78 research outputs found

    Spatially modelling the association between access to recreational facilities and exercise: the ‘Multi-ethnic study of atherosclerosis’

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    Numerous studies have investigated the relationship between the built environment and physical activity. However these studies assume that these relationships are invariant over space. In this study, we introduce a novel method to analyze the association between access to recreational facilities and exercise allowing for spatial heterogeneity. In addition, this association is studied before and after controlling for crime, a variable that could explain spatial heterogeneity of associations. We use data from the Chicago site of the Multi-Ethnic Study of Atherosclerosis of 781 adults aged 46 years and over. A spatially varying coefficient Tobit regression model is implemented in the Bayesian setting to allow for the association of interest to vary over space. The relationship is shown to vary over Chicago, being positive in the south but negative or null in the north. Controlling for crime weakens the association in the south with little change observed in northern Chicago. The results of this study indicate that spatial heterogeneity in associations of environmental factors with health may vary over space and deserve further exploration

    Longitudinal Associations Between Neighborhood Recreational Facilities and Change in Recreational Physical Activity in the Multi-Ethnic Study of Atherosclerosis, 2000-2007

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    Many cross-sectional studies have investigated the relationship between neighborhood physical environment and physical activity. However, few studies have examined this relationship longitudinally, and no study has examined the association between change in objective measurements of physical activity resources and change in physical activity in adults. We used longitudinal data from the Multi-Ethnic Study of Atherosclerosis (2000–2007) of 6,814 adults who were aged 45–84 years at baseline. Physical activity was assessed via a semiquantitative questionnaire at baseline and at 2 follow-up visits (approximately 1.6 and 3.2 years later). We measured the density of recreational facilities within 1 mile of each participant's home address and used linear mixed-effects models to estimate the association between change in recreational facility density and change in physical activity. After adjusting for potential confounders, we found that a greater increase in recreational density was associated with a less pronounced decline in physical activity (mean difference in annual change in physical activity for each 1-unit increase in recreational density over time = 10.3 (95% confidence interval: 0.7, 19.9)). This association was stronger in older adults. Better access to recreational facilities may benefit middle-aged and older adults by enabling them to maintain activity levels as they age

    Dementia in Africa: Current evidence, knowledge gaps, and future directions

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    \ua9 2021 the Alzheimer\u27s Association. In tandem with the ever-increasing aging population in low and middle-income countries, the burden of dementia is rising on the African continent. Dementia prevalence varies from 2.3% to 20.0% and incidence rates are 13.3 per 1000 person-years with increasing mortality in parts of rapidly transforming Africa. Differences in nutrition, cardiovascular factors, comorbidities, infections, mortality, and detection likely contribute to lower incidence. Alzheimer\u27s disease, vascular dementia, and human immunodeficiency virus/acquired immunodeficiency syndrome–associated neurocognitive disorders are the most common dementia subtypes. Comprehensive longitudinal studies with robust methodology and regional coverage would provide more reliable information. The apolipoprotein E (APOE) ε4 allele is most studied but has shown differential effects within African ancestry compared to Caucasian. More candidate gene and genome-wide association studies are needed to relate to dementia phenotypes. Validated culture-sensitive cognitive tools not influenced by education and language differences are critically needed for implementation across multidisciplinary groupings such as the proposed African Dementia Consortium

    Diffuse duodenal nodular lymphoid hyperplasia: a large cohort of patients etiologically related to Helicobacter pylori infection

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    Abstract Background Nodular lymphoid hyperplasia of gastrointestinal tract is a rare disorder, often associated with immunodeficiency syndromes. There are no published reports of its association with Helicobacter pylori infection. Methods From March 2005 till February 2010, we prospectively followed all patients with diffuse duodenal nodular lymphoid hyperplasia (DDNLH). Patients underwent esophagogastroduodenoscopy with targeted biopsies, colonoscopy, and small bowel video capsule endoscopy. Duodenal nodular lesions were graded from 0 to 4 based on their size and density. Patients were screened for celiac sprue (IgA endomysial antibody), immunoglobulin abnormalities (immunoglobulin levels & serum protein electrophoresis), small intestine bacterial overgrowth (lactulose hydrogen breath test), and Helicobacter pylori infection (rapid urease test, and histological examination of gastric biopsies). Patients infected with Helicobacter pylori received sequential antibiotic therapy and eradication of infection was evaluated by 14C urea breath test. Follow up duodenoscopies with biopsies were performed to ascertain resolution of nodular lesions. Results Forty patients (Males 23, females 17; mean age ± 1SD 35.6 ± 14.6 years) with DDNLH were studied. Patients presented with epigastric pain, vomiting, and weight loss. Esophagogastroduodenoscopy showed diffuse nodular lesions (size varying from 2 to 5 mm or more) of varying grades (mean score ± 1SD 2.70 ± 0.84) involving postbulbar duodenum. Video capsule endoscopies revealed nodular disease exclusively limited to duodenum. None of the patients had immunoglobulin deficiency or small intestine bacterial overgrowth or positive IgA endomysial antibodies. All patients were infected with Helicobacter pylori infection. Sequential antibiotic therapy eradicated Helicobacter pylori infection in 26 patients. Follow up duodenoscopies in these patients showed significant reduction of duodenal nodular lesions score (2.69 ± 0.79 to 1.50 ± 1.10; p Helicobacter pylori infection showed no significant reduction of nodular lesions score (2.71 ± 0.96 to 2.64 ± 1.15; p = 0.58). Nodules partially regressed in score in 2 patients, showed no interval change in 10 patients and progressed in 2 patients. Conclusions We report on a large cohort of patients with DDNLH, etiologically related to Helicobacter pylori infection.</p

