A study of the role of nitric oxide in the mechanism of action of hydroalcoholic extract of saffron (Crocus sativus) on the electrophysiological properties of the rabbit atrioventricular node

Biologically active substances of plant origin represent an essential branch of modern cardiovascular pharmacotherapy. Furthermore, drugs of plant origin have the advantage of weaker adverse effects and lower prices than synthetic drugs. Pharmacological studies and traditional medical literature point to the anti-ischemic and hypotensive effects of the Crocus sativus L. (Iridacea). The major goals of the present study were: (1) to determine the negative dormotrophic properties of a hydroalcoholic extract of saffron on an isolated AV node and (2) to establish the role of nitric oxide in the mediating effects of saffron on the electrophysiological properties of the AV node. This was an experimental study. Selective stimulation protocols were used to independently quantify AV nodal recovery, facilitation and fatigue. We used isolated perfused rabbit AV node preparation, in three groups (N=32); in each group, we assessed the plant's effect in comparison with the control. In the pilot study, we used different concentrations (A=9 x 10-2 mg/L, B=19 x 10-2 mg/L and C=27 x 10-2 mg/L) to select the optimum concentration (19 x 10-2 mg/L) of the hydroalcoholic extract of saffron. Saffron has a depressant effect on basic and rate-dependent properties of the AV node. We observed an increasing AVCT (38.8 ±4 to 41.7 ±4 msec) and FRP (157.6 ±3 to 163.7 ±4 msec). Also saffron increased the amount of facilitation and the magnitude of fatigue (5.9 ±0.3 to 11.1 ±1 msec). The NOS inhibitor (L-NAME) has a preventative effect on the depressant effect of saffron on AVCT and FRP

Contributions of anterior cingulate cortex and basolateral amygdala to decision confidence and learning under uncertainty.

The subjective sense of certainty, or confidence, in ambiguous sensory cues can alter the interpretation of reward feedback and facilitate learning. We trained rats to report the orientation of ambiguous visual stimuli according to a spatial stimulus-response rule that must be learned. Following choice, rats could wait a self-timed delay for reward or initiate a new trial. Waiting times increase with discrimination accuracy, demonstrating that this measure can be used as a proxy for confidence. Chemogenetic silencing of BLA shortens waiting times overall whereas ACC inhibition renders waiting times insensitive to confidence-modulating attributes of visual stimuli, suggesting contribution of ACC but not BLA to confidence computations. Subsequent reversal learning is enhanced by confidence. Both ACC and BLA inhibition block this enhancement but via differential adjustments in learning strategies and consistent use of learned rules. Altogether, we demonstrate dissociable roles for ACC and BLA in transmitting confidence and learning under uncertainty

The Study on Relation of Human Papillomavirus High Risk Types with Bladder Transitional Cell Carcinoma

En este programa se hablará sobre las telecomunicaciones, se les contará qué es, como mueve al mundo actualmente y como la Universidad Militar Nueva Granada se prepara para formar a los mejores profesionales en este campo

Stimulation of oxytocin receptor during early reperfusion period protects the heart against ischemia/reperfusion injury: The role of mitochondrial ATP-sensitive potassium channel, nitric oxide, and prostaglandins

Postconditioning is a simple and safe strategy for cardioprotection and infarct size limitation. Our previous study showed that oxytocin (OT) exerts postconditioning effect on ischemic/reperfused isolated rat heart. The aim of this study was to investigate the involvement of OT receptor, mitochondrial ATP-sensitive potassium channel (mKATP), nitric oxide (NO) and cyclooxygenase (COX) pathways in OT postconditioning. Isolated rat hearts were divided into10 groups and underwent 30 min of regional ischemia followed by 120 min of reperfusion (n =6). In I/R (ischemia/reperfusion) group, ischemia and reperfusion were induced without any treatment. In OT group, oxytocin was perfused 5 min prior to beginning of reperfusion for 25 min. In groups 3-6, atosiban (oxytocin receptor blocker), L-NAME (N-Nitro-L-Arginine Methyl Ester, non-specific nitric oxide synthase inhibitor), 5-HD (5-hydroxydecanoate, mKATP inhibitor) and indomethacin (cyclooxygenase inhibitor) were infused prior to oxytocin administration. In others, the mentioned inhibitors were perfused prior to ischemia without oxytocin infusion. Infarct size, ventricular hemodynamic, coronary effluent, malondialdehyde (MDA) and lactate dehydrogenase (LDH) were measured at the end of reperfusion. OT perfusion significantly reduced infarct size, MDA and LDH in comparison with IR group. Atosiban, 5HD, L-NAME and indomethacin abolished the postconditioning effect of OT. Perfusion of the inhibitors alone prior to ischemia had no effect on infarct size, hemodynamic parameters, coronary effluent and biochemical markers as compared with I/R group. In conclusion, this study indicates that postconditioning effects of OT are mediated by activation of mKATP and production of NO and Prostaglandins (PGs). © 2015 Tehran University of Medical Sciences. All rights reserved

Synthesis, characterization and photo behavior of new poly(amide-imide)/montmorillonite nanocomposite containing N,N'-pyrromellitoyl-bis-L-alanine

