Effects of Neutrophil Elastase Inhibitor on Progression of Acute Lung Injury Following Esophagectomy

The purpose of this study was to evaluate the effect of sivelestat sodium hydrate, a selective inhibitor of neutrophil elastase in the systemic inflammatory response, pulmonary function, and the postoperative clinical course following esophagectomy. Patients with hypoxia associated with surgical stress in the intensive care unit (ICU) immediately after an esophagectomy were eligible for this study. The degree of hypoxia was calculated according to the ratio of arterial oxygen tension (PaO₂) to the fractional concentration of inspired oxygen (FiO₂)—PaO₂/FiO₂. Patients with PaO₂/FiO₂ < 300 mmHg were enrolled in this study. Seven patients were treated with sivelestat, and 10 were not so treated. The degree of hypoxia, the criteria for systemic inflammatory response syndrome (SIRS), and the postoperative clinical course were compared between the two groups. The postoperative decreases in the PaO₂/FiO₂ ratio were significantly suppressed in the sivelestat group (p < 0.05, by analysis of variance, or ANOVA). Furthermore, 9 of the 10 control group patients developed SIRS on postoperative day 2, whereas only 2 of 7 of the sivelestat group patients developed SIRS (p < 0.05). The postoperative increases in the heart rate were significantly suppressed in the sivelestat group (p < 0.05, ANOVA). The postoperative decreases in the platelet counts were significantly suppressed in the sivelestat group (p < 0.05, ANOVA). The duration of mechanical ventilation and the length of ICU stay for the sivelestat group were shorter than that for the control group. We demonstrated that the postoperative decreases in the PaO₂/FiO₂ ratio following esophagectomy were significantly suppressed in the sivelestat-treated group. This clinical study showed that a neutrophil elastase inhibitor may thus be a potentially useful drug for treating acute lung injury following esophagectomy.     

The Effect of the Neutrophil Elastase Inhibitor Sivelestat on Early Injury after Liver Resection

Background  

The effects of sivelestat on endotoxin-induced lung injury, postperfusion lung injury, and ischemia–reperfusion are known, yet the benefits of sivelestat during liver surgery have yet to be elucidated. The aim of the present study was to assess the effects of sivelestat, with a focus on postoperative chemical data, in hepatectomized patients.     

Spontaneous Breathing Improves Lung Aeration in Oleic Acid-induced Lung Injury

Background: Experimental and clinical studies have shown reduction in intrapulmonary shunt with improved oxygenation by spontaneous breathing with airway pressure release ventilation (APRV) in acute lung injury. The mechanisms of these findings are not clear. The authors hypothesized that spontaneous breathing results in better aeration of lung tissue and that improvement in oxygenation can be explained by these changes. This hypothesis was studied in a porcine model of oleic acid-induced lung injury.

Methods: Two hours after induction of lung injury, 24 pigs were randomly assigned to APRV with or without spontaneous breathing at a positive end-expiratory pressure of 5 cm H2O. Hemodynamics, spirometry, and end-expiratory lung volume by nitrogen washout were measured at baseline, after 2 h of lung injury, and after 2 and 4 h of mechanical ventilation in the specific mode. Finally, spiral computed tomography of the chest was performed at end-expiratory lung volume in 22 pigs.

Results: Arterial carbon dioxide tension and mean and end-inspiratory airway pressures were comparable between settings. Four hours of APRV with spontaneous breathing resulted in improved oxygenation compared with APRV without spontaneous breathing (arterial oxygen tension, 144 +/- 65 vs. 91 +/- 50 mmHg, P < 0.01 for interaction time x mode), higher end-expiratory lung volume (786 +/- 320 vs. 384 +/- 148 ml, P < 0.001), and better aeration. End-expiratory lung volume and venous admixture were both correlated with the amount of lung reaeration (r2 = 0.62 and r2 = 0.61, respectively).     

