161 research outputs found

    Estimation of the risk of Salmonella shedding by finishing pigs using a logistic model obtained from a survey

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    An analytic epidemiological survey was carried out in 105 French farms to identify factors associated with Salmonella shedding by finishing pigs. This study gave out a list of 7 risk factors using a logistic model. The aim of the present survey was to validate this model on a second sample of batches of pigs in order to estimate their Salmonella status. The validation study was carried out from April 2003 to August 2005 on 64 finishing pig batches distinct from those used originally to generate the logistic model. In each farm, Salmonella shedding of a batch of pigs at the end of the finishing phase was assessed using swabs as described in the analytical study. Questionnaires were filled in with the farmer to collect data related to management routines. Blood samples from10 growing and 10 finishing pigs were taken to assess sanitary risk factors: status vs Lawsonia intracellularis and Porcine Respiratory Coronavirus. Salmonella contamination status of a finishing room before loading, a further identified risk factor, was tested by environmental swabbing procedure. The estimated risk with the standard error, of Salmonella shedding was calculated using the logistic model and compared to the bacteriological Salmonella status of each batch. Several thresholds are proposed and sensitivity, specificity, positive and negative predictive values related to each cut-off value were calculated. A cut-off value of 0.34 maximised both sensitivity (76.9%) and specificity (68.6%) of the model. Whatever the threshold, the accuracy of the Salmonella non-shedding predicted status is better than the Salmonella shedding predicted status. In a bacteriological sampling programme, this model could be a useful tool to identify batches with low risk of Salmonella shedding and to focus attention on those getting a high probability for being positive

    Oxaliplatin use in pressurized intraperitoneal aerosol chemotherapy (PIPAC) is safe and effective: A multicenter study.

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    Pressurized intraperitoneal aerosol chemotherapy (PIPAC) is a new drug delivery method used in patients with peritoneal cancer (PC) of primary or secondary origin. Intraperitoneal use of oxaliplatin raises concerns about toxicity, especially abdominal pain. The objective of this study was to assess the tolerance of PIPAC with oxaliplatin (PIPAC-Ox) in a large cohort of patients and to identify the risk factors for high grade toxicity, discontinuation of treatment and impaired survival. This retrospective cohort study included all consecutive patients treated with PIPAC-Ox (92 mg/m <sup>2</sup> ) in five centers specialized in the treatment of PC. The procedure was repeated every 6 weeks. Outcomes of interest were Common Terminology Criteria for Adverse Events (CTCAE), symptoms and survival (Kaplan-Meier). Univariate risk factors were included in a multinominal regression model to control for bias. Overall, 251 PIPAC-Ox treatments were performed in 101 patients (45 female) having unresectable PC of various origins: 66 colorectal, 15 gastric, 5 ovarian, 3 mesothelioma, 2 pseudomyxoma, 10 other malignancies (biliary, pancreatic, endocrine) respectively. The median PCI was 19 (IQR: 10-28). Postoperative abdominal pain was present in 23 patients. Out of the 9 patients with grade 3 abdominal pain, only 3 needed a change of PIPAC drug. CTCAE 4.0 toxicity grade 4 or higher was encountered in 16(15.9%) patients. The patients had a mean of 2.5 procedures/patient (SD = 1.5). 50 subjects presented with symptom improvement. Oxaliplatin-based PIPAC appears to be a safe treatment that offers good symptom control and promising survival for patients with advanced peritoneal disease

    Physical extraction and fast protein liquid chromatography for purifying flagella filament from uropathogenic Escherichia coli for immune assay

