Mort programmée des cellules germinales testiculaires: causes et mécanismes mis en jeu

Spermatogenesis results from a balance between proliferation and apoptosis. An alteration in this balance could lead to testicular diseases such as testicular tumour or infertility. Apoptosis seem to be important in regulating the processes of spermatogenesis since 60 to 75% of germ cells do not reach the spermatozoa stage. The various molecules of the apoptotic cascade have been detected in rodent or human germ cells, such as effector caspases and upstream proteins from cell death receptor or mitochondrial pathways. One or several different pathways may be involved in the germ cell apoptotic process triggered physiologically, by hormonal deprivation, or by chemical or physical inducers. Finally, caspases appear to play a role in various testicular diseases (particularly infertility).     

Evaluation of a gp63–PCR Based Assay as a Molecular Diagnosis Tool in Canine Leishmaniasis in Tunisia

A gp63PCR method was evaluated for the detection and characterization of Leishmania (Leishmania) (L.) parasites in canine lymph node aspirates. This tool was tested and compared to other PCRs based on the amplification of 18S ribosomal genes, a L. infantum specific repetitive sequence and kinetoplastic DNA minicircles, and to classical parasitological (smear examination and/or culture) or serological (IFAT) techniques on a sample of 40 dogs, originating from different L. infantum endemic regions in Tunisia. Sensitivity and specificity of all the PCR assays were evaluated on parasitologically confirmed dogs within this sample (N = 18) and control dogs (N = 45) originating from non–endemic countries in northern Europe and Australia. The gp63 PCR had 83.5% sensitivity and 100% specificity, a performance comparable to the kinetoplast PCR assay and better than the other assays. These assays had comparable results when the gels were southern transferred and hybridized with a radioactive probe. As different infection rates were found according to the technique, concordance of the results was estimated by (κ) test. Best concordance values were between the gp63PCR and parasitological methods (74.6%, 95% confidence intervals CI: 58.8–95.4%) or serology IFAT technique (47.4%, 95% CI: 23.5–71.3%). However, taken together Gp63 and Rib assays covered most of the samples found positive making of them a good alternative for determination of infection rates. Potential of the gp63PCR-RFLP assay for analysis of parasite genetic diversity within samples was also evaluated using 5 restriction enzymes. RFLP analysis confirmed assignment of the parasites infecting the dogs to L. infantum species and illustrated occurrence of multiple variants in the different endemic foci. Gp63 PCR assay thus constitutes a useful tool in molecular diagnosis of L. infantum infections in dogs in Tunisia.     

Description of the female of Phlebotomus (Larroussius) Chadlii, Rioux, Juminer & Gibily, 1966 (Diptera: Psychodidae). From an example captured from the area of Kef (Tunisia)

The female of Phlebotomus chadlii Rioux, Jumminer & Gibily, 1966 is described and illustrated for the first time from a specimen collected in El Kef region, northwest Tunisia. It was distinguished from P. ariasi by several characters of the spermathecae: 1) the enlarged portion of P. chadlii spermathecae duct appears smooth and better developed than that of P. ariasi; 2) in P. chadlii, this part comprises three quarters of the duct whereas, in P. ariasi, it covers only the half; 3) the spermathecae neck of P. chadlii is shorter than that of P. ariasi. The duct base is compatible with the large aedeagus size of P. chadlii male. Besides, the assignment of this female to the species P. chadlii is supported by: 1) the presence of males in the same area, over the last three years; 2) the total absence in this area of P. ariasi; 3) the concomitant presence, in the same trap station, of the described female with P. chadlii males.     

Chronic crude garlic-feeding modified adult male rat testicular markers: mechanisms of action

Background  

Garlic or Allium sativum (As) shows therapeutic effects such as reduction of blood pressure or hypercholesterolemia but side-effects on reproductive functions remain poorly investigated. Because of garlic's chemical complexity, the processing methods and yield in preparations differ in efficacy and safety. In this context, we clarify the mechanisms of action of crushed crude garlic on testicular markers.     

Small-Quantity Lipid-Based Nutrient Supplements,Regardless of Their Zinc Content,Increase Growth and Reduce the Prevalence of Stunting and Wasting in Young Burkinabe Children: A Cluster-Randomized Trial

