbrical muscles. The first morphological indication of neurointoxication was the appearance in some motor endplates of masses of branching tubular smooth endoplasmic reticulum (SER) on day 2 which correlated with the initial functional disturbances. By the 3rd day, most motor endplates were distended by accumulations of densecored, lucent and synaptic vesicles, abnormally swollen mitochondria, intermediate filaments and branching, tubular SER. Evidence of collateral axonal sprouting was seen first at this time. On days 4 and 5, many motor endplates were markedly enlarged and showed axoplasmic organelle congestion. A significant increase in synaptic vesicle size was noted at these times in some terminals. Interposition of Schwann cell processes between the pre- and postsynaptic membranes and terminal retraction was now evident. Some intramuscular nerves showed hydropic Schwann cell cytoplasm with separation of the outermost myelin lamellae, mitochondrial swelling and adaxonal vacuoles as early as the 1st day. Proliferation and segregation of SER around central cores of neurofilaments was seen in myelinated nerve fibres and preterminals on the 3rd day. At this and later times accumulations of SER and swollen mitochondria were found at sites of axonal varicosities and at the paranodal constrictions at nodes of Ranvier. These ultrastructural data are discussed with regard to reduced terminal Ca2+ content (demonstrated by oxalate-pyroantimonate cytochemistry) and compared with the sequelae of botulinum intoxication.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00687405
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  • 24
    Electronic Resource
    Electronic Resource
    Neuroendocrine markers in central nervous system neuronal tumors (gangliocytoma and ganglioglioma) (1989)
    Springer
    Acta neuropathologica 77 (1989), S. 237-243 
    Details
    ISSN: 1432-0533
    Keywords: Gangliocytoma ; Ganglioglioma ; Ultrastructure ; Immunohistochemistry ; Neuroendocrine markers
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary We studied five cases of central nervous system neuronal tumor, one gangliocytoma and four gangliogliomas, both ultrastructurally and immuno-histochemically, using antibodies to neuroendocrine markers including tyrosine hydroxylase (TH), serotonin (5HT), somatostatin (SOM), met-enkephalin (MEK), leu-enkephalin (LEK), substance P (SP), gastrin, vasopressin, oxytocin, vasoactive intestinal polypeptide, adrenocorticotropic hormone and calcitonin. In all cases, the presence of dense-core vesicles (60–250 nm) in the neuronal elements was the characteristic ultrastructural finding. Synapses were observed in two cases. Immunohistochemically, variable numbers of neuronal cells showed positive staining for SOM in five cases, TH, MEK and LEK in three cases, and 5HT and SP in one case each. The others were negative. Positive immunoreactivity for multiple markers was shown in all cases. SOM, TH, 5HT and SP were present in the small- to medium-sized cells, while MEK and LEK were almost exclusively confined to the large cells. Our study clearly indicated that these tumors contained neuronal cells which were not homogeneous with regard to neuroendocrine markers.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00687574
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  • 25
    Electronic Resource
    Electronic Resource
    A new type of neuronal cytoplasmic inclusion: histological, ultrastructural, and immunocytochemical studies (1989)
    Springer
    Acta neuropathologica 77 (1989), S. 599-604 
    Details
    ISSN: 1432-0533
    Keywords: Neuronal inclusions ; Leigh disease ; Tropomyosin ; Actin ; Ultrastructure
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary A novel type of non-viral cytoplasmic inclusion is described, which was seen in virtually every neuron in the brain and spinal cord of a child with a presumed metabolic disorder whose clinical picture and CNS pathology were compatible with Leigh Syndrome. The ovoid to round inclusions were sharply demarcated, measuring up to 11 μm in diameter. They showed no distinctive staining with a battery of routine histological techniques. The ultrastructural features are unique, comprising non-membrane-bounded aggregates of randomly oriented plate-like structures with parallel linear densities depicting a periodicity of 11–16 nm. Immunocytochemical studies revealed strong staining with antisera to tropomyosin and weaker staining with antisera to actin. There was no reactivity with antibodies against neurofilaments, microtubules and their associated proteins, paired helical filaments, ubiquitin, vinculin or alpha-actinin. It is postulated that the metabolic disorder resulted in a neurodegenerative condition which manifested pathologically with lesions compatible with those of Leigh Syndrome. Associated with the condition was the discrete accumulation of cytoplasmic proteinaceous components, including tropomyosin, in the form of neuronal cytoplasmic inclusions possibly resulting from an alteration of the neuronal cytoskeleton.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00687887
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  • 26
    Electronic Resource
    Electronic Resource
    Morphological studies on cerebral cortical lesions induced by transient ischemia in Mongolian gerbil —Diffuse and peripheral pallor of the neuronal perikarya (1989)
    Springer
    Acta neuropathologica 78 (1989), S. 1-8 
    Details
    ISSN: 1432-0533
    Keywords: Cerebral ischemia ; Ischemic neuronal injury ; Long-term recovery ; Mongolian gerbil ; Electron microscopy
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary Unilateral transient cerebral ischemia was produced in Mongolian gerbils by clipping the left common carotid artery for 1h. About 60% of the gerbils with neurological symptoms had post-ischemic seizures. The majority of those that had seizures died within a few days, and sections of their cerebral cortices contained many dark and shrunken neurons. However, the gerbils that did not have seizures survived without any severe complications. In the cerebral cortex of the latter, the neurons with diffuse or peripheral pallor of the perikarya were seen along with a small number of dark and shrunken neurons. Diffuse pallor occurred within a few hours following ischemia in layers III, V and VI, and disappeared 1 or 2 days after recirculation. Electron microscopically, these neurons showed dispersion of ribosomes, simple and elongated profiles of rough endoplasmic reticulum (r-ER), clustered vacuoles, and mild to moderate mitochondrial swelling. Occasional net-like tubulomembranous structures, probably derived from r-ER, were observed. On the other hand, peripheral pallor became apparent after 5 days following ischemia, usually involving layer II first and gradually extending to the deeper layers. Concomitantly, the amount of neuropil decreased and the dendrites exhibited tortuosity and irregularity in layer II. Electron microscopically, these neurons showed marked swelling of peripheral perikarya and polyribosomes and organelles were located peripherally to the nuclei. In addition, numerous degenerated axon terminals and distended dendrites were observed around the neurons. These observations indicate that diffuse pallor represents damage directly induced by ischemia and subsequent recirculation, while peripheral pallor is the delayed and remote effect of ischemia, probably due to degeneration of neuronal processes.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00687395
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  • 27
    Electronic Resource
    Electronic Resource
    Acute ultrastructural response of hypoxic hypoxia with relative ischemia in the isolated brain (1989)
    Springer
    Acta neuropathologica 78 (1989), S. 637-648 
    Details
    ISSN: 1432-0533
    Keywords: Cerebral hypoxia ; Cerebral ischemia ; Ultrastructure ; Neocortex ; Brain isolation
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary The acute cortical response to surgical brain isolation and subsequent extracorporal normoxic or 30 min hypoxic (PaO2=20 mm Hg) perfusions (hypoxic hypoxia with relative ischemia) was evaluated. Cerebral blood flow, arterial pH and CO2 were maintained constant during both perfusions; only the arterial oxygen content was changed. The isolated brain model used in this and previous investigations produces no qualitative ultrastructural changes in the neocortex following brain isolation and normoxic perfusion. However, the acute cortical structural response to 30 min of hypoxic hypoxia with relative ischemia demonstrated a number of important observations. Hypoxic hypoxia produced ultrastructural responses common to cerebral ischemia such as nuclear chromatin clumping, nucleolar condensation and cytoskeletal breakdown. Although neuronal abnormalities seen after 30 min of hypoxic hypoxia were similar to those acute neuronal changes observed following complete cerebral ischemia without recirculation, they differed three ways: (a) mitochondrial swelling and microvacuolation were observed in many cortical pyramidal neurons. (b) Glycogen particles within astroglial processes were observed even after a 30-min period of hypoxic hypoxia. (c) Perivascular astroglial swelling was minimal despite considerable perineuronal swelling. In contrast, incomplete cerebral ischemia produces mitochondrial changes similar to those in hypoxic hypoxia but also causes the depletion of tissue glycogen and perivascular glial swelling. Thus, hypoxic hypoxia with relative ischemia produces a unique acute ultrastructural response compared to either complete or incomplete cerebral ischemia.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00691291
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  • 28
    Electronic Resource
    Electronic Resource
    Cytomembranous inclusions in the peripheral nerves in AIDS (1989)
    Springer
    Acta neuropathologica 79 (1989), S. 336-339 
    Details
    ISSN: 1432-0533
    Keywords: AIDS ; Cytomembranous inclusions ; Tubuloreticular inclusions ; Ultrastructure ; Peripheral nerve
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary We report finding tubuloreticular inclusions (TRI) in the endothelial cells of endo- and epineurial vessels in the sural nerve of 11 patients with AIDS. Six patients had a painful peripheral neuropathy, one a non-painful sensory neuropathy, one an acute inflammatory demyelinating polyradiculoneuropathy and one a thalidomide-related neuropathy. Two patients had no clinical evidence of neuropathy. The TRI are not specific to one neuropathy and are unlikely to contribute to the pathogenesis of peripheral nerve syndromes in AIDS.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00294672
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  • 29
    Electronic Resource
    Electronic Resource
    Disseminated human neurocysticercosis (1989)
    Springer
    Acta neuropathologica 78 (1989), S. 594-604 
    Details
    ISSN: 1432-0533
    Keywords: Neurocysticercosis ; Pathogenesis ; Histochemistry ; Immunohistochemistry ; Electron microscopy
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary This study was based on two cases of disseminated human neurocysticercosis from India. The material availabel was examined grossly, and by light microscopy, histochemistry, immunomorphology and electron microscopy. The results showed that the parasites commonly embolized to the anatomically discernable gray-white matter junction of the brain and were located in cavities, the walls of which were dilated vascular channels. The parasite-nutrition process was through endocytosis and microtrichal activity. To camouflage themselves from the host-defense mechanisms, the parasites apparently covered themselves with host-tissue-like material. Host reactivity to the parasite was heralded morphologically by the physical anchoring of the parasite by activated endothelial cells, loss of the host-tissue-like cover and an acute polymorphonuclear leucocytic response.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00691286
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  • 30
    Electronic Resource
    Electronic Resource
    Senile plaque-like structures: observation of a probably unknown type of senile plaque by periodic-acid methenamine silver (PAM) electron microscopy (1989)
    Springer
    Acta neuropathologica 78 (1989), S. 137-142 
    Details
    ISSN: 1432-0533
    Keywords: Senile plaque-like structure ; Periodicacid methenamine silver (PAM) method ; Electron microscopy
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary Numerous diffuse senile plaque-like structures (SPLSs) were found in the cerebral cortex from cases with dementia of the Alzheimer type by means of the methenamine-Bodian method. SPLSs varied in shape and size. They were never recognized in the original Bodian, PAS and Congo red preparations, but were positive with anti-β-protein immunostaining and periodic-acid methenamine silver (PAM) methods, which are thought to specifically stain amyloid substance. With PAM electron microscopy, we found sparse aggregations of amorphous, often ramified, structures with fine granular silver deposits in SPLS. Routine electron microscopic examination on the same portion where SPLS were confirmed by PAM electron microscopy revealed amorphous, partially fibrous structures. These structures might be amyloid or amyloid-precursor substance. In SPLSs only a few degenerated neurites and astrocytic processes with glycogen granules were seen. We consider SPLSs to be a kind of senile plaque.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00688201
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  • 31
    Electronic Resource
    Electronic Resource
    Ultrastructural changes in skeletal muscle in ovine muscular dystrophy (1989)
    Springer
    Acta neuropathologica 79 (1989), S. 168-175 
    Details
    ISSN: 1432-0533
    Keywords: Muscular ; Dystrophy ; Ovine ; Ultrastructure
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary The initial ultrastructural changes in skeletal myofibers in ovine muscular dystrophy (MD) consisted of focal degeneration of myofibrils and the formation of Z-disc abnormalities, including nemaline rods, in adjacent sarcomeres. Peripheral and central sarcoplasmic masses, which occurred initially in large diameter fibers, contained a mixture of normal organelles and abnormal tubular and fibrillar formations. Vesiculate sarcolemmal nuclei with prominent nucleoli accumulated in central and subsarcolemmal locations in small clusters and short rows. Deformed individual nuclei were sometimes present within nuclear rows. Loss of the myofibrillar mass, increased density of small spherical nuclei, collections of fibrillar and tubular arrays, excessive folding of the sarcolemma and greatly reduced fiber diameter were seen in the end stage of the dystrophic process. Resting satellite cells were present at all stages of lesion development. The morphological progression of the lesions suggested an inherited inability to effectively replace lost myofibrils with ultimate exhaustion of the capacity for repair followed by pathological fiber atrophy.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00294375
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  • 32
    Electronic Resource
    Electronic Resource
    Localization of aggregation substances of Enterococcus faecalis after induction by sex pheromones (1989)
    Springer
    Archives of microbiology 151 (1989), S. 491-497 
    Details
    ISSN: 1432-072X
    Keywords: Aggregation substance ; Enterococcus faecalis ; Electron microscopy ; Field emission scanning electron microscopy ; Immunogold labelling technique ; Sex pheromone system
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract The distribution of sex pheromone induced aggregation substance was studied on the cell surface of various Enterococcus faecalis strains. In the accompanying paper we have shown that the aggregation substance appears as a layer of hairlike structures. Using direct and indirect immunogold technique, transmission electron microscopy and high resolution scanning electron microscopy we investigated the appearance and distribution of the aggregation substance. The “hairs” increase in number with increasing exposure to sex pheromones (maximum density: 1300/μm2). We show that these structures are unequally distributed over the cell surface, even if the cells were induced by sex pheromones for a long period of time. Statistical analysis of the unequal distribution indicates that aggregation substance is incorporated into pre-existing “old” cell-walls and that this incorporation shows a saturation ca. 40 min after addition of sex pheromones.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00454864
