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  • 1985-1989  (116)
  • 1980-1984
  • 1975-1979  (251)
  • 1986  (116)
  • 1978  (251)
  • Ultrastructure  (194)
  • Electron microscopy
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Years
  • 1985-1989  (116)
  • 1980-1984
  • 1975-1979  (251)
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  • 1
    Electronic Resource
    Electronic Resource
    Springer
    European archives of oto-rhino-laryngology and head & neck 243 (1986), S. 121-125 
    ISSN: 1434-4726
    Keywords: Bacterial labyrinthitis ; Ultrastructure ; Mycobacterium ; Mouse
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary We used electron microscopy to investigate Mycobacterium fortuitum -induced changes in the inner ears of mice. We found that the inner and outer hair cells had degenerated and disappeared in the organ of Corti. Changes in the lower turn of the cochlea were more severe than those of the upper turn while the changes of the outer hair cells were more severe than those of the inner hair cells. Disappearance, fusion and ballooning of the sensory hairs were observed in the vestibular organs. The bacterial extract also induced inner ear damage which was similar to that caused by live M. fortuitum.
    Type of Medium: Electronic Resource
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  • 2
    Electronic Resource
    Electronic Resource
    Springer
    European archives of oto-rhino-laryngology and head & neck 243 (1986), S. 260-264 
    ISSN: 1434-4726
    Keywords: Argyria ; Chemosensory function ; Oral Mucosa ; Ultrastructure ; X-ray microanalysis
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary Generalized argyrosis can produce a number of abnormalities, including skin discoloration, liver and kidney dysfunction. We describe a patient with generalized argyrosis following long-term self-treatment with oral silver intake, in whom skin discoloration, progressive taste and smell disorders, vertigo and hypesthesia were observed. These findings were confirmed by chemosensory tests and electrophysiological investigations. The development of hypogeusia was assessed by subjective tests, while the progression of hyposmia was followed by recording olfactory evoked cortical potentials. Light and electron microscopy of tissue samplings demonstrated electron-dense mineral deposits in basal membranes, in macrophages, in the perineurium of peripheral nerves, along elastic and collagenous fibers, and in necrotic cells of the oral submucosa. Silver and sulfur deposits in affected tissues could be defined by X-ray microanalysis. The quantitative ratio between silver and sulfur in involved tissues was similar to that of an inorganic silver-sulfide (Ag2S) standard. The minute increase in the sulfur content when compared to the inorganic standard suggested a sulfur containing organic matrix of the tissue precipitates. Our findings indicate that the affinity of silver for membrane and neuronal structures and the deposition of silver as an insoluble compound (Ag2S) induce the progression of clinical disease.
    Type of Medium: Electronic Resource
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  • 3
    Electronic Resource
    Electronic Resource
    Springer
    European archives of oto-rhino-laryngology and head & neck 243 (1986), S. 269-273 
    ISSN: 1434-4726
    Keywords: Otitis media with effusion ; Electron microscopy ; Human temporal bones
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary Ultrastructural studies of the middle ear mucosa appear to be of significant value in better understanding the pathology of otitis media with effusion (OME). Our present study was undertaken in order to take advantage of the use of electron microscopy in investigating all areas of the middle ear mucosa. Tissues studied were obtained from the fresh postmortem temporal bones of three patients with OME and terminal head and neck malignancies. In the mucoid type of effusion (cases 1 and 2), goblet cells were seen to proliferate and secretory activity was greatly enhanced. In contrast, there was no evidence of secretory cell proliferation in the serous type of effusion. It was noteworthy that accumulated fluid was not homogeneous in the same ear, as exemplified by case 1, in which both mucoid and serous effusions were present. This occurrence was possibly the result of topographic diversity involving the secretory activity of the middle ear.
    Type of Medium: Electronic Resource
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  • 4
    Electronic Resource
    Electronic Resource
    Springer
    European archives of oto-rhino-laryngology and head & neck 243 (1986), S. 296-303 
    ISSN: 1434-4726
    Keywords: Experimental tympanosclerosis ; Induced calcifications ; Electron microscopy
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary A rat animal model was used to study the ultrastructure of submucosal calcifications induced in the middle ear following inoculation with Streptococcus pyogenes and high doses of parenteral vitamin D3. The morphological changes present in affected animals resembled the classical picture of tympanosclerosis. While calcification occurred about bacterial remnants and myelin structures, the most important calcification centers were lysosomal and non-lysosomal matrix vesicles in the extracellular spaces. These formed band-like calcifications close to the basal membrane without affecting the epithelial layer. This animal model offers the possibility of studying the effect of various therapeutic regimens in the treatment of the dynamic tympanosclerotic process.
    Type of Medium: Electronic Resource
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  • 5
    ISSN: 1432-0584
    Keywords: Karyotype ; Bladder carcinoma ; Ultrastructure ; CSF ; Cell line
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary The cell line 5637 which originated from a human urinary bladder carcinoma is known to produce GM-CSF and Multi-CSF ectopically. Determination of cell surface antigens defined by monoclonal antibodies was recently reported [6]. Here we report on the ultrastructure and karyology of this CSF secreting cell line. At the ultrastructural level the monolayer in vitro culture and the solid tumors formed in nude mice showed all characteristics consistent with a well-differentiated transitional cell carcinoma (TCC). A subclone was found to grow in suspension and did not secrete any CSF activity. High resolution chromsome analysis revealed chromosomal abnormalities which agreed only in few particulars with nonrandom chromosomal aberrations usually found in TCC. Analysis of the cytogenetic results showed that nearly all structural abnormalities present are known to be associated with acute or chronic human leukemia. The possibility that the ectopic production of CSF in this cell line may be correlated to one or more of the described chromosomal aberrations is discussed.
    Type of Medium: Electronic Resource
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  • 6
    Electronic Resource
    Electronic Resource
    Springer
    Archives of dermatological research 278 (1986), S. 398-406 
    ISSN: 1432-069X
    Keywords: Nevocytic nevi ; Congenital ; Ultrastructure ; Nevus cells ; Nerve contacts
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary As only few previous investigations considered size-dependent differences in the histology of congenital nevocytic nevi (CNN) or focused on their ultrastructure, a light- and electron-microscopic study of six giant and six medium-sized CNN was performed. Histologically, giant CNN showed minimal junctional nevus elements and a pandermal, diffuse nevus cell extension including the subcutaneous tissue, while medium-sized CNN exhibited more abundant junctional nests and a rather focal pattern of nevus cell extension into the reticular dermis. Ultrastructurally, giant CNN often showed nevus cells with irregular and indented nuclei and also nevus cells with highly complicated dendrites. Nuclear inclusions, multiple cilia and centrioles, and collagen phagocytosis in nevus cells were found in both groups of CNN. Direct contacts between nevus cells and nerve fibers were observed in mediumsized CNN only. The findings provided no clear morphological indication why giant CNN have a higher risk for malignant degeneration than medium-sized CNN or acquired nevocytic nevi (ANN). On the other hand, the histological differences speak in favor of a different ontogenesis of the various size classes of CNN and ANN.
    Type of Medium: Electronic Resource
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  • 7
    ISSN: 1432-0983
    Keywords: Sugar beet ; Cytoplasmic male sterility ; Mitochondrial DNA ; Electron microscopy
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Summary Mitochondrial (mt) DNAs from normal (N) and male sterile (S) cytoplasms of sugar been have been isolated and investigated by electron microscopy. The results showed that mtDNA was composed of a heterogeneous population of circular molecules. Their contour lengths varied from 0.28 to 51 μm, but unlike in the case of maize, a large difference was not observed in the distribution of molecular classes greater than 1.0 μm between N and S cytoplasms of sugar beet. On the other hand, N and S cytoplasms were shown to contain their own characteristic combinations of small circular mtDNA species with lengths between 0.28 μm and 0.6 μm. Mitochondrial DNAs from various sources of male-sterile cytoplasms were analyzed by agarose gel electrophoresis to determine the extent of cytoplasmic variation. Additional low molecular weight DNA bands appeared in all male-sterile lines examined, and as a result, three distinctive banding patterns were recognized. These data are in general agreement with those based upon restriction endonuclease digestion of mt and chloroplast DNAs and the genetic analysis of fertility restoration in test crosses.
    Type of Medium: Electronic Resource
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  • 8
    ISSN: 1432-2307
    Keywords: Epithelioid haemangioendothelioma ; IVBAT ; Immunohistochemistry ; Ultrastructure
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary Three patients with epithelioid haemangioendothelioma (EHE) are described. Two patients presented with pulmonary infiltrates and one with a hepatic tumour. All had a metastatic disease ending fatally, and all were autopsied. The diagnosis was confirmed either by immunohistological or ultrastructural analysis. All three tumours were cytokeratin-negative and vimentin-positive, while only two contained cells reacting with the antibody of factor VIII-related antigen. Electron microscopy of the third tumour revealed features indicating endothelial differentation. A short literature review is also presented demonstrating that the outlook of EHE is worse than previously thought.
    Type of Medium: Electronic Resource
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  • 9
    ISSN: 1432-2307
    Keywords: Mesothelioma ; Serous membrane ; Localized tumour ; Histogenesis ; Ultrastructure
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary It is uncertain whether localized lesions of serosal membranes have a kinship to mesotheliomas or are truly fibromatous in nature. Ultrastructural and immunohistochemical investigations were carried out on 12 localized benign and malignant pleural and peritoneal tumours from 10 patients. Electron microscopic findings, including the consistent and non-fibroblastic cellular organization of localized neoplasms, the presence of some form of intercellular junctions in 7 of 10 cases, basal lamina deposition in 3 cases, and polarized microvilli in one case indicated a form of mesothelial differentiation. Using monoclonal and polyclonal antibodies, positive immunostaining of tumour cells for cytokeratin peptides was detected in one case, while antibody to vimentin stained four cases. Light microscopic, ultrastructural and immunohistochemical features of one benign localized serosal tumour, with a unique blend of epithelial and spindle cells, provided further evidence for a histogenic link between localized serosal tumours and diffuse epithelial mesotheliomas. On the basis of the current findings and reports in the literature, it would appear that the majority of localized tumours of serosal membranes are a subset of mesothelioma, while a minority are fibromas.
    Type of Medium: Electronic Resource
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  • 10
    Electronic Resource
    Electronic Resource
    Springer
    Virchows Archiv 410 (1986), S. 43-48 
    ISSN: 1432-2307
    Keywords: Endocarditis ; Staphylococcus ; Colonisation ; Morphology ; Ultrastructure
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary The initial colonization, byStaphylococcus aureus, of the catheter damaged aortic valve and aorta of the rabbit, was examined by light and electron microscopy at 15 min, 3 h and 24 h post inoculation (PI). At 15 min PI, the majority of bacteria (80%) were located on the lateral surfaces of the thrombic vegetations while 20% were attached directly to the connective tissue of the aortic valve and aorta in areas where the endothelial lining was disrupted. By 3 h the bacteria on the thrombic vegetations were covered by fibrin. At this time, the bacteria both within the vegetations and on the surface of the vasculature were undergoing multiplication to form small groups. The precipitation of thrombus around the bacteria attached to the surface of the aorta to form microscopic infected vegetations had occurred by 24 h PI. The colonizing bacteria did not elicit any phagocytic response. The colonization of the cardiovasculature byStaph. aureus did not necessarily require pre-existing vegetations.
    Type of Medium: Electronic Resource
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  • 11
    ISSN: 1432-2307
    Keywords: Human acute pancreatitis ; Enzyme immunocytochemistry ; Ultrastructure ; Acinar cell degranulation ; Fat necrosis
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary Human acute pancreatitis results from an autodigestive process frequently associated with alcohol abuse, gall stone disease and shock. Peripancreatic fat necrosis was identified as one of the earliest visible lesions, whereas acinar cell necrosis and haemorrhage were regarded as secondary changes. To examine the alterations in acinar cells in more detail, their enzyme content and fine structural features were studied immunocytochemically using antisera against α-amylase, lipase, trypsin, chymotrypsin and pancreatic stone protein, and electronmicroscopically in pancreatic tissues from patients with severe acute pancreatitis. Peripheral acinar cells in the immediate vicinity of fat necrosis were found to be heavily degranulated, while acinar cells at some distance of necrosis fully retained their enzyme content. Other frequent changes of the acinar cells included cuboidal transformation, loss of microvilli, increased occurrence of autophagosomes, and formation of enlarged acinar lumina. As there was no apparent cell membrane leakage or rupture of duct lumina, it is concluded that the acinar cells adjacent to fat necrosis release their granules by undirected basolateral extrusion. The findings thus suggest that one of the basic defects in acute pancreatitis is the uncontrolled release of enzymes from peripheral acinar cells into the interstitial space which, in turn, presumably by the action of lipase, leads to autodigestive fat necrosis.
    Type of Medium: Electronic Resource
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  • 12
    Electronic Resource
    Electronic Resource
    Springer
    Virchows Archiv 409 (1986), S. 417-431 
    ISSN: 1432-2307
    Keywords: Pituitary neoplasms ; Pituitary hormones ; Immunocytochemistry ; Electron microscopy ; Alpha-subunit ; Acromegaly
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary Immunohistological techniques demonstrate the alpha-subunit of glycoprotein hormones in the majority of endocrine-inactive, undifferentiated pituitary adenomas and pituitary oncocytomas. In about one-fifth of endocrine-active adenomas, the alpha-subunit is produced in combination with either adrenocorticotropic hormone or prolactin, and it is found in combination with growth hormone in about half of those adenomas causing acromegaly. Pure alpha-subunit-producing, endocrine-inactive adenomas characteristically have small secretory granules that are destroyed by direct osmium fixation, but are well preserved after prefixation with glutaraldehyde. As only a few atypical prolactinomas show similar secretory granules, and as they display a positive reaction for the alpha-subunit only exceptionally, this ultrastructural feature can serve as a guide to differentiate such adenomas.
    Type of Medium: Electronic Resource
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  • 13
    ISSN: 1432-2307
    Keywords: Giant-cell ; Virus-like inclusion ; Intranuclear inclusion ; Giant cell tumour of bone ; Paget's disease of bone ; Electron microscopy
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary This paper deals with the paramyxovirus-like intranuclear inclusions observed in giant cells tumours of bone (GCTB). Twenty-one (49%) of 43 cases of GCTB (1977–1985), either fresh and/ or cultured, show these ultrastructural inclusions. Fifty samples of various bone lesions in which giant cell lesions occurred, including aneurysmal cysts, hyperparathyroidism, osteoblastoma, human and rat osteopetrosis, GCT of tendon sheaths, and non skeletal granuloma were used as controls. These, together with 20 samples of normal bone (osteoclasts) did not contain intranuclear or intracytoplasmic viral inclusions.
