二甲基亚硝胺诱发大鼠肝纤维化模型肝脏超微结构形态学与血清透明质酸、层粘连蛋白、Ⅳ型胶原含量的变化

背景:肝纤维化的发展伴随诸多的形态学和机能学的改变,二甲基亚硝胺所致的大鼠肝纤维化模型病变类似于人类肝纤维化病变。目的:观察二甲基亚硝胺诱发大鼠肝纤维化发生过程中形态学与血清透明质酸、层粘连蛋白、Ⅳ型胶原含量的动态变化。设计:随机对照动物实验。单位:延边大学医学院病理教研室实验室。材料:选用80只3月龄Wistar雄性大鼠,清洁级,体质量175～200g,由延边大学医学院动物中心提供。试剂:二甲基亚硝胺美国Sigma公司产品,α-平滑肌肌动蛋白为Dako公司产品,天狼猩红(Siriusred)为Aldrichchem公司产品,血清透明质酸、层粘连蛋白和Ⅳ型胶检测试剂盒为华美生物工程公司产品,兔抗鼠的一抗为Dako,Denmak生物公司的产品。仪器:日本产JEM-1200EX透射电镜;日本产酶联免疫检测仪;北京航空航天大学研制开发的CMTAS多功能真彩色病理图象分析系统。方法:实验于2004-06/2005-12在延边大学医学院完成。摸球法随机将大鼠分成2组。模型组(n=40):给予腹腔注射10g/L二甲基亚硝胺(10μL/kg),1周连续注药3d(1次/d),持续4周;对照组(n=40):在同一时间段内注射同样剂量的生理盐水;分别在实验开始7,14,21,28d处死大鼠,处死前左心室取血,血清样品被冷冻在-70℃的低温冰箱中备实验用,处死后取其肝组织用于光镜和电镜的样品制备。①用ELISA法测定在肝纤维化形成过程中血清透明质酸、层粘连蛋白、Ⅳ型胶原含量的动态变化。②采用苏木精-伊红染色、组织化学的天狼猩红染色观察肝纤维化形成过程中组织形态学变化及对肝纤维化分级(肝纤维化程度分为0～4级,0级:没有肝纤维化;1级:汇管区有纤维化;2级:汇管区与汇管区之间形成纤维间隔;3级:肝小叶中出现纤维间隔,并且肝的正常结构出现病理改变;4级:形成肝硬化),同时计算胶原纤维的面密度。③采用透射电镜技术、免疫组织化学的α-平滑肌肌动蛋白染色观察肝星状细胞的转化情况及分布特点。④对肝纤维化形成过程中胶原纤维面密度的百分比与血清透明质酸、Ⅳ型胶原、层粘连蛋白含量的相关分析。主要观察指标:①肝纤维化形成过程中血清透明质酸、层粘连蛋白、Ⅳ型胶原含量的变化。②肝纤维化形成过程中形态学变化、肝纤维化的分级情况及胶原纤维的面密度。③肝星状细胞的转化情况及分布特点。④肝纤维化形成过程中胶原纤维面密度的百分比与血清透明质酸、Ⅳ型胶原、层粘连蛋白含量的相关分析结果。结果:纳入80只大鼠,实验组34只造模成功,与对照组40只全部进入结果分析。①模型组第7天至28天血清透明质酸、层粘连蛋白、Ⅳ型胶原含量明显高于对照组(P<0.05),其中第28天增加程度最大。②模型组汇管区在腹腔注射二甲基亚硝胺后第7天出现出血坏死,第14天仍可在汇管区观察到出血、坏死,并且还可见较薄的纤维间隔,第21和28天可见较厚的纤维间隔;模型组大鼠腹腔注射二甲基亚硝胺后第7,14,21,28天胶原纤维面密度的百分比明显高于对照组(P<0.05),其中第28天增加的幅度最大;对照组大鼠纤维化病理分级与模型组大鼠各时间点相比差异显著(P<0.01),模型组大鼠的第7天较第14,28天组有明显差异(P<0.01)。③a-平滑肌肌动蛋白染色有阳性细胞出现,并且在这一阶段在电镜下观察到正处在“转化的肝星状细胞”;模型组第21和28天,在电镜下观察到典型的成纤维细胞。④胶原纤维面密度的百分比与血清透明质酸、层粘连蛋白、Ⅳ型胶原含量呈正相关(r=0.707,0.675,0.662,P<0.01)。结论:二甲基亚硝胺诱发大鼠肝纤维化发生过程中,在不同时间段内形态学与血清标志物透明质酸、层粘连蛋白、Ⅳ型胶原呈动态变化,并且在不同的时间段内胶原纤维面密度的百分比与血清透明质酸、层粘连蛋白、Ⅳ型胶原含量呈正相关。     

