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Biomedical subjects

D Richard-Lenoble

Publications and source records attributed to D Richard-Lenoble.

At least 19 recordsLinked to original sources
PubMed2000

An analysis of the safety of the single dose, two drug regimens used in programmes to eliminate lymphatic filariasis.

This review of the safety of the co-administration regimens to be used in programmes to eliminate lymphatic filariasis (albendazole + ivermectin or albendazole + diethylcarbamazine [DEC]) is based on 17 studies conducted in Sri Lanka, India, Haiti, Ghana, Tanzania, Kenya, Ecuador, the Philippines, Gabon, Papua New Guinea, and Bangladesh. The total data set comprises 90,635 subject exposures and includes individuals of all ages and both genders. Results are presented for hospital-based studies, laboratory studies, active surveillance of microfilaria-positive and microfilaria-negative individuals, and passive monitoring in both community-based studies and mass treatment programmes of individuals treated with albendazole (n = 1538), ivermectin (9822), DEC (576), albendazole + ivermectin (7470), albendazole + DEC (69,020), or placebo (1144). The most rigorous monitoring, which includes haematological and biochemical laboratory parameters pre- and post-treatment, provides no evidence that consistent changes are induced by any treatment; the majority of abnormalities appear to be sporadic, and the addition of albendazole to either ivermectin or DEC does not increase the frequency of abnormalities. Both DEC and ivermectin show, as expected, an adverse event profile compatible with the destruction of microfilariae. The addition of albendazole to either single-drug treatment regimen does not appear to increase the frequency or intensity of events seen with these microfilaricidal drugs when used alone. Direct observations indicated that the level of adverse events, both frequency and intensity, was correlated with the level of microfilaraemia. In non microfilaraemic individuals, who form 80-90% of the 'at risk' populations to be treated in most national public health programmes to eliminate lymphatic filariasis (LF), the event profile with the compounds alone or in combination does not differ significantly from that of placebo. Data on the use of ivermectin + albendazole in areas either of double infection (onchocerciasis and LF), or of loiais (with or without concurrent LF) are still inadequate and further studies are needed. Additional data are also recommended for populations infected with Brugia malayi, since most data thus far derive from populations infected with Wuchereria bancrofti.

Albendazole↗
PubMed2000

Isoenzymes of human lice: pediculus humanus and P. capitis.

Human lice (Phthiraptera: Pediculidae) from Africa, America and Europe were electrophoresed for 28 enzymes, with special interest in metabolic factors likely to be involved with insecticide resistance. Zymogram profiles of the body louse (Pediculus humanus L. from France and U.S.A.) and the head louse (P. capitis DeGeer from France, Madagascar, Mali & Senegal) were compared. Only esterase two enzymes, phosphoglucomutase (Pgm) and 3 (Est-3), showed electrophoretic variation. In our starch gel electrophoresis conditions, P. humanus showed three electromorphs of Pgm migrating anodally 6, 11 and 16 mm (designated alleles a, b, c, respectively). Of the putative Pgm alleles, b and c occurred in all samples of both species of lice, whereas allele a was found only in P. humanus lab strain from U.S.A. Esterase 3 had four electromorphs migrating 23, 26, 30 and 35 mm (designated alleles a, b, c and d). Among putative Est alleles, a was found only in P. capitis from Bamako (all 14 specimens aa homozygotes), allele d was found only in P. capitis from Dakar (39% frequency), whereas Est-3 alleles b and c showed apparently balanced polymorphism in all samples of both P. humanus and P. capitis except that from Bamako. Despite the limited amount of isoenzyme variation detected (only 2/31 polymorphic loci), divergences of Est-3 and Pgm among Pediculus populations may be relevant to their biosystematics and resistance.

Animals↗
PubMed1998

Short- and long-term action of multiple doses of ivermectin on loiasis microfilaremia.

One hundred nine Gabonese patients infected with Loa loa microfilariae were treated with ivermectin (200 microg/kg of body weight) at the Parasitology, Mycology and Tropical Medicine Department (Faculte de Medecine et des Sciences de la Sante, Libreville, Gabon). Each was given one dose per month for six consecutive months. The peripheral blood microfilaria (mf) count before and after each dose showed an average decrease in the microfilaremia of 87.3% (short-term-single dose). An annual single-dose mass treatment with 200 microg/kg of ivermectin was sufficient to control the parasite in populations with low (< 400/ml) L. loa mf counts. One month after the sixth dose (short-term-multiple doses), the average microfilaremia rate had decreased by 99.2% compared with the initial infection (35 patients). Samples were taken from 28 patients one month after the first dose and one month after the sixth dose. The average mf count decreased by 96.4% after the first dose and by 99.6% after the sixth dose (average residual mf counts = 13.7 and 1.5 mf/ml, respectively). The mf count after the sixth dose was only 11.2% of the count after the first dose. The low mf count persisted for more than six months after the sixth treatment (long-term-multiple doses). Thus, mass treatment with multiple doses is more appropriate for areas where the blood mf count is very high. These results show that the number of the annual treatments used in mass chemotherapy with ivermectin can be adapted to each population to provide efficient protection.

