乳酸脱氢酶（LDH）37℃参考方法的建立及其临床应用

目的通过建立37℃乳酸脱氢酶（LDH）参考方法．对酶校准品定值,探讨血清LDH测定结果的准确度与一致性。方法依据国际临床化学与检验医学联合会（IFCC）推荐的参考测量程序建立LDH酶催化活性参考方法,用参考方法测定ERM-AD453 LDH参考品．验证参考方法的准确性,并对其精密度进行方法学评价。同时用参考方法对制备的酶校准品进行准确定值,按照NCCLS EP9-A方案分别比较40份人血清用酶校准品校正的非配套常规方法、配套常规方法以及理论K值常规方法和参考方法LDH结果,计算前三种常规方法与参考方法的相对偏倚及相关系数。结果用参考方法测定ERM-AD453 LDH参考品结果500．1U／L,在其给定的502±7U／L范围内。初步建立的37℃LDH参考方法CV〈1％。用制备的酶校准品校准的非配套常规方法、配套常规方法、理论K值常规方法和参考方法比较,相关均良好,分别为0.9867,0.9872和0．9878,而与配套常规方法和理论K值常规方法相比较,酶校准品校准的非配套常规方法与参考方法的相对偏倚明显阵低,在10％以下。结论LDH的参考方法基本建立,采用参考方法定值酶校准品,可以提高临床血清LDH测定结果的准确度和一致性。     

乳酸脱氢酶(LDH) 37℃参考方法的建立及其临床应用

目的通过建立37℃乳酸脱氢酶（LDH）参考方法．对酶校准品定值,探讨血清LDH测定结果的准确度与一致性。方法依据国际临床化学与检验医学联合会（IFCC）推荐的参考测量程序建立LDH酶催化活性参考方法,用参考方法测定ERM-AD453 LDH参考品．验证参考方法的准确性,并对其精密度进行方法学评价。同时用参考方法对制备的酶校准品进行准确定值,按照NCCLS EP9-A方案分别比较40份人血清用酶校准品校正的非配套常规方法、配套常规方法以及理论K值常规方法和参考方法LDH结果,计算前三种常规方法与参考方法的相对偏倚及相关系数。结果用参考方法测定ERM-AD453 LDH参考品结果500．1U／L,在其给定的502±7U／L范围内。初步建立的37℃LDH参考方法CV〈1％。用制备的酶校准品校准的非配套常规方法、配套常规方法、理论K值常规方法和参考方法比较,相关均良好,分别为0.9867,0.9872和0．9878,而与配套常规方法和理论K值常规方法相比较,酶校准品校准的非配套常规方法与参考方法的相对偏倚明显阵低,在10％以下。结论LDH的参考方法基本建立,采用参考方法定值酶校准品,可以提高临床血清LDH测定结果的准确度和一致性。     

γ-谷氨酰转肽酶37℃参考方法的建立在临床中的初步应用

目的 建立37 ℃γ-谷氨酰转肽酶(GGT)的参考方法,并对酶校准品定值,探讨血清GGT测定结果 的准确性与可比性.方法 依据国际临床化学与检验医学联合会(IFCC)推荐的参考测量程序建立GGT酶催化活性参考方法,用参考方法 测定GGT(ERM AD452/IFCC)参考品,验证参考方法 的准确度,并对其精密度进行方法 学评价,同时用参考方法 对制备的酶校准品进行准确定值,按照NCCLS EP9-A方案分别比较40例人血清用酶校准品校正的非配套常规方法 、配套常规方法 、理论K值常规方法 和参考方法 GGT结果,计算常规方法 与参考方法 的相关系数及相对偏倚.结果 用参考方法 测定ERM -AD 452 GGT参考品结果 113.6 U/L,在其给定的(114.1±2.4)U/L范围内.初步建立的37 ℃ GGT参考方法 总CV<1%.用酶校准品校正的非配套常规方法 、配套常规方法 、理论K值常规方法 和参考方法 比较,相关性均良好,r2分别为0.999 8、0.999 6和0.999 5,与配套常规方法 、理论K值常规方法 相比较,酶校准品校正的非配套常规方法 与参考方法 的相对偏倚明显降低,在10%以下.结论 GGT参考方法 基本建立,采用参考方法 为酶校准品定值,可以提高血清GGT测定结果 的准确度和可比性.     