    Type of Medium: Electronic Resource
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  • 14
    ISSN: 1434-0879
    Keywords: Monkey spermatozoa ; Gossypol effect ; In vivo examination ; Ultrastructure
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary The present study examines the ultrastructure of ejaculated spermatoza from bonnet monkey, Macaca radiata under noraml conditions, with gossypol treatment and during recovery from such treatment. Monkeys were fed orally with gossypol acetic acid (GAA) for 3 months (4 mg/monkey/5 days a weak). Semen samples collected by electroejaculation, and the spermatozoa were examined using both light and electron microscopy. The degree of motility was also noted by Kalla et al. [12]. Ejaculated spermatoza were immotile 90 days after GAA treatment, but little evidence for any abnormality in the spermatozoa could be seen by light microscopy. Some ultrastructural changes were observed, but not to the extent previously reported in spermatozoa of Macaca fascicularis [23]. After termination of treatment, semen samples were obtained every 5th day until sperm count and motility recovered to the normal level. After 90 days only a small proportion of spermatozoa showed abnormal structure. We conclude that in a subhuman animal model gossypol induced effects on sperm motility and morphology are reversible.
    Type of Medium: Electronic Resource
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  • 15
    ISSN: 1434-0879
    Keywords: Guinea pig ; Spermatic cord torsion ; Stereology ; Electron microscopy ; Leydig cell
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary An ultrastructural stereological analysis of Leydig cells of the guinea pig testis was carried out following surgically induced testicular torsion. Morphometric analyses of the Leydig cells of the experimental group of animals revealed an increase in the nucelar and mitochondrial volume and a decrease in the lipid volume, in comparison to those in the Leydig cells of the control group of animals. We believe that these changes in the Leydig cells of the experimental group of animals are indicative of cellular hypertrophy. The possible mechanisms of the Leydig cell hypertrophy in the guinea pig testis following the induction of spermatic cord torsion are discussed.
    Type of Medium: Electronic Resource
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  • 16
    Electronic Resource
    Electronic Resource
    Springer
    Anatomy and embryology 173 (1986), S. 295-298 
    ISSN: 1432-0568
    Keywords: Cardiodilatin ; Peptide Hormone ; Heart ; Human ; Immunohistochemistry ; Ultrastructure
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary The immunogold technique was applied to detect cardiodilatin-immunoreactivity (CDD-IR) in human heart. Using antibodies directed against C-terminal regions of CDD, we could identify colloidal gold label in specific atrial granules of human heart. The granules in all areas of the myoendocrine cells were homogeneously labelled and all right atrial biopsy specimen of patients with different heart diseases reacted positively and had the same distribution of label. The Golgi-apparatus and ergastoplasma exhibited and extremely weak CDD-IR. The results indicate a predominant storage of CDD in specific granules.
    Type of Medium: Electronic Resource
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  • 17
    Electronic Resource
    Electronic Resource
    Springer
    Anatomy and embryology 173 (1986), S. 361-370 
    ISSN: 1432-0568
    Keywords: Electrical synapses ; Chemical synapses ; Ultrastructure ; Morphometry
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary Thin sectioning and freeze-fracturing have revealed the distribution of gap junctions and chemical synapses in the synaptic interface of the large myelinated club endings on the lateral dendrite of the goldfish Mauthner cell. In 12 samples of club endings fractured completely or nearly completely, the apposed synaptic membrane area averaged 39.090 μm2, of which 16.6% was occupied by gap junctions and about 4 to 5% by the active zones of chemical synapses. The numerical profile density (number per unit area of the synaptic membrane) of gap junctions varied greatly, from 1.78 to 6.30, and was mostly in inverse proportion to their size. The chemical synapses were located mainly in two places: in the circumferential rim of the synaptic membrane next to the widened extracellular space, and in the margins of intraterminal invaginations of the synaptic cleft. The axoplasm of the preterminal axon, just after losing its myelin sheath, was filled with microtubules, among which neurofilaments gathered into many small bundles. The correlation between the areas of gap junctions and the chemical synapses and the amplitude of the excitatory postsynaptic potentials (EPSP) is discussed.
    Type of Medium: Electronic Resource
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  • 18
    Electronic Resource
    Electronic Resource
    Springer
    Anatomy and embryology 173 (1986), S. 385-391 
    ISSN: 1432-0568
    Keywords: Elastic cartilage ; Chondrogenesis ; External ear ; Rat ; Ultrastructure
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary Selected ultrastructural features of chondrocytes and the extracellular matrix in the developing elastic cartilage of the external ear were studied in rat fetuses and young animals. The cytoplasmic lipid droplets were first observed in the 19-day fetus. They increase in number and size during the first post-natal week. The elastogenesis proceeds in the sequence: oxytalan fibers (17-day fetus), elaunin fibers (1-day rat), elastic fibers (5-day rat). Intermediary stages between the randomly oriented individual microfibrils and bundles of microfibrils (oxytalan fibers) were also observed.
    Type of Medium: Electronic Resource
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  • 19
    Electronic Resource
    Electronic Resource
    Springer
    Anatomy and embryology 174 (1986), S. 27-33 
    ISSN: 1432-0568
    Keywords: Cerebral cortex ; Antisera ; Biopsy ; Postmortem Alzheimer's type dementia ; Ultrastructure ; Epilepsy
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary NPY-containing neuronal structures in the cereoral cortex of surgical tissue samples were compared to those in postmortem material by immunocytochemical methods. However, the quality of preservation of individual neurons and axonal and dendritic plexuses in the neuropil is unusually fine in the surgical specimens. This result is most likely attributable to the excellent fixation that can be regularly achieved by rapid and careful handling of tissue during and after surgical removal. The tissue is suitable for both light and electron microscopy, and the superior preservation also leads to intense, reliable antibody reactions. Postmortem tissue samples can provide good specimens for immunocytochemistry when properly handled as previously described. However the postmortem delays prior to fixation disrupt neuronal integrity in the immunostained structures. Nevertheless, postmortem material from carefully studied subjects of neurological diseases compared with age matched controls can provide valuable information.
    Type of Medium: Electronic Resource
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  • 20
    Electronic Resource
    Electronic Resource
    Springer
    Anatomy and embryology 173 (1986), S. 317-322 
    ISSN: 1432-0568
    Keywords: Paneth cell ; Ultrastructure ; Morphometry ; Germfree rats ; Ex-germfree rats
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary Ultrastructural changes of Paneth cells of germfree (Gf) rats which had been inoculated with bacteria-containing feces from conventionally-reared (SPF) rats were quantitatively examined. 12 and 24 h after inoculation, the Paneth cells showed a striking decrease in the number of secretory granules and the occurrence of large vacuoles. Phagosomes containing bacteria were not seen. After 4 days, the secretory granules reaccumulated and smooth-surfaced apical vesicles increased in number. It is discussed that the large vacuoles may be related to membrane-retrieval events following the massive extrusion of secretory granules whereas the apical vesicles appear to serve this function when exocytosis is not pronounced. In addition to the large secretory granules ca. 10% of Paneth cell profiles contained a few dense-cored vesicles measuring about 150 nm in diameter which resemble peptidergic neurosecretory granules.
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  • 21
    Electronic Resource
    Electronic Resource
    Springer
    Acta neuropathologica 71 (1986), S. 83-87 
    ISSN: 1432-0533
    Keywords: Astrocytes ; Brain neoplasms ; Oligodendroglioma ; Ultrastructure
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary Ultrastructural concentric laminations have previously been thought to be specific to oligodendroglioma. However, these structures were also recognized in fibrillary astrocytomas, a mixed glioma and a glioblastoma. These laminations continued or closely related to attenuated processes or cytoplasm of astrocytic tumor cells. In addition, some lamellae contained glial filaments. It is considered that the concentric laminations are derived from attenuated astrocytic processes and have no relationship with myelin.
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  • 22
    Electronic Resource
    Electronic Resource
    Springer
    Acta neuropathologica 70 (1986), S. 44-52 
    ISSN: 1432-0533
    Keywords: Gliosarcoma ; Myxoid tumor ; Extracranial metastasis ; Ultrastructure ; Immunohistochemistry
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary The case of a 22-year-old female suffering from glioblastoma with sarcomatous component (WHO; gliosarcoma) is presented. The tumor consisted of glioblastomatous and sarcomatouos components, and in part of the pleomorphic astrocytomatous region of the glioblastoma there was a prominent production of myxoid matrix. On the basis of its histochemical and immunohistochemical characteristics, the present case strongly suggested that glial cells of neuroectodermal origin assume part of the responsibility for production of myxoid material.
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  • 23
    ISSN: 1432-0533
    Keywords: Muscular diseases ; Capillar pathology ; Grave's disease ; Hyperthyroidism ; Electron microscopy
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary an electron microscope study of needle biopsies from the quadriceps muscle was carried out in 11 non=selected patients (ten females and one male), with clinically and laboratory-diagnosed hyperthyroid disease. Alterations of the normal structure of muscle fibres were found in all cases. Changes in capillaries were found in ten patients, and ranged from an increase in basement membrane thickness with reduplication, to total destruction of the capillaries. The importance of the vascular involvement in the muscles of patients with Graves-Basedow disease is stressed.
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  • 24
    ISSN: 1432-0533
    Keywords: Folliculo-stellate cell ; Pituitary adenoma ; Glial fibrillary acidic protein ; S-100 protein ; Electron microscopy
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary Folliculo-stellate cells (FS cells) in 40 pituitary adenomas and portions of anterior pituitary adjacent to the tumor in 26 cases were investigated immunohistochemically, using polyclonal antisera to S-100 protein (S-100) and glial fibrillary acidic protein (GFAP). The objective was to clarify the histological behavior of the FS cells. In most pituitary adenomas there were few or no S-100-or GFAP-positive cell, in comparison with numerous positive cells in the parts of the adenohypophyses compressed by adenomas. However, positive FS cells were observed in some types of pituitary adenomas. Growth hormone and prolactin producing adenomas frequently contained significant amounts of FS cells. In non-functioning adenomas, an unique case of FS cell adenoma was present. The adenoma was composed mainly of FS cells and immature glandular cells. The FS cells were sometimes located around follicles containing Periodic acid Schiff-positive material. Therefore, the FS cell adenoma is characterized by S-100- and GFAP-positive FS cells and PAS-positive follicles. In this type of adenoma, FS cells seemed to be the main proliferating component. In parts of the adenohypophyses adjacent to the adenomas, GFAP0-positive FS cells were numerous. In the pathological conditions FS cells may possess the potential of reactive proliferation.
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  • 25
    Electronic Resource
    Electronic Resource
    Springer
    Acta neuropathologica 72 (1986), S. 134-141 
    ISSN: 1432-0533
    Keywords: Cerebral embolism ; Fungal vasculitis ; Paecilomyces javanicus ; Prosthetic valve endocarditis ; Ultrastructure
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary A 41-year-old diabetic woman developed Paecilomyces javanicus endocarditis and subsequent cerebral fungal embolism and vasculitis with massive infarction and hemorrhage 6 years after a mitral valve replacement with porcine heterograft. The organism was identified by the culture from the infected brain tissue and aortic valve. Cerebral infection due to fungus Paecilomyces is rare. This report documents the cerebral manifestations of fungus Paecilomyces javanicus and describes for the first time the ultrastructure of such an organism obtained from the infected tissue. Their ultrastructural findings, similar to those described in Paecilomyces farinosus derived from culture, include a double-layered cell wall, a triple unit plasma membrane, abundant cytoplasmic lipid droplets, vacuoles, membranous profiles and septal formation. This report further demonstrates hyphae with packed 50A filaments and granulofibrillary material and features suggestive of intrahyphal hyphae, not previously described in fungus Paecilomyces.
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  • 26
    Electronic Resource
    Electronic Resource
    Springer
    Acta neuropathologica 70 (1986), S. 127-134 
    ISSN: 1432-0533
    Keywords: Avian muscle spindle ; Denervation ; Intrafusal fiber ; Ultrastructure
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary The role of the nerve in maintaining the ultrastructural integrity of avian muscle spindles was investigated by denervating the pigcon's extensor digitorum communis for periods of 10, 19, and 28 days. The equatorial region of control intrafusal fibers had a reduced density of myofilaments. Sensory endings contained mitochondria and structures resembling synaptic vesicles, and were associated with satellite cells. In the polar region, fibers had a high concentration of myofilaments; small motor endings, unlike sensory endings, lay outside of the fiber's basal lamina. The outer capsule consisted of thin, tightly layered cells which gradually became reduced in number distal to the equatorial region. In both equatorial and polar regions the capsule became more disrupted with longer denervation periods, and lysosomes and phagocytes became more abundant. The equatorial region of denervated fibers contained many myofibrils and some had peripherally-located nuclei, unlike the controls; sensory terminals were absent. The polar region of some fibers had disorganized myofilaments and others had a reduced myofilament density. Fiber diameters increased significantly in both regions. Thus, denervated intrafusal fibers lost some characteristics which distinguish them from extrafusal fibers.
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  • 27
    ISSN: 1432-0533
    Keywords: Ia antigen ; Central nervous system ; Experimental allergic encephalitis ; Immunohistochemistry ; Electron microscopy
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary Ia antigen, encoded within the major histocompatibility complex, plays an important role in the activation of T lymphocytes. Since experimental allergic encephalitis is an essentially T cell-mediated disease, Ia antigen in the central nervous system (CNS) may be pathogenetically relevant. The occurrence of Ia antigen in the CNS of normal rats and of rats with experimental allergic encephalitis was studied by light and electron microscope immunocytochemistry using the monoclonal anti-Ia antibodies Ox 4 and Ox 6. In normal, unsensitized animals a distict population of stellate cells in the meninges and some perivascular mononuclear cells in the nervous tissue carried Ia antigen. In rats with experimental allergic encephalitis a dramatic increase of Ia-positive cells was found. In addition to the positive cells found in normal animals, monocytes, macrophages and many lymphocytes in the meningeal perivascular and parenchymal inflammatory infiltrates as well as “activated microglia” stained for Ia antigen. We did not find evidence for Ia expression on endothelial cells, astrocytes or other components of the CNS in either normal or diseased rats.