Two new samples of poly(amide-imide)-nanocomposites were synthesized by insertion nano silicate particles in poly(amide-imide) (PAI) chains using a convenient solution intercalation technique. PAI as a source of polymer matrix was synthesized by the direct polycondensation reaction of N,N'-pyrromelitoyl-bis-L-alanine with 4,4'-diamino diphenyl ether in the presence of triphenyl phosphite (TPP), CaCl2, pyridine and N-methyl-2-pyrrolidone (NMP). Morphology and structure of the resulting PAI-nanocomposite films with 5 and 10% silicate particles were characterized by FTIR spectroscopy, X-ray diffraction (XRD) and scanning electron microscopy (SEM). The effect of clay dispersion and the interaction between clay and polymeric chains on the properties of nanocomposites films were investigated by using UV-Vis spectroscopy, thermogravimetric analysis (TGA) and water uptake measurements.DOI: http://dx.doi.org/10.4314/bcse.v27i3.1

Diagnostic value of D-dimer�s serum level in Iranian patients with cerebral venous thrombosis

Cerebral venous thrombosis (CVT) is a longterm debilitating vascular brain disease with high morbidity and mortality. It may be associated with rise in D-dimer level. The aim of this study was to examine this potential association and identify the critical D-dimer cut-off level corresponding to increase the risk of CVT. This case-control study was conducted on two groups of patients with and without CVT attending the Rasool Akram Hospital (Iran) during 2014 and 2015. D-dimer levels were measured by the rapid sensitive D-dimer assay. Data were analyzed by Spearman�s correlation coefficient test, independent-samples t-test, backward-selection multiple linear regression and multiple binary logistic regression analyses. Sensitivity-specificity tests were used to detect D-dimer cut-off for CVT. Differences between the D-dimer levels of the case and control groups were significant (P<0.001). It showed that each level of increase in the number of symptoms could increase the risk of thrombosis occurrence for about 3.5 times. All symptom types except for headache were associated with D-dimer level, while headache has negative association with D-dimer level. D-dimer cut-off point for CVT diagnosis was estimated at 350 ng/mg. We concluded that D-dimer serum level significantly rises in CVT patients. A rounded cut-off point of 350 ng/mg can be used as a diagnostic criterion for CVT prediction. © L. Hashami et al., 2016

Experimental wound healing using microamperage electrical stimulation in rabbits

We investigated the effects of microamperage electrical stimulation (MES) on the healing of skin incision in rabbits. Thirty male adult rabbits were randomly divided into sham-treated and experimental groups. Each group was divided into three subgroups, based on the duration of experiment (4, 7, and 15 days). A full-thickness incision was made on the skin of each rabbit. The experimental group received an MES of 200 microamperes current intensity for 2 h/day. Morphometrical and biomechanical evaluations were carried out. The mean number of fibroblasts at day 7 and the mean of tensile strength at day 15 were found to be significantly higher for the experimental group than for those in the sham-treated group (p < 0.01 and p < 0.05, respectively). Daily application of MES significantly accelerated the wound-healing process of full-thickness incision in the rabbits' skin

Review of factors resulting in systemic biases in the screening, assessment, and treatment of individuals at clinical high-risk for psychosis in the United States

BACKGROUND: Since its inception, research in the clinical high-risk (CHR) phase of psychosis has included identifying and exploring the impact of relevant socio-demographic factors. Employing a narrative review approach and highlighting work from the United States, sociocultural and contextual factors potentially affecting the screening, assessment, and service utilization of youth at CHR were reviewed from the current literature. RESULTS: Existing literature suggests that contextual factors impact the predictive performance of widely used psychosis-risk screening tools and may introduce systemic bias and challenges to differential diagnosis in clinical assessment. Factors reviewed include racialized identity, discrimination, neighborhood context, trauma, immigration status, gender identity, sexual orientation, and age. Furthermore, racialized identity and traumatic experiences appear related to symptom severity and service utilization among this population. CONCLUSIONS: Collectively, a growing body of research from the United States and beyond suggests that considering context in psychosis-risk assessment can provide a more accurate appraisal of the nature of risk for psychosis, render more accurate results improving the field\u27s prediction of conversion to psychosis, and enhance our understanding of psychosis-risk trajectories. More work is needed in the U.S. and across the globe to uncover how structural racism and systemic biases impact screening, assessment, treatment, and clinical and functional outcomes for those at CHR

Using Machine Learning Algorithms to Develop a Clinical Decision-Making Tool for COVID-19 Inpatients.

BACKGROUND: Within the UK, COVID-19 has contributed towards over 103,000 deaths. Although multiple risk factors for COVID-19 have been identified, using this data to improve clinical care has proven challenging. The main aim of this study is to develop a reliable, multivariable predictive model for COVID-19 in-patient outcomes, thus enabling risk-stratification and earlier clinical decision-making. METHODS: Anonymised data consisting of 44 independent predictor variables from 355 adults diagnosed with COVID-19, at a UK hospital, was manually extracted from electronic patient records for retrospective, case-control analysis. Primary outcomes included inpatient mortality, required ventilatory support, and duration of inpatient treatment. Pulmonary embolism sequala was the only secondary outcome. After balancing data, key variables were feature selected for each outcome using random forests. Predictive models were then learned and constructed using Bayesian networks. RESULTS: The proposed probabilistic models were able to predict, using feature selected risk factors, the probability of the mentioned outcomes. Overall, our findings demonstrate reliable, multivariable, quantitative predictive models for four outcomes, which utilise readily available clinical information for COVID-19 adult inpatients. Further research is required to externally validate our models and demonstrate their utility as risk stratification and clinical decision-making tools