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R Yanagawa

Publications and source records attributed to R Yanagawa.

At least 91 records · Page 5Linked to original sources
PubMed1982

Antigenic variants of leptospiras detected in peritoneal cavity in early stage of infection in immunized guinea pigs.

Antigenic variants were detected firstly 7 h following intraperitoneal challenge with Leptospira interrogans serovar copenhageni Shibaura in the peritoneal cavity of guinea pigs which had been previously immunized with the homologous strain. The variants appeared at a rate of 63% of the leptospiras which survived in the peritoneal cavity, and the survivors' rate was 0.00005% of the inoculated organisms. The antigenicity of these variants reversed to that of the parent after 3-5 passages in liquid normal serum medium.

Animals↗
PubMed1982

Production and characterization of monoclonal antibodies to lipopolysaccharide antigen of Leptospira interrogans serovar kremastos and canicola.

Monoclonal antibodies to Leptospira interrogans were provided by cell fusions between a myeloma cell line, P3/X63-Ag8.653, and spleen cells of BALB/c mice immunized with two different leptospiral lipopolysaccharide antigens. One antigen was prepared from Leptospira interrogans serovar kremastos strain Kyoto and the other from serovar canicola strain Hond Utrecht IV. Eighteen hybridoma cell lines secreting monoclonal antibodies to the former organisms and five hybridoma cell lines secreting monoclonal antibodies to the latter organisms were established during 6 month cultivation. On the basis of their microscopic agglutination reactivities, 18 anti-kremastos Kyoto monoclonal antibodies were classified into 10 distinct groups, and 5 anti-canicola monoclonal antibodies into 3 distinct groups.

Agglutination Tests↗
PubMed1982

Presence of Vi antigen in a virulent strain of leptospira interrogans serovar pomona and relation of Vi antigens of leptospiras to resistance to leptospiricidal activity mediated by antiserum plus complement.

Vi antigen was found in a virulent strain of Leptospira interrogans serovar pomona. The presence of Vi antigen was shown by the agglutinin-absorption and precipitin-absorption tests. Each strain of pomona and copenhageni which possessed Vi antigen and was resistant to the leptospiricidal activity mediated by the antiserum plus complement lost Vi antigen and became susceptible to the leptospiricidal activity when cultured in the presence of 8-azaguanine. The strains thus treated with 8-azaguanine recovered the resistance and Vi antigen when cultured in medium without 8-azaguanine.

Antigens, Bacterial↗
PubMed1981

Growth of avian and human influenza viruses in organ cultures of duck and chicken colons.

Colons from ducks and chicken 1, 7, 14 and 28 days old maintained near-normal morphology up to 48 and 96 hours respectively in a system using NCTC135 medium (a part) + Dulbecco's modified Eagle's medium (9 parts ), at 37 degrees C and 95 per cent O2/5 per cent CO2. In the colon of 1 and 28 day-old ducks, duck influenza virus (Hav7N2) and budgerigar influenza virus (Hav4Nav1) grew to peak titer by hour 72, whereas human influenza virus (H3N2) did not grow. In the colon of 1 day-old chicken, the three viruses grew in the order of first duck virus, then budgerigar virus and then human virus, but in the colon of 28 day-old chicken, the growth of human virus was much less. Specific fluorescence was demonstrated in the mucosal epithelium of the colon of ducks and chicken, and intensity of fluorescence correlated with virus yield. THe fact that the avian and not the human influenza viruses showed good growth in the duck colons coincided with the fact that influenza viruses possessing avian hemagglutinin subtypes have frequently been isolated in nature from duck intestines.

Animals↗
PubMed1981

Classification of avian paramyxoviruses by immunodiffusion on the basis of antigenic specificity of their M protein antigens.

Seventeen avian paramyxoviruses consisting of ten reference strains and seven recent isolates were classified by immunodiffusion into six species on the basis of the antigenic specificity of their M protein (MP) antigens. The species were represented by the following viruses. (1) Newcastle disease virus, (2) Chicken/California/Yucaipa/56, (3) Turkey/Wisconsin/68, (4) Duck/Mississippi/75, (5) Pigeon/Otaru/76 and (6) Budgerigar/Kunitachi/1/74. The differences in the HN antigens between viruses which were classified into the same species on the basis of the antigenic specificity of their MP antigens, may provide a basis for classifying them into types.

Antigens, Viral↗
PubMed1981

Isolation of antigenically active components from leptospiral serovar-specific lipopolysaccharide antigen by alkaline treatment.

The serovar-specific main antigen (TM antigen) of Leptospira interrogans serovar canicola, which as lipopolysaccharide properties, was treated with 0.1 N sodium hydroxide. This treatment degraded the antigen into two major antigenic components, one of high and one of low molecular weight. The component with the lower molecular weight (approximately 4,000 daltons) consisted mainly of carbohydrates, having lost almost all of the fatty acid and protein components of the original antigen. Although the substance lacked immunoprecipitable activity, it continued to show serovar-specific inhibitory potency in a radioimmunoassay system as well as in a microscopic immunoagglutination reaction of the organisms. The antigenic activity of the compound was also reduced by periodate oxidation as was that of the TM antigen. A component with the same chemical and physicochemical properties was also produced by alkaline treatment from a different serotype TM antigen (serovar kremastos Kyoto), but it showed no antigenic activity.

Bacterial Proteins↗
PubMed1981

Unstable antigenic variation of leptospiras.

