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Biomedical subjects

M Uzan

Publications and source records attributed to M Uzan.

At least 109 records · Page 6Linked to original sources
PubMed1992

Sequence and characterization of the bacteriophage T4 comC alpha gene product, a possible transcription antitermination factor.

We have sequenced a 1,340-bp region of the bacteriophage T4 DNA spanning the comC alpha gene, a gene which has been implicated in transcription antitermination. We show that comC alpha, identified unambiguously by sequencing several missense and nonsense mutations within the gene, codes for an acidic polypeptide of 141 residues, with a predicted molecular weight of 16,680. We have identified its product on one- and two-dimensional gel systems and found that it migrates abnormally as a protein with a molecular weight of 22,000. One of the missense mutations (comC alpha 803) is a glycine-to-arginine change, and the resulting protein exhibits a substantially faster electrophoretic mobility. The ComC alpha protein appears immediately after infection. Its rate of synthesis is maximum around 2 to 3 min postinfection (at 37 degrees C) and then starts to decrease slowly. Some residual biosynthesis is still detectable during the late period of phage development.

Amino Acid Sequence↗
PubMed1992

Fetal cerebral blood flow velocity during labour. Preliminary report.

The authors have tried to ascertain in a preliminary study if monitoring of fetal cerebral blood flow velocity during labour could identify a situation threatening the fetal brain, which could justify a compulsory fetal extraction. Nine patients were explored at term during labour. The Doppler signal was recorded using the abdominal route at the level of the fetal internal carotid. The diastolic carotid index was used (DCI = D/S). In 5 cases, fetal heart rate (FHR) was normal during labour and the DCI was on average comparable for each of the patients and the mean DCI (20.1 +/- 1%) was in close agreement with the values normally seen after 33 weeks of amenorrhoea during pregnancy. The case of isolated deceleration shows that deceleration causes an almost instant drop in the telediastolic flux, but the index increases more rapidly than could be expected from the increase in cardiac frequency if this phenomenon were of purely cardiogenic origin. In the case of bradycardia, it was noticed that during the return to the initial FHR frequency, the DCI was much higher than during the measurements performed before bradycardia. In the 1st case of pathological FHR, the index was very high and remained elevated during all the observation period. The fetus presented at birth a normal Apgar score as well as normal blood pH and neurological examination. In the 2nd case of pathological FHR, the FHR was abnormal with decelerations, the DCI increased rapidly and remained high.(ABSTRACT TRUNCATED AT 250 WORDS)

Blood Flow Velocity↗
PubMed1992

Predictive value of uterine artery velocity waveforms in pregnancies complicated by systemic lupus erythematosus and the antiphospholipid syndrome.

The objective of this study was to see if determination of uterine artery velocity waveforms between 20 and 30 weeks in lupus pregnancy and the antiphospholipid syndrome (APS) have a good predictive value for later fetal distress before labor, intrauterine growth retardation, and preeclampsia. Uterine and umbilical artery blood flow velocity waveforms were determined in 21 pregnancies complicated by systemic lupus erythematosus (SLE): 12 with antiphospholipid antibodies (aPL), 9 without aPL. We also studied 7 pregnancies with APS. This retrospective study was running from January 1st 1986 to July 31st 1991, at the Port-Royal Maternity, Paris, France. Abnormal uterine artery blood flow velocity waveforms were found in 10 out of 28 pregnancies at the first examination performed between 20 and 30 weeks gestational age. All the later adverse fetal and neonatal events were predicted by an abnormal uterine artery blood flow velocity waveform. From the 7 cases of fetal distress diagnosed during pregnancy, 6 were predicted by abnormal uterine waveforms and all of these pregnancies resulted in induced delivery before 32 weeks of gestational age. Twelve pregnancies with aPL and normal uterine artery waveforms were uncomplicated. Only 1 out of 7 pregnancies with abnormal uterine artery waveform and aPL ended without complication. Determination of uterine artery flow velocity waveform is a good adjunct to the management of pregnancies complicated by SLE or aPL. This determination has a better predictive value than the presence of aPL.

Adult↗
PubMed1992

[Preliminary study on the variability of the fetal cerebral velocimetry in various vessels of the Circle of Willis].

