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Biomedical subjects

D Luton

Publications and source records attributed to D Luton.

At least 37 records · Page 2Linked to original sources
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

Maternal smoking during pregnancy and nicotine and cotinine concentrations in maternal and neonatal hair.

OBJECTIVE: Conflicting data have been reported in the association between maternal smoking and adverse effects during pregnancy and in neonates. Some studies, conducted on a limited number of patients have evaluated maternal consumption and fetal exposure by measuring nicotine and cotinine in the hair. Our aims were to evaluate the relationship among maternal cigarette consumption, fetal smoking exposure and outcome of pregnancy in a population of pregnant women who smoked. DESIGN: Mothers smoking during pregnancy were included at their first prenatal visit and followed prospectively. Maternal data (demographic variables, obstetrical history and cigarette consumption), neonatal data and birth indicators (number of weeks of gestation, type of delivery, weight) were collected. Hair samples from the mothers and the babies were collected at birth. SETTING: The present study was conducted in the Department of Obstetrics of the University Hospital Robert Debré in Paris. POPULATION: A total of 254 women smokers were included in the study and 182 mother/neonate pairs were analyzed after exclusion of 50 babies whose hair samples were inadequate and 22 for various other reasons. METHODS: Nicotine and cotinine concentrations in the maternal and neonatal hair were measured at birth by radio-immunoassay. MAIN OUTCOME MEASURES: Cigarette consumption was based on self reporting and quantified each trimester. It was expressed more precisely during the third trimester by the mean number per cigarette per day. Nicotine and cotinine concentrations in the maternal and neonatal hair at birth were also analysed. RESULTS: Nicotine and cotinine concentrations in maternal hair were associated with cigarette consumption during the third trimester of pregnancy (P < 0.003 and P < 0.01, respectively). In neonates, only cotinine concentrations were associated to maternal cigarette consumption (P < 0.0001). This association remained significant in a multivariate analysis, which included maternal cotinine hair concentrations and the ethnic group. CONCLUSIONS: Our results have shown a strong relationship between maternal cigarette consumption and fetal exposure to smoking measured by cotinine concentrations in neonatal hair. Further studies are required to look for associations between fetal exposure and adverse pregnancy outcome.

Adult↗
PubMed2002

[Isolated antenatal pyelic dilatation: postnatal follow-up and care for vesico-ureteral reflux].

OBJECTIVE: To assess the risk of aneuploidia in case of isolated antenatal pyelic dilatation and to detail urological care for these children. METHODS: Prenatal and postnatal follow-up was analyzed in 350 cases. RESULTS: The overall rate of chromosome anomalies was 1.3%. Trisomy 21 was found alone in one case (0.3%). The sex ratio was 26% girls and 74% boys. Vesico-ureteral reflux was similar in both sexes (13%). CONCLUSION: The question of proposing karyotyping in case of isolated pyelic dilatation remains unsolved because minimal subjective signs such as slightly excessive amniotic fluid can completely change the assessment of the risk of aneuploidia. The frequency of postnatal vesico-ureteral reflux associated with prenatal pyelic dilatation warrants complete prenatal ultrasound screening.

Adult↗
PubMed2002

[Severe post-partum hemorrhage: descriptive study at the Robert-Debré Hospital maternity ward].

OBJECTIVE: To analyze the prevalence, cause, treatment, and risk factors of severe post-partum hemorrhage (transfusion, surgery, radiology) observed at the maternity ward of the Robert-Debré Hospital, Paris. Method. This retrospective cohort was collected from a database including 19182 deliveries from 1992 to 1998. The entire medical file was reviewed in cases of severe hemorrhage. RESULTS: The prevalence of severe post-partum hemorrhage was 23 per 10,000 deliveries (44 patients). Transfusion was performed in 44/44 and hysterectomy in 3/44. Three patients were transferred to the intensive care unit. There were no deaths. At multivariate analysis, risk factors for severe post-partum hemorrhage were: abnormal placental insertion (OR=7.2; 95CI: 2.18-18.3), cesarean (OR=5.8; 95CI: 2.9-11.6), multiple pregnancy (OR=3.2; 95CI: 1.3-7.8), prematurity (OR=3, 95CI: 1.5-6.2), hypertension (OR=2.9; 95CI: 1.3-6.3). Twenty-six percent of the patients had no risk factors. CONCLUSION: The prevalence of severe pot-partum hemorrhage is low in our experience. The methodology used for this retrospective cohort does not enable an explanation. Intensive obstetrical care is necessary in case of abnormal placenta insertion. In 10 out of 44 cases, severe post-partum hemorrhage occurred in a context of insufficient monitoring, late or erroneous diagnosis, or incorrect treatment.

