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PubMed1998

Colloidal Sodium and Potassium Phosphates in Organic Medium: Synthesis and Analysis.

Colloidal dispersions of sodium and potassium phosphates in a hydrocarbon medium have been synthesized by reacting, under specific conditions, aqueous sodium or potassium hydroxyde with tetraphosphorous decasulfide in hydrocarbon solvent in the presence of a surfactant such as alkylarylsulfonic acid. The resulting products can be defined as a distribution of inorganic particles stabilized by sodium or potassium alkylaryl sulfonate in a reverse-micelle type association. The chemical structures of the mineral cores are determined using 31P NMR, potentiometric titration and elemental analysis. The core particles were found to be respectively a mixture of sodium (poly)phosphates and a mixture of potassium (poly)phosphates. Inorganic core and organic surfactant balances were determined using thermogravimetric analysis. The weight ratio of mineral core part to organic surfactant part is found about to be 1.6 for Na derivative and 2.4 for K derivative. The morphological characterization of the colloidal dispersion has been investigated using Small Angle X-ray Scattering, Transmission Electron Microscopy and Wide Angle X-ray Scattering. The inorganic particles appear as cristallized particles with diameters ranging from 50 to 360 Å. Copyright 1998 Academic Press.

Journal Article↗

PubMed2001

Loss of homotypic epithelial cell adhesion by selective N-cadherin displacement in bismuth nephrotoxicity.

The nephrotoxicity of single high doses of bismuth (Bi)-containing therapeutic drugs is characterized morphologically by detachment of proximal tubular epithelial cells (PTECs) from each other, followed by cell death. We investigated whether Bi nephrotoxicity is mediated by changes in the distribution of proteins involved in intercellular adhesion. A nephrotoxic dose of colloidal bismuth subcitrate (CBS; 3.0 mmol Bi/kg) was orally administrated to 10 female Wistar rats. After 1 h, N-cadherin had disappeared from the adherence junctions of vital PTECs, whereas ZO-1, a tight junction marker, remained present at the cell-cell border until cell death occurred after 3 h. E-Cadherin, absent in PTECs, remained absent. Exposure of the renal epithelial cell lines NRK-52E and LLC-PK1 to 400 microM Bi(3+) also resulted in the disappearance of N-cadherin expression after 1 h, whereas ZO-1, E-cadherin, and Desmoplakin expression did not resolve before cell death at 24 h, thus confirming in vivo results. Our results are the first to indicate that Bi-induced death of PTECs is preceded by redistribution of N-cadherin and the disruption of homotypic cell adhesion.

Animals↗

PubMed1979

Purine metabolism in cultured coronary endothelial cells.

Endothelial cells from coronary vessels of guinea pig hearts were isolated, cultivated and morphologically characterized. --Cells from confluent cultures contained adenine nucleotides and their dephosphorylated degradatives in exceptionally high amounts. --Adenine nucleotide levels were only slightly influenced by the growth state of the cultures and remained stable during incubation for three days in purine-free medium. In contrast, brief incubation of endothelial cells under anoxic conditions resulted in a substantial breakdown of adenine nucleotides associated with an enhanced formation and release of adenosine. --Measurements of specific activities of enzymes involved in adenine nucleotide synthesis and degradation lend additional support to the view that a very active adenine nucleotide metabolism is a typical feature of cultured coronary endothelial cells.

Adenine Nucleotides↗

PubMed1998

Diagnosis and therapeutic relevance of micrometastases.

The disseminated isolated tumor cell has become a formidable object of solid tumor research for at least three good reasons: it can be identified in organ compartments such as bone marrow, blood, and lymph nodes and, once found, it can be morphologically characterized with respect to tumor-associated antigens, oncogenes, tumor suppressor genes, proliferation markers, and/or growth receptors. Thirdly, it is also an ideal target for immunotherapy directed at accessible, well-defined membrane-associated antigens of the tumor cell.

Antigens, Neoplasm↗

PubMed1983

Ultrastructural evidence of the ion-transporting role of the adult and larval neck organ of the marine gymnomeran Cladocera (Crustacea, Branchiopoda).

