西藏地区糖尿病肾病临床特点分析

目的 分析西藏地区2型糖尿病肾病(DN)的临床特点。 方法 回顾分析2001年5月至2006年10月间在我科住院的306例2型糖尿病（DM）患者的临床资料。 结果 306例DM患者包括151例DN和155例非DN患者，根据尿白蛋白及Scr水平，DN组患者再分为微量白蛋白尿组、临床蛋白尿组和肾功能不全组。DN组尿微量白蛋白、Scr和血、尿β2微球蛋白(MG)均较非DN组显著增高（均P < 0.01）；且尿微量白蛋白与收缩压、血β2-MG呈正相关（r = 0.187， P < 0.05； r = 0.297， P < 0.01），而与GFR呈负相关（r = －0.287，P < 0.01）。DN组高血压发生率高（60.27％），血压显著高于非DN组（P < 0.01），且以收缩压更显著。DN组发生尿毒症者14例（9.27％），死亡8例（5.30％），其中5例死于尿毒症；并发糖尿病视网膜病变20例(13.25%)；发生心脑血管意外者6例(3.97%)。 结论 西藏地区2型糖尿病肾病早期即有明显的蛋白尿、血压及血、尿β2-MG增高，后期GFR急剧下降且并发症多而严重。     

脂氧素A4抑制结缔组织生长因子诱导的系膜细胞产生单核细胞趋化蛋白1

脂氧素A4（LXA4）具有拮抗多种炎症介质、生长因子的作用，被称为炎症反应“刹车信号。结缔组织生长因子（CTGF）参与多种细胞的增殖、迁移和黏附，在肾脏纤维化的发病机制中占据重要地位。我们尚未检索到CTGF对趋化因子合成的调节作用及LXA4对CTGF作用的调节报道。我们检测CTGF对肾小球系膜细胞合成单核细胞趋化蛋白-1（MCP-1）的调节作用，并测定LXA4对CTGF作用的调节，探讨这些作用的细胞内信号转导机制，报告如下。     

脂氧素A4改善肺微血管内皮细胞炎症损伤的体外实验研究

目的 观察脂氧素A4（lipoxin A4,LXA4）对肺微血管内皮细胞（pulmonary microvascular endothelial cells,PMVECs）炎症损伤的治疗作用。方法 体外培养人PMVECs,第一阶段：分为空白对照组（完全培养基培养）和TNF-α组（分别以5、10、20 ng/mL共培养24 h）,采用MTT法检测各组PMVECs存活率,用针头式滤器检测TNF-α损伤前后PMVECs的单层通透性。第二阶段：分为TNF-α组（20 ng/mL处理24 h）和LXA4干预组（1、10、100 μg/L处理24 h）,检测PMVECs存活率和单层通透性,RT-PCR检测PMVECs IL-1β、VCAM-1、NF-κB p65 mRNA的表达。结果 （1）5、10、20 ng/mL TNF-α组的PMVECs存活率分别是（76.39±9.3）%、（61.87±11.7）%、（49.54±12.6）%,与空白对照组比较,均显著降低（P< 0.05）,而经1、10、100 μg/L三种浓度LXA4干预后,20 ng/mL TNF-α组的PMVECs存活率均得到提高,其中100 μg/LLXA4干预后的PMVECs存活率为（82.32±8.7）%,有统计学差异（P < 0.01）;（2）与损伤前[（0.021±0.011）mL/min·cm2·kPa]比较,TNF-α处理60、90 min后PMVECs单层通透系数（Kf值）显著增高[（0.067±0.007）和（0.096±0.007）mL/min·cm2·kPa,P< 0.05）],而LXA4干预60、90 min时Kf值则显著降低[（0.039±0.008）和（0.058±0.011） mL/min·cm2·kPa,P< 0.05）];（3）与对照组比较,TNF-α组的IL-1β、VCAM-1、NF-κB p65 mRNA的表达水平均有显著升高（P < 0.01或P < 0.05）,而LXA4干预组显著改善（P< 0.01或P< 0.05）。结论 TNF-α能引起PMVECs的急性炎症损伤,LXA4对TNF-α引起的PMVECs急性炎症损伤有改善作用。     

