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Biomedical subjects

R Favre

Publications and source records attributed to R Favre.

At least 73 records · Page 4Linked to original sources
PubMed1994

Antenatal diagnosis and treatment of fetal hydrops secondary to pulmonary extralobar sequestration.

Bronchopulmonary sequestration with associated non-immune hydrops has been previously reported with generally poor prognosis for the neonate. The vast majority of sequestrations are discovered postnatally, and less than half are correctly identified as sequestration before birth.Until recently, treatment for pulmonary sequestration was limited to postnatal respiratory support and resection of the sequestered lung. But aggressive respiratory support does not succeed in salvaging infants with underlying pulmonary hypoplasia. In our report, we describe the antenatal treatment of pleural effusions complicated by hydrops fetalis secondary to a bronchopulmonary sequestration, successfully managed with a transthoracic catheter placement. This therapy resulted in the resolution of pleural effusion, polyhydramnios and hydrops, with a good fetal outcome.

Journal Article↗
PubMed1994

Fetal arachnoid cyst: report of two cases.

Two new cases of antenatal diagnosis of arachnoid cyst are described. Diagnosis was made at 2.5 and 32 weeks' gestational age. In the first case, a slight increase in the diameter of the anechoic mass was observed in the second trimester. In the second case, ventricular dilatation was present prenatally. Appropriate surgical therapy was initiated at 2 months in the first case and at 8 days in the second and the neurological development of the two children is considered as normal at 18 months of age. Major features of in utero diagnosis, treatment and follow-up are discussed.

Journal Article↗
PubMed1994

Relative bioavailability of two oral formulations of navelbine in cancer patients.

A study was carried out in 14 cancer patients to assess the relative bioavailability of two oral formulations of navelbine. A single 130 mg oral dose of the drug was given according to a randomized two-way crossover design as two capsules: one contained the drug in powder (formulation A, reference); another contained the drug in solution (formulation B). A 7 d washout period separated each dose. Navelbine was rapidly absorbed after administration of either formulation and exhibited a biphasic concentration decay pattern. The peak plasma level was reached within 2 h of administration in most patients. Formulation B resulted in better navelbine absorption with respect to peak plasma concentration (Cmax) and area under the plasma concentration-time curves (AUC) than did formulation A as ascertained by analysis of variance (ANOVA). The relative bioavailabilities (solution versus powder) were, respectively, 286.0% and 268.0% as estimated from experimental (0-72 h) and extrapolated (0-infinity) AUC.

Absorption↗
PubMed1994

Pharmacokinetics of high-dose methotrexate in adult osteogenic sarcoma.

The pharmacokinetics of 222 infusions of high-dose methotrexate (MTX) with leucovorin rescue were studied in 22 adults with osteosarcoma. To reduce the variability of plasma concentration, we individualized dose regimens using a Bayesian method to reach a concentration of 10(-3) M MTX at the end of an 8-h infusion. The mean concentration observed at the end of the infusion was 1016 +/- 143 mumol/l. The mean dose delivered was 13.2 +/- 2 g/m2. The clearance was 49.1 +/- 11.7 ml min-1 m-2. The decay of the plasma concentration of MTX after completion of the infusion followed a two-compartment model with a t1/2 alpha of 2.66 +/- 0.82 h and a t1/2 beta of 15.69 +/- 8.63 h. The volume of distribution was 0.32 +/- 0.08 l/kg. As compared with previously published data, the interindividual and intraindividual variations in the concentration at the end of the infusion were reduced, with values of 14% and 5.9%-21%, respectively, being obtained. Severe toxicities were avoided, and there were only 3 hematologic and 8 digestive grade 3 side effects and no grade 4 complication. The t1/2 alpha and the MTX plasma concentrations at 23 and 47 h were correlated with renal toxicity (P < 0.001). However, no correlation was found between the pharmacokinetic parameters and other signs of toxicity. There was no significant difference in pharmacokinetics between the toxic and nontoxic groups. In the same manner, the parameters of the group of patients sensitive to MTX were not statistically significant different from those of the group of nonsensitive patients.

