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Biomedical subjects

Y Dumez

Publications and source records attributed to Y Dumez.

At least 37 records · Page 2Linked to original sources
PubMed2002

The effect of a systemic arteriovenous fistula on the pulmonary arterial blood pressure in the fetal sheep.

In order to investigate whether systemic arteriovenous fistula occurring during the fetal period could induce pulmonary hypertension at birth, a fistula was surgically created between the carotid artery and jugular vein of fetal lambs at 120 days' gestation. Mean pressures in the left pulmonary artery, aorta, atrium and ventricles were measured at birth in seven experimental animals and in five control animals. Mean left pulmonary pressure was significantly higher in the lambs with fistula as compared with the control group, suggesting that prenatal occurrence of systemic arteriovenous fistula may induce fetal pulmonary hypertension. The present study provides a new animal model that could be relevant for the study of mechanisms regulating pulmonary vascular tone in the perinatal period.

Animals↗
PubMed2002

[First trimester fetal sex determination in maternal serum using real-time PCR].

OBJECTIVE: Fetal sex prediction can be achieved using PCR targeted at the SRY gene by analyzing cell-free fetal DNA in maternal serum. Unfortunately, the results reported to date, show lack of sensitivity, especially in the first trimester of pregnancy. Therefore, determination of fetal sex by maternal serum analysis can not replace caryotype analysis following chorionic villus sampling. PATIENTS AND METHODS: A new highly sensitive real-time PCR was developed to detect a SRY gene sequence in maternal serum. Analysis was performed on 121 pregnant women during their first trimester of pregnancy (mean gestational age: 11.8 weeks). Among them, 61 had at least one previous male-bearing pregnancy. Results were compared to fetal sex. RESULTS: SRY PCR analysis of maternal serum was in complete concordance with fetal sex. Among the 121 pregnant women, 61 were bearing a male fetus and 60 a female fetus No false negative results were observed. Furthermore, no false positive results results occurred although 27 women carried female fetus during the current pregnancy, had at least one previous male-bearing pregnancy. DISCUSSION AND CONCLUSION: This study demonstrates that a reliable, non-invasive sex determination can be achieved by PCR analysis of maternal serum during the first trimester of pregnancy. This non-invasive approach for fetal sex prediction should have great implications in the management of pregnant women carriers of an X-linked genetic disorder. Prenatal diagnosis is thus performed for male fetuses only, avoiding invasive procedures and the risk of fetal loss for female fetuses.

DNA↗
PubMed2002

Middle cerebral artery Doppler in fetuses with transposition of the great arteries.

OBJECTIVE: A previous anthropometric study has shown that neonates with transposition of the great arteries have a smaller head circumference and intracranial volume, which may be related to a lower oxygen content of blood delivered to the head and upper extremities. The aim of this study was to compare Doppler blood flow velocity waveforms in fetuses with transposition of the great arteries with those in healthy fetuses. METHODS: Doppler blood flow velocimetry was performed in the middle cerebral artery, the umbilical artery, the aorta and the ductus venosus in a consecutive series of 23 fetuses with transposition of the great arteries between 36 and 38 weeks' gestation. The control group consisted of 40 healthy fetuses matched for gestational age. RESULTS: There was no significant difference in pulsatility indices in the umbilical artery, the aorta and the ductus venosus between fetuses with transposition of the great arteries and controls. The median middle cerebral artery pulsatility index in the group with transposition of the great arteries was 1.37 (range, 1.10-2.02) and was significantly lower than that in the control group (median, 1.68; range, 1.46-2.04) (P < 0.001, Mann-Whitney test). CONCLUSIONS: The lower pulsatility indices observed in the middle cerebral artery of fetuses with transposition of the great arteries may reflect a trend towards cerebral vasodilation. This phenomenon could be an indicator of hypoxemia and/or hypercapnia restricted to areas perfused by the preisthmus aorta and be related to the characteristics of the circulation in fetuses with transposition of the great arteries.

Blood Flow Velocity↗
PubMed2002

Prenatal diagnosis of bilateral isolated fetal hyperechogenic kidneys. Is it possible to predict long term outcome?

