CNI-1493对重症急性胰腺炎大鼠外周血多形核粒细胞功能的影响

目的探讨p38MAPK信号传导通路阻断剂(CNI-1493)对大鼠重症急性胰腺炎(severe acute pancreatitis SAP)时外周血多形核粒细胞(polymorphonuclear, PMN)功能影响.方法以胰胆管逆行注射5%牛磺胆酸钠建立SD大鼠SAP模型,将54只SD大鼠随机分为3组:假手术组(SO, n=18);SAP组(SAP n=18);CNI-1493治疗组(CNI, n=18),术后3 h、6 h、12 h取血,用密度梯度法分离PMN,用流式细胞仪测定呼吸爆发功能,并测定PMN释放髓过氧化物酶(MPO)的变化情况.结果 SAP组PMN呼吸爆发亢进,MPO释放明显增加,在各时间点上CNI-1493都能抑制PMN的功能亢进,减少MPO的释放.结论 CNI-1493可以明显抑制SAP时PMN的病理性功能亢进,是治疗SAP的重要机制之一,提示可能具有临床应用的前景.     

实验性重症急性胰腺炎肺内IL—1β及IL—18mRNA的表达

目的：观察实验性重症急性胰腺炎（severe acute pancreatitis,SAP）肺内IL－1β及IL－18mRNA的表达，并探讨其与肺损伤的关系，方法：SD大鼠32只，随机分4组：正常对照组、SAP6h组、SAP12h组、SAP18h组。采用5％牛磺胆酸钠（0.1ml/100g）胆胰管内逆行注射诱导大鼠SAP模型。血清淀粉酶采用HITACHI－7150型自动生化分析仪测定；半定量RT－PCR检测肺组织内IL－1β及IL18mRNA的表达，结果：造模后各时间点血清淀粉酶水平显升高，12h达到高峰，与正常对照组相比，均具有显性差异（P＜0．01）。正常肺组织内可见IL－1β及IL－18mRNA表达；SAP各组肺组织内IL－1β及IL－18mRNA的表达明显增强，与正常对照组比较均有显性差异（P＜0．01），结论：除TNF-α外，肺内生成过多的IL－1β及IL－8在SAP并发急性肺损伤（acute lung injury,ALI）及急性呼吸窘迫综合征（acute respiratory distress sysdrome,ARDS)进程中可能发挥重要的作用。     

第一作者：刘杰工作单位：十堰市人民医院ICU

摘要：目的：研究糖皮质激素对脓毒症大鼠肠道功能的保护作用。方法：45只SD大鼠随机分为3组，对照组（n=5）、脓毒症组（n=20）、糖皮质激素组（n=20）。对照组不予任何处理，脓毒症组和糖皮质激素组采用内毒素注射法制作脓毒症模型，糖皮质激素组在复苏第6h时颈外静脉注射氢化可的松6mg/kg。脓毒症组注射等量生理盐水,24h后测定肠平滑肌肌电慢波活动,然后由腹主动脉采血监测血清SOD和MPO含量，取小肠组织匀浆检测SOD和MPO。结果：脓毒症组血清SOD和肠道SOD均明显低于对照组（P<0.05),糖皮质激素组血清SOD和肠道SOD明显高于脓毒症组，糖皮质激素组血清SOD明显低于对照组，但肠道SOD与对照组无差异。糖皮质激素组的血清MPO和肠道MPO均明显高于对照组，脓毒症组血清MPO和肠道MPO均明显高于对照组和糖皮质激素组。糖皮质激素组的慢波频率明显高于脓毒症组,和对照组无差异。糖皮质激素组的慢波振幅明显高于脓毒症组，但低于对照组。结论：糖皮质激素具有降低氧化应激反应，恢复SOD活性，保护肠道屏障功能的作用。     

