高效毛细管电泳测定海马组织和脑脊液中氨基酸类神经递质

目的建立测定大鼠海马组织和人脑脊液中氨基酸类神经递质的高效毛细管电泳分析方法。方法用高效毛细管电泳技术,选用总长60 cm、有效长度50.5 cm、直径75μm熔融石英毛细管,在20 kV电压下快速分离4种氨基酸。以100 mmol/L硼酸-三羟甲基氨基甲烷（Tris）（1∶1,含1%异丙醇）为电泳缓冲液（pH值为10.35）,激光诱导荧光检测器进行检测,并对此方法进行方法学评价。同时检测45例患者脑脊液的氨基酸含量。结果谷氨酸（GLU）、天冬氨酸（ASP）、γ-氨基丁酸（GABA）、甘氨酸（GLY）4种氨基酸能在15 min内分离,线性范围为1.0~100.0μmol/L,GLU、ASP、GABA、GLY最低检出限分别为10、23、18、15 nmol/L,4种氨基酸的批内精密度范围4.44%~9.72%,批间精密度范围6.96%~10.50%。4种氨基酸的回收率不低于88.1%。全面性大发作癫痫患者GLU、GLY、ASP含量显著高于对照组（P〈0.05）,而GABA较对照组差异无统计学意义;复杂部分性发作癫痫患者4种氨基酸含量较对照组显著增加（P〈0.05）。结论高效毛细管电泳具有快速、灵敏、准确的特点,为临床和科研提供了一种有效的方法。     

高效毛细管电泳法快速测定血清中游离氨基酸

目的 建立快速测定人血清中游离氨基酸的方法.方法 用高效毛细管电泳法对40例健康体检者及32例肾病患者血清氨基酸进行检测.结果 8 min内分离16种氨基酸,线性范围在10～700 μmol/L,最低检出限为2.5～7.9 μmol/L,回收率86.3%～107.4%,批内精密度2.8%～10.3%,批间精密度3.5%～11.6%.对32例肾脏病患者血清中氨基酸测定结果与40例健康对照组氨基酸测定结果进行统计学分析.结论 高效毛细管电泳法具有快速、准确、灵敏等特点,为临床及科研工作中测定氨基酸提供了一种有效的方法.     

脑梗塞患者脑脊液兴奋性氨基酸含量的测定及意义

近年许多研究发现,脑缺血时兴奋性氨基酸(EAAS)明显增高,其在神经元缺血损伤中起重要作用。本文应用高效液相色谱法测定了脑梗塞患者和对照组脑脊液兴奋性氨基酸:谷氨酸(GLU)、天门冬氨酸(ASP)和抑制性神经递质γ—氨基丁酸(GABA)水平。探讨其变化规律及在脑梗塞中的临床意义。     

毛细管电泳分离脑脊液中神经递质类氨基酸及其临床应用

目的建立快速测定人脑脊液中神经递质类氨基酸的方法。方法用高效毛细管电泳-激光诱导荧光法检测了40例正常脑脊液、38例病毒性脑炎病人脑脊液、42例脑出血病人脑脊液神经递质类氨基酸。结果在20 min内分离出4种氨基酸,线性范围为0.1~50μmol/L,峰的迁移时间RSD 0.56%~2.06%,峰面积RSD 2.24%~3.79%;回收率为98%以上。结论高效毛细管电泳-激光诱导荧光法具有快速、准确、灵敏的特点,可作为临床检测脑脊液标本中的神经递质类氨基酸的方法。     

毛细管电泳测定肝癌肝硬化患者血清氨基酸的临床意义

目的　用毛细管电泳的方法测定肝癌肝硬化患者血清氨基酸变化,并探讨其临床意义。方法　用P/ACEMDQ毛细管电泳仪对2 0例正常人、2 0例肝癌患者及2 0例肝硬化患者的血浆游离氨基酸进行测定。结果　在9min内分离12种氨基酸,线性在2 0～10 0 0 μmol/L范围,回收率为77. 5 %～113 .3% ,批内精密度2 . 6 %～11. 4 % ,批间精密度5 . 8%～19. 7%。对结果进行统计学分析,发现肝硬化组酪氨酸、丝氨酸、色氨酸明显升高,丙氨酸明显下降;肝癌组酪氨酸、半胱氨酸、缬氨酸明显升高,脯氨酸明显下降。结论　毛细管电泳测定血浆游离氨基酸对肝癌肝硬化的诊断和治疗有指导意义。     

高效毛细管电泳法快速测定血清中游离氨基酸

目的建立快速测定人血清中游离氨基酸的方法。方法用高效毛细管电泳法检测了４０例健康人，３２例肾病患者血清氨基酸。结果在８分钟内分离１６种氨基酸，线性在１０～７００μｍｏｌ／Ｌ范围，最低检出限为２．５～７．９μｍｏｌ／Ｌ，回收率为８６３％～１０７．４％，批内精密度为２．８％～１０．３％，批间精密度为３．５％～１１．６％。对３２例肾脏病患者血清中氨基酸测定结果与４０例正常人对照组氨基酸测定值进行统计分析。结论高效毛细管电泳法具有快速、准确、灵敏等特点，为临床及科研工作中测定氨基酸提供了一种有效的方法     

