8 resultados para Abdul Hekmat

em BORIS: Bern Open Repository and Information System - Berna - Suiça


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Intrahepatic cholestasis of pregnancy may be complicated by fetal arrhythmia, fetal hypoxia, preterm labor, and, in severe cases, intrauterine death. The precise etiology of fetal death is not known. However, taurocholate has been demonstrated to cause arrhythmia and abnormal calcium dynamics in cardiomyocytes. To identify the underlying reason for increased susceptibility of fetal cardiomyocytes to arrhythmia, we studied myofibroblasts (MFBs), which appear during structural remodeling of the adult diseased heart. In vitro, they depolarize rat cardiomyocytes via heterocellular gap junctional coupling. Recently, it has been hypothesized that ventricular MFBs might appear in the developing human heart, triggered by physiological fetal hypoxia. However, their presence in the fetal heart (FH) and their proarrhythmogenic effects have not been systematically characterized. Immunohistochemistry demonstrated that ventricular MFBs transiently appear in the human FH during gestation. We established two in vitro models of the maternal heart (MH) and FH, both exposed to increasing doses of taurocholate. The MH model consisted of confluent strands of rat cardiomyocytes, whereas for the FH model, we added cardiac MFBs on top of cardiomyocytes. Taurocholate in the FH model, but not in the MH model, slowed conduction velocity from 19 to 9 cm/s, induced early after depolarizations, and resulted in sustained re-entrant arrhythmias. These arrhythmic events were prevented by ursodeoxycholic acid, which hyperpolarized MFB membrane potential by modulating potassium conductance. CONCLUSION: These results illustrate that the appearance of MFBs in the FH may contribute to arrhythmias. The above-described mechanism represents a new therapeutic approach for cardiac arrhythmias at the level of MFB.

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Fog is a potential source of water that could be exploited using the innovative technology of fog collection. Naturally, the potential of fog has proven its significance in cloud forests that are thriving from fog interception. Historically, the remains of artificial structures in different countries prove that fog has been collected as an alternative and/or supplementary water source. In the beginning of the 19th century, fog collection was investigated as a potential natural resource. After the mid-1980s, following success in Chile, fog-water collection commenced in a number of developing countries. Most of these countries are located in arid and semi-arid regions with topographic and climatic conditions that favour fog-water collection. This paper reviews the technology of fog collection with initial background information on natural fog collection and its historical development. It reviews the climatic and topographic features that dictate fog formation (mainly advection and orographic) and the innovative technology to collect it, focusing on the amount collected, the quality of fog water, and the impact of the technology on the livelihoods of beneficiary communities. By and large, the technology described is simple, cost-effective, and energy-free. However, fog-water collection has disadvantages in that it is seasonal, localised, and the technology needs continual maintenance. Based on the experience in several countries, the sustainability of the technology could be guaranteed if technical, economic, social, and management factors are addressed during its planning and implementation.

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Sickle cell anemia (SCA) is a hemolytic disease characterized by the production of abnormal hemoglobin chains and distorted red blood cell morphology or sickling. "Sickle cell crisis" includes vaso-occlusive crisis, a plastic crisis, sequestration crisis, haemolytic crisis and often culminating in serious complications, organ damage and even sudden death. Post-mortem computed tomography (PMCT) findings of sickle cell disease have never been reported in literature. This case of sudden death from acute hemolytic crisis in SCA where post-mortem computed tomography (PMCT) and autopsy findings complemented each other, both revealing findings invisible to the other and both crucial to the case.

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BACKGROUND AND PURPOSE Eligibility criteria are a key factor for the feasibility and validity of clinical trials. We aimed to develop an online tool to assess the potential effect of inclusion and exclusion criteria on the proportion of patients eligible for an acute stroke trial. METHODS We identified relevant inclusion and exclusion criteria of acute stroke trials. Based on these criteria and using a cohort of 1537 consecutive patients with acute ischemic stroke from 3 stroke centers, we developed a web portal feasibility platform for stroke studies (FePASS) to estimate proportions of eligible patients for acute stroke trials. We applied the FePASS resource to calculate the proportion of patients eligible for 4 recent stroke studies. RESULTS Sixty-one eligibility criteria were derived from 30 trials on acute ischemic stroke. FePASS, publicly available at http://fepass.uni-muenster.de, displays the proportion of patients in percent to assess the effect of varying values of relevant eligibility criteria, for example, age, symptom onset time, National Institutes of Health Stroke Scale, and prestroke modified Rankin Scale, on this proportion. The proportion of eligible patients for 4 recent stroke studies ranged from 2.1% to 11.3%. Slight variations of the inclusion criteria could substantially increase the proportion of eligible patients. CONCLUSIONS FePASS is an open access online resource to assess the effect of inclusion and exclusion criteria on the proportion of eligible patients for a stroke trial. FePASS can help to design stroke studies, optimize eligibility criteria, and to estimate the potential recruitment rate.

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BACKGROUND AND AIMS Combined multichannel intraluminal impedance and esophageal manometry (MII-EM) measures concomitantly bolus transit and pressure changes allowing determination of the functional impact of esophageal motility abnormalities. Ten years ago our laboratory reported MII-EM results in 350 consecutive patients. Since then high-resolution impedance manometry (HRIM) became available and the definitions of ineffective esophageal motility (IEM) and nutcracker esophagus were revised. The aim of this study was to assess the impact of these developments on esophageal function testing. METHODS From August 2012 through May 2013, HRIM was performed in 350 patients referred for esophageal function testing. Each patient received 10 liquid and 10 viscous swallows. While taking advantage of the new technology and revised criteria, HRIM findings were classified according to the conventional criteria to allow more appropriate comparison with our earlier analysis. RESULTS Compared with the study performed 10 years ago, the prevalence of normal manometry (36% vs. 35%), achalasia (7% vs. 8%), scleroderma (1% vs. 1%), hypertensive lower esophageal sphincter (LES) (7% vs. 7%), and hypotensive LES (1% vs. 2%) remained the same, whereas the prevalence of distal esophageal spasm (9% vs. 3%), nutcracker esophagus (9% vs. 3%), and poorly relaxing LES (10% vs. 3%) decreased and the prevalence of IEM increased (20% vs. 31%) significantly. Compared with the early study, normal liquid bolus transit was significantly different in patients with hypertensive LES (96% vs. 57%) and poorly relaxing LES (55% vs. 100%). CONCLUSIONS This study brings to light the increase in prevalence of IEM. In addition, it suggests that the hypertensive LES and poorly relaxing LES may each affect bolus transit in about half of these patients.