人工肝支持系统的研究现状及展望

肝功能衰竭导致严重的生理紊乱、毒性物质积聚,进而影响肝细胞的功能及再生,形成恶性循环。人工肝的研究正是基于肝细胞的强大再生能力,通过一个体外的机械或理化装置,担负起暂时辅助或代替严重病变的肝脏的功能,清除各种有害物质,代偿肝脏的代谢功能,从而使肝细胞得以再生直至自体肝脏恢复或等待机会进行肝移植。目前的人工肝多数只能取代肝脏的部分功能,因此又被称为人工肝支持系统(artificial liver support system,ALSS),简称人工肝。 人工肝有三个主要类型:(1)非生物型人工肝:指各种以清除毒素功能为主的装置,包括血液透析、血液滤过、血液/血浆灌流、血浆置换、分子蛋白吸附再循环系统等,其中血浆置换既能清除毒性物质,又     

体外生物人工肝辅助装置生物转化功能的初步研究

为评价培养人肝细胞与中空纤维生物反应器组成的人工肝辅助装置(LAD)的生物功能，采用荧光偏振分析方法，进行了LAD转化安定和利多卡目的体外实验。结果显示；使用2×10^8个混合球形聚集培养的人肝细胞、肝非实质细胞，体外实验5小时后，99．1％的安定和91．1％的利多卡因被转化代谢，其中86．3％的利多卡因和97．3％的安定转化于LAD循环1小时内。实验前后，肝细胞乳酸脱氢酶释放不明显、肝细胞活力和再贴壁能力良好。结果表明，LAD具有肝脏P450系统生物转化功能，该装置对化学药物性肝衰竭可能具有解毒代谢与支持治疗作用。     

体外生物人工肝支持作用的实验研究

目的 构建理想的体外人工肝支持系统，探讨其对暴发性肝衰竭的支持作用。方法 用经体外两步灌流法分离，限制贴壁技术球形聚集混合培养的人肝细胞－肝非实质细胞与中空纤维型生物反应器及由血液透析仪改装的辅助循环装置共同构建的ＥＢＬＳＳ，对门腔静脉分流加入肝血液阻断法建立的ＦＨＦ模型犬进行人工肝支持实验。结果 在平均约１０＾８肝细胞－肝非实质细胞ＥＢＬＳＳ的支持下，治疗组犬存活时间较无细胞空白循环对照组延长近     

人工肝研究的现状及展望

利用人工肝脏(人工肝辅助装置)对肝功能衰竭进行治疗己研究了数十年，由于肝脏功能极为复杂，人工肝脏不易代替全部的肝功能，目前还来取得突破性进展。但是由于生物医学工程、遗传工程、生物医学等学科的迅速发展，人工肝脏的研究己有明显的起色，特别是人工肝辅助装置不但是抢救肝功能衰竭及急性中毒的有利武器、而且是等待肝移植的必须设备、人工肝的研制再度受到重视．有的甚至已进入Ⅰ期临床试验。现将研究现状综述如下：     

肝脏缺血再灌注损伤与钙超载

肝脏缺血再灌注损伤是临床上常见的病理过程,其发生机制与细胞内钙超载有关.钙超载的发生与胞质膜裂隙作用、Na /Ca2 交换、Ca2 -ATP酶活性下降、线粒体功能障碍以及氧自由基有关.钙超载防治措施包括:线粒体ATP敏感的K通道开放剂、麻醉荆、钙离子拮抗剂、线粒体通透性转换孔抑制剂和血红素氧合酶等.     

肝脏CT灌注检测技术在肝脏疾病中的临床应用

肝脏具有双重血供.在各种病理情况下,肝动、静脉和门静脉之间的血流动力学发生复杂的变化.此文综述了CT灌注成像在肝脏疾病的诊断、治疗及评估中的重要价值.     

