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Biomedical subjects

C Sureau

Publications and source records attributed to C Sureau.

At least 55 records · Page 3Linked to original sources
PubMed1993

[What are the medical limits on the desire for pregnancy in the woman at risk?].

Quite a few medical situations are as difficult as the ones where the desire of procreation and the risks associated to it are in conflict. The practitioner's opinion is grounded on his experience, on statistical data, but also on his own sensitivity and subjectivity. His role is not to give the patient the medical data and to leave her deciding alone. He must involve himself in the process of reflexion and decision, recognize and appreciate the depth of the motivations and finally respect them. He must remember that the female intuition bears sometimes more value than the so called scientific knowledge.

Clinical Competence↗
PubMed1992

Production of infectious hepatitis delta virus in vitro and neutralization with antibodies directed against hepatitis B virus pre-S antigens.

Hepatitis delta virus (HDV) particles were produced in Huh7 human hepatoma cells by transfection with cloned hepatitis B virus (HBV) DNA and HDV cDNA. The particles were characterized by their buoyant density, the presence of encapsidated viral RNA, and their ability to infect primary cultures of chimpanzee hepatocytes. Successful infection was evidenced by the appearance of increasing amounts of intracellular HDV RNA after exposure to particles. Infection was prevented when particles were incubated with antibodies directed against synthetic peptides specific for epitopes of the pre-S1 or pre-S2 domains of the HBV envelope proteins before exposure to hepatocytes. These data demonstrate that HDV particles produced in vitro are infectious and indicate (i) that infectious particles are coated with HBV envelope proteins that contain the pre-S1 and pre-S2 regions, (ii) that epitopes of the pre-S1 and pre-S2 domains of HBV envelope proteins are exposed at the surface of HDV particles, and (iii) that antibodies directed against those epitopes have neutralizing activity against HDV.

Animals↗
PubMed1991

Prevention of perinatal consequences of pre-eclampsia with low-dose aspirin: results of the epreda trial. The Epreda Trial Study Group.

A multicentric randomized double-blind trial was realized in order to determine whether a treatment with a low-dose aspirin (150 mg/day) with or without dipyridamole (225 mg/day) was able to prevent the perinatal consequences of pre-eclampsia. This study demonstrated a significant difference in birthweight and incidence of fetal growth retardation between treatment and placebo groups. No difference was demonstrated between aspirin and aspirin + dipyridamole patients.

Abruptio Placentae↗
PubMed1991

Comparison of vaginal examination findings in two antenatal clinics.

Findings of routine vaginal examinations during pregnancy were compared in two teaching hospitals located in the same area of Paris. We selected 2943 women who had had at least one antenatal visit between 29 and 31 weeks of gestation. Large differences in the frequency of maturation signs were observed between the two hospitals for mid-position, soft consistency and expanded lower uterine segment, although the higher frequency of each sign was not found in the same hospital. No difference was observed for dilatation of the internal os. A better reliability in assessing dilatation than other signs of maturation may explain our results and the role of dilatation in the prediction of preterm delivery.

Adult↗
PubMed1991

Tissue culture system for infection with human hepatitis delta virus.

An in vitro culture system was developed for assaying the infectivity of the human hepatitis delta virus (HDV). Hepatocytes were isolated from chimpanzee liver and grown in a serum-free medium. Cells were shown to be infectible by HDV and to remain susceptible to infection for at least 3 weeks in culture, as evidenced by the appearance of RNA species characteristic of HDV replication as early as 6 days postinfection. When repeated experiments were carried out on cells derived from an animal free of hepatitis B virus (HBV), HDV infection occurred in a consistent fashion but there was no indication of infection with the HBV that was present in the inoculum. Despite numerous attempts with different sources of HBV inocula free of HDV, there was no evidence that indicated susceptibility of these cells to HBV infection. This observation may indicate that HBV and HDV use different modes of entry into hepatocytes. When cells derived from an HBV-infected animal were exposed to HDV, synthesis and release of progeny HDV particles were obtained in addition to HBV replication and production of Dane particles. Although not infectible with HBV, primary cultures of chimpanzee hepatocytes are capable of supporting part of the life cycle of HBV and the entire life cycle of HDV.

