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Biomedical subjects

M Metz

Publications and source records attributed to M Metz.

6 recordsLinked to original sources
PubMed1988

Effect of EDRF release from freshly harvested endothelial cells on the coronary circulation of the isolated working rabbit heart.

Vascular relaxation in rabbit aortic preparations by acetylcholine is endothelium-dependent. Because of the short half-life of the endothelium-derived relaxing factor(s) (EDRF), a constant source of this material is necessary to study its effect in perfused hearts or hearts in situ (reported half-life 6-50 sec). To investigate the effect of EDRF(s) on the large coronary arteries and the resistance vessels of the isolated working rabbit heart, freshly harvested porcine endothelial cells were used. The cells were stimulated with acetylcholine to produce EDRF(s). To extend the half-life of EDRF, superoxide dismutase was added to the cell suspension. Left atrial infusion of these cells increased coronary flow and reduced total coronary resistance. No significant effect on the diameter of the endothelium-deprived obtuse marginal coronary artery was noted. The vasoconstrictor effect on resistance vessels of topically applied histamine was significantly reduced during the infusion of activated endothelial cells. It can be concluded that EDRF(s) released from freshly harvested endothelial cells increases coronary flow and diminishes total coronary vascular resistance in the working heart. In this preparation coronary arterioles are more sensitive to EDRF(s) than large coronary arteries. EDRF may contribute to the regulation of regional myocardial flow.

Acetylcholine↗
PubMed1985

Aminoglutethimide in advanced breast cancer: clinical results of a French multicenter randomized trial comparing 500 mg and 1 g/day.

We have conducted a multicenter randomized clinical trial comparing in advanced post-menopausal breast cancer patients 500 mg vs 1 g AG/day. The hydrocortisone dose was 40 mg/day in both groups. One hundred and seventy patients have been randomized; 161 were evaluable for tolerability, 149 for effectiveness. Response rates were similar in both groups, 19 and 24% respectively for the 500 mg and 1 g groups. No difference was observed according to tumor site. Duration of response was the same in both groups (14 months), as was mean time to response (about 3 months). Survival (studies in 125 patients) was similar in both groups (responders and non-responders). No response could be obtained with 1 g after relapse or failure with 500 mg (n = 17). Tolerability was good in 91% of the 500 mg group patients and 78% of the 1 g group patients (P less than 0.03). It was poor in 4 and 15% respectively (P less than 0.03). Side-effects were the same in both groups but less frequent and less severe in the 500 mg group; however, these patients more frequently had 'moon face'.

Aged↗
PubMedDate not supplied

Perfused rabbit heart: endothelium-derived relaxing factor in coronary arteries.

The study was performed to demonstrate the presence of the endothelium-derived relaxing factor (EDRF), previously found to be active in isolated artery preparations in vitro, in the coronary arteries of rabbits remaining in contact with the beating perfused heart. This was accomplished by following the response of the preconstricted obtuse marginal coronary artery to topically administered acetylcholine (ACH). Both intact arteries and arteries in which the endothelium had been removed were studied. Preconstriction of the obtuse marginal coronary artery was accomplished by topical application (spray) of histamine (10 microM), in 2 ml Krebs-Henseleit (KH) solution. This resulted in a decrease in internal diameter of the coronary artery, a decline in coronary flow, and an increase in total coronary vascular resistance. The principal difference between intact coronary arteries and those in which the endothelium had been removed was in the response to ACH. In arteries with intact endothelium preconstricted with histamine, topical administration (spray) of ACH (0.6 mM in 2 ml KH solution) caused, as compared with histamine, an increase in coronary flow, a significant decrease in total coronary vascular resistance, and a rise in internal vascular diameter. Arteries in which the vascular endothelium had been removed, as compared to those pretreated with histamine, responded to topical administration of ACH (0.6 mM in 2 ml KH solution) with a decrease in coronary flow, coronary vascular resistance, and internal vascular diameter. No change in the dose-response curve to histamine between the two preparations was noted. The results demonstrate that coronary vascular endothelium exerts a protective effect in coronary arteries remaining in contact with the perfused beating heart.

Acetylcholine↗
PubMedDate not supplied

Respiratory disease (rhinotracheitis) of turkeys in Brittany, France. III. Interaction of multiple infecting agents.

A candidate breeder flock of turkeys was studied during and after an outbreak of rhinotracheitis. Laboratory studies revealed the presence of three pathogens during the acute phase of the disease. These agents were hemorrhagic enteritis virus (HEV), paramyxovirus type 2 (PMV2), and chlamydia. Twenty-five turkeys in the flock were individually identified, and blood samples from these birds were collected for serological studies each week for 21 weeks. The serological results revealed high titers for HEV and chlamydia but very low titers for PMV2.

Animals↗