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Biomedical subjects

M Uzan

Publications and source records attributed to M Uzan.

At least 19 recordsLinked to original sources
PubMed1995

Uterine Doppler wave form and the prediction of the recurrence of pre-eclampsia and intra-uterine growth retardation in patients treated with low-dose aspirin.

OBJECTIVE: To examine if early uterine Doppler remains a predictor of vascular complications in pregnant women treated with low-dose aspirin for a poor previous obstetrical history. DESIGN: A study of the uterine diastolic index and the uterine notch with a continuous wave Doppler ultrasound. SETTING: The maternity Hospital Port-Royal Baudelocque Paris, France. SUBJECTS: All pregnant women between 1991-1992 (n = 48) early treated with 100 mg daily of aspirin (15.9 (S.D. = 1) weeks) for a poor previous obstetrical history. METHODS: The 48 patients underwent a uterine Doppler examination at 23.8 (S.D. = 2.6) weeks. A diastolic index was calculated and the presence of diastolic notch was noted. MAIN OUTCOME MEASURES: Vascular complications (pre-eclampsia, intra-uterine growth retardation), birth weight. RESULTS: Twenty six patients (54.2%) had an abnormal early uterine Doppler. Nine patients (18.7%) had a vascular complication, which occurred more frequently in pregnant patients with an abnormal uterine Doppler (8/26 vs. 1/22; P < 0.05). The mean birth weight was lower in patients with a pathological uterine Doppler (2419 (S.D. = 679) vs. 2841 (S.D. = 482) g; P < 0.05). CONCLUSIONS: In pregnant, early treated with low-dose aspirin for poor previous pregnancies, early uterine Doppler predicted patients with a high-risk of recurrence of vascular complications.

Adult↗
PubMed1995

A study of the factors affecting the outcome of vertebromedullary injuries.

Between 1982 and 1991, 194 patients were treated for cervical vertebromedullary injuries in the Department of Neurosurgery, Cerrahpasa Medical Faculty of the University of Istanbul. The data were evaluated with the multiple regression method using the SPSS/PC statistical package to predict the factors influencing the outcome. In the initial neurological examination, motor deficit was detected in 63.4% of the patients, sensorial deficit was seen in 53.6% of the patients and respiratory failure in 12.9%. Of these patients 46.4% were treated surgically and 53.6% medically. Evaluating the findings and outcomes with the Frankel scale, no change in neurological status was detected in 44.8% of the patients. Improvement was detected in 36.1% and deterioration in 19.1%, the mortality rate being 18.6%. It is concluded that the main factor predicting the outcome of patients with vertebromedullary injury is the initial neurological status (P < 0.0001).

Adult↗
PubMed1995

Post-transcriptional controls in bacteriophage T4: roles of the sequence-specific endoribonuclease RegB.

Gene regB of bacteriophage T4 encodes a sequence-specific endoribonuclease which introduces cuts in early phage messenger RNAs. In most cases, cutting takes place in the middle of the tetranucleotide GGAG. Efficient cleavages occur in the motifs located in intergenic regions, some of them being Shine-Dalgarno sequences. When located in a coding sequence, this tetranucleotide is poorly recognized or not at all. In this article, we have reviewed the properties of the RegB endoribonuclease, with emphasis on its possible roles in T4 development. We show that the nuclease RegB plays at least two roles: (i) it inactivates a sub-class of early mRNA by cleaving Shine-Dalgarno sequences, and (ii) it is necessary for the degradation of early mRNAs, but not of middle and late mRNAs. Accordingly, we found that middle and late mRNAs avoid processing by RegB, probably for different reasons. Most of the middle mRNAs (mRNAs initiated at MotA-dependent promoters) do not contain the motif GGAG in their intergenic regions, whereas about one-third of the late genes have this motif as Shine-Dalgarno sequence. It is not yet known whether the RNase is inactivated early in the phage cycle, or whether it remains active but cannot recognize late mRNAs as substrates.

Bacteriophage T4↗
PubMed1995

Pre-/postdilution hemofiltration.

Hemofiltration creates the best conditions for toxin removal and cardiovascular stability in the treatment of chronic renal failure patients. The increase in hematocrit due to erythropoietin, the blood flow rate and the necessary volume of substitution fluid limit the post- or the predilution hemofiltration. The technical progress made now offers the possibility to routinely and safely treat patients with pre-/postdilution hemofiltration. When adjusting the substitution flow rate to the blood flow rate, small-molecule clearances are higher than those in hemodialysis and are close to those in hemodiafiltration.