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  • 28
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    Acta neuropathologica 69 (1986), S. 314-321 
    ISSN: 1432-0533
    Keywords: Pacinian corpuscles ; Transplantation to the brain ; Electron microscopy
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary In adult inbred rats of the AVN strain, branches of the crural interosseous nerve were dissected out from donors and transplanted into the brain of recipients, together with a cluster of Pacinian corpuscles, (either into a suction cavity or the cerebral cortex) into a slit 1–2 mm deep. The grafts were fixed and processed for electron microscopy 10 days to 6 months after the operation, and their ultrastructure was examined. Sporadic axons of small diameter grew into the nerve branches of some of the grafts from 11 days onward, and became myelinated during the 2nd month after the operation, but none of the transplanted Pacinian corpuscles became reinnervated. The corpuscles, however, survived denervation and grafting. Most of them retained a well-preserved inner core and an intact capsule, consisting of a normal complement of 29.2±1.0 (mean ±SE) capsular layers (n=8), as did the corpuscles previously examined after denervation in situ. Some of the corpuscles underwent degenerative changes, presumably due to a delayed or restricted revascularization. In this group of corpuscles, the inner core underwent disintegration and was gradually replaced by collagen fibrils, whereas the capsule remained preserved but the number of its layers eventually reduced by 40%. It is assumed that the lack of reinnervation of the grafted Pacinian corpuscles was due to the paucity of regenerating axons, and their failure to form correct projections along those Schwann cell columns connected with the corpuscles.
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  • 29
    ISSN: 1432-0533
    Keywords: Pituitary adenoma ; Basement membrane ; Laminin ; Immunohistochemistry ; Electron microscopy
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary Thirty-eight human pituitary adenomas (24 endocrine active and 14 endocrine inactive tumors) were studied immunohistochemically for the presence of the basement membrane component, laminin, and ultrastructurally for the presence of basement membrane. Immunoreactivity of laminin delineated staining of epithelial and endothelial basement membranes, the reaction product being confined mostly to the perivascular zones. Moreover, a hitherto undescribed presence of intercellular laminin-positive droplets was observed in ten of the active adenomas (nine patients with hyperprolactinemia and/or acromegalia and one patient with Cushing's syndrome). Concurrently, at the ultrastructural level, bunches of basement membrane-like material intermingled between the adenoma cells were demonstrated in seven of these ten active adenomas. Furthermore, secretory granules were entrapped occasionally in this intercellular matrix, indicating a mutual dependence between excessive hormone extrusion and an increase of “misplaced” deposits of basement membrane components, e.g., laminin.
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  • 30
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    Acta neuropathologica 70 (1986), S. 10-16 
    ISSN: 1432-0533
    Keywords: Astroblastoma ; Immunohistopathology ; Electron microscopy
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary The very existence of astroblastoma has been a question of considerable controversy, although there appears now to be sufficient documentation to establish it as a tenable entity. Due to the rarity of this tumor, little information exists in the literature as to its natural history, efficacy of therapy and its pathological and radiological appearance. We report three cases of astroblastoma, describing their natural history, the response to therapeutic interventions and their light microscopic, ultrastructural and immunohistochemical characteristics.
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  • 31
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    Acta neuropathologica 70 (1986), S. 71-74 
    ISSN: 1432-0533
    Keywords: 6-Aminonicotinamide ; Ependymal cell ; Mitosis ; Suckling mice ; Ultrastructure
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary Mitotic ependymal cells were encountered in 10-day-old mice treated with 6-aminonicotinamide, an antagonist of niacin. These occurred along the medial surface of the lateral ventricle and the ventral portion of the aqueduct. Electron microscopy revealed that both mitotic ependymal cells had eccentrically placed chromosomes without a nuclear membrane and well-formed gap junctions in contact with adjacent ependymal cells. Microtubules from a centriole radiated to the chromosomes. These data show that cell division occurs in morphologically matured ependymal cells in the postnatal brain under pathological conditions. We believe this to be the first ultrastructural demonstration of this phenomenon.
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  • 32
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    Anatomy and embryology 174 (1986), S. 379-389 
    ISSN: 1432-0568
    Keywords: Lungs ; Amphibia ; Ultrastructure ; Morphometry ; Surfactant
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary Lungs ofHyla arborea L. were examined by scanning and transmission electron microscopy and morphometric methods. The lungs contain several interconnected folds in a netlike reticular arrangement of first, second and third order, mainly covered with pneumocytes. On the septa of first and second order, irregularly distributed small patches of ciliated epithelium devoid of goblet cells are located. Dome-shaped neuroepithelial bodies can be seen in the vicinity of ciliated epithelium. The pulmonary epithelium consists of one type of pneumocyte, which contain in their cytoplasm three kinds of bodies: lamellar, dense and multivesicular. The dense bodies are precursors of lamellar bodies (LBs), while the multivesicular bodies are incorporated into the LBs, being later secreted to the air space. The lining layer covering the internal lung surface contains numerous transformed LBs but tubular myelin figures are scarce. The surface of the lining layer is coated by a thin film. The air-blood barrier, consisting of three layers: epithelium, interstitial space and endothelium, is 0.6 μm thick.
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  • 33
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    Acta neuropathologica 69 (1986), S. 81-90 
    ISSN: 1432-0533
    Keywords: Creutzfeldt-Jacob disease ; Slow virus infection ; Subacute spongiform encephalopathy ; Ultrastructure ; Synapse
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary Guinea pigs inoculated with brain homogenate from serially passaged Creutzfeldt-Jakob disease (CJD) were killed biweekly starting at week 2 until terminal illness (about 200 days following inoculation). A mild swelling of postsynaptic dendrites and an increase in the number of glial filaments in astrocytic processes was seen at week 4, followed by increased swelling and lucency of axons and dendrites by week 6 post inoculation (p.i.). Severe undulation and focal interruptions of synaptic membranes were also observed both at weeks 4 and 6. By week 8, one could see cystically dilated cellular processes. These sometimes showed continuity with adjacent swollen processes through focally disrupted plasma membranes, and most likely represent a progressive enlargement of vacuoles through fusion and subsequent addition of adjoining processes. The spongiform changes increased mildly between week 8 and week 10 and remained essentially the same in subsequent weeks. After week 24 there was a sharp increase in both the number and size of vacuoles. At week 24 severe structural alterations were present both in the neurons and astrocytes, and numerous intranuclear inclusions were demonstrated in many neuronal nuclei. This study shows that morphological changes in the brain occur considerably earlier than the clinical manifestations of the disease. In the early phase of the disease, there were significant alterations on the dendrites and synapses.
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  • 34
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    Acta neuropathologica 69 (1986), S. 103-110 
    ISSN: 1432-0533
    Keywords: Neurofibroma ; von Recklinghausen's disease ; S-100 protein ; Electron microscopy ; Immunoelectron microscopy
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary The nature of the cells in neurofibromas was studied by electron microscopy and immunoelectron-microscopic examination of S-100 protein. Ultrastructurally, all five neurofibromas studied were found to be composed of Schwann cells, perineurial cells, and intermediate cells, which had features of both perineurial cells and fibroblasts. The Schwann cells had complex, branched cytoplasmic processes and a continuous basal lamina. The perineurial cells were distinguishable from Schwann cells by the presence of numerous pinocytotic vesicles, unbranched slender cytoplasmic processes and a discontinuous basal lamina. The intermediate cells had no basal lamina, but were topographically related to Schwann cells and had a similar fine structure to that of perineurial cells. Thus, they seemed to be modified neoplastic perineurial cells. Immunoelectron-microscopic studies showed the presence of cells with and without S-100 protein in the neurofibromas: cells with S-100 protein resembled Schwann cells ultrastructurally, and those without S-100 protein were perineurial and intermediate cells. Some Schwann cells with S-100 protein in one neurofibroma had numerous pinocytotic vesicles characteristic of perineurial cells, suggesting that Schwann cells and perineurial cells, are functional variants of the same cell type. Thus this study showed that neurofibromas were composed of Schwann cells with S-100 protein and perineurial and intermediate cells, including socalled endoneurial fibroblasts, without S-100 protein. Morphological and functional transition seems to occur between Schwann cells and perineurial cells, and between perineurial cells and intermediate cells.
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  • 35
    ISSN: 1432-0533
    Keywords: Streptozotocin-diabetic rat ; Myenteric plexus ; VIP-ergic nerves ; Ultrastructure
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary Enteric nerves in the ileum of rats 8 weeks after streptozotocin-induction of diabetes were examined under the electron microscope before and after immunolabeling for vasoactive intestinal polypeptide (VIP). These studies have provided evidence of degenerative changes in the myenteric nerve fibres of diabetic rats, many of which were shown to contain VIP. It is suggested that VIP-ergic nerves in the gut may play a role in the developent of gastrointestinal dysfunction in diabetes.
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  • 36
    ISSN: 1432-0533
    Keywords: Farber's disease ; Peripheral nerve ; Subcutaneous nodules ; Electron microscopy ; Ceramidase deficiency
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary Two siblings born from consanguineous tunisian parents are reported. They showed a severe form of Farber's disease with prominent involvement of the central and peripheral nervous system: low conduction velocity was noticed in both children. Macular cherry red spots were observed in one of them. The diagnosis for the girl investigated was confirmed by evidence of ceramidase deficiency in cultured fibroblasts. Here we report the pathological findings in the subcutaneous nodules using light and electron microscopy (one case), and in sural nerves using morphometric studies (both cases). Varying morphological aspects of intracellular inclusions, depending on the tissues involved, are described and discussed. A review of all cases reported since Farber's first paper in 1952 is given.
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  • 37
    ISSN: 1432-0533
    Keywords: Brain tumor ; Rhabdomyosarcoma ; Immunohistochemistry ; Ultrastructure ; Cerebral paragonimiasis
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary A necropsy case of a primary rhabdomyosarcoma with chronic paragonimiasis in the cerebrum of a 68-year-old man is reported. The clinical data showed a right hemiplegia and dysarthria which became lethal in 6 months even though operation and radiation therapy were performed. Computed tomography revealed a large low-density area associated with the peripheral enhancement in the left basal ganglia, and multiple conglomerated calcified masses in the left temporal and occipital lobes. Biopsied and necropsied materials of the tumor in the basal ganglia was reddish brown in color and histologically was composed of purely mesenchymal derivatives with both embryonal and mature striated muscle cells but neither neuronal nor glial elements. Some of the tumor cells with extending slender cytoplasms showed obvious cross striations at the light and electron microscope levels and immunohistochemical reactivity for myoglobin. All tumor cells were also positive for vimentin, but not for glial fibrillary acidic protein. The clinical and necropsy findings revealed no primary lesion anywhere but in the brain. In addition, numerous dead oval eggs ofParagonimus westermani were found in many cystoid lesions encapsulated by thick connective tissues with calcification and/or ossification. Clinicopathological features of 24 cases of primary rhabdomyosarcoma of the central nervous system reported in the literature are reviewed briefly. The histogenesis of this tumor are discussed together with comments on cerebral paragonimiasis.
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  • 38
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    Archives of dermatological research 279 (1986), S. 77-82 
    ISSN: 1432-069X
    Keywords: Lichen nitidus ; Lichen plahus ; Ultrastructure
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary Lichen nitidus (LN) and lichen planus (LP) are considered by some investigators to be two variants of the same disease, and by others to be two distinct dermatoses. In order to obtain further information about the relationship between LN and LP we examined the ultrastructure of lesions from two LN patients. In the central part of the lesion, the basement membrane was absent, or was interrupted by migrating phagocytes or lymphocytes. The basal cells and the lower cells of the stratum spinosum exhibited karyolysis and appeared to be compressed and often necrotic. In the upper dermis irregular cell debris full of clumps of tonofilaments and colloid-body-like structures was observed. A dense dermal infiltrate of macrophages, lymphocytes, fibrocytes, and Sezary-like cells was present. Signs of cooperation between lymphocytes and macrophages were also evident. The periphery of the lesion showed no pathological features except for enlargement of the intercellular spaces and the presence of mononuclear cells scattered through the epidermis. Several normal Langerhans cells were noticed. These ultrastructural findings were quite similar to those reported for LP.
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  • 39
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    Cellular and molecular life sciences 42 (1986), S. 144-147 
    ISSN: 1420-9071
    Keywords: Ultrastructure ; catalase ; D-amino acid oxidase ; fetal mouse liver ; hepatocytes ; peroxisomes ; muscular dysgenesis
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary In the hepatocytes of ‘normal’ fetal mice from mothers which were carriers of muscular dysgenesis, catalase and D-amino acid oxidase (DAAO) positive as well as negative peroxisomes were observed. DAAO reaction product was occasionally localized in patches around cell membranes and DAAO-positive peroxisomes were frequently observed near mitochondria.
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  • 40
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    Experimental brain research 65 (1986), S. 189-199 
    ISSN: 1432-1106
    Keywords: Rat optic nerve ; Gliogenesis ; Myelination ; In vitro ; In vivo ; Electron microscopy ; Immunocytochemistry
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary The question of whether the development of CNS glial cells requires the presence of axons or not can be studied with in vitro systems. In order to compare the differentiation of glial cells during development in vitro with that in situ, we have selected the optic nerve, which is anatomically as well as histotypically a well defined structure. For the in vitro investigations, small explants, called minisegments, of newborn rat optic nerves were cultivated taking four major conditions into account: (1) the regular size of the minisegments should guarantee a permanent exchange of the culture medium in order to avoid cell death, (2) neither mechanical nor enzymatic dissociation of the tissue were applied, (3) the minisegments were explanted into flasks without substrate for cell adhesion and (4) the minisegments were under constant gyratory agitation. The following in situ results were obtained: optic nerves of newborn rats are morphologically characterized by the presence of naked axons, astrocytes, glial precursors, and the absence of both differentiated oligodendrocytes and myelin. At postnatal day 5 myelin sheaths are still absent. Two weeks after birth, differentiated oligodendrocytes and microglial cells are present and numerous axons are surrounded by compact myelin. The in vitro experiments show the following main results, which were obtained after 14 h, 2 d, 5 d and 14 d in culture: during time in culture, the shape of minisegment of newborn rat optic nerves undergoes drastic changes, which indicate high cellular dynamics. After 14 h in vitro, axonal profiles, cells with pyknotic nuclei as well as clusters of astrocytes and glial precursors are present. After 2 days in culture the axonal profiles disappeared and the number of degenerating cells decreased drastically. Many large cells, probably phagocytes containing inclusions and more cells are differentiated. At the stage of 5 d in vitro 4 major types of cells can be distinguished: differentiated oligodendrocytes, which form compact and loose myelin, astrocytes, large and small glioblasts and phagocytes. Immunoprecipitates for myelin basic protein and/or myelin associated glycoprotein were found in oligodendrocytes, in their processes and associated to the myelin. Processes of some astrocytes showed immunoreactive products of glial fibrillary acidic protein. After two weeks in culture, the minisegments were mostly composed of astrocytes, whereas oligodendrocytes became rare and phagocytes disappeared. It can be concluded that CNS glial cells can attain their structural and immunocytochemical characteristics in the total absence of neuronal cell bodies and axons. However, it can be speculated that neurons (or neuronal factors) could regulate the number of astrocytes and oligodendrocytes and keep these glial cells in a physiological equilibrium.