Adolescent↗
PubMed1994

Ultrastructural immuno-localization of CUT-1 and CUT-2 antigenic sites in the cuticles of the nematode Caenorhabditis elegans.

CUT-1 and CUT-2 are two distinct proteins found in cuticlin, the insoluble residue of the cuticles of the nematode Caenorhabditis elegans. They are the products of genes which have been previously characterized molecularly. These proteins have been expressed as recombinant in Escherichia coli and specific antisera have been raised against them. The experiments reported here regard their ultrastructural immuno-gold localization either on purified cuticles or on whole worms of various stages of development of Caenorhabditis elegans. A location in the cortical layer of the isolated cuticles is common to all stages, whereas there is a dauer specific location in the fibrous ribbon underneath the alae. These localizations are compared with immuno-labelling obtained using a serum raised against the whole cuticlin residue. CUT-1 and CUT-2 epitopes are easily and specifically lost during conventional chemical fixation.

Animals↗
PubMed1993

Predictive value of transvaginal uterine Doppler assessment in an in vitro fertilization program.

This study evaluates the prognostic value of uterine Doppler performed on the day of embryo transfer in an in vitro fertilization program. Patients were divided into two groups according to the type of ovarian stimulation. The Doppler investigation was carried out using vaginal sonography. The pulsatility index was used to evaluate the uterine blood flow pattern. The hormonal profile (estradiol, luteinizing hormone (LH) and progesterone) was correlated to Doppler results and to the pregnancy rate. The comparison between patients treated with analogs and those who were not shows a significant difference in their hormonal profile. In the first group, we found a higher estradiol and progesterone serum concentration. The LH level and the pulsatility index were statistically lower. The endometrium was thicker in patients treated with gonadotropin releasing hormone agonists. In the group of patients treated with analogs, the statistical analysis showed no significant difference in the mean pulsatility index value in women who achieved a pregnancy and in those who failed. In the group of patients who received no agonists, only one variable was significantly different: the mean age was lower in women who became pregnant. We observed no ongoing pregnancy in women who had a pulsatility index value higher than two standard deviations (pulsatility index = 3.55). We therefore suggest the use of this value as a threshold. Thus, if a patient has a high uterine artery impedance, cryopreservation should be used and embryo transfer should be postponed to a subsequent cycle, or embryo transfer delayed for a few days using co-culture. This study clearly shows the impact of hormonal response on the Doppler value and on the pregnancy rate. However, the use of a threshold value for uterine artery pulsatility index might have a clinical impact in the future management of patients attending an in vitro fertilization program.

Journal Article↗
PubMed1993

Measurement of limb circumferences with three-dimensional ultrasound for fetal weight estimation.

A large number of formulae have been published for fetal weight estimation. This study examines the possibility of using three-dimensional ultrasound to measure the limb circumference. This technology provides us with the opportunity to visualize two simultaneous, orthogonal planes, allowing the exact determination of the transverse plane at the mid-point of the limb. A total of 157 patients were scanned in the week prior to delivery. The following variables were measured in 154 fetuses: biparietal diameter, head circumference, transverse abdominal diameter, abdominal circumference, femur length, thigh circumference and arm circumference. The whole population was split into three subgroups according to the abdominal circumference centile (< 10th centile, 10-90th centile, and > 90th centile), because this single variable has the strongest correlation with neonatal weight (R = 0.901). With forward stepwise multiple regression analysis, four models were elaborated, one for the whole population and one for each subgroup. The small-for-dates fetuses need a targeted formula including only two variables, thigh circumference and femur length. Our data suggest that the thigh circumference measurement improves the estimation for growth-retarded fetuses and that the arm circumference improves the weight prediction for the others. The measurement of the two variables, made possible with three-dimensional ultrasound, has improved our results in fetal weight estimation.

Journal Article↗
PubMed1993

Analysis of plasma lipids by NMR spectroscopy: application to modifications induced by malignant tumors.

