青年人群腰椎骨密度及标准差对骨质疏松检出率的影响：多中心、大样本分析

背景: 不同地区骨峰值和标准差不同，对骨质疏松诊断率有较大影响。探讨建立一完整数据库为中国人骨质疏松诊断准确性提供依据。 目的：探讨青年人腰椎骨密度和标准差正常参考值影响骨质疏松症检出率的程度。 设计、时间及地点：调查分析，于1997-01/1999-12分别在北京、上海、广州、南京、嘉兴和成都市完成。 对象：采用前瞻性及回顾性方法对全国6个中心骨密度参考数据库中11 418人进行调查统计分析；男3 666人，女7 752人；年龄20岁~90岁；分别来自北京(2 385人)、广州(1 178人)、上海(1 404人)、南京(2 938人)、成都(1 425人)、嘉兴(2 088人),受试者来源于社区调查、健康体检和健康志愿者。 方法：用GE-Lunar公司的DXA仪测量骨密度，调查全国6个中心11 418人L2~L4腰椎后前位和髋部骨密度，建立了骨密度参考数据库。6个中心的仪器内部精度0.3%~0.7%，仪器间的精度1.1%。 主要观察指标：①6个中心不同年龄组腰椎骨密度分布。②青年人群骨密度及其标准差值对骨质疏松症检出率的影响。 结果：中国汉族女性以腰椎进行骨质疏松症诊断的青年人群的骨密度和标准差值，6个中心，最大差值分别为0.098 g/cm2和0.027 g/cm2。用6个中心及总体各自的青年人平均骨密度和标准差值为参考标准，对同一人群计算T-score和获得的骨质疏松症检出率不相同；发现青年人平均骨密度每变化0.01 g/cm2，则骨质疏松症检出率变化1.6%(呈正相关)，其标准差值每变化 0.01 g/cm2，则骨质疏松症检出率变化4%(呈负相关)。 结论：青年人平均骨密度和标准差值不同引起骨质疏松症检出率也不相同。为了让不同中心的骨质疏松症检出率有可比性,建议同一个类型的骨密度仪,同一个种族,同一个地区用一个设计较完善大样本的参考数据库,以其青年人正常参考值计算T-score。     

从兔股骨头中提取总RNA的方法特点

目的:建立一种高效、快速的骨组织总RNA提取方法。方法:实验于2005-01/2006-01在昆明医学院实验动物中心和中国科学院昆明动物研究所中科院细胞与分子进化重点实验室完成。取健康新西兰大白兔1只,截取其股骨头,迅速置于液氮罐中保存,于研钵中研磨,使骨组织始终保存于液氮中,继续研磨,如此重复3次,然后利用Trizol使骨细胞结构迅速破坏,将粉末转入离心管,室温静置5min。随后加入氯仿等有机溶剂处理、离心,使RNA与细胞DNA、蛋白质及其他成分分离从而得到总RNA。最后鉴定RNA的质量、纯度及产率,取2μL提取出的RNA在体积分数为0.008的甲醛变性琼脂糖凝胶上进行电泳,主要观察RNA的28S、18S及5S三个条带是否清晰,有无降解和DNA污染。以99μLDEPC水稀释1μLRNA样品,紫外分光光度计测量其吸光度(A)值,A260/A280之比值表示RNA的纯度,同时根据吸光度值计算其质量浓度。结果:①对提取的兔股骨头RNA进行琼脂糖凝胶电泳,可显示清晰的28S、18S两个条带,5S条带亦可见,表明了RNA是完整的。②用紫外分光光度法测定兔股骨头中提取出的RNAA260/A280,结果表明由本法提取的RNA纯度高,无DNA和蛋白质的污染。③经紫外分光光度计吸收定量,每毫克兔股骨头组织能提取1.0～1.2μg的总RNA。结论:本法提取骨组织总RNA方便、快捷,质量高,可用于骨组织的分子生物学研究。     

缺血预处理程序中心肌环磷酸腺苷含量及环磷酸腺苷依赖蛋白激酶活性的变化

目的:制备大鼠在体缺血再灌注模型,观察缺血预处理程序中心肌环磷酸腺苷含量及环磷酸腺苷依赖蛋白激酶活性的变化。方法:实验于2005-03/2006-10在解放军沈阳军区总医院医学实验动物中心和全军心血管研究所实验室完成。实验分组:选用健康雌性SD大鼠36只,根据预适应程序分为第1,2,3次缺血,第1,2,3次再灌注,每一时间点6只大鼠。实验过程:用手术套管法造成左冠状动脉主干缺血及再灌注。所有实验动物在实验程序结束后,取出心脏迅速置液氮保存备用。实验评估:用放射免疫法测环磷酸腺苷水平,生化法测环磷酸腺苷依赖蛋白激酶活性变化。结果:36只大鼠均进入结果分析。①环磷酸腺苷含量:第1次再灌注组低于第1次缺血组[(0.325±0.015),(0.395±0.024)pmol/g,t=6.06,P<0.001],第2次再灌注组低于第2次缺血组[(0.523±0.017),(0.708±0.067)pmol/g,t=6.56,P<0.001],第3次再灌注组低于第3次缺血组[(0.567±0.031),(0.712±0.038)pmol/g,t=7.24,P<0.001]。②环磷酸腺苷依赖蛋白激酶活性:第1次再灌注组低于第1次缺血组[(10.115±1.000),(16.351±0.849)pkat/g,t=11.12,P<0.001],第2次再灌注组低于第2次缺血组[(11.877±2.213),(14.869±0.619)pkat/g,t=3.31,P<0.01],第3次再灌注组低于第3次缺血组[(11.745±0.987),(14.766±0.329)pkat/g,t=7.09,P<0.001]。③缺血预处理程序中心肌环磷酸腺苷含量及环磷酸腺苷依赖蛋白激酶活性随缺血及再灌注呈周期性波动。在5min缺血预处理时表现为明显增高,而在间隔的再灌注程序中恰呈相反改变,有明显下降的趋势。结论:环磷酸腺苷及环磷酸腺苷依赖蛋白激酶的周期性波动变化可能是激发心肌缺血预处理的机制之一,环磷酸腺苷可能在预处理保护作用中起一些作用。     

