Surfactant and corticosteroid effects on lung function in a rat model of acute lung injury.

OBJECTIVES: To evaluate pulmonary responses to intratracheal administration of surfactant with and without dexamethasone in rats with paraquat-induced lung injury. DESIGN: Prospective, randomized, controlled study. SETTING: University research facility. SUBJECTS: Adult male Sprague Dawley rats. INTERVENTIONS: Rats were anesthetized and underwent a tracheostomy and arterial catheter insertion 3 days after intraperitoneal injection of paraquat (35 mg/kg). The rats were ventilated for 90 mins after sequential designation as controls or as recipients of intratracheal surfactant alone (50 or 100 mg/kg) or surfactant (50 or 100 mg/kg) plus dexamethasone (0.5 mg/kg). MEASUREMENTS AND MAIN RESULTS: Arterial blood gases were determined at 15, 30, 60, and 90 mins. After 90 mins of ventilation, a static pressure-volume curve was performed, and inflammatory cells, total protein content, and cytokines were measured in bronchoalveolar lavage fluid. Postmortem histology was then examined. Treatment with 50 mg/kg dexamethasone/Survanta and 100 mg/kg Survanta with and without dexamethasone significantly increased oxygenation shortly after instillation when compared with the control group, with the response maintained throughout the study period. Static pressure-volume curves showed that the group receiving 100 mg/kg dexamethasone/Survanta had significantly higher lung volumes than the control group. Total cell, neutrophil, and macrophage counts were decreased significantly in the animals treated with 100 mg/kg dexamethasone/Survanta compared with untreated control rats. Total protein recovered from bronchoalveolar lavage fluid in the animals treated with 100 mg/kg Survanta with and without dexamethasone was decreased significantly compared with control animals. The histologic appearance of the lungs was markedly better in the groups treated with surfactant with or without dexamethasone. CONCLUSIONS: Results suggest that the combined administration of high doses of intratracheal surfactant and dexamethasone improves gas exchange, ameliorates lung inflammation, and alleviates lung damage after paraquat-induced lung injury. Surfactant alone and lower doses of surfactant plus dexamethasone had a lesser effect on these measures.     

甲泼尼龙对急性百草枯中毒大鼠肺损伤病理变化的影响

目的：通过研究甲泼尼龙对急性百草枯中毒大鼠肺病理学改变的作用,探讨甲泼尼龙对百草枯中毒大鼠早期肺损伤的保护作用。方法：60只Wistar大鼠,随机分为4组,正常对照组（A组）、模型组（B组）、甲泼尼龙15 mg/kg组（C组）、甲泼尼龙5 mg/kg组（D组）。B、C、D组采用百草枯22 mg/kg腹腔注射一次性染毒,C、D组从染毒后2 h开始,分别予腹腔注射甲泼尼龙15 mg/kg和5 mg/kg,每日1次,同期A、B组用等体积无菌生理盐水腹腔内注射,每日1次,至处死前。染毒后24、72、168 h分批处死大鼠,每组每时间点6只,摘取肺脏,制备肺组织标本,光镜下观察肺组织的病理学改变并行肺损伤评分。结果：光镜下C、D组大鼠肺组织的病理学改变比B组轻,其中以D组减轻最为明显。染毒后24 h C、D组的肺损伤评分明显低于B组（P均〈0.05）;72 h D组的肺损伤评分明显低于B组（P〈0.05）,而B、C组的肺损伤评分比较差异无统计学意义（P〉0.05）;168 h B、C、D组的肺损伤评分均明显高于A组（P〈0.05）,其中C、D组的肺损伤评分明显低于B组（P均〈0.05）,C、D组的肺损伤评分比较差异无统计学意义（P〉0.05）。结论：甲泼尼龙对急性百草枯中毒大鼠的肺损伤具有保护作用,且小剂量（5 mg/kg）甲泼尼龙优于常规剂量（15 mg/kg）。     

