雾化吸入氯胺酮对哮喘大鼠肺组织一氧化氮及一氧化氮合酶的影响

目的通过建立大鼠支气管哮喘模型,观察不同浓度氯胺酮对哮喘大鼠肺组织iNOS活性及NO含量的影响。方法SD大鼠随机分成对照组(N组)、哮喘模型组(A组)、不同浓度氯胺酮预处理组(分别为K1组、K2组)和地塞米松组(D组),每组8只。A组大鼠用卵白蛋白辅以百日咳杆菌菌苗和氢氧化铝为佐剂注射致敏,2周后雾化吸入卵蛋白激发哮喘;氯胺酮处理组大鼠用同样方法致敏,但在激发前分别给予雾化吸入氯胺酮25 g/L(K1组)和50 g/L(K2组);D组在激发前给予雾化吸入0.01%地塞米松;N组用生理盐水替代卵蛋白进行注射和吸入。每组分别测定其肺组织NO2-/NO3-水平、肺组织诱导型NOS(iNOS)和原生型NOS(cNOS)活性水平,并用免疫组织化学法观察iNOS在大鼠哮喘模型肺组织中的分布。结果A组肺组织中NO2-/NO3-和iNOS水平升高,iNOS和肺组织NO2-/NO3-水平呈高度正相关;K1、K2组肺组织中NO2-/NO3-和iNOS水平低于A组(P<0.05);D组肺组织中NO2-/NO3-和iNOS水平亦低于A组(P<0.05)。结论25 g/L或50 g/L的氯胺酮雾化吸入可抑制哮喘大鼠肺组织iNOS活性,降低NO含量,减轻大鼠肺部炎症。     

米力农吸入对急性肺损伤家兔肺iNOS和eNOS表达的影响

目的:观察米力农吸入对急性肺损伤(ALI)家兔肺iNOS和eNOS表达的影响并探讨其保护机制。方法:将45只家兔随机分为对照组(A组),肺损伤组(B组)和米力农吸入组(C组),每组15只,B和C组采用特制多功能撞击机制成急性肺损伤模型,C组经气管给予米力农雾化吸入,分别在0、1、2、3、4h时间点行血气分析,4h后处死动物,测定肺湿干比(W/D)、血清NO、肺组织丙二醛(MDA)和髓过氧化物酶(MPO)含量,免疫组化法检测肺组织iNOS和eNOS表达。结果:与A组相比,B组损伤后PaO2、SaO2显著降低(P<0.05),肺iNOS表达显著增强,eNOS表达明显降低(P<0.05),肺W/D、血清NO、肺MDA和MPO含量显著增高(P<0.05)。C组米力农吸入后,与B组比较,PaO2、SaO2明显升高(P<0.05),肺iNOS表达显著降低,eNOS表达明显升高(P<0.05),肺W/D、血清NO、肺MDA和MPO含量明显降低(P<0.05)。结论:米力农通过抑制肺iNOS异常高表达和增加eNOS表达对急性肺损伤有保护作用。     

肠缺血/再灌注致肺损伤时肺内HO-1/CO与iNOS/NO相互作用的研究

目的观察肠缺血/再灌注(I/R)致肺损伤时肺内HO-1/CO与iNOS/NO的相互作用。方法采用肠缺血/再灌注模型。32只Wistar大鼠随机分为假手术组(Sham组)、肠缺血1 h再灌注6 h组(I/R组)、氨基胍组(AG组)和血晶素组(hemin组)。检测肺组织中HO-1和iNOS的表达,观察肺组织丙二醛(MDA)、血清一氧化氮(NO)及动脉血中氧血红蛋白(Hb-CO)的含量,同时观察肺组织病理形态学改变。结果与Sham组比较,I/R组HO-1和iNOS表达显著增强(均P<0.01);AG组HO-1和iNOS表达较I/R组明显降低(均P<0.05);Hemin组iNOS表达较I/R组明显降低而HO-1表达明显升高(均P<0.05);I/R组肺组织MDA、血清NO、血中HbCO较Sham组显著增加(P<0.05或P<0.01);与I/R组比较,AG组、Hemin组肺组织MDA、血清NO显著降低(P<0.05或P<0.01)。AG组的HbCO明显降低而Hemin组的HbCO明显升高(P<0.05)。病理学检查显示,AG组与Hemin组肺组织损伤程度较I/R组明显减轻。结论NO及CO对肠I/R肺组织具有保护作用,两者之间存在着相互作用,肺内HO-1/CO的大量生成具有使NO产生减少的作用,同时iNOS/NO的过量生成具有上调HO-1表达使CO产生增多的作用。     

