185 research outputs found

    Atmosferische depositie van gewasbeschermingsmiddelen : een verkenning van de literatuur verschenen na 2003

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    In deze verkenning wordt een inventarisatie gegeven van literatuur over atmosferische depositie die na 2003 is verschenen. Er wordt getracht inzicht te krijgen in hoeverre er sprake is van een kwantitatief verband tussen het landbouwkundig gebruik van gewasbeschermingsmiddelen en hun depositie op middenlange afstand, en of atmosferische depositie van belang is voor risico’s voor waterleven (en indien mogelijk: bodemleven) in natuurgebieden. Een groot deel van de studies is uitgevoerd in Canada en de Verenigde Staten van Amerika, maar ook in Aziatische landen werd in deze periode onderzoek naar atmosferische depositie verricht. Binnen Europa blijken vooral in Duitsland en Frankrijk groepen actief. Er werden slechts drie rapportages gevonden die metingen in Nederland beschrijven

    Belasting van de Afgedamde Maas door bestrijdingsmiddelen en meststoffen; een inventarisatie van pobleemstoffen

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    Meetgegevens en modelberekeningen zijn gebruikt om de belasting van de Afgedamde Maas door nutriënten en bestrijdingsmiddelen in beeld te brengen. Naast emissies zijn voor de bestrijdingsmiddelen ook de potentiële ecologische effecten gekwantificeerd.Voor zowel de emissies als de mogelijke effecten blijken de uiteenlopende fysisch-chemische en toxicologische eigenschappen van de afzonderlijke stoffen van groot belang. Er zijn probleemstoffen benoemd waarbij is aangegeven via welke emissieroutes deze stoffen in het oppervlaktewater terechtkomen. Daarnaast zijn de doelgroepen benoemd die verantwoordelijk zijn voor de beschreven emissies en ecologische effecten

    Dutch Environmental Risk Indicator for Plant Protection Products

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    The NMI 3 focusses on indicators for emissions to surface water and the related aquatic risk resulting from agricultural use of pesticides in the Netherlands. The risk indicator is the exposure toxicity ratio. The model also considers the risk to groundwater, soil organisms and the terrestrial ecosystem. The model calculates indicators for emission to surface water resulting from atmospheric deposition, spray drift, drainage flow, point sources, discharge from greenhouses. The model combines a wide range of information about pesticide sales, usage, spray drift mitigation, emission factors, crop maps, surface water, soil, climate, and substance properties. The primary goal is to compare on a relative scale the annual risk at national scale at the starting and end year of the policy period. The results can be used for ranking, for comparing applications of similar type and for visualisation of spatial patterns of indicators. The result cannot be translated into a risk at a specific location and time

    CYP2C19 genotype-guided antithrombotic treatment versus conventional clopidogrel therapy in peripheral arterial disease: study design of a randomized controlled trial (GENPAD)

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    BACKGROUND: Clopidogrel is recommended in international guidelines to prevent arterial thrombotic events in patients with peripheral arterial disease (PAD). Clopidogrel itself is inactive and metabolism is dependent on the CYP2C19 enzyme. About 30% of Caucasian PAD patients receiving clopidogrel carry 1 or 2 CYP2C19 loss-of-function allele(s) and do not or to a limited extent convert the prodrug into its active metabolite. As a result, platelet inhibition may be inadequate which could lead to an increased risk of adverse clinical events related to arterial thrombosis. A CYP2C19 genotype-guided antithrombotic treatment might be beneficial for PAD patients. METHODS: GENPAD is a multicenter randomized controlled trial involving 2,276 PAD patients with an indication for clopidogrel monotherapy. Patients with a separate indication for dual antiplatelet therapy or stronger antithrombotic therapy are not eligible for study participation. Patients randomized to the control group will receive clopidogrel 75 mg once daily without pharmacogenetic guidance. Patients randomized to the intervention group will be tested for carriage of CYP2C19 *2 and *3 loss-of-function alleles, followed by a genotype-guided antithrombotic treatment with either clopidogrel 75 mg once daily for normal metabolizers, clopidogrel 150 mg once daily for intermediate metabolizers, or acetylsalicylic acid 80 mg once daily plus rivaroxaban 2.5 mg twice daily for poor metabolizers. The primary outcome is a composite of myocardial infarction, ischemic stroke, cardiovascular death, acute or chronic limb ischemia, peripheral vascular interventions, or death. The secondary outcomes are the individual elements of the primary composite outcome and clinically relevant bleeding complications. CONCLUSION: The aim of the GENPAD study is to evaluate the efficacy, safety, and cost-effectiveness of a genotype-guided antithrombotic treatment strategy compared to conventional clopidogrel treatment in PAD patients

    Cost Effectiveness of a CYP2C19 Genotype-Guided Strategy in Patients with Acute Myocardial Infarction:Results from the POPular Genetics Trial

