血清维生素K1水平与绝经后女性腰椎骨密度相关性分析

目的探讨绝经后女性骨密度与血清维生素K1水平之间的相关性。方法使用标准化的酶联免疫吸附试验(ELISA)试剂盒测量46例绝经后骨质疏松女性和30名绝经后健康对照女性的血清维生素K1水平。检测腰椎(1～4)的骨密度(bone mineral density, BMD)。结果绝经后骨质疏松女性组血清维生素K1水平明显低于正常对照组(P0.05),绝经后骨质疏松女性血清维生素K1浓度与腰椎BMD呈正相关(R=0.545,P=0.003);绝经后正常对照组血清维生素K1浓度与腰椎BMD呈正相关(R=0.513,P=0.009)。维生素K1对骨质疏松症的诊断敏感性和特异性分别为91%和98%(截止值:0.853 ng/mL);维生素K1的ROC曲线下面积(AUC)为0.985,奇数比为18.88。结论维生素K1与诊断绝经后骨质疏松症呈负相关。     

维生素D、维生素B12和同型半胱氨酸水平与绝经后女性骨密度的相关性研究

目的探索绝经后非骨质疏松症和骨质疏松症女性患者高半胱氨酸、维生素D、维生素B_(12)和骨密度(bone mineral density,BMD)之间的关系。方法选取2017年8～12月在我院就诊的138名女性作为研究对象,根据骨密度将绝经后女性分为骨质疏松组(n=58)和非骨质疏松组(n=80)。记录两组患者的体质量指数(body mass index,BMI)、年龄、腰围等一般资料,检测腰椎L_(1～4)前后位、左侧股骨近端的BMD,测定血清同型半胱氨酸、维生素B_(12)、维生素D、碱性磷酸酶、钙、磷水平。分析两组患者不同指标的差异以及高半胱氨酸、维生素D、维生素B_(12)和BMD之间的相关性。结果两组患者的年龄、BMI、腰围、同型半胱氨酸、维生素D、维生素B_(12)、腰椎L_(1～4)和左股骨颈骨密度比较差异有统计学意义(P均0.05);Rho相关性和回归分析表明,同型半胱氨酸与维生素D和B_(12)在绝经后非骨质疏松症和同型半胱氨酸与维生素B_(12)在绝经后骨质疏松症女性中呈显著负相关。结论高水平同型半胱氨酸可以通过绝经后非骨质疏松症患者维生素D水平和绝经后骨质疏松症女性维生素B_(12)水平预测。     

肌肉强度和肌肉质量与绝经后女性骨密度的相关性研究

目的探索绝经后女性肌肉强度和肌肉质量与骨密度相关性。方法分析了2014年3月至2017年8月在我院就诊的340名绝经后妇女。使用双能量X射线吸收测定法检测股骨颈和腰椎骨密度(bone mineral density,BMD)、全身骨密度和附肢骨骼肌肌肉量(appendicular skeletal muscle,ASM)。ASM指数(ASMI,kg/m~2)按照ASM(kg)除以高度的平方(m~2)计算。测量握力(kg)作为肌肉力量的指标。结果调整ASMI和年龄后(股骨颈标准化偏回归系数β=0. 105,腰椎=0. 116),握力强度与几个骨骼部位BMD呈显著性正相关(P0. 05)。股骨颈和腰椎骨密度的调整平均值显示出握力强度从最低到最高三分位数的显著增加趋势。本研究结果表明肌肉强度与绝经后妇女肌肉量的几个位点的BMD密切相关。无论肌肉大小如何,肌力强健的绝经后妇女都有健康的骨骼状态。结论绝经后女性骨密度和肌肉强度密切相关,与肌肉质量无明显相关性。     

绝经后女性血清硒水平与骨质疏松骨密度和骨代谢指标相关性研究

目的探索血清硒水平与绝经后妇女骨代谢指标以及腰椎和髋部骨密度之间相关性。方法检测156例正常骨密度和162例骨质疏松症的血清硒、25-羟基维生素D、PTH、骨钙素、PINP、CTX和NTX/Cr等指标水平。腰椎和股骨颈的BMD通过双能X线吸收法测量。探索了血清硒水平与骨密度的关系。结果骨质疏松症女性的血清硒水平低于正常骨密度的女性(P0.05)。在骨质疏松症妇女中,血清硒水平与年龄、绝经年限、BMI、PTH、骨钙素、PINP、CTX和NTX/Cr水平呈负相关,与25-羟基维生素D水平呈正相关。在正常骨密度组,血清硒水平与这些参数均未发现明显的相关性。调整年龄和BMI后,腰椎和股骨颈骨密度与血清硒及25-羟基维生素D水平呈显著正相关,与绝经年限、PTH、骨钙素、PINP、CTX和NTX/Cr呈负相关。对年龄和BMI进行调整后,进行多元回归分析以确定BMD的预测因子,血清硒和PINP、CTX是腰椎和股骨颈骨密度的显著预测因子。结论绝经后女性患者血清硒水平降低与腰椎和股骨颈骨密度降低密切有关。     