Montelukast,Leukotriene Inhibitor,Reduces LPS-Induced Acute Lung Inflammation and Human Neutrophil Activation

ObjectivesSome pro-inflammatory lipids derived from 1 lipooxygenase enzyme are potent neutrophil chemoattractant, a cell centrally involved in acute respiratory distress syndrome (ARDS); a syndrome lacking effective treatment. Considering the beneficial effects of the leukotriene receptor inhibitor, montelukast, on other lung diseases, whether montelukast attenuates inflammation in a mouse model of ARDS, and whether it reduces LPS stimulated activation of human neutrophils was investigated.MethodsThirty-five C57Bl/6 mice were distributed into control (PBS) + 24 h, LPS + 24 h (10 μg/mouse), control + 48 h, LPS + 48 h, and LPS 48 h + Montelukast (10 mg/kg). In addition, human neutrophils were incubated with LPS (1 μg/mL) and treated with montelukast (10 μM).ResultsOral-tracheal administration of montelukast significantly attenuated total cells (P < .05), macrophages (P < .05), neutrophils (P < .01), lymphocytes (P < .001) and total protein levels in BAL (P < .05), as well as IL-6 (P < .05), CXCL1/KC (P < .05), IL-17 (P < .05) and TNF-α (P < .05). Furthermore, montelukast reduced neutrophils (P < .001), lymphocytes (P < .01) and macrophages (P < .01) in the lung parenchyma. In addition, montelukast restored BAL VEGF levels (P < .05). LTB4 receptor expression (P < .001) as well as NF-κB (P < .001), a downstream target of LPS, were also reduced in lung parenchymal leukocytes. Furthermore, montelukast reduced IL-8 (P < .001) production by LPS-treated human neutrophils.ConclusionIn conclusion, montelukast efficiently attenuated both LPS-induced lung inflammation in a mouse model of ARDS and in LPS challenged human neutrophils.     

Neutrophil Elastase Inhibitor (Sivelestat) Preserves Antitumor Immunity and Reduces the Inflammatory Mediators Associated with Major Surgery

Purpose To examine the effects of the administration of perioperative sivelestat, a selective neutrophil elastase inhibitor, on tumor immunity and inflammatory mediators in patients who undergo major surgery. Methods Thirteen patients admitted to the hospital for elective surgery were equally randomized into one of two groups: the Sivelestat group (n = 6) and the control group (n = 7). Thereafter, the immunosuppressive acidic protein (IAP), serum interleukin-6 (IL-6), and type 1/type 2 T-helper cell balance were all assessed at several time points before and after surgical intervention. Results The serum IL-6 values at 1 and 12 h after surgery and on postoperative days 1 and 3 were all significantly lower in the sivelestat group than in the control group. The IAP values at postoperative days 7 and 28 in the sivelestat group were also significantly lower than those in the control group. There was a significant correlation between the IL-6 level at 1 h after surgery and the IAP level at postoperative days 7 and 28. Conclusions In this preliminary study, the perioperative administration of sivelestat was thus suggested to reduce surgical stress by decreasing the cytokine release and preserving the antitumor immunity.     

The Protective Effects of Caffeic Acid Phenethyl Ester on Acetylsalicylic Acid-induced Lung Injury in Rats

Aim: We aimed to investigate the protective effect of caffeic acid phenethyl ester (CAPE) on acetylsalicylic acid (ASA)-induced lung damage in rats in the present study. Methods: A total of 40 rats were randomly divided into five groups, with eight rats in each group—group 1: control, not receiving any medication; group 2: ASA (50 mg/kg/day); group 3: ASA (50 mg/kg/day) plus CAPE (20 μg/kg/day); group 4: ASA (100 mg/kg/day); and group 5: ASA (100 mg/kg/day) plus CAPE (20 μg/kg/day). ASA and CAPE were given via orogastric gavage for 5 days. The total oxidant status (TOS), total antioxidant capacity (TAC), oxidant stress index (OSI), and paraoxonase-1 (PON-1) activity of the blood samples and lung tissues were determined. Histopathological examinations of the lung tissues were performed by using light microscopic methods. Results: CAPE treatment significantly increased antioxidant PON-1 level both in the lung tissue and plasma (p < .05). Plasma antioxidant marker (TAC, PON-1) levels significantly increased and oxidant marker (TOS, OSI) levels significantly decreased in CAPE-treated rats (groups 3,5) compared to ASA given no-CAPE groups (group 2,4) (p < .05). Treatment with CAPE improved pulmonary interstitial inflammation and eosinophil accumulation due to ASA histopathologically. Conclusion: Eosinophil-rich inflammation and oxidative stress play important roles in ASA-induced lung toxicity, and CAPE may protect against ASA-induced lung toxicity by reduction of oxidative damage and inflammation in rats.     

