208 research outputs found
Chemical synthesis of the organoarsenical antibiotic arsinothricin
We report two routes of chemical synthesis of arsinothricin (AST), the novel organoarsenical antibiotic. One is by condensation of the 2-chloroethyl(methyl)arsinic acid with acetamidomalonate, and the second involves reduction of the N-acetyl protected derivative of hydroxyarsinothricin (AST-OH) and subsequent methylation of a trivalent arsenic intermediate with methyl iodide. The enzyme AST N-acetyltransferase (ArsN1) was utilized to purify l-AST from racemic AST. This chemical synthesis provides a source of this novel antibiotic for future drug development
Field effect transistors for terahertz detection - silicon versus IIIâV material issue
International audienceResonant frequencies of the two-dimensional plasma in FETs reach the THz range for nanometer transistor channels. Non-linear properties of the electron plasma are responsible for detection of THz radiation with FETs. Resonant excitation of plasma waves with sub-THz and THz radiation was demonstrated for short gate transistors at cryogenic temperatures. At room temperature, plasma oscillations are usually over-damped, but the FETs can still operate as efficient broadband THz detectors. The paper presents the main theoretical and experimental results on detection with FETs stressing their possible THz imaging applications. We discuss advantages and disadvantages of application of III-V GaAs and GaN HEMTs and silicon MOSFETs
Knowledge of Patients with Mechanical Valve Prostheses Concerning Chronic Oral Anticoagulant Therapy
Adherence to chronic Oral Anticoagulant Therapy (OAT) is directly related to patients' understanding of the therapy. This study verified the knowledge of patients with mechanical valve prostheses concerning OAT. This is a contemporary cross-sectional study, the sample is composed of patients with mechanical valve prostheses (MVP) in outpatient follow-up. A 10-question instrument was used; answers were âknow' (1 point), âknow partially' (half point), or âdo not know' (zero). Patients were grouped according to the result obtained: ≤ 4 points was considered insufficient knowledge; > 4 ≤ 8 equated to moderate knowledge; and > 8 was considered appropriate knowledge. Of the 110 patients, 61.8% presented moderate knowledge, 40.9% were not able to name at least one factor that may alter the INR (International Normalized Ratio) and 37.3% were not able to report their INR target range. The majority of patients presented moderate knowledge concerning the treatment. Strategies to improve knowledge on the topic should be implemented to minimize risks.El objetivo de este estudio fue verificar el conocimiento de pacientes con prĂłtesis valvular sobre la terapia de anticoagulaciĂłn oral. La adhesiĂłn a la terapia de anticoagulaciĂłn oral crĂłnica estĂĄ directamente relacionada al entendimiento del paciente sobre esta terapia. Se trata de un estudio transversal contemporĂĄneo, en el cual se incluyeron pacientes de ambulatorio con prĂłtesis valvular mecĂĄnica (PVM). Se aplicĂł un cuestionario con 10 preguntas; las respuestas fueron "sabe" (1 punto), "sabe parcialmente" (medio punto), "no sabe" (cero puntos). Los pacientes fueron agrupados segĂșn la puntuaciĂłn obtenida: ≤ 4 puntos, conocimiento insuficiente; > 4 ≤ 8 puntos, conocimiento regular; > 8 puntos, conocimiento adecuado. De los 110 pacientes incluidos, el 61,8% demostrĂł conocimiento regular, 40,9% no supieron citar un factor que altera el REI (razĂłn estandarizada internacional) y 37,3% no supieron informar su REI objetivo. Se concluyĂł que la mayorĂa de los pacientes demostrĂł conocimiento regular sobre el tratamiento. Se recomienda implantar estrategias para mejorar el conocimiento y minimizar los riesgos de la terapia.A adesĂŁo Ă terapia com anticoagulação oral crĂŽnica estĂĄ diretamente relacionada ao entendimento dos pacientes sobre essa terapia. O objetivo deste estudo foi verificar o conhecimento dos pacientes, com prĂłtese valvar mecĂąnica, sobre terapia de anticoagulação oral. Como mĂ©todo, usou-se o estudo transversal contemporĂąneo. Incluem-se pacientes com prĂłtese valvar mecĂąnica (PVM) em acompanhamento ambulatorial. Aplicou-se instrumento com 10 questĂ”es. As respostas eram sabe (um ponto), sabe parcialmente (meio ponto), ou nĂŁo sabe (zero). Os pacientes foram agrupados conforme a pontuação obtida. Considerou-se ≤4 pontos conhecimento insuficiente, >4 ≤8 conhecimento regular e >8 conhecimento adequado. Os resultados mostram que, dos 110 pacientes, 61,8% apresentaram conhecimento regular, 40,9% nĂŁo souberam citar ao menos um fator que alterasse a razĂŁo normatizada internacional (RNI) e 37,3% nĂŁo souberam informar o seu RNI alvo. Conclui-se que a maioria dos pacientes apresentou conhecimento regular sobre o tratamento. EstratĂ©gias devem ser implementadas para melhorar o conhecimento e, consequentemente, minimizar os riscos dessa terapĂȘutica
