自制椎板钩分散椎弓根螺钉系统应力作用的有限元分析

目的:观察加用自制椎板钩对分散椎弓根螺钉系统应力的作用。方法:实验于2005-10-20在华南理工大学交通学院力学实验中心完成。①建立自行设计的新型椎板钩钉系统有限元模型:椎弓根螺钉长度为40mm,圆棒长度120mm,二者直径均为6mm,椎板钩高度为9mm,长度为22mm。②有限元模型建立:根据以上参数,应用ANSYS8.0软件,按实际大小和结构以二维线梁单元BEAM188建立新型椎板钩钉系统有限元模型,约束尾侧椎弓根螺钉和尾侧椎板钩内表面,垂直于头侧椎弓根螺钉进行加载。③应力测量:前屈扭矩5N·m状态下,对椎弓根螺钉系统不加与加用椎板钩时,整个系统各处的应力变化进行评估。结果:加钩后整个系统受力点增加,受力更加均匀。临床上容易发生断钉的部位应力显著降低。头、尾侧椎弓根钉根部加钩后轴向应力显著降低,以尾侧钉为著,降低37.08%。头、尾侧钉棒连接处加钩后剪切应力下降明显,头侧下降44.02%,尾侧下降60.71%。结论:椎板钩使得椎弓根螺钉系统应力分散,以尾侧椎弓根钉根部及钉棒连接处为著,从而减少椎弓根螺钉断钉的发生。     

The best medicine? The influence of physical activity and inactivity on Parkinson's disease

The incidence of Parkinson's disease (PD) is expected to increase as our population ages and will likely strain the projected capacity of our health care system. Despite being the most common movement disorder, there have been few noninvasive therapeutic advances for people with PD since the first levodopa clinical trial in 1961. The study of PD pathogenesis, combined with an appreciation for the biochemical mechanisms by which physical activity and exercise may impact physiology, has resulted in emerging hypotheses for new modifiable risk factors for PD. Physical activity and exercise as a means of preventing PD, or maintaining the functionality of people with PD, are a promising area of investigation. Conversely, physical inactivity is implicated in many disease states, some of which are also correlated with the development of PD, such as metabolic syndrome. The primary relationship between these diseases is likely rooted in heightened inflammation and oxidative stress at the cellular level. Physical activity and exercise as a means of attenuating inflammation have led to increased interest in related potential therapeutic targets for PD. Ultimately, these findings may translate into low‐cost, universally available therapies for PD disease modification or prevention. © 2016 International Parkinson and Movement Disorder Society     

经冠状动脉自体骨髓单个核细胞移植对扩张型心肌病兔心肌组织病理学的影响

目的:骨髓干细胞在扩张型心肌病动物模型中具有向心肌样细胞和血管内皮细胞分化的潜能。评价经冠脉自体骨髓单个核细胞移植治疗对扩张型心肌病兔心肌组织病理学影响及心功能的变化。方法:实验于2006-09/2007-03在复旦大学附属华山医院心血管研究室完成。①实验材料:3月龄雄性新西兰兔25只,随机数字表法分为正常组5只、模型组10只、冠脉移植组10只。②实验方法:冠脉移植组、模型组兔经耳缘静脉注射盐酸阿霉素建立扩张型心肌病模型。冠脉移植组10只兔麻醉后以髂骨为穿刺点,共采集15mL混有肝素生理盐水的骨髓液,密度梯度离心得到自体骨髓单个核细胞悬液2mL,其中5只兔的骨髓单个核细胞悬液行DAPI标记,经塑性的4F造影导管,模拟临床冠脉内输注细胞悬液。③实验评估:术后4周通过检测血流动力学指标评价心功能的改变;苏木精-伊红、天狼猩红染色观察心肌组织形态学特点,透射电镜观察心肌组织超微结构的改变;TnT间接免疫荧光检测心肌组织DAPI标记情况,以评价骨髓单个核细胞的分化和转归。结果:①血流动力学指标的测定:与基础值比较,细胞移植4周后模型组兔血流动力学指标无明显改变(P>0.05),而冠脉移植组心功能显著改善(P<0.05)。②心肌组织形态学观察:扩张型心肌病兔心肌纤维排列紊乱,坏死区大量淋巴细胞浸润,细胞间隙增宽,心肌间质面积增大。③心肌组织超微结构的变化:造模结束后,模型组心肌细胞线粒体肿胀,肌丝断裂,心肌细胞核呈锯齿状,心肌间质中淋巴细胞浸润,胶原纤维增多。细胞移植4周后,冠脉移植组出现线粒体堆积现象,亦存在巨噬细胞浸润和胶原纤维轻度增生,未发现心肌组织中存在植入的特殊类型细胞。④心肌组织TnT间接免疫荧光检测:DAPI标记的骨髓单个核细胞在心肌组织中富集,血管腔内不存在。结论:①经冠脉自体骨髓单个核细胞移植治疗阿霉素扩张型心肌病兔,利于植入细胞在心肌组织中富集,改善心功能。②透射电镜尚无法证实心肌组织中存在外来的移植细胞。     