Effect of a Polymorphonuclear Elastase Inhibitor (Sivelestat Sodium) on Acute Lung Injury After Cardiopulmonary Bypass: Findings of a Double-Blind Randomized Study

PURPOSE: We evaluated the effect of sivelestat sodium (SiV), a novel synthesized polymorphonuclear (PMN) elastase inhibitor, on acute lung injury (ALI) caused by cardiopulmonary bypass (CPB). METHODS: Fourteen patients who underwent cardiopulmonary surgery using CPB, followed by the development of both systemic inflammatory response syndrome (SIRS) and ALI, were treated with either 0.2 mg/kg per hour SiV (SiV group, n = 7) or saline (control group, n = 7) for 4 days from the time of arrival in the intensive care unit. RESULTS: The SiV group had a significantly lower ratio of serum PMN elastase and interleukin (IL)-8, a significantly lower ratio of the respiratory index, and a significantly higher ratio of PaO(2)/FiO(2) after 24 h of treatment than the control group. CONCLUSION: Sivelestat sodium suppressed the production of PMN elastase and IL-8, resulting in improved respiratory function in patients with ALI caused by CPB.     

Neutrophil Stimulation with Granulocyte Colony-stimulating Factor Worsens Ventilator-induced Lung Injury and Mortality in Rats

Background: Based on the association between the neutrophil and ventilator-induced lung injury, the authors hypothesized that neutrophil inhibition with fucoidin would be beneficial and stimulation with granulocyte colony-stimulating factor (G-CSF) would be harmful in a rat model of lethal ventilator-induced lung injury.

Methods: Animals (n = 111) were randomly assigned to be pretreated with fucoidin, G-CSF, or placebo (control) before 4 h of low-tidal-volume (10 ml/kg) or high-tidal-volume (40 ml/kg) mechanical ventilation.

Results: All low-volume animals survived. With high volumes, compared with controls, fucoidin did not improve survival (3 of 20 control animals and 5 of 20 fucoidin animals died; P = 0.51) but G-CSF significantly worsened it (18 of 22 animals died; P < 0.001). Circulating neutrophils were increased early with G-CSF and late with fucoidin with low and high tidal volumes (P < 0.05 for each treatment and tidal volume). Fucoidin decreased lung neutrophils, but these were only significant with high tidal volumes, whereas G-CSF increased lung neutrophils but only significantly with low tidal volumes (P <= 0.01 for each). Fucoidin did not alter any cardiopulmonary measure significantly. Compared with control, G-CSF increased airway pressures with high tidal volumes and worsened lung edema and arterial oxygen with both tidal volumes (P < 0.05 for each).     

Autologous Transplantation of Endothelial Progenitor Cells Attenuates Acute Lung Injury in Rabbits

Background: Acute lung injury (ALI) and end-stage acute respiratory distress syndrome (ARDS) are among the most common causes of death in intensive care units. Activation and damage of pulmonary endothelium is the hallmark of ALI/ARDS. Recent studies have demonstrated the importance of circulating endothelial progenitor cells (EPCs) in maintaining normal endothelial function as well as endothelial repairing after vascular injury. Here, the authors present the first study demonstrating the therapeutic potential of EPCs in a rabbit model of ALI/ARDS.

Methods: Circulating EPCs were obtained from rabbits using Ficoll centrifugation. One week after culturing, ALI was induced in rabbits by oleic acid (75 mg/kg, intravenous), and autologous EPCs were transplanted intravenously. Vasomotor function of isolated pulmonary artery and degrees of lung injury were assessed 2 days later.

Results: Endothelial dysfunction in the pulmonary artery was significantly attenuated in rabbits treated with EPCs, whereas the endothelium-independent relaxation responses were not different. Expression of inducible nitric oxide synthase was suppressed in the pulmonary artery of EPC-treated animals. Infiltration of leukocytes in the lung parenchyma was significantly reduced after EPC transplantation. EPCs also decreased water content, hyaline membrane formation, and hemorrhage in lungs.     

Olprinone, a Phosphodiesterase III Inhibitor, Reduces Gut Mucosal Injury and Portal Endotoxin Level during Acute Hypoxia in Rabbits

Background: Preservation of gut integrity has become a therapeutic goal to obviate bacterial translocation in the critically ill. The authors examined whether olprinone, a phosphodiesterase III inhibitor, protected functional and structural integrity of gut mucosa against acute progressive hypoxia.

