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  • 1985-1989  (176)
  • 1965-1969
  • 1989  (64)
  • 1985  (112)
  • Ultrastructure
  • 1
    Electronic Resource
    Electronic Resource
    Springer
    Virchows Archiv 414 (1989), S. 113-119 
    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.
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  • 2
    Electronic Resource
    Electronic Resource
    Springer
    Virchows Archiv 414 (1989), S. 459-464 
    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.
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  • 3
    Electronic Resource
    Electronic Resource
    Springer
    Virchows Archiv 415 (1989), S. 145-149 
    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.
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  • 4
    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.
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  • 5
    Electronic Resource
    Electronic Resource
    Springer
    Virchows Archiv 415 (1989), S. 21-29 
    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.
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  • 6
    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.
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  • 7
    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.
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  • 8
    Electronic Resource
    Electronic Resource
    Springer
    Acta neuropathologica 79 (1989), S. 168-175 
    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.
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  • 9
    Electronic Resource
    Electronic Resource
    Springer
    Anatomy and embryology 180 (1989), S. 175-178 
    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.
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  • 10
    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.
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  • 11
    Electronic Resource
    Electronic Resource
    Springer
    Anatomy and embryology 179 (1989), S. 435-442 
    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.
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  • 12
    Electronic Resource
    Electronic Resource
    Springer
    Anatomy and embryology 179 (1989), S. 497-501 
    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.
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  • 13
    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.
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  • 14
    Electronic Resource
    Electronic Resource
    Springer
    Anatomy and embryology 179 (1989), S. 591-604 
    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.
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  • 15
    Electronic Resource
    Electronic Resource
    Springer
    Anatomy and embryology 180 (1989), S. 103-108 
    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.
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  • 16
    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.
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  • 17
    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.
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  • 18
    Electronic Resource
    Electronic Resource
    Springer
    Acta neuropathologica 79 (1989), S. 336-339 
    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.
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  • 19
    Electronic Resource
    Electronic Resource
    Springer
    Acta neuropathologica 77 (1989), S. 654-658 
    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.
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  • 20
    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.
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  • 21
    Electronic Resource
    Electronic Resource
    Springer
    Acta neuropathologica 77 (1989), S. 258-266 
    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.
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  • 22
    Electronic Resource
    Electronic Resource
    Springer
    Acta neuropathologica 79 (1989), S. 86-93 
    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.
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  • 23
    Electronic Resource
    Electronic Resource
    Springer
    Archives of dermatological research 281 (1989), S. 35-39 
    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.
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  • 24
    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.
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  • 25
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    Development genes and evolution 198 (1989), S. 92-102 
    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.
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  • 26
    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.
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  • 27
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    Experimental brain research 76 (1989), S. 12-20 
    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.
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  • 28
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    Sexual plant reproduction 2 (1989), S. 154-166 
    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.
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  • 29
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    Sexual plant reproduction 2 (1989), S. 193-198 
    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.
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  • 30
    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.
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  • 31
    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.
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  • 32
    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.
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  • 33
    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.
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  • 34
    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.
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  • 35
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    Cell & tissue research 258 (1989), S. 203-210 
    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.
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  • 36
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    Cell & tissue research 258 (1989), S. 247-257 
    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.
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  • 37
    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.
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  • 38
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    Cell & tissue research 256 (1989), S. 303-307 
    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.
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  • 39
    ISSN: 1432-0878
    Keywords: Adrenal cortex ; Differentiation ; Tissue culture ; Steroids ; Ultrastructure ; Lipoproteins ; Rat (Sprague-Dawley)
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary We studied the effects of lipoprotein-derived cholesterol on the ACTH-induced differentiation of cultured fetal rat adrenocortical cells. For this purpose human plasma high-density lipoprotein3 (HDL3) or low-density lipoprotein (LDL) was added to culture media devoid of cholesterol, and thereafter the morphological changes in cells were monitored and the amounts of steroids synthesized were measured. It could be demonstrated that, ultrastructurally, upon ACTH-stimulation the adrenocortical cells differentiated into fasciculata-like cells even in the absence of lipoproteins in the culture medium. The addition of either HDL3 or LDL caused an increase in the number and size of cytoplasmic lipid droplets suggesting uptake and deposition of lipoprotein-derived cholesterol into the differentiating cells. The amount of steroids secreted from cells differentiating in media devoid of cholesterol was only half that observed in cells differentiating in serum-supplemented medium. Addition of either HDL3 or LDL increased the ACTH-stimulated steroid synthesis to the levels observed in serum-supplemented medium. This study demonstrates that both HDL3 and LDL are able to provide cholesterol for steroid synthesis accompanying the ACTH-induced differentiation of fetal rat adrenocortical cells.
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  • 40
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    Cell & tissue research 255 (1989), S. 405-410 
    ISSN: 1432-0878
    Keywords: Pituitary gland, pars intermedia ; Bromocriptine ; Secretory granules ; Golgi apparatus ; Ultrastructure ; Rat (Sprague-Dawley)
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary The morphological effect of chronic synthetic and secretory inhibition of the intermediate lobe of the rat pituitary induced by bromocriptine treatment was studied using morphometric techniques in combination with electron microscopy. On the basis of granule diameters, a heterogeneous cell population was shown in the normal intermediate lobe. Bromocriptine treatment did not induce any change in the volume fraction, number or location of electron-dense secretory granules. Instead, there was a shift toward a more homogeneous cell population containing smaller granules, the mean granule volume being reduced by ∼30%. The volume fraction of electron-lucent granules or vacuoles was markedly reduced, indicating a functional significance of these organelles. The volume of the Golgi apparatus was not significantly altered, but the number of condensing granules within the Golgi area was reduced. The volume of the intermediate lobe was decreased, apparently due to a decrease in the mean cell volume.
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  • 41
    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.
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  • 42
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    Cell & tissue research 257 (1989), S. 207-216 
    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.
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  • 43
    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.
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  • 44
    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.
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  • 45
    ISSN: 1432-0878
    Keywords: Zona pellucida ; Ovarian follicles ; Atresia ; Ultrastructure ; Mouse
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary The present study provides further details on the fine-structural three-dimensional architecture of the zona pellucida (ZP) in growing and atretic follicles of mice by use of ruthenium red in combination with the detergents Triton X100 and saponin. These detergents were used for extraction of the “soluble” fraction of the zonal proteins in an attempt to expose the “structural” zonal glycoproteins, which in turn can be viewed as minute three-dimensional networks upon transmission- and scanning electron-microscopic examination. By use of these methods, the ZP of growing follicles appeared to be formed by interconnected filaments which also bind to globular structures building up a three-dimensional lattice. In contrast, the ZP of stage I as well as other (II and III) stages of atretic follicles showed a structure characterized by the presence of closely packed granules connected with short filaments to form a close-mesh reticulum. This structural change of the ZP, which in the present study is also associated with the disappearance of “gap junctions” within the granulosa and cumulus cell population, might represent one of the early events involved in the onset of atresia. These changes, most probably depending on an altered secretory activity of both oocytes and follicle cells, might lead to a degradation of the ZP network structure and to its subsequent increased density (condensation). All these morphodynamic events eventually contribute to a sequestration of the oocyte in the early stage of atresia.
