86 research outputs found
c-di-GMP modulates type IV MSHA pilus retraction and surface attachment in Vibrio cholerae.
Biofilm formation by Vibrio cholerae facilitates environmental persistence, and hyperinfectivity within the host. Biofilm formation is regulated by 3',5'-cyclic diguanylate (c-di-GMP) and requires production of the type IV mannose-sensitive hemagglutinin (MSHA) pilus. Here, we show that the MSHA pilus is a dynamic extendable and retractable system, and its activity is directly controlled by c-di-GMP. The interaction between c-di-GMP and the ATPase MshE promotes pilus extension, whereas low levels of c-di-GMP correlate with enhanced retraction. Loss of retraction facilitated by the ATPase PilT increases near-surface roaming motility, and impairs initial surface attachment. However, prolonged retraction upon surface attachment results in reduced MSHA-mediated surface anchoring and increased levels of detachment. Our results indicate that c-di-GMP directly controls MshE activity, thus regulating MSHA pilus extension and retraction dynamics, and modulating V. cholerae surface attachment and colonization
The Prevalence of Latent Mycobacterium Tuberculosis Infection Based on an Interferon-γ Release Assay: A Cross-Sectional Survey Among Urban Adults in Mwanza, Tanzania.
One third of the world's population is estimated to be latently infected with Mycobacterium tuberculosis (LTBI). Surveys of LTBI are rarely performed in resource poor TB high endemic countries like Tanzania although low-income countries harbor the largest burden of the worlds LTBI. The primary objective was to estimate the prevalence of LTBI in household contacts of pulmonary TB cases and a group of apparently healthy neighborhood controls in an urban setting of such a country. Secondly we assessed potential impact of LTBI on inflammation by quantitating circulating levels of an acute phase reactant: alpha-1-acid glycoprotein (AGP) in neighborhood controls. The study was nested within the framework of two nutrition studies among TB patients in Mwanza, Tanzania. Household contacts- and neighborhood controls were invited to participate. The study involved a questionnaire, BMI determination and blood samples to measure AGP, HIV testing and a Quantiferon Gold In tube (QFN-IT) test to detect signs of LTBI. 245 household contacts and 192 neighborhood controls had available QFN-IT data. Among household contacts, the proportion of QFT-IT positive was 59% compared to 41% in the neighborhood controls (p = 0.001). In a linear regression model adjusted for sex, age, CD4 and HIV, a QFT-IT positive test was associated with a 10% higher level of alpha-1-acid glycoprotein(AGP) (10(B) 1.10, 95% CI 1.01; 1.20, p = 0.03), compared to individuals with a QFT-IT negative test. LTBI is highly prevalent among apparently healthy urban Tanzanians even without known exposure to TB in the household. LTBI was found to be associated with elevated levels of AGP. The implications of this observation merit further studies
Numerical simulation of skin transport using Parareal
In silico investigation of skin permeation is an important but also computationally demanding problem. To resolve all scales involved in full detail will not only require exascale computing capacities but also suitable parallel algorithms. This article investigates the applicability of the time-parallel Parareal algorithm to a brick and mortar setup, a precursory problem to skin permeation. The C++ library Lib4PrM implementing Parareal is combined with the UG4 simulation framework, which provides the spatial discretization and parallelization. The combination’s performance is studied with respect to convergence and speedup. It is confirmed that anisotropies in the domain and jumps in diffusion coefficients only have a minor impact on Parareal’s convergence. The influence of load imbalances in time due to differences in number of iterations required by the spatial solver as well as spatio-temporal weak scaling is discussed
Integrating Global Citizen Science Platforms to Enable Next-Generation Surveillance of Invasive and Vector Mosquitoes
Este artículo contiene 24 páginas, 6 figuras.Mosquito-borne diseases continue to ravage humankind with >700 million infections and
nearly one million deaths every year. Yet only a small percentage of the >3500 mosquito species transmit
diseases, necessitating both extensive surveillance and precise identification. Unfortunately, such
efforts are costly, time-consuming, and require entomological expertise. As envisioned by the Global
Mosquito Alert Consortium, citizen science can provide a scalable solution. However, disparate data
standards across existing platforms have thus far precluded truly global integration. Here, utilizing
Open Geospatial Consortium standards, we harmonized four data streams from three established
mobile apps—Mosquito Alert, iNaturalist, and GLOBE Observer’s Mosquito Habitat Mapper and
Land Cover—to facilitate interoperability and utility for researchers, mosquito control personnel,
and policymakers. We also launched coordinated media campaigns that generated unprecedented
numbers and types of observations, including successfully capturing the first images of targeted invasive and vector species. Additionally, we leveraged pooled image data to develop a toolset of
artificial intelligence algorithms for future deployment in taxonomic and anatomical identification.
