PubMed Health⌕ Search

Biomedical subjects

N Watabe

Publications and source records attributed to N Watabe.

At least 37 records · Page 2Linked to original sources
PubMed1982

Histopathological effects of diflubenzuron on the cirripede crustacean, Balanus eburneus.

Histopathological studies on the cirripede crustacean, Balanus eburneus, at light and electron microscopic levels indicated that the chitin-inhibiting insecticide, diflubenzuron, caused similar disruption of the exoskeleton as observed in insects. Under the light microscope, globular particles were present within the chitinous layers of the cuticle, and these particles appeared electron dense and pleomorphic at the ultrastructural level. The cytoplasm of the cuticle-secreting epidermal cells appeared more dense and showed at least a five-fold increase in multivesicular bodies, which possessed electron dense cores. Barnacles exposed to diflubenzuron for 10 days or longer at 750 and 1,000 ppb were delayed in the premolt phase of cuticle secretion.

Animals↗
PubMed1982

Ultrastructural investigation of spicule formation in the gorgonian Leptogorgia virgulata (Lamarck) (Coelenterata: Gorgonacea).

Ultrastructural examination of original and regenerated branch tips of the gorgonian Leptogorgia virgulata reveals that spicule formation begins with the aggregation of Scleroblasts in the mesoglea. Calcite crystal deposition occurs within a Golgi vacuole containing organic matrix. Vacuole size increases while matrix incorporation and subsequent crystal growth continue, filling the vacuole. At approximately this time, the scleroblasts dissociate and "wart" formation begins. Further spicule growth stretches the cell into a thin envelope. Fusion of vacuole and plasma membrane followed by breach formation during spicule growth, as well as scleroblast atrophy or migration from mature spicules, result in the transition of the spicule from the intracellular to the extracellular environment. The results also reveal aborted spicules and digestive bodies, implying possible relationships among calcification, detoxification, and waste management.

Animals↗
PubMed1981

Gold nephropathy. Ultrastructural, fluorescent, and energy-dispersive x-ray microanalysis study.

The nephrotic syndrome developed in a patient receiving therapy with gold for rheumatoid arthritis. The results of a histopathological examination of the renal biopsy specimen were unremarkable. Immunofluorescent studies showed deposits of immunoglobulins and C3 in a granular pattern in the glomerular basement membranes. Ultrastructurally, the discrete osmiophilic immune complexes were epimembranous. By x-ray microanalysis, gold that was complexed with sulfur was present in proximal tubular cytoplasmic vacuoles and nuclei. Gold and sulfur could not be demonstrated in glomerular epimembranous deposits. The results of these studies suggest that immune complex deposition does not involve gold and sulfur acting as haptens. Gold-salt therapy may result in damage to proximal tubules that leak renal tubular antigens, which in turn complex with autoantibody and produce an autoimmune membranous nephropathy. The evidence for this mechanism is not convincing. Although the data indicate an immune-complex cause for gold-salt nephropathy, the incident antigen (or antigens) and mechanism of action remain unidentified.

Adult↗
PubMed1980

Studies on formation and resorption of fish scales. IV. Ultrastructure of developing scales in newly hatched fry of the sheepshead minnow, Cyprinodon variegatus (Atheriniformes: Cyprinodontidae).

Scale formation in Cyprinodon variegatus was found to be initiated at about 26 to 30 days after hatching. Ultrastructural investigation revealed that within 4 to 6 h in the first-formed scales the marginal cells begin to flatten and differentiate into osteogenic cells, which later change to osteoblasts and fibroblasts. These cells are separated from the surrounding epithelial cells by a basal lamina. The osteoid is formed by the marginal and osteogenic cells; the osseous layer by the osteoblasts; and the fibrillary plate by the fibroblasts. The osteoid is formed within 2 to 3 h after the initiation of the scale, and within 20 to 24 h the osseous layer is formed. Hydroxyapatite crystals are deposited in the matrix of the osseous layer without apparent association with collagen fibers. No matrix vesicles or dense bodies are evident at the sites of calcification. The fibrillary plate arises 18 to 20 h after the initiation of the scale. It is also partially calcified, but not before the third week of scale formation. The crystals develop almost exclusively between the collagen fibers at the extreme edge of the calcifying front, but solid calcification of the fibers results with futher growth of the crystals. The fibroblasts appear to participate in calcification of the fibrillary plate.

Animals↗
PubMed1980

Demonstration of IgG EA (early antigen) and IgM MA (membrane antigen) antibodies in CMV infection of healthy infants and in those with liver disease.

The sequence of antibody production to various virus-specific antigens in CMV infection in infancy was studied. In healthy infants, IgG EA antibody was demonstrated in 18% of cord sera, and disappeared within two months after birth in all cases not shedding virus. The nonmaternal EA antibody was produced following virus excretion and decreased rapidly following cessation of virus excretion. Thus, demonstration of EA antibody in infants after 2 months of age was found to indicate acquired CMV infection, even when CMV could not be isolated. IgM MA antibody did not persist as long as EA antibody, disappearing before cessation of virus excretion. Both IgG EA and IgM MA antibodies were more frequently demonstrated in infants with hepatitis than in healthy infants. These findings suggest the possible association of CMV with hepatitis in infants.