Naloxone in renal ischemia: a functional and microanatomical study

Naloxone HCl (Nx) improves cardiopulmonary performance, reverses cellular hypoxia, and stabilizes lysosomal membranes in shock states. However, no detailed study has yet explored its potential role in renal ischemia, which is inevitable in transplantation and surgical and nonsurgical conditions associated with hypotension and shock. This functional and microanatomical study was carried out on dogs subjected to renal warm ischemia with contralateral nephrectomy. Group I (control; N = 4) had bilateral renal dissection and right nephrectomy. Groups II-IV had their kidney pedicles cross-clamped for 60 min and then reperfused. Group II (N = 9) ischemic kidneys received no treatment. Group III (N = 6) kidneys were flushed with pure Nx HCl (2 mg/kg) during ischemia. Group IV (N = 6) dogs received one iv Nx bolus (2 mg/kg) before clamping and another dose before declamping. Biopsies for adenine nucleotides, histology, and ultrastructure were obtained before ischemia, before reflow, and 15 min and 7 days after reflow. Serum creatinine and blood urea nitrogen were measured daily. Ischemia induced significant renal dysfunction, which was reversed by systemic Nx. Nx offered a remarkable protection against postischemic structural damage. Seventy percent of Group II cortical sections showed grade 4 acute tubular necrosis (ATN), and severe residual damage after a week. Eighty-three percent of Group IV sections showed grade 1 ATN and no residual damage after a week. One week survival was 33% in Group II and 100% in Group IV. Nx can be useful in prevention of acute renal failure in clinical situations with arterial hypotension and shock.     

Role of Pulsatile Perfusion With Tissue Plasminogen Activator in Deceased Donor Kidneys With Extensive Glomerular Thrombosis

Background

Pulsatile perfusion (PP) improves delayed graft function, whereas tissue plasminogen activator (tPA) lyses thrombi. We studied the role of PP with tPA containing perfusate in deceased donor kidneys (DDK) with 50% thrombosed glomeruli.

Methods

Fourteen DDK with extensive glomerular thrombi on biopsies were preserved using PP with histidine-tryptophan-ketoglutarate solution containing tPA. Wedge biopsies were repeated after PP.

Results

Causes of donor death included closed head trauma in 8, anoxia in 2, and stroke in 4. Donors who averaged 33.3 years old displayed a final 24-hour urine volume of 1933 mL, a terminal serum creatinine level of 1.8 mg/dL, a blood urea nitrogen of 20 mg/dL, and a platelet count of 128,000/μL. The initial flow of 47 mL improved to 111 mL/min after 16.17 hours of perfusion. Resistive indices (RI) decreased from 0.69 to 0.26 at 4.2°C. Biopsy specimens after PP showed a reduction in glomerular thrombi from 50% to 23%. Recipients averaged 54.9 years old. Cold ischemia time averaged 35.5 hours. One patient displayed primary allograft nonfunction, 3 required transient dialysis, and 10 showed prompt allograft function. Recipient follow-up averaged 12 months, with serum creatinine levels of 4.3 mg/dL at 1 week, 2.0 mg/dL at 1 month, and 1.6 mg/dL at last follow-up.

Conclusions

Renal allografts with extensive glomerular thrombosis improved their biopsy appearance following PP with tPA. Improvement in PP parameters allowed successful transplantation of such kidneys that otherwise would have been discarded. PP with tPA appears to be beneficial for kidneys with extensive glomerular thrombosis.     

Revascularization of the gastroepiploic artery in pancreas transplant.

Thrombosis accounted for 52.0% of all transplant failures in one recent large series and is felt to result from devascularization of the pancreas during organ procurement. A technique to revascularize the pancreas is described. The operative notes and angiograms of 110 consecutive pancreas transplants were reviewed. Eight pancreata were found deprived of blood supply to the head and the neck of the pancreas on indigocarmine-renograffin table angiograms. During back table reconstruction a distal branch of the superior mesenteric artery (SMA) was dissected and anastomosed end to end to the gastroepiploic artery using 8-0 monofilament suture. Repeated table angiogram showed excellent blood supply to the head of the pancreas, the duodenum and the body and tail of the pancreas. The pancreas transplantation proceeded with iliac artery graft inflow, portal venous outflow and enteric drainage. Simultaneous quadruple therapy with thymoglobulin, CNI, MMF and a 4-day course of steroids was used. All patients became insulin independent and euglycemic. No duodenal leak was observed in the entire series. In summary, 1-ligation of the gastroduodenal artery (GDA) is not a safe procedure, especially when arterial blood supply from the inferior pancreaticoduodenal artery is poor or inexistent, 2-table angiogram helps delineate the high risk hypo-perfused pancreas, 3-preservation of the right gastroepiploic artery and the branches of the SMA allows an easy revascularization of the pancreatic graft.     

Verapamil as an adjunct to local anaesthetic for brachial plexus blocks

Background: Calcium channel blockers potentiate the effects of local anaesthetics. We examined the effect of adding verapamil to local anaesthetic solution on anaesthetic duration in patients undergoing surgery under brachial plexus block.     

Neurohydatidosis

Early and non‐invasive evaluation of hydatid infestation of brain and spine is of paramount importance, especially in endemic areas. We present a spectrum of imaging findings in neurohydatidosis with a brief review of literature.