627 research outputs found

    Glyphosate – Determination of glyphosate and AMPA in urine by GC-MS/MS

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    The working group “Analyses in Biological Materials” of the Permanent Senate Commission for the Investigation of Health Hazards of Chemical Compounds in the Work Area developed and verified the presented biomonitoring method. Glyphosate (N-phosphonomethylglycine) is a synthetic phosphonic acid derivative which has been used as a broad spectrum herbicide since 1974. Its only known metabolite is aminomethylphosphonic acid (AMPA). Exposure in occupational settings is predominantly due to inhalation and dermal contact with glyphosate. The general population is exposed to glyphosate and AMPA via both dietary (plant and animal products) and environmental (soils, surface water, and groundwater) exposure. The aim of this work was to develop a selective method for the determination of glyphosate and AMPA in urine. The method has been comprehensively validated, and the reliability data have been confirmed by replication and verification of the procedure in a second, independent laboratory. The analytes are directly derivatised in the dried urine sample with trifluoroacetic anhydride and trifluoroethanol without an initial extraction step. Calibration is performed using aqueous calibration standards processed analogously to the samples. As internal standards, glyphosate-d2 and 13C,15N-AMPA are added to the urine samples and calibration standards. The derivatives are measured after capillary gas-chromatographic separation with tandem mass-spectrometric detection (GC-MS/MS) using negative chemical ionisation (NCI). The good precision and accuracy data show that the method provides reliable and accurate analytical results. The method is both selective and sensitive, and the quantitation limit of 0.1 ÎŒg/l urine for glyphosate and AMPA is sufficient to determine occupational exposure as well as higher background levels in the general populatio

    Association Between Medication Adherence and the Outcomes of Heart Failure

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    Background Previous studies of heart failure patients have demonstrated an association between cardiovascular medication adherence and hospitalizations or a composite end point of hospitalization and death. Few studies have assessed the impact of treatment adherence within large general medical populations that distinguish the health outcomes of emergency department visits, hospitalization, and death. Objective To determine the association of incremental cardiovascular medication adherence on emergency department visits, hospitalization, and death in adult heart failure patients in Indiana. Design Retrospective cohort study conducted using electronic health record data from the statewide Indiana Network for Patient Care (INPC) between 2004 and 2009. Methods Patients were at least 18 years of age with a diagnosis of heart failure and prescribed at least one cardiovascular medication for heart failure. Adherence was measured as the proportion of days covered (PDC) using pharmacy transaction data. Clinical end points included emergency department visits, hospital admissions, length of hospital stay, and mortality. Generalized linear models were used to determine the effect of a 10% increase in PDC on clinical end points adjusting for age, sex, race, Charlson comorbidity index, and medications. Results Electronic health records were available for 55,312 patients (mean age ± standard deviation [SD] 68 ± 16 years; 54% women; 65% white). Mean PDC for all heart failure medications was 63% ± 23%. For every 10% increase in PDC, emergency department visits decreased 11% (rate ratio [RR] 0.89; 95% confidence interval [CI] 0.89‐0.89), hospital admissions decreased 6% (RR 0.94; 95% CI 0.94‐0.94), total length of hospital stay decreased 1% (RR 0.99; 95% CI 0.99‐1.00), and all‐cause mortality decreased 9% (odds ratio 0.91; 95% CI 0.90‐0.92). Conclusion Incremental medication adherence was associated with reductions in emergency department visits, hospital admissions, length of hospital stay, and all‐cause mortality

    Characterization of resistance to a potent D-peptide HIV entry inhibitor.

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    BACKGROUND: PIE12-trimer is a highly potent D-peptide HIV-1 entry inhibitor that broadly targets group M isolates. It specifically binds the three identical conserved hydrophobic pockets at the base of the gp41 N-trimer with sub-femtomolar affinity. This extremely high affinity for the transiently exposed gp41 trimer provides a reserve of binding energy (resistance capacitor) to prevent the viral resistance pathway of stepwise accumulation of modest affinity-disrupting mutations. Such modest mutations would not affect PIE12-trimer potency and therefore not confer a selective advantage. Viral passaging in the presence of escalating PIE12-trimer concentrations ultimately selected for PIE12-trimer resistant populations, but required an extremely extended timeframe (\u3e 1 year) in comparison to other entry inhibitors. Eventually, HIV developed resistance to PIE12-trimer by mutating Q577 in the gp41 pocket. RESULTS: Using deep sequence analysis, we identified three mutations at Q577 (R, N and K) in our two PIE12-trimer resistant pools. Each point mutant is capable of conferring the majority of PIE12-trimer resistance seen in the polyclonal pools. Surface plasmon resonance studies demonstrated substantial affinity loss between PIE12-trimer and the Q577R-mutated gp41 pocket. A high-resolution X-ray crystal structure of PIE12 bound to the Q577R pocket revealed the loss of two hydrogen bonds, the repositioning of neighboring residues, and a small decrease in buried surface area. The Q577 mutations in an NL4-3 backbone decreased viral growth rates. Fitness was ultimately rescued in resistant viral pools by a suite of compensatory mutations in gp120 and gp41, of which we identified seven candidates from our sequencing data. CONCLUSIONS: These data show that PIE12-trimer exhibits a high barrier to resistance, as extended passaging was required to develop resistant virus with normal growth rates. The primary resistance mutation, Q577R/N/K, found in the conserved gp41 pocket, substantially decreases inhibitor affinity but also damages viral fitness, and candidate compensatory mutations in gp160 have been identified

    NMR and conductivity studies of the mixed glass former effect in lithium borophosphate glasses

