神经根慢性嵌压损伤的动物模型建立

目的：建立一种由自身骨性增生造成神经根慢性嵌压损伤的动物模型，为相关实验提供造模方法一方法：30只健康家猫，手术显露右侧C7、C8和L5、L6冲经根及其椎问孔内口，用牙髓钻破坏椎间孔周围骨皮质后，将“V”形松质骨块沿骨壁嵌于神经根通道的骨性管道内及侧隐窝后方，左侧做正常对照。在造模术前和术后第2、4、8、12、24周行磁刺激运动诱发电位(MEP)检测，每次随机选6只，4～5只行影像学检查，以确定神经根通道的狭窄程度和神经根受压状态，6只均做病理组织学检查和椎间孔截面积测量。结果：术后早期实验侧肢体出现行为异常：而后有不同程度肌萎缩；后期部分肢体远端出现溃疡。影像学检查随着嵌压时间延长．实验侧椎间孔骨痂增多，狭窄加重。神经根受压变形，椎间孔骨性截面积8周后明显减小，与对照侧比较有显著性差异。术后2周，神经根组织学检查主要表现为神经束膜、内膜的水肿。髓鞘肿胀；4周后发生节段性脱髓鞘：8周时神经轴突增粗、断裂，远端瓦勒氏变性；12周后变性冲经结构崩解、吸收，形成空洞：24周时整个神经干纤维化。术后4周时实验侧MEP开始出现潜伏期延长；8周时伴有波形分化不清；12周波幅明显下降：24周MEP的引出困难，部分电位消失。结论：采用椎问孔内自体松质骨植入，造成神经根慢性嵌压性损伤模型成功率高，操作简单，适用于脊柱各个节段，其损伤部位和形式与临床更为接近。     

侧向压力和锉针磨损对声波和超声波根管器械切削效力的影响

[目的]观察器械侧向压力(load)和根管锉的工作磨损(wear)对超声锉和声波锉切削效力的影响。[方法]在0.245 N或0.490 N侧向压力下,使用新或已经使用1 min的根管锉,利用本院自制的根管器械切削效力测试仪观察声波和超声波根管器械对牛骨片的切削能力。[结果]声波根管器械平均较超声波根管器械切削效力高292％,差异具有统计学意义(P<0.01);侧向压力和锉的磨损对声波根管器械切削效力的影响较超声波器械更明显(P<0.01)。[结论]同超声波器械相比,声波根管器械可能具有更高的临床工作效率,但器械容易磨损;临床使用中应谨慎控制声波根管器械侧向压力的大小,防止根管过度切削。     

脑梗死后再发缺血性卒中与脑出血患者微血管病变及预后的比较

【目的】探讨脑梗死后再发缺血性卒中与脑出血患者的临床特点、影像学上微血管病变及预后的异同。【方法】连续收集急性复发性卒中的住院病例（初发事件为脑梗死，复发事件包括脑梗死或脑出血），详细记录临床资料。观察脑内微出血及自质病变的严重程度，随访有无严重血管事件及死亡的发生。【结果】175例再发脑梗死患者。19例复发事件为脑出血的患者进入本研究。155例（88．6％）再发脑梗死患者，以及18例（94．7％）脑出血患者存在自质病变。77例（44％）再发脑梗死患者和16例（84．2％）脑出血患者存在脑内微出血。脑出血组自质病变的严重程度及微出血的数目均明显高于再发脑梗死组（P=0．033，0．016），脑出血组的死亡率及再发脑出血的危险性明显增高（P=0．034，0．036）。【结论】严重的脑自质病变及微出血的出现与脑梗死后再发脑出血有关。多发微出血提示出血风险增高。如复发事件为脑出血，则其死亡率及再次复发脑出血的风险均明显增加。     

Low surface tension calcium hydroxide solution is an effective antiseptic

The antimicrobial effects of a saturated calcium hydroxide solution, and in combination with 10% and 20% detergent, were evaluated on Streptococcus faecalis. Strepto-coccus sanguis, Streptococcus mutans, Streptococcus salivarius, Neisseria sp., diphlheroid, Staphylococcus aureus, Lactobacillus sp., Staphylococcus epidermidis, Bacillus suhtilis and Candida albicans. The saturated calcium hydroxide solution was effective against only four of the 11 microorganisms studied over a 60-min exposure time. The calcium hydroxide solutions con-taining detergent killed all 11 test organisms over a 30-min exposure time. This difference was statistically significant (P<0.01). No statistically significant difference in antimicrobial action was found between the 10% and 20% detergent calcium hydroxide solutions (F>0.01). However, the low surface tension (46.5 × 10^?3 Nm^?1) and high pH (10.8) of the calcium hydroxide solution with 20% detergent establish it as the more effective solution.     