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  • 41
    ISSN: 1432-1106
    Keywords: Optic tectum ; Neurotransmitters ; Cholinergic markers ; Ultrastructure ; Goldfish
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary Neurochemical parameters associated with cholinergic and excitatory amino acid transmission, were measured in synaptosomes of the goldfish optic tectum at different times after unilateral eye ablation. Significant decreases in choline acetyltransferase and acetylcholinesterase were measured 12 and 30 days after enucleation. The high affinity choline uptake did not parallel the decrease in cholinergic enzymes. Instead there was a significant increase of the uptake per unit of protein (though not relative to the total number of tectal synaptosomes). No decrease of the high affinity D-3H aspartate uptake was measured in the deafferentated optic tectum. Electron microscopic observations showed a correspondence between the time course of cholinergic enzyme decrease and the degeneration of retinal afferents to the tectum. The present results support the notion that acetylcholine is a better candidate than the excitatory amino acids for a neurotransmitter role in the fish optic tectum.
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  • 42
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    European journal of pediatrics 145 (1986), S. 422-427 
    ISSN: 1432-1076
    Keywords: CFU-E ; BFU-E ; Electron microscopy ; Sideroblastic anaemia ; Dyserythropoiesis
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Abstract We examined the morphological and functional characteristics of erythroblasts derived from marrow erythroid progenitor cells grown in a methylcellulose microculture, which were taken from a female child with rate atypical sideroblastic anaemia (SA) partially responsive to pyridoxine. Colony formation was within the normal range in three successive cultures (median values: 82.25 CFU-E and 16.4 BFU-E derived colonies/6.6×104 cells) compared to growth by normal cells (65-315 CFU-E and 9-40 BFU-E). We evaluated in vitro differentiation by biochemical microassay of a cytosol enzyme involved in the haeme pathway: uroporphyrinogen I synthase (UROS). The UROS values in the erythroid colonies from SA marrow were at the lower end of the normal range (median values: 6.7±0.3 and 14.4±3.8 pmol uroporphyrinogen/h in CFU-E and BFU-E-derived colonies respectively versus 17.4±7.3 and 25±7.2 pmol/h in CFU-E and BFU-E colonies from normal subjects. Ultrastructural examination of the SA erythroblasts from non-cultured bone marrow or derived from cultured BFU-E revealed the characteristic deposition of iron in mitochondria around the nucleus of most cells (ringed sideroblasts). However, the majority of cultured cells had marked dyserythropoietic featuress, with a large number of bilobulated or trilobulated crythroblasts, multiple cytoplasmic vacuoles, numerous abnormalities of the nucleus, and excessive membrane material beneath the plasma membrane, all features difficult to observe in non-cultured marrows.
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  • 43
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    European journal of pediatrics 144 (1986), S. 557-562 
    ISSN: 1432-1076
    Keywords: Rimmed vacuoles ; Childhood ; Myopathy ; Ultrastructure
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Abstract A 5-year-old boy suffered from a slowly progressive non-familial neuromuscular disease, clinically marked by generalised muscle weakness, atrophy and hypotonia, a “myopathic” EMG and mildly elevated CK values. His gastrocnemius muscle showed marked myopathy, type I fibre predominance, and numerous “rimmed” vacuoles. This boy's condition is regarded as a childhood neuromuscular disease with rimmed vacuoles.
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  • 44
    ISSN: 1432-0738
    Keywords: Cytotoxicity ; Cell morphology ; RL-4 hepatocyte ; Electron microscopy ; In vitro study ; Allyl isothiocyanate ; Benzyl isothiocyanate ; Tert-butylhydroperoxide
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Abstract Since allyl isothiocyanate has been reported to be a bladder carcinogen and benzyl isothiocyanate is a known anti-carcinogen, it is important to know the mode of their cytotoxic action. This was investigated in a RL-4 hepatocyte cell line by studying the morphological effects of increasing concentrations of the isothiocyanates and their glutathione and cysteine conjugates. These effects were compared with those induced by tert-butylhydroperoxide which supposedly has its primary effect upon the cytosolic glutathione status and thus upon the integrity of Ca2+-sequestrating mitochondria. The results agree with the previously postulated role of conjugation in the exposure of cells to isothiocyanates: Conjugates show effects similar to those produced by the free parent compounds because conjugates release free isothiocyanates in aqueous solution. The cytomorphological effects increase in a more or less dose-dependent manner with increasing concentrations of isothiocyanate or exposure time. Probably due to increased exposure, suspended RL-4 cells are more sensitive to the toxic action than cells growing on a substrate. No qualitative differences were found between the effects of allyl and benzyl isothiocyanate, indicating that their different effects in vivo are perhaps related to organ-specific differences in equilibrium between the conjugated and unconjugated forms of the test substances. The first cytomorphological effects of isothiocyanates consist of surface blebbing (zeiosis) and swelling of dictyosomal cisternae. At higher concentrations swelling extends to vesicles of endoplasmic reticulum. Mitochondria are not affected until the cells reach the necrotic phase of injury. In contrast, tert-butylhydroperoxide causes mitochondrial damage in an early pase of toxic injury. The cellular symptoms suggest that the primary target of isothiocyanates is in the plasma membrane and the cellular membrane system, affecting the monovalent cation and water balance of the cell organelles rather than the Ca2+ homeostasis as in cells exposed to tert-butylhydroperoxide. Differences in lipophilicity may be at the basis of this differenc in primary action.
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  • 45
    ISSN: 1432-1459
    Keywords: Cerebral vasospasm ; Myonecrosis ; Myofilament ; Calcium ; Electron microscopy
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary Electron microscopic data on the development of myonecrosis following cerebral vasospasm associated with subarachnoid haemorrhage, meningitis and trans-sylvian surgery are presented. The basic feature of myonecrosis was dissolution of myofilaments with resultant fine granular or filamentous material. The disintegrating cytoplasm often contained numerous glycogen granules, dense bodies, autophagic vacuoles and myelin-like membranous bodies. A well-developed sarcoplasmic reticulum was preserved despite myofilament dissolution, while mitochondria showed marked sweling. The nuclei showed either dilution of chromatin or pyknotic change. The basal lamina was remarkably thickened and maintained an irregular outline of the necrotic smooth muscle cells. Enlarged intercellular space contained abundant cellular debris, vesicular structures and connective tissue fibres. The pathogenesis of these changes is discussed.
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  • 46
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    Archives of microbiology 146 (1986), S. 267-274 
    ISSN: 1432-072X
    Keywords: Photosynthesis ; Membrane structure ; Electron microscopy ; Ectothiorhodospira ; Serial thin sectioning ; Three dimensional reconstruction
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract The three dimensional organization of the complete photosynthetic apparatus of the extremely halophilic, bacteriochlorophyll b containing Ectothiorhodospira halochloris has been elaborated by several techniques of electron microscopy. Essentially all thylakoidal sacs are disc shaped and connected to the cytoplasmic membrane by small membraneous “bridges”. In sum, the lumina of all thylakoids (intrathylakoidal space) form one common periplasmic space. Thin sections confirm a paracrystalline arrangement of the photosynthetic complexes in situ. The ontogenic development of the photosynthetic apparatus is discussed based on a structural model derived from serial thin sections.
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  • 47
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    Archives of microbiology 143 (1986), S. 400-402 
    ISSN: 1432-072X
    Keywords: E. coli relA +/relA ; Starvation survival ; Guanosine tetraphosphate ; Electron microscopy ; Glycogen
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract Amino acid-starved cells of Escherichia coli relA +, which contain a large number of glycogen particles, are able to survive in phosphate buffer for a longer time period than their relaxed counterparts. With regard to NH 4 + starvation differences in the survival of both strains were not found. NH 4 + starved cells of E. coli relA are able to synthesize glycogen but amino acid-starved cells of the relA strain are not. We suggest that the synthesis of glycogen triggered by guanosine tetraphosphate during amino acid starvation is responsible for the prolonged viability of the E. coli relA + strain.
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  • 48
    ISSN: 1432-072X
    Keywords: Bradyrhizobium ; Electron microscopy ; Mutants ; Nitrogen fixation ; Nodulation ; Soybean ; Symbiosis ; Transposon Tn5
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract The genome of the slow-growing Bradyrhizobium japonicum (strain 110) was mutagenized with transposon Tn5. A total of 1623 kanamycin/streptomycin resistant derivatives were screened in soybean infection tests for nodulation (Nod) and symbiotic nitrogen fixation (Fix). In this report we describe 14 strains possessing a stable, reproducible Nod+Fix- phenotype. These strains were also grown under microaerobic culture conditions to test them for free-living nitrogen fixation activity (Nif). In addition to strains having reduced Fix and Nif activities, there were also strains that had reduced symbiotic Fix activity but were Nif+ ex planta. Analysis of the genomic structure revealed that the majority of the strains had a single Tn5 insertion without any further apparent physical alteration. A few strains had additional insertions (by Tn5 or IS50), or a deletion, or had cointegrated part of the vector used for Tn5 mutagenesis. One of the insertions was found in a known nif gene (nifD) whereas all other mutations seem to affect different, hitherto unknown genes or operons. Several mutant strains had an altered nodulation phenotype, inducing numerous, small, widely distributed nodules. Light and electron microscopy revealed that most of these mutants were defective in different stages of bacteroid development and/or bacteroid persistence. The protein patterns of the mutants were inspected by two-dimensional gel electrophoresis after labelling microaerobic cultures with l-(35S)methionine. Of particular interest were mutants lacking a group of proteins the synthesis of which was known to be under oxygen control. Such strains can be regarded as potential regulatory mutants.
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  • 49
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    Child's nervous system 2 (1986), S. 297-300 
    ISSN: 1433-0350
    Keywords: Pineocytoma ; Magnetic resonance imaging ; Computed tomography ; Ultrastructure
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Abstract The radiological and pathological findings in three children with pineocytomas are described. The patients presented with symptoms and signs of increased intracranial pressure. CT scans demonstrated obstructive hydrocephalus, but failed to visualize pineal masses that were subsequently seen on MR scans. A suboccipital, supracerebellar approach was used to obtain tissue for histological diagnosis and, in one case, achieve a total removal. Light microscopy demonstrated typical pineocytomatous rosettes without evidence of gangliocytic or astrocytic differentiation. Electron microscopy revealed numerous dense core vesicles with synaptic ribbons, suggesting neurosecretory capability. These three cases demonstrate the diagnostic advantage of MR imaging for tumors in the pineal region as well as the relatively well-differentiated histopathological characteristics of pineocytomas.
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  • 50
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    Virchows Archiv 408 (1986), S. 329-346 
    ISSN: 1432-2307
    Keywords: Pulmonary fibrosis ; Asbestosis ; Chrysotile ; Macrophages ; Electron microscopy
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary A single instillation of 1 mg chrysotile B with a fiber length between 0.05 and 0.2 µm in 0.1 ml tricaprylin was made via a polyvinyl catheter into the lower lobe of the right lung of 120 six-week-old Wistar rats under anesthesia. The animals were killed at intervals between five minutes and two years. The lower lobes of the right lung were investigated by light and electron microscopy. The process of pulmonary fibrosis induced by asbestos can be subdivided into four phases: these are the phase of phagocytosis (five to 15 min), the phase of granuloma formation (between one and two weeks), the phase of septal fibrosis (between two and six months) and finally the scar stage (after one year). After instillation of small asbestos fibers into the alveoli, a major proportion of these fibers is phagocytosed by alveolar macrophages after five minutes and leaves the lungs via the airways. A proportion of the fibers penetrates through the alveolar wall (mostly conveyed by type I pneumocytes) and reaches the interstitium of the lungs. There, the fibers are taken up by pulmonary tissue macrophages and giant cells. Within the phagolysosomes, the fibers are broken down into fragments less than 0.01 µm in length. Type II pneumocytes produce surfactant in excess. These cells become necrotic, tubular myelin and lamellar bodies pass into the alveoli and into the interstitium. Surfactant is phagocytosed by resident macrophages. These macrophages phages can break down. Besides asbestos and surfactant, mediators of fibrillogenesis are released. Macrophages following up from blood monocytes ingest surfactant and asbestos. This process is perpetuated up to complete scarring. After two years, small asbestos fibers less than 0.01 µm long are present in fibroblasts and pleural mesothelia.
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  • 51
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    Virchows Archiv 409 (1986), S. 163-169 
    ISSN: 1432-2307
    Keywords: Thymoma ; Thymic carcinoma ; Ultrastructure ; Immunohistochemistry
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary A case of thymic carcinoma arising within a lymphocyte rich thymoma is reported. The undifferentiated carcinoma contained cellular elements resembling choriocarcinoma but could be differentiated there-from by positive staining for prekeratin antigen and an absence of staining for B-HCG antigen utilizing immunohistochemical techniques.
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  • 52
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    Theoretical and applied genetics 72 (1986), S. 840-844 
    ISSN: 1432-2242
    Keywords: Chlorophytum comosum ; First pollen mitosis ; Male plastid inheritance ; Ultrastructure
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Summary The behaviour of plastids and mitochondria during the formation and development of the male gametophyte of Chlorophytum comosum has been investigated using electron microscopy. During first pollen mitosis an intracellular polarization of plastids occurs in that the plastids are clustered in the centre of the microspore. The originating generative cell normally lacks plastids. Only in a small number of microspores have plastids been observed near the dividing nucleus of the microspore and later on in the generative cell. These observations agree with the genetic investigations of Collins (1922) on the mode of plastid inheritance which demonstrated a small amount of biparental plastid inheritance in Chlorophytum. The cytological mechanisms underlying plastid polarization during the first pollen mitosis are discussed.