Methods: Thirty-two animals were randomly allocated to a control group (n = 12), a low-dose group (0.2 [mu]g [middle dot] kg-1 [middle dot] min-1 olprinone; n = 10), or a high-dose group (0.6 [mu]g [middle dot] kg-1 [middle dot] min-1 olprinone; n = 10) after preparatory surgery. Ascending aortic and portal blood flow, intramural pH of the ileum, and portal endotoxin levels were measured at normoxia and through three stages of progressive hypoxia (fraction of inspired oxygen = 0.17, 0.13, and 0.10).

Results: At normoxia, ascending aortic flow in the high-dose group was approximately 20% higher than in the control and low-dose groups. During progressive hypoxia, both ascending aortic and portal flow in the control group were depressed, whereas olprinone infusion attenuated such alterations and redistributed blood to the splanchnic area in a dose-dependent manner. On the contrary, the reduction of intramural pH of the ileum and the elevation of portal endotoxin levels observed in the control group were significantly minimized in both the low- and high-dose groups to a similar extent during acute hypoxia. Histopathologic alterations of gut mucosa observed in the control group were minimized by olprinone infusion dose-independently, accompanied by reduction of mortality rate of the animals.     

Cyclosporine Does Not Prevent Microvascular Loss in Transplantation but Can Synergize With a Neutrophil Elastase Inhibitor,Elafin, to Maintain Graft Perfusion During Acute Rejection

The loss of a functional microvascular bed in rejecting solid organ transplants is correlated with fibrotic remodeling and chronic rejection; in lung allografts, this pathology is predicted by bronchoalveolar fluid neutrophilia which suggests a role for polymorphonuclear cells in microcirculatory injury. In a mouse orthotopic tracheal transplant model, cyclosporine, which primarily inhibits T cells, failed as a monotherapy for preventing microvessel rejection and graft ischemia. To target neutrophil action that may be contributing to vascular injury, we examined the effect of a neutrophil elastase inhibitor, elafin, on the microvascular health of transplant tissue. We showed that elafin monotherapy prolonged microvascular perfusion and enhanced tissue oxygenation while diminishing the infiltration of neutrophils and macrophages and decreasing tissue deposition of complement C3 and the membrane attack complex, C5b‐9. Elafin was also found to promote angiogenesis through activation of the extracellular signal‐regulated kinase (ERK) signaling pathway but was insufficient as a single agent to completely prevent tissue ischemia during acute rejection episodes. However, when combined with cyclosporine, elafin effectively preserved airway microvascular perfusion and oxygenation. The therapeutic strategy of targeting neutrophil elastase activity alongside standard immunosuppression during acute rejection episodes may be an effective approach for preventing the development of irreversible fibrotic remodeling.     

Intravenous Lidocaine Attenuates Acute Lung Injury Induced by Hydrochloric Acid Aspiration in Rabbits

Background: Neutrophils play a crucial role in the pathogenesis of acid-induced acute lung injury. Lidocaine inhibits the function of neutrophils. This study aimed to determine whether lidocaine attenuates acute lung injury induced by hydrochloric acid (HCl) instillation.

Methods: In study 1, rabbits were divided into four groups (n = 7 each). Lung injury was induced by intratracheal HCl (0.1 N, 3 ml/kg) in two groups. The other two groups received saline intratracheally. Lidocaine given intravenously (2 mg/kg bolus + 2 mg [center dot] kg-1 [center dot] h-1 infusion) was started 10 min before intratracheal instillation in one HCl and one saline group, and saline was given intravenously in the other two groups. In study 2, rabbits (four groups of seven animals each) received HCl (0.1 N, 3 ml/kg) intratracheally. Treatment with intravenous lidocaine was started 10 min before, 10 min after, or 30 min after acid instillation, or saline was given intravenously 10 min before instillation.