血清γ-谷氨酰基转移酶参考方法在国产试剂量值溯源中的应用

目的 应用血清γ-谷氨酰基转移酶(GGT)参考方法评价国产GGT试剂的溯源性.方法 按照国际临床化学与检验医学联合会(IFCC)有关GGT活性测定的要求建立参考方法;根据美国临床和实验室标准协会(CLSI)系列文件对建立的参考方法的主要性能进行评价;应用建立的参考方法评价国内不同厂家的GGT试剂在罗氏Cobas 6000和日立7170A全自动生化分析仪上测定结果的溯源性,并用经参考方法定值的新鲜人血清作为校准品实现不同检测系统检验结果的一致性和可比性.结果 GGT参考方法的批内不精密度和总不精密度均<1%,与国际参考实验室外部质量评价计划样品靶值的相对偏倚在等效限内;校准前常规检测系统与参考方法GGT检测结果在医学决定水平处的最大偏倚分别达到-47.53%、-34.11%、-30.07%,平均偏倚分别为14.53%、12.88%、12.48%;使用新鲜血清作为校准品校准后,最大偏倚分别降至-17.63%、-5.88%、-4.08%,平均偏倚降至7.50%、2.70%、1.87%.结论 GGT参考方法性能符合要求.应用参考方法赋值的新鲜人血清作为校准品进行校准是实现国内不同厂家酶学试剂检验结果一致性和可比性的有效途径.     

血清酶活性测定中几种K值的应用比较

目的：认识和验证酶校准品在酶活性测定中对K值的校准。方法：分别用试剂盒K值、两种理论K值和两种校准品校准的K值测定同一质控物中常见的7种酶活性，以偏差进行比较。结果：试剂盒K值和理论K值的测定结果偏差最高达78．8％；用罗氏(Roche)校准品校准K值的测定结果偏差除ALP和GGT偏高外，其余项目均小于10％。结论：提倡使用适合实验室仪器和试剂系统的酶校准品进行K值校准。     

血清酶测定标准化的实验研究

目的　通过酶校 (标 )准品在临床实验室中的应用 ,探讨血清酶测定标准化的新途径。方法　向参加实验室 (15 0家 )发放酶校准品 1支和血清样本 3支 ,各实验室用现行方法分别测定校准品和血清样本 ,记录检验结果 ;用校准品定标后再测定血清样本 1次 ,记录检验结果 ;计算校准品测定结果总体均值与标示值间的偏倚和校准前后血清样本测定结果精密度的变化。结果　丙氨酸氨基转移酶 (ALT)、天门冬氨酸氨基转移酶 (AST)、淀粉酶 (AMY)和乳酸脱氢酶 (LD)的测定结果均值与标准品标示值的相对偏倚≤± 6 % ,分别为 3 8% ,- 1 8% ,2 3%和 - 5 2 % ;碱性磷酸酶 (ALP)、γ 谷氨酰基转移酶 (GGT)和肌酶激酶 (CK)的实验室检测结果与标准品标示值间的相对偏倚小于 2 0 % ;分别为13 7% ,- 13 9%和 - 19 2 %。在应用校准品后 ,多数项目测定结果的变异系数 (CV % )得到不同程度的改善 ,ALT由 10 %～ 4 4 %下降至 8%～ 4 2 % ,LD由 16 %～ 39%下降至 8%～ 11%。结论　我国临床实验室对血清ALT、AST、AMY和LD的测定结果有较好的向国际标准溯源性 ;使用酶校准品可改善不同分析系统间测定结果的一致性。     

酶活性测定结果相对一致的可行性探讨

目的　应用新鲜混合定值人血清作为校准品,探讨各医院之间临床常用酶[丙氨酸氨基转移酶 (ALT)、天门冬氨酸氨基转移酶(AST)、碱性磷酸酶(ALP)、γ 谷氨酰基转移酶(GGT)、乳酸脱氢酶(LDH)、肌酸 激酶(CK)]活性测定结果相对一致的可行性。方法　将cfas校准品中6个酶活性的定值传递给新鲜混合人血 清,然后以此作为校准品,校准分析系统后再测定标本值。结果　应用上述方法后,30所医院间6个酶活性测定 结果的可比性明显提高,各级医院之间6个酶活性测定结果的平均变异系数(CV)显著下降,均值和定值亦趋向 一致。结论　应用新鲜混合定值人血清作为校准品,使各医院之间酶活性测定结果相对一致是可行的。     

