原发性细胞癌伴微血管侵犯的危险因素分析

目的探讨原发性肝细胞癌（hepatocellular carcinoma，HCC）伴微血管侵犯的危险因素。方法回顾性复习134例HCC切除术病人的临床资料，分析微血管侵犯与HCC病人临床理资料的相关性。结果134例HCC中46例（34．3％）有微血管侵犯。单因素分析显示肿瘤体积〉3cm、包膜缺失、组织分化恶性程度高、血清AFP阳性（〉20ng／ml）与微血管侵犯显著相关（P〈0．05），而病人年龄、性别、肝炎病毒感染、是否合并肝硬化、组织学类型与微血管侵犯之间无明显相关性。微血管侵犯与HCC大体卫星结节的形成成显著相关（P=0．001）。结论微血管侵犯是HCC的常见恶性事件，肿瘤体积〉3cm、包膜缺失、组织分化恶性程度高、血清AFP阳性是微血管侵犯的危险因素。     

阿司匹林对大鼠脊髓损伤细胞凋亡的保护作用

目的 观察阿司匹林对大鼠慢性压迫性脊髓损伤后神经细胞凋亡及神经功能恢复的影响。方法选择65只体重为220～250g的Wistar大鼠（雌雄不限），于T10部位置入后路渐进式压迫装置，制作成慢性压迫性脊髓损伤模型。随机分为阿司匹林治疗组（A组，30只）、生理盐水对照组（B组，30只）和假手术组（C组，5只）。应用原位末端脱氧核糖核苷酸转移酶介导dUTP标记技术，分别于慢性压迫性脊髓损伤后1、3、7、14、28d做行为学评价，并取材对脊髓损伤区进行细胞凋亡检测。结果A、B组均发现细胞凋亡，A组与B组细胞凋亡率相比差异有显著性（P〈0．05），A组与B组行为学评价相比差异有显著性（P〈0．05），神经细胞凋亡情况与运动功能改变具有相关性。结论 阿司匹林对慢性脊髓压迫损伤后所导致的神经细胞凋亡产生抑制作用。     

胞嘧啶脱氨酶基因修饰神经干细胞及其表达的离体实验研究

目的 探讨胞嘧啶脱氨酶(cytimidine deaminase，CD)基因修饰神经干细胞及其基因表达。方法 通过构建真核表达质粒pCMVCD，限制性内切酶消化鉴定后，采用Lipofectamine 2000脂质体介导法转染新生大鼠室管膜下区神经干细胞(Neural stem cells，NSCs)，G418筛选阳性克隆，加入不同浓度的5-氟胞嘧啶(5-Flourocytosine，5-FC)，MTT比色法测定NSCs的生存率。结果 本实验成功地培养并鉴定了神经干细胞，并将CD基因成功地转染了神经干细胞，G418阳性NSCs对低浓度5-FC高度敏感。结论 CD基因修饰神经干细胞的离体实验研究为干细胞治疗研究提供依据。     

薄层斜轴位T2WI扫描在判断子宫恶性肿瘤宫颈浸润范围中的价值

目的 探讨薄层斜轴位扫描在判断子宫恶性肿瘤宫颈浸润范围中的价值. 资料与方法 回顾性分析53例经手术病理证实的子宫恶性肿瘤患者的MRI资料,比较普通轴位、旁矢状位及薄层斜轴位T2WI 3种扫描方法对判断子宫恶性肿瘤宫颈浸润范围的准确性. 结果 普通轴位、旁矢状位和薄层斜轴位T2WI判断宫颈病变浸润范围的准确性分别为77.36%、60.38%和92.45%.普通轴位与旁矢状位相比（χ2=3.56,P＞0.05）,两者之间差异无统计学意义;薄层斜轴位与旁矢状位比较（χ2=15.13,P＜0.05）,两者之间差异有统计学意义.薄层斜轴位与普通轴位比较（χ2=4.71,P＜0.05）,两者之间差异有统计学意义. 结论 对于宫颈病变浸润程度和范围的准确评价,薄层斜轴位扫描是一种非常必要而且有用的方法,应在常规轴位扫描的基础上加扫薄层斜轴位,提高宫颈病变浸润程度和范围判断的准确性.     

Serial in vivo MR tracking of magnetically labeled neural spheres transplanted in chronic EAE mice.

Neural stem cell (NSC) transplantation has been shown to attenuate the severity of experimental autoimmune encephalomyelitis (EAE), an animal model of multiple sclerosis (MS). Central to the future success of NSC transplantation in MS is the ability of transplanted cells to migrate from the site of transplantation to relevant foci of disease. Using magnetically labeled mouse neurospheres and human embryonic stem cell (hESC)-derived neurospheres, we applied serial magnetic resonance imaging (MRI) to assess the biodynamics of transplanted cell migration in a chronic mouse EAE model. Magnetic labeling did not affect the in vitro and in vivo characteristics of cells as multipotential precursors. Cell migration occurred along white matter (WM) tracts (especially the corpus callosum (CC), fimbria, and internal capsule), predominantly early in the acute phase of disease, and in an asymmetric manner. The distance of cell migration correlated well with clinical severity of disease and the number of microglia in the WM tracts, supporting the notion that inflammatory signals promote transplanted cell migration. This study shows for the first time that hESC-derived neural precursors also respond to tissue signals in an MS model, similarly to rodent cells. The results are directly relevant for designing and optimizing cell therapies for MS, and achieving a better understanding of in vivo cell dynamics and cell-tissue interactions.     

