Rate-dependent and antiarrhythmic reentrant tachycardia (AVNRT) effects of simvastatin in isolated rabbit atrioventricular nodal model

Background and purpose: Several previous studies have shown the direct and indirect effects of statins on supraventricular and ventricular arrhythmia. The purpose of the present study is to determine (1) whether Simvastatin modifies the rate-dependent properties of the AV node, (2) to what extent such changes are related to effect of Simvastatin on the basic properties of AV nodal conduction and refractoriness. Materials and methods: AV nodal refractoriness (AVERP & AVFRP) and rate dependency protocols Fatigue and Facilitation were used to assesse the electrophysiological properties of AV node. We used an isolated perfussed rabbit with AV nodal preparation in one group (N=8). The stimulation protocols were carried out during control phase and in the presence of various concentrations of Simvastatin (0.5 , 0.8 , 1, 3 ,10 μm). Results: Simvastatin in concentration-dependent manner successfully prolonged effective and functional nodal refractory period (AVERP & AVFRP). Also an increase in Wenckebach cycle length was observed. Simvastatin in high concentration (3,10 μm) increases the arrhythmia threshold. Various concentrations of simvastatin increased fatigue, but it reached to significant level only at 30 μM. Conclusion: Simvastatin has potential anti-AVNRT effects by elevating arrhythmia threshold and prolongation of nodal refractoriness

Stress among medical students of Gorgan (South East of Caspian Sea), Iran

Objective: This study aims to estimate the prevalence of psychological stress and association between the levels of stress and study variables among Gorgan medical students. Materials and methods: All three year medical students (129 basic sciences students) in Gorgan Faculty of Medicine, Golestan University of medical Sciences, were asked to complete the Kessler 10 questionnaire. Results: The findings showed mild, moderate and severe stress among 26.22%, 20.50% and 14.75% study subjects. 39.35% of medical students had no stress. There was statistically significant association between year of study and stress levels (p= 0.040). Conclusion: The results indicate that there is a decrease in the psychological health of first year medical students. Provided that stress management courses are organised by medical schools, when the students arrive, they will cope up with the stress in coming years. These courses may reduce the negative effects of stress on medical students. By providing such courses and reducing stress level, medical students may improve their medical education

Studies of Seed Characteristics of Ecotypes of Lucerne, \u3cem\u3eBromus\u3c/em\u3e and \u3cem\u3eAgropyron\u3c/em\u3e in Response to \u3cem\u3eFusarium Oxysporum\u3c/em\u3e and \u3cem\u3eF. Solani\u3c/em\u3e

Vigorous seeds and seedlings are more resistant to pathogens than non-vigorous seeds and seedlings (Kim, 1994). Therefore, it is necessary to assess seed and seedling performance in response to seed borne fungi

Altered levels of nodal excitability by rate-dependent inhibitory effects of essential oil of Citrus aurantium on the electrophysiological properties of isolated perfused rabbit AV-Node. Protective role in the prevention of ouabain toxicity [Alteración de los niveles de excitabilidad nodal por efectos inhibitorios velocidad-dependiente del aceite esencial de Citrus aurantium sobre las propiedades electrofisiológicas del nodo AV aislado y perfundido de conejo. Papel protector en la prevención de toxicidad por ouabaína]

Treatment of supraventricular arrhythmia includes a wide range of medical interventions. Herbal remedies are suitable alternatives to synthetic drugs due to their availability, minimal side effects and lower price. Pharmacological studies and traditional medical literature point to the cardiovascular effects of Citrus aurantium L. (Rutaceae) in many instances. In the present study we used isolated perfused AV-node of rabbit as an experimental model to determine the effect of various concentrations of essential oil of C. aurantium (0.1-0.3 v/v) on the nodal conduction time and refractoriness of an isolated rabbit AV-nodal preparations. Selective stimulation protocols were used to independently quantify AV nodal recovery, facilitation and fatigue in 18 rabbits. Our results showed concentration-dependent and rate-independent suppressive effects of essence of C. aurantium on the Wenchebach cycle length (WBCL), AV Conduction Time (AVCT) and effective and functional refractory periods (ERP & FRP). Functional properties such as facilitation and fatigue were significantly increased by this plant. Citrus aurantium plays a protective role against the toxic effects of ouabaine by increasing AV nodal conduction time and refractoriness. The above results indicated differential effects of C. aurantium on slow and fast pathways, with a dominant role on fast pathways. This research has explained the protective role of C. aurantium on ouabaine toxicity. All results indicated the potential anti-arrhythmic effects of C. aurantium in treating supraventricular tachyarrhythmia

