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Biomedical subjects

J P Chiron

Publications and source records attributed to J P Chiron.

At least 19 recordsLinked to original sources
PubMed2001

Alteration in CD29(high) CD4(+) lymphocyte subset is a common feature of early HIV disease and of active tuberculosis.

Peripheral CD4 T-cell depletion has been observed in human immunodeficiency virus (HIV)-negative patients with pulmonary tuberculosis (TB). To investigate more accurately this alteration, we studied peripheral blood CD45RA(+) and CD29(high) CD4 subsets in 79 TB patients with (HIV(+)TB(+)) or without (HIV(-)TB(+)) HIV infection, 85 HIV-infected patients without TB (HIV(+)TB(-)), and 43 healthy controls, all living in West Africa. The high proportion of CD4(+)CD29(high) T cells observed in controls was dramatically decreased in CDC-A stage HIV(+)TB(-) patients. CD45RA(+) CD4(+) T cells were depleted during the CDC-B stage. Both the percentage and the absolute count of CD29(high)CD4(+) T cells were decreased in HIV(-)TB(+) and HIV(+)TB(+) patients versus controls, but CD45RA(+)CD4(+) T cells were not decreased in TB patients without HIV-infection. Although distinct alterations in the CD4(+) T-cell homeostasis are involved in TB(-) versus HIV-infected subjects, our data suggest that the CD29(+)CD4(+) T-cell depletion observed during the early HIV disease contributes to the risk of active TB, by reducing the pool of T cells able to relocalize to the sites of the M. tuberculosis multiplication.

Acquired Immunodeficiency Syndrome↗
PubMed2000

[Effect of "micronized" C60 fullerene on the microbial growth in vitro].

The effect of C60 "micronized fullerene was tested by a manual and automatised (Analyzer Bioscreen C(R)) micromethod on the microbial growth of 22 collection strains: E. coli (5), P. aeruginosa (2), S. Typhimurium (6), S. aureus (2), L. monocytogenes (2), E. hirae (1), B. cereus (1), B. subtilis (1), B. pumilus (1) et C. albicans (1). No effect on microbial growth was observed with C60 "micronized fullerene (43.2 microg/ml) on all strains studied: no difference was found with doubling time, slope and growth rate constant. The results of cytotoxicity obtained with animal models or in vitro cultures as human monocyte, leukocyte or macrophage confirm the absence of effect of C60 fullerene at a concentration compatible with microbial or biological models. This study is included in research program headed "Therapeutics perspectives of fullerenes.

Bacteria↗
PubMed1998

Toxicity, mutagenicity, and behavioral effects of beta-CIT, a ligand for dopamine transporter exploration by SPECT.

The cocaine analog beta-CIT is one of the most used compounds for SPET examination of the dopamine transporter in drug abuse and Parkinson's disease. However, the toxicity of this agent has not yet been studied. We report here acute toxicity, mutagenicity, and effect on locomotor activity of beta-CIT. Acute toxicity experiments were performed in mice and rats. The LD50 values were about 20 mg and 5 mg for mice and rats, respectively. There was no sex difference. The mutagenicity was evaluated using the Ames' test. No mutagenic effect was observed for beta-CIT. Effects on locomotor activity were measured in mice using the open-field test. beta-CIT increased locomotion (+65%) when injected at a dose of 0.312 mg/kg; the maximal increase (+205%) was observed at a dose of 1.25 mg/kg; at higher doses, the effect was decreased slightly. These pharmacological findings are in agreement with an inhibitory effect of beta-CIT at the dopamine transporter. We conclude that with no mutagenic effects and LD50 more than 6 orders of magnitude higher than the routinely used doses in PET or SPET, it can be assumed that beta-CIT can be safely used as a radioligand in humans.

Animals↗
PubMed1998

[Philippe Maupas : hepatitis B vaccine discoverer].

