肾移植患者骨矿含量的测定及临床意义

测量了６４例肾移植患者移植前后的骨矿含量及骨钙素（ＢＧＰ）、甲状旁腺激素（ＰＴＨ）、血液生化的变化，以探讨它们的相互关系及临床意义。结果术前血肌酐（ＳＣｒ）、尿素氮（ＢＵＮ）、磷（Ｐ）、ＰＴＨ、ＢＧＰ为高水平，血钙（Ｃａ）低，骨矿含量（０．７７７±０．０１５ｇ／ｃｍ２）明显低于对照组（０．８１１±０．０３５ｇ／ｃｍ２）。术后肾功能正常者，ＳＣｒ、ＢＵＮ、Ｃａ、Ｐ及ＰＴＨ、ＢＧＰ均恢复正常，骨矿含量半年后恢复至对照组水平。提示慢性肾功能衰竭及血液透析期间存在明显钙磷代谢异常，严重骨营养不良；肾移植成功后骨矿含量恢复，纠正了肾性骨病；肾移植后骨矿含量低者，往往提示预后不良。     

运动负荷下去势雌性大鼠骨组织计量学和生物力学的改变

目的 探讨运动对去势大鼠骨代谢和生物力学性能的影响。方法 将４个月龄ＳＤ雌性大鼠４２只随机分成７组：正常组、模型组、运动组、服钙组、联合组、激素组和制动组。除正常组外,其余各组大鼠切除卵巢。检测各组大鼠骨密度（ＢＭＤ）、骨组织形态计量学和生物力学有关指标。结果 ⑴ＢＭＤ联合组０．３０６ｇ／ｃｍ＾２,运动组０．３０５ｇ／ｃｍ＾２,模型组０．２７５ｇ／ｃｍ＾２,制动组０．２５６ｇ／ｃｍ＾２。⑵骨组织形     

以腰椎前后位骨矿含量、面积估价骨密度测量的准确性

目的针对前后位腰椎骨密度（ＢＭＤ）受骨质增生或压缩性骨折等因素影响而易造成判断结果的误差，根据ＢＭＤ＝骨矿含量（ＢＭＣ）／面积（Ａｒｅａ）的关系，旨通过对ＢＭＣ及Ａｒｅａ正常范围的评价，进一步判断ＢＭＤ测量的准确性。方法采用双能Ｘ线骨密度仪（ＤＥＸＡ）进行不同性别平衡峰值期ＢＭＤ年龄段的估价、计算其ＢＭＣ及Ａｒｅａ均值，以身高为自变量，ＢＭＤ为应变量分别作直线回归，建立ＢＭＣ、Ａｒｅａ与身高的回归方程，利用其回归方程进行ＢＭＤ正常值的预报。结果平衡峰值ＢＭＤ的年龄，男性为２０～４９岁，女性为３０～４９岁；ＢＭＣ及Ａｒｅａ的均值，男性分别为５６．４７ｇ及４６．３９ｃｍ２，女性分别为４７．４１ｇ及４１．１２ｃｍ２；９０％正常范围：男性ＢＭＣ＝０．３２７×身高（ｃｍ）±１４．７６、Ａｒｅａ＝０．２７１×身高（ｃｍ）±５．９６，女性ＢＭＣ＝０．２９４×身高（ｃｍ）±１１．８５，Ａｒｅａ＝０．２２５×身高（ｃｍ）±５．００。结论在临床工作中仅靠腰椎ＢＭＤ结果进行评价是远远不够的，而应正确评价腰椎的ＢＭＣ与Ａｒｅａ，方能对其ＢＭＤ测量的可靠程度作出判断。     

老年人脊柱压缩性骨折治疗方法的探讨

在７４例单纯性脊椎压缩性骨折的老年病人中，采用一般治疗组３４例，治疗７天、３０无时临床疗效优良率为：（５．９＋２０．６）％和（１７．６＋３８．２）％；ＢＭＤ治疗前后分别为：０．６４０＝０．０５０（ｇ／ｃｍ２）和０．５６２±０．０３２（ｇ／ｃｍ２）．加用密钙息治疗组４０例．治疗７天、３０天时临床疗效优良率为：（３２．５＋４７．５）％和（５２．５＋３７．５）％；ＢＭＤ治疗前后分别为：０．６３９＝０．０４６（ｇ／ｃｍ２）和０．６４０＝０．０２８（ｇ／ｃｍ２）．比较表明，加用密钙息治疗组的临床疗效明显优于一般治疗组．治疗后其ＢＭＤ值也明显高于一般治疗组的ＢＭＤ值．本文对有关治疗方法进行探讨．     

