乌司他丁对心肺转流心脏手术器官保护的临床研究

目的：研究乌司他丁对心肺转流（CPB）心脏手术中缺血一再灌注损伤的器官保护作用。方法：择期CPB心内直视手术20例随机均分为乌司他丁组（U组）和对照组（C组）。U组分别于阻断主动前和开放主动脉后给予乌司他丁各5000μ／kg，C组同时段给予生理盐水，分别于麻醉诱导，阻断主动脉30min，开放主动脉30min，开放主动脉1h，开放主动脉2h采集静脉血，用ELISA法测定样本中肿瘤坏死因子-α（TNF—α），白细胞介素-6（IL-6），白细胞介素-8（IL-8）的水平。结果：两组中各项指标在麻醉诱导期无显著差异（P〉0．05）；两组中各项指标在阻断主动脉30min，开放主动脉30min、1h、2h与麻醉诱导期比较有明显增加（P〈0．05和P〈0．01）；U组中血浆TNF-α、IL-6、IL-8的浓度在阻断主动脉30min，开放主动脉30min，1h、2h与C组比较有显著差异（P〈0．05）。结论：乌司他丁能抑制机体炎症反应，减轻缺血一再灌注损伤，从而达到保护重要脏器的作用，但不能完全阻断炎症反应所致的中性粒细胞增加。     

体外循环小猪心肌缺血再灌注损伤模型c-fos的表达及对细胞凋亡的影响

目的研究c-fos蛋白在心肌缺血再灌注损伤发病机制中的作用及其作为心肌损伤预测指标的可行性。方法五指山小型香猪共8头,随机分成假手术组(S组,n=3)与体外循环组(C组,n=5)。建立小型香猪体外循环动物模型后,假手术组只插管不转机,C组主动脉阻断60 min,复灌180 min,处死动物取材,透射电镜观察心肌超微结构改变,TUNNEL法检测心肌凋亡,并计算凋亡指数(AI),Western blotting检测c-fos在心肌中的表达。结果 C组心肌线粒体评分明显差于S组(2.4±0.45 vs.4.2±0.62,P<0.05)。C组AI明显高于S组(13.11±1.22 vs.1.67±0.19,P<0.05)。C组心肌c-fos表达含量较S组明显上升(7.16±1.11 vs.1.00±0.14,P<0.01)。缺血再灌注损伤的心肌c-fos含量与线粒体评分呈负相关关系(r=-0.79,P<0.01)。结论 c-fos参与了心肌缺血再灌注损伤,可作为心肌损伤的预测指标。     

乌司他丁减轻体外循环肺损伤的临床研究

目的:在临床应用中探讨乌司他丁对体外循环(CPB)后机体细胞因子水平的影响及肺损伤的抑制作用。方法:随机选30例接受CPB患者,分乌司他丁组(U组)和对照组(C组)。在5个时间点检测TNF-α、IL-6和GE,并计算相应的呼吸指数,分别为麻醉后CPB前(T1)、主动脉阻断后30min(T2)、主动脉开放后60min(T3)、120min(T4)、180min(T5)。结果:CPB后各时间点两组病人的指标较基础值(T1)差异有显著性(P<0.01),U组CPB后各时间点细胞因子水平比C组明显下降(P<0.05),而呼吸指数与CPB前无明显差异。结论:乌司他丁能下调体外循环后TNF-α、IL-6、GE水平,减轻CPB后肺损伤,保护肺功能。     

