| Project/Area Number |
08670294
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| Research Category |
Grant-in-Aid for Scientific Research (C)
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| Allocation Type | Single-year Grants |
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| Section | 一般 |
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| Research Field |
寄生虫学(含医用動物学)
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| Research Institution | AICHI MEDICAL UNIVERSITY |
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Principal Investigator |
KADOSAKA Teruki FACULTY OF MEDICINE,AICHI MEDICAL UNIVERSITY,ASSISTANT PROFESSOR, 医学部, 助手 (90109760)
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| Project Period (FY) |
1996 – 1997
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| Project Status |
Completed (Fiscal Year 1997)
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| Budget Amount *help |
¥1,600,000 (Direct Cost: ¥1,600,000)
Fiscal Year 1997: ¥500,000 (Direct Cost: ¥500,000)
Fiscal Year 1996: ¥1,100,000 (Direct Cost: ¥1,100,000)
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| Keywords | Tsutsugamushi disease / salivary gland / Electron microscope / Orientia (Rickettsia) tsutsugamushi / Rickettsial membrane / Leptotrombidium pallidum / budding / Trombiculid mite / 小顆粒 / Orientia(Rickettsia)tsutsugamushi / Leptorombidium pallidum / Budding |
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| Research Abstract |
Scrub typhus or Tsutsugamushi disease is caused by the infection of Orientia tsutsugamushi which is transmitted to man by the bite of larval trombiculid mites infected with the rickettsia. The naturally infected with Orientia tsutsugamushi mite colony of L.pallidum derived from Apodemus spesiosus trapped in Aichi Prefecture, Japan. Only one naturally infected mite was applied to the inside of ear of each nude mouse. Therefore, O.tsutsugamushi was transmitted from naturally infected L.pallidum to the host on and after 6 hours. In the electron micrographs, secretory granules in the salivary gland cell of unfed L.pallidum larva were seen randomly distributed throughout the cytoplasma, and rickettsiae were found scattered among the granules. At 24 hrs after attachment, numerous secretory granules moved toward the apexes of the gland cells, and a large number of typical rickettsiae were observed at the bases of cells. A few rickettsiae could be seen just below the apical surface of the gland cell, and a rickettsia with a host cell membrane escape from the apical surface by budding was recongnized in the lumen. Rickettsiae in the process of escape from the gland cell were located at the free surface of the cell, where occassionally connected to the host cell by a stalk. It is suggested that the rickettsiae in the salivary gland cell migrate to the apical surface and escape from the salivary gland cells by budding through the apical surface. Many small vesicles with Orientia tsutsugamushi-like cell wall were also observed in cytoplasma and apical surface of salivary gland cells. These small vesicles probably escapes from apical surface of salivary gland cells by budding during feeding of larval trombiculid mites.
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