AQC柱前衍生RP-HPLC荧光法测定颅脑损伤患者脑脊液中氨基酸类神经递质

目的:探讨反相高效液相色谱(RP-HPLC)荧光法检测脑脊液中氨基酸类神经递质的方法,观察急性颅脑损伤患者脑脊液中氨基酸类神经递质的变化。方法:运用AQC柱前衍生RP-HPLC荧光法,分别检测15例颅脑损伤患者(颅脑损伤组)及15例对照组患者脑脊液中天冬氨酸(Asp)、谷氨酸(Glu)及γ-氨基丁酸(GABA)递质水平,并进行AQC柱前衍生RP-HPLC方法学考察。结果:本实验条件下,Asp、Glu及GABA3种氨基酸在35min得以较好分离,峰面积与氨基酸浓度的线性关系良好,具有较好的精确性,是一种方便、稳定、可靠的检测方法。颅脑损伤组患者脑脊液Asp、Glu水平明显高于正常对照组(P0.01),GABA水平低于正常对照组(P0.05)。结论:RP-HPLC法是检测脑脊液中氨基酸类神经递质的简便方法,准确度高;颅脑损伤患者脑脊液中Asp、Glu水平显著升高,GABA水平降低。     

高效毛细管电泳法在血清氨甲蝶呤浓度检测中的应用

目的建立快速检测人血清中氨甲蝶呤药物浓度的方法。方法用高效毛细管电泳技术，选用直径75μm，总长60cm，有效长度50．5cm熔融石英毛细管，以75mmoL／L，pH7．4的磷酸盐为电泳缓冲液，检测波长为306nm，在25kV电压下的快速分离检测氨甲蝶呤，并对此方法进行方法学评价。结果氨甲蝶呤的出峰时间在10min内，线性范围在1.1—1100．0μmol／L间，最低检出浓度为0．55μmoL／L，回收率为88．2％-98．2％，批间精密度为5．4％，批内精密度为4．2％。结论高效毛细管电泳方法具有快速、准确且成本低的特点，为临床和科研中测定血清氨甲蝶呤提供了一种有效的手段。     

毛细管电泳法检测糖化血红蛋白的分析性能评估

目的评估毛细管电泳(CE)法检测糖化血红蛋白(Hb A1c)的精密度、正确度、线性和抗干扰性,并与高效液相色谱法(HPLC)进行比对。方法根据不同的评估内容,收集相应样本,分别使用SEBIA CAPILLARYSTM2 Flex Piercing毛细管电泳仪(毛细管电泳法)、ARKRAY HA-8160全自动Hb A1c分析仪(HPLC)和IFCC参考方法检测Hb A1c。采用SPSS 19.0软件进行统计描述及线性回归模型分析。结果毛细管电泳法检测Hb A1c在常见浓度(4.91%~9.67%)下的不精密度均2%;与IFCC参考方法,相关程度较好(R2=0.993);当Hb A1c浓度为5.0%~17.6%时,毛细管电泳法具有良好的线性(R2=0.995),对氨甲酰化血红蛋白、不稳定Hb A1c、胆红素、乳糜微粒等具有较好的抗干扰能力(绝对偏倚≤0.5%)。毛细管电泳法Hb A1c的测定值与HPLC具有较好的相关性(R2=0.993)。结论毛细管电泳法的精密度、正确度、线性和抗干扰性等分析性能均符合临床实验室常规检测Hb A1c的要求。     

两种糖化血红蛋白分析方法的评价

目的对离子交换高压液相层析法与金标免疫渗滤法检测糖化血红蛋白进行方法学分析。方法用离子交换高压液相层析法(X)和金标免疫渗滤法(Y)测定糖化血红蛋白进行线性范围、回收率、精密度、干扰因素、相关性及参考范围的分析。结果离子交换高效液相色谱法(HPLC法)与金标免疫渗滤法(金标法)的线性范围分别为4.3%~17.0%和3.6%~12.5%,两种方法的回收率均为101.3%,批内、批间的变异系数(CV)均<5%;10.2%mmol/L三酰甘油、684μmol/L总胆红素和HbF对两种方法均无干扰。金标法测定糖化血红蛋白的结果较HPLC法明显偏低(P<0.01);回归方程Y=0.89X 0.24(r=0.94,P<0.01);HPLC法与金标法的参考范围分别为4.2%~6.7%和4.1%~6.4%。结论金标法与HPLC法相比,糖化血红蛋白检测结果明显偏低。     

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.     

Guns and Knives in New Mexico: Patterns of Penetrating Trauma, 1978–1993

Objective: To identify patterns of nonfatal and fatal penetrating trauma among children and adults in New Mexico using ED and medical examiner data.
Methods: The authors retrospectively sampled in 5-year intervals all victims of penetrating trauma who presented to either the state Level-1 trauma center or the state medical examiner from a 16-year period (1978–1993). Rates of nonfatal and fatal firearm and stabbing injury were compared for children and adults.
Results: Rates of nonfatal injury were similar (firearm, 34.3 per 100,000 person-years; stabbing, 35.1). However, rates of fatal injury were significantly different (firearm, 21.9; stabbing, 2.7; relative risk: 8.2; 95% confidence interval: 5.4, 12.5). From 1978 to 1993, nonfatal injury rates increased for children (p = 0.0043) and adults (p < 0.0001), while fatal penetrating injury remained constant. The increase in nonfatal injury in children resulted from increased firearm injury rates. In adults, both stabbing and firearm nonfatal injury rates increased.
Conclusions: Nonfatal injury data suggest that nonfatal violence has increased; fatal injury data suggest that violent death rates have remained constant. Injury patterns vary by age, mechanism of trauma, and data source. These results suggest that ED and medical examiner data differ and that both are needed to guide injury prevention programs.