Animals↗
PubMed1990

Immunocytochemical and electron microscopic study of hepatitis B virus antigen and complete particle production in hepatitis B virus DNA transfected HepG2 cells.

The relationship between the presence of hepatitis B virus antigens, their localization and hepatitis B virus replication was studied in different clones of cultured HepG2 hepatoblastoma cells transfected with cloned hepatitis B virus DNA. Intracellular hepatitis B virus antigens were detected by immunofluorescence. The production of these antigens was evaluated in the culture media by enzyme-linked immunoassay. Hepatitis B virus DNA was detected using dot-blot hybridization. Three types of HBcAg staining were observed in transfected HepG2 cells: (a) cells with nuclear HBcAg, (b) cells with cytoplasmic HBcAg and (c) cells with both nuclear and cytoplasmic HBcAg. Cell types b and c also expressed hepatitis B virus DNA in their culture media. Our results suggest that cytoplasmic HBcAg may be more involved than nuclear HBcAg in hepatitis B virus replication. The site of hepatitis B virus formation in hepatocytes was studied by electron microscopic examination of a specific hepatitis B virus producer clone, thereby allowing detection of intracellular Dane particles more easily than liver biopsy samples from infected patients. Dane particles and HBsAg filaments were found in large, dilated structures probably related to the endoplasmic reticulum. Budding of core particles into cisternae of endoplasmic reticulum-related structures appears to be a possible mechanism for hepatitis B virus formation; our results suggest that the exocytosis of cisternae to extracellular spaces may be a mechanism for release of hepatitis B virus particles.

Blotting, Southern↗
PubMed1990

Prediction of preterm delivery: is it substantially improved by routine vaginal examinations?

The ability of routine vaginal examinations to improve the prediction of preterm delivery was assessed in a group of 6909 women who were registered at each prenatal visit and on whom this examination had been carried out. We compared two risk scores, one including known risk factors (maternal characteristics and symptoms reported by women), and the other including these factors and the findings of vaginal examination. These risk scores were computed by multiplying the adjusted odds ratio estimations obtained by logistic regressions. The prediction of preterm delivery was improved significantly by vaginal examination at 25 to 28 weeks' and 29 to 31 weeks' gestation. However, the improvement was not very large: when 30% of nulliparous women were classified as high risk at 29 to 31 weeks, the sensitivity was 55% when considering only the risk factors and 63% when adding the findings of vaginal examination; the percentages were 52% and 55%, respectively, for parous women. These results partially explain why the medical practice of routine vaginal examinations varies from country to country.

Adolescent↗
PubMed1990

A specific base transition occurs on replicating hepatitis delta virus RNA.

Three independent lines of evidence showed that when an infectious clone of hepatitis delta virus of known sequence was used to initiate genome replication, up to 41% of the genomes were specifically mutated in the amber termination codon (UAG to UGG) for the open reading frame of the delta antigen, thereby increasing the length of the predicted protein from 195 to 214 amino acids. This change was detected only on molecules that participated in RNA-directed RNA synthesis.

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

Cloned hepatitis delta virus cDNA is infectious in the chimpanzee.

A head-to-tail trimer of a full-length cDNA clone of the hepatitis delta virus (HDV) genome was examined for infectivity by direct inoculation into the liver of a chimpanzee that was already infected with hepatitis B virus. Five weeks after inoculation, a marked elevation of serum alanine aminotransferase activity was observed, followed by the appearance of high levels of HDV RNA and antigen in both liver and serum and a high level of viral particles in the serum. A transient suppression of hepatitis B virus replication was evident during the acute phase of HDV infection. Seroconversion for antibodies to delta antigen occurred 3 weeks after the onset of the disease. These results demonstrate that a typical HDV infection can be initiated by inoculation of a susceptible animal with recombinant HDV cDNA.

Animals↗