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J Guibourdenche

Publications and source records attributed to J Guibourdenche.

At least 19 recordsLinked to original sources
PubMed2006

Serum anti-Müllerian hormone expression in women with premature ovarian failure.

BACKGROUND: Premature ovarian failure (POF) is generally irreversible. However, developing follicles up to the antral stage are reported in POF and anti-Müllerian hormone (AMH) might be a good indicator of follicular presence. This study analysed serum AMH, ovarian histology and AMH immunoexpression in POF patients. METHODS: A cross-sectional study of 48 POF patients in an Endocrinology Department setting. Patients had an ovarian biopsy simultaneously with serum AMH sampling and/or ovarian AMH immunostaining. RESULTS: Mean serum AMH was 1.04 +/- 1.66 ng/ml. Serum AMH was significantly higher in women with 15 or more follicles at ovarian histology (P = 0.001). Comparison of ovarian AMH immunostaining from POF patients and 10 normal controls revealed a normal AMH expression in POF pre-antral follicles, but a decreased expression at the early antral stages. Serum AMH was undetectable in 77% of the patients with 0-5 AMH immunopositive follicles and detectable in 100% of the patients with more than 15 AMH immunopositive follicles. CONCLUSIONS: AMH levels in POF patients could identify women with persistent follicles. The decrease of AMH immunoexpression in POF antral follicles could suggest a defect of antral development.

Adolescent↗
PubMed2006

Human chorionic gonadotropin expression in human trophoblasts from early placenta: comparative study between villous and extravillous trophoblastic cells.

Human trophoblast differentiates into two pathways: extravillous cytotrophoblasts (EVCT) that invade the uterus wall and villous cytotrophoblasts (VCT) that fuse to form the syncytiotrophoblast (ST) involved in placental exchanges and endocrine function. It is established that hCG is produced and secreted by the ST into the maternal compartment where it plays a key endocrine role and stimulates ST formation in an autocrine manner. Herein, we investigated hCG expression in early placentas by immunohistochemistry using different antibodies. We then compared hCG secretion by primary cultures of VCT and EVCT isolated from the same first trimester human chorionic villi. In situ hCG was immunodetected in EVCT all along their invasive differentiating pathway except in cells near the stromal core of the proximal column. hCG expression was confirmed in vitro by immunocytochemistry and hCG secretion quantified in cell supernatants. Interestingly, whereas hCG secretion increased during VCT differentiation into ST (from 60 to 350UI/L/microg DNA), EVCT secretion remained constant and at a high level during the same culture period (160UI/L/microg DNA). Our data demonstrated that in addition to the ST, invasive EVCT also expressed and secreted high levels of hCG, suggesting a specific paracrine and/or autocrine role for hCG from EVCT origin.

Animals↗
PubMed2006

Modulation of PAPP-A expression by PPARgamma in human first trimester trophoblast.

Pregnancy-associated plasma protein-A (PAPP-A) is a metzincin metalloproteinase that cleaves the insulin-like growth factor (IGF)-dependent binding protein-4 and increases in maternal serum during pregnancy. In human placenta PAPP-A is expressed both in villous cytotrophoblasts (VCT) that cover the chorionic villi and in extravillous cytotrophoblasts (EVCT) of the anchoring villi. Due to the key role of PPARgamma in human trophoblast differentiation such as syncytiotrophoblast formation and EVCT invasion, we studied the effect of PPARgamma activation on PAPP-A expression using our in vitro model of EVCT and VCT primary cultures isolated from the same first trimester chorionic villi. First, we demonstrated that invasive EVCT expressed and secreted 10 times more PAPP-A than VCT did. Then, we showed that activation of PPARgamma inhibited PAPP-A gene expression and secretion in EVCT, whereas it had no effect in VCT. Since we have previously shown that PPARgamma agonist inhibits EVCT invasion in vitro, we suggest that PPARgamma-mediated inhibition of PAPP-A might decrease the amount of bioactive IGFII, a factor known to promote trophoblast invasion.

