电泳法测定血清脂蛋白(a)胆固醇及其临床应用

目的 对一种新型的琼脂糖凝胶电泳定量分析脂蛋白(a)胆固醇[LP(a)-C]含量的方法进行评价，并探讨了其与临床常用LP(a)免疫测定法的相关性。方法 采用HelenaREP全自动快速电泳系统分离血清LP(a)-C，然后结合胆固醇酶染色法测定LP(a)-C的含量，分析了该法的精密度、准确度和干扰因素及正常参考范围，并将该法与临床常用的免疫透射比浊法(ITA)、免疫散射比浊法(INA)进行了比较。结果 电泳法测定LP(a)-C的批内CV为4．7％—5．3％、批间为5．8％—6．4％，检测线性范围为0．058—1．550mmol/L，该法基本不受黄疸、脂血、溶血干扰，LP(a)—C的回收率92．2％—93．1％。电泳法(Y)与免疫透射比浊法(ITA)(X1)测LP(a)的回归方程为Y＝0．635X1 0．011(r＝0．929)，与免疫散射比浊法(X2）(INA)测LP(a)回归方程为：Y＝0．667X2 0．01(r＝0．948)，参考范围为0—0．21mmol/L。结论 电泳法能较完全的分离出LP(a)-C带，其LP(a)—C的测定值与临床常用LP(a)免疫法相关，操作简便，符合临床常规使用的要求。     

低密度脂蛋白胆固醇直接测定法的评价

目的　评价基于选择性水解原理的两种低密度脂蛋白胆固醇 (LDL C)的直接测定法 (Ⅰ法和Ⅱ法 )的精密度、准确度和特异性。方法　将这两种方法与聚乙烯硫酸沉淀法 (PVS法 )作了比较 ,并以超速离心分离的HDL和LDL组分分析了对LDL C测定的特异性与准确性。结果　高、低两种LDL C浓度混合血清所测定的结果表明这两种方法均有良好的精密度 ,总CV值直接测定Ⅰ法 3 96 %～ 4 42 % ,直接测定Ⅱ法 0 78%～ 3 91% ,都可达到临床满意的程度。 48份临床标本测定结果 ( x±s)分别为 3 6 8± 1 2 3mmol/L(PVS法 ) ,3 2 5± 1 11mmol/L(直接测定Ⅰ法 )和 3 37± 1 2 1mmol/L(直接测定Ⅱ法 ) ,直接测定法与PVS法测定结果的差异无统计学意义。PVS法 (X)与直接测定Ⅰ法 (Y)的回归方程为Y =0 .848X +0 .12 1(r=0 .942 7) ,与直接测定Ⅱ法 (Y)的回归方程为Y =0 .914X +0 .0 0 7(r=0 .935 3) ,两种直接测定法与PVS法有良好的相关。对超离心HDL和LDL组分测定的结果表明两种直接测定法对LDL C有较好的特异性。稀释试验的结果表明两种直接测定法均有良好的线性 ,线性范围至少可达 9 2 8mmol/L。结论　以选择性水解法直接测定LDL C具有较好的精密度 ,对LDL有很好的特异性 ,适应自动分析 ,可以真实反映LDL C的水平 ,值得在临床推     

低密度脂蛋白胆固醇的直接测定法研究

目的用甾类糖苷化合物与胆固醇酯酶和胆固醇氧化酶制备的高亲和性酶化舍物,结合特殊表面活性剂,通过对测定条件的优化,建立了低密度脂蛋白胆固醇直接法方法。方法本方法线性范围达12mmol／L,与friedewal公式法（以下简称F法）计算结果及日本第一化学株式会社（以下简称日本一化）试剂测定相关性良好,分别为相关系数（r）：0．9955,Y—1．044X1-0．1535;r：0．9989,Y—1．0058X2＋0．0571。批内变异系数（CV）〈1．5％,日间CV〈2．0％,回收率（100土5）％。TG浓度达20mmol／L,抗坏血酸小于4．5mmol／L、血红蛋白小于4．5g／L和胆红素小于540μmol／L时无显著干扰。当用纯的不同浓度的高密度脂蛋白胆固醇加入准确定值的新鲜血清中,观察脂蛋白在血清中的反应。结果纯高密度脂蛋白胆固醇浓度在6．4mmol／L以内对本法无显著干扰。结论本文建立的低密度脂蛋白胆固醇直接测定法,其性能指标符合临床使用要求。标本无需预处理,精密度好,准确性高,适用于各种自动生化分析仪。     

