何首乌有效成分二苯乙烯甙对神经细胞保护作用的机制

目的：观察2，3，5，4’-四羟基二苯乙烯-2-O-β-D-葡萄糖甙对两种拟痴呆细胞模型的作用，探讨何首乌主要有效成分二苯乙烯甙神经保护作用的机制。为阐明何首乌及以其为主要成分的中药复方的功效机制提供实验依据。方法：不同浓度二苯乙烯甙(5～400μmol／L)分别与SK-N-SH人神经母细胞瘤细胞共孵育6，24h，加人工具药β-amyloid25-35(终浓度25μmol／L)孵育24h或500μmol／L过氧化氢孵育2h。MTT法测定细胞存活率，细胞膜损伤测定乳酸脱氢酶漏出率(LDH％)。结果：①50～400μmol／L二苯乙烯甙与细胞预孵育6h可明显拮抗β-amyloid25-35引起的细胞存活率下降，随剂量增加，保护作用上升，至200μmol／L保护作用最强。200，400μmol／L二苯乙烯甙能拮抗β-amyloid25-35引起的细胞乳酸脱氢酶漏出率增高。5～200μmol／L二苯乙烯甙与细胞预孵育24h，可使β-amyloid25-35引起的细胞存活率下降恢复正常。200μmol／L二苯乙烯甙使β-amyloid25-35引起的细胞LDH％增多恢复正常。②5μmol／L二苯乙烯甙与细胞预孵育6h，即可明显拮抗过氧化氢引起的细胞存活率下降及LDH％增多[LDH％：(62．47&;#177;2．43)％；MTT(A)：0.1093&;#177;0.0074]，至200μmol／L保护作用最强[LDH％：(46．10&;#177;2．10)％；MTT(A)：0.2487&;#177;0.0283]。二苯乙烯甙与细胞预孵育24h，5～400μmol／L二苯乙烯甙均能拮抗过氧化氢引起的细胞存活率下降及LDH%增多(P&;lt;0.05)，呈明显剂量依赖关系，且各浓度保护作用均较药物预孵育6h增加，200μmol／L二苯乙烯甙组细胞存活率及LDH％基本恢复正常。结论：二苯乙烯甙对β-淀粉样蛋白和过氧化氢致神经细胞存活率下降及乳酸脱氢酶漏出增多有明显拮抗作用。二苯乙烯甙作为何首乌的主要有效成分对老年性痴呆等神经系统退性行疾病的防治有良好应用前景。     

何首乌有效成分二苯乙烯甙对神经细胞保护作用的机制

目的:观察2,3,5,4’-四羟基二苯乙烯-2-O-β-D-葡萄糖甙对两种拟痴呆细胞模型的作用,探讨何首乌主要有效成分二苯乙烯甙神经保护作用的机制,为阐明何首乌及以其为主要成分的中药复方的功效机制提供实验依据。方法:不同浓度二苯乙烯甙(5～400μmol/L)分别与SK-N-SH人神经母细胞瘤细胞共孵育6,24h,加入工具药β-amyloid25-35(终浓度25μmol/L)孵育24h或500μmol/L过氧化氢孵育2h。MTT法测定细胞存活率,细胞膜损伤测定乳酸脱氢酶漏出率(LDH%)。结果:①50～400μmol/L二苯乙烯甙与细胞预孵育6h可明显拮抗β-amyloid25-35引起的细胞存活率下降,随剂量增加,保护作用上升,至200μmol/L保护作用最强。200,400μmol/L二苯乙烯甙能拮抗β-amyloid25-35引起的细胞乳酸脱氢酶漏出率增高。5～200μmol/L二苯乙烯甙与细胞预孵育24h,可使β-amyloid25-35引起的细胞存活率下降恢复正常。200μmol/L二苯乙烯甙使β-amyloid25-35引起的细胞LDH%增多恢复正常。②5μmol/L二苯乙烯甙与细胞预孵育6h,即可明显拮抗过氧化氢引起的细胞存活率下降及LDH%增多犤LDH%:(62.47±2.43)%;MTT(A):0.1093±0.0074犦,至200μmol/L保护作用最强犤LDH%:(46.10±2.10)%;MTT(A):0.2487±0.0283犦。二苯乙烯甙与细胞预孵育24h,5～400μmol/L二苯     

