亚低温对大鼠缺血-再灌流后脑梗死体积、神经功能及炎症反应的影响

目的研究亚低温状态下,大鼠局灶性脑缺血再灌流后不同时程脑组织中的细胞间黏附分子1(ICAM1),肿瘤坏死因子(TNFα)和白细胞介素1(IL1β)的动态变化,以探讨亚低温对脑缺血再灌流损伤时的保护机制。方法采用大鼠大脑中动脉(MCA)线栓闭塞/再通法建立大鼠局灶性缺血再灌流模型,常温组和亚低温组分别于脑缺血3h再灌流6h、12h、24h、48h、72h时间点断头取脑,假手术组则于再灌流24h断头取脑,进行ICAM1、TNFα和IL1β免疫组化测定;同时在再灌流24h进行神经功能和脑梗死体积的比较。结果(1)亚低温干预可以改善大鼠脑缺血再灌流后的神经功能障碍,缩小脑梗死体积(P<0.01);(2)脑缺血再灌流后,脑缺血灶ICAM1、TNFα和IL1β的表达出现增高趋势,分别在再灌流48h、24h和6h达高峰,与假手术组比较有显著意义(P<0.01);且亚低温干预明显抑制它们的表达(P<0.01)。结论亚低温干预能明显减轻缺血再灌流后脑组织的炎症反应,亚低温对炎症级联反应的抑制可能是其发挥脑保护作用的重要机制之一。     

醒脑静对家兔脑缺血再灌流时TNF、IL-1β、IL-6水平及脑超微结构影响的实验研究

目的探讨脑缺血再灌流损伤中机体肿瘤坏死因子(TNF)、白细胞介素-1 β(IL-1 β)、白细胞介素-6(IL-6)水平和脑超微结构的变化及醒脑静(XNJ)对其的影响.方法建立家兔急性全脑缺血及缺血再灌流动物模型.于缺血前和再灌流前对照组(A组)静脉注射生理盐水1 ml/kg,醒脑静保护组(B组)静脉注射XNJ 1 ml/kg.观察血、脑组织中TNF、IL-1 β、IL-6水平及脑组织超微结构.结果缺血30分钟时A组TNF与IL-1 β较缺血前升高(P＜0.05),而A组IL-6和B组三种指标升高不显著(P＜0.05).再灌流30、60、120分钟时三种指标A组(P＜0.0 01或P＜ 0.01)与B组(P＜0.01,P＜0.05或P＞0.05)均较缺血前升高,但升高水平B 组明显低于 A组(P＜0.05或P＜0.01).再灌流120分钟后脑组织匀浆中TNF、IL-1 β、IL-6表达水平B 组亦明显低于A组(P＜0.05或P＜0.01).脑组织超微结构病理改变B组明显较轻. 结论家兔脑缺血再灌流损伤时血、脑组织中TNF、IL-1 β、IL-6水平及脑组织超微结构呈明显改变.醒脑静对损伤具有保护作用,其机理可能与减轻细胞因子介导的炎性反应有关.     

脑缺血再灌注损伤中炎性细胞因子与脑超微结构的变化

目的 探讨脑缺血再灌注损伤中机体肿瘤坏死因子 (TNF)、白细胞介素 -1β(IL -1β)、白细胞介素 -6(IL -6)等炎性细胞因子水平和脑超微结构的变化。 方法 以“四管闭塞法”及再开放颈动脉建立家兔急性全脑缺血及缺血再灌注动物模型 ,观察血浆TNF、IL -1β、IL -6表达水平以及脑组织的超微结构。结果 与缺血前比较 ,缺血后30分钟时血浆TNF与IL-1β 已升高(p均<0.05) ,IL -6有所升高 ,但p>0.05。再灌注后30分钟、60分钟、120分钟时TNF、IL -1β、IL-6水平均明显升高 (p<0.001或 p<0.01)。电镜观察脑缺血再灌注120分种后脑组织病理改变严重。结论 家兔脑缺血再灌注损伤时血浆TNF、IL -1β、IL-6水平以及脑组织的超微结构呈明显改变 ,脑缺血再灌注损伤作用与细胞因子介导的炎性反应有关 ,拮抗炎性细胞因子等方法可能有助于脑缺血的治疗     