Chorionic Villi↗
PubMed2004

Fetal and neonatal thyroid function in relation to maternal Graves' disease.

The abundance of published data on the neonatal effects of maternal Graves' disease (GD) contrasts with the paucity of information on fetal effects. In our yet unpublished study, we prospectively studied 72 pregnant women with a history of Graves' disease. Fetal ultrasonography was done at 22 and 32 weeks of gestational age. Fetal goiter was found at 32 weeks in 11 of the fetuses of the 41 mothers with positive TSH-receptor antibodies and/or antithyroid treatment and in none of the fetuses of the 31 other mothers. In the 11 fetuses with goiter, ultrasound findings (thyroid Doppler and bone maturation), fetal heart rate, and maternal antibody and antithyroid drug status effectively discriminated between hypothyroidism (n=7) and hyperthyroidism (n=4). One fetus with hyperthyroidism died in utero at 35 weeks from heart failure. Treatment was successful in the ten other fetuses. One fetus without goiter had moderate hypothyroidism at birth. This study showed that it is of the utmost importance to have the fetal thyroid scrutinized by an expert ultrasonographist and to have team work with obstetricians and paediatric endocrinologists in pregnant mothers with GD. This allowed us to accurately determine fetal thyroid status and to adapt the treatment in mothers successfully. Fetal hyperthyroidism does exist and needs an appropriate aggressive treatment.

Female↗
PubMed2004

Large variability of trophoblast gene expression within and between human normal term placentae.

Human placenta extracts are widely used in clinical and fundamental research, particularly to study the hormonal and exchange functions of the placenta. However, very little is known about the distribution of the main hormone mRNAs in the placenta as a whole. Total placenta extracts are heterogeneous in their cellular components, as they contain material of both fetal and maternal origin, and in their structure. Results vary greatly depending upon the location of the biopsy and the number of biopsies performed. We used real-time quantitative RT-PCR to determine whether transcripts corresponding to the main hormones secreted by the human placenta (e.g. hCG, HPL and PGH) are equally distributed within and between term placentae. We also measured cytokeratin 7 transcripts, which are specifically expressed in the trophoblast, and transcripts corresponding to nuclear receptors PPARgamma and RXRalpha. A comparison of the results obtained with 12 different samples from each of four normal term placentae revealed that the amounts of transcripts differ considerably within and between each placenta. This emphasizes the need to study large numbers of samples when looking for significant differences in gene expression.

Analysis of Variance↗
PubMed2004

Impact of trisomy 21 on human trophoblast behaviour and hormonal function.

Although trisomy 21 (T21) is the most frequent genetic abnormality and some maternal serum markers for this fetoplacental aneuploidy are of placental origin, little is known of its impact on placental development. We therefore studied the influence of T21 on trophoblast behaviour. Using cultured cells from 46 human T21 pregnancies, we confirmed the defective morphological and functional differentiation of the villous cytotrophoblast in this setting; indeed, villous cytotrophoblast cells aggregate normally but fuse inefficiently to form the syncytiotrophoblast. This is in part related to the abnormal oxidative status of the T21 cytotrophoblast, characterized by a gene dosage-related increase in SOD-1 (copper-zinc superoxide dismutase) expression and activity. This was associated with a significant (P < 0.01) increase in catalase activity but no significant change in glutathione peroxidase activity. On the basis of these in vitro findings and studies of large panels of maternal serum, we propose a pathophysiological explanation for trisomy 21 maternal serum markers of placental origin.

Adult↗
PubMed2004

Trophoblast production of a weakly bioactive human chorionic gonadotropin in trisomy 21-affected pregnancy.

