三氧化二砷对肝癌细胞株HLE的细胞毒和诱导凋亡作用

目的：研究As2O3对肝癌细胞株HLE细胞毒和诱导凋亡作用。方法：应用MTT染色，流式细胞仪和电子显微镜观察As2O3对HLE细胞株的诱导凋亡作用和形态学改变，应用共聚焦激光扫描显微镜(CLSM)测试肝癌细胞内[Ca^2 ]i变化。结果：As2O3对肝癌细胞株HLE具有诱导凋亡作用，CLSM检测肝癌细胞内[Ca^2 ]i高浓度As2O3作用下48h达最高峰；在低浓度下96h达高峰。结论：As2O3对肝癌细胞具有较强的细胞毒和诱导细胞凋亡的作用。     

As2O3对乳腺癌细胞系MDA—MB-435s作用的研究

目的：探讨不同浓度三氧化二砷（As2O3）对人乳腺癌细胞系MDA—MB-435s的生长抑制作用及其机理。方法：不同浓度As2O3作用于体外培养细胞MDA—MB-435s，采用MTT法检测细胞生长，倒置显微镜观察细胞形态，并通过DNA梯状电泳和TUNEL检测凋亡。结果：As2O3剂量依赖性抑制细胞生长；观察到典型的细胞凋亡形态学特征性改变；琼脂糖凝胶电泳呈现凋亡DNA梯状条带；As2O3作用组的凋亡指数明显高于阴性对照组（P〈0．05）。结论：As2O3具有抑制乳腺癌MDA—MB-435s细胞生长的作用，其机理与诱导细胞凋亡有关。     

三氧化二砷诱导淋巴瘤Raji细胞凋亡与细胞周期阻滞

本研究探讨研究三氧化二砷（As2O3）对人淋巴瘤Raji细胞株凋亡诱导的作用特点及其机制。用MTT比色法观察不同浓度As2O3对Raji细胞的增殖抑制效应，电子显微镜观察不同浓度As2O3作用不同时间后细胞的凋亡形态，DNA-ladder琼脂糖凝胶电泳观察凋亡条带，流式细胞术检测Raji细胞凋亡、细胞周期分布。结果表明：1—8μmol／LAs2O3能明显抑制Raji细胞的活力，并存在一定的量效、时效关系。2—8μmol／L浓度的As2O3可以诱导Raji细胞周期阻滞及凋亡，而1μmol／LAs2O3不诱导细胞凋亡，只是通过细胞周期阻滞作用抑制细胞增殖。结论一定浓度三氧化二砷可以抑制Raji细胞的增殖，阻滞细胞周期，诱导细胞凋亡。细胞周期阻滞伴随细胞凋亡而发生。     

三氧化二砷对Burkitt淋巴瘤细胞株Raji凋亡的诱导作用及C-myc表达的影响

目的 探讨三氧化二砷(As2O3)对Burkitt淋巴瘤细胞袜Raji凋亡的诱导作用及C-myc表这的影响.方法 通过噻唑蓝比色法检测观察As2 O3对Raji细胞增殖的影响,流式细胞仪观察As2O3对Raji细胞凋亡的诱导作用,逆转录聚合酶链式反应(RT-PCR)法检测As2O3对C-myc mRNA表达的影响.结果 As2O3对Raji细胞生长有抑制作用,呈剂量和时间依赖关系(P＜0.01);As2O3对Raji细胞有诱导凋亡作用,呈剂量和时间依赖关系(P＜0.01);随着As2O3浓度升高,C-myc的表达水平明显下降(P＜0.01).结论 As2O3对Burkitt淋巴瘤细胞株Raji具有增殖抑制和诱导凋亡作用,其作用机制可能与C-myc表达水平明显下降有关.     

雌激素通过NF-κB信号通路影响肝癌细胞的肿瘤学行为研究

目的探讨雌激素对HepG2和BEL7402两种肝癌细胞增殖及迁移能力的抑制和诱导凋亡的作用及其相应机制。方法利用MTS试验检测不同浓度的雌激素在不同时间点对HepG2和BEL7402两种肝癌细胞增殖能力的影响。Annexin V/PI流式细胞术检测不同浓度的雌激素诱导HepG2和BEL7402细胞凋亡的情况。Transwell迁移实验检测雌激素对HepG2和BEL7402细胞迁移能力的影响。采用Western blotting法检测不同浓度下雌激素对肝癌细胞中NF-κB信号通路的活性及其下游相关基因c-Myc、Cyclin D1、基质金属蛋白酶(MMP-9)、血管内皮生长因子(VEGF)和Bcl-2表达的影响。结果 MTS试验结果显示,在不同时间点雌激素有效抑制了HepG2和BEL7402细胞的增殖,并随着雌激素浓度的升高其抑制肝癌细胞增殖的效果逐渐增强,与此同时,雌激素也降低了c-Myc、Cyclin D1等增殖相关基因的表达。Annexin V/PI流式细胞术数据显示雌激素诱导HepG2和BEL7402细胞的凋亡并呈明显剂量依赖性,而抗凋亡蛋白Bcl-2的表达出现下降。Transwell迁移实验证明雌激素明显抑制了HepG2和BEL7402细胞的迁移能力并且降低了MMP-9和VEGF的表达。验证了雌激素可有效抑制HepG2和BEL7402肝癌细胞中NF-κB信号通路的活性。结论雌激素通过下调NF-κB信号通路的活性及下游相关分子的表达,而抑制肝癌细胞的增殖与迁移并诱导其凋亡。     

