Search PubMed⌕ Search

Biomedical subjects

S Chanteau

Publications and source records attributed to S Chanteau.

At least 109 records · Page 6Linked to original sources
PubMed1986

Efficiency of papain-treated microfilariae of Wuchereria bancrofti (var. pacifica) as antigen for serodiagnosis of bancroftian filariasis in French Polynesia.

Papain-treated microfilariae of Wuchereria bancrofti have been used as antigen for indirect fluorescent assay: 0% of non-endemic sera, 8% of healthy exposed Polynesians, 48% of clinical patients and 96% of microfilaraemic subjects were positive by this test. The geometric mean titres were 22, 41, 147 and 605 respectively. Untreated microfilariae were unsuitable for diagnostic purposes. Dirofilaria immitis adult sections showed low reactivity, giving poor discrimination between non-endemic and microfilaraemic sera. The geometric mean titres were 6 and 61 respectively.

Antigens, Helminth↗
PubMed1979

[Enzyme immunoassay for the detection and identification of dengue viruses from infected mosquitoes (author's transl)].

The authors deal with a "double sandwich" enzyme immunoassay for the detection and identification of dengue viruses 1, 2 and 4. They use ground glass-beads (7 mm diameter) coated with human heterospecific anti-dengue antibodies, to bind viruses obtained from infected mosquitoes (Toxorhynchites amboinensis). The mouse antibodies bound to the viruses coated on the beads are revealed by anti-mouse 7S immunoglobulins labelled with peroxydase. The method is practical, sensitive and confident. The standard curves obtained with each type show significant differences from one another until very high dilutions of the viral suspension. Inhibition tests by human immune antibodies and dengue antigens demonstrate the specificity of the reaction. This method is certainly applicable to others arboviruses and allows a large scale epidemiological survey.

Animals↗
PubMedDate not supplied

Finger-prick blood collection and computer-assisted enzyme-linked immunosorbent assay for large-scale serological studies on leprosy.

An immunoglobulin M anti-phenolic glycolipid 1 assay was standardized and optimized using specimens of dried blood collected on commercial precut filter paper discs, followed by a computer-assisted enzyme-linked immunosorbent assay (ELISA). The correlation between venepuncture and finger-prick methods, the calibration of the quantity of absorbed blood, and the reproducibility of the ELISA test were excellent. A slight decline of activity was observed when the samples were stored for 3 months at +4 degrees C. Skimmed milk can be used as diluent instead of bovine serum albumin, contributing to lessening the cost of the test. Using the method described, as many as 300 samples can be collected in the field and 480 ELISAs per day can be run in the central laboratory by one trained person.

Antigens, Bacterial↗
PubMedDate not supplied

One year evaluation of immunogenicity conferred by a Chinese hamster ovary cell recombinant hepatitis B vaccine in a French Polynesian newborn immunization programme.

In 1988, a hepatitis immunization programme, using a Chinese hamster ovary (CHO) cell recombinant vaccine, was implemented for newborn children in the Austral archipelago (French Polynesia). Three different schedules were used: (i) 4 vaccine doses at months (M) 0, M1, M2 and M12; (ii) 3 vaccine doses at M0, M1, M6; and (iii) 3 vaccine doses at M0, M1, M2. Results at the one year follow-up may be summarized as follows. Of 197 infants who received one or more doses of CHO-recombinant vaccine, (i) none was an HBsAg carrier; (ii) 89.5% had anti-HBs-antibody titres greater than 10 miu/ml; and (iii) 95.9% had seroconverted for at least one of the 2 antibodies studied (anti-HBs or anti-pre-S2). After 2 doses (M0, M1), anti-HBs seroconversion rate and geometric mean titre were, respectively, 82.6% and 98.47 miu/ml. After 3 doses, seroconversion rates and geometric mean titres were, respectively, 91.1% and 200.59 miu/ml using schedule M0, M1, M2, and 100% and 1253.4 miu/ml using the M0, M1, M6 schedule. None of the 7 vaccinated neonates born to HBsAg/HBeAg positive mothers was found to be an HBsAg carrier. These preliminary results indicate that, in field conditions, vaccination with a CHO-recombinant vaccine resulted in high immunogenicity.

Female↗
PubMedDate not supplied

Microfilariae recurrence in Polynesian Wuchereria bancrofti carriers treated with repeated single doses of 100 micrograms/kg of ivermectin.

Forty-six Polynesian carriers of Wuchereria bancrofti were treated with 3 successive single doses of ivermectin, 100 micrograms/kg, given every 6 months. Immediate microfilaricidal activity of ivermectin was excellent in all carriers, since residual mean microfilaraemia levels, 2 d after each of the 3 treatments, were less than 1% of pretreatment levels. Before initial treatment, geometric mean microfilaraemia was 500 microfilaria (mf)/ml for the whole group (range 21-6398 mf/ml); 6 months after each successive treatment it was 197, 108 and 87 mg/ml, respectively, 39.4, 21.6 and 17.4% of the pre-initial treatment level. By considering the mean percentage recurrent level at 6 months after the 3rd treatment (36.8%) as a threshold, it was possible to classify the carriers into 2 groups: 17 in whom the percentage recurrent level was > 36.8% and who were considered as 'fast repopulating' individuals, and the remaining 29 who were considered as 'slow repopulating' individuals. In the latter group, 6 months after each of the 3 treatments, the recurrent microfilaremia levels were 22.7%, 8.0% and 4.9% of the pre-initial treatment level, respectively, while they were 95.1%, > 100% and > 100% in the former. The constant recurrence of mf suggests that ivermectin, at a dosage of 100 micrograms/kg, had no effect on adult worms in 'fast repopulating' individuals, whereas the progressive lessening in recurrence of mf suggests some activity (sterilizing or killing) of ivermectin on W. bancrofti macrofilariae in 'slow repopulating' individuals.(ABSTRACT TRUNCATED AT 250 WORDS)

Adolescent↗
PubMedDate not supplied

Low positive predictive value of anti-Brugia malayi IgG and IgG4 serology for the diagnosis of Wuchereria bancrofti.