Total human chorionic gonadotropin (hCG) is high in maternal serum at 14-18 wk of trisomy 21 (T21)-affected pregnancy, despite low placental hCG synthesis. We sought an explanation for this paradox. We first observed that, in T21-affected pregnancies, maternal serum hCG levels peaked at around 10 wk and then followed the same pattern throughout pregnancy as in controls, albeit at a higher (2.2-fold) level. After delivery, hCG clearance was not significantly different from that in controls. We isolated cytotrophoblasts from 29 T21-affected placentas (12-25 wk) and 13 gestational age-matched control placentas and cultured them for 3 d. In this large series, we confirmed that, in the culture medium of trophoblasts isolated from T21 placentas, hCG secretion was significantly lower (P < 0.003) than in controls, in contrast to the high hCG in maternal serum of the same patients. In T21 cultured trophoblasts, transcripts of sialyltransferase-1 and fucosyltransferase-1 were abnormally high. In corresponding culture medium, hCG was abnormally glycosylated; highly acidic [isoelectric points (pHi) = 4.5] as shown by isoelectric focusing, immunoblotting, and lectin binding; and weakly bioactive (46% of control) as determined using the Leydig cell model. In conclusion, T21 trophoblast cells produced hCG that was weakly bioactive and abnormally glycosylated but whose maternal clearance was unaltered.

Antigens, CD↗
PubMed2003

Anti-Müllerian hormone levels in serum from human foetuses and children: pattern and clinical interest.

Serum anti-Müllerian hormone (AMH) determination has been used to investigate gonadal development and abnormal sexual differentiation, but until recently, it was based on assays developed by specialized laboratories. A short time ago, a sensitive assay kit was developed commercially (Immunotech-Beckman Coulter) for clinical use. With this method, we established usual levels of serum AMH in fetuses, newborns, and pre-pubertal children, and evaluated the clinical value of this assay. AMH measurement required only 25 microl of sample and could be performed within 3 h. In females, AMH emerged after birth at low levels (median: 4 ng/ml). In males, AMH levels remained stable during fetal life (median: 44.4 ng/ml), peaked in the first months of life to reach a median of 124.7 ng/ml, then fell with wide individual variations. Cord blood AMH levels at birth may be useful to investigate ambiguous genitalia suspected prenatally. In children with isolated microphallus or hypospadias, decreased AMH values are in favor of testis dysfunction. When testes cannot be palpated, a single determination of serum AMH levels can distinguish between anorchia and cryptorchidism.

Age Factors↗
PubMed2003

Prenatal management of gastroschisis: the place of the amnioexchange procedure.

Gastroschisis is a malformation of the anterior abdominal wall that consists of a right paraumbilical defect with bowel loops bathed in the amniotic fluid. The survival rate is now greater than 90% and the prognosis relies mainly on morbidity attributable to bowel dysfunction. Recent research has examined gastrointestinal waste present in amniotic fluid that induces bowel toxicity and an inflammatory process. The amnioexchange procedure (changing the amniotic fluid regularly) involves a new therapeutic approach: reducing bowel injuries in the fetuses. This article shows that there is an inflammatory reaction in human gastroschisis and in the authors' model, and that the clinical and biological data plead for the practice of amnioexchange in human beings. A randomized, controlled study is now needed.

Amniotic Fluid↗
PubMed2003

Expression of pregnancy-associated plasma protein-A (PAPP-A) during human villous trophoblast differentiation in vitro.

Pregnancy-associated placental protein-A (PAPP-A), first isolated from maternal serum, has been identified as a metalloprotease cleaving insulin-like growth factor binding protein-4 (IGFBP-4). The source of PAPP-A during pregnancy is unclear. We therefore investigated PAPP-A expression during in vitro human villous cytotrophoblast cell (CT) differentiation into syncytiotrophoblast (ST). CT were isolated from normal first trimester, second trimester and term placentae (n=10) and cultured to form ST. PAPP-A mRNA was quantified by real-time PCR, and PAPP-A protein expression was studied by immunocytochemistry and TRACE technology with specific monoclonal antibodies. PAPP-A mRNA expression in total placental extracts increased during the course of pregnancy. PAPP-A protein was detected in the cytoplasm of both CT and ST. ST formation in vitro was associated with a 19-fold increase in PAPP-A mRNA expression and an 8-fold increase in PAPP-A secretion into the culture medium. No significant difference in PAPP-A production was observed between cultured cells isolated from early and term placentae. In conclusion, PAPP-A production in vitro, is associated to the differentiation of villous cytotrophoblast cells into syncytiotrophoblast, independently of the age of gestation.

