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Biomedical subjects

S A Locarnini

Publications and source records attributed to S A Locarnini.

79 records · Page 5Linked to original sources

Purification of hepatitis A virus from human feces.

Hepatitis A virus was purified fecal specimens obtained from 2 patients with naturally acquired hepatitis A. The purification procedure involved differential centrifugation, organic solvent extraction, agarose gel filtration, ion-exchange chromatography, and isopycnic ultracentrifugation in cesium chloride. Using immune electron microscopy and discontinuous SDS-PAGE, this procedure was found to be effective in removing extraneous material from hepatitis A virus. There was significant recovery of virus as judged by immune electron microscopy and solid-phase radioimmunoassay. Using this protocol, it has been possible to obtain virus preparations of sufficient purity and high enough titer to enable biochemical studies to proceed.

Antigen-Antibody Reactions↗

The antibody response following hepatitis A infection.

A specific IgM response to hepatitis A virus was detected in sera from patients suffering acute hepatitis A infection. The presence of virus-specific IgM in 19S components of acute and early convalescent phase sera was detected by immune electron microscopy and solid-phase radioimmunoassay. The presence of virus-specific IgM in whole serum specimens was demonstrated by indirect immunoferritin labeling. Following acute infection, however, the major immunoglobulin response appears to be IgG, since titers of specific 7S and whole serum antibody were very similar.

Antibodies, Viral↗

A prospective study of acute viral hepatitis with particular reference to hepatitis A.

In order to investigate the relationship of hepatitis A antigen to viral hepatitis, a prospective study was carried out on 97 patients admitted to Fairfield Hospital, Melbourne, with suspected viral hepatitis, and 3 of their family contacts. Evidence of infection with hepatitis A virus was obtained by detecting hepatitis A antigen in stools, and/or antibody to it in sera, by immune electron microscopy. Infection with hepatitis B virus was determined by testing for hepatitis B surface antigen and antibody in serum, by solid phase radioimmunoassay. Sixteen patients were found to have diseases other than viral hepatitis and 2 patients (child contacts) suffered no illness. There was clinical and/or biochemical evidence compatible with viral hepatitis in 82 patients, of whom 35 were confirmed as having hepatitis A and 31 as having hepatitis B infections. In the remaining 16 patients there was no evidence of infection with either hepatitis A or B virus. It is possible that some of these patients may have been infected with viral agents as yet unidentified.

Acute Disease↗

Enterovirus type 71 infection in Melbourne.

Between November 1972 and May 1973, 60 strains of a new enterovirus were isolated from 49 patients investigated at Fairfield Hospital for Communicable Diseases, Melbourne. Of these patients 39 were admitted to hospital with aseptic meningitis (which was accompanied by a rash in 6), 5 others had rash alone, 4 had acute respiratory tract infections, and 1 had infective polyneuritis. A representative strain from this outbreak had the physicochemical properties of an enterovirus but could not be identified with antisera prepared against the prototype polio, coxsackie, and echo viruses. Studies, performed in association with the WHO Collaborating Centre for Virus Reference and Research, Houston, TX, USA, showed the outbreak to be due to enterovirus 71. Most of the epidemic strains required sodium deoxycholate treatment before neutralization could be demonstrated.

Adolescent↗