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  • 2015-2019
  • 2000-2004  (25)
  • 1975-1979
  • 1920-1924
  • 2000  (25)
  • Ultrastructure
  • 1
    ISSN: 1432-2161
    Keywords: Key words Giant rice body ; Ultrastructure ; Immunohistochemistry ; Histogenesis
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Abstract  Objective: To report four cases of rice bodies (RBs) showing remarkable size variations and discuss their pathogenesis. Design and patients: Based on analysis of the clinical data, we speculate on the pathogenesis of RBs using immunohistochemical and ultrastructural methods. The patients comprised three men and one woman, three with RBs in the subacromial bursae and one in the wrist synovial sheath, aged 28 (woman), 44, 50 and 81 (wrist) years, respectively. Results: There were no particular differences in clinical data among the patients. T2-weighted MR imaging was very useful for diagnosis of the RBs, allowing their clear delineation from the bursal fluid. The RBs consisted of a layered protein- aceous substance with vague targetoid cut surfaces. Much fibrin and a lesser amount of collagen fibers were recognized together with various mononuclear cells, which were few in number and predominantly T cells. The bursae and synovial sheath had multiple fibrinoid spheroids at the luminal surface. Conclusion: Fibrinoid nodular deposits probably became detached, forming the nuclei of RBs and growing to a giant RB 65 mm in diameter.
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  • 2
    ISSN: 1432-5233
    Keywords: Key words Streptozotocin ; Diabetes ; Ventricular myocyte ; Cardiac muscle ; Ultrastructure
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Abstract Contractile dysfunctions have been demonstrated in different experimental models of diabetes which have similar characteristics to many of the abnormalities found in the clinical setting. Administration of streptozotocin (STZ) to young adult rats induces β-cell necrosis of the pancreas which gives rise to hypoinsulinaemia and hyperglycaemia, features which are also seen in untreated type 1 clinical diabetes. We have investigated the chronic effects of STZ-induced diabetes on contraction in rat ventricular myocytes and ultrastructure of cardiac muscle. Diabetes was induced in male Wistar rats (230–270 g) with a single injection of STZ (60 mg kg−1). At 2 and 10 months after STZ treatment, the amplitude of contraction was larger in diabetic compared to control myocytes. Time to peak contraction was significantly longer at 2 months but appeared to normalise at 10 months after STZ treatment. In contrast, time to half relaxation of contraction was not significantly different after 2 months but was significantly reduced at 10 months after STZ treatment compared to control. Transmission electron microscope examination of cardiac muscle showed that the ultrastructure of cardiac muscle, especially structures associated with contraction, were not greatly altered after STZ treatment. Sarcomere lengths were not significantly different in papillary or ventricular muscle at 4 or 8 months after STZ treatment compared to control. Our data provide evidence that morphological defects in contractile myofilaments and associated structures cannot explain contractile dysfunctions seen in ventricular myocytes from STZ-treated animals.
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  • 3
    Electronic Resource
    Electronic Resource
    Springer
    Mycorrhiza 10 (2000), S. 15-21 
    ISSN: 1432-1890
    Keywords: Anthoceros punctatus ; Arbuscular mycorrhiza ; Bryophytes ; Glomus ; Ultrastructure
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Glomus claroideum (Schenck & Smith emend. Walker & Vestberg) were investigated for ability to form arbuscular mycorrhiza-like symbioses with the hornwort Anthoceros punctatus (L.). Spores were transferred to a cellulose acetate filter on water agar and a small portion of an Anthoceros thallus was placed directly upon the spores. Light-microscope observations 20 days after inoculation revealed branched hyphae growing within the thallus. After 45 days, arbuscules and vesicles were studied by light- and electron-microscopy. After 60 days in water agar culture, the colonised Anthoceros thalli were transferred to a low-nutrient medium agar. Hyphae spread in the agar and newly formed spores were observed 5 weeks after the transfer. After 4 months, about 1000 spores were formed in each Petri dish. This is the first report of an experimentally established arbuscular mycorrhiza-like symbiosis between an identified fungus belonging to the Glomales and a bryophyte.
