Expression of brain derived neurotrophic factor (BDNF), neurotrophin 4 (NT4) and their common receptor, TrkB, by human Muller cells in vitro and vivo.

Neurotrophins are trophic and mitogenic proteins that play a role in the development, differentiation, connectivity and survival of neurons, acting via their specific receptors in the central and peripheral nervous system, including the retina. The preferred receptor for brain derived neurotrophic factor (BDNF) and neurotrophin 4 (NT4) is TrKB. Muller cells may play an important role in neurotrophin function in the nervous system. It has been suggested that neurotrophins exert their effects on photoreceptors by acting indirectly through activation of Muller cells. The aims of the present work were to characterise the expression of BDNF, NT4 and TrkB by human Muller cells in vitro, and to examine whether changes in the expression of these molecules occur in retina from patients with proliferative vitreoretinopathy (PVR) when compared with normal retina. In addition, changes in the expression of BDNF, NT4 and glial fibrillary acidic protein (GFAP) were also investigated in melanoma affected human retina following laser photocoagulation. A variety of techniques were employed to investigate the expression of the above neurotrophins and TrkB at the RNA and protein levels. These included cell culture and mRNA extraction, RT-PCR, Western blot, and Immunocytochemistery. Confocal laser scanning microscopy and light microscopy were used for imaging. The results showed that cultured human Muller cells express BDNF and NT4 as indicated by both mRNA and protein expression. A truncated isoform of TrkB was also shown to be expressed by a spontaneously immortalized human Muller cell line used in the study (MIO-M1). Staining for NT4 was greatly increased in retinal sections from eyes with PVR, compared with normal retina. NT4 expression by Muller cells in situ was confirmed by confocal imaging observations that cells staining for this neurotrophin co-stained for GFAP. By contrast, there was a decrease in TrkB immunostaining in PVR retinectomy sections compared with controls. NT4 staining was also reduced at the site of laser burns in melanoma affected retina. Possible explanations are discussed in the thesis

The Status of Knowledge Management in the Libraries of selected Medical Sciences Universities in Tehran: Using Bukowitz and Williams Model

Introduction: Libraries are considered to be an important link in the knowledge management chain at universities as the basis for gathering, processing, storing and distributing knowledge. So this research was done with the aim of investigating the knowledge management status in selected libraries of medical sciences universities in Tehran using the Beckowitz and William model. Methods: in term of goals, this research is Applicability and was conducted in descriptive way and scrolling method. A questionnaire was used to collect information that its validity was estimated by experts and its reliability was calculated by Cronbach's alpha. The Research community consisted of 153 managers and librarians of central and faculty libraries of Tehran University of Medical Sciences, Iran University of Medical Sciences and Shahid-beheshtie University of Medical Sciences Results: The results showed that the mean scores of knowledge management status in libraries of Tehran University of Medical Sciences were 144/85 and more than average.  Also between the components studied, the mean score for components of knowledge deployment, knowledge learning, knowledge sharing and knowledge removal were more than average, the knowledge creation / maintenance was average and knowledge assessment and finding knowledge were lower than average. Conclusion: The findings showed that the knowledge management selected libraries status of medical sciences universities in Tehran was desirable. Therefore, according to past research and comparison with them, it can be concluded that knowledge management in mentioned libraries progressing

Patient-reported prevalence of metamorphopsia and predictors of vision-related quality of life in vitreomacular traction: a prospective, multi-centre study