心脏术后尿中性粒细胞明胶酶相关脂质运载蛋白和白细胞介素18与急性肾损伤的关系

目的 探讨接受体外循环心脏手术患者尿中性粒细胞明胶酶相关脂质运载蛋白（NGAL）和尿白细胞介素18（IL-18）与急性肾损伤（AKI）的关系。 方法 根据AKI的诊断标准，将33例体外循环心脏手术的患者分为AKI组及非AKI组，分别留取术前及术后不同时间点的血液和尿液标本，测定Scr、尿NGAL和IL-18水平。 结果 33例中有9例发生AKI，发生率为27.27%。AKI组Scr升高峰值出现在12～48 h内。与术前相比， AKI组术后2 h、4 h尿NGAL及IL-18水平升高，差异有统计学意义（P < 0.01）。与非AKI组比较，AKI组术后各时间点的尿NGAL水平、术后2 h及4 h的尿IL-18水平都较高，差异有统计学意义（P < 0.01）。经尿肌酐（Ucr）校正后，相应时间点的NGAL/Ucr和IL-18/Ucr差异仍有统计学意义（P < 0.01）。术后2 h尿NGAL和尿NGAL/Ucr的界定（cutoff） 值分别在250 µg/L和250 µg/mmol时；术后2 h尿IL-18和尿IL-18/Ucr的界定值分别在1800 ng/L和1800 ng/mmol时，体现出较好的敏感性和特异性。 AKI组术后12 h Scr水平与术后2 h尿NGAL水平呈正相关（r = 0.638，P < 0.05）。结论 体外循环下接受心脏手术的患者AKI发生率较高；术后2 h尿NGAL和NGAL/Ucr、术后2 h尿IL-18和尿IL-18/Ucr当达到一定界定值时，均可作为体外循环下心脏手术后AKI发生的早期诊断参考指标，其中术后2 h尿NGAL/Ucr为250 µg/mmol时更敏感。     

脂联素在2型糖尿病肾病患者中的变化

目的：探讨2型糖尿病肾病（DN）患者血清、尿脂联素水平变化及与血浆可溶性血栓调节蛋白（sTM）的关系。方法：根据尿白蛋白排泄率（UAER）将82例2型糖尿病患者分成糖尿病正常白蛋白尿组（DM）、微量白蛋白尿组（DN1）和大量白蛋白尿组（DN2）;应用酶联免疫吸附法（ELAISA）测定各组血清、尿中的脂联素,血浆sTM水平。结果：DN1组的血清脂联素水平高于DM组（P〈0.01）,DN2组的血清脂联素水平高于DN1组（P〈0.01）。DN1组的尿脂联素水平高于DM尿组（P〈0.05）,DN2的尿脂联素水平高于DN1组（P〈0.01）。DN1组的血浆sTM水平高于DM组（P〈0.01）,DN2组的血浆sTM水平高于DM组（P〈0.01）。血清脂联素与尿脂联素、UAER、血浆sTM呈正相关（r=0.564,0.412,0.587,P〈0.01）,与Ccr呈负相关（r=-0.362,P〈0.01）;尿脂联素与Scr、UAER、血浆sTM呈正相关（r=0.292,0.748,0.775,P〈0.01）,与Ccr（r=-0.379,P〈0.01）呈负相关。结论：2型DN患者血清、尿脂联素水平可能是反映DN早期内皮损害的重要生物标记物。     

