Enhanced proliferation and differentiation of neural stem cells grown on PHA films coated with recombinant fusion proteins

Polyhydroxyalkanoates (PHAs) belong to a family of copolyesters with demonstrated biocompatibility. We hypothesize that genetically fusing evolutionarily preserved cell binding motifs, such as RGD or IKVAV, to the PHA-binding protein phasin (PhaP) for surface functionalization of PHA materials could better support the growth and differentiation of neural stem cells (NSCs). This hypothesis is tested on three polyester materials of the same aliphatic family: poly(L-lactic acid) (PLA) and two PHB copolymers, poly(3-hydroxybutyrate-co-3-hydroxyhexanoate) and poly(3-hydroxybutyrate-co-3-hydroxyvalerate-co-3-hydroxyhexanoate) (PHBVHHx). Experimental results indicate that surface coating of the two fusion proteins, PhaP–RGD and PhaP–IKVAV, provides short-term advantages in promoting the adhesion, proliferation and neural differentiation of rat NSCs compared to the PhaP-coated or uncoated material. Among the tested samples, the combination of coating PhaP–IKVAV on an PHBVHHx surface yields the highest levels in cell adhesion and proliferation, while the PLA film coated with PhaP–IKVAV promotes better neural differentiation and neurite outgrowth in the early stage. Because both PhaP–RGD and PhaP–IKVAV could be produced in an inexpensive manner, our data suggest that PhaP–IKVAV is an ideal nonspecific coating agent to functionalize hydrophobic biomaterials in the application of neural tissue engineering.     

Treatment of thoracolumbar fracture with pedicle screws at injury level: a biomechanical study based on three-dimensional finite element analysis

The aim of this study was to investigate the biomechanical mechanisms of treatment of thoracolumbar compression fracture with pedicle screws at injury level based on a three-dimensional finite element method. We constructed one three-dimensional finite element model of T11-L1 in a patient with a compression fracture of the T12 vertebral body(anterior edges of vertebral body were compressed to 1/2, and kyphosis Cobb angle was 18.6°) fixed by four pedicle screws and another model fixed by six pedicle screws at the injured vertebrae, and then assigned different forces to the two models to account for axial compression, flexion, extension, left lateral bending, and rightward axial rotation by Ansys software. After different loading forces were applied to the models, we recorded stress measurements on the vertebral pedicle screws, as well as the maximum displacement of T11. The stress distribution suggested that stress concentration was appreciable at the root of the pedicle screws under different loading modalities. Under axial compression, flexion, extension, left lateral bending, and rightward axial rotation load, the stress for the superior screw was significantly greater than the stress for the inferior screw (P < 0.05). The stress in the six pedicle screw fixation model was significantly decreased compared to the four screw interbody fusion model (P < 0.05), but the maximum displacement of T11 between two models under different loadings was not statistically different. The use of pedicle screws at injured vertebral bodies may optimize internal fixation load and reduce the incidence of broken screws.     

A Psychometric Evaluation of the Quality of Life for Children with Autism Spectrum Disorder Scale

Journal of Autism and Developmental Disorders - Our purpose in this study was to validate the Quality of Life for Children with Autism Spectrum Disorder scale. We first conducted an exploratory...     

电子处方警示系统减少门诊重复用药:以台湾289家医院为例

目的:探讨台湾医院门诊应用电子处方警示系统的效果。方法:采集1998-2009年的医保数据库,纳入各年均有数据库数据的259家医院进行分析。根据台湾医院应用门诊电子处方警示系统的发展,12年分为4个阶段:1998—2000年(T1)、2001-2003年(T2)、2004—2006年(T3)、2007—2009年(T4)。重复用药率是计算每个时间段医院门诊重复用药处方数占全部处方数的比例。应用广义估计方程(Generalized Estimating Equation,GEE)分析4个阶段的重复用药率改变。结果 :T1总体门诊重复用药率11.7%,T2减少到10.4%,但T2-T4维持在10. 5%上下。GEE分析发现重复用药率如期呈现下降,但降幅逐渐减小(T2:b=-2.44; T3:b-3.20;T4:b=-3.30;P0.001)。结论:医院门诊重复用药率随电子处方警示系统应用趋势呈现递减后维持平稳,表示系统虽然有效,但仍有需要持续改善之处。     

