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Biomedical subjects

M S Halpern

Publications and source records attributed to M S Halpern.

At least 73 records · Page 4Linked to original sources
PubMed1976

Viral glycoprotein synthesis studies in an established line of Japanese quail embryo cells infected with the Bryan high-titer strain of Rous sarcoma virus.

Although a glycoprotein with an approximate molecular weight of 43,000 is associated with purified virions of the Bryan high-titer strain of Rous sarcoma virus propagated on R(-)Q cells, these virions lack gp85, the major glycoprotein of the avian tumor virus envelope. As measured by immune precipitation with a specific antiserum, gp85 does not accumulate to detectable levels in R(-)Q cells.

Animals↗
PubMed1976

Subunit structure of the glycoprotein complex of avian tumor virus.

Envelope glycoprotein of avian tumor virus is linked by disulfide bonds in a structure that we have designated VGP to stand for viral glycoprotein. VGP appears to contain one molecule of gp85 and one of gp37. Under nonreducing conditions, VGP is the only glycoprotein component that is stable in the presence of ionic detergent, although in the presence of nonionic detergent two or more VGPs are associated in discrete complexes. The disulfide bonds linking viral glycoprotein are formed before release of virus from infected cells.

Animals↗
PubMed1975

Expression of the Major Viral Glycoprotein of Avian Tumor Virus in Cells of chf(+) Chicken Embryos.

The expression of gp85, the major viral glycoprotein of avian tumor virus, by certain chicken embryonic cells was studied by the use of sera directed to antigenic determinants of subgroup E viral gp85. As analyzed by sodium dodecyl sulfate-polyacrylamide gel electrophoresis of immune precipitates prepared with lysates of cells that had been labeled with [(3)H]glucosamine, chf(+) chicken embryo cells synthesize molecules of gp85 which possess type and probably also group antigenic specificities. Under similar conditions of analysis, no gp85 or antigenically related components could be detected in lysates of chf(-) cells.

Journal Article↗
PubMed1975

Electrophysiologic and pharmacologic studies in a patient with acute myocardial infarction complicated by intraventricular and atrioventricular block.

A patient with an acute anterior wall myocardial infarction complicated by bilateral bundle branch block and paroxysmal AV block is presented. The following new, uncommon or unreported phenomena were documented: the simultaneous occurrence of phase-3 block in the right bundle branch and phase-4 block in the left bundle branch; the simultaneous occurrence of phase-4 block in both main bundle branches; phase-4 left posterior hemiblock associated with escape beats arising from the injured posterior division of the left bundle branch; supernormal conduction in the right bundle branck and 2:1 right bundle branch block related to supernormality. Most of these changes were, of course, not simultaneous, and their successive appearance was related to day-to-day and sometimes hour-to-hour variations in the degree and quality of the multifascicular injury caused by the infarct. In addition, the actions of several drugs upon automaticity and conduction were tested. The effects of amiodarone, lidocaine and isoproterenol were similar to those previously reported under comparable circumstances. At a moment when the patient had repeated episodes of paroxysmal AV block with severe Adams-Stokes seizures, the administration of a single i.v. dose of 0.25 mg of strophanthin suppressed totally the Adams-Stokes attacks through a significant enhancement of ventricular automaticity. If rapid implantation of an artifical pacemaker is not at hand, strophanthin may be life-saving in patients with acute paroxysmal AV block.

Amiodarone↗
PubMed1974

Isolation of the major viral glycoprotein and a putative precursor from cells transformed by avian sarcoma viruses.

Immune precipitation with a monospecific antiserum was employed to study the synthesis of the major viral glycoprotein gp85. Labeled gp85 was detectable by polyacrylamide gel electrophoresis of immune precipitates prepared from lysates of transformed cells which had been labeled for long term with radioactive amino acid or fucose. When immune precipitates were prepared from lysates of cells pulse-labeled with radioactive amino acid, the bulk of the precipitated counts did not appear in gp85 but in a heterogeneous protein fraction with a mean molecular weight of approximately 70,000; this fraction has been designated p70. If, however, the pulse label was followed by incubation of the cells in medium containing excess unlabeled amino acid, the bulk of the precipitated counts comigrated with gp85. Similar pulse-labeling experiments with radioactive fucose and glucosamine suggested that p70 represents incompletely glycosylated precursor to gp85.

Alpharetrovirus↗