OBJECTIVE: To study perinatal and long term outcome following prenatal diagnosis of hyperechogenic kidneys. DESIGN: Prospective observational cohort study. SETTING: The Maternité Port-Royal Hôpital Cochin and at the Departments of Obstetrics and Paediatric Nephrology, Necker Enfants Malades in Paris, France. POPULATION: Forty-three fetuses with isolated bilateral hyperechogenic kidneys. METHODS: All patients referred with isolated bilateral hyperechogenic fetal kidneys were followed up prospectively up to 34-132 months. The following prenatal items were analysed: fetal kidney size, amniotic fluid volume, gestational age at diagnosis, family history and renal ultrasound in parents. Postmortem examination was carried out in cases with perinatal death. Postnatal follow up of survivors included postnatal ultrasound, blood pressure, serum creatinine, proteinuria, need for restricted diet, weight and height and renal biopsy when available. MAIN OUTCOME MEASURES: Aetiology of hyperechogenicity, perinatal mortality and renal function in survivors. RESULTS: The aetiology could be established by family history, postmortem or postnatal data, but not by prenatal ultrasound. There were 20 autosomal recessive, 8 autosomal dominant polycystic kidney diseases, 9 other renal disorders and 6 symptom-free survivors without aetiological diagnosis. There were 19 terminations of pregnancy, 5 neonatal deaths and 19 survivors, of whom 14 had normal renal function three had mild and two had end stage renal failure. None of those with severe oligohydramnios and fetal kidneys > 4 SD survived (n = 14, 10 terminations and 4 neonatal deaths), whereas of the 17 with normal amniotic fluid volume and kidneys < 4 SD, 14 survived, of whom 9 were symptom-free. CONCLUSION: Aetiology could not be established prenatally in the absence of familial data. Kidney size and amniotic fluid volume were the best prenatal predictors of outcome.

Cohort Studies↗
PubMed2001

Prenatal diagnosis of respiratory chain deficiency by direct mutation screening.

Respiratory chain deficiency (RCD) is responsible for a clinically heterogeneous group of early-onset untreatable disorders. Enzymological prenatal diagnosis (PD) can only be offered to a fraction of families. Moreover, due to the two-fold genetic origin of the respiratory chain (nuclear and mitochondrial DNA) and owing to the large number of nuclear genes involved in the respiratory chain assembly, maintenance and functioning, the identification of the disease causing gene in a given family remains challenging. Here, we report on PD of RCD by direct screening of NDUFV1, SDH-Fp, SCO1 and SURF1 mutations in five unrelated families with complex I, II and IV deficiency, respectively. The identification of the disease-causing gene in a given family with RCD is a major issue to provide both adequate genetic counselling and early, reliable PD.

Electron Transport↗
PubMed2001

Successful intrauterine shunting of a sacrococcygeal teratoma (SCT) causing fetal bladder obstruction.

We report a case of a sacrococcygeal teratoma (SCT) diagnosed at 22 weeks with a substantial intrapelvic cystic extension leading to bladder outlet obstruction and hydronephrosis at 27 weeks. Prenatal percutaneous shunting of the cystic teratoma was performed at 28 weeks to avoid prolonged fetal pelvic compression by the tumour that could have adverse effects by stretching the pelvic plexus and sacral nerves. Urinary dilatation resolved completely after shunting and a 3880 g baby girl was delivered at 39 weeks. The potential benefits of in utero shunting to avoid urological complications of SCTs with intrapelvic extension are discussed.

Adult↗
PubMed2001

First-trimester fetal sex determination in maternal serum using real-time PCR.

Fetal sex prediction can be achieved using PCR targeted at the SRY gene by analysing cell-free fetal DNA in maternal serum. Unfortunately, the results reported to date show a lack of sensitivity, especially during the first trimester of pregnancy. Therefore, determination of fetal sex by maternal serum analysis could not replace karyotype analysis following chorionic villus sampling. A new highly sensitive real-time PCR was developed to detect an SRY gene sequence in maternal serum. Analysis was performed on 121 pregnant women during the first trimester of pregnancy (mean gestational age: 11.8 weeks). Among them, 51 had at least one previous male-bearing pregnancy. Results were compared with fetal sex. SRY PCR analysis of maternal serum was in complete concordance with fetal sex. Among the 121 pregnant women, 61 were bearing a male fetus and 60 a female fetus. No false-negative results were observed. Furthermore, no false-positive results occurred, even though 27 women carrying a female fetus during the current pregnancy had at least one previous male-bearing pregnancy. This study demonstrates that a reliable, non-invasive sex determination can be achieved by PCR analysis of maternal serum during the first trimester of pregnancy. This non-invasive approach for fetal sex prediction should have great implications in the management of pregnant women who are carriers of an X-linked genetic disorder. Prenatal diagnosis might thus be performed for male fetuses only, avoiding invasive procedures and the risk of the loss of female fetuses.