    Modeling colorectal cancer: A bio-resource of 50 patient-derived organoid lines

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    Background and Aim Colorectal cancer (CRC) is the second leading cause of cancer death worldwide. To improve outcomes for these patients, we need to develop new treatment strategies. Personalized cancer medicine, where patients are treated based on the characteristics of their own tumor, has gained significant interest for its promise to improve outcomes and reduce unnecessary side effects. The purpose of this study was to examine the potential utility of patient-derived colorectal cancer organoids (PDCOs) in a personalized cancer medicine setting. Methods Patient-derived colorectal cancer organoids were derived from tissue obtained from treatment-naïve patients undergoing surgical resection for the treatment of CRC. We examined the recapitulation of key histopathological, molecular, and phenotypic characteristics of the primary tumor. Results We created a bio-resource of PDCOs from primary and metastatic CRCs. Key histopathological features were retained in PDCOs when compared with the primary tumor. Additionally, a cohort of 12 PDCOs, and their corresponding primary tumors and normal sample, were characterized through whole exome sequencing and somatic variant calling. These PDCOs exhibited a high level of concordance in key driver mutations when compared with the primary tumor. Conclusions Patient-derived colorectal cancer organoids recapitulate characteristics of the tissue from which they are derived and are a powerful tool for cancer research. Further research will determine their utility for predicting patient outcomes in a personalized cancer medicine setting

    Enrolling adolescents in HIV vaccine trials: reflections on legal complexities from South Africa

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    <p>Abstract</p> <p>Background</p> <p>South Africa is likely to be the first country in the world to host an adolescent HIV vaccine trial. Adolescents may be enrolled in late 2007. In the development and review of adolescent HIV vaccine trial protocols there are many complexities to consider, and much work to be done if these important trials are to become a reality.</p> <p>Discussion</p> <p>This article sets out essential requirements for the lawful conduct of adolescent research in South Africa including compliance with consent requirements, child protection laws, and processes for the ethical and regulatory approval of research.</p> <p>Summary</p> <p>This article outlines likely complexities for researchers and research ethics committees, including determining that trial interventions meet current risk standards for child research. Explicit recommendations are made for role-players in other jurisdictions who may also be planning such trials. This article concludes with concrete steps for implementing these important trials in South Africa and other jurisdictions, including planning for consent processes; delineating privacy rights; compiling information necessary for ethics committees to assess risks to child participants; training trial site staff to recognize when disclosures trig mandatory reporting response; networking among relevant ethics commitees; and lobbying the National Regulatory Authority for guidance.</p

    The MeerKAT Galaxy Cluster Legacy Survey: I. Survey overview and highlights

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    Please abstract in the article.The South African Radio Astronomy Observatory (SARAO), the National Research Foundation (NRF), the National Radio Astronomy Observatory, US National Science Foundation, the South African Research Chairs Initiative of the DSI/NRF, the SARAO HCD programme, the South African Research Chairs Initiative of the Department of Science and Innovation.http://www.aanda.orghj2022Physic

    The first 1000 patients on an internet-based colorectal neoplasia database across private and public medicine in australia: Development of a binational model for the colorectal surgical society of Australia and New Zealand

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    Background: Collection of multi-institutional data pertaining to the treatment of bowel cancer has been hindered by poor clinician compliance with data entry and the lack of incentive to participate. Objective: This study aimed to establish if a novel browser-based model of data collection results in complete data capture. Design: A Web-based data collection interface was custom written, offering automated reporting modules for clinical outcome to participants and an automated reporting system for outstanding data fields, and summary reporting of surgical quality outcomes. The software was combined with a clinical feedback system incorporating fortnightly data review meetings, at the time of clinical multidisciplinary meetings. Patients And Setting: Selected were 932 consecutive patients with opt-out consent from 3 hospital sites, including public and private medicine. Main Outcome Measures: The primary outcomes measured were the analysis of data completeness and accuracy and ensuring that the highest-quality data were used for clinical audit of the surgical practices of Australian colorectal surgeons for the purpose of quality assurance. Results: A total of 932 men and women, 22 to 94 years of age, treated for colorectal neoplasia were evaluated. We obtained 100% completion (&gt;27,000 data points) of perioperative data registered by 8 specialist colorectal surgeons and a full-time database manager. Conclusions: Data completeness and validity are essential for clinical databases to serve the purpose of quality assurance, benchmarking, and research. The results confirm the safety and efficacy of colorectal cancer surgery in both the public and private sector in Australia. The combination of a simple multiuser interface, defined data points, automated result-reporting modules, and data-deficiency reminder module resulted in 100% data compliance in nearly 1000 clinical episodes. The unprecedented success of this model has lead to the Colorectal Surgical Society of Australia and New Zealand adopting this model for data collection for Australia and New Zealand as the binational database. © The ASCRS 2014
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