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  • 46
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    Cell & tissue research 257 (1989), S. 405-414 
    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.
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  • 47
    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.
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  • 48
    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.
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  • 49
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    Protoplasma 150 (1989), S. 83-95 
    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.
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  • 50
    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.
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  • 51
    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.
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  • 52
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    Protoplasma 151 (1989), S. 47-56 
    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.
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  • 53
    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.
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  • 54
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    Protoplasma 152 (1989), S. 14-21 
    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.
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  • 55
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    Protoplasma 153 (1989), S. 104-110 
    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.
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  • 56
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    European journal of applied physiology 59 (1989), S. 239-242 
    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.
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  • 57
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    Plant systematics and evolution 164 (1989), S. 65-73 
    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.
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  • 58
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    Plant systematics and evolution 164 (1989), S. 197-208 
    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.
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  • 59
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    Plant systematics and evolution 168 (1989), S. 195-219 
    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.
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  • 60
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    European archives of oto-rhino-laryngology and head & neck 246 (1989), S. 56-60 
    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.
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  • 61
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    European archives of oto-rhino-laryngology and head & neck 246 (1989), S. 169-172 
    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.
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  • 62
    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.
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  • 63
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    New York, NY : Wiley-Blackwell
    Journal of Electron Microscopy Technique 12 (1989), S. 24-28 
    ISSN: 0741-0581
    Keywords: Tissue culture ; Heart muscle cells ; Ultrastructure ; Life and Medical Sciences ; Cell & Developmental Biology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Natural Sciences in General
    Notes: A technique for performing light, scanning, and transverse transmission electron microscopy on cultured cells grown within a single tissue culture flask is described. Permanent light microscopy slides are obtained by removing selected portions of the plastic tissue culture vessel and mounting them on glass slides with an aqueous mounting solution. The images obtained from these slides are superior to viewing through the bottom of the flask with an inverted stage microscope. For scanning electron microscopy, selected areas are also cut from the remainder of the vessel and prepared for viewing. The final portion of the culture container is transferred and attached to a new tissue culture vessel and prepared for transmission electron microscopy using alcohol instead of acetone and propylene oxide during dehydration, infiltration, and embedding.
    Additional Material: 8 Ill.
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  • 64
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    Journal of Electron Microscopy Technique 12 (1989), S. 323-330 
    ISSN: 0741-0581
    Keywords: Chromaffin cells ; Paraganglia ; Paraaortic organs ; Mitosis ; Ultrastructure ; Life and Medical Sciences ; Cell & Developmental Biology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Natural Sciences in General
    Notes: Mitotic activity often has been reported in embryonic and fetal sympathetic neuroblasts, principal sympathoblasts, and primitive sympathetic cells in various species at different stages of development. Postnatal adrenal medullary cells also are known to undergo mitosis, but such dividing capabilities rarely have been observed in the true postnatal extraadrenal chromaffin system. Although few in number, this work nevertheless has clearly identified such cells in varying stages of the mitotic cycle in the young dog, Syrian hamster, mouse, rabbit, and rat. The dividing cells were noted in paraaortic chromaffin organs, paraganglia, and within the inferior mesenteric ganglion as well. They displayed the morphological character usually associated with their adrenal medullary catecholaminergic counterparts, including numerous dense-cored vesicles known to be the harbingers of catecholamines and various peptides. Nerve endings were not noticed upon the mitotic cells. The phenomenon of dividing extraadrenal chromaffin cells augments existing data and perhaps suggests that these cells are more endocrine than neural in type and subservient to the adrenal medulla in its classic endocrine function.
    Additional Material: 9 Ill.
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    European archives of oto-rhino-laryngology and head & neck 241 (1985), S. 203-208 
    ISSN: 1434-4726
    Keywords: Inner ear ; Loop-tail mouse ; Ultrastructure ; Development
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary Homozygous loop-tail (Lp/Lp) mice exhibit defects in the otocyst as well as extensive neural dysraphism. At 9 days of gestation, cells in the otic pit of abnormal embryos are flattened and lack the rounded luminal contours characteristic of otic cells in their normal littermates. Apical filaments also are not as prominent as in normal embryos, and there is an increase in densely stained globular material in cells at the ventral lip of the otic pit. With glutaraldehyde-tannic acid fixation, the basal lamina of the otic pit cells shows differences from that of the normal otic pit. In abnormal specimens, the lamina densa is irregular and clumped, and the adjacent less dense area is spotty and lacks the more uniformly arranged and delicate fibrils characteristic of the normal basal lamina. These defects may reflect faulty developmental interactions between the dysraphic neural tube, mesenchymal cells, and otic anlage.
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  • 66
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    Archives of dermatological research 278 (1985), S. 1-5 
    ISSN: 1432-069X
    Keywords: Lamellar ichthyosis ; Autosomal-dominant inheritance ; Ultrastructure ; Transforming cells ; Genetic counselling
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary Recently, autosomal-dominant lamellar ichthyosis (ADLI) has been shown to be a new genetic trait with clinical and histologic features similar to those of autosomal-recessive lamellar ichthyosis. In two patients affected with ADLI, the malpighian keratinocytes showed ultrastructural signs of increased cellular metabolism. The tonofilaments and keratohyaline granules were regular in structure and number. However, as a distinctive ultrastructural feature, a prominent transforming zone was found between the granular and horny layers. Moreover, a normal keratin pattern and only a limited number of lipid inclusions were observed in the stratum corneum. Thus, ADLI can be distinguished from the autosomal-recessive forms of lamellar ichthyosis, permitting a correct diagnosis when genetic counselling has to be given in sporadic cases.
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  • 67
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    Archives of dermatological research 278 (1985), S. 49-56 
    ISSN: 1432-069X
    Keywords: Congenital nevocytic nevi ; Nevus cells ; Blood vessels ; Lymphatics ; Ultrastructure
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary As congenital nevocytic nevi have an increased risk of malignant degeneration, nevus-cell involvement in blood vessels and lymphatics is of particular interest. The present histological and ultrastructural studies revealed nevus-cell nests in the walls of venules in 1 out of 11 patients with medium-sized nevi, and in subcutaneous veins in 3 out of 8 patients with garment nevi. In all cases, the nests histologically consisted of benign-appearing subendothelial B-type cells. Ultrastructurally, the features of these nevocytes essentially corresponded to those of nevocytes in the surrounding area. In 1 patient with a garment nevus, in whom affected vessels of the lumbar area as well as of the neck were examined, the nevus-cell nests were exclusively situated between the endothelium and its basal lamina. These nevocytes appeared to be more electron dense, but had no unequivocally atypical features. In the region of these nests, the endothelium was often discontinuous; thus, the nevus-cells were in direct contact with the lumen. Some of these cells exhibited slight degenerative changes. The lymphatics were affected in 6 of the 18 cases of garment nevi and in 2 of the 11 cases of medium-sized nevi. The morphological findings were comparable to those for blood vessels. It is concluded that, in garment nevi, morphologically benign nevocytes may be carried off hematogenously as well as lymphogenously.
