AsaGEI2b: a new variant of a genomic island identified in the Aeromonas salmonicida subsp. salmonicida JF3224 strain isolated from a wild fish in Switzerland

Aeromonas salmonicida subsp. salmonicida is the causal agent of furunculosis in salmonids. We recently identified a group of genomic islands (AsaGEI) in this bacterium. AsaGEI2a, one of these genomic islands, has almost exclusively been identified in isolates from North America. To date, Aeromonas salmonicida subsp. salmonicida JF3224, a strain isolated from a wild brown trout (Salmo trutta) caught in Switzerland, was the only European isolate that appeared to bear AsaGEI2a. We analyzed the genome of JF3224 and showed that the genomic island in JF3224 is a new variant of AsaGEI, which we have called AsaGEI2b. While AsaGEI2b shares the same integrase gene and insertion site as AsaGEI2a, it is very different in terms of many other features. Additional genomic investigations combined with PCR genotyping revealed that JF3224 is sensitive to growth at 25°C, leading to insertion sequence-dependent rearrangement of the locus on the pAsa5 plasmid that encodes a type three secretion system, which is essential for the virulence of the bacterium. The analysis of the JF3224 genome confirmed that AsaGEIs are accurate indicators of the geographic origins of A. salmonicida subsp. salmonicida isolates and is another example of the susceptibility of the pAsa5 plasmid to DNA rearrangement

Psychosocial work factors and social inequalities in psychological distress: a population-based study.

BACKGROUND: Mental health problems (MHP) are the leading cause of disability worldwide. The inverse association between socioeconomic position (SEP) and MHP has been well documented. There is prospective evidence that factors from the work environment, including adverse psychosocial work factors, could contribute to the development of MHP including psychological distress. However, the contribution of psychosocial work factors to social inequalities in MHP remains unclear. This study evaluates the contribution of psychosocial work factors from two highly supported models, the Demand-Control-Support (DCS) and the Effort-Reward Imbalance (ERI) models to SEP inequalities of psychological distress in men and women from a population-based sample of Quebec workers. METHODS: Data were collected during a survey on working conditions, health and safety at work. SEP was evaluated using education, occupation and household income. Psychosocial work factors and psychological distress were assessed using validated instruments. Mean differences (MD) in the score of psychological distress were estimated separately for men and women. RESULTS: Low education level and low household income were associated with psychological distress among men (MD, 0.56 (95% CI 0.06; 1.05) and 1.26 (95% CI 0.79; 1.73) respectively). In men, the contribution of psychosocial work factors from the DCS and the ERI models to the association between household income and psychological distress ranged from 9% to 24%. No clear inequalities were observed among women. CONCLUSIONS: These results suggest that psychosocial work factors from the DCS and the ERI models contribute to explain a part of social inequalities in psychological distress among men. Psychosocial factors at work are frequent and modifiable. The present study supports the relevance of targeting these factors for the primary prevention of MHP and for health policies aiming to reduce social inequalities in mental health

The Learner-Centred Status of a Brazilian University Coach Education Program

Previous research has suggested a shift from instructor-centred to learner-centred approaches in an attempt to improve coach education programs. To implement such crucial change it is essential to master the 'new language' and better understand educational contexts. The purposes of this article are to ( a) highlight new social factors indicating an urgent need to change, (b) present a learner-centred framework based on the work of a recognized group of researchers (i.e., Blumberg, Cullen, Harris, and Weimer), and (c) analyse the learner-centeredness of a Bachelor in Physical Education program, especially with respect to its sport performance area. Based on the social factors explored throughout the text and the learner centred principles, results showed inconsistencies between the conceptual orientations mentioned in the 'official documents' and the teaching processes used in the Bachelor program. Recommendations for higher education leaders and instructors are explored

Risk maps for range expansion of the Lyme disease vector, Ixodes scapularis, in Canada now and with climate change