Ultimately, by harnessing the combined powers of citizen science and artificial intelligence, we
establish a next-generation surveillance framework to serve as a united front to combat the ongoing
threat of mosquito-borne diseases worldwide.This research was funded by the National Science Foundation under Grant No. IIS-2014547 to
R.M.C., S.C., R.D.L. and A.B. The GLOBE Observer app and citizen science programming are supported
through National Aeronautics and Space Administration (NASA) cooperative agreement NNX16AE28A
to the Institute for Global Environmental Strategies (IGES) for the NASA Earth Science Education
Collaborative (NESEC, PI: Theresa Schwerin). F.B. and J.R.B.P. acknowledge funding from: (a) the
European Commission, under Grants CA17108 (AIM-COST Action), 874735 (VEO), 853271 (H-MIP),
and 2020/2094 (NextGenerationEU, through CSIC’s Global Health Platform, PTI Salud Global); (b) the
Dutch National Research Agenda (NWA), under Grant NWA/00686468; and (c) “la Caixa” Foundation,
under Grant HR19-00336.Peer reviewe
Aspirin as an adjuvant treatment for cancer:feasibility results from the Add-Aspirin randomised trial
BACKGROUND: Preclinical, epidemiological, and randomised data indicate that aspirin might prevent tumour development and metastasis, leading to reduced cancer mortality, particularly for gastro-oesophageal and colorectal cancer. Randomised trials evaluating aspirin use after primary radical therapy are ongoing. We present the pre-planned feasibility analysis of the run-in phase of the Add-Aspirin trial to address concerns about toxicity, particularly bleeding after radical treatment for gastro-oesophageal cancer.METHODS: The Add-Aspirin protocol includes four phase 3 randomised controlled trials evaluating the effect of daily aspirin on recurrence and survival after radical cancer therapy in four tumour cohorts: gastro-oesophageal, colorectal, breast, and prostate cancer. An open-label run-in phase (aspirin 100 mg daily for 8 weeks) precedes double-blind randomisation (for participants aged under 75 years, aspirin 300 mg, aspirin 100 mg, or matched placebo in a 1:1:1 ratio; for patients aged 75 years or older, aspirin 100 mg or matched placebo in a 2:1 ratio). A preplanned analysis of feasibility, including recruitment rate, adherence, and toxicity was performed. The trial is registered with the International Standard Randomised Controlled Trials Number registry (ISRCTN74358648) and remains open to recruitment.FINDINGS: After 2 years of recruitment (October, 2015, to October, 2017), 3494 participants were registered (115 in the gastro-oesophageal cancer cohort, 950 in the colorectal cancer cohort, 1675 in the breast cancer cohort, and 754 in the prostate cancer cohort); 2719 (85%) of 3194 participants who had finished the run-in period proceeded to randomisation, with rates consistent across tumour cohorts. End of run-in data were available for 2253 patients; 2148 (95%) of the participants took six or seven tablets per week. 11 (0·5%) of the 2253 participants reported grade 3 toxicity during the run-in period, with no upper gastrointestinal bleeding (any grade) in the gastro-oesophageal cancer cohort. The most frequent grade 1-2 toxicity overall was dyspepsia (246 [11%] of 2253 participants).INTERPRETATION: Aspirin is well-tolerated after radical cancer therapy. Toxicity has been low and there is no evidence of a difference in adherence, acceptance of randomisation, or toxicity between the different cancer cohorts. Trial recruitment continues to determine whether aspirin could offer a potential low cost and well tolerated therapy to improve cancer outcomes.FUNDING: Cancer Research UK, The National Institute for Health Research Health Technology Assessment Programme, The MRC Clinical Trials Unit at UCL.</p
Antimicrobial resistance among migrants in Europe: a systematic review and meta-analysis
