Error estimates for Stokes problem with Tresca friction condition

In this work we propose and study a three field mixed formulation for solving the Stokes problem with Tresca-type non-linear boundary conditions. Two Lagrange multipliers are used to enforce div(u)=0 constraint and to regularize the energy functional. The resulting problem is discretised using "P1 bubble/P1-P1" finite elements. Error estimates are derived and several numerical studies are achieved

Toxigenic potential and antimicrobial susceptibility of Bacillus cereus group bacteria isolated from Tunisian foodstuffs

International audienceBackground: Despite the importance of the B. cereus group as major foodborne pathogens that may cause diarrheal and/or emetic syndrome(s), no study in Tunisia has been conducted in order to characterize the pathogenic potential of the B. cereus group. The aim of this study was to assess the sanitary potential risks of 174 B. cereus group strains isolated from different foodstuffs by detecting and profiling virulence genes (hblA, hblB, hblC, hblD, nheA, nheB, nheC, cytK, bceT and ces), testing the isolates cytotoxic activity on Caco-2 cells and antimicrobial susceptibility towards 11 antibiotics. Results: The entertoxin genes detected among B. cereus isolates were, in decreasing order, nheA (98.9%), nheC (97.7%) and nheB (86.8%) versus hblC (54.6%), hblD (54.6%), hblA (29.9%) and hblB (14.9%), respectively encoding for Non-hemolytic enterotoxin (NHE) and Hemolysin BL (HBL). The isolates are multi-toxigenic, harbouring at least one gene of each NHE and HBL complexes associated or not to bceT, cytK-2 and ces genes. Based on the incidence of virulence genes, the strains were separated into 12 toxigenic groups. Isolates positive for cytK (37,9%) harbored the cytK-2 variant. The detection rates of bceT and ces genes were 50.6 and 4%, respectively. When bacteria were incubated in BHI-YE at 30°C for 18 h and for 5 d, 70.7 and 35% of the strains were shown to be cytotoxic to Caco-2 cells, respectively. The cytotoxicity of B. cereus strains depended on the food source of isolation. The presence of virulence factors is not always consistent with cytotoxicity. However, different combinations of enterotoxin genetic determinants are significantly associated to the cytotoxic potential of the bacteria. All strains were fully sensitive to rifampicin, chloramphenicol, ciprofloxacin, and gentamycin. The majority of the isolates were susceptible to streptomycin, kanamycin, erythromycin, vancomycin and tetracycline but showed resistance to ampicillin and novobiocin. Conclusion: Our results contribute data that are primary to facilitate risk assessments in order to prevent food poisoning due to B. cereus group

Claude Poissenot, La nouvelle bibliothèque : contribution pour la bibliothèque de demain

Dans La nouvelle bibliothèque  : contribution pour la bibliothèque de demain, Claude Poissenot développe une réflexion sur l’avenir des bibliothèques à l’heure de l’internet. Il s’interroge sur les missions de ces établissements et les fonctions des professionnels du secteur au moment où les services d’information connaissent de profondes mutations liées à l’expansion des technologies et à la mondialisation de l’information. Le point de départ de l’ouvrage est le constat d’essoufflement du mo..

Hamatum osteoblastoma

SummaryWe report the case of an osteoblastoma of the hamate bone that was successfully treated by curettage. This tumor is very rare in a carpal bone and only nine cases have been reported in the literature. Pathological examination is mandatory before treatment due to the lack of distinctive clinical and radiological features. Osteoblastomas are benign, but potentially aggressive bone tumors. Treatment of the lesion may either be a conservative “intralesional resection” or radical “wide en bloc resection”. The latter option, which has non-negligible functional consequences in the wrist, should be reserved for recurrence after curettage but may also be considered a primary immediate alternative for aggressive forms

First detection of Waddlia chondrophila in Africa using SYBR Green real-time PCR on veterinary samples.