The neck organ of adult and immature forms of four marine gymnomeran Cladocera species (Podonidae) has been characterized morphologically by light-scanning- and electron microscopy. Although displaying some special features, a comparison with organs assuming a comparable regulating function in other organisms indicates that the neck organ of the adult Podonidae exhibits ultrastructural evidence of involvement in ion-transporting mechanisms. The extensive ventral plasma membrane infoldings closely connected with the chondriom and the peculiar organization of the cuticular site associated with the subjacent apical cell limits of the organ are among the chief structural specializations. The fact that similar structures are already present in the embryonic neck organ confirms previous indirect evidence that podonid embryos can hypo-osmoregulate as soon as the ion concentration of the brood chamber rises to that of the outside medium.

Animals↗

PubMed1984

Marginal plates in hepatic peroxisomes of Ichthyophis glutinosus (Amphibia: Gymnophiona). A cytochemical study.

The ultrastructure of hepatic peroxisomes was investigated in Ichthyophis glutinosus (Amphibia: Gymnophiona), employing perfusion fixation and the diaminobenzidine (DAB) technique for the visualization of catalase. The majority of peroxisomes is circular or rod-shaped, although elongated particles occasionally occur. They contain a finely granular matrix, lightly stained after the DAB procedure. Their mean diameter is approximately 0.25 micron. Serial sections reveal that the circular and rod-shaped peroxisomal profiles are cross and oblique sections of highly tortuous, tubular organelles exceeding 2 micron in length. In addition to tubular profiles, elongated, rectangular particles, as well as straight dumbbell-shaped organelles with distinct marginal plates are observed. They range from 900 to 1650 nm in length (mean = 1200 nm). In the flattened, thin central portion of the dumbbell-shaped particle, the peroxisomal membranes form a cisterna enclosing one or two uniformly thick marginal plates, which display a definite substructure with a periodicity of 10 nm. These findings indicate that peroxisomes in the liver of Ichthyophis exhibit a complex organization. It is suggested that the organelles undergo a specific differentiation process, morphologically characterized by the formation of enlarged segments of unusual shape.

3,3'-Diaminobenzidine↗

PubMed1976

Ultrastructural and cytochemical features of SV 40 transformed hypothalamic cell lines.

A continuous cell line was previously obtained by Simian Virus (SV) 40 transformation of primary cultures of dissociated mouse fetal hypothalami. One clone from this cell line has been previously shown to possess some of the ultrastructural features, immunological properties and synthesizing capacities of magnocellular hypothalamic neurons which secrete vasopressin and neurophysins. The present paper reports on the morphological characterization of 14 other clones or subclones of the original cell line, using the following criteria: phase contrast microscopy, electron microscopy, Gomori's aldehyde fuchsin staining, cytochemical detection of beta-glucuronidase, immunochemical staining with antisera against bovine neurophysin I, bovine neurophysin II, lys-vasopressin, oxytocin, LH-RH and TRH. The results allowed the conclusion that the clones as well as the subclones can be distributed into two groups: 1) neurosecretory neurons which all possess several of the ultrastructural and cytochemical features of the neurophysin-vasopressin synthesizing clone, and 2) primitive nerve cells which are devoid of such features but display numerous bundles of filaments. In addition some clones were found to display intermediate features between groups 1 and 2. A similar diversity was observed within clones of the original strain and subclones of a neurosecretory clone. It is suggested that the primitive clones could represent precursors of the neurosecretory clones.

Animals↗

PubMed1975

Catecholamine-containing nerve terminals of the eccrine sweat glands of macaques.

The external layer of the median eminence (ELME) and the arculate nucleus of male rats were studied with the Falck-Hillarp technique and electron microscopy of aldehyde-OsO4 or KMnO4 fixed after various types of hypothalamic deafferentation experiments with the Halász knife. Special reference was paid to the monoamine systems and the results can be summarized as follows. 1. The main monoaminergic input to the ELME comes from the arcuate nucleus-periventricular area via a dorsal approach. A horizontal transection through the arcuate nucleus decreases the percentage of monoamine boutons i.e. boutons with small granular vesicles, from 31.6% in the controls to 4.4% in the lesion group, whereas only a small effect is seen after anterior (or complete) deafferentations. 2. A major input to the ELME enters the basal hypothalamus at the anterior-lateral aspects (see Réthelyi and Halász, 1970). The fibers cut after anterior deafferentations in all probability mainly come from cell bodies localized in the anterior hypothalamus or even further rostrally but some may represent NA axons ascending from the lower brain stem. 3. The degeneration course of nerve endings in the ELME both after anterior deafferentations as well as after lesions in the arcuate nucleus is rapid (within 2-3 days) and morphologically characterized by an initial aggregation of large dense cored vesicles seemingly to electron dense bodies within the boutons and probably also to a closer spacing of the small electron lucent synaptic vesicles (see Raisman, 1972). This type of degeneration seems to take place both in monoamine and non-monoamine neurons. 4. Degenerating boutons are found in the arcuate nucleus after anterior and complete deafferentations. Thus, the anterior hypothalamus may exert an "indirect" control of the pituitary gland via synapses on arcuate neurons although quantitatively the "direct" influence through the projection to the ELME is of more importance. 5. After anterior deafferentations enlarged axons containing large amounts of large dense cored vesicles and other organelles are found caudally of the cut indicating the existence of rostral projections from the medial hypothalamus.

