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Biomedical subjects

C Morita

Publications and source records attributed to C Morita.

At least 91 records · Page 5Linked to original sources
PubMed1987

Four serotypes of haemorrhagic fever with renal syndrome viruses identified by polyclonal and monoclonal antibodies.

Antigenic relationships among 20 strains of haemorrhagic fever with renal syndrome (HFRS) viruses isolated in Korea, China, U.S.S.R., Finland, Japan and U.S.A. were examined with rat immune sera, patient sera, eight monoclonal antibodies against the SR-11 strain and 10 monoclonal antibodies against the 76-118 strain. Antigen analyses by indirect immunofluorescent antibody and immune adherence haemagglutination tests using polyclonal and monoclonal antibodies demonstrated that HRFS viruses may be divided into four serotypes, i.e. Apodemus (Type 1), Rattus (Type 2), Clethrionomys (Type 3) and Microtus (Type 4). Further, it was demonstrated that Type 1 could be divided into three subtypes and Type 3 into two subtypes. The two sets of monoclonal antibodies were useful for identification of the antigenic types of viruses isolated from patients in endemic areas.

Animals↗
PubMed1985

Epidemiological study of hemorrhagic fever with renal syndrome related virus infection among urban rats in two islands in Tokyo Bay, Japan.

A seroepidemiological survey of hemorrhagic fever with renal syndrome (HFRS) virus infection in 403 urban rats (Rattus norvegicus) captured on two different islands in Tokyo Bay was carried out using the indirect immunofluorescent antibody (IFA) test with the SR-11 strain of HFRS virus. Antibody positive sera were detected in 99 out of 355 (27.9%) rats from the island with reclaimed ground area, but none were detected in 48 rats from the other islands. IFA titers of the positive sera varied from 16 to 4,096 (mostly 128) with a peak at 1 : 128, and antibody positive ratios were significantly higher in the small rats (less than 50 g, probably of younger age) than in the large ones. A causative agent antigenically related to HFRS virus was isolated from lung tissue of seropositive rat using Vero-E6 cells. These results revealed the existence of HFRS related virus among urban rats in the coast of Tokyo Bay, Japan.

Animals↗
PubMed1984

An immune adherence assay for discrimination between etiologic agents of hemorrhagic fever with renal syndrome.

Antigens of the viruses that cause hemorrhagic fever with renal syndrome (HFRS) and antibodies to these antigens were titrated in an immune adherence hemagglutination (IAHA) test and a CF test. Vero-E6 cells infected with the SR-11 strain of HFRS virus, an isolate from rats associated with a laboratory outbreak in Japan, and the 76-118 strain of Hantaan virus, the etiologic agent of Korean hemorrhagic fever, were used as antigens in the IAHA, CF, and indirect immunofluorescent antibody (IFA) tests. Sera from patients with different types of HFRS were tested against both strains of virus. Titers of antibody detected by the IFA test were similar for the two strains, but the IAHA test discriminated between antibodies to the two types of HFRS virus. Antigenic differences between HFRS viruses were suggested by the results of the IAHA test.

Animals↗
PubMed1984

Infectivity titration of hemorrhagic fever with renal syndrome virus: use of immune adherence hemagglutination for detection of virus growth.

Serial dilutions of hemorrhagic fever with renal syndrome viruses were inoculated into Vero-E6 cells in microplates. After 2 weeks of incubation, infected cells were disrupted by freezing and thawing, and virus antigens were detected by immune adherence hemagglutination. The infectivity titers of the virus as determined by this method were in close agreement with those obtained by the immunofluorescent antigen endpoint method. Then, a neutralization method was established. Japanese hemorrhagic fever with renal syndrome isolates, strains SR-11 and TR-352, were found to be distinct from Hantaan virus, strain 76-118, by the neutralization test.

Animals↗
PubMed1983

Isolation of virus causing hemorrhagic fever with renal syndrome (HFRS) through a cell culture system.

Twenty-three rat lung specimens collected in outbreaks of hemorrhagic fever with renal syndrome (HFRS) in three medical institutions were inoculated onto the VERO-E6 cell monolayers. After several blind passages, an agent growing serially in the cell cultures and reacting specifically with known HFRS-positive sera was isolated from two of these specimens. The two isolates were antigenically identical each other. The agent, named strain SR-11, was identified as the causative virus of HFRS by its antigenic identity with E6 cell-adapted HFRS virus, Hantaan 76-118 strain, and the specific reactions with sera from various HFRS cases.

Adolescent↗
PubMed1981

Transposon Tn3 encodes a site-specific recombination system: identification of essential sequences, genes, and actual site of recombination.

The bacterial transposon Tn3 encodes a site-specific recombination system. The recombination requires the product of tnpR, a gene previously identified as a repressor of the transposase. This recombination is site specific and takes place somewhere within the sequence C-G-A-A-A-T-A-T-T-A-T-A-A-A-T-T-A-T-C but requires at least one additional sequence outside this. The phenotype of mutations in this recombination system suggests that transposition proceeds by a mechanism in which cointegrates are intermediates.

Base Sequence↗
PubMed1980

Colonization and pathogenicity of Saccharomyces cerevisiae, MC16, in mice and cynomolgus monkeys after oral and intravenous administration.

Saccharomyces cerevisiae, an ascomycetous yeast and a candidate for a host-vector system in recombinant DNA experiments, was examined for its pathogenicity and colonization in mice and cynomolgus monkeys as the models of the biological containment level. Adult mice given perorally with 5.5 or 2.4X10(7) cells of MC16 strain S. cerevisiae excluded them rapidly and no colonization of the cells in the abdominal organs, lymph nodes or gastrointestinal wall was demonstrated. No change in the fecal flora was observed. Cynomolgus monkeys after peroral administration of 4.9X10(7) or 7.8X10(8) cells showed a similar tendency of rapid exclusion and the lack of colonization. Cortisone acetate treatment had no significant effect. Intravenous administration of 3.9X10(7) yeast cells had no pathogenic effect and no viable yeast cell was detected in the blood. The biological containment level of S. cerevisiae was suggested to be not lower than that of E. coli K12 B1 level, and the possibility of achieving the B2 level was also suggested.

Administration, Oral↗