Chevron截骨术对外翻足关节接触特征影响的生物力学研究

目的 探究Chevron截骨术截骨远端外侧位移距离对外翻足关节接触特征的影响,为临床上选择合适的位移距离提供参考依据。方法 测量踝关节中立位状态下正常足、外翻足及外翻足Chevron截骨术截骨远端分别向外侧位移2.0、4.0、6.0 mm后前足、中足和后足各关节接触力、峰值压强和接触面积,并对结果进行分析。结果 与正常足相比,外翻足第1跖楔关节（t=-3.33, P=0.02）、跟骰关节（t=-2.74, P=0.03）和距下关节（后关节面）（t=-2.89, P=0.03）的接触力显著增高;外翻足距舟关节（t=-2.73, P=0.03）与跟骰关节（t=-2.74, P=0.03）的峰值压强显著增高;行Chevron截骨术后,随着截骨远端向外侧位移距离的增加,外翻足第1跖楔关节和跟骰关节的接触力逐渐减小;外翻足距舟关节和跟骰关节的峰值压强逐渐减小。结论 中度外翻足行Chevron截骨术后,当第1跖骨截骨远端向外侧位移6 mm时能有效恢复部分关节间力的分布,且能缓解部分关节局部应力集中现象。     

Evidence against a role of nitric oxide in the indirect negative inotropic-effect of M-cholinoceptor stimulation in human ventricular myocardium

Nitric oxide (NO) has been reported to mediate several effects in response to muscarinic cholinergic stimulation in cardiovascular tissues. Recently, an attenuation of guinea pig cardiac myocyte contraction by NO has been described. The aim of the present study was to determine whether the indirect negative inotropic effect of M-cholinoceptor stimulation in human myocardium is in part due to an effect of endogenous NO. Therefore, the effect of carbachol was studied under control conditions and during inhibition of NO-synthase by pretreatment with N^G-monomethyl-l-arginine (NMMA). Functional experiments were performed in isolated, electrically driven (1 Hz, 37°C) left ventricular papillary muscle strips of human myocardium. Since cytokines have been reported to be increased in the serum of patients with heart failure and could induce NO-synthase activity in failing myocardium, we compared samples from nonfailing and terminally failing (classified as NYHA IV) hearts. The indirect negative inotropic effect of carbachol (10 mol/l) was studied in the presence of the \-adrenoceptor agonist isoprenaline (0.03 mol/l).After stimulation with isoprenaline, carbachol significantly (P < 0.05) reduced force of contraction. This effect was diminished in failing myocardium compared to nonfailing, probably due to the diminished inotropic response most likely due to the lower cAMP levels in response to \-adrenoceptor stimulation in the former condition. Pretreatment with NMMA (100 mol/l) altered the antiadrenergic effect of carbachol neither in nonfailing nor in failing preparations. Furthermore, inhibition of guanylyl cyclase, the target enzyme of NO, by preincubation with methylene blue (10 mol/l) for 30 min had no effect on the carbachol-induced decrease in force of contraction. Basal force of contraction, as well as the positive inotropic effect of isoprenaline remained unaffected by NMMA or methylene blue.The present study provides evidence that the indirect negative inotropic effect of M-cholinoceptor agonists is not due to an effect of NO in the human myocardium. Furthermore, the well known enhancement of cGMP in response to M-cholinoceptor stimulation appears not to be involved in this antiadrenergic effect.     

The epidemiology of occupational contact dermatitis

Occupational contact dermatitis (OCD) ranks first of all occupational diseases in many countries. The incidence rate is believed to be around 0.5–1.9 cases per 1000 full-time workers per year. Epidemiological studies play an important role in observing disease trends, analysing risk factors, and monitoring the effect of preventive measures. In this review article the lack of truly epidemiologic data on OCD and the difficulties of those studies are illustrated. The following issues are highlighted: case ascertainment and bias, the distribution of allergic and irritant contact dermatitis in the working population, the interrelationship between exogenous (allergens, irritants) and endogenous factors, the prognosis, the social and economic impact, and the need for intervention studies. Received: 26 January 1999 / Accepted: 24 April 1999     

Therapy-resistant unilateral chronic blepharokeratoconjunctivitis as the main finding in autoaggression syndrome. Clinicohistopathological findings

Summary Autoaggressive syndromes as causes of diseases underlying chronic blepharitis and keratoconjunctivitis that are refractory to treatment are often difficult to recognize. Patients: Three female patients (age 21, 25, 41 years) and one male patient (age 42 years) had suffered from a right-(4 × ) or left-(1 × ) handed treatment-refractory blepharokeratoconjunctivitis for 1, 2 ,11 and 30 months prior to admission. In each case more than 5 ophthalmologists and 2–6 eye hospitals had been consulted, and extraocular surgery had been performed 1–4 times. Results: Patients presented with a visual acuity of 0.3 p (1 × ), 0.1 (1 × ), FC (1 × ), HM (1 × ). In three patients contact eczema of the facial skin and lids and a corneal pannus were observed; in two patients we saw purulent pseudomembranous and in two patients chronic cicatrizing keratoconjunctivitis. Conjunctival smears grew P. aeruginosa, and S. aureus; impression cytology showed infiltration with neutrophils and epithelial keratinization; histopathology indicated chronic inflammatory, partly purulent subepithelial and stromal conjunctival infiltrate with hyper- and parakeratosis fibrous strands and epithelial cell loss; the lower lids showed parakeratosis, focal necrosis, intercellular edema and a lymphohistiocytic round-cell infiltrate. Furthermore, multiple allergies to antibiotics and preservatives (4 × ), lacerations of the arms and legs (2 × ) and an irritative-toxic dermatitis (1 × ) were substantiated. In the patients who agreed to a psychiatric consultation, somatized-agitated longing for care combined with a dependent and infantile personality (1 × ) and reactive depression (2 × ) were verified. Conclusions: In patients suffering from treatment-refractory unilateral chronic blepharokeratoconjunctivitis correlated with the hand, one must take into consideration the fact that other factors may be involved: possible exacerbation prior to examinations; multiple inpatient diagnostic and surgical procedures in different locations; histopathological mixed inflammatory patterns; and psychiatric syndromes.      