The authors have tried to analyse in a small series, the possibility as well as the variability of blood flow velocity waveforms in the different vessels of the circle of willis using colour Doppler. Fourteen patients were assessed. The 14 fetuses were of normal growth and/or had normal umbilical arterial blood flow velocity waveforms as well as normal uterine blood flow. The mean term at the time of examination was 23.8 +/- 2.9 standard deviation with the extremes going from 28.5 standard deviation to 40.5. The examinations were carried out using colour Doppler (Acuson) machine by the abdominal route with a 3.5-5 MHz bi-frequency sound. The vessels that were explored were the middle cerebral artery (CM), posterior cerebral artery (CP), the internal carotid artery (CI), the anterior cerebral artery (CA) in the region of the circle of Willis. CM and CA were able to be recorded in 100% of the cases, CP and CI in 93% of cases (13 out of 14 cases). The difference between he mean index (D/S, D = residual velocity in the diastole, S = maximum velocity in the systole) in each of these vessels was not statistically significant. In 3 out of 16 measurements (19%) the CP index was considered to be pathological while the index in the other vessels was normal, or when a different form of measurement was carried out in the region of CP, it was normal. This was also the case once for CA, but never for CM or CI.(ABSTRACT TRUNCATED AT 250 WORDS)

Artifacts↗
PubMed1992

[Management of the scarred uterus].

On the basis of 899 cases of uterine scarring following cesarean section, the authors carried out a prophylactic cesarean in 42% of cases. Labor ended in childbirth by the genital tract in 44% of cases. The very low incidence of uterine rupture since segmental hysterotomy has become widespread and the improved fetal and maternal prognosis are all reasons to prefer delivery by the genital tract. One of the factors in choosing the method of childbirth is radiopelvimetry and estimation of the fetal weight; however, the suspicion of a threshold pelvis is not a contraindication to the labor test which was successful in 70% of the authors cases. On condition that strict obstetrical monitoring is possible, oxytocic drugs can be used to induce labor or correct hypokinesia and to administer a peridural analgesic. Routine extraction is no longer necessary during the expulsion phase but the authors remain faithful to uterine revision. In general, the labor test should be suggested as often as possible and should receive the same monitoring and treatment methods as for an intact uterus.

Birth Weight↗
PubMed1991

[Arterial hypertension in pregnancy. Role of maternal and fetal blood velocimetry].

Gravidic hypertension remains one of the most frequent causes of perinatal mortality and morbidity. There are two aims when investigating this disease: evaluate the gravity, try to find early signs of a risk of pre-eclampsia. This last point has become particularly important over the past few years because of the development of preventive treatment (platelet anti-agregates). Mother and fetal blood velocimetry play a more and more important role. Three measurement sites appear to have different and complementary importance: for long-term prediction, measuring the velocimetric index of the uterin artery seems the most interesting because it schematically explores the type of placentations; for mid-term, measuring the ombilical artery evaluates placenta resistance, an essential factor in chronic fetal suffering; at short-term, measuring the fetal cerebral and carotid vessels explores the hemodynamic reactions of fetal adaptation to fetal suffering.

Adult↗
PubMed1991

[Physiopathological elements of pre-eclampsia and the role of the main complementary tests].

The origin of pre-eclampsia lies in uteroplacental ischemia due to an anomaly of the "vascular insertion" of the placenta. Although the cause of this anomaly remains unknown, it would appear to include both a genetic and an immunological origin possibly favourised by special underlying conditions and certain obstetric circumstances. Prostaglandin imbalance (in particular prostacyclins and Thromboxane A2) appears to be one of the chief factors governing these anomalies. One of the consequences of these mechanisms is the onset of hypertension but other disturbances are essential features. In particular, disseminated intravascular coagulation may occur leading to the release of numerous microthrombi which cause placental (leading to chronic fetal distress), renal, hepatic and cerebral lesions.

Disseminated Intravascular Coagulation↗
PubMed1990

Nucleotide sequence and control of transcription of the bacteriophage T4 motA regulatory gene.

A 2116bp segment of the bacteriophage T4 genome encompassing the motA regulatory gene has been sequenced. In addition to motA, five open reading frames were identified in the direction of early transcription. The motA gene encodes a basic protein of 211 amino acids with a predicted molecular weight of 23,559. Measurements of the rate of transcription of motA showed that the promoter of this gene is turned off after only 2 min of T4 development. This early promoter presents a structure which is richer in information than that of a classical constitutive Escherichia coli promoter. In addition to containing conserved sequences centred at -10 and -35, this promoter shares extensive homologies with other subgroups of early promoters in regions centred at +3 and at -55. We discuss the possible role of these different sequence determinants.

Amino Acid Sequence↗
PubMed1990

[The carotid diastolic index: predictive factor for acute fetal distress].

