二级标准检测系统计数血小板的质量保证与应用

目的 评价二级标准检测系统测定血小板结果的准确性与可比性,以确认新鲜血定值结果的准确和可靠程度.方法 参照美国CLSI文件EP9-A2,将二级标准检测系统与参考方法的血小板计数结果进行比对,评价40份静脉血标本检测结果的相关性和偏倚;将NCCL和日本参考实验室的二级标准检测系统的检测结果进行比对;用二级标准检测系统对36份正常新鲜血标本进行定值,将其作为校准物,用于常规实验室36台血细胞分析仪的校准.结果 二级标准检测系统与参考方法检测结果分布范围分别为(108 ～326)×109/L和(110～327)×109/L,具有良好的相关性,相关系数(r)为0.993,偏倚分布范围为-3.8％～3.4％.2009-2010年NCCL检测质控品的结果分布范围为(185 ～203)×109/L,日本参考实验室检测质控品的结果分布范围为(185～ 198)×109/L,比对数据的CV分别为2.0％～3.0％和2.6％ ～3.4％,比对数据的偏倚分布范围为-1.4％～3.7％;验证结果符合要求的20台血细胞分析仪的偏倚分布范围为-2.6％～2.1％,其余需要校准的16台血细胞分析仪校准前后的偏倚由3.4％ ～ 12.6％降至0％ ～2.8％.结论 参考实验室间的结果比对保证了血小板计数结果的准确性和可比性;二级标准检测系统定值的新鲜血作为校准物用于血细胞分析仪的校准是可行的.     

贵阳市二级以上医院全血细胞计数结果准确性和可比性调查

目的对贵阳市二级以上医院临床实验室间全血细胞计数结果的准确性和可比性进行调查。方法通过对20家二级以上医院临床实验室血细胞分析仪进行新鲜血现场检测调查、校准和结果比对,并对校准前、后现场调查结果进行分析。结果在仪器的校准和质控方面存在较多有待规范之处,只有3个实验室定期使用厂家提供的配套校准物对仪器进行校准,其余实验室对仪器进行了不正确的校准或从未校准;有12个实验室室内质控的频度和项目均符合要求,其余实验室室内质控开展的频度和项目均不符合要求。用贵州省临床检验中心的二级标准血细胞分析检测系统定值的新鲜血进行血细胞分析仪校准,对20个临床实验室现场调查结果进行评价：不合格实验室数由17个降至6个,合格率由71％提高到92％。校准前、后现场调查各项目的最大偏差分别为：白细胞15．17％、-7．41％,红细胞8．46％、4．99％,血红蛋白9．47％、-6．64％,红细胞比容-15．85％、-12．81％,血小板-23．87％、-18．27％,校准后各项目平均偏差及变异系数均明显减少。结论使用二级标准血细胞分析检测系统定值的新鲜血校准不同厂家、不同型号的仪器,通过现场调查、现场的结果比对及规范操作,可以明显提高全血细胞计数结果的准确性和可比性。     

北京市三级医院全血细胞计数结果可比性和准确性调查

目的对北京市三级医院间全血细胞计数结果的可比性和准确性进行调查，为开展临床检验结果的互认提供依据。方法共调查41家实验室，以全血细胞计数（complete blood count，CBC）为试点项目，通过现场调查、仪器校准和结果比对等方式，发现存在的问题，制定相应的管理措施、纠正措施和评价方法。结果在仪器校准和室内质量控制方面存在较多有待规范之处，表现为22家实验室（53．6％）无校准记录，甚至有4家实验室（9．8％）从未进行过校准，4家实验室（9．8％）使用质控物而非校准物进行了错误的校准；14家实验室（34．2％）开展室内质量控制项目的数量达不到要求。此外，有4家实验室（9．8％）使用非配套试剂。根据调查数据和检验结果生物变异的文献报道，将北京市血细胞计数结果的允许偏差暂定为：WBC≤15％，Hb≤5％，RBC≤5％，红细胞压积（HCT）≤5％，PLT≤15％。通过使用卫生部临床检验中心血细胞分析校准实验室提供的溯源至参考方法的定值新鲜血对血液分析仪进行校准，使13家医院的14个不合格项目纠正了11个。结论通过现场调查、使用具有溯源性的定值新鲜血校准不同的检测系统、现场的结果比对、质量管理要求的提出以及监督措施的实施，可以明显提高医院间检验结果的可比性和准确性，为开展检验结果的互认提供了依据。     

新鲜血在校准血细胞分析仪中的应用

目的保证血细胞分析仪检测结果的准确性和可比性。方法选择有校准品提供且性能良好的ACT-diffⅡ血细胞分析仪作为参考仪器，用参考仪器给新鲜抗凝全血定值，以定值新鲜血替代校准品，对MEK-8118血细胞分析仪进行校准。结果MEK-8118血细胞分析仪经新鲜血校准后，仪器系统误差得以消除，检测结果准确且具有可比性。结论新鲜血校准血细胞分析仪方法简便、快速，结果准确，可比性好。     