Adult↗
PubMed2002

Esophageal ligature in experimental gastroschisis.

BACKGROUND/PURPOSE: Recently, the authors have shown that in human fetuses suffering from gastroschisis, there is an amniotic fluid inflammatory response and that amniotic fluid exchange designed to disrupt the inflammatory loop seems to have a favorable impact on outcome. The authors, therefore, designed in the fetal sheep a model of gastroschisis in which amnioinfusion significantly improved the deleterious process. They hypothesized that regurgitation and presence of digestive enzyme in the amniotic fluid triggers and maintains the process of inflammation. METHODS: To test this hypothesis, the authors used their model of gastroschisis in the fetal lamb combined with esophageal ligation and compared it with gastroschisis with or without amnioinfusion. RESULTS: Of 34 fetuses operated on at midgestation (days 70 through 80), 11 died in utero or were stillborn, 8 had gastroschisis and amnioinfusion, 8 had gastroschisis and no amnioinfusion, and 7 had gastroschisis and esophageal ligation. There were 9 control fetuses. Fetuses were killed at day 145 by cesarean section. Extraabdominal bowels with fibrous peel were processed for histologic examination. Thickness of bowel muscularis (micrometers) was 82.7 +/- 19 for controls, 159 +/- 56 for the nonamnioinfused fetuses, 126 +/- 21 for the amnioinfused fetuses (P =.001), and 240 +/- 225.8 for fetuses with esophageal ligature combined with gastroschisis. The same results were obtained for thickness of serous fibrosis and plasma cell infiltration. Assay of amniotic fluid ferritin, lipase, and protein showed that only amnioinfusion lowered ferritin and protein to levels similar to those of controls, thus, illustrating its preventive effect on inflammation and that esophageal ligature did not prevent digestive enzyme presence in the amniotic fluid. CONCLUSION: In this model of gastroschisis in the fetal sheep, ligature of the esophagus, which was supposed to protect the extruded bowel by preventing oral regurgitation of digestive enzymes and by creating a relative hydramnios, did not improve the inflammatory and deleterious process, which is best prevented by amnioinfusion.

Amniotic Fluid↗
PubMed2002

Human placental growth hormone--a review.

Placental growth hormone (PGH) is the product of the GH-V gene, predominantly expressed in the syncytiotrophoblast layer of the human placenta. PGH differs from pituitary growth hormone by 13 amino acids and possesses one glycosylation site. It has high somatogenic and low lactogenic activities. In the maternal circulation from 12-20 weeks up to term, PGH gradually replaces pituitary growth hormone, which becomes undetectable. PGH is secreted by the placenta in a non-pulsatile manner. This continuous secretion appears to have important implications for physiological adjustment to gestation and especially in the control of maternal IGF1 levels. PGH secretion is regulated in vitro and in vivo by glucose. Lower maternal levels of PGH are observed in pregnancies with fetal growth retardation. PGH is one example of a trophoblast hormone, which allows maternal metabolic adaptation to pregnancy. In addition, our recent data on its expression in invasive extravillous trophoblasts suggest that the physiological role of PGH might also include a direct influence of this hormone on placental development via an autocrine or paracrine mechanism.

Adult↗
PubMed2001

Improvement of mesenteric superior artery Doppler velocimetry by amnio-infusion in fetal gastroschisis.

