Sähkökemiallisesti valmistetut molekyylimallitetut polymeerit epäpuhtauksien detektoinnissa

New electrochemical molecularly imprinted polymers (e-MIPs) for benzo(a)pyrene (BaP) based on vinylferrocene (VFc) as redox tracer directly integrated into binding cavities during polymerization with crosslinker are reported. Impacts on the BaP detection are discussed according to: 1) the addition or no of 4-vinylpyridine (4VP) as comonomer, 2) the use of ethylene glycol dimethacrylate (EDMA) or divinylbenzene (DVB) as crosslinker. After characterization, these new e-MIPs and their corresponding non-imprinted polymers (e-NIPs) were incorporated in carbon paste electrodes and measurements were carried out by square wave voltammetry. All analyses revealed that e-MIP based on VFc and EDMA is the best to detect the template, with an imprinting factor of 7.3 and a LOD of 0.93 mu mol/L of BaP.Peer reviewe

Effect of porogen solvent on the synthesis of nickel ion imprinted polymer materials prepared by inverse suspension polymerization

Ion-imprinted polymers (IIPs) for nickel were synthesized by inverse suspension copoly-merization of vinylbenzyl iminodiacetic acid (VbIDA) with ethyleneglycol dimethacrylate (EDMA) in the presence of nickel(II) ions with various porogen solvents to study their impact on the IIPs properties. They were prepared with mixtures of acetonitrile and dimethylsulfoxide (DMSO), 50/50%v/v, for IIP-A/D and 2-methoxyethanol and DMSO, 50/50%v/v, for IIP-M/D. The structure and properties of these polymers were compared with those of IIP-D previously prepared with pure DMSO as porogen solvent. Although IIP-A/D and IIP-M/D were less porous than IIP-D, they presented better nickel adsorption properties and selectivity towards Zn2+, Co2+ and Pb2+. This is assumed to be the result of the stabilization of the ligand-metal complex during the polymerization process. Moreover, the nickel binding capacities of the prepared IIPs in competitive conditions are remarkably high (184 mu mol/g for IIP-D, 170 mu mol/g for IIP-A/D and 174 mu mol/g for IIP-M/D). The impact of the VbIDA chelating monomer was highlighted by comparing the adsorption properties of a copolymer of methyl methacrylate (MMA) and EDMA with NIP-D. It was proved that the methacrylic polymer matrix has low binding properties. (C) 2016 Elsevier Ltd. All rights reserved.Peer reviewe

Genetic Background of Escherichia coli and Extended-spectrum β-Lactamase Type

ESBL-producing E. coli may arise from interactions between ESBL type, strain genetic background, and selective pressures in various ecologic niches

Methicillin-resistant Staphylococcus aureus carriage in a long-term care facility: hypothesis about selection and transmission

Background: many studies have identified long-term care facilities (LTCFs) as reservoirs of patients carrying methicillin-resistant Staphylococcus aureus (MRSA). However, few data about the mechanisms of MRSA diffusion in these settings are available.Objectives: the purpose of our study was to suggest hypothesis on the possible ways of MRSA transmission to residents in or outside a LTCF. Methods: data concerning patients on the day of the survey and within the preceding year were collected. Multivariate analysis was performed by logistic regression to identify characteristics associated with MRSA carriage. MRSA strains were analysed by pulsed-field gel electrophoresis (PFGE) and the relatedness between DNA patterns was studied with Gel Compar software. Results: the prevalence of MRSA carriage was 37.6%. Treatment with fluoroquinolones or third-generation cephalosporins [odds ratio (OR) = 12.07; 95% confidence interval (CI) = 5.90–24.7], treatment with other antimicrobial agents (OR = 4.40; 95% CI = 2.43–7.97), at least one medical imaging session (OR = 5.08; 95% CI = 2.66–9.69) within the 12 preceding months, and the presence of a subcutaneous catheter on the day of the survey (OR = 3.09; 95% CI = 1.87–5.10) were independently associated with MRSA carriage. Twenty-eight of the 38 strains tested were clustered in two major groups. In each of these groups, strains had at least a 90% relatedness. These strains were isolated in patients hospitalised in different areas of the LTCF. Conclusion: we identified that both molecular and epidemiological arguments support the hypothesis of the possibility of MRSA cross-transmission inside the LTCF. Further studies are needed to confirm and explain the association identified between MRSA carriage and medical imaging

Histopathological grading of pediatric ependymoma: reproducibility and clinical relevance in European trial cohorts

