Search PubMed⌕ Search

Biomedical subjects

M S Liu

Publications and source records attributed to M S Liu.

At least 127 records · Page 7Linked to original sources
PubMed1977

Perfluoroctylbromide as a diagnostic contrast medium in gastroenterography.

The efficacy and safety of perfluoroctylbromide as a diagnostic contrast medium for gastroenterography was studied in laboratory animals. It was found that perfluoroctylbromide possesses excellent coating properties and a short transit time in the gastrointestinal tract. The conscious animals tolerated 64 ml/kg without any toxic manifestations. Thorough hematologic, serologic and histologic examinations showed no evidence of any adverse effects. Perfluoroctylbromide may be especially useful in patients with advanced inflammatory lesions of the gastrointestinal tract or in those with risk of aspiration of contrast medium into the lungs during gastroenterographic examinations.

Alanine Transaminase↗
PubMed1977

In vitro effects of E. coli endotoxin on fatty acid and lactate oxidation in canine myocardium.

We studied the in vitro effect of E. coli endotoxin on the oxidation of palmitate, palmitoyl CoA, and lactate by canine heart homogenate. Heart homogenates were incubated in calcium-free Krebs-Ringer-phosphate buffer in the presence of a 14C-labeled substrate. Oxidation of the individual substrate was calculated from the rate of 14CO2 production. The rate of oxidation of palmitate, palmitoyl CoA, and lactate was proportionally inhibited by increasing amounts (80-800 microgram) of endotoxin. The decrease in substrate oxidation could be mimicked by adding calcium chloride to the tissue preparation, and could be effectively prevented by the chelating agent, EDTA. Ionic calcium was released from tissue stores during incubation of the tissue preparation with endotoxin. These findings demonstrate that E. coli endotoxin inhibits substrate oxidation by heart homogenates when incubated under in vitro conditions. The data also suggest that the inhibition may be mediated by ionic calcium released from the tissue in response to the action of endotoxin.

Animals↗
PubMed1975

Phosphatidate phosphohydrolase and palmitoyl coenzyme A hydrolase in cardiac subcellular fractions.

The characteristics of the two enzymes related to fatty acid esterifaction were studied in order to provide fundamental information leading to further understanding of the control of myocardial glyceride formation. Palmitoyl-CoA hydrolase and phosphatidate phosphohydrolase are both distributed unevenly among heart subcellular fractions. The activity of the latter enzyme in subcellular fractions changes independently in response to Mg2+ addition and in response to thyroid hormone treatment of animals.

Animals↗
PubMed1974

Characteristics of mitochondrial and microsonal monoacyl- and diacylglycerol 3-phosphate biosynthesis in rabbit heart.

Acylation of sn-glycerol 3-phosphate by heart subcellular fractions was characterized. The enzyme kinetics revealed that the rate of reaction of acylation by mitochondria was slower, but constant for a longer period (up to 20min), than that by the microsomal fraction. The range of palmitate, oleate and linoleate concentrations yielding optimal sn-glycerol 3-phosphate acylation was broader for mitochondria than for the microsomal fraction, the latter showing a preference for linoleate. The mitochondrial fraction synthesized a relatively large quantity of monoacyl-sn-glycerol 3-phosphate, reaching 135% of the microsomal biosynthesis during an assay period of 15min. By contrast, the microsomal fraction formed considerably more diacyl- than monoacyl-sn-glycerol 3-phosphate, except with linoleate as the acyl donor, in which case approximately equal quantities of the two products were produced. The biosynthesis of monoacyl-sn-glycerol 3-phosphate was also observed in experiments in which hepatic subcellular fractions were used to provide supporting evidence. Cardiac mitochondrial diacyl-sn-glycerol 3-phosphate formation was less than 17% of the microsomal formation. However, evidence is presented to exclude the possibility that monoacyl-sn-glycerol 3-phosphate in the mitochondrial fraction is formed by deacylation of the contaminating microsomal diacyl-sn-glycerol 3-phosphate. The participation of the dihydroxyacetone phosphate pathway in the biosynthesis of these substances was minimal. The addition of CTP and the fatty acid specificity of the reaction both provided results that reinforced the postulate that mitochondrial differs from microsomal acylation. Thus our findings demonstrate that the characteristics of acyl-CoA-sn-glycerol 3-phosphate O-acyltransferase (EC 2.3.1.15) in rabbit heart mitochondria are distinct from those of cardiac microsomal enzyme and hepatic enzymes.

Acylation↗