The gamma subunit of the interleukin-2 receptor is expressed in human monocytes and modulated by interleukin-2, interferon gamma, and transforming growth factor beta 1

The interleukin-2 receptor gamma (IL-2R gamma) chain is a newly recognized component of the IL-2R of lymphoid cells that is required for their response to IL-2. We investigated the expression of IL-2R gamma protein in human monocytes by Western blot analysis using an antiserum specific for IL-2R gamma. We found that IL-2R gamma subunit is constitutively expressed in human monocytes and upregulated by the monocyte-activating factors IL-2 and interferon gamma (IFN gamma). Furthermore, we show that transforming growth factor beta 1 (TGF beta 1) downmodulates, in a dose-dependent manner, basal and IL-2-induced, but not IFN gamma-induced, IL-2R gamma chain expression, and this effect may be responsible for TGF beta 1 suppressive activity on IL-2- activated monocytes. Overall, these results show that the expression of the IL-2R gamma subunit in human monocytes is tightly regulated by the cytokine network, suggesting a critical role played by this protein on monocyte activation.     

Unbound immunoglobulins are a major source of error in the quantitation of platelet surface-bound immunoglobulin levels

Analysis of assays for the determination of platelet-associated immunoglobulins (PAIgs) has led to disagreement over the amount of surface-bound Igs in both normal controls and patients with elevated platelet Ig levels. By the use of radiolabeled platelets and platelet counts, it was demonstrated that more than 10(8) platelets are disrupted after each centrifugation during platelet isolation procedures, releasing intraplatelet contents into the fluid phase of resuspended platelets in buffer. It was shown that suspensions of whole washed platelets contain a significant, but generally overlooked, amount of unbound Igs that have been liberated from platelets disrupted during processing. When platelet suspensions are evaluated for Igs with assays that fail to incorporate a final separation of whole platelets from the suspension fluid, unbound Igs as well as those bound to the platelet surface are measured, which yields a logarithmic overestimation of surface-bound Igs. It has been further demonstrated that patients infected with human immunodeficiency virus type 1 can have elevations of PAIgG, PAIgA, and PAIgM in both the thrombocytopenic and nonthrombocytopenic states. These elevations are due to increased internal platelet pools of Igs and not to increased surface-bound Igs.     

硫唑嘌呤和霉酚酸酯对应用环孢素A肾移植患者血脂的影响

目的:肾移植术后环孢素A和皮质醇联合应用可使患者发生高脂血症的风险升高,观察在此基础上应用硫唑嘌呤和霉酚酸酯对肾移植患者血脂的影响。方法:选择2003-01/2006-01解放军第四军医大学西京医院泌尿外科收治的肾移植患者65例,患者均知情同意。①实验分组及方法:按服用免疫抑制剂不同将患者分为2组,硫唑嘌呤组35例,霉酚酸酯组30例。患者肾移植术后1年内均以环孢素A和皮质醇为基础免疫抑制治疗方案,免疫抑制方案始终为环孢素A 硫唑嘌呤 皮质醇或环孢素A 霉酚酸酯 皮质醇。②实验评估:检测两组患者术前、术后3个月、个月及12个月的血脂指标,包括总胆固醇、三酰甘油、高密度脂蛋白胆固醇、低密6度脂蛋白胆固醇和极低密度脂蛋白胆固醇,同时检测血清肌酐水平。结果:65例患者全部进入结果分析,无脱落。①术前患者高脂血症的发生率是35.2%,至术后第3个月为62.7%,术后第6个月为52.3%,术后第12个月为39.3%。②术后1年中两组患者的总胆固醇和三酰甘油水平均较术前显著升高(P<0.05),术后第3个月时霉酚酸酯组的总胆固醇水平显著高于硫唑嘌呤组(P<0.05),但在第6个月以后,两组间总胆固醇与三酰甘油水平差异无显著性意义(P>0.05)。在1年的监测中,两组患者的高密度脂蛋白、低密度脂蛋白和极低密度脂蛋白水平皆未发生显著变化(P>0.05)。结论:在以环孢素和皮质激素为基础免疫抑制方案的肾移植患者中,血清总胆固醇和三酰甘油有明显的升高倾向,而这种升高倾向可能与长期服用硫唑嘌呤或霉酚酸酯无关。     

Bronchopleural complications of nasogastric feeding tubes

Enteral alimentation via small soft feeding tubes is becoming more common as the importance of nutrition is recognized in the debilitated patient. The monofilament wire stylets that stiffen these tubes during their insertion may cause potentially lethal bronchopleural complications unless correct insertion techniques are used and the tube's position is carefully checked before starting enteral nutrition.     

