Biomedical subjects
Publications and source records attributed to L Cedard.
During the last two decades, the incidence of ectopic pregnancy was shown to be rising. At the same time, ectopic pregnancy became less lethal due to improvements in diagnostic procedures, which are now able to confirm the ectopic implantation before the occurrence of life-threatening hemorrhagic complications. Earlier diagnosis has also offered the possibility of conservative surgical and medical treatments.
The mechanism of action of RU 486 (Mifepristone), an antiprogesterone compound, on labor induction and on cervical maturation, is still not well documented. We have investigated the effect of RU 486, alone and in association with a cyclooxygenase inhibitor (Diclofenac) on the induction of preterm delivery and on concomitant changes in the distribution of cervical glycosaminoglycans (GAGs) in pregnant Wistar rats: a control group (n = 18), a RU 486 treated group (n = 36), and a RU 486 and Diclofenac treated group (n = 15). The results of this study confirm the ability of this antiprogesterone treatment to induce preterm delivery in the rat. This effect was antagonized by cyclooxygenase inhibition, suggesting that the action of RU 486 on labor induction could be mediated by prostaglandins. The absence of an increase in plasma prostaglandin E2 (PGE2) levels in RU 486 treated animals could be explained by local uterine changes in prostaglandin concentrations. Mifepristone also induced some of the biochemical features of cervical maturation (i.e. increased hydration and hyaluronic acid concentration). This effect was not inhibited in Diclofenac treated animals suggesting that factors other than prostaglandins play a role in this phenomenon.
The increasing frequency of EP and the need for its early diagnosis have focused our interest on the research of biochemical markers. We have established hormonal values in the plasma of 99 spontaneous ongoing pregnancies between the 4th and 10th weeks of amenorrhea, in 21 EPs, and 20 cases of early abortion. We have examined the predictive values of trophoblastic and CL production in pathological pregnancies. The association of low hCG and low active renin appears to be able to discriminate between ectopic and abortive spontaneous gestations.
In order to study the hormonal control mechanisms of cervical maturation, we investigated cyclooxygenase and 5-lipoxygenase inhibitors-induced changes in the distribution of glycosaminoglycans (GAG) in pregnant Wistar rat uterine cervices at term. The GAG were measured in a control (n = 11), in a Diclofenac (cyclooxygenase inhibitor) treated group (n = 8), in a BW 755C (dual inhibitor of cyclooxygenase and 5-lipoxygenase) treated group (n = 6), and a L 651392 (5-lipoxygenase inhibitor) treated group (n = 9). The results of these studies suggest, that cervical hyaluronic acid metabolism and cervical hydration are controlled in association by prostaglandins and leukotrienes (and perhaps by other phospholipids metabolites), whereas heparan sulphate metabolism is obviously controlled by prostaglandins. Nevertheless complete and normal cervical maturation is probably controlled in association by arachidonic acid metabolites and other factors (steroids and peptides).
This preliminary study was designed to evaluate retrograde cannulation of the Fallopian tubes up to the isthmo-interstitial junction using the new technique of tubal embryo stage transfer (TEST). Follicular aspiration was performed under the guidance of a vaginal ultrasound probe in 51 women treated with GnRH + HMG. The oocytes retrieved were inseminated in vitro with 50,000 motile spermatozoa and kept in Menezo B2 medium without serum, at 37 degrees C, in an atmosphere of air + 5% CO2. The eggs were checked 24 and 36 h after insemination. No fertilization occurred in 23 patients. Cleaved embryos were obtained in the 28 other patients. One to seven embryos at the 2-4-cell stage were transferred with the 'Baudelocque Black Catheter' (BBC) into one tube and spare embryos were frozen. Five pregnancies occurred after retrograde TEST, for a pregnancy rate of 9.8% per cycle and 17.9% per transfer. One patient has given birth to a normal full-term baby. One singleton and one twin pregnancy are ongoing (8 months in June 1989). The other two pregnancies were ectopic.