男性青少年身体成分与骨矿含量的关系

为了解青少年身体成分中瘦体重和体脂含量究竟那种成分对骨矿含量影响起主要作用，我们对５８名男性青少年（年龄１７．２±０．７岁，范围：１５．５—１８．７岁）进行人体测量，计算出瘦体重和体脂含量，用ＢＨ－６０１２型二维扫描单光子骨密度仪测量非优势侧桡骨中远１／３处及桡骨超远端骨矿含量（ＢＭＣ，ｇ）、骨宽（ＢＷ，ｃｍ）、骨密度（ＢＭＤ，ｇ／ｃｍ２），为消除身高的影响分别计算桡骨中远１／３处和桡骨超远端ＢＭＤ／身高值（ＢＭＤ／Ｈ，ｇ／ｃｍ３）。以桡骨中远１／３处及桡骨超远端的ＢＭＣ、ＢＭＤ、ＢＭＤ／Ｈ作因变量，年龄、身高、瘦体重、体脂含量作自变量进行多元线性回归分析，结果表明瘦体重和体脂含量均与骨矿含量有关（Ｐ＜０．０５），但经骨形态即骨宽较正的骨密度及身高校正的ＢＭＤ／Ｈ仅与瘦体重有关（Ｐ＜０．０５），因此说明男性青少年身体成分中瘦体重对桡骨超远端骨密度的影响作用较大。     

骨密度对椎弓根螺钉系统固定的影响之生物力学研究

目的：探讨骨密度（ＢＭＤ）对椎弓根螺钉系统固定的影响。方法：采用６具新鲜腰段脊柱标本，应用ＤＥＸＡ测试每个椎体的ＢＭＤ，并游离成单个完整椎体标本，按ＢＭＤ０．９ｇ／ｃｍ２为正常值的最低限。将标本分为正常组和骨质疏松组。按标准操作安置Ｄｉｃｋ钉，应用生物力学方法，测试螺钉最大轴向拔出力和矢状面摆动１°～５°时的弯矩、旋入螺钉时的最大扭力矩及螺钉拔出过程中的应变、位移和能量吸收率。结果：正常组平均ＢＭＤ为１．０２±０．１２ｇ／ｃｍ２，骨质疏松组为０．７１±０．１６ｇ／ｃｍ２，前者最大轴向拔出力和弯矩分别为１０６２．８±７２．２Ｎ、２．６Ｎ·ｍ，后者为２３２±９２．４Ｎ、０．４９Ｎ·ｍ。ＢＭＤ与最大拔出力有正相关关系（ｒ＝０．９０７）。旋入螺钉时的最大扭力矩与轴向拔出力密切相关（ｒ＝０．８９４）。螺钉在椎体内摆动５°时正常组承受的最大弯矩为２．６Ｎ·ｍ，骨质疏松组为０．４９Ｎ·ｍ。结论：ＢＭＤ对椎弓根螺钉的稳定性具有重要影响，是预测螺钉牢固程度的重要指标，术前应常规测试脊柱的ＢＭＤ，尤其对于老年人更为重要，最大扭力矩是术中预测螺钉稳定性的一个较好的力学指标。     

绝经后女性类风湿性关节炎患者腰椎和股骨近端骨密度测量

为了观察绝经后女性类风湿性关节炎（ＲＡ）患者骨矿物质密度水平的变化，采用双能Ｘ线骨密度仪（ＤＥＸＡ）测量２３例绝经后女性ＲＡ患者和年龄、性别匹配的２３例正常健康者的腰椎２～４（Ｌ２～Ｌ４）和右侧股骨近端（股骨颈、大转子和Ｗａｒｄ＇ｓ三角区）的骨密度（ＢＭＤ）。结果表明，绝经后女性ＲＡ患者Ｌ２～Ｌ４、右侧股骨近端的ＢＭＤ测量值（ｇ／ｃｍ２）明显低于年龄和性别匹配的正常健康者（Ｐ＜０．０５）。绝经后女性ＲＡ患者Ｌ２～Ｌ４骨密度的Ｚ－ｓｃｏｒｅ与糖皮质激素用药时间呈显著负相关（ｒ＝－０．５８，Ｐ＝０．００３，ｎ＝２３）。提示绝经后女性ＲＡ患者存在明显的骨质丢失。     

