高功率激光-血管-组织相互作用的红外试验

目的:通过一系列活体和体外实验来考察激光诱导间质热疗过程中血管及器官受高功率激光作用时的温度场发展规律。方法:实验性家兔1只,麻醉状态下应用波长为10.6mm的KD-Ⅲ型CO2激光器(北京科电微波电子有限公司生产)在不同功率激光照射其耳部不同部位,观察血管稀疏区与丰富区在激光照射下的反应。隔2d,将其麻醉处死,取出胃、肝、肺、肾、心等不同器官,进行激光照射。实验中引入红外成像仪来定量刻画被测对象表面的瞬态温度分布图像。结果:①当激光热量不足以完全切断血管时,血管丰富组织区的复温能力强于血管稀疏区;当激光准确作用于主血管并且达到一定能量时,不仅下游供血及加热可被切断,且上游供血也会受到影响。②在相同的激光频率、功率及作用时间下,胃部的穿透最深,肾部温度变化率最大。结论:①组织局部的血液灌注率会影响激光作用的效果。②不同器官由于热容量不同,且对激光的反射和吸收率存在差异,导致激光穿透厚度及组织温度变化的幅度不同。     

人工关节周围界膜白细胞介素6的表达及健骨二仙丸的干预效应

目的:观察中药健骨二仙丸对体外培养人工关节假体周围界膜白细胞介素6表达的抑制作用,为健骨二仙丸防治人工关节假体周围骨溶解提供科学依据。方法:实验于2006-09/12在深圳市中医院中心实验室(国家级P2实验室)完成。①体外界膜组织培养:将备用的人工关节假体周围界膜(20g,取自右股骨颈骨折人工关节置换术后11年出现假体无菌性松动来深圳市中医院行翻修术患者,女性,74岁,对实验知情同意并经医院伦理委员会批准)放入Hank’s液中清洗后置于RPMI培养液中,然后将界膜标本用眼科剪剪成1mm3大小组织悬浮液。②含药血清制备:按每日中药健骨二仙丸生药12.0g/kg大鼠体质量灌胃(相当于临床剂量的6.25倍),每日固邦用量为1.04mg/kg体质量(相当于临床剂量的6.25倍)。2次/d,间隔5h,连续灌胃3d。末次灌药1h后,从腹主动脉取血,离心获取血清。③分组:取24孔培养板2块,分空白对照组、健骨二仙丸组、固邦组,各组又分别分100g/L,200g/L两个质量浓度亚组,共计6个组,每组8个培养孔。100g/L质量浓度组相应加入0.9mL组织悬液和0.1mL空白血清或健骨二仙丸、固邦含药血清。200g/L质量浓度组相应加入0.8mL组织悬液和0.2mL空白血清或健骨二仙丸、固邦含药血清。④实验评估:各组添加空白血清或含药血清后在体积分数为0.05CO2、37℃饱和湿度下培养72h,取上清液,用酶联免疫吸附法测定白细胞介素6的含量。上述界膜组织标本同时做细菌培养。结果:48个培养孔中的组织培养均成功,全部进入结果分析。①白细胞介素6水平:100g/L与200g/L空白对照组比较差异无显著意义[(97.113±11.989),(96.275±13.087)ng/L,P>0.05]。100g/L健骨二仙丸组[(92.288±10.397)ng/L]与空白对照组相比差异无显著性(P>0.05);200g/L健骨二仙丸组[(82.263±9.580)ng/L]低于空白对照各组(P<0.05)。100g/L与200g/L固邦组[(83.300±9.039),(79.338±11.118)ng/L]低于空白对照各组(P<0.05和P<0.01)。200g/L健骨二仙丸组与100g/L和200g/L固邦组比较,差异无显著性。②人工关节周围界膜组织细菌培养结果为阴性。结论:健骨二仙丸能够抑制磨损颗粒诱导的人工关节假体周围界膜细胞因子的分泌,进而阻止假体周围破骨细胞性骨溶解,对人工关节假体无菌性松动可能具有较好的防治作用。     

Data and safety monitoring during randomized controlled trials of nursing interventions