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  • 4
    Electronic Resource
    Electronic Resource
    Springer
    Journal of comparative physiology 186 (2000), S. 347-357 
    ISSN: 1432-1351
    Keywords: Key words Crustacean ; Sensorimotor ; Ultrastructure ; Multilamellar sheath ; Myelinated axons
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Abstract Speed of nerve impulse conduction is greatly increased by myelin, a multi-layered membranous sheath surrounding axons. Myelinated axons are ubiquitous among the vertebrates, but relatively rare among invertebrates. Electron microscopy of calanoid copepods using rapid cryofixation techniques revealed the widespread presence of myelinated axons. Myelin sheaths of up to 60 layers were found around both sensory and motor axons of the first antenna and interneurons of the ventral nerve cord. Except at nodes, individual lamellae appeared to be continuous and circular, without seams, as opposed to the spiral structure of vertebrate and annelid myelin. The highly organized myelin was characterized by the complete exclusion of cytoplasm from the intracellular spaces of the cell generating it. In regions of compaction, extracytoplasmic space was also eliminated. Focal or fenestration nodes, rather than circumferential ones, were locally common. Myelin lamellae terminated in stepwise fashion at these nodes, appearing to fuse with the axolemma or adjacent myelin lamellae. As with vertebrate myelin, copepod sheaths are designed to minimize both resistive and capacitive current flow through the internodal membrane, greatly speeding nerve impulse conduction. Copepod myelin differs from that of any other group described, while sharing features of every group.
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  • 5
    Electronic Resource
    Electronic Resource
    Springer
    Acta neuropathologica 99 (2000), S. 310-316 
    ISSN: 1432-0533
    Keywords: Key words Ganglioglioma ; Ependymoma (tanycytic variant) ; Neurofibrillary tangle ; Immunohistochemistry ; Ultrastructure
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Abstract We studied a cystic ganglioglioma (GG) located in the right frontal lobe of the brain. Interestingly, the fibrillary spindle glial cells were often arranged in a fascicular pattern, and the generally uniform, round-to-oval delicate nuclei appeared to resemble those of ependymoma; and the neoplastic neurons often contained neurofibrillary tangles (NFTs). The glial component was positive for glial fibrillary acidic protein and occasionally contained granular or microvesicular structures positive for epithelial membrane antigen. Ultrastructural investigation revealed that the glial cells were ependymal in nature; intracytoplasmic lumina and intercellular microrosettes lined with cilia and microvilli, as well as long zonulae adherentes, were evident. In addition, chromogranin A-positive granular staining, neurosecretory-granule-like structures, and parallel arrays of microtubules were sometimes associated with the blood vessels. We considered the present case to be an unusual example of GG with an ependymoma, more precisely a tanycytic ependymoma, as the glial component; to our knowledge, the existence of ependymoma as the main glial component of this particular tumor has not been described before. The occurrence of NFTs, which has been reported in several cases of GG, was an additional, unusual feature.
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  • 6
    Electronic Resource
    Electronic Resource
    Springer
    Acta neuropathologica 99 (2000), S. 214-218 
    ISSN: 1432-0533
    Keywords: Key words Eosinophilic inclusion body ; Inclusion ¶body ; Ependymoma ; Microlumina ; Ultrastructure
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Abstract A study was undertaken to determine the pathological significance of previously unrecognized intracytoplasmic eosinophilic inclusions (IEIs) in ependymoma. The study group consisted of 58 ependymomas, all of which were pathologically characterized and graded according to the 1993 WHO classification. Electron microscopic studies were performed in 16 cases. The study showed that 33 (57%) ependymomas had IEIs and that in 8 cases these were abundant. Round and eosinophilic, their sizes varied from 10 μm to a tiny dot. Similar eosinophilic bodies were also observed between tumor cells. The inclusions were weakly PAS positive. On immunostains, IEIs were frequently positive for glial fibrillary acidic protein, less often for S-100 protein, and for epithelial membrane protein and CAM 5.2. They were negative for AE1/AE3, carcinoembryonic antigen and Ber-EP4. Ultrastructurally, IEIs represented intracytoplasmic lumens containing microvilli and cilia. These microlumina also frequently contained granulo-tubular materials. With reference to tumor subtypes, IEIs occurred most frequently in ordinary and clear cell ependymomas. IEIs were also present in 4 of 6 anaplastic ependymomas studied. In conclusion, IEIs represent microlumina and occur in more than a half of ependymomas including malignant examples. Their finding is a helpful diagnostic feature of ependymoma.
