Recovery of Functional Memory T Cells in Lung Transplant Recipients Following Induction Therapy with Alemtuzumab

Profound T-cell depletion with the monoclonal antibody alemtuzumab facilitates reduced maintenance immunosuppression in abdominal and lung transplantation. While the phenotype of the post-depletional T cells has been characterized, little is known about their function. In the present study, global and CMV-specific T-cell function was assessed longitudinally in 23 lung transplant (LTx) recipients using T-cell assays (ImmuKnow and T Cell Memory, Cylex, Columbia, MD) during the first year posttransplant after induction therapy. Recovery of mitogen responses were seen at 2 weeks posttransplantation (65%PHA; 58% Con A), despite the low number of circulating T cells (<2%). These responses declined at 4-5 months (24%PHA; 54% Con A) and were partially reconstituted by 9 months (46% PHA; 73% Con A). CMV-specific responses recovered in 80% of R+ patients as early as 2 weeks posttransplant (n = 5) and 72% of patients had a memory response by 3 months (n = 11). In contrast, only 2 of 5 patients who did not exhibit memory responses pre-transplant (R-) developed transient CMV-specific T-cell responses. Our results show that profound depletion of T cells induced by alemtuzumab spares the functional subset of CMV-specific memory T cells. Conversely, CMV R- patients predepletion may require a prolonged period of prophylaxis.     

Lung Transplant Metalloproteinase Levels Are Elevated Prior to Bronchiolitis Obliterans Syndrome

Parenchymal disease in the allograft lung is associated with interstitial remodeling believed to be mediated by matrix metalloproteinases (MMPs). Recent studies suggest high levels of MMP-9 are associated with bronchiolitis obliterans syndrome (BOS) in lung transplant recipients. Since BOS occurs late in the posttransplant period and may be preceded by episodes of acute rejection or infection, which are associated with interstitial remodeling, we examined MMP profiles in allograft bronchoalveolar lavage (BAL) fluid in the early posttransplant period (preceding BOS). Gelatin zymography, protein array analysis and specific ELISA on BAL fluids from transplanted lungs indicated that MMP-8, MMP-9 and TIMP-1 were strongly expressed in allograft BAL fluid from stable patients, or those with infection or rejection compared to BAL fluid from normal volunteers. Elevated expression of MMP-8, MMP-9 and TIMP-1 occurred early, and was sustained for the 3.2 years covered in this study. Elevations of MMP-8, MMP-9 and TIMP-1 in the first 2 years posttransplant appear to be associated with lung transplantation itself, and not infection or rejection. These data suggest that ongoing and clinically silent MMP activity could perpetuate progressive disease in the allograft lung.     

分子吸附循环系统联合肝移植治疗急性肝功能衰竭

目的　探讨应用分子吸附循环系统结合肝移植治疗急性肝功能衰竭的效果。方法　 8例急性肝功能衰竭患者 (7例原发病为乙型肝炎后肝硬化 ,1例为Wilson病 )在等待肝移植期间经分子吸附循环系统治疗 3～ 7次 ,所有患者均接受同种异体改良背驮式肝移植术。结果　患者等待供肝时间 8～ 30d ,平均 13d ,所有患者均顺利渡过围手术期 ,痊愈出院。应用分子吸附循环系统治疗后 ,患者的血清丙氨酸转氨酶、天冬氨酸转氨酶及总胆红素水平明显下降 (P <0 .0 1) ,但凝血功能的改善不明显。结论　分子吸附循环系统可暂时替代肝脏的部分功能 ,帮助急性肝功能衰竭患者顺利渡过肝移植等待期。     