脱中性粒细胞温血心脏停搏液连续灌注在心脏手术中心肌保护的研究

目的 :研究体外循环期间常温血脱中性粒细胞心脏停搏液微流量连续灌注对心脏瓣膜置换术中心肌的保护作用。方法 :临床随机选取体外循环时间在 60min以上的风湿性心脏瓣膜病人 2 0例 ,随机分为实验组和对照组 (每组 10例 ) ,分别检测不同时间点血浆心肌肌钙蛋白I(cTnI)水平和血浆MDA水平的变化。结果 :①两组病人在CPB前cTnI含量组间差异无显著性 ,而在主动脉阻断后及主动脉开放后各时间点差异显著 ,对照组cTnI值高于实验组 (P <0 .0 5 ) ;②两组病人在体外循环前及主动脉阻断 3 0min时MDA的含量组间差异无显著性 ,而在主动脉开放各时间点组间差异具有显著性 (P <0 .0 5 ) ,对照组高于实验组。结论 :实验研究证实 ,脱除心脏停搏液中的中性粒细胞后 ,可减轻中性粒细胞介导的心肌损伤 ,有利于心肌保护     

多次缺血预处理对兔脊髓缺血性损伤后脊髓功能和形态学的影响

目的观察多次缺血预处理(IPC)对兔脊髓缺血再灌注损伤的保护作用。方法24只日本大白兔随机分为假手术组(A组)、缺血再灌注组(B组)和IPC保护组(C组),各组均为8只。A组不阻断主动脉,B组左肾下阻断主动脉45min,C组左肾下阻断主动脉5min,开放5min,反复4次后再阻断主动脉45min。术后进行后肢神经功能评分和针电极肌电图(EMG)的描记及脊髓组织形态学改变的观察。结果B组同A、C组相比,后肢EMG亦有显著性病理改变(P<0.01)。结论多次IPC对家兔脊髓缺血再灌注损伤具有快速保护作用。     

氯胺酮预处理对兔脊髓缺血性损伤的保护作用

目的观察氯胺酮预处理对兔脊髓缺血再灌注损伤的保护作用。方法24只日本大白兔随机分为假手术组(A组)、缺血再灌注组(B组)和氯胺酮预处理组(C组),各组均为8只。A组不阻断主动脉,B组左肾下阻断主动脉45min,C组左肾下阻断主动脉前10min及开放后即刻静推氯胺酮30mg·kg-1。术后进行后肢神经功能评分和针电极肌电图(EMG)的描记及脊髓形态学改变的观察。结果B组分别同A、C组相比,神经功能和病理学评分均显著性偏低(P<0.01),且同C组相比,后肢EMG亦有显著性病理改变(P<0.01)。C组1只动物发生迟发性瘫痪。结论氯胺酮预处理对家兔脊髓缺血再灌注损伤具有一定的保护作用。     

大鼠小肠淤血再灌注损伤的实验研究

目的研究淤血后再灌注对大鼠小肠的损伤作用及对肠组织丙二醛(MDA)含量和髓过氧化物酶(MPO)活性的影响。方法SD大鼠20只,雌雄各半,采用阻断门静脉60min开放60min的方法建立大鼠小肠淤血再灌注模型;于小肠淤血前、淤血60min和再灌注60min时分别取末段回肠标本,观察和比较各时间点小肠黏膜的损伤情况,同时测定肠组织中MDA含量利MPO活性的变化。结果①淤血前肠黏膜基本正常,淤血60min后肠黏膜山现损伤,但组织中MDA含量及MPO活性与淤血前相比无明显变化;②再灌注60min后肠黏膜损伤较淤血60min时进一步加重,且组织中MDA含量及MPO活性亦显著增高。结论肠道组织在一定时间淤血后血流再灌注情况下可出现淤血再灌注损伤;脂质过氧化损伤及中性粒细胞(PMN)浸润可能是参与肠组织淤血再灌注损伤的重要因素。     

小肠淤血再灌注损伤的初步实验研究

目的研究淤血再灌注对大鼠小肠的损伤作用。方法SD大鼠20只,采用阻断门静脉60 min开放60 min的方法建立大鼠小肠淤血再灌注模型;于小肠淤血前、淤血60 min和再灌注60 min时分别取末段回肠标本,观察和比较各时间点小肠黏膜的损伤情况,同时测定肠组织中丙二醛(MDA)含量和髓过氧化物酶(MPO)活性的变化。结果淤血前肠黏膜基本正常,淤血60 min后肠黏膜出现损伤,但组织中MDA含量及MPO活性与淤血前相比无明显变化;再灌注60 min后肠黏膜损伤较淤血60 min时进一步加重,且组织中MDA含量及MPO活性亦显著增高。结论淤血后血流再灌注可致肠组织出现淤血再灌注损伤;脂质过氧化损伤及中性粒细胞浸润可能是参与肠组织淤血再灌注损伤的重要因素。     