Studies of Seed Characteristics of Ecotypes of Lucerne, \u3cem\u3eBromus\u3c/em\u3e and \u3cem\u3eAgropyron\u3c/em\u3e in Response to \u3cem\u3eFusarium Oxysporum\u3c/em\u3e and \u3cem\u3eF. Solani\u3c/em\u3e

Vigorous seeds and seedlings are more resistant to pathogens than non-vigorous seeds and seedlings (Kim, 1994). Therefore, it is necessary to assess seed and seedling performance in response to seed borne fungi

Alleviation of experimental allergic encephalomyelitis in C57BL/6 mice by Soy Daidzein

Experimental allergic encephalomyelitis (EAE) is considered as the murine model of multiple sclerosis. Daidzein a phytostrogenic compound of soy is known to impose immunomodulatory and antioxidative effects. We conducted this study to assess the potential protective and therapeutic effects of daidzein on allergic encephalomyelitis. C57BL/6 mice were induced with allergic encephalomyelitis using myelin oligodendrocyte glycoprotein (35-55) and received daidzein or dimethyl sulfoxide as the vehicle control. To assess the protective effect of daidzein, the mice were administered with 20 mg/kg of daidzein from 21 days prior to 21 days post EAE induction on a daily basis. To evaluate the therapeutic effect of daidzein, mice were fed with 300 mg/kg daidzein after the appearance of the first clinical signs for 10 days. One day after the last gavage, the mice were sacrificed. Spleen and brain were removed for further histological and immunological analysis. Feeding mice with low dose of daidzein prior to disease induction did not affect disease severity. However, treating with high dose of daidzein after the onset of the disease reduced interferon-3 and interleukin-12 secretion, enhanced interleukin-10 production, suppressed lymphocyte proliferation, and decreased cytotoxicity as judged by lactate dehydrogenase release. In conclusion, daidzein reduced the extent of demyelination and disease severity. Chronic oral therapy with low dose of daidzein did not prevent experimental autoimmune encephalomyelitis. However, high doses of daidzein could prohibit disease exacerbation. © Summer 2014, Iran J Allergy Asthma Immunol. All rights reserved

Effects of intermittent fasting on experimental autoimune encephalomyelitis in C57BL/6 mice

Several religions recommend periods of fasting. One of the most frequently asked questions of MS patients before the holy month of Ramadan is weather fasting might have an unfavorable effect on their disease course. This debate became more challenging after the publication of experimental studies suggesting that calorie restriction prior to disease induction attenuates disease severity. We conducted this study to assess early and late effects of fasting on the animal model of MS, known as autoimmune encephalomyelitis. EAE was induced in the C57BL/6 mice, using Myelin Oligodendrocyte Glycopeptide (MOG) 35-55 and they fasted every other day either after the appearance of the first clinical sign or 30 days after disease induction for ten days. Thereafter, the mice were sacrificed for further histological and immunological evaluations. Intermittent fasting after the establishment of EAE did not have any unfavorable effect on the course of disease. Moreover, fasting at the early phase of disease alleviated EAE severity by ameliorating spinal cord demyelination. Fasting suppressed the secretion of IFN-γ, TNF-α and raised IL-10 production in splenocytes. Fasting was also associated with a lower percent of cytotoxicity. Intermittent fasting not only had no unfavorable effect on EAE but also reduced EAE severity if started at early phase of disease. © Summer 2016, Iran J Allergy Asthma Immunol. All rights reserved

Health-Related Quality of Life and its Determinants Among Women With Diabetes Mellitus: A Cross-Sectional Analysis

