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Biomedical subjects

A M Rutenburg

Publications and source records attributed to A M Rutenburg.

At least 19 recordsLinked to original sources
PubMed1977

Adenylate cyclase activity in cultured epithelial cells.

The cyclic AMP metabolism of cultured epithelial cells was investigated. Epinephrine or 1-methyl,3-isobutylxanthine (MIX) alone had no effect on cyclic AMP levels in intact cells, whereas the combination of the two agents yielded a 6- to 10-fold increase in cyclic AMP levels. Both basal and stimulated cyclic AMP levels decreased with increasing cell density. Cell-free adenylate cyclase preparations were stimulated markedly by epinephrine or isoproterenol in the absence of MIX. Since the epithelial cells were found to have a relatively small amount of cyclic nucleotide phosphodiesterase (PDE) activity, the requirement for MIX to visualize intact cell responsiveness to epinephrine could be explained only partially by its PDE inhibitory properties.

2',3'-Cyclic-Nucleotide Phosphodiesterases↗
PubMed1976

Mechanical circulatory assistance with intra-aortic balloon counterpulsation for major abdominal surgery.

Intra-aortic balloon counterpulsation (IABC) provides effective mechanical circulatory assistance (MCA) in many patients with cardiac disease characterized by low cardiac output and/or myocardial ischemia. The intra-aortic balloon pump (IABP) has been used almost exclusively in the care of patients with cardiac disease as their primary medical disorder. This report presents use of the IABP in three cases where cardiac disease was present, but abdominal pathology necessitating urgent surgical intervention was the primary medical concern. Experience with these three cases suggest that operative and early postoperative use of IABC in patients with documented heart disease undergoing major non-cardiac surgical procedures may reduce the high incidence of cardiac complications.

Abdomen↗
PubMed1974

The role of adenosine 3':5'-cyclic monophosphate in the division of WI 38 cells. The cellular response to prostaglandin E1 and the effects of an cyclic adenosine 3':5'-cyclic monophosphate analogue and prostaglandin E1 on cell division.

Inhibition of growth and DNA synthesis was observed in WI 38 cells incubated with 8-methylthioadenosine 3':5'-cyclic monophosphate or prostaglandin E(1). The effect of both compounds on cell growth was reversible. On removal of these compounds from culture media the cells initiated DNA synthesis and divided. In addition, prostaglandin E(1) stimulated cyclic AMP formation in these cells to over 40 times the normal basal value. The increase in cyclic AMP concentration in WI 38 cells after addition of prostaglandin E(1) showed a marked variation. Cells that had recently been treated with trypsin and plated at a lower cell density exhibited a smaller response to addition of prostaglandin E(1) than cells that had divided and reached confluence.

Cell Division↗
PubMed1974

Relationship between chloramphenicol acetyltransferase activity and the number of resistance genes.

Various mutants of an Escherichia coli K-12 strain were prepared, in which a chloramphenicol (CM) resistance gene (cml) derived from an R factor, R100-1, was integrated into the chromosome. The CM acetyltransferase (CATase) activity of these strains and the strain carrying R100-1 were determined during exponential growth with the following results. (i) The CATase activity varied, depending upon the site of integration of the cml gene on the chromosome. Activity was found to be higher when the cml gene was integrated nearer the replication origin of the chromosome, the total enzyme activity found was the sum of activities coded by each gene separately. (iii) When the cml gene was in a cytoplasmic state on an R factor, R100-1, the expressed enzyme activity was four-to eightfold higher than that in the chromosomal state, suggesting the existence of about four to eight copies of R factor per chromosome. The CATase activity returned to the level of that expressed by R100-1 when the chromosomal cml gene was detached and picked up by an R factor.

Acetyltransferases↗