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Biomedical subjects

C Janot

Publications and source records attributed to C Janot.

At least 55 records · Page 3Linked to original sources

[Prevalence and epidemiologic features of subjects found to be infected with HIV when donating blood. CTS of the "Retrovirus" Study Group of the Société Nationale de Transfusion Sanguine].

HIV seroprevalence decreased from 0.62% in 1985 to 0.11% in the first 1990 semester. However, the number of regular blood donors screened as seropositive remains constant since 1988: 48 in 1988, 49 in 1989 and 25 in the first 6 months of 1990. From these data, from reports on recipients and due to the exclusion of 30% of such donors by anti-HBc screening, the residual risk to transmit HIV by blood transfusion was estimated to 17 blood donations per year in France. No significant change was observed throughout these years either in sex ratio or in the repartition into age groups. The number of HIV-infected subjects through the heterosexual route has not increased. The number of homosexuals and of IVDA has dramatically decreased since 1985, homosexuals still representing the major at-risk group.

Adult↗

[Importance of the RIBA test for the diagnosis of antibodies against hepatitis C virus. "Viral Hepatitis" Study Group].

The Chiron RIBA HCV (Hepatitis C Virus) test system is proposed to biological laboratories for detection and confirmation of antibody anti-HCV. The RIBA HCV test is an in vitro qualitative immuno-assay based on recombinant HCV antigens (c100-3 and c5-1-1) immobilized on nitrocellulose strips. This study was performed on 764 blood donors reactive by Elisa Ortho anti-HCV and selected upon the Elisa ratio (1/3 of sera with low ratio 1-2, medium 2-4 and high greater than 4). The results show that 32% of samples are reactive (242/765), 42% (319/764) are non reactive and 26% (203/764) are indeterminate. The RIBA results according of the Elisa ratios and the ALT levels show that 65% of seras with ratios greater than 4 and 83% of seras with ALT greater than 2 N are reactive. None of 60 samples with ratios greater than 4 and ALT greater than 2 is negative.

Alanine Transaminase↗

Toxicity of HPA-23 (ammonium-21-tungsto-9-antimoniate) for normal human myeloid progenitor cells (GM-CFU) in vitro.

HPA-23 is a competitive inhibitor of the RNA-dependent DNA polymerase (reverse transcriptase) of the human immunodeficiency virus (HIV). It may therefore potentially benefit patients with HIV infection. This study aimed at defining the haematopoietic toxicity of this drug and particularly its effects on the normal human granulocyte-macrophage progenitor cells (GM-CFU). Our in vitro studies, in semi-solid agar, have shown an inhibitory effect of increasing concentrations of HPA-23 on colony and cluster formation. This effect is probably dose-dependent. An almost complete inhibition of colony formation was observed at doses of more than 20 micrograms/ml. Regarding cluster formation, a similar although much more progressive inhibitory effect was found. Our experimental data should be extrapolated with caution to clinical situations. However, they must be kept in mind for optimal design of HPA-23 therapy in HIV infected patients.

Acquired Immunodeficiency Syndrome↗

[Epidemiologic study of HIV serology in blood donors from 5 departments in northeastern France (1985-1989)].

Between July 1985 and June 1989, the prevalence of HIV antibody was studied in 503,019 blood donations tested in 5 administrative areas ("departments") of north east France: 91 seropositive donations (donors) were detected (prevalence: 0.18%). The prevalence was 0.41% in 1985, 0.22% in 1986, 0.14% in 1987, 0.10% in 1988 and 0.11% in 1989: in each year, it was found lower than the national prevalence. 14 (15.4%) of the 91 seropositive donors were females, and the prevalences of HIV antibody in blood donations from female and male donors were 0.07% and 0.26% respectively. All seropositive donors were younger than 50 and 83 (91.2%) younger than 40. The prevalence of HIV antibody was higher in blood units at first donation (occasional donors) as compared with blood units collected from regular donors (0.60% versus 0.09%). The prevalence of HIV antibody was higher in blood donations from military donors as compared with donations from civilian donors (0.49% versus 0.07% in 1987, 1988 and 1989). Most seropositive military donors were young male recruits of the national armed forces conscription system. We believe that these recruits are subjects with risk factors which must be taken into account for the determination of national blood supply policies.

Adult↗

HIV 2 infection among blood donors and other subjects in France. The "Retrovirus" Study Group of the French Society of Blood Transfusion.