脂肪因子Omentin-1、脂联素与中老年女性骨密度相关性研究

目的观察脂肪因子Omentin-1、脂联素与中老年女性骨密度之间的相关性。方法选取2017年3月至2018年4月在佛山市中医院就诊的338名女性,按照绝经状态分为围绝经期/绝经期组(n=194)和绝经后组(n=124)。将参研人员年龄、体质量指数(bone mass index,BMI)、腰围、吸烟状况、身体活动、脂联素、Omentin-1和激素进行多变量调整(ANCOVA),用于研究其脂肪因子和骨密度(bone mineral density,BMD)之间的潜在关系。结果与绝经后女性的腰椎BMD [(0. 69±0. 08)g/cm~2]相比,围绝经期女性的腰椎BMD[(0. 89±0. 09) g/cm~2]更高;在围绝经期/绝经期组女性中,脂联素和Omentin-1均与腰椎BMD无显著相关性(P0. 05);在绝经后组女性中,脂联素与腰椎BMD无相关性(P 0. 05);而在绝经后组女性中,Omentin-1与腰椎BMD呈显著负相关(P0. 05)。结论绝经后女性的Omentin-1与腰椎BMD呈负相关。     

昆明地区绝经后妇女腰椎QCT测量分析

目的通过对昆明地区绝经后妇女腰椎定量CT(QCT)测定值进行分析,以探讨昆明地区绝经后妇女骨密度(BMD)变化的规律,不同年龄段骨质疏松症(OP)的检出率。方法以出生并生活在昆明市区的50～79岁、绝经1年以上的社区女性208例为研究对象,用定量CT法测量其腰1至腰5的骨密度(BMD)。结果绝经1年以上的妇女BMD均值均进入骨质疏松期,随着年龄的增加其BMD均值逐渐降低,且昆明地区绝经后妇女各年龄段的BMD均值均较北方同年龄段人稍低,绝经后妇女骨量减少和骨质疏松症的发生率均随年龄的增加而明显增高(P0.01),其中50～59岁年龄段上升速度较快,60岁以后上升速度明显趋缓。结论 QCT诊断绝经后妇女骨质疏松具有较高的敏感性、准确性及可重复性,昆明地区绝经后妇女骨密度均值稍低于北方同年龄组,骨质疏松的程度稍重一些,昆明地区绝经后妇女骨量减少和骨质疏松症的发生率均随年龄的增加而明显增高,明显增高年龄段主要在55～59岁。     

IL-33与绝经后骨质疏松女性骨密度和骨代谢指标相关性研究

目的 探索血清白细胞介素-33(IL-33)与绝经后骨质疏松女性骨密度和骨代谢指标相关性。方法 采用酶联免疫吸附法测定50例绝经后骨质疏松患者和50例正常绝经后妇女血清IL-33水平。采用双能X线骨密度仪(DXA)测量患者和对照组的骨密度(BMD)。检测维生素D、钙、碱性磷酸酶(ALP)、甲状旁腺激素(PTH)水平,以及1型胶原C末端肽(CTX)和1型前胶原N端前肽(P1NP)等骨转换指标。结果 在绝经后骨质疏松症女性中,IL-33水平显著低于健康对照组[(3.53±2.45) pg/mL vs (13.72±5.39) pg/mL,P=0.007];Spearman相关分析表明血清IL-33水平与年龄、BMI、PTH、CTX和P1NP水平呈负相关,与腰椎BMD和股骨颈BMD呈正相关。多元回归分析表明,年龄、BMI、腰椎BMD、PTH、股骨颈BMD和血清CTX和P1NP水平是骨质疏松症患者血清IL-33水平降低的独立预测因子。结论 血清IL-33降低是绝经后骨质疏松患者股骨颈和腰椎骨密度降低和骨转换增速的危险因素。     