关节镜辅助下微创髌前“8”字张力钢丝内固定治疗髌骨骨折

目的探讨关节镜辅助下微创髌前＂8＂字张力钢丝内固定治疗髌骨骨折的手术方法及疗效。方法对我科2005年5月～2009年12月髌骨骨折的29例行关节镜辅助下微创髌前＂8＂字张力钢丝内固定治疗,总结手术经验。结果 27例完成微创手术,2例中转开放手术,平均手术时间48min。均获得12个月随访,髌骨骨折均愈合,未形成髌骨关节面＂阶梯＂,无内固定断裂,关节功能优。结论关节镜辅助下髌前＂8＂字张力钢丝内固定治疗髌骨骨折内固定可靠,术中能直观评估关节面复位情况,手术创伤小,有利于早期功能锻炼。     

Neural classifier construction using regularization, pruning and test error estimation

In this paper we propose a method for construction of feed-forward neural classifiers based on regularization and adaptive architectures. Using a penalized maximum likelihood scheme, we derive a modified form of the entropic error measure and an algebraic estimate of the test error. In conjunction with optimal brain damage pruning, a test error estimate is used to select the network architecture. The scheme is evaluated on four classification problems.     

A p65/p95 Neural Surface Receptor is Expressed at the S-G2 Phase of the Cell Cycle and Defines Distinct Populations

A surface receptor complex of M _r˜65 000 (p65) and ˜95 000 (p95) is expressed in cells of the central nervous system of mice. This receptor is recognized by monoclonal antibody 87.92.6 or by reovirus type 3 haemagglutinin as unnatural ligands. The p65/p95 receptor is expressed mostly in neural embryonic precursors undergoing proliferation, especially those in the S-G₂ phase of the cell cycle. Receptor expression decreases progressively throughout embryogenesis to low but detectable levels in the adult brain. Biochemical characterization revealed that the neural p65/p95 receptor complex is indistinguishable from the p65/p95 receptor expressed in T cells, where receptor ligation leads to a mitogenic block. In neural and lymphoid tissues the p65/p95 receptor (or an associated protein) possesses a tyrosine kinase enzymatic activity. Receptor ligation in neural cells resulted in the rapid tyrosine phosphorylation of cellular proteins which are different from substrates phosphorylated in T cells. Differential substrate coupling to the receptor may account for differences in signal transduction and biology between neural cells and T cells. Further study of this receptor complex may help define important features of neural proliferation, differentiation and survival.     

Assessment of the invasive potential of human gynecological tumor cell lines with the in vitro Boyden chamber assay: influences of the ability of cells to migrate through the filter membrane

The Boyden chamber assay is widely used for in vitro measurement of the invasive capacity of cells. However, results can be affected significantly if certain precautions are not taken. Using the Boyden chamber assay we investigated in vitro the invasive potential of a variety of human gynecological tumor cell lines to degrade and migrate through the artificial basement membrane matrix Matrigel. However, in the absence of this Matrigel layer large differences were observed in the ability of cells to adhere to, migrate through and attach to the lower side of the filter membranes. These differences were influenced by cell density, degree of directional locomotion, and the size of the filter pores. To adjust for these influences (which are not directly correlated to the capacity of cells to traverse the Matrigel layer), invasion results were corrected for the ability of cells to migrate through the filter membrane. In addition, the invasion of MDA-MB-231 cells was used as an internal standard to compensate for variations in the Matrigel layer between different experiments. Overall, in our experimental set up, the five human breast cancer cell lines were the most invasive (mean invasion ± SEM relative to MDA-MB-231 invasion: 104.7 ± 6.1%), the five human ovarian cancer cell lines the least invasive (60.2 ± 2.2%) and the six human endometrial cancer cell lines showed an intermediate capacity (79.1 ± 3.5%). In conclusion, the Boyden chamber assay can be used reliably for studying the invasive potential of cells in vitro, if the ability of the cells to migrate through the filter is taken into account, and a reference cell line is included to enable comparison of the data obtained from independently performed experiments on different cell lines.     

Deep brain stimulation for Parkinson's disease dissociates mood and motor circuits: a functional MRI case study.

Behavioral disturbances have been reported with subthalamic (STN) deep brain stimulation (DBS) treatment in Parkinson's disease (PD). We report correlative functional imaging (fMRI) of mood and motor responses induced by successive right and left DBS. A 36-year-old woman with medically refractory PD and a history of clinically remitted depression underwent uncomplicated implantation of bilateral STN DBS. High-frequency stimulation of the left electrode improved motor symptoms. Unexpectedly, right DBS alone elicited several reproducible episodes of acute depressive dysphoria. Structural and functional magnetic resonance imaging (fMRI) imaging was carried out with sequential individual electrode stimulation. The electrode on the left was within the inferior STN, whereas the right electrode was marginally superior and lateral to the intended STN target within the Fields of Forel/zona incerta. fMRI image analysis (Analysis of Functional NeuroImages, AFNI) contrasting OFF versus ON stimulation identified significant lateralized blood oxygen level-dependent (BOLD) signal changes with DBS (P < 0.001). Left DBS primarily showed changes in motor regions: increases in premotor and motor cortex, ventrolateral thalamus, putamen, and cerebellum as well as decreases in sensorimotor/supplementary motor cortex. Right DBS showed similar but less extensive change in motor regions. More prominent were the unique increases in superior prefrontal cortex, anterior cingulate (Brodmann's area [BA] 24), anterior thalamus, caudate, and brainstem, and marked widespread decreases in medial prefrontal cortex (BA 9/10). The mood disturbance resolved spontaneously in 4 weeks despite identical stimulation parameters. Transient depressive mood induced by subcortical DBS stimulation was correlated with changes in mesolimbic cortical structures. This case provides new evidence supporting cortical segregation of motor and nonmotor cortico-basal ganglionic systems that may converge in close proximity at the level of the STN and the adjacent white matter tracts (Fields of Forel/zona incerta).