Philippe Maupas Day 8th February 1981, an official ceremony with all the Profession, the Tours Faculty of Pharmacy was called Philippe Maupas, Hepatitis B vaccine discoverer - Galien Prize 1981. This communication presents the man, the scientist and the teacher. Born on 30th June 1939 in Toulon (south of France), married and the father of two children, Ph. Maupas was a man of action and an humanist. Full of enthusiasm, always available, passionate about his work, he never hesitated to brave the odds if he felt it would be of use to the community. With a pluridisciplinary training - Veterinary Doctor (1965), Pharmacist (1970), Science Doctor (1970) and Physician Doctor (1976) - he was Professor of Microbiology and Dean of the Faculty of Pharmacy of Tours. His scientific career fully illustrates his thirst for knowledge and his unflagging struggle against infectious diseases. Ph. Maupas approached his research work in a relaxed, imaginative frame of mind. Always passionate about his work and fired by spirit of Louis Pasteur, he was moved by a preoccupation of efficacy and a will of prevention in Public Health. He carried out research into both animal and human infectious diseases as well as anthropozoonosis. Ph. Maupas's most remarkable discoveries concerned the hepatitis B virus: he produced the first vaccine against hepatitis B and applied it to the prevention in man of this disease (1976); he confirmed the aetiological link between the hepatitis B and primary liver cancer.

France↗
PubMed1996

Impact of short-course therapy on tuberculosis drug resistance in South-West Burkina Faso.

SETTING: The Regional Tuberculosis Centre and the Muraz Centre in Bobo-Dioulasso, Burkina Faso. OBJECTIVES: To observe the trend of primary drug resistance in pulmonary tuberculosis patients 5 years into a short-course treatment programme and to assess the possible implementation of a further programme. DESIGN: Bacteriological study of stains isolated from all newly diagnosed tuberculosis patients (n = 300), all relapse cases (n = 20) and all failure cases (n = 58) from the Houet province, during the period from April 1992 to April 1994. Human immunodeficiency virus (HIV) serostatus was determined for the first 119 patients included in the study. RESULTS: Mycobacterium tuberculosis was the predominant species as shown by 75.1% of the isolates; next was M. africanum, then atypical mycobacteria and finally M. bovis, representing 18.4%, 6.5% and 0.4% of the isolates respectively. Primary resistance (excluding atypical strains) was as follows: isoniazid 7.6%, ethambutol 1.0%, rifampicin 2.5%, and streptomycin 12.4%; 33.6% of the patients tested for HIV were HIV positive. There was no relationship between HIV serostatus and the identity of strains or drug resistance. However, negative acid-fast bacilli smear microscopy with positive culture was significantly more frequent in HIV-positive patients than in HIV-negative patients. CONCLUSION: This study shows a drop in primary resistance compared with previous studies carried out in Bobo-Dioulasso under the same conditions (setting, materials and methods, sampling procedures) in 1982 and 1986. This is consistent with the hypothesis that treatment monitoring and the introduction of short-course therapy in 1989 (2 HERZ/4 HR or 2 HRSZ/4 HR) have contributed to lower rates of primary drug resistance.

AIDS-Related Opportunistic Infections↗
PubMed1995

A study of Toxoplasma and Cytomegalovirus serology in tuberculosis and in HIV-infected patients in Burkina Faso.

Seroreactivity to Toxoplasma gondii (Tg) and to Cytomegalovirus (Cmv) was compared between symptomatic HIV-infected patients (40 with pulmonary tuberculosis and 38 with AIDS) and HIV-seronegative patients (40 tuberculosis patients and 30 healthy patients), in an urban area of Burkina Faso. Prevalence of IgG antibodies to Tg antigens (> 50.0%) did not differ amongst the four groups, but tuberculosis HIV+ patients and AIDS patients showed more higher titers of Tg antibodies more often than healthy patients (p < 0.05 and p < 0.005, respectively). Prevalence of specific IgG to Cmv was higher in tuberculosis HIV-seronegative patients (97.5%) and in AIDS patients (100%) than in healthy patients (82%; p < 0.03 and p < 0.001, respectively). Higher Cmv antibodies titers were found in relation to AIDS but also to tuberculosis. Tuberculosis HIV+ as tuberculosis HIV-patients showed higher Cmv antibodies titers than healthy patients (p < 0.002 and < 0.02 respectively). These data emphasize the need for taking into account the risk of Tg reactivation during the follow-up of HIV infected patients in Burkina Faso and suggest possible relationships between Cmv and tuberculosis reactivations.