<p>Abstract</p> <p>Background</p> <p>Lyme disease is the commonest vector-borne zoonosis in the temperate world, and an emerging infectious disease in Canada due to expansion of the geographic range of the tick vector <it>Ixodes scapularis</it>. Studies suggest that climate change will accelerate Lyme disease emergence by enhancing climatic suitability for <it>I. scapularis</it>. Risk maps will help to meet the public health challenge of Lyme disease by allowing targeting of surveillance and intervention activities.</p> <p>Results</p> <p>A risk map for possible Lyme endemicity was created using a simple risk algorithm for occurrence of <it>I. scapularis </it>populations. The algorithm was calculated for each census sub-division in central and eastern Canada from interpolated output of a temperature-driven simulation model of <it>I. scapularis </it>populations and an index of tick immigration. The latter was calculated from estimates of tick dispersion distances by migratory birds and recent knowledge of the current geographic range of endemic <it>I. scapularis </it>populations. The index of tick immigration closely predicted passive surveillance data on <it>I. scapularis </it>occurrence, and the risk algorithm was a significant predictor of the occurrence of <it>I. scapularis </it>populations in a prospective field study. Risk maps for <it>I. scapularis </it>occurrence in Canada under future projected climate (in the 2020s, 2050s and 2080s) were produced using temperature output from the Canadian Coupled Global Climate Model 2 with greenhouse gas emission scenario enforcing '<it>A2</it>' of the Intergovernmental Panel on Climate Change.</p> <p>Conclusion</p> <p>We have prepared risk maps for the occurrence of <it>I. scapularis </it>in eastern and central Canada under current and future projected climate. Validation of the risk maps provides some confidence that they provide a useful first step in predicting the occurrence of <it>I. scapularis </it>populations, and directing public health objectives in minimizing risk from Lyme disease. Further field studies are needed, however, to continue validation and refinement of the risk maps.</p

Inflammatory Myofibroblastic Tumor of the Right Atrium

Cardiac inflammatory myofibroblastic tumor (IMT) is a rare entity and is associated with distinct clinical, pathological and molecular features. The clinical behavior, natural history, biological potential, management and prognosis of such tumors are unclear. We present herewith an adolescent girl who presented with similar entity involving the junction of the right atrium and the inferior vena cava (IVC) in association with thrombocytosis and IVC thrombosis leading to obstruction of blood flow. Diagnostic tools included imaging and immuno-histopathology studies. Surgical management included resection of the tumor and thrombo-embolectomy of the IVC under cardiopulmonary bypass. This case is unique due to association of complete obstruction of IVC caused by the strategic location of the tumor, thrombosis of vena cava and association of thrombocytosis. These features have not been reported yet in relation to the cardiac IMT. This report will help in better understanding and management of similar cases in terms of planning cannulation of femoral veins or application of total hypothermic circulatory arrest during cardiopulmonary bypass and prompt us to look for recurrence or metastasis during follow up using echocardiography and laboratory investigations. The possibility of IMT should be kept in the differential diagnosis of cardiac tumors especially in children and adolescents

Variants of a genomic island in Aeromonas salmonicida subsp. salmonicida link isolates with their geographical origins

Aeromonas salmonicida subsp. salmonicida is a fish pathogen. Analysis of its genomic characteristics is required to determine the worldwide distribution of the various populations of this bacterium. Genomic alignments between the 01-B526 pathogenic strain and the A449 reference strain have revealed a 51-kb chromosomal insertion in 01-B526. This insertion (AsaGEI1a) has been identified as a new genomic island (GEI) bearing prophage genes. PCR assays were used to detect this GEI in a collection of 139 A. salmonicida subsp. salmonicida isolates. Three forms of this GEI (AsaGEI1a, AsaGEI1b, AsaGEI2a) are now known based on this analysis and the sequencing of the genomes of seven additional isolates. A new prophage (prophage 3) associated with AsaGEI2a was also discovered. Each GEI appeared to be strongly associated with a specific geographic region. AsaGEI1a and AsaGEI2a were exclusively found in North American isolates, except for one European isolate bearing AsaGEI2a. The majority of the isolates bearing AsaGEI1b or no GEI were from Europe. Prophage 3 has also a particular geographic distribution and was found only in North American isolates. We demonstrated that A. salmonicida subsp. salmonicida possesses unsuspected elements of genomic heterogeneity that could be used as indicators to determine the geographic origins of isolates of this bacterium.Keywords : Bacteria, Genomics-functional genomics-comparative genomics; Furunculosis; Aeromonas salmonicida; Fish pathogen; Genomic island; Geographical distributio

