烫伤大鼠细胞免疫抑制与肠源性内毒素血症的关系

采用大鼠４０％ＴＢＳＡⅢ度烫伤模型，将动物随机分成烫伤对照组和选择性消化道脱污染（ＳＤＤ）防治组，探讨烫伤大鼠全身性细胞免疫抑制与肠源性内毒素血症的关系。结果显示，大鼠４０％Ⅲ度烫伤后脾细胞对促有丝分裂原增殖应答反应、诱生白介素－２（ＩＬ－２）活性及Ｔ细胞亚群（Ｔｈ／Ｔｓ）比值明显下降。预防性进行ＳＤＤ动物，内毒素血症发生率显著降低，脾细胞增殖应答反应和ＩＬ－２活性的诱生能力均明显恢复（Ｐ＜０．０５～０．０１），但外周血中Ｔｈ／Ｔｓ比值与对照组相比差异无显著意义（Ｐ＞０．０５）。提示烫伤所致肠道细菌／内毒素移位可能与诱发机体细胞免疫功能异常密切相关。ＳＤＤ预处理可防止动物细菌／内毒素移位，从而减轻创伤后的免疫抑制     

烫伤大鼠细胞免疫抑制与肠源性内毒素血症的关系

采用大鼠40%TBSAⅢ度烫伤模型,将动物随机分成烫伤对照组和选择性消化道脱污染(SI)D)防治组,探讨烫伤大鼠全身性细胞免疫抑制与肠源性内毒素血症的关系。结果显示,大鼠40%Ⅲ度烫伤后睥细胞对促有丝分裂原增殖应答反应、诱生白介素-2(IL-2)活性及 T 细胞亚群(Th/Ts)比值明显下降。预防性进行 SDD 动物,内毒素血症发生率显著降低,脾细胞增殖应答反应和 IL-2活性的诱生能力均明显恢复(P0.05)。提示烫伤所致肠道细菌/内毒素移位可能与诱发机体细胞免疫功能异常密切相关。SDD 预处理可防止动物细菌/内毒素移位,从而减轻创伤后的免疫抑制。     

静脉注射小剂量rhTNF－α对烫伤大鼠T淋巴细胞功能的影响

将ＳＤ大鼠９０只随机分为体内和体外实验组，体外实验组又分为假伤、烫伤和ｒｈＴＮＦ－α治疗组，观察重组人肿瘤坏死因子－α（ｒｈＴＮＦ－α）对烫伤大鼠Ｔ淋巴细胞功能的影响。结果表明，小剂量静脉注射ｒｈＴＮＦ－α可以改善烫伤大鼠脾脏Ｔ淋巴细胞亚群的分布，并使Ｔｈ／Ｔｓ比值升高（Ｐ＜０．０５）、Ｗ３／２５（Ｔｈ）数量增加，ＯＸ－８（Ｔｓ）数量减少；体外实验表明，ｒｈＴＮＦ－α可以改善Ｔ淋巴细胞对ＣｏｎＡ的反应能力，增强烫伤大鼠脾脏Ｔ淋巴细胞分泌ＩＬ－２的能力，使伤后７２、１２０和１６８ｈ的ＩＬ－２分别较烫伤组增加１０８％、１４９％和１８３％（Ｐ＜０．０５）。ｒｈＴＮＦ－α作用呈剂量依赖关系，小剂量（ｒｈＴＮＦ－α≤１０ｎｇ／２．５×１０６细胞）对Ｔ淋巴细胞体外增殖起促进作用，超过此剂量则呈抑制作用。结果提示ｒｈＴＮＦ－α的抗感染作用与其增强机体免疫功能有关，适当剂量的ｒｈＴＮＦ－α不但可以改善Ｔ淋巴细胞亚群的分布，而且还可增强Ｔ淋巴细胞免疫活性。     

小儿肾病综合征白介素－2诱生及受体表达与病理形态关系的研究

探讨白介素－２（ＩＬ－２）、白介素－２受体（ＩＬ－２Ｒ）与小儿肾病综合征病理类型关系。方法利用体外淋巴细胞培养方法，检测了小儿肾病综合征（ＮＳ）外周血淋巴细胞诱生白细胞介素－２（ＩＬ－２）能力及受体（ＩＬ－２Ｒ）的表达。结果小儿ＮＳ外周血ＩＬ－２的诱生与正常对照组无显著性差异（Ｐ＞０．０５）；而ＩＬ－２Ｒ表达较正常对照组明显增强（Ｐ＜０．０１），且与患儿肾脏病理形态改变有一定的关系。结论小儿ＮＳ患者ＩＬ－２Ｒ表达异常与肾脏病理类型之间具有某种内在联系。     

