Decision Trees for Applicability of Evolution Rules in Transition P Systems

Transition P Systems are a parallel and distributed computational model based on the notion of the cellular membrane structure. Each membrane determines a region that encloses a multiset of objects and evolution rules. Transition P Systems evolve through transitions between two consecutive configurations that are determined by the membrane structure and multisets present inside membranes. Moreover, transitions between two consecutive configurations are provided by an exhaustive non-deterministic and parallel application of active evolution rules subset inside each membrane of the P system. But, to establish the active evolution rules subset, it is required the previous calculation of useful and applicable rules. Hence, computation of applicable evolution rules subset is critical for the whole evolution process efficiency, because it is performed in parallel inside each membrane in every evolution step. The work presented here shows advantages of incorporating decision trees in the evolution rules applicability algorithm. In order to it, necessary formalizations will be presented to consider this as a classification problem, the method to obtain the necessary decision tree automatically generated and the new algorithm for applicability based on it

Prediction of Liver-Related Events Using Fibroscan in Chronic Hepatitis B Patients Showing Advanced Liver Fibrosis

Liver stiffness measurement (LSM) using transient elastography (FibroScan®) can assess liver fibrosis noninvasively. This study investigated whether LSM can predict the development of liver-related events (LREs) in chronic hepatitis B (CHB) patients showing histologically advanced liver fibrosis.Between March 2006 and April 2010, 128 CHB patients with who underwent LSM and liver biopsy (LB) before starting nucleot(s)ide analogues and showed histologically advanced fibrosis (≥F3) with a high viral loads [HBV DNA ≥2,000 IU/mL] were enrolled. All patients were followed regularly to detect LRE development, including hepatic decompensation (variceal bleeding, ascites, hepatic encephalopathy, spontaneous bacterial peritonitis, hepatorenal syndrome) and hepatocellular carcinoma (HCC).The mean age of the patient (72 men, 56 women) was 52.2 years. During the median follow-up period [median 27.8 (12.6-61.6) months], LREs developed in 19 (14.8%) patients (five with hepatic decompensation, 13 with HCC, one with both). Together with age, multivariate analysis identified LSM as an independent predictor of LRE development [P<0.044; hazard ratio (HR), 1.038; 95% confidence interval (CI), 1.002-1.081]. When the study population was stratified into two groups using the optimal cutoff value (19 kPa), which maximized the sum of sensitivity (61.1%) and specificity (86.2%) from a time-dependent receiver operating characteristic curve, patients with LSM>19 kPa were at significantly greater risk than those with LSM≤19 kPa for LRE development (HR, 7.176; 95% CI, 2.257-22.812; P = 0.001).LSM can be a useful predictor of LRE development in CHB patients showing histologically advanced liver fibrosis

Síndrome metabólico y trastornos nutricionales

El síndrome metabólico es un tema actual y de debate en la comunidad científica; su enfoque es esencial, pues se relaciona con enfermedades cardiovasculares (ECV) y diabetes, lo que implica un mayor riesgo de mortalidad, mientras que, los trastornos nutricionales son manifestaciones extremas de una variedad de preocupaciones por el peso y la comida experimentados por mujeres y hombres. Bajo este contexto, dentro del presente manuscrito se describen aspectos generales donde se destaca apartados tales como: definición del síndrome metabólico, requerimientos nutricionales en la adolescencia, hábitos nutricionales de la adolescencia ecuatoriana, factores que afectan a la nutrición, grupos alimenticios, estado nutricional de los adolescentes en el Ecuador y realidad alimentaria, cada uno de estos apartados cuenta con sustento teórico que ayuda a una mejor comprensión del lector, es decir, todo esto bajo un enfoque bibliográfico

Effects of electret coating technology on coronary stent thrombogenicity

Stent thrombosis (ST) is a catastrophic event and efforts to reduce its incidence by altering blood-stent interactions are longstanding. A new electret coating technology that produces long-lasting negative charge on stent surface could make them intrinsically resistant to thrombosis. We assessed the thrombogenicity of stents using an annular perfusion model with confocal microscopy, and determined the efficacy of electret coating technology to confer thrombo-resistant properties to standard stents. Using an annular perfusion chamber, Bare Metal Stent (BMS), standard uncoated DES (DES), and Electret-coated DES (e-DES) were exposed to human blood under arterial flow conditions. Deposits of fibrinogen and platelets on the stent surface were analyzed using immunofluorescence staining and confocal microscopy. Surface coverage by fibrinogen and platelets and the deposit/aggregate size were quantified using computerized morphometric analysis. The experimental methodology produced consistent, quantifiable results. Area of stent surface covered by fibrinogen and platelets and the average size of the deposits/aggregates were lowest for e-DES and highest on BMS, with DES in the middle. The size of fibrinogen–deposits showed no differences between the stents. The testing methodology used in our study successfully demonstrated that electret coating confers significant antithrombotic property to DES stents. These findings warrant confirmation in a larger study

