哺乳动物心脏微血管形态学研究——Ⅰ.正常心脏微血管的分布和走行

利用墨汁灌注、双色素灌注制作透明标本以及双色素微血管铸型的方法,研究了小鼠、大白鼠、家兔、家犬、猪等动物心脏微血管的分布和走行,并对铸型微血管的溅射样品进行了扫描电镜观察。心肌内的冠状动脉为终末动脉。心肌的微循环单位为终末毛细血管管袢。管袢的形态相同,大小相似。两条冠状动脉微血管野交界处的毛细血管管袢平行分布,其方向相同;或呈犬牙交错。心外微血管膜和脂肪层内的微血管侧枝较多,相互缠络成网状结构,但这个网状微血管膜与心肌内的微血管野之间没有联结通路。心肌细动脉可呈螺旋状。心脏的二尖瓣,三尖瓣、主动脉瓣和肺动脉瓣内未发现血管。     

大鼠小肠的微血管构筑

目的为探讨小肠微血管构筑与小肠的消化吸收等功能的关系.方法通过甲基丙烯酸甲酯血管铸型、扫描电镜观察的方法对大鼠小肠的微血管构筑进行了研究.结果大鼠小肠的微血管构筑分为粘膜下层、肌层和粘膜层三层.粘膜下动脉丛除有少量分支供应肌层外,大部分血管伸向粘膜层,浆膜层无毛细血管存在.肌层血管分为两层,每层毛细血管的排列方向均与其肌纤维的走向一致.绒毛血管丛为"喷泉型”,由绒毛微动脉、绒毛毛细血管网、绒毛微静脉组成.在绒毛血管丛的边缘,连有一条"边缘毛细血管”,到达绒毛基底部后,与相邻绒毛毛细血管网的基底部相连.结论"边缘毛细血管”及其与相邻绒毛关系的发现使我们认识到,小肠绒毛的血液除了由绒毛微静脉汇入粘膜下静脉外,还存在一条侧副循环途径,即由"边缘毛细血管”将血液引流入相邻绒毛血管丛,使小肠微血管的构筑更适应小肠的蠕动和消化吸收功自.     

实验性顿抑心肌微血管结构和功能改变

目的 探讨心肌顿抑时心肌微血管结构和功能改变。方法 制备冠状动脉左前降支（LAD）不同阻断时间（15min和60min)后再灌注犬心肌顿抑模型，在不同观察时间点静脉注射含全氟丙烷声振白蛋白微泡造影剂，采用二次谐波成像和间歇发射技术行心肌声学造影。由主动脉根部分别注射乙酰胆碱（ACH）和硝酸甘油（NG）后重复心肌声学造影，并计算用药后／前二维超声上所示心肌灰阶峰值比值（PVIR）和顿抑区与正常区心肌灰阶峰值比值的比值PVIRR。心肌标本行透射电镜检查。结果 （1）LAD阻断15min组再灌注早期NG－PVIR和ACH－PVIR明显减低，但分别在再灌注60min和120min时恢复至结扎前水平；（2）LAD阻断60min组再灌注早期NG－PVIR减低，至再灌注120min时才恢复到结扎前水平，而再灌注ACH-PVIR明显减低，随着再灌注时间的延长虽有逐渐回升趋势，但至再灌注120min仍未恢复至结扎前水平；（3）两组PVIRR的变化与PVIR一致，唯恢复稍慢；（4）LAD阻断15min组心肌毛细血管和内皮细胞结构未见明显改变，而LAD阻断60min组毛细血管内皮细胞肿胀，内皮细胞间连接间隙稍增宽。结论 顿抑心肌微血管舒张功能受损，缺血时间较长则还有微血管结构改变，其受损的细胞主要是内皮细胞。     

心得安对急性心肌缺血时微血管损伤的作用

冠状动脉闭塞后不仅在心肌细胞,而且在毛细血管、小静脉和供应心肌的小动脉发生缺血性损伤。某些药物具有对抗微血管破坏的保护作用,从而能保存侧枝血流,这是它们保护缺血心肌的作用机理之一。本文旨在判断β-受体阻滞剂心得安能否减少微血管的缺血性损伤。方法:麻醉狗先第一次闭塞冠状动脉左前降支15分钟,然后放松,给予再灌注30分钟,随机分为两组,10只狗在第二次闭塞前10分钟静脉注射生理盐水,7只狗给予每公斤2毫克心得安。两组狗在第二次闭塞1小时后,经左心房导管注射胶体碳黑(300颗粒)1毫升/公斤体重,恢复再灌注2小时     