外伤角膜瘢痕无晶状体眼戴角膜接触镜后的角膜地形图改变

目的 探讨外伤性角膜瘢痕无晶状体眼戴硬性透气性接触镜前,后角膜表面的改变。方法 对戴该镜者１７眼及对照组（不戴镜）１２眼,在戴镜前后进行角膜地形图检测。结果 戴镜后平均８．４月,角膜散光减少（Ｐ〈０．０１）,角膜表面变得比较规则（Ｐ〈０．０５）,角膜表面的屈光度有变得相对比较平均的趋势。结论 戴硬性透气性角膜接触镜能使角膜瘢痕所致角膜散光减少,角膜表面变得较为规则。     

Paederus dermatitis: An easy diagnosable but misdiagnosed eruption

Paederus dermatitis is a perculiar irritant contact dermatitis characterised by erythemato-bullous lesions of sudden onset on exposed areas of the body. The disease is provoked by an insect belonging to genusPaederus. This beetle does not bite or sting, but accidental brushing against or crushing the beetle over the skin provokes the release of its coelomic fluid which contains paederin, a potent vesicant agent. Due to the pathogenic mechanism, the morphology and location of the dermatitis change from case to case. The lesion usually resembles the accidental dropping of a caustic or hot liquid. The uncommon association of acute dermatitis with minimal or no complaints, which would be noteworthy in the case of chemical or thermal burns, facilitates diagnosis which is corroborated by the season and by the case history.     

A force transducer and a length-ramp generator for mechanical investigations of frog-heart myocytes

An apparatus for studying the mechanics of isolated frog heart myocytes is described. The cells are held horizontal in a through of Ringer solution by means of two suction micropipettes. Myocyte force is measured with an opto-electronic system recording the deflection of the tip of one micropipette, which acts as a cantilever force probe. The force probes are selected for compliance according to the force a myocyte is expected to develop in a given condition, so as to limit myocyte shortening during force development to no more than 1% of the slack cellular length (l ₀). The other micropipette, which is stiff relative to the forces measured, is mounted on an electromagnetic-loudspeaker motor by which controlled-velocity length changes, of preset size and in either direction, are imposed on myocytes. The force transducer has a sensitivity of 5–10 mV/nN, with a frequency response of 700–900 Hz in Ringer solution and a resolution of 0.5–1 nN. The motor with a suction micropipette can complete controlled-velocity length ramps within 1.5–2.0 ms, across a range of ±100 m at a resolution of 8.0 nm. These values correspond, for frog-heart myocytes 200 m and 400 m long, to 25%–50% l ₀ and 0.002%–0.004% l ₀ respectively.     

山西省严重急性呼吸综合征病例接触史和传播链分析

目的　了解严重急性呼吸综合征 (SARS)的传播过程 ,分析其接触史以及可能导致个别 SARS病例接触史不详的原因 ,对流行病学调查质量做出评估。方法　 SARS病例个案调查与接触史专题调查相结合 ,用传播链示意图分析传播关系。结果　 4 4 8例 SARS病例中 ,有明确接触史者 4 11人 ,占 91.7% ,发现传播链 31条 ,涉及 2 0 8人 ,占有接触史总数的 5 0 .6 %。续发病例最多四代 ,以二代为多 ,占 6 8.8%。结论　引起医院传播和家庭聚集性暴发案例 ,虽然与超级传播者或“毒王”有关 ,但用对其传染性认识不足 ,就诊环境设置不合理 ,污染严重 ,个体防护不当解释更为科学、客观。传播链研究不仅可用于 SARS潜伏期的计算 ,而且还可作为评价 SARS防控效果的一个重要指标。     

通过杀菌试验观察隐形眼镜护理液杀菌活性成分的吸附作用

目的：为观察隐形眼镜护理液杀菌活性成分的吸附作用。方法：采用悬液定量杀菌试验方法。结果：对分别含0．00014％西吡氯铵（CPC）和含0．0001％聚亚已基缩二胍（PHMB）的两种隐形眼镜护理掖进行杀菌试骏。结果显示：（1）对含0．00014％西吡氯铵（CPC）的护理液．作用时间6h：用经护理液样品预处理过的玻璃和塑料试管进行试验，对金黄色葡萄球菌．大肠杆菌、绿脓杆菌三种细菌的平均杀灭率在99．90％以上；而用未经护理液样品预处理过的玻璃和塑料试管进行试验，对三种细菌的平均杀灭率在99．90％以下。试管处理与否对三种细菌的杀菌效果存在明显差异。（2）对含0.0001％聚亚已基双胍（PHMB）的护理液，作用时间4小时：塑料试管处理与否对三种细菌的杀菌效果无明显差异；玻璃试管处理与否对金黄色葡萄球菌和大肠杆菌的杀菌效果有影响。结论：玻璃和塑料试管壁对CPC都有吸附作用。玻璃试管对PHMB有少量吸附作用。