重症急性胰腺炎大鼠肠—肝—肺轴免疫单核吞噬细胞变化

目的 观察重症急性坏死性胰腺炎（SAP）大鼠肠壁、肝脏和肺组织中免疫单核吞噬细胞分布的变化,并探讨谷氨酰胺对其的调节作用。方法　SD大鼠54只,随机分3组:假手术组（SO,n=18）;SAP组（SAP,n=18）;SAP谷氨酰胺治疗组（GLN,n=18）。采用5％牛磺胆酸钠溶液胆胰管内逆行注射诱导大鼠SAP模型。大鼠中心静脉置管,微量输液泵输注含等氮、等热卡的氨基酸溶液,GLN组加入3％丙氨酸-谷氨酰胺双肽（相当于2％谷氨酰胺溶液,剂量0.5g.kg-1·d-1）。术后24h、48h、72h分批处死大鼠并留取标本,分别采用鲎试剂比色法及免疫组化法测定血浆内毒素水平、肠上皮淋巴细胞、肝脏和肺单核吞噬细胞分布的变化。结果 血浆内毒素在SAP组明显高于SO组（P<0.05）,且随着时间延长而递升;GLN治疗组血浆内毒素较SAP组显著下降（P<0.05）。SAP组肠上皮中淋巴细胞数较SO组明显减少（P<0.05）;GLN治疗组则较SAP组明显上升（P<0.05）。溶菌酶组织化学染色显示,SO组肝脏和肺脏中单核吞噬细胞呈散在分布;而SAP组中单核吞噬细胞聚集成团,以术后24h最为显著;GLN治疗组阳性染色细胞聚集状态减弱。结论 肠道局部免疫功能的变化及由于内毒素等物质刺激而导致的肝、肺单核吞噬细胞过度活化促进了SAP的进一步发展。谷氨酰胺通过调节肠道局部、肝脏和     

SB203580对SAP大鼠胰腺组织MPO、TNF-α、IL-6和IL-8表达的影响

目的观察p38丝裂原蛋白（p38MAPK）信号传导通路阻断剂SB203580对急性重症胰腺炎（SAP）大鼠胰腺组织髓过氧化物酶（MPO）及促炎因子TNF-α、IL-6和IL-8表达的影响。方法 46只健康雄性SD大鼠,随机分为观察组22只和SAP组24只。采用3.5%牛磺胆酸钠溶液胰胆管注射法制作SAP动物模型。观察组大鼠制模前半小时股静脉注射SB203580。造模后0.5、6、24 h取两组大鼠胰腺组织,用紫外分光光度法检测MPO活性,用放射免疫法检测TNF-α、IL-6和IL-8。结果造模后6、24 h观察组大鼠胰腺组织中MPO、TNF-α、IL-6、IL-8均低于SAP组（P均〈0.05）。结论 SB203580可以降低大鼠胰腺组织中MPO、TNF-α、IL-6、IL-8的表达。     

白细胞介素-18在实验性重症急性胰腺炎肝损伤中的作用

自细胞介素（IL）-18是一种新发现的促炎细胞因子，其血清水平与重症急性胰腺炎（SAP）合并肝损伤明显相关，然而关于其在SAP急性损伤肝组织中的变化和意义鲜有报道。目的：研究IL-18在SAP大鼠肝组织中的表达．探讨IL-18在SAP肝损伤中的作用。方法：以4％牛磺胆酸钠胰胆管逆行注射诱导大鼠SAP模型。32只大鼠随机分为对照组和SAP6h、12h、18h组。动态测定血清淀粉酶、丙氨酸氨基转移酶（ALT）、天冬氨酸氨基转移酶（AST）水平和腹水量；光学显微镜下观察胰腺和肝组织损伤情况；以免疫组化方法检测IL-18在肝组织中的表达和定位：以蛋白质印迹法检测肝组织中IL-18前体和成熟IL-18的表达。结果：SAP组各时间点血清淀粉酶、ALT、AST水平均明显升高，腹水量增多，与对照组相比差异有统计学意义（P〈0．01），与胰腺和肝脏的组织病理学改变相一致。造模后IL-18在肝脏Kupffer细胞胞质中呈强阳性表达，阳性Kupffer细胞数增多，成熟IL-18表达明显增加，各时间点与对照组相比差异均有统计学意义，以12h组为著（P〈0．01）。结论：Kupffer细胞是肝脏成熟IL-18的主要来源．成熟IL-18表达上调可能在SAP早期肝损伤中发挥重要作用。     

