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Biomedical subjects

R Purcell

Publications and source records attributed to R Purcell.

28 records · Page 2Linked to original sources
PubMed1985

Genetic relatedness among human rotaviruses.

The genetic relatedness of 81 clinical rotavirus isolates to the human rotavirus prototype strains Wa (subgroup 2, serotype 1) and DS-1 (subgroup 1, serotype 2) was examined by RNA hybridization techniques. Labeled single-stranded (+) transcripts of Wa or DS-1 virus were incubated with denatured genomic rotaviral RNAs, and the resulting hybrids were subjected to gel electrophoresis and autoradiography. Nineteen of the specimens contained subgroup 1 rotavirus with a "short" RNA migration pattern. These viruses were found to be closely related to the DS-1 strain and were associated with illness of short duration. The remaining 62 isolates belonged to subgroup 2 and exhibited a "long" RNA migration pattern. Fifty-four of these isolates exhibited significant hybridization with the Wa strain probe. Four isolates yielded multiple hybrid bands with the Wa probe but also possessed at least one gene segment homologous to the DS-1 strain. The remaining four subgroup 2 rotaviruses did not exhibit significant homology in the form of labeled hybrid bands when tested with either the Wa or DS-1 probe. These findings suggest that most clinical rotavirus isolates belong to one of two human rotavirus "families" defined as Wa-like or DS-1-like. Our observations also suggest that reassortment occurs in vivo between rotaviruses belonging to the two human rotavirus "families" and that there are one or more additional families of human rotavirus.

Genes, Viral↗
PubMed1983

Complexes of hepatitis B surface antigen and immunoglobulin M in the sera of patients with hepatitis B virus infection.

Hepatitis B surface antigen (HBsAg) bound to immunoglobulin M (IgM) was detected in sera of HBsAg carriers by a radioimmunoassay based on selective absorption of the immunoglobulin on a solid phase coated with antiserum to human IgM. Isopycnic banding and rate-zonal sedimentation have shown that the reaction is related to particulate forms of the HBsAg complexed with IgM. The binding of IgM possibly occurred because of a selective affinity of these molecules to the surface of HBsAg particles. HBsAg/IgM was found transiently in 24 of 25 (96%) patients with acute self-limited hepatitis B and persistently in 6 of 25 patients whose acute hepatitis B progressed to chronicity. It was also found in 20 of 39 (51%) chronic HBsAg carriers with inactive and asymptomatic infection. The HBsAg/IgM phenomenon is not dependent on replication of hepatitis B virions; its persistence in patients with acute hepatitis B may provide complementary evidence of transition of the infection to chronicity.

Animals↗
PubMedDate not supplied

The natural history of liver disease in former drug users.

Three hundred and twenty drug-free former narcotic addicts were studied with regard to persistence of abnormalities of liver function and morphology, and their relation to hepatitis B infection. Hepatitis B antibody was present in 52.4 per cent, while HBs antigen was detected in only 6 per cent. Transaminase abnormalities, initially present in 39 per cent, were found in 22 per cent six months after cessation of drug abuse. Abnormalities tended to persist thereafter, although there was some continued return to normal levels. Liver biopsy findings of chronic persistent and aggressive hepatitis correlated with persistence of HBs antigenemia and transaminase elevation. Follow-up liver biopsies in seven subjects showed decreased inflammatory reaction in five. None showed progressive liver disease. We conclude that: (1) 15 to 20 per cent of former narcotics addicts have chronic persistent hepatitis or chronic aggressive hepatitis after cessation of drug absuse for six months or more; (2) serologic evidence of exposure to HBs antigen is frequent, and rapidly develops after the start of needle use; (3) although histologic ad chemical abnormalities usually persist, progression did not occur, and some individuals demonstrated spontaneous improvement.

Acute Disease↗