Small-quantity lipid-based nutrient supplements (SQ-LNS) are promising home fortification products, but the optimal zinc level needed to improve growth and reduce morbidity is uncertain. We aimed to assess the impact of providing SQ-LNS with varied amounts of zinc, along with illness treatment, on zinc-related outcomes compared with standard care. In a placebo-controlled, cluster-randomized trial, 34 communities were stratified to intervention (IC) or non-intervention cohorts (NIC). 2435 eligible IC children were randomly assigned to one of four groups:1) SQ-LNS without zinc, placebo tablet; 2) SQ-LNS containing 5mg zinc, placebo tablet; 3) SQ-LNS containing 10mg zinc, placebo tablet; or 4) SQ-LNS without zinc and 5mg zinc tablet from 9–18 months of age. During weekly morbidity surveillance, oral rehydration salts were provided for reported diarrhea and antimalarial therapy for confirmed malaria. Children in NIC (n = 785) did not receive SQ-LNS, tablets, illness surveillance or treatment. At 9 and 18 months, length, weight and hemoglobin were measured in all children. Reported adherence was 97±6% for SQ-LNS and tablets. Mean baseline hemoglobin was 89±15g/L. At 18 months, change in hemoglobin was greater in IC than NIC (+8 vs -1g/L, p<0.0001), but 79.1% of IC were still anemic (vs. 91.1% in NIC). Final plasma zinc concentration did not differ by group. During the 9-month observation period, the incidence of diarrhea was 1.10±1.03 and of malaria 0.54±0.50 episodes per 100 child-days, and did not differ by group. Length at 18 months was significantly greater in IC compared to NIC (77.7±3.0 vs. 76.9±3.4cm; p<0.001) and stunting prevalence was significantly lower in IC (29.3%) than NIC (39.3%; p<0.0001), but did not differ by intervention group within IC. Wasting prevalence was also significantly lower in IC (8.7%) than in NIC (13.5%; p = 0.0003). Providing SQ-LNS daily with or without zinc, along with malaria and diarrhea treatment, significantly increased growth and reduced stunting, wasting and anemia prevalence in young children.

Trial Registration

ClinicalTrials.gov NCT00944281     

Biocatalytic properties of a peroxidase-active cell-free extract from onion solid wastes: caffeic acid oxidation

The exploitation of food residual sources consists of a major factor in reducing the polluting load of food industry wastes and developing novel added-value products. Plant food residues including trimmings and peels might contain a range of enzymes capable of transforming bio-organic molecules with potential phytotoxicity, including hydrolases, peroxidases and polyphenoloxidases. Although the use of bacterial and fungal enzymes has gained interest in studies pertaining to bioremediation applications, plant enzymes have been given less attention or even disregarded. In this view, this study aimed at the investigating the use of a crude peroxidase preparation from onion solid by-products for oxidising caffeic acid, a widespread o-diphenol, whose various derivatives may occur in food industry wastes, such as olive mill waste waters. Increased enzyme activity was observed at a pH value of 5, but considerable activity was also retained for pH up to 7. Favourable temperatures for increased activity varied between 20°C and 40°C, 30°C being the optimal. Liquid chromatography-mass spectrometry analysis of a homogenate/H₂O₂-treated caffeic acid solution revealed the existence of a tetramer as major oxidation product. Based on the data generated, a putative pathway for the formation of the peroxidase-mediated caffeic acid tetramer was proposed.     

Screening and Characterization of RAPD Markers in Viscerotropic Leishmania Parasites

Visceral leishmaniasis (VL) is mainly due to the Leishmania donovani complex. VL is endemic in many countries worldwide including East Africa and the Mediterranean region where the epidemiology is complex. Taxonomy of these pathogens is under controversy but there is a correlation between their genetic diversity and geographical origin. With steady increase in genome knowledge, RAPD is still a useful approach to identify and characterize novel DNA markers. Our aim was to identify and characterize polymorphic DNA markers in VL Leishmania parasites in diverse geographic regions using RAPD in order to constitute a pool of PCR targets having the potential to differentiate among the VL parasites. 100 different oligonucleotide decamers having arbitrary DNA sequences were screened for reproducible amplification and a selection of 28 was used to amplify DNA from 12 L. donovani, L. archibaldi and L. infantum strains having diverse origins. A total of 155 bands were amplified of which 60.65% appeared polymorphic. 7 out of 28 primers provided monomorphic patterns. Phenetic analysis allowed clustering the parasites according to their geographical origin. Differentially amplified bands were selected, among them 22 RAPD products were successfully cloned and sequenced. Bioinformatic analysis allowed mapping of the markers and sequences and priming sites analysis. This study was complemented with Southern-blot to confirm assignment of markers to the kDNA. The bioinformatic analysis identified 16 nuclear and 3 minicircle markers. Analysis of these markers highlighted polymorphisms at RAPD priming sites with mainly 5′ end transversions, and presence of inter– and intra– taxonomic complex sequence and microsatellites variations; a bias in transitions over transversions and indels between the different sequences compared is observed, which is however less marked between L. infantum and L. donovani. The study delivers a pool of well-documented polymorphic DNA markers, to develop molecular diagnostics assays to characterize and differentiate VL causing agents.