自控静脉镇痛对老年人上腹部手术后内分泌和呼吸功能的影响

目的观察老年病人上腹部手术后病人自控静脉镇痛（PCIA）对内分泌和呼吸功能的影响。方法37例65岁以上全麻下行上腹部手术的老年人随机分为两组。Ⅰ组（对照组n=18例）术后按需肌肉注射哌替啶50叫次。Ⅱ组（PCIA组n=19例）术后行PCIA镇痛，分别于麻醉前、术毕1h、24h、48h、72h采血测定血糖（Glu）、皮质醇浓度（Col），同时监测呼吸频率（RR）、潮气量（Vt）、每分钟通气量（MY）和脉搏血氧饱和度（Sp02）。结果Ⅱ组病人VAS评分低，血糖于术后48h基本恢复至术前水平，24h皮质醇基本恢复正常；而Ⅰ组病人48h后血糖及皮质醇仍居高不下。同时，Ⅱ组呼吸功能改善明显。结论PCIA改善了老年人术后的肺功能，减轻了应激反应。     

骨髓间充质干细胞移植对大鼠梗死心脏核因子KB活性的影响

目的观察骨髓间充质干细胞对心肌梗死的治疗效果，以及心肌梗死后炎症因子表达的影响，探讨其治疗心肌梗死的可能机制。方法提取SD大鼠骨髓间充质干细胞，体外培养、纯化扩增。采用结扎冠状动脉前降支方法复制大鼠心肌梗死模型，将建立的模型随机分为：1）假手术组（仅穿线不结扎血管，n=8）；2）PBS溶液注射组（n=8）；3）干细胞移植组（n=8）。模型制作成功即刻，将骨髓间充质干细胞通过心外膜分4点注射到梗死周边部位。4周后测定血流动力学指标。随后通过Western blot方法测定核因子KB活性，RT-PCR和western blot法测定肿瘤坏死因子α、白介素6 mRNA和蛋白表达。结果1）4周后，假手术组大鼠死亡率20％（2／10），治疗阴性对照组大鼠死亡率33．3％（4／12），干细胞移植组大鼠死亡率20％（2／10），3组死亡率没有统计学差异（P=0．646）；2）与注射PBS溶液相比，骨髓间充质干细胞移植可以改善心肌梗死大鼠血流动力学指标；3）骨髓间充质干细胞可以抑制大鼠梗死心肌核因子kB活性，下调肿瘤坏死因子α和白介素6 mRNA和蛋白表达水平。结论骨髓间充质干细胞可以改善心肌梗死大鼠的心功能，同时可调节大鼠梗死心脏炎症反应。     

急性坏死性胰腺炎大鼠心肌核因子-κB激活及重组葡激酶的干预作用

目的研究重症急性胰腺炎（SAP）心肌功能损害时心肌核因子-κB（NF—κB）的活化及葡激酶的干预作用。方法63只SD大鼠随机分为假手术组（n=9）、ANP组（n=27）、葡激酶干预组（n=27），ANP模型采用5％的牛磺胆酸钠胰胆管逆行注射方法建立。干预自造模前2d腹腔注射葡激酶1．5mg／kg体重，一天2次，共4次。ELISA法测定制模后6h、12h、24h各时点血TNF—α、IL-6含量；RT—PCR检测心肌NF—κB mRNA的表达；免疫组化法检测心肌NF—κB蛋白的表达，常规观察胰腺及心肌组织的病理变化。结果ANP组术后6h大鼠心肌NF—κB mRNA及NF—κB蛋白表达异常增高，TNF—α、IL-6呈进行性升高，干预组胰腺及心肌组织的病理变化减轻。心肌NF—κB mRNA及蛋白表达下调，血TNF—α、IL-6明显下降，与ANP组比较，差异均显著（P〈0．05）。结论ANP大鼠的心肌损伤可能与循环中TNF—α、IL-6水平升高导致的心肌NF—κB活化有关。葡激酶对SAP并发的心肌损伤具有防治作用。     