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  • 33
    Electronic Resource
    Electronic Resource
    Microscopic examination and fatty acid characterization of filamentous bacteria colonizing substrata around subtidal hydrothermal vents (1989)
    Springer
    Archives of microbiology 152 (1989), S. 64-71 
    Details
    ISSN: 1432-072X
    Keywords: Thiothrix sp. ; Beggiatoa sp. ; Sulfideoxidizing ; Polyunsaturated ; Fatty acids ; Inclusions ; Sheath ; Southern California ; Ultrastructure ; Sulfur
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract Microscopic examination of the whitish mat that covered the substrata around subtidal hydrothermal vents at White Point in southern California revealed a “Thiothrix-like” bacterium containing sulfur inclusions as the dominant filamentous form in this microbial community. The matlike appearance developed as a result of the closely-packed manner inwhich the basal ends of the filaments were anchored to the substrate. The dominant phospholipid fatty acids of these filaments (16:0, 16:1w7c, 18:0, 18:1w7c) were similar to those recovered from a sample of Beggiatoa isolated from a spring in Florida. Filaments from both sources contained small quantities of C18 and C20 polyunsaturated fatty acids, as well. A larger but less abundant sheathless, filamentous form, which also contained sulfur inclusions and displayed a cell wall structure similar to a previously described Thioploca strain, also colonized the substrata around the subtidal mat. The preservation methods used in the preparation of thin-sections of the subtidal mat material were found to be inadequate for defining some key cellular structures of the large filaments. Nevertheless, the results demonstrate that the filamentous bacteria comprising the microbial mat in the vicinity of the subtidal vents exhibit some of the features of the free-living filamentous microorganisms found in deep-water hydrothermal areas.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00447013
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    Electronic Resource
    Electronic Resource
    The ultrastructure of chemolithoautotrophic Gallionella ferruginea and Thiobacillus ferrooxidans as revealed by chemical fixation and freeze-etching (1989)
    Springer
    Archives of microbiology 151 (1989), S. 245-251 
    Details
    ISSN: 1432-072X
    Keywords: Gallionella ferruginea ; Thiobacillus ferrooxidans ; Iron bacteria ; Chemolithoautotrophy ; Ultrastructure ; Freeze-etching ; Cell wall organization ; Intracytoplasmic membranes ; Carboxysomes
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract By using sodium thioglycolate to dissolve the high amount of excreted stalk material in axenic cultures of the chemolithoautotrophic iron bacterium Gallionella ferruginea, the ultrastructure of Gallionella cells from pure cell suspensions could be studied without any loss of viability or disturbance by dense ferric stalk fibers, and compared with Thiobacillus ferrooxidans, also grown chemolithoautotrophically with ferrous iron as energy source. Both organisms were chemically fixed or freeze-etched. Particular structural differences between these iron-bacteria could be ascertained. G. ferruginea possesses intracytoplasmic membranes and soluble d-ribulose-1,5-bisphosphate-carboxylase, whereas T. ferrooxidans contains carboxysomes but no intracytoplasmic membranes; Gallionella forms poly-β-hydroxybutyrate and glycogen as storage material; T. ferrooxidans produces only glycogen. Both organisms also differ from each other with respect to the freeze fracture behaviour of the cell envelope layers. Whereas the cells of T. ferrooxidans exhibit a characteristic double cleavage, exposing the plasmic fracture face and exoplasmic fracture face of the outer membrane and cytoplasmic membrane, the exceptionally thin multilayered cell envelope of G. ferruginea revealed a particularly intimate association between the layers, resulting in a visualisation of the supramolecular organisation of only the inner fracture face of the cytoplasmic membrane. The results are discussed predominantly in relation to the extremely distinct environments of both organisms.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00413137
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    Electronic Resource
    Electronic Resource
    Immunogold localization of coenzyme F420-reducing formate dehydrogenase and coenzyme F420-reducing hydrogenase in Methanobacterium formicicum (1989)
    Springer
    Archives of microbiology 151 (1989), S. 307-313 
    Details
    ISSN: 1432-072X
    Keywords: Methanobacterium formicicum ; Formate dehydrogenase ; F420-hydrogenase ; Immunogold ; Ultrastructure ; Methanogen
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract The ultrastructural locations of the coenzyme F420-reducing formate dehydrogenase and coenzyme F420-reducing hydrogenase of Methanobacterium formicicum were determined using immunogold labeling of thin-sectioned, Lowicryl-embedded cells. Both enzymes were located predominantly at the cell membrane. Whole cells displayed minimal F420-dependent formate dehydrogenase activity or F420-dependent hydrogenase activity, and little activity was released upon osmotic shock treatment, suggesting that these enzymes are not soluble periplasmic proteins. Analysis of the deduced amino acid sequences of the formate dehydrogenase subunits revealed no hydrophobic regions that could qualify as putative membrane-spanning domains.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00406556
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  • 36
    Electronic Resource
    Electronic Resource
    Neural crest origin of clear cell sarcoma of tendons and aponeuroses (1989)
    Springer
    Virchows Archiv 415 (1989), S. 51-60 
    Details
    ISSN: 1432-2307
    Keywords: Clear cell sarcoma ; Melanosomes ; Cytochemistry ; Electron microscopy ; Nude mouse
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary In order to clarify the histogenesis of clear cell sarcoma of tendons and aponeuroses (CCS), two cases of human and one nude mouse-transplanted CCS line were studied using an ultrastructural and enzyme cytochemical approach. Most of the tumour cells obtained from the primary and transplanted CCS demonstrated melanosomes in various stages of development within the cytoplasm, whereas no melanosomes could be identified in the metastatic CCS. However, cholinesterase and tyrosinase activities could be demonstrated not only in the melanotic primary and transplanted CCS but also in the amelanotic metastatic CCS. The results therefore support the hypothesis that CCS is a soft tissue tumour derived from the neural crest.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00718604
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  • 37
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    Electronic Resource
    An immunohistochemically defined non-Hodgkin's lymphoma showing intercellular junctions (1989)
    Springer
    Virchows Archiv 415 (1989), S. 297-300 
    Details
    ISSN: 1432-2307
    Keywords: Non-Hodgkin's lymphoma ; Electron microscopy ; Immunohistochemistry ; Intercellular junction
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary A rare example of pleomorphic B cell non-Hodgkin's lymphoma is described in which tumour cells possessed simple intercellular junctions.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00724918
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  • 38
    Electronic Resource
    Electronic Resource
    Sebaceous carcinoma of the parotid gland (1989)
    Springer
    Virchows Archiv 414 (1989), S. 459-464 
    Details
    ISSN: 1432-2307
    Keywords: Sebaceous carcinoma ; Parotid gland ; Salivary gland ; Ultrastructure ; Immunohistochemistry
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary Sebaceous carcinoma of salivary gland origin is extremely rare and, because of its rarity, the clinicopathological characteristics and the histogenesis are not fully understood. We present a case of sebaceous carcinoma of the parotid gland which brings the total number of reported cases to 22. The tumor showed epithelial cell nests which were mainly composed of sebaceous cells with marked cellular atypia. In most of the nests, glandular spaces lined by ductal epithelium were present. Scattered mucous cells and flattened eosinophilic cells at the periphery of the nests were also seen. Ultrastructural and immunohistochemical observations of the tumour revealed coexistence of sebaceous and glandular differentiations in some tumour cells. Tumour cells with lipid granules often participated in the formation of glandular structures or exhibited intracytoplasmic lumina, and immunohistochemical localization of lactoferrin and secretory component, the functional markers of ductal epithelium of salivary gland, was demonstrated not only in duct-forming tumour cells but also in many sebaceous tumour cells. It seems likely that sebaceous carcinoma originates from pluripotential duct cells which can differentiate into sebaceous, ductal and mucous cells.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00718631
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  • 39
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    Electronic Resource
    Immunocytochemical and morphometric analysis of acinar zymogen granules in human acute pancreatitis (1989)
    Springer
    Virchows Archiv 415 (1989), S. 115-124 
    Details
    ISSN: 1432-2307
    Keywords: Human acute pancreatitis ; Zymogen granules ; Acinar cells ; Electron microscopy ; Immunocytochemistry ; Morphometry
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary In the present study fine structural changes of acinar zymogen granules were investigated in human acute pancreatitis. Pancreatic tissue was obtained at surgery from 6 patients, prepared for ultrastructural analysis, and stained immunocytochemically for trypsinogen. Stereological parameters of zymogen granules were evaluated. The density of the immunocytochemical labelling for trypsinogen was estimated over zymogen granules, the rough endoplasmic reticulum, Golgi apparatus and the acinar lumina. In acute pancreatitis the number of zymogen granules was diminished and their size reduced. The density of the labelling for trypsinogen was unchanged over zymogen granules but showed a significant reduction over the rough endoplasmic reticulum, Golgi apparatus, and the acinar lumina. In general the integrity of zymogen granules was well preserved. Focally degenerative changes of zymogen granules and large autophagosomes were observed. From the immunogold labelling a disturbance of enzyme synthesis and secretion was suggested. Evidence is given that a disruption of the zymogen granule membranes and a fusion with lysosomal bodies might contribute to the pathogenesis of human acute pancreatitis.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00784348
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  • 40
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    Electronic Resource
    Paracrystalline inclusions in metaplastic ciliated cells of the human gastric mucosa (1989)
    Springer
    Virchows Archiv 415 (1989), S. 145-149 
    Details
    ISSN: 1432-2307
    Keywords: Paracrystalline inclusion ; Microtubule ; Ciliogenesis ; Gastric ciliated cell ; Ultrastructure
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary Unusual electron-dense paracrystalline inclusions were found in metaplastic ciliated cells in the stomachs of three Japanese male patients with gastric carcinoma. These patients had not been given antitumour drugs before surgery and ethrane (enflurane) was used as the anaesthetic. Ciliated cells in the gastric mucosa are found not infrequently in the pyloric glands in association with intestinal metaplasia in elderly Japanese patients. Paracrystalline inclusions were found only in the ciliated cells and never in any other types of gastric mucosal cell. These inclusions were located in the apical portion of the ciliated cells in intimate association with the basal bodies. They consisted of twisted strings about 27 nm wide with a regularly repeated spacing of about 30 nm. On highly magnified electron micrographs, granules about 4 nm in diameter were detected. These paracrystalline inclusions have never been reported previously, although their location in ciliated cells and their morphological characteristics suggest an intimate relationship with the ciliogenesis of metaplastic ciliated cells in the human stomach.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00784352
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  • 41
    Electronic Resource
    Electronic Resource
    Salivary gland myoepithelioma variants (1989)
    Springer
    Virchows Archiv 416 (1989), S. 25-42 
    Details
    ISSN: 1432-2307
    Keywords: Salivary gland ; Myoepithelioma ; Neoplasm ; Electron microscopy ; Immunohistochemistry ; Cytoplasmic filaments
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary The histological and ultrastructural features of five major salivary gland tumours, which have little or no evidence of duct- or gland-type differentiation in routine sections, are described. Four of the cases have the tumour cells organized as narrow, anastomosing cords of cells separated by a myxoid and vascularized stroma; we have designated such lesions as reticular-type myoepitheliomas. The fifth case has a solid growth pattern and is largely composed of hyaline cells, that is, a plasmacytoid myoepithelioma. Ultrastructurally, one reticular myoepithelioma reveals myoepithelial cell differentiation with microfilament aggregates, while the other three examples are composed of modified myoepithelial cells displaying widened intercellular spaces, prominent synthesis of extracellular glycosaminoglycans, distinct basal lamina development, and obvious accumulations of cytoplasmic intermediate filaments. In electron micrographs, the modified myoepithelial cells of the plasmacytoid variant closely resemble the tumour cells in the reticular form. Three cases had expression of both glial fibrillary acid protein (GFAP) and vimentin, but only one of the myoepitheliomas contained muscle-specific actin. At least focally, each of the cases exhibited a considerable spectrum of cytokeratin filaments. Using double-labeled immunofluorescent microscopy of one reticular variant and the plasmacytoid myoepithelioma, there was individual tumour cell co-expression of GFAP and vimentin focally in the plasmacytoid myoepithelioma, but co-expression of cytokeratins 13, 16 and GFAP were not noted in either case. As expected, co-expression of high- and low-molecular weight cytokeratin filaments was wide-spread in both myoepitheliomas. Most described myoepitheliomas have a solid growth pattern and are composed of spindle and plasmacytoid cells, but based on cytological features and growth patterns in this series, it is apparent that polygonalshaped cells with novel architecture can occur in myoepitheliomas. The results also indicate the close relationship between pleomorphic adenoma and such variants of myoepithelioma.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF01606467
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  • 42
    Electronic Resource
    Electronic Resource
    Ultrastructure of metaplastic ciliated cells in human stomach (1989)
    Springer
    Virchows Archiv 414 (1989), S. 113-119 
    Details
    ISSN: 1432-2307
    Keywords: Gastric mucosa ; Intestinal metaplasia ; Ciliated cell ; Ciliated metaplasia ; Ultrastructure
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary Intestinal metaplasia of the gastric mucosa occurs commonly in aged Japanese patients and has been discussed in relation to the high incidence of gastric cancer in Japanese. Ciliated cells in the gastric mucosa have frequently been found in association with intestinal metaplasia in the pyloric gland and rarely in the cardiac gland in many Japanese patients, and exceptionally in one Chinese and in one Swedish patient. Electron microscopic examination of 12 Japanese patients has revealed that these structures are not metaplastic stereocilia, but true cilia. Ciliated cells have been found in the basal part of the gastric glands and never in the surface epithelium. The fine structure of the gastric cilia was almost the same as that of normal respiratory cilia. However, in the gastric cilia, most dynein arms were inconspicuous even after tannic acid fixation, indicating that ciliary beating of the gastric cilia is problematic. Abnormal cilia and basal bodies also were found. Ciliated cells have always occurred in association with intestinal metaplasia, therefore this phenomenon might be a type of metaplasia and is named “ciliated metaplasia” of the gastric mucosa.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00718590
