大白鼠急性DIC模型的复制

DIC的主要改变是在微循环内发生血管内凝血,故观察微循环改变是主要的指标之一。大白鼠的肠系膜或提睾肌微循环,均可进行动态观察微循环的变化,但肠系膜微循环标本的制作损伤较大,不适宜做较长时间的观察。已     

大鼠提睾肌缺血再灌注损伤时血管平滑肌细胞和内皮细胞的增殖与凋亡

目的研究大鼠提睾肌缺血再灌注后血管平滑肌细胞和内皮细胞的增殖和凋亡。方法以免疫组织化学SP法和末端脱氧核苷酸转移酶介导生物素标记法 (TUNEL)对大鼠提睾肌缺血再灌注后的血管平滑肌细胞和内皮细胞的Bcl-2、Bax、P53和增殖细胞核抗原 (PCNA)的表达进行观察研究。结果缺血再灌注后 ,血管平滑肌细胞和内皮细胞均有Bcl-2、Bax、P53和PCNA的表达 ,在平滑肌细胞 ,Bcl-2阳性细胞数量明显高于Bax和P53。PCNA阳性细胞明显增多。在内皮细胞 ,Bax和P53的表达最强 ,TUNEL阳性细胞率最高。结论大鼠提睾肌缺血再灌注可造成平滑细胞的增殖和内皮细胞的凋亡 ,其结果可能与微循环障碍有关。     

钙剂对急性DIC形成作用的实验观察

采用提睾肌微循环监测及血液检查包括血气分析的测定，观察健康雄性大白鼠在微循环障碍情况下，Ｃａ＋＋对急性ＤＩＣ的形成的作用。结果：实验组２０只大鼠（加钙组）造病后有典型的急性ＤＩＣ变化，２０只大鼠于３～２４ｈ内相继死亡，经病理组织学检查，部分大鼠的肺毛细血管和小血管内有白色微血栓。而对照组５只鼠微循环障碍为暂时性的红细胞粘连聚集，５只鼠均存活。提示：在微循环障碍情况下，Ｃａ＋＋可促进急性ＤＩＣ形成，应引起临床工作者警惕。     

毛细血管质量传递数学模型的进展

典型的微循环一般由微动脉、后微动脉、毛细血管前括约肌、真毛细血管、通血毛细血管、动-静脉吻合枝和微静脉等七个部分组成。其中微动脉与后微动脉从功能上来说称为阻力血管。真毛细血管和通血毛细血管是交换血管,是血液和组织进行物质交换的主要场所。本文所综述的数学模型,主要是后面这一部分。再接下去是微循环的容量血管,是指微静脉而言。     

自发性高血压大鼠微循环变化及异搏定的干预

本实验通过对自发性高血压大鼠(SHR)提睾肌微血管口径、密度、形态分布等指标的观察,我们发现SHR微循环水平的血管口径缩小,形态分布异常,毛细血管数目减少及“网络结构”形成,是增加外周阻力和升高血压的表达形式.异搏定对SHR有降血压和改善微循环的效应.随着血压下降,毛细血管密度增加,两者呈负相关关系.在正常血压大鼠(WKy),SHR及耐药性高血压大鼠(R-SHR)中,这种相关性由强到弱,相关系数分别为-0.89,-.24、0,说明其微循环调节机能逐渐减弱.     

胎儿盲肠微血管构筑特点及其相互关系

目的为盲肠微循环提供形态学基础资料。方法通过墨汁灌注组织切片、揭层透明、微血管铸型扫描电镜等方法,观察30具胎儿尸体盲肠微血管构筑并探讨其相互关系。结果盲肠浆肌层在系膜缘侧毛细血管网眼呈与盲肠长轴平行的矩形,而靠近对系膜缘侧的毛细血管网眼多为不规则的五边形;环肌层可见环行肌束间动脉多呈"叶脉状"分为二支,分支间有横行粗短的多曲状吻合支,并由吻合支发蚓状血管;黏膜下层血管较粗网眼密度低。黏膜的毛细血管围绕结肠腺构成毛细血管丛,腺周毛细血管围成椭圆形,腺口毛细血管环均呈四边形。结论胎儿盲肠各层毛细血管网眼形状和密度均有所不同,说明盲肠血供存在部位的差异。     

人心室壁微血管构筑的扫描电镜研究

以甲基丙烯酸酯微血管铸型法观察了2例成年男性尸体标本的心室壁微血管构筑,并与实验动物(犬4例、山羊2例、绵羊2例、兔4例、豚鼠4例,大鼠4例)作了比较。结果表明,人和上述实验动物心室壁微血管构筑无明显不同;左、右室壁微血管构筑基本相似。1.左心室肌层毛细血管密度:浅层、中层、深层毛细血管密度相似,均约2,000支/mm~2,肉柱和乳头肌内毛细血管密度较高,约3,000支/mm~2左右。2.微循环单位:心室壁微循环似以肌束区分范围;在肌束内,又可区分出微循环单位。肌束间有与之平行的微动脉和微静脉。由微动脉沿途发出的终末微动脉,垂直进入肌束。在     