重组葡激酶加中药对重症急性胰腺炎大鼠心肌核转录因子κB的激活作用

[目的]研究重症急性胰腺炎（SAP）心肌功能损害时心肌核转录因子κB（NF-κB）的活化及葡激酶的干预作用。[方法]63只SD大鼠随机分为假手术组（n=9）、对照组（n=27）、葡激酶合用益活清胰汤治疗组（n=27），SAP模型采用5％牛磺胆酸钠胰胆管逆行注射方法建立。ELISA法测定6、12、24h各时点血肿瘤坏死因子α（TNF-α）、白细胞介素6（IL-6）水平，RT-PCR检测心肌NF-κB mRNA的表达，免疫组化法检测心肌NF-κB蛋白的表达，苏木精-伊红染色光镜下观察胰腺及心肌组织的病理变化。[结果]术后6h大鼠心肌NF-κB mRNA及其蛋白表达异常增高，TNF-α、IL-6呈进行性升高，治疗组用药后心肌NF-κB mRNA及蛋白表达下调，血TNF-α、IL-6明显下降，与对照组相比P＜0．05，治疗组胰腺及心肌组织的病理变化减轻。[结论]SAP大鼠心肌损伤可能与循环中TNF-α、IL-6水平升高导致的心肌NF-κB活化有关，益活清胰汤合用葡激酶对SAP并发的心肌损伤具有防治作用。     

白介素-18在急性胰腺炎大鼠中性粒细胞凋亡中的作用

目的:探讨白介素-18(IL-18)在重症急性胰腺炎(SAP)时外周血中性粒细胞(PMN)凋亡中的作用.方法:SD大鼠60只,随机分为2组,每组30只,分别建立大鼠急性坏死性胰腺炎组(ANP)及假手术组(SO)模型,在制模后3、6、12h分期分批处死大鼠,抽取下腔静脉血测定血淀粉酶含量及血清中IL-18的含量,作中性粒细胞分离并检测外周血中性粒细胞凋亡率;同时对大鼠胰腺组织行病理切片HE染色,并对胰腺组织进行病理评分.结果:ANP组中性粒细胞(PMN)凋亡率较SO组明显降低,并随着时间的延长逐渐明显(P<0.01),至术后12h降至2.15%±0.45%;ANP组血清中IL-18的含量较SO组明显升高,而且随着时间的延长更明显(P<0.01),在12h达到4705.70±296.30;ANP组PMN的凋亡率与血清中IL-18的水平呈负相关(r=-0.78,P<0.01).结论:ANP组外周血PMN的凋亡明显延迟,血清中IL-18的含量明显增高,IL-18可能在急性胰腺炎外周血的PMN凋亡中发挥作用.     

Role of myeloperoxidase in the respiratory burst of human neutrophils

Myeloperoxidase (MPO), a heme enzyme present in the primary granules of polymorphonuclear leukocytes (PMNs), has been demonstrated to participate in the oxygen-dependent microbicidal activity of these cells. Evidence for the importance of MPO in this role comes in part from studies of normal PMNs treated with the heme enzyme inhibitor, sodium azide. MPO has also been suggested to regulate the respiratory activity of PMNs during phagocytosis. The role of MPO in PMN oxygen metabolism was examined by studying parameters of the respiratory burst of PMNs from a number of unrelated MPO-deficient subjects; in addition, the ability of heme enzyme inhibitors to duplicate the MPO-deficient state was studied by treating normal and MPO-deficient cells with these compounds. MPO-deficient PMNs were found to have a time-dependent hypermetabolic response as assessed by measurement of oxygen consumption, superoxide generation, hydrogen peroxide release, and hexose monophosphate shunt activity. Catabolic pathways for hydrogen peroxide were normal, suggesting the increased recovery of oxygen metabolites reflects increased production rather than decreased catabolism of H2O2. These observations support the concept that MPO may play an important role in terminating the respiratory burst of normal PMNs. The three heme enzyme inhibitors studied--sodium azide, potassium cyanide, and 3-aminotriazole--differed greatly in the degree to which they inhibited various enzymatic systems in the PMN. Nonetheless, as a group, they exerted qualitatively similar effects on oxygen metabolism of normal and of MPO-deficient PMNs. This indicates that many of the mechanisms by which heme enzyme inhibitors influence PMN metabolism are independent of the inhibition of MPO. Conclusions from studies using such treatment of PMNs should be interpreted with caution.     