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  • 43
    Electronic Resource
    Electronic Resource
    Early bronchopulmonary lesions in rat lung after normobaric 100% oxygen exposure and their evolution (1989)
    Springer
    Virchows Archiv 414 (1989), S. 135-145 
    Details
    ISSN: 1432-2307
    Keywords: Hyperoxia ; Lung broncho-vascular reaction ; Electron microscopy ; Rat
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary In order to clarify the early phenomena involved in the lung reaction to hyperoxia, twenty adult male rats were exposed to 100% oxygen at 1 ATA. Morphological pulmonary lesions were detectable after only 24 h hyperoxia, and included vasoconstriction and perivascular oedema, bronchiolar constriction, and pericyte reaction. The lesions were irregularly scattered within the lung parenchyma and occurred preferentially in areas centred on bronchiolo-vascular stems. Even at the latest stages, pulmonary heterogeneity was obvious, from the coexistence of areas damaged at different times. Neuro-epithelial-bodies were found under the bronchiolar epithelium; the morphological aspect of the neuro-endocrine cells observed was consistent with hyperoxia-induced modulation of their secretory activity. Taken together, our findings show the speed of development of hyperoxia-induced pulmonary changes and raise some pathogenic considerations.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00718593
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  • 44
    Electronic Resource
    Electronic Resource
    Liver parenchymal cell parasitism in human visceral leishmaniasis (1989)
    Springer
    Virchows Archiv 415 (1989), S. 1-6 
    Details
    ISSN: 1432-2307
    Keywords: Visceral leishmaniasis ; L. donovani ; Parasitism ; Liver pathology ; Electron microscopy
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary Liver parenchymal cell parasitism with the amastigotes form ofL. donovani was detected by electron microscopy in human visceral leishmaniasis. Endocytosis was considered to be the mechanism by which the leishmania entered the cell. Evidence of well preserved parasites within hepatocytes suggest this parasitism as a possible reservoir for recrudescence.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00718599
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  • 45
    Electronic Resource
    Electronic Resource
    Collagen secretion granules in reactive stromal myofibroblasts, with preliminary observations on their occurrence in spindle cell tumours (1989)
    Springer
    Virchows Archiv 415 (1989), S. 437-445 
    Details
    ISSN: 1432-2307
    Keywords: Collagen secretion granule ; Myofibroblast ; Spindle cell tumour ; Electron microscopy ; Diagnosis
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary Collagen secretion granules, representing stages in the intracellular packaging, transport and secretion of collagen-fibril precursor, have been studied by transmission electron microscopy in non-neoplastic human myofibroblasts and in neoplastic cells from a preliminary study of tumours exclusively or partly of spindle cell type. Vesicles, newly separated from Golgi saccules and containing finely fibrillar material, were identified as early presecretory granules, the most immature type of granule. Later stages exhibited longitudinally arranged, densely fibrillar bundles. Subsequently, secretory granules developed more homogeneously dense content. Fibril-containing cisternae near the plasma membrane were interpreted as either endocytotic or lysosomal structures, or as participants in the final stages of secretion. The features by which collagen secretion granules can be distinguished from other Golgi products, in particular melanosomes, Weibel-Palade bodies and lysosomes, are pointed out. The significance of these organelles for cell identification and tumour diagnosis is discussed.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00747745
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  • 46
    Electronic Resource
    Electronic Resource
    Malignant fibrous histiocytoma: Similarities to the “fibrohistiocytoid cells” in chronic inflammation (1989)
    Springer
    Virchows Archiv 414 (1989), S. 285-298 
    Details
    ISSN: 1432-2307
    Keywords: Malignant fibrous histiocytoma ; Ultrastructure ; Enzyme histochemistry ; Immunohistochemistry ; “Fibrohistiocytoid cell”
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary Ultrastructural, enzyme histochemical and immunohistochemical studies were performed on tissue obtained from eight cases of malignant fibrous histiocytoma (MFH) and five cases of sacral decubitus ulcer. The MFH was composed of two major tumour cell types: fibroblast-like and histiocyte-like cells. Both cell types demonstrated abundant branching, fragmented rough endoplasmic reticulum (rER), many free ribosomes, occasional small mitochondria, an oval, elliptical or irregularly shaped nucleus with one or two prominent nucleoli and often a few dense bodies. However, pseudopodial projections, multivesicular bodies and phagosomes, common histiocyte organelles, were not seen. With little difference between cases or selection sites, the MFH cells reacted to acid phosphatase (AcP) and α-naphtyl butyrate esterase (ANBE) by enzyme histochemistry and with ferritin (Fer), α1-antitrypsin (AT), α1-antichymotrypsin (ACT), fibronectin (FN), HLA-DR, HLA-DP, Leu 10 and OKT 9 in immunohistochemical studies. MFH tumour cells did not immunostain with monocyte/macrophage markers (Leu M1, Leu M3, Mo 1, Mo 2 and Macrophage) although non-neoplastic histiocytes did react to these markers. In addition, granulation tissue, such as that found in sacral decubitus ulcers, was examined and the existence of a specific cell type called the “fibrohistiocytoid (FH) cell” was documented. The FH cell was short, spindle shaped and elliptical. Ultrastructurally, it had fragmented rER distributed in a branching pattern, dispersed free ribosomes, small mitochondria and a few dense bodies, but lacked diverse fused lysosomes and distinct pseudopodial cytoplasmic extensions. The FH cells reacted with AcP, alkaline phosphatase and ANBE but not with peroxidase using enzyme histochemistry and with Fer, AT, ACT, FN, HLA-DR, HLA-DP, Leu 10 and OKT 9 but not with monocyte/macrophage markers, C3d receptor, C3bi receptor in immunohistochemical studies. The FH cells had morphological, enzyme histochemical and immunohistochemical characteristics intermediate between fibroblasts and histiocytes. Similarities between MFH cells and the FH cells seen in chronic inflammation are discussed.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00734082
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  • 47
    Electronic Resource
    Electronic Resource
    Liver cell shedding and phagocytic rveaction in alcoholic liver disease (1989)
    Springer
    Virchows Archiv 415 (1989), S. 21-29 
    Details
    ISSN: 1432-2307
    Keywords: Alcoholic liver disease ; Ultrastructure ; Phagocytosis ; Cell shedding
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary Sinusoidal macrophages were studied by light and electron microscopy in 49 liver biopsies from alcohol-abusers with a variety of alcohol-related liver lesions or with near-normal livers. Changes were related to those in nearby hepatocytes. A reduction in the number of macrophages was noted in the more severely damaged livers. Hepatocytes formed blebs at their sinusoidal poles, and these protruded into the space of Disse and into the sinusoidal lumen. It is postulated that reduced phagocytic activity in the livers of patients with severe alcohol-related liver disease leads to increased shedding of hepatocellular material into the circulation. This may promote the development of autoimmune reactions directed against hepatocytes.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00718601
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  • 48
    Electronic Resource
    Electronic Resource
    Biologic roles of the innermost cell layer of the outer root sheath in human anagen hair follicle: further electron microscopic study (1989)
    Springer
    Archives of dermatological research 281 (1989), S. 254-259 
    Details
    ISSN: 1432-069X
    Keywords: Innermost cell layer ; Tonofilaments ; Huxley's cells ; Henle's cells ; Anagen hair follicles ; Electron microscopy
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary To elucidate the biologic roles and further cytologic characteristics of the innermost cell (IMC) layer of the outer root sheath (ORS), human anagen hair follicles were ultrastructurally examined. In the lower follicle, the transeversely running tonofilaments in the inner side of the cytoplasm of the IMCs showed a massive accumulation, facing the keratinized part of a Huxley's cell protruding through a Henle's pore. In a rare instance, a spindle-shaped cell was seen between the IMC layer and the keratinized Henle's layer. At the lower isthmus portion, some of the IMCs containing a large number of tonofilaments showed a partial degeneration of the inner side of the cytoplasm. More distally, intercellular spaces between the keratinized IMCs and keratinized Henle's cells were partly dilated and contained amorphous substances. It is suggested that the IMCs in the lower follicle may play a role to support and cover the inner hair structures, tightly as hoops of a barrel. In the isthmus portion, the IMCs may loosely support and guide the keratinized Henle's cells undergoing degeneration.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00431059
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  • 49
    Electronic Resource
    Electronic Resource
    Ultrastructural study of pseudo-Kaposi's sarcoma (Bluefarb-Stewart type) (1989)
    Springer
    Archives of dermatological research 281 (1989), S. 35-39 
    Details
    ISSN: 1432-069X
    Keywords: Pseudo-Kaposi's sarcoma ; Bluefarb-Stewart syndrome ; Ultrastructure
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary An ultrastructural study of the skin lesion of a young patient affected by pseudo-Kaposi's sarcoma of the Bluefarb-Stewart type (BSS) is reported. The neoplasm consisted of a proliferation of vascular structures mostly consisting of a solid bud of endothelial cells surrounded by a thinned and polystratified basement membrane and several pericytes. Both endothelial cells and pericytes were of normal ultrastructural appearance. Intervascular “stromal” cells were few and morphologically identified as macrophages and/or phagocytic fibroblasts. Masses of hemosiderin were detected outside the cells and in the macrophages, endothelial cells, and pericytes. Intracytoplasmatic crystalloid inclusions similar to those found in fetal endothelium and hemangiomas were observed in a few endothelial cells. These findings are different from those of previously reported cases of pseudo-Kaposi's sarcoma and may be helpful in distinguishing Kaposi's sarcoma from BSS. The role of immunodeficiency in the onset of BSS is discussed.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00424270
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  • 50
    Electronic Resource
    Electronic Resource
    Netherton's syndrome: ultrastructure of the active lesion under retinoid therapy (1989)
    Springer
    Archives of dermatological research 281 (1989), S. 165-172 
    Details
    ISSN: 1432-069X
    Keywords: Netherton's syndrome ; Retinoid therapy ; Etretin ; Electron microscopy
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary A young female patient, expressing the symptom triad of Netherton's syndrome, i.e., ichthyosis linearis circumflexa Comèl, trichorrhexis invaginata and other hair shaft defects, and atopic diathesis, has been treated successfully with the new retinoid preparation Etretin. Our electron microscopical study especially focused on the ultrastructural effect on the characteristic, active part of the skin lesions, which is only found within a narrow borderline just preceding the lesion's margin. In untreated skin, this part is characterized by dermal inflammation, immigrating inflammatory cells, and specific keratinization disturbances: synthesis of keratinization proteins is suppressed, serum exudates invade the epidermis, either filling the intercellular spaces of the upper spinous and the granular layer as finely granular, amorphous material, or they are partly phagocytosed and lie within intracellular, round-oval inclusions. The portions of the lesions lying towards the center are unspecific and represent recovery stages, ultrastructurally resembling stages of normal wound repair. Oral therapy with Etretin did not heal the basic defect, but drastically reduced exoserosis and the deposition of intra- and extracellular material. Keratinization seemed to normalize. The condition of the hair was also improved.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00456387
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  • 51
    Electronic Resource
    Electronic Resource
    Total muscle mitochondrial volume in relation to aerobic capacity of horses and steers (1989)
    Springer
    Pflügers Archiv 413 (1989), S. 343-347 
    Details
    ISSN: 1432-2013
    Keywords: Exercise ; Heart ; Mitochondria ; Oxygen uptake ; Respiration ; Ultrastructure
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Abstract The relationship between maximal oxygen consumption rate ( $$\dot V{\text{O}}_{{\text{2max}}}$$ ) and mitochondrial content of skeletal muscles was examined in horses and steers (n=3 each). Samples of the heart left ventricle, diaphragm,m. vastus medialis, m. semitendinosus, m. cutaneous thoracicus andm. masseter, as well as samples of muscles collected in a whole-body sampling procedure, were analyzed by electron microscopy. $$\dot V{\text{O}}_{{\text{2max}}}$$ per kilogram body mass was 2.7× greater in horses than steers. This higher $$\dot V{\text{O}}_{{\text{2max}}}$$ was in proportion to the higher total volume of mitochondria in horse versus steer muscle when analyzed from the whole-body samples and from the locomotor muscle samples. In non-locomotor muscles, total mitochondrial volume was greater in horses than steers, but not in proportion to their differences in $$\dot V{\text{O}}_{{\text{2max}}}$$ . The $$\dot V{\text{O}}_{{\text{2max}}}$$ of the mitochondria was estimated to be close to 4.5 ml O2·ml−1 mitochondria in both species. It is concluded that in a comparison of a highly aerobic to a less aerobic mammalian species of similar body size, a higher oxidative potential may be found in all muscles of the more aerobic species. This greater oxidative potential is achieved by a greater total volume of skeletal muscle mitochondria.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00584481
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  • 52
    Electronic Resource
    Electronic Resource
    Mitochondrial encephalomyopathy with pilovacuolar inclusion or phenocopy with mitochondrial artefact? (1989)
    Springer
    Journal of neurology 236 (1989), S. 361-363 
    Details
    ISSN: 1432-1459
    Keywords: Mitochondrial encephalomyopathy ; MELAS ; Mitochondrial inclusion ; Pilovacuolar inclusion ; Electron microscopy
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary The case of a 33-year-old man with clinical features of mitochondrial encephalomyopathy is presented. He suffered from recurrent cerebral infarctions, cerebellar ataxia, deafness, retinopathy, weakness, and cardiac and renal disorders. Biochemical and light microscope investigations of skeletal muscle did not show any mitochondrial abnormality. Electron microscopy revealed the presence of a hitherto unreported peculiar “pilovacuolar” inclusion in numerous mitochondria, composed of an electron dense pile or rod within a vacuole, while globular or crystalline inclusions were absent.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00314383
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  • 53
    Electronic Resource
    Electronic Resource
    Human fetal endometrium -light and electron microscopic study (1989)
    Springer
    Archives of gynecology and obstetrics 246 (1989), S. 169-179 
    Details
    ISSN: 1432-0711
    Keywords: Human fetal endometrium ; Electron microscopy