AIDS-Related Opportunistic Infections↗
PubMed1994

Twelve-year follow-up study of hepatitis B immunization of Senegalese infants.

Numerous studies have documented the efficacy and safety of plasma-derived and recombinant hepatitis B vaccines. However, little is known about the long-term protection of hepatitis B vaccine, when anti-HBs declines to low or undetectable levels. This study reports results from a 9-12-year period follow up of infants immunized against hepatitis B in Senegal. At the end of the follow-up period anti-HBs were detected in 81% of children who received a booster dose at school age and in 68% of those who did not. HBsAg was detected in 19% of infants from the control group compared to only 2% of immunized infants, corresponding to a protective efficacy of 88%. The results show that long-term protection against HBsAg carriage of hepatitis B vaccination is very high and that a booster dose at school age does not significantly increase this protection.

Child↗
PubMed1994

Child defecation behaviour, stool disposal practices, and childhood diarrhoea in Burkina Faso: results from a case-control study.

OBJECTIVE: To investigate the association between where young children defecate, where stools are disposed of, and the presence of human stools on the ground in the compound and the rate of hospital admission with diarrhoea. DESIGN: This was a case-control study with two control groups. SETTING: The study took place in Bobo-Dioulasso, the second city of Burkina Faso in West Africa. PARTICIPANTS: Three groups of children aged 36 months and under, and living in Bobo-Dioulasso were studied. Cases were 757 children admitted to hospital with symptoms of diarrhoea or dysentery. The first control group comprised 757 neighbourhood control children approximately matched on age and date of recruitment, and the second, 631 children admitted to the same hospital without symptoms of diarrhoea or dysentery. MAIN RESULTS: There was no evidence of any association between where the child was reported to defecate and hospital admission with diarrhoea or dysentery (odds ratio = 1.10; 95% confidence interval (CI) 0.78, 1.57, cases v neighbourhood controls; odds ratio = 0.84; 95% CI 0.60, 1.18, cases v hospital controls). There was evidence of an association between where the mother reported disposing of the child's stools and hospital admission with diarrhoea or dysentery (odds ratio = 1.50; 95% CI 1.09, 2.06, cases v neighbourhood controls; odds ratio = 1.31; 95% CI 0.96, 1.79, cases v hospital controls). Human stools were more frequently observed in the yards of cases than controls (odds ratio = 1.38; 95% CI 0.98, 1.95, cases compared with neighbourhood controls; odds ratio = 1.33; 95% CI 0.96, 1.84, cases compared with hospital controls). CONCLUSIONS: The findings suggest that it is not where the child defecates that matters but how the mother then deals with the child's stools.

Age Distribution↗
PubMed1993

High human malarial infectivity to laboratory-bred Anopheles gambiae in a village in Burkina Faso.

The malarial infectivity of an African village population was tested by selecting a demographically representative sample of individuals for study, regardless of parasitemia or gametocytemia. The infectivity of this population people to laboratory-bred mosquitoes was investigated using membrane feeding techniques. Tests on 322 subjects (greater than four years of age) indicated that approximately 48.4% were capable of infecting mosquitoes. There were similar proportions of infectious individuals among gametocyte carriers (52.5%) and nongametocyte carriers (46.6%). All age groups appeared to contribute equally to this infective reservoir. Most of the infections resulted in low oocyst loads (1.8 oocysts) on the midgut of the positive mosquitoes and only a few mosquitoes per batch were infected (11.5%). A previous entomologic survey estimated 90 infected bites/person/year and a low parity index in Anopheles gambiae (< 60%) as well as in An. funestus (< 40%), the two main malaria vectors in this region. This low parity index could indicate a low life expectancy for infected mosquitoes and could therefore explain an inoculation rare lower than expected considering the high degree of infectivity of the human population studied.