Enzyme-linked immunosorbent assays (ELISAs) for anti-Brugia malayi immunoglobulin (Ig) G and IgG4 were evaluated on sera from 1561 subjects in French Polynesia for the serodiagnosis of Wuchereria bancrofti filariasis, compared with the test for Onchocerca gibsoni circulating antigen (Og4C3) as a 'gold standard'. The sensitivity of the ELISA-IgG and ELISA-IgG4 assays was 90.8% and 94.5%, and the specificity was 45.9% and 50.7%. The positive predictive values were 41% and 45% respectively for an antigen prevalence rate of 30%. Thus antibody prevalences exceeded by two-fold the antigen prevalence, which itself exceeded by two-fold the prevalence of microfilaraemia.

Adolescent↗
PubMedDate not supplied

Double-blind controlled trial of a single dose of the combination ivermectin 400 micrograms/kg plus diethylcarbamazine 6 mg/kg for the treatment of bancroftian filariasis: results at six months.

In 1993, a three-arm double-blind controlled trial was implemented in French Polynesia to compare the tolerance and efficacy of a single dose of the combination ivermectin (IVR) 400 micrograms/kg plus diethylcarbamazine (DEC) 6 mg/kg vs. IVR 400 micrograms/kg alone vs. DEC 6 mg/kg alone, for treatment of Wuchereria bancrofti carriers. Of the 57 treated male patients in whom microfilaria (mf) densities ranged from 22 to 4709 mg/mL, 3 groups of 19 were randomly selected and allocated to one of the 3 treatments. Side effects were experienced by 34 patients (60%), but none suffered a severe reaction. Grade of reaction did not differ between treatment group, but was significantly correlated with the pretreatment mf density. Six months after treatment, 26%, 32% and 53% of patients were amicrofilaraemic in the DEC, IVR and IVR+DEC groups, respectively. Mf levels were 6.3%, and 3.1% and 1.0% of the pretreatment level, respectively, significantly lower in the IVR+DEC group than in both the IVR and DEC comparison groups. The combination IVR+DEC showed promise in term of sustained mf decrease, and could be an effective alternative for lymphatic filariasis control programmes.

Adult↗
PubMedDate not supplied

Ivermectin 400 micrograms/kg: long-term suppression of microfilariae in Bancroftian filariasis.

Forty-three Wuchereria bancrofti carriers were given 4 successive semi-annual single doses of ivermectin 100 micrograms/kg (IVER 100). The geometric mean microfilaremia (mf) recurrence percentages, compared to the pre-initial treatment mf level, were 35%, 21%, 17% and 17% at 6, 12, 18 and 24 months respectively. However, the recurrence of mf 6 months after the fourth treatment remained high in 15 individuals, considered as 'bad responders'. At month 24, the subjects were randomly allocated into 2 groups: the first group was treated with a fifth dose of IVER 100 and the second with a first, single dose of 400 micrograms/kg of ivermectin (IVER 400). At month 30, the mf recurrence percentage was significantly higher in patients treated with IVER 100 than in those receiving IVER 400 (61% vs. 8%, P < 0.05). In the IVER 100 group, 6 of the 8 'bad responders' remained 'bad responders', whereas only 2 of 7 did so in the IVER 400 group. Only 3 additional patients in the IVER 100 group became consistently amicrofilaraemic, whereas 9 did so in the IVER 400 group. Two 'good responders' in the IVER 100 group became 'bad responders'. A single dose of 400 micrograms/kg of ivermectin has been demonstrated to be efficient for the treatment of carriers refractory to repeated doses of 100 micrograms/kg and to result in better long-term mf suppression. These results suggest a possible effect of 400 micrograms/kg of ivermectin on macrofilaria.

Adolescent↗
PubMedDate not supplied

Plague, a reemerging disease in Madagascar.

Human cases of plague, which had virtually disappeared in Madagascar after the 1930s, reappeared in 1990 with more than 200 confirmed or presumptive cases reported each year since. In the port of Mahajanga, plague has been reintroduced, and epidemics occur every year. In Antananarivo, the capital, the number of new cases has increased, and many rodents are infected with Yersinia pestis. Despite surveillance for the sensitivity of Y. pestis and fleas to drugs and insecticides and control measures to prevent the spread of sporadic cases, the elimination of plague has been difficult because the host and reservoir of the bacillus, Rattus rattus, is both a domestic and a sylvatic rat.

Animals↗
PubMedDate not supplied

Transferable plasmid-mediated resistance to streptomycin in a clinical isolate of Yersinia pestis.

Plasmid-mediated high-level resistance to multiple antibiotics was reported in a clinical isolate of Yersinia pestis in Madagascar in 1997. We describe a second Y. pestis strain with high-level resistance to streptomycin, isolated from a human case of bubonic plague in Madagascar. The resistance determinants were carried by a self-transferable plasmid that could conjugate at high frequencies to other Y. pestis isolates. The plasmid and the host bacterium were different from those previously associated with multiple-drug resistance, indicating that acquisition of resistance plasmids is occurring in this bacterial species. Emergence of resistance to streptomycin in Y. pestis represents a critical public health problem since this antibiotic is used as the first-line treatment against plague in many countries.

Conjugation, Genetic↗