494 research outputs found

    Emergence of Stenotrophomonas maltophilia co-harboring tetM and smqnr and over-expressing different efflux pumps among clinical isolates from tertiary care hospitals in Alexandria, Egypt

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    Background: Stenotrophomonas maltophilia (S. maltophilia), is a remarkable nosocomial pathogen, packed with different intrinsic mechanisms of resistance to most antimicrobials. Trimethoprim/Sulfamethoxazole (SXT) is the treatment of choice for S. maltophilia infections. However, different acquired factors may render SXT ineffective. Our aim was to investigate the susceptibility pattern to levofloxacin (LEV) and minocycline (MIN) among SXT non-susceptible isolates, as well as the different expression levels of different efflux pumps.   Methods: Susceptibility pattern to LEV and MIN was investigated as well as the expression level of different efflux pumps SmeABC, SmeDEF and SmrA and the presence of smqnr and tetM. Results: Among the 19 SXT non-susceptible isolates, 57.89% were susceptible to LEV and 10.52% were susceptible to MIN. It was found that 68.42%, 15.78% and 36.84% of the isolates showed over-expressed SmeABC, SmeDEF and SmrA, respectively. The results showed no significant correlation between over-expression of efflux pumps and resistance to LEV and MIN. Moreover, smqnr was detected in 4 out of 8 LEV non-susceptible isolates, while tetM was present in 11 out of 17 MIN non-susceptible isolates. Conclusion: As far as previously reported, this is the first study dedicated to SXT non-susceptible S. maltophilia isolates, that reported the presence of tetM and smqnr and the over-expression of SmeABC, SmeDEF, and SmrA among clinical isolates in Alexandria, Egypt. The findings emphasize that LEV can be used as a suitable option in managing S. maltophilia infections

    Batch kinetics, isotherm and thermodynamic studies of adsorption of strontium from aqueous solutions onto low cost rice-straw based carbons.

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    Present study explored the feasibility of using waste rice-straw based carbons as adsorbent for the removal of strontium under different experimental conditions. The batch sorption is studied with respect to solute concentration (2.8 - 110 mg/L), contact time, adsorbent dose (2.5 - 20 g/L) and solution temperature (25 - 55oC). The Langmuir and Dubinin-Radushkevich adsorption models were applied to experimental equilibrium data and isotherm constants were calculated using linear regression analysis. A comparison of kinetic models applied to the adsorption of strontium on rice-straw carbon was evaluated for the pseudo-second-order, Elovich, intraparticle diffusion and Bangham’s kinetics models. The experimental data fitted very well the pseudosecond-order kinetic model and also followed by intra-particle diffusion model, whereas diffusion is not only the rate-controlling step. The results show that the sorption capacity increases with an increase in solution temperature from 25 to 55 oC. The thermodynamics parameters were evaluated. The positive value of ΔH (40.93 kJ) indicated that the adsorption of strontium onto RS1 carbon was endothermic, which result was supported by the increasing adsorption of strontium with temperature. The positive value of ΔS (121.8 kJ/mol) reflects good affinity of strontium ions towards the rice-straw based carbons. The results have establishedgood potentiality for the carbons particles to be used as a sorbent for the removal of strontium from wastewater

    Characterization of activated carbon prepared by phosphoric acid activation of olive stones

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    AbstractThe effects of activating agent concentration on the pore structure and surface chemistry of activated carbons derived from olive stone with chemical activation method using phosphoric acid as the activating agent were studied. Mass changes associated with the impregnation, carbonization and washing processes were measured. With H3PO4 dilute solutions (60, 70, and 80 wt% H3PO4), the loading of substance on CS increases with concentration. The concentration of the H3PO4 solution seems to control the processes of impregnation, carbonization and washing in the preparation of AC from olive stones by H3PO4 chemical activation. ACs have been characterized from the results obtained by N2 adsorption at 77K. Moreover, the fractal dimension (D) has been calculated in order to determine the AC surface roughness degree. Optimal textural properties of ACs have been obtained by chemical activation with H3PO4 80wt.%. The BET surface areas and total pore volumes of the carbons produced at H3PO4 80wt.% are 1218m2/g and 0.6cm3/g, respectively

    LES CHANGEMENTS DES SYSTÈMES DE CONTRÔLE DE GESTION CAS DES ENTREPRISES ALGÉRIENNES

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    Ce présent article a pour objectif de présenter les résultats d’une enquête menée auprès de 40 entreprises Algériennes afin d’évaluer les changements apportés aux outils de contrôle de gestion sur la période 2010 – 2014 en se basant sur le cadre conceptuel de Libby et Waterhouse (1996) et la typologie de Sulaiman et Mitchell (2005). Les résultats de la recherche montrent que le nombre moyen des changements des systèmes de contrôle de gestion par entreprise pour la période 2010 – 2014 en Algérie est de 5,15, le nombre moyen de changement par an par entreprise est de 1.03

    Record Linkage Based on Entities\u27 Behavior

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    Record linkage is the problem of identifying similar records across different data sources. Traditional record linkage techniques focus on using simple database attributes in a textual similarity comparison to decide on matched and non-matched records. Recently, record linkage techniques have considered useful extracted knowledge and domain information to help enhancing the matching accuracy. In this paper, we present a new technique for record linkage that is based on entity’s behavior, which can be extracted from a transaction log. In the matching process, we measure the improvement of identifying a behavior when comparing two entities by merging their transaction log. To do so, we use two matching phases; first, a candidate generation phase, which is fast and provide almost no false negatives, while producing low precision. Second, an accurate matching phase, which enhances the precision of the matching at high run time cost. In the candidates phase generation, behavior is represented by points in the complex plan, where we perform approximate evaluations. In the accurate matching phase, we use a heuristic called compressibility, where identified behaviors are more compressible. Our experiments show that the proposed technique can be used to enhance the record linkage quality while being practical for large logs. We also perform extensive sensitivity analysis for the technique’s accuracy and performance

