口腔病理学研究性学习教学改革的尝试

为了培养有自学能力、信息获取能力、沟通能力和临床思维能力的高素质医学人才,建立适应人才培养需要的口腔病理学教学方法,本文采用行动研究方法,对基于问题解决为中心、研究性学习的教学方法进行了实验性研究,旨在探讨如何充分利用网络资源进行口腔医学教学改革的思路,希望对今后教学改革具有启示作用。     

亚麻籽胶的胶凝性质

采用流变学法测定了亚麻籽胶溶液的胶凝点、熔化点，并采用质构仪、扫描电镜和原子力显微镜等手段研究了影响亚麻籽胶凝胶强度的因素，结果表明亚麻籽胶具有胶凝性，它能形成一种热可逆的冷致凝胶，亚麻籽胶溶液的胶凝点低于其凝胶的熔化点，且亚麻籽胶溶液的胶凝点及其凝胶的熔化点均随冷却的起始温度的升高而升高。亚麻籽胶浓度、溶解温度、pH、NaCl、CaCl2及复合磷酸盐能影响亚麻籽胶的凝胶强度，亚麻籽胶的凝胶强度随着浓度的增加及溶解温度的升高而增强；在pH6～9的范围内，亚麻籽胶的凝胶强度达到最大；NaCl和复合磷酸盐可以降低亚麻籽胶的凝胶强度，低浓度（〈0．3％）的CaCl2可以增强亚麻籽胶的凝胶强度，而高质量分数（〉0．3％）的CaCl2能降低亚麻籽胶的凝胶强度。     

黄栌中漆黄素提取工艺及含量测定方法的研究进展

本文综述了近10年来黄栌中漆黄索的提取工艺和测定方法的研究进展，并对各种提取工艺和测定方法进行了评价。为更好地开发利用漆黄素提供参考。     

Action Research: a valuable research technique for service delivery development

The evaluation of healthcare practice and service delivery is fraught with difficulties. Service development and / or delivery occurs within socially dynamic settings which are in a continual state of change. Service development also often involves large elements of improvisation. The action research approach is useful for health service research, as it supports collaboration between researchers and practitioners, and not only allows but makes explicit that the action researcher has both roles within the setting being studied. This paper discusses action research methodology and offers insight into principles that favor its use for service delivery development. This includes consideration of the interactive variables within studies of health care systems and the importance of evaluating relationships between stakeholders to understand how these factors or variables, which cannot be controlled for, are responsible for successful development of the service. Action research facilitates change and helps bridge the heory--practice gap. With the current dynamic changes within both the pharmacy profession and national health services, researchers may find the action research technique of value when considering new roles and innovative ways of engaging in collaborative, multi-disciplinary working to improve delivery of patient care.Accepted july 2004     

兔精原干细胞培养及生物学特征的初步研究

目的:建立精原干细胞的培养方法并对培养细胞的生物学特征进行研究.方法:用饲养层和无饲养层两种方法培养幼家兔精原干细胞,在倒置相差显微镜下观察培养细胞的生长和形态变化,并对细胞的糖原、脂质及c-kit受体的细胞化学和免疫细胞化学染色结果进行分析.结果:成功的分离并培养幼家兔精原干细胞.在培养细胞中精原干细胞为主体细胞,并可见少量间质细胞.根据精原干细胞体积大小和形态特点,可分为大、小两种类型.PAS染色,精原干细胞胞质呈阳性反应;免疫细胞化学染色显示,体积较小的精原干细胞c-kit受体呈强阳性反应,体积较大的大精原干细胞呈弱阳性反应;间质细胞PAS染色和c-kit受体染色呈阴性反应,而脂质染色呈强阳性反应.精原干细胞培养无论有无饲养层,均能呈集落状生长,但有饲养层的培养,细胞的生长明显优于无饲养层培养.结论:青春期前的睾丸生精小管是精原干细胞最集中、数量最多,且容易获取分离的部位;精原干细胞的成功培养为今后重建完整的生精细胞系的治疗性移植和对这类定向干细胞的发育及分化潜能的研究提供了细胞模型.     

