142 research outputs found

    Observed Reductions in Schistosoma mansoni Transmission from Large-Scale Administration of Praziquantel in Uganda: A Mathematical Modelling Study

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    To date schistosomiasis control programmes based on chemotherapy have largely aimed at controlling morbidity in treated individuals rather than at suppressing transmission. In this study, a mathematical modelling approach was used to estimate reductions in the rate of Schistosoma mansoni reinfection following annual mass drug administration (MDA) with praziquantel in Uganda over four years (2003-2006). In doing this we aim to elucidate the benefits of MDA in reducing community transmission.Age-structured models were fitted to a longitudinal cohort followed up across successive rounds of annual treatment for four years (Baseline: 2003, TREATMENT: 2004-2006; n = 1,764). Instead of modelling contamination, infection and immunity processes separately, these functions were combined in order to estimate a composite force of infection (FOI), i.e., the rate of parasite acquisition by hosts.MDA achieved substantial and statistically significant reductions in the FOI following one round of treatment in areas of low baseline infection intensity, and following two rounds in areas with high and medium intensities. In all areas, the FOI remained suppressed following a third round of treatment.This study represents one of the first attempts to monitor reductions in the FOI within a large-scale MDA schistosomiasis morbidity control programme in sub-Saharan Africa. The results indicate that the Schistosomiasis Control Initiative, as a model for other MDA programmes, is likely exerting a significant ancillary impact on reducing transmission within the community, and may provide health benefits to those who do not receive treatment. The results obtained will have implications for evaluating the cost-effectiveness of schistosomiasis control programmes and the design of monitoring and evaluation approaches in general

    James Hutton’s geological tours of Scotland : romanticism, literary strategies, and the scientific quest

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    This article explores a somewhat neglected part of the story of the emergence of geology as a science and discourse in the late eighteenth century – James Hutton’s posthumously published accounts of the geological tours of Scotland that he undertook in the years 1785 to 1788 in search of empirical evidence in support of his theory of the Earth and that he intended to include in the projected third volume of his Theory of the Earth of 1795. The article brings some of the assumptions and techniques of literary criticism to bear on Hutton’s scientific travel writing in order to open up new connections between geology, Romantic aesthetics and eighteenth-century travel writing about Scotland. Close analysis of Hutton’s accounts of his field trips to Glen Tilt, Galloway and Arran, supplemented by later accounts of the discoveries at Jedburgh and Siccar Point, reveals the interplay between desire, travel and the scientific quest and foregrounds the textual strategies that Hutton uses to persuade his readers that they share in the experience of geological discovery and interpretation as ‘virtual witnesses’. As well as allowing us to revisit the interrelation between scientific theory and discovery, this article concludes that Hutton was a much better writer than he has been given credit for and suggests that if these geological tours had been published in 1795 they would have made it impossible for critics to dismiss him as an armchair geologist

    Vegan and omnivorous high protein diets support comparable daily myofibrillar protein synthesis rates and skeletal muscle hypertrophy in young adults.