骨胳肌微血管立体构筑的扫描电镜观察

本文报道应用微血管腐蚀铸型扫描电镜技术,观察了2例3岁男童的翼内肌和咬肌的微血管系统。在扫描电镜下观察,可见微动脉的分支分为三种类型;1.树叉样边分支;2.对称性分支;3.细丛状分支。本文描述了动脉和静脉铸型表面上的内皮细胞核压痕的差别;前毛细血管括约肌压痕的形态特征;拱形动脉的Ⅱ级吻合形式及其生理学意义。毛细血管铸型的直径为5.6±1.9μm。2～3条静脉湍毛细血管汇合成毛细血管后微静脉。可见1条独立的毛细血管直接注入微静脉干。上述形态学因素在骨胳肌的微循环方面,有着重要的生理学意义。     

心肌微循环改变在缺血再灌注损伤中作用的探讨

目的探讨缺血与再灌注时心肌组织微循环的改变.方法采用家兔心肌缺血与再灌注模型,观察心肌组织毛细血管腔内和管壁的变化以及心肌细胞与间质的形态学改变,并测定血浆神经肽Y和内皮素水平及心肌组织微动脉、微静脉和毛细血管截面积.结果与对照组比较,实验组心肌组织毛细血管显著扩张(P＜0.001),微动脉、微静脉显著收缩(P＜0.05),实验组心肌缺血时血浆神经肽Y和内皮素水平显著上升(P＜0.001),再灌注时进-步上升(P＜0.001).心肌组织毛细血管内皮细胞脱落、固缩、变性和坏死,管腔内血细胞排列成串,心肌细胞水肿、变性、坏死,肌浆溶解,心内膜和心外膜下心肌间质广泛出血,心肌间质中性粒细胞呈小片状浸润,部分形成微脓肿.结论心肌组织微循环的改变在缺血再灌注损伤的发生机制中可能占重要地位.     

心肌微循环改变在缺血与再灌注损伤中作用的探讨

目的探讨缺血与再灌注时心肌组织微循环的改变。方法采用家兔心肌缺血与再灌注模型 ,观察心肌组织毛细血管腔内和管壁的变化以及心肌细胞与间质的形态学改变 ,并测定血浆神经肽Y和内皮素水平及心肌组织微动脉、微静脉和毛细血管截面积。结果与对照组比较 ,实验组心肌组织毛细血管腔显著扩张 (P<0.001) ,微动脉、微静脉显著收缩 (P<0.05)。实验组心肌缺血时神经肽Y和内皮素水平显著上升 (P<0.001) ,再灌注时进一步上升 (P<0.001)。心肌组织毛细血管内皮细胞脱落、固缩、变性和坏死 ,管腔内血细胞排列呈串 ,心肌细胞水肿、变性、坏死 ,肌浆溶解 ,心内膜和心外膜下心肌间质广泛出血 ,心肌间质中性粒细胞呈小片状浸润 ,部分形成微脓肿。结论心肌组织微循环的改变在缺血再灌注损伤的发生机制中可能占重要地位     

Microemboli detection and classification by innovative ultrasound technology during simulated neonatal cardiopulmonary bypass at different flow rates, perfusion modes, and perfusate temperatures

The objective of this study was to detect and classify the number and size of gaseous microemboli in a simulated pediatric model of cardiopulmonary bypass. Tests were conducted at five different flow rates (400-1,200 ml/min in 200 ml/min increments), pulsatile versus nonpulsatile perfusion modes, and under normothermic, hypothermic, and deep hypothermic (35 degrees C, 25 degrees C, and 15 degrees C) conditions, yielding 180 total experiments. The circuit was primed with lactated Ringer's solution and filled with heparinized bovine blood. At the beginning of each experiment, 5 ml of air were injected into the venous line via the luer port of the oxygenator. Microemboli were quantified and classified by size for 5 minute segments at three transducer sites: postpump, postoxygenator, and postarterial filter. The purge line of the arterial filter was closed during all experiments. In all but one experiment, 90% of emboli at the postpump site were found to be smaller than 40 microm. At the postarterial filter site, nearly 99% of the emboli were smaller than 40 microm. Additionally, increasing microemboli counts were observed when the flow rate was increased and when the temperature was decreased. Lower temperatures, higher flow rates, and pulsatile perfusion were all associated with higher emboli counts. The majority of gaseous microemboli found in the simulated circuit was significantly below 40 microm; the smallest level detectable by traditional Doppler devices.     