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary Human fetal endometrium was examined by light and electron microscopy. Our study shows the following new morphological aspects: (1) Glands are already present. (2) Endometrium undergoes a maturation process during gestation and at late gestational age resembles late proliferative endometrium. (3) The nuclear bodies are present in cell nuclei throughout gestation. (4) Nucleolar channel systems (NCS) sometimes appear at a late gestational age. (5) Cells with the same morphology as that of endocrine cells are found in the basal layers of endometrium at a late gestational age. The significance of these morphological aspects is discussed.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00934078
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  • 54
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    Electronic Resource
    Morphology of tyrosine hydroxylase-immunoreactive neurons in the human cerebral cortex (1989)
    Springer
    Experimental brain research 76 (1989), S. 12-20 
    Details
    ISSN: 1432-1106
    Keywords: Distribution ; Ultrastructure ; Biopsy ; Catecholamines ; Interneurons
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary In freshly fixed biopsies of human cerebral cortex obtained at surgery, immunocytochemical staining with antibodies against tyrosine hydroxylase (the rate limiting biosynthetic enzyme for catecholamines) revealed, in addition to a dense axonal plexus, a population of immunoreactive cell bodies. The neuronal nature of these cells was ascertained by: i) the presence of a rich rough endoplasmic reticulum in the cell body and of synapses on the cell body and dendrites, and ii) the demonstration of the lack of reactivity with the astroglial marker, glial fibrillary acidic protein, in the tyrosine hydroxylase-immunoreactive cells. The tyrosine hydroxylase-immunoreactive neurons were found in all areas of cortex sampled, and were located almost exclusively in the infragranular layers. Most tyrosine hydroxylase-immunoreactive cells were bipolar and were vertically oriented, but a few had a multipolar or horizontal dendritic arbor. The dendrites of these cells were varicose and aspiny, and the axons were very thin. Tyrosine hydroxylase-immunoreactive neurons were reported to be present transiently in the developing mammalian cerebral cortex and only recently in cerebral cortex of mature mammalian brains. Internuncial neurons in the human cerebral cortex containing a catecholamine synthesizing enzyme would be significant, in particular considering that catecholamines are likely to be involved in some major mental disorders.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00253618
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  • 55
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    Electronic Resource
    Rodent and primate adrenal medullary cells in vitro: phenotypic plasticity in response to coculture with C6 glioma cells or NGF (1989)
    Springer
    Experimental brain research 76 (1989), S. 38-46 
    Details
    ISSN: 1432-1106
    Keywords: Nerve growth factor ; C6 glioma cells ; Chromaffin cells histofluorescence ; Electron microscopy ; Immunocytochemistry
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary In order to maintain a chronic supply of growth factor for medulla cells in vitro, chromaffin cells from rat, African green monkeys and man were co-cultured with C6 glioma cells, which secrete growth factors that sustain sympathetic neurons in vitro. The response of chromaffin cells to coculture was compared to treatment of medullary cells with nerve growth factor (NGF) alone. Dispersed chromaffin cell preparations were obtained by a trypsin-collagenase procedure, and subjected to differential plating on collagen-coated surfaces. With both human and monkey tissue, non-chromaffin cells did attach to the culture plates and an enriched chromaffin cell population could be replated. Rat adrenal medulla cells survived very poorly in vitro and were not enriched in this procedure. Cultured human and monkey chromaffin cells survived as epithelial cells (50%) and showed neuritic outgrowth on 55 to 66% of the cells after eight days when treated with nerve growth factor (NGF). These cells showed strong catecholamine histofluorescence, tyrosine hydroxylase (TH) and dopamine beta hydroxylase (DBH) immunoreactivity. In contrast, only ten percent of adult rat chromaffin cells survived in culture, although NGF treatment rescued an additional 20% of the cells and induced neuritic outgrowth after one week in vitro. C6 glioma cells were treated with mitomycin C bromodeoxyuridine to inhibit mitosis and were plated with the various medulla cells in a one to one ratio. Both human and monkey chromaffin cells expressed extensive and enhanced neuritic arborization within eight days of co-culture, (64–82% respectively) and exhibited intimate contact with the glioma cells as seen at the ultrastructural level. Importantly, survival of adult rat adrenal medulla cells was enhanced to 50% or more with 40% of the cells extending neurites when co-cultured with glioma cells for seven days. Chromaffin cells from all three species reacted for TH, DBH and PNMT in co-culture and were histofluorescent. The majority of these cells were also immunoreactive for serotonin and enkephalin, while only 37% of chromaffin cells indicated the presence of NPY. These data indicate that adrenal medulla can be maintained in vitro as the neuronal phenotype when co-cultured with growth factor producing cells and that this strategy may be useful for in vivo transplantation studies.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00253621
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  • 56
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    Electronic Resource
    An ultrastructural study of the hypertrophied human papillary muscle cell with special emphasis on specific staining patterns, mitochondrial projections and association between mitochondria and SR (1989)
    Springer
    Virchows Archiv 414 (1989), S. 187-198 
    Details
    ISSN: 1432-2307
    Keywords: Human heart ; Papillary muscle ; Hypertrophy ; Mitochondria ; Specific staining ; Electron microscopy
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary Biopsy material of the hypertrophied human papillary muscle has been processed according to various electron microscopical techniques in order to study the mitochondrial ultrastructure and the association between mitochondria and sarcoplasmic reticulum (SR).En bloc staining with a Cu-Pb citrate solution resulted in specifically contrasted mitochondrial and sarcotubular membranes, characterized by numerous, discrete, electron-dense particles. The differences in staining patterns between the perinuclear mitochondria and their subsarcolemmal and interfibrillar counterparts suggest differences in chemical properties and/or metabolic activities. The selectively contrasted mitochondrial particles may represent a conglomorate of extrinisic and intrinisic respiratory enzymes and other membrane-associated proteins, while the majority of the electron-dense particles of the sarcotubular membrane may represent positively stained Ca2+-pumps. Ultrastructural findings in the present study strongly indicate that the slender mitochondrial projections represent an initial stage in a process leading to the formation of large and pleomorphic mitochondria. Intimate contact between adjacent mitochondria as well as between mitochondria and SR are documented. In the contact regions some of the specifically contrasted particles of the adjacent membranes had fused with each other. It is suggested that these particles represent membrane-bound transport proteins providing a system for interorganelle exchanges of metabolites and/or ions.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00822022
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  • 57
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    Electronic Resource
    Ultrastructural and electron immunohistochemical features of medullary thyroid carcinoma (1989)
    Springer
    Virchows Archiv 414 (1989), S. 375-384 
    Details
    ISSN: 1432-2307
    Keywords: Thyroid neoplasms ; Electron microscopy ; Immunohistochemistry ; Calcitonin
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary An ultrastructural study, both morphological and immunohistochemical, has been carried out on eight thyroglobulin-positive and nine thyroglobulin-negative medullary carcinomas of the thyroid. The morphometric analysis of granule size showed that all tumours contained cells with small granules and cells with medium size granules, whereas eight tumours had additional cells with large granules. The small granules had an electron dense core, while the medium and large sized granules were both pale-cored and dense-cored. The cells with small, medium or large secretory granules were all immunoreactive for calcitonin and CGRP. No ultrastructural differences were observed between thyroglobulin-positive and thyroglobulin-negative cases of medullary carcinoma of the thyroid.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00718620
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    Carcinosarcoma of the urinary bladder (1989)
    Springer
    Virchows Archiv 415 (1989), S. 91-95 
    Details
    ISSN: 1432-2307
    Keywords: Carcinosarcoma ; Urinary bladder ; Immunohistochemistry ; Electron microscopy ; Rhabdomyoblast
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary A case of urinary bladder carcinosarcoma (UBCS) is reported with light, immunohistochemical and electron microscopical findings. The tumour consisted of a squamous cell carcinoma, variable spindle cell stromal elements compatible with fibrosarcoma, and rhabdomyoblasts. Intermediate filament co-expression of cytokeratin and vimentin was shown by immunohistochemistry. Electron microscopy (EM) confirmed the nature of the three components, and indicated some similarities between the three cell-types present. Comparisons with the previous UBCS in the literature are made.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00718608
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  • 59
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    Electronic Resource
    A histopathological study on the prognosis of childhood IgA nephropathy and glomerular basement membrane lesions (1989)
    Springer
    Pediatric nephrology 3 (1989), S. 242-247 
    Details
    ISSN: 1432-198X
    Keywords: IgA nephropathy ; Electron microscopy ; Glomerular basement membrane lesions ; Prognosis
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Abstract Seventy-three patients with IgA nephropathy (IgAGN), under the age of 15 years at the time of the discovery of the disease, were investigated with respect to glomerular basement membrane (GBM) lesions. Irregular attenuation or widening of GBM, especially on the epithelial side, was observed in 28 cases (38%). These two changes are referred to aslysis of GBM and were considered to be the primary and specific changes among the GBM lesions in IgAGN. GBM thickening with layering of lamina densa was found in 37 of 73 cases (51%), but this change has been observed in other types of glomerular diseases. GBM lesions similar to those seen in IgAGN were also observed in Henoch-Schönlein purpura nephritis (HSPN) and poststreptococcal acute glomerulonephritis (PSAGN). Lysis of GBM was observed only in IgAGN, HSPN and PSAGN. Subepithelial and intramembranous deposits appeared to have an important role in the development of these GBM lesions. The presence of GBM lesions was correlated with a high incidence of cellular crescents but not with other clinical or light microscopic findings. The presence of these GBM lesions in IgAGN does not have a significant effect on the prognosis, at least in childhood. The affected GBM seemed to recover without leaving any significant residual damage in most cases. In the long-term prognosis of the disease non-immunological factors, such as ageing or hypertension, seem to be important.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00858523
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  • 60
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    Electronic Resource
    Retinal axons innervate the embryonic chick diencephalon in an in-vivo-like pattern in expiant co-cultures (1989)
    Springer
    Experimental brain research 75 (1989), S. 563-568 
    Details
    ISSN: 1432-1106
    Keywords: Retina ; Diencephalon ; Co-culture ; Synapses ; Electron microscopy
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary Explants of chick embryo diencephalon co-cultured with explants of retina display areas of complex neuropil containing large retinal-like endings which establish synaptic contact with conventional and presynaptic dendrites. Transection of fibre bundles linking retinal to diencephalic explants results in the degeneration of endings of this type, suggesting that axons of extrinsic (retinal) origin innervate the diencephalic explants in an in-vivo-like manner.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00249907
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  • 61
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    Electronic Resource
    Light and electron microscopic studies of calcitonin gene-related peptide-like immunoreactive terminals in the central nucleus of the amygdala and the bed nucleus of the stria terminalis of the rat (1989)
    Springer
    Experimental brain research 77 (1989), S. 217-220 
    Details
    ISSN: 1432-1106
    Keywords: Calcitonin gene-related peptide (CGRP) ; Bed nucleus of the stria terminalis ; Central nucleus of the amygdala ; Ultrastructure ; Rat
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary Light and electron microscopic analysis of calcitonin gene-related peptide (CGRP)-like immunoreactive (LI) terminals in the bed nucleus of the stria terminalis (BST) and the central nucleus of the amygdala (Ce) was carried out using the peroxidase-antiperoxidase method. CGRP-LI fibers were densely distributed in the dorsal subdivision of the lateral BST (BSTL) and the lateral and lateral capsular subdivisions of the Ce, where the CGRP-LI terminals formed symmetrical and asymmetrical axo-dendritic, and symmetrical axosomatic synapses. One of the most characteristic features of the CGRP-LI terminals was the presence of large, long boutons, each of which surrounded a cell soma and made many synaptic contacts. These findings suggest that CGRP exerts a significant influence on neurons in the BSTL and Ce.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00250584
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  • 62
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    A quantitative analysis of the synaptic development of the lobus parolfactorius of the chick (Gallus domesticus) (1989)
    Springer
    Experimental brain research 78 (1989), S. 425-434 
    Details
    ISSN: 1432-1106
    Keywords: Avian forebrain ; Synapses ; Stereology ; Disector ; Electron microscopy
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary The lobus parolfactorius (LPO) of the chick has been shown to undergo an increase in the mean synaptic numerical density (Nv syn) in response to one-trial passive avoidance learning (Stewart et al. 1987). The present study was undertaken in order to describe the pattern of normal development of synapses in the LPO, to further investigate the significance of this plastic response. The LPO's from each hemisphere of pre-hatch (16 days), and post-hatch (1 day, 9 day and 22 day old) chicks were processed for electron microscopy. Synapses were classified into asymmetric spine, asymmetric shaft, symmetric spine, and symmetric shaft synapses, on the basis of the density of the post-synaptic thickening and the nature of the post-synaptic target. A 3-dimensional stereological probe was used (the ‘disector’) to calculate Nv syp, and mean projected height (H syp) of the post-synaptic density (PSD). Mean values for each age and hemisphere were compared with a 2-way analysis of variance test using paired samples. A six-fold increase in Nv syp was seen between 16 days in ovo, and 9 days post-hatch. There was a hemispheric asymmetry at 9 days post-hatch, with the left hemisphere LPO containing 1.6 times as many synapses per μm-3. There was a subsequent period of reduction in synaptic density in the left hemisphere LPO between 9 and 22 days post-hatch. The Nv of all classes of synapse increased with age, but the proportions of the symmetrical synapses with respect to the total number of synapses, decreased with age. This decrease was of a similar magnitude for each hemisphere. A hemispheric difference was seen in post-hatch asymmetric synapses, with a greater proportion of asymmetric spine synapses in the left hemisphere. The magnitude of the hemispheric asymmetry was constant throughout the 3 week period of post-hatch development, but was not present in pre-hatch chicks. The PSD increased in length in each hemisphere by approximately 40% between post-hatch day 1 and post-hatch day 9. These data show that the LPO contains a synaptic population which undergoes substantial modification during the first week post-hatch. An asymmetry exists at post-hatch day 9 which is not present at the earlier ages investigated, nor indeed after 22 days post-hatch. This may have significance with regard to studies of passive avoidance learning in the one-day old chick, where an increase in both the size and number of synapses in the LPO has been demonstrated (Stewart et al. 1987). It is possible that ‘training’, in this situation, may simply enhance the timing of synaptic events that result as a consequence of normal development.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00228916