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  • 68
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    Virchows Archiv 406 (1985), S. 271-277 
    ISSN: 1432-2307
    Keywords: Cimetidine ; Duodenal ulcer ; Gastrin producing cells ; Ultrastructure
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary Ultrastructural examination of the antral G cells has been carried out on 11 patients with chronic duodenal ulcer, before and after treatment with a histamine H-2 - receptor antagonist (cimetidine 1 g/ day) for 8 weeks. The study demonstrated an increased area of the Golgi complex, rough endoplasmic reticulum and electron-dense granules, indicating increased G cell activity during treatment. An increased number of lysosomes was a constant feature during treatment. As an hypothesis we suggest that these lysosomes may participate in the secretory mechanism of human G cells, by destroying superfluous (Gastrin) components produced during hyperactivity.
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  • 69
    ISSN: 1432-2307
    Keywords: Gastrin ; Gastrinomas ; Ultrastructure ; Immunogold technique
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary Localisation of C-terminal gastrin immunoreactivity has been studied, using the immunogold staining procedure, on ultrathin sections of 6 human gastrinomas conventionally processed for electron microscopy. The specific labelling, whose density depended on the mean diameter of the gold marker, was restricted to endocrine secretory granules. However, in poorly differentiated cells from malignant tumours, a number of granules remained unreactive. The labelling pattern depended also on the functional state of each cell. The immunoreactive granules showed various morphological features. A moderate number of gold particles was demonstrated over the floccular content of the infrequent diagnostic G-type granules. Non-diagnostic round granules of varying size and electron density were prevalent in most cells; their usually strong immunostaining allowed immediate recognition of cell specificity. Dense granules which were large in size and angular in shape and present in one case, were also intensely labelled. In the same tumour, unequal labelling occurred over polymorphous, often elongated granules, of varying size. Granules of different types, including intermediate forms, could be found in the same cell, indicating a spectrum of granule maturation towards well-defined types of the fetal or adult normal tissues. The present methodology would help to identify gastrin-producing cells in prospective or retrospective electron microscopy studies of multihormonal endocrine tumours.
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  • 70
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    Virchows Archiv 406 (1985), S. 351-365 
    ISSN: 1432-2307
    Keywords: Neuroepithelioma ; Histology ; Immunohistochemistry ; Neuron-specific enolase ; Ultrastructure
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary Seventeen cases of malignant peripheral neuroectodermal tumour (MPNT) were studied by means of light microscopy, immunohistochemistry and electron microscopy. There were nine males and eight females. The mean age of the 17 patients was 10 years with a range of seven months to 20 years. The vast majority of tumours was located in the trunk. Histologically, they closely resembled Ewing's sarcoma, although minor differences were obvious. Special findings included ganglion cells and Flexner rosettes. In 10/11 cases positive staining for neuron-specific enolase (NSE) was obtained. Five of 10 tumours were positive for protein S-100. Three contained vimentin, two neurofilaments and one vimentin, neurofilaments and GFAP. Neurosecretory granules were noted in the three cases studied. Five patients died, three are alive with disease and five patients are alive without evidence of disease. It is concluded that these tumours form a homogeneous group, although the grade of differentiation varies. The prognosis in most cases is poor. Distinction from Ewing's sarcoma is possible by staining for NSE and by electron microscopy.
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  • 71
    ISSN: 1432-2307
    Keywords: Glycogen-rich adenoma ; Salivary gland ; Epithelial cell ; Ultrastructure
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary A glycogen-rich adenoma occurring in the minor salivary gland of the nasopharynx in a 41-year-old woman was studied ultrastrucrurally. The cytoplasm of the tumour cells was abundantly filled with glycogen particles. The tumour cells possessed many mitochondria, a great number of microvillous processes and microvilli and were joined to each other by desmosomes. These findings suggest that this adenoma is of salivary duct epithelial origin most probably from storing striated ductal cells, and is a variant of monomorphic oxyphilic adenoma.
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  • 72
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    Virchows Archiv 408 (1985), S. 29-41 
    ISSN: 1432-2307
    Keywords: Kaposi's sarcoma ; AIDS ; Ultrastructure ; Immunohistology
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary Comparison of idiopathic Kaposi's sarcoma in Europe and Africa and Kaposi's sarcoma in connection with AIDS shows an identical morphological appearance in all three types. Ultrastructural and immunohistological investigations indicate that the tumour originates from the endothelial cells of proliferating capillaries and is therefore a vascular tumour. The clinical course and the sites of manifestation differ slightly in idiopathic cases and those occurring in connection with AIDS. This effect may be determined by the general condition of the patient, the state of immune deficiency and the influence of opportunistic infections.
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  • 73
    ISSN: 1432-2307
    Keywords: Leukemia ; Liver ; Ultrastructure ; Endothelium ; Guinea pig
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary The possible routes of transvascular migration of leukemic cells in the liver were studied in guinea pigs with an L2C lymphoblastic cell-line inoculation leukemia. Invasion of the hepatic parenchyma theoretically can occur in three ways: 1. Through the intact sinusoidal endothelium, utilizing either pre-existent gaps (normal in the liver), or newly created pores, whether interendothelial or intraendothelial. We could not convincingly demonstrate this, but could not wholly exclude this either. 2. After destruction or retraction of the endothelium, either on account of the remarkable sinusoidal engorgement and distension by masses of leukemic cells, or by direct assault on the endothelium by the leukemic cells. We can clearly demonstrate the former, and hold it to be the major cause of hepatic infiltration. Evidence for a direct endotheliolytic effect was not uncovered in our studies. 3. Secondary infiltration from the portal triads. Heavy leukemic infiltration of the triads, whether from the portal or hepatic veins, or from the lymphatics, is indeed and early an consistent feature - but the infiltration of the hepatic lobule shows no peripheral, or any other zonal preference. In both portal and hepatic veins, leukemic cells transverse the endothelium through a cytoplasmic “pore”, adjacent to cell junctions, without obvious damage to the endothelium.