Estimated research and development costs of rotavirus vaccines

Diseases like rotavirus afflict both upper- and lower-income countries, but most serious illnesses and deaths occur among the latter. It is a vital public health issue that vaccines for these types of global diseases can recover research and development (R&D) costs from high-priced markets quickly so that manufacturers can offer affordable prices to lower-income nations. Cost recovery depends on how high R&D costs are, and this study attempts to replace high, unverified estimates with lower, more verifiable estimates for two new vaccines, RotaTeq (Merck) and Rotarix (GlaxoSmithKline or GSK), based on detailed searches of public information and follow-up interviews with senior informants. We also offer a new perspective on “cost of capital” as a claim for recovery from public bodies. Our estimates suggest that companies can recover all fixed costs quickly from affluent markets and thus can offer these vaccines to lower-income countries at prices they can afford. Better vaccines are a shared project between companies and public health agencies; greater transparency and consistency in reporting of R&D costs is needed so that fair prices can be established.     

静脉性脑梗死动物模型的建立及相关研究

静脉性脑梗死动物模型的建立是通过不同的栓塞方法闭塞实验动物上矢状窦的不同部位，其目的是观察脑组织的血流量、血氧饱和度、脑组织水含量、脑灌注压、及各种影像学表现等参数指标的变化，从病理生理角度探讨静脉性脑梗死的发病机理及演变过程。     

The effect of intraosseous graft length on tendon-bone healing in anterior cruciate ligament reconstruction using flexor tendon

The current study was performed to understand the relationship between graft length placed within the bone tunnel and intraosseous graft healing in anterior cruciate ligament (ACL) reconstruction. Twenty-four adult beagle dogs were divided into two groups of 12 animals each. In each animal, ACL reconstruction using a 4-mm diameter autogenous flexor tendon graft was done in the left knee. In groups I and II, the graft having a length of 15 and 5 mm, respectively, was placed within the tibial tunnel. The proximal end of the graft was placed through the over-the-top route in all animals. In each group, five animals were sacrificed immediately after surgery, and the remaining seven were sacrificed at 6 weeks postoperatively. Biomechanical and histologic evaluations were performed. In pull out testing, the ultimate failure load and the linear stiffness of the graft-tibia complex harvested at 6 weeks were significantly greater than those harvested at the time-zero period. There were no significant differences in those parameters between groups I and II at 6 weeks. In each group, the perpendicular collagen fibers connecting the tendon to the bone tunnel wall were observed only in the narrow area located close to the intra-articular tunnel outlet. In conclusion, excessively long placement of the flexor graft within the bone tunnel does not result in an additional increase of anchoring strength and stiffness of the graft in ACL reconstruction.     

MRI的选购定位

对MRI若干主要参数进行总结,结合实际应用体会,对我院MRI设备选购进行讨论,以期对MRI设备的选购定位提供参考.     

Inadequate dietary magnesium intake increases atherosclerotic plaque development in rabbits

Epidemiological studies have shown dietary magnesium (Mg) intake and serum Mg levels to be inversely correlated with the development of atherosclerosis. We hypothesized that low levels of Mg would promote atherosclerotic plaque development in rabbits. New Zealand white rabbits (4 months old, n = 22) were fed an atherogenic diet containing 0.12% (−Mg), 0.27% (control), or 0.43% (+Mg) Mg for 8 weeks. Blood samples were obtained at baseline, 2, 4, 6, and 8 weeks and were assayed for total cholesterol, high-density lipoprotein (HDL), non-HDL, triglycerides (TG), C-reactive protein, serum Mg, and erythrocyte Mg. Aortas from −Mg had significantly more plaque, with an intima thickness 42% greater than control and 36% greater than +Mg. Serum cholesterol levels rose over time, and at 8 weeks, −Mg had the highest and +Mg the lowest total and non-HDL cholesterol and TG levels, although these results did not reach significance. Over time, serum Mg levels increased, and erythrocyte Mg levels decreased. C-reactive protein significantly increased in all groups at 4 and 6 weeks but returned to baseline levels by 8 weeks. This study supports the hypothesis that inadequate intake of Mg results in an increase in atherosclerotic plaque development in rabbits.