Lipid extracts of plasma were studied by 31P and 1H NMR spectroscopy at 9.4 T. Signals recorded on lipid mixtures were assigned to different lipid classes using a data base built with two-dimensional 1H COSY spectra of seven standard lipids. Signals unique to glycerophospholipids, sphingolipids, and triacylglycerols were identified. 31P and 1H NMR spectroscopy was used to study qualitative and quantitative modifications induced in plasma by malignant tumors. The results show a significant increase in triglyceride/phospholipid ratio and a concomitant decrease of total phospholipids in patients with cancer. In order to check for the possible presence of particular lipids such as glycolipids in these patients, 1H COSY spectra were recorded on the intact plasma and on extracts of plasma lipids in patients with cancer and in healthy subjects. Only in one case of ovarian cancer, a cross-peak at 1.35 and 4.15 ppm, corresponding to fucose residue in glycolipids, was detected.

Databases, Factual↗
PubMed1993

[Teratogenicity of retinoids. A case and review of the literature].

Retinoids are vitamin A derivatives used in dermatology. One of them, isotretinoin, is frequently prescribed for refractory juvenile acne. The teratogenetic power of this drug is substantial, being estimated at 15 to 45% of exposures in utero. The risk is maximum in the first trimester of pregnancy and persists up to one month after treatment has been discontinued. The most frequently described multiple malformation syndrome involves the face, the central nervous system and the heart. There is also a 20 to 30% rate of spontaneous abortion. The authors report a case where exposure during the first trimester did not result in foetal malformation. From a full review of the literature the various malformations observed, the presumed mechanisms of teratogenesis and the strict rules of prescription and surveillance in women child-bearing age are presented. The problem of the measures to be taken in case of retinoid treatment during pregnancy is discussed. The teratogenic risk from other retinoids is dealt with.

Adult↗
PubMed1992

[Medical treatment of chylous effusions in newborn infants. Apropos of 3 cases].

BACKGROUND: Chylous effusions are the most frequent cause of non immunologic hydrops fetalis. They can be recognized antenatally by ultrasonography. Their evacuation is sometimes necessary and medical treatment often effective. CASE REPORTS: Case n. 1: fetal ascites was detected by ultrasonography at the 30th week of gestation. Paracentesis was performed at 36 weeks, followed 3 days later by spontaneous delivery. The newborn was fed milk formula. A second paracentesis showed a milky fluid, rich in cholesterol, triglycerides and chylomicrons. The child was fed formula rich in medium-chain triglycerides and the chylous ascites disappeared completely within 2 weeks. Case n. 2: a diagnosis of bilateral hydrothorax and hydramnios was made at the 27th week of gestation. An in utero evacuation of the hydrothorax performed at the 30th week was ineffective and a pleuro-amniotic drainage was performed 2 weeks later. The baby was born at the 35th week, and presented a moderate respiratory distress due to the hydrothorax and ascites. Aspiration of the thoracic fluid confirmed its chylous origin. The chylous effusions completely disappeared when the child was fed a high medium chain triglycerides diet. A lymphedema of legs appeared at the age of 1 month. Case n. 3: ascites, hydramnios, hydrothorax and peripheral edema were found at the 21st week of a third pregnancy (the 2 first pregnancies were complicated by lethal hydrops fetalis). Bilateral hydrothorax and peripheral edema were found again after birth at the 37th week. Diuresis and albumin-infusion led to recovery, but chylothorax and chylous ascites reaccumulated after introduction of milk formula, despite repeated evacuations and feeding medium-chain triglycerides formula. The thoracic fluid remains chylous at the age of 9 months. CONCLUSIONS: In utero, and sometimes post-natal, evacuation of fluid present in the thoracic and peritoneal cavities can be necessary, depending of the functional tolerance. Medical management including feeding a low fat and/or high medium-chain triglycerides diet, and sometimes temporary total parental nutrition, is necessary, together with salt restriction, diuresis and albumin infusion as required. Most cases recover spontaneously or as a result of therapy within a few weeks.