Background: Diabetes is a chronic and threatening condition. However, there are controversies on the factors affecting the health related quality of life (HRQOL) in patients with diabetes. Objectives: The current study aimed to evaluate HRQOL and its determinants among females with type II diabetes referred to Diabetes Clinic of Khoy city, Northwest of Iran. Patients and Methods: This cross-sectional study was performed on 352 eligible females with diabetes referring to Diabetes Clinic of Khoy. The study data were collected using a three-part instrument including a socio-demographic questionnaire, a questionnaire to assess patients’ knowledge on diabetes and the world health organization’s quality of life (WHOQOL-BREF) questionnaire. Based on descriptive and inferential statistics, analyses were conducted using frequency, independent samples t–test, correlation coefficient and regression analysis. Results: The total mean score of QOL was 58.02 ± 17.63. The lowest and the highest mean scores were observed in physical health and social relationship domains (53.84 ± 17.09) and (65.08 ± 14.87), respectively. The regression models revealed that age, education, duration of disease, and family income were significantly associated with all areas of quality of life (P < 0.05). The results also revealed that co-morbidity was significantly correlated with the overall quality of life and the physical health domain (P < 0.01). Conclusions: The mean score of quality of life (QOL) in females with diabetes was far from desirable condition. These findings can help physicians and healthcare providers to design suitable interventions to improve the patients QOL

Effect of oral genistein administration in early and late phases of allergic encephalomyelitis

Objective(s): Experimental allergic encephalomyelitis (EAE) is an autoimmune disease validated as animal model of multiple sclerosis (MS). Administration of genistein, a phytoestrogenic component of soy, to mice at the onset of EAE is known to attenuate the clinical signs of the disease. The potential effects of genistein on established EAE is less studied. In the current study, we aimed to compare the effects of genistein administration on EAE severity in early and late phases of the disease. Materials and Methods: The C57BL/6 mice were induced with EAE, using MOG 35-55 and gavaged with genistein (300 mg/kg) either after the appearance of the first clinical sign or 30 days post disease induction for ten days. 24 hr after the last gavage, mice were sacrificed. Brains and spleens were removed for assessing lymphocyte proliferation, cell cytotoxicity, and cytokine profile. Spinal cords were dissected to assess the amount of demyelination using Luxol fast blue/cresyl violet staining. Results: Administering mice with genistein, after the establishment of EAE, did not reverse the clinical signs of disease. However, treating with genistein at the onset of disease alleviated the clinical signs by reducing neuronal demyelination. Genistein suppressed the production of IFN-γ and enhanced IL-10 secretion in splenocyte and brain. Genistein also reduced IL-12 and TNF-α secretion in splenocytes, suppressed the proliferation of T-cells, and reduced the cell cytotoxicity. Conclusion: Genistein oral therapy might only reduce EAE severity if started in early phases of the disease

Age-dependent dynamic electrophysiological field potential behavior of atrioventricular node during experimental AF in rabbit

Introduction: Electrophysiological studies have demonstrated a relationship between aging and atrioventricular (AV) nodal conduction and refractoriness. The aim of the present study was to determine the effects of nodal aging on dynamic AV nodal field potential recording during atrial fibrillation (AF) in rabbit. Methods: Two groups of male New Zealand rabbits (neonatal 2-week-olds and adult 12-week-olds, n=14 each group) were used in this study. Field potential recordings were executed by silver electrodes with a diameter of 100 μM. Pre-defined stimulation protocols of AF, zone of concealment (ZOC) and concealed conduction for determination of the electrophysiological properties of the AV-node were separately applied in each group. Results: Results of the study showed that mean ventricular rate (HH) during atrial fibrillation was smaller in the neonatal compared to the adult group (229.1 ± 8.3 versus 198.6 ± 13.1 msec, respectively). Also ventricular distribution conduction pattern showed two peaks in the adult and one peak in the neonatal group. Analyzing the zone of concealment in different rates and after concealed beat indicated that the zone of concealment in neonates were significantly smaller compared with adult rabbits and increasing zone of concealment, which is accompanied with increasing ventricular rate is abrogated in the neonatal group (5 ± 3.3, 12.2 ± 6.3 msec). Conclusion: The results of this study showed that the electrophysiological protective dynamic behavior of the AV node during atrial fibrillation is smaller in neonates compared to adults. Narrower zone of concealment, abrogation rate dependent trend of the zone of concealment and shorter nodal refractoriness can account for the specific nodal electrophysiological properties of neonatal rabbits