Diagnostic hepatic haemodynamic techniques: safety and radiation exposure

BACKGROUND & AIMS Hepatic venous pressure gradient (HVPG) and transjugular liver biopsy (TJLB) are increasingly used in the management of patients with liver disease. We aimed to describe the safety profile of these procedures, providing data on the intra- and periprocedure complications, radiation exposure and amount of iodinated contrast material used. METHODS In 106 consecutive patients undergoing HVPG and TJLB data on fluoroscopy time (FT), absorbed radiation dose, equivalent effective dose (mSv) and volume of iodinated contrast material (ICM) were prospectively collected and reviewed, together with clinical and laboratory data. Incidence and severity of procedure-related complications were assessed. In 28 hospitalised patients, creatinine values after 72 hours of the procedure were reviewed to identify contrast-induced nephropathy (CIN). RESULTS Median effective radiation dose was 5.4 mSv (IQR 10 mSv). A total 28.3% of patients exceeded an effective exposure of 10 mSv and 9.4% exceeded 20 mSv. Only age and BMI correlated with radiation dose (R = .327, P=.001 and R = .410, P<.0001 respectively), and only BMI remained independently associated with an exposure over 20 mSv. Procedure-related complications occurred in eight patients (7.5%), and were minor in six cases. Median ICM volume was 12.5 mL. 6/28 patients met the diagnostic criteria for CIN. CONCLUSIONS Hepatic venous pressure gradient and Transjugular liver biopsy show a good safety profile and radiation exposure associated with these procedures is in most of the cases low. In hepatic haemodynamic procedures, efforts should be made to reduce the radiation dose in patients with overweight/obesity and to use the minimal possible ICM volume in patients with acute-on-chronic liver failure

Endothelin (ET)-1 Inhibits Nicotinamide Adenine Dinucleotide Phosphate Oxidase Activity in Human Abdominal Aortic Endothelial Cells: A Novel Function of ETB1 Receptors

Endothelin (ET)-1 stimulates nicotinamide adenine dinucleotide phosphate (NADPH) oxidases and increases superoxide production in some cells such as vascular smooth muscle cells. Here, we reported that ET1 inhibited NADPH oxidase activity, superoxide generation, and cell proliferation in human abdominal aortic endothelial cells (HAAECs) via the ETB1-Pyk2-Rac1-Nox1 pathway. Superoxide production was determined by assessing ethidium fluorescence using flow cytometry in HAAECs exposed to ET1 (10–30 nm) at different time intervals. ET1 significantly decreased superoxide production in HAAECs in the presence of NG-nitro-L-arginine methyl ester, indicating that ET1 suppressed superoxide generation independent of nitric oxide synthase. ET1 significantly attenuated NADPH oxidase activity and cell proliferation, which could be abolished by silence of Nox1 gene, suggesting that ET1-induced inhibition of NADPH oxidase activity was mediated by Nox1. Furthermore, RNA interference silence of ETB1 receptors significantly increased NADPH oxidase activity, and blocked the inhibitory effect of ET1 on NADPH oxidase activity. Activation of ETB1 receptors by ET1 suppressed protein phosphorylation of pyk2 (Y402) and Rac1, suggesting that ET1 inhibited NADPH oxidase activity via ETB1-Pyk2-Rac1 pathway. Indeed, inhibition of Pyk2 by AG-17 abolished ET1-induced suppression of NADPH oxidase activity. ET1 also attenuated angiotensin II-induced activation of NADPH oxidase and cell proliferation. This study demonstrated, for the first time, that ET1, via ETB1, inhibited NADPH oxidase activity in HAAECs by suppressing the Pyk2-Rac1-Nox1 pathway. This finding reveals a novel function of ETB1 receptors in regulating endothelial NADPH oxidase activity, superoxide production, and cell proliferation, opening a new avenue for understanding the role of ETB1 receptors in protecting endothelial cells