    M1 Polarization Markers Are Upregulated in Basal-Like Breast Cancer Molecular Subtype and Associated With Favorable Patient Outcome

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    Background: Breast cancer heterogeneity is an essential element that plays a role in the therapy response variability and the patient’s outcome. This highlights the need for more precise subtyping methods that focus not only on tumor cells but also investigate the profile of stromal cells as well as immune cells. Objectives: To mine publicly available transcriptomic breast cancer datasets and reanalyze their transcriptomic profiling using unsupervised clustering in order to identify novel subsets in molecular subtypes of breast cancer, then explore the stromal and immune cells profile in each subset using bioinformatics and systems immunology approaches. Materials and Methods: Transcriptomic data from 1,084 breast cancer patients obtained from The Cancer Genome Atlas (TCGA) database were extracted and subjected to unsupervised clustering using a recently described, multi-step algorithm called Iterative Clustering and Guide-gene Selection (ICGS). For each cluster, the stromal and immune profile was investigated using ESTIMATE and CIBERSORT analytical tool. Clinical outcomes and differentially expressed genes of the characterized clusters were identified and validated in silico and in vitro in a cohort of 80 breast cancer samples by immunohistochemistry. Results: Seven unique sub-clusters showed distinct molecular and clinical profiles between the well-known breast cancer subtypes. Those unsupervised clusters identified more homogenous subgroups in each of the classical subtypes with a different prognostic profile. Immune profiling of the identified clusters showed that while the classically activated macrophages (M1) are correlated with the more aggressive basal-like breast cancer subtype, the alternatively activated macrophages (M2) showed a higher level of infiltration in luminal A and luminal B subtypes. Indeed, patients with higher levels of M1 expression showed less advanced disease and better patient outcomes presented as prolonged overall survival. Moreover, the M1 high basal-like breast cancer group showed a higher expression of interferon-gamma induced chemokines and guanylate-binding proteins (GBPs) involved in immunity against microbes. Conclusion: Adding immune profiling using transcriptomic data can add precision for diagnosis and prognosis and can cluster patients according to the available modalities of therapy in a more personalized approach

    Parent-offspring transmission of adipocytokine levels and their associations with metabolic traits

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    Adipose tissue secreted cytokines (adipocytokines) have significant effects on the physiology and pathology of human metabolism relevant to diabetes and cardiovascular disease. We determined the relationship of the pattern of these circulating hormones with obesity-related phenotypes and whether such pattern is transmitted from parent to offspring. A combined total of 403 individuals from 156 consenting Saudi families divided into initial (119 families with 123 adults and 131 children) and replication (37 families with 58 adults and 91 children) cohorts were randomly selected from the RIYADH Cohort study. Anthropometrics were evaluated and metabolic measures such as fasting serum glucose, lipid profiles, insulin, leptin, adiponectin, resistin, tumor necrosis factor alpha (TNFa), activated plasminogen activator inhibitor 1 (aPAI1), high sensitivity C-reactive protein (hsCRP) and angiotensin II were also assessed. Parent-offspring regressions revealed that with the exception of hsCRP, all hormones measured showed evidence for significant inheritance. Principal component (PC) analysis of standardized hormone levels demonstrated surprising heritability of the three most common axes of variation. PC1, which explained 21% of the variation, was most strongly loaded on levels of leptin, TNFa, insulin, and aPAI1, and inversely with adiponectin. It was significantly associated with body mass index (BMI) and phenotypically stronger in children, and showed a heritability of ,50%, after adjustment for age, gender and generational effects. We conclude that adipocytokines are highly heritable and their pattern of co-variation significantly influences BMI as early as the pre-teen years. Investigation at the genomic scale is required to determine the variants affecting the regulation of the hormones studied

    Association of vitamin B12 with pro-inflammatory cytokines and biochemical markers related to cardiometabolic risk in Saudi subjects

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    Background: This study aimed to examine the relationship between changes in systemic vitamin B12 concentrations with pro-inflammatory cytokines, anthropometric factors and biochemical markers of cardiometabolic risk in a Saudi population. Methods: A total of 364 subjects (224 children, age: 12.99 ± 2.73 (mean ± SD) years; BMI: 20.07 ± 4.92 kg/m2 and 140 adults, age: 41.87 ± 8.82 years; BMI: 31.65 ± 5.77 kg/m2) were studied. Fasting blood, anthropometric and biochemical data were collected. Serum cytokines were quantified using multiplex assay kits and B12 concentrations were measured using immunoassay analyzer. Results: Vitamin B12 was negatively associated with TNF-α (r = −0.14, p < 0.05), insulin (r = −0.230, p < 0.01) and HOMA-IR (r = −0.252, p < 0.01) in all subjects. In children, vitamin B12 was negatively associated with serum resistin (r = −0.160, p < 0.01), insulin (r = −0.248, p < 0.01), HOMA-IR (r = −0.261, p < 0.01). In adults, vitamin B12 was negatively associated with TNF-α (r = −0.242, p < 0.01) while positively associated with resistin (r = 0.248, p < 0.01). Serum resistin was the most significant predictor for circulating vitamin B12 in all subjects (r2 = −0.17, p < 0.05) and in children (r2 = −0.167, p < 0.01) while HDL-cholesterol was the predictor of B12 in adults (r2 = −0.78, p < 0.05). Conclusions: Serum vitamin B12 concentrations were associated with pro-inflammatory cytokines and biochemical markers of cardiometabolic risks in adults. Maintaining adequate vitamin B12 concentrations may lower inflammation-induced cardiometabolic risk in the Saudi adult population
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