牙髓根管感染厌氧菌培养结果分析

从３４例牙髓根管感染中共分离出厌氧菌１１８株，经菌属分类依次为消化链球菌属，拟杆菌属，梭杆菌属，放线菌属，韦荣氏球菌属和珠网菌属，其中前３属为７７株，分离率为６５．３％，这一结果显示该３属细菌与极管感染有密切关系，是牙髓根管感染的优势菌。     

Dorsal root ganglia cocultured with macrophages: an in vitro model to study experimental demyelination

The present investigation introduces an in vitro model to study macrophage properties during demyelination. Rat dorsal root ganglia (DRG) were cultured for obtaining myelinated peripheral nerve fibers. These cultures were exposed to non-resident macrophages. In untreated control cultures, there was no indication of myelin removal by the added macrophages. DRG were exposed to enzymatically generated oxygen radicals using the xanthin/xanthin oxidase or the glucose/glucose oxidase system. Assessment of Schwann cell viability and ultrastructural morphology revealed different patterns of cell cytotoxicity and morphological changes in different experiments. High concentrations caused complete tissue necrosis of the DRG, while low concentrations did not affect either cell viability or ultrastructural morphology. Under intermediate experimental conditions, oxygen radicals caused non-lethal Schwann cell damage leading to Schwann cell retraction and myelin sheath rejection. Myelin lamellae were disrupted and decompacted. These changes were followed by a selective macrophage attack on myelin sheats, resulting in demyelination. Axons, Schwann cells and sensory ganglion cells survived this attack. The specificity of the oxygen radical effects was tested in experiments using the oxygen radical scavengers catalase and superoxide dismutase. Catalase prevented the described effects on cell morphology and subsequently blocked demyelination by non-resident macrophages.Supported by a grant from the Deutsche Forschungsgemeinschaft (DFG) (Br 1274/1-1)     

糖尿病肾病患者血液白细胞的变化

目的观测糖尿病肾病患者血液白细胞的变化,分析炎症在糖尿病肾病中的作用。方法对436例糖尿病住院病人,分为糖尿病肾病组(n=102)和糖尿病无肾病组(n=334),检测血液白细胞总数和中性粒细胞数。结果糖尿病肾病组白细胞总数为(7.10±2.21)×109/L,糖尿病无肾病组为(5.61±1.34)×109/L,两组相比,差异有非常显著性意义(t=8.270,P<0.001);中性粒细胞计数值糖尿病肾病组(4.47±2.03)×109/L明显高于糖尿病无肾病组(3.18±1.04)×109/L,差异有非常显著性意义(t=8.481,P<0.001)。相关分析,白细胞数与肌酐(C r)呈正相关(r=0.155,P>0.05)、与尿素(Urea)呈明显正相关(r=0.295,P<0.01)、与血糖(GLU)无明显相关(r=0.055,P>0.05);中性粒细胞与C r、Urea呈明显正相关(r=0.260,0.398,P<0.01)、与GLU呈正相关(r=0.163,P>0.05)。结论糖尿病肾病患者血液白细胞计数升高,与肌酐、尿素水平呈正相关。糖尿病肾病患者存在炎症反应,炎症在糖尿病肾病发生发展中起一定作用。     

ROOT ZX根管长度测量仪临床应用评价

目的 评价森田ROOT ZX根管长度测量仪临床应用价值.方法 用根管长度测量仪对108例根管进行根管测量,以此长度进行根管预备后,按测量长度插入牙胶尖摄X线牙片,计算出实际根管长度,求得测量准确率.结果 ROOT ZX测量准确率为92.6%.结论 ROOT ZX根管长度测量仪应用安全可靠、准确率高.     

An Autopsied Case of Interferon Encephalopathy

Abstract: A 78-year-old male with renal carcinoma was treated with a high dose infusion of interferon-alpha (IFN-alpha) for eight months. The patient had evidence of organlc brain syndrome such 88 : dysfunction of memory, slowing of behavior, and development of mental confusion that appeared eight months after the treatment. MRI at the time of mental confusion revealed difise white matter lesions. Neuropathologic findings were compatible to Binswanger's disease and Senile Dementia of Alzheimer Type (SDAT), Preexisting neurologic abnormalities including intracerebral arteriosclerosis and cerebral atrophy may increase susceptibility to unacceptably severe IFN neurotoxicity.     

The use of coaxially aligned freeze-thawed skeletal muscle autografts in the repair of the cauda equina — in the sheep

Summary The aim was to develop a model for study of nerve regeneration in nerve roots above the level of the dorsal root ganglion and to investigate the use of freeze-thawed muscle autografts for repair of nerve roots at this level.Four adult sheep were used for the experiment. A laminectomy was performed at the lumbosacral junction and the S2 root identified. Both the dorsal and ventral S2 roots were divided unilaterally within the dura and a freeze-thawed muscle graft was inserted into the nerve gap.When assessed at 6 months an action potential was recordable from the ventral root in one sheep. Histological examination of the nerve roots showed evidence of regeneration across the graft in the ventral roots of all the sheep and the dorsal roots of some.This preliminary work indicates a capacity for regeneration of the cauda equina and that freeze-thawed muscle can support this. It provides a useful model for further study of nerve root repair.