[Malaria and intestinal parasitosis in pregnant woman at Abobo district (Abidjan, Côte d'Ivoire)]. / Paludisme et parasitoses digestives chez la femme enceinte de la commune d'Abobo (Abidjan, Côte d'Ivoire).

A prospective study was carried out from 2010 to 2012 at the Hôpital Général d'Abobo (HGA) in Abidjan, in order to determine the impact of infectious and parasitic diseases on child cognitive development. Blood samples were examined by means of thick drop and blood smear; as for stool by direct examination and concentration by formalin-ether method. We evaluated the prevalence, the parasite load of malaria and gastrointestinal parasites; then we investigated the risk factors for these disorders. Overall, 331 pregnant women in the last trimester of their pregnancy were enrolled. The plasmodic index was 3.9% with infestation specific rates of P. falciparum from 100%. Concerning digestive protozoa, it has been observed 71.3% of nonpathogenic, against 9.7 % of pathogens, either an overall prevalence of 51.4% of digestive parasites. The calculated average parasitic loads revealed 3089.2 tpz/µl of blood (95 % CI: 591.1-5587.3) for malaria, 6.5 eggs per gram of stool (95 % CI: 0.4-13.4) for intestinal helminths and one parasite by microscopic field for protozoa (common infestation). It has been shown that the occurrence of malaria has been linked to the non-use of impregnated mosquito nets (x2 = 0.012; p = 0.018), not to age. No link could be established between the presence of digestive parasites and the age of pregnant women, or socioeconomic conditions (level of education, profession, type of toilet). Malaria is less common in pregnant women while the rate of digestive parasites remains high.

Evidence that Fas-induced apoptosis leads to S phase arrest.

Cell death by apoptosis is an efficient mechanism of eliminating unwanted or aberrant cells. Triggering of Fas, a member of the tumor necrosis factor (TNF) receptor superfamily, by anti-Fas antibodies or by the Fas ligand (FasL), has been shown to cause cell death by apoptosis. A recent study from our laboratory has demonstrated that Fas crosslinking leads to the dephosphorylation of the tumor suppressor retinoblastoma protein (Rb) and that this dephosphorylation is inhibited by calyculin A, a serine/threonine phosphatase inhibitor. In this investigation, we compared the effect of Fas crosslinking by CH11, an anti-Fas mAb, with two cyclin-dependent kinase (CDK) inhibitors, a peptide that specifically inhibits CDK2 (cdk2 inh) and roscovitine, which inhibits CDK2, CDC2, and CDK5. We illustrate that roscovitine induced DNA fragmentation, whereas cdk2 inh did not. In contrast to Fas-induced apoptosis, roscovitine-induced apoptosis was resistant to calyculin A. Both cdk2 inh and roscovitine induced cleavage of poly (ADP-ribose) polymerase (PARP) within 2 h. Roscovitine, however, led to the degradation of Rb, whereas cdk2 inh did not. Furthermore, both CH11 and roscovitine caused cell cycle arrest in S phase. In contrast, cdk2 inh did not have any effect on Jurkat cell cycle progression. Taken together, our results strongly suggest that the maintenance of Rb in its hyperphosphorylated form during S phase may be necessary for cell survival and that Rb dephosphorylation during S phase may constitute a crucial step in Fas-induced apoptosis.

Fas-mediated apoptosis in T cells involves the dephosphorylation of the retinoblastoma protein by type 1 protein phosphatases.

Apoptosis is triggered by a number of different stimuli including the activation of Fas antigen, a member of the TNF family, by the Fas ligand. The signal transduction events implicated in apoptosis are complex and remain only partially understood. In this study, we used calyculin A, a potent inhibitor of serine/threonine (ser/thr) phosphatases types 1 and 2A, to investigate the role of ser/thr phosphatases in Fas-induced apoptosis. We showed that calyculin A inhibited Fas-induced DNA fragmentation and cytolysis in Jurkat cells and that this inhibition was not due to the modulation of Fas. Okadaic acid also inhibited Fas-induced apoptosis of Jurkat cells, but at much higher concentrations (microM level), thus implicating that type 1 phosphatases rather than type 2A are inhibited at nM concentrations. Cross-linking Fas led to the dephosphorylation of the retinoblastoma gene product (Rb) within 5 min, and to PARP cleavage within 2 h. Both events were inhibited by calyculin A indicating that apoptotic death triggered by Fas cross-linking involves the activation of type 1 ser/thr phosphatases.

Over-expression of multidrug resistance P-glycoprotein inhibits NK granule-mediated lytic ability without affecting the Fas lytic pathway.

Multidrug resistance (MDR) in tumor cells is commonly associated wich the over-expression of P-glycoprotein (Pgp), the product of the MDR1 gene. In this study, we investigated whether over-expression of Pgp in natural killer (NK) cells would influence their granule- as well as fas-mediated cytolytic activities. YT-INDY, a human NK-like cell line, was transfected with the MDR 1 gene, then tested for Pgp activity the presence of various concentrations of R-verapamil, a potent Pgp inhibitor. We showed that, unlike control YT-INDY, the Pgp activity of the transfectants (YT-mdr(+)) was only partially inhibited by R-verapamil. We also showed that Fas lytic activity was unaltered and that the loss of granule-mediated cytotoxicity was not due to reduced LFA-1 expression or to a decrease in target cell (TC) binding. Our data indicate that Pgp may be involved in the release of cytotoxic molecules.

Optimized blood cell profiling method for genomic biomarker discovery using high-density microarray.

High-quality biomarkers for disease progression, drug efficacy and toxicity liability are essential for improving the efficiency of drug discovery and development. The identification of drug-activity biomarkers is often limited by access to and the quantity of target tissue. Peripheral blood has increasingly become an attractive alternative to tissue samples from organs as source for biomarker discovery, especially during early clinical studies. However, given the heterogeneous blood cell population, possible artifacts from ex vivo activations, and technical difficulties associated with overall performance of the assay, it is challenging to profile peripheral blood cells directly for biomarker discovery. In the present study, Applied BioSystems' blood collection system was evaluated for its ability to isolate RNA suitable for use on the Affymetrix microarray platform. Blood was collected in a TEMPUS tube and RNA extracted using an ABI-6100 semi-automated workstation. Using human and rat whole blood samples, it was demonstrated that the RNA isolated using this approach was stable, of high quality and was suitable for Affymetrix microarray applications. The microarray data were statistically analysed and compared with other blood protocols. Minimal haemoglobin interference with RNA labelling efficiency and chip hybridization was found using the TEMPUS tube and extraction method. The RNA quality, stability and ease of handling requirement make the TEMPUS tube protocol an attractive approach for expression profiling of whole blood to support target and biomarker discovery.