Myeloperoxidase mediates neutrophil activation by association with CD11b/CD18 integrins

Recruitment and activation of polymorphonuclear neutrophils (PMNs) reflects a primary immunological response to invading pathogens and has also emerged as a hallmark of vascular inflammation. One of the principal enzymes released upon PMN activation is myeloperoxidase (MPO), a heme protein that not only generates cytotoxic oxidants but also impacts deleteriously on nitric oxide-dependent signaling cascades within the vasculature. Because MPO also associates with the membrane of PMN, we evaluated whether MPO could also function as an autocrine modulator of PMN activation. The extent of PMN membrane-associated MPO was elevated in patients with acute inflammatory vascular disease compared with healthy individuals. Isolated PMNs bound free MPO by a CD11b/CD18 integrin-dependent mechanism. PMNs exposed to MPO were characterized by increased tyrosine phosphorylation and p38 mitogen-activated protein kinase activation. Also, nuclear translocation of NFkappaBin PMN was enhanced after incubation with MPO, as was surface expression of CD11b. Binding of PMN to MPO-coated fibronectin surfaces amplified PMN degranulation, as evidenced by increased release of MPO and elastase. MPO also augmented PMN-dependent superoxide (O(2)(*-)) production, which was prevented by anti-CD11b antibodies, but not MPO inhibitors. Collectively, these results reveal that binding of MPO to CD11b/CD18 integrins stimulates PMN signaling pathways to induce PMN activation in a mechanism independent of MPO catalytic activity. These cytokine-like properties of MPO thus represent an additional dimension of the proinflammatory actions of MPO in vascular disease.     

Iron deficiency and neutrophil function: different rates of correction of the depressions in oxidative burst and myeloperoxidase activity after iron treatment

The polymorphonuclear granulocyte (PMN) kills ingested bacteria by mechanisms that include myeloperoxidase (MPO) and a sudden increase in oxygen consumption (the oxidative burst), both of which are iron dependent. The magnitude of the oxidative burst and activity of MPO were determined in PMNs during the progression of iron deficiency (ID) and following its treatment in rats. As ID developed, the oxidative burst after zymosan activation was less depressed than the activity of MPO. There was no change in the oxidative burst after activation with phorbol myristate acetate (PMA) or in the generation of superoxide (O2- ) by NADPH oxidase-containing particles from PMNs. Following iron treatment, impairment of the oxidative burst after zymosan activation was corrected after 1 day. In contrast, the deficit in MPO activity was not corrected until 7 days after initiation of iron treatment. The pattern of recovery in MPO activity after iron treatment corresponded to the prolonged period of maturation of the PMN primary granule since the formation of primary granules, which contain MPO, takes place only in the early, mitotic stages of maturation. The tendency of the PMN to maintain the oxidative burst allows the cell to preserve its capacity for bacterial killing during the progression of iron deficiency.     

CNI-1493, an inhibitor of proinflammatory cytokines, retards cartilage destruction in rats with collagen induced arthritis

OBJECTIVE: To investigate if administration of CNI-1493, an inhibitor of the synthesis of proinflammatory cytokines and NO, protects against development of joint destruction in collagen induced arthritis (CIA) in rats. METHODS: In a placebo controlled experiment, CNI-1493 was given once daily intraperitoneally after onset of clinical arthritis in DA rats. Disease progression was studied by clinical scoring of arthritis, serial measurement of serum levels of COMP, and histological examination of joints. RESULTS: Clinical signs of arthritis were significantly reduced in the CNI-1493 treated group of rats in comparison with the placebo treated group. Histological examinations of paws demonstrated a significant reduction of cartilage destruction in the CNI-1493 treated group, but marked destruction of cartilage in the placebo group. Serum levels of COMP increased in the placebo group, whereas in the CNI-1493 treated group levels were low and decreased significantly during the observation time. CONCLUSIONS: Treatment with CNI-1493 provides efficient protection against synovial inflammation and cartilage destruction when used therapeutically in CIA. The protective effect against cartilage destruction can be monitored by measuring serum COMP. These observations make CNI-1493 an attractive candidate for therapeutic studies in human arthritis, and COMP an attractive serum marker for monitoring joint protective effects.     

