[Evaluation of modified scene simulation teaching of endodontics in pre -clinical practice].

PURPOSE: To evaluate the effect of modified scene simulation teaching of endodontics in pre-clinical teaching. METHODS: Forty students were randomly divided into the experimental group and control group, there were 20 students in each group. Students in the experimental group were taught with modified scene simulation teaching method, while students in the control group were taught with traditional teaching method. The teaching quality was compared with SPSS 18.0 software package. RESULTS: The score of the experimental group was significantly higher than the control group in history taking, medical records writing and practical performance(P<0.05). CONCLUSIONS: The teaching effect of modified scene simulation teaching in pre-clinical teaching is better than traditional teaching method. It makes students better grasp the clinical medical essentials and feels the patient's feelings, as well as help the students to improve their subjective initiative of learning.

Alterations of White Matter Connectivity in Preschool Children with Autism Spectrum Disorder.

Purpose To investigate the topologic architecture of white matter connectivity networks in preschool-aged children with a diagnosis of autism spectrum disorder (ASD) versus typical development (TD). Materials and Methods Forty-two participants were enrolled, including 21 preschool children with ASD (14 male children and seven female children; mean age, 4.56 years ± 0.97 [standard deviation]) and 21 children with TD (11 males and 10 females; mean age, 5.13 years ± 0.82). The diagnosis of ASD was determined according to the Diagnostic and Statistical Manual of Mental Disorders Global Assessment of Functioning scores (mean score, 8.00 ± 0.50). All participants underwent diffusion-tensor imaging (DTI) and T2-weighted imaging on a 3-T magnetic resonance system. A graph theoretical analysis was applied to investigate the topologic organization of the brain network including global and local topologic parameters. Statistical analysis was then performed for the comparison between the groups. Results Compared with the TD group, children with ASD demonstrated shortened characteristic path length (t1 = 0.536, t2 = 0.534, t3 = 0.523, t4 = 0.510, and t5 = 0.501; P < .05) and increased global efficiency (t1 = 0.499, t2 = 0.497, t3 = 0.486, t4 = 0.473, and t5 = 0.465; P < .05) and clustering coefficient (t1 = 0.673, t2 = 0.750, t3 = 0.757, t4 = 0.738, and t5 = 0.741; P < .05). Significant increases in nodal efficiency were mainly found in left pallidum (0.037 vs 0.032, respectively; P < .01) and right caudate nucleus (0.037 vs 0.032, respectively; P < .01) of the basal ganglia network. Conclusion Significantly altered patterns of global and local brain network topography may underlie the abnormal brain development in preschool children with ASD compared with those who have TD. The identification of altered structural connectivity in basal ganglia and paralimbic-limbic networks may point toward potential imaging biomarkers for preschool-age patients with ASD. © RSNA, 2018.

Inhibition of mTOR pathway restrains astrocyte proliferation, migration and production of inflammatory mediators after oxygen-glucose deprivation and reoxygenation.

Glial scar is a major impediment to axonal regeneration in central nervous system (CNS) disorders. Overcoming this physical and biochemical barrier might be crucial for axonal regeneration and functional compensation during the progression of CNS disorders. The mammalian target of rapamycin (mTOR) is an evolutionarily conserved serine/threonine kinase, involved in process of cell proliferation, migration, autophagy and protein synthesis. Rapamycin, an inhibitor of mTOR signaling, can exert neuroprotective effects in several CNS diseases. However, its role in the process of reactive astrogliosis including cell proliferation, migration and cytokine production after cerebral ischemia still remains largely unknown. In this study, we investigated the effects of mTOR blockade in cultured astrocytes exposed to oxygen-glucose deprivation/reoxygenation (OGD/R), a wildly used cellular ischemia model which mimics ideally cerebral ischemia model in vivo. We found that astrocytes became activated after OGD/R, characterized by change of astrocytic morphology, upregulation of GFAP expression, the increase number of Edu positive cells, and accompanied with phosphorylation of mTOR protein and its substrate S6K1. Rapamycin significantly inhibited mTOR signal pathway, suppressed proliferation of astrocytes via modulation of cell cycle progression. Moreover, rapamycin attenuated astrocytic migration and mitigated production of inflammatory factors such as TNF-α and iNOS induced by astrocytes exposed to OGD/R. Taken together, our findings indicated that mTOR blockade by rapamycin attenuates astrocyte migration, proliferation and production of inflammation mediators. We suggest that targeting mTOR pathway in astrocyte activation may represent a potentially new therapeutic strategy against deleterious neurotoxic processes of reactive astrogliosis in CNS disorders such as ischemic stroke.