选择性冠状静脉动脉化后心肌微血管水平再灌注质量

目的:评估选择性冠状静脉动脉化对慢性缺血心肌微血管水平的灌注质量和心肌收缩功能的影响。方法:建立杂种犬慢性心肌缺血模型,采用结扎心大静脉(GCV)近心端,游离左内乳动脉(LIMA)与 GCV行端侧吻合,建立静脉动脉化逆行灌注模型。采用心肌声学造影(MCE)观察缺血区微血管水平的声学密度并判断其再灌注质量。心脏超声测定左室射血分数(LVEF)及左室前壁收缩期增厚率(AWT),评价心肌收缩功能。结果:经冠状静脉动脉化后缺血区心肌微血管水平声学密度明显提高,LVEF及AWT均明显增加(均P<0.05)。结论:选择性冠状静脉动脉化能有效提高慢性缺血区心肌微血管水平的血流灌注,从而增强心肌收缩功能。     

微血管顿抑

微血管顿抑(Microvascular Stunning)指心肌暂时性缺血再灌注后出现的微血管功能可逆性损伤,亦称微血管再灌注损伤。主要表现为微血管的扩张功能受损,冠脉储备减低,微血管通透性增加以及组织学的相应改变。其可能的发生机制为氧自由基作用,白细胞-内皮相互作用,或二者共同引起。     

冠状动脉微血管功能障碍的研究进展

梗死相关动脉开通后,微血管功能障碍常常是影响急性心肌梗死患者生存率的重要因素。冠脉微血管功能障碍被认为是由于微血管阻塞/抵抗和/或再灌注损伤及炎症反应导致。对于微血管功能障碍的深入认识,有助于提高急性心肌梗死患者的组织灌注水平,提高患者生存率。     

冠脉系统微血管的研究进展

心肌微循环系统是心肌正常功能的基本保障,冠状微血管结构与功能均可发生异常,目前已证明动脉微血管可发生内皮功能障碍,且与动物的种类、实验模型的不同无关,这可以用各种刺激因素证明内皮功能障碍的存在。动脉粥样硬化病人的冠状微血管在基础状态下和药物刺激期间也已显示出NO利用度的降低。本文针对目前冠状动脉系统微血管的研究进展作一综述。1冠状微血管的定义和结构特点冠状动脉系统的微血管是指内径小于300滋m的血管,它包括血流从微血管一直到毛细血管(即血管壁只有内皮细胞组成)的“动脉微血管”,以及血流由毛细血管流入的“静脉微…     

冠状动脉微循环及微血管性心绞痛的研究进展

冠状动脉微循环在心肌的血供中起着重要作用。心肌声学造影是诊断微循环水平心肌灌注的新技术,可同时观察心脏的结构、心肌局部和整体功能以及心肌的各级血流灌注,有利于研究冠状动脉微循环的病理生理机制并可能检出早期微血管内皮功能不全。在正常健康人,肌源性血流依赖性微动脉扩张和微循环代谢产物导致的冠状动脉微循环收缩形成互相制约的平衡调节机制,保持正常血流灌注。在冠心病心肌缺血如劳力性心绞痛时由于心肌代谢增加氧耗增加导致心肌缺血时,微血管反而收缩加剧缺血。研究表明这类患者是由于小冠状动脉扩张储备减低或冠状动脉收缩而导致心肌缺血,冠状前小动脉是调节心肌血液灌注的主要功能部位。     

冠心病的微血管损伤研究进展

微血管损伤在冠心病发病机制中起到一定的作用 ,本文从心肌缺血—再灌注期间微血管损伤、微血管性心绞痛心肌血流量的异常分布、减少白细胞数量和组织型纤维蛋白溶酶原激活剂、去铁铵对损伤的微血管中血栓形成的影响、急性心肌梗死后微血管完整性与钠积蓄时间过程和血管紧张素转换酶抑制剂等冠状动脉系统微血管功能与调节和冠心病微血管损伤防治方面进行了最新研究综述     