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  • 7
    ISSN: 1432-0533
    Keywords: Key words Alzheimer disease ; Fibrillar amyloid-β ; Astrocytes ; Microglial cell ; Ultrastructure
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Abstract Ultrastructural three-dimensional reconstruction of human classical plaques in different stages of development shows that microglial cells are the major factor driving plaque formation by fibrillar amyloid-β (Aβ) deposition. The amount of fibrillar Aβ released by microglial cells and the area of direct contact between amyloid and neuron determine the extent of dystrophic changes in neuronal processes and synapses. The volume of hypertrophic astrocytic processes separating fibrillar amyloid from neuron is a measure of the protective activation of astrocytes. On the bases of the volume of amyloid star, microglial cells, dystrophic neurites, and hypertrophic astrocytic processes, and spatial relationships between plaque components, three stages in classical plaque development have been distinguished: early, mature, and late. In early plaque, the leading pathology is fibrillar Aβ deposition by microglial cells with amyloid star formation. The mature plaque is characterized by a balance between amyloid production, neuronal dystrophy, and astrocyte hypertrophy. In late classical plaque, microglial cells retract and expose neuropil on direct contact with amyloid star, enhancing both dystrophic changes in neurons and hypertrophic changes in astrocytes. In late plaques, activation of astrocytes predominates. They degrade amyloid star and peripheral amyloid wisps. The effect of these changes is classical plaque degradation to fibrillar primitive and finally to nonfibrillar, diffuse-like plaques.
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  • 8
    ISSN: 1432-0533
    Keywords: Key words GM1-gangliosidosis ; Ultrastructure ; Electrospray ionisation tandem mass spectrometry ; Diagnosis
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Abstract The post-mortem diagnosis of lysosomal storage diseases can be confounded by the unavailability of suitable material. Here we report the diagnosis of GM1-gangliosidosis in a cross-bred dog, from which only formalin-fixed brain was available, by a combination of electron microscopy and the detection of elevated levels of GM1-ganglioside within the tissue using the novel technique of electrospray ionisation tandem mass spectrometry. Electron microscopic examination of ultrathin sections of resin-embedded tissue revealed cytoplasmic inclusions (membranous cytoplasmic and zebra bodies) in brain stem and cerebellar neurons that were characteristic of a gangliosidosis. Glycolipids were extracted from the fixed tissue and analysed by tandem mass spectrometry. Two major ions were detected, which corresponded to GM1 (d18:1–C18:0) and GM1 (d20:1–C18:0). Their identity was confirmed by comparison of their fragmentation patterns with those of authentic standards. The concentration of GM1 was approximately sixfold higher on a wet weight basis than in the brain of a normal control dog, confirming the diagnosis of GM1-gangliosidosis.
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  • 9
    ISSN: 1432-2013
    Keywords: Key words Pineal organ ; Photoreceptor cells ; Ultrastructure ; Proteus anguinus ; Regressive evolution
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Abstract We studied ultrastructure of the photoreceptor cells in the pineal organ of blind, depigmented, neotenic cave salamander, Proteus anguinus. Unlike in epigean vertebrates the outer segments of most photoreceptor cells consists of concentrically arranged lamellae, however; in few cells, the outer segments contain 7-9 plasma membrane disks. In both types of photoreceptor cells the outer segments enclose lumps of vesicles of different sizes. The photoreceptor cells of Proteus anguinus are similar to those in other cavernicolous fish species.
