80 research outputs found

    A global assessment of surveillance methods for dominant malaria vectors

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    The epidemiology of human malaria differs considerably between and within geographic regions due, in part, to variability in mosquito species behaviours. Recently, the WHO emphasised stratifying interventions using local surveillance data to reduce malaria. The usefulness of vector surveillance is entirely dependent on the biases inherent in the sampling methods deployed to monitor mosquito populations. To understand and interpret mosquito surveillance data, the frequency of use of malaria vector collection methods was analysed from a georeferenced vector dataset (> 10,000 data records), extracted from 875 manuscripts across Africa, the Americas and the Asia-Pacific region. Commonly deployed mosquito collection methods tend to target anticipated vector behaviours in a region to maximise sample size (and by default, ignoring other behaviours). Mosquito collection methods targeting both host-seeking and resting behaviours were seldomly deployed concurrently at the same site. A balanced sampling design using multiple methods would improve the understanding of the range of vector behaviours, leading to improved surveillance and more effective vector control

    Zoonotic malaria transmission and land use change in Southeast Asia: what is known about the vectors

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    Zoonotic Plasmodium infections in humans in many Southeast Asian countries have been increasing, including in countries approaching elimination of human-only malaria transmission. Most simian malarias in humans are caused by Plasmodium knowlesi, but recent research shows that humans are at risk of many different simian Plasmodium species. In Southeast Asia, simian Plasmodium species are mainly transmitted by mosquitoes in the Anopheles leucosphyrus and Anopheles dirus complexes. Although there is some evidence of species outside the Leucosphyrus Group transmitting simian Plasmodium species, these await confirmation of transmission to humans. The vectors of monkey malarias are mostly found in forests and forest fringes, where they readily bite long-tailed and pig-tailed macaques (the natural reservoir hosts) and humans. How changing land-uses influence zoonotic malaria vectors is still poorly understood. Fragmentation of forests from logging, agriculture and other human activities is associated with increased zoonotic Plasmodium vector exposure. This is thought to occur through altered macaque and mosquito distributions and behaviours, and importantly, increased proximity of humans, macaques, and mosquito vectors. Underlying the increase in vector densities is the issue that the land-use change and human activities create more oviposition sites and, in correlation, increases availably of human blood hosts. The current understanding of zoonotic malaria vector species is largely based on a small number of studies in geographically restricted areas. What is known about the vectors is limited: the data is strongest for distribution and density with only weak evidence for a limited number of species in the Leucosphyrus Group for resting habits, insecticide resistance, blood feeding habits and larval habitats. More data are needed on vector diversity and bionomics in additional geographic areas to understand both the impacts on transmission of anthropogenic land-use change and how this significant disease in humans might be controlled

    Effect of sitagliptin on energy metabolism and brown adipose tissue in overweight individuals with prediabetes:a randomised placebo-controlled trial

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    Aims/hypothesis: The aim of this study was to evaluate the effect of sitagliptin on glucose tolerance, plasma lipids, energy expenditure and metabolism of brown adipose tissue (BAT), white adipose tissue (WAT) and skeletal muscle in overweight individuals with prediabetes (impaired glucose tolerance and/or impaired fasting glucose). Methods: We performed a randomised, double-blinded, placebo-controlled trial in 30 overweight, Europid men (age 45.9 \xc2\xb1 6.2\xc2\xa0years; BMI 28.8 \xc2\xb1 2.3\xc2\xa0kg/m2) with prediabetes in the Leiden University Medical Center and the Alrijne Hospital between March 2015 and September 2016. Participants were initially randomly allocated to receive sitagliptin (100\xc2\xa0mg/day) (n = 15) or placebo (n = 15) for 12\xc2\xa0weeks, using a randomisation list that was set up by an unblinded pharmacist. All people involved in the study as well as participants were blinded to group assignment. Two participants withdrew from the study prior to completion (both in the sitagliptin group) and were subsequently replaced with two new participants that were allocated to the same treatment. Before and after treatment, fasting venous blood samples and skeletal muscle biopsies were obtained, OGTT was performed and body composition, resting energy expenditure and [18F] fluorodeoxyglucose ([18F]FDG) uptake by metabolic tissues were assessed. The primary study endpoint was the effect of sitagliptin on BAT volume and activity. Results: One participant from the sitagliptin group was excluded from analysis, due to a distribution error, leaving 29 participants for further analysis. Sitagliptin, but not placebo, lowered glucose excursion (\xe2\x88\x9240%; p < 0.003) during OGTT, accompanied by an improved insulinogenic index (+38%; p < 0.003) and oral disposition index (+44%; p < 0.003). In addition, sitagliptin lowered serum concentrations of triacylglycerol (\xe2\x88\x9229%) and very large (\xe2\x88\x9246%), large (\xe2\x88\x9235%) and medium-sized (\xe2\x88\x9224%) VLDL particles (all p < 0.05). Body weight, body composition and energy expenditure did not change. In skeletal muscle, sitagliptin increased mRNA expression of PGC1\xce\xb2 (also known as PPARGC1B) (+117%; p < 0.05), a main controller of mitochondrial oxidative energy metabolism. Although the primary endpoint of change in BAT volume and activity was not met, sitagliptin increased [18F] FDG uptake in subcutaneous WAT (sWAT; +53%; p < 0.05). Reported side effects were mild and transient and not necessarily related to the treatment. Conclusions/interpretation: Twelve weeks of sitagliptin in overweight, Europid men with prediabetes improves glucose tolerance and lipid metabolism, as related to increased [18F] FDG uptake by sWAT, rather than BAT, and upregulation of the mitochondrial gene PGC1\xce\xb2 in skeletal muscle. Studies on the effect of sitagliptin on preventing or delaying the progression of prediabetes into type 2 diabetes are warranted. Trial registration: ClinicalTrials.gov NCT02294084. Funding: This study was funded by Merck Sharp & Dohme Corp, Dutch Heart Foundation, Dutch Diabetes Research Foundation, Ministry of Economic Affairs and the University of Granada

