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Biomedical subjects

G Pontonnier

Publications and source records attributed to G Pontonnier.

At least 37 records · Page 2Linked to original sources
PubMed1987

[Fetal blood sampling under ultrasonic control].

Withdrawing foetal blood from the umbilical cord under ultrasonic control requires close co-ordination between obstetricians and echographists. The most important indications for this procedure are infections and foetal karyotype determination.

Blood Specimen Collection↗
PubMed1987

Randomized trial of two media used for in vitro fertilization.

Culture media are important components of IVF. Their selection must meet the need for efficiency, and also economic and practical requirements. From these standpoints, we compared two widely used media: Ham's F10 supplemented with cord serum and Menezo B2 used without serum. The test followed a randomized protocol using two series of 159 and 162 oocytes. Since no difference was seen in efficiency assessed from cleavage rate, the discussion focuses on cost and ease of use.

Cleavage Stage, Ovum↗
PubMed1987

Choice of an ovarian stimulation protocol according to the follicular puncture method in an in vitro fertilization programme.

In order to ascertain the adequacy of ovarian stimulation protocols with a type of follicular puncture, 126 women undergoing in vitro fertilization received either combination clomiphene/hMG or hMG alone according to a randomized test protocol. Within both groups patients for whom a pelvic examination was required had laparoscopies, while others had transvaginal ultrasonically guided punctures as far as possible. Clomiphene/hMG was more efficient than hMG alone as assessed from the cleavage rate (68% vs. 54%; p less than 0.01) and the pregnancy per attempt rate (16% vs. 5%; p less than 0.05). Laparoscopic punctures were more efficient than ultrasonically guided punctures (mean number of recovered oocytes: 4.8 +/- 2.6 vs. 3 +/- 2.5; p less than 0.001), but slightly better results were achieved by this latter method in ongoing pregnancy per puncture rate (18% vs. 8%; NS). With ultrasonically guided punctures, stimulation by clomiphene/hMG allowed better oocyte recoveries (3.8 +/- 2.5 vs. 2.3 +/- 1.9, p less than 0.05). Such results constitute an argument for preferential use of the clomiphene/hMG stimulation protocol with ultrasonically guided punctures.

Clomiphene↗
PubMed1987

High density lipoprotein and low density lipoprotein utilization by human granulosa cells for progesterone synthesis in serum-free culture: respective contributions of free and esterified cholesterol.

Human preovulatory granulosa cells cultured in serum- and gonadotropin-free medium secreted progressively less progesterone as time elapsed. Addition of purified high density lipoproteins (HDL) as well as low density lipoproteins [very low density (VLDL) plus low density lipoproteins (LDL)] restored optimal synthesis of progesterone, and HDL was as effective as VLDL + LDL. The use of cholesterol doubly labeled lipoproteins allowed calculation of the proportions of free and esterified cholesterol converted into progesterone. Granulosa cells used either free or esterified cholesterol from VLDL + LDL. In contrast, HDL-esterified cholesterol was a poor substrate for progesterone synthesis, while HDL-free cholesterol was used preferentially. LH increased the use of both kinds of lipoproteins without changing the way in which they were used. Pretreatment of HDL by purified phospholipase A2 increased the conversion of free cholesterol into progesterone. Similar treatment of VLDL + LDL had little effect on progesterone secretion. We conclude that HDL as well as VLDL + LDL can provide cholesterol to human preovulatory granulosa cells and that utilization of HDL-cholesterol may depend on gonadotropin (LH) and enzymatic (phospholipase) regulation.

Cells, Cultured↗
PubMed1987

Transcutaneous carbon dioxide measurements in the fetus during labor.

Continuous transcutaneous carbon dioxide partial pressure (tcPco2) was monitored in 40 spontaneous labors. The electrode was attached by glue fixation. An interpretable tracing was obtained in 36 cases. All cases but 2 were normal pregnancies. Thirty-two patients had epidural analgesia while the others had no analgesia. All infants had an Apgar score above 7 at five minutes after delivery and only two had a pH of the umbilical artery of less than 7.16. Mean duration of the recordings was 116 minutes (range: 15-300) and mean time for reaching steady-state was 27 minutes (range: 10-45 minutes). Mean value of tcPco2 was 48 mmHg (SD: 6) before 6 cm of dilatation, 47 mmHg (SD: 8) between 6 and 10 cm, and 47 mmHg (SD: 15) at the second stage of labor. Mean umbilical artery Pco2 was 48 mmHg (SD: 14) and mean umbilical artery pH was 7.25 (SD: 0.06). The range of tcPco2 obtained in these normal cases was 20 to 62 mmHg. Comparison of the results with those of other authors and with previous studies of normal labor and epidural analgesia show a higher tcPco2 compared to scalp Pco2. In contrast to other studies in these series no correlation was found in the series between umbilical artery Pco2 and tcPco2 values. This lack of correlation could be explained either by the small number of cases in which both measurements were available (9 cases) and by the small range of variation or by some inaccuracy in the measurements.(ABSTRACT TRUNCATED AT 250 WORDS)

Blood Gas Monitoring, Transcutaneous↗
PubMed1986

[Variations in birth weight as a function of various fetal and maternal characteristics. The application to the diagnosis of hypotrophy].

