Food preservatives sodium sulfite and sorbic acid suppress mitogen-stimulated peripheral blood mononuclear cells

Antioxidant preservatives prolong the quality of food and ensure the nutritional adequacy, palatability and safety of many processed foods and beverages. Effects of sodium sulfite (E221) and sorbic acid (E200) were investigated in human peripheral blood mononuclear cells (PBMC) which were purified from blood of healthy donors. Cells were stimulated with the mitogen phytohaemagglutinin in vitro, which induces proliferation of T-cells and the production of Th1-type cytokines like interferon-γ. The latter triggers enzyme indoleamine (2,3)-dioxygenase, which degrades tryptophan, and GTP cyclohydrolase I, which leads to increased neopterin production, in monocyte-derived macrophages. Sodium sulfite and sorbic acid suppressed both these biochemical changes in a dose-dependent way (P < 0.01 at 1 mM sodium sulfite and 50 mM sorbic acid). Data demonstrate a suppressive influence of sodium sulfite and sorbic acid on the activated Th1-type immune response.     

A Prospective Randomized Trial of Steroid-Free Maintenance Regimens in Kidney Transplant Recipients—An Interim Analysis

We compared three maintenance immunosuppressive regimens in a rapid discontinuation of prednisone protocol. From March 1, 2001, through December 31, 2003, 239 first and second kidney transplant recipients (166 LD; 73 DD) were randomized. All recipients were treated with Thymoglobulin; all received steroids intraoperatively and for 5 days postoperatively. Randomization was to cyclosporine-mycophenolate mofetil (n = 85); high-level tacrolimus (TAC) (8-12 ng/mL)-low-level sirolimus (SRL) (3-7 ng/mL) (n = 72); or low-level TAC (3-7 ng/mL)-high-level SRL (8-12 ng/mL) (n = 82). We found no difference at 24 months between groups in patient, graft, death-censored graft, or acute rejection-free graft survival, or in kidney function. Wound complications were more common in SRL-treated recipients (p = 0.02); we found no other differences between groups in complication rates. Our data suggest that excellent patient and graft survival and low rejection rates can be obtained using a variety of maintenance protocols without prednisone.     

CD4-specific monoclonal antibody can prolong cardiac allograft survival without T-cell depletion

Current immunosuppressive regimens for clinical transplantation are immunologically non-specific, are associated with acute and chronic toxic side-effects [1] and are unable to prevent chronic graft loss in a significant proportion of patients. Additionally, new and increasingly powerful drugs are being introduced to induce non-specific immunosuppression, and therefore this is likely to be followed by an increase in related complications such as the induction of cancers. Hence, there is a need for an alternative approach. It has been shown that long-term survival of murine cardiac grafts can be induced by the monoclonal antibody YIS 191 that depletes CD4 ⁺T cells in vivo [2]. In this study, we have investigated the ability of a non-depleting antibody to produce better graft survival.     

应用羟基荧光素二醋酸琥珀酰亚胺脂探讨新型免疫抑制剂J2作用机制

目的探讨基于CIM立体构型设计的新型免疫抑制剂（J2）在小鼠体内的免疫抑制作用以及其作用机制。方法将羧基荧光素二醋酸琥珀酰亚胺酯（CFSE）标记的C57BL／6（H-2b）小鼠的淋巴细胞4×10^6～6×10^6经尾静脉注入经印钴照射（900拉德）后的DBA／2（H-2d）小鼠体内构建模型。将DBA／2小鼠随机分为5组，每组5只，模型建立后即刻腹腔注射J2，每天1次。对照组注射生理盐水、CsA组注射环孢素A（10mg／kg体重）；实验组J2A组（1mg／kg体重）、J2B组（4mg／kg体重）、J2C组（8mg／kg体重）。给药3d后分组处死DBA／2小鼠取脾制备淋巴细胞，用CD3、CD4、CD8单抗分别标记受检T细胞，FACS流式细胞仪检测CD4^＋T细胞和CD8^＋T细胞在小鼠体内分裂增殖的情况，并检测CD4^＋T细胞的凋亡情况。结果CFSE标记C57BL/6小鼠的脾淋巴细胞着染率大于99％。对照组分裂的CD4^＋T细胞（75．34±1．58）％、分裂的CD8^＋T细胞（83．48±1．25）％明显多于CsA组和实验组（P〈0．01）。J2B组和J2C组分裂的细胞数分别与CsA组比较差异无统计学意义（P〉0．05），但J2A组多于CsA组（P〈0．05）。对照组CD4^＋T细胞早期凋亡的比例（41．1±3．4）％明显高于其他各组（P〈0．01）。J2A组（35．6±4．1）％、J2B组（24．0±3．7）％和J2C组（13．6±2．3）％CD4^＋T细胞早期凋亡的比例显著高于CsA组（7．4±1．9）％（P〈0．05）。结论J2可能抑制T细胞亚群CD4^＋T细胞的活化，从而进一步抑制CD8^＋T细胞的分裂增殖而具有免疫抑制作用。     