汉中市中小学教师教育技术应用情况的归因分析

以参加"亚行贷款灾后重建技术援助教育子项目"培训的教师为研究对象,在中小学教师教育技术能力现状调查的基础上,针对应用情况进行研究,分析了影响汉中市中小学教师教育技术应用的因素。结果显示:影响该地区教师教育技术应用的主要因素是教师信息技术能力、学校的态度政策以及对教育技术基本理论的掌握,并在此基础上提出具体建议。     

Decreased expression of phospholipase C-beta 2 isozyme in human platelets with impaired function

Platelets from a patient with a mild inherited bleeding disorder and abnormal platelet aggregation and secretion show reduced generation of inositol 1,4,5-trisphosphate, mobilization of intracellular Ca2+, and phosphorylation of pleckstrin in response to several G protein mediated agonists, suggesting a possible defect at the level of phospholipase C (PLC) activation (see accompanying report). A procedure was developed that allows quantitation of platelet PLC isozymes. After fractionation of platelet extracts by high-performance liquid chromatography, 7 out of 10 known PLC isoforms were detected by immunoblot analysis. The amount of these isoforms in normal platelets decreased in the order PLC- gamma 2 > PLC-beta 2 > PLC-beta 3 > PLC-beta 1 > PLC-gamma 1 > PLC- delta 1 > PLC-beta 4. Compared with normal platelets, platelets from the patient contained approximately one-third the amount of PLC-beta 2, whereas PLC-beta 4 was increased threefold. These results suggest that the impaired platelet function in the patient in response to multiple G protein mediated agonists is attributable to a deficiency of PLC-beta 2. They document for the first time a specific PLC isozyme deficiency in human platelets and provide an unique opportunity to understand the role of different PLC isozymes in normal platelet function.     

Treatments of unruptured brain arteriovenous malformations: A systematic review and meta-analysis

Background:The best therapeutic option for unruptured brain arteriovenous malformations (bAVMs) patients is disputed.Objective:To assess the occurrence of obliteration and complications of patients with unruptured bAVMs after various treatments.Methods:A systematic literature search was performed in PubMed, EMBASE, Web of Science, and so on to identify studies fulfilling predefined inclusion criteria. Baseline, treatment, and outcomes data were extracted for statistical analysis.Results:We identified 28 eligible studies totaling 5852 patients. The obliteration rates were 98% in microsurgery group (95% confidence interval (CI): 96%–99%, I² = 74.5%), 97% in surgery group (95%CI: 95%–99%, I² = 18.3%), 87% in endovascular treatment group (95%CI: 80%–93%, I² = 0.0%), and 68% in radiosurgery group (95%CI: 66%–69%, I² = 92.0%). The stroke or death rates were 1% in microsurgery group (95%CI: 0%–2%, I² = 0.0%), 0% in surgery group (95%CI: 0%–1%, I² = 0.0%), 4% in endovascular treatment group (95%CI: 0%–8%, I² = 85.8%), and 3% in radiosurgery group (95%CI: 3%–4%, I² = 82.9%). In addition, the proportions of hemorrhage were 2% in microsurgery group (95%CI: 1%–4%, I² = 0.0%), 23% in endovascular treatment group (95%CI: 7%–39%), and 12% in radiosurgery group (95%CI: 12%–13%, I² = 99.2%). As to neurological deficit, the occurrence was 9% in microsurgery group (95%CI: 6%–11%, I² = 94.1%), 20% in surgery group (95%CI: 13%–27%, I² = 0.0%), 14% in endovascular treatment group (95%CI: 10%–18%, I² = 64.0%), and 8% in radiosurgery group (95%CI: 7%–9%, I² = 66.6%).Conclusions:We found that microsurgery might provide lasting clinical benefits in some unruptured bAVMs patients for its high obliteration rates and low hemorrhage. These findings are helpful to provide a reference basis for neurosurgeons to choose the treatment of patients with unruptured bAVMs.     