血浆低密度脂蛋白胆固醇测定参考方法的建立

目的建立一种新的预期用作低密度脂蛋白胆固醇（low density lipoprotein cholesterol,LDL-C）准确测定的参考方法。方法采用密度梯度超速离心技术,从新鲜血浆中分离出低密度脂蛋白（low density lipoprotein,LDL）和其它各类脂蛋白。参考并筒化应用目前国际上公认的胆目醇测定参考方法Abell—Levy—Brodie—Kendall（ALBK）法,以分离的LDL为检测样本,重复多次测定LDL—C,用Excel软件对结果进行统计分析,计算总不精密度（总变异系数CV）、平均批内不精密度（平均批内变异系数CV）和测量不确定度（u）等精密度检验标度,对所建立方法进行精密度评价;并通过回收实验、干扰实验的结果分析对建立方法进行准确度评价。结果密度梯度超速离心成功分离出LDL和其它几类脂蛋白,用ALBK法测定LDL—C的方法学精密度为：总CV为3．21％～4．51％,平均批内CV为1．78％～4．05％,测量不确定度u为0．031～0．042,胆田醇平均回收率达107．2％,血红蛋白（Hb）〈1．95g／L时对该方法干扰度较小。结论密度梯度超速离心技术分离LDL耗费低、易操作;ALBK法直接测定LDL—C,方法学精密度统计分析结果显示该方法重复性好,回收实验、干扰实验的准确度评价结果显示所建立方法稳定、抗干扰能力强,超速离心结合ALBK法可望用作LDL—C的参考方法。     

胆固醇脱氢酶测定血清胆固醇方法的建立

目的 评价胆固醇脱氢酶测定法在临床应用的可行性。方法 胆固醇酯在胆固醇酯酶的作用下，水解为游离胆固醇，后者被胆固醇脱氢酶还原为胆烷-4-烯-3-酮，同时B—NAD^ 还原为β-NADH H^ 。联胺能清除其反应产物胆烷-4-烯-3-酮，使反应完全。结果 回收率为99．9％和100．1％，在1．1～20．28mmol／L内为线性；批内CV为0．29％～0．39％，批间CV为0．42％～0．45％；乳酸脱氢酶无影响；与化学比色法(X1)和胆固醇氧化酶法(X2)比较，回归方程分别为Y=0．992X1—0．006，r=0．997；Y=0．989X2-0．048，r=0．999。结论 本法结果准确、可靠、易自动化。     

电泳法测定血清各种脂蛋白胆固醇

目的　采用琼脂糖凝胶电泳分离脂蛋白 ,结合胆固醇酶染色同时测定血清脂蛋白HDL C、LDL C、VLDL C和Lp(a) C。方法　运用HelenaREP全自动快速电泳系统分离血清HDL、LDL、VLDL和Lp(a) ,经胆固醇酶染色同时扫描测定HDL C、LDL C、VLDL C和Lp(a) C的百分比 ,输入血清TC ,计算各脂蛋白中胆固醇含量。结果　本法HDL C、LDL C、VLDL C批内CV分别为3 88%～ 5 96 %、1 36 %～ 3 2 5 %、5 19%～ 6 6 8% ,批间CV分别为 4 33 %～ 6 6 8%、2 98%～ 4 37%、8 15 %～ 11 8% ;灵敏度为每条带胆固醇 0 11mmol/L ,检测线性为TC 1 2 6～ 10 36mmol/L ;平均回收率HDL C、LDL C、VLDL C分别为 86 8%、93 5 %、94 2 % ;胆红素 <342 μmol/L、血红蛋白 <3 5g/L、Trig <11mmol/L对结果无显著影响 ;当Trig <2 2 6mmol/L ,HDL C、LDL C电泳法与直接法相关性良好 (r分别为 0 99、0 97)。结论　电泳法可同时测定血清各脂蛋白胆固醇含量 ,当Trig <2 2 6mmol/L与直接法有良好的相关性。该法简便经济快速 ,能精密准确定量各脂蛋白中胆固醇含量 ,尤其适用于对高脂血症的常规检查和研究。     

低密度脂蛋白胆固醇保护性试剂匀相测定法的临床评价

目的 对低密度脂蛋白胆固醇(LDT-C)保护性试剂匀相测定法进行临床评价。 方法 分析了保护性试剂匀相测定法的精密度、准确性、特异性和干扰因素.并随机选取了219份病人血清标本,比较分析用保护性试剂匀相测定法直接测定与Friedewald公式和Planella公式计算的LDL—C结果。 结果 保护性试剂匀相测定法具有较好的精密度(批内、批间CV和总CV均小于3％)。线性范围至10.4mmol/L,最低检测浓度为0.08mmol/L,平均同收率为101.2％:基本不受极低密度脂蛋白(VLDL)、高密度脂蛋白(HDL)和血红蛋白的影响。在TG<4.52mmol/L时,用匀相测定法与Friedewald公式和Planella公式的计算法结果之间相关性良好,两种公式计算法结果之间的也有较好相关性;而在TG>4.52mmoL/L时,匀相测定法与两种计算法之间的相关性差。结论 保护性试剂匀相测定法简便、快速、结果准确,易于自动分析,适合在临床实验室常规检测应用。     

