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T Nunoya

Publications and source records attributed to T Nunoya.

At least 19 recordsLinked to original sources
PubMed1992

Isolation and serial propagation of porcine epidemic diarrhea virus in cell cultures and partial characterization of the isolate.

Porcine epidemic diarrhea virus (PEDV) was isolated in Vero cell cultures from the small intestine of a piglet experimentally infected with porcine coronavirus 83P-5, that had been isolated during outbreaks of porcine acute diarrhea and passaged in piglets. The isolation of the PEDV was successful only in Vero cells maintained in the maintenance medium (MM) containing trypsin. Infected Vero cell cultures exhibited CPE characterized by cell-fusion and syncytial formation, as well as cytoplasmic fluorescence when examined by the indirect immunofluorescent test using rabbit anti-83P-5 virus serum. The isolate was adapted to serial propagation in Vero cell cultures by adding trypsin to MM. Vero cell-adapted PEDV was successfully propagated in the MA104, CPK and ESK cell lines in the presence of trypsin in MM. Vero cell-adapted PEDV had morphologic and physicochemical characteristics similar to those of other members of the coronaviridae. The isolate differed serologically from porcine transmissible gastroenteritis (TGE) and porcine hemagglutinating encephalomyelitis viruses, and no antigenic relationship between the isolate and TGE virus could be detected by the indirect immunofluorescent test. Attempts to isolate PEDV in 6 types of primary fetal pig cell cultures and 6 of 10 established cell lines resulted in the failure, probably because these cells were damaged by the action of trypsin.

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PubMed1991

Primary culture of chicken bursal plical epithelium.

Plical epithelial cells were obtained by trypsin-EDTA treatment of chicken bursa of Fabricius and cultured in the presence of type IV collagen. The culture became confluent six to seven days after seeding. The grown cells showed a positive reaction for cytokeratin by immunostaining and had ultrastructural characteristics of the epithelial cells in vivo. The cell culture will be useful for parasitological and virological studies.

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PubMed1990

Occurrence of a canine distemper-like disease in aquarium seals.

Outbreaks of a canine distemper-like acute disease brought high mortalities to seal populations in north-west Europe and Lake Baikal from late 1987 to 1988. During these outbreaks three seals which were introduced from Lake Baikal to an aquarium in Japan developed a distemper-like disease and other seals raised in the same room were similarly affected. Clinical signs of dead seals were anorexia, diphasic fever, dyspnea, and neuromuscular tics. Characteristic microscopic lesions of acute interstitial pneumonia seen in the lung were accompanied with hyperplasia and syncytial giant cell formation of type II pneumocytes. Eosinophilic intranuclear and cytoplasmic inclusion bodies were present in bronchial epithelial cells, type II pneumocytes, epithelial cells of bile ducts and interlobular ducts of pancreas, transitional epithelium of renal pelvis, and reticular cells of lymph nodes. Ultrastructure of inclusion bodies was similar to that seen in cells infected with morbilliviruses. Serum samples from recovered seals had virus-neutralization antibodies against canine distemper virus. The present cases were the first report of morbillivirus infection of aquarium seals in Japan.

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PubMed1988

Identification of B-L antigens on reticular epithelial cells of the bursa of Fabricius.

We have established two monoclonal antibodies against B-L antigens (chicken Ia-like antigens). The specificity of the antibodies for B-L antigens was determined by two criteria, the cellular expression and the molecular structure of antigens with which they reacted. They reacted with antigens expressed on bursacytes, Con A-blast thymocytes, macrophages, and MDCC MSB1, but not with thymocytes and erythrocytes. In molecular basis, they recognized 64,000 dalton glycoprotein consisting of two polypeptides, 35,000 and 32,000 dalton, which bound non-covalently. To investigate the distribution of B-L antigens on non-lymphoid cells of the bursa of Fabricius, which were thought to play important roles in the differentiation of B cells, anti-B-L antigen and anti-chicken immunoglobulin (Ig) monoclonal antibodies were used. B-L antigen-positive cells were detected in both cortical and medullary areas, whereas Ig-positive lymphoid cells were confined to the medullary areas of normal chicken bursal follicles. In the bursal follicles of cyclophosphamide (CY)-treated chickens, lymphoid cells were depleted but epithelial cells remained intact. And B-L antigen-positive but Ig-negative cells were easily detected in the medullary areas of almost all follicles. These cells were identified to be reticular epithelial cells (REp cells) from the result of their keratin expression.