Microscopic-sized "microthymoma" in patients with myasthenia gravis

BACKGROUND: In 2005, Cheuk et al reported two patients with microscopic-sized thymomas and proposed the term microthymoma to distinguish it from the nodular hyperplasia of thymic epithelium, so-called microscopic thymoma. Here, we present microthymomas that were found in 196 patients with myasthenia gravis (MG) who had undergone thymectomy. MATERIALS AND METHODS: Thymic tissues in 196 patients with MG who underwent thymectomy or thymothymomectomy were examined. Of these patients, 73 patients had thymoma indicated by CT before surgery, and the other 123 patients had no mediastinal tumors. From the resected thymic tissues, an average of 14 hematoxylin-eosin-stained sections (range, 4 to 55 sections) were prepared for microscopic examination. The histologic type of the thymoma was classified according to the World Health Organization (WHO) classification. RESULTS: From the 196 patients, we found three microthymomas in 3 patients (1.5%). While these three tumors could not be seen grossly in pathology section, they were found microscopically (range, 2 to 4 mm). The histologic subtype according to the WHO classification system was B1 in one patient and B2 in two patients. CONCLUSION: Microthymoma was found in 3 of 196 patients (1.5%) with MG. Microthymoma might exist in thymus of patients with MG, even in patients who have no thymoma indicated by CT.     

Portable exhaled nitric oxide measurement: Comparison with the "gold standard" technique

Background:The measurement of fractional exhaled nitric oxide (FENO) can assist in the diagnosis of asthma and may also act as a useful surrogate inflammatory marker on which to base treatment decisions in asthma management algorithms. Until recently, this technique was confined to research facilities and secondary care institutions. A portable nitric oxide analyzer (MINO; Aerocrine AB; Smidesvägen, Sweden) has been developed, but few data exist comparing this device with established, larger laboratory-based analyzers (NIOX; Aerocrine AB).Methods:A total of 101 asthmatic patients (64 treated with regular inhaled corticosteroids) and 50 healthy volunteers had simultaneous FENO measurements undertaken using NIOX and MINO devices.Results:In both asthmatic patients and healthy volunteers, there was a good correlation between the measurements obtained using each device (r= 0.94 and 0.96, respectively). Altman-Bland plots confirmed this agreement. Receiver operating characteristic curves discriminating asthmatic patients from healthy volunteers obtained using the NIOX and MINO showed a sensitivity of 83.2% and a specificity of 72% using cutoff values of 13 and 12.5 parts per billion, respectively.Conclusion:FENO values obtained using a portable analyzer correlate well with those obtained using an established laboratory analyzer and can be used to discriminate asthmatic from nonasthmatic patients. This may facilitate the measurement of asthmatic airway inflammation in primary care.     

World Trade Center "sarcoid-like" granulomatous pulmonary disease in New York City Fire Department rescue workers

BACKGROUND: Previous reports suggest that sarcoidosis occurs with abnormally high frequency in firefighters. We sought to determine whether exposure to World Trade Center (WTC) "dust" during the collapse and rescue/recovery effort increased the incidence of sarcoidosis or "sarcoid-like" granulomatous pulmonary disease (SLGPD). METHODS: During the 5 years after the WTC disaster, enrollees in the Fire Department of New York (FDNY) WTC monitoring and treatment programs who had chest radiograph findings suggestive of sarcoidosis underwent evaluation, including the following: chest CT imaging, pulmonary function, provocative challenge, and biopsy. Annual incidence rates were compared to the 15 years before the WTC disaster. RESULTS: After WTC dust exposure, pathologic evidence consistent with new-onset sarcoidosis was found in 26 patients: all 26 patients had intrathoracic adenopathy, and 6 patients (23%) had extrathoracic disease. Thirteen patients were identified during the first year after WTC dust exposure (incidence rate, 86/100,000), and 13 patients were identified during the next 4 years (average annual incidence rate, 22/100,000; as compared to 15/100,000 during the 15 years before the WTC disaster). Eighteen of 26 patients (69%) had findings consistent with asthma. Eight of 21 patients (38%) agreeing to challenge testing had airway hyperreactivity (AHR), findings not seen in FDNY sarcoidosis patients before the WTC disaster. CONCLUSION: After the WTC disaster, the incidence of sarcoidosis or SLGPD was increased among FDNY rescue workers. This new information about the early onset of WTC-SLGPD and its association with asthma/AHR has important public health consequences for disease prevention, early detection, and treatment following environmental/occupational exposures.     

