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Biomedical subjects

O Sibony

Publications and source records attributed to O Sibony.

At least 37 records · Page 2Linked to original sources
PubMed1998

In utero fetal cerebral intraparenchymal ischemia diagnosed by nuclear magnetic resonance.

Fetal brain damage can have many causes, the most common being possibly asphyxia which is often associated with intrauterine growth retardation. Early recognition of cerebral lesions is important in guiding obstetrical management. A case of antenatal cerebral intraparenchymal ischemia diagnosed by nuclear magnetic resonance (NMR) earlier than cerebral ultrasound examination is reported. This case report indicates that NMR may be a useful tool for the early detection of cerebral impairment in severe fetal growth retardation.

Adult↗
PubMed1997

The c-ets1 protooncogene is expressed in human trophoblast during the first trimester of pregnancy.

Expression of the c-Ets1 protooncogene which codes for a transcription factor is associated with neovascularization and invasive processes. In order to determine c-Ets1 expression at the mRNA level, during the process of implantation during the first trimester of human pregnancy, samples of trophoblast were retrieved at the time of legal abortion and processed for in situ hybridization. We found that c-Ets1 mRNAs are transcribed in the endothelial cells of villous trophoblast and in the extravillous trophoblastic cells invading the uterine vessels. However, no transcript was found in maternal endothelial cells. We conclude that c-Ets1 plays a role in angiogenesis occurring in the development of the villous tree and is involved during the invasive process of the endometrium and maternal vessels by trophoblastic cells; this latter physiological event is crucial for a normal development of the fetus, its failure leading to pathological cases. We suggest that the role of the c-Ets1 protooncogene is related to the regulation of metalloproteinase genes transcription, a gene family which is known to be a target for Ets protein.

Antigens, CD34↗
PubMed1997

Computerized microscope morphometry of umbilical vessels from pregnancies with intrauterine growth retardation and abnormal umbilical artery Doppler.

Computerized microscope morphometry was used to study cross sections from the vessels of the umbilical cord in placentas of patients with intrauterine growth retardation (IUGR) that displayed either normal or abnormal umbilical arteries (UA) Doppler flow velocity waveforms (FVW). Cords from 63 eutrophic fetuses with normal Doppler (controls), 47 IUGR fetuses with normal Doppler and 32 IUGR fetuses with abnormal Doppler underwent morphometric analysis using a highly optimized microscope environment (HOME) and "CordHOME" software. IUGR with an accompanying normal Doppler versus control showed a reduction of Wharton jelly and both the total and lumen vein areas. IUGR with an accompanying pathological Doppler showed a comparable reduction in wall thickness and areas of every vessel. These findings indicate that the hypoplastic umbilical vessels are associated with an increase in placental vascular resistance that may be the consequence of underdevelopment in response to a chronic reduction in placental blood flow.

Blood Flow Velocity↗
PubMed1997

Fetal fibronectin in the cervical secretion predicts accurately the onset of labor at term.

OBJECTIVE: The objective of our study was to check if presence of fetal fibronectin in the cervical secretion of full term patient predicts accurately the onset of labour at term. STUDY DESIGN: 78 women in the term period were included in the study, serial samples for fetal fibronectin were assessed, each patient underwent spontaneous labour, delay between last sample and delivery were analysed. RESULTS: Patient with positive fetal fibronectin delivered within 3 +/- 1.9 days where as patient with negative fetal fibronectin delivered within 5.7 +/- 3.9 days (P = 0.01). CONCLUSION: Presence of fetal fibronectin in cervical secretions seems to be a powerful tool to predict in a short delay the onset of labour at term, it should be used in conjunction with clinical and fetal assessment data.

Adult↗
PubMed1996

[Amnioinfusion: indications and results].

Amnioinfusion is a recent procedure introduced for routine obstetrical care fifteen years ago. The most widely recognized indication for amnioinfusion is in labor, to reduce fetal distress due to variable decceleration associated with oligohydramnios and probable presence of thick meconium stained amniotic fluid. During pregnancy, amnioinfusion can help in the diagnosis and morphologic evaluation in case of anamnios. The indication for amnioinfusion in the management of oligohydramnios at term before labour remains controversial. As a new procedure amnioinfusion must be managed with extreme caution.

Amnion↗
PubMed1996

Can blood gas values predict pulmonary hypoplasia in antenatally diagnosed congenital diaphragmatic hernia?