肝脏的CT灌注成像及其应用

灌注成像作为一种无创性的功能成像,能在病变产生形态学改变之前较早反映病变组织的血流动力学改变,因此,在疾病的影像诊断与鉴别诊断方面具有重要的作用,特别是对各种治疗方法的疗效评估及监测方面具有重要的指导意义。此文综述了肝脏CT灌注成像的原理、灌注参数、灌注的技术要求及其在肝脏疾病影像诊断中的应用价值,目的在于推广该技术在肝脏疾病诊疗领域的临床应用。     

脂肪肝患者肝脏灌注状况的多普勒评价

用彩色多普勒超声评价脂肪肝的肝脏灌注状况，以求达到更为有效、简便、定量评价脂肪肝。     

肝脏干细胞研究和应用展望

慢性乙型肝炎是我国的一种常见疾病,而且随着社会经济的发展和生活水平的提高,脂肪肝、酒精性肝炎等患者也越来越多。这些疾病不断发展,逐渐演变为肝纤维化和肝硬化,最终导致肝功能衰竭,给人们的生命带来严重的威胁。早期的对症治疗不能解决根本问题,为此医学工作者进行了不懈的努力,寻找延缓肝纤维化发展和治疗肝功能衰竭的新办法。原位肝移植为肝功能衰竭患者带来一片曙光,但是肝移植供体的缺乏、费用昂贵、长期使用免疫抑制剂等因素束缚了其广泛应用;人工肝是近几年逐渐推崇的一种新疗法,它将肝衰竭的治疗向前推进了一大步,但目前的人工肝发展尚不完善,而且部分上市产品还不是真正意义上的人工肝,仍然摆脱不了血液透析的老路,其治疗效果当然也就可想而知了。     

Effect of aging process on liver function in extracorporeal rat liver perfusion

BACKGROUND/AIMS: Liver function appears to be well maintained in old age. However, the current state of knowledge about liver aging processes is incomplete. In this study, using extracorporeal liver perfusion model, we evaluated the differences between liver function in young and old rats. METHODOLOGY: Livers were harvested from groups of young (2 months) and old (12 months) rats and perfused for 2 hours with a perfusion fluid. After 10, 30, 60, 90 and 120 minutes of perfusion, glucose concentration as well as enzyme levels (alanine aminotransferase, aspartate aminotransferase and lactic dehydrogenase) were measured. On completion of perfusion all bile produced was collected. RESULTS: All measured parameters changed significantly as a function of perfusion time in both groups. Changes in enzyme levels were most evident between 90 and 120 minutes of perfusion. In contrast to old rats, where glucose concentration decreased during all time periods of perfusion, in young rats the glucose concentration increased at the beginning of perfusion. CONCLUSIONS: The results suggest that livers obtained from older rats are damaged to a greater extent and are more susceptible to unfavorable conditions during perfusion than livers obtained from younger rats. Also, single measurement of liver enzymes is not enough for complete liver function assessment.     

Plasminogen activator in bile during extracorporeal perfusion of pig liver

Plasminogen activator activity was studied in bile and perfusate during extracorporeal pig liver perfusion. Plasminogen activator activity in bile was up to 58 times greater than in perfusate. A high level of plasminogen activator activity in bile was also found after the addition of urokinase to the perfusate. These results suggest that bile is the main route of active excretion of plasminogen activator and urokinase from the liver in experimental liver perfusion.     

Preservation of non-heart-beating donor livers in extracorporeal liver perfusion and histidine-trytophan-ketoglutarate solution

AIM： To compare the preservation of non-heart- beating donor （NHBD） livers in cold histidine-trytophan- ketoglutarate （HTK） solution and extracorporeal liver perfusion （ECLP）. METHODS： Livers harvested from health pigs were stored for 10 h in cold HTK solution （group A, n = 4） or perfused with oxygenated autologous blood at body temperature （group B, n = 4）. Both groups were then tested on the circuit for 4 h. Bile production, hemodynamic parameters, hepatocyte markers and reperfusion injury of extracorporeal livers were tested in each group. Liver tissues from each group were examined at the end of reperfusion. RESULTS： At 1, 2, 3 and 4 h after reperfusion, bile production, hemodynamic parameters, hepatocyte markers and reperfusion injury of livers in group A were statistically different from those in group B （P 〈 0.05 or P 〈 0.01）. CONCLUSION： ECLP is better than HTK solution to preserve NHBD livers. ECLP can assess the graft viabilitybefore liver transplantation.