1,102 research outputs found

    Analysis of the linearized supersonic flow about pointed bodies of revolution by the method of characteristics

    Get PDF
    Linearized supersonic flow about pointed bodies of revolution by method of characteristic

    Clinical Trial Simulation to Evaluate Population Pharmacokinetics and Food Effect: Capturing Abiraterone and Nilotinib Exposures

    Get PDF
    The objectives of this study were to determine (1) the accuracy with which individual patient level exposure can be determined and (2) whether a known food effect can be identified in a trial simulation of a typical population pharmacokinetic trial. Clinical trial simulations were undertaken using NONMEM VII to assess a typical oncology pharmacokinetic trial design. Nine virtual trials for each compound were performed for combinations of different level of between-occasion variability, number of patients in the trial and magnitude of a food covariate on oral clearance. Less than 5% and 20% bias and precision were obtained in individual clearance estimated for both abiraterone and nilotinib using this design. This design resulted biased and imprecise population clearance estimates for abiraterone. The between-occasion variability in most trials was captured with less than 30% of percent bias and precision. The food effect was detectable as a statistically significant covariate on oral clearance for abiraterone and nilotinib with percent bias and precision of the food covariate less than 20%. These results demonstrate that clinical trial simulation can be used to explore the ability of specific trial designs to evaluate the power to identify individual and population level exposures,covariate and variability effects

    Association Between Frailty and Atrial Fibrillation in Older Adults: The Framingham Heart Study Offspring Cohort

    Get PDF
    Background: Frailty is associated bidirectionally with cardiovascular disease. However, the relations between frailty and atrial fibrillation (AF) have not been fully elucidated. Methods and Results: Using the FHS (Framingham Heart Study) Offspring cohort, we sought to examine both the association between frailty (2005-2008) and incident AF through 2016 and the association between prevalent AF and frailty status (2011-2014). Frailty was defined using the Fried phenotype. Models adjusted for age, sex, and smoking. Cox proportional hazards models, adjusted for competing risk of death, assessed the association between prevalent frailty and incident AF. Logistic regression models assessed the association between prevalent AF and new-onset frailty. For the incident AF analysis, we included 2053 participants (56% women; mean age, 69.7+/-6.9 years). By Fried criteria, 1018 (50%) were robust, 903 (44%) were prefrail, and 132 (6%) were frail. In total, 306 incident cases of AF occurred during an average 9.2 (SD, 3.1) follow-up years. After adjustment, there was no statistically significant association between prevalent frailty status and incident AF (prefrail versus robust: hazard ratio [HR], 1.22 [95% CI, 0.95-1.55]; frail versus robust: HR, 0.92 [95% CI, 0.57-1.47]). At follow-up, there were 111 new cases of frailty. After adjustment, there was no statistically significant association between prevalent AF and new-onset frailty (odds ratio, 0.48 [95% CI, 0.17-1.36]). Conclusions: Although a bidirectional association between frailty and cardiovascular disease has been suggested, we did not find evidence of an association between frailty and AF. Our findings may be limited by sample size and should be further explored in other populations

    Potential Impact of Amantadine on Aggression in Chronic Traumatic Brain Injury

    Get PDF
    Objective: To assess the effects of amantadine on anger and aggression among individuals with a chronic traumatic brain injury (TBI). Methods: A cohort of 118 persons with chronic TBI (>6 months postinjury) and moderate-severe aggression selected from a larger cohort of 168 participants enrolled in a parallel-group, randomized, double-blind, placebo-controlled trial of amantadine 100 mg twice daily (n = 82) versus placebo (n = 86) for treatment of irritability were studied. Anger and aggression were measured at treatment days 0, 28, and 60 using observer-rated and participant-rated State-Trait Anger Expression Inventory-2 (STAXI-2) and Neuropsychiatric Inventory-Agitation/Aggression domain (NPI-A) Most Problematic and Distress scores. Results: Participant-rated day 60 NPI-A Most Problematic (adjusted P = .0118) and NPI-A Distress (adjusted P = .0118) were statistically significant between the 2 groups, but STAXI-2 differences were not significant after adjustment for multiple comparisons. Substantial improvements were noted in both amantadine and placebo groups (70% vs 56% improving at least 3 points on day 60 Observer NPI-A; P = .11). Conclusion: Amantadine 100 mg twice daily in this population with chronic TBI appears to be beneficial in decreasing aggression from the perspective of the individual with TBI. No beneficial impact on anger was found

    Is axonal degeneration a key early event in Parkinson’s disease?