糖尿病大鼠肾小动脉内膜中膜厚度比与骨基质蛋白的相关性

目的 观察糖尿病大鼠肾小动脉骨基质蛋白表达情况及内膜中膜厚度比变化，探讨其相关关系及对糖尿病肾病血管病变的影响。 方法 70只健康雄性SD大鼠被随机分为糖尿病肾病组（DN，n = 40）和健康对照组(N，n = 30)。DN大鼠模型采用链脲佐菌素（STZ）腹腔注射诱导，成功35只。N组予同等剂量柠檬酸缓冲液。分别于4、12、24周处死动物，应用免疫组化方法检测各时间点肾小动脉中骨基质蛋白核心结合因子（Cbfα1）、骨形态蛋白2（BMP-2）的表达。原位杂交法检测其基因表达。应用免疫荧光方法检测肾小动脉内膜中膜厚度比。实时荧光定量PCR法测定BMP-2及基质Gla蛋白（MGP）的基因表达。 结果 DN组各时间点血糖及尿蛋白量(24 h)均较N组显著增高（P < 0.05），自第12周开始，DN组血肌酐、血磷较N组显著增高（P < 0.05）。免疫组化显示DN组肾小动脉4周时已有Cbfα1、BMP-2表达，随时间延长表达逐渐增强，24周表达最强，各时间点均显著高于N组（P < 0.05）。原位杂交显示Cbfα1、BMP-2仅在肾小动脉中有表达，表达趋势同免疫组化结果；4周时主要表达于血管内弹力层；12周后外弹力层及肌层表达也增强。实时荧光定量PCR显示DN组4周时BMP-2 mRNA已有表达，随时间延长表达逐渐升高，24周最高（P < 0.05）； DN组MGP表达量 4周最高，随时间延长表达逐渐降低，24周最低（P < 0.05）。而N组BMP-2和MGP mRNA各时间点表达量差异均无统计学意义。免疫荧光显示第4、12周时，DN组内膜中膜厚度比与N组差异均无统计学意义；24周时显著高于N组（P < 0.05）。DN组Cbfα1与BMP-2呈正相关（r = 0.670, P < 0.01）；与MGP呈负相关（r = －0.466，P < 0.05）；小动脉内膜中膜厚度比与Cbfα1、BMP-2呈正相关（r = 0.727，P < 0.01； r = 0.581，P < 0.01）。 结论 DN早期小动脉内膜中膜厚度比与Cbfα1、BMP-2呈正相关。Cbfα1、BMP-2、MGP可能参与了DN血管病变。     

CD4+CD25+调节性T细胞、Foxp3 mRNA及可溶性白细胞介素2受体检测在肾移植中的意义

目的 观察肾移植患者外周血中CD4+CD25+调节性T细胞水平及其表面特异性标志物Foxp3和可溶性白细胞介素2受体（sIL-2R）的变化，探讨其在诊断移植肾急性排斥反应中的作用和价值。 方法 选取42例维持性血液透析接受同种异体肾移植治疗的患者及30例健康体检对照者。在患者移植前、移植后1、2、4、8周或发生排斥反应时，以流式细胞仪检测外周血中CD4+CD25+调节性T细胞水平；荧光定量PCR检测Foxp3 mRNA表达；双抗体夹心酶联免疫吸附法（ELISB）检测血浆中sIL-2R水平。 结果 (1)移植后第1、2、4、8周急性排斥反应组CD4+CD25+调节性T细胞、Foxp3 mRNA水平明显低于同期未发生排斥的肾功能稳定组，而sIL-2R水平却显著高于肾功能稳定组。(2)血液透析患者外周血CD4+CD25+调节性T细胞[(9.22±3.53)%]、Foxp3 mRNA[（0.82±0.36）×10-3]及sIL-2R[（856.30±108.24） U/ml]水平与健康对照组[分别为(6.09±1.99)%、(0.50±0.28)×10-3、(247.35±11.24) U/ml]比较，差异均有统计学意义(P < 0.01)。(3)肾移植后随着肾功能的恢复，外周血CD4+CD25+调节性T细胞[(16.53±4.14)%]、Foxp3 mRNA[(4.97±1.94)×10-3]显著升高(P < 0.01)，而sIL-2R[（463.72±31.23）U/ml]水平明显降低(P < 0.01)。(4)当发生急性排斥反应时，CD4+CD25+调节性T细胞[(12.18±2.86)%]、Foxp3 mRNA[(3.15±1.22)×10-3]显著降低(P < 0.01)，而sIL-2R[(748.36±115.41) U/ml]水平明显升高(P < 0.01)，并且这些变化早于Scr的变化。(5)患者移植前后外周血CD4+CD25+调节性T细胞百分率与Foxp3 mRNA水平均呈正相关（分别为r ＝ 0.904、0.932，P < 0.01），但与sIL-2R水平无相关。 结论 外周血CD4+CD25+调节性T细胞、Foxp3 mRNA及sIL-2R水平的测定均可以作为肾移植患者移植后发生急性排斥反应的早期预测指标，并可判断预后。     