Animals↗

PubMed1975

Projections to the median eminence and the arcuate nucleus with special reference to monoamine systems: effects of lesions.

The external layer of the median eminence (ELME) and the arcuate nucleus of male rats were studied with the Falck-Hillarp technique and electron microscopy of aldehyde-OsO4 or KMnO4 fixed material after various types of hypothalamic deafferentation experiments with the Haláz knife. Special reference was paid to the monoamine systems and the results can be summarized as follows. 1. The main monoaminergic input to the ELME comes from the arcuate nucleus-periventricular area via a dorsal approach. A horizontal transection through the arcuate nucleus decreases the percentage of monoamine boutons i.e. boutons with small granular vesicles, from 31.6% in the controls to 4.4% in the lesion group, whereas only a small effect is seen after anterior (or complete) deafferentations. 2. A major input to the ELME enters the basal hypothalamus at the anterior-lateral aspects (see Réthelyi and Halsáz, 1970). The fibers cut after anterior deafferentations in all probability mainly come from cell bodies localized in the anterior hypothalamus or even further rostrally but some may represent Na axons ascending from the lower brain stem. 3. The degeneration course of nerve endings in the ELME both after anterior deafferentations as well as after lesions in the arcuate nucleus is rapid (within 2-3 days) and morphologically characterized by an initial aggregation of large dence cored vesicles seemingly to electron dense bodies within the boutons and probably also to a closer spacing of the small electron lucent synaptic vesicles (see Raisman, 1972). This type of degeneration seems to take place both in monoamine and non-monoamine neurons. 4. Degenerating boutons are found in the arcuate nucleus after anterior and complete deafferentations. Thus, the anterior hypothalamus may exert an "indirect" control of the pituitary gland via synapses on arcuate neurons although quantitavely the direct influence through the projection to the ELME is of more importance. 5. After anterior deafferentations enlarged axons containing large amounts of large dense cored vesicles and other organelles are found caudally of the cut indicating the existence of rostral projections from the medial hypothalamus.

Animals↗

PubMed1986

Minisegments of newborn rat optic nerves in vitro: gliogenesis and myelination.

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: the regular size of the minisegments should guarantee a permanent exchange of the culture medium in order to avoid cell death, neither mechanical nor enzymatic dissociation of the tissue were applied, the minisegments were explanted into flasks without substrate for cell adhesion and 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.(ABSTRACT TRUNCATED AT 400 WORDS)

Animals↗

PubMed1994

Quantitative neuropathologic analysis of Pick's disease cases: cortical distribution of Pick bodies and coexistence with Alzheimer's disease.

Pick's disease is characterized morphologically by severe atrophy of the frontal and temporal lobes and the presence in the cerebral cortex of degenerative neuronal lesions referred to as Pick bodies. In the present study, we analyzed the regional and laminar distribution of Pick bodies in a series of 16 Pick's disease cases. These distribution and density patterns were compared with those observed for neurofibrillary tangles in Alzheimer's disease. Very high densities of Pick bodies were observed Ammon's horn, subiculum, entorhinal cortex, and in the granule cell layer of the dentate gyrus. In the frontal and temporal neocortex, they were preferentially distributed in layers II and VI. All of the Pick's disease cases also exhibited neurofibrillary tangles in the frontal and temporal areas and in the hippocampal formation, with higher densities in layers II-III than in layers V-VI of the neocortical regions. Interestingly, this laminar distribution of neurofibrillary tangles was strikingly different from that observed in Alzheimer's disease cases, where they were more numerous in the infragranular layers than in the supragranular layers. In addition, a few Pick's disease cases also had cortical senile plaques. These results suggest that the presence of neurofibrillary tangles in Pick's disease may be more frequent than previously reported, and that Pick's disease and Alzheimer's disease may coexist in certain cases. The lesion distribution patterns suggest that different populations of cortical neurons are affected in Pick's and Alzheimer's disease, and that alterations of select corticocortical and corticosubcortical projections may distinguish these forms of dementia. It is also possible that these two disorders share certain pathogenetic mechanisms, even though both display specific patterns of regional and neuronal vulnerability to the degenerative processes.

