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Biomedical subjects

Y Brossard

Publications and source records attributed to Y Brossard.

At least 55 records · Page 3Linked to original sources

HIV infection at outcome of pregnancy in the Paris area, France.

The prevalence of HIV infection in women at end of pregnancy, irrespective of outcome, was determined in a comprehensive survey of both women and medical centres during successive 4-week periods in four areas of the Paris region, France. Blood samples were tested anonymously for antibodies to human immunodeficiency virus (HIV)-1 and HIV-2. Of the 11,593 blood samples 0.40% (95% confidence interval [CI] 0.28-0.51) were positive for HIV-1 and 0.02% (95% binomial interval [BI] 0.002-0.065) for HIV-2. Seroprevalence was higher among women with ectopic pregnancy (2%) (95% BI 0.24-7.04); the rate in women having an elective or therapeutic abortion was more than twice that in those delivering babies (0.70% vs 0.28%, p less than 0.05, relative risk 2.54, 95% CI 1.36-4.75). Studies with neonatal HIV seroprevalence as a surrogate for HIV prevalence in pregnant women would underestimate prevalence in these women.

Abortion, Therapeutic↗

Hematopoietic progenitors cells in cord blood.

Human umbilical cord blood was evaluated as an alternative to bone marrow as a source of stem cells for hematopoietic transplantation. In order to define an optimal collection procedure, we have studied the parameters that influence the collection, handling and storage of cord blood. We have attempted to correlate the quality of the samples with obstetrical and neonatal parameters. Using culture techniques we have studied the long term viability of the cells. Cell separation was also investigated. Our results suggest that most of the sample collected could be suitable for transplantation, in term of progenitors. However the observed variability between samples suggest that an efficient control of the quality of the samples is important.

Blood Banks↗

Clinical applications of stem cell transfusion from cord blood and rationale for cord blood banking.

Umbilical cord blood collected and cryopreserved at birth contains enough hematopoietic progenitor stem cells for engraftment. HLA identical sibling cord blood transplant has been performed for the first time, in a child with Fanconi anemia. Three years latter, this child is alive with a complete donor type bone marrow. Since this first attempt, several other patients with other diseases have been transplanted successfully. Cord blood banking is a safe and easy procedure. Due to the high proliferative capacity of neonatal hematopoietic progenitors and to the relative immunological functional immaturity of neonatal lymphocytes cord blood cells could be used for matched unrelated or partially mismatched transplants.

Adult↗

Thymic abnormalities in fetuses aborted from human immunodeficiency virus type 1 seropositive women.

Pathological abnormalities of the thymus were found in 3 of 37 fetuses aborted from human immunodeficiency virus (HIV)-infected mothers. These lesions were located predominantly in the thymic cortex, which contains mostly immature lymphocytes. Areas of focal lymphocyte depletion were infiltrated with CD4+ macrophages and were associated with abnormalities of the epithelial stromal network. No evidence of extensive HIV infection in any of the 37 thymuses was detected by either immunofluorescence or in situ hybridization techniques, although rare cells that expressed HIV antigens were found in 3 fetuses. Although less extensive, this thymic fetopathy was similar to that described in postnatal acquired immunodeficiency syndrome thymuses, strongly suggesting that the lesions were related to HIV infection. Thymic fetopathy might represent the initial injury to the lymphoid system in HIV-infected infants in whom early and severe immunosuppression develops.

Abortion, Induced↗

[Prevention of perinatal hepatitis B virus transmission. Epidemiology and cost/efficacy ratio in the Paris region].

The HBs antigen (AgHBs) was detected in 152 out of 6605 (2.3 percent) pregnant women who attended four representative maternity clinics in the Paris region. In 98 percent of the cases this finding reflected chronic hepatitis B virus infection. Among women born outside France (47 percent of the women tested, 79 percent of the AgHBs positive women), the relative risk was 6 for Asiatics, 5.5 for Africans and 4 for French women born in overseas departments or territories. Whatever the women's geographical origin, studies of their medical history revealed no significant difference between AgHBs positivity and AgHBs negativity. Overcrowding and multiparity correlated globally with the presence of AgHBs, but this correlation was absent in French women born in France. In non-African and non-Asiatic women detection guided by medical and socio-familial criteria would not be efficacious. The authors recommend systematic detection of AgHBs in pregnant women and estimate at about 180,000 french francs the cost of prevention for each case evolving toward the vital complications of chronic hepatitis B virus infection, an outcome which in the long term may affect 600 individuals born each year and who had contracted the infection during the perinatal period.