Gaseous microemboli detection in a simulated pediatric CPB circuit using a novel ultrasound system

The objective of this study was to evaluate the effect of flow rate and perfusion mode on the delivery of gaseous microemboli in a simulated pediatric cardiopulmonary bypass (CPB) circuit with an open arterial filter purge line using a novel ultrasound detection system. The circuit was primed with 450 ml fresh, heparinized bovine blood plus 200 ml Lactated Ringer's solution (total volume 650 ml, corrected Hct 25%). After the injection of 5 ml air into the venous line, an Emboli Detection and Classification (EDAC) Quantifier (Luna Innovations, Inc., Roanoke, VA) was used to simultaneously record microemboli counts at postpump, postoxygenator, and postarterial filter sites. Trials were conducted at four different flow rates (500, 750, 1,000, 1,250 ml/min) and two perfusion modes (pulsatile, nonpulsatile). Microemboli counts uniformly increased with increasing pump flow rates. In all trials, the majority of gaseous microemboli detected in the simulated pediatric CPB circuit were <20 microm in diameter. At the lowest flow rate tested (500 ml/min), all microemboli (>10 microm) were cleared from the circuit by the oxygenator and arterial filter. Clearance efficiency was decreased at higher flow rates (750-1,250 ml/min). Over 98% of microemboli detected at the postoxygenator site were <40 microm in diameter. In general, pulsatile flow delivered more microemboli to the circuit at postpump and postoxygenator sites than nonpulsatile flow. The results of this study confirmed that entrained air from the venous line could be delivered to the systemic circulation (as represented by our pediatric pseudo patient) at flow rates from 750 to 1,250 ml/min, despite the presence of an arterial filter and open arterial filter purge line. All of the microemboli distal to the arterial filter were smaller than the conventional detectable level of 40 microm.     

Microemboli generation, detection and characterization during CPB procedures in neonates, infants, and small children

In our laboratory, we study different factors that influence the microemboli counts in the extracorporeal circuit using a simulated pediatric cardiopulmonary bypass (CPB) model identical to the one used in our operating rooms. For monitoring and classification of microemboli, we use the novel Emboli Detection and Classification (EDAC) Quantifier system which allows for real-time monitoring, localization, and size characterization of microemboli as small as 10 microm. Our results show that high flow rates, low perfusate temperature, use of vacuum assisted venous drainage (VAVD), use of roller pump, and pulsatile flow results in higher microemboli counts at postpump site. Microemboli counts at postoxygenator, and postfilter sites are significantly less. This indicates that hollow fiber membrane oxygenator was able to remove most of the microemboli, and an opened arterial filter purge line augments the removal of microemboli that were not captured by the oxygenator. Majority of the microemboli detected at all sites were <40 microm in size. Based on the results of our studies, we started using the EDAC Quantifier system in our operating rooms at Penn State Hershey Children's Hospital. More basic science studies and clinical outcome data are needed for further study in minimizing the adverse effects of pediatric CPB procedure.     

参附注射液的微循环作用研究

观察参附注射液对各种微循环状态的影响，用微循显微分析系统观察给予参附注射液的小鼠耳廓微动脉在各种状态（正常状态、肾上腺素或内毒素导致循环障碍状态）下的直径，毛细血管交叉网点数及血流速度，并与生理盐水对照组，参麦组，地塞米松组的上述指标进行比较，结果表明，参附注射液均使各种状态下的小鼠耳廓微动脉直径扩大，毛细血管交叉网点数及血流速度增加，其中对肾上腺素，内毒素所致外周血循环障碍作用尤为显著，其作用较参麦注射液明显，与地塞米松作用相似，对内毒素攻击所致小鼠体表温度降低有明显对抗作用。     

冷刺激对青年人甲襞微循环及微区血流量的影响

目的:观察冷刺激对青年人甲襞微循环及微区血流量的影响。方法:应用显微电视录像技术和激光多普勒微循环血流仪,检测33例青年人(包括男12例、女21例)冷刺激后3min甲襞微循环形态、流态和袢周状态以及微区血流量的变化。结果:冷刺激后甲襞微循环由实验前的线流或线粒流变为粒线流或粒流,流速变慢,总积分值增大;微区血流量减少(由5.51±1.18mv减少为5.16±1.38mv,P<0.05)。结论:冷刺激可造成甲襞微循环障碍与甲襞微区血流量减少。     

