胆固醇结石患者胆囊胆汁中凝血和纤溶状态的初步研究

目的：通过研究胆固醇结石患者胆囊胆汁中凝血纤溶状态与交联纤维蛋白生成和降解的关系来探讨胆囊结石的形成机制。方法：收集胆固醇结石（简称胆石）患者胆囊胆汁20份和非胆囊结石患者胆囊胆汁15份,测定胆汁中的纤维蛋白特异性降解产物D－二聚体抗原和部分凝血纤溶因子抗原和活性水平。结果：胆囊结石组建者胆汁中D－二聚本抗原高于非胆囊结石组（P＜0．01）,抗凝血酶Ⅲ抗原高于非胆囊结石组（P＜0．05）,抗凝血酶Ⅲ活性低于非胆石组（P＜0．05）,胆石组抗凝血酶Ⅲ抗原与活性之比与非胆石组相比明显增高（P＜0．01）,胆石组纤溶酶活性较非胆石组增高（P＜0．05）,纤溶酶活性与凝血活性指标之比明显低于非胆石组（P＜0．05）,两组间纤溶酶原激活性抑制活性差异无显著性。结论：胆固醇患者胆囊胆汁中的凝血和行 性均高于非胆石组,但纤溶活性增高的程度与凝血活性比则明显减低,从而使交联纤维蛋白折生成增多,而降解相对减少,导致成石组胆囊胆汁中交联纤维蛋白积累,促进胆囊结石的形成。     

胆囊黏膜ABCA1的表达和胆囊胆固醇息肉发病关系的研究

目的：研究ABCA1在胆囊黏膜的表达及其表达与胆囊胆固醇息肉发病的关系。方法：收集因胆囊疾患而行腹腔镜胆囊切除术病人的胆石、胆汁、胆囊黏膜及胆囊壁全层组织共计42例,其中胆囊胆固醇息肉15例,胆囊胆固醇结石15例,对照组12例（胆囊腺瘤5例,非胆固醇胆囊结石7例）。分别测定胆石胆固醇含量、胆汁胆固醇、胆汁酸、磷脂的浓度;实时PCR定量检测胆囊黏膜ABCA1、LXRα、RXRα的mRNA表达：胆囊壁全层组织做病理切片;免疫组化显示ABCAl蛋白在胆囊黏膜的表达．结果：胆固醇息肉组胆汁胆固醇饱和指数为1．0±0．2,较对照组胆固醇饱和指数0．6±0．3明显增高,其差别有统计学显著性（P〈0．01）。免疫组化显示ABCA1在胆囊黏膜上皮细胞有明显表达。息肉组、结石组和对照组胆囊黏膜ABCAI、LXRa、RXRα mRNA相对表达量比较,各组之间差异无统计学意义。结论：胆囊黏膜ABCA1的表达可能并不是导致胆囊胆固醇息肉发病的重要原因。     

胆囊黏膜ABCG5和ABCG8基因在胆固醇结石病中的作用

目的探讨ABCG5和ABCG8基因在胆囊黏膜中的表达与胆固醇结石病的关系。方法采集28例胆囊胆固醇结石病患者和10例无胆石对照的胆囊黏膜和胆汁、胆石。测定胆汁胆固醇、胆汁酸和磷脂含量;Real-time PCR测定胆囊黏膜中ABCG5和ABCG8的表达量。结果胆石组中胆固醇摩尔百分比和饱和指数均较对照组显著升高(P<0.01);ABCG5和ABCG8的表达呈显著正相关(r=0.55,P<0.01),胆石组中ABCG5和ABCG8的mRNA表达分别是对照组的2.8倍(P<0.01)和1.9倍(P<0.05)。结论胆固醇结石病患者的胆囊黏膜ABCG5和ABCG8基因表达增高,限制了胆囊上皮对胆固醇的吸收,使胆汁过饱和状态得以维持。     