DNA↗
PubMed2001

[Opinions of couples on care during medical termination of pregnancy].

OBJECTIVES: To study the medical care, staff attitudes and patients' satisfaction from the decision to the post-intervention medical visit for termination of pregnancy for fetal abnormalies. PATIENTS AND METHODS: All patients and their spouses having a termination of pregnancy at the "Unite de Medecine Foetale" in Port-Royal Hospital between November 1996 and July 1997 were contacted for the study. A self-administered questionnaire was mailed six to eight weeks after intervention. Forty seven women and 42 men returned a completed questionnaire, the response rates were respectively 68% and 61%. RESULTS: The patients and their spouses rated globally very high their satisfaction about the care received. The delay before intervention, the length and pain of labour were rated less positively. The factors associated with satisfaction were the quality of the relationship with the staff, and of information. Positive feelings about delivery were linked with the consideration and relief of pain. Most respondents mentioned that their physical and psychological state has improved at the moment of the survey but the psychological distress subsisted or has increased in one fourth of the cases. On the whole the answers made within the couples were correlated. CONCLUSION: The positive results should be moderated by the number of non-respondents. In a context of very high rates of satisfaction, psychological distress is still present for one respondent out of four, six to eight weeks after termination of pregnancy for fetal abnormalies.

Abortion, Therapeutic↗
PubMed2001

Fetal lung volume measurement by magnetic resonance imaging in congenital diaphragmatic hernia.

OBJECTIVE: To study the potential for prenatal magnetic resonance imaging to predict pulmonary hypoplasia in congenital diaphragmatic hernia. DESIGN: Prospective observational study. SETTING: Tertiary care centre. PARTICIPANTS: Thirteen cases of congenital diaphragmatic hernia (11 left, 2 right) without associated anomalies and 74 controls. METHODS: Measurements by magnetic resonance imaging of fetal lung volume were achieved. In the control fetuses, a regression analysis was performed to associate fetal lung volume with gestational age. This yielded a formula allowing calculation of the expected fetal lung volume as a function of gestational age. In the cases with congenital diaphragmatic hernia, the observed/expected fetal lung volume ratio was compared with perinatal outcome. MAIN OUTCOME MEASURES: Neonatal mortality and pulmonary hypoplasia, which was defined as lung/body weight ratios less than 0.012. RESULTS: The expected fetal lung volume was derived from the following formula: Fetal lung volume (mL) = exp (1.24722 + 0.08939 x gestational age in weeks). The observed/expected fetal lung volume ratio was significantly lower in congenital diaphragmatic hernia (median: 0.31, range: 0.06-0.63), than in controls (median: 0.99, range: 0.42-1.94). This ratio was significantly less in the infants with congenital diaphragmatic hernia who died (median: 0.26, range: 0.06-0.63) compared with those who survived (median: 0.46, range: 0.35-0.56). The observed: expected fetal lung volume ratio was significantly correlated with the post mortem lung: body weight ratio. CONCLUSION: In isolated congenital diaphragmatic hernia, fetal lung volume measurement by magnetic resonance imaging is a potential predictor of pulmonary hypoplasia and postnatal outcome. Further studies are required to establish the clinical value of magnetic resonance imaging for the prenatal assessment of fetal lungs.

Case-Control Studies↗
PubMed2000

[Fetal pain].

IN UTERO CARE: The definition of pain proposed by the International Association for the Study of Pain is not adapted to the newborn or to the fetus because it assumes recognition and verbal expression of an unpleasant experience. Neonatologists have however demonstrated that full term and highly premature infants experience pain. In addition, the health of these infants improves with proper management. Such an approach is indispensable, not only from an obvious humane point of view, but also because treatment of pain in utero could have a beneficial effect for the fetus. PRENATAL PAIN AND ITS CONSEQUENCES: As it is impossible to resolve the question of conscious perception of pain by the fetus, we use experimental or clinical arguments favoring sensitivity to pain to assess pain during fetal life. We have also investigated the deleterious consequences of antenatal pain and how to evaluate them clinically in order to propose therapeutic care. It can be accepted that the fetus is able to perceive pain as early as 26 weeks gestation, possibly from 20 weeks. In the short-term, fetal pain causes changes in behavior, hemodynamics and hormonal functions but the long-term consequences remain unknown. ANTENATAL ANALGESIA: As no validated data on assessment of pain in the fetus are available, prevention becomes primordial in all at risk situations (pregnancy termination beyond 24 weeks gestation, in utero interventions). Morphine derivatives (sufentanil) would be the analgesic of choice for antenatal pain.

