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T Yagihashi

Publications and source records attributed to T Yagihashi.

At least 37 records · Page 2Linked to original sources

Diversity in nicotinamide-adenine dinucleotide requirement for the growth of different strains of Mycoplasma synoviae.

The type strain WVU 1853 and field strains SG, N26 and A642 of Mycoplasma synoviae were examined for their requirement for nicotinamide-adenine dinucleotide (NAD) for in vitro growth. All the strains grew and could be repeatedly passaged in Frey broth medium supplemented with filter-sterilised NAD. In modified Frey broth medium from which NAD was omitted and broth medium for which the supplements including yeast extract and NAD were autoclaved, only strains N26 and A642 could be grown and passaged. The growth curves of strain N26 determined in broth media with and without NAD were similar. These results indicated that there are differences in NAD-requirement for in vitro growth among strains of M synoviae.

Animals↗

Isolation of ureaplasmas from poultry and experimental infection in chickens.

Ureaplasmas were isolated from the oropharynxes of 47 of 247 (19 per cent) Leghorn chickens (Gallus gallus domesticus) and from five Japanese bantams but none was isolated from the oropharynx or cloaca of other poultry comprising 10 Japanese game, 75 common quails (Coturnix coturnix japonica), 17 turkeys (Meleagris gallopavo) and 10 guinea fowls (Numida galeata). In apparently healthy chickens, ureaplasmas were found at various sites, including the conjunctiva, nasal cavity, oropharynx, upper and lower tracheas, but not from the air sac, lungs, yolk, oviduct, urine or cloaca. All the isolates were antigenically similar but had no serological relation to those isolated from man, monkey, cattle, goat, sheep, dog and cat. In chickens experimentally infected with an avian ureaplasma, the organisms infected the oropharynx and nasal cavity but none of the birds inoculated demonstrated any clinical signs or macroscopic lesions.

Animals↗

Capsular material of Mycoplasma gallisepticum and its possible relevance to the pathogenic process.

A ruthenium red-staining capsule was observed on two pathogenic strains, but not on one nonpathogenic strain of Mycoplasma gallisepticum. The capsule appeared to mediate cytadsorption of mycoplasmas to the chicken tracheal epithelium without evidence of membrane fusion. No relationship was seen between the presence of capsule and hemagglutination titers of the strains examined.

Adhesiveness↗

Interaction of Mycoplasma hyopneumoniae with the porcine respiratory epithelium as observed by electron microscopy.

An in vivo-passaged strain of Mycoplasma hyopneumoniae attained viability titers of 10(6) to 10(8) color-changing units per mg of tissue in pig lungs and caused gross and histological pulmonic lesions. Mycoplasmas were readily located in the lumina of the respiratory tract by electron microscopy. In sections of tissue fixed in glutaraldehyde-osmium, the organisms were found to possess many radial fibrils on the outer surface of the limiting membrane. These fibrils appeared to interconnect adjacent mycoplasmas and to extend between the organism and epithelial cell. Ruthenium red staining demonstrated a thick, dark layer of capsular material enveloping the entire mycoplasma cell. The capsular material was seen to bridge the space between the mycoplasma and host cell. The general morphology of the in vitro-passaged strains grown in broth medium was essentially similar to that of the in vivo-passaged strain. In these organisms, however, no long fibrils were seen, although a fuzzy layer was present outside the cell membrane. The ruthenium red-positive capsule was stained less intensely, and its width was only about one-half that observed for the in vivo-passaged strain. In negatively stained preparations, the cells had an outer fringe of amorphous material apparently corresponding to the fuzzy layer seen in thin sections. The in vitro-passaged strain grew poorly in pig lungs and lost its ability to produce gross pulmonic lesions. The organisms in the respiratory tract had a capsule much thinner than that of the in vivo-passaged strain.

Animals↗

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.

Animals↗

[Pheochromocytoma].

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Adrenal Gland Neoplasms↗

Comparison of immunity induced with a Mycoplasma gallisepticum bacterin between high- and low-responder lines of chickens.

Chickens of the high-responder line GSP and low-responder line BM-C, which had been known to have different antibody responses to Mycoplasma gallisepticum (MG) antigen, were immunized by intramuscular injection and by subsequent intratracheal instillation of MG bacterin. They were then challenged with the pathogenic strain SAS of MG. The preventive effects of local antibodies detectable in the trachea, saliva, and lacrima were compared between the two lines of chickens. The local antibody responses, as determined by an enzyme-linked immunosorbent assay, were higher in line GSP than in line BM-C before and after challenge. Following challenge, chickens of both lines were protected from colonization by MG and the development of respiratory lesions. The degree of protection in line GSP was higher than that of line BM-C. The results suggest that local antibodies may play an important role in the host defense mechanism to respiratory MG infection.

Animals↗