同种异体反应性淋巴细胞克隆疫苗回输诱导受体特异性免疫耐受研究

目的 探讨同种异体移植抗原特异性耐受诱导的新途径。方法 以同种异体反应性淋巴细胞克隆在体外培养条件下大量增殖后作为自身独特性疫苗,体内注射免疫家兔,以混合淋巴细胞反应来观察免疫前和免疫后对供体淋巴细胞刺激指数（SI）的变化。结果 同种异体反应性自身独特淋巴细胞疫苗具有显著诱导特异性免疫应答抑制现象,SI值显著降低（P＜0．005）,而对卡介苗诱导的特异性免疫应答并未因独特型淋巴细胞疫苗的应用下降。结论 同种异体反应性自身独特型淋巴细胞疫苗可能成为诱导抗原特异性免疫耐受的一种手段,作为心肺移植受体的术前准备。     

肝特异性抗原的同种异体免疫原性

目的：研究肝特异性抗原的同种异体免疫原性及其意义。方法：用近交系F344大鼠的肝特异性抗原作为免疫原，通过小剂量长期足垫免疫、门静脉及胸腺大剂量免疫等不同的方法免疫近交系Lew大鼠，以环磷酰胺150mg/kg腹腔注射作为诱导淋巴细胞凋亡的阳性对照，用混合淋巴细胞（MLC）培养、混合淋巴细胞肝细胞（MLHC）培养，Western印迹、DNA凝胶电泳分析及TUNEL等检测手段，对外周及中枢淋巴器官的功能进行分析，以确定免疫后机体的免疫状态。结果：在取材时间点，各实验组均出现不同程度的特异性低免疫应答：MLC变化不明显，但MLHC却均较对照组明显降低，而各实验组Caspase-3的表达均明显增高，脾细胞的DNA凝胶电泳表现出抗原特异性的淋巴细胞凋亡，胸腺TUNEL结果，各实验组均出现不同程度的凋亡细胞。结论：肝特异性抗原具有同种异体免疫原性，可能是一种重要的移植抗原，为诱导同种移植免疫耐受开拓新的途径；对移植肝或细胞免疫原性的调变，不但要针对同种异体主要组织相容复合物（MHC）抗原，而且也应针对非MHC抗原。     

T细胞疫苗诱导大鼠同种异体肢体移植免疫耐受的实验研究

目的 探讨T细胞疫苗（TCV）诱导大鼠同种异体肢体移植特异性免疫耐受的作用。方法 制备受者Lewis大鼠针对供者DA大鼠的TCV，应用TCV，免疫正常Lewis大鼠共3次，每周1次。设TCV组和TCV未接种组，在接种前及接种后5d进行混合淋巴细胞培养（MLR）；设TCV组、CsA组和空白对照组，于接种后7d进行DA大鼠针对Lewis大鼠的同种异体肢体移植，在术后7d进行淋巴细胞毒检测，术后21d进行嵌合分析。结果 MLR显示，Lewis大鼠的脾细胞反应程度接种组显著低于未接种组（P〈0．01）；微量细胞毒测定显示，死亡细胞百分率在TCV组、CsA组、空白对照组3组比较性差异有统计学意义（P〈0．01）；嵌合分析显示经处理的Lewis大鼠脾脏，胸腺中检测出了DA大鼠源性的骨髓嵌合体。结论 T细胞疫苗可以抑制受者对供者的免疫应答；作为骨髓移植前预处理手段，T细胞疫苗接种后行吻合血管的骨髓移植成功地诱导出同种异体肢体移植嵌合耐受。     

大鼠T细胞疫苗的制备及其抗移植皮肤排斥作用的实验研究

目的 探讨T细胞疫苗(TCV)的制备方法及其抗移植皮肤排斥反应的作用.方法 制备针对特定SD大鼠的供体特异性T细胞疫苗,将其免疫受体Wistar大鼠;然后取免疫前和每次免疫后第五天的受体Wistar的淋巴细胞(反应细胞)与供体SD的淋巴细胞(刺激)进行体外单向混合淋巴细胞反应(MLR),以MTT法检测细胞免疫增值反应情况,比较疫苗接种后诱导淋巴细胞反应受抑制的情况:再将SD大鼠皮肤移植到TCV免疫后的Wistar大鼠,观察皮肤移植反应并统计移植物存活的时间.排斥反应的移植物行病理检查.结果 TCV组受体淋巴细胞反应程度比接种前显著减弱(P＜0.05);特异性TCV组皮肤移植物存活时间较非特异性TCV组及对照组延长(P＜0.05).移植皮肤排斥反应病理表现更轻.结论 TCV经腹腔接种可以诱导出针对同种抗原特异性免疫耐受,TCV能够延长同种异体移植皮肤的存活时间,有一定抗移植排斥反应作用.     

