[Evidence of an urban, local transmission of malaria in Antananarivo, Madagascar]. / Mise en évidence d'une transmission urbaine autochtone du paludisme à Antananarivo, Madagascar.

Madagascar presents a large heterogeneity in terms of climate and altitude, which explains the uneven spread of malaria throughout the island. The capital, Antananarivo, counts more than one million inhabitants, altitude between 1250 and 1470 m, in an area where the transmission is low but malaria may cause deadly epidemic outbreaks. Numerous malaria cases are reported, without biological confirmation, and reliable data about urban malaria transmission are lacking. The " Institut Pasteur de Madagascar" together with the Malagasy Ministry of Health performed in 2003 a study about malaria transmission in Antananarivo. A prevalence survey of malaria among fever syndromes, with data collected from 43 urban dispensaries, showed that confirmed malaria cases represented only 2% of the total fever cases (15 cases out of 779 fever syndromes). The vast majority was imported from costal areas (13 cases out of 15), where malaria is hyperendemic. However, a local urban transmission was found for two patients and five other subjects identified during a proximity survey. Vectors A. arabiensis and A. funestus were found inside the patient houses, located in close proximity of flooded rice fields. Genetic analysis of P. falciparum strains allowed to distinguish three genotypes, aggregated by house. The analysis of parasite genome polymorphism proves here its validity for epidemic surveys in areas where malaria is unstable, with no premunition in the local urban population.

Mise en evidence d'une transmission urbaine autochtone du paludisme a Antananarivo; Madagascar

La repartition du paludisme a Madagascar est caracterisee par son heterogeneite; du fait des vari ations climatiques et geographiques marquees dans l'ile. La capitale; Antananarivo; regroupe plus d'un million d'habitants entre 1 250 et 1 470 m d'altitude; dans une zone ou la transmission est irreguliere; mais le paludisme peut parfois sevir par vagues epidemiques meurtri res. De nombreux cas de paludisme sont declares dans la capitale sans confimation biologi u e; et des donnees fiables sur l'existence d'une transmission urbaine font defaut. C'est pourquoi l'Institut Pasteur de Madagascar et le Ministere de la Sante de Madagascar ont realise en 2003 une etude sur la transmission palustre dans la Communaute Urbaine d'Antananarivo. Une enquete de prevalence du paludisme parmi les syndromes febriles; realisee dans 43 dispensaires urbains; a montre que les cas de paludisme confi rmes ne representaient que 2des cas de fievre inclus dans l'etude (15 cas sur 779 syndromes febriles). La majorite etait importee des zones cotieres (13 cas sur 15); ou la transmission est pere n n e. Cependant; une transmission urbaine autochtone a ete constatee chez 2 des consultants et 5 autres sujets identifies lors d'une enquete de proximite. Les vecteurs Anopheles arabiensis et Anopheles funestus ont ete retrouves dans les maisons des malades; toutes situees a proximite de rizieres. L'analyse genetique des souches de Plasmodium falciparum a permis de distinguer trois genotypes; agreges par groupe d'habitation. L'analyse du polymorphisme des genomes parasitaires prouve son interet dans le cadre de la surveillance du risque epidemique dans une zone de paludisme instable; ou la population citadine ne presente pas de premunition

Analysis of interactions between huGATA-3 transcription factor and three GATA regulatory elements of HIV-1 long terminal repeat, by surface plasmon resonance.

Relative affinities of transcriptional regulatory elements for their respective factor have been essentially studied by bandshift analysis. Here we report a real-time study of factor/DNA interactions using a surface plasmon resonance approach and further characterization of recovered proteins involved in this interaction. For this purpose, human GATA-3, either recombinant or in nuclear extracts, and three natural GATA elements of the HIV-1 long terminal repeat (sites 1, 2, and 3) were chosen, in which only site 2 is a noncanonical GATA site. Direct analysis of sensorgrams, with recombinant huGATA-3, allowed the comparison of association and dissociation profiles of the three DNA regions and their ranking according to their relative affinities. This result, confirmed by competitions with each GATA site, demonstrated the higher relative affinity (at least sevenfold) of site 3. Interactions between the canonical and unique GATA site 3 and nuclear extracts were also studied in real time and provided information on its association and dissociation rates for native huGATA-3. Finally, recovered protein was identified as genuine huGATA-3 by SDS-PAGE, Western blotting, and bandshift assays.

