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.     

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。     

滥用药物与生命质量退化的伦理思考

本文从生命质量的内涵入手,分析了滥用药物的直接和间接、近期和远期的危害,通过论证得出了滥用药物必将引起人类生命质量退化的结论.以期从一个新的认识度唤起人们对滥用药物问题的重视、并由此引出了一些对医学目的以及滥用药物控制措施的思考.     

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.     

便携式野战—Ⅰ型多功能骨科手术器械

一种便携式野战多功能骨科手术器械。重量仅１．１ｋｇ，体积为２１５ｍｍ×１０５ｍｍ×１５ｍｍ，如铅笔盒，而功能多达３３种，具有结构紧凑、操作简便、一械多用、轻巧便携。价廉实用、效价比高的特点。是基层巡诊、抢险救灾救治中适用的骨科器械。