Antibodies, Viral↗
PubMed1979

Studies on the biology of fish bone. III. Ultrastructure of osteogenesis and resorption in osteocytic (cellular) and anosteocytic (acellular) bones.

The comparative ultrastructure of fish bone osteogenesis and resorption induced by scale removal was described in the osteocytic (cellular-boned) Carassius auratus and the anosteocytic (acellular-boned) Tilapia macrocephala. Osteocytes, present in osteocytic bone, were lacking in anosteocytic bone. In osteocytic bone the osteoblast secreted a collagenous preosseous matrix in which it became enmeshed and then was termed a preosteocyte. When the preosseous matrix mineralized, the preosteocyte was termed an osteocyte and was completely surrounded by bone. In anosteocytic bone the osteoblasts receded from the mineralizing front and never became trapped as osteocytes. During resorption, types A and B resorptive cells, present in both bone types, invaded the matrix and demineralized the osseous zone. These cells were characterized by large amounts of granular endoplasmic reticulum and intracellular inclusions containing crystal-like material. Although functionally similar to mammalian osteoclasts, these cells lacked a characteristic ruffled border and were not multinucleated. The osteocytes of cellular bone did not appear to be involved during demineralization.

Animals↗
PubMed1979

Studies on fish scale formation and resorption. III. Fine structure and calcification of the fibrillary plates of the scales in Carassius auratus (Cypriniformes: Cyprinidae).

Electron microscopic investigation of scales of the goldfish Carassius auratus revealed that the lamellae of fibrillary plates contain sheet-like structures composed of vertically oriented collagen fibers embedded in an organic matrix. The fibers (TC fibers) are smaller in diameter (35-45 nm) than those of the lamellae and the matrix is stained intensely with lead citrate. The sheet-like structures as well as the lamellae are formed by fibroblasts located beneath the lamellae. The orientation of collagen fibers of the sheets and the lamellae seems to be controlled by the orientation of the ridges and invaginations of the surface of the fibroblasts. The fibrillary plate of C. auratus was found to be partially calcified. Calcification was initiated by the deposition of needle-like or flaky crystals of hydroxyapatite in the organic matrix of the sheet-like structure and proceeded into the TC fibers and the matric region of the lamellae. The potassium pyroantimonate-osmium tetroxide method showed a heavy concentration of calcium in the osteoblasts, fibroblasts, and in the matrix regions of the fibrillary plate. Calcium-containing precipitates were also present in the "hole zone" of the collagen fibers in the lamellae, but the significance of this location in calcification remains to be elucidated.

Animals↗
PubMed1978

Roentgeno-histological studies on serial alveolography.

Using the lung obtained from a 22-year-old female at autopsy, roentgeno-histological studies were carried out on serial alveolography. The pulmonary lymphatics were shown to play an important role in the wash-out of the contrast media. The contrast media injected into the alveolus was gradually transferred on and into the alveolar wall and finally entered the subpleural space. Inflow of the contrast media was further noted into the portion probably representing the "juxta-alveolar lymphatic capillary" according to Lauweryns. Since local edema occurs artificially in serial alveolography, the functional aspects of fluid clearance may also be studied simultaneously unlike the conventional alveolography with its emphasis on morphological diagnosis.

Adult↗
PubMed1977

Serial alveolography-preliminary report.

Serial alveolography using a contrast medium for indirect lymphography was developed at our department. With this technique radiograms comparable to so-called barium-imbibed preparations of resected lung are possible. Furthermore, the procedure has the advantage of demonstrating serial radiographic changes as well as the local contrast medium wash-out or clearance, a local functional aspect of the lung, successively in a very short time. It is practical to accomplish simultaneous examinations in both morphological and functional (most probably concerned with the local pulmonary lymph) aspects with the new procedure. Significant differences in radiographic features have been demonstrated between the normal lung and chronic pulmonary emphysema or fibrotic pulmonary diseases.

Adult↗
PubMed1976

Calcified arteries in a gastropod.

The anterior aorta and major arteries of the land pulmonate snail Anguispira alternata have large calcium deposits in their walls. These deposits occur inside spherule cells, which line the walls of these vessels. The calcium occurs as amorphous calcium carbonate, in the form of intracellular spherules having alternating layers of organic and inorganic material. The spherule cells appear to be degenerating connective tissue cells; they are characterized by large numbers of spherules and by a cytoplasm which is totally empty except for a nucleus, scattered glycogen particles and a few membrane remnants. The injection of 45Ca into the foot of the snail results in rapid incorporation of this calcium into the spherule cells. Although calcium-containing spherules are now known from a wide variety of invertebrate tissues, they have not been previously recorded from arterial walls. The physiologic significance of these deposits is not known.

Animals↗
PubMed1976

Ultrastructural investigation of the mechanism of muscle attachment to the gastropod shell.

The ultrastructure of the muscle-shell attachment was investigated in the land pulmonate snails Helix aspersa, Anguispira alternata, in the freshwater pulmonate Laevipex sp., and in the freshwater prosobranch Pomacea paludosa. In all cases, a collagenous intercellular matrix and a specialized epithelium (tendon cells) intervene between the columellar muscle and the shell. These tendon cells are characterized by hemidesmosomes at both apical and basal ends, connected by thick bundles of microfilaments. The tendon cells do not insert into the shell directly by microvilli, as formerly thought, but by an extensive network of extracellular organic fibers.

Animals↗