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。     

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。     

毛细管电泳-激光诱导荧光法分离四种神经递质类氨基酸的条件优化

目的探讨毛细管电泳分离神经递质类氨基酸的影响因素。方法采用毛细管电泳法分离4种神经递质类氨基酸的荧光素异硫氰酸酯(FITC-AAs)衍生物,分析电泳缓冲液、表面活性剂以及衍生条件对分离的影响。结果电泳缓冲液的组成、浓度、pH值、表面活性剂以及衍生条件对4种FITC-AA衍生物分离有很大影响,在以75 mm ol/L,pH 9.42硼酸盐含100 mm ol/LSDS为电泳缓冲液,50 mmol/LpH 9.8硼酸盐为衍生缓冲液,4种FITC-AA衍生物20 min内得到很好分离。结论通过条件优化,毛细管电泳-激光诱导荧光技术分离神经递质类氨基酸的分离效果能得到很大提高。     

RP-HPLC-荧光法测定大鼠海马组织中5种氨基酸类神经递质

目的采用反相高效液相色谱(RP-HPLC)-荧光检测技术建立一种用于测定脑海马组织中5种氨基酸[天门冬氨酸(Asp)、谷氨酸(Glu)、天冬酰胺(Aspa)、谷胺酰胺(Gln)、甘氨酸(Gly)]类神经递质的方法。方法采用甲醇∶水=1∶1提取大鼠脑海马组织中多种氨基酸类神经递质。用6-氨基喹啉基-N-羟基-琥珀酰亚胺氨基甲酸酯(AQC)柱前衍生RP-HPLC-荧光法测定海马组织中Asp、Glu、Aspa、Gln、Gly含量。结果 5种氨基酸类神经递质在15 min内完全分离,分离效果良好;在0.5~100.0μg/μL范围有较好的线性关系,相关系数(r)≥0.999 90;Asp、Glu、Aspa、Gln、Gly的检出限分别为0.05、0.068、0.037、0.05、0.02μg/μL。精密度[相对标准偏差(RSD)]为0.4%~2.5%,加样回收率为70.27%~128.20%,RSD均5%;8只正常大鼠海马组织中Asp、Glu、Aspa、Gln、Gly含量分别为38.98±9.66、126.42±34.06、216.00±0.75、90.44±33.75、(12.95±4.42)μg/g。结论 RP-HPLC-荧光法快速、准确、灵敏度高,适用于脑组织中氨基酸类神经递质含量的测定。     

高效液相色谱法快速测定氨基酸类神经递质

目的建立一种同时快速测定大鼠纹状体中谷氨酸(G lu)、天冬氨酸(Asp)、γ-氨基丁酸(GABA)、甘氨酸(G ly)、牛磺酸(Tau)5种氨基酸类神经递质的高效液相色谱法。方法采用Krom asil C18(4.6×250 mm,5μm)为色谱柱,丹酰氯为柱前衍生试剂,以曲唑酮为内标,以0.1 mol/L醋酸钠缓冲液∶甲醇=58∶42、14 mmol/L庚烷磺酸钠为流动相等度洗脱。结果在1~200 mg/L范围内,各组分线性关系良好(r=0.999)。各氨基酸的平均回收率为79.1%~92.9%。结论本方法简便、快速、准确,可用于临床大样本测定和研究神经及精神疾病氨基酸类神经递质的改变。     

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.     

持续性植物状态患者意识状态与氨基酸类神经递质水平的关系

目的:应用高效液相色谱分析法检测持续性植物状态(persistentvegetativestate,PVS)患者脑脊液中氨基酸类神经递质,观察其与临床表现的相关性。方法:46例PVS患者按照PVS评分的不同分为3组,与20例对照患者同期采集脑脊液,分别检测天冬氨酸、谷氨酸、甘氨酸、丙氨酸的含量。结果:在该实验条件下,4种氨基酸在25min内得以较好分离。对照组4种氨基酸含量分别为:(3.54±1.02),(3.12±0.87),(14.9±3.23),(16.2±4.35)mmo/L。PVS组4种递质水平均高于对照组,且递质水平与PVS评分呈负相关,PVS评分<6分组4种氨基酸含量分别为:(7.92±2.40),(5.80±1.34),(33.80±7.60),(45.70±9.51)mmo/L,与对照组的差异有统计学意义(P<0.01)。结论:PVS患者脑脊液中氨基酸类神经递质与临床表现有一定的相关性。     

高效液相色谱-荧光检测法快速测定脊髓和脑内氨基酸

目的建立快速测定脊髓和脑内氨基酸浓度的方法。方法通过邻苯二甲醛和β-巯基乙醇柱前衍生、反相高效液相色谱结合荧光(激发波长280nm,发射波长340nm)检测氨基酸浓度。用0.1mol/L磷酸盐缓冲液(pH值6.00~6.25)和甲醇(46%)混合液(加入四氢呋喃2%)作流动相,流速为1ml/min。结果在0.1~40.0μmol/L范围内,氨基酸浓度与相对峰面积之间的相关系数(r)均值为0.9992,日内和日间变异系数(CV)分别为2.41%~5.23%、3.51%~6.48%,平均回收率为90.13%~98.47%。结论本法灵敏度高、快速、简便易行,可用于脊髓和脑内氨基酸测定。     

混合型固相萃取技术及毛细管电泳检测血浆和尿液中4种喹诺酮类药物

目的建立固相萃取及毛细管电泳法快速检测血浆和尿液中喹诺酮类药物洛美沙星、加替沙星、环丙沙星和氧氟沙星的方法。方法毛细管为熔融石英毛细管(75/365μm,40/47cm),运行缓冲液为40mmol/L硼砂缓冲液(pH 9.0),电压13kV,柱温为20℃,检测波长280nm。样品经固相萃取后进样分析。结果 4种喹诺酮类药物在6min内完全分离。在1~40μg/mL浓度范围内,洛美沙星、加替沙星、环丙沙星和氧氟沙星峰面积和浓度的线性关系良好,相关系数r分别为0.998 7、0.997 6、0.998 3和0.994 2。尿液和血浆中4种喹诺酮类药物加标回收率为80.1%~107.6%,精密度相对标准差(RSD)为2.1%~6.2%。结论该方法具有快速、简便、准确度和精密度高等特点,适用于血浆和尿液中洛美沙星、加替沙星、环丙沙星和氧氟沙星水平的快速检测。     

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.