Analysis of Variance↗
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

Acyclovir prophylaxis in late pregnancy prevents recurrent genital herpes and viral shedding.

Neonatal herpes affects about 1 in 15,000 newborns and the prognosis for disseminated disease with encephalitis is poor. We investigated whether acyclovir prophylaxis in late pregnancy effectively reduces the risk of viral shedding and, hence, of mother-to-child transmission at delivery. A prospective study was conducted. Pregnant women who had at least one episode of genital herpes during pregnancy were randomly assigned to two groups: group 1 (n=167) received oral acyclovir from 36 weeks of gestation to term; group 2 (n=121) received no treatment. Group 3 (n=201) comprised women not given prophylaxis who had a history of genital herpes, but no active episodes during pregnancy. No specific instruction were set up for obstetrical management except for cesarean section in case of a suspected herpes lesion at the time of labor. The rate of Cesarean section was 8.4% in group 1, 16.5% in group 2, and 9.9% in group 3 (p<0.001). 75% of cesareans in group 2 and 10% in group 3 were done for genital herpes. Percentage of viral shedding was, respectively, 0% (group1), 5% (group2), and 0.5%(group3) (p<0.05). These findings underline the value of antiviral prophylaxis in late pregnancy for women with a known history of genital herpes. Such prophylaxis only partly prevents neonatal herpes infection, because it is not applicable to patients with no known clinical history but may excrete the virus.

Acyclovir↗
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

Pathologic and laboratory correlation in microcephaly associated with prenatal cocaine exposure.

The Authors report a case where cocaine abuse during pregnancy assessed by drug analysis at various site was associated with foetal microcephaly. Foetal pathologic findings revealed anomalies in neuronal migration and in the vascular architecture in the brain. Such anomalies might be the result of prolonged exposure to cocaine in utero, aggravated by the high concentration of cocaine metabolites in the amniotic fluid over a prolonged period.

Abnormalities, Drug-Induced↗
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↗
PubMed2001

Biochemical investigation of foetal and neonatal thyroid function using the ACS-180SE analyser: clinical application.

Despite sonographic detection of foetal goitre, uncertainty persists in the initial diagnosis of thyrotoxicosis and hypothyroidism. The aim of this study was to establish foetal and neonatal iodothyronine and thyrotrophin reference values for the ACS-180SE analyser. From 22 to 36 weeks of gestation, median foetal serum free thyroxine (FT4) levels increased from 6.0 pmol/L to 143 pmol/L, while free tri-iodothyronine (FT3) levels increased from 0.7 pmol/L to 1.9 pmol/L and mean thyrotrophin (TSH) levels remained stable (10.2 +/- 3.8mU/L; n = 33). At birth, concentrations were independent of gender and gestational age. Among the 10 cases of sonographically detected foetal goitre, serum TSH and FT4 were measured in five, showing hypothyroidism (3/5) or hyperthyroidism (2/5). Cord blood TSH levels reflected the efficacy of prenatal therapy. Measurement of foetal FT4 and TSH can be used to confirm foetal thyroid dysfunction, whereas treatment efficacy can be assessed sonographically and confirmed by measurement of TSH assay at birth.

Female↗
PubMed2001

Overexpression of copper zinc superoxide dismutase impairs human trophoblast cell fusion and differentiation.

The syncytiotrophoblast is the major component of the human placenta, involved in feto-maternal exchanges and secretion of pregnancy-specific hormones. Multinucleated syncytiotrophoblast arises from fusion of mononuclear cytotrophoblast cells. In trisomy 21-affected placentas, we recently have shown that there is a defect in syncytiotrophoblast formation and a decrease in the production of pregnancy-specific hormones. Due to the role of oxygen free radicals in trophoblast cell differentiation, we investigated the role of the key antioxidant enzyme, copper/zinc superoxide dismutase, encoded by chromosome 21 in in vitro trophoblast differentiation. We first observed that overexpression of superoxide dismutase in normal cytotrophoblasts impaired syncytiotrophoblast formation. This was associated with a significant decrease in mRNA transcript levels and secretion of hCG and other hormonal markers of syncytiotrophoblast. We confirmed abnormal cell fusion by overexpression of green fluorescence protein-tagged superoxide dismutase in cytotrophoblasts. In addition, a significant decrease in syncytin transcript levels was observed in superoxide dismutase-transfected cells. We then examined superoxide dismutase expression and activity in isolated trophoblast cells from trisomy 21-affected placentas. Superoxide dismutase mRNA expression (P < 0.05), protein levels (P < 0.01), and activity (P < 0.05) were significantly higher in trophoblast cells isolated from trisomy 21-affected placentas than in those from normal placentas. These results suggest that superoxide dismutase overexpression may directly impair trophoblast cell differentiation and fusion, and superoxide dismutase overexpression in Down's syndrome may be responsible at least in part for the failure of syncytiotrophoblast formation observed in trisomy 21-affected placentas.