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  • 74
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    Virchows Archiv 405 (1985), S. 439-452 
    ISSN: 1432-2307
    Keywords: T-cell lymphoma ; Microvasculature ; Ultrastructure ; Immunohistochemistry ; Ulex europaeus lectin I
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary The microvasculature of lymph nodes of 55 cases of T-cell lymphoma was studied by light microscopy, immunohistochemistry and electron microscopy. A modified peroxidase-antiperoxidase (PAP) method was used for staining paraffin sections with lectin I of Ulex europaeus (UEA-I), which is a specific marker for vascular endothelial cells. The T-cell nature of each case was proven by immunohistochemistry, including immunoperoxidase staining of frozen sections with monoclonal T-cell antibodies. The cases were subclassified according to previously established criteria, but with the addition of a separate group showing a high content of clear cells. For the purpose of the present study, the small blood vessels were separated into two main variants, viz.: high endothelial venules (HEV) and all other types of vessels with flat endothelium (SVFE). The development of each of these variants and the extent of lymphocyte migration through the vascular wall were assessed semiquantitatively. The findings suggest that the blood microvasculature, as a whole, is similar in all types of T-cell lymphoma. There were distinct differences, however, in the development of the two main categories of small vessels between the various types. Chronic lymphocytic leukaemia of T-type (T-CLL) and Sézary's syndrome were poor in SVFE and rich in HEV, and there was considerable lymphocyte traffic through the latter. In contrast, T-immunoblastic and especially T-lymphoblastic lymphomas showed numerous SVFE, only a few or no HEV and minimal lymphocyte traffic. The appearance of the microvasculature varied markedly in the various subtypes of “pleomorphic T-cell lymphoma”. In the small cell subtype HEV predominated and SVFE represented only a small or moderate fraction of the microvasculature. As the size of the neoplastic lymphoid cells increased towards the medium-sized and large cell
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  • 75
    ISSN: 1432-2307
    Keywords: Human bladder tumour ; Inverted papilloma ; Ultrastructure
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary Three cases of inverted papilloma of the urinary bladder were studied by transmission electron microscopy. Scanning electron microscopic observation was made in one of these. The surfaces of the outermost tumour cells were covered with short stubby microvilli. Multiple bud like proliferations of the tumour cells were compatible with a trabecular type of inverted papilloma. The tumour cells of the trabeculum mimicked the intermediate and basal cells of the epithelium which covered the surface. Microcysts are believed to be formed by epithelial migration into pits, creating an epithelial inversion, and do not represent central necrosis. Ultrastructure suggests that inverted papilloma is a very well differentiated tumour.
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  • 76
    ISSN: 1432-2307
    Keywords: Immunohistochemistry ; Ultrastructure ; Oncofoetal ; Antigens ; Bowel ; Carcinoma
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary Seven large bowel carcinomas were examined by light and electron microscopy for the presence of five oncofoetal antigens. Ultrastructural investigations involved a novel method whereby thick sections of gluteraldehyde-fixed material were cut on a vibratome and then labelled using slight modifications of a standard unlabelled antibody-enzyme (PAP) technique, before further processing. Ultrastructural preservation, staining properties and the retention of antigen activity was seemingly better than that achieved by other investigators. Specific, positive labelling for carcinoembryonic antigen (CEA), colon specific antigen (CSA) and pregnancy-specificβ-1-glycoprotein (SP1) was seen in every case. Clear positive labelling for placental alkaline phosphatase (PLAP) and human chorionic gonadotropin (HCG) was seen in two cases. Extracellular labelling was found in areas of cell debris, free lying or in phagocytic cells and on tumour cell brush borders. The pattern of intracellular labelling, however, was different for each antigen and reflected the probable sites of synthesis and release from the cells. Thus CEA, a complex glycoprotein, was localised within the golgi apparatus, small apical cytoplasmic vesicles and mucous droplets in relatively well differentiated tumour cells. CSA, a chemically related glycoprotein, had a similar, but less dense distribution. SP1, by contrast, was localised within basally-located vesicles associated with the ribosomal endoplasmic reticulum and appeared to be released and persist as debris or taken up by phagocytic cells below the basal lamina. PLAP and HCG, both proteins, were found within simple single membrane-bound vesicles within relatively undifferentiated cells.
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  • 77
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    Virchows Archiv 407 (1985), S. 369-378 
    ISSN: 1432-2307
    Keywords: Breast ; Lymphocytes ; Macrophages ; Ultrastructure ; Immunocytochemistry
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary In this study the presence of intraepithelial cells within the normal breast parenchyma was investigated by electron microscopy and immunocytochemistry. Cells were observed which could be differentiated from the epithelial and myoepithelial cells by their cytoplasmic and nuclear morphology and the absence of cell junctions. Two cell types (lymphocytes and macrophages) were identified ultrastructurally and the bone marrow origin of the cells was confirmed by immunocytochemistry. The intraepithelial lymphocytes and macrophages were present in all samples irrespective of the physiological state. In the “resting”, pregnant, and lactating breast the majority of cells were lymphocytes while in the involuting breast there was a marked increase in the proportion of macrophages. The rarity of lymphoma of the breast may be related to the relatively small amount of lymphoid tissue present and the passive nature of the environment.
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  • 78
    ISSN: 1432-2307
    Keywords: Herpes simplex lymphadenitis ; Viral particles ; Ultrastructure ; Immunolabelling ; Histopathology ; Intra cellular viral antigen
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary A patient treated for Hodgkin's disease and presenting 12 years later with a left inguinal lymphadenopathy mimicking a relapse is reported. Histopathological study disclosed large histiocytic granulomas in the sinuses. Some of these granulomas showed necrotic areas with numerous neutrophils. At the edge of the necrotic zones, cells of undetermined origin exhibited intra-nuclear inclusions typical of Herpes simplex virus. The diagnosis was confirmed by immunolabelling, revealing Herpes simplex viral antigens in frozen and paraffin sections, and by ultrastructural studies. The diagnostic value of the histological methodology and pathological changes and the significance of the disease, appearing in a patient treated for Hodgkin's disease are discussed.
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  • 79
    ISSN: 1432-2307
    Keywords: Small cell carcinoma ; Amylase ; ACTH ; Ultrastructure ; Immunohistochemistry
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary Tumour tissue from a lung cancer patient who showed elevated serum amylase and adrenocorticotropin (ACTH) was studied ultrastructurally, immunohistochemically and biochemically. Histologically the tumour was a small cell carcinoma. On electron microscopic examination the tumour cells contained large zymogen-like granules within the cytoplasm. Furthermore, cells which possessed many small dense core granules of the endocrine type were also observed. It was of interest that the large zymogen-like granule-containing tumour cells had microvilli at the apical border, connected by desmosomes and forming lumina showing adenocarcinomatous differentiation. Electrophoretic analysis of the serum revealed that the major elevated amylase was of the salivary type with minor components. Immunostaining clearly demonstrated that most of the tumour cells possessed immunoreactive ACTH, whereas salivary amylase was only found in occasional clusters of the tumour cells. The results seem to indicate that the tumour showed both endocrine and exocrine characteristics - an amphicrine carcinoma, expressing amylase and ACTH simultaneously.