Adolescent↗
PubMed1993

[Diarrheic diseases in children. Rationalization of fecal test].

The level of diarrheic diseases among children in Burkina Faso is very high. The identification of aetiologic agents of diarrhoea in hospitalized children (0-36 months) is one of the objectives of the study. All children less than 37 months old admitted to the Pediatric Unit of the National Hospital Souro Sanou of Bobo-Dioulasso between January 1990 and March 1991, were investigated by a standardized clinical examination, and in addition, we do an analysis of a rectal swab at admission and a stool to identify aetiologic enteric agents. As a conclusion to the study: an agent was isolated in 56% of the children with diarrhoea, and in 40% of the children without diarrhoea; some germs (such Salmonella, Shigella, Entamoeba) are found in children both with and without diarrhoea; also, the total of these examinations comes to 20 US $ per episode, or 100 US $ per children/year in Burkina Faso where the number of bouts reaches 5 times per year per infant who is less than 5 years old. Stool samples are not beneficial for children with diarrhoea, neither for the diagnosis nor for the treatment. There fore these types of routine exams should not be used in Sub-Saharan Africa.

Burkina Faso↗
PubMed1992

Comparative immunogenicity in children of mammalian cell-derived recombinant hepatitis B vaccine and plasma-derived hepatitis B vaccine.

Three doses of hepatitis B vaccine were given at 2, 4 and 9 months of age to 220 Senegalese infants living in the Dakar area of Senegal. Half of the infants received 5 micrograms plasma-derived hepatitis B vaccine (Hevac B) and the remainder 20 micrograms mammalian cell-derived recombinant hepatitis B vaccine (GenHevac B). Both vaccines contain S and pre-S2 encoded proteins; however, the recombinant vaccine had a much higher pre-S2 content than the plasma-derived vaccine. Adverse reactions to both vaccines were limited to mild and transient soreness at the injection site. Fever was reported in 14-21% of the infants and was likely to be related to DTP-polio vaccine which was given simultaneously. After the two first doses, seroconversion rates and geometric mean titres of anti-HBs were higher in infants receiving the recombinant vaccine than in infants receiving the plasma-derived vaccine. After completion of vaccination, all infants in both groups had protective levels of anti-HBs antibodies. The recombinant vaccine induced more rapidly antibodies directed against S and pre-S2 epitopes. Anti-pre-S2 antibodies were detected after the first injection of GenHevac B and only after the third injection of Hevac B. From the data, GenHevac B vaccine is expected to be as effective as Hevac B vaccine for controlling hepatitis B infection.

Amino Acid Sequence↗
PubMed1992

[The evaluation of sexual behavior and knowledge of AIDS in the schools of Burkina Faso. A Knowledge, Attitude, Belief and Practice (KABP) survey in Banfora among 474 adolescents of 14-to-25-years old].

The results of a survey carried out in 1990 on the knowledge, attitudes, beliefs, and practice (KABP) concerning AIDS are presented and discussed. The population surveyed was a random sample of 474 secondary school students (SSS), aged 14-25, in Banfora (Burkina Faso). Among the SSS, a high level of general knowledge about AIDS as a sexually transmitted disease (92.2%) and about condoms (83.1%) is noted. More specific knowledges however, such as the notion of seropositivity, is less well understood (36.7%). Their sources of information are essentially the radio (57.8%) and newspapers (45.4%). The SSS are afraid of AIDS and report that they have changed their behaviour (71.7%). Sexual experiences at young age and risky sexual behaviour (no use of condoms) are however reported. The place of residence, religion, and job and income of their parents or other relatives they are living with, seem to have no effect on the age of the first sexual experience. At present, the SSS of Banfora are aware of the AIDS problem but have not changed their sexual behaviour accordingly, even if they report having done so. The SSS are a prime target population group for any AIDS prevention program.

Acquired Immunodeficiency Syndrome↗
PubMed1991

Scheduling of revaccination against hepatitis B virus.