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  • 10
    Electronic Resource
    Electronic Resource
    Springer
    Anatomy and embryology 201 (2000), S. 51-61 
    ISSN: 1432-0568
    Keywords: Key words Female prostate (Skene gland) ; Ultrastructure ; Secretory (luminal) cells ; Basal (reserve) cells ; Intermediary cells
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Abstract  The predominant cells of female prostatic glands lining their lumen were found to be tall cylindrical secretory cells with short stubby microvilli, protuberances of the apical cytoplasm, and with bleb formation. Abundant secretory vacuoles and granules, rough endoplasmic reticulum, developed Golgi complexes and numerous mitochondria are characteristic of their active secretory configuration with apocrine (apical blebs) and merocrine (secretory vacuoles and granules) type of secretion. Basal (reserve) cells were seen to be located between the secretory (luminal) cells and the basement membrane. Their ground cytoplasm is dense with rough endoplasmic reticulum and mitochondria. Their nuclei, unlike those of secretory cells, possess more peripheral condensed chromatin, denser dispersed chromatin and sporadic nucleoli. Besides the two basic types of mature prostatic cells intermediary cells were also seen, located between the basal and secretory cells or in their close vicinity. Their cytoplasm exhibits numerous profiles of rough endoplasmic reticulum and free ribosomes. Secretory vacuoles and granules were mostly practically absent (type 1 intermediary cells) so that they resembled basal (reserve) cells. In some of them, however, as in secretory cells, such secretory elements do gradually appear (type 2 intermediary cells). The finding of intermediary cells in the lining of prostatic glands supports the role of basal (reserve) cells in the renewal of cells in glands of the female prostate. The first ultrastructural analysis of the normal female prostate performed by transmission electron microscopy showed that, as in the postpubertal male, the prostatic glands in the adult female display mature secretory and basal cells. The results of the presented study further corroborate the contemporary concept of the female prostate as a functional genitourinary organ.
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  • 11
    ISSN: 1439-7609
    Keywords: Key words Septic arthritis ; Surface antigens ; Ultrastructure ; Burkholderia pseudomallei ; IEM
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Abstract Burkholderia pseudomallei is the causative agent of melioidosis, a disease that frequently runs a protracted course and is very difficult to eradicate. The mechanisms that this organism uses to escape from host defense mechanisms and antibiotics are not well understood. The aim of the study was to compare the morphological characteristics and surface antigen expression of B. pseudomallei in naturally infected human synovial tissues with the characteristics of bacteria grown in culture media. Immunoelectron microscopic study was performed in four synovial biopsies taken from four B. pseudomallei septic arthritis patients. Colonies of pathogenic B. pseudomallei collected from culture media were used as positive controls. Polyclonal antibody to whole cell B. pseudomallei was used as a primary antibody. Complete bacteria-like particles were demonstrated both extracellularly and intracellularly in all four synovial specimens. The intracytoplasmic location of B. pseudomallei and mononuclear phagosome containing microcolony-like structures were demonstrated. B. pseudomallei found in the synovial membrane samples were mostly atypical, with fewer cytoplasmic electron lucent granules. Immunogold staining of bacterial surface antigens was weaker than staining of positive controls. We demonstrated atypical forms of B. pseudomallei and evidence for suppression of its surface antigens in naturally infected human synovial tissues. This adaptation may help bacteria to survive despite host immune surveillance and treatment with antibiotics.
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  • 12
    Electronic Resource
    Electronic Resource
    Springer
    Virchows Archiv 436 (2000), S. 249-256 
    ISSN: 1432-2307
    Keywords: Key words Endothelial cells ; Cell culture ; Ultrastructure
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Abstract  The aim of the present work was to examine and compare the ultrastructure of bovine retinal endothelial cells (BRECs) in vitro during several passages in a medium selective for endothelial cells. The identity of the endothelial cells was confirmed immunohistochemically, up to the tenth passage. Changes in their ultrastructure in comparison to endothelial cells in vivo occurred at the onset of culturing and not progressively with repeated passages. The cultured BRECs show high metabolic activity in all passages. While retaining their identity as endothelial cells, they modify their lipid metabolism, so that lipids are stored. This change in lipid metabolism was induced by the medium.
