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Biomedical subjects

R Yanagawa

Publications and source records attributed to R Yanagawa.

At least 109 records · Page 6Linked to original sources
PubMed1980

pH-dependent adhesion of piliated Corynebacterium renale to bovine bladder epithelial cells.

The adhesion of Corynebacterium renale 115 to bovine bladder epithelial cells was studied with two clones of the bacteria, piliated (P+) and nonpiliated (P-). The percentage of the cells with attached P+ bacteria was greater than that of the cells with attached P- bacteria, and the number of attached P+ bacteria was higher than that of the P- bacteria. The adhesion of P+ bacteria was found to be pH dependent, which was supported by the following facts: the number of attached bacteria was high at a pH above 7.6 and low at a pH below 6.8; the adhering P+ bacteria were eluted immediately after the pH was decreased from 7.4 to 6.4; and the P+ bacteria unattached at pH 6.4 adhered to the cells immediately after the pH was increased to pH 7.4. The adhesion of P+ bacteria was inhibited by anti-pilus antiserum. The adhesion was not inhibited by amino acids or sugars, including mannose, and was not influenced by Ca2+ and Mg2+. P- bacteria hardly attached to the epithelial cells, irrespective of the pH and other factors.

Amino Acids↗
PubMed1980

Duck influenza lacking evidence of disease signs and immune response.

Influenza viruses A/duck/Hokkaido/5/77 (Hav7N2), A/budgerigar/Hokkaido/1/77 (Hav4Nav1), A/Kumamoto/22/76 (H3N2), A/Aichi/2/68 (H3N2), and A/New Jersey/8/76 (Hsw1N1) were experimentally inoculated into Pekin ducks. Of these, the influenza viruses of duck and budgerigar origin replicated in the intestinal tract of the ducks. The infected ducks shed the virus in the feces to high titers, but did not show clinical signs of disease and scarcely produced detectable serum antibodies. Using immunofluorescent staining, we demonstrated that the target cells of the duck virus in ducks were the simple columnar epithelial cells which form crypts in the large intestines, especially in the colon. After primary infection, the birds resisted reinfection with the duck virus at least for 28 days, but from 46 days onward they were susceptible to reinfection. These infections were quickly restricted by a brisk secondary immune response, reflected in the rapid appearance of high titers of antibody after reinoculation. In contrat to the avian influenza viruses, the remaining three influenza viruses of human origin did not replicate in the intestinal tract but did cause a serum antibody response.

Animals↗
PubMed1980

Comparative studies on two antigens (F4 and TM) extracted from leptospires.

F4 and TM antigens extracted from Leptospira interrogans serovars pomona, icterohaemorrhagiae, and copenhageni were compared by immunodiffusion, by hemagglutination inhibition, and by selective absorption of antisera. These data, together with previous information on the serological specificities of the two antigen preparations, suggest that F4 and TM are different antigens.

Absorption↗
PubMed1980

Isolation of revertants from antigenic variants of leptospiras.

The revertants were isolated from the antigenic variants of Leptospira interrogans serovar copenhageni Shibaura by plating the variants on the solid medium containing the homologous immune serum, and by noting the growth of small colonies. The revertants which produced the small colonies were antigenically identical with the parents. The variants which retained their antigenicity for 2 to 3 years produced only a small number of revertants. On the other hand, the variants which phenotypically changed to the parent during the same period of maintenance produced many revertants. The revertant-clones and the variant-clones showed a similar generation time. No revertant was isolated from the variants of hebdomadis Hebdomadis.

Animals↗
PubMed1979

Experimental infection of mink with influenza A viruses. Brief report.

Mink were found to be susceptible to the intranasal inoculation of human, swine, equine and avian influenza A viruses. The viruses were recovered until the 7th post inoculation (p.i.) day from the respiratory tract. The inoculated mink showed antibody response against these viruses. Contact infection in mink with A/Kumamoto/22/77 (H3N2) was possible.

Animals↗
PubMed1979

Radioimmunoassay system using a serovar-specific lipopolysaccharide antigen of Leptospira.

The serovar-specific main (TM) antigen of Leptospira interrogans serovar kremastos strain Kyoto was labeled with sodium boro[3H]hydride after 1 h of oxidation with periodate. When 50 ng of the labeled compound was employed, 50% of the compound was bound to the antibodies contained in 7.5 x 10(-2) nl of anti-kremastos Kyoto serum. Under this condition, only 9 ng of the homologous TM antigen was required for 50% inhibition of serovar kremastos Kyoto 3H-TM antigen-anti-kremastos Kyoto serum binding, whereas 5,000 times as much TM antigen of serovar hebdomadis, which belongs to the same Hebdomadis serogroup as serovar kremastos, was required for the same inhibition. The TM antigens from serovars pomona, icterohaemorrhagiae, and copenhageni, which belong to different serogroups, showed no inhibition in an amount of up to 3 x 10(3), 2 x 10(5), and 2 x 10(5) ng, respectively. In the inhibition study using the serovar hebdomadis TM antigen, inhibition values slightly fluctuated due to the antigen's insolubility. When the TM antigens were solubilized with 0.1% sodium taurodeoxycholate, the fluctuation in inhibition values was minimized, and the cross-reactivity of the serovar hebdomadis TM antigen with anti-kremastos Kyoto serum was diminished, while the inhibitory activity of the serovar kremastos Kyoto TM antigen was enhanced.