BACKGROUND: Rates of antimicrobial resistance (AMR) are rising globally and there is concern that increased migration is contributing to the burden of antibiotic resistance in Europe. However, the effect of migration on the burden of AMR in Europe has not yet been comprehensively examined. Therefore, we did a systematic review and meta-analysis to identify and synthesise data for AMR carriage or infection in migrants to Europe to examine differences in patterns of AMR across migrant groups and in different settings. METHODS: For this systematic review and meta-analysis, we searched MEDLINE, Embase, PubMed, and Scopus with no language restrictions from Jan 1, 2000, to Jan 18, 2017, for primary data from observational studies reporting antibacterial resistance in common bacterial pathogens among migrants to 21 European Union-15 and European Economic Area countries. To be eligible for inclusion, studies had to report data on carriage or infection with laboratory-confirmed antibiotic-resistant organisms in migrant populations. We extracted data from eligible studies and assessed quality using piloted, standardised forms. We did not examine drug resistance in tuberculosis and excluded articles solely reporting on this parameter. We also excluded articles in which migrant status was determined by ethnicity, country of birth of participants' parents, or was not defined, and articles in which data were not disaggregated by migrant status. Outcomes were carriage of or infection with antibiotic-resistant organisms. We used random-effects models to calculate the pooled prevalence of each outcome. The study protocol is registered with PROSPERO, number CRD42016043681. FINDINGS: We identified 2274 articles, of which 23 observational studies reporting on antibiotic resistance in 2319 migrants were included. The pooled prevalence of any AMR carriage or AMR infection in migrants was 25·4% (95% CI 19·1-31·8; I2 =98%), including meticillin-resistant Staphylococcus aureus (7·8%, 4·8-10·7; I2 =92%) and antibiotic-resistant Gram-negative bacteria (27·2%, 17·6-36·8; I2 =94%). The pooled prevalence of any AMR carriage or infection was higher in refugees and asylum seekers (33·0%, 18·3-47·6; I2 =98%) than in other migrant groups (6·6%, 1·8-11·3; I2 =92%). The pooled prevalence of antibiotic-resistant organisms was slightly higher in high-migrant community settings (33·1%, 11·1-55·1; I2 =96%) than in migrants in hospitals (24·3%, 16·1-32·6; I2 =98%). We did not find evidence of high rates of transmission of AMR from migrant to host populations. INTERPRETATION: Migrants are exposed to conditions favouring the emergence of drug resistance during transit and in host countries in Europe. Increased antibiotic resistance among refugees and asylum seekers and in high-migrant community settings (such as refugee camps and detention facilities) highlights the need for improved living conditions, access to health care, and initiatives to facilitate detection of and appropriate high-quality treatment for antibiotic-resistant infections during transit and in host countries. Protocols for the prevention and control of infection and for antibiotic surveillance need to be integrated in all aspects of health care, which should be accessible for all migrant groups, and should target determinants of AMR before, during, and after migration. FUNDING: UK National Institute for Health Research Imperial Biomedical Research Centre, Imperial College Healthcare Charity, the Wellcome Trust, and UK National Institute for Health Research Health Protection Research Unit in Healthcare-associated Infections and Antimictobial Resistance at Imperial College London
Prevalence of latent tuberculosis infection and predictive factors in an urban informal settlement in Johannesburg, South Africa: a cross-sectional study