Aged↗

PubMed1975

Studies on intra-arterial cushions. I. Morphology of the cushions at the origins of intercostal arteries in mice.

The origins of intercostal arteries in mice are surrounded by cushions which project into the aortal lumen. A boat-like structure, whose bow is directed against the blood stream, is formed by the cushions. The shape of this formation depends on the dilatation of the aortal wall, becoming flatter when the aortal wall is stretched. Grooves direct the blood into the initial segment of the branching artery which is narrowed in moderately distended or relaxed states of the aorta. The cushions are covered by an endothelial layer which continues to the endothelium of the aorta and of the branching artery. Ramified smooth muscle cells are found in the stroma of the cushions, while connective tissue are absent. Ramifications of the lamina elastica interna project into the stroma and faint elastic fibres reach the apical margins of the cushions. Basement membranes of ramified smooth muscle cells form a three-dimensional network which is connected with the basement membrane of the endothelium. Contacts between processes of endothelial cells and those of ramified smoot; muscle cells occur. Collagen fibrols are absent or extremely rare. In the interstitial space clusters of electron dense granules (mean diameter 500 A) are found which might be secreted by the specialized ramified smooth muscle cells. This peculiar morphology characterizes the intraaortal cushions as autonomous formations and excludes their being regarded as simple retroextension of the branching artery.

Animals↗

PubMed1995

Polarized epithelial cells of the hamster seminal vesicle in a serum-free bicameral culture system: evidence of secretory and endocytic activities.

Primary cultures of epithelial cells from the hamster seminal vesicle were established in a chemically defined medium supplemented with hormones and growth factors. Epithelial cell clusters were prepared combining enzymatic dissociation and mechanical disaggregation and then seeded in bicameral systems equipped with collagen-membrane inserts. A growth curve was generated and the cells were characterized morphologically and morphometrically by light and electron microscopy. The immunocytochemical detection of cytokeratins and the measurement of transepithelial electrical resistance were also performed. The secretory activity was studied by fluorography using L-[35S]methionine as a precursor, and endocytosis was approached using horseradish peroxidase as a tracer. Our results show that epithelial cells of the seminal vesicle can be grown as a monolayer of morphological and functionally polarized cells which retain secretory and endocytic activities. These cell cultures might therefore prove useful to investigate further the regulation of secretion and endocytosis in the seminal vesicle and are a promising model to approach, in a broader scope, cell polarity and protein sorting and targeting.

Animals↗

PubMed1981

Liquid stored erythrocytes: agglomeration, morphology, sialic acid, and toluidine blue uptake studies.

Increased tendency to reversible agglomeration in erythrocytes in outdated units has been previously demonstrated. This phenomenon occurred while post transfusion viability was still acceptable. In the present study erythrocytes of units with early agglomeration were investigated and compared with those with late agglomeration. There was no morphological characterization of these erythrocytes and their sialic acid content and the toluidine blue uptake were not lower than in late agglomeration. Thus, it seems that agglomeration reflects membranal changes, but is not directly related to the sialic acid content of the membrane or to its toluidine blue uptake.

Blood Preservation↗

PubMed1991

Cytogenetic and molecular aspects of position effect variegation in Drosophila. III. Continuous and discontinuous compaction of chromosomal material as a result of position effect variegation.