Hemodilution↗
PubMed1994

Statistical analysis of the factors affecting the outcome of extradural haematomas: 115 cases.

115 traumatic extradural haematoma cases who were treated surgically at Cerrahpasa Medical Faculty Neurosurgery Department between 1987 and 1992 are evaluated. When factors affecting the outcome were examined, a strong correlation was found between the result and Glasgow coma scale (GCS) (p < 0.00001). The existence of a fracture, the interval between onset of haematoma symptoms and intervention and the existence of an intracerebral haematoma together with contusion accompanying intradural haematoma, affect the outcome in a negative direction. There was no statistical correlation between the outcome and the age of patient, localization of the haematoma and aetiology.

Adolescent↗
PubMed1994

Some properties of HU are modified after the infection of Escherichia coli by bacteriophage T4.

Escherichia coli HU, an abundant, nucleoid-associated, DNA-binding protein, plays a role in several biological processes including DNA replication. Many other bacteria have well-conserved HU homologs, and there are several more-distantly related members of the family, including TF1, encoded by Bacillus subtilis phage SPO1. We have asked whether coliphage T4, like SPO1, encodes an HU homolog or whether it alters the properties of host HU. We have been unable to detect a T4-specified HU homolog, but we have shown that E. coli HU extracted from phage-infected cells differs in some properties from that extracted from uninfected cells. First, HU from uninfected cells inhibits a reconstituted T4 DNA replication system, whereas HU from infected cells does not. Second, HU from infected cells appears to bind a T4-encoded polypeptide, as shown by coimmunoprecipitation. We propose that such binding alters HU function in T4-infected cells.

Bacterial Proteins↗
PubMed1993

Dual role of the sequence-specific bacteriophage T4 endoribonuclease RegB. mRNA inactivation and mRNA destabilization.

Gene regB of bacteriophage T4 encodes a sequence-specific endoribonuclease that introduces cuts in early phage messenger RNAs. Cutting takes place specifically in the middle of the tetranucleotide GGAG, as soon as the first minute of infection. Out of the 20 processing sites so far identified, seven are in Shine-Dalgarno sequences. The others are localized in intercistronic regions or within coding sequences. In the latter case, cutting efficiency is much lower. regB-dependent cleavages can occur within AU-rich sequences downstream of processed GGAG motifs that are not in effective translation initiation sites. We looked for possible consequences of regB-dependent cuts on gene expression in two early regions of the T4 chromosome. In the comC alpha region, none of the three major RegB cleavage sites is in a Shine-Dalgarno sequence, and in the motA region the unique regB-dependent processing site is found within the Shine-Dalgarno sequence of the gene. We find that in the region of gene comC alpha, RegB decreases two- to threefold the chemical half-life of early transcripts, but does not change the functional half-life of mRNAs coding for protein ComC alpha. The amount of MotA protein synthesized by the wild-type is half that obtained in a regB mutant infection. We show that this is a direct consequence of mRNA processing by RegB at the Shine-Dalgarno sequence of motA. This regB-mediated translation inhibition is not accompanied by an important modification in motA mRNA chemical half-life. We show that rapid shut-off of MotA protein synthesis that occurs soon after infection results both from RegB processing within the translation initiation region of motA and from early transcription inhibition followed by regB-independent breakdown of the motA mRNA.

Bacterial Proteins↗
PubMed1993

[Cervical cancer in the young woman].

OBJECTIVE: To study the frequency, the histological type, the stages, and prognosis of cancer of the cervix in women under 35 years of age or less. METHOD: A retrospective analysis of a series of 1,024 cases notes of which 63 dealt with young women. The therapeutic modalities are the same throughout the whole duration of the study from 1975-1988. RESULTS: There was no increase in the incidence of cancer in young women. The incidence of epidermoid cancer dropped. However, mixed adenosquamous tumours were more frequent. There is a predominance of stages I cancers. The survival taking all stages together is at 5, 10 and 15 years better in young women. All the same, taking stage by stage there is no difference in the prognosis.

Adenocarcinoma↗
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↗