局灶性脑缺血再灌注后白细胞介素—6，肿瘤坏死因子—β的表达及川芎嗪对其表达的影响

目的：探讨大鼠局灶性脑缺血再灌注后各时相的白细胞介素－6（IL－6），肿瘤坏死因子－α（TNF－α）的表达及中药川芎嗪对其表达的影响。方法：采用放免法测定IL－6，TNF－α的动态变化。结果：对照组IL－6表达在12h时显增高（P＜0．05），实验组在再灌注6h时表达显增高（P＜0．05），12h时仍显增高（P＜0．05），对照组TNF－α缺血早期表达即增高，再灌注12h时最显，而实验组明显降低（P＜0．05）。结论：TNF－α加重脑缺血再灌注损伤，IL－6作为一种脑缺血后神经细胞死亡的内生拮抗剂，起到神经保护作用，种芎嗪可抑制脑缺血再灌注后TNF－α的表达，使IL－6的表达提前，可能是川芎嗪对抗脑缺血再灌注损伤的机制之一。     

动态观察心肌梗死溶栓后细胞因子变化的意义

目的　探讨心肌梗死病人溶栓后血清细胞因子的变化。方法　 6 0例急性心肌梗死 (AMI)病人溶栓治疗。于发病后 2d～ 6个月进行超声心动仪测定LVRM发生情况。健康对照组 6 0例。测定血清白细胞介素 8(IL - 8)和肿瘤坏死因子α(TNF -α)。结果　 6 0例AMI病人LVRM总发生率 48 3%。溶栓再通组LVRM发生率显著低于非再通组 (P <0 0 5 )。IL - 8和TNF -α显著高于对照组 (P <0 0 1)。IL - 8溶栓后 9 6h达到高峰 ,13 5h迅速下降 ;TNF -α于溶栓后 11 9h达高峰 ,2 4 4h后迅速下降。LVRM组IL - 8和TNF -α再度升高。结论　IL - 8和TNF -α参与心肌缺血再灌注损伤过程。冠脉再通可明显降低IL - 8和TNF -α的水平和减少LVRM的发生。IL - 8和TNF -α水平再度增高是LVRM发生的一个标志。     

葛根素对脑缺血-再灌流时大鼠肿瘤坏死因子-α和白细胞介素-1β表达的影响

目的　探讨全脑缺血 再灌流时葛根素的脑保护作用机制。方法　将实验大鼠随机分为空白对照 (S)组、全脑缺血 再灌流 (IR)组、葛根素 (P)组。采用Pulsinelli法制备大鼠全脑缺血 再灌流损伤模型 ,以原位杂交法分别测定全脑缺血 再灌流 2 ,6 ,12 ,2 4 ,4 8h各时点海马CA1 区肿瘤坏死因子 α (TNF α)mRNA、白介素 1β (IL β)mRNA的表达 ,HE染色光镜下计数存活神经元数的变化。 结果　与IR组相比 ,P组各对应时点TNF αmRNA、IL 1βmRNA的表达均有显著下降 (P <0 0 5 ) ,而存活神经元数目均有明显增加 (P <0 0 1或P <0 0 5 )。结论　葛根素通过下调TNF αmRNA、IL 1βmRNA的表达 ,抑制脑缺血再灌流炎症反应而对脑有保护作用     