维持性血液透析病人NK－IL－2－IFNr系统的动态观察

本文检测了４０例维持性血液透析（ＭＨＤ）患者自然杀伤细胞（Ｎｋ）活性，并同时检测了患者外周血单个核细胞（ＰＢＭＣ）在植物血凝素（ＰＨＡ）刺激下白细胞介素２（ＩＬ－２）和免疫干扰素（ＩＦＮｒ）产生水平。结果发现ＭＨＤ患者ＮＫ活性、ＩＬ－２活性和ＩＦｖｒ水平均显著低于正常对照组（Ｐ＜０．０１）；单次血液透析后ＭＨＤ患者的ＮＫ活性、ＩＬ－２和ＩＦＮｒ诱生水平均有不同程度的升高；长期血液透析对ＮＫ活性、ＩＬ－２和ＩＦＶｒ诱生水平影响不大，正常对照ＮＫ活性与ＰＢＭＣ诱生ＩＬ－２和ＩＦＮｒ水平存在直线正相关，而ＭＨＤ患者相关性无显著意义，但透析后ＭＨＤ患者ＮＫ活性与ＩＬ－２活性相关性有显著意义。提示：ＭＮＤ淋巴细胞存在多方面功能受损，包括免疫调节环路的紊乱；血液透析能部分纠正这些免疫学异常；但长期血液透析无助于改善ＭＨＤ病人的免疫功能受损。     

维持性血液透析病人NK—IL—2—IFNr系统的动态观察

本文检测了４０例维持性血液透析（ＭＨＤ）患者自然杀伤细胞（ＮＫ）活性，并同时检测了患者外周血单个核细胞（ＰＢＭＣ）在植物血凝素（ＰＨＡ）刺激下白细胞介素２（ＩＬ－２）和免疫干扰素（ＩＦＮｒ）产生水平。结果发现ＭＨＤ患者ＮＫ活性、ＩＬ－２活性和ＩＦＮｒ水平均显著低于正常对照组（Ｐ〈０．０１）；单次血液透析后ＭＨＤ患者的ＮＫ活性、ＩＬ－２和ＩＦＮｒ诱生水平均有不同程度的升高；长期血液透析对ＮＫ活性、Ｉ     

烧伤小鼠活化T细胞内游离钙浓度、蛋白激酶C活性的变化及意义

采用ＴＢＳＡ１０％Ⅲ度烧伤小鼠模型探讨了烧伤后小鼠活化Ｔ细胞内游离钙浓度（［Ｃａ２＋］ｉ）蛋白激酶Ｃ（ＰＫＣ）活性的变化及其同Ｔ细胞功能之间的关系。结果显示，烧伤后活化Ｔ细胞内［Ｃａ２＋ｉ］降低，ＰＫＣ活性下降，且这一变化同烧伤小鼠Ｔ细胞白介素２（ＩＬ－２）ｍＲＮＡ、ＩＬ－２受体α（ＩＬ－２Ｒα）ｍＲＮＡ水平降低，ＩＬ－２生成减少，ＩＬ－２Ｒα表达受抑，Ｔ淋巴细胞转化降低密切相关。钙离子导入剂Ａ２３１８７及ＰＫＣ激活剂ＴＰＡ在体外可分别提高烧伤小鼠活化Ｔ细胞内［Ｃａ２＋］ｉ、ＰＫＣ活性至正常对照水平，也可明显提高烧伤小鼠Ｔ细胞ＩＬ－２及ＩＬ－２Ｒα的基因表达水平，但不能使之恢复正常。提示活化Ｔ细胞内［Ｃａ２＋］ｉ、ＰＫＣ活性降低是导致烧伤后Ｔ细胞功能受抑的原因之一。     

冷冻保存对带血管异体关节移植排斥反应的影响实验研究

目的 观察冷冻保存和环孢霉素Ａ（ＣｙＡ）对鼠带智力这异体关节移植斥反应的作用。方法 ４０只ＳＤ大鼠随机分成４组：１组、新鲜同系移植;２组、新鲜异体移植;３组,冷冻保存异体移植;４组、冷冻保存异体移植术后用ＣｙＡ。术后进行血管造影,测定ＩＬ０－２活性及Ｔ细胞亚群（ＣＤ４／ＣＤ８）的变化,按照Ｓａｋａｉ等评分标准进行组织这评分。结果 ２组通畅率为０,与科各组比较差异有显著性（Ｐ〈０．０１）。ＩＬ－２及     