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  • 80
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    Research in experimental medicine 185 (1985), S. 259-268 
    ISSN: 1433-8580
    Keywords: Small bowel resection ; Ultrastructure ; Morphometry ; Intestinal adaptation
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary The aim of the present study was to evaluate in terms of quantitative measurements whether the well-known histomorphological and functional adaptive changes in the intestinal mucosa after small bowel resection are accompanied by alterations on the ultrastructural level. Therefore, samples of the ileal remnants after a 60% proximal resection were processed for ultrastructural evaluation and analyzed employing point counting planimetry and direct measurements. Microvillus surface area increased from the bottom of the crypts to the villus tips in both resected and sham-operated animals. This increase in microvillus surface area from the crypt to the villus was significantly less pronounced after proximal resection, while there were no changes in the crypt compartment. No significant differences of the relative areas of the nuclei, mitochondria, and the rough endoplasmic reticulum were observed when comparing the different positions along the villus crypt axis in normal and hyperplastic mucosa. In agreement with functional and enzyme histochemical results, these ultrastructural findings provide further evidence for an altered pattern of enterocyte maturation after proximal resection, which is most probably due to an increase in the migration rate of the enterocytes.
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  • 81
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    Anatomy and embryology 172 (1985), S. 265-275 
    ISSN: 1432-0568
    Keywords: Ultrastructure ; Human knee joint capsule ; Free nerve endings ; Ruffini corpuscles ; Pacini corpuscles
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary The ultrastructure of sensory nerve endings in the human knee joint capsule was studied. Three types of nerve endings were found: free nerve endings (FNE), Ruffini corpuscles and Pacini corpuscles. In the joint capsule, FNE are located below the synovial layer and within the fibrous layer near blood vessels. These nerve terminals derive from myelinated Aδ-fibres or from unmyelinated C-fibres. Their structure is almost identical to FNE in human hairy and non-hairy skin. Ruffini corpuscles are present within the fibrous layer and the ligaments of the capsule in three variations: small Ruffini corpuscles without a capsule, small with a connective tissue capsule, and large Ruffini corpuscles with an incomplete perineural capsule. Their afferent axons are myelinated and measure 3–5 μm in diameter. Inside the corpuscle, nerve terminals are anchored in the connective tissue belonging to the fibrous layer or to the ligaments respectively. The presence of an incomplete perineural capsule depends on the structure of the surrounding connective tissue. In ligaments with collagenous fibrils oriented in a parallel fashion, the perineural capsule is well-developed and the Ruffini corpuscle resembles a Golgi tendon organ; in areas where the fibrils show no predominant orientation, Ruffini corpuscles lack a capsule. Small Pacini corpuscles are situated within the fibrous layer near the capsular insertion at the meniscus articularis or at the periost. They consist of one or several inner cores and a perineural capsule of 1–2 layers. Larger Pacini corpuscles with one or several inner cores and a perineural capsule consisting of 20–30 layers are found on the outer surface of the fibrous layer. The ultrastructure of these nerve endings is compared with the ultrastructure of articular receptors of various animals and with the ultrastructure of sensory nerve endings in the skin of several mammalian species including man.
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    Anatomy and embryology 172 (1985), S. 331-337 
    ISSN: 1432-0568
    Keywords: Ovary ; Oocyte ; Ovulation ; Follicle ; Ultrastructure
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary Follicular ruptures with intra-ovarian oocyte release (IOR) were studied in 17, 21 and 24-day-old rats by morphological methods. Using a light microscope, it was seen that IOR occurred at all times and the IOR frequency did not change. IOR developed in preantral follicles. Their oocytes were mostly found within the follicular compartment (incomplete IOR). Using an electron microscope, a circumscribed dissolution of the basal lamina was observed. IOR granulosa cells appeared activated. They rarely underwent typical necrosis after herniation into the extrafollicular area. Herniated granulosa cells tended either to stay intact or to shed cytoplasmic components into the extracellular space. whilst nuclei of active cell function were maintained. Tissue adjacent to an IOR seemed inactive with the exception of endothelial cells. Some endothelial cells underwent necrosis. Additionally, the endothelium was discontinous. The morphological data support the hypothesis that the mechanism of follicular rupture represents an inside to outside process.
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  • 83
    ISSN: 1432-0568
    Keywords: Dopamine-β-hydroxylase ; Anterior column ; Ultrastructure ; Immunohistochemistry ; Rat
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary Dopamine-β-hydroxylase (DBH) immunohistochemistry was used to demonstrate the noradrenergic fibers and terminals in the anterior column of the rat lumbosacral spinal segments. PAP-positive varicose fibers were widely distributed in the gray matter with preferential accumulation in the nuclear regions containing motoneurons involved in the contraction of perineal striated muscles. Unmyelinated DBH fibers were composed of nodular enlargements (varicosities, 0.4–3.0 μm in diameter) and very fine, short intervals (intervaricose segments, 0.1–0.2 μm in diameter and 1.0–4.0 μm in length). DBH-positive dense products were electron microscopically often confined within small granular particles and less frequently within large granules. Additionally, in order to characterize the innervation pattern of noradrenergic fibers on dendritic bundles organized in the motoneuronal pools innervating the pelvic small muscles, semi-quantitative analysis was done in the area of the dorsolateral nucleus endowed with especially well-developed dendritic bundles. DBH terminals contacting with unreactive dendrites were more common (67.9%) than those with neuronal somata (15.1%), and the remainder (17%) had no contacts with surrounding neuronal elements. Furthermore, specialized synaptic formations were observed in only 20.1% of these nodules. The results suggest that bulbospinal descending noradrenergic neuron systems influence the functioning of pelvic muscles principally via the neuronal contacts with dendritic bundles in the spinal cord.
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    Anatomy and embryology 171 (1985), S. 305-310 
    ISSN: 1432-0568
    Keywords: Pancreas ; Development ; Ultrastructure ; Freeze-fracture ; Intercellular junction
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary The formation of gap junctions was studied in pancreatic exocrine cells of rats and mice during late embryonic and neonatal development by the freeze-fracture replica method. Small gap junctions were present in association with tight junctional strands near the cell apex during embryonic development. Independently of tight junctions, small gap junctions were sometimes seen more basally on day 13 to 15 of gestation. The gap junctions increased in number and were rapidly enlarged by day 18 to 20 of gestation. Large particles 12–13 nm in diameter were frequently associated with the gap junction, which consisted of 10 nm particles. The large particles were either irregularly distributed or arranged in hexagonal patterns. The number of large particles decreased with time, so that they sparsely rimmed the gap junction in postnatal animals. This suggests that large particles are precursors of typical gap junctional particles, and that they participate in rapid growth of the gap junction during late embryonic development. It may be also possible that large particles represent functionally different gap junctions.