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    Alkali ion charge transport has been studied in a series of mixed glass former lithium borophosphate glasses of composition 0.33Li2O + 0.67[xB2O3 + (1 – x)P2O5]. The entire concentration range, 0.0 ≀ x ≀ 1.0, from pure glassy Li2P4O11 to pure glassy Li2B4O7 has been examined while keeping the molar fraction of Li2O constant. Electrical conductivity measurements and nuclear magnetic resonance techniques such as spin relaxometry, line shape analysis, and stimulated-echo spectroscopy were used to examine the temperature and frequency dependence of the Li+ ion motion over wide ranges of time scale and temperature. By accurately determining motional time scales and activation energies over the entire composition range the ion dynamics and the charge transport are found to be fastest if the borate and the phosphate fractions are similar. The nonlinear variation of the charge conduction, the most notable feature of the mixed glass former effect, is discussed in terms of the composition dependence of network former units which determine the local glass structure

    Triamterene Enhances the Blood Pressure Lowering Effect of Hydrochlorothiazide in Patients with Hypertension

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    BACKGROUND: Triamterene, because of its potassium-sparing properties, is frequently used in combination with hydrochlorothiazide (HCTZ) to treat patients with hypertension. By inhibiting the epithelial sodium channel (ENaC) in the cortical collecting duct, triamterene reduces potassium secretion, thus reducing the risk of hypokalemia. Whether triamterene has an independent effect on blood pressure (BP) has not been well studied. OBJECTIVE: To determine if triamterene provides an effect to further lower BP in patients treated with HCTZ. DESIGN: We conducted an observational study using electronic medical record data from the Indiana Network for Patient Care. Participants were 17,291 patients with the diagnosis of hypertension between 2004 and 2012. MAIN MEASURES: BP was the primary outcome. We compared the BP between patients who were taking HCTZ, with and without triamterene, either alone or in combination with other antihypertensive medications, by using a propensity score analysis. For each medication combination, we estimated the propensity score (i.e., probability) of a patient receiving triamterene using a logistic regression model. Patients with similar propensity scores were stratified into subclasses and BP was compared between those taking triamterene or not within each subclass; the effect of triamterene was then assessed by combining BP differences estimated from all subclasses. KEY RESULTS: The mean systolic BP in the triamterene + HCTZ group was 3.8 mmHg lower than in the HCTZ only group (p < 0.0001); systolic BP was similarly lower for patients taking triamterene with other medication combinations. Systolic BP reduction was consistently observed for different medication combinations. The range of systolic BP reduction was between 1 and 4 mm Hg, depending on the concurrently used medications. CONCLUSIONS: In the present study, triamterene was found to enhance the effect of HCTZ to lower BP. In addition to its potassium-sparing action, triamterene's ability to lower BP should also be considered

    Compulsive checking behavior of quinpirole-sensitized rats as an animal model of Obsessive-Compulsive Disorder(OCD): form and control

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    BACKGROUND: A previous report showed that the open field behavior of rats sensitized to the dopamine agonist quinpirole satisfies 5 performance criteria for compulsive checking behavior. In an effort to extend the parallel between the drug-induced phenomenon and human obsessive-compulsive disorder (OCD), the present study investigated whether the checking behavior of quinpirole rats is subject to interruption, which is an attribute characteristic of OCD compulsions. For this purpose, the rat's home-cage was placed into the open field at the beginning or the middle of a 2-hr test. RESULTS: Introduction of the home-cage reduced checking behavior, as rats stayed inside the cage. After 40 min, checking resurfaced, as quinpirole rats exited the home-cage often. An unfamiliar cage had no such effects on quinpirole rats or saline controls. CONCLUSIONS: Checking behavior induced by quinpirole is not irrepressible but can be suspended. Results strengthen the quinpirole preparation as an animal model of OCD compulsive checking

    Dermanyssus gallinae in layer farms in Kosovo: a high risk for salmonella prevalence

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    Background The poultry red mite (PRM), Dermanyssus gallinae (D.g.) is a serious ectoparasitic pest of poultry and potential pathogen vector. The prevalence of D. g. and the prevalence of Salmonella spp. within mites on infested laying poultry farms were investigated in Kosovo. Findings In total, 14 populated layer farms located in the Southern Kosovo were assessed for D. g. presence. Another two farms in this region were investigated 6 months after depopulation. Investigated flocks were all maintained in cages, a common housing system in Kosovo. A total of eight farms were found to be infested with D. g. (50%) at varying levels, including the two depopulated farms. The detection of Salmonella spp. from D. g. was carried out using PCR. Out of the eight layer farms infested with D. g., Salmonella spp. was present in mites on three farms (37.5%). Conclusions This study confirms the high prevalence of D. g. in layer flocks in Kosovo and demonstrates the link between this mite and the presence of Salmonella spp. on infested farms

    aflow.org: A Web Ecosystem of Databases, Software and Tools

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    To enable materials databases supporting computational and experimental research, it is critical to develop platforms that both facilitate access to the data and provide the tools used to generate/analyze it - all while considering the diversity of users' experience levels and usage needs. The recently formulated FAIR principles (Findable, Accessible, Interoperable, and Reusable) establish a common framework to aid these efforts. This article describes aflow_org, a web ecosystem developed to provide FAIR - compliant access to the AFLOW databases. Graphical and programmatic retrieval methods are offered, ensuring accessibility for all experience levels and data needs. aflow_org goes beyond data-access by providing applications to important features of the AFLOW software, assisting users in their own calculations without the need to install the entire high-throughput framework. Outreach commitments to provide AFLOW tutorials and materials science education to a global and diverse audiences will also be presented.Comment: 32 pages, 8 figure
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