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  • 13
    ISSN: 1432-2307
    Keywords: Key words Arteriogenesis ; Collateral vessels ; Ultrastructure ; Cell adhesion molecules
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Abstract  Previous studies in the canine heart had shown that the growth of collateral arteries occurs via proliferative enlargement of pre-existing arteriolar connections (arteriogenesis). In the present study, we investigated the ultrastructure and molecular histology of growing and remodeling collateral arteries that develop after femoral artery occlusion in rabbits as a function of time from 2 h to 240 days after occlusion. Pre-existent arteriolar collaterals had a diameter of about 50 µm. They consisted of one to two layers of smooth muscle cells (SMCs) and were morphologically indistinguishable from normal arterioles. The stages of arteriogenesis consisted of arteriolar thinning, followed by transformation of SMCs from the contractile- into the proliferative- and synthetic phenotype. Endothelial cells (ECs) and SMCs proliferated, and SMCs migrated and formed a neo-intima. Intercellular adhesion molecule (ICAM-1) and vascular cell adhesion molecule (VCAM-1) showed early upregulation in ECs, which was accompanied by accumulation of blood-derived macrophages. Mitosis of ECs and SMCs started about 24 h after occlusion, whereas adhesion molecule expression and monocyte adhesion occurred as early as 12 h after occlusion, suggesting a role of monocytes in vascular cell proliferation. Treatment of rabbits with the pro-inflammatory cytokine MCP-1 increased monocyte adhesion and accelerated vascular remodeling. In vitro shear-stress experiments in cultured ECs revealed an increased phosphorylation of the focal contacts after 30 min and induction of ICAM-1 and VCAM-1 expression between 2 h and 6 h after shear onset, suggesting that shear stress may be the initiating event. We conclude that the process of arteriogenesis, which leads to the positive remodeling of an arteriole into an artery up to 12 times its original size, can be modified by modulators of inflammation.
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  • 14
    Electronic Resource
    Electronic Resource
    Springer
    Neurological sciences 21 (2000), S. S27 
    ISSN: 1590-3478
    Keywords: Key words Neuronal ceroid lipofuscinoses ; Lipopigments ; Ultrastructure ; Classification ; Genes ; Neuronal loss
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Abstract Morphological aspects of the neuronal ceroid lipofuscinoses (NCL) encompass two main features: loss of nerve cells and accumulation of autofluorescent lipopigments within cellular compartments. The former requires histology and morphometry for assessment, while the latter necessitates fluorescence microscopy, electron microscopy, and immunohistochemistry. Accumulation of lipopigments is widespread throughout the central nervous system and extracerebrally. The latter feature enables diagnosis of NCL and its clinical subtype. Loss of neurons is most pronounced in cerebral and cerebellar cortices, in early childhood forms. In subcortical grey matter and in later-onset forms, juvenile and adult NCL, reduction in neurons and possible preceding dendritic pathology may only correctly be ascertained by age-matched, controlled morphometric investigations which, to date, have not yet completely assessed subcortical neuronal damage. Presently, clinical and morphological evaluations are mandatory for genetic analysis, genetic counselling, and prenatal diagnosis, the latter often being based on combined genetic and morphological studies.
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  • 15
    ISSN: 1615-6102
    Keywords: Arabidopsis thaliana ; Cryopreservation ; Dehydration ; Thermal analysis ; Sucrose ; Ultrastructure
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Summary Arabidopsis thaliana suspension cells were preserved in liquid nitrogen for over three years, using embedding of cells in calcium-alginate prior to subculture in sucrose-enriched medium, air-drying, and direct quenching in liquid nitrogen. Survival of cells reached 34%, yielding regrowth at the surface of all cryopreserved beads in less than 7 days. Following pretreatment and dehydration, the water content dropped from 2300% to 34% with respect to dry weight. Differential scanning calorimetry showed that glass transition occurred on cooling, followed by a slight crystallization event on rewarming. The survival of cells was independent of the cooling rate. The tolerance of the acute dehydration step increased progressively with sucrose pretreatment duration, indicating the requirement for adaptative cellular alterations. Ultrastructural studies revealed several changes in cells after sucrose pretreatment prolonged from 1 to 7 days: reversal of the initially plasmolyzed state, microvacuolation, numerous autophagic structures, scarcity of ribosomes, increase in number and size of starch grains. No cell division seemed to occur during this period. After air-drying and after a freeze-thaw cycle, followed by 24 h rehydration, regenerating cells had recovered a high level of ultrastructural organization and contained numerous polysomes suggesting an intense metabolic activity. Trehalose, a cryoprotective disaccharide not considered to be a metabolic substrate, yielded only 70% regrowth after freezing. Biochemical analysis showed that soluble sugars accumulated during the pretreatment, essentially sucrose or trehalose; the monosaccharide content also increased. In the light of these results, the action of sucrose in inducing freezing tolerance is discussed.