Complement and polymorphonuclear leukocyte activation each play a role in determining myocardial ischemia-reperfusion injury.

Cobra venom factor (CVF) transiently activates polymorphonuclear leukocytes (PMN) by complement activation, followed by rapid complement depletion and gradual reversal of PMN activation. Utilizing these sequential changes caused by CVF, the individual and combined effects of complement and PMNs on myocardial infarct size (IS) were investigated. Rats were treated with CVF, and/or anti-PMNs. Complement was depleted, but circulating PMNs were being activated at 4h after CVF administration, and at 36h after, complement was depleted, but PMNs were in a near basal condition. Under anesthesia, the rats had a 30-min coronary occlusion followed by 6h of reperfusion. The IS was assessed by tetrazolium staining. CVF, as well as anti-PMNs, reduced myeloperoxidase (MPO) activity in the risk area and the reduced MPO resulted in a reduced IS, which was also the effect of anti-PMNs, but complement depletion by CVF, during which circulating PMNs were activated, failed to reduce the IS despite low MPO activity. These results suggest that complement and the condition of PMNs each play a role in determining the IS, and ischemic reperfusion injury might be produced even by relatively low myocardial MPO activity.     

The tetravalent guanylhydrazone CNI-1493 blocks the toxic effects of interleukin-2 without diminishing antitumor efficacy

The use of interleukin 2 (IL-2) as an antineoplastic agent has been limited by the serious toxicities that accompany the doses necessary for a tumor response. Elevation of nitric oxide (NO) and tumor necrosis factor (TNF) both have been implicated in IL-2 toxicities. CNI-1493, a tetravalent guanylhydrazone, is an inhibitor of macrophage activation including the synthesis of TNF and other cytokines. Doses of CNI-1493 as low as 1 mg/kg/day conferred complete protection against fatal toxicity of IL-2 with IL-2 doses tenfold higher than the safely tolerated level in Sprague–Dawley rats. Moreover, typical pathologic changes in the lungs, kidneys, and the liver caused by IL-2 infusion were blocked by cotreatment with CNI-1493. When animals bearing established hepatomas were given IL-2 and CNI-1493 combination therapy, 10 of 10 hepatomas regressed from 1 cm³ to <1 mm³. Intracytoplasmic TNF levels were increased in normal tissues from IL-2 treated animals, and treatment with CNI-1493 maintained TNF at control levels. The degree of apoptosis measured by terminal deoxynucleotidyltransferase-mediated dUTP-biotin nick end labeling staining of tumors following IL-2 therapy was not reduced compared with IL-2 cotreated with CNI-1493. In contrast, apoptosis in the liver and lung parenchyma following IL-2 therapy was blocked completely by cotreatment with CNI-1493. Taken together, these data showed that low and infrequent doses of CNI-1493 markedly protected animals from IL-2 systemic toxicities whereas not affecting tumor response to IL-2 therapy. With the protection afforded by CNI-1493 treatment, IL-2 therapy dose levels could be increased to provide significant antitumor effects in animals with established hepatomas.     

Induction of neutrophil responsiveness to myeloperoxidase antibodies by their exposure to supernatant of degranulated autologous neutrophils