Abstract Background South Africa has one of the highest burdens of latent tuberculosis infection (LTBI) in high-risk populations such as young children, adolescents, household contacts of TB cases, people living with HIV, gold miners and health care workers, but little is known about the burden of LTBI in its general population. Methods Using a community-based survey with random sampling, we examined the burden of LTBI in an urban township of Johannesburg and investigated factors associated with LTBI. The outcome of LTBI was based on TST positivity, with a TST considered positive if the induration was ≥5 mm in people living with HIV or ≥10 mm in those with unknown or HIV negative status. We used bivariate and multivariable logistic regression to identify factors associated with LTBI Results The overall prevalence of LTBI was 34.3 (95 % CI 30.0, 38.8 %), the annual risk of infection among children age 0–14 years was 3.1 % (95 % CI 2.1, 5.2). LTBI was not associated with HIV status. In multivariable logistic regression analysis, LTBI was associated with age (OR = 1.03 for every year increase in age, 95 % CI = 1.01–1.05), male gender (OR = 2.70, 95 % CI = 1.55–4.70), marital status (OR = 2.00, 95 % CI = 1.31–3.54), and higher socio-economic status (OR = 2.11, 95 % CI = 1.04–4.31). Conclusions The prevalence of LTBI and the annual risk of infection with M. tuberculosis is high in urban populations, especially in men, but independent of HIV infection status. This study suggests that LTBI may be associated with higher SES, in contrast to the well-established association between TB disease and poverty
c-di-GMP modulates type IV MSHA pilus retraction and surface attachment in Vibrio cholerae
Biofilm formation by Vibrio cholerae facilitates environmental persistence, and hyperinfectivity within the host. Biofilm formation is regulated by 3’,5’-cyclic diguanylate (c-di-GMP) and requires production of the type IV mannose-sensitive hemagglutinin (MSHA) pilus. Here, we show that the MSHA pilus is a dynamic extendable and retractable system, and its activity is directly controlled by c-di-GMP. The interaction between c-di-GMP and the ATPase MshE promotes pilus extension, whereas low levels of c-di-GMP correlate with enhanced retrac- tion. Loss of retraction facilitated by the ATPase PilT increases near-surface roaming motility, and impairs initial surface attachment. However, prolonged retraction upon surface attach- ment results in reduced MSHA-mediated surface anchoring and increased levels of detachment. Our results indicate that c-di-GMP directly controls MshE activity, thus reg- ulating MSHA pilus extension and retraction dynamics, and modulating V. cholerae surface attachment and colonization
Genome profiling of ERBB2-amplified breast cancers
<p>Abstract</p> <p>Background</p> <p>Around 20% of breast cancers (BC) show <it>ERBB2 </it>gene amplification and overexpression of the ERBB2 tyrosine kinase receptor. They are associated with a poor prognosis but can benefit from targeted therapy. A better knowledge of these BCs, genomically and biologically heterogeneous, may help understand their behavior and design new therapeutic strategies.</p> <p>Methods</p> <p>We defined the high resolution genome and gene expression profiles of 54 <it>ERBB2</it>-amplified BCs using 244K oligonucleotide array-comparative genomic hybridization and whole-genome DNA microarrays. Expression of ERBB2, phosphorylated ERBB2, EGFR, IGF1R and FOXA1 proteins was assessed by immunohistochemistry to evaluate the functional ERBB2 status and identify co-expressions.</p> <p>Results</p> <p>First, we identified the <it>ERBB2</it>-<it>C17orf37</it>-<it>GRB7 </it>genomic segment as the minimal common 17q12-q21 amplicon, and <it>CRKRS </it>and <it>IKZF3 </it>as the most frequent centromeric and telomeric amplicon borders, respectively. Second, GISTIC analysis identified 17 other genome regions affected by copy number aberration (CNA) (amplifications, gains, losses). The expression of 37 genes of these regions was deregulated. Third, two types of heterogeneity were observed in <it>ERBB2</it>-amplified BCs. The genomic profiles of estrogen receptor-postive (ER+) and negative (ER-) <it>ERBB2</it>-amplified BCs were different. The WNT/β-catenin signaling pathway was involved in ER- <it>ERBB2</it>-amplified BCs, and <it>PVT1 </it>and <it>TRPS1 </it>were candidate oncogenes associated with ER+ <it>ERBB2</it>-amplified BCs. The size of the <it>ERBB2 </it>amplicon was different in inflammatory (IBC) and non-inflammatory BCs. <it>ERBB2</it>-amplified IBCs were characterized by the downregulated and upregulated mRNA expression of ten and two genes in proportion to CNA, respectively. IHC results showed (i) a linear relationship between <it>ERBB2 </it>gene amplification and its gene and protein expressions with a good correlation between ERBB2 expression and phosphorylation status; (ii) a potential signaling cross-talk between EGFR or IGF1R and ERBB2, which could influence response of <it>ERBB2</it>-positive BCs to inhibitors. FOXA1 was frequently coexpressed with ERBB2 but its expression did not impact on the outcome of patients with <it>ERBB2</it>-amplified tumors.</p> <p>Conclusion</p> <p>We have shown that ER+ and ER- <it>ERBB2</it>-amplified BCs are different, distinguished <it>ERBB2 </it>amplicons in IBC and non-IBC, and identified genomic features that may be useful in the design of alternative therapeutical strategies.</p
Mortality and pulmonary complications in patients undergoing surgery with perioperative SARS-CoV-2 infection: an international cohort study
Background: The impact of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) on postoperative recovery needs to be understood to inform clinical decision making during and after the COVID-19 pandemic. This study reports 30-day mortality and pulmonary complication rates in patients with perioperative SARS-CoV-2 infection. Methods: This international, multicentre, cohort study at 235 hospitals in 24 countries included all patients undergoing surgery who had SARS-CoV-2 infection confirmed within 7 days before or 30 days after surgery. The primary outcome measure was 30-day postoperative mortality and was assessed in all enrolled patients. The main secondary outcome measure was pulmonary complications, defined as pneumonia, acute respiratory distress syndrome, or unexpected postoperative ventilation. Findings: This analysis includes 1128 patients who had surgery between Jan 1 and March 31, 2020, of whom 835 (74·0%) had emergency surgery and 280 (24·8%) had elective surgery. SARS-CoV-2 infection was confirmed preoperatively in 294 (26·1%) patients. 30-day mortality was 23·8% (268 of 1128). Pulmonary complications occurred in 577 (51·2%) of 1128 patients; 30-day mortality in these patients was 38·0% (219 of 577), accounting for 81·7% (219 of 268) of all deaths. In adjusted analyses, 30-day mortality was associated with male sex (odds ratio 1·75 [95% CI 1·28–2·40], p\textless0·0001), age 70 years or older versus younger than 70 years (2·30 [1·65–3·22], p\textless0·0001), American Society of Anesthesiologists grades 3–5 versus grades 1–2 (2·35 [1·57–3·53], p\textless0·0001), malignant versus benign or obstetric diagnosis (1·55 [1·01–2·39], p=0·046), emergency versus elective surgery (1·67 [1·06–2·63], p=0·026), and major versus minor surgery (1·52 [1·01–2·31], p=0·047). Interpretation: Postoperative pulmonary complications occur in half of patients with perioperative SARS-CoV-2 infection and are associated with high mortality. Thresholds for surgery during the COVID-19 pandemic should be higher than during normal practice, particularly in men aged 70 years and older. Consideration should be given for postponing non-urgent procedures and promoting non-operative treatment to delay or avoid the need for surgery. Funding: National Institute for Health Research (NIHR), Association of Coloproctology of Great Britain and Ireland, Bowel and Cancer Research, Bowel Disease Research Foundation, Association of Upper Gastrointestinal Surgeons, British Association of Surgical Oncology, British Gynaecological Cancer Society, European Society of Coloproctology, NIHR Academy, Sarcoma UK, Vascular Society for Great Britain and Ireland, and Yorkshire Cancer Research
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