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  • 63
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    Electronic Resource
    Encapsulated nerve corpuscles in the human tympanic membrane (1989)
    Springer
    European archives of oto-rhino-laryngology and head & neck 246 (1989), S. 169-172 
    Details
    ISSN: 1434-4726
    Keywords: Tympanic membrane ; Ultrastructure ; Sensory receptors ; Nerve endings
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary Encapsulated nerve endings were found in both the subepidermal connective tissue and the lamina propria of a human tympanic membrane. The structure of the corpuscles was round or oval and contained a number of axon terminals with mitochondria and Schwann cell processes. Amorphous materials were present in the intercellular space. These features appear to be advantageous in transmitting mechanical forces on the capsule to the axon terminals and are comparable to the function of a mechanoreceptor. Resultant changes in the shape and stiffness of the tympanic membrane as the result of its dislocation indicate similar changes in the pressure on the corpuscle. The arrangement of the sensory corpuscles suggests that they may play a role in detecting pressure changes in the middle ear cavity.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00456661
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    An experimental study of mucociliary pathology of the eustachian tube in otitis media with effusion induced by irradiation (1989)
    Springer
    European archives of oto-rhino-laryngology and head & neck 246 (1989), S. 428-432 
    Details
    ISSN: 1434-4726
    Keywords: Otitis media with effusion ; Mucociliary system ; Eustachian tube ; Electron microscopy
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary We have examined the function and fine structure of the mucociliary system of the eustachian tube in an experimental study of otitis media with effusion induced by X-ray irradiation. Functional examination demonstrated that the ciliary activity was diminished in such a condition, while morphological observations showed pathological findings including compound cilia, vacuolation of ciliated cells and expansion of intercellular space. These findings show that irradiation-induced otitis media with effusion results in impairment of the mucociliary system. As evidenced by these studies, the mucociliary system in the eustachian tube has an important role in the clearance of fluid produced in the tympanic cavity as well as affording improvement in this disease.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00464303
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  • 65
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    Ultrastructural localization of carbonic anhydrase in the vestibular end organs of the guinea pig (1989)
    Springer
    European archives of oto-rhino-laryngology and head & neck 246 (1989), S. 56-60 
    Details
    ISSN: 1434-4726
    Keywords: Carbonic anhydrase ; Vestibular organ ; Guinea pig ; Histochemistry ; Ultrastructure
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary Carbonic anhydrase activity was demonstrated cytochemically on an ultrastructural level in the vestibular end organs of the guinea pig. Reaction product was found in the dark cells, transitional cells, cells of the planum semilunatum and supporting cells. In the dark cells, reaction product was observed in the cytoplasm as well as in the basal infoldings. Reaction product was also observed in the basal infoldings of the transitional cells and the cells of the planum semilunatum. The globular structures inside the supporting cells, transitional cells and the cells of the planum semilunatum were also surrounded by the reaction product. These findings suggest that carbonic anhydrase may have different functions, such as water and ion transport, respiration, nutrition and calcium carbonate deposition in the vestibular end organs.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00454136
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  • 66
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    The ultrastructure of polymorphic pollen grains of Canna indica L. (1989)
    Springer
    Sexual plant reproduction 2 (1989), S. 193-198 
    Details
    ISSN: 1432-2145
    Keywords: Polymorphism ; Ultrastructure ; Pollen grains ; Canna indica L ; Tannin
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Summary Our investigations on Canna indica L. indicate that the pollen of this species is polymorphic: there are two types of pollen — a larger type and a comparatively smaller type. Transmission electron microscopy (TEM) revealed the presence of small vacuoles containing tannic substances in the generative cell (GC) of the larger grains: the GC of the mature grain contained a higher quantity of tannins than the GC of the immature grain. Mitochondria, lipid bodies, rough endoplasmic reticulum (RER) and microtubular bundles were present in the cytoplasm of the GC. Numerous mitochondria, lipid bodies and plastids were also present in the vegetative cell (VC), with the mitochondria clustered around the vegetative nucleus. The plastids were observed to be associated with the RER cisterns. During the maturation process, the number of starch grains contained in the plastids decreased.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00192766
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    Electronic Resource
    An electron microscope study on in vitro parthenogenesis in sunflower (1989)
    Springer
    Sexual plant reproduction 2 (1989), S. 154-166 
    Details
    ISSN: 1432-2145
    Keywords: Helianthus annuus ; Unfertilized ovule culture ; Parthenogenesis ; Ultrastructure ; Proembryo
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Summary Electron microscope studies have been conducted on the parthenogenesis induced by in vitro culture of unfertilized ovules of sunflower (Helianthus annuus). In comparison with the state of the egg prior to inoculation, some eggs 5 days after culture show striking ultrastructural changes, which include, among others, nuclear migration, an increase in the number and activity of the organelles, a loss of polarity and wall formation at the chalazal end of the cell. Most of these changes are similar to those that occur normally in the zygote, indicating that parthenogenic development has been triggered in these eggs. Such eggs have been termed activated and are presumed to be capable of undergoing parthenogenesis. The parthenogenic proembryos which result share some features in common with zygotic proembryos. In addition, some parthenogenic proembryos exhibit unique properties not found in zygotic proembryos. These include embryos that consist of two parts differing markedly in density, an inversion of polarity, the frequent occurrence of autophagic vacuoles, the thickening of cell walls, a centripetal growth mode of wall formation, the appearance of an incomplete cell wall, free nuclear division, amitosis and degeneration. We believe that these ultrastructural peculiarities are the effects of in vitro culture.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00192762
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  • 68
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    Cell mediated calcification in collagen gel cultures of fetal rat calvaria cells. Loss of gap junctions precedes calcification (1989)
    Springer
    Journal of bone and mineral metabolism 7 (1989), S. 6-17 
    Details
    ISSN: 1435-5604
    Keywords: Intercellular communication ; Gap junction ; Calcification ; Collagen gel ; Ultrastructure
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary To analyze the mechanism of initiation of cell-mediated calcification in hard tussue and its relationship to the frequency of gap junctions, enzymatically isolated cells from fetal rat calvaria cultured in collagen gels were observed ultrastructurally over a time course. Calcification was observed at 2–3 weeks after the initiation of culture when the seeding cellularity and the concentration of β-glycerophosphate were sufficiently high. In the collagen gels, round cells (R), spindle or stellate cells (S), and fat cells (F) were characterised morphologically. The ultrastructural features of initial calcification could be classified into 4 subtypes: 1) a large mass greater than 10 µm in diameter (Type I), 2) deposition associated with dead R cells or matrix vesicles (Type II), 3) intracellular deposition (Type III), and 4) other than Types I–III (Type IV). Type II was the most frequent (44.5%) and Type III was the least (6.8%). Gap junction was observed frequently between 1) R cells, 2) S cells, 3) between R cells and S cells. The frequency of gap junctions in collagen gels decreased statistically (X2-test; p〈0.001), when calcification was initiated. This cell culture system can be regarded as a useful model to analyze the initiation of cell mediated calcification in hard tissue. Gap junctions might function in cell communication and a decrease in their numbers could lead to cell death and, subsequently to calcification.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF02399048
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    Electronic Resource
    Synovial lining cells (1989)
    Springer
    Rheumatology international 9 (1989), S. 49-51 
    Details
    ISSN: 1437-160X
    Keywords: Synovium ; Monoclonal antibodies ; Immunohistochemistry ; Electron microscopy
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary The cells making up the lining of the synovium have long been known as type A and B synoviocytes, with an intermediate form sometimes also described. Accumulating evidence shows that the type A cells are macrophages and the type B cells are fibroblasts. Recently, a definite orientation of these cells within the synovial lining has been observed. The number of synovial lining cells increases in joint disease, and this now seems more likely to be due to cellular recruitment rather than local proliferation.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00270244
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  • 70
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    Electronic Resource
    Revascularization of isolated autologous bone grafts following microsurgical implantation of arteries and veins (1989)
    Springer
    European journal of plastic surgery 12 (1989), S. 29-34 
    Details
    ISSN: 1435-0130
    Keywords: Revascularization ; Vessel implantation ; Bone grafts ; Corrosion casts ; Electron microscopy
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary The microsurgical implantation of a saphenous vascular axis into free transplanted autologous isolated rib segments in Beagle dogs led to complete revascularization of the bone after two, three and four weeks. Indian ink and Mercox-injected specimens showed a vascular network which penetrated the entire cortical layer. Semi-thin sections revealed osteoblasts and osteoclasts visible in the canals of the revascularized cortical layer, while the control specimen without vessel implantation showed nothing but ground substance. The revascularized bones did not contain any necrotic areas. The newly formed vascular system consisted of arteries, veins and their anastomoses. The veins appeared to produce a greater number of new vessels than the arteries.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00226918
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  • 71
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    Ultrastructure ofCyanoptyche gloeocystis f.dispersa (Glaucocystophyceae) (1989)
    Springer
    Plant systematics and evolution 164 (1989), S. 65-73 
    Details
    ISSN: 1615-6110
    Keywords: Algae ; Glaucocystophyceae ; Cyanoptyche gloeocystis f.dispersa ; Ultrastructure ; endocytobiosis ; cyanelles
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract Cyanoptyche gloeocystis f.dispersa (Geitler)Starmach is a palmelloid colonial alga that contains prokaryotic blue-green endocytobionts (cyanelles) instead of chloroplasts. The periphery of the host cell shows a peculiar lacunae system with underlying microtubules. Vegetative cells possess two rudimentary flagella. Zoospores are dorsiventrally shaped with two heterokont and heterodynamic flagella which originate from a subapical depression. This depression can also be seen in vegetative cells. Both flagella possess non-tubular mastigonemes. Main reserve product is starch lying freely in the cytoplasm. Cyanelles, enclosed singly in a host vesicle, are provided with a remnant cell wall. Thylakoids are arranged concentrically. The central part of each cyanelle harbours its DNA and one large polyhedral body, probably a carboxysome.Cyanoptyche gloeocystis f.dispersa shares all taxonomically essential characters with the monadoidCyanophora, the palmelloidGloeochaete, and the coccoidGlaucocystis. All of them are members of the cyanelle-bearing small algal classGlaucocystophyceae. Members of this class serve as model organisms for the evolution of chloroplasts from cyanophycean ancestors.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00940430
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  • 72
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    Cell multiplication and ultrastructure ofMicrasterias denticulata (Desmidiaceae) grown under salt stress (1989)
    Springer
    Plant systematics and evolution 164 (1989), S. 197-208 
    Details
    ISSN: 1615-6110
    Keywords: Algae ; Chlorophyta ; Desmidiaceae ; Micrasterias ; Ultrastructure ; electron microscopy ; cell multiplication ; salt stress
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract Cells ofMicrasterias denticulata Bréb. were kept in nutrient solution of high osmolality (salt stress) for four weeks. In a special cell multiplication test it was established that cell division is gradually inhibited at increasing salt concentrations and totally arrested at the highest concentration (26 mosm/kg). “Recovery studies” proved that even cells from the highest concentration range start dividing immediately after being placed in aqua bidest. thus indicating the full reversibility of the inhibiting effect. — Cells of the highest concentration range show marked ultrastructural changes. Besides an enormous accumulation of starch and oil bodies and a condensed appearance of the ground plasma, a reduction of mitochondria, ER and the Golgi-system is found. The most striking effect occurs on the vacuolar system which appears extremely reduced and condensed. The cell wall is thickened by the formation of an additional cell wall layer with a “spongy” electron microscopical appearance. Through the cell wall many droplets of a probably fat-like substance are excreted. — In summary, salt stress induces growth-inhibited “akinete” cells in the sense ofFritsch; these can be reactivated by decreasing the salt concentration. The salt-induced “akinete state” seems to be an ecological adaption to unfavourable conditions rather than a degeneration of the cells.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00940437
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    Comparative ultrastructure of the zoospores of nine species ofNeochloris (Chlorophyta) (1989)
    Springer
    Plant systematics and evolution 168 (1989), S. 195-219 
    Details
    ISSN: 1615-6110
    Keywords: Algae ; Chlorophyta ; Chlorophyceae ; Pleurastrophyceae ; Hydrodictyon ; Neochloris ; Pediastrum ; Sphaeroplea ; Ultrastructure ; flagellar apparatus