Antibodies against myeloperoxidase (MPO) and proteinase 3 (PR3) are the predominant autoantibodies present in antineutrophil cytoplasmic antibody (ANCA)-associated vasculitis. Their binding to the corresponding antigen on the surface of polymorphonuclear neutrophils (PMNs) is believed to trigger the disease process. Cytokines released during an inflammatory reaction are thought to prime resting PMNs, making them responsive to autoantibodies. In the present study we found that MPO but not PR3 could be detected on the cell surface of unstimulated PMNs after incubation with the supernatants of activated autologous PMNs. MPO was shown to be acquired from these supernatants, because PMNs did not express MPO when the supernatants were specifically MPO-depleted. In addition, purified soluble MPO bound to unstimulated PMNs. Unstimulated PMNs that had passively acquired MPO released oxygen radicals when incubated with monoclonal antibody anti-MPO or the immunoglobulin G fraction of a patient with MPO-ANCA. The data presented here suggest that, in ANCA-associated vasculitis, soluble MPO released by activated PMNs may bind to unstimulated PMNs, thereby making them reactive to anti-MPO antibodies. This mechanism of dispersing PMN activation would be specific for MPO-ANCA and may explain differences in the pathologic and clinical expression of MPO-ANCA versus PR3-ANCA vasculitis. (Blood. 2000;96:2822-2827)     

Increased degranulation of human myeloperoxidase-deficient polymorphonuclear leucocytes

Myeloperoxidase (MPO)-deficient neutrophils (PMN) released considerably more beta-glucuronidase, lysozyme and vitamin B12-binding activities, when exposed to opsonized zymosan (STZ), than the normal counterpart. Release of the soluble enzyme lactate dehydrogenase was not appreciably changed over the incubation time with particles in either cell type. MPO-deficient PMN and normal PMN ingested STZ particles at a similar rate at early times, but thereafter phagocytosis by MPO-deficient PMN was significantly higher than that by normal PMN. The difference in degranulation between the two cell types greatly exceeded the difference in ingestion and was evident already at early phagocytosis times when no difference in phagocytosis was observed; this suggested that the higher degranulation in MPO-deficient PMN was at least in part independent of the increased ingestion. This was confirmed by experiments with the soluble stimulant N-formyl-L-norleucyl-L-leucyl-phenylalanine (FNLLP). MPO-deficient PMN and normal PMN exhibited a comparable respiratory burst when exposed to FNLLP plus cytochalasin B, but the defective cells released more azurophilic and specific granule markers than normal PMN. These results indicate that MPO-deficient PMN degranulate more than normal PMN and suggest a role for MPO in the regulation of degranulation.     

Impact of hepatitis C virus infection on neutrophil oxidative burst function in hemodialysis patients

Polymorphonuclear leukocyte (PMN) functions have been studied extensively in hemodialysis (HD) patients; however, results are contradictory and the mechanisms that modulate phagocytosis and oxidative burst are not completely understood. Hepatitis C virus (HCV) is a frequent complication of HD that may be associated with disturbed PMN function; however, the impact of HCV infection on neutrophil oxidative burst function in HD patients is unknown. We investigated Neutrophil oxidative burst function in 24 HD patients (15 HCV-positive and, 9 HCV-negative patients) before and after dialysis. HCV-RNA was detected by RT-nested PCR while, quantitative measurement of oxidative burst function was assessed by flowcytometry. Neutrophil Oxidised burst function was significantly diminished in HD patients as comapred to controls (P = 0.001, oxidised PMN (%); P = 0.02 mean flueresnce intensity, MFI), and in pre-dialysis as compared to post-dialysis samples (oxidised PMNs (%): 60.5 +/- 3.2 vs. 72.1 +/- 3.9, P = 0.02); (MFI: 352 +/- 42 vs. 500 +/- 50, P = 0.03). Alteration in Neutrophil oxidative burst function in the pre-dialysis samples was significant in HCV-positive patients as compared to HCV-negative patients (oxidized PMNs (%): 50 +/- 2.9 vs. 63 +/- 5.1, P = 0.02); (MFI: 291 +/- 31 vs. 438 +/- 64, P = 0.006). Marked reduction in E. coli induced burst in pre-dialysis samples compared to post-dialysis was found in HCV-positive when compared to HCV-negative patients (oxidized PMNs (%): 50 +/- 2.9 vs. 74.8 +/- 4.7, P = 0.001), (MFI: 291 +/- 31 vs. 493 +/- 63, P = 0.002). In conclusion, a possible role of concomitant HCV infection in alteration of Neutrophil oxidative burst function is highly suggested.