绵羊二尖瓣置换动物模型的制作

目的:探索人工二尖瓣置换绵羊动物模型制作的外科技术。方法:实验于2006-01/04在南方医科大学动物实验中心完成。①选用健康雄性绵羊6只,制作人工机械心脏瓣膜置换动物模型;另外取6只羊每只采血1500mL后处死。②人工机械心脏瓣膜由兰州飞控医疗仪器厂生产,为C-LⅠ型短柱人工机械心脏瓣膜,瓣架为高强度耐酸铬镍合金,瓣片的内部为石墨基体,表面为沉积热解碳,瓣环为涤纶长丝织物。③二尖瓣置换模型制备:术中右颈静脉建立通路用于测静脉压、输液等;右股动脉置管连续监测动脉压;连续监测心电图、血氧饱和度;检测血气分析、血钾和全血激活凝血时间;监测鼻咽及肛温,计尿量。麻醉后气管内插管接麻醉机。降主动脉插供血管,右心耳或者上、下腔静脉插引流管,升主动脉根部插灌注管和左肺静脉插左心引流管,建立体外循环。主动脉阻断,灌注心肌保护液;阻断上下腔静脉。体外循环为新鲜羊血预充,转流降温至鼻咽温度27～30℃。经左心耳切口显露二尖瓣,切除瓣叶、腱索及部分乳头肌。放置人工瓣膜,连续缝合二尖瓣环。开放循环,心脏自动复跳,循环稳定后脱离体外循环并拔管,放置左胸引流后常规关胸。术后常规使用血管活性药,麻醉清醒后拔除气管插管,青霉素预防感染,华法令口服抗凝治疗。结果:6只羊手术过程均顺利,心脏全部自动复跳,术后全部存活且超过1个月。术中体外循环过程平稳,监测血气分析无大的波动;平均手术时间为(129±11)min,平均转流时间为(61±7)min,平均主动脉阻断时间为(30±6)min,预充血量为(700±89)mL,转流中鼻咽温为(28.7±1.3)℃。术后呼吸机辅助时间12～30h,术后血管活性药使用时间6～37h,均在24h内拔除胸腔引流管。3只羊并发肺部感染经抗炎治疗后治愈。术后口服华法令抗凝治疗,剂量6.0～12mg,国际标准化比值控制在2.1～3.2之间。结论:经左心耳入路行二尖瓣置换制作绵羊动物模型是可行的。采用同种新鲜羊血预充、术中保持良好的引流和组织灌注、术后加强呼吸道管理以及抗凝治疗是提高手术成功率的重要保证。     

Further studies of canine von Willebrand's disease

Additional characterization of von Willebrand's disease (VWD) in a family of German shepherd dogs is presented. Genetic studies of three generations of affected dogs indicate that about 50% of the progeny are affected if one parent has VWD and about 60% if both parents have the defect. Some of these progeny manifested an incomplete form of VWD, suggesting autosomal dominant inheritance with variable expressivity. The disease become progressively less severe with advancing age and repeated pregnancies. Ristocetin-induced platelet aggregation was significantly reduced in VWD dogs as compared with normal, thrombopathic, and hemophilic carrier dogs. Immunodiffusion and electroimmunodiffusion studies with rabbit anticanine factor VII showed the level of factor VII-related antigen to be low in VWD dogs but present in increased amounts in hemophilic dogs. VWD affected dogs had markedly delayed hemostatic plug formation, but their plugs appeared normal by light and electron microscopy. Their platelet nucleotides, ATP/ADP ration, and platelet protein content were normal. Platelet and fibrinogen survival times with [75Se] selenomethionine were also normal, although platelets from VWD dogs incorporated more radioactivity than did those from normal dogs or from dogs with incomplete VWD.     

Death at cardiac catheterization: coronary artery embolization of calcium debris from Ionescu-Shiley bioprosthesis

The case described is a death due to embolization of calcium debris from a bioprosthesis, dislodged at cardiac catheterization. As more bioprosthetic valves are implanted, and more of them fail long-term with calcification, such complications of the invasive study of these valves may be expected.     

Heparin-Coated Coronary Stents

The development of the heparin-coated (HC)-stent should be viewed against the backdrop of the early unfavorable results with noncoated stents in the pre-intravascular ultrasound and pre-ticlopidine era. Notwithstanding, results of pilot and randomized trials show a surprisingly low incidence of (sub)acute stent thrombosis under challenging circumstances, such as acute coronary syndromes. Considering the quite low incidence of early complications with noncoated second-generation stents, it may require large trials to prove the clinical efficacy of the heparin- coating against noncoated devices. However, even if the "added value" of the heparin-coating will never be clinically proven, it has helped to enhance the penetration of stent therapy in interventional cardiology. Unlike the situation in 1992, very few cardiologists will now disagree with the statement that stents contribute to the state-of-the-art treatment of patients with angina pectoris or acute myocardial infarction. A preliminary comparison of available trials also suggests that the heparin-coated Palmaz-Schatz stent (Cordis Corp., Waterloo, Belgium) is as effective as the noncoated stent plus abciximab treatment.