Animals↗
PubMed2000

Prenatal diagnosis of pyloric atresia-junctional epidermolysis bullosa syndrome in a fetus not known to be at risk.

Junctional epidermolysis bullosa with pyloric atresia (PA-JEB) is a highly lethal, inherited, autosomal recessive disease. Thus far, prenatal diagnosis of this syndrome was only realized on pregnancies at risk for recurrence. We report the case of a 26-year-old woman, first cousin to her husband, who had undergone amniocentesis for polyhydramnios. The karyotype was normal but the amniotic fluid contained acetylcholinesterase. A targeted scan at 25 weeks' gestation did not find spina bifida, but polyhydramnios with a dilated stomach, and several other anomalies: echogenic particles in the amniotic fluid, a thin skin which closely adhered to the nasal bones, narrow nostrils, abnormal ears, fisted hands, malposition of both first toes, and kidney malformation. Despite no previous case in the family, it was thought that sonographic findings were suggestive of the PA-JEB syndrome. A fetal skin biopsy was carried out at 28 weeks' gestation. The ultrastructural examination of fetal skin displayed JEB. Genetic analysis detected a homozygous mutation in the gene encoding integrin alpha 6. Termination of pregnancy was carried out at 29 weeks' gestation. These results illustrate that in the case of a fetus not known to be at risk, diagnosis of PA-JEB can be achieved by ultrasound findings leading to fetal skin biopsy and ultrastructural examination of blistered epidermis. Some new sonographic signs should raise the possibility of significant cutaneous desquamation and blister formation in a fetus, especially when there is positive amniotic acetylcholinesterase coupled with elevated alpha-fetoprotein or suspected pyloric atresia.

Abnormalities, Multiple↗
PubMed2000

Determination of enzyme activities for prenatal diagnosis of respiratory chain deficiency.

Genetic counselling and prenatal diagnosis are major issues of mitochondrial respiratory chain deficiency, especially as these conditions are largely untreatable. In the absence of known mitochondrial or nuclear gene mutations, measurement of respiratory chain enzyme activities represents the only possibility to prevent recurrence of the disease in affected families. We carried out enzymatic prenatal diagnosis in 21 pregnancies from 10 unrelated couples using uncultured choriocytes and/or amniocytes. Twelve babies were born and are healthy, seven pregnancies were discontinued early on because of an enzyme deficiency detected prenatally. In two cases, a fetus which appeared normal after early and/or late prenatal diagnosis, turned out to be affected. We conclude that a deficient enzyme activity is indicative of recurrence, but a normal result at 10 weeks of gestation does not give conclusive evidence as to the outcome of the pregnancy. We therefore suggest the following procedure: (1) a choriocentesis or an amniocentesis in early pregnancy when the proband expresses the disease in cultured skin fibroblasts; (2) a second amniocentesis at 28 weeks' gestation should be offered to avoid false negative results due to a possible late expression of the disease, in combination with: (3) a careful and repeated ultrasound survey for detection of growth failure in the third trimester; (4) prenatal diagnosis should not be performed in case of late onset clinical symptoms in the proband; and (5) parents should be aware of the possibility of false negative results. Prenatal diagnosis should not be proposed for a complex I deficiency as this enzyme activity cannot be accurately measured in fetal cells.

Adult↗
PubMed2000

Twin-to-twin transfusion syndrome. Role of the fetal renin-angiotensin system.

The twin-to-twin transfusion syndrome (TTS) results from an unbalanced blood supply through placental anastomoses in monochorionic twins. It induces growth restriction, renal tubular dysgenesis, and oliguria in the donor and visceromegaly and polyuria in the recipient. A better understanding of its pathophysiology could contribute to improving the management of TTS, which still carries a high perinatal mortality in both twins. As well as several other candidates, the renin-angiotensin system might be involved in TTS. To evaluate its role in the pathogenesis of the syndrome, we studied the kidneys of 21 twin pairs who died from TTS at 19 to 30 weeks, compared with 39 individuals in a control group, using light microscopy, immunohistochemistry, and in situ hybridization. The overexpression of the renin protein and transcript with frequent evidence of renin synthesis by mesangial cells was observed in the donor kidneys, presumably as a consequence of chronic renal hypoperfusion. This upregulation of renin synthesis might be beneficial to restore euvolemia. In severe cases of TTS, however, angiotensin-II-induced vasoconstriction acts as an additional deleterious factor by further reducing the renal blood flow in donors. In recipients, renin expression was virtually absent, possibly because it was down-regulated by hypervolemia. However, in addition to congestion and hemorrhagic infarction, there were severe glomerular and arterial lesions resembling those observed in polycythemia- or hypertension-induced microangiopathy. We speculate that fetal hypertension in the recipient might be partly mediated by the transfer of circulating renin produced by the donor, through the placental vascular shunts.