胆囊黏膜ABCG5和ABCG8与胆囊胆固醇息肉关系的研究

目的:研究胆囊黏膜ABCG5和ABCG8的基因表达与胆囊胆固醇息肉发病的关系.方法:收集63例因胆囊疾患而行腹腔镜胆囊切除术患者的胆石、胆汁及部分胆囊黏膜组织,其中胆囊胆固醇息肉32例,胆囊胆固醇结石18例,对照13例(胆囊腺瘤6例,非胆固醇胆囊结石7例),分别测定胆石胆固醇含量,胆汁胆固醇、胆汁酸、磷脂的浓度,实时定量PCR检测胆囊黏膜ABCG5和ABCG8的mRNA表达.结果:胆固醇息肉组胆汁胆固醇饱和指数较对照组明显增高(P<0.01),结石组胆囊黏膜ABCG5和ABCG8的表达量较息肉组和对照组显著增高,息肉组和对照组ABCG5和ABCG8的表达量差异无统计学意义(P>0.05).结论:胆囊黏膜ABCG5/ABCG8 mRNA的相对低水平表达,可能是导致胆囊胆固醇息肉发病的重要因素之一.     

氨肽酶N在胆固醇结石成因中作用的初步研究

目的　观察胆固醇结石病人和无结石者之间胆囊胆汁中氨肽酶N(APN)活性的变化及熊去氧胆酸 (UDCA)对APN活性的影响。方法　选择胆结石病人 ,随机分成两组 ,服用UDCA组和非服药组 ,无结石行上腹部手术的病例作为对照组。测定胆囊胆汁中蛋白质、APN活性、胆固醇、磷脂、胆盐、胆固醇饱和指数 ,比较各组结果。结果　发现APN活性在胆固醇结石病人胆囊胆汁中含量较无结石者高 (1 2 37± 0 371vs0 895± 0 2 47) ,P <0 0 5 ,服用UDCA后胆汁中APN活性较不服用UDCA者降低 (0 711± 0 2 45vs 1 2 37± 0 371) ,P <0 0 5。结论　本实验显示胆固醇结石病人与无结石者之间存在着APN活性上的差别 ;UDCA能够在降低胆固醇饱和指数的同时 ,也降低APN活性。     

磷脂代谢紊乱在胆固醇结石形成中的作用(文献综述)

最近十多年对胆囊结石(后文简称胆石)发病机理的研究,人们渐渐认识到肝脏代谢功能紊乱分泌胆固醇过饱和胆汁、胆囊内促成核因子增加和胆囊收缩功能下降是胆石形成过程中的三个必不可少环节.在成核因子中,粘糖蛋白的促成核作用尤其引人关注,这是一种高分子的糖蛋白多聚物,是胆囊上皮细胞分泌的主要物质.本文将着重讨论磷脂代谢紊乱与粘糖蛋白分泌的关系.胆汁磷脂的组成和磷脂的功能胆汁磷脂中80～95%为磷脂酰胆碱(PC),其余还有磷脂酰乙醇胺(PE)、磷脂酰肌醇(PI)、磷脂酰丝氨酸(PS)及鞘磷脂(SM)等物质.正常肝胆汁和致石肝胆汁中都不含溶血磷脂酰胆碱(LPC),无菌的胆囊胆汁中磷脂酶A_2(PLA_2)也无活性.人胆汁中,70～80%PC是Sn-1软脂酰、Sn-2油酰、亚油酰或花生四酰.磷脂是胆汁中的四种主要成份之一,它在胆汁中     

家族性胆固醇结石患者肝组织CYP7A1 mRNA的表达

目的:研究家族遗传性胆囊胆固醇结石患者、散发性胆固醇结石患者和非结石患者肝组织CYP7A1基因mRNA的表达改变及其与胆汁成石性变化的关系.方法:应用逆转录-聚合酶链反应(RT-PCR)技术,研究了28例具有家族遗传性胆囊胆固醇结石患者、30例散发性结石患者和32例非结石患者肝组织CYP7A1 mRNA的表达变化;并采用生物化学技术行胆汁脂质分析,计算成石指数.结果:家族遗传性和散发性胆固醇结石组CYP7A1 mRNA表达水平较非胆固醇结石组降低,差异有显著性;在家族遗传性和散发性胆固醇结石组两组间无统计学差别;各组肝组织CYP7A1 mRNA表达与胆汁成石指数(LI)呈负相关.结论:胆囊胆固醇结石患者肝组织CYP7A1 mRNA水平降低,因而CYP7A1 mRNA表达下调可能是胆囊胆固醇结石形成的重要原因之一;CYP7A1是决定胆汁成石性和胆囊胆固醇结石发生的一个重要基因.     