三氧化二砷与顺铂联用对肝癌HepG2细胞的作用

目的：探讨三氧化二砷（As2O3）与顺铂（CDDP）联合对肝癌细胞HepG2的作用。方法：应用普通光学显微镜、荧光显微镜、流式细胞仪分别观察As2O3、CDDP和两者联合应用时对HepG2细胞株的形态学改变和诱发凋亡率。结果：AO／EB荧光染色法显示在联合应用药物后,可看到较典型的细胞凋亡形态学改变。噻唑蓝（MTT）法检测各个浓度的As2O3与CDDP联合应用时,对HepG2细胞的生长抑制率均较单用相应一种药物时增强,而低浓度联合用药组合的生长抑制率增加尤为明显。结论：在体外Aa2O3和CDDP两种化疗药物联合应用具有明显的协同抗肝癌作用,显著抑制人肝癌细胞HepG2的细胞株的生长,并且具有明显的剂量时效关系。两药联用有显著的协同诱导肝癌细胞凋亡的作用。     

三氧化二砷对类风湿性关节炎滑膜细胞凋亡影响的体外研究

目的 类风湿性关节炎(Rheumatoid arthrithis,RA)滑膜细胞体外原代培养并传代至第三代,定量分析三氧化二砷(arsenic trioxide,As2O3)对滑膜细胞凋亡诱导作用.方法 双酶消化法体外传代人关节滑膜细胞.采用3代滑膜细胞;应用MTT、流式细胞术对BA滑膜细胞凋亡进行分析.结果 ①MTT法显示不同浓度的As203作用48 h后,能够抑制BA滑膜细胞增殖,且在10～80 μmol/L浓度范围内其抑制作用呈剂量依赖性.②流式细胞仪检测发现不同浓度的As2O3作用48 h后,RA滑膜细胞发生不同比率凋亡,并且在10～80 μmol/L浓度范围内其作用呈剂量依赖性.结论 不同浓度的As2O3作用48 h后RA滑膜细胞均发生凋亡并且呈剂量依赖性.     

As2O3对KM3细胞端粒酶及其逆转录酶作用的研究

为了探讨三氧化二砷(As2O3)对多发性骨髓瘤(MM)细胞株KM3的作用及其可能机制，用台盼蓝拒染法检测细胞生长抑制率，用光镜、透射电镜观察形态变化，用DNA电泳观察As2O3诱导KM3细胞凋亡，用流式细胞仪检测细胞周期的变化，用TRAP-PCR-EUSA法检测As2O3作用KM3细胞后的端粒酶活性变化，并用半定量RT-PCR法检测端粒酶逆转录酶(hTERTmRNA)的表达水平。结果表明：As2O3抑制KM3细胞的生长，具有诱导细胞凋亡的作用；As2O3阻滞细胞于G2期；As2O3可抑制KM3细胞的端粒酶活性和hTERTmRNA的表达，且hTERTmRNA下降趋势与端粒酶活性相一致。结论：端粒酶及其逆转录酶活性的下调可能在As2O3诱导KM3细胞凋亡的过程中起了重要作用。     

重组TRAIL对2种不同癌株凋亡效应的研究

目的观察重组TRAIL对7402肝癌细胞和HeLa宫颈癌细胞的抑癌活性。方法采用MTT法和AnnexinV-FITC法及流式细胞仪技术测定重组TRAIL对7402肝癌细胞和HeLa宫颈癌细胞的抑制活性。结果 MTT和流式细胞仪检测结果显示,重组TRAIL在体外可抑制7402肝癌细胞的生长,凋亡率可达31%,而对HeLa宫颈癌细胞无明显抑制作用。结论不同癌株对TRAIL的敏感性不同,7402肝癌细胞对TRAIL非常敏感,可为后续肿瘤治疗提供更多的实证材料。     

三氧化二砷诱导急性淋巴细胞性白血病细胞系凋亡

目的：了解三氧化二砷（As2O3）对急性淋巴细胞性白血病细胞系的可能作用。方法：以急性淋巴细胞性白血病细胞系MOLT－4为体外模型,在观察As2O3对细胞生长、活力及形态学影响的基础上,应用流式细胞仪检测细胞DNA含量分布,以评判细胞凋亡与否。结果：As2O3抑制MOLT－4细胞的生长呈浓度依赖性,1.0μmol／L,的As2O3诱导MOLT－4细胞凋亡。结论：As2O3能有效地诱导急性淋巴细胞性白血病细胞系调亡．并可能为As2O3在临床上治疗此类患者提供理论依据。     

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.