临床路径对医疗资源使用的效益——以腹腔镜胆囊切除手术患者为例

目的:应用医院病例数据评价临床路径对腹腔镜胆囊切除手术患者医疗资源使用的管理效果。方法:采集深圳市7家公立医院2015年12月—2016年9月的病案首页,研究对象为第一诊断是胆囊结石伴慢性胆囊炎(ICD10:K80. 1)且行腹腔镜胆囊切除手术(ICD-9-CM:51. 23)。统计分析方法采用独立t检验、卡方检验以及广义线性回归分析。结果:共有932例符合研究对象的定义,其中路径组696例,平均住院天日7. 15天,住院费用15 181. 5元;非路径组236例,平均住院天日9. 42天,住院费用19 774. 8元。校正其他影响因素后,路径组的住院天日比非路径组少1. 51天(P 0. 001),住院费用少3 818元(P 0. 001)。结论:患者的疾病状况虽然是影响住院天日与住院费用的重要因素,但本研究发现临床路径实施对腹腔镜胆囊切除患者的医疗质量与医疗资源管理具有影响,建议未来有更多实证研究检验临床路径效果,以供相关政策参考。     

An Ensemble of Complementary Models for Deep Tracking

Cognitive Computation - Convolutional neural networks (CNNs) have shown favorable performance in recent tracking benchmark datasets. Some methods extract different levels of features based on...     

Gray matter atrophy and corresponding impairments in connectivity in patients with anti-N-methyl-D-aspartate receptor encephalitis

Anti-N-methyl-D-aspartate receptor (NMDAR) encephalitis is a severe autoimmune disease that is commonly accompanied by cognitive impairment and various neurological and psychiatric symptoms, advanced image analyses help explore the pathogenesis of this disease. Therefore, this study aimed to explore specific structural and functional alterations and their relationship with the clinical symptoms of anti-NMDAR encephalitis. In this study, twenty-two patients with anti-NMDAR encephalitis after the acute stage and 29 controls received cognitive assessments and magnetic resonance imaging. Grey matter atrophy was measured using voxel-based morphometry, and functional alterations in abnormal regions were subsequently investigated using resting state functional connectivity (RSFC). Finally, correlation analyses were performed to explore the associations between imaging alterations and cognitive assessments. The patients demonstrated significant gray matter atrophy in the bilateral triangle part of the inferior frontal gyrus (triIFG.L and triIFG.R) and right precuneus, decreased RSFC between triIFG.L and bilateral Heschl gyrus (HES), decreased RSFC between triIFG.R and HES.R, decreased RSFC between right precuneus and left cerebellum, and increased RSFC between triIFG.R and left superior frontal gyrus. Further correlation analyses showed that the gray matter volume in triIFG.R and decreased RSFC between triIFG.L and HES.R were associated with decreased memory scores, whereas decreased RSFC between triIFG.R and HES.R was marginally correlated with the disease course in patients. In conclusion, this study suggests that cognitive impairments in patients with anti-NMDAR encephalitis may be mainly associated with gray matter atrophy and abnormal RSFC in the triIFG. These findings provide new insights into anti-NMDAR encephalitis pathogenesis and help explore potential treatments.

     

The organochlorine p,p′-dichlorodiphenyltrichloroethane induces colorectal cancer growth through Wnt/β-catenin signaling

Dichlorodiphenyltrichloroethane (DDT), an organochlorine pollutant, is associated with several types of cancer. However, the relationship between DDT and colorectal cancer is uncertain. In this study, the impact of p,p′-DDT on colorectal cancer growth was evaluated using both in vitro and in vivo models. Our results indicated that the proliferation of human colorectal adenocarcinoma DLD1 cells was significantly promoted after exposed to low concentrations of p,p′-DDT ranging from 10⁻¹² to 10⁻⁷ M for 96 h. Exposure to p,p′-DDT from 10⁻¹⁰ to 10⁻⁸ M led to upregulation of phospho-GSK3β (Ser9), β-catenin, c-Myc and cyclin D1 in DLD1 cells. RNA interference of β-catenin inhibited the proliferation of DLD1 cells stimulated by p,p′-DDT. Inhibiting of estrogen receptors (ERs) had no significant effect on the action of p,p′-DDT. Treatment with p,p′-DDT induced production of intracellular reactive oxygen species (ROS) and inhibited superoxide dismutase (SOD) activity in DLD1 cells. Treatment with N-acetyl-L-cysteine (NAC), a ROS inhibitor, suppressed the induction of Wnt/β-catenin signaling and DLD1 cell proliferation by p,p′-DDT. Moreover, in a mouse xenograft model, 5 nmol/kg p,p′-DDT resulted in increased tumor size, oxidative stress and Wnt/β-catenin signaling. These results indicated that low concentrations of p,p′-DDT promoted colorectal cancer growth through Wnt/β-catenin signaling, which was mediated by oxidative stress. The finding suggests an association between low concentrations of p,p′-DDT exposure and colorectal cancer progression.