Adolescent↗
PubMed1998

[Toxoplasmosis in Dakar. Seroepidemiologic sampling of 353 women of reproductive age].

Thanks to a serological survey carried out in Dakar from January to November 1993 among 353 procreative women, immune cover regarding toxoplasmosis was assessed using ELISA methodology: 40.2% of the surveyed population had antibodies of toxoplasmosis. No evidence of age, pregnancy, number of previous pregnancies was noted in antitoxoplasmosis antibodies prevalence. The seroconversion risk seems to be low even when it has existed during pregnancy. Contamination occurred during childhood. Some sanitary education should be provided to the procreative population in order to achieve a better compliance with basic hygiene regulations during pregnancy.

Adolescent↗
PubMed1997

[Congenital toxoplasmosis with hydrocephalus diagnosed in utero: outcome of treatment].

BACKGROUND: The neurological outcome for severe toxoplasmosis can be poor despite appropriate management. CASE REPORT: A maternal toxoplasma infection occurred at 16 weeks of amenorrhoea; prenatal diagnosis was attempted at 20 weeks, fetal infection was confirmed by mouse inoculation at the 30th week. Pyrimethamine plus sulfadiazine treatment was initiated. However, at 37 weeks of amenorrhoea, sonographic examination of the fetus detected hydrocephalus. Despite prompt ventriculo-peritoneal shunting after birth and medical treatment of toxoplasmosis, the neurological developmental outcome was complicated and prognosis is poor at 5 years of age. CONCLUSION: This case shows that parents must be carefully warned about risks of a prenatal toxoplasmosis.

Anti-Infective Agents↗
PubMed1997

Light microscopic changes in Plasmodium falciparum from Gabonese children treated with artemether.

The changes in Plasmodium falciparum in four Gabonese children suffering from severe malaria and treated with pure artemether were observed in thin blood smears fixed and stained with Giemsa and examined by light microscopy. Peripheral blood samples were taken every 8 hr up to 72 hr from three children and every 3 hr up to 9 hr from the other child. The morphologic changes involved all development stages (trophozoites, schizonts, and gametocytes); they were first seen 3 hr after the start of treatment and all parasites were abnormal after 24 hr. After two days of treatment, all infected erythrocytes disappeared except for a few with necrotic trophozoites. The morphologic changes were similar to the ultrastructural changes previously described in vivo and in vitro in experimental models. They confirm the rapid effect of artemisinin derivatives on parasite clearance and clinical recovery, particularly in cases of cerebral malaria.

Animals↗
PubMed1996

[Cryopreservation of isolates of Toxoplasma gondii in cell culture].

For a better preservation and identification of Toxoplasma gondii isolates, we propose a new method of freezing of toxoplasma growth in THP-1 cell culture. A cystogenic strain isolated from foetal blood has been grown in these cells and frozen in liquid nitrogen. After thawing, toxoplasma recover the same growth rate and morphology in vitro and the same capacity to form brain cysts into mice compared to the initial strains. The freezing of the cell suspension provides a simple and appropriate method for preservation of Toxoplasma gondii within "bank" isolates.

Animals↗
PubMed1996

Detection of circulating antigens in Gabonese patients with Loa loa filariasis.

Circulating antigens were detected in sera of Gabonese patients with Loa loa filarial infection by co-electrosyneresis (Co-ES). The serum samples selected for this study were exposed to rabbit hyperimmune antifilarial antisera and human immune antisera: specific arcs were observed in 35/60 filarial patients, of whom 24/47 were microfilaraemic and 11/13 amicofilaraemic. The identity of rabbit hyperimmune antisera and loiasial immune sera was confirmed by the continuity of precipitation arcs. These preliminary studies were carried out to develop diagnostic tools for loiasis and to study the physiopathology of immune complexes.

Animals↗
PubMed1995

Hepatitis B, C, D, and E markers in rural equatorial African villages (Gabon).