"Synaptic" Ribbons in the Pineal Gland of the Horse

Previous studies on the ultrastructure of the horse pineal gland did not report the presence of "synaptic" ribbons, functionally enigmatic pinealocyte organelles regularly occurring in other mammalian species. The aim of the present study was to reinvestigate the horse pinealocyte in this respect. Careful investigations here reported allowed detection of "synaptic" ribbons in the pinealocytes of all the examined animals, although in a relatively low number (5.4 +/- 2.0 per 20,000 microns 2 of pineal tissue; mean +/- SD). The ultrastructure of "synaptic" ribbons in pinealocytes of the horse resembles closely that observed in other mammalian species.     

"Ultrasound comet-tail images": a marker of pulmonary edema: a comparative study with wedge pressure and extravascular lung water

BACKGROUND: Echographic examination of the lung surface may reveal multiple "comet-tail images" originating from water-thickened interlobular septa. These images could be useful for noninvasive assessment of interstitial pulmonary edema. STUDY OBJECTIVE: The purpose of this study was to assess the diagnostic accuracy of lung comet-tail images compared with chest radiography, wedge pressure, and extravascular lung water (EVLW) quantified by the indicator dilution method (PiCCO System, version 4.1; Pulsion Medical Systems; Munich, Germany). METHODS AND PATIENTS: We enrolled 20 patients (mean age, 62.6 +/- 11.5 years [+/- SD]). Patients were studied before, immediately after, and 24 h following cardiac surgery with chest ultrasound, chest radiography, pulmonary artery catheterization, and the PiCCO system. Performing echo scanning (right and left hemithorax, from second to fourth intercostal space, from parasternal to midaxillary line), an individual patient comet score was obtained by summing the number of comets in each scanned space. RESULTS: A total of 60 comparisons were obtained. Significant positive linear correlations were found between comet score and EVLW determined by the PiCCO System (r = 0.42, p = 0.001), between comet score and wedge pressure (r = 0.48, p = 0.01), and between comet score and radiologic lung water score (r = 0.60, p = 0.0001). CONCLUSIONS: The presence and the number of comet-tail images provide reliable information on interstitial pulmonary edema. Therefore, ultrasonography represent an attractive, easy-to-use, bedside diagnostic tool for assessing cardiac function and pulmonary congestion.     

Echocardiographically detected mass "in transit" in early amniotic fluid embolism.

BACKGROUND: Amniotic fluid embolism is a catastrophic illness related to the passage of fetal material into the pulmonary circulation causing cardiovascular collapse. CASE: A 29-year-old female sustained cardiopulmonary arrest during delivery presumably due to amniotic fluid embolism. A right atrial mass "in transit" was detected by echocardiography. It had an appearance and pattern of motion that was suggestive of a gelatinous consistency and is likely to have been an amniotic fluid embolus. There was also evidence of acute right ventricular overload. CONCLUSION: We recommend that echocardiography be considered early on such conditions to gain more insight into the pathogenesis of this complication.     

补肾益精方对切除卵巢大鼠骨质疏松模型腰椎骨生物力学性能的影响

目的：探讨被 肾益精方对去卵巢大鼠骨质疏松模型松质骨生物力学性能的影响,方法：40只10月龄Wistar雌性大鼠随机分为正常对照组,模型对照组,补肾益精方组和倍美力组,每组10只,正常对照组做假手术,其余3组做卵巢切除术,术后3个月开始给药,连续用药满90天,处死,取出第3腰椎,测定其骨质含量并进行压应力测试与分析,结果：补肾益精方组比模型组腰椎骨的骨质含量提高了6．19％,最大承载力增加了21．66％,极限强度增加了16．93％,结论：应用补肾益精方可以明显改善去卵巢大鼠骨质疏松模型松质骨的生物力学性能。     