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    Anatomy and embryology 173 (1985), S. 247-252 
    ISSN: 1432-0568
    Keywords: Ultrastructure ; Spermatozoa ; Zona pellucida ; Cumulus cells ; Human egg investments
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary The ultrastructure of human spermatozoa located in the cumulus cells and the zona pellucida of a pronuclear egg, and in the zona pellucida of a two-cell egg, both fertilized in-vivo, has been analysed in order to understand how the human spermatozoon penetrates the investing coats of the oocyte. Among the 36 spermatozoa found in the cumulus cells, 31 were phagocytosed by cumulus cells and 5 were wedged in the matrix between the cells. These spermatozoa were acrosome-reacted and their equatorial segment was intact. Six of the seven spermatozoa found in the zona pellucida (four spermatozoa in the pronuclear egg and three in the two-cell egg) had lost the equatorial segment, while the other one was partially reacted. The sperm heads were located in slits with sharp edges. From these findings it was concluded that in the human (1) only few and normal spermatozoa seem to reach the cumulus cells after natural insemination, (2) the acrosome reaction probably occurs sometime before the spermatozoa reach the vicinity of the corona cells, (3) the reaction of the equatorial segment seems to occur during or before the initial phase of zona penetration, since the spermatozoa located in the matrix of the zona pellucida had no equatorial segment. No evidence of the presence of spermatozoa with an intact acrosome in the matrix of cumulus cells or with an intact equatorial segment in the zona pellucida were found.
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    Acta neuropathologica 68 (1985), S. 224-229 
    ISSN: 1432-0533
    Keywords: Dalmatian dogs ; Lipopigments ; Retina ; Retinopathy ; Ultrastructure ; Ceroidlipofuscinosis
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary Ultrastructural studies of the retinae in two NCL-affected Dalmatian dogs revealed ubiquitous accumulation of lipopigments in numerous cell types of the retina, the fine structure of which closely resembled that seen in NCL-affected English setters. Photoreceptors and other retinal cell types were largely intact. These findings show that the retinal involvement in NCL of our Dalmatian dogs is identical to that of NCL-affected English setters. It also shows that in canine NCL a severe retinopathy, regularly encountered in human childhood NCL, does not develop. Thus, the NCL of Dalmatian dogs —and English setters — represents a reliable model to study human NCL, but for human retinopathia pigmentosa perhaps only at its earliest stage.
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    Acta neuropathologica 67 (1985), S. 254-264 
    ISSN: 1432-0533
    Keywords: Capillary ; Cerebellum ; Endothelial cell ; Hemangioblastoma ; Morphometry ; Pericyte ; Ultrastructure
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary Electron microscopy and computerized morphometric techniques were employed to examine pericyte ultrastructure and to assess quantitatively their relationship to endothelial cells in five cases of cerebellar capillary hemangioblastoma. A total of 97 cross-sectioned capillary profiles were studied. Pericyte coverage of capillary ranged from 30.2% to 97.3% with a mean value of 68.7%, which is higher as compared with the available data from the cerebral cortex, skeletal and cardiac muscle, and pulmonary capillaries. The higher pericyte coverage of capillary suggests that pericyte is an active component of cerebellar capillary hemangioblastoma and may have a close functional relationship to endothelial cells. Pericytes contained bundles of parallel microfilaments along the adluminal side and in the terminal processes, and exhibited an intimate “peg-and-socket” relationship with endothelial cells, suggesting a contractile function of pericytes and their possible role in regulating capillary lumina and focal blood flow. The finding of abundant micropinocytic vesicles along the abluminal side of the cytoplasmic membrane indicates an active metabolic exchange between pericytes and the interstitium. It is possible that in cerebellar hemangioblastoma pericytes may act as a mechanical and metabolic monitor barrier for endothelial cells.
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    Anatomy and embryology 171 (1985), S. 259-265 
    ISSN: 1432-0568
    Keywords: Man ; Myoepithelial cell ; Submandibular gland ; Ultrastructure ; Cytochemistry
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary In human submandibular glands, two types of myoepithelial cells can be distinguished in serial, ultrathin sections. The dark myoepithelial cell type was stellate in shape and exhibited a pronouneced electron density due to numerous myofilaments with focal densities. Dark cell types accounted for the greater part (76%) of the myoepithelial cells and furthermore showed adenosine triphosphatase activity. This type of myoepithelial cell is considered to be that previously observed in mammalian salivary glands. Occasionally, desmosomes could be found between the processes of adjacent dark myoepithelial cell types, which is appropriate with respect to the strong compression of acinar or intercalated duct cells. The light myoepithelial cell type was large and ellipsoid with a few short-thick processes, and was characterized by an electron lucent cytoplasm which included scant and unevenly distributed myofilaments. Light cell types showed positive adenosine triphosphatase activity and accounted for only a small part (17%) of the myoepithelial cell number. Transitional forms between these two types were also observed. The light myoepithelial cell type may mature into the dark myoepithelial cell type by means of the transitional form. In addition, clear cells were sometimes encountered between the myoepithelial cell and the acinar or intercalated duct cells.
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  • 89
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    Anatomy and embryology 171 (1985), S. 297-304 
    ISSN: 1432-0568
    Keywords: Placenta (guinea pig) ; Permeability ; Freeze-Tracturing ; Ultrastructure ; Cell junctions ; Tracers
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary Permeability of the fetal endothelium within the guinea pig placental labyrinth is studied by means of horse-radish peroxidase (HRP) and ionic lanthanum as diffusion tracers. The paracellular transport of HRP is restricted by the occluding junctions of the fetal endothelium. In contrast, ionic lanthanum readily permeates most of the intercellular junctions and rapidly infiltrates the basal lamina. Freeze-fracture replicas reveal zonulae occludentes connecting the fetal endothelial cells. The network of the zonulae occludentes is variable, exhibiting highly complex areas as well as single strand interconnections. A correlation between the permeability studies and freeze-fracture findings is discussed.