场电子发射器件中实际电子发射点密度达到实用程度的标准

目前薄膜场致电子发射平板显示方面的研究越来越深入,其制备的器件场发射性能也越来越接近实用的程度。但有关其发射点密度达到何值时,即可达到最基本可以应用的程度至今也没有一个可以直接参考的实用标准。因此提出一个这样的客观标准对于场发射显示器今后的应用来讲具有重要的实际意义。作者结合自身10多年从事碳基薄膜场致电子发射研究的经历和相应的光学理论,提出一个场电子发射器件中实际电子发射点密度可达到实用程度的标准。当薄膜场电子发射点密度在场发射器件全部发射区域内都超过106sites/cm2时,肉眼将无法在屏幕上分辨出各个发射点,此时电子发射点已连成肉眼无法分辨出的面,也就是说这时单纯从场发射均匀性上来讲,场发射器件已达到可以应用的程度。     

人表皮细胞与角膜上皮细胞蛋白质组的差异表达初步研究

目的：应用蛋白质组技术比较人表皮细胞与角膜上皮细胞之间的蛋白质表达差异。方法：实验于2005-11，2006-10在中山大学中山眼科中心国家眼科学重点实验室完成。分别培养人表皮细胞与角膜上皮细胞，裂解原代细胞抽提总蛋白，精确定量后进行双向电泳，扫描电泳凝胶获得二维总蛋白图谱。图谱使用软件辅助比较分析，找出差异表达点，从凝胶中抠取差异点，胶内酶解后用基质辅助激光解吸附，电离飞行时间串级质谱法鉴定差异蛋白。结果：人表皮细胞与角膜上皮细胞蛋白质凝胶分析获得600余个清晰的蛋白质斑点，在比较分析出的26个差异点中初步鉴定出4个差异表达蛋白，分别是细胞内氯离子通道1、Psodasin、乳酸脱氢酶B和丝氨酸蛋白酶抑制因子。结论：人表皮细胞与角膜上皮细胞在蛋白质表达上有较高的相似性以及较好的可比性，为探索表皮细胞横向分化成角膜上皮细胞的分子机制做出了有益的尝试，并提供了具有一定可操作性的实验方法。     

Scales to assess sleep impairment in Parkinson's disease: Critique and recommendations

There is a broad spectrum of sleep disturbances observed in Parkinson's disease (PD). A variety of scales have been applied to the evaluation of PD sleep and wakefulness, but only a small number have been assessed specifically for clinimetric properties in the PD population. The movement disorder society has commissioned this task force to examine these scales and to assess their use in PD. A systematic literature review was conducted to explore the use of sleep scales in PD and to determine which scales qualified for a detailed critique. The task force members, all of whom have extensive experience in assessing sleep in PD reviewed each of the scales using a structured proforma. Scales were categorized into recommended, suggested and listed according to predefined criteria. A total of 48 potential scales were identified from the search and reviewed. Twenty‐nine were excluded because they did not meet review criteria or were variations of scales already included, leaving 19 scales that were critiqued and rated by the task force based on the rating criteria. Only six were found to meet criteria for recommendation or suggestion by the task force: the PD sleep scale (PDSS) and the Pittsburgh sleep quality index (PSQI) are recommended for rating overall sleep problems to screen and to measure severity, the SCOPA‐sleep (SCOPA) is recommended for rating overall sleep problems both to screen and to measure severity, and for rating daytime sleepiness; the Epworth sleepiness scale (ESS) is recommended for rating daytime sleepiness to screen and to measure severity; the inappropriate sleep composite score (ISCS) is suggested for rating severe daytime sleepiness or sleep attacks to screen and to measure severity; and the Stanford sleepiness scale (SSS) is suggested for rating sleepiness and to measure severity at a specific moment. The task force does not recommend the development of new scales, but emphasizes the need for educational efforts to train physicians in sleep interview techniques and polysomnography. © 2010 Movement Disorder Society     

Stimulation-induced parkinsonism after posteroventral deep brain stimulation of the globus pallidus internus for craniocervical dystonia

The authors report on a patient with craniocervical dystonia who was treated with bilateral GPi stimulation, with excellent improvement in dystonia but at the cost of stimulation-induced, reversible parkinsonism. Stimulation through ventral contacts resulted in maximal relief of craniocervical dystonia but induced considerable hypophonia, bradykinesia, rigidity, freezing, and impaired postural reflexes. Stimulation through dorsal contacts alleviated parkinsonism, but resulted in the return of dystonia. No stimulation parameters could alleviate the dystonia without inducing parkinsonism over the course of his 4-year follow-up.     

Factors predicting the occurrence of germline mutations in candidate genes among patients with cutaneous malignant melanoma from South Italy

Clinical predictors for germline mutations of candidate genes in large clinic based population of patients with cutaneous malignant melanoma (CMM) are widely awaited. Using denaturing high-performance liquid chromatography (DHPLC) analysis and DNA sequencing, 557 consecutively-collected CMM patients originating from South Italy were screened for CDKN2A germline mutations; subsets of them were screened for mutations in the BRAF and BRCA2 genes. Seven CDKN2A mutations were detected in 14 (2.5%) CMM patients. Relative risk of carrying a CDKN2A mutation for CMM patients was demonstrated to significantly increase with the presence of familial recurrence of melanoma (risk ratio (RR)=6.31; p=0.0009), multiple primary melanomas (RR=3.43; p=0.0014), and early onset age (RR=4.56; p=0.0026). All CDKN2A mutations were observed in non-Sardinian patients (14/441; 3.2%), whereas BRAF and BRCA2 genes were found mutated in Sardinian patients (3/116; 2.6%). Such indicators of the presence of CDKN2A mutations will be useful in counselling patients about undergoing genetic testing. Our findings strongly suggest that mutation rates of candidate cancer genes may deeply vary among CMM patients from different geographical areas.