腰交感神经毁损术对股骨头缺血性坏死患者微循环和血管活性物质的作用

目的:观察腰交感神经损毁术(LS)对股骨头缺血性坏死(ANFH)患者微循环和血管活性物质水平的影响。方法:运用LS治疗20例ANFH,观察治疗前后患者足甲襞微循环、血浆内皮素(ET)和降钙素基因相关肽(CGRP)、血栓素B2(TXB2)和6-酮-前列腺素(6-Keto-PGF1a)的水平变化,并与20例健康体检者进行比较。结果:与治疗前比较,ANFH患者治疗后足甲襞微循环各项积分、ET和TXB2含量均明显下降,CGRP和6-Keto-PGF1a含量均明显上升(P均<0.01),接近正常值水平。结论:LS能有效改善ANFH微循环障碍,纠正ANFH患者血管活性物质的代谢失衡,有利于改善股骨头的缺血缺氧状态。     

Pulmonary hypertension attributable to neoplastic emboli: An autopsy study of 20 cases and a review of literature

Twenty cases of pulmonary hypertension attributable to neoplastic emboli were the subject of this retrospective autopsy study (1951–1990) at the Mayo Clinic. Fourteen patients were women, and ages ranged from 18 to 82 years (mean 49). In three patients, tumor was clinically occult, and in only one case was the diagnosis of neoplastic pulmonary hypertension considered clinically. The mean interval between diagnosis of malignancy and development of respiratory symptoms was 14 months, but the mean interval between respiratory symptoms and death was only one month. At autopsy, the three most common primary sites for neoplasm were breast (40%), stomach (15%), and lung (10%). All 20 cases revealed subacute changes of pulmonary hypertension, either with medial hypertrophy of muscular pulmonary arteries (70%) or with right ventricular hypertrophy (45%) or dilatation (40%). However, three subgroups were identified based on microscopic and gross features: (i) 6 patients with predominantly neoplastic microemboli, (ii) 10 patients with mixed neoplastic and thrombotic microemboli, and (iii) 4 cases with both neoplastic microemboli and large, fatal tumor emboli (primary tumors in kidney, femur, cervix, and thyroid). In conclusion, neoplastic pulmonary hypertension is most commonly associated with carcinoma of the breast, accounting for the observed female preponderance. It is generally associated with a rapid clinical course once respiratory symptoms develop, and large, fatal, acute neoplastic emboli account for a substantial number of deaths (20% in the present series).     

体位改变对儿童足甲襞微循环的影响

应用微循环显微镜和微循环图像处理系统，对52名年龄均为6岁的健康儿童行左足甲襞微循环观测。受试儿童取仰卧位、坐位及站立位．分别观测三种体位下的足甲襞微循环十九项指标，并进行三种体位下微循环两两比较，探讨体位改变对儿童足甲襞微循环的影响。结果表明，儿童足甲襞微循环管襻数目、输入校和输出枝长度、输入枝和输出枝及襻顶直径、微循环血流速度等随体应改变出现显著性变化，其余指标无明显改变。指出观测儿童足甲襞微循环时，特别是动态监测的病例，应固定在同一体位下观测，以减少观测误差，提高足甲襞微循环的研究水平。认为仰卧位是儿童足甲襞微循环观测的最佳体位。     

茶色素对中老年人血脂和甲襞微循环的影响

目的：研究25例健康中老年人口服茶色素前后血脂、甲襞微循环的变化。方法：服茶色素每日3次，每次250mg，连服3个月。服药前后查血脂及甲襞微循环。仪器用日立7150型生化仪、XY－3型DOC显示器，BCAC教育型微循环显微镜按田氏加权积分进行检测。结果：25例中老年人口服茶色素前后各项指标均有显著性差异（P＜0．01）。结论：茶色素对中老年人有降低胆固醇，改善微循环的作用，对防治心脑血管疾病有效。     

尾加压素Ⅱ对大鼠肠系膜微循环的影响

目的: 探讨尾加压素(UII)对于大鼠肠系膜微循环的影响。方法: 采用活体微循环观测技术观察UII对于SD大鼠肠系膜微血管内径、血流速度的作用,采用激光多普勒血流量仪测定肠壁血流量的变化。结果: 正常对照组肠系膜细动脉和细静脉血管内径分别为(21.4±2.3) μm和(38.1±3.6) μm,UII组于滴加UII(10^-7mol/L)后即刻细动脉和细静脉出现收缩,1 min时细动脉和细静脉收缩达到高峰,血管内径分别为(14.1±1.4) μm和(22.2±5.2) μm(与正常对照组比较,P<0.05);细动、静脉内血流速度无明显变化(与正常对照组比较P>0.05);肠壁血流量于滴加UII(10^-7 mol/L)后1 min开始升高,5 min达到高峰 。结论: UII可以使大鼠肠系膜微血管收缩,血流量增加。