血管紧张素Ⅱ及其受体拮抗剂对胎粪诱导肺损伤中炎症反应的作用

目的:研究胎粪吸入所致肺炎症损伤与血管紧张素Ⅱ(AngⅡ)两者之间的相关性及AngⅡ受体拮抗剂的抗炎作用。方法:30只S-D大鼠,随机分为生理盐水对照组、胎粪吸入组和拮抗剂治疗组,每组10只。模型制备后24h取材,观察其肺组织病理损伤并检测湿/干重比及进行病理评分;检测AngⅡ在肺组织的表达情况及用图像分析方法检测其含量;测定肺组织中肿瘤坏死因子-α(TNF-α)的含量及肺匀浆髓过氧化物酶(MPO)活性。结果:胎粪组肺组织病理损伤严重,病理评分及湿/干重比较对照组和治疗组明显增加(P<0.05),对照组和治疗组差异无显著意义;各组间AngⅡPU值、TNF-α含量及MPO活性差异有显著性(P<0.01);并且各组中TNF-α含量及MPO活性与其肺组织中AngⅡPU值呈显著正相关(P<0.01),相关系数分别为0.744和0.747。结论:AngⅡ可增加胎粪吸入肺损伤中炎症因子和炎症细胞含量。受体拮抗剂沙拉欣的治疗可以减轻炎症反应导致的肺损伤。     

肺表面活性物质对大鼠肺内源性急性肺损伤的作用

目的观察外源性肺表面活性物质对大肠杆菌(E.coli)导致的大鼠急性肺损伤(ALI)的作用。方法设立正常大鼠组(N组)和3个实验组[E.coli导致的ALI大鼠PaO2FiO2<200mmHg(1mmHg=0.133kPa)]:对照组(C组,不用药)、表面活性物质组(PS组,经气管插管滴入CurosurfR2ml kg,160mg kg)、生理盐水组(NS组,经气管插管滴入NS,2ml kg)。每30min检测血气、胸肺有效动态顺应性,180min结束实验,进行肺病理检查,测肺指数、支气管肺泡灌洗液(BALF)蛋白含量和TNFα浓度。结果①PS组各时点PaO2较给药前升高约70%,与C组、NS组比较明显升高(P<0.05);②PS组PaCO2、pH以及胸肺有效动态顺应性各时点好于NS组(P<0.05);③PS组肺指数明显低于C组[(0.38±0.05)%对(0.43±0.05)%,P<0.05]和NS组[(0.47±0.06)%,P<0.01];④PS组肺透明膜形成较NS组减少(P<0.05),较C组有减少趋势(P=0.055);⑤PS组BALF蛋白含量明显低于C组[(0.63±0.30)mg ml对(0.96±0.25)mg ml,P<0.05]和NS组[(1.03±0.27)mg ml,P<0.01];TNFα浓度明显低于NS组[(0.35±0.23)ng ml对(2.14±1.02)ng ml,P<0.01],较C组(0.61±0.28)ng ml有减低趋势(P>0.05)。结论肺表面活性物质对E.coli所致的大鼠肺内源性ALI有治疗作用,可改善氧合,减轻肺水肿,并有减少肺透明膜形成和TNFα释放趋势。     

辛伐他汀对脂多糖诱导肺损伤大鼠的一氧化氮合酶的影响

目的 探讨辛伐他汀对脂多糖(LPS)诱导急性肺损伤大鼠的一氧化氮合酶(NOS)的影响.方法 30只SD大鼠随机分为对照组、LPS组和辛伐他汀治疗组,治疗组又分1 h、3 d和7 d组,每组6只.治疗组大鼠在实验前经胃管分别给予辛伐他汀10 mg/kg(4 ml/kg)治疗1 d,3 d,7 d,每天1次;对照组和LPS组则给予蒸馏水(4 ml/kg),每天1次,连续7 d.在最后一次给药1 h后,LPS组和治疗组大鼠从尾静脉注射LPS 5 mg/kg(2.5 ml/kg),对照组则予注射无菌生理盐水(2.5 ml/kg).观察6 h,处死大鼠,取样,比色法测定血清和肺匀浆诱导型一氧化氮合酶(iNOS)、构成型一氧化氮合酶(cNOS)和一氧化氮(NO)水平,免疫组化法检测肺组织iNOS和内皮型一氧化氮合酶(eNOS)的表达.结果 LPS组血清和肺匀浆NO均高于对照组(p<0.001),治疗组则低于LPS组(P<0.05);LPS组血清和肺匀浆iNOS活力均高于对照组而cNOS活力则降低(P<0.05),治疗组肺匀浆iNOS活力显著低于LPS组而eNOS显著升高(P<0.001);免疫组化显示:LPS组肺组织iNOS表达强于对照组,而eNOS表达则显著减弱,治疗组的iNOS表达弱于LPS组,eNOS表达则显著增强,与其减轻肺损伤相关.结论 辛伐他汀可逆转LPS诱导的肺组织iNOS活性的升高和eNOS活性的下降,减轻内毒素性肺损伤.     

