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Biomedical subjects

M Dreyfus

Publications and source records attributed to M Dreyfus.

At least 109 records · Page 6Linked to original sources
PubMed1995

Colposcopy and directed biopsy reliability during pregnancy: a cohort study.

The reliability of cytology, colposcopy, and directed biopsy were assessed in pregnancy and compared with that observed in a matched non-pregnant control group in order to evaluate the influence of pregnancy. One hundred and seventeen gravidas in which the final pathology could be ascertained and 234 control patients were examined by the same colposcopist. Concordance between cytology and final diagnosis was complete or within one degree of severity in 55.6% and 77.8% of patients, respectively. Unsatisfactory colposcopy was significantly less frequent in pregnant patients than in controls (12.8% vs. 23.1%, P = 0.023). In pregnant patients, colposcopy provided concordance, overestimation and underestimation of the final diagnosis in 72.6%, 17.6% and 9.8%, respectively. In the same group, the concordance between the histologic findings of directed biopsy and final diagnosis was complete or within one degree of severity in 83.7% and 95.9%, respectively. The reliability of cytology, colposcopy and directed biopsy was not related to pregnancy. These data show that the physiological changes which occur in pregnancy do not significantly alter the reliability of colposcopy and directed biopsy, if the colposcopist is aware of the peculiar difficulties and does not overreact to the accentuated patterns that may occur during pregnancy.

Adolescent↗
PubMed1995

[Acute liver failure caused by paracetamol: should treatment with N-acetylcysteine be prolonged?].

BACKGROUND: Some cases of paracetamol-induced acute hepatic failure may require liver transplantation but the present shortage of graft urges the search for an alternate therapeutic approach. CASE REPORT: A 17 year-old girl was admitted for sleepingness and vomiting after about 15 hours of voluntary but denied absorption of paracetamol. Plasma paracetamol concentration was 120 mg/l; factors VII+X level were 55% and factor V 106%. The patient was given IV N-acetylcysteine, 150 mg/kg/30 min, then 50 mg/kg/4 hours. Further decrease in facteur VII level led to pursue administration of N-acetylcysteine (total dose: 350 mg/kg/2 hours). While indication of liver transplantation was considered, clinical and laboratory findings definitely improved. CONCLUSIONS: N-acetylcysteine may be effective even if administered late. Repeated determination of factor VII could be a good means for managing such a severe condition.

Acetaminophen↗
PubMed1995

Spontaneous regression of fetal pulmonary sequestration.

The prenatal diagnosis of pulmonary sequestration can usually be made by the third trimester of pregnancy, from the combination of an intrathoracic mass and indirect signs such as cardiac deviation, fetal hydrops, pleural effusion and polyhydramnios. We describe four cases in which pulmonary hyperechogenicity was detected before 26 weeks' gestation. In three cases the hyperechogenic mass was isolated. In all cases it had mostly regressed during the pregnancy. A review of the cases of isolated pulmonary sequestration that have been diagnosed during the antenatal period is presented. Antenatal evolution was found to be unpredictable regardless of the type or severity of the case at the first diagnosis. We propose a classification to define more clearly the optimal management of pulmonary sequestration.

Adult↗
PubMed1995

Replacement therapy with a monoclonal antibody purified protein C concentrate in newborns with severe congenital protein C deficiency.

Protein C replacement therapy with a monoclonal antibody purified, virus inactivated protein C concentrate was carried out in nine infants (three male, six female) with severe congenital protein C deficiency and life-threatening purpura fulminans and/or thrombosis associated with disseminated intravascular coagulation (DIC). Eight infants were homozygous for protein C deficiency; one was a compound heterozygote. The treatment period varied from 22 days to three years. The half-life of protein C was found to be as short as two to three hours during activation of the coagulation system, increasing to approximately ten hours after stabilization. During the acute phase, protein C levels of 0.10 to 0.25 IU/mL were associated with elevated markers of coagulation activation indicating DIC, while protein C levels greater than 0.25 were associated with normalization of coagulation markers. No product-related side effects were reported. Episodes of bleeding or purpura recurred in all patients who were switched to oral anticoagulant therapy, necessitating reinstatement of protein C replacement therapy, either as needed to control symptoms, or on a long-term prophylactic schedule, alone or in addition to oral anticoagulation. Home treatment with protein C concentrate allowed a near-normal life-style for patients who otherwise would be hospitalized for long periods of time.

Antibodies, Monoclonal↗
PubMed1995

[Gastroschisis. Management. 50 cases].