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    Flagella are expressed on the surface of a wide range of bacteria, conferring motility and contributing to virulence and innate immune stimulation. Host-pathogen interaction studies of the roles of flagella in infection, including due to uropathogenic Escherichia coli (UPEC), have used various methods to purify and examine the biology of the major flagella subunit protein, FliC. These studies have offered insight into the ways in which flagella proteins interact with host cells. However, previous methods used to extract and purify FliC, such as mechanical shearing, ultracentrifugation, heterologous expression in laboratory E. coli strains, and precipitation-inducing chemical treatments have various limitations; as a result, there are few observations based on highly purified, non-denatured FliC in the literature. This is especially relevant to host-pathogen interaction studies such as immune assays that are designed to parallel, as closely as possible, naturally-occurring interactions between host cells and flagella. In this study, we sought to establish a new, carefully optimized method to extract and purify non-denatured, native FliC from the reference UPEC strain CFT073 to be suitable for immune assays. To achieve purification of FliC to homogeneity, we used a mutant CFT073 strain containing deletions in four major chaperone-usher fimbriae operons (type 1, F1C and two P fimbrial gene clusters; CFT073Δ4). A sequential flagella extraction method based on mechanical shearing, ultracentrifugation, size exclusion chromatography, protein concentration and endotoxin removal was applied to CFT073Δ4. Protein purity and integrity was assessed using SDS-PAGE, Western blots with anti-flagellin antisera, and native-PAGE. We also generated a fliC-deficient strain, CFT073Δ4ΔfliC, to enable the concurrent preparation of a suitable carrier control to be applied in downstream assays. Innate immune stimulation was examined by exposing J774A.1 macrophages to 0.05-1 μg of purified FliC for 5 h; the supernatants were analyzed for cytokines known to be induced by flagella, including TNF-α, IL-6, and IL-12; the results were assessed in the context of prior literature. Macrophage responses to purified FliC encompassed significant levels of several cytokines consistent with prior literature reports. The purification method described here establishes a new approach to examine highly purified FliC in the context of host-pathogen interaction model systems

    Study of Salmonella contamination of pig slurry in France

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    A study was carried out from April 2003 to August 2005 In 69 French pig farms to detect Salmonella contaminated pig batches and to assess the level of contamination of their slurry. In each herd, a batch of finishing pigs was included in the survey. In the selected room, Salmonella shedding was assessed using swabs method, pools of faecal material and 4 litres of slurry stored in the pit below the pigs. All samples were analysed for the presence of Salmonella enlerica in a classical bacteriological four-step protocol. Quantification of Salmonella was performed in pools of faecal material and slurry samples according to the most probable number method. Using the swabbing procedure, 20.3% of the batches tested Salmonella positive at the end of the finish1ng phase and 11 .6 % according to the pools of faeces (8/69). Quantification of Salmonella 1n faeces could be performed 1n 6 out of 8 pos1tive batches with levels ranging from 2.4 to 350 Salmonella/gram. The slurry of 11 .8% of the batches (8/68) was found to be Salmonella contaminated. A quantification was achieved in 3 of them Levels of less than 11 0 Salmonellalml were found. The study Indicates that pig slurry may be contammated by Salmonella enterica. However, the percentage of pos1tive samples was rather low and Salmonella could only be detected 1n slurry stored 1n the pit under the slatted floor of moderately or highly shedding batches. Since storage without introduction of new fresh slurry is known to reduce Salmonella surv1val, the probability of spreading the bactena in the environment IS expected to be low as far as adequate storage conditions are applied

    Association between a high number of isolated lymph nodes in T1 to T4 N0M0 colorectal cancer and the microsatellite instability phenotype

