73 research outputs found

    Adult Patients with Congenital Adrenal Hyperplasia Have Elevated Blood Pressure but Otherwise a Normal Cardiovascular Risk Profile

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    Contains fulltext : 96615.pdf (publisher's version ) (Open Access)OBJECTIVE: Treatment with glucocorticoids and mineralocorticoids has changed congenital adrenal hyperplasia (CAH) from a fatal to a chronic lifelong disease. Long-term treatment, in particular the chronic (over-)treatment with glucocorticoids, may have an adverse effect on the cardiovascular risk profile in adult CAH patients. The objective of this study was to evaluate the cardiovascular risk profile of adult CAH patients. DESIGN: Case-control study. PATIENTS AND MEASUREMENTS: In this case-control study the cardiovascular risk profile of 27 adult CAH patients and 27 controls, matched for age, sex and body mass index was evaluated by measuring ambulatory 24-hour blood pressure, insulin sensitivity (HOMA-IR), lipid profiles, albuminuria and circulating cardiovascular risk markers (PAI-1, tPA, uPA, tPA/PAI-1 complex, hsCRP, adiponectin, IL-6, IL-18 and leptin). RESULTS: 24-Hour systolic (126.3 mmHg+/-15.5 vs 124.8 mmHg+/-15.1 in controls, P = 0.019) and diastolic (76.4 mmHg+/-12.7 vs 73.5 mmHg+/-12.4 in controls, P<0.001) blood pressure was significantly elevated in CAH patients compared to the control population. CAH patients had higher HDL cholesterol levels (P<0.01), lower hsCRP levels (P = 0.03) and there was a trend toward elevated adiponectin levels compared to controls. Other cardiovascular risk factors were similar in both groups. CONCLUSION: Adult CAH patients have higher ambulatory blood pressure compared to healthy matched controls. Other cardiovascular risk markers did not differ, while HDL-cholesterol, hsCRP and adiponectin levels tended to be more favorable

    Toward Good Read-Across Practice (GRAP) guidance.

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    Grouping of substances and utilizing read-across of data within those groups represents an important data gap filling technique for chemical safety assessments. Categories/analogue groups are typically developed based on structural similarity and, increasingly often, also on mechanistic (biological) similarity. While read-across can play a key role in complying with legislations such as the European REACH regulation, the lack of consensus regarding the extent and type of evidence necessary to support it often hampers its successful application and acceptance by regulatory authorities. Despite a potentially broad user community, expertise is still concentrated across a handful of organizations and individuals. In order to facilitate the effective use of read-across, this document aims to summarize the state-of-the-art, summarizes insights learned from reviewing ECHA published decisions as far as the relative successes/pitfalls surrounding read-across under REACH and compile the relevant activities and guidance documents. Special emphasis is given to the available existing tools and approaches, an analysis of ECHA's published final decisions associated with all levels of compliance checks and testing proposals, the consideration and expression of uncertainty, the use of biological support data and the impact of the ECHA Read-Across Assessment Framework (RAAF) published in 2015

    Lightweight Statistical Model Checking in Nondeterministic Continuous Time

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    Lightweight scheduler sampling brings statistical model checking to nondeterministic formalisms with undiscounted properties, in constant memory. Its direct application to continuous-time models is rendered ineffective by their dense concrete state spaces and the need to consider continuous input for optimal decisions. In this paper we describe the challenges and state of the art in applying lightweight scheduler sampling to three continuous-time formalisms: After a review of recent work on exploiting discrete abstractions for probabilistic timed automata, we discuss scheduler sampling for Markov automata and apply it on two case studies. We provide further insights into the tradeoffs between scheduler classes for stochastic automata. Throughout, we present extended experiments and new visualisations of the distribution of schedulers.</p

    Iterative approximation of k-limited polling systems

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    The present paper deals with the problem of calculating queue length distributions in a polling model with (exhaustive) k-limited service under the assumption of general arrival, service and setup distributions. The interest for this model is fueled by an application in the field of logistics. Knowledge of the queue length distributions is needed to operate the system properly. The multi-queue polling system is decomposed into single-queue vacation systems with k-limited service and state-dependent vacations, for which the vacation distributions are computed in an iterative approximate manner. These vacation models are analyzed via matrix-analytic techniques. The accuracy of the approximation scheme is verified by means of an extensive simulation study. The developed approximation turns out be accurate, robust and computationally efficient