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    INTRODUCTION: The POPular Genetics trial demonstrated that a CYP2C19 genotype-guided P2Y12 inhibitor strategy reduced bleeding rates compared with standard treatment with ticagrelor or prasugrel without increasing thrombotic event rates after primary percutaneous coronary intervention (PCI). OBJECTIVE: In this analysis, we aimed to evaluate the cost effectiveness of a genotype-guided strategy compared with standard treatment with ticagrelor or prasugrel. METHODS: A 1-year decision tree based on the POPular Genetics trial in combination with a lifelong Markov model was developed to compare costs and quality-adjusted life-years (QALYs) between a genotype-guided and a standard P2Y12 inhibitor strategy in patients with myocardial infarction undergoing primary PCI. The cost-effectiveness analysis was conducted from a Dutch healthcare system perspective. Within-trial survival and utility data were combined with lifetime projections to evaluate lifetime cost effectiveness for a cohort of 1000 patients. Costs and utilities were discounted at 4 and 1.5%, respectively, according to Dutch guidelines for health economic studies. Besides deterministic and probabilistic sensitivity analyses, several scenario analyses were also conducted (different time horizons, different discount rates, equal prices for P2Y12 inhibitors, and equal distribution of thrombotic events between the two strategies). RESULTS: Base-case analysis with a hypothetical cohort of 1000 subjects demonstrated 8.98 QALYs gained and €725,550.69 in cost savings for the genotype-guided strategy (dominant). The deterministic and probabilistic sensitivity analysis confirmed the robustness of the model and the cost-effectiveness results. In scenario analyses, the genotype-guided strategy remained dominant. CONCLUSION: In patients undergoing primary PCI, a CYP2C19 genotype-guided strategy compared with standard treatment with ticagrelor or prasugrel resulted in QALYs gained and cost savings. TRIAL REGISTRATION: Clinicaltrials.gov number: NCT01761786, Netherlands trial register number: NL2872

    Effect of Adding Ticagrelor to Standard Aspirin on Saphenous Vein Graft Patency in Patients Undergoing Coronary Artery Bypass Grafting (POPular CABG) A Randomized, Double-Blind, Placebo-Controlled Trial

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    BACKGROUND: Approximately 15% of saphenous vein grafts (SVGs) occlude during the first year after coronary artery bypass graft surgery (CABG) despite aspirin use. The POPular CABG trial (The Effect of Ticagrelor on Saphenous Vein Graft Patency in Patients Undergoing Coronary Artery Bypass Grafting Surgery) investigated whether ticagrelor added to standard aspirin improves SVG patency at 1 year after CABG. METHODS: In this investigator-initiated, randomized, double-blind, placebo-controlled, multicenter trial, patients with ≥1 SVGs were randomly assigned (1:1) after CABG to ticagrelor or placebo added to standard aspirin (80 mg or 100 mg). The primary outcome was SVG occlusion at 1 year, assessed with coronary computed tomography angiography, in all patients that had primary outcome imaging available. A generalized estimating equation model was used to perform the primary analysis per SVG. The secondary outcome was 1-year SVG failure, which was a composite of SVG occlusion, SVG revascularization, myocardial infarction in myocardial territory supplied by a SVG, or sudden death. RESULTS: Among 499 randomly assigned patients, the mean age was 67.9±8.3 years, 87.1% were male, the indication for CABG was acute coronary syndrome in 31.3%, and 95.2% of procedures used cardiopulmonary bypass. Primary outcome imaging was available in 220 patients in the ticagrelor group and 223 patients in the placebo group. The SVG occlusion rate in the ticagrelor group was 10.5% (51 of 484 SVGs) versus 9.1% in the placebo group (43 of 470 SVGs), odds ratio, 1.29 [95% CI, 0.73-2.30]; P=0.38. SVG failure occurred in 35 (14.2%) patients in the ticagrelor group versus 29 (11.6%) patients in the placebo group (odds ratio, 1.22 [95% CI, 0.72-2.05]). CONCLUSIONS: In this randomized, placebo-controlled trial, the addition of ticagrelor to standard aspirin did not reduce SVG occlusion at 1 year after CABG. Registration: URL: https://www.clinicaltrials.gov; Unique identifier: NCT02352402

    A Putative P-Type ATPase Required for Virulence and Resistance to Haem Toxicity in Listeria monocytogenes

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    Regulation of iron homeostasis in many pathogens is principally mediated by the ferric uptake regulator, Fur. Since acquisition of iron from the host is essential for the intracellular pathogen Listeria monocytogenes, we predicted the existence of Fur-regulated systems that support infection. We examined the contribution of nine Fur-regulated loci to the pathogenicity of L. monocytogenes in a murine model of infection. While mutating the majority of the genes failed to affect virulence, three mutants exhibited a significantly compromised virulence potential. Most striking was the role of the membrane protein we designate FrvA (Fur regulated virulence factor A; encoded by frvA [lmo0641]), which is absolutely required for the systemic phase of infection in mice and also for virulence in an alternative infection model, the Wax Moth Galleria mellonella. Further analysis of the ΔfrvA mutant revealed poor growth in iron deficient media and inhibition of growth by micromolar concentrations of haem or haemoglobin, a phenotype which may contribute to the attenuated growth of this mutant during infection. Uptake studies indicated that the ΔfrvA mutant is unaffected in the uptake of ferric citrate but demonstrates a significant increase in uptake of haem and haemin. The data suggest a potential role for FrvA as a haem exporter that functions, at least in part, to protect the cell against the potential toxicity of free haem