胆固醇结石病人与非胆石症人群胆道细菌感染状况及与免疫球蛋白相关性的对照研究

目的 明确细菌在胆固醇结石发病机制中的地位。方法 用半定量PCR结合16SrRNA序列对照法，测定38例胆囊结石病人的胆石、胆汁和胆囊黏膜细菌DNA阳性率和菌落数，并取17例非胆石病人的胆汁和胆囊黏膜作为对照。用散射比浊法测定相应胆汁和黏膜中IgA、IgG、IgM含量。结果 胆石组和非胆石组胆汁细菌DNA阳性率分别为77％和67％，菌落数分别为3．23cfu(对数值)和2．43cfu，胆囊黏膜细菌DNA阳性率分别为64％和69％，菌落数分别为3．28cfu和3．67cfu，两组间均无显著差异。两组间胆汁和黏膜IgA、IgG、IgM含量也无显著差异。菌落数与免疫球蛋白含量无相关性。结石核心和外周的细菌DNA阳性率分别为79％和82％，菌落数分别为3．19cfu和3．26cfu纯胆固醇结石细菌DNA阳性率为100％(3／3)。结石中胆固醇含量与细菌DNA阳性率无关。胆石组细菌DNA阳性者与阴性者的胆囊黏膜IgA、IgG含量均有显著差异。术前1h用抗生素者胆汁菌落数显著减少，但是黏膜菌落数无显著差异。结论 胆固醇结石病人与非胆石症人群胆道细菌感染率相似，不能仅凭结石中存在细菌来肯定细菌对胆固醇结石形成的作用。胆囊黏膜细菌与IgA、IgG含量增高有关，可能间接参与胆固醇结石形成过程。     

胆固醇结石病人肝脏SRBI及其转录调节因子LRH-1基因表达的研究

目的:研究胆固醇结石病人BI型清除剂受体(scavengerreceptorBtypeI,SRBI)及其转录调节因子肝脏受体类似物1(liverreceptorhomologue1,LRH-1)的表达,以探讨胆固醇结石发病的机制。方法:对20例胆囊胆固醇结石病人和10例无胆石症对照者测定血清脂质、胆汁成分和计算胆汁胆固醇饱和指数。以实时定量PCR法测定肝脏SRBI和LRH-1mRNA的表达量。结果:胆石组胆石平均胆固醇含量(86.68±5.26)%,均为胆固醇结石。胆石组病人血清高密度脂蛋白(HDL)显著低于对照组[(0.86±0.62)mmol/L比(1.42±0.56)mmol/L,P<0.01]。胆石组胆汁胆固醇在总脂中的摩尔百分比和胆固醇饱和指数显著高于对照组[(7.80±2.06)mol%比(5.26±2.80)mol%,P<0.05]。胆石组SRBI基因mRNA表达量与对照组比较显著增高(2.48±0.44比1.00±0.23,P<0.05),胆石组LRH-1表达也高于对照组(2.05±0.29比1.00±0.28,P<0.05)。结论:胆固醇结石病的主要病理生理异常为胆汁胆固醇过饱和。肝脏LRH-1、SRBI表达增高,参与了胆固醇过饱和胆汁形成,并促进了胆固醇结石形成。     

胆囊胆固醇息肉和胆囊结石发病关系的研究

目的 探讨胆囊胆固醇息肉和胆囊结石的发生关系.方法 选择2008年4～9月上海交通大学医学院附属瑞金医院外科微创中心行腹腔镜胆囊切除术病人62例,分别收集病人的胆石、胆汁及胆囊壁全层组织,其中胆固醇息肉31例,胆固醇胆囊结石18例,对照组13例.入院后上午餐前及餐后1h行B超胆囊三径测量,计算胆囊排空率对比显示胆囊功能.测定结石胆固醇含量及胆汁胆固醇、磷脂、胆汁酸浓度,胆囊壁组织做病理检查.结果 胆固醇息肉组病人平均胆囊排空率为(47.3±18.6)%.较健康成人平均胆囊排空率(71.7±8.1)%明显降低,其差异有统计学意义(P<0.01),而胆固醇息肉组和胆固醇结石组病人平均胆囊排空率(47.6±23.7)%比较,差异无统计学意义.胆固醇息肉组胆汁胆固醇饱和指数为(1.0±0.2),较对照组胆固醇饱和指教(0.6±0.3)明显增高,其差异有统计学意义(P<0.01),而胆固醇息肉组和胆固醇结石组胆固醇饱和指数(1.0±0.2)比较,差异无统计学意义.31例胆固醇息肉病人中,合并胆囊结石13例,结石发病率为41.9%.结论 胆囊胆固醇息肉的存在可以促使胆囊结石形成.     