绝经后妇女血清基质金属蛋白酶-9和基质金属蛋白酶抑制因子-1与骨密度的关系

目的 探讨绝经后妇女血清基质金属蛋白酶-9(MMP-9)和基质金属蛋白酶抑制因子-1(TIMP-1)与骨密度(BMD)之间的关系.通过观察绝经后妇女不同骨密度条件下MMP-19、TIMP-1浓度的变化,探讨两者在骨质疏松症(OP)中的作用,为临床OP诊断与干预治疗提供依据.方法 选择绝经后妇女80例.采用Challenge双能x线骨密度仪(DXA)测量腰椎(L2-L4)侧位和左侧髋部(股骨颈、大转子、Ward三角区)6个骨骼区域的骨密度(BMD).分为正常对照组(骨密度正常组,21例)、低骨量组(20例)、骨质疏松组(23例)和严重骨质疏松组(骨质疏松骨折组,16例),对各组进行身高、体重等常规检查并用酶联免疫吸附试验(ELISA法)测定各组血清MMP-9和TIMP-1的浓度.结果 绝经后女性血清MMP-9水平随骨密度的降低呈现升高趋势.以骨质疏松骨折组为著;低骨量组、骨质疏松组TIMP-1水平与对照组比较没有统计学意义;正常对照组、低骨量组、骨质疏松组MMP-9与TIMP-1的比率依次升高,致使MMP-9与TIMP-1的比率失调.结论 绝经后妇女血清MMP-9水平升高及MMP-9与,TIMP-1的比率失调可能为绝经后骨质疏松症发生的重要影响因素.     

绝经后2型糖尿病妇女血脂水平和骨密度的关系

目的探讨绝经后2型糖尿病妇女血脂和骨密度改变的相关性。方法将290例绝经后2型糖尿病妇女按T值分成骨质疏松组和非骨质疏松组;检测各组患者血清总胆固醇(TC)、甘油三脂(TG)、高密度脂蛋白胆固醇(HDL-C)、低密度脂蛋白胆固醇LDL-C)以及腰椎骨密度(BMD),然后分析血脂和骨密度的关系;对骨密度和血脂、年龄、绝经年龄等变量之间的关系进行多元逐步回归分析。结果(1)绝经后2型糖尿病妇女的HDL-C与腰椎BMD存在负相关(r=-0.305,P=0.001),LDL-C、TG、TC与腰椎BMD无相关;(2)在校正体重指数、年龄和绝经年限影响因素后,绝经后2型糖尿病妇女的HDL-C与腰椎BMD仍存在负相关(r=-0.160,P=0.018),而LDL-C、TG、TC与腰椎BMD仍无相关。(3)在多元逐步回归分析中,HDL-C(β1=-0.199,P=0.005)仍与骨密度独立相关。结论绝经后2型糖尿病妇女的HDL-C与腰椎BMD存在负相关而TC、TG、LDL-C与腰椎BMD无相关。     

促甲状腺素抑制对分化型甲状腺癌术后女性腰椎骨密度的影响

目的观察促甲状腺素抑制(thyroid-stimulating hormone suppression,TSHS)对分化型甲状腺癌(differential thyroid cancer,DTC)术后女性腰椎骨密度(bone mineral density,BMD)的影响。方法纳入225名2015～2016年期间DTC术后的绝经后妇女。将她们分为TSHS组[中位甲状腺素(TSH)0. 3μIU/mL]和绝经后对照组[中位甲状腺素(TSH)0. 3μIU/mL]。腰椎(L_(1～4))的BMD水平通过双能X射线吸收测定法(DXA)在基线和随访6、12和24个月检测。所有患者均补充钙和维生素D。骨量减少(-1 SDT≥-2. 5 SD)和骨质疏松症(T-2. 5 SD)的诊断根据WHO指南进行。结果 TSHS组有154名患者,未抑制的TSH组(绝经后对照组)有71名患者。在TSHS和未抑制TSH患者的治疗前后,基线和治疗前后6、12和24个月腰椎骨密度没有显著差异。与TSHS治疗前相比,2年随访时腰椎(L_(1～4))骨密度降低了1. 9%。TSHS组(103/152)和绝经后对照组(32/68)随访24个月时骨量减少和骨质疏松症患者数量发现有显著差异(χ~2=2. 88,P=0. 004)。TSHS不是骨丢失的重大风险,但会增加DTC绝经后妇女骨量减少的发生率。结论 2年的随访数据表明,TSHS对绝经后DTC女性的BMD几乎没有影响。     

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.