Malformations vasculaires au cours du syndrome de Williams-Beuren: à propos de trois nouvelles observations

Le syndrome de Williams-Beuren est une maladie génétique rare, il associe classiquement une dysmorphie  faciale assez spécifique, des malformations cardiovasculaires et un profil neuropsychologique particulier. Nous rapportons les observations de trois enfants atteints du syndrome de Williams-Beuren en insistant surtout sur les anomalies vasculaires observées sur l'angio-scanner et angio-IRM.Key words: Williams Beuren, sténose supra aortique, angioscanner, angio IR

Computational genomics-proteomics and Phylogeny analysis of twenty one mycobacterial genomes (Tuberculosis & non Tuberculosis strains)

The genus Mycobacterium comprises different species, among them the most contagious and infectious bacteria. The members of the complex Mycobacterium tuberculosis are the most virulent microorganisms that have killed human and other mammals since millennia. Additionally, with the many different mycobacterial sequences available, there is a crucial need for the visualization and the simplification of their data. In this present study, we aim to highlight a comparative genome, proteome and phylogeny analysis between twenty-one mycobacterial (Tuberculosis and non tuberculosis) strains using a set of computational and bioinformatics tools (Pan and Core genome plotting, BLAST matrix and phylogeny analysis).Results Considerably the result of pan and core genome Plotting demonstrated that less than 1250 Mycobacterium gene families are conserved across all species, and a total set of about 20,000 gene families within the Mycobacterium pan-genome of twenty one mycobacterial genomes.Viewing the BLAST matrix a high similarity was found among the species of the complex Mycobacterium tuberculosis and less conservation is found with other slow growing pathogenic mycobacteria. Phylogeny analysis based on both protein conservation, as well as rRNA clearly resolve known relationships between slow growing mycobacteria.Conclusion Mycobacteria include important pathogenic species for human and animals and the Mycobacterium tuberculosis complex is the most cause of death of the humankind. The comparative genome analysis could provide a new insight for better controlling and preventing these diseases

Computational genomics-proteomics and Phylogeny analysis of twenty one mycobacterial genomes (Tuberculosis & non Tuberculosis strains)

The genus Mycobacterium comprises different species, among them the most contagious and infectious bacteria. The members of the complex Mycobacterium tuberculosis are the most virulent microorganisms that have killed human and other mammals since millennia. Additionally, with the many different mycobacterial sequences available, there is a crucial need for the visualization and the simplification of their data. In this present study, we aim to highlight a comparative genome, proteome and phylogeny analysis between twenty-one mycobacterial (Tuberculosis and non tuberculosis) strains using a set of computational and bioinformatics tools (Pan and Core genome plotting, BLAST matrix and phylogeny analysis).Results Considerably the result of pan and core genome Plotting demonstrated that less than 1250 Mycobacterium gene families are conserved across all species, and a total set of about 20,000 gene families within the Mycobacterium pan-genome of twenty one mycobacterial genomes.Viewing the BLAST matrix a high similarity was found among the species of the complex Mycobacterium tuberculosis and less conservation is found with other slow growing pathogenic mycobacteria. Phylogeny analysis based on both protein conservation, as well as rRNA clearly resolve known relationships between slow growing mycobacteria.Conclusion Mycobacteria include important pathogenic species for human and animals and the Mycobacterium tuberculosis complex is the most cause of death of the humankind. The comparative genome analysis could provide a new insight for better controlling and preventing these diseases

Cytotoxic effect on lymphocytes of Tat from human immunodeficiency virus (HIV-1)

AbstractThe human immunodeficiency virus type 1 (HIV-1) genome codes for trans-activator Tat, an 86-residue protein whose expression is critical for viral replication. Full-length Tat and Tat peptides from HIV-1 were chemically synthesized using optimized solid phase technique. Synthetic Tat2 in86, was found not only to inhibit antigen-induced human peripheral blood lymphocyte (PBL) proliferation in vitro, as described by Viscidi et al. [1989, Science 246, 1606-1608], but also mitogen-induced PBL proliferation, with 50% inhibition obtained at 0.9 and 8 μ;M, respectively. To assess the mechanism by which Tat exert its inhibitory effect, we analysed its interaction and effect on CD4+-cells. Direct fluorescence and indirect immunofluorescence assays analysed by flow cytometry showed that fluorescein isothiocyanate-labeled and -unlabeled Tat interact (>0.2 μ;M) with CD4-expressing lymphoid cells (CEM cell line). Experiments of chromium-51 release and Trypan blue exclusion on these tumor cells in vitro have demonstrated the capacity of Tat to modify cellular membrane permeability and cell viability, in a dose-dependent manner. The use of Tat peptides revealed that those containing the Tat basic region from 49 to 57 were able to bind to the cell membrane and to exhibit a cytotoxic activity on lymphocytes. Together, the data suggest that the potential cytotoxicity of Tat on lymphocytes could be directly implicated in virus-induced immune dysfunction observed in HIV-1 infected patients

