4,490 research outputs found
Scopolamine reduces the density of M1 muscarinic neurons in rats' hippocampus
Cholinergic system in CNS is involved in learning and memory. Scopolamine as muscarinic acetylcholine receptor antagonist is used for creation of memory impairment. The purpose of this study is evaluation of scopolamine-based amnesia on memory retention and the effect of this phenomenon on the number of neurons contains M1-receptors in the male Wistar rats hippocampal regions. Thirty-five male Wistar rats (200±20 g) were distributed randomly into five groups. Control group (intact samples) and 3 experimental groups with sham group (saline) were tested by the method of passive avoidance (shuttle box) in doses of 0.2, 0.5 and 1 mg/kg (intraperitoneally) as a single dose. After one week, memory test was taken from the rats. Finally, brains dissected from sacrificed rats, and then processed tissues were stained with antibody against M1 receptors (Immunohistochemistry technique) followed by counting of hippocampal CA1, CA3 and DG regions. Our results showed significant decrease in neurons contains M1-receptors in all area of hippocampus. We found that the less number of M1-neurons showed in 1 mg/kg dose of scopolamine. We concluded that scopolamine as muscarinic acetylcholine receptor antagonist can reduce dose-dependently the density of M1-neurons in all areas of hippocampus
Morphine/codeine ratio, a key in investigating a case of doping
Introduction: Consumption of codeine can lead to positive urine test for morphine in athletes. Morphine is classified as a prohibited doping drug while Codeine is not. Morphine/codeine ratio is used in forensic medicine to distinguish the consumption of codeine from abuse of morphine and other narcotics. Case Presentation: We present an athlete with positive urine test for morphine with a history of consumption of codeine. The disciplinary committee came to conclusion that the athlete had not consumed morphine and did not violate doping code based on morphine/codeine ratio. Conclusions: Analysis of codeine to morphine metabolism rate is needed when we are using morphine/codeine ratio to rule out abuse of narcotics. WADA should consider analysis for the CYP2D6 alleles (main metabolizer of codeine) in case of including morphine/codeine ratio in future prohibited list. The possibility of ultra-rapid CYP2D6 cannot be ruled out in certain results of morphine/codeine near the cut point. © 2015, Sports Medicine Research Center
Knowledge of medical professionalism in medical students and physicians at Shahid Beheshti University of Medical Sciences and affiliated hospitals-Iran
Although medical professionalism is a fundamental aspect of competence in medicine and a distinct facet of physicians' competence, evidence suggests that the subject of professionalism is not taught or assessed as part of medical students' curricula in Iran and many other countries. Assessing the knowledge of medical students and physicians about medical professionalism seems to be helpful in identifying the weaknesses of training in the field of professionalism and devise plans for future training on the subject. The present cross-sectional, quantitative, observational, and prevalence study recruited 149 medical interns, clinical residents, physicians, and professors working in hospitals selected through stratified random sampling using a questionnaire designed by the researchers and confirmed for its validity and reliability. The results were analyzed by Stata at a significance level of 0.05. Out of 149 cases, 61.64 were male with the mean age of 30.81 years. A total of 66 participants (44.29) (95 confidence interval CI: 36.44%-52.44%) had heard and 83 (55.70%) (95% CI: 47.55%-63.55%) had not heard the term 'medical professionalism' before the study. After adjusting for potential confounders, age and degree did not have statistically significant difference in assessed knowledge of medical professionalism, but sex had (mean difference: 5.88, P=0.045), and the mean of the female was significantly higher than that of the male participants. The mean percentage of correct answers was 47.67. The present study demonstrated that the medical professionals working in the national healthcare system have an unfavorable theoretical knowledge about medical professionalism in Iran; although this does not indicate that their practices are unethical, it should be noted that one of the prerequisites of possessing a high level of medical professionalism and for establishing a proper relationship between the medical community and the patients is to have a proper knowledge of this concept. Improving behaviors and performances in medical professions requires adequate training on the concepts of medical professionalism and consequently the assessment of the levels of professionalism achieved in medical professionals. © 2016 the Author(s). Published by Wolters Kluwer Health, Inc. All rights reserved
Universal spectral statistics in Wigner-Dyson, chiral and Andreev star graphs II: semiclassical approach
A semiclassical approach to the universal ergodic spectral statistics in
quantum star graphs is presented for all known ten symmetry classes of quantum
systems. The approach is based on periodic orbit theory, the exact
semiclassical trace formula for star graphs and on diagrammatic techniques. The
appropriate spectral form factors are calculated upto one order beyond the
diagonal and self-dual approximations. The results are in accordance with the
corresponding random-matrix theories which supports a properly generalized
Bohigas-Giannoni-Schmit conjecture.Comment: 15 Page
Analysis of the effect of subcutaneous injection of omental-derived cells on the healing of third degree burns in rats: A preliminary study Effet de l�injection sous-cutanée de cellules épiploïques sur la cicatrisation de brûlures du troisième degré chez le rat: �tude préliminaire
Burn injury is considered a global health issue. Third degree burn wounds do not heal spontaneously and require skin grafts. Some factors could contribute to wound healing. In this study we assessed the effect of non-fatty omental cells in burn wound healing. Similar third degree burn wounds were induced on the back of 192 rats. Forty-eight of these rats were put in a control group that did not receive any treatment. The rest of the rats were put in 3 groups, each receiving a different treatment regime. Rats in group 2 had a daily application of silver sulfadiazine; group 3 rats were injected with omental cells, and group 4 rats were injected with phosphate buffer saline (PBS) once, followed by daily application of Vaseline to the burned region. Parameters such as open epidermis length, number of epidermal cell layers, granulation tissue thickness (GTT) and neutrophil density were evaluated in each group. The average open epidermis length in the omental cell group was less than in the other groups on days 10 and 20 (P<0.05). The thickness of epidermal cell layers in the group receiving cells was greater than in the other groups on all days. On the 20th day, there was a significant difference in GTT between the four groups (P<0.05). The injection of non-fatty omental cells has a positive effect on third degree burn wounds in rats. © 2018, Mediterranean Club for Burns and Fire Disasters. All rights reserved
Mutations of the ret protooncogene in German multiple endocrine neoplasia families: Relation between genotype and phenotype.
