血清结合胆红素酶法测定在自动生化分析仪上的应用

目的　建立酶法测定血清结合胆红素的全自动分析方法 ,并在肝胆疾病患者中临床应用。方法　通过试剂的合理组合 ,分析参数和操作程序的设定 ,建立结合胆红素 (CB)的全自动分析方法 ,同时对总胆红素进行自动化酶法测定。结果　酶法CB测定 :精密度 ,批内n =2 0 , x =6 .4 8μmol/L ,s=0 .11,CV =1.7%和n =2 0 , x =77.9μmol/L ,s=0 .4 2 ,CV =0 .5 3% ;批间n =10 , x =9.4 6 μmol/L ,s=0 .17,CV =1.83%和n =10 , x =5 9.7μmol/L ,s=1.4 3,CV =2 .39% ;线性范围至少可达 340 μmol/L ;比对实验 :与Beckman重氮法试剂 (在BeckmanCX7型生化分析仪上 )比较 ,Y(酶法 ) =0 .75 9X1- 2 .82、r =0 .991,与IagnosticumRT重氮法试剂 (日立 76 0 0 0 2 0型分析仪 )比较 ,Y =0 .84 1X2 - 4 .39、r=0 .96 3。临床研究显示 :与重氮法直接胆红素值相比 ,本法测定CB值能够更灵敏地反映黄疸患者的胆红素分泌功能。结论　建立的CB全自动分析方法具有良好的分析特性 ,可在临床推广应用。     

酶法测定结合胆红素的方法学评价

目的评价胆红素酶法测定血清结合胆红素(CB il),并与干化学法作比较。方法在pH值5.5、120mmol/L苯二甲酸氢钾缓冲液中,胆红素氧化酶(BOD)选择性地氧化CB il,引起450 nm处吸光度(A)值下降,求得CB il浓度。加入氟化钠(NaF)和N-乙酰半胱氨酸(NAC),抑制BOD对未结合胆红素(UB il)和δ-胆红素(δB il)的氧化,消除其干扰。结果BOD法测定的线性范围达230μmol/L,批内变异系数(CV)为4.1%(低值)、1.4%(高值),批间CV为11.65%(低值)、10.26%(高值),平均回收率为97.8%。BOD法与干化学法比较,Y干化学法=1.016 0X酶法 1.603 1,r=0.990 7。结论该法能有效地抑制BOD对UB il和δB il的氧化,特异性的检测CB il,并可用于自动生化分析仪。     

酶法测定结合胆红素的方法学评价

目的评价胆红素酶法测定血清结合胆红素（CBil），并与干化学法作比较。方法在pH值5．5、120mmoL／L苯二甲酸氧钾缓冲液中，胆红索氧化酶（BOD）选择性地氧化CBil，引起450nm处吸光度（A）值下降，求得CBil浓度。加入氟化钠（NaF）和N-乙酰半胱氨酸（NAC），抑制BOD对未结合胆红素（UBil）和δ-胆红素（δBil）的氧化，消除其干扰。结果BOD法测定的线性范同达230μmol／L，批内变异系数（CV）为4．1％（低值）、1．4％（高值），批问CV为11．65％（低值）、10．26％（商值），平均回收率为97．8％。BOD法与干化学法比较，Y干化学法=1．0160X酶法＋1．6031，r=0．9907。结论该法能有效地抑制BOD对UBil和δBil的氧化，特异性的检测CBil，并可用于自动牛化分析仪。     

重氮法与钒酸盐氧化法测定血清胆红素的初步比较分析

目的：探讨重氮法与钒酸盐氧化法测定血清胆红素的差别。方法：从精密度、线性范围及回收率三个方面对两种方法测定血清胆红素的结果进行比较。结果：重氮法测定的总胆红素和直接胆红素的批间和批内CV％为1．33与1．36和3．1与3．4，线性范围为260μmol／L与μmol／L，回收率为99．3％和99．9％；钒酸盐法分别为1．30与1．24和2．95与3．31，520μmol／L与260μmol／L，99．8％和99．8％。结论：重氮法在精密度和线性范围两项指标上不如钒酸盐法，在回收率上两者均较好。     

胆红素氧化酶法测定血清结合胆红素

介绍使用国产胆红素氧化酶和二牛磺酸胆红素校准物建立血清结合胆红素测定方法。测定缓冲液为０．１ｍｏｌ／Ｌ柠檬酸盐缓冲液（ｐＨ＝５．０），胆红素氧化酶浓度５００Ｕ／Ｌ，反应（终点）时间１５分钟。本法线性范围可达２４０μｍｏｌ／Ｌ，批内不精密度＜１０％，回收率为９８．３％～１０７．１％，与重氮方法比较，回归方程为Ｙ（酶法）＝０．９５６Ｘ（重氮法）－０．５１３。本法测定人血清结合胆红素参考值２．５７±２．５６μｍｏｌ／Ｌ（ｎ＝９５）。     

