The contribution of aestivating mosquitoes to the persistence of Anopheles gambiae in the Sahel

<p>Abstract</p> <p>Background</p> <p>Persistence of African anophelines throughout the long dry season (4-8 months) when no surface waters are available remains one of the enduring mysteries of medical entomology. Recent studies demonstrated that aestivation (summer diapause) is one mechanism that allows the African malaria mosquito, <it>Anopheles gambiae</it>, to persist in the Sahel. However, migration from distant localities - where reproduction continues year-round - might also be involved.</p> <p>Methods</p> <p>To assess the contribution of aestivating adults to the buildup of populations in the subsequent wet season, two villages subjected to weekly pyrethrum sprays throughout the dry season were compared with two nearby villages, which were only monitored. If aestivating adults are the main source of the subsequent wet-season population, then the subsequent wet-season density in the treated villages will be lower than in the control villages. Moreover, since virtually only M-form <it>An. gambiae </it>are found during the dry season, the reduction should be specific to the M form, whereas no such difference is predicted for S-form <it>An. gambiae </it>or <it>Anopheles arabiensis</it>. On the other hand, if migrants arriving with the first rain are the main source, no differences between treated and control villages are expected across all members of the <it>An. gambiae </it>complex.</p> <p>Results</p> <p>The wet-season density of the M form in treated villages was 30% lower than that in the control (P < 10^-4, permutation test), whereas no significant differences were detected in the S form or <it>An</it>. <it>arabiensis</it>.</p> <p>Conclusions</p> <p>These results support the hypothesis that the M form persist in the arid Sahel primarily by aestivation, whereas the S form and <it>An. arabiensis </it>rely on migration from distant locations. Implications for malaria control are discussed.</p

Sexual Dimorphism of Metabolomic Profile in Arterial Hypertension

International audienceMetabolomic studies have demonstrated the existence of biological signatures in blood of patients with arterial hypertension, but no study has hitherto reported the sexual dimorphism of these signatures. We compared the plasma metabolomic profiles of 28 individuals (13 women and 15 men) with essential arterial hypertension with those of a healthy control group (18 women and 18 men), using targeted metabolomics. Among the 188 metabolites explored, 152 were accurately measured. Supervised OPLS-DA (orthogonal partial least squares-discriminant analysis) showed good predictive performance for hypertension in both sexes (Q2cum = 0.59 in women and 0.60 in men) with low risk of overfitting (p-value-CV ANOVA = 0.004 in women and men). Seventy-five and 65 discriminant metabolites with a VIP (variable importance for the projection) greater than 1 were evidenced in women and men, respectively. Both sexes showed a considerable increase in phosphatidylcholines, a decrease in C16:0 with an increase in C28:1 lysophosphatidylcholines, an increase in sphingomyelins, as well as an increase of symmetric dimethylarginine (SDMA), acetyl-ornithine and hydroxyproline. Twenty-nine metabolites, involved in phospholipidic and cardiac remodeling, arginine/nitric oxide pathway and antihypertensive and insulin resistance mechanisms, discriminated the metabolic sexual dimorphism of hypertension. Our results highlight the importance of sexual dimorphism in arterial hypertension

Analyse biochimique multi-paramétrique révélant une augmentation de l'homocystéinémie et du NT-ProBNP chez les patients hypertendus à Bamako (Mali)

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