12-脂氧化酶对糖尿病肾病鼠肾小球p27kip1表达的影响

目的 探讨12-脂氧化酶(12-LO)对糖尿病肾病肾小球内p27kip1表达的影响。方法 在有或无p38 MAPK（p38）抑制剂（SB203580,1 μmol/L）的条件下,用12-LO作用产物12羟二十烷四烯酸[ 12(S)-HETE,10－7 mmol/L]刺激系膜细胞24 h。雄性SD大鼠分为普通饮食对照组、普通饮食+12-LO抑制剂（CDC,8 mg/kg,3次/周,皮下注射）处理组、高脂饮食结合小剂量链脲菌素（STZ,35 mg/kg,腹腔注射）诱导2型糖尿病组、高脂饮食结合小剂量STZ诱导2型糖尿病+CDC处理组,连续皮下注射CDC 1个月。野生型和12-LO基因敲除C57BL/6小鼠随机分成野生型对照组、12-LO基因敲除组、野生型STZ（200 mg/kg,腹腔注射）诱导1型糖尿病组、12-LO基因敲除STZ诱导1型糖尿病组,饲养16周。实验结束后收集尿、血液、提取肾脏,用系列过筛方法分离肾小球。Western印迹和免疫组织化学方法检测p38 活性和p27kip1蛋白表达的变化。 结果 抑制p38 活性可有效阻断12(S)-HETE诱导的系膜细胞内p27kip1的表达（P < 0.01）。CDC可抑制2型糖尿病大鼠肾小球体积增大,降低尿白蛋白量（24 h）,阻止肾小球内p38 活性和p27kip1蛋白表达增加,与CDC未处理2型糖尿病大鼠比较差异均有统计学意义（均P < 0.01）。与野生型糖尿病小鼠比较,12-LO基因敲除糖尿病小鼠p38活性、p27kip1蛋白表达及细胞外基质积聚显著减少,差异有统计学意义（均P < 0.01）。 结论 12-LO可通过p38通路上调糖尿病肾小球内p27kip1的表达。     

慢性肾脏病中、晚期患者矿物质和骨代谢紊乱的知晓率、治疗率和控制率

目的 调查我院慢性肾脏病（CKD）中、晚期非透析和透析患者矿物质和骨代谢紊乱的知晓率、治疗率和控制率。 方法 选取503例CKD 3期以上的非透析和透析患者,通过问卷的形式,结合实验室检查了解患者对矿物质和骨代谢紊乱的知晓率、治疗率和控制率。 结果 CKD中、晚期患者矿物质和骨代谢紊乱知识知晓率以血液透析患者最高,腹膜透析患者其次,非透析患者最低,差异有统计学意义（P < 0.01）。知识调查总得分显示,腹膜透析[11（9,12）]和血液透析[13（11,15）]患者显著高于非透析患者[6（5,8）]（P < 0.01）。相关知识的了解程度与年龄（r = -0.11,P < 0.05）呈负相关;与文化程度（r = 0.226,P < 0.01）、肾脏病病程（r = 0.597,P < 0.01）和透析龄（r = 0.366,P < 0.01）呈正相关。医护人员宣教是CKD中、晚期患者获取知识的主要渠道,在非透析、腹膜透析和血液透析患者中分别占94.0%、79.5%和69.4%。腹膜透析（88.6%）和血液透析（96.9%）患者的矿物质和骨代谢紊乱治疗率均显著高于非透析患者（58.2%）（均P < 0.01）。在控制率方面,以K/DOQI指南为标准,非透析患者血钙、血磷、钙磷乘积和甲状旁腺素（PTH）等的达标率明显优于透析患者;在各项指标的达标数量上也显著优于透析患者（均P < 0.01）。以KDIGO指南为标准,非透析（46.7%）和腹膜透析（36.9%）患者的血磷达标率均显著高于血液透析患者（23.6%）（均P < 0.01）。 结论 CKD中、晚期非透析患者矿物质和骨代谢紊乱的知晓率和治疗率较低,控制率较高;而透析患者的知晓率和治疗率较高,但控制率较低。     