Effect of pirfenidone on pulmonary fibrosis due to paraquat poisoning in rats

Background. This study investigated the effectiveness of pirfenidone compared with antioxidants, in the prevention of pulmonary fibrosis and increasing the survival in acutely paraquat poisoned rats. Methods. Five groups of ten rats were included in this study. Three groups were poisoned with intraperitoneal injection of 15 mg/kg paraquat. Among these poisoned groups, one group was treated with vitamin C (500 mg/kg, intraperitoneal), vitamin E (200 mg/kg, intraperitoneal) and N-acetylcysteine (250 mg/kg, intravenous); two others were treated with either normal saline or pirfenidone (200 mg/kg, intravenous); two groups were not poisoned and received normal saline or pirfenidone (200 mg/kg, intravenous). All injections except paraquat were repeated in four consecutive days. On the 15th day of study a semi-quantitative determination of lung fibrosis was done using Ashcroft staging criteria on the lung sections. Results. Pirfenidone decreased paraquat induced lung fibrosis (p?相似文献   

Effect of pirfenidone on pulmonary fibrosis due to paraquat poisoning in rats

Background. This study investigated the effectiveness of pirfenidone compared with antioxidants, in the prevention of pulmonary fibrosis and increasing the survival in acutely paraquat poisoned rats. Methods. Five groups of ten rats were included in this study. Three groups were poisoned with intraperitoneal injection of 15 mg/kg paraquat. Among these poisoned groups, one group was treated with vitamin C (500 mg/kg, intraperitoneal), vitamin E (200 mg/kg, intraperitoneal) and N-acetylcysteine (250 mg/kg, intravenous); two others were treated with either normal saline or pirfenidone (200 mg/kg, intravenous); two groups were not poisoned and received normal saline or pirfenidone (200 mg/kg, intravenous). All injections except paraquat were repeated in four consecutive days. On the 15th day of study a semi-quantitative determination of lung fibrosis was done using Ashcroft staging criteria on the lung sections. Results. Pirfenidone decreased paraquat induced lung fibrosis (p?<?0.001) while antioxidants did not decrease the lung fibrosis (p =?0.413). Life expectancy decreased in paraquat + normal saline (11 days, 95% CI 7.94–14.05) and paraquat + antioxidant (11 days, 95% CI 7.77–14.23) groups. The increase in the survival of rats in paraquat/pirfenidone group was insignificant (13.4 days, 95% CI 11.13–15.67). Conclusion. This study showed that pirfenidone is able to decrease pulmonary fibrosis following paraquat poisoning in a rat model.     

丙酮酸乙酯对百草枯中毒小鼠肺损伤的保护作用

目的:探讨百草枯(paraquat)时小鼠肺损伤的作用机制,及丙酮酸乙酯对肺损伤的保护作用.方法:C57BL 小鼠腹腔注射百草枯(20mg/kg)诱导损伤(PI组);2h后腹腔注射丙酮酸乙酯(40 mg/kg).在损伤6、12、24 h后,酶联免疫吸附法(ELIS)检测血清血浆肿瘤坏死因子-α(TNF-α)、白介素-1β(IL-1β)水平;24 h后观察肺病理改变;免疫组织化学检测Caspase-3的蛋白表达.结果:PI组小鼠血清TNF-α和IL-1β水平在给予百草枯后迅速升高,约在6 h达高峰,之后迅速下降.经丙酮酸乙酯治疗,血清TNF-α和IL-1β水平均低于PI组,且在6h差异显著(P<0.01).结论:百草枯可引起小鼠细胞炎性因子TNF-α和IL-1β大量产生,TNF-α和IL-1β可能参与肺损伤过程;早期给予丙酮酸乙酯能降低TNF-α和IL-1β的释放,降低caspase-3蛋白的表达,抑制细胞凋亡,可以减轻肺组织损伤.     

