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Biomedical subjects

C Longuet

Publications and source records attributed to C Longuet.

10 recordsLinked to original sources
PubMed1999

Increased incidence of cycloguanil resistance in malaria cases entering France from Africa, determined as point mutations in the parasites' dihydrofolate-reductase genes.

The incidence of cycloguanil resistance in 501 Plasmodium falciparum isolates from individuals entering France from Africa was estimated by a method based on PCR-restriction-fragment-length polymorphisms. None of the subjects had taken antifol prophylaxis. Annual incidence of the resistance, detected as a point mutation at codon 108 in the parasite's dihydrofolate-reductase gene, increased from 19.8% in 1995 to 43.6% in 1997 (P < 0.001). The proportion of isolates found to be susceptible (i.e. wild-type) among travellers returning from the African countries known as Group 2 in France (i.e. Burkina Faso, Côte d'Ivoire, Gambia, Ghana, Guinea, Liberia, Madagascar, Mali, Mauritania, Niger, Senegal, Sierra Leone, Tchad and Togo) was reasonably high (62.9%) and much higher than in the other subjects returning from other identifiable countries in Africa (35.3%). The antimalarial prophylaxis recommended in France to those travelling to Group-2 countries, chloroquine-proguanil, therefore still seems reasonable, although cycloguanil resistance may seriously undermine the efficacy of this drug combination in the future.

Africa↗
PubMed1998

Efficacy and tolerability of stavudine plus lamivudine in treatment-naive and treatment-experienced patients with HIV-1 infection.

BACKGROUND: A combination of two nucleoside analogues is currently the core of any antiretroviral regimen for HIV-1 infection. Stavudine plus lamivudine has shown an additive effect in vitro, as well as an absence of overlapping toxicity and cross-resistance. OBJECTIVE: To evaluate the antiviral efficacy of stavudine plus lamivudine in treatment-naive patients and in patients previously treated with other nucleoside reverse transcriptase inhibitors. DESIGN: Prospective, open-label pilot study. SETTING: Three urban clinical centers in Paris. PATIENTS: 83 patients with CD4+ cell counts between 50 and 400 cells/mm3 (42 treatment-naive and 41 treatment-experienced patients). INTERVENTIONS: Stavudine, 40 mg twice daily (30 mg twice daily in patients with a body weight < or = 60 kg), and lamivudine, 150 mg twice daily. MEASUREMENTS: Primary end points for efficacy included changes in plasma viral load and CD4+ cell count at 24 weeks compared with baseline. RESULTS: Therapy with stavudine plus lamivudine resulted in a median decrease of 1.66 log10 (10(1.66)) (range, -3.04 to -0.79 log10) in plasma HIV-1 RNA; the median increase in CD4+ cell count was 108 cells/mm3 (range, -58 to 406 cells/mm3) at week 24 in treatment-naive patients. In treatment-experienced patients, the median reduction in plasma HIV-1 RNA was 0.55 log10 (range, -2.86 to 0.52 log10), and the median increase in CD4+ cell count was 46 cells/mm3 (range, -188 to 311 cells/mm3). The percentages of patients with less than 3000 HIV-1 RNA copies/mL and less than 400 copies/mL at 24 weeks were, respectively, 57% (95% CI, 41% to 72%) and 26% (CI, 12% to 40%) among treatment-naive patients and 22% (CI, 10% to 38%) and 5% (CI, 1% to 17%) among treatment-experienced patients. Of 82 patients, 14 (17%) experienced grade 3 or 4 toxicity and 2 discontinued therapy because of intolerance toward treatment. CONCLUSION: Stavudine plus lamivudine seems to have a potent antiviral effect in treatment-naive and treatment-experienced patients. No major drug-limiting toxicity was found. This two-nucleoside combination should be considered in multidrug therapy for HIV.

Adult↗
PubMed1998

[Considering disparities in resistance of Plasmodium falciparum in Africa in chemoprevention decisions].

