跳水运动员颈椎损伤的生物力学研究

作者通过在新鲜成人颈椎标本上做了椎体静力性负荷和动力性负荷实验,表明颈椎在后伸位应力为前屈位的50%,最大应力位于颈椎4-6,是跳水运动员头颈部入水时引起颈椎致伤的生物力学因素。     

兔坐骨神经挤压伤的MRI与SEP对比研究

目的:探讨磁共振成像和体感诱发电位以及两者结合在坐骨神经急性挤压伤中的诊断价值。方法:24只兔按钳夹力的不同随机分为A、B两组,左后肢为损伤侧,右后肢为对照侧,建立坐骨神经急性挤压伤模型,于伤后1、2、4、8周行MR扫描,同时行双侧体感诱发电位检查。结果:损伤侧24条神经,有23条MR显示异常,诊断正确率95.8%,假阴性率4.17%(1/24);24条损伤侧坐骨神经,有22条SEP显示异常,诊断正确率91.6%,假阴性率8.3%(2/24)。MRI与SEP对神经损伤的正确诊断率无统计学差异(P>0.05)。MRI与SEP结合起来,24条损伤神经均显示异常,诊断正确率100%。结论:MR与SEP检查可无创、准确地判断神经损伤,两者结合可明显提高神经损伤的正确诊断率,重复性好,可作为神经损伤的较好诊断手段。     

The Fort McMurray demonstration project in social marketing: health- and safety-related behaviour among oil sands workers

This is the first round in a series of surveys conducted inFort McMurray as part of the Fort McMurray Demonstration Projectin social marketing. This component of the survey was intendedto focus on the most prominent group of employed workers inthe community and to compare their patterns of response withthe community as a whole. Respondents to the survey were overwhelminglymale (96%), married (72.9%) and living in households of twoto five persons (87.9%). They were predominantly aged 30–44(55%) and graduates of high school (53.5%). Younger male workers(below age 30) were more likely to have a high school diploma(78.3%) or some additional technical or vocational training(21.7% compared to 12.5% overall) and to be unmarried or separated.Attitudes toward safety-related behaviours were stronger thanfor respondents from the community as a whole. Approximately70–100% of all age groups and both sexes showed strongagreement with attitudes involving child car seats and the unacceptabilityof drinking and driving. These attitudes include strong advocacyof vigorous enforcement of occupational health and safety standards.However, they showed a variability similar to the communityas a whole in behaviour at home compared to work, generallyreporting more consistent use of personal protection on thejob than in their own homes, particularly hearing protection.Even so, they were much less likely to perform stretching andwarm-up exercises prior to exertion than community residentsin general. The potential may exist to transfer the technologyand attitudes from workplace health and safety to communitysafety. One possible strategy to accomplish this is to involveworkers in this industry directly in community initiatives.This strategy may be generalizable to any community in whichthere are major employers who place a heavy emphasis on riskcontrol and occupational health and safety.     

Nontraumatic glenohumeral instability and coracoacromial impingement in swimmers

Competitive swimming is one of the most demanding and time-consuming sports. Swimmers at elite level practice 20–30 h per week. During 1 year's practice, the average top level swimmer performs more than 500,000 stroke revolutions per arm. These innumerable repetitions over many years of hard training together with an increasing muscular imbalance around the shoulder girdle seem to be the main etiological factors in the development of the overuse syndrome swimmer's shoulder. Shoulder pain in swimmers has in general been regarded as synonymous with coracoacromial impingement, i.e. anterior shoulder pain due to rotator cuff tendinitis, but new knowledge suggests that a concomitant glenohumeral instability plays an additional role. The diagnostic complexity of the problem is as challenging as the search for the gold standard of treatment. The condition should ideally be diagnosed as early as possible, and intensive functional rehabilitation of the shoulder girdle including the scapular muscles should be started in order to restore muscle balance. The surgical possibilities include subacromial decompression in cases of purely mechanical impingement. If a painful glenohumeral instability persists after intensive functional rehabilitation, anterior capsulolabral reconstruction can be performed. Still, however, short- and long-term results show that surgery is less successful in elite athletes involved in overhead sports. Prevention protocols include education of coaches in primary injury prophylaxis and the institution of resistance strength training in prepubescent swimmers. Emphasis should be made to improve muscular balance around the glenohumeral and scapulothoracic joints.     

