不同培养基对骨髓间充质干细胞免疫学特性的影响

目的比较ScienCell(SCI)干细胞培养基和低糖(LG)完全培养基培养下骨髓间充质干细胞(BMSC)的免疫学特性。方法利用流式细胞分析BMSC表面标志物的表达;通过体外成骨和成脂诱导,鉴定BMSC的多向分化能力;应用混合淋巴细胞反应实验,比较SCI组和LG组BMSC的免疫原性及免疫调节功能;采用流式细胞仪分析IFN-γ刺激前后BMSC表面免疫分子的表达情况。结果混合淋巴细胞反应结果显示,两组培养基培养的BMSC均具有低免疫原性和免疫抑制功能,但SCI组单向混合淋巴细胞增殖率显著高于LG组,而两组双向混合淋巴细胞增殖率未见显著差异。流式细胞仪分析结果显示,SCI组BMSC中免疫共刺激因子CD40阳性的细胞比例显著高于LG组,而HLA-DR以及免疫共抑制因子B7-H1和B7-DC阳性细胞比例均显著低于LG组。IFN-γ刺激后可显著上调两组BMSC中HLADR的阳性细胞比例至90%以上。低浓度的IFN-γ(10 U/mL)仅轻微上调LG组BMSCs的CD40的表达水平;而高浓度IFN-γ(1 000 U/mL)可显著提高两组BMSC中CD40和B7-H1的阳性细胞比例,以及SCI组BMSC中B7-DC的阳性细胞比例。结论在体外,含有不同成分的干细胞培养基可改变BMSC免疫分子的表达水平;SCI组BMSC的免疫原性显著高于LG组,但免疫抑制功能两组无明显差异。     

骨髓间充质干细胞与嗅鞘细胞联合移植治疗脊髓损伤的早期观察

[目的]探讨自体骨髓间充质细胞和异体嗅鞘细胞共培养及其联合移植修复脊髓损伤的可行性,为临床治疗提供一种新方法。[方法]无菌条件下采集自体骨髓间充质细胞和胎龄4～6个月的引产胎儿的嗅鞘细胞,分别培养至传代后再共培养,将共培养的混合细胞通过手术直视下移植至脊髓损伤部位。[结果]8例脊髓损伤患者接受自体骨髓间充质细胞和异体嗅鞘细胞联合移植,并获得1～6个月的随访,所有接受细胞移植的8例患者术后均无不良反应,其中1例术后1个月开始出现双下肢深浅感觉恢复,其余7例比细胞移植前无明显改善。[结论]自体骨髓间充质细胞和异体嗅鞘细胞共培养两者之间无相互抑制现象,近期观察二者联合移植修复脊髓损伤是安全的。     

未分化骨髓间充质干细胞的免疫学特性研究

目的 研究骨髓间充质干细胞表面MHC-Ⅰ、MHC-Ⅱ类抗原与共刺激分子CD80（B7—1）和CD86（B7—2）的表达及探讨MSC的抗原性。方法 采用流式细胞技术检测MSC表面MHC-Ⅰ、MHC-Ⅱ类抗原与共刺激分子CDS0（B7—1）和CD86（B7—2）的表达，测定淋巴细胞MSC混合反应的强度。结果 MSC表达高水平的MHCⅠ类抗原，不表达MHCⅡ类抗原，低表达CD86（B7—2），不表达CD80（B7—1），IFN-γ刺激48h后，MHCⅠ类抗原表达增加，MHCⅡ类抗原表达，CD80（B7—1）、CD86（B7—2）也均有表达。未分化的MSC经γ-干扰素（IFN-γ）刺激之后，不会引起很强的免疫排斥反应，表现为弱免疫原性。结论 未分化的MSC抗原性较弱，具有同种异体移植的可能。     

