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Biomedical subjects

A Demoulin

Publications and source records attributed to A Demoulin.

At least 37 records · Page 2Linked to original sources
PubMed1986

Inhibin concentration in the culture media of human oocyte-cumulus-corona cell complexes is not related to subsequent embryo cleavage.

We have demonstrated an in vitro secretion of inhibin by human OCCC, not related to subsequent egg cleavage. A putative signal, released by OCCC, that could modulate inhibin secretion by granulosa cells has not been discovered. Inhibin secretion by OCCC has no predictive value concerning the further fertilization and cleavage of the oocytes.

Blastomeres↗
PubMed1986

Low doses of pulsed ultrasound and chromosomal abnormalities in male mouse germ cells.

Male mice were exposed to pulsed ultrasound (intensity less than 1 mW, frequency 3.5 MHz) for 30 min or to sham treatment. After 30 h, 11, 12 or 13 days, the testes were cytologically and histologically examined (using squash preparations, air-drying and sections). The resulting damage was studied at diakinesis-metaphase I and II, spermatogonial metaphase and anaphase. The investigation by air-drying did not show any significant increase in chromosome damage, 30 h, 11, 12 and 13 days after treatment (spermatogonial and spermatocytic metaphases). There was, however, a significant increase of the frequency of aneuploid cells detected at metaphase II. Investigations by squash techniques or sections did not reveal adverse effects on the spindles at spermatogonial and spermatocytic anaphases. We suggest that the reduction of fertility previously observed in our clinic could be explained by an increase of aneuploidy if germ cells are exposed to ultrasound during diakinesis of the first meiotic division.

Anaphase↗
PubMed1985

Release of immunoreactive oxytocin and neurophysin I by cultured luteinizing bovine granulosa cells.

We investigated the production of oxytocin (OT) and oxytocin-neurophysin (bNpI) by bovine granulosa cells cultured in presence of 10% foetal calf serum, a condition known to induce spontaneous luteinization of these cells. The production of immunoreactive OT was significantly higher in the cultures of granulosa cells harvested from large follicles than in those derived from small follicles. Chromatography on Sephadex G-25 showed similar elution sites of ovarian and synthetic OT, while high performance liquid chromatography revealed two peaks of OT-immunoreactivity, one of which (+/- 65% of the total immunoreactivity) coincided with synthetic OT. In another experiment, we could observe a gradual increase of OT, bNp I and progesterone production by granulosa cells derived from large follicles, in relation with the incubation time. The mean molar ratio OT: bNp I was 2.2 +/- 0.5 (SEM), and we found a significant positive correlation between the production of OT and bNp I (r = 0.77; P less than 0.01) and between the production of OT and progesterone (r = 0.80; P less than 0.01). Furthermore, the cellular OT and bNp I content of large follicles-derived granulosa cells before culture was 4-5 times lower than the total amount of OT and bNp I produced during a 72-h incubation, suggesting an active synthesis of these peptides. These data show that bovine granulosa cells are able to produce OT and bNp I, probably by an active biosynthesis as observed in the hypothalamo-neurohypophysial system and that the granulosa productions of OT, bNp I and progesterone are closely related.

Animals↗
PubMed1985

Influence of oral contraceptives and pregnancy on constituents of the kallikrein-kininogen system in plasma.

We measured kininogens of low and high molecular mass along with prokallikrein activity in plasma of women with a normal menstrual cycle. We observed no difference between results for the follicular and luteal phases. We assayed the same constituents in women who were taking oral contraceptives (combined estroprogestative) and found that activity of prokallikrein and concentrations of low- and high-molecular-mass kininogens were significantly increased. Lastly, we studied the components of the kallikrein-kininogen system during pregnancy. We also observed a marked increase in their concentrations in plasma, despite a decrease in total proteins. Specifically, prokallikrein and kininogens increase continuously with gestational age, reaching their maxima around the eighth month of pregnancy. At that time, more than 50% of observed results fall outside the normal reference interval. Our observations are even more striking when prokallikrein and kininogens are expressed in units per gram of total proteins, to account for the hemodilution. After delivery, the concentrations of prokallikrein and low- and high-molecular-mass kininogens decline promptly, returning to normal within three days.

Adult↗
PubMed1985

[Value of the measurement of SP1 protein in the early diagnosis of pregnancy induced with Pregnyl].

Successive dilutions of Pregnyl have been submitted to a radioimmunoassay of SP1. We have observed that Pregnyl cross-reacts with SP1. Chromatography of Pregnyl demonstrates that the contaminating substance is different from native SP1. As its concentration is low, it is however not detected in the serum of patients after the administration of exogenous Pregnyl. SP1 measurement can be helpful in detecting early pregnancies after hCG induction of ovulation.

Adult↗
PubMed1984

[Monitoring of follicular growth. Significance of echography].

Follicular growth and ovulation may be estimated by various techniques: basal body temperature charts, cervical score and vaginal smears examination, gonadal steroids or gonadotropin measurement and more recently, pelvic echography. Echographic monitoring permits the determination of the number and the size of ovarian follicles and the prediction of the time of ovulation. 1065 cycles of patients consulting in an artificial insemination with donor semen program have been analyzed. Follicular growth is superimposable in spontaneous and hMG-induced cycles, but clomiphene treatment leads to the formation of larger follicles. Only one dominant follicle (greater than or equal to 15 mm) is generally observed in spontaneous cycles; multiple dominant follicles are visualized in respectively 11,8 and 24,3% cycles treated with either hMG or clomiphene. These follicles are localized in only one ovary in half of the cases. Consecutive monitoring in several cycles shows that the ovaries do not alternate systematically. While this type of monitoring does permit a reduction in the number of straws used, it does not improve the success rate of artificial insemination.

Female↗
PubMed1984

[Religion confronting insemination].

The author attempts the difficult task of summarising the attitude of Catholicism, the Protestant religion, Jehovah's Witnesses, the Greek Orthodox and the Jewish Churches, as well as Islam, to artificial insemination, especially by donor. He discusses reasons for forbidding artificial insemination even from the husband because of onanism. He shows that the Protestant religion alone does not object to AIH and that its role as far as AID is flexible. As far as other religions AID is absolutely proscribed.

Belgium↗
PubMed1984

[The normal testis: structure, function and recent endocrinologic advances].

The embryology, the anatomy and the histology of the testis are briefly described. Then, the endocrinology of the organ is explained. Under the influence of pituitary LH, Leydig cells synthetize and release steroids that are principally testosterone. These act on the hypothalamo-pituitary axis, on the peripheral target organs and directly on the testis so as to control spermatogenesis and Sertoli cell function. Sertoli cells are implicated in spermatogenesis, steroidogenesis, and the synthesis of protein hormones and cybernin . Current knowledge about the antimullerian hormone, androgen binding protein, GnRH-like peptide, inhibin, testicular chalone, FSH receptor binding inhibitor and stimulator, PRL inhibiting substance and relaxin is reviewed.

Adult↗
PubMed1983

[Determination of substances inhibiting and stimulating the binding of FSH to its receptors].

We describe a method to estimate binding of human 125I-FSH to a preparation of bovine testicular receptors. Various experimental conditions are tested and the validity of the method is demonstrated. Using this method, the presence of biological substances modifying the FSH binding is measured in various fractions of ram retetestis fluid submitted to several steps of purification by chromatography. FSH receptor binding inhibitor (FSHRBI) activity is obtained in a low molecular weight fraction and FSH receptor binding stimulator activity in a larger one. These cybernin activities are isolated in fractions different from the ones observed with inhibin and GnRH like activities.

Animals↗