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  • 53
    ISSN: 1432-2242
    Keywords: Mitochondrial DNA of plants ; Electron microscopy ; Suspension culture ; Vicia faba
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Summary A comparative analysis of the Vicia faba mitochondrial genome in whole plants and in longterm suspension culture has been conducted. Restriction fragment patterns of the mtDNA isolated from these two sources were notably different. Electronmicroscopic analysis also revealed significant differences. Large circular mtDNA patterns shifted from a 37–80 kb subpopulation, which was predominant in whole plants, to 18–34 kb subpopulations although in both classes notable quantities of circular molecules of 80 to 120 kb and more were also found. Both in whole plant and suspension culture cells very large circular DNAs were observed. Some of them had lengths nearly 290 kb and could be considered as evidence of the existence of master chromosomes. The minicircular DNA population was also altered. In the suspension culture we observed a notable increase of percentage of minicircles with sizes near 1 kb. Simultaneously, the percentage of minicircles with sizes near 3.5–10 kb significantly increased in suspension culture cells. In addition, a new peak (10–12 kb) of minicircles appeared. Copy number alterations for some sequences homologous to CCC1A, CCC1B and CCC2 (Negruk et al. 1982, 1985) were shown. Southern hybridization revealed the existence of a family of minicircles having sizes 1.4–2 kb with predominance of CCC1A, CCC1B and CCC2. The copy numbers of CCC1B and some minor minicircles was changed in the suspension culture when compared with the whole plants.
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  • 54
    ISSN: 1432-0878
    Keywords: Glucocorticoids ; Cartilage ; Growth ; Histochemistry ; Ultrastructure ; Rat
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary The effects of different doses of various steroids on growth, and on costal and epiphyseal chondrocytes, have been studied in prenatal, immature, and adult Long-Evans rats using histochemical techniques, and both light and electron microscopy. Both prenatal and postnatal treatments have been employed. The steroids used were cortisone (CA), betamethasome (BM), and, in the prenatal group only, dexamethasone (DM). Body weight is reduced in all treated rats (except the low dose of CA) by day 17 of gestation, with greater weight reductions occurring in rats receiving the higher dose level of each steroid. In rats treated prenatally or neonatally, and sacrificed postnatally on days 39–43 or days 116–127, body weights, and tibial and tail lengths, are less than in correspondingly aged controls, thus showing a persistence of the effects of treatment. Costal and epiphyseal cartilages in prenatal rats show cellular, synthetic, and ultrastructural alterations induced by treatment with glucocorticoids but the responses are not necessarily comparable. Except for the low dose of DM, the higher doses of each steroid are more effective in inhibiting, or altering, growth and cellular differentiation in the developing fetuses. Surprisingly, a low dose of DM has a more devastating effect on the cells and extracellular matrix of both costal and epiphyseal cartilage, than do higher dose-levels of the various steroids. Low doses of CA and BM are also effective in inhibiting or altering growth and cellular differentiation, but their effectiveness is largely limited to 17 days of gestation. The order of effect of the various doses of the different steroids on fetal cartilage, listed in decreasing order of severity, is as follows: 0.12 DM, 0.24 DM, 0.42 BM, 50 CA, with 25 CA and 0.18 BM being approximately equal and only slightly different from control cartilages. The effect of prenatal or neonatal glucocorticoid treatment on chondrocytes is minimal in the 30–43 day, or 116–127 day, postnatal groups. In immature and adult rats, cortisone affects the chondrocytes more deleteriously than does betamethasone, and a 5.0 mg dose of CA seems to affect chondrocytes, body weight, and tibial and tail lengths more than 0.2 or 7.5 mg doses.
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  • 55
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    Cell & tissue research 244 (1986), S. 385-394 
    ISSN: 1432-0878
    Keywords: Cetaceans ; Lamellar bodies ; Epidermal lipids ; Permeability barrier ; Electron microscopy ; Phocena phocena
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary Biochemical and ultrastructural analysis of epidermis from the porpoise, Phocena phocena, revealed certain similarities and differences between cetaceans and terrestrial mammals. The predominant cell of cetacean epidermis, not found in normal terrestrial mammals, is a lipoker-atinocyte, which elaborates not only keratin filaments, but also two types of lipid organelles: first, lamellar bodies, morphologically identical to those of terrestrial mammals, are elaborated in great abundance in all suprabasal epidermal layers, forming intercellular lipid bilayers in the stratum corneum interstices: and second, non-membrane-bounded droplets appear and persist in all epidermal layers. Although the porpoise lipokeratinocyte morpologically resembles the sebokeratocyte of avians in certain respects, nonmembrane-bounded lipid droplets are not released into the intercorneocyte space as they are in avian stratum corneum. Whereas phospholipid/neutral lipid gradients are similar in porpoise and terrestrial mammals, PAS-positive glycoconjugates, specifically glycosphingolipids, are retained in porpoise stratum corneum, but lost from these layers in terrestrials. The novel, non-polar acylglucosyl-ceramides, which also are lost during cornification in terrestrial mammals, are retained in porpoise stratum corneum. The lipid components of porpoise lipokeratinocytes appear to subserve not only barrier function in a hypertonic milieu, but also underlie the unique buoyancy, streamlining, insulatory, and caloric properties exhibited as adaptations to the cetacean habitat.
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  • 56
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    Cell & tissue research 244 (1986), S. 443-448 
    ISSN: 1432-0878
    Keywords: Collagen ; Uterus ; Decidua ; Mouse ; Electron microscopy
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary An ultrastructural study of the features and distribution of collagen fibrils was performed in the endometrium of virgin and pregnant (2nd to 11th day) mice. Collagen-containing structures were observed in the cytoplasm of fibroblasts on the 2nd day of pregnancy. Treatment of tissues with lanthanum nitrate established that these structures were intracytoplasmic. Their association with lysosome-like bodies suggested the occurrence of intracellular digestion of collagen, probably connected with remodeling of the endometrial stroma prior to decidualization. On the 4th day of pregnancy, very few collagen fibrils were present in the intercellular space. From the 6th day of pregnancy onwards, “thick” collagen fibrils were observed between decidual cells. The diameter of these fibrils measured up to 300 nm whereas the fibrils present in the endometrium of virgin mice measured 40–68 nm.
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  • 57
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    Cell & tissue research 244 (1986), S. 457-466 
    ISSN: 1432-0878
    Keywords: Microthrix ; Microvillus ; Ultrastructure ; Fixation ; Tapeworm ; Hymenolepis diminuta
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary The ultrastructure of microtriches of the rat tapeworm, Hymenolepis diminuta, was examined with a number of electron-microscopic techniques. Fixatives containing different buffers, non-ionic detergents, chelators, tannic acid and various concentrations of aldehydes were tested for ability to stabilize cytoskeletal components while extracting background material. These methods revealed features unique to these specialized microvilli, and permitted construction of a detailed model of microthrix architecture. The microtriches of H. diminuta are comprised of a microfilament-containing base, a dense cap and a complex junctional region between the base and cap. The microfilaments of the base are contiguous distally with a tubular structure (the junctional tubule) within the junctional region; proximally, the microfilaments end abruptly: a terminal web appears to be absent. A beveled bilayered cylinder of dense material (the core tunic) encircles the microfilamentous core. The core tunics and junctional tubules of the microtriches are specifically and uniformly aligned along the strobila. Microtriches therefore can be distinguished from other microvilli (e.g., those of enterocyte brush borders) by their complex ultrastructure and precise orientation upon the cytoplasmic surface.
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  • 58
    ISSN: 1432-0878
    Keywords: Duodenum ; Cholecystokinin ; Gastrin ; Immunocytochemistry ; Ultrastructure ; Man
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary Human duodenal endocrine cells reactive with antibodies to cholecystokinin (CCK) 33 (10–20) and/or gastrin 34 (1–15) were studied by a combination of immunohistochemical and electron-microscopic methods. By immunohistochemistry, three types of endocrine cells were distinguished in human duodenal mucosa, i.e., those only positive for only CCK, those positive for both CCK and gastrin and those only positive for only gastrin. Ultrastructurally, the first cell type is characterized by many secretory granules with an eccentric dense core (mean diameter; 271+-74 nm). The second cell type, which was less frequent than the other two, has ultrastructural features that resemble type-I cells. The last cell type was composed of two types of cells containing small secretory granules identical to those of IG cells (mean diameter; 171+-31 nm) or large secretory granules indistinguishable from those of I cells (mean diameter; 286+-50 nm).
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  • 59
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    Cell & tissue research 246 (1986), S. 39-44 
    ISSN: 1432-0878
    Keywords: Ultimobranchial glands ; Cysts ; C-cells ; Ultrastructure ; Chicken (Gallus gallus)
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary The ultimobranchial glands of the chicken were examined by electron microscopy and immunocytochemistry using a calcitonin antiserum. Electron microscopy confirmed the presence of C-cells, containing numerous secretory granules storing calcitonin, in the luminal lining of cyst-like structures found in these glands. These cells were furnished with prominent microvillar projections at their luminal surface, and the cytoplasm of the apical region was filled with fibril material. Furthermore, the cells contained prominent junctional complexes and desmosomes at their apico-lateral surfaces. In these C-cells, secretory granules were concentrated near the lumen and some were attached to the apical cell membrane. The luminal content of the cysts had a colloid-like and flocculent appearance, and was frequently seen attached to the cytoplasmic projections or apical cell membrane of the C-cells. Since the cysts progressively increase in volume and number with age, it is suggested that they may partly play a role in the storage of excess or unneeded hormonal products.
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  • 60
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    Cell & tissue research 244 (1986), S. 605-612 
    ISSN: 1432-0878
    Keywords: Heart innervation ; Tissue culture ; Autonomic ganglia ; Non-neuronal cells ; Cell interrelationships ; Electron microscopy ; Guinea-pig
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary The present study describes the ultrastructure of non-neuronal cells and their interrelationships with intracardiac neurones present in cultures dissociated atria and interatrial septum from newborn guinea-pig. When compared with the in situ preparation, most of these features in culture were similar to those observed in situ, but some differences were also apparent. Both mature and immature Schwann cells were observed in culture, and as in situ, the latter were closely associated with intracardiac neurones, whilst the former were more widely separated. The ultrastructure of satellite cells was more variable in culture than in situ: three general types were distinguished on the basis of their 10-nm filament content. This variation could be due to conditions of culture. Interstitial cells were present in culture and closely resembled those described in situ, although there was less space between cultured interstitial cells and their associated cells. Many fibroblasts, some myoblasts and a few mast cells were also found in the culture preparations.
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  • 61
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    Cell & tissue research 244 (1986), S. 595-604 
    ISSN: 1432-0878
    Keywords: Heart innervation ; Tissue culture ; Autonomic ganglia ; Neurones ; Small granule-containing cells ; Electron microscopy ; Guinea-pig
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary The ultrastructure of cultured intrinsic neurones and SIF (small intensely fluorescent) cells dissociated from the atria and interatrial septum of newborn guinea-pig heart has been studied for the first time and compared with these cells in situ. Mononucleate and binucleate neuronal somata and their processes were observed in the culture preparation; their ultrastructure was similar to that of neurones in intracardiac ganglia observed in situ. The number of neurites associated with neuronal cell bodies increased after the first week in culture. A subpopulation of intracardiac neurones showed abnormalities in culture, comparable to the changes previously described in neurones of the monkey heart after unilateral vagotomy in situ. Small granule-containing cells were observed in culture, corresponding to those described in the heart in situ. One type of large process in the culture preparation containing densely packed mitochondria has not been seen in situ, suggesting that changes in cell ultrastructure due to the conditions of culture cannot be discounted. However, the ultrastructure of the cultured cells was, for the most part, consistent with that of the same cell type in situ, indicating that the culture preparation may be a useful model for investigation of the roles and interactions of intramural neurones in the heart, which are inaccessible for such studies in situ.
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  • 62
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    Cell & tissue research 246 (1986), S. 163-168 
    ISSN: 1432-0878
    Keywords: Cytoskeletal organization ; Filaments ; Triton extraction ; Replica technique ; Electron microscopy ; Amoeba proteus
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary Various stabilization and extraction procedures were tested to demonstrate the ultrastructural organization of the cytoskeleton in normal, locomoting Amoeba proteus. Most reliable results were obtained after careful fixation in glutaraldehyde/lysine followed by prolonged extraction in a polyethylene glycol/Triton X-100 solution. Before dehydration in a graded series of ethanol and critical-point drying, the amoebae were split by the sandwich-technique, i.e., by mechanical cleavage of cells mounted between two poly-L-lysine-coated glass slides. Platinum-carbon replicas as well as thin sections prepared from such cell fragments revealed a cytoskeleton composed of at least four different types of filaments: (1) 5–7-nm filaments organized as a more or less ordered cortical network at the internal face of the plasma membrane and probably representing F-actin; (2) 10–12-nm filaments running separately or slightly aggregated through the cytoplasm and probably representing intermediate filaments; (3) 24–26-nm filaments forming a loose network and probably representing microtubules; and (4) 2–4-nm filaments as connecting elements between the other cytoskeleton constituents. Whereas microfilaments are responsible for protoplasmic streaming and other motile phenomena, the function of intermediate filaments and cytoplasmic microtubules in amoebae is still obscure.
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  • 63
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    Cell & tissue research 245 (1986), S. 91-100 
    ISSN: 1432-0878
    Keywords: Testis ; Leydig cells ; Crystalloids ; Ultrastructure ; Rat, Rattus fusdpes
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary The ultrastructure of Leydig cells in a seasonally breeding rodent, Rattus fuscipes, was studied in the breeding and non-breeding season and compared with Leydig cell morphology after suppression of gonadotrophin secretion induced by hypophysectomy or chronic administration of testosterone. Serum luteinizing hormone (LH) and testosterone (T) were measured and in-vitro T production by testes was assessed by stimulation with human chorionic gonadotrophin (hCG). In non-breeding wild-trapped rats and rats with experimental suppression of gonadotrophins, the Leydig cells were atrophied and exhibited variable amounts of cytoplasmic lipid and crystalloid inclusions, the latter commonly dominating the cytoplasmic area. Compared with fertile rats, serum LH and hCG-stimulated T production of experimentally regressed rats was significantly reduced, confirming structural features indicative of Leydig cell inactivity. Atrophy of Leydig cell nuclei was accompanied by the formation of unusual intranuclear vesicles sometimes containing small crystalloids. Ultrastructural analysis suggested transfer of the vesicles to the cytoplasm where their unification gave rise to much larger crystalloid bodies. Crystalloids occurred when serum LH was depressed and with either full (T treatment) or arrested spermatogenesis (hypophysectomy) suggesting that their formation is governed by pituitary function and is not dependent upon the degree of spermatogenic activity.