重组腺病毒介导CD40L和CTLA4Ig的共表达和对人混合淋巴细胞反应的抑制作用

CD40／CD40L和B7／CD28是两条重要的共刺激通路，在T淋巴细胞活化过程中提供共刺激信号，在自身免疫性疾病和移植排斥反应的发生、发展过程中起重要作用，干预其相互作用，可有效地预防和治疗自身免疫性疾病和排斥反应。本研究基于我们构建的重组腺病毒CIMOL-IRES-CTLA4Ig，观察其体外的共表达情况和对人外周血混合淋巴细胞反应（MLR）的作用。     

负载胰岛素样生长因子-1的骨髓间充质干细胞与壳聚糖-胶原复合物修复大鼠骨缺损的实验研究

背景：目前已有较多研究表明将种子细胞复合于支架材料进行骨缺损的修复能够取得良好的效果,但仍需探索有效的生长因子以促进修复过程。 目的：探讨负载胰岛素样生长因子-1（insulin-like growth factor,IGF-1）的骨髓间充质干细胞与壳聚糖-胶原复合物对大鼠骨缺损的修复作用。 方法：分离大鼠骨髓间充质干细胞,流式细胞术鉴定细胞表面标志物;将骨髓间充质干细胞进行成骨诱导后检测碱性磷酸酶的活性以鉴定其成骨能力;IGF-1过表达载体转染骨髓间充质干细胞并筛选稳转细胞系,Real-time PCR以及Western blot鉴定稳转细胞系中IGF-1的表达。扩培细胞,并与壳聚糖-胶原进行复合培养。同时建立大鼠骨缺损模型,造模成功后将20只大鼠随机分为4组,每组5只。实验组植入负载IGF-1的骨髓间充质干细胞复合支架,支架修复组植入未经细胞复合的支架,干细胞复合支架修复组植入单纯骨髓间充质干细胞复合支架,空白对照组缺损处未植入任何物质。术后分别通过X射线和组织学切片观察比较各组大鼠的骨缺损修复情况。 结果：流式细胞术鉴定结果显示细胞CD44阳性率为98.19%,CD45阳性率为3.65%,CD90阳性率为97.62%。成骨诱导后碱性磷酸酶浓度升高至（11.57±0.48）U/L,显著高于未经成骨诱导的细胞（5.55±0.63）U/L（〈0.05）。Real-time PCR以及Western blot检测结果IGF-1稳定转染的细胞中IGF-1 mRNA以及蛋白的表达均显著升高（〈0.05）。X射线以及组织学观察结果表明空白组骨缺损不能自行修复,壳聚糖-胶原支架与骨髓间充质干细胞复合物植入大鼠后未见明显的免疫排斥反应,与其他组相比负载IGF-1的骨髓间充质干细胞与壳聚糖-胶原复合物组的成骨及修复效果均较为明显。 结论：骨髓间充质干细胞是较为理想的骨组织工程种子细胞,将IGF-1负载于骨髓间充质干细胞能够促进骨组织的修复。     

CD40/CD40L和B7-1/CD28在小鼠叶酸性肾病中的作用

目的研究CD40／CD40L、B7—1／CD28在肾小管间质浸润的免疫活性细胞、损伤的肾组织固有细胞上的表达以及其可能的作用。方法一次性腹腔注射叶酸制作CD1小时鼠叶酸性肾病模型。在第1、2、3、7、14、21天分别处死动物，取其右肾进行免疫组织化学染色；取左肾提取蛋白进行蛋白印迹分析；采血检测BUN、Scr。以抗B7—1功能性单克隆抗体（B7-1mAb）联合叶酸应用，观察21d后，采血行BUN、Scr检测，病理图像分析肾病变区域及保护率。结果小鼠在给予叶酸后第1天，CD40、B7-1在肾小管上皮表达上调，并持续至第21天。通过蛋白印迹半定量检测，CD40在各时间点实验组肾组织表达量均增加5倍以上（P均〈0．01），在间质区域浸润的免疫活性细胞上可见CD28和CD40L的表达。经B7-lmAb干预性治疗，小鼠死亡率从47．83％下降到11．01％。P〈0．01；BUN、Scr水平明显降低；肾组织保护率从7．45％上升至66．51％。结论在小鼠叶酸性肾病中．肾组织CD40／CD40L和B7-1／CD28的表达上调并参与了肾小管上皮细胞损伤、免疫活性细胞浸润和肾小管间质纤维化的过程。B7-1mAb干预治疗能减轻上述的肾损害，为肾间质纤维化的特异性免疫治疗提供新的途径。     