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PubMed1987

Cytoplasmic crystalline inclusions in hepatocytes of a steer with shipping fever.

Needle-shaped crystalline inclusion bodies were found in vacuolated liver cells of a steer affected with pneumonic pasteurellosis. The inclusions were eosinophilic and refractive, and ranged in size from 3 to 6 microns long and from 150 to 250 nm wide. Histochemical examination revealed that they contained lipid and protein. Electron microscopic examination showed finely fibrillar or granular material. Cross-striations with a periodicity of 45 nm were seen in longitudinal section of the inclusions. The possible origin and pathogenic significance of the inclusions are discussed.

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PubMed1987

Decrease in catalase activity of cultured cells by Mycoplasma gallisepticum infection.

The effect of Mycoplasma gallisepticum infection on the host cell catalase activity was histochemically examined in cultured chicken embryo fibroblasts (CEF) and kidney cells. The activity in normal cells was detected as fine, brown granules in the cytoplasm, which appeared ultrastructurally to correspond to anucleoid microbodies. By infecting cultured cells with a CEF-passaged strain of M. gallisepticum, the catalase-positive granules clearly decreased in amount, whereas the UV light-killed mycoplasma and the original strain failed to decrease the granules. The cell-passaged strain was able to induce cytopathic effects and this appeared to be due to its enhanced adherent ability as compared with the original strain. These findings suggest that attachment of viable organisms to cells is crucial to decrease the catalase activity and that the decreased activity may be an important process for the subsequent development of cytopathic effects.

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PubMed1985

A new mutant strain of Syrian hamster with myelin deficiency.

A new disorder of central myelination was found in black mutant hamsters showing trembling. The condition was inherited in an autosomal recessive mode. Histologically, a marked myelin deficiency was distributed throughout the central nervous system (CNS), and it was closely related to clinical manifestations observed in the mutants Ultrastructurally, abnormally thin myelin sheaths were observed in all axons with different diameters, and most axons below 1 micron in diameter were unmyelinated in the white matter of the spinal cord. There was no overt evidence of demyelination, but some myelin sheaths showed an aberrant configuration. The numbers of glial cells were not reduced, and there were no striking morphological abnormalities in them. It was suggested that there may be a dysfunction of oligodendrocytes resulting in retarded or defective myelination. This trembling hamsters may be a suitable animal model for the study of normal and abnormal myelinogenesis.

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PubMed1979

An ultrastructural study on the interaction of Mycoplasma gallisepticum with the chicken tracheal epithelium.

Seven-day-old chickens wee intratracheally inoculated with Mycoplasma gallisepticum. The tracheas collected 6 and 14 days after chickens were inoculated were subjected to titration of mycoplasma and examination by light and electron microscopy. The mycoplasma organisms grew well; 10(7) to 10(8) color-changing units in a milligram of tissue were determined. Tracheal lesions occurred in close association with the presence of mycoplasmas and were characterized by degeneration of the epithelial cells and inflammatory cellular infiltration of the mucosa. Mycoplasmas were predominantly found extracellularly and only rarely in phagocytic vacuoles of the epithelial cells. Although the mycoplasmas exhibited considerable pleomorphism in size and shape, most of them were oval or round, and the largest diameters were between 300 and 700 mn. Elongated and irregular forms were also observed, particularly in those mycoplasmas adhering to the epithelial cells. The organism had a limiting unit membrane, the fibrillar nuclear area, the peripheral cytoplasmic area containing numerous ribosomes, and a terminal bleb structure. Mycoplasmas attached to the epithelial cells by their blebs close to the host cell membrane. At the attachment site, neither fusion of the membranes of the mycoplasma and host cell nor injury to the host cell membrane could be demonstrated. Nevertheless, seemingly, the intimate association between the adhering mycoplasmas and the epithelial cells might be an important factor in pathogenesis of the disease.

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