PubMed Health⌕ Search

Biomedical subjects

F Clavel

Publications and source records attributed to F Clavel.

At least 73 records · Page 4Linked to original sources

Familial susceptibility to breast cancer: a complex inheritance.

The main results of segregation analysis aimed at identifying a major genetic factor involved in susceptibility to breast cancer are reviewed. They show that the existence of a single major gene is not sufficient to explain the distribution of the disease observed in the families concerned and suggest that the genetic inheritance involved is heterogeneous and complex. Heterogeneity has been explored in various studies according to epidemiological criteria. From these analyses, genetically homogeneous subgroups emerged (for instance families with breast cancer only or with affected males). The study of such homogeneous subgroups might help to better locate the susceptibility gene(s) on the chromosome map by analysis of genetic linkage using different markers. The results of segregation analysis depend on how epidemiological factors are taken into account. It is of major importance that epidemiological data on the proband (i.e., the individual prompting selection of a family) as well as on the members of his/her family are taken into consideration to improve understanding of the complexity of breast cancer transmission.

Breast Neoplasms↗

Coffee, alcohol, smoking and cancer of the pancreas: a case-control study.

A hospital case control study on smoking, alcohol and coffee consumption as risk factors for pancreatic cancer, in which 161 cases were matched to 268 control patients, was conducted in France between 1982 and 1985. The results showed no association between tobacco or alcohol consumption and cancer of the pancreas, whereas coffee consumption was associated with an increased risk [OR of 2 or more cups per day vs. less: 2.27 (1.11-4.64) and 1.45 (0.82-2.55) among females and males respectively]. A dose-response relationship was observed with coffee consumption in both sexes, stronger among females than among males: the linear increase estimates were 2.00 (1.22-3.29) and 1.32 (0.91-1.92) respectively. No interaction was found between coffee and tobacco, whereas the effect of coffee appeared to be limited to non-drinkers of alcohol.

Adolescent↗

Genetic recombination of human immunodeficiency virus.

We investigated genetic recombination of the human immunodeficiency virus (HIV) in a tissue culture system. A clonal cell line expressing a single integrated HIV provirus with a termination codon affecting pol gene expression was transfected with different defective mutants derived from an infectious molecular clone of HIV. Replication-competent viral particles were recovered, passaged, and plaque purified. Restriction analyses of the proviral DNA corresponding to several of these viruses indicated that their emergence was the result of genetic recombination.

Cells, Cultured↗

Decreased mortality among male prisoners.

The mortality among a population of male prisoners between 1977 and 1983 was compared with that among the general French population. The overall mortality rate (for all deaths except external causes) was lower among prisoners (SMR = 84; p less than 0.05). Moreover, the risk of dying from all causes, as well as from malignant neoplasms, diseases of the circulatory system, and suicides fell significantly with increasing duration of imprisonment. These findings suggest that the lifestyle specific to imprisonment might overcome the prejudicial effect of risk factors such as alcohol, tobacco, or drug abuse that tend to be common among prisoners.

Adolescent↗

Human immunodeficiency virus type 2 infection associated with AIDS in West Africa.

We recently reported the isolation of a new retrovirus, termed human immunodeficiency virus type 2 (HIV-2), from two West African patients with the acquired immunodeficiency syndrome (AIDS). This virus is related to but distinct from the well-characterized AIDS retrovirus, human immunodeficiency virus type 1 (HIV-1). We report here evidence of infection with HIV-2 in 30 patients, almost all from West Africa. Seventeen of them had a clinical syndrome indistinguishable from AIDS (7 of these 17 died). Others had either the AIDS-related complex or no HIV-related symptoms. All patients had serum antibodies reacting with HIV-2 in an indirect immunofluorescence assay. All serum tested contained antibodies reacting with the envelope glycoprotein of the virus in an immunoprecipitation assay. Cross-reactivity of serum antibodies with HIV-1 was detected in a minority of patients and varied according to the assay used. Retroviral isolates were obtained from the blood lymphocytes of 11 patients and were all identified as HIV-2 by nucleic acid hybridization; none hybridized with an HIV-1 probe. These findings indicate that some cases of AIDS in West Africa may be caused by HIV-2, but the extent of the spread of this virus and its clinical correlates will require careful epidemiologic investigation.

AIDS-Related Complex↗

Lymphadenopathy-associated virus type 2 in AIDS and AIDS-related complex. Clinical and virological features in four patients.

Lymphadenopathy-associated virus type 2 (HIV 2) was isolated from 3 patients with AIDS and 1 with AIDS-related complex. Clinical features were similar to those in patients infected with HIV 1. Viral isolates were characterised by hybridisation with HIV 1 and HIV 2 DNA probes. HIV 1 and HIV 2 serological studies were performed by enzyme-linked immunosorbent assay (ELISA), western blot, and radioimmunoprecipitation assay. HIV 2 IgG antibodies were detected in all sera. The molecular weights of the most representative HIV 2 proteins were determined by immunoblot. Cross-reactivity was restricted to HIV 1 and HIV 2 core proteins. In all 4 patients the neurotropism of HIV 2 was demonstrated by virus isolation from the cerebrospinal fluid and/or by evidence of intrathecal HIV 2 IgG synthesis. All sera were antibody negative by HIV 1 ELISA. An assay specific for HIV 2 is needed for screening of blood donations and for diagnosis and seroepidemiological study of HIV 2 infection.

