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Biomedical subjects

G Germain

Publications and source records attributed to G Germain.

51 records · Page 3Linked to original sources
PubMed1984

Electromyographical study of uterine activity in the human during labour induced by prostaglandin F2 alpha.

In full-term pregnant women, electrical and mechanical activity of the uterus was monitored throughout the course of labour promoted by intravenous infusion of Pg F2 alpha. The recorded potentials were mostly biphasic and characterized by their long duration ranging from 1 to 2s. A wide range of potential amplitudes (100 microV to 1.8 mV) was observed according to the various patients. Early at the beginning of labour induction, the electrical complexes firing at various uterine sites were proved to be in close relationship and also well correlated with the mechanical events. This feature remained unchanged during labour. Potential amplitudes also remained unchanged during the same period of time. Under these conditions, improvement of uterine coordination does not appear to be the mechanism by which the increase of uterine contractile strength, necessary to expel the fetus, is obtained at the end of gestation.

Action Potentials↗
PubMed1983

Conformational study of two polymorphs of spiperone: possible consequences on the interpretation of pharmacological activity.

A second polymorph of spiperone, 8-[3-(p-fluorobenzoyl)-propyl]-1-phenyl-1,3,8-triazaspiro[4,5] decan-4-one, has been isolated and characterized by thermal analysis and IR spectrometry. Its structure was solved by X-ray diffraction analysis. The results are compared with those previously obtained on spiperone, the main difference being in the conformation of the side chain and in the nature of the hydrogen bonding.

Butyrophenones↗
PubMed1983

Adenosine phosphorylase activity in mycoplasma-free growth media for mammalian cells.

Mammalian cells have enzymes that deaminate adenosine to inosine, which can readily be phosphorolysed to hypoxanthine. They do not, however, possess enzymes to form adenine by the cleavage of adenosine. For this reason, the release of adenine from adenosine by mammalian cell cultures has usually been interpreted as indicating the presence of mycoplasma, a frequent microbial contaminant that contains high levels of adenosine phosphorylase. We found that some human lymphoblast cultures free of mycoplasma showed high levels of adenosine cleavage and that this activity resulted from adenosine phosphorylase in the bovine serum used as the culture growth supplement. A survey of 13 serum supplements disclosed that fetal bovine serum (six lots) contains the highest adenosine phosphorylase activity, ranging from 9 to 648 nmol adenine produced per hour per ml serum; newborn calf serum (four lots) has much less activity, ranging from 0 to 5 nmol adenine produced per hour per ml serum; and donor horse serum (three lots) contains no detectable activity. These results suggest that mycoplasma tests dependent on the presence of adenosine phosphorylase or other enzyme activities may give false-positives with cultures containing fetal bovine serum supplements.

Adenosine↗
PubMed1982

Electrical activity of the pregnant uterus in the cynomolgus monkey.

Electromyographic activity in six pregnant cynomolgus monkeys was recorded in vivo by means of bipolar electrodes individually attached to the surface of the uterine corpus. These data were compared with recordings of intra-amniotic pressure obtained simultaneously by means of an open-ended, fluid-filled catheter placed in the amniotic cavity. During the last third of pregnancy, the electromyograms showed recurrent electrical complexes (trains of potentials, TOP) which lasted for about 2 minutes and whose rate of occurrence varied during the nyctohemeral period. The initiation of electrical activity in various uterine areas was always synchronous with and was related to mechanical contraction. The complex, polyphasic contractions that were observed can be explained, largely, by the variations of potentials within a train of potentials. However, a simple quantitative relationship between the mean frequency of the potentials within the TOP and the mean amplitude of the change in pressure could not be demonstrated. In contrast to data available on the woman, the increase in contractile strength at the onset of labor in the macaque appears to be due to a higher frequency of excitation of individual cells rather than the result of an improved functional coordination between the active muscular elements.

Action Potentials↗
PubMed1980

[Cervical muscular tissue in pregnant women and Macaca monkey females. Functional evaluation "in vivo" using an electrophysiological technique].

In vivo recordings of electrophysiological activity of the muscular tissue in the cervix, in both the pregnant human female and Macaca monkey, showed that most of the cervix did not present a measureable electrical activity. Only muscular tissue located in the peripheral, supra vaginal portion of the cervix, exhibited a noticeable propagated E.M.G. activity, which always originated in the fundus. This accords well with histological studies which demonstrate that this portion of the cervix is the richest in muscular tissue. It is however possible that the other muscular cells of the cervix have a role other than a contractile one, and may be responsible for synthetizing or catabolizing constituant parts of the cervical connective tissue.

Adult↗