Serologic markers of hepatitis B virus (HBV), including HBV DNA, and of hepatitis delta virus were measured in three villages in Gabon. Of 303 subjects studied, 19% were carriers of hepatitis B surface antigen (HBsAg); 8.5% of these had anti-delta antibodies. No difference among the three villages was observed. All HBV DNA carriers were children less than 11 years of age. In the 2-9-year-old group, 71% of the HBsAg-positive children tested were HBV DNA carriers. These results indicate that HBV prevalence is high in Gabon and emphasize the importance of horizontal transmission of HBV in Africa. Antibodies to hepatitis C virus, assessed in one of the three villages, were found with a prevalence of 35% with a second generation enzyme-linked immunosorbent assay (ELISA) and 24% with a third generation ELISA. None of 35 subjects tested for antibodies to hepatitis E virus was positive.

Adolescent↗
PubMed1995

[Cutaneous candidiasis due to Candida parapsilosis occurring in the course of idiopathic aplastic anemia].

Candida parapsilosis is a very common and saprophytic fungus. Its pathogenic role has been reported in intensive care units after invasive instrumentations. We report a case of dermal candidiasis due to Candida parapsilosis occurring in an immunocompromised patient suffering from aplastic anemia treated with corticosteroids. The histopathological aspect was non specific, showing a polymorphous granulomatous reaction in the middermis. Findings of periodic acid-Schiff and Grocott-Gomori stains revealed a large number of pseudohyphae and spores. Candida parasilosis was cultured from a skin biopsy. The route of skin infection is discussed: direct inoculation or septic localization after fungemia.

Adrenal Cortex Hormones↗
PubMed1994

Nontyphoidal salmonellal septicemia in Gabonese children infected with Schistosoma intercalatum.

Relapses of enteric fever induced by Schistosoma intercalatum have been observed to occur in central Africa. In Libreville, Gabon, 70 children (ages, 2.1-15.9 years) who were seronegative for human immunodeficiency virus and were hospitalized for septicemic salmonellosis underwent rectal biopsy for diagnosis of S. intercalatum infection. A nontyphoidal Salmonella species was isolated from 53 of the 70 patients: Salmonella typhimurium in 14 cases; Salmonella enteritidis in 7 cases; Salmonella galiema in 4 cases; Salmonella arizonae in 3 cases; and other species in 25 cases. Schistosomal eggs were present in the rectal mucosa of 48 (90.6%) of these 53 patients, in 11 (64.7%) of 17 patients with septicemia due to Salmonella typhi or Salmonella paratyphi, and in 21 (38.2%; P < .001) of 55 controls. Clinical symptoms were not different among patients coinfected with S. intercalatum and nontyphoidal Salmonella vs. those with enteric fever. Treatment with antibiotics induced apyrexia only after administration of antiparasitic therapy in 30 patients. These data strongly suggest interactions between S. intercalatum and Salmonella in infected children with clinically severe nontyphoidal salmonellal septicemia.

Adolescent↗
PubMed1994

Evaluation of Onchocerca volvulus-specific IgG4 subclass serology as an index of onchocerciasis transmission potential of three Gabonese villages.

The major objective of this study was to evaluate the usefulness of IgG4 ELISA and Western blot analysis, using a crude extract of Onchocerca volvulus adult worms as antigens, for diagnosing onchocerciasis in a Gabonese paediatric population with mixed filarial infections. The subjects had loaisis, streptocercosis or mansonellosis in addition to onchocerciasis. Control sera from loaisis or mansonellosis subjects residing outside the endemic zone were used to provide the cut-off point for positive results. The IgG4 ELISA had a specificity of 96% but a lower sensitivity of 78.7%. It detected 25 onchocerciasis cases out of 65 individuals who were negative on parasitological examination. Furthermore, the ELISA provided a more accurate picture of onchocerciasis transmission in a village with very low skin microfilarial load. A 27.5-kD antigen was identified on Western blots as a marker of onchocerciasis. The paediatric population provided a reliable window for assessing the parasitologic and serologic parameters in the three villages with disparate levels of onchocerciasis transmission.

Adolescent↗
PubMed1993

[Bilharziasis caused by Schistosoma intercalatum, a recent and forgotten form of schistosomiasis].

Schistosoma intercalatum schistosomiasis is confined to the western regions of equatorial Africa. It is often asymptomatic but it produces microscopic lesions in the intestine (mainly the rectum), the liver and the genital organs of both men and women, the latter lesions being more insidious and insufficiently explored. Its treatment, like that of other schistosomiases, consists of one course of praziquantel. Naturally, S. intercalatum may be hybridized with S. haematobium in Gabon and Cameroun which are the two countries where the two parasites coexist.

Animals↗