人红细胞膜脂蛋白的分离及其胆固醇含量的测定

建立了分离人红细胞膜脂蛋白的方法并就测定其胆固醇含量及其相关因素进行了探讨。通过此法，成功地分离了人红细胞膜的HDL和LDL成份，但未能分离出VLDL成份，而且可用胆固醇酶试剂测定各自的胆固醇含量，但用甘油三酯酶试剂未能测出甘油三酯。因此，证明人红细胞膜无VLDL或甘油三酯的存在。还用沉淀法所测的LDL－C同计算所得的LDL－C进行了相关分析，结果r＝0．959，Y＝1．08X－0．39，表明相关良好，因此，LDL－C可以直接计算。该法批内CV（CT、HDL－C、LDL－C）分别为4．5％，7．0％，9．6％；批间CV分别为7．2％，12．8％，7．5％。该文所建立的方法将为从细胞水平观察脂蛋白同某些疾病的联系提供了有效的手段。     

免疫分离法测定血浆脂蛋白残粒胆固醇的临床评价

目的　对免疫分离法测定血浆脂蛋白残粒胆固醇 (RLP C)进行方法学评价 ,并探讨其临床应用价值。方法　分析免疫分离法测定血浆RLP C的精密度、准确度、干扰因素 ,并将该法与超速离心法 (UC)进行比较 ,同时用该法测定 80例正常人、70例冠心病患者、72例 2型糖尿病患者和2 5例Ⅲ型高脂蛋白血症患者空腹血浆RLP C水平。结果　免疫分离法测定血浆RLP C的批内CV为 2 .78%～ 4 .98% ,批间CV为 3.99%～ 7.5 7% ,RLP C浓度 2 .4 4mmol/L以下时线性良好 ,r =0 .992。分析灵敏度为 0 .0 5mmol/L ,回收率为 92 .1%～ 98.3% ,免疫分离法 (X)与超速离心法 (Y)具有良好的相关性 ,Y =1.0 2 2X +0 .0 2 1,r =0 .989。甘油三酯 (TG) <15 .3mmol/L ,血红蛋白 (Hb) <5g/L ,低密度脂蛋白胆固醇 (LDL C) <7.0mmol/L ,高密度脂蛋白胆固醇 (HDL C) <3.0mmol/L ,胆红素 <342 μmol/L ,抗坏血酸 <15 0mmol/L时对方法无显著干扰。冠心病患者、2型糖尿病患者和Ⅲ型高脂蛋白血症组空腹血浆RLP C分别为 (0 .4 4 5± 0 .2 5 1)mmol/L、(0 .336± 0 .172 )mmol/L和(0 .878± 0 .6 72 )mmol/L ,均显著高于正常人 [(0 .190± 0 .0 70 )mmol/L],P <0 .0 0 1。结论　免疫分离法测定RLP C操作简单 ,结果准确可靠 ,精密度好 ,符合临床常规使用     

高密度脂蛋白胆固醇的直接测定法研究

目的用甾类糖苷化合物、胆固醇酯酶和胆固醇氧化酶制备的高亲和性酶化合物结合特殊表面活性荆,通过对测定条件的优化,建立了高密度脂蛋白胆固醇的直接测定方法。方法本法与磷钨酸镁沉淀法和葡聚糖-氯化镁沉淀法相关性良好。结果纯低密度脂蛋白胆固醇浓度在10．0mmol／L以内对本法无显著干扰,磷钨酸镁沉浸法和葡聚糖-氯化镁沉淀法结果分别为相关系数（r）=0．9901、Y=1．0160X-0．0818和r=0．9960,Y=1．008 0X=0．0630,批内变异系数（CV）〈1．6％,日间CV〈2．1％,线性范围达5．4mmol／L,回收率（100±5）％。三酰甘油浓度达30mmol／L、抗坏血酸小于3．5mmol／L、血红蛋白小于4．8g／L和胆红素小于540μmol／L时无显著干扰。应当用纯的不同浓度的低密度脂蛋白加入准确定值的新鲜血清中观察脂蛋白在血清中的反应。结论本文建立的高密度脂蛋白胆固醇直接测定法,其性能指标符合临床使用要求。标本无需预处理,精密度好,准确性高,适用于各种自动生化分析仪。     

Determination of creatine kinase isoenzyme MB activity in serum using immunological inhibition of creatine kinase M subunit activity. Activity kinetics and diagnostic significance in myocardial infarction.