Cell Differentiation↗
PubMed2001

Monochorionic monoamnionic twins: vaginal delivery.

Monochorionic monoamnionic pregnancies are rare and have a poor obstetric prognosis. A single amniotic sac promotes cord knotting and entanglement with a high risk of fetal anoxia. The response to this risk has been obstetric management consisting of routine cesarean section at 32 weeks of gestation or when pulmonary maturity is attained. This approach is called into question by the series of seven monochorionic monoamnionic pregnancies we present here. Such pregnancies do indeed require increased surveillance to term, but we think it is possible to apply the usual obstetric management of twin pregnancies.

Adult↗
PubMed2001

Fetal cerebral cortex: normal gestational landmarks identified using prenatal MR imaging.

BACKGROUND AND PURPOSE: Few investigators have analyzed the MR imaging patterns of fetal gyration. Our purpose was to establish, with a large prospective series, the normal sulcation landmarks according to gestational age by using in utero MR imaging and to correlate our findings with established neuroanatomic timetables. METHODS: A standardized fetal cerebral MR examination was performed in 173 normal fetuses at 22 to 38 weeks' gestation. Eight T1- and T2-weighted coronal, axial, and sagittal slices were obtained for each fetus and systematically analyzed. The sequential development of the different fissures and sulci of the cerebral cortex with respect to gestational age were tabulated. RESULTS: Sulcation of the medial, lateral, and inferior surfaces of the brain was depicted, and a timetable for the MR depiction of the primary and secondary sulci was established for the 22- to 38-week gestational period. This timetable was in good agreement with the neuroanatomic standards of reference, with a mean lag time of 1 week. CONCLUSION: This analysis of fetal brain sulcation in a large series of fetuses contributes to a better understanding of the maturation of the fetal cortex on MR imaging studies. It furthermore provides a standard of reference that can be used to assess the normality of fetal sulcation and to diagnose gyrational abnormalities with prenatal MR imaging.

Cerebral Cortex↗
PubMed2001

[Antenatal atrial tachycardia. Two case reports].

The authors report two cases of foetal supraventricular tachycardia in healthy hearts with 1/1 atrioventricular conduction which turned out to be atrial tachycardias in the postnatal period. The first foetus had permanent tachycardia at 190/minute at 34 weeks' amenorrhea with left ventricular dysfunction at 36 weeks. In the postnatal period, treatment with digoxine and amiodarone restored sinus rhythm and normal left ventricular function. Permanent foetal tachycardia, even at a rate of less than 200 beats/minute, should suggest an arrhythmia and may lead to left ventricular dysfunction in utero. The other foetus had an aneurysm of the foramen ovale with paroxysmal tachycardias at 220/minute without cardiac dysfunction. A Holter at 1 month showed paroxysmalatrial tachycardia. Postnatal rhythm monitoring is necessary in paroxysmal foetus tachycardia, especially with prenatal aneurysm of the foramen ovale.

Adult↗
PubMed2000

Analysis of uncultured amniocytes by comparative genomic hybridization: a prospective prenatal study.

Comparative genomic hybridization (CGH) is a new molecular cytogenetic technique which can detect and map whole and partial aneuploidies throughout a genomic specimen DNA without culturing specimen cells. Thus, CGH may be used as a comprehensive and rapid screening test in prenatal unbalanced chromosomal abnormalities detection. We report the results of the first prospective study to evaluate the use of the CGH technique on uncultured amniocytes. Seventy-one amniotic fluid samples, obtained by transabdominal amniocentesis between the 14th and 35th weeks of gestation, were simultaneously investigated using CGH and conventional cytogenetics. Amniocentesis were done for advanced maternal age (21.1%), fetal ultrasound anomalies (73.3%) and high level of biochemical markers in maternal serum (5.6%). Sixty-six (93%) informative results were generated on a total of 71 analysed specimens. Fifty-nine samples were reported as disomic for all autosomes with a normal sex chromosome constitution using CGH and conventional cytogenetics. Among them, three pericentromeric chromosomal inversions were undetected by CGH analysis. Seven numerical aberrations were characterized, including one case of trisomy 13, one case of trisomy 18 and five cases of trisomy 21. Advantages and limitations of CGH for a rapid prenatal screening of unbalanced chromosomal aberrations are discussed.

Amniocentesis↗