The prognosis of antenatally diagnosed congenital diaphragmatic hernias (CDH) is clearly related to the degree of pulmonary hypoplasia (PH). After birth, controversies remain regarding the implementation of various therapies, especially the use of extracorporeal membrane oxygenation (ECMO). In the literature, the persistence of a Pao2 below 100 mm Hg and of Paco2 above 40 mm Hg despite optimal conventional therapy indicates poor prognosis. Therefore, since 1992, published and personal experiences led the authors to exclude CDH patients from ECMO when conventional therapy (including high-frequency oscillatory ventilation and nitric oxide) did not obtain Pao2 of above 80 mm Hg and Paco2 of below 60 mm Hg. The aim of this retrospective study is to determine whether blood gas results correlate with postmortem findings. Between July 1990 and July 1994, 32 cases of CDH were monitored antenatally and managed postnatally at the authors' institution. Six patients survived; 26 died, including one immediately at birth. Thirteen were treated by ECMO. Seventeen had a best Pao2 of above 80 mm Hg, including the six survivors. Fourteen did not reach this level, and none of them survived. Twenty-three infants underwent postmortem examination. PH was assessed using two criteria: (1) lung weight to body weight ratio (LW/BW) and (2) radial alveolar count (RAC). Two patients did not have hypoplasia (LW/BW > 0.018). Twenty-one patients had PH; 12 of them had an LW/BW ratio of less than .009; for 9, the LW/BW ratio was between .009 and .018, and the RAC (< 3.1) confirmed PH. All infants with a best Pao2 of less than 80 mm Hg had PH. Patients with a best Pao2 of greater than 80 mm Hg included two infants who died from complications without PH, eight infants with demonstrated PH, and the six survivors. In conclusion. (1) No infant with nonhypoplastic lungs has been deprived of ECMO by the authors' criteria. (2) Adequate values of blood gases may not eliminate PH. Therefore, this probably justifies starting ECMO when conventional therapy fails. (3) Conversely, permanent poor values of Pao2 allowed the prediction of PH in all cases. Such patients probably can be excluded from ECMO treatment.

Carbon Dioxide↗
PubMed1996

Direct and reversible inhibition of platelet factor 4 on megakaryocyte development from CD34+ cord blood cells: comparative studies with transforming growth factor beta1.

Mechanisms of the action of platelet factor 4 (PF4) on the growth of megakaryocyte (MK) progenitor cells in CD34+ cord blood (CB) cells were studied in comparison with transforming growth factor beta1 (TGFbeta1). Development of MK from CD34+ CB cells in both plasma clot culture and liquid culture was significantly inhibited by either purified human PF4 and by recombinant human TGFbeta1. Inhibition of MK colony formation by PF4 was reversible because CD34+ cells preincubated with PF4 could regenerate colonies after washing and replating into secondary cultures. In contrast, TGFbeta1-preincubated CD34+ cells gave rise to few colonies following replating. Moreover, incubation of CD34+ cells with PF4 in liquid culture caused the increased number of both stem cell factor (SCF)-binding cells and CD34 antigen-bearing cells. In addition, PF4-preincubated CD34+ cells exhibited a higher potential in MK colony formation in the presence of 5-fluorouracil (5FU). These results demonstrate that both PF4 and TGFbeta1 inhibit MK development from CD34+ CB cells by different mechanisms, and suggest that PF4, unlike TGFbeta1, exerts its inhibitory effect on the growth of the target cells in a reversible manner which results in a preservation of a more immature and 5FU-resistant cell population.

Antigens, CD34↗
PubMed1995

Spectral analysis of fetal heart rate in flat recordings.

Flat heart rate recordings may be observed in different fetal states such as chronic distress and sleep. Their visual analysis do not allow the distinction between these two states. We used spectral analysis to study the heart rate patterns in 25 fetuses. Two significant (P < 5 x 10(-5)) groups were apparent from the determination of the position of the maximum energy peak (PMEP) in the high-frequency band (0.20-0.50 Hz): a PMEP at about 0.20 Hz (group 1), and another around 0.30 Hz (group 2). The two groups did not differ in spectral density (SD). The outcome of neonates showed that group 1 fetuses made good progress and produced healthy neonates; whereas group 2 comprised cases of chronic fetal distress, or even death in utero, and neonatal distress. The significance of this difference in PMEP between fetal heart rate patterns in chronic distress and sleep is unclear. Studies combining the assessment of fetal movements and the determination of PMEP are planned.

Female↗
PubMed1995

Effects of neuromuscular blockade on fetal heart rate variability: a power spectrum analysis.

Spectral analysis of fetal heart rate variability allows quantitative determination of the main components that affect this variability. The physiological significance of these components is unclear; however, movements appear to contribute to variability. We studied six fetuses in which immobility required for in utero magnetic resonance or invasive fetal procedures was achieved by fetal intravascular injection of curare between 32 and 36 amenorrhea weeks. For each fetus, we compared spectral density parameters of heart rate variability. After curare administration, mean spectrum power was halved. We did not observe a larger significant decrease in any (very low, low, or high) frequency band. The other parameters of spectral analysis of variability were unaltered. Fetal movements accounted for a significant proportion of human fetal heart rate variability but did not constitute a unique frequency component.