BACKGROUND: Principal investigators have a responsibility to ensure and maintain the scientific integrity of their research studies and to protect the safety of the participants. Data and safety monitoring is required for all types of clinical trials, and the nature and degree of the monitoring must be related to the degree of risk involved. OBJECTIVES: This article aims to define the purpose of a data and safety monitoring board (DSMB), to describe the functions of a DSMB and distinguish them from the activities of an institutional review board, and to discuss the development and implementation of a DSMB plan. METHODS: The literature on data and safety monitoring is reviewed, and the process and key issues are illustrated with examples from the authors' clinical trial and others. RESULTS: The principal role of the DSMB is to monitor the data from the trial periodically, to review and assess the performance of its operations, and to make recommendations based on interim results (e.g., modification of the study protocol, or possible early termination of the study). Although the roles of a DSMB and institutional review board complement one another, the main focus of their responsibilities is different and carried out independently of one another. The members of a DSMB are selected on the basis of their methodologic, statistical, or clinical expertise. CONCLUSION: The multiple scientific, ethical, safety, recruitment, intervention, and budgetary responsibilities of a principal investigator can be complex. The role of the DSMB is crucial and offers independent evaluation to ensure participant safety and good science.     

Specific E‐selectin targeting with a superparamagnetic MRI contrast agent

Targeting of the endothelial inflammatory adhesion molecule E‐selectin by magnetic resonance imaging (MRI) was performed with a superparamagnetic contrast agent in the context of in vitro and in vivo models of inflammation. The specific contrast agent was obtained by grafting a synthetic mimetic of sialyl Lewis^x (sLe^x), a natural ligand of E‐selectin expressed on leukocytes, on the dextran coating of ultrasmall particles of iron oxide (USPIO). This new contrast agent, called USPIO‐g‐sLe^x, was tested, in vitro, on cultured human umbilical vein endothelial cells (HUVECs) stimulated to express inflammatory adhesion molecules, and in vivo, on a mouse model of hepatitis. In vitro, HUVECs were stimulated with the pro‐inflammatory cytokine tumor necrosis factor alpha (TNF‐α) and were then incubated with USPIO‐g‐sLe^x or ungrafted USPIO. In vivo, hepatitis was induced on NMRI mice by injection of concanavalin A (Con A). USPIO‐g‐sLe^x and ungrafted USPIO were injected intravenously. In vitro results showed an extensive retention of USPIO‐g‐sLe^x on TNF‐α stimulated HUVECs. Image intensity and R₂ measurements performed on T₂‐weighted MR images demonstrated a significantly higher binding of USPIO‐g‐sLe^x on stimulated HUVECs. In vivo, USPIO are known to pass through the fenestrae of the liver and to be captured by Kupffer cells, inducing a loss of signal intensity on T₂‐weighted MR images. Unexpectedly, when injected to Con A‐treated mice, USPIO‐g‐sLe^x induced a significantly lower attenuation of liver signal intensity than USPIO or USPIO‐g‐sLe^x injected to healthy mice, or USPIO injected to Con A‐treated mice, suggesting that the specific contrast media is retained extracellularly by an interaction with E‐selectin overexpressed on the vascular endothelium. Both in vitro and in vivo results therefore indicate that USPIO‐g‐sLe^x is recognizing endothelial E‐selectin. USPIO‐g‐sLe^x is thus well suited for the MRI diagnosis of inflammation and for the in vitro evaluation of endothelial cells activation. Copyright © 2006 John Wiley & Sons, Ltd.     

Epidemiology of Crohn's Disease in Indian Migrants and the Indigenous Population in Leicestershire

A retrospective, epidemiological community study of Crohn'sdisease was performed in Leicestershire from 1972 to 1989. Thecounty population of 930,000 includes 93,000 South Asians. Potentialcases were identified from hospital departments of pathology,endoscopy and medical records, in addition to general practitioners.There were 582 cases in Europeans and 28 in South Asians. Theincidence of Crohn's disease in Europeans and South Asians hasincreased, particularly in Muslims. The standardized incidencein South Asians during the 1980s was 2.4/10⁵/year in Hindus,3.4/10⁵/year in Sikhs and 5.4/10⁵/year in Muslims. The standardizedincidence in Europeans has risen significantly to 4.7/10⁵/yearfrom 3.4/105/year in the 1970s (     

