A thousand total colonoscopies: what is the relationship between distal and proximal findings?

BACKGROUND: Flexible sigmoidoscopy is indicated for colorectal cancer screening. The decision about who needs total colonoscopy based on distal findings is still controversial because of the uncertainty of the associations between distal and proximal findings. AIM: The purpose of the study was to characterize distal findings in patients with total colonoscopy, to investigate its importance as markers of advanced proximal lesions and to evaluate the usefulness of a clinical Predictive Index, already published in the literature, in the identification of these lesions. METHODS: Retrospective analysis of the patients submitted to total colonoscopy between January 2006 and February 2007, with selection of 1000 consecutive cases with reference to polyps. We analysed demographic data, indication for the exam and morphological and histological characteristics of the polyps. Advanced lesion was defined as any adenoma larger than 10 mm or any polyp with villous characteristics, high grade dysplasia or cancer. The Predictive Index was obtained through the assignment of points to 3 categories: sex, age and distal findings, which result in 3 groups: low, intermediate and high risk. RESULTS: The mean age of patients was 64,69 years and 65,1% were male. Distal and proximal polyps were identified in 829 (82,9%) and 369 (36,9%) patients, respectively. Advanced distal lesion was found in 342 patients (34,2%) and advanced proximal lesion in 98 (9,8%). 587 patients (58,7%) were in the high risk group. In the group of patients with advanced proximal lesion, a third presented low and intermediate risk, 52% had no distal polyps, 88,7% had less than three distal polyps and 71,4% had no advanced distal lesion. Sensitivity values for these four categories ranged between 11,2% and 66,6%. CONCLUSION: If the decision to perform total colonoscopy is based on distal colonic findings or on the Predictive Index, the ability to identify advanced proximal lesion is markedly reduced, endangering the aim of a screening program

How the co-benefits of addressing climate change can motivate action across the world

It is traditionally thought that the public must be convinced of the reality and importance of anthropogenic climate change in order to take personal and political action. However, convincing the broad public involves overcoming powerful ideological obstacles1-4, and in many places climate change is slipping in public importance5,6. Here we examined whether beliefs about the “co-benefits” of mitigating climate change7 can avoid these obstacles by motivating behavior in both those who accept climate change and those who are unconvinced or unconcerned. We describe an integrative framework for assessing co-benefits8, distinguishing sociological dimensions (e.g., pollution, disease, economic development), and community character (e.g., benevolence, competence). Data from all inhabited continents (24 countries; N=6059), showed that two types of co-benefits, Development (economic and scientific advancement) and Benevolence (a more moral and caring community), rivalled climate change importance in the strength of their relationships with motivations to act. These co-benefits showed effects independent of climate change importance beliefs, and showed similar effects for both climate change believers and skeptics. Communicating these co-benefits of addressing climate change can help motivate action on climate change where traditional approaches have stalled

Acute hepatitis C virus infection assessment among chronic hemodialysis patients in the Southwest Parana State, Brazil

BACKGROUND: Chronic hemodialysis patients are at higher risk for acquiring hepatitis C virus (HCV). The prevalence varies among different countries and hemodialysis centers. Although guidelines for a comprehensive infection control program exist, the nosocomial transmission still accounts for the new cases of infection. The aim of this study was analyze the follow up of newly acquired acute hepatitis C cases, during the period from January 2002 to May 2005, in the Hemodialysis Center, located in the Southwest region of Parana State, Brazil and to analyze the effectiveness of the measures to restrain the appearance of new cases of acute hepatitis C. METHODS: Patients were analyzed monthly with anti-HCV tests and ALT measurements. Patients with ALT elevations were monitored for possible acute hepatitis C. RESULTS: During this period, 32 new cases were identified with acute hepatitis C virus infection. Blood screening showed variable ALT levels preceding the anti-HCV seroconversion. HCV RNA viremia by PCR analysis was intermittently and even negative in some cases. Ten out of 32 patients received 1 mcg/kg dose of pegylated interferon alfa-2b treatment for 24 weeks. All dialysis personnel were re-trained to strictly follow the regulations and recommendations regarding infection control, proper methods to clean and disinfect equipment were reviewed and HCV-positive patients were isolated. CONCLUSION: Laboratory tests results showed variable ALT preceding anti-HCV seroconversion and intermittent viremia. The applied recommendations contributed importantly to restrain the appearance of new cases of acute hepatitis C in this center and the last case was diagnosed in May 2004

Identification of Coevolving Residues and Coevolution Potentials Emphasizing Structure, Bond Formation and Catalytic Coordination in Protein Evolution