OBJECTIVE: Demonstrate the need for a multidisciplinary antenatal approach to laparoschisis. MATERIAL AND METHODS: A retrospective series of 50 children who underwent surgery for laparoschisis between 1975 and 1994 in the Infant Surgery Department of the Strasbourg University Hospitals. Postoperative outcomes were evaluated as a function of the stage of laparoschisis and surgical technique. Follow-up was also examined. RESULTS: Depending on the periods evaluated, ultrasound diagnosis varied from 16 to 92% and was made at 21 weeks gestation on the average. Lesions observed were atresia of the bowel (10%), complete intestinal involution (2%), and perivisceritis (88%). Complete parietal closure was achieved after bowel emptying in 58% of the newborns. Postoperative mortality, usually in vere severe forms, fell from 46% to 15% over the 20-years study period. CONCLUSION: Antenatal echography can confirm the diagnosis of laparoschisis. It can be used to define risk factors (size, bowel dilatation(s), mesenteric blood flow) allowing planned extraction in an Infantile Surgery Unit. This multidisciplinary attitude should help to improve overall outcome.

Abdominal Muscles↗
PubMed1995

Antibodies to macromolecular platelet factor 4-heparin complexes in heparin-induced thrombocytopenia: a study of 44 cases.

As heparin-PF4 (H-PF4) complexes are the target for antibodies associated to heparin-induced thrombocytopenia (HIT), an ELISA has been developed and optimised for testing antibodies binding to H-PF4. This test was consistently negative in 50 healthy subjects (A492 < 0.3) and 35 patients with other causes of thrombocytopenia (A492 < 0.5). In contrast, 43 out of 44 HIT patients showed antibodies to H-PF4 (A492 = 1.70 +/- 0.81) including 5 patients with a negative platelet aggregation test. In one patient with HIT, antibodies to H-PF4 were already present at day 7, whereas platelet counts dropped < or = 100 x 10(9)/l only at days 11-12. Surprisingly, among 41 patients under heparin for > 7 days, 5 showed antibodies to H-PF4, without HIT. These findings underline the major interest of this ELISA for the early diagnosis of HIT. We also showed that LMWH as well as other sulphated polysaccharides can bind to HIT antibodies in the presence of PF4 and that their reactivity is dependent on the molecular weight and the sulphation grade. The mechanism for HIT involves platelet PF4 receptors which bind the macromolecular H-PF4 complexes formed in the presence of a well defined heparin/PF4 ratio.

Adolescent↗
PubMed1995

Germ-line p53 mutations in 15 families with Li-Fraumeni syndrome.

Germ-line mutations of the tumor-suppressor gene p53 have been observed in some families with the Li-Fraumeni syndrome (LFS), a familial cancer syndrome in which affected relatives develop a diverse set of early-onset malignancies including breast carcinoma, sarcomas, and brain tumors. The analysis of the p53 gene in LFS families has been limited, in most studies to date, to the region between exon 5 and exon 9. In order to determine the frequency and distribution of germ-line p53 mutations in LFS, we sequenced the 10 coding exons of the p53 gene in lymphocytes and fibroblast cell lines derived from 15 families with the syndrome. Germ-line mutations were observed in eight families. Six mutations were missense mutations located between exons 5 and 8. One mutation was a nonsense mutation in exon 6, and one mutation was a splicing mutation in intron 4, generating aberrant shorter p53 RNA(s). In three families, a mutation of the p53 gene was observed in the fibroblast cell line derived from the proband. However, the mutation was not found in affected relatives in two families and in the blood from the one individual, indicating that the mutation probably occurred during cell culture in vitro. In four families, no mutation was observed. This study indicates that germ-line p53 mutations in LFS are mostly located between exons 5 and 8 and that approximately 50% of patients with LFS have no germ-line mutations in the coding region of the p53 gene.(ABSTRACT TRUNCATED AT 250 WORDS)

Adolescent↗
PubMed1994

mRNAs can be stabilized by DEAD-box proteins.

Eubacterial messenger RNAs are synthesized and translated simultaneously; moreover the speed of ribosomes usually matches that of RNA polymerase. We report here that when in Escherichia coli the host RNA polymerase is replaced by the eightfold faster bacteriophage T7 enzyme for the transcription of the lacZ gene, the beta-galactosidase yield per transcript is depressed 100-fold. But the overexpression of DEAD-box proteins greatly improves this low yield by stabilizing the corresponding transcripts. More generally, it stabilizes inefficiently translated E. coli mRNAs. Ribosome-free mRNA regions, such as those lying behind the fast T7 enzyme or between successive ribosomes on inefficiently translated transcripts, are often unstable and we propose that DEAD-box proteins protect them from endonucleases. These results pinpoint the importance of transcription-translation synchronization for mRNA stability, and reveal an undocumented property of DEAD-box RNA helicases. These proteins have been implicated in a variety of processes involving RNA but not mRNA stability.

Amino Acid Sequence↗
PubMed1994

The use of a tRNA as a transcriptional reporter: the T7 late promoter is extremely efficient in Escherichia coli but its transcripts are poorly expressed.

