多系统萎缩的临床分型和影像学改变特点分析

目的探讨多系统萎缩（multiple system atrophy，MSA）的临床表现类型与神经影像学改变新特征（脑桥“十字征”和“壳核裂隙征”）的关系，为临床尽早做出诊断提供依据。方法按照Gilman诊断标准回顾性分析11例MSA患者的临床表现、分型和头颅MRI资料。结果本组诊断为很可能MSA11例，其中橄榄体脑桥小脑萎缩（MSA-C型）8例。2例在发病后3年头颅MRI脑桥“十字征”达Ⅰ期；1例在病后2年达Ⅱ期；3例分别在病后1年、3年、5年达Ⅲ期；另外2例分别在病后2年和7年达Ⅳ期。8例“壳核裂隙征”均为0期。黑质纹状体变性（MSA-P型）2例：1例病后6年脑桥“十字征”0期，“壳核裂隙征”Ⅰ期，另1例发病后9年“壳核裂隙征”Ⅱ期，脑桥“十字征”Ⅳ期。Shy-Drager综合征（MSA-A型）1例：病程5年，MRI检查脑桥“十字征”和“壳核裂隙征”分期均为0期。结论临床表现与头颅MRI检查发现的脑桥“十字征”和“壳核裂隙征”可作为及早识别MSA-C型的神经影像学改变特征，“壳核裂隙征”可作为识别MSA-P型的神经影像学改变特征。     

Neural network based tracking control of a flexible macro-micro manipulator system.

In this paper, we address the problem of stable tracking control of a flexible macro-micro manipulator (M(3)) system. A two-layer neural network is utilized to approximate the nonlinear robot dynamic behavior of the M(3) system, and the controllers for the macro and micro arms are developed without any need for prior knowledge of the dynamic model of the controlled M(3) system. A learning algorithm for the neural network using Lyapunov stability theory is derived. It is shown that both the tracking error and the weight-tuning error are uniformly ultimately bounded under this new control scheme. Simulation results are presented and compared to those obtained using a PD controller.     

糖尿病大鼠膀胱储尿期功能改变的实验研究

目的 研究糖尿病膀胱病变(Diabetic cystopathy，DCP)储尿期尿动力学特征及膀胱感觉功能障碍，为阐明DCP的发病机制提供实验依据。方法 分别以链脲佐菌素(STZ)、蔗糖诱导制作大鼠DCP模型及利尿模型，正常大鼠作对照。采用免疫组化结合图像分析技术观察膀胱感觉神经递质CGRP及其纤维改变；制备离体全膀胱，作膀胱灌注测压观察膀胱顺应性改变；放免法测定逼尿肌舒张信号转导分子cAMP。结果 DCP8周时，膀胱壁尤其是粘膜下层的CGRP及其神经纤维明显减少；离体膀胱测压显示糖尿病膀胱顺应性升高；膀胱舒张作用明显弱于对照组和利尿组，逼尿肌cAMP含量显著低于后者。结论 ①DCP对膀胱功能的损害是多方面的：CGRP为主要递质的粘膜下层膀胱容量感觉纤维明显减少，膀胱顺应性改变是DCP的致病机制之一。②DCP早期即已发生储尿期功能障碍，并且可能是膀胱收缩功能损伤的因素。③非糖尿病性利尿状态(多尿)对膀胱功能构成一定的损害作用，但不是DCP形成的主要原因。提示临床上对糖尿病患者作必要的尿动力学检查能较早发现DCP，有助于保护膀胱功能。     

Particle size and morphology of UHMWPE wear debris in failed total knee arthroplasties--a comparison between mobile bearing and fixed bearing knees.

