Evaluation of VirB binding site contribution to the regulation of the icsP promoter in Shigella flexneri

Shigella species are gram-negative, rod-shaped bacteria that are closely related to Escherichia coli. Virulent Shigella spp. are intracellular pathogens that invade, replicate and spread through epithelial cells of the lower intestine and cause bacillary dysentery in humans. This disease is characterized by a robust inflammatory response that results in fever, abdominal pain, and bloody diarrhea (3). According to the CDC, approximately 14,000 cases are reported each year in the United States alone. This number however, does not reflect the actual incidence of this disease as many cases go unreported. The molecular pathogenesis of these bacteria lies in the large virulence plasmid (~230-kb) that is found in all virulent Shigella spp. Two key virulence determinants include the ability to invade colonic epithelia (mediated by the ipa-mxi-spa gene locus) and the ability to spread to adjacent cells, a process known as actin-based-motility (mediated and controlled by icsA and icsP respectively). These events are largely regulated by VirB, a transcription factor (2, 3). Canonically, transcription factors are known to bind sequences proximal to the transcriptional start site (within 200-bp). Recent work has focused on the regulation of icsP (encodes a protease of the outer membrane) by VirB and has shed light on a novel regulatory strategy, whereby VirB regulates the activation of icsP from sites located more than 1-kb upstream of the transcriptional start site (1). Nine putative VirB binding sites have been found upstream of the icsP gene. This work seeks to characterize the contribution made by these putative binding sites to the VirB-dependent regulation of icsP

Combination of VirB binding site mutations to evaluate collective impact on icsP promoter activity in Shigella flexneri

Shigella flexneri is a gram-negative, invasive bacterial pathogen that afflicts the human colonic epithelium, causing shigellosis, an illness triggering severe dysentery. The World Health Organization cites the disease burden of shigellosis near 90 million episodes and 108,000 deaths per year. The motility and spread of Shigella is modulated by icsP, a virulence gene. The transcription factor VirB positively regulates many virulence genes encoded by the Shigella virulence plasmid. Two distal binding sites of VirB have been shown to regulate the promoter activity of icsP, despite their location of more than 1 kb upstream of the transcription start site. Five VirB binding sites are located between these two sites and the transcription start site, and two are located in close proximity downstream of the transcription start site. Investigation into the impact of the VirB binding sites is part of a larger effort to understand the workings of VirB, which is the major switch that controls virulence gene expression in Shigella

Evaluating Katrina: A Snapshot of Renters’ Rights Following Disasters

Hurricane Katrina destroyed the homes of many people living in parts of the Gulf Region. The storm displaced as many as 800,000 victims and it is still difficult for them to return home. Consequently, many homeowners have turned to renting because of the slow recovery process. Renters face added difficulties; they are often the last in line for government benefits and other assistance. There is much hostility towards the rights of renters, creating even more difficulties for them. This article focuses on the difficulties facing evacuee renters in New Orleans following the disaster. These renters face such obstacles as scarcity of land, increases in costs for repairs, higher insurance, infrastructure uncertainty, rental property inflation, uncertainty over flood protection, zoning restrictions, and criminalization. This article discusses legislation and attempted legislation impacting renters post Katrina. The article explores the increase in rent after disasters and a suggested control. It further discusses the manner in which criminal backgrounds determine rental options following disasters. Specifically, the article focuses on legislation limiting access to rentals and suggests, with the right legislation in place, New Orleans will be able to successfully rebuild its lower and middle income housing

Workplace violence in a large correctional health servce in New South Wales, Australia: a retrospective review of incident management records