Sturge–Weber Syndrome Is Associated with Cortical Dysplasia ILAE Type IIIc and Excessive Hypertrophic Pyramidal Neurons in Brain Resections for Intractable Epilepsy

Sturge–Weber syndrome (SWS) is a rare syndrome characterized by capillary‐venous malformations involving skin and brain. Many patients with SWS also suffer from drug‐resistant epilepsy. We retrospectively studied a series of six SWS patients with epilepsy and extensive neurosurgical resections. At time of surgery, the patients' age ranged from 11 to 35 years (with a mean of 20.2 years). All surgical specimens were well preserved, which allowed a systematic microscopical inspection utilizing the 2011 ILAE classification for focal cortical dysplasia (FCD). Neuropathology revealed dysmorphic‐like neurons with hypertrophic cell bodies reminiscent to those described for FCD type IIa in all cases. However, gross architectural abnormalities of neocortical layering typical for FCD type IIa were missing, and we propose to classify this pattern as FCD ILAE type IIIc. In addition, our patients with earliest seizure onset also showed polymicrogyria (PMG; n = 4). The ictal onset zones were identified in all patients by subdural electrodes, and these areas always showed histopathological evidence for FCD type IIIc. Four out of five patients had favorable seizure control after surgery with a mean follow‐up period of 1.7 years. We concluded from our study that FCD type IIIc and PMG are frequently associated findings in SWS. FCD type IIIc may play a major epileptogenic role in SWS and complete resection of the associated FCD should be considered a prognostic key factor to achieve seizure control.     

Morphological and serum hyaluronic acid, laminin and type Ⅳ collagen changes in dimethylnitrosamine-induced hepatic fibrosis of rats

AIM: To study the morphological and serum hyaluronic acid (HA), laminin (LN), and type Ⅳ collagen changes in hepatic fibrosis of rats induced by dimethylnitrosamine (DMN).METHODS: The rat model of liver fibrosis was induced by DMN. Serum HA, type Ⅳ collagen, and LN were measured by ELISA. The liver/weight index and morphological changes were examined under electron microscope on d 7, 14, 21, and 28 by immunohistochemical alpha smooth muscle actin α-SMA staining as well as Sirius-red and HE staining.RESUJLTS: The levels of serum HA, type Ⅳ collagen and LN significantly increased from d 7 to d 28 (P = 0.043).The liver/weight index increased on d 7 and decreased on d 28. In the model group, the rat liver stained with HE and Sirius-red showed evident hemorrhage and necrosis in the central vein of hepatic 10 lobules on d 7. Thin fibrotic septa were formed joining central areas of the liver on d 14. The number of α-SMA positive cells was markedly increased in the model group. Transitional hepatic stellate cells were observed under electron microscope.All rats in the model group showed micronodular fibrosis in the hepatic parenchyma and a network of α-SMA positive cells. Typical myofibroblasts were embedded in the core of a fibrous septum. Compared to the control group, the area-density percentage of collagen fibrosis and pathologic grading were significantly different in the model group (P＜0.05) on different d (7, 14, and 28). The area-density percentage of collagen fibrosis in hepatic tissue had a positive correlation with the levels of serum HA, LN, and type Ⅳ collagen.CONCLUSION: The morphological and serum HA, type Ⅳ collagen, and LN are changed in DMN-induced liver fibrosis in rats.     

Radiofrequence ablation of liver cancers

Primary and secondary malignant liver cancer are some of most common malignant tumors in the world. Chemotherapy and radiotherapy are not very effective against them. Surgical resection has been considered the only potentially curtive option, but the majority of patients are not candidates for resection because of tumor size, location near major intrahepatic blood vessels and bile ducts, precluding a margin-negative resection, cirrhotic, hepatitis virus infection or multifocial. Radiofrequence ablation (RFA), which is a new evolving effective and minimally invasive technique, can produce coagulative necrosis of malignant tumors. RFA should be used percutaneously, laparascopically, or during the open laparotomy under the guidance of ultrasound, CT scan and MRI. RFA has lots of advantages superior to other local therapies including lower complications, reduced costs and hospital stays, and the possibility of repeated treatment. In general, RFA is a safe, effective treatment for unresectable malignant liver tumors less than 7.0 cm in diameter. We review the principle, mechanism, procedures and experience with RFA for treating malignant liver tumors.