During a 3 year period, from August 1985 to August 1988, 18 HIV 2-infected blood donors were detected in France as a result of systematic HIV 1 screening. These sera were characterized as HIV 2 by specific Western blot and synthetic peptides. Within the same period, 40 other HIV 2 infected subjects were identified by our study group, independently of blood donations. Thirty of these 58 subjects living in France originate from West Africa (8 blood donors), 3 (I blood donor) are Portuguese men who had lived in West Africa and 25 (9 blood donors) are of French origin; among these, 16 have had a known close contact with West Africa. When HIV 2-infected subjects were asymptomatic, cross reactivity between antibodies to HIV 2 and HIV 1 proteins was generally observed with the two-step ELISA assays using total HIV 1 proteins; it was poor with the competitive assays and variable with the assays using recombinant proteins. When the subjects had signs of immunodeficiency, cross reactivity decreased. The data confirm that HIV 2 is not widespread in France and that most of HIV 2-infected but asymptomatic subjects are recognized by several HIV 1 ELISA assays. Accordingly, systematic screening for HIV 2 with an additional test cannot be recommended at the present time, but a combined HIV 1 and HIV 2 test will be useful when available.

Acquired Immunodeficiency Syndrome↗

Amodiaquine-induced agranulocytosis: report of a case with in vitro studies of granulocyte-macrophage progenitor cells.

We report a case of amodiaquine-induced agranulocytosis in a 60-year-old woman. Four months after the agranulocytosis episode we investigated the effect of the drug using in vitro agar culture techniques. Amodiaquine at increasing concentrations (0.005, 0.05 and 0.5 microgram/ml) displayed an inhibitory effect, probably dose-dependent, on the growth of the patient's bone marrow GM-CFU colonies in the absence of autologous serum. In contrast, no effect was found on the colony and cluster growth of bone marrow samples from 13 healthy controls. Though it has been shown in several cases that amodiaquine-induced agranulocytosis occurs via immune-mediated mechanisms, our data are in support of a direct toxic effect of the drug on abnormally sensitive myeloid progenitor cells.

Agranulocytosis↗

[Post-transfusion cytomegalovirus infection in premature infants weighing less than 1,500 g].

The incidence of cytomegalovirus (CMV) infection among 107 low birth weight transfused infants (birth weight less than or equal to 1,500 g) admitted to an intensive care nursery over an 18 month period was evaluated. The diagnosis of CMV infection was based on specific serologic tests (presence of IgM, increased IgG by ELISA technic) and identification of the virus in the urine. During the first 8 months, the infants received untested blood and CMV disease occurred in 8 infants out of 44 (18.2%). During the following 10 months, all transfusions performed in 63 infants were supposed to be CMV negative. However, 32 infants received untested blood due to emergency, and 5 of them developed a CMV infection (15.6%). Finally, only 31 infants received CMV negative blood without any case of CMV infection. These data clearly demonstrate that, considering the severity of the CMV disease in the premature infants, transfusions should be performed with CMV negative blood products.

Cytomegalovirus↗

Vitamin status, immunity and infections in an elderly population.

The relations between vitamin status and immunological parameters or number of infections have been investigated in self-sufficient healthy individuals aged 60 and over. A total of 411 subjects agreed to participate, but 202 were discarded from the main statistical analysis since they could have had their immune or nutritional status modified by a recent infection, vaccination or drug consumption. Plasma concentrations of retinol, alpha-tocopherol, ascorbic acid and vitamin B6 were determined. Three indices of cellular immunity were measured: percentages of T-cell subsets, lymphoproliferative response to phytohaemaglutinin and delayed-type hypersensitivity to 7 ubiquitous antigens. A questionnaire about past infections was presented. Two results, supported by previous experimental observations, should be underlined. Vitamin B6 status was positively related to percentages of T-cell subsets: the lowest percentages of CD5 and CD4 cells were observed in the low B6 status group (50.6 and 32.6 per cent) and the highest percentages in the high B6 status group (62.0 and 41.0 per cent), with intermediate values in the medium group (57.6 and 39.5 per cent). Vitamin E status was negatively related to the number of past infections: subjects with a high alpha-tocopherol plasma concentration had fewer infections during the last 3 years (1.0) than those with a medium (2.2) or a low (2.3) concentration. In spite of these two observations, cellular immunity did not seem to be strongly related to vitamin status in the supposedly healthy population studied.

Aged↗

Analysis of blood CD4+ and CD8+ T-lymphocyte subsets with monoclonal antibodies. Comparison of the Genetic Systems CD4/CD antigen typing kit with conventional indirect immunofluorescence microscopy and the automated Technicon-H1 Enzyme Immunoassay (EIA).

The Genetic Systems Technique (GS: direct immunofluorescence microscopy with ethidium bromide counterstaining of nuclei) was tested for quantitative analysis of T-lymphocyte subsets in human peripheral blood. The monoclonal antibodies anti-CD4 and anti-CD8 were used for detection of T-helper and T-suppressor cells respectively and the results compared to those obtained by conventional indirect immunofluorescence microscopy and the Technicon Enzyme Immunoassay (EIA) with automated reading. The GS technique provided results correlating well with both indirect immunofluorescence and EIA techniques. Moreover, this method has two advantages: it is less time-consuming than the indirect immunofluorescence microscopy and necessitates less expensive and more commonly available equipment than the automated EIA technique.

Antibodies, Monoclonal↗