Curare↗
PubMed1994

Quantification of the fetal heart rate variability by spectral analysis of fetal well-being and fetal distress.

Our objectives were to increase the discrimination between fetal distress and fetal well-being, using fetal heart rate spectral analysis. Monitoring of the heart rate from 259 fetuses was done between 26 and 42 weeks, interpreted with classical criteria, and analysed with the spectral analysis method we developed. The fetal heart rate spectrum analysis performed on these recordings allow discrimination of fetal distress from the normal state using the energy value and frequency of the maximal energy in the high frequency band. We can conclude that the spectral analysis produces two significant parameters which could contribute to a multivariate approach to assessments of the physiological mechanisms of heart rate variability.

Female↗
PubMed1994

[Has the use of indomethacin during pregnancy consequences in newborn infants? Prospective study of 83 pregnant women and 115 newborn infants].

BACKGROUND: Prolonged exposure of pregnant women to indomethacin for tocolysis may have significant effects on the fetus or neonate, but their incidence is still debated. POPULATION AND METHODS: From January 1990 to July 1991, 83 pregnant women were prospectively given indomethacin for treatment of premature labor, after ineffective course of salbutamol. The initial dose of indomethacin was 100 mg, then the daily dose was 50 mg while salbutamol was continued. Indomethacin was discontinued beyond the 33rd week of gestational age. Efficacy of indomethacin was judged upon the disappearance of uterine contractions and the increased duration of pregnancy from the onset of treatment until delivery. Adverse effects of treatment were evaluated in the neonates. RESULTS: The mean duration of indomethacin administration was 16 days (range: 1-62 days); the mean total dose was 900 mg (range: 100-4500 mg). The reason for discontinuation of the treatment was its efficacy (41 patients), a gestational age of 33 weeks (12 patients), oligoamnios (21 patients), demonstration of fetal abnormalities (two patients). The mean interval between discontinuation of treatment and delivery was 5 weeks. Fourty three of the 58 patients who were given indomethacin before the 30rd week were delivered after the 33rd week. There was no adverse effect in the women and babies; all oligoamnios were spontaneously reversible. One hundred and fifteen babies were born including 12 who died during the first post-natal days. The rate of admission in an intensive care unit was similar to that of untreated pregnancies. CONCLUSIONS: Indomethacin can be safely used for treatment of premature labor provided that its administration is carefully monitored.

Female↗
PubMedDate not supplied

Antenatal diagnosis of Bart's hydrops fetalis [correction of homozygous alpha thalassemia]. A case report.

OBJECTIVE: Diagnosis of the Bart's hydrops fetalis [corrected]. METHOD: Bart's hydrops fetalis [corrected] was discovered by chance in the fetus of a female Chinese patient. Major intrauterine growth retardation, oligohydramnios, an immobile fetus, and cardiomegaly were the principal echographic signs. Cordocentesis showed fetal anemia, and electrophoresis of fetal hemoglobin revealed the presence of Bart's hemoglobin. RESULT: As there is no known effective treatment, termination of pregnancy was proposed to the patient. CONCLUSIONS: Bart's hydrops fetallis [corrected] is a lethal condition. Early echographic signs (cardiothoracic index >0.50, placental thickening) can be screened during weeks 17-18 or even during weeks 13-14 of gestation. These signs would permit a reduction of invasive examinations in couples at risk.

Anemia↗
PubMedDate not supplied

Effect of amnioinfusion on the outcome of prenatally diagnosed gastroschisis.

OBJECTIVE: Following recent data showing that an inflammatory response exists in the amniotic fluid of gastroschisis-affected fetuses, we hypothesized that amniotic fluid exchange or amnioinfusion would improve the prognosis of prenatally diagnosed gastroschisis. METHODS: We compared the outcome of prenatally amnioinfused fetuses with gastroschisis to non-amnioinfused fetuses with gastroschisis. 10 patients undergoing this procedure were matched with 10 patients of our previous study. Comparisons were done on data including surgical procedure, follow-up in the NICU and the gastro-pediatric unit. RESULTS: Our results show that gastroschisis-affected fetuses undergoing amnioinfusion had a lower duration of curarization after surgery (2.2 +/- 1.9 vs. 6.8 +/- 6.9 days, p = 0.019), a shorter delay before full oral feeding (49.7 +/- 21.5 vs. 72.3 +/- 56.6 days, NS), and a shorter overall length of hospitalization (59.5 +/- 19.7 vs. 88.5 +/- 73.6 days, NS). We confirmed our previous data showing that amniotic fluid displays a chronic inflammation profile. CONCLUSION: Our data suggest that amnioinfusion could improve the outcome of gastroschisis affected fetuses. The hypothesis by which this improvement could be due to a reduction of an inflammatory response remains to be proved.

Adult↗