Bacterial genotoxins induce T cell senescence

Several types of pathogenic bacteria produce genotoxins that induce DNA damage in host cells. Accumulating evidence suggests that a central function of these genotoxins is to dysregulate the host's immune response, but the underlying mechanisms remain unclear. To address this issue, we investigated the effects of the most widely expressed bacterial genotoxin, the cytolethal distending toxin (CDT), on T cells—the key mediators of adaptive immunity. We show that CDT induces premature senescence in activated CD4 T cells in vitro and provide evidence suggesting that infection with genotoxin-producing bacteria promotes T cell senescence in vivo. Moreover, we demonstrate that genotoxin-induced senescent CD4 T cells assume a senescence-associated secretory phenotype (SASP) which, at least partly, is orchestrated by the ATM-p38 signaling axis. These findings provide insight into the immunomodulatory properties of bacterial genotoxins and uncover a putative link between bacterial infections and T cell senescence

High variety of known and new RNA and DNA viruses of diverse origins in untreated sewage

Deep sequencing of untreated sewage provides an opportunity to monitor enteric infections in large populations and for high-throughput viral discovery. A metagenomics analysis of purified viral particles in untreated sewage from the United States (San Francisco, CA), Nigeria (Maiduguri), Thailand (Bangkok), and Nepal (Kathmandu) revealed sequences related to 29 eukaryotic viral families infecting vertebrates, invertebrates, and plants (BLASTx E score, <10(−4)), including known pathogens (>90% protein identities) in numerous viral families infecting humans (Adenoviridae, Astroviridae, Caliciviridae, Hepeviridae, Parvoviridae, Picornaviridae, Picobirnaviridae, and Reoviridae), plants (Alphaflexiviridae, Betaflexiviridae, Partitiviridae, Sobemovirus, Secoviridae, Tombusviridae, Tymoviridae, Virgaviridae), and insects (Dicistroviridae, Nodaviridae, and Parvoviridae). The full and partial genomes of a novel kobuvirus, salivirus, and sapovirus are described. A novel astrovirus (casa astrovirus) basal to those infecting mammals and birds, potentially representing a third astrovirus genus, was partially characterized. Potential new genera and families of viruses distantly related to members of the single-stranded RNA picorna-like virus superfamily were genetically characterized and named Picalivirus, Secalivirus, Hepelivirus, Nedicistrovirus, Cadicistrovirus, and Niflavirus. Phylogenetic analysis placed these highly divergent genomes near the root of the picorna-like virus superfamily, with possible vertebrate, plant, or arthropod hosts inferred from nucleotide composition analysis. Circular DNA genomes distantly related to the plant-infecting Geminiviridae family were named Baminivirus, Nimivirus, and Niminivirus. These results highlight the utility of analyzing sewage to monitor shedding of viral pathogens and the high viral diversity found in this common pollutant and provide genetic information to facilitate future studies of these newly characterized viruses

Global patient outcomes after elective surgery: prospective cohort study in 27 low-, middle- and high-income countries.

BACKGROUND: As global initiatives increase patient access to surgical treatments, there remains a need to understand the adverse effects of surgery and define appropriate levels of perioperative care. METHODS: We designed a prospective international 7-day cohort study of outcomes following elective adult inpatient surgery in 27 countries. The primary outcome was in-hospital complications. Secondary outcomes were death following a complication (failure to rescue) and death in hospital. Process measures were admission to critical care immediately after surgery or to treat a complication and duration of hospital stay. A single definition of critical care was used for all countries. RESULTS: A total of 474 hospitals in 19 high-, 7 middle- and 1 low-income country were included in the primary analysis. Data included 44 814 patients with a median hospital stay of 4 (range 2-7) days. A total of 7508 patients (16.8%) developed one or more postoperative complication and 207 died (0.5%). The overall mortality among patients who developed complications was 2.8%. Mortality following complications ranged from 2.4% for pulmonary embolism to 43.9% for cardiac arrest. A total of 4360 (9.7%) patients were admitted to a critical care unit as routine immediately after surgery, of whom 2198 (50.4%) developed a complication, with 105 (2.4%) deaths. A total of 1233 patients (16.4%) were admitted to a critical care unit to treat complications, with 119 (9.7%) deaths. Despite lower baseline risk, outcomes were similar in low- and middle-income compared with high-income countries. CONCLUSIONS: Poor patient outcomes are common after inpatient surgery. Global initiatives to increase access to surgical treatments should also address the need for safe perioperative care. STUDY REGISTRATION: ISRCTN5181700

Endoscopy

BACKGROUND: Esophagogastroduodenoscopy (EGD) is the standard method for diagnosis of esophageal and gastric varices in children. In this prospective study we evaluated the use of PillCam esophageal capsule endoscopy (ECE) in pediatric patients. METHODS: Patients aged 7 to 18 years presenting with portal hypertension and/or cirrhosis underwent ECE (PillCam ESO 2, Given Imaging Ltd.) followed by EGD. RESULTS: 102 patients were screened, 81 (52 boys; mean age 13.96 +/- 0.25 years) were included and 21 were excluded (16 for "candy test" failure). Esophageal varices were identified by EGD in 62 patients (77 %) and by ECE in 57 patients (70 %) using the de Franchis classification (DFC). The sensitivity of ECE for esophageal varices was 92 % and the specificity was 100 % using DFC. Based upon 57/81 patients with small, medium, and large varices on both ECE and EGD, using DFC, the sensitivity, specificity, positive (PPV) and negative predictive value (NPV) were 55 %, 92 %, 89 %, and 63 %, respectively, giving a total overall accuracy of 72 %. To improve sensitivity and specificity in classification of esophageal varices, we propose using a modified score. This score detected esophageal varices with 100 % sensitivity, 93 % specificity, 94 % PPV, and 100 % NPV, giving a total overall accuracy of 97 %. All patients preferred ECE over EGD. No capsule retention was recorded. CONCLUSIONS: ECE is a well-tolerated and safe procedure in children. Using the modified score, the sensitivity of ECE is currently sufficient to detect esophageal varices and replace EGD in infants with suspicion of esophageal varices or when EGD is refused