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  • 64
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    Cell & tissue research 246 (1986), S. 607-621 
    ISSN: 1432-0878
    Keywords: Rod photoreceptor ; Light damage ; Albino rat ; Ultrastructure ; Reversible change
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary The temporal sequence of ultrastructural changes induced in the rat rod photoreceptor by 80 lux light-stress has been studied. The changes seen were compared with those produced by a much dimmer (3 lux) illumination. Some of the early signs of abnormality were (1) degradation of some disk membranes at the tips of outer segments, (2) disaggregation and detachment of ribosomes, (3) lighter matrices in swollen mitochondria, (4) disappearance of the Golgi apparatus, (5) proliferation of autophagic bodies in the inner segments, and (6) appearance of perimitochondrial membrane whorls in the synaptic terminals. No single change could be identified that would inexorably lead to cell death. The overall picture, however, suggested that an inability of the cell to maintain its anabolic balance is responsible for the pyknosis that occurs when the 80 lux exposure exceeds 12–15 h. All changes were reversible when exposure duration did not exceed 12 h, the normal length of the light cycle for these rats.
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  • 65
    ISSN: 1432-0878
    Keywords: Smooth-muscle cell ; Cell culture ; Ultrastructure ; Optical measurement ; Cell contraction ; Rat
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary In numerous investigations using cultured smooth-muscle cells, investigators have consistently added 10–20% fetal calf serum (FCS) to the medium to maintain viable cells. In the present study we utilized an optical technique to investigate whether smooth-muscle cells, cultured with or without FCS, maintain their contractile activity in vitro. With such optical measurement, we were able to detect signals due to spontaneous contractions, in muscle cells cultured in FCS-free medium for up to 8 days, and, for the first time, were also able to observe the conduction of these cell contractions. The ultrastructural characteristics of cultured smooth-muscle cells during contractile activity, were also examined by electron microscopy. The cells were mature and well-differentiated, and were packed with numerous myofilaments. They had developed long cell processes, and were linked to one another by gap junctions. These observations indicated that the smooth-muscle cells, cultured without FCS for 7 to 8 days, were morphologically mature and maintained their contractile activity, whereas the cells cultured in FCS-containing medium showed no detectable signs of contractile activity.
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  • 66
    ISSN: 1432-0878
    Keywords: Electron microscopy ; Malaria parasites ; Merozoites ; Surface coat ; Maturation ; Plasmodium knowlesi
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary The surface of extracellular merozoites of P. knowlesi is covered with a coat 15–20 nm thick, made up of clusters of filaments standing erect on the plasma membrane. Filaments have stems 2 nm thick, the peripheral ends of which are complex, branching or ending in long trailing threads. Coat filaments occur on the surface of the parasite in regular rows at an early schizont stage, and persist until well after merozoite release. They are sensitive to trypsin and papain, and bind ethanolic phosphotungstate, indicating a proteinaceous nature. They are also removed by exposure to phosphate-buffered saline. Filaments bear negative charges, binding cationised ferritin throughout the depth of the coat and staining with ruthenium red. They cover the whole merozoite surface and mediate intercellular adhesion at distances of 15–150 nm, membrane to membrane. It is suggested that these filaments correspond to a major merozoite surface protein, and are important in the initial capture of red cells.
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  • 67
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    Cell & tissue research 245 (1986), S. 397-404 
    ISSN: 1432-0878
    Keywords: Leech ; Nephridium ; Innervation ; Electron microscopy ; Cobalt filling ; Hirudo medicinalis
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary The main organs for salt and water homeostasis in the medicinal leech, the nephridia, were found to be densely innervated by a single branch of the corresponding median anterior segmental nerve. The projections of two different neurons into the nephridia are described: 1. Dendritic projections of the previously identified, afferent ‘nephridial nerve cell’, a possible salt receptor, lie between the urine forming cells and the blood vessels supplying the nephridium without making any contact. 2. Projections of an unidentified neuron which contains dense-core vesicles (85 nm) as well as smaller clear vesicles (45 nm) contact the primary urine forming canaliculus cells. The neurosecretory role of these neurons is considered.
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  • 68
    ISSN: 1432-0878
    Keywords: Chemoreceptor ; Ultrastructure ; Parasitic copepod crustacean ; Pachypygus gibber
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary The topography, external structure and ultrastructure of a cephalic sense organ, described for the first time, were studied by light and electron microscopy in the parasitic copepod Pachypygus gibber. This species is unusual in that it has three reproductive sexual forms (two males, one female).The cephalic organ, present only in the atypical male, is made up of numerous functional units, each composed of 4 cells: two sensory cells, one basal enveloping cell and one apical canal-forming cell opening outside via a pore. Many hundred pores are situated within the cuticle of the ventral pleural borders. Through each pore protrude two ciliary endings. An interesting feature is that the ciliary ends are without cuticular cover and thus, directly exposed to the surroundings, a situation unique in arthropods. The structural characteristics of this sense organ and the particular mode of life of the atypical male (with an additional free planktonic phase), lead to the hypothesis that its function is linked to chemical reception in the complex behavioural patterns such as host and sex recognition, during the free life.
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  • 69
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    Cell & tissue research 245 (1986), S. 457-460 
    ISSN: 1432-0878
    Keywords: Anterior pituitary ; Somatotroph ; Lactotroph ; Ultrastructure ; Immunocytochemistry ; Fetal and neonatal rat
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary The ultrastructure of immunoreactive somatotrophs and lactotrophs in pituitaries of fetal rats at 19, 20 and 21 days of gestation and on the day of birth was studied. Somatotrophs, first detectable at 19 days of gestation, undergo only minor modifications before reaching the structure described for adults. In particular there is an increase in the endoplasmic reticulum and Golgi apparatus. Lactotrophs, first identifiable in newborn rats, are very different in ultrastructure from adult cells, because the secretory granules are generally small, but variable in shape and size, and the Golgi complex is prominent.
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  • 70
    ISSN: 1432-0878
    Keywords: Organ culture ; Amelogenesis ; Dentinogenesis ; Ultrastructure ; Rat
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary Molar tooth germs from three-day-old rats were cultured successfully for fourteen days, permitting the study of the development in vitro of both extracellular matrix and cellular elements such as odontoblasts and ameloblasts. The ultrastructure of the cultured tooth germs was compared with the ultrastructure of tooth germs in vivo at a comparable developmental stage. Progenitor cells of odontoblasts and ameloblasts were found to differentiate in vitro. Odontoblasts seemed to contain more lysosome-like bodies and fewer secretory granules than in vivo. They formed normally mineralizing dentine or a thick layer of dense, unmineralized predentine with incidentally some amorphous, extracellular material. Enamel was exclusively present opposite well developed dentine. It was often hyperor hypomineralized and enamel rods were not as regularly shaped as in vivo. In places where no enamel formation had taken place, large amounts of amorphous extracellular material were sometimes seen. From these observations it can be concluded that cellular development in cultured tooth germs appeared more or less normal, but extracellular matrix formation and mineralization were sometimes disturbed.
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  • 71
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    Cell & tissue research 244 (1986), S. 165-171 
    ISSN: 1432-0878
    Keywords: Iridophores ; Motility ; Innervation ; Ultrastructure ; Teleost (Odontobutis obscura)
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary Reflecting chromatophores in the dermis of the skin of a freshwater goby, Odontobutis obscura, are of an iridophore type. These chromatophores contain numerous reflecting platelets, which are similar to those in iridophores of other fish and amphibian species. It was found that these iridophores are motile, i.e., these cells respond to certain stimuli with translocation of the platelets within the cells. K+ ions induced dispersion of the platelets in excised scale preparations, but not in excised scales from chemically denervated fish. Norepinephrine and melatonin also induced dispersion of the platelets. Alpha-MSH was effective in aggregating these organelles into the centrospheres of the cells. The conclusions reached are: (1) iridophores of O. obscura are motile; (2) the movement of the iridophores is under nervous and hormonal control.
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  • 72
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    Cell & tissue research 243 (1986), S. 405-414 
    ISSN: 1432-0878
    Keywords: Leydig cells ; Ethane dimethanesulphonate ; Ultrastructure ; Destruction ; Gonadotrophins ; Testosterone ; Rat
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary The cytotoxic effects of ethane dimethanesulphonate upon rat Leydig cells were examined ultrastructurally up to 3 days after treatment and related to changes in serum levels of gonadotrophins and testosterone. Six hours after administration of ethane dimethanesulphonate the usual tubulo-vesicular morphology of Leydig-cell smooth endoplasmic reticulum was converted to small vesicles and the Golgi apparatus showed focal hypertrophy into anastomosing tubules. These changes became more marked by 12 h with many Leydig cells exhibiting karyopyknosis and hyperchromatism. Necrotic Leydig cells were often engulfed by macrophages, the latter containing pyknotic fragments of Leydig cells within their cytoplasm. One day after administration, advanced necrosis of Leydig cells occurred, many of which were phagocytosed by macrophages, and on day 3, destruction of Leydig cells was complete resulting in their elimination from the interstitial tissue, which contained only loose connective tissue and macrophages. Structural alterations to the Leydig cells from 6–24 h was reflected by a significant reduction in serum testosterone levels which further declined to the limits of detection accompanying the abolition of Leydig cells on day 3. These changes were paralleled by a significant elevation of serum LH and FSH levels suggesting diminished feedback regulation of pituitary gonadotrophin secretion. The results indicate that ethane dimethanesulphonate is a rapidly acting Leydig cell toxin which may be a useful experimental tool in further studies of spermatogenic function mediated via Sertoli cell-Leydig cell interaction.
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  • 73
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    Cell & tissue research 243 (1986), S. 517-524 
    ISSN: 1432-0878
    Keywords: Muscle receptor organ ; Electron microscopy ; Tubular body ; Mechanosensory transduction ; Locust, Locusta migratoria migratorioides (R.&F.)
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary The coxo-trochanteral muscle receptor organ of the hind leg of the locust Locusta migratoria migratorioides (R.&F.) has been investigated by use of scanning and transmission electron microscopy with special emphasis on its distal attachment site. The overall morphology of the receptor muscle, the sensory neuron and its dendrites was found to share many common features with other arthropod sense organs of that type with two important differences: (1) the connective tissue segment (= intercalated tendon) is extremely short compared to that of other muscle receptor organs; (2) the naked dendritic terminals of the non-ciliated, multipolar sensory neuron of the organ contain clusters of microtubules, interconnected by an amorphous matrix, that resemble the tubular bodies of ciliated, epithelial receptor cells.
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  • 74
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    Cell & tissue research 244 (1986), S. 493-499 
    ISSN: 1432-0878
    Keywords: Endothelium ; Capillaries ; Kidney ; Ultrastructure ; Mouse
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary A new endothelial cell structure, named the endothelial pocket, has been found by combined transmission and scanning electron microscopic studies of renal peritubular capillaries. Transmission EM observations made on these and other fenestrated capillaries demonstrated that each pocket consists of an attenuated fold of fenestrated endothelium that projects 200 nm into the lumen above the rest of the endothelial surface. Beneath this luminal fold, there is a space and then another layer of fenestrated endothelium which abuts the basal lamina. The linear density of endothelial pockets was measured in the capillaries of the kidney cortex, intestinal mucosa and exocrine pancreas in mice and determined to be 0.067, 0.017 and 0.007 pockets·μm-1 respectively. Cationic ferritin decoration of the anionic sites on the luminal surface of the endothelium in these capillary beds revealed that both unlabelled and labelled diaphragms are clustered. In such specimens, the majority of the luminal diaphragms on endothelial pockets did not have cationic ferritin binding sites detectable by either scanning or transmission EM. On this account as well as on account of their general morphology, endothelial pockets appear to be multifold versions of the simple transendothelial channel.
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  • 75
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    Cell & tissue research 243 (1986), S. 649-654 
    ISSN: 1432-0878
    Keywords: Median eminence ; Peptidergic projections ; Aminergic projections ; Electron microscopy ; Autoradiography ; Frog (Rana temporaria)
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary The median eminence (ME) of the adult frog, Rana temporaria, was studied by means of electron microscopy including quantitative electron-microscopic autoradiography. In frogs captured in May and June numerous peptidergic neurosecretory fibres extending via the internal zone to the pars nervosa display large swellings containing few granules, mitochondria, neurotubules and cisternae of the smooth endoplasmic reticulum. In addition, few secretory globules up to 1.5 μm in diameter occur in these varicosities. In animals collected during the autumn period many of these neurosecretory swellings filled with neurosecretory granules and polymorphic inclusions resemble Herring bodies. Three types of granule-containing neurosecretory fibres were observed in the external zone (EZ) of the ME of adult R. temporaria. Peptidergic A1- and A2-type fibres are characterized by granules 150–220 nm and 100–160 nm in diameter, respectively. Monoaminergic fibres of type B with granules approximately 100 nm in diameter represent ∼ 50% of all neurosecretory elements in the EZ of the frog ME; ∼12% of the total number of granule-bearing axons in the EZ actively taking up radiolabelled 5-hydroxytryptophan are thought to be serotoninergic terminals. Neurosecretory terminals of all types and glial vascular endfeet establish direct contacts with the perivascular space of the primary portal capillaries. Some neurosecretory terminals are separated from the lumen of the third ventricle by a thin cytoplasmic lamella of tanycytes. The possible physiological significance of this structural pattern is discussed.
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  • 76
    ISSN: 1432-0878
    Keywords: Capillary ; Epithelium ; Retina ; Retinal pigment epithelium ; Ultrastructure ; Rat
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary Light- and urethane-induced retinopathies in rats are characterized by loss of photoreceptors. Retinal capillaries subsequently become incorporated into the normally avascular retinal pigment epithelium. These models provided an opportunity to study the response of epithelial cells to closely apposed capillaries, in order to determine if capillaries contribute to the polar organization of epithelial cells. Pigment epithelial cells reorganized their lateral plasma membrane where the latter faced intraepithelial capillaries. This normally flat, undifferentiated membrane developed attachment sites, folds and intracytoplasmic tubules, and exhibited endocytosis and putative basal lamina secretion. These structural and functional specializations are normally restricted to the basal plasma membrane — the normal vascular front of the cell facing the dense meshwork of capillaries constituting the choriocapillaris. We conclude that RPE cells, and perhaps epithelia in general, polarize in response to an adjacent capillary bed.
