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Biomedical subjects

M Leclerc

Publications and source records attributed to M Leclerc.

At least 91 records · Page 5Linked to original sources
PubMed1978

Intramolecular energy transfer in molecules with a large number of conformations.

The equations representing the decay kinetics of fluorescence of a donor luminophore in the presence of an acceptor in the same flexible molecule are discussed. The assumption that distances between luminophores attached to chain ends are not correlated with the relative orientations of luminophores is tested by theoretical calculations for the unperturbed chains Tyr-(Ala)(n)-Tyr with n equal to 4 and 9. It appears that for these chains, in which the conformation is dominated by entropic factors, the above assumption is satisfactory even for chains with a small number of repeating units (n = 4).

Journal Article↗
PubMed1977

Reactions induced in vertebrates by invertebrate cell suspensions. I/Specific effects of sea star axial organ cells injection.

Starfish axial organ cell suspensions injected subcutaneously into irradiated mice induce a characteristic angiogenesis reaction. The size of the reaction appears to be dependent upon the number of injected starfish cells. Axial organ cells also provoke a splenomegaly positive test in 16 day old chick embryos. No significant angiogenesis nor splenomegaly were induced by heat killed axial organ cells, ovocytes or branchial digestive organ cells. These results support our hypothesis that echinoid axial organ represents an ancestral primary lymphoid organ.

Animals↗
PubMed1977

Reactions induced in vertebrates by invertebrate cell suspensions. II/Non adherent axial organ cells as effector cells.

In contrast to starfish axial organ cells, coelomocytes of Asterias rubens do not induce a significant reaction of angiogenesis after subcutaneous injection into irradiated mice. Axial organ cells are separated into adhering and nonadhering cells by attachment ot plastic surface. Nonadhering cells consisting mainly of small lymphocyte-like cells appear to be effector cells in the reaction. Phytogenetic implications of these observations are discussed.

Animals↗
PubMed1977

[Electrophoretic mobility of antithrombin III in an agarose gel with heparin. (author's transl)].

The electrophoretic mobility of several forms of antithrombin III in an agarose gel has been compared with the mobility in a gel containing heparin. When a serum was studied, three different compounds were observed. The inactige antithrombin III with higher molecular size, separated by gel filtration, was found to be homogenous even if there was heparin in the gel. A purified antithrombin III, prepared by affinity chromatography, contained an immunoreactive material of higher molecular size which has no activity and a higher mobility in agarose gel. When heparin is incorporated in the agarose plate, the electrophoretic mobility of this polymerized antithrombin III is not modified.

Antithrombins↗
PubMed1976

[Hemodynamic effects of intravenous injections of amiodarone chlorhydrate in normal subjects and coronary patients].

A study has been made of the haemodynamic affects of a single intravenous injection of amiodarone chorhydrate (5 mg/kg); the injection was given at rest to six normal subjects and six patients with coronary insufficiency due to atherosclerosis. The effects of the drug are most marked at the fifteenth minute after injection, and are: slowing of the heart rate; lessened cardiac output and left ventricular effort; a significant increase in mean pulmonary arterial pressure and diastolic pressure; slight variations in flow in the coronary sinus, with an increase in the ratio of coronary sinus flow to cardiac output. Amiodarone chlorhydrate appears to exert a favourable action upon the heart because, while it maintains myocardial perfusion, it tends to diminish the myocardial oxygen requirement by decreasing the rate of contraction and the contractility of the myocardium.

Adult↗
PubMed1975

Discontinued thrombolytic treatment: initial biological results.

Changes in blood coagulation following the action of intermittent treatment with streptokinase are studied : 1) Fibrinogenemia remains at a concentration slightly higher than that obtained after the first 16 hour perfusion. 2) The thrombin time becomes considerably longer on the first day, then becomes shorter and remains slightly long throughout treatment. The theoretical interest of the rise in plasminogen levels during interruption of perfusions of streptokinase is discussed.

Humans↗
PubMed1975

The N2 closing volume test in population studies: sources of variation and reproducibility.

Sources of variation in the nitrogen closing volume test and derived measurements were examined in the results of 13 subjects, each of whom performed 3 sequential trials on 2 occasions 30 to 60 minutes apart, on 2 separate days 1 week apart (156 trials in all). Results were examined to evaluate the relative sensitivity of the various measurements for differences between sujbects and, by implication, their potential value in population studies. Using the ratio of signal (between-subject variance) to noise (within-subject variance) as the criterion, the sensitivities of the ratio of closing volume to vital capacity (CV/VC,%) and the ratio of closing capacity to total lung capacity (CC/TLC,%) were comparable; contrary to expectation, sensitivity decreased rather than increased with side-by-side compared to independent tracing analysis. Comparison of various test schedules showed the greatest sensitivity when the mean of 3 measurements was used, with a single measurement of CV/VC,% being only one-third as sensitive, and a single measurement of CC/TLC,% being one-half as sensitive as the mean. In addition, the validity of the measurements of total lung capacity from nitrogen dilution in a single oxygen breath was confirmed by the demonstration of good agreement with helium dilution values.

Adult↗