重度创伤患者外周血T细胞亚群、淋巴细胞IL-2R表达及IL-2诱生能力的动态观察

选择３０例重度复合伤患者，住院治疗中连续监测受伤当日、伤后第３、１０、２０日及出院前一日外周血Ｔ细胞亚群、淋巴细胞ＩＬ－２Ｒ表达和ＩＬ－２诱生能力变化，借以判断创伤后细胞免疫功能状况。结果发现创伤患者外周血Ｔ细胞、Ｔ辅助细胞百分率自受伤当日至出院前均显著低于健康对照值；Ｔ辅助／Ｔ抑制细胞比值在创伤后２０日内均显著低于对照值。同时发现活化淋巴细胞ＩＬ－２Ｒ表达和ＩＬ－２诱生能力从受伤当日至出院前均显著地低于健康对照值（Ｐ＜０．０１）。实验结果提示重度创伤后患者出现了严重的细胞兔疫功能障碍。     

原发性肝癌患者可溶性白细胞介素-2受体的变化及其临床意义

对３４例原发性肝癌（ＰＬＣ）患者外周血可溶性白细胞介素－２受体（ｓＩＬ－２Ｒ）、ＮＫ活性、Ｔ淋巴细胞亚群进行测定。结果：ＰＬＣ患者ｓＩＬ－２Ｒ水平明显高于健康对照组（Ｐ＜０．０１），ＮＫ活性、Ｔ淋巴细胞亚群ＣＤ３、ＣＤ４、ＣＤ４／ＣＤ比值均低于正常人（Ｐ＜０．０１），而ＣＤ８高于正常对照组（Ｐ＜０．０５）。Ⅱ、Ⅲ期ＰＬＣ患者ｓＩＬ－２Ｒ水平显著高于Ⅰ期患者（Ｐ＜０．０１）。ｓＩＬ－２Ｒ水平≥１０００ｕ／ｍｌ、５００～１０００ｕ／ｍｌ、＜５００ｕ／ｍｌ者６个月内的死亡率分别为８０．０％、２９．４％、０％。肝癌切除术后２周ｓＩＬ－２Ｒ水平较术前低（Ｐ＜０．０５），免疫治疗后４周ｓＩＬ－２Ｒ水平亦较治疗前低（Ｐ＜０．０５）。细胞免疫水平都有所改善。提示测定外周血ｓＩＬ－２Ｒ水平可作为ＰＬＣ的免疫状态、病情严重程度、疗效观察及预后估计的生物学指标。     

Role of gut-derived endotoxaemia and bacterial translocation in rats after thermal injury: effects of selective decontamination of the digestive tract

This study was performed to investigate: (1) the role of gut-derived endotoxin/bacterial translocation in the pathogenesis of sepsis, and (2) the possible effects of selective decontamination of the digestive tract (SDD) on mortality in rats following 40 per cent full-thickness scald injury. In the SDD-treated group, Enterobacteriaceae and yeasts were eradicated from the caecal mucosa, while the mucosal flora consisting of mainly anaerobes was well preserved, within 3 days. The incidence of bacterial translocation to the mesenteric lymph nodes (MLN) and viscerae was significantly lowered on postburn days 1, 3 and 5 (P < 0.05−0.01). Meanwhile, pretreatment with SDD resulted in reductions of the faecal endotoxin levels in different segments of intestinal tract to less than 0.5 per cent (0.04 – 0.45 per cent) of the untreated control; there was also a significant attenuation of the elevation of endotoxin concentrations in both portal and systemic blood. Intestinal diamine oxidase (DAO) activity returned to baseline on day 5 in rats receiving SDD but not in controls. The 5-day survival rate in the SDD-treated group was elevated by 26.7 per cent as compared with controls (P < 0.05). These data suggested that endotoxin/bacterial translocation took place early and commonly, which in turn contributed to postburn sepsis and mortality. SDD was effective in preventing gut origin endotoxaemia and bacterial translocation, and improving the survival rate in rats following severe thermal injuries.     