    Functional Hair Cell Mechanotransducer Channels Are Required for Aminoglycoside Ototoxicity

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    Aminoglycosides (AG) are commonly prescribed antibiotics with potent bactericidal activities. One main side effect is permanent sensorineural hearing loss, induced by selective inner ear sensory hair cell death. Much work has focused on AG's initiating cell death processes, however, fewer studies exist defining mechanisms of AG uptake by hair cells. The current study investigated two proposed mechanisms of AG transport in mammalian hair cells: mechanotransducer (MET) channels and endocytosis. To study these two mechanisms, rat cochlear explants were cultured as whole organs in gentamicin-containing media. Two-photon imaging of Texas Red conjugated gentamicin (GTTR) uptake into live hair cells was rapid and selective. Hypocalcemia, which increases the open probability of MET channels, increased AG entry into hair cells. Three blockers of MET channels (curare, quinine, and amiloride) significantly reduced GTTR uptake, whereas the endocytosis inhibitor concanavalin A did not. Dynosore quenched the fluorescence of GTTR and could not be tested. Pharmacologic blockade of MET channels with curare or quinine, but not concanavalin A or dynosore, prevented hair cell loss when challenged with gentamicin for up to 96 hours. Taken together, data indicate that the patency of MET channels mediated AG entry into hair cells and its toxicity. Results suggest that limiting permeation of AGs through MET channel or preventing their entry into endolymph are potential therapeutic targets for preventing hair cell death and hearing loss

    Self-compassion and bedtime procrastination: an emotion regulation perspective

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    The current study extended previous research on self-compassion and health behaviours by examining the associations of self-compassion to bedtime procrastination, an important sleep-related behaviour. We hypothesized that lower negative affect and adaptive emotion regulation would explain the proposed links between self-compassion and less bedtime procrastination. Two cross-sectional online studies were conducted. Study 1 included 134 healthy individuals from the community (mean age 30.22, 77.4% female). Study 2 included 646 individuals from the community (mean age 30.74, 68.9% female) who were screened for the absence of clinical insomnia. Participants in both studies completed measures of self-compassion, positive and negative affect and bedtime procrastination. Participants in study 2 also completed a measure of cognitive reappraisal. Multiple mediation analysis in study 1 revealed the expected indirect effects of self-compassion on less bedtime procrastination through lower negative affect [b = − .09, 95% CI = (− .20, − .02), but not higher positive affect. Path analysis in study 2 replicated these findings and further demonstrated that cognitive reappraisal explained the lower negative affect linked to self-compassion [b = − .011; 95% CI = (− .025; − .003)]. The direct effect of self-compassion on less bedtime procrastination remained significant. Our novel findings provide preliminary evidence that self-compassionate people are less likely to engage in bedtime procrastination, due in part to their use of healthy emotion regulation strategies that downregulate negative mood

    Light-traffic analysis for queues with spatially distributed arrivals

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    We consider the following continuous polling system: Customers arrive according to a homogeneous Poisson process (or a more general stationary point process) and wait on a circle in order to be served by a single server. The server is ''greedy,'' in the sense that he always moves (with constant speed) towards the nearest customer. The customers are served according to an arbitrary service time distribution, in the order in which they are encountered by the server. First-order and second-order Taylor-expansions are found for the expected configuration of customers, for the mean queue length, and for expectation and distribution function of the workload. It is shown that under light traffic conditions the greedy server works more efficiently than the cyclically polling server

    Efficient simulation of backlogs in fluid flow lines

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    An Importance Sampling procedure to efficiently estimate overflow probabilities in continuous flow lines is described. The corresponding change of measure is found by generalizing the procedure that yields the change of measure for an ordinary fluid queue. Empirical results demonstrate the validity and effectiveness of the approach
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