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Biomedical subjects

S Moore

Publications and source records attributed to S Moore.

At least 37 records · Page 2Linked to original sources
PubMed1977

Ribonuclease inhibitor from human placenta. Purification and properties.

A soluble ribonuclease inhibitor from the human placenta has been purified 4000-fold by a combination of ion exchange and affinity chromatography. The inhibitor has been isolated in 45% yield (about 2 mg/placenta) as a protein that is homogeneous by sodium dodecyl sulfate-gel electrophoresis. In common with the inhibitors of pancreatic ribonuclease from other tissues that have been studied earlier, the placental inhibitor is an acidic protein of molecular weight near 50,000; it forms a 1:1 complex with bovine pancreatic RNase A and is a noncompetitive inhibitor of the pancreatic enzyme, with a Ki of 3 X 10(-10) M. The amino acid composition of the protein has been determined. The protein contains 30 half-cystine plus cysteine residues determined as cysteic acid after performic acid oxidation. At pH 8.6 the nondenatured protein alkylated with iodoacetic acid in the presence of free thiol has 8 free sulfhydryl groups. The inhibitor is irreversibly inactivated by sulfhydryl reagents and also by removal of free thiol from solutions of the protein. Inactivation by sulfhydryl reagents causes the dissociation of the RNase - inhibitor complex into active RNase and inactive inhibitor.

Amino Acids↗
PubMed1977

Pharmacological effects of introducing a double bond into a binding site of oxytocin. Analogues with L-3,4-dehydroproline in position 7.

The side chain of the proline residue in position 7 of oxytocin has been proposed as a binding site of the hormone for the uterotonic receptor. This is the first in a series of studies in which the possibility is explored that amino acid residues located at such sites and bearing unsaturated side chains may contribute more strongly to binding than neutral, aliphatic side chains. To test this hypothesis [7-(L-3,4-dehydroproline)]oxytocin, [1-beta-mecaptopropionic acid,7-(L-3,4-dehydroproline)]oxytocin, and [1-L-alpha-hydroxy-beta-mercaptopropionic acid,7-(L-3,4-dehydroproline)]oxytocin were prepared by the solid-phase technique of peptide synthesis. Some of the pharmacological properties of the analogues were determined, and the following specific activities, respectively, were found: rat uterotinic, 1071 +/- 59, 1066 +/- 95, 880 +/- 180; avian vasodepressor, 548 +/- 10, 1008 +/- 42, 1295 +/- 62; rat antidiuretic 5.9 +/- 0.2, 23.3 +/- 1.1, 76.7 +/- 2.3. All analogues possess a lower rat pressor activity than ocytocin. Compared to oxytocin, [7-(L-3,4,-dehydroproline)]oxytocin exhibits a parallel displacement of the cumulative uterotonic log dose vs. response curve toward lower concentration (pD2 = 9.26 vs. 8.63) but elicits the same maximum response. These data would seem to support the hypothesis that the introduction of unsatuation into binding element of a peptide hormone can enhance the affinity of the hormone for some of its receptors and thereby its selectivity.

Animals↗
PubMed1977

Explanation of the observation of pancreatic ribonuclease activity at pH 4.5.

A recent conclusion that beef pancreas contained a molecular species of ribonuclease with intrinsically high activity at pH 4.5 has been found to be incorrect. The particular assay used in the earlier experiments gives anomalous results at acid pH in the presence of low concentrations of ions such as phosphate which was used during the fractionation. By turning to the more widely employed form of the perchloric acid precipitation assay, interference is avoided and the ribonuclease in beef pancreas is confirmed as consisting almost completely of the molecular species well-characterized as ribonuclease A. The clarification of the assay question permits a clear interpretation of the results of each step of the chromatographic purification procedure that led to the initial conclusion, including an artifact that arose when gel filtration was attempted with distilled water rather than with buffer.

Animals↗
PubMed1977

A further example of human blood group chimaerism.

Blood group chimaerism was detected in a healthy fertile woman, not known to be a twin. Her peripheral lymphocytes had a male karyotype (46/XY); fibroblasts cultured from her skin had a female karyotype (46/XX). The mechanism of chimaerism could not be established.

ABO Blood-Group System↗
PubMed1977

Resolution of lipid-containing atherosclerotic lesions induced by injury.

In previous experiments, injury-induced atherosclerosis has been shown to be associated with the development of fatty streaks. The findings suggested that fatty streaks might represent a stage in healing of intimal injury evolving to fibrous plaques, free of lipid. The present experiment was designed to study the incidence and evolution of these lesions during a 2-week period of lesion retrogression following removal of a catheter placed in the aorta for 1 week. The findings indicate that as fat-containing lesions, either of the thromboatherosclerotic or fatty streak varieties, decreased, the amount of nonlipid-containing fibrous lesions increased.

Animals↗
PubMed1977

The effect of thrombocytopenia on experimental arteriosclerotic lesion formation in rabbits. Smooth muscle cell proliferation and re-endothelialization.

This study was designed to investigate the mechanisms involved in fibromusculoelastic lesion formation produced by selective de-endothelialization by the intra-arterial balloon catheter technique in thrombocytopenic rabbits. Thrombocytopenia was induced and maintained for up to 30 days by daily injections fo highly specific sheep anti-rabbit platelet sera (APS). Evidence for re-endothelialization was obtained by i.v. Evans blue dye 30 min before sacrifice. Rabbits received daily injections of APS, which reduced the mean platelet count to 5,600/cm3; control animals received identically treated normal sheep sera on the same schedule, and had mean daily platelet counts of 363,000/cm3. Evaluation of intimal thickness was assessed by counting cell layers in semithin sections. Intimal thickening in aortae from rabbits treated with APS was strikingly suppressed, in contrast to those from normal sheep sera-treated animals which showed a mean intimal thickness of 18 cell layers within 28 days often after de-endothelialization. Re-endothelialization was not affected by APS treatment. These results indicate that the proliferation of smooth muscle cells is dramatically inhibited by reduction of platelets.

Animals↗
PubMed1977

Dieldrin residues in soybeans in Illinois, 1965, 1966, 1967, 1971, and 1974.

The Illinois soybean crop was monitored in 1965, 1966, 1967, 1971, and 1974 for dieldrin residues resulting from aldrin applied to corn in the years before soybean cultivation. Residue levels of dieldrin in soybeans increased between 1965 and 1974. The percent of fields which had soybeans with a dieldrin level above 0.03 ppm increased between 1965 and 1974. Dieldrin residue levels in soybeans grown in Illinois are expected to decline now that the use of aldrin has diminished and will soon cease. No significant correlation was evident between the dieldrin levels in soybeans and the area of the State where they had grown, the date of planting, or the variety.

Acetonitriles↗
PubMed1977

Platelets, thrombosis and atherosclerosis.

The interaction of platelets with the vessel wall can contribute to the early stages in the development of atherosclerosis through effects on smooth muscle cell proliferation, endothelial permeability, and possibly by causing vessel wall injury. Platelets are involved in the development of thrombi in response to vessel injury, and the repeated formation of platelet emboli and platelet-fibrin emboli from the mural thrombi may be one of the factors that cause clinical complications of atherosclerosis. Drugs which inhibit platelet function, particularly those that prolong shortened platelet survival (sulfinpyrazone and dipyridamole) may prove to be important in inhibiting the response of blood to vessel injury and thereby modifying the extent of atherosclerosis and its complications.

Arteries↗