彩色多普勒超声评估老年男性高尿酸和高三酰甘油血症患者的血管内皮功能

目的:探讨彩色多普勒超声评估老年男性高尿酸和高三酰甘油血症患者血管内皮依赖性舒张功能和非内皮依赖性舒张功能的规律及特点。方法:于2003-10/2006-10选择沈阳军区总医院正常体检人员中无症状男性高尿酸血症和高三酰甘油血症患者各35例。另选32例门诊体检尿酸、血脂正常的健康老年男性为正常对照组。实验经医院伦理委员会审批,受试者均知情同意并自愿参加。实验评估:①采用Olympas全自动生化仪检测血尿酸、三酰甘油浓度。②采用彩色多普勒超声检测肱动脉内皮依赖性舒张功能及硝酸甘油介导的非内皮依赖性舒张功能。内皮依赖性舒张功能:肱动脉内径变化率=(充血状态下肱动脉内径-基础状态下肱动脉内径)/基础状态下肱动脉内径×100%;非内皮依赖性舒张功能:肱动脉内径变化率=(服用硝酸甘油后肱动脉内径-基础状态下肱动脉内径)/基础状态下肱动脉内径×100%;肱动脉血流量(mL/min)=(60×π×肱动脉平均流速×肱动脉内径2)/4。结果:纳入受试者102名,均进入结果分析。①血尿酸、三酰甘油浓度:高尿酸血症组血尿酸浓度高于正常对照组[分别为(510±35),(260±70)μmol/L],差异有显著性意义(t=18.731,P<0.01);高三酰甘油血症组三酰甘油浓度高于正常对照组[分别为(3.2±1.3),(1.3±1.1)mmol/L],差异有显著性意义(t=6.427,P<0.01)。②血管内皮依赖性舒张功能:基础状态下,3组间肱动脉血管内径、肱动脉血流量差异无显著性意义(F=1.292,0.740,P>0.05)。反应性充血状态下,3组患者肱动脉血管扩张、肱动脉血流量增加,3组间差异有显著性意义(F=42.779,26.406,P<0.01),高尿酸血症组肱动脉内径变化率与正常对照组相比有所下降(q=8.841,P<0.05),肱动脉血流量明显低于正常对照组(q=3.786,P<0.05)。高三酰甘油血症组肱动脉内径变化率与高尿酸血症组、正常对照组相比,明显下降(q=4.724,P<0.05),肱动脉血流量明显低于高尿酸血症组及正常对照组(q=7.267,P<0.05)。3组患者对硝酸甘油诱导引起的肱动脉血管扩张、肱动脉血流量增加反应存在,但3组间差异无显著性意义(F=1.272,1.431,P>0.05)。结论:①应用彩色多普勒超声可简便、有效地评估老年男性高尿酸和高三酰甘油血症患者的血管内皮功能。②老年男性高尿酸和高三酰甘油血症患者肱动脉内皮依赖性舒张功能及非内皮依赖性舒张功能均受损,老年男性高三酰甘油血症患者内皮功能紊乱更严重。     

Effect of bench height on sit-to-stand in children without disabilities and children with cerebral palsy

OBJECTIVE: To evaluate the effect of seat height on sit-to-stand (STS) in children with cerebral palsy (CP) and in children without disabilities. DESIGN: A mixed design (subject type by seat height) with repeated measures for seat height. SETTING: Motion analysis laboratory. PARTICIPANTS: Ten children with mild CP (mean age, 10.9+/-2.7 y) and 10 children without disabilities (mean age, 8.7+/-2.4 y). INTERVENTIONS: Kinematic and force measurements of STS were completed with 6 infrared cameras and 2 forceplates. MAIN OUTCOME MEASURES: Phase duration of the STS movement, amplitude and timing of ground reaction forces, and maximum head velocity during the movement. RESULTS: Children with CP took significantly longer to rise to standing (1.71 s) than children without disabilities (1.24 s) (F(1,18)=16.97). The extension phase of STS was also significantly longer for children with CP (.85 s) than for children without disabilities (.45 s) (F(1,18)=18.73). Seat height did not affect time to stand for either children with CP or children without disabilities (F(1,18)=2.82, P>.05). The duration of the extension phase, maximum horizontal and vertical velocity of the head, and maximum vertical ground reaction force were all significantly greater when children stood from the low bench height than from the higher bench height, although we found no significant differences by subject type for maximum horizontal and vertical head velocity or for maximum vertical ground reaction force. CONCLUSIONS: Although children with CP were able to modify their motor programs for STS to accommodate changes in seat height as readily as nondisabled children, the speed with which they extended against gravity was slower; therefore, the total STS movement took longer for them to complete than for children without disabilities. Because the time to complete STS from the low and high bench did not differ, it would appear that time to ascend from sitting may be invariant and therefore be a motor control parameter for the STS movement.