The antigenic variants which were found in leptospiras, Leptospira interrogans serovar copenhageni Shibaura grown in a liquid medium containing a homologous antiserum were found to be unstable. The unstable variants showed decreased agglutinability against the homologous antiserum. The decreased agglutinability of the unstable variants reverted to the parent's level of agglutinability after 1 or 2 passages through the normal serum medium. The unstable variants differed antigenically from the parent in the agglutinin-absorption test; however, the agglutinin-absorption test was found to be inadequate for showing the antigenic difference between the parent and the unstable variants because their difference was diminished when the agglutinin-absorbed antigen was increased. The application of Laurell rocket immunoelectrophoresis (LRI) to the SDS-extracted antigens revealed the distinct difference between the parent and the unstable variants. Other findings presented herein indicated the difference between the antigens of the parent and the unstable variants to be one of quantity. The magnitude of the quantitative difference between the antigens could be modified by the medium containing various concentrations of the homologous antiserum. The clones of the unstable variant showed antigenic characteristics which were similar to the original unstable variant.

Agglutination Tests↗
PubMed1981

Inhibition of Leptospiricidal reaction by the type-specific main antigen of Leptospira.

The serovar-specificity of the leptospiricidal activity test mediated by antiserum and complement was demonstrated by the fact that the leptospiricidal activity of the antiserum against the serovar-specific main (TM) antigen of copenhageni shibaura and the antiserum against the whole cells of the same strain were inhibited by the homologous but not the heterologous TM antigens. The inoculation of TM antigen produced in a rabbit the antibodies which react in the leptospiricidal activity test. These results may also show that the substance which participates in the leptospiricidal activity test may be the TM antigen.

Animals↗
PubMed1981

Comparison of the effects of a multi-component vaccine and a formalin-killed cell vaccine on protection against enzootic of hemorrhagic pneumonia due to Pseudomonas aeruginosa in mink.

Effectiveness of a multi-component vaccine consisting of the common antigen (OEP) derived from Pseudomonas aeruginosa strain N 10 (serotype E) and toxoids of protease and elastase was compared with that of formalin-killed cells of strain N 10 on protection against enzootic of hemorrhagic pneumonia due to P. aeruginosa in mink. One administration of the multi-component vaccine (100 microgram each of OEP, protease toxoid and elastase toxoid) clearly prevented enzootic of hemorrhagic pneumonia due to P. aeruginosa (serotype G) in mink, while a vaccination of formalin-killed cells was much less effective in preventing an epidemic. The difference in mortality rates between two vaccines was remarkable.

Animals↗
PubMed1981

Antigenic variants of leptospiras selected by antiserum-complement mediated-killing.

The presence of antigenic variants of leptospiras was confirmed by the leptospiricidal reaction mediated by the antiserum plus complement. More than 99% of the organisms of virulent L. copenhageni Shibaura were destroyed microscopically after treatment with the anti-L. copenhageni Shibaura antiserum (1: 2000) plus guinea pig complement (1: 20). The leptospiras which survived treatment with the antiserum plus complement produced colonies on the solid serum medium at a rate of 0.09%. Eighty-seven percent of the survivors were found to be antigenic variants. The antigenicity of these variants reversed to that of the parent after 3--5 passages in the liquid normal serum medium.

Animals↗
PubMed1981

Specificity of leptospiricidal activity test mediated by antiserum and complement.

A leptospiricidal activity test mediated by immune serum plus guinea pig complement using 11 serovars of leptospiras belonging to 3 serogroups, Icterohaemorrhagiae, Pomona and Mini, indicated that the reaction was generally serogroup-specific. The immune serum from which the homologous or heterologous agglutinin was absorbed was then examined with the result that the anti-L. icterohaemorrhagiae and anti-L. sarmin antisera which absorbed with L. icterohaemorrhagiae and L. sarmin respectively did not agglutinate, but instead destroyed their homologous leptospiras in conjunction with complement. Many of the antisera which absorbed with the heterologous serovars did not agglutinate, but instead destroyed their respective heterologous strain. These findings indicate that the leptospiricidal activity test is more sensitive and more cross reactive than agglutination.

Agglutination Tests↗
PubMed1981

Correlation of virulence, susceptibility to leptospiricidal activity test mediated by antiserum plus complement and colonial morphology of five lines of a strain of Leptospira interrogans serovar copenhageni.

Correlation of virulence, susceptibility to leptospiricidal activity test mediated by antiserum plus complement (LAT) and colonial morphology was investigated using five lines of Leptospira interrogans serovar copenhageni Shibaura. Line No. 2, a moderately virulent strain, passaged in guinea pigs for 24 successive times caused occasional death of guinea pigs. Leptospiras recovered from deceased animals were characterized by decreased susceptibility to LAT and predominance of hazy colonies upon culture. Leptospiras recovered from surviving guinea pigs were of increased susceptibility to LAT and grew predominantly in non-hazy colonies. Virulent line No. 1 subjected to passage through liquid medium for 20 successive times resulted in a slight decrease in virulence and slight increase in susceptibility to LAT, but the predominance of hazy colonies upon culture was invariable. The other three lines, Nos. 3, 4 and 5 which have been maintained for more than 10 years by passage through different media respectively, were avirulent, susceptible to LAT and produced only non-hazy colonies.

Animals↗
PubMed1981

Isolation of influenza A viruses from migratory waterfowls in San-in District, Western Japan in 1979-1980.

From December, 1979 to April, 1980, winter migratory waterfowls of some species staying in San-in District, western Japan were surveyed for influenza virus. A total of 27 influenza A viruses, 11 Hav1 Neq1 and 16 Hav6 Nav3, were isolated from 90 fecal specimens of whistling swans. A total of 13 influenza A viruses, 11 Hav1 Neq1 and one Hav6 Nav3, were isolated from 245 fecal samples of black-tailed gulls. Two viruses (Hav1 Neq1) were isolated from 40 tufted ducks. Sampling date, incidence and the antigenic subtype of the isolates were correlated.

Animals↗