青海"三江源"地区鼠疫血清流行病学调查分析

目的对青海省"三江源"地区开展鼠疫血清流行病学调查,了解分析流行态势,为该地区鼠疫防治措施的制定与落实提供依据。方法对历年的鼠疫细菌学资料进行总结分析,对"三江源"部分地区人及各种动物采血做血清抗体调查。结果该地区发现15种动物可自然感染鼠疫,10种动物血清存在鼠疫抗体,人群血清鼠疫抗体阳性率达2.47%。结论"三江源"地区动物鼠疫持续流行,参与染疫的动物种类多,时常波及人间造成人间鼠疫流行,人群存在部分隐性感染鼠疫者。尚有部分地区需进行深入的自然疫源地调查。     

电针足三里穴对兔肺缺血再灌注损伤脂质过氧化反应的影响

目的研究电针足三里穴对在体家兔肺缺血再灌注损伤的影响。方法28只新西兰家兔采用在体肺热缺血再灌注损伤模型．随机分四组（n=7）。A组：假手术组。左开胸游离支气管和肺动脉、静脉后维持通气180min。B组：缺血再灌注组，左开胸游离支气管和肺动脉、静脉后阻断左肺门60min．开放再通气120min。C组：阻断左肺门60min后．开放再通气即刻电针足三里穴旁5mm处30 min．继续双肺通气90min。D组：电针足三里穴＋缺血再灌注组，阻断左肺门60min后。开放再通气即刻电针足三里穴30min．继续双肺通气90min。观察并记录各组动物术中平均动脉压和心率的改变及实验结束时肺组织丙二醛（MDA）和髓过氧化物酶（MPO）含量以及肺组织湿/干重比（W/D）和血气变化。结果各组动物相应时间点的心率比较，均无统计学意义（P〉0.05）。自再灌注30min开始，与B组比较。C组平均动脉压显著降低（P〈0．05），D组平均动脉压与B组比较无统计学意义（P〉0．05）。B组肺组织MDA和MPO含量、W／D及PaCO2值均较A组升高．pH和PaO2值显著降低（P〈0．05或P〈0．01）；D组肺组织MDA和MPO含量、W／D及PaCO2值均较B组降低，pH和PaO2值显著升高（P〈0．05或P〈0．01）。结论电针家兔足三里穴可明显抑制肺缺血再灌注损伤时肺组织MDA和MPO的产生，减轻肺水肿的发生，改善血气变化及酸碱失衡．对在体家兔肺缺血再灌注损伤有一定的保护作用。     

Gelatin "shots" as a new method for alcohol administration in a laboratory setting

BACKGROUND: This experiment was designed to compare gelatin "shots"-a new procedure for administering alcohol in a laboratory setting-to the alcohol beverage method. We proceeded to test whether the two methods were comparable in terms of alcohol absorption, metabolism, and effects on mood and whether gelatin "shots" were better than the beverage in disguising alcohol in a blind, placebo comparison. METHODS: Healthy volunteers participated in a two-phase trial. In the first phase they completed 2 days of testing during which the effects of alcohol-delivered in beverage (1 day) or gelatin "shots" (alternative day)-on blood and breathalyzer concentrations and mood were assessed. In the second phase participants completed 2 days of testing and were asked to identify if samples contained alcohol or placebo. The presentation of alcohol and placebo and the presentation of beverage or gelatin "shots" were random. RESULTS: In the first phase there was a significant time-by-condition interaction in the blood alcohol concentration. Two-and-a-half hours after the alcohol was administered, those given gelatin "shots" had slightly lower but statistically significant blood alcohol concentrations. There was a significant time effect for breathalyzer alcohol levels but no condition or condition-by-time interaction. There were no differences between the two methods on any of the subjective mood measures. In the second phase of the study there were differences in the ability to differentiate alcohol from placebo between the two conditions with significantly more participants making errors in the gelatin "shots" than in the beverage condition. CONCLUSIONS: Our findings indicate that gelatin "shots" are an effective method for delivering alcohol to humans in a laboratory setting. This method may be superior to the alcohol beverage mixture in a placebo-controlled design because gelatin "shots" mask the alcohol much better than a beverage and are easier to administer.