Survenue des obstructions tubaires chez les femmes à Cotonou (Bénin) : rôle des bactéries

Les trompes utérines jouent un rôle très important dans la reproduction humaine. Elles peuvent être facilement atteintes par diverses pathologies dont l’obstruction tubaire. La présente étude a permis de déterminer le taux d’obstructions tubaires dues aux infections et de relever les bactéries en cause à Cotonou. Pour ce faire, 111 femmes venues pour hystérosalpingographie (HSG) ont été soumises aussi à des prélèvements sanguins et cervicaux (bilans microbiologiques). Au total, 51,3% de femmes souffrent d’obstructions tubaires. La majorité d’entre elles (89,4%) a un âge compris entre 25 et 39 ans. Les germes banaux, les mycoplasmes et Chlamydia trachomatis ont été isolés dans respectivement 28,1%, 38,6% et 36,8% des cas. Les différents germes étudiés se retrouvent aussi bien chez les sujets souffrant d’obstructions  tubaires que chez celles qui n’en souffrent pas. Les infections dues aux germes banaux, aux mycoplasmes et à C. trachomatis pourraient engendrer une obstruction tubaire, d’où l’intérêt d’un traitement correct de ces infections afin d’éviter qu’elles ne deviennent chroniques.Mots clés : Obstructions tubaires, Hystérosalpingographie, Infections

A pyramid MOT with integrated optical cavities as a cold atom platform for an optical lattice clock

We realize a two-stage, hexagonal pyramid magneto-optical trap (MOT) with strontium, and demonstrate loading of cold atoms into cavity-enhanced 1D and 2D optical lattice traps, all within a single compact assembly of in-vacuum optics. We show that the device is suitable for high-performance quantum technologies, focusing especially on its intended application as a strontium optical lattice clock. We prepare 2 × 104 spin-polarized atoms of 87Sr in the optical lattice within 500 ms; we observe a vacuum-limited lifetime of atoms in the lattice of 27 s; and we measure a background DC electric field of 12 V m−1 from stray charges, corresponding to a fractional frequency shift of (−1.2 ± 0.8) × 10−18 to the strontium clock transition. When used in combination with careful management of the blackbody radiation environment, the device shows potential as a platform for realizing a compact, robust, transportable optical lattice clock with systematic uncertainty at the 10−18 level

Process development for manufacturing of cellular structures with controlled geometry and properties

This study presents experimental results on the behaviour of aluminium alloy metal structures and foams manufactured by lost-wax casting and using 3D printed components for internal structure definition. Results for tensile tests, metallurgical properties, surface quality and geometry tolerances were obtained and discussed. The analysis focused on development geometries, used for adjusting manufacturing parameters and prototype geometries intended for geometrical and mechanical validation. The results are indicative of the viability of the method for producing foam structures suitable for mechanical loading.The authors are grateful to the Portuguese Foundation for Science and Technology (FCT) who financially supported this work, through the project PTDC/EME-PME/115668/2009.info:eu-repo/semantics/publishedVersio

Genome of the Avirulent Human-Infective Trypanosome—Trypanosoma rangeli

Background: Trypanosoma rangeli is a hemoflagellate protozoan parasite infecting humans and other wild and domestic mammals across Central and South America. It does not cause human disease, but it can be mistaken for the etiologic agent of Chagas disease, Trypanosoma cruzi. We have sequenced the T. rangeli genome to provide new tools for elucidating the distinct and intriguing biology of this species and the key pathways related to interaction with its arthropod and mammalian hosts.  Methodology/Principal Findings: The T. rangeli haploid genome is ,24 Mb in length, and is the smallest and least repetitive trypanosomatid genome sequenced thus far. This parasite genome has shorter subtelomeric sequences compared to those of T. cruzi and T. brucei; displays intraspecific karyotype variability and lacks minichromosomes. Of the predicted 7,613 protein coding sequences, functional annotations could be determined for 2,415, while 5,043 are hypothetical proteins, some with evidence of protein expression. 7,101 genes (93%) are shared with other trypanosomatids that infect humans. An ortholog of the dcl2 gene involved in the T. brucei RNAi pathway was found in T. rangeli, but the RNAi machinery is non-functional since the other genes in this pathway are pseudogenized. T. rangeli is highly susceptible to oxidative stress, a phenotype that may be explained by a smaller number of anti-oxidant defense enzymes and heatshock proteins.  Conclusions/Significance: Phylogenetic comparison of nuclear and mitochondrial genes indicates that T. rangeli and T. cruzi are equidistant from T. brucei. In addition to revealing new aspects of trypanosome co-evolution within the vertebrate and invertebrate hosts, comparative genomic analysis with pathogenic trypanosomatids provides valuable new information that can be further explored with the aim of developing better diagnostic tools and/or therapeutic targets

SAG2A protein from Toxoplasma gondii interacts with both innate and adaptive immune compartments of infected hosts

Abstract\ud \ud \ud \ud Background\ud \ud Toxoplasma gondii is an intracellular parasite that causes relevant clinical disease in humans and animals. Several studies have been performed in order to understand the interactions between proteins of the parasite and host cells. SAG2A is a 22 kDa protein that is mainly found in the surface of tachyzoites. In the present work, our aim was to correlate the predicted three-dimensional structure of this protein with the immune system of infected hosts.\ud \ud \ud \ud Methods\ud To accomplish our goals, we performed in silico analysis of the amino acid sequence of SAG2A, correlating the predictions with in vitro stimulation of antigen presenting cells and serological assays.\ud \ud \ud \ud Results\ud Structure modeling predicts that SAG2A protein possesses an unfolded C-terminal end, which varies its conformation within distinct strain types of T. gondii. This structure within the protein shelters a known B-cell immunodominant epitope, which presents low identity with its closest phyllogenetically related protein, an orthologue predicted in Neospora caninum. In agreement with the in silico observations, sera of known T. gondii infected mice and goats recognized recombinant SAG2A, whereas no serological cross-reactivity was observed with samples from N. caninum animals. Additionally, the C-terminal end of the protein was able to down-modulate pro-inflammatory responses of activated macrophages and dendritic cells.\ud \ud \ud \ud Conclusions\ud Altogether, we demonstrate herein that recombinant SAG2A protein from T. gondii is immunologically relevant in the host-parasite interface and may be targeted in therapeutic and diagnostic procedures designed against the infection.The authors thank Marley Dantas Barbosa and Zilda Mendonça da Silva Rodrigues for technical assistance. This work was supported by Brazilian funding agencies CNPq, CAPES and FAPEMIG.The authors thank Marley Dantas Barbosa and Zilda Mendonça da Silva Rodrigues for technical assistance. This work was supported by Brazilian funding agencies CNPq, CAPES and FAPEMIG