    Get PDF
    Author Posting. © The Author(s), 2016. This is the author's version of the work. It is posted here by permission of IOS Press for personal use, not for redistribution. The definitive version was published in Journal of Parkinson's Disease 6 (2016): 703-707, doi:10.3233/JPD-160881.Recent research suggests that in Parkinson’s disease the long, thin and unmyelinated axons of dopaminergic neurons degenerate early in the disease process. We organized a workshop entitled ‘Axonal Pathology in Parkinson’s disease’, on March 23rd, 2016, in Cleveland, Ohio with the goals of summarizing the state-of-the-art and defining key gaps in knowledge. A group of eight research leaders discussed new developments in clinical pathology, functional imaging, animal models, and mechanisms of degeneration including neuroinflammation, autophagy and axonal transport deficits. While the workshop focused on PD, comparisons were made to other neurological conditions where axonal degeneration is well recognized

    Determinants of physicians' purchase intention for innovative services: Integrating professional characteristics with technology acceptance model and theory of planned behaviour

    Get PDF
    © 2015 Imperial College Press. This paper seeks to explore the factors that influence physicians' purchase intention for supplementary professional services that have been recently introduced to the market. For that reason, a model has been developed and empirically tested using data collected from 100 physicians regarding an innovative e-detailing service. Results show that physicians' purchase intention is significantly influenced by five factors. Three of them derive from the integration of Technology Acceptance Model (TAM) with the Theory of Planned Behaviour (TPB), i.e., perceived usefulness, perceived ease of use and professional image. The rest, namely work experience, working status and innovativeness, refer to physicians' professional characteristics. Work experience and innovativeness were found to have a significant effect on physicians' perceptions of the innovative service, whereas, physicians' current working status was not found to have significant influence on either their perceptions of the innovative service or their purchase intention

    Chronic, low-dose rotenone reproduces Lewy neurites found in early stages of Parkinson's disease, reduces mitochondrial movement and slowly kills differentiated SH-SY5Y neural cells

    Get PDF
    <p>Abstract</p> <p>Background</p> <p>Parkinson's disease, the most common adult neurodegenerative movement disorder, demonstrates a brain-wide pathology that begins pre-clinically with alpha-synuclein aggregates ("Lewy neurites") in processes of gut enteric and vagal motor neurons. Rostral progression into substantia nigra with death of dopamine neurons produces the motor impairment phenotype that yields a clinical diagnosis. The vast majority of Parkinson's disease occurs sporadically, and current models of sporadic Parkinson's disease (sPD) can utilize directly infused or systemic neurotoxins.</p> <p>Results</p> <p>We developed a differentiation protocol for human SH-SY5Y neuroblastoma that yielded non-dividing dopaminergic neural cells with long processes that we then exposed to 50 nM rotenone, a complex I inhibitor used in Parkinson's disease models. After 21 days of rotenone, ~60% of cells died. Their processes retracted and accumulated ASYN-(+) and UB-(+) aggregates that blocked organelle transport. Mitochondrial movement velocities were reduced by 8 days of rotenone and continued to decline over time. No cytoplasmic inclusions resembling Lewy bodies were observed. Gene microarray analyses showed that the majority of genes were under-expressed. qPCR analyses of 11 mtDNA-encoded and 10 nDNA-encoded mitochondrial electron transport chain RNAs' relative expressions revealed small increases in mtDNA-encoded genes and lesser regulation of nDNA-encoded ETC genes.</p> <p>Conclusion</p> <p>Subacute rotenone treatment of differentiated SH-SY5Y neuroblastoma cells causes process retraction and partial death over several weeks, slowed mitochondrial movement in processes and appears to reproduce the Lewy neuritic changes of early Parkinson's disease pathology but does not cause Lewy body inclusions. The overall pattern of transcriptional regulation is gene under-expression with minimal regulation of ETC genes in spite of rotenone's being a complex I toxin. This rotenone-SH-SY5Y model in a differentiated human neural cell mimics changes of early Parkinson's disease and may be useful for screening therapeutics for neuroprotection in that disease stage.</p
    • …
    corecore