卡巴胆碱对肠缺血-再灌流动物脏器功能的保护作用

目的研究卡巴胆碱对肠缺血再灌流动物脏器功能的保护作用及对肠组织和白细胞炎症介质表达的影响。方法检测肠缺血再灌流大鼠和肠部分缺血再灌流兔伤后脏器功能指标、白细胞中细胞因子表达和血浆、肠组织TNFα含量。结果卡巴胆碱治疗组大鼠再灌流2h后血浆ALT、BUN和CK低于对照组,白细胞中TNFα表达下调,IFN、IL4和IL10表达上调;治疗组兔血浆ALT、Cr和CKMB在缺血和再灌流早期增加幅度低于实验组,再灌流后趋于恢复,实验组渐升高;肠组织TNFα含量低于实验组。结论卡巴胆碱改善肠缺血再灌流动物脏器功能,抑制肠组织TNFα的合成,调节白细胞致炎和抗炎因子的表达比例。     

急性心肌梗死与再灌注后血浆肿瘤坏死因子α、白细胞介素-6的变化

目的：观察急性心肌梗死（AMI）再灌注治疗患者血浆肿瘤坏死因子α（TNF－α）、白细胞介素－6（IL－6）浓度的动态变化评价其意义，方法：对发病6h内AMI患者48例进行溶栓治疗。测定患者溶栓前、溶栓后0．5、1、2、4、12、48h及1周血浆TNF－α、IL－6浓度。结果：36例再通，12例未通。溶栓前TNF－α、IL－6浓度都升高。溶栓后未通组TNF－α、IL－6均于48h达高峰。峰值都大于再通组。再通组TNF－α高峰不明显。IL－6于12h达峰后回落。结论：AMI患者血浆TNF－α、IL－6动态变化反映AMI炎性反应。再灌注挽救心肌而减轻的炎症足以抵消再灌注损伤。     

运动预处理对脑缺血再灌注大鼠血清炎症因子水平的影响

目的探讨运动预处理对脑缺血再灌注大鼠血清白细胞介素-1β(IL-1β)、白细胞介素-6(IL-6)及肿瘤坏死因子α(TNF-α)含量的影响。方法雄性Sprague-Dawley大鼠24只分为运动预处理组(n=8)、模型组(n=8)、假手术组(n=8)。线栓法制备大鼠大脑中动脉阻塞(MCAO)缺血再灌注模型。再灌注后2 h、24 h分别行神经功能缺损评分。随后取材,HE染色观察大鼠缺血侧脑组织病理形态变化,酶联免疫吸附法检测血清TNF-α、IL-1β及IL-6的含量。结果脑缺血再灌注后24 h,运动预处理组神经功能评分较模型组改善(P0.05),血清TNF-α、IL-1β及IL-6含量明显降低(P0.01);脑缺血区皮质病理损伤减轻,间质水肿程度减轻,细胞排列较整齐,缺血区变性和坏死的神经元数量明显减少。结论运动预处理可以降低急性脑缺血再灌注大鼠炎症反应,降低神经功能缺损。     

大鼠急性全脑缺血再灌注时NF-κB表达及意义

【目的】观察全脑缺血再灌注时核因子κB(NF κB)、IL 1β、TNF α和存活神经元数目水平的变化 ,探讨NF κB在全脑缺血再灌注时的作用。【方法】采用Pulsinelli法建立大鼠全脑缺血再灌注模型 2 5例 ,分别于缺血再灌注后 2h、6h、12h、2 4h、4 8h时取脑海马CA1区组织切片行HE染色和免疫组化方法测定NF κB ,原位杂交方法测定IL 1β、TNF α并进行图像分析。【结果】大鼠脑海马CA1区NF κB和IL 1β、TNF α水平在全脑缺血再灌注后均明显增加 (P <0 .0 5 ) ,且三者间的变化呈显著正相关 (P <0 .0 1) ;NF κB与存活神经元数目呈显著负相关 (P <0 .0 5 )。【结论】NF κB在全脑缺血再灌注时与IL 1β、TNF α间可相互促进表达 ,并显著降低存活神经元数目 ,提示NF κB可能参与了脑缺血再灌注损伤的病理生理过程。     

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.