AIDS-Related Complex↗

Nicotine dependence and secondary effects of smoking cessation.

The secondary effects of smoking cessation among subjects included in a randomized trial, performed to test the efficacy of acupuncture and nicotine chewing gum vs. the control group, are reported according to nicotine dependence. After 1 month of cessation, ex-smokers had modified their nutritional intake, had gained weight, and felt more irritable compared to subjects still smoking. After 1 year, secondary effects concerned greater weight gain and irritability. The percentage of subjects who presented these secondary effects was more frequent among high-dependent than among low-dependent ex-smokers.

Behavior Therapy↗

Cholangitis in the acquired immunodeficiency syndrome: report of two cases and review of the literature.

We report the cases of one patient with the acquired immunodeficiency syndrome as a result of human immunodeficiency virus type 1/lymphadenopathy associated virus type 1/human T-cell lymphotrophic virus type III (HIV-1/LAV-1/HTLV-III) infection and of another patient with AIDS related complex caused by human immunodeficiency virus type 2/lymphadenopathy associated virus type 2 (HIV-2/LAV-2) infection, who were suffering from cholangitis. The manifestations and possible mechanisms for cholangitis in these patients and in 10 previously reported similar cases are reviewed.

Acquired Immunodeficiency Syndrome↗

Exposure to vinyl chloride monomer: report on a cohort study.

In 1980 a prospective exposed/non-exposed cohort study was initiated in France by the Institut National de la Santé et de la Recherche Médicale (INSERM U 287) to evaluate the association between mortality and cancer morbidity and occupational exposure to vinyl chloride monomer (VCM). Eleven hundred VCM exposed subjects and 1100 VCM non-exposed controls matched for age (+/- 2 years), plant, and physician were included and followed up over a five year period for vital, health, and occupational status. The percentages of deaths observed among the exposed (1.8%) and non-exposed subjects (1.6%) did not differ. Eighteen (1.6%) and 15 (1.4%) cases of cancer were reported among exposed and non-exposed subjects, respectively (NS). One case of angiosarcoma of the liver occurred among the exposed group; six cases of lung cancer occurred among exposed subjects and two among non-exposed subjects (NS). The percentage of diseases of the circulatory system was higher (p less than 0.02) in the exposed group than in the non-exposed group: this difference was explained mainly by the high incidence of Raynaud's disease (p less than 0.006). The percentages of diseases of the respiratory system did not differ between the two groups.

Adult↗

Isolation of a new human retrovirus from West African patients with AIDS.

The etiological agent of AIDS, LAV/HTLV-III, is common in Central Africa but is not endemic in other areas of that continent. A novel human retrovirus, distinct from LAV/HTLV-III, has now been isolated from two AIDS patients from West Africa. Partial characterization of this virus revealed that it has biological and morphological properties very similar to LAV but that it differs in some of its antigenic components. Although the core antigens may share some common epitopes, the West African AIDS retrovirus and LAV differ substantially in their envelope glycoproteins. The envelope antigen of the West African virus can be recognized by serum from a macaque with simian AIDS infected by the simian retrovirus termed STLV-IIImac, suggesting that the West African AIDS virus may be more closely related to this simian virus than to LAV. Hybridization experiments with LAV subgenomic probes further established that this new retrovirus, here referred to as LAV-II, is distantly related to LAV and distinct from STLV-IIImac.

Acquired Immunodeficiency Syndrome↗

A monoclonal antibody against LAV gag precursor: use for viral protein analysis and antigenic expression in infected cells.

A murine monoclonal antibody (MAb), named C.V.K., was produced after immunization with highly purified and sonicated lymphadenopathy-associated virus (LAV). No monoclonal antibody was observed with intact virus used as immunogen. C.V.K. MAb recognizes an epitope present on the precursor gag protein of 55 kilodaltons. Western blot analysis and pulse-chase experiments support the interpretation that after p55 cleavage into p25, p18, and p13, only p18 expresses this epitope. C.V.K. MAb selectively stained only LAV-infected lymphocytes. This intracytoplasmic staining appears 3 days after the infection and is correlated with reverse transcriptase activity. Neither membrane immunofluorescence of infected lymphocytes nor neutralizing activity was observed with C.V.K. MAb. These facts suggest that p55 and p18 are not expressed at the cell membrane or on the viral envelope. C.V.K. MAb should prove useful not only in the purification of core proteins but also for detecting infected cells producing the virus in suspension or on histologic sections.

Acquired Immunodeficiency Syndrome↗

[LAV type II: a second retrovirus associated with AIDS in West Africa].

A second retrovirus, named LAV-II, has been isolated from two West-African patients with AIDS. By its genomic sequences and its proteins, this virus is different from the LAV-I/HTLV-III, isolated from U.S.A., Europe and Central Africa. It differs also from STLV-III, isolated from Rhesus Macaques with AIDS, but displays an antigenic relationship with the latter virus, at the level of its external envelope protein. The tropism of LAV-II for T4 lymphocytes and the induction of cytopathic effect in infected cells are similar to those of LAV-I.

Acquired Immunodeficiency Syndrome↗