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- Ademuyiwa, Adesoji O., et al.
(författare)
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Determinants of morbidity and mortality following emergency abdominal surgery in children in low-income and middle-income countries
- 2016
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Ingår i: BMJ Global Health. - : BMJ Publishing Group Ltd. - 2059-7908. ; 1:4
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Tidskriftsartikel (refereegranskat)abstract
- Background: Child health is a key priority on the global health agenda, yet the provision of essential and emergency surgery in children is patchy in resource-poor regions. This study was aimed to determine the mortality risk for emergency abdominal paediatric surgery in low-income countries globally.Methods: Multicentre, international, prospective, cohort study. Self-selected surgical units performing emergency abdominal surgery submitted prespecified data for consecutive children aged <16 years during a 2-week period between July and December 2014. The United Nation's Human Development Index (HDI) was used to stratify countries. The main outcome measure was 30-day postoperative mortality, analysed by multilevel logistic regression.Results: This study included 1409 patients from 253 centres in 43 countries; 282 children were under 2 years of age. Among them, 265 (18.8%) were from low-HDI, 450 (31.9%) from middle-HDI and 694 (49.3%) from high-HDI countries. The most common operations performed were appendectomy, small bowel resection, pyloromyotomy and correction of intussusception. After adjustment for patient and hospital risk factors, child mortality at 30 days was significantly higher in low-HDI (adjusted OR 7.14 (95% CI 2.52 to 20.23), p<0.001) and middle-HDI (4.42 (1.44 to 13.56), p=0.009) countries compared with high-HDI countries, translating to 40 excess deaths per 1000 procedures performed.Conclusions: Adjusted mortality in children following emergency abdominal surgery may be as high as 7 times greater in low-HDI and middle-HDI countries compared with high-HDI countries. Effective provision of emergency essential surgery should be a key priority for global child health agendas.
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- Botvinik-Nezer, Rotem, et al.
(författare)
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Variability in the analysis of a single neuroimaging dataset by many teams
- 2020
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Ingår i: Nature. - : Springer Science and Business Media LLC. - 0028-0836 .- 1476-4687. ; 582, s. 84-88
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Tidskriftsartikel (refereegranskat)abstract
- Data analysis workflows in many scientific domains have become increasingly complex and flexible. Here we assess the effect of this flexibility on the results of functional magnetic resonance imaging by asking 70 independent teams to analyse the same dataset, testing the same 9 ex-ante hypotheses(1). The flexibility of analytical approaches is exemplified by the fact that no two teams chose identical workflows to analyse the data. This flexibility resulted in sizeable variation in the results of hypothesis tests, even for teams whose statistical maps were highly correlated at intermediate stages of the analysis pipeline. Variation in reported results was related to several aspects of analysis methodology. Notably, a meta-analytical approach that aggregated information across teams yielded a significant consensus in activated regions. Furthermore, prediction markets of researchers in the field revealed an overestimation of the likelihood of significant findings, even by researchers with direct knowledge of the dataset(2-5). Our findings show that analytical flexibility can have substantial effects on scientific conclusions, and identify factors that may be related to variability in the analysis of functional magnetic resonance imaging. The results emphasize the importance of validating and sharing complex analysis workflows, and demonstrate the need for performing and reporting multiple analyses of the same data. Potential approaches that could be used to mitigate issues related to analytical variability are discussed. The results obtained by seventy different teams analysing the same functional magnetic resonance imaging dataset show substantial variation, highlighting the influence of analytical choices and the importance of sharing workflows publicly and performing multiple analyses.
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- Beyder, Arthur, et al.