Antibodies to a conserved region of HLA class I molecules, capable of modulating CD8 T cell-mediated function, are present in pooled normal immunoglobulin for therapeutic use.

Intravenous immunoglobulin (IVIg) is increasingly used for the treatment of autoimmune diseases and the prevention of infections and of graft versus host reactions in recipients of allogeneic bone marrow transplants. The immunomodulatory effects of IVIg are largely dependent on their ability to interact with membrane molecules of lymphocytes. We report here that IVIg recognizes the B07.75-84 peptide, corresponding to a conserved region of the alpha I helix of the first domain of HLA-B7 01, which represents a nonpolymorphic determinant of HLA class I molecules. Intact IVIg and its F(ab')2 fragments bound to the peptide as well as to purified soluble HLA and to HLA on a human T cell line. Binding of IVIg to HLA was assessed by ELISA, immunofluorescence, and real-time analysis of the interaction using the BIAlite system. The binding of antipeptide antibodies to HLA was inhibited by free peptide. Antipeptide antibodies isolated from IVIg by affinity chromatography inhibited CD8 cell-mediated cytotoxicity of an influenza virus-specific human T cell line. The presence in IVIg of antibodies to critical regions of HLA class 1 molecules suggests a possible role for IVIg in modulation of class-I-restricted cellular interactions in the immune response.

[Health indicators of a population in an agro-industrial complex of southern Cameroon]. / Indicateurs de santé dans la population d'un complexe agro-industriel du Sud Cameroun.

An agro-industrial program involving sugar cane farming was established in Mbandjock (Cameroon) in the 1960's. We studied the impact of this development project on the health of the population by determining the prevalence and distributions of the major parasitic diseases according to district, ethnic origin, age and sex. Three main conclusions can be drawn. First, in the study area, economic development was not associated with deteriorating health conditions. Indeed, the incidence of parasitic disease was lower in Mbandjock than in surrounding areas. Second, imported diseases (loaiasis and schistosomiasis for example) did not develop locally despite the large population concentrations created by the implantation of the agro-industrial complex. Third, endemic parasitic diseases (malaria, onchocerciasis and intestinal infection by helminths or protozoan) were found only in a few districts. Thus, integrated control measures should be taken in these areas as a priority.

Automation of large-scale HLA oligotyping using a robotic workstation.

The ability to amplify specific genomic segments by the PCR has made the analysis of DNA polymorphism with oligonucleotidic probes a practical approach to HLA class II typing. However, to make this method more accurate and applicable to large-scale typing, technical and logistic limitations must be overcome and the risk of human errors must be reduced. To address this problem, we developed an automated procedure, using the Biomek 1000. The system consists of a workstation with a robotic arm and an instrument tablet, an electronic interface unit and an IBM PC. It was modified by the addition of a dot-blot apparatus. Automatic preparation of 96 samples for simultaneous DNA amplification is possible, together with PCR product dilution, distribution and dot-blotting. The robot prevents sample contamination, eliminates human errors and reduces operating costs by decreasing the working time by 50%. Thus, the system is suitable for routine analysis, and it also improves typing accuracy. Furthermore, this system can be adapted for a variety of new DNA-typing strategies that require an initial DNA amplification step.

Etude clinique et parasitologique de l'onchocercose dans huit villages de la vallee du Mbam (Province du Centre; Cameroun)

Une etude a ete entreprise dans la Vallee du Mbam afin de mieux repartir l'onchocercose dans cette region. Dans chacun de ces villages; environ 150 sujets ages de cinq ans et plus ont ete examines du point de vue clinique et parasitologique. Il ressort de cette etude que tous ces villages etudies sont hyperendemiques. Cependant; les charges microfilariennes moyennes varient largement. Ainsi; cette enquete confirme qu'au Cameroun; en zone de transition savane-foret; l'onchocercose a des repercussions oculaires graves. Un traitement de masse par ivermectine serait certainement souhaitable dans la region de Bafia