乙酰肝素酶在糖尿病肾病大鼠蛋白尿发生中的作用

目的 观察糖尿病肾病大鼠肾组织乙酰肝素酶（HPA）的表达，探讨其在糖尿病肾病大鼠蛋白尿发生中的作用。 方法 SD健康大鼠被随机分为健康对照组（n = 6）、糖尿病6周组(DM6w, n = 10)和糖尿病12周组(DM12w, n = 10)，采用一次性腹腔注射链脲菌素（STZ）的方法建立糖尿病大鼠模型。分别于造模后6周和12周末测定各组大鼠相对肾质量、血糖、尿素氮、血肌酐、24 h尿量及尿蛋白量(24 h)等指标，并观察肾脏病理改变。RT-PCR和免疫组织化学法检测各组大鼠肾组织HPA mRNA和蛋白表达变化，并分析其与蛋白尿发生的相关性。 结果 （1）DM6w和DM12w组大鼠的相对肾质量、血糖、尿素氮、24 h尿量及尿蛋白量(24 h)与健康对照组相比明显升高, 差异均有统计学意义(P < 0.05或P < 0.01)。（2）DM6w和DM12w组大鼠HPA mRNA和蛋白表达比健康对照组均显著增高(P < 0.01)。（3）大鼠肾组织HPA mRNA和蛋白表达与尿蛋白量(24 h)之间均呈正相关 (r = 0.783，P < 0.01；r = 0.793，P < 0.01)。 结论 HPA在糖尿病肾病中的表达升高可能参与了糖尿病肾病蛋白尿的发生。     

Fifteen-S-hydroxyeicosatetraenoic acid (15-S-HETE) specifically antagonizes the chemotactic action and glomerular synthesis of leukotriene B4 in the rat.

In models of experimental glomerulonephritis, there is temporal concordance between the shift in the glomerular cellular infiltrate from neutrophils (PMN) to macrophages/monocytes and the suppression of glomerular leukotriene B4 (LTB4) generation. Since macrophages are a rich source of 15-lipoxygenase (15-LO) products, we investigated whether the principal product of arachidonate 15-lipoxygenation, 15-S-hydroxyeicosatetraenoic acid (15-S-HETE), was capable of antagonizing the proinflammatory actions of LTB4 in the rat. PMN exhibited chemotaxis to LTB4 in a dose dependent manner with an LC50 of 10(-8) M. When rat neutrophils were pre-treated with 15-S-HETE, chemotaxis to LTB4 was inhibited in a dose dependent manner (maximal at 30 microM 15-S-HETE) but, the same concentration did not inhibit chemotaxis to n-formyl-1-methionyl-1-phenylalanine (FMP). 12-S-HETE (30 microM) did not inhibit chemotaxis to LTB4. Glomeruli from rats injected with nephrotoxic serum three hours earlier generated increased levels of LTB4; prior exposure of such glomeruli to 15-S-HETE totally normalized LTB4 production. The glomerular production of 15-S-HETE and LTB4 was also determined 3 hours, 72 hours and 2 weeks after administration of nephrotoxic serum. Whereas there was an early, short-lived, burst of LTB4 followed by a return to baseline levels, the production of 15-S-HETE increased steadily over the two week period and was present in amounts fivefold greater than LTB4. Thus, these studies assign a role for locally generated 15-LO derivatives in arresting LTB4-promoted PMN infiltration and suppressing LTB4 synthesis.(ABSTRACT TRUNCATED AT 250 WORDS)     

Monocyte chemoattractant protein-1 and interleukin-8 levels in children with acute poststreptococcal glomerulonephritis