This study aimed to analyse the influence of amnio-infusion on superior mesenteric Doppler velocimetry and to correlate Doppler data with outcome in fetuses presenting with gastroschisis. Umbilical and intra- and extra-abdominal superior mesenteric artery Doppler velocimetry was measured prospectively before and after amnio-infusion in fetuses with gastroschisis. Doppler index values and changes were correlated with the following outcome parameters: importance of fibrous coating, duration of hospitalization in the neonatal intensive care unit, total duration of hospitalization, duration of parenteral feeding, duration of ventilatory assistance, and the interval to initiation of oral feeding. A significant improvement of diastolic flow was observed in the extra-abdominal superior mesenteric artery with amnio-infusion. No similar change was seen in the intra-abdominal superior mesenteric or in the umbilical artery. Pre-amnioinfusion extra-abdominal mesenteric Doppler index was correlated with maximal diameter of exteriorized bowel and slightly with duration of hospitalization in the neonatal intensive care unit, but no other relation between Doppler index and outcome parameter could be ascertained. Amnio-infusion induces modifications in the vascularization of exteriorized bowel in gastroschisis. This could partly explain the beneficial effect of this procedure on fetal gut.

Amniotic Fluid↗
PubMed2001

Establishment of reference values of five amniotic fluid enzymes. Analytical performances of the Hitachi 911. Application to complicated pregnancies.

OBJECTIVES: to evaluate the analytical performances of the Hitachi 911 analyzer (Roche Diagnostics, F) for gamma-glutamyl-transferase, 5'nucleotidase, amylase, aspartate-amino-transferase and total-alkaline-phosphatase assay in amniotic fluid. To establish reference intervals for these five enzymes throughout gestation. To determine their antenatal diagnostic value. DESIGN AND METHODS: amniotic fluid samples were collected between 14 and 35 weeks of gestation. Weekly numbers ranged from 31 to 92. Techniques developed for serum enzyme assays were applied to amniotic fluid. Two pools of amniotic fluid containing low and high marker levels were used. Within-day and between-day variations were calculated, together with the limits of detection and linearity. Reference ranges were established on 508 amniotic fluid samples, including 23 samples from pregnancies with chromosomal aberrations, 14 with gastrointestinal tract defects and 5 with gastroschisis. RESULTS: the assay technique for total-alkaline-phosphatase assay had to be adapted to amniotic fluid, but no adaptation was necessary for the other markers. The within-day CV ranged between 2.2 and 11.2% for low-level samples and from 1.1 to 3.4% for high-level samples. The between-day CV ranged from 6.3 to 13.3% for low-level samples and 1.2 to 4.7% for high-level samples. Total-alkaline-phosphatase activity fluctuated throughout gestation. Amylase levels and aspartate-amino-transferase levels increased whereas gamma-glutamyl-transferase and 5'nucleotidase levels fell until delivery. All trisomy 18 and trisomy 13 pregnancies, 65% of Down's syndrome pregnancies and all pregnancies with digestive tract defects were associated with marked changes in the level of at least one enzyme. CONCLUSION: The Hitachi 911 is suited to rapid, reliable quantification of amniotic fluid enzymes with only minor adaptation. Useful reference intervals can be obtained throughout gestation. Gamma-glutamyl-transferase, 5'nucleotidase, total-alkaline-phosphatase and amylase assay can help to confirm echographic evidence of bowel disorders and thereby improve patient management especially in case of gastroschisis.

Alkaline Phosphatase↗
PubMed2001

Correlations between serum assays of human chorionic gonadotrophin (hCG) and human placental lactogen (hPL) and pre-eclampsia or intrauterine growth restriction (IUGR) among nulliparas younger than 38 years.