Selective retrograde trans-cervical salpingography was carried out in four patients in whom ectopic pregnancy was suspected. The Fallopian tube was catheterized using a catheter set designed in our centre. The 6F catheter was placed in the cornua and an inner coaxial catheter was easily introduced into the proximal portion of the Fallopian tube, guided by tactile impression. Contrast medium was then injected and a round haloed mass was seen. Thereafter, the Fallopian tube was catheterized using a metallic guidewire until its tip was adjacent to the ectopic pregnancy. The coaxial catheter was then advanced along the guidewire and after removal of the latter, 5-35 mg of methotrexate was injected into the Fallopian tube. This new procedure was simple, well tolerated and had no side effects. A tubal pregnancy was demonstrated and surgery was avoided in all cases.
An instrument has been designed and manufactured to measure precisely in clinical practice the distensibility index of the human uterine cervix expressed as centimeters per kilogram. Operation of the instrument and possible errors measuring the cervical distensibility index in nonpregnant patients, during gestation and during the postpartum period, are presented. The ability to easily quantify the mechanical characteristics of the uterine cervix in humans throughout gestation will now allow one to carry out precise studies concerning pharmacologically induced cervical maturation or pathological modifications of the uterine cervix in cervical incompetence or threatened premature labor.
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The high rate of implantation failure in humans following in vitro fertilization (IVF) has been attributed to a lack of production of immunosuppressive factors by cleaved embryos, rendering them vulnerable to maternal immune attack just before or around implantation. Systemic as well as blastocyst-secreted suppressor factors have been described and claimed to be responsible for successful pregnancy. Experimentally, we have screened in a double-blind fashion the suppressive activity of human embryo culture media (B2 Menezo system, France) in which zygotes after decoronization were individually cultured during 24 hr on lymphocyte proliferation as well as natural killer (NK) activity. Suppressive activity in media from cleaved and uncleaved ova did not differ significantly, and activity in media from transferred embryos was not correlated significantly with successful pregnancy. The implications of these data are discussed.
The concentrations of prorenin (PR) and active renin (AR) were determined sequentially during ovarian hyperstimulated cycles for in-vitro fertilization-embryo transfer or gamete intra-Fallopian transfer. AR and PR increased during the early luteal phase and PR was highly correlated with the progesterone concentration. In fertile cycles, AR increased more rapidly after HCG injection and AR and PR levels were significantly higher during the late luteal phase. These results confirm the role of the renin angiotensin system in ovarian physiology.
The determination of steroids in saliva provides useful information in the clinical study of various endocrine functions, and salivary progesterone concentration has been widely used for assessing corpus luteum function during the spontaneous menstrual cycle and early pregnancy. However, the determination of oestradiol in saliva (SE2) has previously been found unsatisfactory. SE2 profiles and saliva/plasma E2 ratios were established (during the different periods of the menstrual cycle) by a highly sensitive radioimmunoassay method during normal menstrual cycle. During cycles hyperstimulated for in-vitro fertilization and embryo transfer, the SE2 pattern is similar to the corresponding profile in plasma with a peri-ovulatory oestradiol peak. There is a significant difference between fertile and non-fertile cycles with a higher saliva/plasma ratio in conception cycles.
