Exchange potentials of phosphorus between sediments and water coupled to alkaline phosphatase activity and environmental factors in an oligo-mesotrophic reservoir

We investigated the exchange potentials of phosphates at the water-sediment interface together with in situ benthic-chamber fractionated alkaline phosphatase activity and bacteria estimates during September and October 1998 at two stations: station 1, which received immediately the urban inputs from the Taounate city, and station 2, located in the centre of the Sahela reservoir (Morocco). The results showed that low oxygenation enhanced both the bacterial abundance and the alkaline phosphatase activity. Size-fractionated (0.65-100 microm) bacteria attached to dead organic matter together with algae and zooplankton contributed strongly (78%) to the total alkaline phosphatase synthesis in the two sampled stations, suggesting that attachment to organic particles stimulated phosphatase activities. The appearance of anoxic conditions and the decrease of pH supported the dissolution of particulate phosphorus and the release of soluble reactive phosphorus. This latter, together with persisting discharges of organic matter, sewage, and olive mill waste will exacerbate the eutrophication of the reservoir.     

Impact of genotyping on outcome of prostatic biopsies: a multicenter prospective study

Single nucleotide polymorphisms (SNPs) have been associated with prostate cancer (PCa) risk and tumor aggressiveness in retrospective studies. To assess the value of genotyping in a clinical setting, we evaluated the correlation between three genotypes (rs1447295 and rs6983267[8q24] and rs4054823[17p12]) and prostatic biopsy outcome prospectively in a French population of Caucasian men. Five hundred ninety-eight patients with prostatic-specific antigen (PSA) >4 ng/mL or abnormal digital rectal examination (DRE) participated in this prospective, multicenter study. Age, familial history of PCa, body mass index (BMI), data of DRE, International Prostate Symptom Score (I-PSS) score, PSA value and prostatic volume were collected prospectively before prostatic biopsy. Correlation between genotypes and biopsy outcome (positive or negative) and Gleason score (≤6 or >6) were studied by univariate and multivariable analysis. rs1447295 and rs6983267 risk variants were found to be associated with the presence of PCa in univariate analysis. rs6983267 genotype remained significantly linked to a positive biopsy (odds ratio [OR] = 1.66, 95% confidence interval [CI]: 1.06-2.59, P = 0.026) in multivariable analysis, but rs1447295 genotype did not (OR = 1.47, 95% CI: 0.89-2.43, P = 0.13).When biopsy outcome was stratified according to Gleason score, risk variants of rs1447295 were associated with aggressive disease (Gleason score ≥7) in univariate and multivariable analysis (OR = 2.05 95% CI: 1.10-3.79, P = 0.023). rs6983267 GG genotype was not related to aggressiveness. The results did not reach significance concerning rs4054823 for any analysis. This inaugural prospective evaluation thus confirmed potential usefulness of genotyping PCa assessment. Ongoing clinical evaluation of larger panels of SNPs will detail the actual impact of genetic markers on clinical practice.     

Transmission patterns of Leishmania tropica around the Mediterranean basin: Could Morocco be impacted by a zoonotic spillover?

Cutaneous leishmaniasis (CL) due to Leishmania tropica is a neglected tropical disease characterized by a wide geographical distribution in the Mediterranean basin and is endemic in several of its countries. In addition, the vector Phlebotomus sergenti is abundantly present all around the basin. Its transmission cycle is still subject to debate. In some countries, the presence of an animal reservoir has been confirmed. In Morocco, CL due to L. tropica has risen since the 1980s and has spread widely to become the most abundant form of leishmaniasis in the territory. However, the anthroponotic transmission is so far the only recognized mode, despite recordings of L. tropica infection in animal hosts. In this review article, we assess the situation of CL due to L. tropica in the Mediterranean basin with a focus on Morocco and gather knowledge about any potential zoonotic transmission in the country. A concomitant zoonotic transmission could explain the persistence of the disease in areas where human protective measures combined with vector management did not help reduce the disease burden.     

An improved synthesis of 5-thio-D-ribose from D-ribono-1,4-lactone

5-Thio-D-ribopyranose was synthesized from D-ribono-1,4-lactone (1) by two approaches: (i) 5-bromo-5-deoxy-D-ribono-1,4-lactone (2) was successively transformed into 5-bromo-5-deoxy, 5-S-acetyl-5-thio or 5-thiocyanato-D-ribofuranose derivatives; appropriate treatment then lead to 5-thio-D-ribopyranose (7) in 46-48% overall yield and; (ii) 2 was transformed into the 5-S-acetyl-5-thio-D-ribono-1,4-lactone derivative (11). Reduction and deprotection of 11 afforded 5-thio-D-ribopyranose (7) in 57% overall yield.     

The kinesin KIF9 and reggie/flotillin proteins regulate matrix degradation by macrophage podosomes

Podosomes are actin-based matrix contacts in a variety of cell types, most notably monocytic cells, and are characterized by their ability to lyse extracellular matrix material. Besides their dependence on actin regulation, podosomes are also influenced by microtubules and microtubule-dependent transport processes. Here we describe a novel role for KIF9, a previously little-characterized member of the kinesin motor family, in the regulation of podosomes in primary human macrophages. We find that small interfering RNA (siRNA)/short-hairpin RNA-induced knockdown of KIF9 significantly affects both numbers and matrix degradation of podosomes. Overexpression and microinjection experiments reveal that the unique C-terminal region of KIF9 is crucial for these effects, presumably through binding of specific interactors. Indeed, we further identify reggie-1/flotillin-2, a signaling mediator between intracellular vesicles and the cell periphery, as an interactor of the KIF9 C-terminus. Reggie-1 dynamically colocalizes with KIF9 in living cells, and, consistent with KIF9-mediated effects, siRNA-induced knockdown of reggies/flotillins significantly impairs matrix degradation by podosomes. In sum, we identify the kinesin KIF9 and reggie/flotillin proteins as novel regulators of macrophage podosomes and show that their interaction is critical for the matrix-degrading ability of these structures.