Lisinopril ameliorates paraquat-induced lung fibrosis

BACKGROUND: Paraquat is a controversial and one of the most commonly used herbicides in the world. Although liver, kidney, heart and CNS are affected, lung damage resulting to pulmonary fibrosis is the usual cause of deaths in the cases with intoxication. The mechanism of paraquat toxicity is not clear but probably includes the induction of lipid peroxidation of unsaturated fatty acids. Lisinopril, an angiotensin-converting enzyme inhibitor (ACEI), an antihypertensive drug, has beneficial effects on the treatment of fibrosis. The antifibrotic effect of lisinopril has shown to be due to inhibition of synthesis of angiotensin II that causes stimulation of fibroblast proliferation and collagen synthesis. METHOD: Male albino Wistar rats were used in the experiments (weighing 150-300 g). The animals were divided into 5 groups: group I received saline, group II received lisinopril (1 mg/kg; po), group III was given a single i.p. dose of 20 mg/kg paraquat, group IV (treatment group) received lisinopril after single a i.p. dose of 20 mg/kg paraquat, and group V (pre-treatment group) received lisinopril before a single i.p. dose of 20 mg/kg paraquat. After 21 days of treatment, the level of hydroxyproline and the degree of lipid peroxidation were determined in the lung tissue of the animals and the lungs were examined histologically for fibrosis. RESULT: Paraquat caused a significant increase in hydroxyproline content and lisinopril significantly decreased the amount hydroxyproline (p<0.001) in the lung tissue of the rats. The histological examination also indicated that lisinopril can effectively protect the paraquat-induced lung fibrosis. The lipid peroxidation levels in the lung were not significantly changed when compared to the control group. CONCLUSION: The antifibrotic effect of lisinopril may be due to inhibition of angiotensin II or proline moiety, which is a common structural in all ACEI, drugs.     

Effects of C1 inhibitor and r-SP-C surfactant on oxygenation and histology in rats with lavage-induced acute lung injury

OBJECTIVE: To assess the effects of C1 inhibitor (INH) administration and r-SP-C surfactant application on oxygenation and lung histology in an acute respiratory distress syndrome model. DESIGN AND SETTING: Randomized, controlled experimental study in an animal research laboratory. Material: 36 adult male Sprague-Dawley rats. INTERVENTIONS: Animals were subjected to repetitive lung lavage. Four experimental groups and two control groups were studied: groups 1 and 2 served as controls. Animals of groups 3-6 received 200 U/kg body weight C1-INH (group 3), 25 mg/kg r-SP-C surfactant (group 4) or both (group 5) at 60 min postlavage (pl). Animals of group 6 were treated with 200 U/kg C1-INH1 at 10 min pl. Animals of group 1 were killed 60 min (min) pl, animals of groups 2-6 were killed at 210 min pl. Thereafter the lungs were excised for histological examination. MEASUREMENTS AND RESULTS: Hyaline membrane formation, intra-alveolar neutrophil (PMN) accumulation and intra-alveolar/perivascular haemorrhage were graded semiquantitatively (0-4). Blood gases were determined 120, 150, 180 and 210 min pl. At 210 min pl pO(2) in group 4 (456+/-74 mmHg) and group 5 (387+/-155 mmHg) was significantly higher than in controls (72+/-29 mmHg) or after C1-INH monotherapy (group 3: 120+/-103, group 6: 63+/-12 mmHg). PMN infiltration after C1-INH monotherapy was significantly less severe than in controls. The combination of r-SP-C surfactant and C1-INH led to significantly lower PMN infiltration than surfactant monotherapy. CONCLUSION: In this lavage-induced acute respiratory distress syndrome model the administration of C1-INH might be followed by a higher clinical efficacy of exogenously supplied recombinant SP-C surfactant.     

贯叶连翘提取物对百草枯诱导肺纤维化保护作用的实验研究

目的：探讨贯叶连翘提取物对百草枯诱导的大鼠肺纤维化模型的干预作用及机制。方法：20只Sprague-dawly大鼠随机等分为4组：百草枯组,贯叶连翘提取物组,百草枯＋贯叶连翘提取物组和对照组。百草枯液按80 mg/kg一次性灌胃,贯叶连翘提取物按400 mg/kg灌胃,连用3 d,对照组仅用生理盐水。于21 d处死后取肺脏行HE染色鉴定,并用碱水解法测羟脯氨酸含量,同时以八木国夫荧光法测定肺组织脂质过氧化产物,盐酸羟胺法测定组织总超氧化物歧化酶的酶活力。结果：百草枯染毒动物可致肺纤维化,羟脯氨酸和丙二醛含量明显增高。百草枯＋贯叶连翘提取物组与百草枯组比较,第21天时肺纤维化减轻,羟脯氨酸和丙二醛含量减少（P〈0.05）,与对照组相比总超氧化物歧化酶无明显变化（P〉0.05）。结论：贯叶连翘提取物对百草枯诱导的大鼠肺纤维化模型有抑制作用,其机制可能与抑制脂质过氧化有关。     