Studies have shown that to maintain protection against infection after a primary course of hepatitis B immunisation, revaccination can be scheduled on the basis of an anti-hepatitis B virus surface antigen (anti-HBs) titre obtained 1 month after the booster dose. However, schemes which require post-booster testing may present practical difficulties. We applied a random-effects regression model to data from 118 Senegalese infants given three injections of hepatitis B vaccine about 6 weeks apart and a booster injection at 13 months, and show that revaccination can be scheduled on the basis of an anti-HBs titre recorded at the time of the booster dose. We also show that titre-at-booster is no less accurate in predicting future titre than 1-month post-booster titre. In several other studies the post-booster decline in anti-HBs conforms to the same mathematical description, indicating the generality of our findings.

Hepatitis B↗
PubMed1990

Hepatitis B surface antigen reactivity in man due to a new variant of hepatitis B virus.

A new type of hepatitis B virus (HBV) infection has been encountered in Senegalese infants and French adults characterized by serum hepatitis B surface antigen (HBsAg) without antibodies to the core antigen (anti-HBc). As the infection is not associated with the presence of the e antigen, it differs from HBV in its core antigen. After the loss of HBsAg, neither anti-HBc nor antibodies to HBsAg (anti-HBs) become detectable. This new infection (called HBV2 as opposed to the classical HBV1 infection) was found in infants with anti-HBs, either naturally acquired or produced by immunization against HBV. The use of monoclonal anti-HBs antibodies showed that two epitopes of HBV1 surface antigen could be detected in HBV2-positive sera. HBV DNA sequences could only be found in one of 15 HBV2-infected children using a DNA-DNA hybridization procedure; low levels of HBV DNA were also detected in 58% of the HBsAg-positive adult sera tested. If this new infection, apparently related to HBV1, is shown to cause chronic liver disease, hepatitis B vaccine should also contain surface antigen from HBV2.

Adult↗
PubMed1989

Hepatitis B virus infection in lepromatous and tuberculoid patients from Senegal.

Hepatitis B Virus (HBV) seric markers (HBs Ag, anti-HBs, and HBe Ag) were studied in 987 Senegalese leprosy patients (lepromatous: LL; tuberculoid: TT) in comparison with 6187 healthy adults (controls). Two populations of leprosy patients from ILAD (Institut de Léprologie Appliquée de Dakar) were studied: The First study (i.e.: study I) between 1973 and 1977 included 553 patients (329 LL; 224 TT). The Second study (i.e.: study II) between 1982 and 1986 included 434 patients (236 LL; 198 TT). HBV serological markers were tested by various techniques. By RIA, they were present in 98% and 96.5% in the studies I and II respectively. Each marker was studied and compared to the control population. HBs Ag detected by RIA was present in 25.5% (study I) and 23.0% (study II) when comparing to 15.2% in the control group. This marker was correlated with leprosy forms (LL and TT), age, sex, ethnic group.

Female↗
PubMed1988

Anti-pre-S2 antibodies in natural hepatitis B virus infection and after immunization.

Anti-pre-S2 antibodies were detected by enzyme-linked immuno-absorbant assay using a synthetic peptide analogue of pre-S2 protein, in different groups of hepatitis-B-infected subjects, including patients presenting with cirrhosis and liver cancer, and also in infants immunized with hepatitis B vaccine. Anti-pre-S2 antibodies were not detected in hepatitis B surface antigen (HBsAg) chronic carriers, including patients with cirrhosis or primary liver cancer. Anti-pre-S2 antibodies were not detected in HBsAg-positive sera during the early phase of acute hepatitis. They were only noted upon recovery, when anti-HBs antibodies are detectable at the same time as HBsAg. After recovery, anti-pre-S2 antibodies were noted in 57% of test sera and were still detectable in 16% of anti-HBs-positive sera obtained years after HBV infection. Anti-pre-S2 antibodies were detected in 70% of infants immunized with 2 or 5 micrograms doses of Hevac B Pasteur vaccine, confirming that this vaccine contains pre-S2 antigen. Anti-pre-S2 detection was correlated with the anti-HBs antibody titre.

Carrier State↗