OBJECTIVE: To study the relation between serum human chorionic gonadotrophin (hCG) levels measured at 15-18 weeks and gestational disorders, assess their correlation with the artery uteroplacental Doppler (AUD) at 24 weeks among nulliparas, and assess the predictivity of the hCG/hPL (human placental lactogen) ratio for pre-eclampsia. STUDY DESIGN: Retrospective study of two groups of women younger than 38 years old: one with an elevated serum hCG level (2 MoM (multiples of the median) or more) and a normal fetal karyotype (group A), and the other with a lower hCG level (group B). Within each group, we studied the nulliparas separately (respectively groups AO and BO). We analyzed the double screening, elevated hCG levels with abnormal AUD, for the predicting of hypertensive disorders. RESULTS: Elevated hCG levels were significantly (p<0.05) more prevalent among women who developed gestational diabetes (groups A and AO) and among nulliparas with pregnancy-induced hypertension and pre-eclampsia (AO). Among nulliparas, the combination of the hCG assay and a subsequent Doppler increased the positive predictive value (PPV) of the assay from 19 to 75%, without reducing its negative predictive value (NPV) for gestational vascular disorders. The hCG/hPL ratio did not improve the predictivity of the hCG assay alone for pre-eclampsia. CONCLUSIONS: An hCG level of 2 MoM or more at 15-18 weeks identifies a group of women at risk of gestational vascular disorders; it therefore ought to lead to an AUD at 24 weeks. This double screening should be able to define a population of women at risk of developing a hypertensive disorder, who could thus benefit from a preventive treatment, as aspirin.

Adult↗
PubMed2001

Failure of cervical fibronectin to predict premature delivery in a population of monofetal pregnancies with idiopathic preterm labor.

OBJECTIVE: The purpose of the study was to evaluate the correlation between the presence of cervical fibronectin in a high-risk population of women with symptoms of preterm labor and the occurrence of preterm delivery or the need for aggressive tocolysis. STUDY DESIGN: One hundred and thirty women presenting with symptoms of threatened preterm labor were included. Cervical sampling for detection of fibronectin was performed on admission and every day until discharge or delivery. Time to delivery, length of hospital stay, use of indomethacin, delivery before 37 weeks of GA, mean term of delivery and failure of tocolysis to prevent delivery were compared to fibronectin test results. Data were analyzed using Student's t-test for continuous variables and the chi(2) test or Fisher exact test for discrete variables. RESULTS: No correlation could be found between the results of fibronectin cervical sampling on admission and any of the outcome parameters studied. Test performances were low (sensitivity 28%, specificity 57%, positive predictive value 19%, negative predictive value 69%). Results were not modified when the findings of repeated tests were taken into account. CONCLUSION: Cervical fibronectin failed to discriminate a subgroup of symptomatic women delivering prematurely. The prognostic value of fibronectin testing was not better than clinical data in our series. This observation is in disagreement with previous studies on the diagnostic value of vaginal or cervical fibronectin in preterm labor.

Cervix Uteri↗
PubMed2001

Defect of syncytiotrophoblast formation and human chorionic gonadotropin expression in Down's syndrome.

The syncytiotrophoblast (ST) is a major component of the human placenta as it is involved in feto-maternal exchanges and the secretion of pregnancy-specific hormones. We have studied the formation and function of the ST in normal and trisomy 21 (T21)-affected placenta using the in vitro model of cytotrophoblast differentiation into ST. Cytotrophoblast cells were isolated from first trimester, second trimester and term placentae. In vitro cytotrophoblast cells isolated from normal placenta fused to form the ST. This was associated with an increase in the transcript levels and the secretion of human chorionic gonadotropin (hCG). However, the secretion of hCG decreased through pregnancy. In T21-affected placentae, we observed a defect (or a delay) in ST formation and a dramatic decrease in the synthesis and secretion of this hormone compared with cultured cells isolated from control age-matched placentae. These results were confirmed by a significant (P < 0.05) decrease in transcript levels of alpha and beta subunits of hCG in total homogenates of T21-affected placentae compared with controls. These results suggest a decrease in functional mass of ST in T21 placenta, and therefore a decrease in production of placental pregnancy-specific polypeptide hormones.

Adult↗