Vasopressor hormone response following mesenteric traction during major abdominal surgery

Background : We investigated the vasopressor hormone response following mesenteric traction (MT) with hypotension due to prostacyclin (PGI₂) release in patients undergoing abdominal surgery with a combined general and epidural anesthesia. Methods : In a prospective, randomized, placebo-controlled study we administered 400 mg ibuprofen (i.v.) in 42 patients scheduled for abdominal surgery. General anesthesia was combined with epidural anesthesia (T4-L1). Before as well as 5, 15, 30, 45, and 90 min after MT we recorded plasma osmolality, hemodynamics and measured 6-keto-PGFlα (stabile metabolite of PGI₂), TXB₂ (stabile metabolite of thromboxane A₂) active renin, and arginine vasopressin (AVP) plasma concentrations by radioimmunoassay. Catecholamine levels were assessed by high-pressure liquid chromatography (HPLC) with electrochemical detection. Results : Following MT, arterial hypotension occurred along with a substantial PGI₂ release. This was completely abolished by ibuprofen administration. Although plasma levels of 6-keto-PGF_1α (1133 (708) vs. 60 (3) ng/L, median (median absolute deviation), P=0.0001, placebo vs. ibuprofen) remained significantly elevated, blood pressure was restored within 30 min after MT in the placebo group. At the same point in time plasma concentrations of TXB² (164 (87) vs. 58 (1) ng/L, P=0.0001), epinephrine (46 (33) vs. 14 (6) ng/L, P=0.001), AVP (41 ± (18) vs. 12 (7) ng/L, P=0.0004), and active renin (27 (12) vs. 12 (4) ng/L, P = 0.001) were significantly higher in placebo-treated patients. Conclusion : Under combined general and epidural anesthesia arterial hypotension following MT due to endogenous PGI₂ release is associated with enhanced release of AVP, active renin, epinephrine and thromboxane A₂, presumably contributing to hemodynamic stability within 30 min after MT.     

A Teaspoon Pump for Pumping Blood with High Hydraulic Efficiency and Low Hemolysis Potential

Abstract: Virtually all blood pumps contain some kind of rubbing, sliding, closely moving machinery surfaces that are exposed to the blood being pumped. These valves, internal bearings, magnetic bearing position sensors, and shaft seals cause most of the problems with blood pumps. The original teaspoon pump design prevented the rubbing, sliding machinery surfaces from contacting the blood. However, the hydraulic efficiency was low because the blood was able to "slip around" the rotating impeller so that the blood itself never rotated fast enough to develop adequate pressure. An improved teaspoon blood pump has been designed and tested and has shown acceptable hydraulic performance and low hemolysis potential. The new pump uses a nonrotating "swinging" hose as the pump impeller. The fluid enters the pump through the center of the swinging hose; therefore, there can be no fluid slip between the revolving blood and the revolving impeller. The new pump uses an impeller that is comparable to a flexible garden hose. If the free end of the hose were swung around in a circle like half of a jump rope, the fluid inside the hose would rotate and develop pressure even though the hose impeller itself did not "rotate"; therefore, no rotating shaft seal or internal bearings are required.     

Microspheres Based Detoxification System: A New Method in Convective Blood Purification

Abstract: A variety of protein-bound or hydrophobic substances, accumulating as a result of pathologic conditions such as exogenous or endogenous intoxications, are removed poorly by conventional detoxification methods because of low accessibility (hemodialysis), insufficient adsorption capabilities (hemosorption), low efficiency (peritoneal dialysis), or economic limitations (high-volume plasmapheresis). Combining advantages of existing methods with microspheric technology, a module-based system was designed. Major operating parameters of the latter can be modified to allow for adjustment to individual clinical situations. An extracorporeal blood circuit including a plasmafilter is combined with a secondary high-velocity plasma circuit driven by a centrifugal pump. Different microspheric adsorbers can be combined in one circuit or applied in sequence. Thus, a prolonged treatment can be tailored using specially designed selective adsorber materials. Comparing this system with existing methods (high-flux hemodialysis, molecular adsorbent recycling system), results from our in vitro studies and animal experiments demonstrate the superior efficiency of substance removal.     

