不同检测系统甲胎蛋白测定结果的可比性研究

目的 探讨不同检测系统测定甲胎蛋白（AFP）结果的可比性。方法 取拜尔、德普不同水平的质控物，以及31例不同浓度的患者新鲜血清，在4个不同的化学发光免疫检测系统（拜尔ACS180、拜尔CENTAUR、强生VITROS ECI、德普immulite-1000仪器及其配套的校准物、质控物和试剂）上进行AFP检测，并对结果进行统计分析。结果 经配伍组设计资料的方差分析，不同厂家、不同水平的质控物和不同浓度的患者新鲜血清AFP测定结果在各检测系统的组间差异均有显著性（P〈0．01）；各检测系统AFP测定结果的信度系数α接近1；各检测系统问的相关系数均〉0．975。以强生VITROS ECI系统作为目标检测系统，对其他检测系统作临床可接受性能评价，拜尔ACS180、拜尔CENTAUR、德普immulite-1000检测系统临床均可接受。结论 4个检测系统测定AFP结果的精密度符合临床要求，临床可接受性能评价具有可比性。     

不同检测系统甲胎蛋白测定结果的可比性研究

目的探讨不同检测系统测定甲胎蛋白(AFP)结果的可比性。方法取拜尔、德普不同水平的质控物,以及31例不同浓度的患者新鲜血清,在4个不同的化学发光免疫检测系统(拜尔ACS180、拜尔CENTAUR、强生VITROS EC I、德普immu lite-1000仪器及其配套的校准物、质控物和试剂)上进行AFP检测,并对结果进行统计分析。结果经配伍组设计资料的方差分析,不同厂家、不同水平的质控物和不同浓度的患者新鲜血清AFP测定结果在各检测系统的组间差异均有显著性(P<0.01);各检测系统AFP测定结果的信度系数α接近1;各检测系统间的相关系数均>0.975。以强生VITROS EC I系统作为目标检测系统,对其他检测系统作临床可接受性能评价,拜尔ACS180、拜尔CENTAUR、德普immu lite-1000检测系统临床均可接受。结论4个检测系统测定AFP结果的精密度符合临床要求,临床可接受性能评价具有可比性。     

不同检测系统游离甲状腺素测定结果的可比性研究

目的：探讨不同检测系统测定游离甲状腺素（嘎）结果的可比性。方法：取Bayer、德普和自制不同水平的质控物，以及39例不同浓度的患者新鲜血清，在4种不同的化学发光免疫检测系统（拜尔ACS180、拜尔CENTAUR240、强生VITROSECI、德普immulite-1000）上进行FT4检测．并对结果进行比较分析。结果：经配伍组设计资料的方差分析．不同水平的质控物和不同浓度的患者新鲜血清FT4测定结果在各检测系统的组间差异均有显著性（P〈0.01），各检测系统FT4测定结果的可靠性系数α接近1，各检测系统间的相关系数均大于0．975。以强生VITROSECI作为目标检测系统，对其他检测系统作临床可接受性能评价，拜尔ACSJ80、拜尔CENTAUR240临床均可接受、德普immulite-1000临床部分可接受。结论：4个检测系统测定FT4结果临床可接受性能评价存在部分不可比性．当同一实验室同一检验项目存在两个以上的检测系统时．应进行方法比对和偏倚评估，以保证检验结果的可比性。     

不同化学发光免疫检测系统HCG测定结果的可比性研究

目的:探讨不同检测系统测定人绒毛膜促性腺激素(HCG)结果的可比性。方法:分别选用拜尔、德普和自制不同水平的质控物和34例不同浓度的患者新鲜血清,在4个不同的化学发光免疫检测系统(拜尔ACS180、拜尔CENTAUR、强生VITROSECI、德普immulite-1000化学发光免疫检测系统)检测HCG,并对数据进行相关统计学分析。结果:经随机区组设计资料的方差分析,不同厂家、不同水平的质控物和不同浓度的患者新鲜血清的测定结果在各检测系统间差异均有显著性(P<0.01);各检测系统间的相关系数均大于0.975;可靠性分析信度系数α均接近1;以ACS180作标准检测系统对其它检测系统作临床可接受性能评价,CENTAUR、VITROSECI临床部分可接受,immulite-1000临床不接受。结论:4个检测系统测定HCG结果精密度符合临床要求,但临床可接受性能评价存在不可比性。     

不同检测系统促甲状腺激素测定结果的偏倚评价

目的评价不同检测系统测定血清促甲状腺激素(TSH)结果是否存在偏倚。方法分别选用拜尔、德普和自制不同水平的质控物和不同浓度的患者新鲜血清,应用4个不同的化学发光免疫检测系统(拜尔ACS180、拜尔CENTAUR、强生VITROSECI、德普Immulite-1000化学发光免疫检测系统)检测TSH,并对数据进行相关统计学分析。结果经随机区组设计资料的方差分析,不同厂家、不同水平的质控物和不同浓度的患者新鲜血清的测定结果在各检测系统间差异均有统计学意义(P<0.01);各检测系统间的相关系数均大于0.975;可靠性分析信度系数α均接近1;以CEN-AUR作目标检测系统,对其他检测系统作临床可接受性能评价,ACS180检测系统临床可接受,但另2个检测系统临床均部分接受。结论4个检测系统测定TSH结果精密度符合临床要求,但临床可接受性能评价部分存在不可比性。     