This is a new method for the determination of creatine kinase isoenzyme MB activity in serum. The method uses direct activity measurement of creatine kinase B subunit activity after blocking of CK-M subunit activity by inhibiting antibodies. The test takes no longer than 15 min. The method yields an intra-serial C.V. of 2.0-12.9%, and a C.V. from day to day of 5.5%. The detection limit is 3.4 U/l creatine kinase MB. In the 95 cases with proven myocardial infarction several types of creatine kinase MB activity kinetics could be determined. The percentage of creatine kinase MB of peak CK-total is 6-25%, with a mean of 11.1%. The amount of creatine kinase MB with respect to total CK activity after reinfarction is higher than the amount after initial infarction.     

Dissociable correlates of two classes of retrieval processing in prefrontal cortex

Although substantial evidence suggests that the prefrontal cortex (PFC) implements processes that are critical for accurate episodic memory judgments, the specific roles of different PFC subregions remain unclear. Here, we used event-related functional magnetic resonance imaging to distinguish between prefrontal activity related to operations that (1) influence processing of retrieval cues based on current task demands, or (2) are involved in monitoring the outputs of retrieval. Fourteen participants studied auditory words spoken by a male or female speaker and completed memory tests in which the stimuli were unstudied foil words and studied words spoken by either the same speaker at study, or the alternate speaker. On "general" test trials, participants were to determine whether each word was studied, regardless of the voice of the speaker, whereas on "specific" test trials, participants were to additionally distinguish between studied words that were spoken in the same voice or a different voice at study. Thus, on specific test trials, participants were explicitly required to attend to voice information in order to evaluate each test item. Anterior (right BA 10), dorsolateral prefrontal (right BA 46), and inferior frontal (bilateral BA 47/12) regions were more active during specific than during general trials. Activation in anterior and dorsolateral PFC was enhanced during specific test trials even in response to unstudied items, suggesting that activation in these regions was related to the differential processing of retrieval cues in the two tasks. In contrast, differences between specific and general test trials in inferior frontal regions (bilateral BA 47/12) were seen only for studied items, suggesting a role for these regions in post-retrieval monitoring processes. Results from this study are consistent with the idea that different PFC subregions implement distinct, but complementary processes that collectively support accurate episodic memory judgments.     

俯卧位通气对高海拔地区肺复张治疗无效急性呼吸窘迫综合征患者氧合的影响

目的 探讨俯卧位通气对高海拔地区肺复张术(RM)治疗无效急性呼吸窘迫综合征(ARDS)患者的治疗作用.方法 从海拔2260m的地区医院筛选RM治疗无效的41例ARDS患者[平均氧合指数( PaO2/FiO2)较RM前升高＜20％视为RM无效],依不同病因分为肺内源性ARDS组(ARDSp组)和肺外源性ARDS组(ARDSexp组),每组再按信封法随机分为俯卧位组和仰卧位组,即ARDSp俯卧位组(11例)、ARDSp仰卧位组(9例)、ARDSexp俯卧位组(10例)、ARDSexp仰卧位组(11例).在通气前及通气1、2、3、4h监测动脉血氧分压( PaO2)、PaO2/FiO2、静态顺应性(Cst)、气道阻力(Raw)的变化.结果 通气lh时,ARDSexp俯卧位组PaO2/FiO2( mm Hg,l mm Hg=0.133 kPa)即较通气前显著升高(157.4±40.6比129.3±48.7,P＜0.05),并随通气时间延长呈持续增高趋势,4h达峰值(219.1 ±41.1);且ARDSexp俯卧位组通气3h内PaO2/FiO2较其他3组显著增高,另3组间则差异无统计学意义.ARDSp俯卧位组、ARDSexp俯卧位组通气4h时PaO2/FiO2均较相应仰卧位组显著增高(208.8±39.7比127.4±47.1,219.1±41.1比124.9±50.8,均P＜0.05).4组通气前后Cst无显著改变,各组间差异也无统计学意义.ARDSp俯卧位组通气4h时Raw(cmH2O·L-1·s-1)较通气前显著降低(6.8±1.7比10.7±1.8,P＜0.05),且明显低于其他3组;其他3组各时间点Raw组内及组间比较差异均无统计学意义.结论 俯卧位通气作为ARDS机械通气重要策略之一,可以改善RM无效高原ARDS患者的氧合,为抢救患者赢得宝贵的时间.     