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  • 16
    ISSN: 1615-6102
    Keywords: Beta vulgaris ; Cyst nematodes ; Histology ; Resistance mechanism ; Syncytium ; Ultrastructure
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Summary Using susceptible and resistant sugar beet lines, comparative analyses of root histology and ultrastructure were made during invasion by nematodes and the induction and formation of specific feeding structures (syncytia).The resistant line carried the resistance geneHs1pro−1.Nematodes were able to invade and induce functional syncytia in roots of resistant and susceptible lines. However, syncytia in resistant roots were smaller and less hypertrophied. The vacuolar system of syncytia in susceptible plants contained many small vacuoles. In resistant plants vacuoles were larger but less numerous. Smooth endoplasmic reticulum prevailed in syncytial protoplasts of susceptible plants, whereas almost only rough endoplasmic reticulum occurred in syncytia in resistant plants. The most conspicuous and hitherto undescribed trait of syncytia in resistant roots was the initial appearance of loose, and later compact, aggregations of the endomembrane system which composed most of the endoplasmicreticulum system of syncytia at later stages. Syncytia in resistant plants usually degraded before the nematodes reached their adult stage. The appearance of membrane aggregations and the other resistance-specific features are discussed in relation to their possible effects on syncytium function and role in nematode resistance.
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  • 17
    Electronic Resource
    Electronic Resource
    Springer
    Protoplasma 211 (2000), S. 94-102 
    ISSN: 1615-6102
    Keywords: Androgenesis ; Embryogenesis ; Microspore culture ; Pollen ; Ultrastructure ; Wheat
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Summary We have made a detailed cytological examination of the development of wheat embryoids, monitoring their initial divisions from two to ten cells by both light and electron microscopy. According to our observations the first embryogenic division is symmetrical. After the androgenesis induction treatment, there is a decrease in ribosome population with cells that have inactive nucleoli made up almost exclusively of a dense fibrillar component. This population is restored after initial embryogenic divisions. During the initial divisions the embryogenic pollen grains do not appear to change in size and the pollen wall remains intact. The exine undergoes no modification but the intine thickens, and we have observed that the thickness of the intine can be used as a cytological marker of androgenesis. The walls separating the cells obtained after embryogenic division contained numerous plasmodesmata. The beginnings of embryo polarization and cell differentiation could be made out in the very early pollen embryoids.
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  • 18
    ISSN: 1615-6102
    Keywords: Glutathione ; Root ; Chromosomal aberration ; Ultrastructure ; Picea abies
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Summary Young spruce seedlings (Picea abies [L.] Karst.) grown in hydroponic culture were exposed to three different concentrations (50,100, and 500 μM) of reduced glutathione for 24 h. These physiologically relevant concentrations of glutathione had a multiple effect on the investigated tissue. Feeding of glutathione to roots increased the concentrations of thiols (glutathione, cysteine, and γ-glutamyl-cysteine) in roots, decreased the rate of cell divisions, induced mitotic abnormalities, and affected the cell ultrastructure. Electron micrographs showed effects such as advanced vacuolation, dilated rough-endoplasmic-reticulum cisternae, and separations of the plasma membrane from the cell wall.
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  • 19
    ISSN: 1861-387X
    Keywords: Hemangioblastoma ; Supratentorial tumor ; Immunohistochemistry ; Ultrastructure
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Abstract Supratentorial hemangioblastomas are rarely seen, especially in children and adolescents. We report the case of a 17-year-old male with supratentorial hemangioblastoma. Neuroimaging demonstrated a cystic lesion within the right parietal lobe. Systemic examination revealed no abnormality. The lesion was not attached to the dura and was not associated with von Hippel-Lindau disease. It was very difficult to confirm the final diagnosis of this case, in spite of extensive examination by light microscopy, immunohistochemical studies, and electron microscopy.