Tissue perfusion in relation to cardiac output during continuous positive-pressure ventilation and administration of propranolol or verapamil

Background : Our objective was to determine whether administration of propranolol or verapamil modifies the hemodynamic adaptation to continuous positive-pressure ventilation (CPPV), in particular the regional distribution of cardiac output (CO).
Methods : General hemodynamics and regional blood flows assessed by microsphere technique (15 (μm) were recorded in 16 anesthetized pigs during spontaneous breathing (SB) and CPPV with 8 cm H₂O end-expiratory pressure (CPPV8) before and after intravenous administration of propranolol (0.3 mg · kg⁻¹ followed by 0.15 mg · kg⁻¹ · h⁻¹, n=8) or verapamil (0.1 mg · kg⁻¹ followed by 0.3 mg · kg⁻¹ · h⁻¹, n=8).
Results : CPPV8 depressed CO by 25% without shifts in its relative distribution with the exception of a noteworthy increase in adrenal perfusion. Propranolol increased arterial blood pressure, and due to a fall in heart rate, CO dropped by 25%. The kidneys and, to a lesser extent, the splanchic region and central nervous system received increased fractions of the remaining CO at the expense of skeletal muscle flow. Similar patterns were seen during SB and CPPV8 such that the combination of propranolol and CPPV8 depressed CO by 50%. The circulatory effects of verapamil were less evident but myocardial perfusion tended to increase.
Conclusions : The combination of propranolol or verapamil with CPPV does not result in any specific hemodynamic interaction in anesthetized pigs, except that the combined effect of propranolol and CPPV may severely reduce CO.     

Volatile anaesthetics reduce adhesion of blood platelets under low-flow conditions in the coronary system of isolated guinea pig hearts

Background : Inhibitory effects of volatile anaesthetics on platelet aggregation have been demonstrated in several studies. However, the influence of volatile anaesthetics on intracoronary platelet adhesion has not been elucidated so far.
Methods : Isolated hearts of guinea pigs were perfused with buffer in the absence or presence of volatile anaesthetics (0.5 and 1 MAC) at constant coronary flow rates of 5 ml/min for 25 min, then 1 ml/min for 30 min and again 5 ml/min for 10 min. Before, during and after low-flow perfusion, a bolus of human platelets was applied into the coronary system. To simulate thrombogenic conditions, 0.3 U/ml human thrombin was infused during low-flow perfusion and reperfusion. The number of platelets sequestered to the endothelium was calculated from the difference between coronary in- and output of platelets. The myocardial production of lactate and consumption of pyruvate and coronary perfusion pressure were also determined.
Results : At a flow rate of 5 ml/min only about 3% of the applied platelets did not emerge from the coronary system, in any group. In contrast, 13.1±1.2% (mean±SEM) of infused platelets became adherent in low-flow perfusion in the control group without anaesthetic. The adherence was reduced with each 1 MAC isoflurane (to 6.2±1.2%), sevoflurane (to 4.4±0.9%) or halothane (to 3.2±1.5%) (each P <0.05 vs. control). Volatile anaesthetic, 0.5 MAC, did not inhibit platelet adhesion to a statistically significant extent in any case. Perfusion pressure and metabolic parameters were not statistically different between the control and the hearts exposed to anaesthetics.
Conclusion : Volatile anaesthetics in a concentration of 1 MAC can reduce the adhesion of platelets in the coronary system under reduced flow conditions. This action does not arise from vasodilation or inhibition of ischaemic stress.     

Bariatric Surgery in Some "Central and East-European (former Eastern bloc)"Countries - Current Status and Prediction for the Next Millennium

Background: Obesity is increasing globallly, including in the formerly "Eastern Bloc" countries. Methods: A survey was made of obesity and bariatric surgery. Results: In the 8 East and Central European countries studied, with total population 300 million, roughly 43% of the population was overweight (BMI 25-30), 23% obese (BMI > 30), with about 15 million people morbidly obese (BMI > 40). From 0-10 morbidly obese individuals/100,000/year undergo bariatric surgery. Conclusion: Most countries were found to provide inadequate treatment for obesity.The majority of the morbidly obese are not treated effectively. However, health-care awareness of obesity and bariatric surgeons are slowly increasing.     