Female↗
PubMed2000

Fetal serum beta2-microglobulin predicts postnatal renal function in bilateral uropathies.

BACKGROUND: Predicting postnatal renal function is crucial for the prenatal evaluation of fetal bilateral uropathies. Prenatal ultrasound can identify intrauterine terminal renal failure, but is not sensitive enough to identify those infants who would survive with an impaired renal function. Because it reflects fetal glomerular filtration, fetal serum beta2-microglobulin is a potential predictor of postnatal renal function. METHODS: Fetal serum beta2-microglobulin (beta2m) was assayed in 61 cases of bilateral or low obstructive uropathy, 74 controls, and 17 cases of bilateral renal agenesis, and was correlated with renal function. RESULTS: Fetal serum beta2m was 3.2 mg/L (range 1.5 to 4.7) in controls (N = 74), 9.5 mg/L (range 6.7 to 11.3) in bilateral renal agenesis (N = 17), 7 mg/L (5.1 to 10.6) in uropathy in which terminal renal failure resulted in termination of pregnancy (N = 26), and 3.7 mg/L (range 2.3 to 11.2) in live births with uropathy (N = 35). In the latter subgroup, fetal serum beta2m was significantly and positively correlated (r2 = 0.91) with postnatal serum creatinine. All survivors with a postnatal serum creatinine < or =50 micromol/L ha a fetal serum beta2m lower than 5 mg/L. Four of 6 survivors with a postnatal serum creatinine> 50 micromol/L had a fetal serum beta2m greater than 5 mg/L. CONCLUSION: Fetal serum beta2-microglobulin is a marker for renal function and predicts postnatal serum creatinine in bilateral or low fetal obstructive uropathy.

Biomarkers↗
PubMed2000

Maternal uniparental heterodisomy of chromosome 14: chromosomal mechanism and clinical follow up.

To our knowledge, 22 cases of chromosome 14 maternal uniparental disomy (UPD(14)mat) have been reported so far. The majority of cases were ascertained because of an abnormal phenotype associated with a Robertsonian translocation involving chromosome 14. We report here on a child with UPD(14)mat detected prenatally and resulting from trisomy rescue in a maternal meiosis I non-disjunction trisomic zygote. After four years of clinical follow up, in addition to intrauterine growth retardation (IUGR), only short stature and small hands and feet were observed. These clinical data as well as the ascertainment and mechanism of origin of UPD(14)mat were compared with those observed in previously reported cases. It appears that the clinical spectrum of UPD(14)mat is milder in our patient than in patients with UPD(14)mat resulting from other chromosomal mechanisms. In addition, a hypothesis based on abnormal imprinting is proposed to explain the variability of the UPD(14)mat.

Adult↗
PubMed1999

First prenatal diagnosis of defects in the HsPDX1 gene encoding protein X, an additional lipoyl-containing subunit of the human pyruvate dehydrogenase complex.

We have previously reported a genetic study of a neonatal lactic acidosis linked to a pyruvate dehydrogenase complex deficiency due to the absence of the protein X subunit. This rare autosomal recessive disorder is associated with specific deletions in this polypeptide which is encoded by the HsPDX1 gene, located on chromosome 11p1.3. The pathology of the patient was considered to arise from a large homozygous deletion (78del85) found at the 5' end of the HsPDX1 coding sequence. Her heterozygous mother underwent prenatal diagnosis during a subsequent pregnancy. Chorionic villus samples were used for three independent studies: (1) normal levels of the protein X component of the PDH complex were detected by immunoblotting; (2) RT-PCR analysis showed no deletion at the 5' end of the cDNA but the presence of a distinct heterozygous deletion (965del59) at its 3' end inherited from the father; (3) haplotype analysis revealed the presence of the father's mutated allele and the mother's normal allele. It was concluded that the fetus was heterozygous for this separate 3' deletion, so, it was likely to be not affected. This study permitted us to characterize more precisely the genetic abnormalities of the HsPDX1 cDNA occurring in each family's member.

Blotting, Western↗