Immunochemical Methods for Ochratoxin A Detection: A Review

The safety of food and feed depends to a great deal on quality control. Numerous compounds and organisms may contaminate food and feed commodities and thus pose a health risk for consumers. The compound of interest in this review is ochratoxin A (OTA), a secondary metabolite of the fungi Aspergillus and Penicillium. Due to its adverse health effects, detection and quantification are of utmost importance. Quality control of food and feed requires extraction and analysis, including TLC, HPLC, MS, and immunochemical methods. Each of these methods has its advantages and disadvantages. However, with regard to costs and rapidity, immunochemical methods have gained much interest in the last decade. In this review an introduction to immunochemistry and assay design will be given to elucidate the principles. Further, the application of the various formats to the detection and quantification of ochratoxin will be described, including the use of commercially available kits

Envelope Deglycosylation Enhances Antigenicity of HIV-1 gp41 Epitopes for Both Broad Neutralizing Antibodies and Their Unmutated Ancestor Antibodies

The HIV-1 gp41 envelope (Env) membrane proximal external region (MPER) is an important vaccine target that in rare subjects can elicit neutralizing antibodies. One mechanism proposed for rarity of MPER neutralizing antibody generation is lack of reverted unmutated ancestor (putative naive B cell receptor) antibody reactivity with HIV-1 envelope. We have studied the effect of partial deglycosylation under non-denaturing (native) conditions on gp140 Env antigenicity for MPER neutralizing antibodies and their reverted unmutated ancestor antibodies. We found that native deglycosylation of clade B JRFL gp140 as well as group M consensus gp140 Env CON-S selectively increased the reactivity of Env with the broad neutralizing human mAbs, 2F5 and 4E10. Whereas fully glycosylated gp140 Env either did not bind (JRFL), or weakly bound (CON-S), 2F5 and 4E10 reverted unmutated ancestors, natively deglycosylated JRFL and CON-S gp140 Envs did bind well to these putative mimics of naive B cell receptors. These data predict that partially deglycoslated Env would bind better than fully glycosylated Env to gp41-specific naïve B cells with improved immunogenicity. In this regard, immunization of rhesus macaques demonstrated enhanced immunogenicity of the 2F5 MPER epitope on deglyosylated JRFL gp140 compared to glycosylated JRFL gp140. Thus, the lack of 2F5 and 4E10 reverted unmutated ancestor binding to gp140 Env may not always be due to lack of unmutated ancestor antibody reactivity with gp41 peptide epitopes, but rather, may be due to glycan interference of binding of unmutated ancestor antibodies of broad neutralizing mAb to Env gp41

Le lymphangiome kystique axillaire chez l’enfant.

Les lymphangiomes kystiques restent des tumeurs congénitales rares, qui ne représentent que 6% des tumeurs bénignes de l’enfant. Environ 20% des localisations sont axillaires. Le but de notre travail est de proposer une synthèse actualisée des différentes modalités de diagnostic et de traitement des lymphangiomes axillaires. Notre travail consiste en une étude rétrospective étalée sur 16 ans, entre octobre 1993 et juin 2009, représentée par 7 cas de lymphangiomes kystiques axillaires colligés au service de Chirurgie A de l’Hôpital d’Enfants de Rabat. L’âge d’apparition des lésions chez nos patients allait de la naissance jusqu’à deux ans, le sexe ratio filles-garçons était de 0,75. Dans la totalité des cas, le lymphangiome a été révélé par des tuméfactions cutanées de taille variable siégeant au niveau de la région axillaire, de consistance molle parfois rénitente, mobile par rapport au deux plans, non douloureuse à la palpation, augmentant de volume progressivement, sans atteintes vasculo-nerveuses. L’échographie axillaire et la tomodensitométrie ont permis d’évoquer le diagnostic de la lésion chez nos enfants. L’exérèse chirurgicale était le traitement de première intention chez 6 de nos patients (86%) et un seul malade a bénéficié d’un traitement par sclérothérapie aux corticoïdes (14%). L’exérèse était totale dans 5 cas avec sacrifice des structures nobles chez 2 malades, et partielle dans un cas du fait que la tumeur était intimement liée au pédicule vasculo-nerveux. Seul l’examen anatomo-pathologique de la pièce opératoire a permis d’établir le diagnostic de certitude du lymphangiome. Les suites opératoires immédiates étaient en général simples, l’évolution a été marquée par une récidive de la tumeur chez le patient traité par sclérothérapie ce qui a imposé une intervention chirurgicale. Le diagnostic anténatal est actuellement performant basé sur des données échographiques au cours du deuxième trimestre de la grossesse et aidé par l’imagerie par résonnance magnétique fœtale. La sclérose percutanée représente un traitement de choix, efficace, peu risqué et pouvant être proposée en première intention

Antibody biotechnology

Antibodies are the support of adaptive humoral immunity and they are characterized by their high diversity, clonality and specificity. The extremely diverse fields of application of monoclonal antibodies(mAbs) have continuously stimulated the development of antibody engineering especially after the discovery hybridoma by Köhler and Milstein (1975). This review summarize the main antibody biotechnology approaches that have lead to the development of murine mAbs, chimeric mAbs, humanized mAbs , combinatorial antibody libraries and entirely human mAbs