It has been suggested that not only the position but also the nature of the mutations of the ret protooncogene strongly correlate with the clinical manifestation of the multiple endocrine neoplasm type 2 (MEN 2) syndrome. In particular, individuals with a Cys634-Arg substitution should have a greater risk of developing parathyroid disease. We, therefore, analyzed 94 unrelated families from Germany with inherited medullary thyroid carcinoma (MTC) for mutation of the ret protooncogene. In all but 1 of 59 families with MEN 2A, germline mutations in the extracellular domain of the ret protein were found. Some 81% of the MEN 2A mutations affected codon 634. Phenotype-genotype correlations suggested that the prevalence of pheochromocytoma and hyperparathyroidism is significantly higher in families with codon 634 mutations, but there was no correlation with the nature of the mutation. In all but 1 of 27 familial MTC (FMTC) families, mutations were detected in 1 of 4 cysteines in the extracellular domain of the ret protooncogene. Half of the FMTC mutations affected codon 634. Mutations outside of codon 634 occurred more often in FMTC families than in MEN 2A families. In all but 1 of 8 MEN 2B patients, de novo mutations in codon 918 were found. These data confirm the preferential localization of MEN 2-associated mutations and the correlation between disease phenotype and the position of the ret mutation, but there was no correlation between the occurrence of hyperparathyroidism or pheochromocytoma and the nature of the mutation
Comparison of dosimetric parameters of small-field electron beams between Advanced Markus, Semiflex 3D, and Diode E responses
The usage of dosimetry of small fields in radiotherapy to measure radiation dose is difficult because of high-dose gradients, lateral electronic disequilibrium, and detector volume effects. In this study, three dosimeters namely, Markus, Semiflex 3D, and Diode E were tested using the Elekta-accelerator electron beams. The electron beam parameters, penumbra, and output factor were determined using these dosimeters for each field size and energy. According to the results, Diode E and Advanced Markus exhibited the greatest difference in Rq among the electron beam parameters. Furthermore, the greatest difference in penumbra was observed between Diode E and Advanced Markus for the field size of 3 cm2 at 10 MeV. In terms of output factor, three dosimeters exhibited the greatest difference between Diode E and Advanced Markus for the field size of 3 cm2 at 10 MeV. The findings indicate that the Semiflex 3D can be regarded as an appropriate dosimeter for electron small-field dosimetry. © 2020, Japanese Society of Radiological Technology and Japan Society of Medical Physics
Overview of host miRNA properties and their association with epigenetics, long non-coding RNAs, and Xeno-infectious factors
MicroRNA-derived structures play impressive roles in various biological processes. So dysregulation of miRNAs can lead to different human diseases. Recent studies have extended our comprehension of the control of miRNA function and features. Here, we overview some remarkable miRNA properties that have potential implications for the miRNA functions, including different variants of a miRNA called isomiRs, miRNA arm selection/arm switching, and the effect of these factors on miRNA target selection. Besides, we review some aspects of miRNA interactions such as the interaction between epigenetics and miRNA (different miRNAs and their related processing enzymes are epigenetically regulated by multiple DNA methylation enzymes. moreover, DNA methylation could be controlled by diverse mechanisms related to miRNAs), direct and indirect crosstalk between miRNA and lnc (Long Non-Coding) RNAs as a further approach to conduct intercellular regulation called �competing endogenous RNA� (ceRNA) that is involved in the pathogenesis of different diseases, and the interaction of miRNA activities and some Xeno-infectious (virus/bacteria/parasite) factors, which result in modulation of the pathogenesis of infections. This review provides some related studies to a better understanding of miRNA involvement mechanisms and overcoming the complexity of related diseases that may be applicable and useful to prognostic, diagnostic, therapeutic purposes and personalized medicine in the future. © 2021, The Author(s)
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