    The Characterization of Helicobacter pylori DNA Associated with Ancient Human Remains Recovered from a Canadian Glacier

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    Helicobacter pylori is a gram-negative bacterium that colonizes the stomach of nearly half of the world's population. Genotypic characterization of H. pylori strains involves the analysis of virulence-associated genes, such as vacA, which has multiple alleles. Previous phylogenetic analyses have revealed a connection between modern H. pylori strains and the movement of ancient human populations. In this study, H. pylori DNA was amplified from the stomach tissue of the Kwäday Dän Ts'ìnchi individual. This ancient individual was recovered from the Samuel Glacier in Tatshenshini-Alsek Park, British Columbia, Canada on the traditional territory of the Champagne and Aishihik First Nations and radiocarbon dated to a timeframe of approximately AD 1670 to 1850. This is the first ancient H. pylori strain to be characterized with vacA sequence data. The Tatshenshini H. pylori strain has a potential hybrid vacA m2a/m1d middle (m) region allele and a vacA s2 signal (s) region allele. A vacA s2 allele is more commonly identified with Western strains, and this suggests that European strains were present in northwestern Canada during the ancient individual's time. Phylogenetic analysis indicated that the vacA m1d region of the ancient strain clusters with previously published novel Native American strains that are closely related to Asian strains. This indicates a past connection between the Kwäday Dän Ts'ìnchi individual and the ancestors who arrived in the New World thousands of years ago

    The association between skeletal muscle measures and chemotherapy-induced toxicity in non-small cell lung cancer patients

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    BACKGROUND: Chemotherapy-induced toxicities frequently occur in non-small cell lung cancer (NSCLC) patients treated with platinum-based chemotherapy. Low skeletal muscle mass (SMM) has been associated with a higher incidence of toxicities for several types of cancers and cytostatics. The aim of this study was to evaluate the association between skeletal muscle measures and chemotherapy-induced toxicity in a large cohort of NSCLC patients. METHODS: A multicentre prospective follow-up study (PGxLUNG, NTR number NL5373610015) in NSCLC patients was conducted. Included were patients diagnosed with NSCLC (stage II-IV) treated with first-line platinum-based (cisplatin or carboplatin) chemotherapy of whom pretreatment imaging was available. Skeletal muscle area (SMA) segmentation was performed on abdominal imaging at the level of the third lumbar vertebra (L3). SMA at the level of L3 was corrected for squared height (m2 ) to yield the lumbar skeletal muscle mass index (LSMI). Skeletal muscle density (SMD) was calculated as the mean Hounsfield Unit (HU) of the segmented SMA. SMM and SMD were categorized as low, intermediate, and high, based on LSMI and mean HU tertiles, respectively. Chemotherapy-induced toxicity was scored using CTCAE v4.03 and categorized into haematological (anaemia, leukocytopenia, neutropenia, and thrombocytopenia), non-haematological (nephrotoxicity, neurotoxicity, and esophagitis), and dose-limiting toxicity (DLT) (treatment switch, delay, de-escalation, discontinuation, or hospitalization). The relationship between SMM, SMD, and toxicities was assessed with logistic regression modelling taking into account potential confounders like gender and body mass index (BMI). RESULTS: In total, 297 patients (male n = 167, median age 64 years) were included. Haematological toxicity grade 3/4 was experienced in 36.6% (n = 108) of the patients, 24.6% (n = 73) experienced any non-haematological toxicity grade ≥2, and 55.6% (n = 165) any DLT. Multivariate logistic regression analysis showed that low SMM (ORadj 2.41, 95% CI 1.31-4.45, P = 0.005) and age at diagnosis >65 years (ORadj 1.76, 95% CI 1.07-2.90, P = 0.025) were statistically significantly associated with overall haematological toxicity grade 3/4. No statistically significant associations were found between low SMM or low SMD and non-haematological toxicities. Low SMM (ORadj 2.23, 95% CI 1.23-4.04, P = 0.008) and high SMD (ORadj 0.41, 95% CI 0.23-0.74, P = 0.003) were statistically significantly associated with a higher respectively lower risk of DLT. CONCLUSIONS: Non-small cell lung cancer patients with pretreatment low SMM are at significant higher risk for haematological toxicities grade 3/4 and DLT. NSCLC patients with high SMD are at significant lower risk for DLT. Further studies should be aimed to investigate whether platinum dosing based on skeletal muscle measurements and/or improvement of pretreatment SMM/SMD could reduce the risk of toxicity without compromising efficacy
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