The infiltration of leukocytes into the glomeruli is a major factor in inflammatory glomerular damage in acute poststreptococcal glomerulonephritis (APSGN). Chemokines participate in leukocyte infiltration. The aim of the present study was to investigate the role of monocyte chemoattractant protein-1 (CCL2/MCP-1) and interleukin-8 (CXL8/IL-8) in APSGN with special emphasis on their role in the clinical course of renal disease. Twenty-one children with APSGN were studied. Serum and urinary CCL2/MCP-1 and CXL8/IL-8 levels were measured by ELISA. The relationships between urinary chemokines and the degree of proteinuria were investigated. Serum and urinary CCL2/MCP-1 levels were significantly higher in the acute phase than in the resolution phase and in controls ( P <0.05). Urinary CCL2/MCP-1 levels in the control group were significantly lower than in both the acute and resolution phases ( P =0.01 and P =0.001, respectively). In the acute phase, urinary CCL2/MCP-1 correlated with the extent of proteinuria ( r =0.58, P =0.006) but not with serum CCL2/MCP-1 levels ( r =0.21, P =0.36). Urinary and serum CXL8/IL-8 levels were significantly elevated in the acute phase compared with the resolution phase and controls ( P <0.05). A consistent increase in urinary CCL2/MCP-1 was found in the acute phase of patients with APSGN, and this correlates with the degree of proteinuria. Our results emphasize the important role of locally produced chemokines in immune-mediated glomerular injury.     

Significance of glomerular cell apoptosis in the resolution of acute post-streptococcal glomerulonephritis.

BACKGROUND: Glomerular hypercellularity due to resident glomerular cell proliferation and leucocyte infiltration has been described in acute post-streptococcal glomerulonephritis (APSGN). APSGN usually resolves without progression. However, the mechanism of resolution remains to be determined. METHODS: Renal biopsy tissues from 15 patients with APSGN (obtained 1-31 days after disease onset) and five control patients with minor glomerular abnormality were evaluated with respect to glomerular resolution. Apoptotic cells were assessed by terminal deoxynucleotidyl transferase-mediated dUTP nick end-labelling (TUNEL) as well as by immunostaining of single-stranded DNA (ssDNA). RESULTS: The number of glomerular cells was high in the early-phase of APSGN and decreased over time. No TUNEL+ glomerular cells were found in control subjects, whereas prominent glomerular TUNEL+ cells were observed in APSGN patients, particularly in the early phase of the disease. The number of glomerular TUNEL+ cells decreased exponentially but was still prominent in renal tissue biopsied at 31 days after disease onset. Double staining for ssDNA and glomerular cell markers showed that glomerular apoptotic cells were predominantly mesangium and endothelial cells, with some neutrophils and macrophages. CONCLUSIONS: These results suggest that apoptosis exists in the glomerulus in patients with APSGN from the early to the late stages of the disease and contributes to the resolution of glomerular hypercellularity.     

Regulation of apoptosis in eicosapentaenoic acid-treated HL-60 cells

BACKGROUND: Neutrophil apoptosis is an important physiological process in the resolution of pulmonary inflammation. Previous studies have shown that eicosapentaenoic acid (EPA; 20:5n-3) increases the rate of apoptosis in a concentration- and time-dependent manner in HL-60 cells. However, it is not known if the EPA-induced apoptosis involves the lipoxygenase (LO) and cyclooxygenase (COX) enzymes or the downstream metabolic products of these enzymes. Thus, the objective of this study was to determine the effects of inhibitors LO and COX enzymes on apoptosis, viability, and necrosis in EPA-treated HL-60 cells. MATERIALS AND METHODS: Cells were incubated with 50 mum EPA in the presence of an enzyme inhibitor (1-10 microm) for 12 h. Compounds were used to inhibit COX 1 and 2 (ibuprofen), 5-, 12-, 15-LO (NDGA), 12-LO (baicalein), 5-LO (AA-861), and 5-LO activating protein (MK-886). Eicosanoid (0.001-1.0 mum) add-back experiments were also conducted; LTB(4) and 5-HETE with 5-LO inhibition and 12-HETE with 12-LO inhibition. Flow cytometry was used to assess apoptosis. RESULTS: Inhibition of COX 1 and 2 had no effect on apoptosis. Inhibition of 5-LO and 12-LO significantly increased apoptosis in EPA-treated HL-60 cells. Addition of LTB(4) reduced apoptosis to levels significantly lower than in HL-60 cells treated with EPA alone; 5-HETE and 12-HETE also lowered apoptosis to control levels. CONCLUSIONS: These data indicate that inhibition of LO, particularly 5-LO, increased apoptosis in EPA-treated HL-60 cells. Furthermore, this study demonstrated that the products of the LO enzymes, particularly LTB(4), are critical in the regulation of apoptosis in EPA-treated HL-60 cells.     