Waddlia chondrophila is a strict intracellular microorganism belonging to the order Chlamydiales that has been isolated twice from aborted bovine fetuses, once in USA and once in Germany. This bacterium is now considered as an abortigenic agent in cattle. However, no information is available regarding the presence of this bacterium in Africa. Given the low sensitivity of cell culture to recover such an obligate intracellular bacterium, molecular-based diagnostic approaches are warranted. This report describes the development of a quantitative SYBR Green real-time PCR assay targeting the recA gene of W. chondrophila. Analytical sensitivity was 10 copies of control plasmid DNA per reaction. No cross-amplification was observed when testing pathogens that can cause abortion in cattle. The PCR exhibited a good intra-run and inter-run reproducibility. This real-time PCR was then applied to 150 vaginal swabs taken from Tunisian cows that have aborted. Twelve samples revealed to be Waddlia positive, suggesting a possible role of this bacterium in this setting. This new real-time PCR assay represents a diagnostic tool that may be used to further study the prevalence of Waddlia infection

IL10-driven STAT3 signalling in senescent macrophages promotes pathological eye angiogenesis

Macrophage dysfunction plays a pivotal role during neovascular proliferation in diseases of ageing including cancers, atherosclerosis and blinding eye disease. In the eye, choroidal neovascularization (CNV) causes blindness in patients with age-related macular degeneration (AMD). Here we report that increased IL10, not IL4 or IL13, in senescent eyes activates STAT3 signalling that induces the alternative activation of macrophages and vascular proliferation. Targeted inhibition of both IL10 receptor-mediated signalling and STAT3 activation in macrophages reverses the ageing phenotype. In addition, adoptive transfer of STAT3-deficient macrophages into eyes of old mice significantly reduces the amount of CNV. Systemic and CD163(+) eye macrophages obtained from AMD patients also demonstrate STAT3 activation. Our studies demonstrate that impaired SOCS3 feedback leads to permissive IL10/STAT3 signalling that promotes alternative macrophage activation and pathological neovascularization. These findings have significant implications for our understanding of the pathobiology of age-associated diseases and may guide targeted immunotherapy

Prescription of Proton Pump Inhibitors in Elderly Subjects in Real Life: A Retrospective Study in a Gastroenterology Department

The proton-pump inhibitor (PPI) is an effective and widely used treatment but may cause side effects, especially for the elderly. Materials and methods: this is a cross-sectional study including 45 patients older than 65 years, followed at our outpatient and treated with PPIs for at least a year. The indication for PPI, the results of any endoscopy, and the quality of the tolerance of these molecules is specified by the data folder. During the consultation, we conducted an interrogation to an update of the history and medications to our patients and a type checking of the molecule, the dose, and the quality of the observance. Results: patients were divided into 32 women and 13 men with a mean age of 75 ± 7 years (65–92). The average length of PPI use was 6 ± 4 years (1–16) with a consumption of a double dose for at least 1 year in 28.8% of cases. The prescribed dose was higher than the recommended dose in at least 15.5% of cases. PPIs were well tolerated. One patient had presented a microscopic colitis, revealed by diarrhea regressed after discontinuation of PPIs. Conclusion: PPIs were prescribed in elderly subjects by gastroenterologists, in a university center, with a high dose and long. In our series, this treatment is well tolerated in the elderly

Ureaplasma urealyticum, Ureaplasma parvum, Mycoplasma hominis and Mycoplasma genitalium infections and semen quality of infertile men