Variations in compaction of chromosomal material of the rearrangements Dp(1;f) 1337, Dp(1;f) R, Dp(1;1)pn2b, and T(1;4)wm258-21, which display an extended position effect, were characterized. Morphological changes found in these rearangements were assigned to two major types: (i) continuous compaction, in which bands and interbands located distal to the eu/heterochromatin junction fuse into one compacted block of chromatin. The extent of compaction is increased by enhancers of position effect (low temperature, removal of the Y or 2R chromosome heterochromatin). In extreme cases compaction extends over dozens of bands. (ii) Discontinuous compaction, in which at least two zones of compaction separated by morphologically normal zones can readily be identified. As a result, some regions located at a greater distance from heterochromatin may be compacted more frequently than others that map nearer to it. A few regions (1D, 2B1-12, 2D) were shown to be most frequently compacted in all rearrangements investigated. The 2B13-18, 2C1-2, 2E, and 2F regions exhibited the lowest frequencies of compaction. Compaction of the zone containing the 2B1-12 bands is always accompanied by inactivation of the ecs locus, which maps in the 2B3-5 puff. At the same time the 2C1-2 and 2E bands located nearer to the breakpoint can retain normal morphology and puffing in response to ecdysterone. The results are interpreted as morphological manifestations of the discontinuity of the spreading effect.

Animals↗

PubMed1978

[The malignant fibrous histiocytoma of bone (author's transl)].

The primary malignant fibrous histiocytoma of bone (Stout) is a rare and autonomous sarcoma of the bone which has to be separated from the osseous sarcoma and the osseous fibrosarcoma. The malignant histiocytoma is morphologically characterized by the storiform pattern of interlacing spindle cell bundles and functionally by the phagocytosis of lipids, glycogen, hemosiderin and hematoidin. Contrary to the osteosarcomas, the main age of osseous histiocytomas are the fifth and sixth decade. Location of predilection are the metaphyses of the long tubular bones. The X-rays show moth-eaten spongiolysis, endosteal erosion and perforation of the cortex. Early metastases in the lungs are frequent. The primary treatment is a surgical one. Case record of a typical malignant osseous histiocytoma from the proximal metaphysis of the left femur with metastases in the lung of a female child, aged 14 years.

Adolescent↗

PubMed1991

Amyloid angiopathy--a rare cause of intracerebral hemorrhage.

The cerebral amyloid angiopathy (CAA), morphologically characterized by amyloid deposition in the vessel walls which are altered to rigid tubes, is a chronic disease of the cortical and meningeal vessels and can cause intracerebral hemorrhages (1.5% of all intracerebral bleedings). We report the course of five surgically treated patients with lobar space-occupying intracerebral hemorrhages and CAA confirmed by histological examination. All patients were elderly (74-84 years), in good condition, and self-providing before the hemorrhage. There were no signs of dementia of the Alzheimer's type. In four cases, CT showed a hematoma in the parieto-occipital, and in one case in the temporo-parietal, region. After surgical evacuation, two patients recovered, one patient remained in bad condition, and two patients died from recurrent hemorrhage within two weeks. Spontaneous intracerebral hemorrhage of lobar localization in an elderly patient strongly suggests CAA. The prognosis seems to be poor in cases with recurrent hemorrhage, the other patients presented an uneventful course, comparable with patients operated on for intracerebral bleeding of other origin. Further investigations are necessary to elucidate the prognosis of this entity.

Aged↗

PubMed1983

Manifestation and ultrastructural typing of amyloid deposits in the heart.

Using light and electron microscopy, 65 cases of amyloid deposits in the heart were examined. Five different groups were distinguished: I. isolated atrial amyloidosis, II. senile cardiac amyloidosis, III. cardiac amyloid accompanying chronic infections and tumors, IV. cardiac amyloid accompanying plasma cell dyscrasia, V. idiopathic cardiac amyloidosis. Seen structurally, no principal differences in the precise localization of the amyloid deposits were found in any of the groups investigated. Amyloid is always deposited in the vicinity of cells with myocytic cell differentiation (i.e. the heart muscle cells, non-striated muscle cells of the vessels), whereby the relevant basement membranes serve as conductors. A systematic relationship between amyloid and the collagenous fibers of the interstitium or the tunica adventitia of the vessels could not be demonstrated, which shows the concept "pericollagen" to be inadequate for the morphological characterization of amyloid deposits in the heart. Whereas for group I a localized mechanism for the production of amyloid must be considered, in the case of groups II-V a vascular principle expression of a generalized amyloidosis seems to be the major factor. The question of the differing concentration of amyloid deposits in the heart suggests that localized factors (e.g. changes in the myocytic basement membranes) and quantitative changes of the amyloid-building proteins may also be important.

Adolescent↗