Adult↗

HIV proteins absent from placentas of 75 HIV-1-positive women studied by immunohistochemistry.

Recent epidemiological and virological data suggest that the incidence of maternofetal transmission of HIV-1 infection is between 20 and 30%. The available evidence points to a possible role of peri- and postnatal contamination, but the isolation of HIV from fetuses shows that transplacental transmission also occurs. We attempted to detect, by means of an immunohistochemical method, HIV proteins in frozen placentas from 75 HIV-1-positive women (30 at term, 45 induced abortions). In addition, in situ hybridization using HIV-specific probes was performed in three cases. Neither HIV proteins nor nucleic acid sequences were detected, but CD4+ mononuclear cells were present in the chorion and villi, regardless of the clinical and biological status of the mother (particularly in the nine cases in which the infants were infected). There are several possible mechanisms involving the placenta in the maternofetal transmission of HIV, including active transport of the HIV-immunoglobulin G complex via Fc receptors on trophoblastic cells, passive transplacental passage of HIV during a viraemic episode, the passage of infected maternal cells, and infection of the placenta itself. The methods we used could not rule out the presence of HIV DNA provirus within the genome of placental cells. In any event, immunohistochemical detection of HIV proteins in the placenta is not a technique suitable for the prenatal diagnosis of HIV infection or for identifying newborns likely to develop HIV infection.

Adult↗

[The perinatal transmission of the hepatitis B virus in the Paris area].

HBsAg was detected in 152 pregnant women among 6,605 (2.3%) screened in the prenatal clinics of four hospitals representative of the Paris metropolitan area. In 98% of cases, HBsAg positivity indicated chronic HBV carrier status. Among patients born out of continental France (47% of screened women, 79% of positive women) relative risk of chronic infection was 6 in Asians, 5.5 in Africans, and 4 in French women born in non-continental France. No significant difference in medical history was seen between HBsAg-positive and HBsAg-negative patients, in any of the birthplace groups. In women born out of continental France, number of children and crowding in the home were correlated with HBsAg-positivity; these correlations were not found in French women born in continental France. In non-African, non-Asian women, screening on the basis of medical, social and familial criteria (simulated in this study) would not be effective. Routine screening for HBsAg in pregnancy is advocated. The cost of the prevention of each case of perinatally acquired chronic HBV infection by routine screening followed by prophylactic treatment of a risk neonates was estimated at 180,000 French Francs (35,000 dollars). This approach is the only means of preventing the long-term life-threatening complications of chronic HBV infection in the 600 neonates born each year in France to HBsAg-positive mothers.

Africa↗

[Perinatal transmission of the hepatitis B virus in Paris region].

HBsAg was detected in 152 pregnant women among 6,605 (2.3%) screened in the prenatal clinics of four hospitals representative of the Paris metropolitan area. In 98% of cases, HBsAg positivity indicated chronic HBV carrier status. Among patients born out of continental France (47% of screened women, 79% of positive women) relative risk of chronic infection was 6 in Asians, 5.5 in Africans, and 4 in French women born in non-continental France. No significant difference in medical history was seen between HBsAg-positive and HBsAg-negative patients, in any of the birthplace groups. In women born out of continental France, number of children and crowding of the home were correlated with HBsAg-positivity; these correlations were not found in French women born in continental France. In non-African, non-Asian women, screening on the basis of medical, social and familial criteria (simulated in this study) would not be effective. Routine screening for HBsAg in pregnancy is advocated. The cost of the prevention of each case of perinatally acquired chronic HBV infection by routine screening followed by prophylactic treatment of at risk neonates was estimated at 180,000 French Francs (35,000 dollars). This approach is the only means of preventing the long-term life-threatening complications of chronic HBV infection in the 600 neonates born each year in France to HBsAg-positive mothers.

Female↗