一氧化氮及一氧化氮合酶在哮喘大鼠气道高反应中的作用

目的:探讨一氧化氮及一氧化氮合酶(nitricoxidesynthase,NOS)在哮喘大鼠气道炎症中的作用及激素对其活性的影响,以期为该病的预防、康复措施介入提供理论依据。方法:实验选用雄性豚鼠30只,按随机数字法将豚鼠分为3组:①哮喘组:用100g/L卵蛋白腹腔注射1mL致敏,2周后用10g/L卵蛋白超声雾化吸入致其哮喘发作。②激素组:诱喘同前,每次诱喘前腹腔内注射甲基强的松龙10mg/kg。③对照组:用生理盐水代替诱喘剂。每组分别测定其血浆和肺组织NO2-/NO3-水平、肺组织诱导型NOS(induciblenitricoxidesynthase,iNOS)和原生型NOS(constitutenitricoxidesynthase,cNOS)活性水平,并用组织化学染色法观察NOS在豚鼠哮喘模型肺组织中的分布。结果:3组豚鼠血浆NO2-/NO3-水平差异无显著性意义(P>0.05),哮喘组肺组织中NO2-/NO3-和iNOS活性水平犤(0.87±0.08)μmol/g,(56±14)nmol/g犦明显高于对照组和激素组犤(0.19±0.06)μmol/g,(12±6)nmol/g;(0.18±0.07)μmol/g,(12±5)nmol/g犦(P<0.01)。对照组肺组织化学方法显示的阳性产物呈蓝色沉淀,主要分布于各级支气管上皮细胞,哮喘组及激素组阳性产物变化不明显。哮喘组肺组织i-NOS活性水平和肺组织NO2-/NO3-水平呈高度正相关(r=0.782,P<0.05)。结论:一氧化氮可引起气道高反应性而     

急性肺损伤患者血清中中性粒细胞弹性蛋白酶活性的变化

目的检测急性肺损伤(ALI)患者血清中中性粒细胞弹性蛋白酶(NE)的活性,探讨其临床意义。方法选择符合ALI患者22例,健康对照组15例。计算动脉血氧分压(PaO2)与吸入气氧浓度(FiO2)比值,测定NE活性、α1抗胰蛋白酶α1AT)浓度和活性、白介素6(IL6)和白介素8(IL8)浓度等。结果ALI患者的NE活性、IL6和IL8均明显高于健康对照组,而α1AT活性较健康组降低(P<0.05)。ALI患者中死亡组(10例)的NE活性明显高于存活组(12例)(P<0.01)。而且ALI患者的血清NE活性与PaO2FiO2呈显著负相关(r=-0.874,P<0.01)。结论ALI患者的NE活性明显升高,α1AT活性显著降低,出现蛋白酶抗蛋白酶失衡,而且血清NE活性水平与患者的肺损伤严重程度和预后密切相关。     

力竭性运动对大鼠脑组织中一氧化氮合成酶活性的影响

目的研究力竭性运动对机体脑组织中一氧化氮合成酶(NOS)活性的影响.方法大鼠进行力竭游泳,测定脑组织中构建型NOS(cNOS)和诱导型NOS(iNOS)活性.结果力竭性运动后,脑组织中iNOS活性显著升高,而cNOS活性无显著变化.结论力竭运动可使脑组织中iNOS活性升高,,从而诱导合成大量的NO,这可能是导致中枢性运动疲劳产生的原因.     

吸入一氧化氮对急性肺损伤小鼠肺组织炎症反应的影响

目的 :探讨吸入一氧化氮 (NO)对内毒素〔即脂多糖 (L PS)〕诱导的急性肺损伤小鼠肺组织炎症反应的影响。方法 :利用腹腔内注射 L PS诱导小鼠急性肺损伤模型 ,按随机数字表法将动物分为 L PS组和 L PS 吸入 NO2 0× 10 - 6组。 L PS注射前 (0时 ,即正常对照 )及注射后 1、3、6和 12小时处死小鼠 (n=6 ) ,分别测定肺组织湿重 /干重 (W/D)比值 ,同时用迁移率改变电泳法 (EMSA)检测核因子κB(NFκB)的活性 ,用酶联免疫吸附法 (EL ISA )检测肿瘤坏死因子α(TNFα)和白介素 10 (IL 10 )的浓度 ,用逆转录聚合酶链反应(RT PCR)法检测 TNFα m RNA及 IL 10 m RNA的表达 ,并观察肺组织病理改变。结果 :L PS注射后 3、6、12小时 ,W/D分别为 4 .80± 0 .31、4 .82± 0 .10和 4 .6 3± 0 .18,明显高于正常对照 (3.6 7± 1.0 4 ,P均 <0 .0 5 )。吸入 2 0× 10 - 6 NO后 3和 12小时 ,W/D分别为 4 .0 4± 0 .77和 4 .2 4± 0 .75 ,显著低于 L PS组 (P均 <0 .0 5 )。吸入 NO2 0× 10 - 6 6小时后 ,小鼠肺组织核蛋白 NFκB活性为 2 5 0 .6± 5 1.5 ,明显低于 L PS组 (40 5 .7± 6 2 .4 ,P<0 .0 5 )。与 L PS组比较 ,吸入 NO后 3～ 12小时 ,肺组织匀浆中 TNFα和 IL 10浓度均明显降低。吸入 NO后 6小时 ,肺组织匀浆中 TNFα     

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.