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Biomedical subjects

A M Schultz

Publications and source records attributed to A M Schultz.

43 records · Page 3Linked to original sources
PubMed1979

Post-translational modification of Rauscher leukemia virus precursor polyproteins encoded by the gag gene.

Post-translational modifications of retrovirus gag gene-encoded polyproteins include proteolytic cleavage, phosphorylation, and glycosylation. To study the sequence of these events, we labeled JLS-V9 cells chronically infected with Rauscher murine leukemia virus in pulse-chase experiments with the radioactive precursors [35S]methionine, [14C]mannose, [3H]glucosamine, and [32P]phosphate. Newly synthesized gag polyproteins which incorporated label, and the modified products derived from them, were identified by immunoprecipitation of cell lysates with anti-p30 rabbit serum, followed by sodium dodecyl sulfate-polyacrylamide gel electrophoresis and autoradiography. Pulse-chase experiments were carried out in the presence as well as in the absence of tunicamycin, an inhibitor of glycosylation. Among the three major polyproteins synthesized in the absence of tunicamycin, two were found to be glycosylated but not phosphorylated. These were designated gPr80gag and gP94gag. Both shared identical [35S]methionine peptides with Pr65gag and p30. Of the two nonglycosylated precursors, Pr65gag and Pr75gag, only Pr65gag was found to be detectably phosphorylated, and Pr75gag could be readily identified only when glycosylation was inhibited. On the basis of these results, a scheme for the post-translational modification of gag polyproteins is proposed. According to this scheme the gag gene-encoded polyproteins are processed from a common precursor, Pr75gag, by two divergent pathways: one leading through the intermediate Pr65gag to internal virion components via cleavage and phosphorylation and the other via tunicamycin-sensitive mannosylation to the intermediate gPr80gag, which is further glycosylated to yield cell surface polyprotein gP94gag.

Genes, Viral↗
PubMed1975

Inhibition of the metabolism of amino sugars with 2-deoxy-2-(2-fluoroacetamido)-alpha-D-glucopyranose.

The metabolism of amino sugars in extracts of mouse cells was studied by the use of 2-acetamido-2-deoxy-alpha-D-glucopyranose, 2-acetamido-2-deoxy-alpha-D-manno-pyranose, and N-acetylneuraminic acid as tracers with or without added 0.5mM 2-deoxy-2-(2-fluoroacetamido)-alpha-D-glucopyranosyl pyrophosphate) and cytidine 5'-(N-acetylneuraminyl monophosphate) was inhibited by the fluoro sugar.

Acetamides↗
PubMedDate not supplied

Postdural puncture headache and back pain after spinal anesthesia with 27-gauge Quincke and 26-gauge Atraucan needles.

BACKGROUND AND OBJECTIVES: The purpose of this study was to determine whether the 26-gauge Atraucan needle shows any benefit on the incidence of postdural puncture headache (PDPH) and back pain as compared with the 27-gauge Quincke needle. METHODS: We investigated 388 patients, 171 men and 217 women, who were receiving spinal anesthesia for subumbilical surgery. We compared spinal anesthesia via the 27-gauge Quincke needle in 202 patients (group Q) and via the 26-gauge Atraucan needle in 186 patients (group A). RESULTS: The incidence of PDPH was 2.97% (6 of 202) in group Q and 2.69% (5 of 186) in group A. The incidence of back pain was 4.95% (10 of 202) in group Q and 5.91% (11 of 186) in group A. There was no statistically significant association of needle type, age, or sex with the incidence of PDPH and back pain. CONCLUSIONS: Both needles are associated with very low incidences of PDPH and back pain, which are not affected by which needle is chosen.

Adolescent↗