In gene expression studies, promoters are often fused to a protein-encoding reporter gene, the expression of which is then taken as an indirect measure of their strength. Here, we advocate the use of a tRNA reporter for the direct quantification of promoter strength. Using this method, we have studied the bacteriophage T7 gene 10 promoter in an E. coli strain that produces saturating amounts of T7 RNA polymerase. At 37 degrees C in aminoacid-glycerol medium, we show that this promoter ranks amongst the strongest known, directing ca 1.1 transcription events per second, 2.2-fold more than the promoters for rRNA operons, or 15-fold more than the induced lac promoter. Surprisingly, compared to the lac promoter, the T7 promoter is far less efficient in driving the expression of protein-encoding genes such as cat, neo or lacZ. Therefore, the polypeptide yield per transcript is lower when the T7 RNA polymerase is used instead of the E. coli RNA polymerase. The former enzyme travels faster than the translating ribosomes, and we suggest that this desynchronization lowers the polypeptide yield per transcript.

Bacteriophage T7↗
PubMed1994

[Fetal-neonatal thrombocytopenia of immunologic origin: current aspects].

Fetal/neonatal immune thrombocytopenias result from increased platelet destruction by maternal antiplatelet antibodies. There is a risk of intracerebral haemorrhage and therefore of neurological impairment or death during the thrombocytopenic period, especially if a defective platelet function co-exists. As no maternal parameter is predictive of the fetal platelet count, the only reliable assessment of the fetal status depends on the fetal blood sampling. Only in case of materno-fetal alloimmunisation the therapy initiated to reverse fetal thrombocytopenia was shown to be effective, but the optimal mode of antenatal treatment is currently under study. As the neonatal therapy and the management of subsequent pregnancies are somehow different it is mandatory to make the distinction between the auto or allo-origin of the fetal thrombocytopenia. The definition of high risk pregnancies will be of help for the development of a routine screening program.

Antigens, Human Platelet↗
PubMed1994

[Pruritus specific to pregnancy].

Many pregnancies are complicated by a pruritus. A study of the liver functions, including a determination of plasma bile acids, and a biopsy of each doubtful dermatological lesion with direct immunofluorescence allow to distinguish the specific pruritic diseases of the pregnancy: pemphigoid gestationis, papulous and pruritic dermatitis and cholestasis of pregnancy. The pemphigoid gestationis is an autoimmune bullous acquired dermatosis, which recurs at each pregnancy; a positive direct immunofluorescence is specific of the disease; the fetal prognosis seems to be good; a systemic corticotherapy is necessary. The papulous and pruritic dermatitis are the most common dermatosis during the gestation: the maternal and fetal prognosis are excellent, but this diagnosis remains a diagnosis of elimination. The cholestasis of pregnancy is characterized by an isolated pruritus which rapidly disappears in the postpartum period; its pathogeny probably includes many factors, but it seems to be favoured by a genetic ground; the determination of plasma bile acid, even if it is not specific, leads toward the diagnosis. The mother often requires an aggressive symptomatic treatment but the delivery can be delayed till the pulmonary maturity is obtained.

Bile Acids and Salts↗
PubMed1994

[Audiophonologic aspects of the decision and follow-up of cochlear implants in children].

Based on the audiologic, audioprosthetic, psychological and orthophonic criteria involved in the decision for a cochlear implant in 16 children (age 5 to 18), a protocol including 10 criteria was developed for children with severe deafness and a low to very low level of oral language acquisition. The importance of the motivation of the family, their capacity to become implicated and their desire to listen to the child and communicate orally with him, as well as the role of the specialist teachers were emphasized. In this series of 16 children the results of the implantation work-up lead to only 9 cases of implantation.

Adolescent↗
PubMed1994

Homozygous type I protein C deficiency in two unrelated families exhibiting thrombophilia related to Ala136-->Pro or Arg286-->His mutations.

Separate single nucleotide mutations have been identified in two unrelated homozygous type I protein C deficient individuals suffering from thrombophilia. Each mutation, initially established by direct DNA sequencing of polymerase chain reaction amplification products, results in an amino acid substitution. The first mutation (PCClamart) results in an Ala136 to Pro substitution in the protein's second epidermal growth factor-like domain. The second mutation (PCMünchen) results in an Arg286 to His substitution in the serine protease domain. Comparison of the location of these two mutations and the relative conservation of the two regions in homologous vitamin K-dependent plasma proteins is consistent with the difference in severity of protein C deficiency and disease in the two individuals. Both mutations result in the abolition of a naturally occurring restriction endonuclease site, thereby allowing independent confirmation of the mutations and rapid and unambiguous genetic analysis of protein C deficiency in family members. In both families, the genetic analysis has proven useful in cases where an assignment of the protein C status based upon clinical laboratory measurements was either ambiguous or incorrect.

Adolescent↗