© 2018, The Author(s). Objectives: To report the prevalence and severity of metamorphopsia, estimate its impact on vision-related quality of life (VRQoL) and evaluate predictors of VRQoL in patients with vitreomacular traction (VMT). Patients and methods: A prospective, cross-sectional multi-centre study in the United Kingdom of 185 patients with VMT, with or without a full thickness macular hole (FTMH). Self-reported metamorphopsia was determined using the metamorphopsia questionnaire. VRQoL was assessed using the Visual Function Questionnaire (VFQ-25). Physicians recorded clinical and ocular characteristics in both eyes including a physician assessment of metamorphopsia. ANOVA and predicted least-squares means were used to estimate the impact of metamorphopsia on VRQoL. Predictors of VRQoL were assessed using ordinary-least-squares regression adjusting for clinically important variables. Results: The prevalence of self-reported metamorphopsia was 69.7% (95% CI 62.6–76.3%) and was higher in eyes with a concomitant FTMH vs. without FTMH (85.4% vs. 64.2%). Physician assessment of metamorphopsia was 53.0% (95% CI: 45.5–60.3%). Comparing eyes with metamorphopsia vs. without metamorphopsia, the VFQ-25 composite score was lower (82.3 vs. 91.4), and mean VA (LogMAR) was worse (0.44 vs. 0.33). The largest difference in VFQ-25 scores was observed for near activities (metamorphopsia: 75.3, No metamorphopsia: 90.2). The adjusted model showed that metamorphopsia severity and age were significantly associated with lower VFQ-25 scores. Conclusion: Metamorphopsia was highly prevalent in patients with VMT and associated with significantly lower VRQoL. Physician assessment of symptoms underestimated the self-reported presence of metamorphopsia. Metamorphopsia severity acts as a predictor of impaired VRQoL, over and above decrements due to reduced vision

Expression of brain derived neurotrophic factor (BDNF) and neutrotrophin-4 (NT4) and their common receptor, Trk B, by human Müller cells in vitro and in vivo

EThOS - Electronic Theses Online ServiceGBUnited Kingdo

Evaluation and Ranking of Persian Mobile Apps for COVID-19

Introduction: Recently developed mobile apps for controlling COVID-19 have the potential to help fight the pandemic. But assurance regarding the quality of available apps is essential to proving their validity for usage. This study was aimed at evaluating and ranking the apps in Persian developed for COVID-19 in Iran. Material and Methods: 122 apps for COVID-19 in the Persian language were founded in the Miket, CafeBazar, ParsHub, and Charkhooneh app markets. Based on inclusion criteria, 13 apps were selected. The apps were evaluated by two independent reviewers and ranked according to a validated evaluation and ranking tool specifically for the Persian apps for information content, usability, design, ethics, security, privacy, and subjective quality. Kendall’s coefficient of concordance was used to calculate the agreement between two raters based on the mean of their scores for each app (p-value<0.05). Results: Five functional and subjective quality criteria were used. Mask was the app with the highest level of the specific score (mean score: 4.10, subjective quality: 4). The Corona test-Davoudi was the app with the lowest level of the specific score (mean score: 1.85, subjective quality: 1.50), which needs more improvement. The reviewed apps mainly need improvement for data security and privacy, requiring more technical tasks. Conclusion: There is a need for improvement, particularly in terms of privacy and data security, for Persian COVID-19 apps. Develop a valid guideline that could be effective in improving app quality. In addition, the modern technologies that have already proven successful worldwide should be considered by mobile app developers

Evaluation of the Seismic Behavior Based on the Performance of Special Steel Moment Frames by Modified Energy Method and Force Design Method

Although conventional methods in seismic design consider such parameters as force, displacement, and ductility, the behavior of a significant number of structures that have been designed and experienced earthquakes shows that the existing criteria are insufficient and more comprehensive ones should be used. In this regard, the energy-based design method may be considered one of the suitable solutions. This method is based on creating a balance between the input and output energy of structures. It is possible to have a more appropriate estimate of the energy input as well as dissipated energy by the structure and use it in the design of the structure. In the modified energy method that has been used in this study, control of items such as the creation of a soft story, establishment of the Strong-Column Weak-Beam concept, the uniform distribution of loads in the members, the nonconcentration of force and local damage, and simultaneous drift control of the structure with the optimal distribution of plastic hinges have been considered. Also, modifications have been made to the energy balance equation. In this paper, 8-, 16-, and 24-story frames with lateral force resisting system of special steel moment frame have been modified by energy method and compared by the design force method of AISC code. Performance level criteria of the ASCE41-17 code have been applied in the design, and the P−Δ effects have also been considered in the nonlinear analysis. The results show that, for the frame which is designed by the energy method, the plastic hinges are created in the upper stories and beams; however, in the frame designed by the LRFD method, several plastic hinges are formed in the columns of the upper stories, and a local mechanism is created. Also, in 8- and 16-story structures, the weight of the structure which is designed by the energy method is less than that obtained by the LRFD method. The results also showed that, in contrast to the energy method, the relationships presented in the codes regarding the Strong-Column Weak-Beam rule cannot prevent local and undesirable mechanisms in severe earthquakes