BackgroundLittle is known about workplace violence among correctional health professionals. This studyaimed to describe the patterns, severity and outcomes of incidents of workplace violenceamong employees of a large correctional health service, and to explore the help-seekingbehaviours of staff following an incident.MethodsThe study setting was Justice Health, a statutory health corporation established to providehealth care to people who come into contact with the criminal justice system in New SouthWales, Australia. We reviewed incident management records describing workplace violenceamong Justice Health staff. The three-year study period was 1/7/2007-30/6/2010.ResultsDuring the period under review, 208 incidents of workplace violence were recorded. Verbalabuse (71%) was more common than physical abuse (29%). The most (44%) incidents ofworkplace violence (including both verbal and physical abuse) occurred in adult maleprisons, although the most (50%) incidents of physical abuse occurred in a forensic hospital.Most (90%) of the victims were nurses and two-thirds were females. Younger employees andmales were most likely to be a victim of physical abuse. Preparing or dispensing medicationand attempting to calm and/or restrain an aggressive patient were identified as ‘high risk’work duties for verbal abuse and physical abuse, respectively. Most (93%) of the incidents ofworkplace violence were initiated by a prisoner/patient. Almost all of the incidents receivedeither a medium (46%) or low (52%) Severity Assessment Code. Few victims of workplaceviolence incurred a serious physical injury – there were no workplace deaths during the studyperiod. However, mental stress was common, especially among the victims of verbal abuse(85%). Few (6%) victims of verbal abuse sought help from a health professional.ConclusionsAmong employees of a large correctional health service, verbal abuse in the workplace wassubstantially more common than physical abuse. The most incidents of workplace violenceoccurred in adult male prisons. Review of the types of adverse health outcomes experiencedby the victims of workplace violence and the assessments of severity assigned to violentincidents suggests that, compared with health care settings in the community, correctionalsettings are fairly safe places in which to practice

A microarray study of MPP(+)-treated PC12 Cells: Mechanisms of toxicity (MOT) analysis using bioinformatics tools

BACKGROUND: This paper describes a microarray study including data quality control, data analysis and the analysis of the mechanism of toxicity (MOT) induced by 1-methyl-4-phenylpyridinium (MPP(+)) in a rat adrenal pheochromocytoma cell line (PC12 cells) using bioinformatics tools. MPP(+ )depletes dopamine content and elicits cell death in PC12 cells. However, the mechanism of MPP(+)-induced neurotoxicity is still unclear. RESULTS: In this study, Agilent rat oligo 22K microarrays were used to examine alterations in gene expression of PC12 cells after 500 μM MPP(+ )treatment. Relative gene expression of control and treated cells represented by spot intensities on the array chips was analyzed using bioinformatics tools. Raw data from each array were input into the NCTR ArrayTrack database, and normalized using a Lowess normalization method. Data quality was monitored in ArrayTrack. The means of the averaged log ratio of the paired samples were used to identify the fold changes of gene expression in PC12 cells after MPP(+ )treatment. Our data showed that 106 genes and ESTs (Expressed Sequence Tags) were changed 2-fold and above with MPP(+ )treatment; among these, 75 genes had gene symbols and 59 genes had known functions according to the Agilent gene Refguide and ArrayTrack-linked gene library. The mechanism of MPP(+)-induced toxicity in PC12 cells was analyzed based on their genes functions, biological process, pathways and previous published literatures. CONCLUSION: Multiple pathways were suggested to be involved in the mechanism of MPP(+)-induced toxicity, including oxidative stress, DNA and protein damage, cell cycling arrest, and apoptosis

Cadecol, a heavy equipement provided with a 190m3 shielded cell allowing destructive radioactive waste characterization and inventory operations

International audienc

Contrôle vertical et thérapeutique orthopédique

Le contrôle du développement vertical de la face est un élément capital du succès des thérapeutiques orthopédiques, tant par ses effets sur la dimension verticale antérieure que par son influence sur la correction du décalage sagittal des mâchoires. Ce contrôle est basé sur le respect de l'équilibre entre la face postérieure et la face antérieure, décrit par Schudy. Les auteurs rappellent les mécanismes d'action des thérapeutiques orthopédiques sur les différents éléments de cet équilibre, avant de présenter les modalités du contrôle vertical selon les appareils