Chylothorax↗
PubMed1991

Pharmacokinetics of navelbine after oral administration in cancer patients.

The pharmacokinetic behavior of navelbine was investigated in 19 patients presenting with advanced cancers (mainly women with breast cancer). Navelbine was given orally at seven dose levels of up to 200 mg/week. For a given dose, patients received four successive weekly treatments. Five subjects also received two different doses. After drug administration, plasma was collected for 48 or 72 h and monitored for navelbine concentration by radioimmunoassay. Absorption of navelbine was very rapid after oral administration: maximal drug concentrations were reached within the first 1 or 2 h (Tmax, 0.9-1.75 h; cmax, 70.9-832.6 ng/ml), with absorption constants ranging from 0.85 to 2.42 l/h. A comparison of dose-normalised plasma concentration profiles revealed significant time dependence in six evaluable patients (P less than 0.001). Only four subjects who received low doses (less than or equal to 100 mg/week) exhibited time-independent kinetics. All of the five patients who were treated at different doses displayed apparent dose dependence (P less than 0.001). No individual profile was characterised by both time- and dose-independent pharmacokinetics. In all, 18 patients presented biphasic plasma concentration-decay patterns, and only 1 subject exhibited monophasic decay kinetics. The navelbine pharmacokinetic parameters obtained following oral administration were similar to those observed after i.v. bolus injection and were characterised by high oral clearance (0.43-1.45 1 h-1 kg-1), a large apparent volume of distribution (27.4-45.9 1/kg), and a long terminal half-life (24.2-56.5 h). Large intra- and inter-individual variations in pharmacokinetic parameters were observed. Moreover, after a high dose of 200 mg, an enterohepatic cycle and/or a delay in navelbine's absorption at a distal intestinal site as evidenced by a marked plasma level rebound was observed.

Administration, Oral↗
PubMed1991

Standard curves of cerebral Doppler flow velocity waveforms and predictive values for intrauterine growth retardation and fetal acidosis.

Cerebral Doppler measurements seem to be a future method to evaluate the degree of fetal hypoxemia. The aim of this study was (1) to elaborate standard curves for the different cerebral vessels in our own population, and (2) to describe the predictive value of Doppler measurements for intrauterine growth retardation (IUGR) and fetal acidosis. We recorded cerebral flow velocity waveforms from 71 normal pregnancies to establish standard curves for the following vessels: proximal middle cerebral artery, distal middle cerebral artery and posterior cerebral artery. Finally, we calculated the cerebroplacentar index (CPI) for each case. The predictive values from the different vessels were determined in 24 patients with IUGR and 17 cases with fetal acidosis. The poor sensitivity and the low positive predictive value of each cerebral vessel is probably explained by the rather long interval between the last Doppler assessment and delivery (22 +/- 23 days). Reducing the interval to less than 7 days, the distal middle cerebral artery and the CPI were pathological in 4 cases out of 5 fetuses that underwent cesarean section for fetal distress. These latter results have encouraged us to use cerebral Doppler flow velocity to detect fetal hypoxemia. In conclusion, the middle cerebral artery blood flow in its distal part seems to be the finest parameter to predict fetal acidosis, and this vessel should be used to optimize obstetrical management of high-risk pregnancies.

Acidosis↗
PubMed1991

[First clinical evaluation of the CHUV ballistic lithoclast].

The authors present the first clinical evaluation of the ballistic lithoclast CHUV based upon results of 55 treated patients. Their conclusion is that the lithoclast CHUV is a simple, reliable, easy to use, efficient and patient-friendly machine.

Equipment Design↗
PubMed1991

[Middle cerebral artery fetal velocimetry: criteria for extraction in severe growth retardation].