甲泼尼龙联合环孢素A对百草枯中毒的防治

目的 在建立百草枯(paraquat,PQ)中毒致肺纤维化大鼠模型的基础上,探讨早期大剂量甲泼尼龙联合环孢素A治疗对PQ中毒大鼠肺组织病理变化、氧化一抗氧化指标和肺纤维化特异性指标的影响,以判断疗效.方法 (1)PQ中毒致肺纤维化大鼠模型的建立:40只雄性Wistar大鼠随机(随机数字法)分为5组,分别采用20 mg/kg,25 mg/kg,30 mg,/kg,35mg/kg和40 mg/kg5个PQ剂量水平进行染毒.计算各组大鼠的两周死亡率及观察肺组织病理形态学变化.以肺组织病理表现为纤维化、死亡率在可接受范围之内作为模型染毒剂量,并以生化指标验证.(2)甲泼尼龙联合环孢素A对PQ中毒大鼠肺纤维化的疗效观察:72只雄性Wistar大鼠随机分为正常对照组(8只)、模型组(16只)、药物干预组(48只)3组.正常对照组注射25 mg/kg生理盐水;其余组PQ 25 mg/kg染毒.药物干预组再随机分为3组(每组16只),分别于染毒后2 h,24 h,72 h三个时间点单次应用甲泼尼龙(90 mg/kg)联合环孢素A(22.5 mg/kg).染毒后7 d,14 d观察大鼠肺组织病理变化,采用碱水解法、黄嘌呤氧化酶法和硫代巴比妥酸法分别测定肺组织超氧化物歧化酶(SOD)、丙二醛(MDA)和羟脯氨酸(HPY)的含量.组间比较采用两因素析因设计的方差分析,组内比较采用单因素3水平设计的方差分析.结果 25 mg/kg为肺纤维化大鼠模型的PQ染毒剂量.与模型组比较,各药物干预组大鼠肺组织肺泡数量明显增多,成纤维细胞增生程度较轻,胶原及纤维含量较少.与模型组比较,各药物干预组大鼠肺组织SOD含最增加,HPY和NDA含量明显降低(P＜0.05或P＜0.01).与72 h药物干预组比较,2 h,24 h药物干预组大鼠肺组织成纤维细胞增生程度较轻,胶原、纤维较少,肺组织SOD含量明显升高(P＜0.05或P＜0.01),MDA含量明显降低(P＜0.01).结论 早期联合应用大剂量甲泼尼龙和环孢素A治疗PQ中毒大鼠,可以显著减轻PQ中毒所致的肺组织氧化损伤和肺纤维化程度,改善预后.     

中性粒细胞趋化因子在大鼠早期急性肺损伤肺组织中的动态变化

目的建立大鼠急性肺损伤(ALI)模型,检测肺组织中性粒细胞趋化因子(CINC)的动态变化,探讨CINC与急性肺损伤发病的关系。方法48只SD大鼠随机分为急性肺损伤组(ALI组)和正常对照组(NC组)。通过腹腔注射脂多糖(LPS,3 mg/kg)建立急性肺损伤模型。用免疫组织化学法和半定量RT-PCR分别检测CINC蛋白及其mRNA在造模后1、2和6 h肺组织中的表达变化。结果CINC在急性肺损伤组肺组织中表达明显高于正常对照组;正常肺组织中有微量CINC mR-NA表达,给药2 h后迅速上升,至6 h时其表达进一步增强(P<0.001)。而在正常组CINC的蛋白和基因水平表达均不明显。结论CINC在急性肺损伤中扮演重要的角色,参与急性肺损伤早期发病过程。     

Elucidation of the early events contributing to zymosan-induced multiple organ dysfunction syndrome using MIP-1alpha, C3 knockout, and C5-deficient mice