Immune system deregulation in hypertensive patients chronically RAS suppressed developing albuminuria
Albuminuria development in hypertensive patients is an indicator of higher cardiovascular (CV) risk and renal damage. Chronic renin-angiotensin system (RAS) suppression facilitates blood pressure control but it does not prevent from albuminuria development. We pursued the identification of protein indicators in urine behind albuminuria development in hypertensive patients under RAS suppression. Urine was collected from 100 patients classified in three groups according to albuminuria development: (a) patients with persistent normoalbuminuria; (b) patients developing de novo albuminuria; (c) patients with maintained albuminuria. Quantitative analysis was performed in a first discovery cohort by isobaric labeling methodology. Alterations of proteins of interest were confirmed by target mass spectrometry analysis in an independent cohort. A total of 2416 proteins and 1223 functional categories (coordinated protein responses) were identified. Immune response, adhesion of immune and blood cells, and phagocytosis were found significantly altered in patients with albuminuria compared to normoalbuminuric individuals. The complement system C3 increases, while Annexin A1, CD44, S100A8 and S100A9 proteins showed significant diminishment in their urinary levels when albuminuria is present. This study reveals specific links between immune response and controlled hypertension in patients who develop albuminuria, pointing to potential protein targets for novel and future therapeutic interventions.Sin financiaciĂłn4.122 JCR (2017) Q1, 12/64 Multidisciplinary Sciences0.809 SJR (2017) Q2, 4/10 OptometryNo data IDR 2017UE
Internet and game behaviour at a secondary school and a newly developed health promotion programme: a prospective study
<p>Abstract</p> <p>Background</p> <p>This study investigated the Internet and game use of secondary school children, the compulsiveness of their use and the relationship with other health behaviours. It also evaluated the preliminary results of a recently developed school health promotion programme, implemented at a secondary school in the Netherlands in January 2008. This programme is one of the first to combine seven health behaviours in one educational programme and is a pilot project for a case-control study.</p> <p>Methods</p> <p>A total of 475 secondary school children completed an extensive questionnaire before and a year after starting the programme. Of these children, 367 were in first, second and third grade; the grades in which the lessons about internet and game behaviour were implemented. Questionnaires contained questions about personal information, Internet and game use (Compulsive Internet Use Scale), and other health behaviours (alcohol use, physical activity, psychosocial wellbeing and body mass index).</p> <p>Results</p> <p>Heavy Internet use was significantly associated with psychosocial problems, and heavy game use was significantly associated with psychosocial problems and less physical activity. No relationship was found with alcohol use or body mass index. The time spent on Internet (hours/day) and the number of pathological Internet users increased during the study. The number of game users decreased but heavy game use increased.</p> <p>Conclusion</p> <p>The association between heavy Internet use and psychosocial problems and between game use and psychosocial problems and less physical activity emphasizes the need to target different health behaviours in one health education programme. A case-control study is needed to further assess the programme-induced changes in Internet and game behaviour of school children.</p
Correction: Pulsed moxifloxacin for the prevention of exacerbations of chronic obstructive pulmonary disease: a randomized controlled trial
