T Muraguchi

Kyoto University, Kioto, Kyōto, Japan

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Publications (10)17.28 Total impact

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    ABSTRACT: In anti-red blood cell autoantibody transgenic (autoAb Tg) mice almost all B cells are deleted except for B-1 cells in the peritoneal cavity and the gut. About one-half of the auto Ab Tg mice suffer from autoimmune hemolytic anemia (AIHA) in the conventional condition. Oral administration of lipopolysaccharides activates B-1 cells and induces autoimmune symptoms in the Tg mice, suggesting that the autoimmune disease in anti-RBC autoAb Tg mice is triggered by infections. To examine the association of bacterial infections with the generation of B-1 cells and the occurrence of the autoimmune disease, we analyzed anti-RBC autoAb Tg mice bred in germ-free and specific pathogen-free conditions. In germ-free conditions, few peritoneal B-1 cells were detected, while a significant number of peritoneal B-1 cells existed in specific pathogen-free conditions. In both conditions, no mice suffered from AIHA. However, when these Tg mice were transferred to the conventional condition or injected with lipopolysaccharide, peritoneal B-1 cells expanded and some of these mice suffered from AIHA. These results clearly showed that bacterial infections are responsible for both the expansion of B-1 cells and the onset of the autoimmune disease in these Tg mice.
    Journal of Experimental Medicine 03/1997; 185(4):791-4. · 13.21 Impact Factor
  • T Serikawa, K Kitada, T Muraguchi, J Yamada
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    ABSTRACT: To determine the frequency of Pneumocystis carinii infection in mouse colonies maintained for biomedical research in medical colleges or medical faculties in universities in Japan, 409 nu/nu mice were sent to 43 animal facilities from a P. carinii-free colony. The animals were housed for 6 months in groups of 3 to 10 animals per room, and examined for the presence of parasites and infection. Colonies in 10 (24.4%) of 41 facilities were positive for the infection. Of 383 animals in 69 rooms, the organism was detected in 66 (17.2%) animals in 13 (18.8%) rooms. The difference in the proportion of rooms where mice were positive for P. carinii is clearly seen among these three groups; SPF mouse rooms (4 of 38 rooms, 10.5%), SPF mouse rooms with breeding units (5 of 25 rooms, 20.0%) and conventional mouse rooms (4 of 6 rooms, 66.7%). The survey indicates that strict housing arrangements and husbandry techniques are necessary to keep SPF mice free from P. carinii infection.
    Laboratory animal science 11/1991; 41(5):411-4.
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    T Serikawa, S Iwaki, M Mori, T Muraguchi, J Yamada
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    ABSTRACT: A cell wall antigen of Brucella canis was purified by immunosorbent columns. The antigen contained two proteins of 30 and 28 kilodaltons and a polysaccharide exhibiting a 12-kilodalton band upon 12.5% sodium dodecyl sulfate-polyacrylamide gel electrophoresis. Antibody to the purified antigen, which specifically reacted with the polysaccharide, was used as the first coating antibody in an enzyme-linked immunosorbent assay (ELISA) for serological diagnosis of canine brucellosis. Dogs inoculated orally with live B. canis were positive and dogs from B. canis-free colonies were negative in the ELISA. Of 199 dogs from a brucellosis-contaminated area, 116 with negative titers in the tube agglutination test (TAT), using heat-inactivated whole B. canis cells as the antigen, were also negative in the ELISA. Seventy-eight of the dogs with questionable titers in the TAT were divided into two groups: 20 dogs that were positive in the ELISA and 58 that were negative. Of five dogs with positive titers in the TAT, three were positive in the ELISA and the gel immunodiffusion test (GD) with crude B. canis extract as the antigen and were also culture positive for B. canis. One dog was positive in the ELISA and GD but gave a negative culture result. Serum from the remaining dog, which was positive with high titer in the TAT but negative in the ELISA and in culture for B. canis, formed a spur precipitate with a homologous precipitate in the GD. These results indicate that the ELISA is a specific serological test for B. canis infection in dogs.
    Journal of Clinical Microbiology 06/1989; 27(5):837-42. · 4.07 Impact Factor