烫伤延迟复苏大鼠组织白细胞介素18mRNA表达的变化

目的 探讨烫伤延迟复苏后不同组织白细胞介素18（IL－18）mRNA的动态表达规律。方法 采用大鼠TBSAⅢ度烫伤延迟复苏模型,54只大鼠随机分为正常对照组、烫伤延迟复苏组、选择性消化道脱污染（SDD）预防组,分别在伤前及伤后2、8、16、24h,采用逆转录聚合酶链式反应,检测肠、肺、肝、肾等组织IL－18 mRNA含量。结果 烫伤延迟复苏后体循环内毒素水平显升高,8、24h达高峰（P＜0．01）,给予SDD预防治疗可显降低内毒素峰值（P＜0．05）;另一方面,烫伤后2h,肺、肝、肾等组织IL－18 mRNA含量表达较伤前值有显升高,烫伤后8h达高峰（P＜0．01）,且一直持续至伤后24h,给予SDD预防后可不同程度抑制IL－18 mRNA的表达（P＜0．05－0．01）。相关分析显示,体循环内毒素水平同肠、肺、肝组织IL－18 mRNA呈显正相关（r值分别为0．298、0．290、0．365,P＜0．05－0．01）。结论 肠、肺、肝、肾等组织IL－18 mRNA表达在烫伤早期即显增多,并呈逐渐升高的趋势,创伤后内毒素血症对机体多种组织IL－18 mRNA基因表达具有重要影响。     

选择性消化道脱污染对烫伤大鼠脏器的保护作用

目的 探讨选择性消化道脱污染对烫伤大鼠组织白细胞介素－18mRNA表达的影响及脏器保护作用。方法 采用大鼠30％体表面积Ⅲ度烫伤延迟复苏模型，肠、肺组织IL－18、IFN－γ mRNA含量采用逆转录聚合酶链式反应检测；ELISA法测定IFN－γ含量；同时检测肠、肺功能指标。结果 肠、肺组织IL－18、IFN－γ mRNA表达较伤前有显著升高，烫伤后8h达高峰，且一直持续至伤后24h，给予SDD预治疗后可不同程度抑制IL－18、IFN－γ mRNA的表达；严重烫伤后，出现广泛的脏器功能，预防性SDD处理可不同程度地保护脏器。结论 肠、肺组织IL－18、IFN－γ mRNA表达在烫伤后显著增多，并逐渐升高，后者对脏器具有重要影响。SDD预治疗后可不同程度抑制IL－18 mRNA的表达并保护脏器。     

Effects of interleukin-1alpha administration on intestinal ischemia and reperfusion injury,mucosal permeability,and bacterial translocation in burn and sepsis

OBJECTIVE: To evaluate the effect of interleukin-1alpha (IL-1alpha) on the mesenteric circulation, intestinal mucosal integrity, and bacterial translocation in a burn/endotoxemia chronic porcine model. SUMMARY BACKGROUND DATA: Major burn and sepsis are associated with a high mortality, ischemia/reperfusion injury to the intestine, and an increased rate of bacterial translocation. Pathologic alterations of IL-1 synthesis, degradation, and binding to receptors have been reported. Manipulation of IL-1-mediated effects might be of therapeutic utility. METHODS: Twenty-one female pigs were instrumented with an ultrasonic flow probe on the superior mesenteric artery and a catheter into the superior mesenteric vein. After 5 days, all animals were anesthetized, and 14 received 40% total body surface area third-degree burn. IL-1alpha was administered intravenously at 1,000 ng/kg to seven pigs immediately after burn. Eighteen hours after burn, 100 microg/kg lipopolysaccharide (LPS) was administered intravenously. Systemic and splanchnic hemodynamics were measured and blood samples were drawn for blood gas analysis. Intestinal permeability was assessed every 6 hours by measuring the lactulose/mannitol (L/M) excretion ratio. At the end of the study (42 hours), tissue samples were harvested for bacteriologic cultures. RESULTS: Mesenteric blood flow was significantly decreased after burn and endotoxin. Administration of IL-1alpha significantly improved mesenteric blood flow postburn and post-LPS. Mesenteric oxygen supply and consumption showed a significant reduction after burn. In contrast, animals treated with IL-1alpha showed an increase in postburn mesenteric oxygen supply and consumption. LPS-induced mesenteric hypoxia was also ameliorated by IL-1alpha treatment. Intestinal permeability, as assessed by the L/M ratio, showed a 7- and 10-fold elevation after thermal injury and LPS, respectively. In contrast, IL-1alpha-treated animals showed an increase of only three- and fourfold in the L/M ratio, respectively. Bacterial translocation was significantly increased in the burn/endotoxin group. IL-1alpha significantly reduced the rates of bacterial translocation. CONCLUSIONS: IL-1alpha treatment attenuates mesenteric ischemia and reperfusion injury induced by thermal injury and endotoxemia by improving mesenteric blood flow and oxygenation. Subsequently, IL-1alpha reduces intestinal permeability and bacterial translocation after burn and sepsis.     