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  • 20
    ISSN: 1437-773X
    Keywords: Key words Mitogen-activated protein kinase (MAPK) ; Ischemia reperfusion injury ; Heart ; Ultrastructure ; Immunohistochemistry
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Abstract The mitogen-activated protein kinase (MAPK) family is considered to be activated by stress, but the role of the MAPK family is still unknown in cardiac pathology. In the present study, not only the localization of MAPKs such as the extracellular responsive kinase (ERK), c-jun N-terminal kinase (JNK), and p38 MAPK (p38), but also ultrastructural changes were investigated in the ischemia-reperfusion model of Wistar rats. At 5, 10, 30, 60, and 180 min reperfusion after 30 min ischemia by occluding the coronary artery, the expression of these MAPKs was increased in blood vessels and cardiomyocytes by Western blotting and immunohistochemical methods. In addition, after ischemia reperfusion, various ultrastructural changes such as decreased glycogen granules, mitochondrial swelling, and myolysis were observed in the blood vessels and cardiomyocytes. These results suggest that protein kinases may regulate numerous biological processes, including the regulation of contraction and ion transport.
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  • 21
    ISSN: 1437-773X
    Keywords: Key words Gonadotroph adenoma ; FSH ; Childhood ; Ultrastructure ; Immunohistochemistry
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Abstract Female gonadotroph adenomas with endocrinological symptoms are uncommon. Six cases of such adenomas have been reported in the literature: two were girls who presented with precocious puberty and four were premenopausal women with accompanying multiple ovarian cysts. We describe here a 10-year-old Japanese girl with a gonadotroph macroadenoma and present detailed morphological findings of the tumor. The patient's chief complaints were nausea, abdominal distention, and abdominal pain. Abdominopelvic ultrasonography and magnetic resonance imaging (MRI) revealed bilateral multiple ovarian cysts. Endocrinological assays showed elevated serum follicle-stimulating hormone (FSH) (33.7 mIU/ml) and estradiol (3840 pg/ml). MRI of the head showed a large pituitary tumor. Two transsphenoidal operations and subsequent radiation therapy were performed. Immunohistochemically, more than half the tumor cells were positive for anti-FSH-β monoclonal antibody. Ultrastructurally, the tumor cells exhibited a fairly uniform picture of rounded cells. Their nuclei were slightly irregular and contained heterochromatin, and their cytoplasm contained many round, dense core granules, measuring 140–260 nm in diameter, together with well-developed organelles. An in vitro study showed that the tumor cells in primary culture produced FSH (1089.0 mIU/ml). To our knowledge, this is the first immunohistochemical and ultrastructural study of an FSH-secreting gonadotroph adenoma occurring in childhood.
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  • 22
    ISSN: 1437-773X
    Keywords: Key words Apoptosis ; Helicobacter pylori ; Fibroblasts ; Smooth muscle cells ; Ultrastructure ; Gastroduodenal ulcer
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Abstract It has been considered that Helicobacter pylori (H. pylori) infection is a major cause of human gastritis and gastroduodenal ulcers (G-DU). Many investigations of the relationship between H. pylori and apoptosis have been reported recently. However, these studies focused mostly on epithelium, using the TUNEL method. In the present study, we evaluated by electron microscopy the occurrence of apoptosis in the mesenchymal cells of lamina propria mucosae infected with H. pylori. Gastric biopsy specimens from 37 H. pylori-infected G-DU patients and 8 noninfected volunteers were examined with both light and electron microscopy and analyzed by the TUNEL method. The TUNEL method showed no significant difference between H. pylori-infected and noninfected cases. In contrast, electron microscopy revealed significant numbers of apototic fibroblasts and smooth muscle cells in H. pylori-infected lamina propria mucosae, with a diminished number of collagen fibers in surrounding areas. These areas showed edematous changes histopathologically. These results indicated that H. pylori infection induces apoptosis of fibroblasts and smooth muscle cells in lamina propria, with decrease in the numbers of collagen fibers, suggesting that these alterations may be affected by exaggerate acid secretion, decrease mucus protecting factors, and result in ulcer formation.