<p>Abstract</p> <p>Background</p> <p>Histopathological grading of ependymoma has been controversial with respect to its reproducibility and clinical significance. In a 3-phase study, we reviewed the pathology of 229 intracranial ependymomas from European trial cohorts of infants (2 trials - SFOP/CNS9204) and older children (2 trials - AIEOP/CNS9904) to assess both diagnostic concordance among five neuropathologists and the prognostic utility of histopathological variables, particularly tumor grading.</p> <p>Results</p> <p>In phase 1, using WHO criteria and without first discussing any issue related to grading ependymomas, pathologists assessed and independently graded ependymomas from 3 of 4 trial cohorts. Diagnosis of grade II ependymoma was less frequent than grade III, a difference that increased when one cohort (CNS9204) was reassessed in phase 2, during which the pathologists discussed ependymoma grading, jointly reviewed all CNS9204 tumors, and defined a novel grading system based on the WHO classification. In phase 3, repeat independent review of two cohorts (SFOP/CNS9904) using the novel system was associated with a substantial increase in concordance on grading. Extent of tumor resection was significantly associated with progression-free survival (PFS) in SFOP and AIEOP, but not in CNS9204 and CNS9904. Strength of consensus on grade was significantly associated with PFS in only one trial cohort (AIEOP). Consensus on the scoring of individual histopathological features (necrosis, angiogenesis, cell density, and mitotic activity) correlated with PFS in AIEOP, but in no other trial.</p> <p>Conclusions</p> <p>We conclude that concordance on grading ependymomas can be improved by using a more prescribed scheme based on the WHO classification. Unfortunately, this appears to have utility in limited clinical settings.</p

Enhanced Virulence of Chlamydia muridarum Respiratory Infections in the Absence of TLR2 Activation

Chlamydia trachomatis is a common sexually transmitted pathogen and is associated with infant pneumonia. Data from the female mouse model of genital tract chlamydia infection suggests a requirement for TLR2-dependent signaling in the induction of inflammation and oviduct pathology. We hypothesized that the role of TLR2 in moderating mucosal inflammation is site specific. In order to investigate this, we infected mice via the intranasal route with C. muridarum and observed that in the absence of TLR2 activation, mice had more severe disease, higher lung cytokine levels, and an exaggerated influx of neutrophils and T-cells into the lungs. This could not be explained by impaired bacterial clearance as TLR2-deficient mice cleared the infection similar to controls. These data suggest that TLR2 has an anti-inflammatory function in the lung during Chlamydia infection, and that the role of TLR2 in mucosal inflammation varies at different mucosal surfaces

Molecular and Evolutionary Bases of Within-Patient Genotypic and Phenotypic Diversity in Escherichia coli Extraintestinal Infections

Although polymicrobial infections, caused by combinations of viruses, bacteria, fungi and parasites, are being recognised with increasing frequency, little is known about the occurrence of within-species diversity in bacterial infections and the molecular and evolutionary bases of this diversity. We used multiple approaches to study the genomic and phenotypic diversity among 226 Escherichia coli isolates from deep and closed visceral infections occurring in 19 patients. We observed genomic variability among isolates from the same site within 11 patients. This diversity was of two types, as patients were infected either by several distinct E. coli clones (4 patients) or by members of a single clone that exhibit micro-heterogeneity (11 patients); both types of diversity were present in 4 patients. A surprisingly wide continuum of antibiotic resistance, outer membrane permeability, growth rate, stress resistance, red dry and rough morphotype characteristics and virulence properties were present within the isolates of single clones in 8 of the 11 patients showing genomic micro-heterogeneity. Many of the observed phenotypic differences within clones affected the trade-off between self-preservation and nutritional competence (SPANC). We showed in 3 patients that this phenotypic variability was associated with distinct levels of RpoS in co-existing isolates. Genome mutational analysis and global proteomic comparisons in isolates from a patient revealed a star-like relationship of changes amongst clonally diverging isolates. A mathematical model demonstrated that multiple genotypes with distinct RpoS levels can co-exist as a result of the SPANC trade-off. In the cases involving infection by a single clone, we present several lines of evidence to suggest diversification during the infectious process rather than an infection by multiple isolates exhibiting a micro-heterogeneity. Our results suggest that bacteria are subject to trade-offs during an infectious process and that the observed diversity resembled results obtained in experimental evolution studies. Whatever the mechanisms leading to diversity, our results have strong medical implications in terms of the need for more extensive isolate testing before deciding on antibiotic therapies

DMTs and Covid-19 severity in MS: a pooled analysis from Italy and France

We evaluated the effect of DMTs on Covid-19 severity in patients with MS, with a pooled-analysis of two large cohorts from Italy and France. The association of baseline characteristics and DMTs with Covid-19 severity was assessed by multivariate ordinal-logistic models and pooled by a fixed-effect meta-analysis. 1066 patients with MS from Italy and 721 from France were included. In the multivariate model, anti-CD20 therapies were significantly associated (OR&nbsp;=&nbsp;2.05, 95%CI&nbsp;=&nbsp;1.39–3.02, p&nbsp;&lt;&nbsp;0.001) with Covid-19 severity, whereas interferon indicated a decreased risk (OR&nbsp;=&nbsp;0.42, 95%CI&nbsp;=&nbsp;0.18–0.99, p&nbsp;=&nbsp;0.047). This pooled-analysis confirms an increased risk of severe Covid-19 in patients on anti-CD20 therapies and supports the protective role of interferon

Facteurs de risque d'infection à clostridium difficile chez les patients d'hépatologie (étude cas / témoin)

PARIS-BIUP (751062107) / SudocSudocFranceF

Etude de l'environnement génétique du site d'intégration du "mecDNA" ("SCCmec"), support de la résistance à la méticilline de "Staphylococcus aureus"

PARIS-BIUP (751062107) / SudocSudocFranceF