<p>Abstract</p> <p>Background</p> <p>Genital ureaplasmas (<it>Ureaplasma urealyticum </it>and <it>Ureaplasma parvum</it>) and mycoplasmas (<it>Mycoplasma genitalium </it>and <it>Mycoplasma hominis</it>) are potentially pathogenic species playing an etiologic role in both genital infections and male infertility. Reports are, however, controversial regarding the effects of these microorganisms infections in the sperm seminological variables. This study aimed at determining the frequency of genital ureplasmas and mycoplasmas in semen specimens collected from infertile men, and at comparing the seminological variables of semen from infected and non-infected men with these microorganisms.</p> <p>Methods</p> <p>A total of 120 semen samples collected from infertile men were investigated. Semen specimens were examined by in-house PCR-microtiter plate hybridization assay for the presence of genital ureaplasmas and mycoplasmas DNA. Semen analysis was assessed according to the guidelines of the World Health Organization. Standard parametric techniques (<it>t</it>-tests) and nonparametric techniques (Wilcoxon tests) were used for statistical analysis.</p> <p>Results</p> <p>The frequency of genital ureaplasmas and mycoplasmas detected in semen samples of infertile men was respectively 19.2% (23/120) and 15.8% (19/120). The frequency of <it>Ureaplasma urealyticum </it>(15%) was higher than that of <it>Mycoplasma hominis </it>(10.8%), <it>Ureaplasma parvum </it>(4.2%) and <it>Mycoplasma genitalium </it>(5%). Mixed species of mycoplasmas and ureaplasmas were detected in 6.7% of semen samples.</p> <p>Comparison of the parameters of the standard semen analysis between the male partners of the infertile couples with and without genital ureaplasmas and mycoplasmas infection showed that the presence of <it>Mycoplasma hominis </it>DNA in semen samples is associated with low sperm concentration (<it>p </it>= 0.007) and abnormal sperm morphology (<it>p </it>= 0.03) and a negative correlation between sperm concentration and the detection of <it>Mycoplasma genitalium </it>in semen samples of infertile men (<it>p </it>= 0.05). The mean values of seminal volume, pH, vitality, motility and leukocyte count were not significantly related either to the detection of genital mycoplasmas DNA or to the detection of ureaplasmas DNA in semen specimens.</p> <p>Conclusion</p> <p>Our results demonstrate that genital mycoplasmas and ureaplasmas seem to be widespread among the male partners of infertile couples in Tunisia. Genital mycoplasmas infections of the male genital tract could negatively influence semen quality. Our results also indicate that PCR-microtiter plate hybridization assay method provides a rapid and effective technique to detect human genital mycoplasmas and ureaplasmas which is useful for etiological and epidemiological studies of these pathogens.</p

Evaluation of an in silico predicted specific and immunogenic antigen from the OmcB protein for the serodiagnosis of Chlamydia trachomatis infections

<p>Abstract</p> <p>Background</p> <p>The OmcB protein is one of the most immunogenic proteins in <it>C. trachomatis </it>and <it>C. pneumoniae </it>infections. This protein is highly conserved leading to serum cross reactivity between the various chlamydial species. Since previous studies based on recombinant proteins failed to identify a species specific immune response against the OmcB protein, this study evaluated an <it>in silico </it>predicted specific and immunogenic antigen from the OmcB protein for the serodiagnosis of <it>C. trachomatis </it>infections.</p> <p>Results</p> <p>Using the ClustalW and Antigenic programs, we have selected two predicted specific and immunogenic regions in the OmcB protein: the N-terminal (Nt) region containing three epitopes and the C-terminal (Ct) region containing two epitopes with high scores. These regions were cloned into the PinPoint Xa-1 and pGEX-6P-1 expression vectors, incorporating a biotin purification tag and a glutathione-S-transferase tag, respectively. These regions were then expressed in <it>E. coli</it>. Only the pGEX-6P-1 has been found suitable for serological studies as its tag showed less cross reactivity with human sera and was retained for the evaluation of the selected antigens. Only the Ct region of the protein has been found to be well expressed in <it>E. coli </it>and was evaluated for its ability to be recognized by human sera. 384 sera were tested for the presence of IgG antibodies to <it>C. trachomatis </it>by our in house microimmunofluorescence (MIF) and the developed ELISA test. Using the MIF as the reference method, the developed OmcB Ct ELISA has a high specificity (94.3%) but a low sensitivity (23.9). Our results indicate that the use of the sequence alignment tool might be useful for identifying specific regions in an immunodominant antigen. However, the two epitopes, located in the selected Ct region, of the 24 predicted in the full length OmcB protein account for approximately 25% of the serological response detected by MIF, which limits the use of the developed ELISA test when screening <it>C. trachomatis </it>infections.</p> <p>Conclusion</p> <p>The developed ELISA test might be used as a confirmatory test to assess the specificity of serological results found by MIF.</p