骨髓间充质干细胞输对移植肾的保护作用

目的体外培养大鼠骨髓间充质干细胞（MSCs），探讨其对移植肾的保护作用。方法无菌条件下取大鼠股骨、胫骨，用直接贴壁法分离纯化MSCs，体外扩增，在注射MSCs的基础上，行同种异体肾移植，实验大鼠分为注射大鼠骨髓MSCs肾移植组（Ⅰ组）和单纯肾移植组（Ⅱ组），环孢素A治疗肾移植组（Ⅲ组）术后5d结扎受体右肾动脉（左侧为移植肾）；观察右肾动脉结扎术后受体存活时间，检测右肾术后移植肾的形态学变化，肌酐水平。结果Ⅰ组、Ⅲ组大鼠生存期（15．50±6．35）d和（18．50±5．97）d较Ⅱ组（6．50±3．11）d明显延长，且前者移植肾形态学观察和功能状态均明显优于后者。结论骨髓间充质干细胞在体外很容易分离培养和扩增，骨髓间充质干细胞对早期移植肾具有保护作用。     

RNA干扰阻断BT／CD28共刺激通路在小鼠心脏移植中的抗排斥作用

目的探讨RNA干扰（RNAi）技术阻断B7／CD28共刺激通路对小鼠异体心脏移植排斥反应的影响及其机制。方法经体外转录合成针对CD80 mRNA和CD86 mRNA序列特异性小片段干扰RNA（siRNA），转染供者骨髓来源的树突状细胞（DC），半定量逆转录聚合酶链反应、流式细胞仪检测DC转染CD80siRNA、CD86siRNA前后CD80 mRNA和CD86 mRNA的表达水平以及细胞表面CD80及CD86的表达情况。在小鼠异位心脏移植前7d，经静脉给受者输注经siRNA干扰后的DC（干扰DC组），同时设立同种异体对照组、环孢素A（CsA）治疗组（术后皮下注射CsA 5mg／d）、同系移植对照组和未干扰DC组（移植前输注未转染DC），观察各组移植心脏的存活时间，对移植物的排斥反应进行病理分级，并测定移植物组织中白细胞介素2（IL-2）、γ干扰素（IFN-γ）及IL-10的mRNA表达水平。结果siRNA转染DC后，其CD80 mRNA及CD86 mRNA的表达受到明显抑制，CD80、CD86的阳性率分别由84％和67％下降至35％和30％。与同种异体对照组和未干扰DC组比较，干扰DC组移植心脏存活时间明显延长（P〈0．01），组织排斥反应病理分级显著降低（P〈0．01），移植心脏组织中IL-2 mRNA和IFN-γ mRNA的表达水平明显降低（P〈0．01），而IL-10 mRNA的表达水平明显升高（P〈0．01）。结论利用RNAi敲减供者骨髓来源的DC表面B7分子的表达，以阻断BT／CD28共刺激通路，具有抑制小鼠心脏移植排斥反应的作用，其机理可能是通过诱导T淋巴细胞无能并使T辅助细胞分化向Tn2型方向偏移。     

FK506和RS-61443对大鼠异体肢体移植的联合免疫抑制作用

目的　通过大鼠异体肢体移植模型 ,旨在分析 FK5 0 6和 RS- 6 14 4 3对大鼠异体肢体移植中急性排斥反应的免疫抑制作用。　方法　选择雄性 Wistar和 SD大鼠为供、受体 ,以 FK5 0 6和 RS- 6 14 4 3为免疫抑制剂 ,对照组为术后不用药组 ,实验组根据用药剂量和药物不同分为 6组 ,各组用药时间均为 5周 (每日 1次共 2周 ,然后每周 2次共 3周 ) ,进行了 10 1例异体肢体移植动物实验。观察大鼠一般情况、移植肢体排斥反应及存活时间。　结果　对照组肢体平均存活时间为 (7.0 0± 0 .78)天 ;实验组 1～ 6组移植肢体平均存活时间分别为 (17.0 8± 4 .5 0、2 3.2 0± 5 .0 5、11.19±2 .2 8、16 .33± 1.83、13.33± 3.2 2和 5 8.76± 6 .81)天。　结论　 FK5 0 6和 RS- 6 14 4 3能抑制大鼠同种异体肢体移植术后急性移植排斥反应的发生 ,并能延长移植肢体的存活时间。     

Cyclosporine in the treatment of azathioprine-induced red cell aplasia following renal transplantation

Azathioprine, a well-known immunosuppressive agent, is used extensively in renal transplantation. There have been several case reports of pure red cell aplasia induced by this drug following a successful kidney transplant. Previous management of azathioprine-induced red cell aplasia included reduction of azathioprine dose, or treatment with cyclophosphamide. We propose the substitution of cyclosporine for azathioprine, in this clinical setting. Not only does cyclosporine allow recovery of bone marrow function, but it maintains a level of immunosuppression which stabilizes renal function in the post-transplant patient.     

Lessons to be learned from a complicated case of rhino-cerebral mucormycosis in a renal allograft recipient

Fungal infections still represent a serious complication after organ transplantation. Early diagnosis and aggressive treatment are crucial. Because of the many diagnostic problems involved, we present a case of mucormycosis--primarily affecting the paranasal sinuses with later intracranial extension--in a highly immunized recipient of a third renal transplant. Although fungal infection was suspected from various imaging techniques, only the detection of typical fungal hyphae in the infected tissue was diagnostic. Neither the blood tests and cerebrospinal fluid examinations performed nor cultures from maxillary sinus fluid were of any diagnostic help. Surgical debridement from a transnasal as well as an intracranial approach and systemic amphotericin B together with the discontinuation of immunosuppression after removal of the rejected graft were able to save the patient. This case stresses the importance of early diagnosis that can only be made from tissue biopsies and allows appropriate timely treatment.