The use of insect pathogenic fungi is a promising alternative to chemical control against mosquitoes. Among the Hyphomycetes isolated from insects for mosquito control, the genus Aspergillus remains the least studied. In September 2005, four fungi were isolated from the Senegalese locust, Oedaleus senegalensis Kraus (Orthoptera: Acrididae), collected in Dakar, Senegal. One of these fungi, identified as Aspergillus clavatus, Desmazières (Eurotiales: Trichocomaceae) was highly pathogenic against larvae of the mosquitoes Aedes aegypti L., Anopheles gambiae s.l. Giles and Culex quinquefasciatus Say (Diptera: Culicidae). An application of 1.2 mg/ml dry conidia yielded 100% mortality after 24 hours against both Ae. aegypti and Cx. quinquefasciatus while with An. gambiae it was 95%. With unidentified species in the genus Aspergillus, mortality after 24 h was <5% against all the larval species. Application of A. clavatus produced in a wheat powder medium using doses ranging between 4.3 to 21×107 spores/ml, caused 11 to 68% mortality against Cx. quinquefasciatus at 24h, and 37 to 100% against Ae. aegypti. Microscopic observations showed fungal germination on both Ae. aegypti and Cx. quinquefasciatus larvae. Histological studies revealed that A. clavatus penetrated the cuticle, invaded the gut and disintegrated its cells. Some Cx. quinquefasciatus larvae, treated with A. clavatus reached the pupal stage and produced infected adults. However, the infection was mainly located on the extremity of their abdomen. These results suggest that A. clavatus could be an effective tool to manage mosquito proliferation.

Treatment and comparative analysis of the properties of aqueous extracts of seed kernel of Azadirachta indica A. Juss (neem) was carried out on Aedes aegypti larvae. The aim of this work was to evaluate lethal effects of neem products (1% Suneem, formulated neem oil and neem powder) on A. aegypti larvae. Assays showed that A. indica was toxic to larvae of A. aegypti. For 1% Suneem, 1% formulated neem oil and neem powder, the lethal concentrations and lethal time at 50% (LC 50 and LT 50 ) for A. aegypti were 2 and 8 mg/l after 24 h and 3 mg/l after 120 h, respectively. Assays showed that Suneem and Formulated neem oil were more toxic to A. aegypti than Neem powder. Both products of the neem (A. indica, A. juss) have a remarkable influence on the development of A. aegypti larvae, causing an inhibition of nymphs and adults emergency. The Histopathological results revealed a serious damage on the epithelial columnar cells, a perturbation of alimentary flow, slightly hypertrophied cells, a beginning of vacuolisation on apical level, and a bursting of some cells in posterior part of the gut. However, nuclei, adipose tissue and muscles seem to keep normal appearance.

In order to analyse human papillomavirus (HPV) infection in the Senegalese population, HPV DNA was sought in 65 women with evidence of cervical cytological abnormality and in 72 pregnant women. Ninety-four percent of the patients were positive for HPV DNA as compared to 24% of pregnant women. HPV 16 was detected in cervical smears in 42% of cases, HPV 18 in 39%, HPV 6 in 26%, HPV 11 in 15%, HPV 45 in 10%, HPV 52 in 3%, and HPV 31, HPV 33 and HPV 68 in 1.5%. HPV 16 and HPV 18 were detected in 16% and 7% respectively of pregnant women. HPV DNA of unknown type was detected in 6% of cases, and multiple HPV infections were observed in 28% of cases. Low risk genital HPVs (6/11) were detected in smaller proportions (17%) among high grade squamous intraepithelial lesions (SILs) than the low grade SILs (43%). High risk HPVs (16/18) were detected in high proportions both in low and high grade SIL lesions, though the highest frequency (70%) was observed among patients with high grade lesions. In conclusion, the results confirm that HPV infections are frequent in Senegal and that HPV 18 and 45 are detected in a high proportion of patients in Africa.

Trophoblast cell adhesion and migration are carefully coordinated during normal placental development. We have compared the expression of three adhesion molecules, E-cadherin, β-catenin, and Lewis x, by immunohistochemistry during normal trophoblast differentiation, and in hydatidiform moles and choriocarcinomas. Both E-cadherin and β-catenin were expressed in normal placenta cytotrophoblast, and this expression decreased with trophoblast maturation. E-cadherin was mainly localized along the contact between cytotrophoblast and syncytiotrophoblast, which indicates its role in the differentiation of the syncytial layer. Lewis x disappeared progressively during differentiation of normal villous vessels, and was expressed in molar pregnancies. Interestingly, whereas choriocarcinomas were not, or poorly, stained, invasive hydatidiform moles (invHMs) strongly expressed Lewis x in vascular structures. This observation correlated well with E-cadherin and β-catenin expression and suggests that these three markers are associated with the invasive transformation. The presence of robust endothelial structures in invHMs could also explain their ability to maintain organized villous architecture (contrary to metastatic choriocarcinomas) during their invasion of extrauterine tissues such as the lung or the brain after dissemination through the blood flow. In our hands, Lewis x appeared to be a new, reliable marker that can be used to clearly distinguish invHMs from choriocarcinomas.

The L1 major capsid protein of human papillomavirus type 16 (HPV-16) was expressed in Sf-21 insect cells with a recombinant baculovirus. Virus-like particles obtained were purified and used to develop an enzymelinked immunosorbent assay for detection of anti-HPV-16 antibodies in sera from 76 women with evidence of genital HPV infection and 79 controls. HPV-16-infected individuals developed antibodies directed at HPV-16 virions since reactivity against recombinant HPV-16L1 capsids was observed in 50% of them compared with only 6% in the general adult population. However, some cross-reactivities with sera from women infected with others HPV types were observed.