T淋巴细胞凋亡与移植免疫耐受的研究进展

细胞凋亡是生物学领域的重大发现,是细胞在生理状态下的特征性死亡形式,近年来研究发现细胞凋亡在移植免疫中发挥重要作用.在同种异基因移植中,受者对移植物的排斥是移植成功的主要障碍.同种异基因移植排斥主要是受者T细胞介导的、针对同种异型抗原的免疫应答.通过多种途径导致机体反应性T淋巴细胞的凋亡可以诱导免疫耐受.某些免疫抑制剂可是通过细胞凋亡途径起作用.本文主要对T细胞凋亡与移植免疫耐受的研究进展作简要综述.     

霉酚酸酯对未成熟树突状细胞抗原递呈功能的影响

目的研究霉酚酸酯(MMF)在体外对小鼠未成熟树突状细胞抗原递呈功能的影响。方法在骨髓来源未成熟树突状细胞的培养过程中加入MMF，表型鉴定之后，做抗原递呈功能分析，观察抗原特异性增殖反应、混合淋巴细胞反应以及T淋巴细胞抗原特异性低反应性。结果以MMF处理的未成熟树突状细胞向T淋巴细胞递呈可溶性抗原的能力减弱，在同基因型的树突状细胞和T淋巴细胞接触条件下不能刺激致敏T淋巴细胞的有效增殖；MMF处理的树突状细胞在体外的同种混合淋巴细胞培养反应中能够维持树突状细胞于未成熟状态，不能充分活化CD4^ T淋巴细胞和诱发TH1反应，诱导了T淋巴细胞对同种抗原的低反应性；MMF处理的树突状细胞诱导的T淋巴细胞低反应性具有同种抗原特异性。结论在体外培养过程中给予MMF干预能够降低未成熟树突状细胞的抗原递呈能力，增强同种未成熟树突状细胞的免疫耐受诱导作用。     

T细胞疫苗诱导免疫耐受与外周血T细胞凋亡的关系探讨

目的　探讨T细胞疫苗诱导特异性免疫耐受与外周血T细胞凋亡的关系。方法　制备针对Wistar大鼠的SD大鼠T细胞疫苗 ,然后用该疫苗免疫健康SD大鼠 ,每周 1次 ,连续 3周 ,作为实验组 (n =6)。对照组 (n =6)用RPMI 164 0培养液替代T细胞疫苗。以被免疫的SD大鼠的脾细胞作为反应细胞 ,以Wistar大鼠的脾细胞作为刺激细胞 (经丝裂霉素处理 ) ,于接种前和每次接种后第 5天进行单向混合淋巴细胞反应 (3 H TDR掺入法 ) ,测定其cpm值 ;用流式细胞仪对外周血T细胞凋亡情况进行检测。结果　混合淋巴细胞反应结果显示 ,实验组SD大鼠脾细胞免疫应答能力于接种后受到显著抑制 ,其cpm值较接种前显著降低 (P<0 .0 1) ;对照组接种前后各时点比较 ,其差异无显著性(P>0 .0 5 ) ;接种后相同时点的cpm值组间比较 ,实验组显著低于对照组 (P <0 .0 1) ;与接种前比较 ,接种后实验组外周血T细胞凋亡率显著增高 (P<0 .0 1) ,且随着疫苗接种次数的增加而升高 ,而对照组接种后各时点T细胞凋亡率与接种前比较差异无显著性 (P>0 .0 5 )。结论　T细胞疫苗可以诱导同种特异性免疫耐受 ,其机理可能是通过诱导外周血T细胞凋亡 ,清除抗原特异性反应性T细胞克隆来实现的。     