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    ABSTRACT: Orchitis, epididymitis and prostatitis have been reported in male dogs infected with Brucella canis (B. canis), but the pathogenesis of infertility in male dogs has not been clarified yet. We examined localization of B. canis in the tissue of infected male reproductive organs and production of autoantibody to spermatozoa in male dogs by immunofluorescence and unlabeled antibody peroxidase-antiperoxidase (PAP) methods and electron microscopy. B. canis were found in the cytoplasm of macrophages and epithelial cells in testis, epididymis and prostate. Particularly in the prostate, B. canis multiplied in the cytoplasm of epithelial cells and emerged in the glandular lumen with destroyed epithelial cells. Head-to-head agglutination of spermatozoa was found in the semen, urine and epididymal duct with varying degrees of intensity among the infected dogs. Appearance of the spermagglutination began following the detection of B. canis in urine and semen, suggesting invasion of the organisms in male reproductive organs. In the sera from the dogs orally inoculated with B. canis, (Ig M), Ig G and Ig A anti-spermantibodies were detected in parallel with the appearance of the serum spermagglutinating activity. The heads of agglutinated spermatozoa in the epididymal duct and semen were coated with Ig A antibody, which is considered to be anti-spermautoantibody locally produced. The target of these circulating and local antibodies was acrosome of the dog spermatozoa and spermatids. It seems probable that multiplication of B. canis in epithelial cells is the direct cause of damage to the infected cells, and the damage acts as a trigger of the production of autoantibody to spermatozoa.
    Developments in biological standardization 02/1984; 56:295-305.
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    T Serikawa, T Muraguchi, J Yamada, H Takada
    Nippon juigaku zasshi. The Japanese journal of veterinary science 09/1981; 43(4):469-90.
  • T Serikawa, T Muraguchi, J Yamada, H Takada
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    ABSTRACT: Six male dogs orally inoculated with 3.2 X 10(8) Brucella canis and 2 male dogs naturally infected with the organisms were examined weekly for the presence of the organisms in urine and blood as well as for agglutinin titers in serum. Excretion of the organisms into urine started on 1 to 3 weeks after onset of bacteremia, i.e. 4 to 8 weeks after inoculation, and lasted for about 1 to 1.5 years. Non-bacteremic intervals, intermittent or lasting for about 1 to 6 months, followed the initial period of abundant excretion of viable organisms in urine. The highest urinary concentrations of the organisms, 2.5 X 10(4) to 1.5 X 10(6) cells per ml, were obtained in all dogs between the 6th and 14th weeks after the oral inoculation. Serum agglutinin titer rose on the 3rd to 5th weeks after the inoculation and then the titers remained at 1 : 640-1 : 2,560. The titers showed a downward trend over the 40 th to 56th weeks after the inoculation. In one of the spontaneously infected cases, the organisms were demonstrable only from urine for half a year with suspicious serum agglutinin titer of 1 : 160 after the bacteremic phase.
    Jikken dobutsu. Experimental animals 02/1981; 30(1):7-14.
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    T Serikawa, T Muraguchi
    Nippon juigaku zasshi. The Japanese journal of veterinary science 01/1980; 41(6):607-16.
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    T Serikawa, T Muraguchi, N Nakao, Y Irie
    Nippon juigaku zasshi. The Japanese journal of veterinary science 07/1978; 40(3):353-5.
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    T Serikawa, T Muraguchi, N Nakao
    Nippon juigaku zasshi. The Japanese journal of veterinary science 01/1978; 39(6):635-42.
  • T Serikawa, T Muraguchi, N Nakao, J Yamada
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    ABSTRACT: A micro-agglutination test method for detecting antibodies to Brucella canis was developed. Heat-killed Brucella canis antigens were diluted to an optical density of 0.8 at 420 nm using a spectrophotometer. A volume of 0.025 ml of the antigen was incubated with the same volume of serially diluted sera for 18 to 24 hr at 37 C. Titers of selected dog sera obtained by the present micro-test method were well correlated with those obtained by the classical tube test with satisfactory reproducibility. The micro-test method is more advantageous for screening the antibodies of dog sera because the test can be performed with: (1) smaller volume of the test sera and the antigen (2) shorter period for incubation, and (3) lesser labor.
    Jikken dobutsu. Experimental animals 05/1977; 26(2):139-41.