Ursodeoxycholic acid upregulates ERK and Akt in the protection of cardiomyocytes against CoCl2.

Ursodeoxycholic acid (UDCA) is used to treat liver diseases and demonstrates cardioprotective effects. Accumulation of the plasma membrane sphingolipid sphingomyelin in the heart can lead to atherosclerosis and coronary artery disease. Sphingomyelinases (SMases) break down sphingomyelin, producing ceramide, and inhibition of SMases activity can promote cell survival. We hypothesized that UDCA regulates activation of ERK and Akt survival signaling pathways and SMases in protecting cardiac cells against hypoxia. Neonatal cardiomyocytes were isolated from 0- to 2-day-old Sprague Dawley rats, and given 100 µM CoCl2, 150 µM H2O2, or placed in a hypoxia chamber for 24 h. The ameliorative effects of 100-µM UDCA treatment for 12 h were then assessed using MTS, QuantiGene Plex (for Smpd1 and Smpd2), and SMase assays, beating rate assessment, and western blotting (for ERK and Akt). Data were analyzed by the paired Student t-tests and one-way analyses of variance. Cell viability decreased significantly after H2O2 (85%), CoCl2 (50%), and hypoxia chamber (52%) treatments compared to the untreated control (100%). UDCA significantly counteracted the effects of chamber- and CoCl2- induced hypoxia on viability and beating rate. However, no significant differences were observed in acid SMase gene and protein expression between the untreated, CoCl2, and UDCA-CoCl2 groups. In contrast, neutral SMase gene and protein expression did significantly differ between the latter two groups. ERK and Akt phosphorylation was higher in hypoxic cardiomyocytes treated with UDCA than those given CoCl2 alone. In conclusion, UDCA regulates the activation of survival signaling proteins and SMases in neonatal rat cardiomyocytes during hypoxia.

Whole-brain imaging of freely-moving zebrafish.

One of the holy grails of neuroscience is to record the activity of every neuron in the brain while an animal moves freely and performs complex behavioral tasks. While important steps forward have been taken recently in large-scale neural recording in rodent models, single neuron resolution across the entire mammalian brain remains elusive. In contrast the larval zebrafish offers great promise in this regard. Zebrafish are a vertebrate model with substantial homology to the mammalian brain, but their transparency allows whole-brain recordings of genetically-encoded fluorescent indicators at single-neuron resolution using optical microscopy techniques. Furthermore zebrafish begin to show a complex repertoire of natural behavior from an early age, including hunting small, fast-moving prey using visual cues. Until recently work to address the neural bases of these behaviors mostly relied on assays where the fish was immobilized under the microscope objective, and stimuli such as prey were presented virtually. However significant progress has recently been made in developing brain imaging techniques for zebrafish which are not immobilized. Here we discuss recent advances, focusing particularly on techniques based on light-field microscopy. We also draw attention to several important outstanding issues which remain to be addressed to increase the ecological validity of the results obtained.

The effectiveness of virtual interactive video in comparison with online classroom in the stroke topic of theoretical neurology in COVID-19 pandemic.

BACKGROUND: Sufficient interaction between the trainers and the trainees in medical education is always one of the biggest challenges for an educational system. This study was designed to evaluate the effect of virtual interactions within the educational content of stroke on the effectiveness of teaching for general medicine students during COVID-19 crisis. MATERIALS AND METHODS: Eight medical students applying for stroke education were divided into two groups by simple random sampling (Rafsanjan Medical School, 2020). The first group participated in an online classroom via the Adobe Connect platform without virtual interaction. The second group used a video presentation containing interaction scenarios. The effectiveness evaluation of each type of educational content was done by comparison of the final exam scores and the results of an electronic satisfaction questionnaire in each group. Finally, using SPSS software version 18, the data were analyzed with independent samples t-test. RESULTS: This study showed that the mean of the examination scores of the interactive virtual content group (6.14 ± 1.46) was significantly higher than the online class group (4.50 ± 1.50) (P < 0.001), and also the results of satisfaction assessment showed that this group was more satisfied with their educational content (P = 0.005). CONCLUSION: Evaluation of the virtual stroke training effectiveness for general medical students shows that the educational approach of video with virtual interactions is an effective learning method in medical topics and can be considered as an efficacious educational model in online teaching.

Effect of chalazion excision on refractive error and corneal topography.

PURPOSE: To evaluate refractive and corneal topographic changes following excision of chalazia. METHODS: This prospective noncomparative quasi-experimental clinical trial includes consecutive patients older than 7 years with chalazia of minimum duration of 1 month who underwent excision of the lesions by an internal or external approach. RESULTS: Overall, 253 lids from 228 eyes of 195 patients including 110 female subjects with mean age of 31-/+14 years (range 7-71) were studied. Mean duration of presenting symptoms was 4-/+2.8 months (range 1-24). Lesions were equally distributed in medial, central, and lateral areas of the eyelids. The chalazia were single in 172 (88.2%) and multiple in 23 (11.8%) patients. Mean change in best-corrected visual acuity, spherical equivalent refractive error, and difference of keratometry (corneal astigmatism) were 0.0004-/+0.007 logMAR (p=0.3), -0.06-/+0.6 D (p=0.1), and 0.34-/+0.35 (p<0.0001) after surgery, respectively. Corneal topographic analysis revealed significant changes in surface regularity index (0.13), surface asymmetry index (0.09), and potential visual acuity (0.06-/+0.1 logMAR) after the procedure (p<0.0001 for all comparisons). Single, central, and firm chalazia were compared with multiple, peripheral, and soft lesions; change in difference of keratometry and spherical equivalent were 0.75-/+0.42 D versus 0.22-/+0.15 D (p=0.001) and -0.35-/+0.19 versus -0.11-/+0.30 D (p=0.1), respectively, implying more induced astigmatism with the former type of lesions. CONCLUSIONS: Chalazion excision can decrease corneal astigmatism and irregularity, which is more prominent in single, firm, and central upper lid lesions. These findings may have implications in pediatric patients at risk for amblyopia.