Synergistic interaction between the effects of propofol and midazolam with fentanyl on phrenic nerve activity in rabbits

Background: It has been shown that the depressive effects of both propofol and midazolam on consciousness are synergistic with opioids, but the nature of their interactions on other physiological systems, e. g. respiration, has not been fully investigated. The present study examined the effect of propofol and midazolam alone and in combination with fentanyl on phrenic nerve activity (PNA) and whether such interactions are additive or synergistic. Methods: PNA was recorded in 27 anaesthetised and artificially ventilated rabbits. In three groups, propofol, fentanyl and midazolam were administered intravenously in incremental doses to construct dose-response curves for the depressant effects of each one on PNA. In another two groups, the effect of pretreatment with either fentanyl 1 μg · kg^?1 i. v. or midazolam 0.05 mg · kg^?1 i. v. on the effects of propofol and fentanyl respectively on PNA were studied. Results: Propofol and fentanyl caused a dose-dependent depression of PNA with complete abolition at the highest total doses of 16 mg · kg^?1 i. v. and 32 μg · kg^?1 i. v., respectively. In contrast, midazolam in incremental doses to a total of 0.8 mg · kg^?1 reduced mean PNA by 63%, but approximately 12% of PNA remained at a total dose as high as 6.4 mg · kg^?1. The mean ED₅₀s, calculated from dose-response curves, were 5.4 mg · kg^?1, 3.9 μg · kg^?1 and 0.4 mg · kg^?1 for propofol, fentanyl and midazolam, respectively. Initial doses of either fentanyl 1 μg · kg^?1 i. v. or midazolam 0.05 mg · kg^?1 i. v. acted synergistically with subsequent doses of either propofol or fentanyl to abolish PNA at total doses of 8 mg · kg^?1 and 8 μg · kg^?1, respectively. Conclusion: Fentanyl has a synergistic interaction with both propofol and midazolam on PNA and hence potentially on respiration.     

Influence of dopexamine hydrochloride on haemodynamics and regulators of circulation in patients undergoing major abdominal surgery

Background: Catecholaminergic support is often used to improve haemodynamics in patients undergoing major abdominal surgery. Dopexamine is a synthetic vasoactive catecholamine with beneficial microcirculatory properties. Methods: The influence of perioperative administration of dopexamine on cardiorespiratory data and important regulators of macro- and microcirculation were studied in 30 patients undergoing Whipple pancreaticduodenectomy. The patients received randomized and blinded either 2 μg · kg^?1 · min^?1 of dopexamine (n=15) or placebo (n=15, control group). The infusion was started after induction of anaesthesia and continued until the morning of the first postoperative day. Endothelin-1 (ET-1), vasopressin, atrial natriuretic peptide (ANP), and catecholamine plasma levels were measured from arterial blood samples. Measurements were carried out after induction of anaesthesia, 2 h after onset of surgery, at the end of surgery, 2 h after surgery, and on the morning of the first postoperative day. Results: Cardiac index (CI) increased significantly in the dopexamine group (from 2.61±0.41 to 4.57±0.78 1 · min^?1 · m^?2) and remained elevated until the morning of the first postoperative day. Oxygen delivery index (DO₂I) and oxygen consumption index (VO₂I) were also significantly increased in the dopexamine group (DO₂I: from 416±91 to 717±110 ml/m² · m²; VO₂I: from 98±25 to 157±22 ml/m² · m²), being significantly higher than in the control group. pHi remained stable only in the dopexamine patients, indicating adequate splanchnic perfusion. Vasopressive regulators of circulation increased significantly only in the untreated control patients (vasopressin: from 4.37±1.1 to 35.9±12.1 pg/ml; ET-1: from 2.88±0.91 to 6.91±1.20 pg/ml). Conclusion: Patients undergoing major abdominal surgery may profit from prophylactic perioperative administration of dopexamine hydrochloride in the form of improved haemodynamics and oxygenation as well as beneficial influence on important regulators of organ blood flow.     

Immunomodulation in Transplantation with Photopheresis

Abstract: Photopheresis is a technique in which peripheral blood mononuclear cells, in the presence of a photoacti-vatable compound, are exposed extracorporeally to ultraviolet A light and reinfused, inducing a host autoregula-tory immune response. Experimental work and ongoing clinical studies are helping to define the role of this novel, safe, and non-toxic immunomodulating technology in the field of transplantation.