The authors studied 165 patients, 161 of them having been examined at least once for their umbilical diastolic index, uterine diastolic index and carotid diastolic index (CDI) during pregnancy. Four patients have been examined only for the umbilical and carotid indexes. These patients presented either a pathological pregnancy (37% of arterial hypertension; 34% of intrauterine growth retardation; 8% other causes) or previous pathological gestations (21%). Particular emphasis was given to the study of the prediction of CDI with respect to fetal heart rate (FHR) abnormalities or an intrauterine fetal death (IUFD). A mean of 1.4 measurements of CDI per patient were performed, ranging from 1 to 5. The average time lag of the first CDI measurement was of 30 weeks of pregnancy, ranging from 21 to 36.5 weeks. The mean time lag of the children's deliveries was of 35 weeks, ranging from 27 to 40 weeks of pregnancy. The mean time lag of the last CDI measurement with respect to delivery was of 15 days (1 day to 15 weeks). The CDI (CDI = D/S; D = residual diastolic velocity; S = maximal systolic velocity) was considered as pathological when exceeding 22% up to 30 weeks of pregnancy and when exceeding 26% after 30 weeks. 50% of the children born in this series were hypotrophic. When presenting identical umbilical and uterine indexes, the percentage of hypotrophic offspring was the same, whether the carotid index was normal or pathological.(ABSTRACT TRUNCATED AT 250 WORDS)

Acute Disease↗
PubMed1989

[Compared course of clinical, biologic, echographic and speedometric parameters in retroplancetal hematoma].

The authors have studied 27 cases of Abruptio Placentae (A.P.) (for an observation time of 15 months). These 27 patients where divided into 3 groups: 6 patients without pregnancy follow-up, 5 with a regular follow-up and 16 with an intensive pregnancy follow-up. In this last group following parameters were studied: blood pressure, proteinuria, uricemia, hematocrit, platelet count, FDP, plasma volume, Fetal (umbilical artery) and Maternal (uterine artery velocities with doppler reclude Fetal heart Rate. The total number of intra uterine death and post natal death remained very high: 15 over 27 cases. However this rate was lower in the intensive group, where 10 fetuses with were delivered safely. Studying the evolution of clinical, biological and ultrasonic parameters during the last month before the AP we tried to establish curves of their mean value (every week for the last 4 weeks and every day for the last week). Almost all parameters showed a late significant variation (in the last week). Two of them were modified in the last two days: (FDP and Fetal heart rate acceleration). Two of them were "positive" (in 60 p. 100 of cases) 3 of 4 weeks before the AP: Maternal Plasma volume decrease, Presence of a Notch on the uterine artery doppler curve. In conclusion fetal or neonatal death after AB remains high and even with an intensive follow-up 30 p. 100 of the cases cannot be predicted.

Female↗
PubMed1989

[Fetal telemonitoring].

There is a definite increase in the number of cases in which it is helpful to know about the fetal heart rate. These are: intra-uterine growth retardation whether associated with hypertension or not, or whether the patients have lost a fetus in utero before. In these cases it is necessary to hospitalize the patient for a long time or make them come to the clinic very often. Watching these patients at home (using either midwifery or hospital staff) is often difficult, so it seemed useful to us to develop another system of monitoring these patients at home. We have been testing, for the last year and a half, a simple system of recording the fetal heart rhythm that can be used by the patient herself at home. The recordings are transmitted daily or twice daily by telephone. The midwife in the maternity unit can look at the tracing and ask the patient to come if the tracing is insufficient or suspicious. We present here the results of 816 tracings carried out in 402 patients: --the tracings correspond completely to those taken at the same time by the usual machines as far as the fetal ECG is concerned. Their interpretation does not give rise to any problems as compared with those of usual tracings. --about 80% of the tracings could be interpreted. They vary according to how far on the pregnancy has progressed (73% at 32 weeks of pregnancy and 84% at term). Telephone transmission was carried out in 84% of cases. Isolated monitoring of fetal heart rhythm (without recording tracings of uterine contractions) makes it possible to monitor these patients at risk of having chronic fetal distress.

Electrocardiography↗
PubMed1989

[Results of autopsy examination of the knee cartilage of 120 patients dying in the hospital. II. The femoro-tibial joint].

The authors have studied the autopsy results of both tibio-femoral joints in 120 patients: 57 women and 63 men, 112 of whom were over the age of 50. The condylar and tibial cartilages were classified into 5 categories: no lesion (0); slight fissure (I); severe fissure (II); slight deep ulceration (III); large ulceration (in more than 25 p. cent of the cartilage surface) exposing the sub-chondral bone (IV). In 120 patients, the 4 condyles in 58 patients (43.8 p. cent) and both tibio-femoral joints in 51 patients (42.5 p. cent) did not present any degenerative lesions beyond stage I. Stage III and IV cartilaginous lesions are rare before the age of 50. Their frequency suddenly increases after the ages of 70 in women and 80 in men. 44 p. cent of women and 31 p. cent of men presented tibio-femoral cartilaginous lesions of stages II or IV in at least one knee; 15.8 p. cent of women and 4.7 p. cent of men presented tibio-femoral lesions, stage IV, in at least one knee. In 58 p. cent of stage III and IV knee lesions, the menisci were abnormal: atrophic or torn. A menisco-chondrocalcinosis was found in 50 knees (20.8 p. cent of knees) of 28 patients (23.3 p. cent of patients). After the age of 60, the cartilaginous lesions were more severe and more extended in knees with menisco-chondrocalcinosis).

Age Factors↗