Traditional fetal extraction criteria based on the cardiotocogram (group 1) probably occur too late to serve as extraction criteria in cases of severe growth retardation. We suggest that Doppler ultrasound of the middle cerebral artery (M.C.A.) (group 2) would be used to assess the optimal moment for fetal extraction. This method has enabled us to modify perinatal mortality from 37% to 0% (p less than 0.01). The percentage rate of cerebral hemorrhage and/or neurological sequelae was 41% (9/22) in the first group whereas no infant in group 2 or 3 (control group) had these complications. The percentage rate of neonatal complication was 67% in group 1 versus 28% in group 2 (p less than 0.01). Group 1 spent 53 days (+/- 35) in intensive neonatal care unit versus 43 days (+/- 22) for group 2. Neonatal outcome was quite similar between group 2 and the control group. Cerebral Doppler could allowed us to extract severe IUGR fetuses just before cerebral ischemia and irreversible tissue damage.

Cardiotocography↗
PubMed1991

[Value of Doppler velocimetry of the umbilical artery, aorta, cerebral artery, and uterine artery in pathological pregnancies].

This prospective study try to evaluate the predictive value of Doppler umbilical artery in the diagnosis of intra-uterine retardation (IUGR) and fetal distress requiring operative delivery. We use the blood flow class (BFC) to characterize the blood velocity waveform. Like others, we found a strong negative correlation between the blood flow class and fetal weight at delivery. When the umbilical BFC is abnormal in case of suspicion of IUGR, the diagnosis is confirmed at delivery in 100%, but in case of umbilical BFC 0, we found only 53% of IUGR. If we consider the mode of delivery, we found 7% of cesarean section for fetal distress in BFC 0, 38% in BFC1 and 78% in BFC 2-3. We had 5 fetal death, two cases with malformations, non-immunologic hydrops and trisomy 18. The others three were severe IUGR, in all cases the umbilical Doppler BFC was abnormal. Another parameter was significantly modified in case of fetal distress: the cerebro-placental index. This confirm the brain sparing phenomenon. We found a prevalence of IUGR of 43% in the high risk pregnancies group. The positive predictive value of umbilical Doppler is 82%, but the sensitivity is low, 44%. The efficacy of umbilical Doppler to predict the occurrence of operative delivery for fetal distress is better, because the prevalence is lower, 18%, the positive predictive value is 60% and the sensibility 70%. There is non doubt that, fetal blood flow is a secondary test of great value in identifying fetuses at risk of perinatal hypoxia.

Adult↗
PubMed1991

[Value of Doppler of the uterine arteries and the association of uterine and umbilical velocimetry in pregnancies at risk].

This study was designed to evaluate the role of Doppler velocimetry of uterine artery and of the association of uterine and umbilical artery. We use the index of Stuart S/D to characterize the uterine waveform. A value greater than or equal to 3 and/or the persistence of a notch is considered abnormal. When the uterine artery is pathological, we find more proteinuric hypertension, the incidence of intrauterine growth retardation (IURG) twice (p less than 0.001), the birthweight is significantly lower; the caesarean section rate for fetal distress is 35% for 11% in the other group (p less than 0.005), but the caesarean section rate for maternal indication is the same in the two groups. If we test the efficiency of the uterine Doppler study in prediction IUGR, we obtain a sensitivity of 42.5% and a positive predictive value of 74%. The population of high risk pregnancies is divided into four groups according to the Doppler findings. The first group contain normal values in the uteroplacental circulation and in the umbilical vessels, this association predict a normal outcome. The second group contain normal umbilical artery flow velocity waveform (FVW) and abnormal uteroplacental FVW, this pattern is associated with more severe hypertension and a rate of caesarean section of 16%. The final two groups contain patients with abnormal umbilical FVW and either normal or abnormal uteroplacental FVW. We find in these two groups the more complicated neonatal evolution, the incidence of caesarean section for fetal distress is more than 50%, the rate of IUGR is between 82% and 100%. The examination of the uteroplacental vessels permit the selection of patients with high risk of chronic fetal distress, therefore these pregnancies will have intensive surveillance with biophysical profile, umbilical and cerebral Doppler.

Adult↗