The structure and function of a protein is dependent on coordinated interactions between its residues. The selective pressures associated with a mutation at one site should therefore depend on the amino acid identity of interacting sites. Mutual information has previously been applied to multiple sequence alignments as a means of detecting coevolutionary interactions. Here, we introduce a refinement of the mutual information method that: 1) removes a significant, non-coevolutionary bias and 2) accounts for heteroscedasticity. Using a large, non-overlapping database of protein alignments, we demonstrate that predicted coevolving residue-pairs tend to lie in close physical proximity. We introduce coevolution potentials as a novel measure of the propensity for the 20 amino acids to pair amongst predicted coevolutionary interactions. Ionic, hydrogen, and disulfide bond-forming pairs exhibited the highest potentials. Finally, we demonstrate that pairs of catalytic residues have a significantly increased likelihood to be identified as coevolving. These correlations to distinct protein features verify the accuracy of our algorithm and are consistent with a model of coevolution in which selective pressures towards preserving residue interactions act to shape the mutational landscape of a protein by restricting the set of admissible neutral mutations

Search for new phenomena in final states with an energetic jet and large missing transverse momentum in pp collisions at √ s = 8 TeV with the ATLAS detector

Results of a search for new phenomena in final states with an energetic jet and large missing transverse momentum are reported. The search uses 20.3 fb−1 of √ s = 8 TeV data collected in 2012 with the ATLAS detector at the LHC. Events are required to have at least one jet with pT > 120 GeV and no leptons. Nine signal regions are considered with increasing missing transverse momentum requirements between Emiss T > 150 GeV and Emiss T > 700 GeV. Good agreement is observed between the number of events in data and Standard Model expectations. The results are translated into exclusion limits on models with either large extra spatial dimensions, pair production of weakly interacting dark matter candidates, or production of very light gravitinos in a gauge-mediated supersymmetric model. In addition, limits on the production of an invisibly decaying Higgs-like boson leading to similar topologies in the final state are presente

Transmission of Aerosolized Seasonal H1N1 Influenza A to Ferrets

Influenza virus is a major cause of morbidity and mortality worldwide, yet little quantitative understanding of transmission is available to guide evidence-based public health practice. Recent studies of influenza non-contact transmission between ferrets and guinea pigs have provided insights into the relative transmission efficiencies of pandemic and seasonal strains, but the infecting dose and subsequent contagion has not been quantified for most strains. In order to measure the aerosol infectious dose for 50% (aID50) of seronegative ferrets, seasonal influenza virus was nebulized into an exposure chamber with controlled airflow limiting inhalation to airborne particles less than 5 µm diameter. Airborne virus was collected by liquid impinger and Teflon filters during nebulization of varying doses of aerosolized virus. Since culturable virus was accurately captured on filters only up to 20 minutes, airborne viral RNA collected during 1-hour exposures was quantified by two assays, a high-throughput RT-PCR/mass spectrometry assay detecting 6 genome segments (Ibis T5000™ Biosensor system) and a standard real time RT-qPCR assay. Using the more sensitive T5000 assay, the aID50 for A/New Caledonia/20/99 (H1N1) was approximately 4 infectious virus particles under the exposure conditions used. Although seroconversion and sustained levels of viral RNA in upper airway secretions suggested established mucosal infection, viral cultures were almost always negative. Thus after inhalation, this seasonal H1N1 virus may replicate less efficiently than H3N2 virus after mucosal deposition and exhibit less contagion after aerosol exposure

Structural and Functional Roles of Coevolved Sites in Proteins

Understanding the residue covariations between multiple positions in protein families is very crucial and can be helpful for designing protein engineering experiments. These simultaneous changes or residue coevolution allow protein to maintain its overall structural-functional integrity while enabling it to acquire specific functional modifications. Despite the significant efforts in the field there is still controversy in terms of the preferable locations of coevolved residues on different regions of protein molecules, the strength of coevolutionary signal and role of coevolution in functional diversification.In this paper we study the scale and nature of residue coevolution in maintaining the overall functionality and structural integrity of proteins. We employed a large scale study to investigate the structural and functional aspects of coevolved residues. We found that the networks representing the coevolutionary residue connections within our dataset are in general of 'small-world' type as they have clustering coefficient values higher than random networks and also show smaller mean shortest path lengths similar and/or lower than random and regular networks. We also found that altogether 11% of functionally important sites are coevolved with any other sites. Active sites are found more frequently to coevolve with any other sites (15%) compared to protein (11%) and ligand (9%) binding sites. Metal binding and active sites are also found to be more frequently coevolved with other metal binding and active sites, respectively. Analysis of the coupling between coevolutionary processes and the spatial distribution of coevolved sites reveals that a high fraction of coevolved sites are located close to each other. Moreover, approximately 80% of charge compensatory substitutions within coevolved sites are found at very close spatial proximity (<or= 5A), pointing to the possible preservation of salt bridges in evolution.Our findings show that a noticeable fraction of functionally important sites undergo coevolution and also point towards compensatory substitutions as a probable coevolutionary mechanism within spatially proximal coevolved functional sites