大剂量维生素C对肠粘膜屏障保护作用的实验研究

本实验应用大剂量维生素Ｃ治疗出血性休克和内毒素所致肠粘膜屏障破坏，旨在为预防和治疗严重创伤等所致肠源性感染开拓新的途径。数据显示维生素Ｃ治疗动物肠道细菌移居发生率明显低于休克组（Ｐ〈０．０１）；细菌移居量显著低于休克组（Ｐ〈０．０１）和内毒素组（Ｐ〈０．０１）；小肠病理损伤程度亦明显轻于休克组和内毒素组。大剂量维生素Ｃ对出血性休克和内毒素以致肠粘膜屏障破坏有明显治疗作用，但其对前者的疗效明显优于后     

大黄对大鼠肠粘膜及肠血管通透性的影响

目的：研究大黄对肠粘膜及肠血管通透性的影响。方法：选用低血容量性休克和内毒素性休克大鼠动物模型，以荧光标记白蛋白和小肠湿／干重比值检测内毒素性休克肠血管通透性，以血浆内毒素含量来衡量肠粘膜通透性。结果：内毒素能引起小肠组织明显水肿，其湿／干重比值显著增高，同时明显提高肠血管壁对荧光标记白蛋白的通透性；而大黄能减轻肠壁水肿和湿／干重比值（内毒素组为３．７５±０．６８，大黄组为１．６６±０．３３，Ｐ＜０．０１），降低肠血管通透性〔小肠组织荧光标记白蛋白含量：内毒素组为（１．２５４±０．１１７）μｍｏｌ／ｇ，大黄组为（０．９００±０．０７１）μｍｏｌ／ｇ，Ｐ＜０．０１〕。低血容量性休克能破坏肠粘膜屏障，提高肠粘膜对内毒素的通透性，而大黄可明显降低低血容量性休克大鼠肠粘膜通透性，抑制肠道内毒素的吸收〔血浆内毒素含量：休克组为（０．５５７±０．０６９）ＥＵ／ｍｌ，大黄组为（０．３４５±０．０５５）ＥＵ／ｍｌ，Ｐ＜０．０１〕。结论：大黄能保护肠粘膜屏障，抑制肠道内毒素吸收，降低肠粘膜及肠毛细血管通透性。     

大黄对肠源性感染治疗作用的实验研究

肠源性感染是出血性休克后一个常见的病理过程。本实验旨在证明大黄对出血性休克所致的肠粘膜屏障破坏具有治疗作用。大黄（１５０ｍｇ／ｋｇ）于复苏后即刻，６，１２小时分次经胃管注入。复苏生２４小时活杀大鼠，分离肝，脾，肠系膜淋巴结作肠道细菌移居量测定。结果显示：单纯手术组无肠道细胞移居，出血性休克组肠道细菌移居至肠系膜淋巴结，肝脏，脾脏，两组间有显著差异（Ｐ＜０．０１）大黄治疗组细菌移居发生率和移居量明显     

大黄煎剂延迟并下调肠道相关淋巴细胞凋亡

目的：探讨药用大黄煎剂的肠粘膜屏障保护作用机制。方法：制备小鼠肠系上动脉缺血－再灌注损伤的实验模型,术后６,１２和２４ｈ处死动物并以标本,检测血浆总抗氧化能力、内毒素,小肠组织相对含水量和肠粘膜上皮细胞（ＥＣ）、固有层淋巴细胞（ＬＰＬ）及Ｐｅｙｅｒ’ｓ结节淋巴细胞（ＰＰＬ）凋亡情况。结果：药用大黄煎剂可以显著提高小鼠的血浆总抗氧化能力（Ｐ〈０．０１）,降低血浆内毒素水平和小肠组织含水量（Ｐ〈０．０     