Antibodies, Bacterial↗
PubMed1979

Protection against hemorrhagic pneumonia of mink by Pseudomonas aeruginosa multicomponent vaccine.

An attempt to prevent epidemics of hemorrhagic pneumonia in mink due to Pseudomonas aeruginosa was made in the course of epidemics with injection of the multicomponent vaccine consisting of common protective antigen (OEP) of P. aeruginosa mixed with toxoids of protease and elastase of the bacillus. Enzootics of hemorrhagic pneumonia, due to P. aeruginosa serotype 8, broke out from August to October 1977 in a total of 13 sheds of 3 farms (A, B and C) which were located in the northeast area of Hokkaido. These farms were raising 7,452, 2,553 and 10,639 mink respectively. The mortality rate of the mink on farms A, B and C were 11.8%, 13.0% and 1.0% respectively. The vaccination was performed on the 3 farms 5, 8 and 21 days after the onset of the disease. Inoculation of each mink with 200 micrograms or 100 micrograms of each of the three components of the multicomponent vaccine was effective in most of the male and female groups of mink. The period required for revealing the effect of the vaccination was very short, in some cases only a few days. Administration of the vaccine 21 days after the onset of the enzootic was also effective.

Animals↗
PubMed1979

Isolation of antigenic variants from leptospiras grown in vitro and from heart blood of guinea pigs inoculated with a clonized strain of Leptospira.

A clonized culture of Leptospira interrogans serovar copenhageni strain Shibaura (Cl-Shibaura) was inoculated into guinea pigs. The heart blood of the guinea pigs, obtained at the febrile stage and inoculated onto the solid serum medium containing the homologous immune serum, produced large and small colonies. The serological examinations revealed that the large colonies were found mainly to be the antigenic variants, while the small colonies were mostly the parent. The antigenic variants accounted for 16.4% of all the colonies from the blood of the guinea pigs infected with Cl-Shibaura, and for 1.2% of all the colonies from the blood of the guniea pigs infected with Cl-Shibaura, and for 1.2% of all the ll colonies. The serological examinations revealed that the large colonies were found mainly to be the antigenic variants, while the small colonies were mostly the parent. The antigenic variants accounted for 16.4% of all the colonies from the blood of the guniea pigs infected with Cl-Shibaura, and for 1.2% of all the colonies from the culture of Cl-Shibaura in the normal serum medium. Antigenic variants were also isolated in vitro from the culture of 2 other serovars. The fact that the frequency of the antigenic variants of leptospiras was higher in vivo than in vitro is discussed.

Animals↗
PubMed1979

Isolation of a new avian paramyxovirus from a rock pigeon (Columba livia).

A hemagglutinating agent identified as paramyxovirus was isolated from the respiratory organs of a rock pigeon captured in Hokkaido, Japan. The virus was serologically distinct from the known members of genus Paramyxovirus. Of the 160 pigeons collected in Hokkaido, 6 possessed the antibodies to the virus. The virus was designated as Paramyxovirus/pigeon/Otaru/76.

Animals↗
PubMed1978

Nature of antigenic determinant of serovar-specific antigen of Leptospira interrogans serovar hebdomadis.

The nondialyzable delipidized serovar-specific main antigen (NDTM antigen) of Leptospira interrogans serovar hebdomadis strain Hebdomadis (a variant which can grow in a synthetic medium) showed a strong inhibition of the complement fixation between the serovar-specific main (TM) antigen of this strain and the homologous antiserum. The inhibitory effect of the NDTM antigen was completely lost by treating the antigen with proteolytic enzymes, and the fractions of TM antigen containing amino sugar, neutral sugars, and lipids did not show any inhibition of complement fixation, indicating that the antigenic determinant of this strain is related to proteins. NDTM antigen contained more hydrophilic amino acids than hydrophobic amino acids, whereas TM antigen contained more hydrophobic amino acids than hydrophilic amino acids. The amino acid compositions of NDTM antigens of hebdomadis strain Hebdomadis (variant) and kremastos strain Kyoto, which belonged to the same serogroup, were considerably similar. Difference was found in the amounts of methionine, arginine, lysine and glutamine acid.

Amino Acids↗