胸腺内注射异基因抗原诱导鼠神经移植免疫耐受的实验研究

目的探讨小鼠胸腺内注射异基因抗原在同种异体异基因坐骨神经移植免疫耐受中的作用。方法自供体小鼠C57BL／6的脾细胞中提取MHC抗原注人受体鼠Balb／c小鼠胸腺内，于2周后移植供体鼠坐骨神经。48只Balb／c小鼠随机分为4组，A组（胸腺内注射组）、B组（自体神经移植组）、C组（冷冻异体神经移植组）、D组（异体神经移植加用免疫抑制剂组）。于3周后进行电生理学、组织学、免疫学检测。结果A组运动神经传导速度（38．23m／s）与D组（36．39m／s）相比无显著性差异（P〉0．05），组织学、电镜、免疫学（混合淋巴细胞培养及迟发性超敏反应）检测结果均证实B组分别优于A组、D组和C组。结论胸腺内注射异基因MHC抗原可诱导大鼠对异体坐骨神经移植的特异性免疫耐受。     

同种器官移植免疫耐受的研究进展

虽然同种组织及器官移植已有近半个世纪的历史，但移植后的排斥反应仍是亟待解决的关键问题。如何有效地诱导产生免疫耐受，成为移植免疫学研究领域的重要课题，迄今已取得如下进展：一、主动免疫诱导同种移植免疫耐受乃通过接种具有移植物抗原特异性的Ｔ细胞疫苗（ＴＣＶ...     

异体手移植的组织配型探讨

目的：研究组织配型在异体肢体移植中的基础作用和意义。方法：对患者和供者进行ABO血型和Rh血型，群体反应性抗体（PRA）检测及淋巴细胞毒性试验，测定人类白细胞抗原（HLA），结果：ABO血型（B－B）Rh血型相符，PRA和淋巴毒性交叉实验均为阴性，人类白细胞抗原（HLA）配型HLA－B，D，DR，DQ位点有4个抗原相合，手术后联合免疫抑制剂，移植双手成功，结论：理想的组织配型可避免异体手移植发生排斥反应，提高异体手移植成功率。     

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.     

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.     

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.     

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.     

Systemic analgesia adapted to the children's condition

A concept of balanced analgesia using nonsteroidal anti-inflammatory drugs (NSAIDs), paracetamol (acetaminophen), opioids, and corticosteroids can also be used in patients with pre-existing illnesses. NSAIDs are the most effective treatment for acute pain of moderate intensity in children; however, these drugs should be avoided in patients at increased risk for serious side effects, e.g. patients with renal impairment, bleeding tendency, or extreme prematurity. NSAIDs can be given with minimal risks to the younger child with mild to moderate asthma, and, in these patients, the use of steroids can be encouraged; in addition to their antiemetic and analgesic action, a beneficial effect on asthma symptoms can be expected. In the non-intubated child with cerebral trauma, exaggerated sedation caused by opioids and increased bleeding tendency caused by NSAIDs must be avoided. In neonates and small infants, the oral administration of sucrose or glucose is helpful to minimize pain reaction during short uncomfortable interventions.     

A comparison of the inhibitory effects of four volatile anaesthetics on the metabolism of chlorzoxazone, a substrate for CYP2E1, in rabbits

Background: Halothane inhibits in vitro and in vivo activity of cytochrome P-450 (CYP) 2E1. There are several fluorinated volatile anaesthetics besides halothane, and most of them are defluorinated by CYP2E1. It is unclear whether other fluorinated anaesthetics inhibit the in vivo activity of CYP2E1.
Methods: We compared the inhibitory effects of therapeutic concentrations of four inhalational anaesthetics, halothane, enflurane, isoflurane, and sevoflurane, on chlorzoxazone metabolism in rabbits receiving artificial ventilation.
Results: All four inhalational anaesthetics decreased arterial blood pressure and increased plasma chlorzoxazone concentration. However, no significant differences in the plasma chlorzoxazone concentration were found between the four anaesthetics. The estimated chlorzoxazone clearance increased after beginning inhalation with all four agents, but no significant difference in clearance was noted between agents.
Conclusions: At therapeutic concentrations, the in vivo inhibitory effect on chlorzoxazone metabolism was similar for all four inhalational anaesthetics examined, even though their chemical characteristics and extent of hepatic metabolism differ considerably.