Five-lipoxygenase products in glomerular immune injury.

Leukocyte infiltration, proliferation, and activation are central pathogenetic components of immune injury in the glomerulus. Initial cellular infiltration by polymorphonuclear leukocytes (PMN) is a consequence of the deposition of immune complexes at discreet sites in the glomerulus. This is often followed by macrophage/monocyte infiltration, as well as proliferation of resident mesangial macrophages. Activated leukocytes constitute a rich source of lipid-derived bioactive autacoids, in particular, oxygenated metabolites of arachidonic acid. Here, we assess the role of the five-lipoxygenase (5-LO) family of eicosanoids, in particular, leukotrienes D4 and B4 (LTD4 and LTB4) in mediating functional and structural deterioration during immune inflammatory reactions in the glomerulus. LTD4 and other peptidyl LT appear to play a central role in the reductions in GFR in the acute phases of injury by virtue of their potent vasoactive properties, in particular, their capacity to reduce the glomerular capillary ultrafiltration coefficient, likely through contraction of smooth muscle elements in glomerular mesangial cells. The latter cells possess specific receptors for LTD4 in both humans and rat and contract in vitro when exposed to LTD4 after receptor-mediated activation of phospholipase C. LTB4, a nonvasoconstrictor LT, is released in the early phases of immune injury, likely from leukocyte sources as well as from transcellular metabolism of its precursor, LTA4, by the enzyme LTA4-hydrolase in glomerular mesangial and endothelial cells. LTB4, a potent promoter of PMN attraction, adhesion, and activation exacerbates glomerular functional impairment and structural damage by amplifying PMN-dependent mechanisms of injury. In their totality, 5-LO products of arachidonic acid contribute to the impairment of the normal glomerular filtration and sieving functions that attend acute inflammatory injury in the renal glomerulus and to the subsequent progression of glomerular destruction. This is high-lighted by the significant degree of protection afforded by the selective inhibition of arachidonate 5-LO in vivo in acute and chronic models of experimental glomerulonephritis.     

Role of leukotrienes B4 and C4 in liver allograft rejection

Previous studies have shown that eicosanoids may act in vitro as immunoregulatory substances. In this study, the concentrations of leukotriene B4 (LTB4) and leukotriene C4 (LTC4) were measured in a model of allograft rejection. Six orthotopic allotransplants of the liver were performed in dogs without the administration of immunosuppressives. LTB4 levels showed an increase coinciding with the start of rejection, significant differences being present between the basal levels and those measured 24 h post-revascularization (P < 0.05), and every day from the 3rd postoperative day (P < 0.01). LTB4 rose before the parameters generally used in evaluating rejection. LTC4 levels increased significantly (P < 0.001) in the first 24 h, and experienced no further variations. LTB4 may play an important role in the mechanisms which bring about the response to the allograft. This substance could be a specific and early marker for rejection.     

Detection of IgG-rheumatoid factor in sera of patients with acute poststreptococcal glomerulonephritis and its relationship with circulating immunecomplexes

Rheumatoid factors (RF) were measured in sera from 75 patients with acute poststreptococcal glomerulonephritis (APSGN) and compared with normal controls, patients with rheumatoid arthritis in activity and acute rheumatic fever. Using two sensitive and specific solid phase radioimmunoassays, IgM-RF and IgG-RF were detected, respectively, in 15% and 32% of the patients with APSGN. A positive correlation (r = 0.37, n = 75, p less than 0.05) was obtained between serum levels of IgG-RF and circulating immune complexes determined by conglutinin assay. Chromatographic studies in serum from two patients with APSGN demonstrated that the circulating IgG-RFs were mainly free, not complexed. It is suggested that RFs, particularly of the IgG class, may participate in the pathogenesis of the renal injury in some patients with APSGN.     