Results: In study 1, HCl caused deterioration of the partial pressure of oxygen (PaO2), lung leukosequestration, decreased lung compliance, and increased the lung wet-to-dry weight ratio and albumin, interleukin-6 (IL-6), and IL-8 levels in bronchoalveolar lavage fluid. Lidocaine pretreatment attenuated these changes. Hydrochloric acid increased superoxide anion production by neutrophils and caused morphologic lung damage, both of which were lessened by lidocaine. In study 2, lidocaine given 10 min after acid instillation was as effective as pretreatment in PaO2, lung mechanics, and histologic examination. However, PaO2 changes in lidocaine 30 min after injury were similar to those in saline given intravenously.     

Effects of Peak Inspiratory Flow on Development of Ventilator-induced Lung Injury in Rabbits

Background: A lung-protecting strategy is essential when ventilating acute lung injury/acute respiratory distress syndrome patients. Current emphasis is on limiting inspiratory pressure and volume. This study was designed to investigate the effect of peak inspiratory flow on lung injury.

Methods: Twenty-four rabbits were anesthetized, tracheostomized, ventilated with a Siemens Servo 300, and randomly assigned to three groups as follows: 1) the pressure regulated volume control group received pressure-regulated volume control mode with inspiratory time set at 20% of total cycle time, 2) the volume control with 20% inspiratory time group received volume-control mode with inspiratory time of 20% of total cycle time, and 3) the volume control with 50% inspiratory time group received volume-control mode with inspiratory time of 50% of total cycle time. Tidal volume was 30 ml/kg, respiratory rate was 20 breaths/min, and positive end-expiratory pressure was 0 cm H2O. After 6 h mechanical ventilation, the lungs were removed for histologic examination.

Results: When mechanical ventilation started, peak inspiratory flow was 28.8 +/- 1.4 l/min in the pressure regulated volume control group, 7.5 +/- 0.5 l/min in the volume control with 20% inspiratory time group, and 2.6 +/- 0.3 l/min in the volume control with 50% inspiratory time group. Plateau pressure did not differ significantly among the groups. Gradually during 6 h, Pao2 in the pressure regulated volume control group decreased from 688 +/- 39 to a significantly lower 304 +/- 199 mm Hg (P < 0.05) (mean +/- SD). The static compliance of the respiratory system for the pressure regulated volume control group also ended significantly lower after 6 h (P < 0.05). Wet to dry ratio for the pressure regulated volume control group was larger than for other groups (P < 0.05). Macroscopically and histologically, the lungs of the pressure regulated volume control group showed more injury than the other groups.     

参附注射液对兔移植肺缺血-再灌注损伤的保护作用

目的观察参附注射液对供肺缺血-再灌注损伤的保护作用。方法将20只新西兰白兔随机分为实验组和对照组,每组各10只,建立兔左肺自体原位移植模型,分别用参附注射液和生理盐水对兔肺进行预处理和供肺灌注。于主动脉阻断前、再灌注后15min、30min和60min各时点检测左肺静脉血中丙二醛(MDA)含量、总超氧化物歧化酶(SOD)的活力,于再灌注60min后称左肺组织的干湿比重(D/W),并观察其病理变化。结果主动脉阻断前两组MDA含量差异无统计学意义(P0.05);再灌注15min后实验组MDA含量较主动脉阻断前下降;再灌注30min和60min时,两组MDA含量均呈上升趋势,但实验组明显低于对照组(P0.05)。主动脉阻断前实验组SOD活力明显高于对照组(P0.05),再灌注后两组SOD活力均呈下降趋势,以对照组下降幅度明显(P0.05)。实验组的D/W显著高于对照组(0.23±0.01vs.0.19±0.02,P0.05)。对照组肺组织水肿明显,大量的炎性细胞浸润,肺泡腔内有片状渗出;而实验组表现为肺泡间隔水肿轻微,少量炎细胞浸润,渗出不明显。结论参附注射液对供肺的缺血-再灌注损伤有较好的保护作用。     

Intramuscular Gene Transfer of Interleukin-10 Reduces Neutrophil Recruitment and Ameliorates Lung Graft Ischemia-Reperfusion Injury

