Anticonvulsant effect of melatonin through ATP-sensitive channels in mice

Melatonin is a neurohormone secreted principally by the pineal gland. This molecule has various pharmacological properties including improving immune system, prevent cancer, anti-aging, and anti-oxidant effects. The anticonvulsant effects of melatonin have been proved by previous studies. Adenosine triphosphate (ATP)-sensitive potassium (KATP) channels are considered as an important target in the seizure modulation. The aim of the present study was to investigate the anticonvulsant effect of melatonin in pentylenetetrazole (PTZ)-induced seizures in mice, focusing on its ability to regulate KATP channels. Acute intraperitoneal administration of melatonin (40 and 80 mg/kg) increased clonic seizure threshold induced by intravenous administration of PTZ. Melatonin (40 and 80 mg/kg) increased the latency of clonic seizure and reduced its frequency in mice receiving an intraperitoneal injection of PTZ. Administration of glibenclamide, a KATP channels blocker, before intravenous injection of PTZ reduced melatonin anticonvulsant effect. Diazoxide and cromakalim, as KATP channels openers, increased antiseizure effect of melatonin in PTZ model of seizures. These findings suggest that the antiseizure effect of melatonin probably is gained through increasing the opening of KATP channels. © 2019 Société Française de Pharmacologie et de Thérapeutiqu

Identification of Hepatitis B Virus Surface Antigen (HBsAg) Genotypes and Variations in Chronic Carriers from Isfahan Province, Iran

Background: Hepatitis B virus (HBV) gene and protein variations are frequently been seen in chronic patients. The aims of study were to determine the genotypes as well as the patterns of variations distribution in chronically-infected patients from the central part of Iran.Methods: The surface gene was amplified, sequenced and subsequently aligned using international and national Iranian database. Results: All strains belonged to genotype D, subgenotype D1 and subtype ayw2. Of all 62 mutations occurred at 39 nucleotide positions, 31 (50%) were missense (amino acid altering) and 31 (50%) were silent (no amino acid changing). At the amino acid level, 30 substitutions occurred, however, 3 were in positions 122 and 127, corresponded to subtypic determination. 22 (73%) out of 30 amino acid mutations occurred in different immune epitopes within surface protein, of which 12 (54.54%) in B cell epitopes in 10 residues; 5 (45.45%) in T helper epitopes in positions; 5 (22.73%) in inside CTL epitopes in 4 residues. Conclusion: The distribution of amino acid mutations as well as the ratio between silent and missense nucleotide mutations showed a narrowly focused immune pressure had already been on the surface protein in these patients, led to the emergence of escape mutants in these patients

Impact of perceived connectivity on intention to use social media: Modelling the moderation effects of perceived risk and security

The main objective of this study is to assess the impact of perceived connectivity (PC) on the intention to use (IU) social media in organizations, as well as the moderating effects of perceived risk (PR) and perceived security (PS) on this relationship. Data were collected from 2, 556 social media users across Australia, Canada, India, the UK, and the US to test our proposed research model. Our results found that PC has a significant positive effect on the IU social media in organizations, and non-significant moderating effects of PR and PS. The study concludes with the implications for practice and research

Cyberloafing in IT classrooms: exploring the role of the psycho-social environment in the classroom, attitude to computers and computing courses, motivation and learning strategies

The purpose of this study is to find out the level of cyberloafing behaviors of the students in information technologies (IT) classrooms; and to examine the relationship between cyberloafing behaviors and the psycho-social perceptions, attitudes and motivation for the courses and learning strategies. Correlational method was utilized; and structural equation modelling is applied to analyze the data. The study was carried out with the students who take Computing I course in the IT classroom. Data were collected from 607 university students by utilizing five self-report instruments: demographic information form', cyberloafing activities scale', what is happening in this class? questionnaire', attitude to computers and computing courses questionnaire' and motivated strategies for learning questionnaire'. The results demonstrate that students' cyberloafing behaviors are influenced by their psycho-social perceptions, attitudes and learning strategies. However, the results demonstrate that students' cyberloafing behaviors aren't influenced by their motivation for the courses. Further research studies and implications are presented and discussed