OBJECTIVES: Assess the efficacy of preventive and curative treatments of imported malaria. METHODS: The in vitro drug susceptibility of mefloquine, chloroquine and cycloguanil was determined against African isolates of Plasmodium falciparum from imported malaria cases by an isotopic in vitro test or a genomic approach. RESULTS: Plasmodium falciparum resistance to mefloquine, chloroquine or to the dihydrofolate reductase inhibitor was present in 5.2%, 46% and 42% of isolates respectively. Plasmodium falciparum drug resistance to chloroquine or antifolinics was more frequent in permanent than in seasonal malarial transmission areas. Simultaneous resistance to chloroquine and antifolinics was observed in 17% of isolates between 1991 and 1994 and in 28% between 1995 and 1997.

Africa↗
PubMed1998

[Human transmission and plasmodium resistance].

There is no longer malaria transmission in Europe and North America, while the transmission decreases in sub-tropical areas and increases in tropical countries. Most of malarias are now due to Plasmodium falciparum and happen in Africa. In the regions where the transmission is high, malaria is stable, baby mortality is high, and protective immunity is achieved in early childhood. Falciparum resistant malaria originates from mutations on drug target decreasing affinity to antifols, or mutations preventing accumulation of chloroquine in parasitized red blood cells. Resistance is a rapid event following large use of antifols, even associated, while falciparum chloroquine resistance is now widespread. Resistance to quinine, mefloquine and halofantrine is still at low levels out of Thailand, as their use remains through medical hands. Non resistance was observed yet with artemisinin derivatives.

Africa↗
PubMed1998

[Malaria prophylaxis].

Malaria, occurring in 1 to 2% of unprotected travellers to sub-Saharian Africa, remains a real risk because of its potential severity. In Asia or Latin America, the risk appears to be much lower, and in some cases, prevention can be limited to measures to avoid mosquito bites. Chemoprophylaxis by chloroquine-proguanil, mefloquine or, less frequently cyclines, is efficacious but poor compliance and frequent adverse events limits its interest. No regimen is totally effective and malaria must be considered in any traveller coming back from an endemic area with fever, even still receiving an appropriate prophylaxis.

Antimalarials↗
PubMed1998

[Resistance to chloroquine and cycloguanil of Plasmodium falciparum in patients arriving in France after travel in Africa without chemoprophylaxis].

The in vitro susceptibility of chloroquine and the genomic profile of dihydrofolate reductase (DHFR) codon 108 was determined against african isolates of P. falciparum (Pf) from imported malaria cases without previous drug intake by an isotopic microtest or PCR + RFLP. Pf resistance to chloroquine or to the DHFR inhibitor was present in 49% and 46% of isolates, respectively. Pf drug resistance was more frequent in permanent than in seasonal malarial transmission areas and chloroquine plus DHFR resistance reached 28% in years 1995-97. Updating the guidelines for the prevention of malaria in travellers to Africa is necessary.

Africa↗
PubMed1997

[Drug sensitivity of falciparum malaria imported into France in 1995].

The National Reference Centre for Malaria Chemosusceptibility (CNRCP) and the Tropical Medicine Institute of the Health Department for the Army (IMTSSA) monitor the chemosusceptibility of falciparum malaria introduced in France. In 1995, 353 isolates of P. falciparum are sent to the CNRCP and IMTSSA from malaria cases presenting in 49 civil and military hospitals distributed all over the french country. The patients are mostly Africans living in France and have mainly stayed in West Africa. Half of them did not take any chemoprophylaxis and a quarter took only chloroquine more or less regularly. The curative treatment, when known, is halofantrine alone in 52% of cases and quinine alone in 28% of cases. Three halofantrine failures are reported including 1 incorrect regimen and 4 quinine failures including 3 incorrect regimens. In 1995, in vitro resistance of P. falciparum isolates imported in France to the chemoprophylactic and therapeutic drugs is not worsening. In vitro quinine resistance is rare (1/108), mefloquine resistance (2/20) and halofantrine resistance (12/211) are limited, cycloguanil resistance (42/185) is stable and chloroquine resistance (84/230) is even decreasing (less selective pressure in Africa?).

Adolescent↗
PubMedDate not supplied

[Intestinal parasitoses in the south-eastern district of the Dominican Republic].

A prevalence test about parsitism in the South-East district of Dominique Island was carried out from 2 populations samples: some people preparing foods, and out patients in day care Centers. The parasites, the most frequently identified are: ankylostomae, ascaris and whipworms. The prevalence rate of parasitic infestation in this Island appears to be a suitable socio-economical development index.

Adolescent↗