LY367385对谷氨酸钠及缺糖缺氧引起的培养小鼠大脑皮层神经元损伤的保护作用

目的观察LY367385对谷氨酸钠(Glu)及缺糖缺氧(OGD)引起的小鼠大脑皮层神经元损伤的保护作用. 方法以细胞乳酸脱氢酶(LDH)漏出、光镜下细胞形态变化为指标,观察培养液中加入Glu或因OGD引起的神经元损伤,以及LY367385的保护作用;用免疫细胞化学和免疫荧光染色法检测神经元代谢型谷氨酸受体1α(mGluR1α)的表达.结果 OGD 1 h或0.1 mmol/L的Glu可明显造成神经元损伤,使LDH漏出明显增加( P<0.01);LY367385(50 μmol/L)可明显拮抗OGD或Glu引起的神经元损伤,使LDH漏出明显减少( P<0.01);免疫组化检测显示体外培养神经元mGluR1α阳性表达.结论 OGD或Glu可能通过激活皮层神经元mGluR1α引起神经元损伤,LY367385通过拮抗mGluR1α保护神经元.     

异丙酚对胚胎大鼠中脑神经细胞缺氧复氧损伤的影响

目的观察不同浓度异丙酚(Propofol)对大鼠胚胎中脑神经细胞缺氧损伤的保护作用。方法建立原代培养神经细胞缺氧损伤模型,形态学观察以及细胞存活率,测定乳酸脱氢酶(LDH)释放量、细胞内超氧化物歧化酶(SOD)和谷胱甘肽(GSH)活性、丙二醛(MDA)含量。结果异丙酚能明显改善缺氧损伤神经细胞的形态改变,提高细胞存活率,减少细胞内LDH的漏出,并可显著提高细胞内SOD活性,减少脂质过氧化产物MDA的产生。结论异丙酚对神经元缺氧损伤具有明显的保护作用。     

三七总皂甙对大鼠海马神经细胞凋亡的影响

目的:以原代培养的大鼠海马神经细胞缺氧/缺糖再给氧为模型,观察三七总皂甙对神经细胞凋亡的抑制作用。方法:流式细胞术检测凋亡细胞百分率,激光共聚焦扫描显微镜检测细胞内Ca2 浓度,荧光显微镜观察细胞形态学变化和坏死细胞百分率,同时,测定细胞LDH的释放。结果:神经细胞缺氧/缺糖5h后再给氧3h时,细胞凋亡百分率明显增高,为19.06%(P<0.01),细胞坏死百分率为6.83%(P<0.01),细胞内Ca2 浓度为169.32nmol/LCa2 浓度(P<0.01),LDH的释放率为27.63%(P<0.01);神经细胞缺氧/缺糖5h后再给氧24h时,细胞凋亡百分率为49.85%(P<0.01),细胞坏死百分率为11.49%(P<0.01),细胞内Ca2 浓度为298.11nmol/L(P<0.01),LDH的释放率为60.35%(P<0.01)。三七总皂甙(25,50mg/L)能降低神经细胞凋亡及坏死的百分率,降低细胞内Ca2 浓度,减少LDH的释放,三七总皂甙的作用随剂量增加而作用增加。结论:三七总皂甙对缺血再灌注损伤后海马神经元的凋亡过程具有抑制作用,这种作用可能与其能降低细胞内Ca2 浓度有关。     

栝楼桂枝颗粒抗缺血性脑卒中大鼠神经元及原代海马神经元凋亡研究

目的:观察栝楼桂枝颗粒(GLGZG)抗缺血性脑卒中大鼠神经元及原代海马神经元凋亡的作用,探讨其作用机制,为其治疗脑卒中提供依据。方法:建立谷氨酸诱导原代海马神经元兴奋性毒性损伤模型、大鼠脑缺血再灌注损伤模型,采用MTT、LDH法测定GLGZG对原代海马神经元细胞活性和LDH活性的影响,采用Western Blot、Real-time PCR检测GLGZG对原代海马神经元及大鼠海马组织中Caspase-3、Bcl-2、Bax m RNA及蛋白表达水平的影响。结果:用不同浓度(100μg/m L、200μg/m L、300μg/m L)的GLGZG分别作用于原代海马神经元24 h,3个剂量组细胞存活率较谷氨酸组细胞存活率升高,其中GLGZG 200μg/m L、300μg/m L 2组细胞活力显著升高(P0.05,P0.01);3个剂量组LDH活力较谷氨酸组显著降低,其中GLGZG 200μg/m L、300μg/m L 2组可显著抑制谷氨酸损伤神经元LDH的释放(P0.05,P0.01)。GLGZG 200μg/m L、300μg/m L 2组干预后,与谷氨酸组比较可显著降低原代海马神经元Caspase-3 m RNA、Bax m RNA的表达(P0.05,P0.01),升高Bcl-2 m RNA的表达(P0.05),蛋白表达的趋势与m RNA相似;GLGZG组与模型组比较,可降低大鼠海马组织Caspase-3、Bax蛋白的表达(P0.05或P0.01),升高Bcl-2蛋白的表达(P0.01)。结论:GLGZG对缺血性脑卒中大鼠及原代海马神经元有一定的保护作用,其保护作用与其抗细胞凋亡作用有关。     