(författare)
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Loss-of-Function of the Voltage-Gated Sodium Channel Na(V)1.5 (Channelopathies) in Patients With Irritable Bowel Syndrome
- 2014
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Ingår i: Gastroenterology. - : Elsevier BV. - 0016-5085 .- 1528-0012. ; 146:7, s. 1659-1668
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Tidskriftsartikel (refereegranskat)abstract
- BACKGROUND & AIMS: SCN5A encodes the a-subunit of the voltage-gated sodium channel Na(V)1.5. Many patients with cardiac arrhythmias caused by mutations in SCN5A also have symptoms of irritable bowel syndrome (IBS). We investigated whether patients with IBS have SCN5A variants that affect the function of Na(V)1.5. METHODS: We performed genotype analysis of SCN5A in 584 persons with IBS and 1380 without IBS (controls). Mutant forms of SCN5A were expressed in human embryonic kidney-293 cells, and functions were assessed by voltage clamp analysis. A genome-wide association study was analyzed for an association signal for the SCN5A gene, and replicated in 1745 patients in 4 independent cohorts of IBS patients and controls. RESULTS: Missense mutations were found in SCN5A in 13 of 584 patients (2.2%, probands). Diarrhea-predominant IBS was the most prevalent form of IBS in the overall study population (25%). However, a greater percentage of individuals with SCN5A mutations had constipation-predominant IBS (31%) than diarrhea-predominant IBS (10%; P < .05). Electrophysiologic analysis showed that 10 of 13 detected mutations disrupted Na(V)1.5 function (9 loss-of-function and 1 gain-of-function function). The p. A997T-Na(V)1.5 had the greatest effect in reducing Na(V)1.5 function. Incubation of cells that expressed this variant with mexiletine restored their sodium current and administration of mexiletine to 1 carrier of this mutation (who had constipation-predominant IBS) normalized their bowel habits. In the genome-wide association study and 4 replicated studies, the SCN5A locus was strongly associated with IBS. CONCLUSIONS: About 2% of patients with IBS carry mutations in SCN5A. Most of these are loss-of-function mutations that disrupt Na(V)1.5 channel function. These findings provide a new pathogenic mechanism for IBS and possible treatment options.
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4. |
- Beyder, Arthur, et al.
(författare)
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Loss-of-function of the voltage-gated sodium channel NaV1.5 (channelopathies) in patients with irritable bowel syndrome.
- 2014
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Ingår i: Gastroenterology. - : Elsevier BV. - 0016-5085 .- 1528-0012. ; 146:7
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Tidskriftsartikel (refereegranskat)abstract
- BACKGROUND & AIMS: SCN5A encodes the α-subunit of the voltage-gated sodium channel NaV1.5. Many patients with cardiac arrhythmias caused by mutations in SCN5A also have symptoms of irritable bowel syndrome (IBS). We investigated whether patients with IBS have SCN5A variants that affect the function of NaV1.5.METHODS: We performed genotype analysis of SCN5A in 584 persons with IBS and 1380 without IBS (controls). Mutant forms of SCN5A were expressed in human embryonic kidney-293 cells, and functions were assessed by voltage clamp analysis. A genome-wide association study was analyzed for an association signal for the SCN5A gene, and replicated in 1745 patients in 4 independent cohorts of IBS patients and controls.RESULTS: Missense mutations were found in SCN5A in 13 of 584 patients (2.2%, probands). Diarrhea-predominant IBS was the most prevalent form of IBS in the overall study population (25%). However, a greater percentage of individuals with SCN5A mutations had constipation-predominant IBS (31%) than diarrhea-predominant IBS (10%; P < .05). Electrophysiologic analysis showed that 10 of 13 detected mutations disrupted NaV1.5 function (9 loss-of-function and 1 gain-of-function function). The p. A997T-NaV1.5 had the greatest effect in reducing NaV1.5 function. Incubation of cells that expressed this variant with mexiletine restored their sodium current and administration of mexiletine to 1 carrier of this mutation (who had constipation-predominant IBS) normalized their bowel habits. In the genome-wide association study and 4 replicated studies, the SCN5A locus was strongly associated with IBS.CONCLUSIONS: About 2% of patients with IBS carry mutations in SCN5A. Most of these are loss-of-function mutations that disrupt NaV1.5 channel function. These findings provide a new pathogenic mechanism for IBS and possible treatment options.
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- Choung, Rok Seon, et al.