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  • 77
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    Keywords: VIP ; Nerve fibers ; Ganglion cells ; Chromaffin cells ; Ultrastructure ; Adrenal gland ; Rat
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary VIP-like immunoreactivity was revealed in a few chromaffin cells, medullary ganglion cells and a plexus of varicose nerve fibers in the superficial cortex and single varicose fibers in the juxtamedullary cortex and the medulla of the rat adrenal gland. VIP-like immunoreactive chromaffin cells were polygonal in shape without any distinct cytoplasmic processes and they appeared solitarily. Their cytoplasm contained abundant granular vesicles having a round core and the immunoreactive material was localized to the granular core. VIP-immunoreactive ganglion cells were multipolar and had large intracytoplasmic vacuoles. The immunoreactive material was localized not only in a few granular vesicles but also diffusely throughout the axoplasm. VIP-immunoreactive varicose nerve fibers in the superficial cortex were characterized by abundant small clear vesicles and some large granular vesicles, while those in the juxtamedullary cortex and medulla and the ganglionic processes were characterized by abundant large clear vesicles, as well as the same vesicular elements as contained in the nerves in the superficial cortex. The immunoreactive material was localized on the granular cores and diffusely in the axoplasm in both nerves. Based on the similarity and difference in the composition of the vesicles contained in individual nerves, it is likely that the VIP-immunoreactive nerve fibers in the medulla and the juxtamedullary cortex are derived from the medullary VIP-ganglion cells, while those in the superficial cortex are of extrinsic origin. The immunoreactive nerve fibers in both the cortex and the medulla were often in direct contact with cortical cells and chromaffin cells, where no membrane specializations were formed. The immunoreactive nerve fibers were sometimes associated with the smooth muscle cells and pericytes of small blood vessels in the superficial cortex. In addition they were often seen in close apposition to the fenestrated endothelial cells in the cortex and the medulla, only a common basal lamina intervening. Several possible mechanisms by which VIP may exert its effect in the adrenal gland are discussed.
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  • 78
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    Cell & tissue research 245 (1986), S. 563-577 
    ISSN: 1432-0878
    Keywords: Chick retina ; Tissue culture ; Electron microscopy ; Development, ontogenetic ; Differentiation
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary The differentiation of cells and synapses in explants of 9-day-old chick embryo retina has been studied by light and electron microscopy over a period of 35 days in vitro, and samples of retina from the 9-day chick foetus were directly fixed and prepared for study. At the time of explantation the retinae were poorly differentiated and no lamination was apparent. From day 14 onwards, (i) outer and inner nuclear layers (ONL, INL) separated by a layer of neuropil corresponding to the outer plexiform layer (OPL) and (ii) a layer of scattered large ganglion cells separated from the INL by a zone of neuropil resembling the inner plexiform layer (IPL) were apparent, and (iii) a well-differentiated outer limiting membrane was established close to the surface of the explants. In the oldest cultures some development of photoreceptor outer segments occurred but a distinct optic nerve fibre layer did not form. Although cell identification presented problems even in the oldest cultures, the major retinal cell types described in vivo could be identified. Photoreceptor cells developed pedicles in the OPL which became filled with synaptic vesicles and synaptic ribbons and established ribbon synapses (including triads) with and were commonly invaginated by processes from horizontal and bipolar cells. Processes of bipolar cells in the IPL formed simple and dyad synapses. At least two types of presynaptic amacrine cells were also identified in the INL, one of which contained large numbers of dense-core vesicles. The ganglion cells, though sparse, were large and well differentiated. These findings show that all the major neuronal types of the retina are capable of developing and differentiating in vitro, lagging behind the time-table of development and differentiation in vivo by approximately 7 days, but resulting in a histotypically organised retina with synaptic neuropil showing many similarities to the corresponding neuropil in vivo.
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  • 79
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    Cell & tissue research 243 (1986), S. 137-144 
    ISSN: 1432-0878
    Keywords: Lung ; Blood-air barrier ; Surfactant ; Ultrastructure ; Freeze fracture ; Birds ; Penguin (Aptenodytes forsten)
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary Of all avian species the emperor penguin is the best adapted bird to attain the greatest diving depths and diving durations. Therefore the lung of this bird was investigated with electron-microscopic, i.e., freeze-fracture and thin-section methods. The parabronchi are surrounded by bundles of smooth muscle cells innervated by varicosities of autonomic nerves. The parabronchial epithelium is flat, bears a few microvilli and does not show any conspicuous ultrastructural specializations; only individual cells contain secretory granules. The atrial epithelial cells bear apical microvilli and are interconnected by adhering and tight junctions (5–10 sealing strands), the latter presumably forming an effective barrier against paracellular fluid movements. The cells contain lamellar inclusions of two types: (i) round membrane-bounded granules, the lamellar content of which is fixation-labile, and (ii) large polymorphic compact deposits of well-preserved lamellae. In both types of inclusions the individual lamellae can be of trilaminar appearance, whereas their fracture faces are smooth. Lamellar material also covers the epithelium of atria, infundibula and air capillaries. In thin areas the diameter of the morphological blood-air barrier measures 220–330 nm. Usually the endothelium of the blood capillaries is thicker (40–180 nm) than the air capillary epithelium (25–150 nm). Both epithelium and endothelium are interconnected by tight junctions, which seem to be more extensive and presumably tighter in the epithelium than in the endothelium. Frequently the common basal lamina is the thickest individual component of the blood-air barrier, measuring between 170–230 nm. Often collagen fibrils occur in this area of the barrier. In comparison with that of other birds the entire blood-air barrier of the emperor penguin is relatively thick, probably owing to an adaptation of the lung tissue which must resist high hydrostatic pressure during diving excursions.
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  • 80
    ISSN: 1432-0878
    Keywords: Parathyroid gland ; Protein A-gold technique ; Ultrastructure ; Storage granules ; Mammals
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary Electron-microscopic immunocytochemistry for the demonstration of parathormone in parathyroid chief cells was performed in adult male rats, gerbils, mice, and dogs, using the protein A-gold technique. Protein A-gold particles were detected over both large and small secretory granules in all the animals examined. In the former, they were concentrated not only over type-I granules with a large core, but also over type-II granules with a small core. They were also located over atypical granules, including heterogeneously dense granules, granules having vesicles in a finely particulate core, and distorted granules. All labelled secretory granules were characterized by the presence of a clear halo of varying width around the core. Occasionally, Golgi cisternae as well as Golgi vacuoles with a finely particular content were also labelled. The labelling of the secretory granules was strong in dogs, moderate in rats and gerbils, and weak in mice. In addition, it was more intense in the non-osmicated preparations than in the osmicated preparations. The frequency of both types of large granules showed species differences. The possible factors involved in these differences are discussed.
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  • 81
    ISSN: 1432-0878
    Keywords: Cholinesterase ; Genital tract ; Mesenchyme ; Histochemistry ; Electron microscopy ; Mouse embryo
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary In the genital tract of male and female mouse embryos cholinesterase activity is described that is independent from innervation. The enzyme activity is localized in the mesenchyme at the junction of Wolffian and Müllerian ducts with the urogenital sinus. During male development prostate buds and vesicular glands grow out into the cholinesterase-active mesenchyme. During female development the active mesenchyme participates in the downgrowth of the vaginal anlage. Ultrastructurally the cholinesterase activity is localized in the perinuclear cisterna and in smooth endoplasmic reticulum of the mesenchymal cells. The enzyme activity disappears with definitive differentiation of the tissue. The embryonic cholinesterase is a component of a primitive muscarinic system. Its relation to the morphogenetic action of testosterone and its possible general functions are discussed.
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  • 82
    ISSN: 1432-0878
    Keywords: Peripolar cells ; Juxtaglomerular apparatus ; Kallikrein ; Ultrastructure ; Mammals
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary Peripolar cells are granulated glomerular epithelial cells that form a cuff around the vascular pole of the glomerulus. Quantitation of these cells in 17 species of mammals (including man, several laboratory animals and a variety of other species) indicated that they were detectable by light microscopy in all but one of the mammals that were examined (the Australian hopping mouse). In adult mammals with detectable peripolar cells, the “peripolar cell index” (the percentage of randomly sectioned glomeruli that displayed peripolar cells in histological sections of kidney) ranged from 0.15 (for echidna) to 11.86 (for sheep). Newborn lambs and rats showed strikingly high values (23.30 and 10.76, respectively) compared with their adult counterparts. Using electron microscopy, peripolar cells were observed in all species that were examined, including the Australian hopping mouse. Morphologically, peripolar cells were similar in all species although their size and granule population varied. They showed a predominantly outer cortical glomerular distribution and a close anatomical relationship with the renin-containing myoepithelioid cells. These findings indicate that peripolar cells are present in a wide variety of species and support the view that such cells may play a significant role in the regulation of normal renal function.
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  • 83
    ISSN: 1432-0878
    Keywords: Uterus ; Epithelium ; Ultrastructure ; Pig
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary The ultrastructure of the endometrial epithelium of the pig was studied during the estrous cycle and early pregnancy up to implantation. Special attention was given to the luminal epithelium and morphological indications of protein synthesis. Although the general morphology of the luminal and glandular epithelia is similar (both tissues consist of secretory cells and ciliated cells at all the stages studied), it appears that the two epithelia should be considered as two functionally different units in the pre-implantation period. Morphological evidence suggests the presence of at least three different secretory products within luminal epithelial cells; they are released at different times, i.e. at estrus, between day 8 and 10 and after day 11. The glandular epithelium shows release of secretory products from day 10–11. Increasing amounts of glycogen were found within epithelial cells, especially in pregnant gilts from day 12. The possible significance of secretory activity of the epithelium is discussed in relation to the development of the embryos.
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  • 84
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    Plant systematics and evolution 153 (1986), S. 259-264 
    ISSN: 1615-6110
    Keywords: Gymnosperms ; Angiosperms ; Pteridosperms ; Caytoniales ; Caytonanthus ; Ultrastructure ; pollen
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract The pollen grain wall structure ofCaytonanthus arberi was studied with SEM and TEM. The monosulcate, bisaccate pollen grain of this taxon has an alveolar wall structure that is more like that found in saccate Conifers than primitive Angiosperms. Pollen grain morphology does not support a Caytonialean ancestry for the Angiosperms.
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    Plant systematics and evolution 154 (1986), S. 31-39 
    ISSN: 1615-6110
    Keywords: Angiosperms ; Lactoridaceae ; Ultrastructure ; pollen ; fossil pollen (Cretaceous)
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract The pollen wall ultrastructure of the primitive AngiospermLactoris fernandeziana Phil. (Lactoridaceae) is described. The monosulcate aperture, granular wall structure and sacci (all primitive features) suggest placement of this family in theMagnoliales. Pollen ofLactoris is compared to fossil dispersed pollen from the Lower and lower-Upper Cretaceous. The fossil pollen shares characteristics which are restricted to theLactoridaceae suggesting that this family was present during the early Cretaceous.
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    Protoplasma 131 (1986), S. 1-10 
    ISSN: 1615-6102
    Keywords: Cell division ; Lomentaria ; mitosis ; Red algae ; Rhodophyta ; Ultrastructure
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Summary Mitosis in the marine red algaLomentaria baileyana (Rhodymeniales, Rhodophyta) was studied with the electron microscope. Nucleus associated organelles known as polar rings (PRs) migrate to establish the division poles at prophase. At prometaphase, shallow invaginations in the nuclear envelope (NE) form on two sides of each PR and soon rupture. The gaps that are consequently formed contain several small fragments of NE. A larger region of NE remains intact between the two gaps. By metaphase several cisternae of perinuclear endoplasmic reticulum (PER) have enclosed most of the nucleus but remain absent from the polar regions. The nucleolus disperses partially and a typical metaphase plate of chromosomes is formed. Each PR has disjoined into separate proximal and distal portions. MTs converge widely on all regions of the polar area, but do not extend into the cytoplasm. Some MTs end near or at the chromosomes while others extend slightly farther past the chromosomes or diagonally to the NE. As chromosomes move to opposite poles at anaphase, they are accompanied by nucleolar material. An interzonal midpiece (IZM) is created as the pole to pole distance increases and the NE remains intact except for the polar gaps. Following detachment from the IZM, the daughter nuclei are separated by a large central vacuole as a cleavage furrow develops and eventually constricts to form two cells following pit connection formation. It is suggested that mitosis inLomentaria represents an evolutionary intermediate between that seen in the higher and lower groups of red algae. This conclusion is in agreement with conventional morphological and light microscopic criteria used to placeLomentaria in theRhodymeniales, which is considered to be the next to most advanced order in theRhodophyta.
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    Protoplasma 134 (1986), S. 154-162 
    ISSN: 1615-6102
    Keywords: Cell division ; Leishmania ; Mitosis ; Ultrastructure ; Kinetoplastida
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Summary The interphase nucleus ofLeishmania adleri has clumps of chromatin associated with the nuclear envelope and a large centrally located nucleolus. Prior to mitosis the basal bodies replicate at the cell anterior. Subsequently, dense plaques appear in the equatorial region of the nucleus at the time of spindle development. Microtubules appear in the nucleus adjacent to the nuclear envelope and embedded in the matrix of the plaques. A central spindle composed of a single bundle of microtubules develops and spans the nucleus. Plaques and nucleolar components laterally associate with the spindle and migrate towards the poles. The central spindle elongates to three to four times its original length separating the forming daughter nuclei and producing an interzonal spindle. A remnant of the interzonal spindle remains attached to each of the daughter nuclei until late into cytokinesis. The kinetoplast does not divide until after the completion of mitosis.