Lipoxin A4 Attenuates Acute Rejection Via Shifting Th1/Th2 Cytokine Balance in Rat Liver Transplantation

Aims

To study the role of lipoxin A4 (LXA4) in rat liver transplant rejection.

Methods

An acute rejection model of liver transplantation was established in inbred rats DA to LEW that were randomly divided into a control group and a LXA4 group. Liver morphologic changes were examined using hematoxylin/eosin staining. Alanine aminotransferase (ALT) and aspartate aminotransferase (AST) were quantified to measure liver injury. Intragraft mRNA and protein expressions of interferon (IFN)-γ interleukin and (IL)-10 were detected by real-time polymerase chain reaction and Western blots, respectively. The serum levels of IFN-γ and IL-10 were assayed by enzyme-linked immunosorbent assay.

Results

LXA4 treatment improved hepatic tissue injury as indicated by morphologic analysis. Serum ALT and AST levels were significantly decreased at day 7 post-transplantation (P < .05). Concurrently, expression of IFN-γ was downregulated (P < .05) and secretion of IL-10 was enhanced (P < .05).

Conclusions

LXA4 attenuated acute rejection with a parallel shift from Th1 to Th2 responses in rat liver transplantation.     

Plasma terminal complement complexes in acute poststreptococcal glomerulonephritis

In most instances of acute poststreptococcal glomerulonephritis (APSGN), activation of the complement system occurs, as reflected by decreased levels of the complement proteins C3, C5, and properdin (P). Recent studies implicate terminal complement complexes (TCC) in the pathogenesis of glomerular injury. The fluid phase TCC, SC5b-9, reflects the formation of membrane-bound C5b-9 and has been used as a clinical marker in various diseases. Plasma concentrations of SC5b-9 were measured with an enzyme immunoassay using a monoclonal antibody to a neoantigen expressed on the SC5b-9 complex in 13 children who presented with clinical and pathologic features of APSGN. SC5b-9 was significantly elevated in all plasmas obtained within 30 days after onset of clinical glomerulonephritis. Concentrations of SC5b-9 in acute plasmas were significantly higher than those of paired convalescent samples. For individual patients, as SC5b-9 concentration returned to normal there was a coincident decrease in serum creatinine concentration and urinary protein excretion, signifying clinical improvement in glomerulonephritis. Thus, TCC generation commonly occurs in the early stages of APSGN and may be of importance in the pathogenesis of the condition.     

Streptococcal exotoxin B increases interleukin-6, tumor necrosis factor alpha,interleukin-8 and transforming growth factor beta-1 in leukocytes

Previous reports have shown the presence of streptococcal erythrogenic exotoxin type B (ETB), leukocyte infiltration, interleukin-8 (IL-8), transforming growth factor-beta (TGF-β) and glomerular proliferation in renal biopsies from patients with acute post-streptococcal glomerulonephritis (APSGN). In addition, increased levels of plasma interleukin-6 (IL-6) and tumor necrosis factor alpha (TNFα), and urinary IL-6, have also been reported in this disease. To determine the effect of streptococcal proteins on leukocyte proliferation and leukocyte production of IL-6, TNFα, IL-8 and TGF-β1, we cultured human mononuclear leukocytes with ETB or ETB precursor (ETBP). After 24 h, 48 h and 96 h, culture supernatants were assessed for cytokines by enzyme-linked immunosorbent assay (ELISA), and for leukocyte proliferation by a monoclonal antibody anti-proliferating cellular nuclear antigen (PCNA). A significant increase in all cytokines was found in ETB- or ETBP-treated cultures when compared with controls. A polyclonal anti-ETB antibody diminished the cytokine stimulatory effect of ETB. An increased number of PCNA-positive cells was observed in ETB or ETBP treated cultures at 48 h and 96 h. Cytokine production and proliferation were not correlated. The stimulatory effect of streptococcal exotoxin B on leukocyte cytokine production may be relevant in renal tissue during the course of APSGN.