蝙蝠葛苏林碱通过拮抗缓激肽诱导的胞内钙升高发挥神经保护作用

目的:研究蝙蝠葛苏林碱(DS)对缓激肽(BK)诱导神经细胞胞内钙升高的影响,并探讨其神经保护作用。方法:原代培养大鼠皮质神经元,应用BK(1μmol/L)诱导细胞内钙离子浓度升高;将细胞分为对照组,BK组,DS低、中、高剂量组;对照组不做任何处理,BK组给予1μmol/L的BK处理,DS低、中、高剂量组分别给予相应浓度(1×10~(-6)mol/L、1×10~(-5)mol/L、1×10~(-4)mol/L)的DS预孵育3 min,然后给予1μmol/L的BK处理。通过细胞内双波长荧光钙成像系统观察胞内游离钙离子的变化,采用MTT染色法检测神经元的损伤程度。结果:BK诱导可迅速升高原代培养大鼠皮质细胞内的钙离子水平。DS干预可部分逆转BK对胞内钙离子升高的影响(P0.05)。MTT结果显示,BK组神经元存活率明显低于对照组(P0.05);DS低、中、高剂量组的存活率均高于BK组(P0.05)。结论:DS可拮抗缓激肽诱导的细胞内钙升高,对胞内钙紊乱所致的神经细胞损伤具有一定保护作用。     

莫诺苷抑制过氧化氢诱导的SH-SY5Y神经细胞钙超载和细胞毒

目的 研究莫诺苷抑制过氧化氧诱导的SH-SY5Y神经细胞钙超载和细胞毒作用.方法 体外培养的人神经母细胞瘤细胞系SH-SY5Y细胞分别加入莫诺苷1μmol/L、10μmol/L、100 μmol/L预孵育24 h,加入H2 O2 300～500 μmol/L,作用18 h,检测细胞内游离钙离子浓度、乳酸脱氢酶(LDH)释放率.结果 与未加莫诺苷预孵育的细胞相比,莫诺苷10μmol/L、100μmol/L能抑制神经细胞内游离钙离子浓度增加,莫诺苷1μmol/L、10μmol/L、100 μmol/L能降低LDH的释放率.结论 莫诺苷能够抑制H2O2诱导的SH-SY5Y神经细胞钙超载和细胞毒,有神经保护作用.     

参麦注射液对大鼠海马神经细胞凋亡的影响

目的以缺氧/缺糖再给氧为模型,观察参麦注射液对神经细胞凋亡的抑制作用。方法流式细胞术检测凋亡细胞百分率,激光共聚焦扫描显微镜检测细胞内Ca2+浓度,荧光显微镜观察细胞形态学变化和坏死百分率。结果缺氧/缺糖5h后再给氧可诱导神经细胞凋亡和细胞坏死,并显著增加细胞内Ca2+浓度和LDH的释放。与对照组相比有显著性差异(P<0.01)参麦注射液能显著降低神经细胞凋亡及坏死的百分率,降低细胞内Ca2+浓度,减少LDH的释放,其作用随剂量增加而增加。结论参麦注射液具有拮抗海马神经细胞凋亡的作用,这种作用可能与其能降低细胞内Ca2+浓度有关。     

吡咯喹啉醌对NMDA诱发大鼠海马神经元损伤的影响

目的探讨吡咯喹啉醌（PQQ）对N-甲基-D-天冬氨酸（NMDA）诱发海马神经元损伤的影响。方法体外原代培养新生大鼠海马神经元，毒性剂量的NMDA诱致海马神经元损伤，预加PQQ，镜下观察神经元的形态变化，琼脂糖凝胶电泳观察细胞的死亡情况，激光共聚焦显微镜观察细胞内Ca^2＋浓度的变化。结果体外培养8d的海马神经用0．1mmol／LNMDA处理后，细胞内Ca^2＋快速增加，细胞以坏死和凋亡两种形式死亡，细胞的存活率降低；预先给予PQQ可明显减少细胞内Ca^2＋的增加，减少细胞死亡。结论PQQ对NMDA诱发的海马神经元损伤具有保护作用。     

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.