Nelfinavir, an HIV-1 Protease Inhibitor, Induces Oxidative Stress–Mediated, Caspase-Independent Apoptosis in Leishmania Amastigotes

Visceral leishmaniasis is the most severe form of disease caused by the parasite Leishmania. It is a major concern in South America, Africa, India and the Middle East. Additionally, it has now emerged as an important opportunistic disease in patients coinfected with HIV-1. This is due, in part, to the increasing overlap between urban centers and rural areas endemic for Leishmania. Although more efficient combinatorial antiviral drug regimens for treating HIV-1 infection have been developed, the impact of such therapies on HIV-1/Leishmania coinfection is yet to be explored. In this study, we investigated the effect of nelfinavir, a well-characterized anti-HIV-1 drug, on Leishmania. Treating the parasite with nelfinavir activates events that are hallmarks of programmed cell death (also called apoptosis). Among these are oxidative stress, changes in DNA replication and fragmentation, and release of mitochondrial enzymes. Furthermore, these events occur without the participation of caspases, which are classically linked to apoptosis; however, this atypical apoptosis requires the translocation of endonuclease G from mitochondria to the cytoplasm. These findings provide insights for the design of new anti-parasitic therapies, particularly in the case of Leishmania/HIV-1 coinfections

Permanently compromised NADPH-diaphorase activity within the osmotically activated supraoptic nucleus after in utero but not adult exposure to Aroclor 1254

Stimulated vasopressin (VP) release from magnocellular neuroendocrine cells in the supraoptic nucleus (SON) of hyperosmotic rats is inhibited by treatment with the industrial polychlorinated biphenyl (PCB) mixture, Aroclor 1254. Because VP responses to hyperosmotic stimulation are regulated by nitric oxide (NO) signaling, we studied NO synthase (NOS) activity in the SON of hyperosmotic rats as potential target of PCB-induced disruption of neuroendocrine processes necessary for osmoregulation. To examine PCB-induced changes in NOS activity under normosmotic and hyperosmotic conditions, male Sprague-Dawley rats were exposed to Aroclor 1254 (30mg/kg/day) in utero and NADPH-diaphorase (NADPH-d) activity was assessed in SON sections at three ages: postnatal day 10, early adult (3-5 months) or late adult (14-16 months). Hyperosmotic treatment increased mean NADPH-d staining density of oil hyperosmotic controls by 19.9% in early adults and 58% in late adulthood vs normosmotic controls. In utero exposure to PCBs reduced hyperosmotic-induced upregulation of NADPH-d activity to control levels in early adults and by 28% in late adults. Basal NADPH-d was reduced in postnatal rats. Rats receiving PCB exposure as early adults orally for 14 days displayed normal responses. Our findings show that developmental but not adult exposure to PCBs significantly reduces NOS responses to hyperosmolality in neuroendocrine cells. Moreover, reduced NADPH-d activity produced by in utero exposure persisted in stimulated late adult rats concomitant with reduced osmoregulatory capacity vs oil controls (375±9 vs 349±5mOsm/L). These findings suggest that developmental PCBs permanently compromise NOS signaling in the activated neuroendocrine hypothalamus with potential osmoregulatory consequences

Étude sur le contrôle de la croissance des cellules transformées: effets des glycolipides extraits des mutants R de Salmonella Minnesota

