图形翻转视觉诱发电位在视神经管减压后视神经损伤不同时期的变化特征

目的:观察视神经损伤动物模型在损伤后和不同时期视神经管减压后视觉诱发电位的变化,了解创伤性视神经损伤的手术时机与疗效的关系。方法:实验于2005-03/05在解放军南京军区南京总医院动物实验中心完成。①实验分组:30只新西兰白兔随机分为正常对照组、术后2d减压组、术后7d减压组、术后14d减压组、术后不减压组,每组6只。②造模:除正常对照组外,其余各组在视神经孔中塞入一细端为2mm直径的圆锥软硅胶,阻塞视神经孔,造成视神经的挤压伤。③指标检测:采用图形翻转视觉诱发电位检测损伤前、损伤后1h、减压前1h、减压后2周视功能变化,记录NPN曲线主波(P波)的绝对潜伏期、绝对波幅。正常对照组仅采集一组数据作为对照。结果:30只实验动物均进入结果分析。①正常对照组家兔图形翻转视觉诱发电位检查均引出典型NPN波型曲线,视神经挤压伤后1hNPN波形低阔扁平,P波潜伏期延长,波幅降低。②P波潜伏期:术后2d减压组减压后短于减压前[(71.25±8.51),(86.47±14.28)ms,P<0.05];术后7d减压组减压前后比较差异无显著性(P>0.05);术后14d减压组减压后明显长于减压前[(158.73±15.16),(116.35±17.13)ms,P<0.05]。术后2d减压组和术后7d减压组短于术后不减压组(P<0.01)。术后7,14d减压组和术后不减压组明显长于正常对照组(P<0.01)。③P波波幅:术后2d减压组减压后高于减压前[(5.25±0.78),(4.42±0.42)μV,P<0.05]。术后2d减压组减压后低于术后7d减压组、术后14d减压组(P<0.01),术后14d减压组低于术后7d减压组(P<0.05);术后7d减压组、术后14d减压组、术后不减压组低于正常对照组(P<0.01)。结论:神经元继发性损伤是视功能进行性下降的重要原因,视神经减压术有利于减轻视神经间接损伤,较早期(损伤后48h以内)减压可阻止轴突继发性损伤,避免视功能进一步下降,并在一定程度上逆转视功能的损害。     

三维CT评估发育性髋关节脱位的骨性形态学特征

目的:通过使用CT三维测量髋臼发育情况及髋臼对股骨头覆盖率对比性观察,整体反映髋臼发育情况。方法:①观察对象:选择2003-06/2005-04对41例发育性髋关节脱位患者55个髋关节。其中男12例,女29例;年龄18个月～6岁。患髋右侧23例,左侧32例,其中双侧12例。健康侧27髋。患儿家属均知情同意。②实验方法:所有患儿使用PQ6000型多层螺旋CT扫描,扫描数据进行骨组织三维重建。将测量数据制成图表,显示三维的髋臼发育情况,并量化表示髋臼的缺损情况。③实验评估:计算不同截面正常侧髋臼指数、中心边缘角(假设符合正态分布)的均数、标准差、分布范围及95%可信区间。观察发育性髋关节脱位术前术后骨骼形态学变化。分别在术前、术后测量患者患侧髋臼指数、中心边缘角和前倾角,测量值均分别与正常值进行对比。结果:患侧55个髋,健康侧27髋,均进入结果分析。①发育性髋关节脱位术前术后骨骼形态学变化:术前55侧发育性髋关节脱位髋关节脱位程度为,参照T"nnis分类方法,Ⅰ度5髋(9.1%),Ⅱ度11髋(20%),Ⅲ度32髋(58.2%),Ⅳ度7髋(12.7%)。术后患者均表现髋臼α角均>90°,头臼呈同心圆对位,Shenton线连续,股骨头较术前明显发育,原先未出现头骺的患者,出现头骺,但较正常仍偏小;髋臼口呈类圆形,髋臼边缘欠光滑,髋臼整体呈一定程度前倾。②术前术后髋臼指数、中心边缘角和前倾角变化对比:术后患者的髋臼指数和前倾角与正常对照组之间差异无显著性(P>0.05),术后患者的中心边缘角大于正常对照组[(33.4±2.6)°(29.1±2.0)°,P<0.01],术后患者的髋臼指数和前倾角测量值均小于术前(P<0.01)。结论:介绍了一种对髋臼形态测量的新方法,它能够全面反映髋臼的发育情况,不但增加了对中心边缘髋臼病理改变的认识程度,还为手术提供了精确的可信度较高的矫形设计方案。     