肠源性内毒素血症家兔血浆氨基酸谱的变化及Re型内毒素抗血清对其变化的影响

应用创伤后肠源性感染导致家兔内毒素血症模型，观察血浆氨基酸谱变化及Ｒｅ型内毒素抗血清对其变化的影响。动物随机分为实验组和治疗组。结果：自伤后２４ｈ始，实验组动物各时点血浆内毒素水平均明显升高，同时伴有血浆谷氨酸、丙氨酸和苯丙氨酸显著增加及支链氨基酸的显著降低（Ｐ＜０．０１～０．００１）。治疗组动物血浆内毒素水平及氨基酸浓度仅于伤后２４ｈ发生显著变化（Ｐ＜０．０５～０．０１）。研究结果提示：家兔血浆内毒素变化与血浆氨基酸改变有显著相关性。Ｒｅ型内毒素抗血清具有降低血浆内毒素水平及改善氨基酸代谢紊乱的作用。     

大黄对大鼠肠缺血再灌注所致肺损伤过程肿瘤坏死因子、一氧化氮和磷脂酶A2的影响

目的：观察肿瘤坏死因子（ＴＮＦ）、内源性一氧化氮（ＮＯ）和磷脂酶Ａ２（ＰＬＡ２）在大鼠小肠缺血再灌注（ＩＲ）所致肺损伤发病过程中的作用,及大黄对ＴＮＦ、ＮＯ和ＰＬＡ２的影响,探讨大黄防治肠源性肺损伤的机制。方法：ＳＤ大鼠随机分为肠缺血再灌注组、假手术组、大黄治疗组和安慰剂组。以１２５Ｉ标记小牛血清白蛋白（ＢＳＡ）肺摄取指数作为评价肺损伤的指标,以髓过氧化物酶（ＭＰＯ）作为评价多形核白细胞（ＰＭＮ）在组织中聚集的指标,分别测定各组动物不同时间血浆、肺组织ＴＮＦ含量,血浆（血清）、肺及小肠组织内源性ＮＯ含量及ＰＬＡ２活性。结果：大黄可显著改善ＩＲ导致的低血压状态并明显抑制再灌注导致的肺ＭＰＯ活性升高（Ｐ＜０．０１）;抑制肠缺血和再灌注早期出现的血浆及肺组织ＴＮＦ水平升高（Ｐ＜０．０１）;抑制肠缺血期和再灌注期血清、肺及小肠组织ＰＬＡ２活性升高（Ｐ＜０．０５或Ｐ＜０．０１）及再灌注期的内源性ＮＯ释放（Ｐ＜０．０５或Ｐ＜０．０１）;降低肺毛细血管通透性（Ｐ＜０．０１）。结论：缺血再灌注早期应用大黄能明显防治大鼠ＩＲ所致的肺损伤,这种作用可能是通过抑制ＴＮＦ、内源性ＮＯ及ＰＬＡ２等介质的释放实现的。     

“717复方”制剂对内毒素损伤大鼠肝细胞线粒体的保护作用

目的：观察“７１７复方”制剂对内毒素休克大鼠肝细胞线粒体的保护作用。方法：采用静脉注射内毒素制备大鼠内毒素休克模型，观察“７１７复方”对休克大鼠肝细胞线粒体功能的影响。结果：模型组大鼠肝细胞线粒体呼吸控制率（ＲＣＲ）明显下降，与正常对照组比较（４．５８±０．３１比５．７３±０．３５）有显著性差异（Ｐ＜０．０５）；电镜下，内毒素休克模型线粒体明显肿胀，嵴减少、模糊不清。“７１７复方”制剂组大鼠肝细胞线粒体ＲＣＲ（５．６８±０．４１）则接近正常，与模型组比较有极显著性差异（Ｐ＜０．０１）；其电镜下超微结构病变也较轻。体外实验测定肝细胞线粒体膜通透性（膜吸光度下降百分比），“７１７复方”制剂组明显低于内毒素组（Ｐ＜０．０１）。结论：“７１７复方”制剂具有拮抗内毒素损伤线粒体的作用     