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  • 23
    Electronic Resource
    Electronic Resource
    Springer
    Medical electron microscopy 33 (2000), S. 109-114 
    ISSN: 1437-773X
    Keywords: Key words Ciliogenesis ; Ciliated cell ; Abnormal cilia ; Basal body ; Ultrastructure ; Human
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Abstract Cilia are motile processes extending from the basal bodies, playing important roles in the mucociliary clearance in the respiratory tract and the transport of the ovum from the ovary to the uterus in mammals. Ciliogenesis is divided into four stages: (1) duplication of centrioles; (2) migration of centrioles to the apical cell surface to become basal bodies; (3) elongation of cilia containing the axoneme; and (4) formation of accessory structures of basal bodies. The orderly course of ciliogenesis appears to be disturbed by various internal and external factors and, as a result, various unusual forms of the ciliary apparatus develop in the cell. Inhibition of basal body migration results in development of intracytoplasmic axonemes, cilia within periciliary sheaths, and intracellular ciliated cysts. Swollen cilia and the bulging type of compound cilia are formed during ciliary budding and elongation. This review also discusses the origin, composition, and function of the centriolar precursor structures.
    Type of Medium: Electronic Resource
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  • 24
    ISSN: 1437-773X
    Keywords: Key words Adenoid basal carcinoma ; Uterine cervix ; Ultrastructure
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Abstract Adenoid basal carcinoma of the uterine cervix is a rare tumor with a favorable prognosis. A case of adenoid basal carcinoma (ABC) of the uterine cervix was studied using light and electron microscopy. The patient was a 74-year-old Japanese woman who had undergone hysterectomy due to cervical intraepithelial neoplasia 3. Incidentally, ABC was found in the resected uterus. The tumor cells made small nests and infiltrated the cervical portion of the uterus. In the nests, glands, cribriform patterns with glandlike structures, and squamous differentiation were seen. Immunohistochemically, the glandlike structures were positive for laminin and type IV collagen. Ultrastructurally, the tumor cells had irregular nuclei, scanty cytoplasm, and cribriform patterns in which glandlike structures were covered with basal lamina. No myoepithelial differentiation of the tumor cells was seen. These findings suggest a similarity between adenoid basal carcinomas and adenoid cystic carcinomas. Furthermore, both tumors are considered to originate in the reserve cells of the uterine cervix. Because their outcomes are different, they should be distinguished from each other.
    Type of Medium: Electronic Resource
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  • 25
    Electronic Resource
    Electronic Resource
    Springer
    Medical electron microscopy 33 (2000), S. 135-142 
    ISSN: 1437-773X
    Keywords: Key words Elastic system fiber ; Ultrastructure ; Fibrotic human liver ; Oxytalan fiber ; Elaunin fiber
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Abstract The network of elastic system fibers in human fibrotic liver was investigated by histological methods, immunohistochemical staining, and electron microscopy. Type III collagen was seen not only in regions of portal fibrosis but also in the sinusoidal wall. However, elastic system fibers were not found in the Disse space of the sinusoidal wall. Elastic system fibers including oxytalan, elaunin, and elastic fibers were found successively in the course of elastogenesis. A few normal oxytalan fibers and abnormal oxytalan fibers were observed in the periportal tracts. Few normal elaunin and abnormal elaunin fibers were observed in regions of portal fibrosis but not in the surrounding margin. Elastic fibers, only in scarce amounts, were observed around the portal veins in the case of chronic active hepatitis but not in acute hepatitis. Abnormal oxytalan fibers were seen as a bundle of wavelike microfibrils and had an irregular arrangement. Abnormal elaunin fibers were not associated with bundles of microfibrils. Abnormal elaunin fibers in large amounts were found interspersed with spiraled collagen, which most likely indicates that the oxytalan fibers degenerated in the course of elastogenesis. Thus, in a fibrotic liver it is possible that synthesis of normal elaunin and elastic fibers does not occur or that the quantity of such fibers synthesized may be small because of the effect of the degenerated oxytalan fibers. As a characteristic of liver fibrosis, the composition of abnormal elastic system fibers and spiraled collagen differs from that in other fibrotic organs.
    Type of Medium: Electronic Resource
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