尿钙、尿钠与男性青少年骨矿含量

目的　研究北方男性青少年尿钙排出的影响因素,及尿钙排出量对骨矿含量、骨密度的影响。方法　我们对５１ 名发育正常,身体健康的男性青少年（年龄１７．２±０．７,１５．５～１８．７ 岁）进行人体测量,三天称重法膳食调查,采空腹静脉血、收集２４ 小时尿液,用ＢＨ－６０１２ 型二维扫描单光子骨密度仪测量非优势侧桡骨中远１／３ 处及桡骨超远端骨矿含量（ＢＭＣ,ｇ／ｃｍ ）、骨密度（ＢＭＤ,ｇ／ｃｍ ２）、骨宽（ｃｍ ）。对有关变量进行直线相关分析和多元逐步回归分析。结果　膳食钙摄入量为５４４ｍ ｇ／人日,蛋白质摄入量为８６ｇ／人日,尿钠排出量１４３．８５ｍ ｍ ｏｌ／ｄ,尿钙排出量为４．０４ｍ ｍ ｏｌ／ｄ。尿钠排出量是影响尿钙排出量的主要因素之一,［尿钙（ｍ ｍ ｏｌ／ｄ）＝ ２．３８１３＋ ０．０１１５×尿钠（ｍ ｍ ｏｌ／ｄ）,ｒ＝ ０．２８１１,Ｐ＜ ０．０５］。尿钠排出量与膳食钠摄入量呈较强正相关,尿钠排出量（ｍ ｍ ｏｌ／ｄ）＝ ６７．４７７８＋ ０．０２１５×膳食钠摄入量（ｍ ｍ ｏｌ／ｄ）,（ｒ＝ ０．６０７７,Ｐ＜ ０．０００１）。用前进法多元回归得出,尿钙排出量与桡骨中远１／３ 处骨矿含量、骨密度及桡骨超远端骨密度呈负相关（Ｐ＜     

118例甲亢患者骨密度及骨代谢指标的研究

目的：为探讨甲亢患者骨密度与骨代谢指标的改变。方法：本文测定了１１８例甲亢患者腰椎（Ｌ２～４）及股骨上端（Ｎｅｃｋ、Ｗａｒｄ三角、Ｔｒｏｃｈ）骨密度、血清骨钙素（ＢＧＰ）、甲状旁腺素中间片段（ＰＴＨ－ｍ）及尿脱氧吡啶啉（Ｄｐｄ）。结果：甲亢患者骨密度低于正常对照组，ｔ检验具显著差异（ｐ＜０．０１）、血清ＢＧＰ及Ｄｐｄ高于正常对照组，ｔ检验具显著差异（ｐ＜０．０１），与骨密度呈负相关ｒ＝－０．２１３５、－０．２０５０（ｐ＜０．０５）；而ＰＴＨ－ｍ低于正常对照组，与骨密度无相关性ｒ＝０．０８３０（ｐ＞０．０５）。结论：甲亢为高转换型骨质疏松，ＢＧＰ、Ｄｐｄ可作为骨形成及骨吸收的敏感指标     

迅速纠正代谢性酸中毒对慢性肾功能衰竭继发性甲旁亢患者的作用

为探讨纠正代谢性酸中毒对慢性肾功能衰竭（ＣＲＦ）继发性甲旁亢（ＳＨＰ）的作用。方法对１５例透析前ＣＲＦ患者迅速纠正代谢性酸中毒前后甲状旁腺素（ＰＴＨ）和１，２５（ＯＨ）２Ｄ３水平进行了比较。结果治疗后血清ｍＰＴＨ、ｉＰＴＨ和ＰＯ３－４等水平明显下降（２．２９±１．２６ｖｓ１．７４±０．８３μｇ／Ｌ，Ｐ＜０．００５；４６１．８±２７０．９ｖｓ３３２．１±１９９．７μｇ／Ｌ，Ｐ＜０．０１；５．３３±２０．８ｖｓ４８．７±２０．４ｍｇ／ｌ，Ｐ＜０．００１）；１，２５（ＯＨ）２Ｄ３水平有所升高，但尚不显著；血浆游离钙（ｉＣａ）、血清总钙（ｔＣａ）等水平均无明显变化。结论纠正代谢性酸中毒可降低慢性肾衰ＳＨＰ患者血清ＰＴＨ水平，有利于ＳＨＰ的改善；代谢性酸中毒对慢性肾衰ＳＨＰ的发生或发展可能起重要作用     

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.