大黄对肠粘膜屏障保护作用的机制探讨

利用失血性休克和内毒素对肠粘膜屏障的致伤模型，对大黄的肠粘膜屏障保护作用机制进行了部分研究。失血性休克模型的肠粘膜病理检查显示：大黄能促进肠粘膜内杯状细胞大量增生，增加肠腔内粘液的分泌，保护肠粘膜。内毒素模型的生化检查结果表明：大黄对肠道、肝脏和血浆中的氧自由基有明显清除作用。由此推测：大黄对肠粘膜屏障保护作用部分机制可能通过此二途径实现     

口饲乳果糖对失血性休克大鼠预后的影响

为了进一步阐明失血性休克预后与继发性内源性内毒素血症的直接关系，作者探讨了用口饲乳果糖清除肠道内毒素对大鼠失血性休克的保护作用。造成休克前，首先给大鼠口腔管饲２０％乳果糖（５ｍｌ／ｄ）或等容量生理盐水７天，每天给药２次。结果：休克后４８ｈ，乳果糖组大鼠存活率要明显高于盐水组（１０／１０与４／９，Ｐ＜０．０１）。休克后９０ｍｉｎ和１２０ｍｉｎ，乳果糖组大鼠血浆内毒素、ＴＮＦ水平均显著低于盐水组。提示：继发于失血性休克的内源性内毒素血症及肿瘤坏死因子在促使休克向不可逆性发展中可能起重要作用。作者认为，临床上对严重的失血性休克患者，除作复苏外，还应针对感染，尤其是内毒素血症尽早采取防护措施。     

牛珀至宝丹对内毒素休克大鼠血液流变学的影响

目的：探讨牛珀至宝丹抗内毒素休克的作用机制。方法：采用静注致死量灭活大肠杆菌内毒素造成大鼠重症感染性休克模型，以牛珀至宝丹预先处理动物（实验组），并与正常组、内毒素体克组进行对照观察。结果：实验组血压下降幅度显著低于休克组；血液流变学指标中全血粘度、血浆比粘度、红细胞聚集指数、红细胞刚性指数和红细胞压积实验组较休克组均明显降低，红细胞电泳时间缩短；与正常组比较无显著性差异（Ｐ＞０．０５），但与休克组比较有显著性差异（Ｐ＜０．０５或＜０．０１）。结论：牛珀至宝丹能明显改善内毒素休克大鼠血液流变性，并对内毒素休克大鼠有一定的升压作用。     

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.     

手转胎头术失败的原因与分娩结局临床分析

目的 探讨手转胎头术失败的原因与分娩结局.方法 选择2008年1月至2010年12月于我院住院分娩的持续性枕横位、枕后位产妇198例,根据行手转胎头术后结果分为成功组126例、失败组72例.比较两组分娩结局,对比分析失败原因.结果 失败组胎儿体质量≥3500 g的发生率[76.4％(55/72)]明显高于成功组[31.7％(40/126)],差异有统计学意义(x2=30.177,P=0.001)、失败组宫缩乏力发生率[58.3％(42/72)]高于成功组[38.1％ (48/126)],差异有统计学意义(x2=7.569,P=0.006)、失败组骨盆临界或轻度狭窄发生率[38.9％ (28/72)]高于成功组[23.8％(30/126)],差异有统计学意义(x2 =5.030,P=0.002)、失败组手转胎头时机不当(宫口开大＜6 cm、胎头位于坐骨棘上及宫口开大8～10 cm、胎头位于坐骨棘下≥2 cm)发生率[61.1％(44/72)]高于成功组[38.9％(49/126)],差异有统计学意义(x2=9.084,P=0.003).失败组母儿并发症(产后出血、产褥病率、胎儿窘迫、新生儿窒息)发生率高于成功组(x2 =9.586,P=0.002、x2=9.334,P=0.002、x2=5.910,P=0.015、x2=5.240,P=0.022)、失败组剖宫产发生率[72.2％(52/72)]明显高于成功组[34.1 ％(43/126),x2=26.641,P=0.001)].结论 手转胎头术能使难产变顺产,降低剖宫产率,减少母儿并发症,但须积极预防、处理导致手转胎头术失败的原因,对矫正失败后继续矫正及试产应慎重.