BACKGROUND: Acute exacerbations contribute to the morbidity and mortality associated with chronic obstructive pulmonary disease (COPD). This proof-of-concept study evaluates whether intermittent pulsed moxifloxacin treatment could reduce the frequency of these exacerbations. METHODS: Stable patients with COPD were randomized in a double-blind, placebo-controlled trial to receive moxifloxacin 400 mg PO once daily (N = 573) or placebo (N = 584) once a day for 5 days. Treatment was repeated every 8 weeks for a total of six courses. Patients were repeatedly assessed clinically and microbiologically during the 48-week treatment period, and for a further 24 weeks' follow-up. RESULTS: At 48 weeks the odds ratio (OR) for suffering an exacerbation favoured moxifloxacin: per-protocol (PP) population (N = 738, OR 0.75, 95% confidence interval (CI) 0.565-0.994, p = 0.046), intent-to-treat (ITT) population (N = 1149, OR 0.81, 95% CI 0.645-1.008, p = 0.059), and a post-hoc analysis of per-protocol (PP) patients with purulent/mucopurulent sputum production at baseline (N = 323, OR 0.55, 95% CI 0.36-0.84, p = 0.006).There were no significant differences between moxifloxacin and placebo in any pre-specified efficacy subgroup analyses or in hospitalization rates, mortality rates, lung function or changes in St George's Respiratory Questionnaire (SGRQ) total scores. There was, however, a significant difference in favour of moxifloxacin in the SGRQ symptom domain (ITT: -8.2 vs -3.8, p = 0.009; PP: -8.8 vs -4.4, p = 0.006). Moxifloxacin treatment was not associated with consistent changes in moxifloxacin susceptibility. There were more treatment-emergent, drug related adverse events with moxifloxacin vs placebo (p < 0.001) largely due to gastrointestinal events (4.7% vs 0.7%). CONCLUSIONS: Intermittent pulsed therapy with moxifloxacin reduced the odds of exacerbation by 20% in the ITT population, by 25% among the PP population and by 45% in PP patients with purulent/mucopurulent sputum at baseline. There were no unexpected adverse events and there was no evidence of resistance development. TRIAL REGISTRATION: ClinicalTrials.gov number, NCT00473460 (ClincalTrials.gov)
Extended Thromboprophylaxis with Betrixaban in Acutely Ill Medical Patients
Background
Patients with acute medical illnesses are at prolonged risk for venous thrombosis. However, the appropriate duration of thromboprophylaxis remains unknown.
Methods
Patients who were hospitalized for acute medical illnesses were randomly assigned to receive subcutaneous enoxaparin (at a dose of 40 mg once daily) for 10±4 days plus oral betrixaban placebo for 35 to 42 days or subcutaneous enoxaparin placebo for 10±4 days plus oral betrixaban (at a dose of 80 mg once daily) for 35 to 42 days. We performed sequential analyses in three prespecified, progressively inclusive cohorts: patients with an elevated d-dimer level (cohort 1), patients with an elevated d-dimer level or an age of at least 75 years (cohort 2), and all the enrolled patients (overall population cohort). The statistical analysis plan specified that if the between-group difference in any analysis in this sequence was not significant, the other analyses would be considered exploratory. The primary efficacy outcome was a composite of asymptomatic proximal deep-vein thrombosis and symptomatic venous thromboembolism. The principal safety outcome was major bleeding.
Results
A total of 7513 patients underwent randomization. In cohort 1, the primary efficacy outcome occurred in 6.9% of patients receiving betrixaban and 8.5% receiving enoxaparin (relative risk in the betrixaban group, 0.81; 95% confidence interval [CI], 0.65 to 1.00; P=0.054). The rates were 5.6% and 7.1%, respectively (relative risk, 0.80; 95% CI, 0.66 to 0.98; P=0.03) in cohort 2 and 5.3% and 7.0% (relative risk, 0.76; 95% CI, 0.63 to 0.92; P=0.006) in the overall population. (The last two analyses were considered to be exploratory owing to the result in cohort 1.) In the overall population, major bleeding occurred in 0.7% of the betrixaban group and 0.6% of the enoxaparin group (relative risk, 1.19; 95% CI, 0.67 to 2.12; P=0.55).
Conclusions
Among acutely ill medical patients with an elevated d-dimer level, there was no significant difference between extended-duration betrixaban and a standard regimen of enoxaparin in the prespecified primary efficacy outcome. However, prespecified exploratory analyses provided evidence suggesting a benefit for betrixaban in the two larger cohorts. (Funded by Portola Pharmaceuticals; APEX ClinicalTrials.gov number, NCT01583218. opens in new tab.
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