转化生长因子β1在大鼠纤维化腹膜组织中的表达及作用

目的:检测转化生长因子β1在腹膜透析大鼠腹膜内表达,并探讨其在腹膜纤维化中的意义。方法:实验于2005-06/2006-03在中南大学湘雅二医院肾内科实验室完成。①实验材料:雄性SD大鼠,体质量180～240g,由中南大学湘雅二医院动物实验中心提供。②实验方法:将28只大鼠按随机数字表随机分为4组,每组7只。正常对照组不予任何干预;生理盐水组腹腔注射20mL生理盐水;低糖透析液组腹腔注射20mL1.5%葡萄糖透析液;高糖透析液组腹腔注射20mL4.25%葡萄糖透析液,均为1次/d。4周后,向大鼠腹腔注射4.25%葡萄糖腹膜透析液20mL,4h后于大鼠右下腹缓慢插入带有多个侧孔的10号静脉留置针,缓慢低位引流腹透液,量取引流液。③实验评估:取大鼠壁层腹膜组织,以苏木素-伊红染色,镜下测量腹膜厚度,采用免疫组织化学方法检测大鼠腹膜中转化生长因子β1及纤连蛋白。结果:28只大鼠均进入结果分析。①高糖透析液组、低糖透析液组超滤量均明显低于正常对照组与生理盐水组,并且高糖透析液组超滤量明显少于低糖透析液组(P均<0.05)。②高糖透析液组腹膜明显增厚,表面粗糙,间皮细胞肿胀,脱落,间皮下有大量血管生成以及胶原纤维沉积,还可见单核细胞等炎症细胞浸润,与其他组比较,腹膜厚度明显增加(P<0.05)。③高糖透析液组转化生长因子β1、纤连蛋白表达量均明显高于其他组;低糖透析液组转化生长因子β1、纤连蛋白表达量均明显高于正常对照组与生理盐水组(P<0.05)。④大鼠腹膜组织转化生长因子β1蛋白与纤连蛋白表达量、腹膜厚度之间呈明显的正相关(r=0.86,0.83,P<0.05)。结论:葡萄糖透析液可诱导腹膜组织转化生长因子β1明显上调,腹膜转化生长因子β1高表达与腹膜透析腹膜纤维化密切相关。     

A prospective survey of risk factors in young adults with arterial occlusive disease

Few studies have presented a thorough analysis of young adults with symptoms of arterial occlusive disease. To learn more about the possible risk factors of vascular disease playing a role in these young patients, we have reviewed all patients of 45 years of age and younger with symptoms of arterial occlusive disease who had been referred to our department between 1978 and 1987. Thirty-seven patients (28 males and 9 females) were included in the study. The mean age at which the first symptoms occurred was 34 years. Most patients presented with chronic arterial obliterations of the lower extremities (31/37, 84%). In addition, 4 patients showed signs of ischaemic heart disease. A strongly positive family history of arteriosclerosis was obtained from 13 patients (35%). Hypertension was present in 7 patients (19%), diabetes in three (8%) and nicotine abuse was found in 27 patients (73%). Fifty-four percent of the patients (20/37) had undergone vascular reconstructive surgery, 19% (7/37) underwent transluminal dilatation, and 3 had had subsequent treatment of newly developed lesions. For this study, all patients were recalled to the outpatient clinic. A complete case history was taken followed by a physical examination and ECG. Laboratory examinations were performed to analyse parameters of: (a) coagulation; (b) fibrinolysis; (c) fat- and (d) methionine metabolism. Clear-cut laboratory abnormalities were found in 33 patients (33/37, 89%). Coagulation parameters were abnormal in 11 patients (30%) (protein S deficiency: 3 pts). Fibrinolysis was impaired in 15 patients (40%).(ABSTRACT TRUNCATED AT 250 WORDS)     

Essential steps in developing best practices to assess reflective skill: A comparison of two rubrics

Purpose: Medical education lacks best practices for evaluating reflective writing skill. Reflection assessment rubrics include the holistic, reflection theory-based Reflection-on-Action and the analytic REFLECT developed from both reflection and narrative-medicine literatures. To help educators move toward best practices, we evaluated these rubrics to determine (1) rater requirements; (2) score comparability; and (3) response to an intervention.

Methods: One-hundred and forty-nine third-year medical students wrote reflections in response to identical prompts. Trained raters used each rubric to score 56 reflections, half written with structured guidelines and half without. We used Pearson’s correlation coefficients to associate overall rubric levels and independent t-tests to compare structured and unstructured reflections.

Results: Reflection-on-Action training required for two hours; two raters attained an interrater-reliability?=?0.91. REFLECT training required six hours; three raters achieved an interrater-reliability?=?0.84. Overall rubric correlation was 0.53. Students given structured guidelines scored significantly higher (p?<?0.05) on both rubrics.

Conclusions: Reflection-on-Action and REFLECT offer unique educational benefits and training challenges. Reflection-on-Action may be preferred for measuring overall quality of reflection given its ease of use. Training on REFLECT takes longer but it yields detailed data on multiple dimensions of reflection that faculty can reference when providing feedback.     

A population-based study of the extent of surgical resection of potentially curable colon cancer

Background We attempted to determine factors contributing to the extent of initial curative resection for colon cancer in a population-based cohort. Total abdominal colectomy with ileorectal anastomosis (TAC-IR) may be considered for young patients or those with a colorectal cancer family history to prevent metachronous lesions and facilitate surveillance. Methods All Ontario patients newly diagnosed with colon cancer over 12 months beginning in July 1997 were staged at the time of surgery. The extent of resection was compared with variables, including familial risk obtained from the Ontario Familial Colon Cancer Registry. Results Complete staging was possible for 86% of patients. A total of 1223 patients had a potentially curative resection: 17%, 46%, and 36% were stage I, II, and III, respectively. Patients were more likely to receive a TAC-IR if they were ≤50 years old (odds ratio [OR], 3.5; 95% confidence interval [CI], 1.8–6.6), if they had a synchronous lesion (OR, 28.37; 95% CI, 12.2–61.2), or if they were at a teaching hospital (OR, 2.8; 95% CI, 1.6–4.7), but not if they had a family history (OR, 7; 95% CI, 3–1.5). Conclusions Young age, teaching hospital, and multiple cancers but not family history were important factors for performing a TAC-IR.