胆红素氧化酶法测定血清结合胆红素

介绍使用国产胆红素氧化酶和二牛磺酸胆红素校准物建立血清结合胆红素测定方法。测定缓冲液为０．１ｍｏｌ／Ｌ柠檬酸盐缓冲液（ｐＨ＝５．０），胆红素氧化酶浓度５００Ｕ／Ｌ，反应（终点）时间１５分钟。本法线性范围可达２４０μｍｏｌ／Ｌ，批向不精密度＜１０％，回收率为９８．３％～１０７．１％，与重氮方法比较，回归方程为Ｙ（酶法）＝０９５６Ｘ（重氮法）－０．５１３。本法测定人血清结合胆红素参考值２．５７±２．５     

固蓝B单一试剂显色法测定血清总胆红素的探讨

用固蓝B、HCl、尿素已制单一试剂测定血清总胆红素。方法学评价结果：线性范围0～342．0μmol／L，批内CV1．52％，批间CV2．10％，回收率98．2％～102．9％，表观摩尔消光因数K630＝1．0007×105cm2／mol，Hb≤2．5g／L，NaN3≤2．0g／L基本不影响胆红素测定，与改良J－G法比较，γ＝0.999，Y（本法）＝0．99X＋0．15。     

钒酸氧化法测定血清胆红素的实验评价

目的对钒酸氧化法测定血清胆红素进行方法学评价。方法收集40例高、中、低浓度的血清样本进行钒酸氧化法与重氮法的比对，分析钒酸氧化法的精密度、灵敏度、稳定性并做干扰实验。结果钒酸氧化法测定血清总胆红素（TBil）批内变异系数（CV）为1．58％，批间CV为2．94％；血清直接胆红素（DBil）批内CV为1．23％，批间CV为2．7％；平均回收率TBil为101．1％，DBil为100．1％。维生素C（Vit C）≤0．5g/L时对钒酸氧化法和重氮法均无干扰，三酰甘油≤6mmol／L时对钒酸氧化法无干扰，对重氮法有明显干扰。血红蛋白浓度≤8g/L时对钒酸氧化法无干扰，对重氮法有较大干扰。结论钒酸氧化法测定TBil和DBil是较理想的方法。     

对钒酸氧化法测定血清中胆红素的评价

目的:评价钒酸氧化法测定血清中总胆红素和直接胆红素。方法:钒酸氧化法的精密度、准确度实验及其与重氨法相关和干扰因素实验。结果:批内CV总、直接胆红素分别为0.8％与1.3％。日间CV为1.8％与1.7％,平均回收总胆红素为101.1％,直接胆红素100.1％,与重氮试剂法相关(J-G法)总胆为y(本法)=1.015x(重氮法)-0.119,r=0.998,直接胆红素为y(本法)1.101x(重氮法)+0.81,r=0.952。相关良好,血红蛋白浓度和脂血分别高达3g/L和9.0mmol/L不干扰。结论:该法简单、快速、稳定,而且对溶血、乳糜等干扰因素的影响比重氮法小。     

钒酸盐氧化法测定血清总胆红素、直接胆红素的方法评价

目的 对钒酸盐氧化法测定血清总、直接胆红素进行方法学评价。方法 采用钒酸盐氧化法测定血清总、直接胆红素，与重氮法测定血清总、直接胆红素进行了比较。结果 钒酸盐氧化法（Y）与重氮法（X）相关性良好，相关方程：YTBIL=1.184XTBIL-1.29(r=0.9954),YDBIL=0.982XDBIL 1.43(r=0.9947)；总胆红素批内、批间平均变异系数分别为1.67%、3．02%,平均回收率达98．3％，在0－628μmol/L范围内线性良好。直接胆红素批内、批间平均变异系数分别为1．72％、3．28％，平均回收率达97．6％，在0．229μmol/L范围内线性良好。标本中甘油三酯含量≤5mmol/L、维生素C含量≤0.5g/L时，对钒酸盐氧化法测定总、直接胆红素均无干扰，但对重氮法有明显干扰；血红蛋白对钒酸盐氧化法和重氮法测定总、直接胆红素均产生正干扰。结论 钒酸盐氧化法是一种准确、灵敏、特异性较重氮法高的方法，适用于常规自动化测定血清总、直接胆红素，但在抗血红蛋白干扰方面有待改进。     

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.