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  • 90
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    Anatomy and embryology 172 (1985), S. 101-113 
    ISSN: 1432-0568
    Keywords: Yolk sac ; Marmoset ; Ultrastructure ; Hydrolase cytochemistry
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary Yolk sacs from Callithrix jacchus were investigated light and electron microscopically as well as by qualitative light microscopic enzyme histochemistry on days 35 to 126 of gestation. The thin yolk sac wall of the early stages (day 35–41) consists of the cuboid, endodermal epithelium, the mesothelium of the exocoelom and some interposed blood vessels. The inner endodermal surface is rather smooth. At later stages, the epithelium becomes highly prismatic and forms folds which are lined by a mesenchyme and blood vessels. Microvilli and a small number of endocytotic vesicles are observed at the apices of the epithelial cells, which are interconnected by gap junctions, desmosomes and interdigitations. The cytoplasm of the epithelial cells is characterized by a well-developed rough endoplasmie reticulum, a large Golgi apparatus and glycogen deposits. Four different membrane-bordered types of inclusions can be distinguished in the cytoplasm of the epithelial cells: The type I and II inclusions are considered as secretion granules. Their increase and their localization in the cavities of the endoplasmic reticulum at later stages are ascribed to an inhibition of the intracellular transport at the onset of involution. The type III and IV inclusions may represent lysosomes and related organelles. Bile capillary-like spaces exist between the epithelial cells. The basement membrane is incomplete below the epithelium and absent around the capillaries, the endothelium of which is porous in certain areas. Aminopeptidase M is highly active in the plasmalemma and the bile capillary-like structures of the epithelium, dipeptidylpeptidase IV in the mesothelium and alkaline phosphatase in the blood vessel endothelium. Other membrane hydrolases are absent. Acid proteases, glycosidases, non-specific phosphatases and non-specific esterases can be detected stage-dependently with moderate to high activities in the yolk sac epithelium. Compared with other organs, the yolk sac structure and hydrolase equipment are similar to those of the liver and may, therefore, have similar functions, e.g. synthesis and secretion of proteins. In addition, however, the yolk sac epithelium might also be involved in resorptive processes of material from the lumen followed by lysosomal digestion. The Callithrix jacchus yolk sac starts involution on day 80 of gestation by disintegration of the cells. On day 100, this process is completed. the stage of involution which is late in comparison with other primates, e.g. man and Rhesus monkey, is ascribed to the strongly delayed development of Callithrix jacchus.
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  • 91
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    Anatomy and embryology 172 (1985), S. 247-254 
    ISSN: 1432-0568
    Keywords: Mouse ; Spermiogenesis ; Cytoplasmic organelles ; Ultrastructure ; Cytochemistry
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary An electron microscopic Ag-staining method was used to study the argyrophilia of specific cytoplasmic organelles that appear during mouse spermiogenesis. The microtubuli of the centrioles are surrounded by a thin layer of argyrophilic material that also surrounds the microtubuli of their derivatives, e.g., the centriolar adjunct, the axoneme, and some structures of the connecting piece. As the mantle, i.e., the junctional complex between Sertoli cell and spermatid, develops, the involved regions of its plasma membranes are covered with silver precipitates. The apical portion of the nuclear ring as well as that of the perforatorium show clear argyrophilia. Besides these structures, a number of ring-shaped and spheroidal bodies at various sites in the cell also are decorated with silver precipitates. Most of these argyrophilic structures show a positive reaction with the EDTA method, too, suggesting that they contain ribonucleoprotein and might be of nucleolar orgin. Since, furthermore, most of these structures are known to contain distinct cytoskeletal proteins, it is assumed that the staining reaction might be caused by proteins that are associted with the genuine cytoskeletal proteins.
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  • 92
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    Anatomy and embryology 172 (1985), S. 145-156 
    ISSN: 1432-0568
    Keywords: Afferent nerve fiber ; Nociceptor ; Sensory terminal ; Tendon innervation ; Ultrastructure
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary In sympathectomized cats the innervation of the Achilles tendon by fine afferent nerve fibers was studied with semithin and ultrathin sections. Several different types of sensory endings of group III and group IV nerve fibers were identified. Of the five different types of endings in the group III range (T III endings), two are located within vessel walls. One of them ends in the circumference of the venous vessels (T III/VV). Its lanceolate terminals have characteristic receptor areas at their edges. The second type ends in the adventitia of lymphatic vessels (T III/LV). Its receptive areas are scattered along their terminal course. Two further group III endings ramify within the connective tissue compartments of the vessel-nerve-fascicles of the peritenonium externum and internum. One type is tightly surrounded by collagen fibrils (T III/PTic); the other terminates between the collagen fiber bundles (T III/PTgc). The latter arrangement recalls the ultrastructural relation between nerve terminals and collagen tissue in Golgi tendon organs. The fifth type innervates the endoneural connective tissue of small nerve fiber bundles (T III/EN). At least some of them come into close contact with bundles of collagen fibers which penetrate the perineural sheath to terminate within the endoneurium. The endings of group IV afferents (T IV endings) show a striking topographic relationship to the blood and lymphatic vessels of all connective tissue compartments of the Achilles tendon. They form penicillate endings which may contain granulated vesicles. In any event, they can easily be discriminated from the T III endings in the vessel walls. In close neighborhood to Remak bundles, a cell has been regularly found which fulfilled all ultrastructural criteria for mast cells. But this cell is not a mast cell proper because it is surrounded by a basal lamina (pseudo mast cell).
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  • 93
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    Anatomy and embryology 172 (1985), S. 183-194 
    ISSN: 1432-0568
    Keywords: Cholinesterase ; Limb bud ; Chick embryo ; Ultrastructure ; Chondrogenesis ; Myogenesis
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary Cholinesterase (ChE) is transiently expressed in undifferentiated embryonic cells. In the chick limb bud ChE-activity was found in the apical ectodermal ridge and in the subridge mesenchyme. The reaction was localized in the perinuclear cisterna, in an extensive network of narrow profiles of endoplasmic reticulum (ER), and in the Golgi complex The chondroblasts emerging from the subridge mesenenyme, also showed strong ChE-activity. During differentiation the enzyme first disappeared from the Golgi zone. Then, the narrow ChE-positive ER was successively replaced by ChE-negative extended rough ER characteristic for the differentiated chondrocyte. The myoblasts showed weak ChE-activity with the same ultrastructural localization as in other mesenchymal cells. After fusion the myotubes exhibited strong ChE-activity in the perinuclear cisterna and the developing sarcoplasmic reticulum. In later stages of myogenesis the myoblasts were closely attached to the myotubes and had lost their ChE-activity. During mitosis of ChE-positive cells, ChE-activity was retained in fragments of perinuclear cisterna and ER. In ChE-active mesenchymal cells and chondroblasts we observed specialized contact zones between ER and plasma membrane. ChE-active cisternae of ER run parallel to the plasma membrane with a gap of approximately 10–15 nm. We discuss a possible function of a cholinergic system during morphogenesis.
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  • 94
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    Anatomy and embryology 172 (1985), S. 281-293 
    ISSN: 1432-0568
    Keywords: Pig ; Blastocyst ; Endometrium ; Implantation ; Ultrastructure
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary To elucidate the morphology of the initial stages of epitheliochorial placentation in the pig, material from 10 sows of the Danish Landrace and from one Göttinger minipig gilt from day 13 to day 26 of gestation was processed for scanning and transmission electron microscopy. The observed foetomaternal interaction from day 19 1/2 minipig placenta corresponded well to the observations on the Danish Landrace placenta. From the results and the discussion it was concluded that the following structures were implicated in the initial phases of placentation in the pig: (1) Protruding epithelial proliferations of the uterine epithelium enclosed by chorionic caps serving to immobilize the blastocyst (days 13 and 14). (2) A thick glycocalyx on the maternal and a thin one on the foetal epithelium before contact. (3) Close apposition between the apical plasma membranes from trophoblastic and uterine epithelium (day 14). (4) Development of interdigitating microvilli (days 15–16). (5) Formation of apical domes on the uterine epithelium closely related to the trophoblast provided with long cytoplasmic extensions into a luminal space between the apical domes, apparently representing a transition from histiotropic to haemotrophic nutrition (days 15–20). (6) Placentation, development of interdigitating microvilli between foetal and maternal epithelium, was extended but not terminated in the peripheral zone at day 26.