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract Nine species ofNeochloris can be divided into three groups on the basis of comparative ultrastructure of the flagellar apparatus, the cell wall and the pyrenoid of zoospores. In Group I,N. wimmeri andN. minuta, zoospores are thin-walled, pyrenoids are penetrated by stromal channels, and the basal bodies are in the clockwise absolute orientation and connected by the distal and two proximal fibers. In Group II,N. aquatica, N. vigenis, N. terrestris, N. pyenoidosa, andN. pseudostigmatica, zoospores are naked or covered by fuzzy material, pyrenoids are covered by a continuous starch sheath or invaginated by cytoplasmic channels, basal bodies are directly opposed, the distal fiber is differentiated into a ribbed structure at the central region, a striated microtubule-associated component (SMAC) is continuous between opposite two-membered rootlets and connected to the ribbed structure, proximal ends of basal bodies are covered by partial caps, each two-membered rootlet and a basal body are connected by a striated fiber to the X-membered rootlet associated with the opposite basal body, and the basal bodies, when oriented at wide angles, are joined at their proximal ends by core extensions. In Group III,N. pseudoalveolaris andN. cohaerens, zoospores are naked, pyrenoids are traversed by parallel thylakoids, basal bodies are in the counterclockwise absolute orientation and overlapped, and each X-membered rootlet is connected to the end of the opposite basal body by a terminal cap. It is suggested that the genusChlorococcopsis gen. nov. be erected for the Group I species. Group II, which includes the type species,N. aquatica, should be preserved asNeochloris. The group appears to be closely related to the coenobial generaPediastrum, Hydrodictyon, andSorastrum, and to have affinities with the coenocytic generaSphaeroplea andAtractomorpha as well. It is also suggested that the genusParietochloris gen. nov. be erected in thePleurastrophyceae for the species of Group III.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00936099
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    Effect of disuse on the ultrastructure of the achilles tendon in rats (1989)
    Springer
    European journal of applied physiology 59 (1989), S. 239-242 
    Details
    ISSN: 1439-6327
    Keywords: Collagen fibre ; Achilles tendon ; Disuse ; Atrophy ; Ultrastructure
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary We examined the influence exerted, through disuse of the hindlimb, on the collagen fibres of the achilles tendon in rats. With disuse the body mass decreased by 28%, and the mass of soleus muscle decreased by 20%. A decrease in the surface area and diameter was observed in the experimental group when compared to the control group. A histogram of the collagen fibres showed a decrease of the thick fibres in the experimental group. The maximum surface area of collagen fibres in the experimental group was seen to be only 43% of that of the control group. These results showed a decrease in the thickness of the collagen fibres of the achilles tendon through disuse. This seemed to suggest that resistance to tension is decreased by disuse.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF02386194
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  • 75
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    Electronic Resource
    Ultrastructural responses of tobacco pollen tubes to heat shock (1989)
    Springer
    Protoplasma 153 (1989), S. 104-110 
    Details
    ISSN: 1615-6102
    Keywords: Nicotiana sylvestris ; Pollen tube growth ; Heat shock ; Ultrastructure ; Endoplasmic reticulum ; Mitochondria ; Golgi apparatus
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Summary The effect of elevated temperatures on semivivo growth and ultrastructure of tobacco pollen tubes was investigated. Tube growth was decreased by about 50% at 35 °C, independent of the duration of treatment, and at 40 °C and above there was no growth of tubes. Heat treatment caused ultrastructural changes like accumulation of membranous materials, concentric stacking of rough endoplasmic reticulum, reduction in vesicle production by dictyosomes, increase in the fenestrated regions of the Golgi cisternae, swelling of mitochondrial saccules and increase in the electron density of the mitochondrial matrix. Furthermore, the dictyosomes of the treated tubes showed significant increase in the number of cisternae from 30 to 45 °C. The temperature induced changes were persistant at least for 24 h in 35 °C grown pollen tubes. The possible reasons for the tube growth inhibition are discussed on the basis of the ultrastructural alterations caused by elevated temperatures.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF01322470
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    Ultrastructural studies of spermatogenesis inAnthocerotophyta V. Nuclear metamorphosis and the posterior mitochondrion ofNotothylas orbicularis andPhaeoceros laevis (1989)
    Springer
    Protoplasma 151 (1989), S. 137-150 
    Details
    ISSN: 1615-6102
    Keywords: Bryophyte ; Notothylas ; Nuclear metamorphosis ; Phaeoceros ; Posterior mitochondrion ; Spermatogenesis ; Ultrastructure
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Summary Ultrastructural observations reveal that the spermatozoids of the hornwortsNotothylas andPhaeoceros contain two mitochondria and not one as described previously. Mitochondrial ontogeny and nuclear metamorphosis during spermiogenesis in these plants differ from all other archegoniates. The discovery that the posterior region of the coiled nucleus (when viewed from the anterior aspect) lies to the left of the anterior, in striking contrast to the dextral coiling of the nucleus of spermatozoids of other embryophytes, underlines the isolated nature of the hornworts among land plants. As the blepharoplast develops, the numerous ovoid mitochondria initially present in the nascent spermatid fuse to form a single elongated organelle which is positioned subjacent to the MLS and extends down between the nucleus and plastid. At the onset of nuclear metamorphosis, the solitary mitochondrion has separated into a larger anterior mitochondrion (AM) associated with the MLS and a much smaller posterior mitochondrion (PM) adjacent to the plastid. The PM retains its association with the plastid and both organelles migrate around the periphery of the cell as the spline MTs elongate. By contrast, in moss spermatids, where mitochondria undergo similar fusion and division, the AM is approximately the same size as the PM and the latter is never associated with the spline. As in other archegoniates, except mosses, spline elongation precedes nuclear metamorphosis in hornworts. Irregular strands of condensed chromatin compact basipetally to produce an elongated cylindrical nucleus which is narrower in its mid-region. During this process excess nucleoplasm moves rearward. It eventually overarches the inner surface of the plastid and entirely covers the PM.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF01403451
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    Ultrastructural changes in maturing pollen grains ofApium nodiflorum L. (Apiaceae), with special reference to the endoplasmic reticulum (1989)
    Springer
    Protoplasma 152 (1989), S. 69-76 
    Details
    ISSN: 1615-6102
    Keywords: Apiaceae ; Apium nodiflorum ; Endoplasmic reticulum ; Pollen grain ; Polysaccharide particles ; Ultrastructure
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Summary The ultrastructural events in 3-cellular pollen grains ofApium nodiflorum L. are investigated during pollen maturation. Three distinct developmental stages are distinguished from the formation of sperm cells up to anthesis, whereby the rough endoplasmic reticulum (RER) is mainly involved. The most conspicious form is the highly dilated RER in the vegetative cytoplasm of the youngest pollen grains, which changes to vesicular RER in the following stage. In mature pollen grains the RER has a narrow cisternal configuration and often forms stacks. Pollen activation is preceded by the accumulation of polysaccharide particles.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF01323064
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  • 78
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    Ultrastructure of the nitrogen-fixing, filamentous, nonheterocystous cyanobacterium,Plectonema boryanum (1989)
    Springer
    Protoplasma 152 (1989), S. 130-135 
    Details
    ISSN: 1615-6102
    Keywords: Plectonema boryanum ; Cyanobacteria ; Ultrastructure ; Nitrogen fixation ; Nitrogen starvation ; Immunogold localization
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Summary The ultrastructure of fructose-supplemented and unsupplemented nitrogen-fixing (fix +) and nonfixing (fix −)Plectonema boryanum UTEX 581 cells was examined by transmission electron microscopy. The most prominent structural differences included the arrangement and morphology of the thylakoids and alterations in the appearance of the interthylakoidal spaces. These ultrastructural differences, together with other observations such as glycogen content and presence of nitrogenase (using acetylene reduction assay and immunogold localization), readily distinguished nonfixingP. boryanum from nitrogen-fixing cells.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF01323072
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  • 79
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    The role of kinetosome-associated organelles in the attachment of encysting secondary zoospores ofSaprolegnia ferax to substrates (1989)
    Springer
    Protoplasma 149 (1989), S. 163-174 
    Details
    ISSN: 1615-6102
    Keywords: Adhesion ; Carbohydrates ; Exocytosis ; K-bodies ; Lectins ; Saprolegnia ; Ultrastructure
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Summary Electron and fluorescence microscopy were used to identify organelles involved in attachment of secondary zoospores ofSaprolegnia ferax as they were transformed into secondary cysts. When secondary zoospores were exposed to 1.0% peptone in the absence or presence of a substrate, they began to encyst. If substrates were present when encystment was induced, the groove surface of the secondary zoospores adhered to them. The first event in attachment was secretion of contents of the kinetosome-associated organelle (K-body), which was typically oriented with the tubule-filled cavity positioned toward the cell surface of the groove region in the zoospore. The tubules which contained carbohydrates became coarsely granular, the matrix became more fibrous, and the shell remained along the membrane concavity that was formed as the K-body fused with the plasma membrane. Five minutes later, a cyst coat appeared, and cysts were not readily dislodged from a substrate. The concavity was no longer found, presumably because it had evaginated; but a layered pad of adhesion material was between the cyst coat and substrate. The layers of the adhesion pad corresponded to the structure of the matrix of K-bodies. As with the tubules of the K-body, the coarsely granular portion at the edge of the pad stained for carbohydrates. Similarly, the lectins WGA and GS-II labeled with fluorescein stained the rim of the adhesion pad on cysts, indicating the presence of glycoconjugates containing N-acetylglucosamines. Because globular areas near the kinetosomes and groove of zoospores (where K-bodies were located) also bound WGA and GS-II, K-bodies contained the same carbohydrates as the adhesion pad. We conclude that K-bodies function in the attachment of encysting zoospores to substrates as the cell differentiates. The tubular portion of the K-body matrix contains carbohydrates which might assist in the adhesion process.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF01322988
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  • 80
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    The cytoskeletal involvement in cellularization of theDrosophila melanogaster embryo (1989)
    Springer
    Protoplasma 150 (1989), S. 83-95 
    Details
    ISSN: 1615-6102
    Keywords: Drosophila melanogaster embryo ; Cellularization ; Cleavage furrow ; Ultrastructure ; Cytoskeleton ; Mitosis
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Summary The distribution and arrangement of cytoskeletal components in the early embryo ofDrosophila melanogaster were examined by thin-section electron microscopy to elucidate their involvement in the formation of the cellular blastoderm, a process called cellularization. During the final nuclear division in the cortex of the syncytial blastoderm bundles of astral microtubules were closely associated with the surface plasma membrane along the midline where a new gutter was initiated. Thus the new gutter together with the pre-formed ones compartmentalized the embryo surface to reflect underlying individual daughter nuclei. Subsequently such gutters became deeper by further invagination of the plasma membrane between adjacent nuclei to form so-called cleavage furrows. Nuclei simultaneously elongated in the direction perpendicular to the embryo surface and numerous microtubules from the centrosomes ran longitudinally between the nucleus and the cleavage furrow. Microtubules often appeared to be in close association with the nuclear envelope and the cleavage furrow membrane. The plasma membrane at the advancing tip of the furrow was always undercoated with an electron-dense layer, which could be shown to be mainly composed of 5–6 nm microfilaments. These microfilaments were decorated with H-meromyosin to be identified as actin filaments. As cleavage proceeded, each nucleus with its perikaryon became demarcated by the furrow membrane, which then extended laterally to constrict the cytoplasmic connection between each newly forming cell and the central yolk region. The cytoplasmic strand thus formed possessed a prominent circular bundle of microfilaments which were also decorated with H-meromyosin and bidirectionally arranged, similar in structure to the contractile ring in cytokinesis. These observations strongly suggest that both microtubules and actin filaments play a crucial role in cellularization ofDrosophila embryos.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF01403663
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  • 81
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    The effect of fuel oil on the ultrastructure of the chlorococcal algaScenedesmus armatus (1989)
    Springer
    Protoplasma 151 (1989), S. 47-56 
    Details
    ISSN: 1615-6102
    Keywords: Scenedesmus ; Fuel oil ; Ultrastructure
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Summary Characteristic changes in the ultrastructure of the green algaScenedesmus armatus, grown in batch culture in the presence of aqueous fuel-oil extract (AFOE) have been observed. The changes affected mainly chloroplasts and mitochondria. The regular arrangement of the thylakoid stacks became distorted and the whole chloroplast lobed. Plastoglobules were more numerous in the treated cells than in the controls, especially after long-term exposure to AFOE. The mitochondrial matrix cells exposed to AFOE were more electron-translucent. An increase in the number of small mitochondrial profiles was observed after prolonged treatment with AFOE. The number and size of osmophilic bodies increased markedly in the cytoplasm of the treated cells. The cytochemical reaction of these bodies with Sudan black B indicated their lipid composition. Plasmalemma invagination into the cytoplasm and vacuoles, cytoplasmic “layers”, and an increase in size of the vacuolar compartment were observed in cells exposed to AFOE for a long time. The possibility that detoxification, involving microbody activity, may have occurred inScenedesmus is suggested.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF01403300
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  • 82
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    An unusual feature of developing protophloem sieve elements in roots ofTriticum aestivum L. (1989)
    Springer
    Protoplasma 152 (1989), S. 14-21 
    Details
    ISSN: 1615-6102
    Keywords: Differentiation ; Heterochronic lysis ; Polarity ; Root protophloem sieve elements ; Triticum aestivum ; Ultrastructure