血清酶检测K因子的探讨分析

目的：探讨血清酶校准品及定值质控血清在室内质量控制中的溯源性,建立血清酶检测K因子的可靠方法。方法在OlympusAU‐5400全自动生化分析仪上用贝克曼酶复合校准品以单点定标方式定标和理论校准参数K因子法对定值质控血清检测,分别测定定值质控血清中的丙氨酸氨基转移酶（ALT）、天门冬氨酸氨基转移酶（AST）、碱性磷酸酶（ALP）、肌酸激酶（CK）、乳酸脱氢酶（LD）、γ‐谷氨酰转移酶（γ‐GT）等6种酶的活性,比较其X和相对偏倚（D％）。结果使用校准品检测ALP、LD、ALT、AST、CK所得实际K因子与理论K因子差异巨大,只有γ‐GT所得实际K因子与理论K因子相对偏倚小于3．5％。结论血清酶校准品校准后检测定值质控血清与定值标示结果非常相近,显示用酶校准品校准检测血清酶的方法具有较好的溯源性,在无血清酶校准品时,甚至可以用定值质控血清代替以校准理论KS值。     

谷丙转氨酶37℃参考方法的建立及其应用研究

目的通过建立37℃谷丙转氨酶（ALT）参考方法，对酶校准品定值，探讨血清ALT测定结果的准确性与可比性。方法依据国际临床化学与检验医学联合会（IFCC）推荐的参考测量程序建立ALT酶催化活性参考方法，用参考方法测定ERM-AD 454 ALT参考品，验证参考方法的准确度，并对其精密度、线性范围和干扰因素进行方法学评价，同时用参考方法对制备的酶校准品进行准确定值，按照NCCLS EP9-A方案比较40份人血清用酶校准品校正的常规方法和参考方法ALT结果。结果用参考方法测定ERM-AD454 ALT参考品结果186．4U／L，在其给定的186&#177;4U／L范围内。初步建立的37℃ALT参考方法总CV0．89％～1．12％，线性范围1．3～300U／L。ALT测定结果在32U／L左右偏差超过5％的干扰物浓度分另4为游离胆红素205．2μmol／L、结合胆红素136．8μmol／L；ALT在123U／L左右测定结果偏差超过5％的干扰物浓度分别为游离胆红素256．5μmol／L、结合胆红素273．6μmol／L。血红蛋白在2g／L和三酰甘油在10mmol／L以下时对两种浓度的ALT干扰分别均大于5％和仍然小于5％。用制备的酶校准品校准的常规方法和参考方法进行比较，相关良好（r^2=0．9992）。前者结果与后者相对偏倚在&#177;10％之内。结论ALT参考方法基本建立，采用参考方法为酶校准品定值，可以提高血清ALT测定结果的准确度和可比性。     

校准品与理论K值在血清酶测定中的应用比较

目的 探讨校准品校准与理论K值校准血清酶测定结果的差异.方法 采用相同的生化分析仪和试剂,在进行校准品校准和理论K值校准后对相同标本进行检测.结果 校准品校准血清酶测定结果与理论K值校准测定结果比较差异有统计学意义(P＜0.05);校准品校准测定结果更接近靶值.结论 在血清酶检测工作中,不能机械套用理论K值,而应用校准...     

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.     

手转胎头术失败的原因与分娩结局临床分析

目的 探讨手转胎头术失败的原因与分娩结局.方法 选择2008年1月至2010年12月于我院住院分娩的持续性枕横位、枕后位产妇198例,根据行手转胎头术后结果分为成功组126例、失败组72例.比较两组分娩结局,对比分析失败原因.结果 失败组胎儿体质量≥3500 g的发生率[76.4％(55/72)]明显高于成功组[31.7％(40/126)],差异有统计学意义(x2=30.177,P=0.001)、失败组宫缩乏力发生率[58.3％(42/72)]高于成功组[38.1％ (48/126)],差异有统计学意义(x2=7.569,P=0.006)、失败组骨盆临界或轻度狭窄发生率[38.9％ (28/72)]高于成功组[23.8％(30/126)],差异有统计学意义(x2 =5.030,P=0.002)、失败组手转胎头时机不当(宫口开大＜6 cm、胎头位于坐骨棘上及宫口开大8～10 cm、胎头位于坐骨棘下≥2 cm)发生率[61.1％(44/72)]高于成功组[38.9％(49/126)],差异有统计学意义(x2=9.084,P=0.003).失败组母儿并发症(产后出血、产褥病率、胎儿窘迫、新生儿窒息)发生率高于成功组(x2 =9.586,P=0.002、x2=9.334,P=0.002、x2=5.910,P=0.015、x2=5.240,P=0.022)、失败组剖宫产发生率[72.2％(52/72)]明显高于成功组[34.1 ％(43/126),x2=26.641,P=0.001)].结论 手转胎头术能使难产变顺产,降低剖宫产率,减少母儿并发症,但须积极预防、处理导致手转胎头术失败的原因,对矫正失败后继续矫正及试产应慎重.