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    This is the final version. Available from Elsevier via the DOI in this record.Data availability: Data described in the manuscript may be made available upon request, pending application.BACKGROUND: It remains unclear whether non-animal-derived dietary protein sources (and therefore vegan diets) can support resistance training-induced skeletal muscle remodeling to the same extent as animal-derived protein sources. METHODS: In Phase 1, 16 healthy young adults (m = 8, f = 8; age: 23 ± 1 y; BMI: 23 ± 1 kg/m2) completed a 3-d dietary intervention (high protein, 1.8 g·kg bm-1·d-1) where protein was derived from omnivorous (OMNI1; n = 8) or exclusively non-animal (VEG1; n = 8) sources, alongside daily unilateral leg resistance exercise. Resting and exercised daily myofibrillar protein synthesis (MyoPS) rates were assessed using deuterium oxide. In Phase 2, 22 healthy young adults (m = 11, f = 11; age: 24 ± 1 y; BMI: 23 ± 0 kg/m2) completed a 10 wk, high-volume (5 d/wk), progressive resistance exercise program while consuming an omnivorous (OMNI2; n = 12) or non-animal-derived (VEG2; n = 10) high-protein diet (∼2 g·kg bm-1·d-1). Muscle fiber cross-sectional area (CSA), whole-body lean mass (via DXA), thigh muscle volume (via MRI), muscle strength, and muscle function were determined pre, after 2 and 5 wk, and postintervention. OBJECTIVES: To investigate whether a high-protein, mycoprotein-rich, non-animal-derived diet can support resistance training-induced skeletal muscle remodeling to the same extent as an isonitrogenous omnivorous diet. RESULTS: Daily MyoPS rates were ∼12% higher in the exercised than in the rested leg (2.46 ± 0.27%·d-1 compared with 2.20 ± 0.33%·d-1 and 2.62 ± 0.56%·d-1 compared with 2.36 ± 0.53%·d-1 in OMNI1 and VEG1, respectively; P 0.05). Resistance training increased lean mass in both groups by a similar magnitude (OMNI2 2.6 ± 1.1 kg, VEG2 3.1 ± 2.5 kg; P > 0.05). Likewise, training comparably increased thigh muscle volume (OMNI2 8.3 ± 3.6%, VEG2 8.3 ± 4.1%; P > 0.05), and muscle fiber CSA (OMNI2 33 ± 24%, VEG2 32 ± 48%; P > 0.05). Both groups increased strength (1 repetition maximum) of multiple muscle groups, to comparable degrees. CONCLUSIONS: Omnivorous and vegan diets can support comparable rested and exercised daily MyoPS rates in healthy young adults consuming a high-protein diet. This translates to similar skeletal muscle adaptive responses during prolonged high-volume resistance training, irrespective of dietary protein provenance. This trial was registered at clinicaltrials.gov as NCT03572127.Marlow Foods Ltd

    Schistosomiasis and Urinary Bladder Cancer in North Western Tanzania: A Retrospective Review of 185 Patients.

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    Worldwide, cancers of the urinary bladder are well known to be associated with environmental chemical carcinogens such as smoking and occupational exposure to polycyclic aromatic hydrocarbons. These cancers are typically transitional cell carcinoma (urothelial carcinoma). In areas where schistosomiasis is endemic there is a high incidence of squamous cell carcinoma of the urinary bladder. Schistosomiasis causes chronic granulomatous cystitis leading to squamous metaplasia of transitional epithelium, and subsequently development of squamous cell carcinoma. The western part of Tanzania on the shores of Lake Victoria is such an endemic area. This study was done to document the burden of urinary bladder cancer associated with schistosomiasis in this region. This was a descriptive retrospective study of histologically confirmed cases of urinary bladder cancer seen at the Department of Pathology Bugando Medical Centre (BMC) over a period of 10 years. Data were retrieved from the records of the Departments of Pathology, Medical Records and Surgery. Data were analyzed by the use of contingency tables. A total of 185 patients were diagnosed with cancer of the urinary bladder during the study period, where as 90 (48.6%) were males and 95 (51.4) were females. The mean age at diagnosis was 54.3 years. Squamous cell carcinoma was the most frequent histological type (55.1%), followed by conventional transitional cell carcinoma (40.5%). Eighty three of all cancer cases (44.9%) were found to have schistosomal eggs. Schistosomiasis was commonly associated with squamous cancers compared to non squamous cancers. Most of the cancers associated with schistosomiasis had invaded the muscularis propria of the urinary bladder at the time of diagnosis (p<0.001) and such cancers were frequent below 50 years of age with a significant statistical difference (p<0.001). Poorly differentiated tumors were more frequent in females than males with a significant statistical difference (p=0.006). The majority of urinary bladder cancers seen in the Lake Region were squamous cell carcinoma associated with schistosomiasis. These cancers showed an aggressive behavior and were commonly seen in the younger age groups. Effective control of schistosomiasis in this region should significantly reduce the burden of urinary bladder cancer

    Daily protein-polyphenol ingestion increases daily myofibrillar protein synthesis rates and promotes early muscle functional gains during resistance training