Digital imaging among medical facilities

The Department of Veterans Affairs (VA) in the USA operates a network of 172 medical centres which all utilize a hospital information system (HIS) which has been developed and is currently maintained by the VA. During the past several years, an image management and communication module has been developed, installed and clinically utilized at the Washington DC and Maryland VA Medical Centres. This image management and communication system, referred to as the decentralized hospital computer program (DHCP) imaging system, is fully integrated with a commercial picture archiving and communication system (PACS). The system is utilized to capture, archive, and display all images generated within the hospital including radiology, nuclear medicine, pathology, endoscopy, bronchoscopy, and dermatology, intraoperative photographs, ECG data, and a limited number of paper documents. The ultimate goal of the project is to have all patient text and image data available at any clinical workstation to any authorized user anywhere within the network of medical centres. Clinical requirements for an imaging workstation include ease of use, rapid and reliable access to the complete set of patient information, and images which are of acceptable quality to meet the requirements of the user and the subspecialty. Patient confidentiality and data security must be safeguarded at all times. Integration of the images with the remainder of the patient's database was found to be critical to the success of the project. The experience at the Washington and Maryland facilities suggests that an imaging system that is successfully integrated with a hospital information system can provide substantial clinical and economic benefits both within and among medical centres. Clinical acceptance and utilization of the system has been excellent, particularly in diagnostic radiology where DHCP Imaging has been interfaced to a commercial PAC system. Based upon this initial experience, the VA has begun to deploy the system throughout its large network of medical centres.     

Myocardial elastography at both high temporal and spatial resolution for the detection of infarcts

Myocardial elastography is a novel method for noninvasively assessing regional myocardial function, with the advantages of high spatial and temporal resolution and high signal-to-noise ratio (SNR). In this paper, in-vivo experiments were performed in anesthetized normal and infarcted mice (one day after left anterior descending coronary artery [LAD] ligation) using a high-resolution (30 MHz) ultrasound system (Vevo 770, VisualSonics Inc., Toronto, ON, Canada). Radiofrequency (RF) signals of the left ventricle (LV) in longitudinal (long-axis) view and the associated electrocardiogram (ECG) were simultaneously acquired. Using a retrospective ECG gating technique, 2-D full field-of-view RF frames were acquired at an extremely high frame rate (8 kHz) that resulted in high-quality incremental displacement and strain estimation of the myocardium. The incremental results were further accumulated to obtain the cumulative displacements and strains. Two-dimensional and M-mode displacement images and strain images (elastograms), as well as displacement and strain profiles as a function of time, were compared between normal and infarcted mice. Incremental results clearly depicted cardiac events including LV contraction, LV relaxation and isovolumetric phases in both normal and infarcted mice, and also evidently indicated reduced motion and deformation in the infarcted myocardium. The elastograms indicated that the infarcted regions underwent thinning during systole rather than thickening, as in the normal case. The cumulative elastograms were found to have higher elastographic SNR (SNR(e)) than the incremental elastograms (e.g., 10.6 vs. 4.7 in a normal myocardium, and 6.0 vs. 2.4 in an infarcted myocardium). Finally, preliminary statistical results from nine normal (m = 9) and seven infarcted (n = 7) mice indicated the capability of the cumulative strain in differentiating infracted from normal myocardia. In conclusion, myocardial elastography could provide regional strain information at simultaneously high temporal (>/=0.125 ms) and spatial ( approximately 55 microm) resolution as well as high precision ( approximately 0.05 microm displacement). This technique was thus capable of accurately characterizing normal myocardial function throughout an entire cardiac cycle, at the same high resolution, and detecting and localizing myocardial infarction in vivo.     

Clinical Pharmacokinetics of Morphine

Morphine, the most widely used mu-opioid analgesic for acute and chronic pain, is the standard against which new analgesics are measured. A thorough understanding of the pharmacokinetics of morphine is required in order to safely and effectively use this analgesic in a wide variety of patients with different levels of organ function. A MEDLINE search was conducted to identify literature published between 1966 and January 2002 relevant to the pharmacokinetics of morphine. These publications were reviewed and the literature summarized regarding unique and clinically important elements of morphine disposition relative to its parenteral administration (including intravenous, intramuscular, subcutaneous, epidural and intrathecal administration), absorption profile (immediate release, controlled release, and sublingual/buccal, and rectal administration), distribution, and its metabolism/ excretion. Special populations, including infants, elderly, and those with renal/liver failure, have a unique morphine pharmacokinetic profile that must be taken into account in order to maximize analgesic efficacy and reduce the risk of adverse events.