抗凝新鲜血在血细胞分析仪校准和比对中的应用探讨

目的探讨用抗凝新鲜血在血细胞分析仪校准和比对的应用价值。方法选择Sysmex TX-2000i血液分析仪为参比仪,迈瑞BC-3000血液分析仪为比对仪。(1)采集体检健康人用乙二胺四乙酸二钾抗凝新鲜血在参比仪按规范的操作方法进行定值,然后用该血液校准比对仪。(2)每天选择无细胞聚集和碎片的新鲜血标本,在参比仪和比对仪分别测试3次并记录均值结果,为期2个月共检测180例标本,采用直线回归分析检验结果的相关性和一致性。结果 (1)比对仪经定值新鲜血校准后其测定结果与参比仪测定结果的偏差比校准前明显降低,差异有统计学意义(P<0.01)。(2)参比仪与比对仪测定结果各参数之间相关密切(r2>0.95),一致性良好。结论利用抗凝新鲜血用于血细胞分析仪的校准和比对,经济有效,可以提高血液分析仪结果的准确性和可比性。     

BC-5500全自动血细胞分析仪的校准及校准后比对

目的对新进BC-5500全自动血细胞分析仪使用新鲜全血进行校准及校准后比对，确保其结果与本实验室其他血细胞分析仪可溯源到同一个测量基准。方法取体检健康志愿者的新鲜全血，分别在F-820血细胞分析仪和BC-5500全自动血细胞分析仪上检测，以F-820血细胞分析仪作为溯源目标系统，计算BC-5500全自动血细胞分析仪各参数的偏差，根据判断标准决定是否需要对BC-5500全自动血细胞分析仪进行校准。各参数均符合规定后使用临床病人新鲜全血样本进行比对试验。结果校准前各参数偏差均超出范围，白细胞计数（WBC）、红细胞计数（RBC）、血红蛋白（HB）、红细胞平均体积（MCV）、血小板计数（PLT）偏差结果依次为：11．2％、3．4％、2．5％、1．97％、13．5％；调试仪器并调整校准系数后，各参数均能符合要求，WBC、RBC、HB、MCV、PLT偏差结果依次为：0．02％、0．4％、0．62％、0．43％、0．84％；校准后比对试验结果，RBC、HB、MCV符合率都为80％，WBC、PLT符合率为90％，比对通过，校准系数可以接受。结论使用新鲜血校准血细胞分析仪的方法简便、快速，但必须在校准后进行比对试验并通过比对，才能保证实验室不同品牌、不同系列的血细胞分析仪结果间具有可比性，满足临床实验室认可的需要。     

贵州省二级标准检测系统在血细胞分析仪新鲜血校准中的应用

血细胞分析仪的应用越来越普遍,但实验室在使用血细胞分析仪时存在很多问题及难题,影响到血细胞分析仪检测结果的准确性,使医疗机构间以及医疗机构内不同检测系统的检测结果可比性差,不能实现检测结果的相互通用.贵州省临床检验中心通过血细胞分析二级标准检测系统对新鲜全血定值,探讨用定值新鲜血对医疗机构实验室的血细胞分析仪进行校准的可行性.     

抗凝新鲜血在血液分析仪质量控制及评价中的应用

目的　探讨抗凝新鲜血在血液分析仪室内质量控制及室间质量评价中的应用。方法　将当天采集制作的抗凝新鲜血分发至各医院临检实验室 ,当天完成血液分析仪的比对。仪器校准后 ,进行室内、室间质控物的检测。结果　各实验室血液分析仪经定值抗凝新鲜血比对及校准后 ,室间质评抗凝新鲜血各项目检测结果的CV、平均VIS明显减小 ,优秀率提高到 95 %以上。结论　抗凝新鲜血用于质控 ,提高了北京市各医院临检实验室血液分析仪的检测水平 ,使各医院的血液分析仪有了可溯源的参考标准 ,提高了血常规检验报告的准确性和可比性。     

血细胞分析仪白细胞分类计数量值溯源性的建立

目的 应用参考方法[1]对血细胞分析仪白细胞分类计数(DIFF)进行校准,建立其量值溯源性.方法 采用手工目视显微镜法作为白细胞分类计数的参考方法对新鲜全血进行定值,以确定靶值;用该手工定值的新鲜全血对五台血液分析仪的DIFF参数进行校准,建立白细胞分类计数量值溯源性;校准完毕后进行新鲜全血比对试验.结果 DIFF参数手工分类靶值:NEUT,LYMPH,MONO,EOS和BASO分别为67.25%,26.58%,3.92%,2.00%和0.25%,五台仪器检测结果与手工分类靶值相比较,均在可信允许范围内;新鲜全血比对结果符合标准要求.结论 应用参考方法校准血细胞分析仪白细胞分类计数,可以实现其检测结果具有溯源性和准确性,同时可促进不同临床实验室DIFF检测结果互认.白细胞手工分类计数的准确性直接影响仪器分类参数校准的效果,实验室应定期进行人员手工分类能力比对.     

我国血细胞分析参考系统的建立

为了解决血液分析仪的校准存在的问题，卫生部临床检验中心按照国际血液学标准化委员会和国际标准化组织颁布的国际标准，在部中心建立了血细胞计数的参考系统，研究的主要内容包括：（1）建立了血细胞分析校准实验室，并作为医学实验室中的首家实验室通过了国家实验室认可委员会ISO17025校准实验室的认可；（2）首次在国内建立了血细胞分析的参考方法并与国外的参考实验室长期进行结果的比对；（3）使用参考系统定值的新鲜血或校准物为常规检测实验室提供校准服务，开辟了血液分析仪校准的新途径；（4）建立了二级标准检测系统的方法并与国外参考实验室进行长期的结果比对，同时将经验推广到全国26个省、自治区、直辖市，建立了比对实验室网络；（5）起草了多个卫生部行业标准和技术要求。目前该系统的应用领域主要包括：临床检验中心、医疗机构的临床实验室、体外诊断试剂的政府管理机构、疾病控制系统等。     

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.