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  • 88
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    Protoplasma 131 (1986), S. 166-173 
    ISSN: 1615-6102
    Keywords: Chloroplast development ; Pisum sativum ; Prolamellar body ; Ultrastructure
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Summary We analyzed transformation, recrystallization, splitting and dispersion of prolamellar bodies during chloroplast development in pea seedlings illuminated by white, red and blue light of low intensity. With the help of a stereometric method we determined that there was a significant increase of prolamellar body number and a sharp decrease of their volume in differentiating chloroplast even in the first 2 hours of illumination. Decrease of prolamellar body dimensions was due both to gradual dispersion of its elements into primary thylakoids (indicated by the decrease of total volume of prolamellar bodies in plastid) and to splitting of prolamellar bodies (indicated by the increase of number of promellar bodies in plastid). Red light was more effective in transformation, splitting and dispersion of prolamellar bodies than blue light during the first 8–12 hours. Longer treatment with blue light had a stronger influence on these processes and on complete recrystallization than other light treatments.
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  • 89
    ISSN: 1615-6102
    Keywords: Cytoplasm ; Electron microscopy ; Nucleolus ; Virus-like particles ; Wheat
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Summary Wheat roots from germinating seedlings of Chinese spring wheatTriticum aestivum grown for 36 hours at 20°C were examined by conventional thin-section electron microscopy. Virus-like particles were seen inside a large cytoplasmic intrusion into the nucleus having the appearence of a nucleolar vacuole. The particles were isometric and about 50 nm in diameter with a membrane-like coat and a small core. The cytoplasmic intrusion was bounded by nuclear envelope with pores apparent where it abutted nucleoplasm. The particles are similar to previously reported solitary particles “S bodies” from a range of plants but are also similar in size and morphology to the retroposon particles associated with copia like elements in other organisms. The position of the virus-like particles in the young wheat roots is discussed in relation to interactions with components of the cell skeleton.
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  • 90
    ISSN: 1615-6102
    Keywords: Chlamydomonas ; Endoplasmic reticulum ; Golgi apparatus ; Wall mutants ; Ultrastructure
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Summary Ultrastructural observations on the principal endomembranes (endoplasmic reticulum, Golgi apparatus) of synchronously growing of wild type and mutant (CW 2, CW 15) strains ofChlamydomonas reinhardii have been carried out. The dictyosomes of the Golgi apparatus in all three cases are highly polar in morphology but lack intercisternal filaments. A clear spatial relationship between dictyosomes and endoplasmic reticulum is seen and a transfer of vesicles from the latter to the former is easily visualized. Coated vesicles invariably appear to be restricted to the trans-pole of the dictyosomes. The endoplasmic reticulum adjacent to the cis pole of dictyosomes is considerably hypertrophied in the case of the wild type, only partially so in the mutant CW 2 but not at all in the mutant CW 15. In the wild type this swelling is most extreme during the period of wall deposition and for several hours afterwards. The results are discussed in relation to the biosynthesis and intracellular transport of, particularly O-glycosidically linked, glycoproteins.
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  • 91
    ISSN: 1615-6102
    Keywords: Chloroplast development ; Grana formation ; Pisum sativum ; Ultrastructure
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Summary We analyzed the formation of thylakoids and grana during the development of pea chloroplasts, illuminated by white, red and blue low intensity light. The total length of granal and intergranal thylakoids, and the length of granal thylakoids per unit area of plastid section were measured. Initially the greatest increase in length of granal thylakoids and the highest incidence of grana with large thylakoid content occurred in red light. On the other hand, with illumination times of over 12 hours blue light appeared to be more efficient in stimulating grana formation and thylakoid growth.
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  • 92
    ISSN: 1615-6102
    Keywords: Chara corallina ; Charasome development ; Chloride transport ; Electron microscopy
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Summary Internodal cells ofChara, grown in culture either at pH 5.7, 6.5 or 7.5, were studied to determine their chloride influx capability, the quantitative aspects of charasome morphology and the degree to which these two parameters could be correlated. In cells grown at pH 5.7 the charasomes were relatively small, were widely spaced on the plasma membrane, and contributed only a 0.6% increase to the surface area of the plasma membrane in the acid region of the cell. In contrast, the charasome membrane surface area of cells grown at pH 7.5 had increased × 19, the density of charasomes on the cell surface increased × 42, thus producing a × 3.57 increase in the acid region plasma membrane surface area. Chloride influx in cells grown at pH 7.5 was × 8.7–12.7 greater than in cells grown at pH 5.7. Cells that had been starved of chloride exhibited a × 2.4 average increase in the rate of chloride influx. Our observations establish the existence of a positive correlation between the rate of chloride influx and the increase in membrane surface area due to charasomes, although other factors, such as the effect of pH on transport-related enzymes, and the effect of charasome structure on chemical equilibria, may also be of importance.
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  • 93
    ISSN: 1615-6102
    Keywords: Diapensia lapponica ; Mitochondria ; Morphometry ; Seasonal variation ; Ultrastructure
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Summary Seasonal changes in the mitochondrial ultrastructure were examined in palisade parenchyma cells of a tuft-formingDiapensia lapponica L. collected at monthly intervals in Northern Finland. Quantitative analyses to measure volume and surface densities were conducted during different periods of growth (stages of growth, acclimation, winter period and deacclimation) in the annual cycle. The volume density was highest in the summer and lowest in the spring; the difference was significant with both fixatives used GA and GA/FA. The largest membrane area (the mitochondrial outer membrane and the cristal membranes together) was observed in the summer and autumn, and was significantly less in the winter and spring. This correlated with fewer mitochondria in the spring and a smaller number of cristae in the winter and spring. In the material fixed in GA/FA the distribution of length/width ratios of mitochondria was relatively uniform in all seasons. However, the mitochondrial ultrastructure had the most varied appearance during the winter. Hypertonie GA/FA solution did not cause significant differences either in the ultrastructure or the volume and surface densities of the mitochondria.
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    Protoplasma 135 (1986), S. 102-111 
    ISSN: 1615-6102
    Keywords: Ultrastructure ; Haptoglossa mirabilis ; Differentiation ; Gun cell
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Summary The most prominent ultrastructural characteristics of the cyst ofHaptoglossa mirabilis are a large centrally-placed nucleus which is partially ringed by three or four parallel cisternae of rough endoplasmic reticulum (r-ER), a centriole pair and single large Golgi complex which occupy the anterior end of the cell, and a population of provacuoles which occupies the posterior. During germination these organelles migrate into a narrow germ tube which subsequently expands to form the gun cell initial. The extracellular components of the attack apparatus (i.e. missile and injection tube) are formed entirely in the developing gun cell; indirect evidence suggests that both the Golgi complex and r-ER are involved in their synthesis. The intra-cellular component of the attack apparatus comprises the posterior, anterior and apical vacuoles. The posterior vacuole forms by fusion and expansion of the original cyst provacuoles; the formation of the anterior and apical vacuoles occurs late in gun cell differentiation and involves fusion of Golgi-derived vesicles.
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  • 95
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    Electronic Resource
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    Protoplasma 134 (1986), S. 102-110 
    ISSN: 1615-6102
    Keywords: Isoelectric focusing ; Isolation ; Potato tuber cell walls ; Purification ; Salt extraction ; Ultrastructure
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Summary A preparative procedure for cell wall isolation and purification was developed. The purity of the isolated cell walls was judged biochemically by the lack of activity of cytoplasmic marker enzymes and morphologically by examination at both the light and electron microscope levels. The purified cell walls were extracted with various salt treatments and the molecular weight range of most of the extracted proteins was between 14 and 31 kDa. The salt extracted hydrolytic enzymes were basic in nature (pI〉7.0) compared to their cytosolic counterparts (pI〈7.0). Some enzymes were readily extracted from cell walls (β-glucosidase and β-NAcglucosaminidase) with high salt treatment while most of the α-mannosidase activity associated with purified cell walls could not be removed even with sequential high salt treatments.
    Type of Medium: Electronic Resource
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  • 96
    ISSN: 1615-2573
    Keywords: Inorganic phosphate ; Normoxia/anoxia ; ATP ; Glycogen ; Cardiac function ; Electron microscopy
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary The possible role of inorganic phosphate (Pi) in depressing the contractility of oxygen-deficient myocardium was investigated by examining the effects of 30 mM Pi on the cardiac function and myocardial biochemistry and fine structure in normoxic and anoxic Langendorff-perfused isolated rat hearts. In normoxia, the intracellular Pi level increased three-fold, the ATP content remained normal, and there was moderate loss of glycogen only. Contractile performance (as assessed from systolic pressure recordings) was significantly depressed, as was the heart rate for the first 10 min. The myocardial fine structure showed persistent glycogen, marked relaxation of myofibrils, and a higher incidence of vacuolation than in hearts with normal Pi. In anoxia, the intracellular Pi level was comparable with that of the perfusate and both ATP and glycogen were severely depleted. Contractile performance and heart beat ceased completely at 15 min, although in anoxic controls both persisted at low levels for at least 25 min. In anoxia, Pi also depressed coronary flow rate. In the inner half of the ventricular wall of oxygen-depleted hearts, where flow became reduced after 15 or more min, Pi markedly reduced the formation of intramitochondrial densities and augmented mitochondrial swelling and ischaemic contracture, which extended out through the mid-myocardium. In the outer half of the wall, where flow remained high, it promoted severe dilatation of the sarcoplasmic reticulum vesicles and undifferentiated regions of the intercalated discs. The observed effects in normoxia are probably attributable at least in part to the lowering of the free Ca2+ concentration of the perfusate by the increased Pi level. The effects in anoxia may be related chiefly to the critical reduction of available intracellular Ca2+ and the more rapid and extensive development of ischaemic contracture.
    Type of Medium: Electronic Resource
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  • 97
    Electronic Resource
    Electronic Resource
    Springer
    Protoplasma 135 (1986), S. 119-129 
    ISSN: 1615-6102
    Keywords: Differentiation ; Pectin ; Phytophthora ; Surface ; Ultrastructure ; Zoospore
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Summary Populations ofPhytophthora palmivora zoospores induced to undergo synchronous differentiation by the addition of pectin showed an ordered sequence of surface changes. Within 10 seconds “blebs” and “microvilli” appeared on the cell and flagellar surfaces. These projections gave the zoospore a highly irregular and even convoluted surface for up to 30 seconds poststimulation. Between 30 and 40 seconds, pits appeared on the surface, which began to assume a smoother texture. Zoospores then rounded up and by 4 minutes had assumed an almost spherical form. At this time the surface became wrinkled as though shrinkage had occurred. Germ tubes could be seen emerging from almost all cells by 40 minutes, and as germ tubes enlarged, the cell surface became smooth again but with a fibrous texture. Many zoospores retained their flagella through to the germling stage. When cells were stimulated in iso-osmotic rather than hypo-osmotic media, germ tubes in most cases emerged at or very near the site of flagellar attachment. Differentiation in iso-osmotic media showed the same sequence except that the cells did not assume the spherical shape normally characteristic of cysts and germlings differentiating under hypo-osmotic conditions. Strontium-induced differentiation again followed the same general sequence as desribed above, although the cell surface was noticeably more convoluted and irregular prior to the stage of the formation of pits, and flagella were always shed between 40 seconds and 1 minute. Calcium addition up to 20 seconds after the initiation of differentiation with pectin prevented a high proportion of zoospores from encysting, the cells remained motile, and although the frequency of surface blebs and microvilli increased, pits did not appear. These surface changes are consistent with those expected during stimulus-mediated secretion, and it appears that calcium is able to inhibit differentiation only before the secretory step (pit formation).
    Type of Medium: Electronic Resource
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  • 98
    ISSN: 1615-6102
    Keywords: Dark-stress ; Recovery ; Root-nodules ; Soybean ; Ultrastructure
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Summary Root-nodules of soybean plants dark-stressed for 8 days and then allowed to recover for up to 17 days were examined by transmission electron microscopy. Control nodules possessed all the ultrastructural features characteristic of infected and uninfected nodule cells. Minimal changes in the appearance of host cells and bacteroids occurred during the first four days of dark stress. After 8 days of dark stress, damage was observed in the cellular and organelle membranes; however, very few changes were observed in the bacteroids. Nodule structure continued to degrade during the first two days of recovery after which time nodules either recovered or completely degraded. In the former case, structural integrity returned to all nodule cells. In the latter case all structural integrity of the host cell disappeared; however, bacteroids appeared intact suggesting that they remained viable.
    Type of Medium: Electronic Resource
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  • 99
    ISSN: 1615-6102
    Keywords: Root meristems ; Cell plate ; Ultrastructure ; 2,6-dichlorobenzonitrile
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Summary The effect of 2,6-dichlorobenzonitrile on cytokinesis of meristematic cells of onion root during both treatment and recovery has been studied by electron microscopic techniques. 2,6-dichlorobenzonitrile interferes with cell plate formation in such a way that Golgi apparatus vesicles of treated cells appear to be different than controls and seem to coalesce as anomalous partial cell plates. During recovery, an apparently normal progression of cytokinesis is observed and abnormal portions of the cell plate are retained. Nuclear constrictions are observed frequently during recovery as a result of temporal alterations in cytokinesis. Our results show that 2,6-dichlorobenzo-nitrile induces anomalous and/or incomplete cell plates, which might be caused by an altered function of Golgi apparatus.
    Type of Medium: Electronic Resource
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  • 100
    Electronic Resource
    Electronic Resource
    Springer
    Molecular genetics and genomics 202 (1986), S. 421-428 
    ISSN: 1617-4623
    Keywords: Recombination intermediates ; Mitochondrial DNA ; Electron microscopy ; Saccharomyces cerevisiae
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Summary To study the structure of in vivo mitochondrial DNA recombination intermediates in Saccharomyces cerevisiae, we used a deletion mutant of the wild type mitochondrial genome. The mtDNA of this petite is composed of a direct tandem repetition of an ∼4,600 pb monomer repeat unit with a unique HhaI restriction enzyme site per repeat. The structure of native mtDNA isolated from log phase cells, and mtDNA crosslinked in vivo with trioxsalen plus UVA irradiation, was studied by electron microscopy. Both populations contained crossed strand “Holliday” type recombination intermediates. Digestion of both non-crosslinked and crosslinked and mtDNA with the enzyme HhaI released X and H shaped structures composed of two monomers. Electron microscopic analysis revealed that these structures had pairs of equal length arms as required for homologous recombination intermediates and that junctions could occur at points along the entire monomer length. The percentage of recombining monomers in both non-crosslinked and trioxsalen crosslinked mtDNA was calculated by quantitative analysis of all the structures present in an HhaI digest. The relationship between these values and the apparent dispersive replication of mtDNA in density-shift experiments and mtDNA fragility during isolation is discussed.
    Type of Medium: Electronic Resource
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