Biomedical subjects

Y Moritsugu

Publications and source records attributed to Y Moritsugu.

9 recordsLinked to original sources

PubMed1979

Prevalence of antibody to hepatitis A virus in Sri Lanka.

Antibody to hepatitis A virus was studied by immune adherence hemagglutination using 287 serum specimens collected in 1975 by random sampling from healthy individuals living in Colomobo, Sri Lanka. The overall prevalence of antibody to the virus was 76.9% and the prevalence between males and females was approximately the same. The age-specific prevalence of the antibody indicated that hepatitis A in the area is mainly an infection during the early childhood.

Adolescent↗

PubMed1978

A preliminary serologic study of hepatitis A virus infection in Japan.

Ninety-eight acute non-B hepatitis cases recently observed in Japan and household contacts with these cases were subjected to serologic examinations for hepatitis A; 400 serum specimens obtained in 1971 from healthy individuals living in areas near Tokyo and 16 preparations of human immunoglobulin produced in Japan in 1975 and 1976 were examined for antibody to hepatitis A antigen. Hepatitis A virus infection was confirmed in all 25 patients and in 8 of 26 household contacts found in association with non-B hepatitis outbreaks, and also in 11 of 60 sporadic non-B hepatitis patients, but in none of 13 non-B hepatitis patients found in association with blood transfusion. There was no difference between males and females in the prevalence of antibody to hepatitis A antigen among healthy individuals, however, there was a strong relationship to age. Rates of antibody positives were only 2.5% in the groups younger than 20 years of age. An ample amount of antibody to hepatitis A antigen was detected in the preparations of human immunoglobulin. Hepatitis A virus was thus found to be endemic in Japan, but considered not popular during at least these 20 years. Infection with non-A non-B hepatitis virus(es) seems to be common in Japan especially in such cases as sporadic non-B hepatitis or post-transfusion non-B hepatitis.

Adolescent↗

PubMed1978

[Hepatitis A].

Explore the source record for details and available documents.

Animals↗

PubMed1977

Hepatitis B e antigen and infectivity of hepatitis B virus.

For confirmation of the difference in the infectivity of hepatitis B surface antigen (HBS Ag)-positive serum according to differences in the e antigen system, four chimpanzees were inoculated with serum positive for hepatitis B e antigen (HBe Ag), and three chimpanzees were inoculated with serum positive for antibody to HBe Ag (anti-HBe). Since the infectivity titrations are not yet completed, the end infectivity titer of each serum is not known. All four chimpanzees given injections of 10(-1), 10(-4), or 10(-8) dilutions of HBe Ag-positive serum developed hepatitis B virus infection, whereas the one chimpanzee injected with undiluted anti-HBe-positive serum became infected, and other chimpanzees injected with diluted anti-HBe-positive sera did not. As judged from the length of the incubation period before appearance of HBS Ag in blood, there seemed to be a remarkable difference in infectivity between the HBe Ag-positive serum and the anti-HBe-positive serum; the former serum was 10(8) times more infectious than the latter.

Animals↗

PubMed1976

Purification of hepatitis A antigen from feces and detection of antigen and antibody by immune adherence hemagglutination.

Hepatitis A antigen (HA Ag) was purified from feces collected during acute illness from patients with naturally occurring viral hepatitis, type A. Positive fecal specimens were identified by immune electron microscopy, but for detection of HA Agduring purification immune adherence hemagglutination (IAHA) and microtiter solid-phase radioimmunoassay were used. Isopycnic banding in cesium chloride, rate-zonal separation in sucrose, and preparative zonal electrophoresis were used in various combinations for successive purification, and the purified antigen was successfully used in a test for antibody by IAHA. Seronconversions to HA Ag were demonstrated by IAHA in 20 instances of hepatitis A virus infection, but in none of six cases of type B hepatitis or three cases of post-transfusion hepatitis unrelated to heaptitis A or B viruses, nor in two individuals without hepatitis. In addition, the temporal pattern of antibody development during type A hepatitis was studied in serial sera from an experimentally infected chimpanzee. Antibody titers by IAHA correlated well with antibody ratings determined by immune electron microscopy.

Antibodies, Viral↗

PubMed1976

Hepatitis B antigen-associated deoxyribonucleic acid polymerase activity and e antigen/anti-e system.

Serum samples of 403 asymptomatic blood donors carrying hepatitis B surface antigen (HB5Ag) were concentrated threefold and tested for e antigen and antibody to e antigen (anti-e) by immunodiffusion. Hepatitis B antigen (HBAg)-associated deoxyribonucleic acid (DNA) polymerase activity was specifically determined by the difference in incorporation of [methyl-3H]thymidine 5' -triphosphate into DNA by an aliquot of centrifuged serum samples after it had been treated either with normal rabbit serum or with rabbit antibody to HBSAg. All of 58 serum samples containing e antigen revealed HBAg-associated DNA polymerase activity, whereas none of 96 samples containing anti-e did. In the remaining 249 samples in which neither e antigen nor anti-e was found, 62 showed specific DNA polymerase activity, although at lower levels than the samples containing e antigen.

Antibodies, Viral↗

PubMed1976

A microtiter solid-phase radioimmunoassay for hepatitis A antigen and antibody.

A microtiter solid phase radioimmunoassy for hepatitis A antigen (HA Ag) and antibody (anti-HA) was developed. The test was more sensitive than immune adherence hemagglutination for detecting HA Ag and almost as sensitive for detecting anti-HA. The specificity and sensitivity of reagents were examined and optimum conditions for the test were determined. Radioimmunoassay, immune adherence hemagglutination, and immune electron microscopy were compared for detecting anti-HA. A serologic response to HA Ag was detected in paired sera from patients with type A hepatitis but not from patients with type B or non-A, non-B hepatitis by all three techniques.

Animals↗

PubMed1975

Clinical and serological analysis of transfusion-associated hepatitis.

Of 108 prospectively followed, multiply transfused, open-heart-surgery patients, 12 (11%) developed hepatitis. Patients received only volunteer donor blood tested for hepatitis-B surface antigen (HBsAg) prior to transfusion by counterelectrophoresis (C.E.P.). 4 of the 12 patients developed hepatitis-B-virus infection. Subsequent testing of donor serums by solid-phase radioimmunoassay (R.I.A.) revealed that an R.I.A.-positive, C.E.P.-negative blood unit was transfused to 3 of the 4 type-B hepatitis cases, but to none of the remaining 104 patients; 3 hepatitis-B cases could probably have been prevented by prescreening of donors by solid-phase R.I.A. 8 hepatitis cases were serologically unrelated to the hepatitis-B virus, the hepatitis-A virus, the cytomegalovirus, or the Epstein-Barr virus. Had R.I.A.-positive donors been excluded, 8 of the 9 residual hepatitis cases (89%) would have represented "non-A, non-B" hepatitis. The existence of previously unrecognised human hepatitis virus(es) is probable.

Adult↗

PubMed1975

Hepatitis B core antigen. Detection of antibody by radioimmunoprecipitation.

Radioactive cores were prepared from concentrated Dane particles by DNA polymerase reaction followed by CsCl density gradient centrifugation. Two radioactive peaks were obtained: one peak with an average density of 1.36 g/cm-3 in CsCl contained cores that possessed full serologic reactivity; the other peak, with a density of 1.28 to 1.32 g/cm-3, contained cores associated with globulin. A double antibody immunoprecipitation test was developed, using the radioactive heavy cores as a source of antigen. The test was at least 300 times as sensitive as complement fixation for detecting antibody to core.

Animals↗