Les glycolipides bactériens, surtout les endotoxines des grams négatifs, sont des substances antitumorales reconnues depuis longtemps. Le présent travail porte sur l'étude de l'action des glycolipides extraits des mutants R de "Salmonella minnesota sur la croissance "in vitro" des fibroblastes d'embryons de rat, normaux (ER), spontanément transformés (RT) et transformés par le virus SV40 (RSV40). Les différents glycolipides n'ont aucun effet sur la croissance des cellules normales (ER). Par contre, la croissance des cellules transformées (RT, RSV40) est inhibée par ces agents antitumoraux. L'inhibition varie selon la structure moléculaire du glycolipide. Ainsi, une augmentation dans la longueur de la chaine saccharidique amène une diminution de l'inhibition. Les glycolipides bactériens, aux concentrations utilisées, ne sont pas cytotoxiques. Nous avons démontré par immunofluorescence qu'ils se fixent à la membrane cytoplasmique des cellules transformées. Les cellules transformées montrent une forte fluorescence membranaire, tandis que les cellules normales sont négatives. Cette différence dans la composition de la surface membranaire entre les cellules normales et transformées est aussi mise en évidence lors de i'agglutination des cellules transformées par la Concanavaline A. Etant donné que les endotoxines sont reconnues pour induire la formation de l'interféron et que de fortes concentration d'interféron inhibent la croissance des cellules transformées, nous avons voulu vérifier si les glycolipides, aux concentrations utilisées, induisaient la formation d'interféron. La vérification de ce fait nous a permis d'exclure l'induction de l'interféron comme mécanisme d'action. Nous avons donc cherché à déterminer quelle phase du cycle cellulaire était modifiée par les glycolipides bactériens. Au cours de ce travail, nous avons mis au point une nouvelle méthode, simple et rapide, pour l'analyse du cycle cellulaire. Cette technique est basée sur l'utilisation de cultures synchrones préparées par blocage spécifique à la thymidine. En suivant graphiquement la cinétique d'incorporation de thymidine tritiée et l'index mitotique une fois le deuxième bloc levé, il est possible d'établir graphiquement le cycle cellulaire. Les résultats obtenus par cette méthode sont comparables avec les résultats obtenus par la méthode du "pulse chase". Ceci a permis de démontrer que les glycolipides modifiaient la phase Sen l'allongeant. Le cycle des cellules normales n'est pas affecté. De plus, l'analyse du nomb're de cellules en phase S dans une population asynchrone nous a permis de montrer que le nombre de cellules en phase S est significativement plus élevé chez les cellules traitées par le glycolipide mR595. Pensant que l'adénosine 3',5' monophosphate cyclique (cAmp) pourrait avoir un rôle à jouer dans la modification de la phase S étant donné que les glycolipides se fixent en surface des cellules transformées et augmentent le niveau de cAmp qui est le messager des signaux reçus à la membrane cellulaire, nous avons étudié l'effet du N6-o2-dibutyryl cAmp (But 2cAmp) sur la croissance des cellules normales et transformées. Le But 2cAmp inhibe les cellules transformées tout comme le glycolipide mR595. Toutefois, la croissance des cellules normales est aussi affectée jusqu'à l'obtention de la confluence cellulaire. Ceci nous permet de supposer qu'une augmentation de nucléotide cyclique causée par le glycolipide pourrait être responsable de l'inhibition des cellules transformées. Puisque les glycolipides bactériens agissent sur la phase S, nous avons vérifié l'incorporation et le trans-port de thymidine et de leucine tritiées par les cellules synchrones normales et transformées durant cette phase. Les résultats indiquent que les deux précurseurs sont incorporés moins rapidement dans la fraction acido-insoluble et qu'ils pénitrent plus lentement chez les cellules transformées traitées par le glycolipide mR595. Les cellules normales ne sont pas affectées. Le mode d'action du But 2 cAmp sur l'incorporation et le transport diffire du mode d'action des glycolipides. En plus d'inhiber l'incorporation et le transport chez les cellules transformées, le But 2 cAmp inhibe l'incorporation et le transport chez les cellules normales