    Meer water met regelbare drainage?

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    Dit rapport geeft aan de hand van resultaten van vijf Nederlandse praktijkproeven inzicht in de mogelijkheden van regelbare of peilgestuurde drainage. Deze vorm van drainage - waarbij boeren de grondwaterstand op hun percelen flexibel kunnen regelen - houdt in tegenstelling tot conventionele drainage veel beter rekening met de uiteenlopende wensen en behoeften vanuit de landbouw, natuur, milieu en waterbeheer. Dit kan de realisatie van waterkwaliteits- en waterkwantiteitsdoelstellingen door waterschappen bevorderen en tegelijkertijd de bedrijfsvoering van agrariërs verbeteren

    Growth differentiation factor 15 is not modified after weight loss induced by liraglutide in South Asians and Europids with type 2 diabetes mellitus

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    Abstract: Glucagon-like peptide-1 receptor (GLP-1R) agonists induce weight loss in patients with type 2 diabetes mellitus (T2DM), but the underlying mechanism is unclear. Recently, the mechanism by which metformin induces weight loss could be explained by an increase in growth differentiation factor 15 (GDF15), which suppresses appetite. Therefore, we aimed to investigate whether the GLP-1R agonist liraglutide modifies plasma GDF15 levels in patients with T2DM. GDF15 levels were measured in plasma samples obtained from Dutch Europids and Dutch South Asians with T2DM before and after 26 weeks of treatment with daily liraglutide (n = 44) or placebo (n = 50) added to standard care. At baseline, circulating GDF15 levels did not differ between South Asians and Europids with T2DM. Treatment with liraglutide, compared to placebo, decreased body weight, but did not modify plasma GDF15 levels in all patients, or when data were split by ethnicity. Also, the change in plasma GDF15 levels after treatment with liraglutide did not correlate with changes in body weight or HbA1c levels. In addition, the dose of metformin used did not correlate with baseline plasma GDF15 levels. Compared to placebo, liraglutide treatment for 26 weeks does not modify plasma GDF15 levels in Dutch Europid or South Asian patients with T2DM. Thus, the weight loss induced by liraglutide is likely explained by other mechanisms beyond the GDF15 pathway. Highlights: What is the central question of this study? Growth differentiation factor 15 (GDF15) suppresses appetite and is increased by metformin: does the GLP-1R agonist liraglutide modify plasma GDF15 levels in patients with type 2 diabetes mellitus (T2DM)? What is the main finding and its importance? Plasma GDF15 levels did not differ between South Asians and Europids with T2DM and were not modified by 26 weeks of liraglutide in either ethnicity. Moreover, there was no correlation between the changes in plasma GDF15 levels and dosage of metformin administered, changes in body weight or HbA1c levels. The appetite-suppressing effect of liraglutide is likely exerted via pathways other than GDF15

    Erratum to: 36th International Symposium on Intensive Care and Emergency Medicine

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    [This corrects the article DOI: 10.1186/s13054-016-1208-6.]

    Optimisation of structural transfer zones in multi-use building

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    Design and ConstructionCivil Engineering and Geoscience
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