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Summary Developing protophloem sieve elements in roots of wheat are arranged in single vertical files. In the last immature differentiating sieve element bearing ribosomes the proximal end of the cytoplasm displays a diluted appearance in contrast to the distal end where the cytoplasm exhibits a considerably increased electron density. Differences can also be observed in ribosome quantity, organelle ultrastructure and the time of initiation of cell component degradation, those at the proximal end disorganizing first, suggesting a nonsimultaneous disorganization of the cell components in the two areas. This phenomenon, termedheterochronic lysis, is presumably an expression of an existing polarity not detectable in younger stages, but it might also be the result of an asynchronous enzymatic activity.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF01354235
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  • 83
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    Mallomonas alphaphora (Chrysophyceae), a new species from Western Australia (1989)
    Springer
    Plant systematics and evolution 164 (1989), S. 209-214 
    Details
    ISSN: 1615-6110
    Keywords: Algae ; Chrysophyceae (Synurophyceae) ; Mallomonadaceae ; Mallomonas alphaphora ; Electron microscopy ; phytoplankton ; scale-bearing flagellate ; taxonomy
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract A new species ofMallomonas, M. alphaphora (Chrysophyceae), was found in freshwater ponds in the Perth region, Western Australia. It is distinguished from other species ofMallomonas by its very distinctive scale and bristle morphology and is placed in a new section,Alphaphorae, of the genusMallomonas.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00940438
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  • 84
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    System-specific distribution of zinc in the chick brain (1989)
    Springer
    Cell & tissue research 258 (1989), S. 247-257 
    Details
    ISSN: 1432-0878
    Keywords: Zinc ; Timm method ; Ultrastructure ; Synapses ; Avian brain ; Domestic fowl
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary The brain of young domestic chicks was investigated using a Timm sulfide silver method. Serial Vibratome sections were analyzed under the light microscope, and the localization of zinc-positive structures in selected areas was determined at the ultrastructural level. Both strong and differential staining was visible in the avian telencephalon whereas most subtelencephalic structures showed a pale reaction. The highest staining intensity was found in the nonprimary sensory regions of the telencephalon such as the hyperstriatum dorsale, hyperstriatum ventrale, hippocampus, palaeostriatum augmentatum, lobus parolfactorius and caudal parts of neostriatum. There was an overall gradient of staining intensity in neostriatal areas from rostral to caudal with the heaviest zinc deposits in the caudal neostriatum. Primary sensory projection areas, such as the ectostriatum (visual), hyperstriatum intercalatum superius (visual), nucleus basalis (beak representation), the input layer L2 of the auditory field L and the somatosensory area rostral to field L were selectively left unstained. Fiber tracts throughout the brain were free of zinc deposits except for glial cells. In electron micrographs of stained regions, silver grains were localized in some presynaptic boutons of asymmetric synapses (Gray type I), within the cytoplasm of neuronal somata and sporadically in the nucleus. The possible involvement of zinc in synaptic transmission and other processes is discussed.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00239445
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  • 85
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    Ultrastructural changes in granule cell somata and mossy fibers of the rat hippocampus during picrotoxin-induced convulsions (1989)
    Springer
    Cell & tissue research 255 (1989), S. 261-267 
    Details
    ISSN: 1432-0878
    Keywords: Hippocampus ; Mossy fibers ; Picrotoxin ; Ultrastructure ; Rat (Wistar)
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary Ultrastructural changes in hippocampal granule cells, mossy fibers and mossy fiber boutons were examined following the administration of picrotoxin in adult rats. Generalized seizures occurred within 5–10 min after the intraperitoneal injection of picrotoxin. The electron-microscopic examination of hippocampal tissues from rats that had been perfused with fixative during the seizure revealed that the large dense-core vesicles increased in number and accumulated on the presynaptic membranes of mossy fiber boutons; some of these vesicles appeared to be fused with the membranes, and omega-shaped exocytotic profiles were frequently seen. Furthermore, greatly increased numbers of coated vesicles (60–90 nm in diameter) were observed on the maturing faces of Golgi fields of granule cells. Thus, our study not only indicates an increased incidence of exocytosis of large dense-core vesicles during picrotoxin-induced seizures, but also suggests that these vesicles are replaced in excess from the perikaryon of the granule cell.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00224107
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  • 86
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    Distribution of peroxidase and iodination activity in the endostyles of Oikopleura albicans and Oikopleura longicauda (Appendicularia, Chordata) (1989)
    Springer
    Cell & tissue research 255 (1989), S. 505-510 
    Details
    ISSN: 1432-0878
    Keywords: Endostyle ; Peroxidase cytochemistry ; Autora diography ; Ultrastructure ; Oikopleura albicans, Oikopleura longicauda (Appendicularia)
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary Oikopleura albicans and O. longicauda belong to the two subgenera Vexillaria and Coecaria, respectively. The morphology and ultrastructure of their endostyles were investigated with conventional microscopic procedures as well as with DAB cytochemistry and 125I autoradiography at both light- and electron-microscopic levels. As expected, the general morphology of these endostyles is similar to all hitherto examined endostyles. They possess a ventral portion consisting of alternating glandular and ciliated cell zones, probably serving food capture, and a dorsal region, the corridor. Autoradiographic grains were found mainly in the corridor lumen associated with the apical surface of the two central rows of corridor cells. The same cells also gave strong positive reactions for peroxidase, the iodinating enzyme. Peroxidase activity was found in the apical plasma membrane as well as in the nuclear envelope, rough endoplasmic reticulum, Golgi area and cytoplasmic vesicles. Definitive conclusions concerning an apical uptake and subsequent release into the body fluid of iodinated material could not be made from the present experiments. Our investigations indicate that the two central rows of corridor cells in both subgenera of oikopleurids constitute the protothyroid region, possibly homologous to the vertebrate thyroid gland.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00218785
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    Terminal processes of serotonin neurons in the caudal spinal cord of the molly, Poecilia latipinna, project to the leptomeninges and urophysis (1989)
    Springer
    Cell & tissue research 255 (1989), S. 619-625 
    Details
    ISSN: 1432-0878
    Keywords: Serotonin-containing cells ; Urophysis ; Spinal Cord ; Ultrastructure ; Leptomeninges ; Poecilia latipinna (Teleostei)
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary The caudal neurosecretory complex of poeciliids has previously been shown to be innervated by extranuclear and intrinsic serotonergic projections. In the present study, immunohistochemical techniques were used to characterize fibers originating from serotonin neurons intrinsic to the caudal spinal cord. Bipolar and multipolar neurons were oriented ventromedially, and contained numerous large granular vesicles. Three types of serotonergic fibers were distinguished based on their distribution and morphology. Intrinsic Type-A fibers branched into varicose segments near the ventrolateral surface of the spinal cord and contacted the basal lamina beneath the leptomeninges. Type-B fibers coursed longitudinally to enter the urophysis, where they diverged and terminated around fenestrated capillaries. Labelled vesicles in Type-A and Type-B terminals were the same size as those in labelled cells and in unlabelled neurosecretory terminals in the urophysis. Type-C small varicose fibers branched within the neuropil of the caudal neurosecretory complex. Serotonin may be secreted into the submeningeal cerebrospinal fluid, the urophysis, and the caudal vein by Type-A and Type-B fibers, whereas, Type-C fibers may be processes of serotonergic interneurons in the neuroendocrine nucleus. The possibility that urotensins I and II or arginine vasotocin were colocalized in the processes of the intrinsic serotonin neurons was investigated immunohistochemically. The negative results of these experiments suggest that serotonin-containing neurons may represent a neurochemically distinct subpopulation in the caudal neurosecretory complex.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00218799
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  • 88
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    Immature rat epididymal epithelial cells grown in static primary monolayer culture on permeable supports (1989)
    Springer
    Cell & tissue research 256 (1989), S. 573-580 
    Details
    ISSN: 1432-0878
    Keywords: Epididymis ; Epithelium ; Monolayer culture ; Histochemistry ; Electron microscopy ; Rat (Sprague-Dawley)
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary N-acetylglucosaminidase (NAG), acid phosphatase (ACP) and alkaline phosphatase (AKP) were localised histochemically in fixed cells from the 37-day-old rat epididymis grown in static monolayer culture for 2–8 days. ACP and NAG were cytosolic enzymes found in perinuclear positions, whereas staining of AKP was consistent with a membranous position. These enzymes were also examined in frozen tissue sections of the epididymis, from rats of the equivalent age, where NAG had intense activity in both supra- and infra-nuclear cytoplasm and ACP was more active apically. For the first time AKP was localised along basolateral membranes of the epithelium and in the lumen of the mid-caput region. The monolayer in culture was of principal cells only and they maintained their polarity and ultrastructural characteristics, but the height of the cells was reduced compared to that obtained in situ.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00225606
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  • 89
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    Morphogenesis of rat cranial meninges (1989)
    Springer
    Cell & tissue research 257 (1989), S. 207-216 
    Details
    ISSN: 1432-0878
    Keywords: Morphogenesis ; Meninges ; Mesenchyme ; Ultrastructure ; Rat (Wistar)
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary The meninges of albino Wistar rat embryos, aged between the 11th embryonic day (ED) and birth, were sectioned using a specially constructed device. This technique permits optimal microanatomical preservation of all tissues covering the convexity of the brain: skin, muscle, cartilage or bone, and the meninges. At ED11, the zone situated between the epidermis and the brain is occupied by a mesenchymal network. At ED12, part of this delicate network develops as a dense outer cellular layer, while the remainder retains its reticular appearance, thus forming an inner layer (the future meningeal tissue). At ED13, the dura mater starts to differentiate. At ED14, the bony anlage of the skull can be identified, and along with the proceeding maturation of dura mater some fibrillar structures resembling skeletal muscle fibers appear in the developing arachnoid space. At ED15–17, a primitive interface zone — dura mater/ arachnoid — is formed, comprised by an outer electronlucent and an inner electron-dense layer marking the outer aspect of the arachnoidal space. At ED18–19, the innermost cellular row of the inner durai layer transforms into neurothelium, which is separated from the darker arachnoidal cells by an electron-dense band. The arachnoidal trabecular zone with the leptomeningeal cells is formed at ED19. By the end of the prenatal period (ED20–21), its innermost part organizes into an inner arachnoidal layer and an outer and inner pial layer. The results from this study indicate (i) that dura mater and leptomeninges develop from an embryonic network of connective tissue-forming cells, and (ii) that the formation of cerebrospinal fluid (CSF)-containing spaces accompanies the differentiation of the meningeal cellular layers.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00221652
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  • 90
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    Two types of mammosomatotropes in mouse adenohypophysis (1989)
    Springer
    Cell & tissue research 256 (1989), S. 645-648 
    Details
    ISSN: 1432-0878
    Keywords: Mammosomatotropes ; Adenohypophysis ; Electron microscopy ; Immunohistochemistry ; Mouse (SMA)
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary Two types of mammosomatotropes (MS), the small-granule and vesicle-granule MS, were detected in mouse adenohypophysis by electron microscopy and immunohistochemistry. Both cell-types were immunoreactive to prolactin (PRL) and growth hormone (GH) antisera. The small-granule MS contained small, round, solid secretory granules about 100 nm in diameter, and were smaller than the classical GH and PRL cell-types. The vesicle-granule MS contained secretory granules like cored vesicles, and were larger than classical GH and PRL cells. Small-granule MS were immunoreactive to both PRL and GH antisera in the same region of the cell cytoplasm; the vesicle-granule MS, however, were immunoreactive to only PRL antiserum in most cytoplasmic areas, and a positive response to both PRL and GH antisera was confined to only certain small areas.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00225615
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  • 91
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    Localization of cholesterol in the colonic epithelium of the guinea pig: regional differences and functional implications (1989)
    Springer
    Cell & tissue research 258 (1989), S. 339-347 
    Details
    ISSN: 1432-0878
    Keywords: Proximal colon ; Distal colon ; Cholesterol ; Filipin ; Freeze-fracture ; Electron microscopy ; Guinea Pig
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary It is generally accepted that variations in membrane cholesterol content affect the fluidity of the bilayer, thus altering its permeability. In the biological membranes, in physiological conditions, a high cholesterol content rigidifies the bilayer decreasing its permeability, a lower cholesterol content induces the opposite effect by increasing the permeability. Since differences in the epithelial permeability for short chain fatty acids have previously been demonstrated in the proximal and distal colon of the guinea pig, these two regions were investigated to establish whether differences in membrane cholesterol content of the absorbing cells can be demonstrated. Freeze-fracture replicas of filipin-treated colonic tissue were used. The results show that in the proximal colon the density of filipin cholesterol complexes located on the luminal plasma membrane of the columnar absorbing cells was significantly higher (about twice) than in the distal colon. Therefore the lower amount of cholesterol present in the membrane of the absorbing cells in the distal colon indicates a greater fluidity of the membranes of the epithelial cells in this region. Such fluidity could be correlated to the higher absorption rates of shortchain fatty acids characteristic of this region.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00239454
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  • 92
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    Quantitative electron microscopy of endocrine cells in oxyntic mucosa of normal human stomach (1989)
    Springer
    Cell & tissue research 255 (1989), S. 41-48 
    Details
    ISSN: 1432-0878
    Keywords: Stomach ; Endocrine cells ; Electron microscopy ; Morphometry ; Man