The known variations in weight for gestational age as well as compounding maternal and/or fetal factors, puts into question the usual definition of small for gestational age (SGA) which is based on gestational age alone. On the basis of more than 20,000 births studied in 4 maternity hospitals from 3 separate regions in France, the authors propose a new definition for growth retardation in full-term babies, taking into account 4 factors: gestational age, sex, birth rank, height and usual weight of mothers. This definition allows constitutionally SGA newborns to be considered normal, while some babies previously classified as normal would now lead one to suspect intra-uterine growth retardation (IUGR). This approach tries to take constitutional and environmental risk factors into account in fetal growth hopefully allowing for help better detection of IUGR.

Adult↗
PubMed1985

IgG subclasses and Gm allotypes of anti-D antibodies during pregnancy: correlation with the gravity of the fetal disease.

The IgG subclasses and the Gm allotypes of anti-D antibodies were studied in 103 isoimmunized pregnancies with Rh-positive infants. No allelic exclusion phenomena were observed in patients heterozygous for the studied genes. An analysis of the correlation between the severity of fetal disease and the type of anti-D antibodies shows a greater hemolytic action of the IgG1 subclass and, within this group, those marked by the Gm(4) allotype. These results suggest that the prognostic value of anti-D antibody titers during pregnancy could be modulated by a study of the IgG subclasses and their allotypes.

Bilirubin↗
PubMed1985

Lipoprotein and phospholipid distribution in human follicular fluids.

Human preovulatory follicular fluids, obtained in the course of stimulated cycles, were analyzed for their lipid and protein compositions. By combining different methods, a single class of lipoprotein, high-density lipoprotein, was detected in all cases. The phospholipid distribution revealed an accumulation of lysophosphatidylcholine. These data are discussed in view of the possible roles of the follicular fluid during fertilization and in relation to the high levels of estradiol and progesterone measured in those fluids.

Body Fluids↗
PubMed1984

Multicentred controlled trial of cervical cerclage in women at moderate risk of preterm delivery.

A total of 506 women at moderate risk of preterm delivery were randomly allocated to either cervical cerclage or a control group. Significantly more women in the group allocated to cerclage were admitted to hospital for reasons other than the operation and more received oral tocolytic drugs. There were also more caesarean sections and more preterm deliveries in the women allocated to cerclage although the differences between the two groups were small and not statistically significant.

Adult↗
PubMed1984

[Beta-blockers and arterial hypertension in pregnancy].

In theory, the pharmaceutical properties of beta-blockers would make their use in hypertension in pregnancy undesirable. Practically, however, these drugs are used more and more in pregnancy. This contradiction has been based on a whole number of clinical trials of which the results have been conflicting. This can be explained by the fact that many of these trials have not been carried out according to a scientific protocol for a trial of a drug. Only random studies are therefore analysed by this author. He concludes that beta-blockers can be used in pregnancy in some cases of hypertension.

Adrenergic beta-Antagonists↗
PubMed1983

Placental kappa binding site : interaction with dynorphin and its possible implication in hCG secretion.

We have previously demonstrated that human placenta contains a homogenous population of kappa binding sites. The selective interaction of dynorphin with these opiate binding sites suggests a possible physiological implication of this endogenous opioid system in the placenta physiology. Ethylketocyclazocine stimulate K+-induced hCG release. This fact favours the hypothesis of a participation of placental opiate receptor on hCG secretion.

Analgesics, Opioid↗
PubMed1983

Assessment of the predictive value of X-ray pelvimetry and biparietal diameter in cephalopelvic disproportion.

The value of X-ray pelvimetry and ultrasonic measurement of the biparietal diameter for trial of labor prognosis was assessed in 172 healthy primiparas with suspected cephalopelvic disproportion. A decision diagram which is able to correctly predict 50% of the cesarean sections without increasing the number of unnecessary cesarean sections is proposed. In addition, the study confirms the superfluity of X-ray pelvimetry in cases of high station of the fetal head at the end of pregnancy.

Apgar Score↗