异丙酚对兔主动脉阻断脊髓细胞凋亡的影响

目的探讨异丙酚对家兔主动脉阻断所致脊髓细胞凋亡的影响及其可能的作用机制。方法24只家兔随机分为假手术组(A组)、缺血再灌注损伤组(B组)和异丙酚组(C组)。B、C组阻断腹主动脉40min,再灌注7d;C组于阻断腹主动脉前10min静脉注射异丙酚5mg/kg,继以微量泵静脉持续输注异丙酚20mg·kg-1·h-1直至松夹。分别测定阻断前10min(C10)、开放即刻(C40)、再灌注60min(R60)及7d(R7d)血清丙二醛(MDA)、超氧化物歧化酶(SOD)值;检测脊髓凋亡神经元及Bax、Bcl2蛋白表达;观察术后后肢神经功能。结果1缺血、及再灌注后B组MDA值明显高于C10值及A组相应时间点值(P<0.05或P<0.01),SOD值变化同MDA变化相反;C组MDA值明显高于C10值(P<0.05),但显著低于B组相应时间点值(P<0.05),较A组差异无显著性。2B组Bax蛋白表达明显高于A组(P<0.05),Bcl2蛋白表达明显低于A组(P<0.01);C组Bax蛋白表达明显低于B组,但高于A组(P<0.01和P<0.05),Bcl2蛋白表达明显高于B组及A组(P均<0.01)。3B组凋亡细胞指数明显多于A组;C组明显少于B组,但高于A组(P<0.01和P<0.05)。4C组瘫痪发生率明显低于B组,其后肢神经功能明显好于B组(P均<0.01)。结论异丙酚能抑制家兔主动脉阻断所致的脊髓细胞凋亡的发生,其机制可能与其抗过氧化反应、抑制Bax蛋白、增强Bcl2蛋白的表达有关。     

乌司他丁对体外循环肺静脉血炎性介质的影响

目的探讨乌司他丁对体外循环患者肺静脉血中炎性介质CD11bI、CAM-1、NE、ET-1的影响。方法选择40例主动脉阻断时间30 min以上的心内直视手术患者,分成乌司他丁实验组(U组)和氯化钠溶液对照组(C组),每组20例。实验组(U组)于麻醉诱导后静脉注射乌司他丁1.2×104U/kg,氯化钠溶液对照组(C组)不用乌司他丁,用等量氯化钠溶液代替。分别在麻醉诱导后(T1)、主动脉开放10 min(T2)、停机后10 min(T3)和1h(T4)测定肺静脉血黏附分子CD11bI、CAM-1、NE、ET-1浓度,流式细胞仪测定中性粒细胞CD11b活性表达,ELISA法测定肺静脉血ICAM-1、NE、ET-1浓度。结果 (1)麻醉诱导后两组患者肺静脉血CD11bI、CAM-1、NE、ET-1水平差异无统计学意义(P>0.05)。(2)CPB开始后各时点CD11b、NE、ET-1的水平明显上升(P<0.05)。U组明显低于C组(P<0.05)。(3)停机后1 h(T4),肺静脉ICAM-1值逐渐上升并超过基础值,两组比较U明显低于C组(P<0.05)。结论 (1)体外循环可引起静脉中炎性介质CD11bI、CAM-1、NE、ET-1水平升高,导致肺损伤。(2)乌司他丁通过抑制炎性介质CD11b、ICAM-1、NE、ET-1表达,减轻肺部炎症反应,对体外循环所致肺损伤提供保护作用。     

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.