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary An ultrastructural morphometric study of the endocrine cells of the oxyntic mucosa of the stomach in gastric biopsies collected from five male and five female healthy volunteers aged 19–31 was performed. No sex-related differences were disclosed. Endocrine cells accounted for 1.2±0.4% of the epithelial volume and 0.9±0.4% of the mucosal volume, i.e., including the lamina propria. After classification of the specific endocrine cell types according to the ultrastructural morphology of secretory granules, the volume densities of ECL, P and D cells (30±9%, 24±7%, and 22±4% of the entire endocrine cell mass, respectively) were higher than those of other endocrine cell types. In particular, EC cells contributed less than 10% and X cells represented a very low proportion of the total cells. Non-granulated profiles of cells which in all other respects appeared to be endocrine were also found with a volume density of 8±4%. D cells were distinguished by the high fraction of cytoplasm occupied by secretory granules (31±5%). Subdivision of the whole mucosa into four horizontal segments revealed the endocrine cells to be mostly distributed in the three lower, with virtually no endocrine cells in the superficial segment. The quantitative ultrastructural analysis of the endocrine cell population of the normal human oxyntic mucosa provided by this study may allow a better evaluation of physiological and pharmacological variations of the endocrine cell population.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00229064
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  • 93
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    Neural activity pattern is not necessary for the development of adult ultrastructure in katydid (Neoconocephalus robustus) singing muscles (1989)
    Springer
    Cell & tissue research 255 (1989), S. 641-644 
    Details
    ISSN: 1432-0878
    Keywords: Insect muscle ; Denervation ; Ultrastructure ; Development, ontogenetic ; Neoconocephalus robustus (Insecto)
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary The singing muscles of the katydid Neoconocephalus robustus develop adult ultrastructure late in the last nymphal instar and during the first few days of adult life. The ultrastructural changes during early adulthood were not affected by unilateral axotomy shortly after the adult molt. Both denervated and innervated muscles developed adult proportions of mitochondria, myofibril, and sarcoplasmic reticulum and transverse tubules.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00218802
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  • 94
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    Gestational changes in hamster adrenal cortex: Morphometric and ultrastructural stereologic studies (1989)
    Springer
    Cell & tissue research 256 (1989), S. 241-246 
    Details
    ISSN: 1432-0878
    Keywords: Adrenal cortex ; Pregnancy ; Electron microscopy ; Stereology ; Golden hamster
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary In the hamster, the weight of the adrenal glands increases during the course of gestation, with the highest value at day 5. In comparison to non-pregnant control animals, there were no changes in the volume of the zona glomerulosa (ZG) and zona fasciculata (ZF), while the volume of the zona reticularis (ZR) increased notably. The average volume of ZG-cells rose at day 5 of pregnancy and thereafter gradually decreased to that of control hamsters. A marked drop in the volume of ZF-cells was seen at days 5 and 10 of pregnancy, whereas at day 15 the cells were larger than in controls. At day 5 of pregnancy, a conspicuous increase in the cell volume was found in ZR, followed by lower values at day 10 and again higher than in control hamsters at day 15. The total number of parenchymal cells in hamster adrenal cortex increased at day 10 of gestation, then underwent a marked decrease, reaching the control value at the final day of pregnancy; this drop was mainly due to a reduction in the number of ZF-cells. The changes in the cell volume were paralleled by rather proportional changes in the volume of the mitochondrial compartment and in the quantity of smooth endoplasmic reticulum. The volume of the lipid-droplet compartment significantly rose in the course of gestation in both ZF- and ZR-cells. The cortisol output by adrenal homogenates gradually decreased during pregnancy.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00218881
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  • 95
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    Electronic Resource
    Effects of long-term hypergastrinaemia on the ultrastructure of enterochromaffin-like cells in the stomach of the rat, hamster and guinea pig (1989)
    Springer
    Cell & tissue research 256 (1989), S. 247-257 
    Details
    ISSN: 1432-0878
    Keywords: Enterochromaffin-like cells ; Ultrastructure ; Hypertrophy ; Hypergastrinaemia ; Gastrin infusion ; Omeprazole ; Rat (Sprague Dawley) ; Syrian hamster ; Guinea pig
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary The present report describes the ultrastructure of the enterochromaffin-like (ECL) cells in the stomach of the rat, hamster and guinea pig, and the ultrastructural consequences of long-term hypergastrinaemia evoked either by continuous infusion of synthetic human (Leu15)-gastrin-17 for 4 weeks (rats) or by daily treatment with large doses of the antisecretory agent omeprazole for 2–10 weeks (rats, hamsters and guinea pigs). As a result, the ECL cells increased greatly in size (maximal effect after 2 weeks of omeprazole treatment, no further gain in size after 4 or 10 weeks). Also the endoplasmic reticulum and Golgi area were enlarged. The most conspicuous feature of the ECL cells is the cytoplasmic vesicles, which are of varying size and either devoid of a dense core or with a small, often eccentrically located dense core. The vesicles probably represent the main storage site of the secretory products of the ECL cell. In addition, the cytoplasm contains granules, which differ from the vesicles in that they possess a more or less electron-dense core, surrounded by a narrow halo. The size of the vesicles ranged from small to very large, while the granules were uniformly small. Many vesicles were seen to lie very close together, some displaying an irregular outline (vacuole-like vesicles), at times giving the impression that they were undergoing fusion. The profile size (median value) of the vesicles was unaffected by gastrin infusion for 4 weeks. However, there was a tendency to a relative increase in the number of very small vesicles. In contrast, the vesicles became larger during the omeprazole treatment. Also, the number of vesicles that seemed to be engaged in fusion increased after omeprazole treatment but not after gastrin infusion. The observations support the view that ECL cells are influenced by gastrin. The effects of gastrin infusion and of omeprazole treatment on ECL cell ultrastructure were not completely identical. It cannot be excluded that the omeprazole-evoked achlorhydria evokes effects unrelated to those of hypergastrinaemia on the ECL cells, or that endogenous gastrins may evoke effects that are in some ways distinct from those of synthetic human (Leu15)-gastrin-17. Alternatively, the additional effects seen after long-term omeprazole treatment may reflect simply the duration of the hypergastrinaemic stimulus.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00218882
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  • 96
    Electronic Resource
    Electronic Resource
    Morphological changes in the junctional complex of cells in the arachnoid layer of the rat after cold injury (1989)
    Springer
    Cell & tissue research 256 (1989), S. 303-307 
    Details
    ISSN: 1432-0878
    Keywords: Arachnoid cells ; Tight and gap junctions ; Cold injury ; Ultrastructure ; Freeze-fracture technique ; Rat
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary The junctional complexes of cells in the outer arachnoid layer overlying the cerebral cortex of 2-week-old rats were examined with freeze-fracture electron microscopy up to 60 min after transcranial cold injury to the dorsal surface of the brain. Within 30 min after injury, areas of gap and tight junctions with morphological features characteristic of junction formation and/or junction disruption were found scattered among normal junctional complexes in some arachnoid cells. Within 60 min after injury, tight junctions with features typical of less leaky zonulae occludentes were present in all arachnoid cells examined. These morphological features include increases in the number of tight junctional strands and the number of strand-to-strand anatomoses. Gap junctions were interspersed among the tight junctional strands, and many were completely encircled by the strands. The increase in the number and complexity of the tight junctional strands in response to brain injury may be the morphological basis for the maintenance of the cerebrospinal fluid-blood dural barrier.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00218887
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  • 97
    Electronic Resource
    Electronic Resource
    Glomerular podocytes in cultured rat kidney slices (1989)
    Springer
    Cell & tissue research 256 (1989), S. 419-429 
    Details
    ISSN: 1432-0878
    Keywords: Kidney ; Glomerulus ; Podocytes ; Tissue culture ; Electron microscopy ; Morphometry ; Rat (Sprague Dawley)
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary The ultrastructure of rat glomerular epithelial cells (podocytes) in kidney slices in vitro was examined using qualitative and quantitative electron microscopy. The kidney slices were cultured in Medium 199 with Hanks' salts in a 5% CO2/95% O2 environment for up to 14 days. Few changes in podocyte ultrastructure occurred in the first 12 h of culture, but by 24 h cell bodies were rounded, microvilli were present on all podocyte surfaces, and some foot processes had been replaced by flattened expanses of cytoplasm. These changes were more pronounced by 3 days, when some podocytes had developed pseudopodal extensions and appeared to be migrating from glomeruli onto the slice surface. Podocytes could still be identified after 8, 10 and 14 days of culture, although relatively few glomeruli remained at 14 days. Morphometric methods were used to analyse podocyte shape, volume and surface area during the first 4 days of culture. The most significant change involved loss of foot processes: the number of filtration slits per 100 μm of basement membrane decreased from 211.8 ± 15.0 (mean ± SD) at the commencement of culture, to 55.3 ± 22.6 after 2 days (P 〈 0.001). These data provide baseline information for in vitro studies on the effects of nephrotoxins on podocytes.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00218900
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  • 98
    Electronic Resource
    Electronic Resource
    Smooth muscle fiber types and a novel pattern of thick filaments in the wing of the pteropod mollusc Clione limacina (1989)
    Springer
    Cell & tissue research 257 (1989), S. 405-414 
    Details
    ISSN: 1432-0878
    Keywords: Mollusc ; Ultrastructure ; Musculature ; Hydroskeleton ; Retraction reflex ; Clione limacina (Mollusca)
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary Wing (parapodial) retraction in the pteropod mollusc Clione limacina is a reflex triggered by tactile stimulation. Light and transmission electron microscopy revealed three groups of smooth muscles in the wing hemocoel that participate in retraction movements: transverse, longitudinal, and dorsoventral. Among these, two subtypes of muscle cells were identified. The first (type A) appears in all three groups and forms a well-organized lattice-like structure. The second (type B) is the major component of transverse muscles and runs in one direction only. Quantitative ultrastructural comparisons of dimensions, abundance, and organization of dense bodies, thick and thin filaments, membrane invaginations, sarcoplasmic reticulum, and mitochondria suggest that type A cells are able to contract and relax more quickly with less endurance whereas type B cells are capable of generating stronger contractions with more endurance and slower relaxation speed. Furthermore, type A cells have a unique pattern of thick filament organization, here referred to as pseudosarcomeres. The roles played by the different cell types in wing retraction are discussed.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00261843
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  • 99
    Electronic Resource
    Electronic Resource
    Ultrastructural changes induced by precocene II and 3,4-dihydroprecocene II in the corpora allata of Blattella germanica (1989)
    Springer
    Cell & tissue research 258 (1989), S. 91-99 
    Details
    ISSN: 1432-0878
    Keywords: Corpora allata ; Ultrastructure ; Precocenes ; Juvenile hormone ; Blattella germanica (Insecta)
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary Ultrastructural studies on corpora allata (CA) from different stages during the first gonadotropic cycle of the cockroach Blattella germanica have shown well defined changes which have a correspondence with oocyte length, CA volume and juvenile hormone (JH) biosynthesis. The most significant variations concern the mitochondria and the endoplasmic reticulum. Topically applied precocene II (P II) at a dose of 200 ⧎g induced a transient arrest of CA function, although cytotoxic effects were occasionally observed. When CA were maintained in vitro with 10-3 M of P II, a relationship between the time of treatment (3, 6 or 9 h) and the intensity of the effects was apparent. The 9-h treatment led to an irreversible inhibition of JH production which parallels the severe damages observed in the CA (membrane lysis, nuclear pyknosis, vacuolization). Equivalent studies performed with the chroman derivative 3,4-dihydroprecocene II (DHP II) showed that it is less active than P II. Only treatments as severe as 12 h of incubation with a 10-3 M concentration elicited cytotoxic effects which could be due to radical species involved in the in situ oxidative bioactivation of DHP II. Thus, this compound could be regarded as a new type of pro-allatocidin.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00223148
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  • 100
    Electronic Resource
    Electronic Resource
    Structural features of the epididymis in a dasyurid marsupial (Antechinus stuartii) (1989)
    Springer
    Cell & tissue research 258 (1989), S. 203-210 
    Details
    ISSN: 1432-0878
    Keywords: Epididymis ; Histology ; Ultrastructure ; Antechinus stuartii (Marsupialia)
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary The ductus epididymidis of the marsupial mouse Antechinus stuartii was divided into caput, corpus, and caudal regions using several constant morphological landmarks. Tubule diameter and epithelial height increased gradually from caput to cauda. In contrast, the surface area of the lumen of the ductus epididymidis increased to a maximum in the distal caput region, but decreased markedly in the distal cauda in association with characteristic changes in lumen shape (from circular to slit-shaped) and epithelial height. Epithelial cells of the ductus epididymidis were generally similar in structure to those described in other mammalian species. Principal and basal cells were common throughout the epithelium. Clear and mitochondria-rich cells were also identified, but occurred less frequently. Regional variations in cell ultrastructure were observed only in principal cells. Numerous vesicular inclusions occurred in the apical cytoplasm of cells in caput segments, membrane-bounded, electron-dense bodies were common in distal corpus regions, and a brush border of microvilli characterized the luminal surface of principal cells in caudal segments. Sperm index increased in the proximal caput, declined to basal levels in the distal caput and proximal corpus, and then increased to a maximum in segment 9 of the distal corpus and remained at about this level throughout the cauda epididymidis. Nuclear rotation, loss of cytoplasmic droplets, and other sperm maturational changes were observed along the epididymis. Discarded cytoplasmic droplets collected in large masses interspersed between aggregates of spermatozoa throughout the distal regions of the duct. There was no evidence of phagocytosis by principal cells of cytoplasmic droplets. The epididymis of A. stuartii differs from that of other mammals. The unusual caudal region, which has little storage capacity for sperm, is an unusual adaptation in a species in which the male is known to be polygamous.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00223158
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