(författare)
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Community-Based Study of Celiac Disease Autoimmunity Progression in Adults
- 2020
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Ingår i: Gastroenterology. - : Elsevier BV. - 1528-0012 .- 0016-5085. ; 158:1, s. 151-159
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Tidskriftsartikel (refereegranskat)abstract
- Background & Aims: Celiac disease can develop at any age, but outcomes of adults with positive results from serologic tests for tissue transglutaminase antibodies (tTGA) without endoscopic determination of celiac disease (called celiac autoimmunity) have not been thoroughly evaluated. We investigated the proportion of adults with celiac autoimmunity at a community medical center and their progression to celiac disease. Methods: We analyzed waste blood samples from a community clinic from 15,551 adults for tTGA and, if titer results were above 2 U/mL, for endomysial antibody. The blood samples had been collected at 2 time points (median interval, 8.8 years) from 2006 through 2017. We collected data from the clinic on diagnoses of celiac disease based on duodenal biopsy analysis. Results: Of the serum samples collected at the first time point, 15,398 had negative results for tTGA, and 153 had positive results for tTGA (>4 U/mL). Based on medical records, 6 individuals received a diagnosis of celiac disease, for a cumulative incidence of celiac disease diagnosis of 0.06% (95% confidence interval, 0.01–0.11). Forty-nine (0.32%) individuals with a negative result from the first serologic test for tTGA had a positive result from the second test. Among the 153 adults who were tTGA positive at the first time point, 31 (20%) had a subsequent diagnosis of celiac disease, 81 (53%) remained positive for tTGA without a clinical diagnosis of celiac disease, and 41 (27%) had negative test results for tTGA at the second time point. Higher initial tTGA titers, female sex, and a history of hypothyroidism and autoimmune disease were associated with increased risks of subsequent diagnosis of celiac disease. Interestingly, adults whose first blood sample had a positive test result but second blood sample had a negative result for tTGA were older, had lower-than-average initial tTGA titer results, and had a higher mean body mass index than adults whose blood samples were positive for tTGA at both time points and adults later diagnosed with celiac disease. Conclusions: In an analysis of serum samples collected from a community clinic an average of 8.8 years apart, we found that fewer than 1% of adults with negative results from an initial test for tTGA have a positive result on a second test. Of adults with positive results from the test for tTGA, only 20% are later diagnosed with celiac disease; the remaining individuals maintain persistent increases in tTGA without diagnoses of celiac disease or have negative results from second tests.
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- Camilleri, John J., 1986, et al.
(författare)
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An online database of root-and-pattern verbs
- 2013
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Ingår i: 4th International Conference on Maltese Linguistics.
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Konferensbidrag (övrigt vetenskapligt/konstnärligt)abstract
- This work introduces an online database of root-and-pattern verbs in Maltese. Based on (Spagnol 2011)’s exhaustive enumeration of around 2000 roots and over 4000 verbs, the need arose to convert this information from spreadsheet form into a more accessible and manageable storage format. A relational database schema for Maltese roots and verbs was designed, and the contents of the spreadsheet were semi-automatically imported into the database via comma-separated value (CSV) format. A web-based interface was then built around this database, providing powerful search options for searching by root and/or verb using regular expression syntax. In addition to information on roots, classes and derived forms from the original source, fields for English gloss, transitivity information, and verb frequency were also added. This information was partially automatically imported from one of the authors’ personal notes. The rest of the data is being added manually, and we invite other interested researchers to contribute to the database. Hosted by the Maltese Language Resource Server (MRLS), this database is intended to be an open-access resource usable by other researches, students and Maltese language teachers. Apart from the web interface, its contents are also accessible via a REST web service and can additionally be downloaded locally for offline use. This work has already been used as a substantial part of the lexicon for a computational grammar of Maltese (Camilleri 2013). In conjunction with the computational morphology being developed for Maltese, we hope to expand the database to include full-form entries, covering all conjugation and suffixation possibilities. This would boost the number of word forms to roughly 4 million (and that is only counting the root-and-pattern verbs). We also plan to extend the database to cover loan verbs, as well as other lexical categories. We believe this work could serve as the basis for a complete open-access online Maltese lexicon, useful both to end-users and researchers.
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