Prevalence and risk factors associated with malaria infection among pregnant women in a semi-urban community of north-western Nigeria.

BACKGROUND: Malaria during pregnancy remains a serious public health problem, with substantial risks for the mother, her foetus and the newborn. The aim of this study was to determine the prevalence of malaria and possible risk factors for malaria infection among pregnant women in a semi-urban area in north-western Nigeria. Pregnant women are among the most susceptible to malaria infection. Knowledge of their malaria infection status is an important yardstick to measure the effectiveness of any malaria control programme. METHODS: We conducted a cross sectional study in the semi-urban area of Argungu, Kebbi State Nigeria. Two hundred and fifty five pregnant women were included in the study after informed verbal consent was obtained. For each participant, the socio-demographic profile, stage of pregnancy and attitude to the use of insecticide- treated nets (ITNs) were investigated using a questionnaire. Peripheral blood samples were collected and thick blood smears were prepared and stained with Giemsa stains to check for malaria parasitaemia. The associations between age, education level and use of ITNs with occurrence of malaria infection during pregnancy were analysed using the chi-square test. RESULTS: One hundred and six (41.6%) out of 255 pregnant women were infected with malaria parasites, with a mean parasite density of 800 parasitesµl(-1). It was found that prevalence and parasite density decreased as age increased. The chi-square test indicated that a lack of education and non-usage of ITNs were significantly associated with malaria infection. CONCLUSION: Malaria is still a major public health issue among pregnant women mainly due to illiteracy and non -compliance to using ITNs. Increasing awareness about malaria preventive measures and early attendance of antenatal care services will help to reduce malaria and, consequently, its associated morbidities and mortalities.

Activation of c-Raf kinase by ultraviolet light. Regulation by retinoids.

The present study highlights retinoids as modulators of c-Raf kinase activation by UV light. Whereas a number of retinoids, including retinol, 14-hydroxyretroretinol, anhydroretinol (AR), and retinoic acid bound the c-Raf cysteine-rich domain (CRD) with equal affinity in vitro as well as in vivo, they displayed different, even opposing, effects on UV-mediated kinase activation; retinol and 14-hydroxyretroretinol augmented responses, whereas retinoic acid and AR were inhibitory. Oxidation of thiol groups of cysteines by reactive oxygen, generated during UV irradiation, was the primary event in c-Raf activation, causing the release of zinc ions and, by inference, a change in CRD structure. Retinoids modulated these oxidation events directly: retinol enhanced, whereas AR suppressed, zinc release, precisely mirroring the retinoid effects on c-Raf kinase activation. Oxidation of c-Raf was not sufficient for kinase activation, productive interaction with Ras being mandatory. Further, canonical tyrosine phosphorylation and the action of phosphatase were essential for optimal c-Raf kinase competence. Thus, retinoids bound c-Raf with high affinity, priming the molecule for UV/reactive oxygen species-mediated changes of the CRD that set off GTP-Ras interaction and, in context with an appropriate phosphorylation pattern, lead to full phosphotransferase capacity.