Pregnancy-associated plasma protein-A (PAPP-A) is a human macromolecular glycoprotein produced by the trophoblast and possibly by the decidua. Its biological function is unknown, but in vitro, PAPP-A has been reported to be an inhibitor of granulocyte elastase. The present study was undertaken to see if pregnant cynomolgus monkeys could be an animal model sufficiently close to the human situation to study the physiology of PAPP-A. An antiserum to pregnant cynomolgus plasma was raised in rabbits. After adsorption with normal monkey plasma, this antiserum was used together with radioiodinated human PAPP-A to develop an heterologous radioimmunoassay for measurements of monkey PAPP-A. On polyacrylamide gel electrophoresis, it was shown that this polyspecific-antiserum bound the same molecular species of radioiodinated human PAPP-A as the available anti-human PAPP-A antiserum. The concentrations of cynomolgus PAPP-A (cPAPP-A) throughout pregnancy follow the same pattern as human PAPP-A (hPAPP-A) with an almost exponential increase up to term. The doubling time of cPAPP-A was similar to that of hPAPP-A. After RU 486-induced abortion or after spontaneous abortion, the levels of cPAPP-A decreased, with an apparent half-life of 2-3 days. Preliminary characterization of cPAPP-A revealed that although cPAPP-A was only immunologically related to hPAPP-A, it was biochemically very similar: they had the same PI and the same molecular weight, and both PAPP-As bound heparin. It is concluded that pregnant cynomolgus monkeys are a good model to study the physiology of PAPP-A.
The presence of receptors for GnRH in human ovary has been investigated by quantitative autoradiography. Simultaneous visualization and characterization of specific receptors on frozen sections were obtained on six pairs of human ovaries. Among them only one exhibited a large preovulatory follicle. This dominant follicle exhibited a specific and high affinity binding capacity for 125I-GnRHa exclusively localized on the granulosa cell layer. Analysis of saturation curve indicates a Kd value of 0.22 nM and Bmax of 9.6 fmol/mg protein. In contrast LH-hCG binding sites were present in all antral follicles. These data demonstrate for the first time the presence of high affinity GnRH receptors in human granulosa cells at a late stage of follicular maturation.
The measurement of steroid concentrations is recommended in the exploration of the different endocrine functions. The salivary concentrations are the reflect of the free biologically active fraction in the plasma. In this study we have used a sensitive and specific method that can be routinely applied in salivary extradiol (SE2) RIA, using a 3 CMO 125I histamine derivative as a tracer. This study related to 12 normal spontaneous menstrual cycles and two abnormal spontaneous cycles. Saliva samples were collected daily throughout the menstrual cycle. Plasma samples were collected simultaneously to compare the salivary and plasma patterns. In the follicular phase SE2 was low: M +/- SD = 9.4 +/- 2.4 pmol/l. During the periovulatory period, the mean level of SE2 the day of the preovulatory peak was 27.6 +/- 8.6 pmol/l. In the luteal phase the SE2 levels fluctuated in a serrated manner with a mean of 11.7 +/- 3.4 pmol/l. The difference between the different phases is significant at the probability threshold 0.01. We have compared the salivary and plasma patterns during the different phases. At the beginning the salivary/plasma ratio was 3.4 +/- 0.9%. During the periovulatory period this ratio was only 2.5 +/- 0.6% and the end of the cycle 2.8 +/- 1%. The statistic study showed that these differences were significant at the probability threshold 0.01.
The procedures used for programming and ovarian stimulation in GIFT are identical to those used for in-vitro fertilization. At the Baudelocque Hospital, the hypophyseal gonadal axis is suppressed by administering a gonadotrophin-releasing hormone analogue (Decapeptyl, D-Trp-6-LHRH). Programming for the week of GIFT is then possible by controlling three stages: the beginning of treatment, which is independent of the date of the patient's period, the duration of treatment, which has 5 days' maximum variation, and an end-point of suppressing the spontaneous LH surge.