不同发光检测系统总前列腺抗原测定结果的对比研究

目的探讨不同检测系统测定总前列腺抗原(TPSA)结果的可比性。方法取百乐、德普不同水平的质控物以及38份不同浓度的患者新鲜血清,在4个不同的化学发光免疫检测系统上进行TPSA检测,并对结果进行统计分析。结果经配伍组设计资料的方差分析,不同厂家、不同水平的质控物和不同浓度的患者新鲜血清TPSA测定结果在各检测系统的组间差异均有统计学意义(P0.01);各检测系统TPSA测定结果的信度系数a接近1;各检测系统问的相关系数均大于0.980。以雅培AXSYM系统作为目标检测系统,对其他检测系统作临床可接受性能评价,罗氏2010、贝克曼Access、德普Immulite-1000检测系统临床均可接受。结论 4个检测系统测定TPSA结果的精密度符合临床要求,临床可接受性能评价具有可比性。     

4种发光检测系统血清铁蛋白测定结果对比分析

目的评价不同发光检测系统测定血清铁蛋白(SF)的结果的可比性。方法分别应用伯乐、贝克曼不同水平的质控物,以及35例不同浓度的患者新鲜血清,在4种不同的化学发光免疫检测系统(贝克曼Dxi800、罗氏2010、雅培i1000、西门子ADVIACentaur仪器及其配套的校准物、质控物和试剂)上进行SF检测,并对结果进行统计学分析。结果经对照组计量资料的方差分析,不同厂家、不同水平的质控物和不同浓度的患者新鲜血清SF测定结果在各检测系统的组间差异均有统计学意义(P<0.01);各检测系统SF测定结果的信度系数a接近1;各检测系统间的相关系数均大于0.983。以贝克曼Dxi800系统作为参照检测系统,对其他检测系统作临床可接受性能评价,罗氏2010、雅培i1000、西门子ADVIACentaur检测系统临床均可接受。结论 4种检测系统检测SF的精密度符合临床要求,临床可接受性性能评价具有可比性。     

不同型号仪器测定凝血酶原时间的可比性研究

目的探讨不同型号血凝仪检测凝血酶原时间（PT）的检测结果是否具有可比性。方法分别采用不同水平STAGO质控物、DADE质控物和75例不同浓度的患者新鲜血浆，在2个不同的检测系统（STA—R、CA7000）测定PT，并对其检测结果进行相关的统计学分析。结果5个水平的质控物测定结果经t检验，各组间的差异均有显著性（P〈0．01）。各检测系统间不同浓度的患者新鲜血浆测定结果差异有非常显著性（P〈0．01）；相关系数均=0．975。以STA—R作标准检测系统对其他检测系统作临床可接受性能评价，CA7000可接受。结论2个检测系统测定PT精密度和临床可接受性能评价均符合临床要求，应定期对以上的检测系统进行比对实验，以保证检验结果间的可比性。     

不同检测系统AST测定结果的可比性研究

目的探讨不同检测系统测定A ST结果的可比性。方法取RANDOX水平2和水平3,以及41例不同浓度的患者新鲜血清,在五个不同的生化分析系统[日立7170A(1);岛津CL 7200;强生V itros250;罗氏Com bus;日立7170A(2)及其配套的校准物、试剂、质控物等,分别命名为检测系统1~5。]上进行A ST检测,并对数据进行相关的统计学分析。结果经随机区组设计资料的方差分析,不同水平的质控物和不同浓度的患者新鲜血清A ST测定结果在各检测系统的组间总体差异均有显著性(P<0.001);各检测系统A ST测定结果的可靠性参数α接近1;各检测系统间的相关系数均大于0.975。以检测系统1作为目标检测系统,对其它检测系统作临床可接受性能评价,检测系统4临床可接受、检测系统2临床部分接受、检测系统3和5临床不接受。结论5个检测系统测定A ST结果的精密度符合临床要求,临床可接受性能评价除检测系统4外均无可比性。应采取整改措施,保证结果的可比性。     

不同检测系统测定丙氨酸氨基转移酶结果的可比性研究

目的探讨不同检测系统丙氨酸氨基转移酶(ALT)测定结果的可比性.方法分别在3个检测系统酶法测定ALT朗道质控物(水平2和水平3)各20次和新鲜血清标本45份.结果朗道质控物和新鲜血清标本ALT测定经随机区组设计资料的方差分析,各检测系统间的总体差异均有显著性(P＜0.001).各检测系统新鲜血清标本ALT测定可靠性系数α为0.9981,各系统间的相关系数均大于0.975.各检测系统测定ALT的精密度变异系数均小于6.7%,以可溯源的检测系统1为目标检测系统,临床接受性能评价中检测系统2未超过而检测系统3超过T±10%允许范围.结论3个检测系统测定ALT结果的精密度符合临床要求,临床接受性能评价中检测系统3无可比性,需采取纠正措施,实现可比性.     

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.