大鼠脊髓缺血再灌流时脊髓神经元对躯体和内脏传入刺激的反应

５０只大鼠用乌拉坦麻醉，箭毒制动。通过阻断腹主动脉血流以模拟腰段脊髓的局部缺血和再灌流损伤，玻璃微电极记录Ｌ２节段脊髓单位放电（ＳＣＵＤｓ），观察缺血再灌流时脊髓神经元对腓神经刺激（ＰＮＶ），内脏大神经刺激（ＶＬＮＶ）及两者同时刺激（ＳＶ）的反应。结果在缺血前所记录的１３３个自发放电单位中，对３种刺激均产生兴奋（Ｅ）、抑制（Ｉ）及无反应（ＮＲ）３种形式的反应，表明大鼠Ｌ２节段脊髓存在躯体、内脏和躯体内脏反应性神经元，并有会聚和阻塞现象。在脊髓缺血再灌流时，神经元对ＰＮＶ、ＶＬＮＶ、ＳＶ也产生Ｅ、Ｉ、ＮＲ３种形式的反应，提示脊髓缺血再灌流时神经元对躯体和内脏传入刺激的反应形式不受影响；但缺血时ＳＣＵＤｓ对ＰＮＶ、ＶＬＮＶ产生反应的单位数减少，这表明脊髓缺血损伤时神经元对躯体和内脏传入刺激的反应性减弱，随着缺血损伤加重，脊髓神经元对躯体内脏信号的整合功能下降     

角膜损伤后神经再生的实验研究

应用神经组织化学技术观察了兔角膜NA能神经及AchE阳性神经在角膜损伤后的再生,证实术后1月,两种神经均有再生轴突进入植片;术后3月可见交界区和植床内神经密度明显增加;同时,对术后两种神经再生的功能意义进行了讨论。     

Features of pediatric head injury in Hong Kong

Head injury in children causes special concern in most communities. From 1989 to 1994, 2,785 children younger than 16 years old were admitted to our neurosurgical service because of head injury. Fall from a height was the major cause of head injury leading to admission in infants and children in preschool age groups, whereas traffic-related or bicycle-related accidents were more likely to be the cause of head injury for those aged 11–15 years. In all age groups there was a male preponderance. The overall mortality was 0.6%. Traffic-ralated accidents caused more severe injury and accounted for 67% of all fatalities. For patients under 6 years old, about 40% of head injuries occurred at home. Preventive measures for pediatric head injury in Hong Kong are suggested.     

电针对沙鼠急性脑缺血再灌注后神经原损伤的保护作用

本实验利用沙鼠急性脑缺血再灌注模型，研究电针对脑缺血及再灌注各期脑电活动的影响及组织病理学的改变。结果表明：缺血１０ｍｌｎ，脑电幅度受到严重抑制，甚至变平坦，总功率大大下降，再灌注后总功率难以恢复，在１２０ｍｉｎ时仅恢复到缺血前的２７．３９±１１．３１％，以后即不再进一步恢复，电针组动物缺血１０ｍｉｎ再灌注后，脑电的恢复明显比对照组快，１２０ｍｉｎ时恢复至缺血前的７１．４５±１６．４６％（Ｐ＜０．０１），２４０ｍｉｎ时继续恢复至缺血前的７５．２７±１８．４３％。同时电针能明显减轻缺血１０ｍｉｎ后再灌注２４小时的神经原缺血性损伤。结果提示：电针对急性脑缺血引起的神经原损伤具有保护作用，并能促进脑功能的恢复。     

Cyclosporine overcomes cold preservation/reperfusion injury of liver graft: Chemokine release and liver ultrastructure

There is a growing body of evidence that the cytokine, tumor necrosis factor-α (TNF-ga), plays an important role in the development of hepatic ischemia/reperfusion injury. We found that the immunosuppressants, cyclosporine-A (CsA), azathioprine, and FK506, have protective effects on such injury. The purpose of the present study was to elucidate mechanisms involved in these beneficial effects of the immunosuppressant, CsA, on liver injury following cold preservation and transplantation, with special reference to the suppression of TNF-α release. Rat livers were stored in Euro-Collins solution (EC) at 4°C for 6h and orthotopically transplanted. The animals allotted to two groups: group A (untreated controls) and group B (CsA pretreatment of recipients). CsA (10 mg/kg, p.o.) was given for 3 consecutive days preoperatively. CsA pretreatment of the recipients significantly improved the 2-week survival rate (0/6 for group A, 3/6 for group B;P<0.05) and this was associated with a significant decrease in serum TNF-α levels 2h posttransplantation (group A, 69.8±15.7 pg/ml; group B, 22.8±6.8; mean±SEM;n=12 each;P<0.05) and amelioration of sinusoidal endothelial injury, assessed by electron microscopy. Plasma endotoxin levels following reperfusion of the grafts were not altered by the CsA therapy. Morphologically, CsA pretreatment of the recipients did not alter activation of Kupffer cells. CsA pretreatment of the recipient aids in preventing cold preservation/reperfusion injury of the liver graft, possibly by modulating effects of TNF-α.