Bacterial genotoxins induce T cell senescence

Several types of pathogenic bacteria produce genotoxins that induce DNA damage in host cells. Accumulating evidence suggests that a central function of these genotoxins is to dysregulate the host's immune response, but the underlying mechanisms remain unclear. To address this issue, we investigated the effects of the most widely expressed bacterial genotoxin, the cytolethal distending toxin (CDT), on T cells—the key mediators of adaptive immunity. We show that CDT induces premature senescence in activated CD4 T cells in vitro and provide evidence suggesting that infection with genotoxin-producing bacteria promotes T cell senescence in vivo. Moreover, we demonstrate that genotoxin-induced senescent CD4 T cells assume a senescence-associated secretory phenotype (SASP) which, at least partly, is orchestrated by the ATM-p38 signaling axis. These findings provide insight into the immunomodulatory properties of bacterial genotoxins and uncover a putative link between bacterial infections and T cell senescence

Bacterial genotoxins induce T cell senescence

Several types of pathogenic bacteria produce genotoxins that induce DNA damage in host cells. Accumulating evidence suggests that a central function of these genotoxins is to dysregulate the host&apos;s immune response, but the underlying mechanisms remain unclear. To address this issue, we investigated the effects of the most widely expressed bacterial genotoxin, the cytolethal distending toxin (CDT), on T cells-the key mediators of adaptive immunity. We show that CDT induces premature senescence in activated CD4 T cells in vitro and provide evidence suggesting that infection with genotoxin-producing bacteria promotes T cell senescence in vivo. Moreover, we demonstrate that genotoxin-induced senescent CD4 T cells assume a senescence-associated secretory phenotype (SASP) which, at least partly, is orchestrated by the ATMp38 signaling axis. These findings provide insight into the immunomodulatory properties of bacterial genotoxins and uncover a putative link between bacterial infections and T cell senescence

Examining the potential of web-based multimedia to support complex fine motor skill learning: An empirical study

Research on the utilization of the Web for complex fine motor skill learning that involves whole body movements is still scarce. The aim of this study was to evaluate the impact of the introduction of a multimedia web-based learning environment, which was targeted at a rhythmic gymnastics routine consisting of eight fine motor skills, into an undergraduate course in a physical education department, as a complementary tool to campus-based instruction. The impact was evaluated in terms of: acquisition of knowledge regarding the routine skills by students, improvement of students' ability to execute the routine, and students' responses to the environment. The study followed a pretest/posttest experimental design and involved 76 students randomly split into two groups: The Multimedia Web-based Learning Group (MWLG) students (N = 38), who attended campus-based instruction on the routine and also used the environment in their own space and time, and the Traditional On-site Instruction Group (TOIG) students (N = 38), who only attended campus-based instruction. The research data were gathered through student questionnaires and ratings of students' performances. It was found that the use of the environment as a supplement to campus-based instruction increased the effectiveness of this instruction as regards the cognitive component of motor skill learning (i.e. acquisition of knowledge regarding the routine skills) and was well-accepted by the students, although it did not have any significant contribution to the physical component of motor skill learning (i.e. performance of the routine skills). These findings partially support the future wider adoption of multimedia web-based learning environments within physical education and other academic disciplines that involve complex fine motor skill learning. Relevant implications are discussed. © 2013 Springer Science+Business Media New York

Can learning of basketball be enhanced through a web-based multimedia course? An experimental study

This study's aim is the creation of a web-based multimedia course for Physical Education (PE) students' familiarization with the teaching of basketball, and the evaluation of its use as a complementary tool to conventional instruction, in terms of learning effectiveness and student acceptance. The course includes multimedia learning material as well as interactive learning activities and quizzes on the cognitive components of basic basketball skills and on other basketball-related topics (history of the sport, referee's signals, training aids, basketball court). The study involved 88 undergraduate students during one semester. They were randomly assigned to two groups: a group that used the web-based multimedia course and also attended a conventional face-to-face course on the teaching of basketball (N = 45), and another group that only attended the conventional face-to-face course (N = 43). A pretest/posttest research design was followed. For both groups basketball knowledge was measured at the beginning and at the end of the semester through written questionnaires. The responses of the students of the first group towards the web-based course were also assessed, at the end of the semester, through a written feedback questionnaire. Within both groups, significant increases in students' basketball knowledge were found. However, the web-based multimedia course in combination with conventional face-to-face instruction was significantly more effective than conventional face-to-face instruction alone in increasing students' cognitive learning regarding the sport of basketball, at the same time being well-accepted by the students. These findings support the effectiveness of blended learning for PE at higher education level as well as the acceptance of this mode of learning by PE students. © 2012 Springer Science+Business Media, LLC