Prorenin (PR) an inactive high molecular weight form of renin normally circulates in human plasma at a concentration of about 10 times that of active renin (AR) and this proenzyme seems to be linked to the reproductive function. It has been demonstrated that AR and PR are present at high concentrations in follicular fluid when the ovaries are stimulated with gonadotropins and that the PR plasma levels increase steadily after hCG injection with a correlation between blood PR and the number of developing follicles and corpora lutea. From September 1986 we studied the profile of immunoreactive active renin (AR) and prorenin (PR) in plasma during hyperstimulated cycles for IVFET or GIFT. All women were treated with a protocol combining GnRH analog (Decaptyl Ipsen Biotech, Paris France) and human menopausal gonadotropins until injection of 5,000 IU hCG. AR has been assayed in frozen samples by specific immunoradiometry (Renin RIA code 79 795, Pasteur Diagnostic, France) using two complementary monoclonal antibodies. A second assay of total renin was carried out after trypsin activation which revealed the inactive form. Progesterone (P), estradiol (E2) were measured by radioimmuno-assays. During the follicular phase, from day 1 of hMG administration to the day before hCG, no significant difference could be found between two groups, 63 pregnant or 60 nonpregnant cycles matched for age and number of oocytes retrieved, for E2, P, PR and AR. During the periovulatory period (D - 1, Do = day of hCG injection and D 1) no difference could be found for E2, P and PR (tabl. 1). In the 2 groups the mean E2 levels increased after hCG injection, as well as P and PR. But a significant difference appeared for AR which increased in the plasma immediately after hCG administration in the pregnant group whereas it decreased in the non-pregnant group (+2.5 vs -2 pg/ml) the mean variation between Do and D + 1 being significantly different in fertile cycles and in nonfertile cycles.(ABSTRACT TRUNCATED AT 400 WORDS)
Low density lipoproteins (LDL) were conjugated to colloidal gold to visualize the route for internalization of LDL in the cultured cells of human term placenta. Cells were obtained from placental villi (caesarian section) by a standard trypsin-DNase dispersion method followed in some cases by a Percoll gradient centrifugation step. Employing electron microscopy it was observed that after 3 days of culture, cells obtained by trypsin-DNase dispersion were a mixture of macrophages, mononucleated cells and large multinucleated cells. When the cells were incubated for 3 days after the Percoll purification, essentially multinucleated cells identical to the syncytiotrophoblast were present. The number of LDL receptor was increased by preincubation in medium with lipoprotein depleted serum. In binding experiments cells incubated at 4 degrees C for 2 h with medium containing gold LDL conjugates showed gold LDL attached to the plasma membrane without characteristic localization. After incubation with gold LDL at 37 degrees C for various times, the three cellular types showed ligand internalization. Gold LDL endocytosis involved first coated pits but also uncoated plasmalemmal invaginations. Then gold LDL was further observed in coated and non coated vesicles, smooth walled endosomes, multivesicular bodies and tubular vesicles. Lastly free gold particles were observed in lysosome like dense bodies. These results prove the internalization of gold LDL conjugates by human cultured placental cells, particularly by syncytiotrophoblast like multinucleated cells. This accumulation of LDL (the major cholesterol carrying protein in humans) is recognised to be responsible for the exogenous cholesterol supply indispensable to the progesterone biosynthesis and cellular growth of the placenta.
In a 41-year-old hirsute woman, severe hypercalcemia led to the discovery of hyperparathyroidism related to the involvement (hyperplasia/or adenoma) of the 4 parathyroid glands. Plasma and urinary DHA, plasma DHA-sulfate and delta 5 steroid precursors were elevated. Steroid hormone hypersecretion was stimulated by hCG and ACTH, and exhibited a paradoxical rise during dexamethasone administration. Computerized tomography scanning as well as arteriography disclosed bilateral adrenal hyperplasia and left adrenal adenoma. Bilateral adrenal vein catheterization indicated a left/right gradient for delta 5 steroids and delta 5 steroid sulfates. At surgery a left brown adrenal encapsulated adenoma was removed with a hyperplastic adrenal gland. Results of in vitro studies (adrenal steroid content and incubation) together with postadrenalectomy hormonal results suggest that the left brown adrenal adenoma was the main source of excessive androgen production. The infrequent association of an androgen-producing adrenal adenoma with hyperparathyroidism raises the hypothesis of multiple endocrine neoplasia syndrome. However, evidence for this diagnosis is lacking in the absence of other glandular involvement and of family history.