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    Hypothèse : Les carcinomes colorectaux de stade I ou II microsatellites instables (MSI) sont caractérisés par plus de ganglions lymphatiques isolés sur la pièce de résection par rapport à leurs homologues microsatellites stables (MSS). Conception : Étude prospective. Patients : Le statut MSI a été déterminé de façon prospective chez 135 patients opérables, par l’utilisation d’une PCR pentaplex. Puis, les défauts de réparation des mésappariements de l’ADN ont été étudiés par immunohistochimie. Résultats : Parmi les 82 cancers colorectaux de stade I ou II, 11 étaient MSI et 71 MSS, avec une moyenne (écart-type) de 23,6 (3,1) et 13,7 (1,0) ganglions négatifs, respectivement (p = .001). Le nombre moyen de ganglions pour tous les cancers colorectaux de stade I ou II analysés dans notre hôpital était de 15. La prévalence des MSI dans les tumeurs avec plus de 15 ganglions prélevés était de 25 % (9 sur 36) et 82 % (9 sur 11) des tumeurs MSI appartenaient à ce groupe. Conclusions : Un nombre élevé de ganglions isolés en cas de cancer colorectal de stade I ou II est associé au phénotype MSI. Le bon pronostic qui est habituellement associé à des tumeurs ayant un nombre élevé de ganglions N0 pourrait refléter la prévalence élevée des MSI chez ces tumeurs. Le nombre de ganglions examinés comme un critère de qualité doit être utilisé avec prudence. Limiter le phénotypage MSI aux tumeurs colorectales de stade I ou II ayant plus que le nombre moyen de ganglions identifie presque toutes les tumeurs MSI.Hypothèse : Les carcinomes colorectaux de stade I ou II microsatellites instables (MSI) sont caractérisés par plus de ganglions lymphatiques isolés sur la pièce de résection par rapport à leurs homologues microsatellites stables (MSS). Conception : Étude prospective. Patients : Le statut MSI a été déterminé de façon prospective chez 135 patients opérables, par l’utilisation d’une PCR pentaplex. Puis, les défauts de réparation des mésappariements de l’ADN ont été étudiés par immunohistochimie. Résultats : Parmi les 82 cancers colorectaux de stade I ou II, 11 étaient MSI et 71 MSS, avec une moyenne (écart-type) de 23,6 (3,1) et 13,7 (1,0) ganglions négatifs, respectivement (p = .001). Le nombre moyen de ganglions pour tous les cancers colorectaux de stade I ou II analysés dans notre hôpital était de 15. La prévalence des MSI dans les tumeurs avec plus de 15 ganglions prélevés était de 25 % (9 sur 36) et 82 % (9 sur 11) des tumeurs MSI appartenaient à ce groupe. Conclusions : Un nombre élevé de ganglions isolés en cas de cancer colorectal de stade I ou II est associé au phénotype MSI. Le bon pronostic qui est habituellement associé à des tumeurs ayant un nombre élevé de ganglions N0 pourrait refléter la prévalence élevée des MSI chez ces tumeurs. Le nombre de ganglions examinés comme un critère de qualité doit être utilisé avec prudence. Limiter le phénotypage MSI aux tumeurs colorectales de stade I ou II ayant plus que le nombre moyen de ganglions identifie presque toutes les tumeurs MSI

    M19 Modulates Skeletal Muscle Differentiation and Insulin Secretion in Pancreatic β-Cells through Modulation of Respiratory Chain Activity

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    Mitochondrial dysfunction due to nuclear or mitochondrial DNA alterations contributes to multiple diseases such as metabolic myopathies, neurodegenerative disorders, diabetes and cancer. Nevertheless, to date, only half of the estimated 1,500 mitochondrial proteins has been identified, and the function of most of these proteins remains to be determined. Here, we characterize the function of M19, a novel mitochondrial nucleoid protein, in muscle and pancreatic β-cells. We have identified a 13-long amino acid sequence located at the N-terminus of M19 that targets the protein to mitochondria. Furthermore, using RNA interference and over-expression strategies, we demonstrate that M19 modulates mitochondrial oxygen consumption and ATP production, and could therefore regulate the respiratory chain activity. In an effort to determine whether M19 could play a role in the regulation of various cell activities, we show that this nucleoid protein, probably through its modulation of mitochondrial ATP production, acts on late muscle differentiation in myogenic C2C12 cells, and plays a permissive role on insulin secretion under basal glucose conditions in INS-1 pancreatic β-cells. Our results are therefore establishing a functional link between a mitochondrial nucleoid protein and the modulation of respiratory chain activities leading to the regulation of major cellular processes such as myogenesis and insulin secretion

    Plasticity of maritime pine (Pinus pinaster) wood-forming tissues during a growing season

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    Research• The seasonal effect is the most significant external source of variation affecting vascular cambial activity and the development of newly divided cells, and hence wood properties. Here, the effect of edapho-climatic conditions on the phenotypic and molecular plasticity of differentiating secondary xylem during a growing season was investigated. • Wood-forming tissues of maritime pine (Pinus pinaster) were collected from the beginning to the end of the growing season in 2003. Data from examination of fibre morphology, Fourier-transform infrared spectroscopy (FTIR), analytical pyrolysis, and gas chromatography/mass spectrometry (GC/MS) were combined to characterize the samples. Strong variation was observed in response to changes in edapho-climatic conditions. • A genomic approach was used to identify genes differentially expressed during this growing season. Out of 3512 studied genes, 19% showed a significant seasonal effect. These genes were clustered into five distinct groups, the largest two representing genes over-expressed in the early- or late-wood-forming tissues, respectively. The other three clusters were characterized by responses to specific edapho-climatic conditions. • This work provides new insights into the plasticity of the molecular machinery involved in wood formation, and reveals candidate genes potentially responsible for the phenotypic differences found between early- and late-wood
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