Insulin-like growth factor-I/insulin-like growth factor binding protein-3 alters lymphocyte responsiveness following severe burn

PURPOSE: Following severe burn, patients are immunocompromised, making them at increased risk for infection. Exogenous growth hormone has been shown to partially restore immune function. Herein, we investigated Th1/Th2 cytokine profiles and cellular proliferation in isolated mononuclear cells after treatment with exogenous insulin-like growth factor-I (IGF-I), the indirect mediator of many growth hormone effects, in severely burned patients. METHODS: Eight children and 2 adults with >20% total body surface area burns were prospectively randomized to receive either placebo or 4 mg/kg rhIGF-I/IGFBP-3 for one-week intervals (2 groups), with another group receiving placebo for both cycles. Normal children were examined for comparison. Isolated whole blood lymphocyte production of Th1 (IL-2, IFN-gamma) and Th2 (IL-4, IL-10) cytokines, and proliferative responses to specific T-cell mitogens were measured. RESULTS: Depressed Th1 and exaggerated Th2 cytokine responses were seen in all burned subjects compared to non-burned controls (P < 0.05). IL-2 and IFN-gamma production increased in patients treated with IGF-I/IGFBP-3 (P < 0.05). IL-4 production significantly decreased, while IL-10 levels did not change. Cytokine production did not change in those receiving two courses of placebo. Proliferative responses of isolated mononuclear cells to IL-2 as a Th1 specific mitogen increased with IGF-I/IGFBP-3 treatment (P < 0.05). CONCLUSIONS: Following severe burn, a shift occurs toward a predominant Th2 phenotype. Exogenous IGF-I/IGFBP-3 treatment partially reverses this response.     

烧伤创面应用硝酸铈的实验研究

为探讨硝酸铈的应用价值,比较了烧伤创面行硝酸铈湿敷和早期切痂对严重烧伤后大鼠存活率和 T 细胞亚群变化的影响。结果表明:大鼠30%TBSA Ⅲ度烧伤后第14天,存活率低,外周血 Th/Ts 比值显著降低,而烧伤后早期手术切痂或创面硝酸铈湿敷则能明显提高大鼠存活率和外周血 Th/Ts比值。认为,早期切痂或创面硝酸铈湿敷均有防止烧伤后 T 细胞 Th/Ts 比值下降和提高存活率的作用。烧伤休克期,如不具备早期手术切痂的条件,用硝酸铈湿敷是一种简便有效的治疗方法。     

烧伤创面应用硝酸铈的实验研究

为探讨硝酸铈的应用价值，比较了烧伤创面行硝酸铈湿敷和早期切痂对严重烧伤后大鼠存活率和Ｔ细胞亚群变化的影响。结果表明：大鼠３０％ＴＢＳＡⅢ度烧伤后第１４天，存活率低，外周血Ｔｈ／Ｔｓ比值显著降低，而烧伤后早期手术切痂或创面硝酸铈湿敷则能明显提高大鼠存活率和外周血Ｔｈ／Ｔｓ比值。认为，早期切痂或创面硝酸铈湿敷均有防止烧伤后Ｔ细胞Ｔｈ／Ｔｓ比值下降和提高存活率的作用。烧伤休克期，如不具备早期手术切痂的条件，用硝酸铈湿敷是一种简便有效的治疗方法。     

Induction of xenoreactive CD4+ T-cell anergy by suppressor CD8+CD28- T cells

BACKGROUND: The underlying mechanism of immune suppression mediated by regulatory T cells is not completely understood. In previous studies we have shown that antigen-specific human T suppressor cells (Ts) can be generated in vitro by multiple rounds of stimulation with allogeneic, xenogeneic, or antigen-pulsed autologous antigen-presenting cells (APC). Human Ts express the CD8+CD28- phenotype and require specific recognition of MHC class I/peptide complexes on the surface of APC to block proliferation of T helper cells (Th). The aim of the present study was to explore the activation requirements of Ts as well as the nature of Th unresponsiveness to xenogeneic (swine) antigens induced by Ts. METHODS AND RESULTS: We investigated whether specific antigenic stimulation of Ts is required for their ability to inhibit early activation of xenoreactive Th (up-regulation of CD40 ligand). Flow cytometry studies indicated that Ts function required specific recognition of MHC class I on the surface of the stimulating APC. However, neither proliferation nor protein synthesis was required for the ability of Ts to inhibit Th. Ts drastically reduced the capacity of xenoreactive Th cells to produce interleukin (IL)-2 in response to the specific APC, without affecting their surface expression of IL-2 receptor. The suppressor effect that Ts exerted on Th proliferation could not be circumvented by CD40 ligation on the surface of the APC but could be reversed by the addition of exogenous IL-2. CONCLUSION: These data indicate that Ts induce anergy of xenoreactive human Th cells upon specific recognition of MHC class I antigens. Hence, Ts may prevent the activation of T cell-mediated immune responses against xenogeneic transplants.