门静脉高压症患者脾切除后外周血B7-1/CD28表达的变化

目的探讨B7-1/CD28对门静脉高压症（portal hypertension,PHT）患者免疫功能的影响和作用。方法采用流式细胞分析技术对30例门静脉高压症患者进行研究,检测门静脉高压症患者行脾切除前后外周血淋巴细胞中以及脾脏中B7-1/CD28的表达情况,分析其与患者淋巴细胞亚群以及免疫功能的关系。对患者外周血B7-1/CD28和淋巴细胞进行检测。利用免疫组化方法检测B7-1/CD28在脾脏中的表达,与10例外伤性脾破裂行脾切除之脾脏组织进行比较。结果门静脉高压症患者外周血中淋巴细胞亚群和B7-1/CD28表达较低,脾切除后短期内升高。其脾脏中表达的B7-1/CD28较正常人群高。结论门静脉高压症患者全脾切除后外周血B7-1/CD28通路被激活,患者免疫功能得到部分恢复。     

骨髓间充质干细胞定向分化肝细胞及肝内移植研究

目的 观察体外诱导骨髓问充质干细胞分化及肝纤维化形成环境中移植情况。方法 首先行骨髓间充质干细胞提取、分离和培养，加入肝细胞生长因子（HGF，20μg／L）和表皮生长因子（EGF，1．5mg／L）诱导定向分化。肝纤维化形成的大鼠随机分成2组，每组10只。使用5-溴脱氧尿苷（BrdU）标记诱导的骨髓间充质干细胞，经门静脉向肝纤维化形成的SD大鼠肝脏移植，对照组用BrdU标记未经诱导的骨髓间充质干细胞。2周后通过免疫组织化学方法检测大鼠肝脏标记细胞的分布及BrdU^＋／ALB^＋细胞数量。结果 体外诱导骨髓间充质干细胞定向分化的细胞CK8及ALB表达阳性。移植2周后大鼠肝脏均可检测到BrdU标记细胞，与对照组相比诱导后骨髓问充质干细胞组BrdU^＋／ALB^＋细胞数较多，差异有统计学意义（P〈0．05）。结论 经体外诱导骨髓间充质干细胞能分化为肝细胞，移植在大鼠肝纤维化形成环境中，白蛋白表达细胞数更多。     

共刺激分子B7在肿瘤免疫中的作用（文献综述）

抗肿瘤免疫以细胞免疫为主，特异性T细胞的活化需双信号刺激，共刺激分子发挥了相当重要的作用，其中B7分子是当今研究热点，本文对B7分子的结构，功能及其在肿瘤免疫研究中的进展进作一综述。     

同种大鼠骨髓间充质干细胞诱导调节性B淋巴细胞的免疫负调节作用

目的 研究骨髓间充质干细胞(MSC)诱导调节性B淋巴细胞(Breg细胞)的免疫负调节作用.方法 取DA大鼠MSC和Lewis大鼠B淋巴细胞共培养后,酶联免疫吸附试验(ELISA)检测MSC和B淋巴细胞混合培养组上清液中白细胞介素10(IL-10)的水平和分泌因子的变化;采用流式细胞技术分析B淋巴细胞增殖、凋亡、表型的变化和对抗原特异性T淋巴细胞增殖的影响,采用激光共聚焦显微镜观察Breg细胞对免疫复合物吞噬能力的变化.结果 MSC成功诱导产生高分泌IL-10的Breg细胞产生,表型为CD19+ CD1d+ CD5+,MSC显著抑制B淋巴细胞的增殖,Breg细胞能抑制抗原特异性T淋巴细胞的增殖,并增加对免疫复合物的吞噬能力.结论 MSC诱导的Breg细胞具有明显的免疫负调节作用.     

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.     

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.     

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.