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  • 95
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    Archives of dermatological research 277 (1985), S. 220-224 
    ISSN: 1432-069X
    Keywords: Mycobacterium leprae ; Ultrastructure ; Fixation methods
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary The micromorphology of Mycobacterium leprae is described. After fixation with osmium tetroxide supplemented with calcium ions, the cell wall was seen to be composed of three layers; the cytoplasmic membrane exhibited the architecture of an elementary membrane. The mesosomes were best visualized after fixation with glutaraldehyde; they were sometimes in contact with the nuclear equivalent. Only one sort of phosphate body was found. The nucleoid was best visualized after fixation with osmium tetroxide.
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  • 96
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    Acta neuropathologica 67 (1985), S. 6-12 
    ISSN: 1432-0533
    Keywords: Cerebellar hemangioblastoma ; Ultrastructure ; Stromal cells ; Cytoplasmic process ; Adjacent brain
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary Five cases of hemangioblastoma were studied by electron microscopy with particular attention to the stromal cells and their surrounding structures. Most of the stromal cells of the tumor had abundant clear cytoplasm containing rough endoplasmic reticulum, mitochondria, scattered fibrils, and large lipid inclusions. They were usually aggregated without intervening cells. In the perivascular areas, their sufaces facing the perivascular collagen were surrounded by basal lamina. Their apposed cell membranes had occasional adhesive devices. Occasional, long, apparently cylindrical processes of the stromal cell cytoplasm were observed in some cases. These processes contained intermediate filaments of undetermined nature and microtubules. In the border zone between the tumor and the surrounding brain, the stromal cells were occasionally surrounded by narrow sheets of dark cell processes containing fibrils and glycogen granules, consistent with astrocytic processes. Altered neuronal elements were also observed inthis area.
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  • 97
    ISSN: 1432-0533
    Keywords: Becker's muscular dystrophy ; Neuromuscular junction ; Ultrastructure
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary Ultrastructural studies on muscle biopsies from three patients with Becker's muscular dystrophy showed that the i.m. nerves presented loss or disarrangement of the neurofilaments and an increased number of glycogen granules and/or myelin figures not infrequently in the myelinated and unmyelinated nerve fibers. The neuromuscular junctions showed markedly widened sole-plate areas, and several terminal axons frequently abutted and formed neuromuscular junctions on the same fiber. The secondary synaptic clefts were markedly decreased in number and short in length in type I fibers but not in type II fibers. Most terminal axons showed no degenerative changes. Therefore, the participation of a neural factor might be suggested as the cause of Becker's muscular dystrophy, although it does not mean denervation in the conventional sense of an axonal degeneration.
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  • 98
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    Acta neuropathologica 67 (1985), S. 201-210 
    ISSN: 1432-0533
    Keywords: Gliosarcoma ; GFAP ; Factor VIII/RAg ; Ulex europaeus I agglutinin ; Ultrastructure ; Weibel-Palade bodies
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary Thirty-nine cases of gliosarcomas, two initiating as fibrosarcomas, 25 as mixed gliomas and sarcomas, and 12 as anaplastic gliomas with secondary sarcomas, were studied by light microscopy, immunohistochemistry, using GFAP, factor VIII/RAg, andUlex europaeus I agglutinin (UEA I), electron microscopy and tissue culture. GFAP was found variably positive in the glial areas; F VIII/RAg and UEA I, markers of both normal and neoplastic endothelial cells and their derivatives, were found in vessels of both gliomatous and sarcomatous parts of GS, less intensive in hyperplastic glomeruloid structures and, with decreasing intensity, in adjacent fibrosarcomatous areas, while UEA I, giving stronger reaction than F VIII/RAg, was occasionally demonstrated in sarcomatous cells. In vitro studies confirmed previous data of a separate growth of glial and mesenchymal cells with a divergent migratory speed. Electron microscopy demonstrated the frequent close admixture of glial and mesenchymal tumor cells, which showed the feature of either fibrosarcoma or angiosarcoma. The frequent resemblance of the latter with endothelial cells was supported by the occasional demonstration of Weibel-Palade-like bodies in both vascular endothelial and adjacent sarcomatous cells. These observations confirm the hypothesis that at least part of the sarcomatous components in many GS originate from vascular endothelial proliferation and obviously represent the final stage of a process starting with the endothelial hyperplasia in anaplastic gliomas.
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  • 99
    ISSN: 1432-0533
    Keywords: Blood-brain barrier ; Morphometry ; Ultrastructure ; Experimental glioma
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary Cerebral edema, a major complication of tumors in the brain, is the result of an alteration in the blood-brain barrier (B-BB). The vascular ultrastructural changes that underlie edema formation have been described in a variety of tumors. Interendothelial junction abnormalities, fenestrations, and large numbers of tubulo-vesicular profiles in the tumor vascular endothelium have been presumed to represent permeability routes that permit the escape of serum constituents into the tumor, from where they flow into the surrounding brain. Descriptive studies do not provide information on the relative frequency of these presumptive permeability routes. In the study reported here we have quantified ultrastructural features associated with the B-BB in the vessels of an experimental glioma in rat. We found that approximately 60% of the tumor vessel profiles have junctional abnormalities and 30% have one or more fenestrations. The density of tubulo-vesicular profiles, however, was not increased. In addition, tumor vessel walls were thicker than normal vessels of the same caliber and the mitochondrial density was in the range of that for non-barrier vessels. Vessels in peritumoral regions were not altered in any of the parameters measured.
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  • 100
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    Acta neuropathologica 67 (1985), S. 242-246 
    ISSN: 1432-0533
    Keywords: Chick embryo ; Optic tectum ; Blood vessels ; Ultrastructure ; Hypoxia
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary The maturation process of blood vessels has been ultrastructurally investigated in the optic tectum of chick embryos kept in a condition of aerogenic hypoxia and of chickens born from fertilized eggs incubated under hypoxia but kept in the open air after hatching. By comparing the fine structure of the intratectal vessels of chick embryos exposed to hypoxia to that of embryos developed under normal conditions, the conclusion has been drawn that O2 deprivation does not prevent the temporal sequence of appearance and/or differentiation of the various vascular wall components (endothelium, endothelial basement lamina, pericytes, perivascular glia), but it produces, at least in a part of the latter, modifications, the type and degree of which apparently depend upon hypoxia duration.
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