IL-4与IL-10联合诱导异种骨移植免疫耐受的体外研究

目的　探讨 IL - 4和 IL - 10在诱导异种骨移植免疫耐受中的作用。方法　反应细胞为 BAL B/c小鼠脾淋巴细胞 ,刺激细胞为新西兰白兔血淋巴细胞 ,刺激抗原为兔骨上清液。采用经典的混合淋巴细胞培养法及骨上清液与淋巴细胞混合培养法作为异种骨移植的体外实验模型。在各培养液中分别加入 IL - 4、IL - 10及两者联合应用 ,通过测定其 3H- Td R掺入率 ,观察不同细胞因子对刺激淋巴细胞增殖的影响。结果　无论在细胞刺激组还是骨上清液刺激组 ,IL- 4对淋巴细胞增殖均有显著抑制作用 (P<0 .0 0 1和 P<0 .0 5 ) ,IL- 10未表现出抑制作用 (P>0 .0 5 )。在两组 IL- 4和 IL - 10联合应用均产生比 IL - 4单独应用更为明显的细胞增殖抑制作用 (P<0 .0 0 1和 P<0 .0 5 )。结论　 IL - 4对由细胞或骨上清液刺激产生的淋巴细胞增殖均有很好的抑制作用 ,IL- 10没有表现出抑制作用 ;IL- 4与 IL- 10联合应用有协同抑制作用。     

大鼠移植胰腺冷缺血再灌注后细胞凋亡的变化

目的　探讨移植胰腺冷缺血再灌注后胰腺细胞凋亡的变化过程。方法　 6 5只SD大鼠随机分成 7组 :假手术组 ,冷缺血 2h组 ,冷缺血 2h再灌注 1、3、6、9、12h组。通过HE染色后光镜及电镜观察各组的胰腺组织的病理变化 ;采用脱氧核糖核苷酸末端转移酶介导的缺口末端标记法(TUNEL)检测凋亡细胞的分布及计数。结果　胰腺移植后早期即可观察到细胞凋亡的典型改变 ,胰腺冷缺血再灌注后发生凋亡的高峰期为再灌注后 3h[AI为 (9.4 6± 2 .91) % ,P <0 .0 1) ,再灌注 6h较 3小时细胞凋亡有所减少 [AI为 (5 .74± 1.6 6 ) % ,P <0 .0 1],再灌注 9h及 12h细胞凋亡进一步减少 [AI分别为 (3.6 0± 1.6 4 ) %及 (3.2 6± 1.35 ) % ,P <0 .0 5 ]。结论　细胞凋亡是胰腺移植后的早期事件 ,移植胰腺冷缺血再灌注后早期主要的死亡方式是凋亡 ;移植胰腺冷缺血再灌注后的凋亡高峰发生在再灌注后 3h。     

肾移植术后发生高尿酸血症的机制

目的：探讨肾移植术后发生高尿酸血症的机制及防治策略。方法：分析480例肾移植术后患者的临床资料。结果：肾移植术后移植肾功能正常而血尿酸增高者43例(9％)，其中痛风7例，移植肾肾盂或输尿管结石3例。随访1～5年，1例痛风患者血尿酸及症状控制不理想，余血尿酸均控制在正常水平，未见并发症的发生。结论：高尿酸血症是肾移植术后较常见的问题，发生原因较多，但主要与环孢素A的作用有关；长期降尿酸及碱化尿液治疗安全、有效。     

肾移植术后肺部真菌感染的诊治

目的　探讨肾移植术后肺部真菌感染的诊断与治疗。　方法　回顾性分析 4 3例肾移植术后肺部真菌感染患者的临床资料。男 35例 ,女 8例 ,平均年龄 32岁。发病时间平均为术后 5 9d。　结果　 4 3例患者中 ,白色念珠菌 16例 ,克柔念珠菌 4例 ,近平滑念珠菌 2例 ,曲霉菌 4例 ,毛霉菌 3例 ,新型隐球菌 1例 ,奴卡菌 2例 ,其中 14例有细菌、巨细胞病毒混合感染。 11例培养阴性。氟康唑10 0mg/次 ,3次 /d ,连续 10d ,治愈 2 3例 ;两性霉素B脂质体 5 0mg/d ,连续 10d ,治愈 17例 ;死亡 3例。　结论　肺部真菌感染是肾移植术后的严重并发症 ,死亡率高。早期诊断与治疗效果良好。     