Osteolysis induced by ultrahigh molecular weight polyethylene wear debris has been recognized as the major cause of long-term failure in total joint arthroplasties. In a previous study, the prevalence of intraoperatively identified osteolysis during primary revision surgery was much higher in mobile bearing knee replacements (47%) than in fixed bearing knee replacements (13%). We postulated that mobile bearing knee implants tend to produce smaller sized particles. In our current study, we compared the particle size and morphology of polyethylene wear debris between failed mobile bearing and fixed bearing knees. Tissue specimens from interfacial and lytic regions were extracted during revision surgery of 10 mobile bearing knees (all of the low contact stress (LCS) design) and 17 fixed bearing knees (10 of the porous-coated anatomic (PCA) and 7 of the Miller/Galante design). Polyethylene particles were isolated from the tissue specimens and examined using both scanning electron microscopy and light-scattering analyses. The LCS mobile bearing knees produced smaller particulate debris (mean equivalent spherical diameter: 0.58 microm in LCS, 1.17 microm in PCA and 5.23 microm in M/G) and more granular debris (mean value: 93% in LCS, 77% in PCA and 15% in M/G).     

Differential risks of subsequent vascular events for transient ischaemic attack and minor ischaemic stroke.

Using a prospective hospital-based registry, 146 patients with transient ischaemic attack (TIA) were compared with 376 patients with minor first-ever ischaemic stroke with respect to the 3-month risk of subsequent vascular events, in order to clarify the distinctions between the disease entities. All patients were enrolled within 48 h of onset. The risk factor distribution for the two groups was comparable, except that the TIA patients had more previous TIAs. Large artery atherosclerosis (34%) and small vessel occlusion (32%) were the main aetiologies in the TIA group, whereas small vessel occlusion (49%) was the major cause in the stroke group. The 3-month risk of combined endpoints of stroke, myocardial infarction, and vascular death for TIA patients was higher than that for the minor stroke group (15.1% vs. 3.2%; hazard ratio 4.6, 95% confidence interval 2.3-9.3 in multivariate analysis). Large artery atherosclerosis and male sex were the other significant predictors. TIA may demand more urgent management than minor stroke. The fact that aetiology is a predictor, highlights the need for rapid diagnostic tests to establish pathogenesis.     

颈椎骨折类型与脊髓损伤关系之临床观察

通过对９２例颈椎骨折病例的分析，发现屈曲型损伤最多见（５３％），其次为过伸型（２６％），压缩型（２１％）。屈曲型和压缩型多见于年轻人，而屈曲损伤导致的脱位及过伸型则多见于年龄较大者。爆裂骨折引起的神经损害最重，其次为屈曲型、过伸型及压缩（非爆裂）骨折。神经功能改善率以爆裂型骨折最差，死亡率亦最高，以压缩（非爆裂型）骨折最好，其次为过伸型及屈曲型。文内对各型的特点进行了详细讨论。     

小包装全氟丙烷气体动力学实验研究

为检验塑料小包装全氟丙烷气体（C3F8）在不同包装和储存方法时浓度变化，将装有5～7mlC3F8的聚氯乙烯小袋，根据不同储藏温度和外包装方法随机分成四组：（1）22℃聚乙烯外包装，（2）36℃聚乙烯外包装，（3）22℃铝箔真空外包装，（4）-29℃聚乙烯外包装；每一组C3F8小袋气体存放一定时间后，应用气相色谱分析方法进行浓度测量。结果：第3组C3F8浓度最高和稳定，第2组浓度随放置时间降低最明显，第4组是临床应用气体的储藏和包装方法，其30天样本浓度和第3组相等，但放置一年时浓度降低。结果显示：塑料小包装C3F8予以铝箔真空外包装是一种可行的方法，利于C3F8运输和普及；聚乙烯外包装的C3F8，应放在-29℃保存，时间不超过一年。     

A method for calculating the mean absorption time of drugs undergoing reversible and first-pass metabolism

A method has been derived for calculating the mean absorption time of an oral drug and its interconversion metabolite which is generated from the drug systemically and presystemically. The method evolves from the convolution integral and requires plasma AUC and AUMC values after separate intravenous administration of the drug and its interconversion metabolite and oral administration of the drug. It can also be used to calculate the mean input time of a drug undergoing reversible metabolism and administered by any other extravascular route. Results of a simulation study using both errorless and errant data indicate that, when the absorption rate constant of a drug or its interconversion metabolite is not much larger than the apparent elimination rate constant, the proposed method performs satisfactorily. However, when the absorption rate constant of a drug or its interconversion metabolite is much larger than the apparent elimination rate constant, the proposed method appears to be inaccurate.