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    This is the final version. Available on open access from the American Physiological Society via the DOI in this recordFactors underpinning the time-course of resistance-type exercise training (RET) adaptations are not fully understood. The present study hypothesized that consuming a twice-daily protein-polyphenol beverage (PPB; n=15; age, 24 ± 1 years; BMI, 22.3 ± 0.7 kg·m-2) previously shown to accelerate recovery from muscle damage and increase daily myofibrillar protein synthesis (MyoPS) rates would accelerate early (10 sessions) improvements in muscle function and potentiate quadriceps volume and muscle fiber cross-sectional area (fCSA) following 30 unilateral RET sessions in healthy, recreationally active, adults. Versus isocaloric placebo (PLA; n=14; age, 25 ± 2 years; BMI, 23.9 ± 1.0 kg·m-2), PPB increased 48 h MyoPS rates after the first RET session measured using deuterated water (2.01 ± 0.15 %·d-1 vs. 1.51 ± 0.16 , respectively; P<0.05). Additionally, PPB increased isokinetic muscle function over 10 sessions of training relative to the untrained control leg (%U) from 99.9 ± 1.8 pre-training to 107.2 ± 2.4 %U at session 10 (versus 102.6 ± 3.9 to 100.8 ± 2.4 %U at session 10 in PLA; interaction P<0.05). Pre-to-post-training, PPB increased type II fCSA (PLA: 120.8 ± 8.2 to 109.5 ± 8.6 %U; PPB: 92.8 ± 6.2 to 108.4 ± 9.7 %U; interaction P<0.05), but the gain in quadriceps muscle volume was similar between groups. Similarly, PPB did not further increase peak isometric torque, muscle function or MyoPS measured post-training. This suggests that although PPB increases MyoPS and early adaptation, it may not influence longer term adaptations to unilateral RET.University of ExeterNational Institute of AgingNational Institute for Health Research (NIHR

    Estimation of changes in the force of infection for intestinal and urogenital schistosomiasis in countries with Schistosomiasis Control Initiative-assisted programmes

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    The last decade has seen an expansion of national schistosomiasis control programmes in Africa based on large-scale preventative chemotherapy. In many areas this has resulted in considerable reductions in infection and morbidity levels in treated individuals. In this paper, we quantify changes in the force of infection (FOI), defined here as the per (human) host parasite establishment rate, to ascertain the impact on transmission of some of these programmes under the umbrella of the Schistosomiasis Control Initiative (SCI)

    Maternal nutrition at conception modulates DNA methylation of human metastable epialleles.

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    In experimental animals, maternal diet during the periconceptional period influences the establishment of DNA methylation at metastable epialleles in the offspring, with permanent phenotypic consequences. Pronounced naturally occurring seasonal differences in the diet of rural Gambian women allowed us to test this in humans. We show that significant seasonal variations in methyl-donor nutrient intake of mothers around the time of conception influence 13 relevant plasma biomarkers. The level of several of these maternal biomarkers predicts increased/decreased methylation at metastable epialleles in DNA extracted from lymphocytes and hair follicles in infants postnatally. Our results demonstrate that maternal nutritional status during early pregnancy causes persistent and systemic epigenetic changes at human metastable epialleles

    Continued Decline of Malaria in The Gambia with Implications for Elimination

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    BACKGROUND: A substantial decline in malaria was reported to have occurred over several years until 2007 in the western part of The Gambia, encouraging consideration of future elimination in this previously highly endemic region. Scale up of interventions has since increased with support from the Global Fund and other donors. METHODOLOGY/PRINCIPAL FINDINGS: We continued to examine laboratory records at four health facilities previously studied and investigated six additional facilities for a 7 year period, adding data from 243,707 slide examinations, to determine trends throughout the country until the end of 2009. We actively detected infections in a community cohort of 800 children living in rural villages throughout the 2008 malaria season, and assayed serological changes in another rural population between 2006 and 2009. Proportions of malaria positive slides declined significantly at all of the 10 health facilities between 2003 (annual mean across all sites, 38.7%) and 2009 (annual mean, 7.9%). Statistical modelling of trends confirmed significant seasonality and decline over time at each facility. Slide positivity was lowest in 2009 at all sites, except two where lowest levels were observed in 2006. Mapping households of cases presenting at the latter sites in 2007-2009 indicated that these were not restricted to a few residual foci. Only 2.8% (22/800) of a rural cohort of children had a malaria episode in the 2008 season, and there was substantial serological decline between 2006 and 2009 in a separate rural area. CONCLUSIONS: Malaria has continued to decline in The Gambia, as indicated by a downward trend in slide positivity at health facilities, and unprecedented low incidence and seroprevalence in community surveys. We recommend intensification of control interventions for several years to further reduce incidence, prior to considering an elimination programme
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