Interleukin-10 (IL-10) has potent anti-inflammatory properties but its direct effects on neutrophil trafficking in lung transplant ischemia-reperfusion (I/R) injury are unknown. This study was performed to determine if recipient intramuscular IL-10 gene transfer reduces neutrophil infiltration in lung isografts and ameliorates I/R injury. Twenty-four hours before transplantation, recipient rodents received intramuscular injection with 1 x 10(10) plaque-forming units (pfu) adenovirus encoding human IL-10 (hIL-10), 1 x 10(10) pfu adenovirus control encoding p-galactosidase, or saline. Gene expression in muscle and plasma was confirmed. Lung grafts were harvested, stored at 4 degrees C for 18h, and assessed 24 h after transplantation. Peak muscle and plasma expression of hIL-10 was achieved 24h after gene transfer and returned to baseline by 7 days (p < 0.05 vs. controls). Gene transfer of hIL-10 reduced neutrophil sequestration and emigration in lung grafts as measured by morphometry and myeloperoxidase activity (p < 0.03 vs. controls). Furthermore, hIL-10 improved graft oxygenation and reduced lung edema (p <0.01 vs. controls). Intramuscular gene transfer of hIL-10 releases hIL-10 protein into plasma and reduces neutrophil sequestration and emigration in lung isografts. This is associated with a reduction in I/R injury with improved isograft oxygenation and reduced tissue edema. Intramuscular gene transfer may be a useful strategy to reduce clinical l/R injury.     

Effects of L-Nitro-Arginine Methyl Ester, an Inhibitor of Nitric Oxide Biosynthesis, on Intestinal Ischemia/Reperfusion Injury in Rabbits

To study whether treatment with L-nitro-arginine methyl ester (L-NAME), an inhibitor of nitric oxide biosynthesis, attenuates intestinal dysfunction caused by ischemia (I) and/or reperfusion (R), rabbits were treated with L-NAME (15 mg · kg⁻¹, intervenously) or saline olution (SS) prior to I (60 minutes) induced by occlusion of superior mesenteric artery and/or R (120 minutes). After I or I/R, isolated jejunal segments (2 cm) were mounted in an organ bath to study nerve-mediated contractions stimulated by electrical pulses or KCI using a digital recording system. Thin jejunal slices were stained (hematoxylin and eosin) for analysis by optical microscopy. Compared with a sham group, the jejunal contractions were similar in the I/R + L-NAME, but reduced in I + SS, I/R + SS, and I + L-NAME groups. The jejunal enteric nerves were damaged in the I + SS, I/R + SS, and I + L-NAME cohorts, but not among the I/R + L-NAME cohort. These results suggested that L-NAME attenuated intestinal dysfunction caused by R but not by I.     

基质金属蛋白酶-9抑制剂对犬体外循环肺损伤的影响

目的研究外源性基质金属蛋白酶-9(matrix metalloproteinases-9,MMP-9)抑制剂多西环素(Doxycycline)对体外循环(CPB)引起肺损伤的保护作用。方法将20只健康杂种幼犬(体重10～12kg),采用随机数字表法随机分为对照组(n=10)和实验组(n=10);对照组:CPB前后不采取任何肺保护措施;实验组:CPB术前3d每天饲料拌食多西环素(30mg/kg体重)。采用酶联免疫吸附(ELISA)法检测血浆MMP-9浓度;监测两组犬血流动力学和呼吸参数,计算术前和术后肺泡-动脉氧分压差(A-aDO2)和呼吸指数(RI);比色法测定支气管肺泡灌洗液(BALF)髓过氧化物酶(MPO)活性;考马斯亮蓝G-250法测定BALF总蛋白。CPB后,在光学显微镜和电子显微镜下观察肺组织形态学改变;计算肺组织干湿重系数(W/D)。结果两组犬血浆MMP-9浓度随CPB时间延长而显著增高,CBP150min和270min时实验组血浆中MMP-9含量较对照组显著下降(9.45±5.29ng/mlvs.18.66±5.90ng/ml,t=3.664,P=0.005;16.63±2.90ng/mlvs.26.17±5.96ng/ml,t=5.216,P=0.001)。实验组MPO活性,BALF中总蛋白浓度,肺组织W/D,术后A-aDO2和RI均较对照组均明显减低,差异有统计学意义(t=5.622,P=0.000;t=5.081,P=0.001;t=2.266,P=0.050;t=4.927,P=0.001;t=6.679,P=0.000)。肺组织病理和电子显微镜显示实验组损伤明显减轻。结论多西环素通过抑制MMP-9的分泌,降低细胞基底膜的降解,减轻肺泡白细胞浸润和肺水肿,可起到对肺的保护作用。