大鼠胰腺十二指肠移植的手术技巧

目的探讨建立大鼠胰腺十二指肠移植模型的手术技巧。方法不阻断体循环，采用双套管将供胰所带腹主动脉、门静脉分别与受鼠的左肾动、静脉进行套管吻合，尽量减轻对全身血流动力学的影响；同时行十二指肠空肠端侧吻合引流胰液，重建胰腺外分泌途径；围手术期注意补液、保暖及抗凝。结果100例手术中83例手术成功，术后移植胰腺具有内分泌功能，胰腺轻度充血水肿。结论该移植模型不阻断体循环且操作简单实用，其成功的关键在于手术操作及围手术期处理。     

Mutant ryanodine receptors in catecholaminergic polymorphic ventricular tachycardia generate delayed afterdepolarizations due to increased propensity to Ca2+ waves.

AIMS: Mutations in cardiac ryanodine receptors (RyR2s) are linked to catecholaminergic polymorphic ventricular tachycardia (CPVT), characterized by risk of polymorphic ventricular tachyarrhythmias and sudden death during exercise. Arrhythmias are caused by gain-of-function defects in RyR2, but cellular arrhythmogenesis remains elusive. METHODS AND RESULTS: We recorded endocardial monophasic action potentials (MAPs) at right ventricular septum in 15 CPVT patients with a RyR2 mutation (P2,328S, Q4,201R, and V4,653F) and in 12 control subjects both at baseline and during epinephrine infusion (0.05 microg/kg/min). At baseline 3 and during epinephrine infusion, four CPVT patients, but none of the control subjects, showed delayed afterdepolarizations (DADs) occasionally coinciding with ventricular premature complexes. In order to study the underlying mechanisms, we expressed two types of mutant RyR2 (P2,328S and V4,653F) causing CPVT as well as wild-type RyR2 in HEK 293 cells. Confocal microscopy of Fluo-3 loaded cells transfected with any of the three RyR2s showed no spontaneous subcellular Ca(2+) release events at baseline. Membrane permeable cAMP analogue (Dioctanoyl-cAMP) triggered subcellular Ca(2+) release events as Ca(2+) sparks and waves. Cells expressing mutant RyR2s showed spontaneous Ca(2+) release events at lower concentrations of cAMP than cells transfected with wild-type RyR2. CONCLUSION: CPVT patients show DADs coinciding with premature action potentials in MAP recordings. Expression studies suggest that DADs are caused by increased propensity of abnormal RyR2s to generate spontaneous Ca(2+) waves in response to cAMP stimulation. Increased sensitivity of mutant RyR2s to cAMP may explain the occurrence of arrhythmias during exercise or emotional stress in CPVT.     

大龄腭裂患者的手术治疗方法与语音治疗效果的对比研究

目的 对单纯行裂隙关闭术和同期行咽后壁咽成形术的大龄腭裂患者,术前、术后发音效果进行检测分析和对比研究,评定手术的治疗效果.方法 对24例同期行腭裂关闭术及咽后壁组织瓣咽成形术治疗和12例单纯行裂隙关闭术的大龄腭裂患者,术前、术后用鼻咽纤维镜检测其腭咽闭合情况,应用通用音频谱分析系统,对本组术后患者腭裂语音进行声学分析.结果 所有腭裂修复术后,创口均达到临床Ⅰ期愈合,语音也有不同程度改善.大龄腭裂患者采用腭裂关闭及同期咽成形术的修复组,术后发音明显优于单纯行裂隙关闭组.结论 大龄腭裂患者,采用腭裂关闭及同期咽成形术,是提高腭咽闭合和改善发音较好的手术方法.