Using a zymosan-induced mouse model of multiple organ dysfunction syndrome (MODS), it has been shown that the absence of MIP-1alpha increased mortality fourfold, whereas the absence of C5 decreased mortality fourfold. The purpose of the present study was to determine the early events following zymosan injection in MIP-1alpha knockout and C5-deficient mice. B10.D2/nSnJ (C5-sufficient) and B10.D2/0SnJ (C5-deficient) and genetically matched MIP-1alpha +/+ and MIP-1alpha -/- mice were divided into 3 groups: Group1 received no injection, Group 2 received intraperitoneal saline injection (1.0 mL), and Group 3 were given intraperitoneal zymosan (1 mg/gm, 1.0 mL). Two hours, 24 h, and 48 h after injection, peritoneal exudate leukocyte counts, total WBC count, lung MPO levels, and organ histology were examined for signs of changes in cellular infiltration. An acute local and systemic inflammatory response characterized by an increase in the peritoneal leukocyte count, total WBC counts, and circulating neutrophil levels was observed within 2-48 h of zymosan injection. Lack of MIP-1alpha attenuated local recruitment of phagocytes into the peritoneal cavity, and absence of MIP-1alpha or C5 caused a decrease in circulating neutrophil levels. The presence or absence of either C5 or MIP-1alpha did not affect early pulmonary neutrophil sequestration. Organ histopathology suggested early neutrophil infiltration in the lung and spleen within 48 h. These studies indicate that MIP-1alpha and C5 play a critical role in modulating cellular changes associated with lethality in a zymosan model of MODS.     

线粒体ATP敏感钾通道开放剂对大鼠肺缺血-再灌注损伤的保护作用

目的 探讨线粒体ATP敏感钾通道开放剂二氮嗪(DE)对肺缺血-再灌注损伤(I/R)的保护作用.方法 建立大鼠肺I/R模型,随机设立假手术(sham)组、I/R组、DE组、线粒体ATP敏感钾通道阻断剂5-羟基葵酸(5-HD)组,每组10只,观察各组肺组织病理形态学变化,测定肺湿/干质量比,检测肺组织髓过氧化物酶(MPO)活性、丙二醛(MDA)含量及超氧化物歧化酶(SOD)活性.结果 与sham组比较,I/R组肺组织出现明显损伤性病理形态学变化,肺湿/干质量比明显增加(P<0.05),肺组织MPO活性显著增高、MDA含量显著增加和SOD活性显著降低(P<0.05).与I/R组比较,DE组肺组织损伤明显减轻,肺湿/干质量比降低(P<0.05),肺组织MPO活性降低、MDA含量减少、SOD活性增高(P< 0.05).5-HD组各观察指标与I/R组差异无统计学意义(P>0.05).结论 线粒体ATP敏感钾通道开放剂DE可通过抑制中性粒细胞聚集、减少自由基产生、增强抗氧化能力对大鼠肺缺血-再灌注损伤产生明显保护作用,该保护作用可被线粒体ATP敏感钾通道阻断剂5-HD所拮抗.     

Repeated pulse of methylprednisolone and cyclophosphamide with continuous dexamethasone therapy for patients with severe paraquat poisoning

OBJECTIVE: Paraquat is widely used in the world, and all treatments for paraquat poisoning have been unsuccessful. Many patients have died of paraquat poisoning in developing countries. A novel anti-inflammation method was developed to treat severe paraquat-poisoned patients with >50% to <90% predictive mortality: initial pulse therapy with methylprednisolone (1 g/day for 3 days) and cyclophosphamide (15 mg/kg/day for 2 days), followed by dexamethasone 20 mg/day until Pao2 was >11.5 kPa (80 mm Hg) and repeated pulse therapy with methylprednisolone (1 g/day for 3 days) and cyclophosphamide (15 mg/kg/day for 1 day), which was repeated if Pao2 was <8.64 kPa (60 mm Hg). DESIGN: Randomized controlled trial. SETTING: Academic medical center in Taiwan. PATIENTS: Twenty-three paraquat-poisoned patients with >50% and <90% predictive mortality assessed by plasma paraquat levels were prospectively and randomly assigned to the control and study groups at a proportion of 1:2. INTERVENTIONS: The control group received conventional therapy and the study group received the novel repeated pulse treatment with long-term steroid therapy. MEASUREMENTS AND MAIN RESULTS: We measured patient mortality during the study period. There was not a different distribution of basal variables between the two study groups. The mortality rate (85.7%, six of seven) of the control group was higher than that of the study group (31.3%, five of 16; p = .0272). CONCLUSIONS: The novel anti-inflammatory therapy reduces the mortality rate for patients with severe paraquat poisoning.     

Glucocorticoid suppresses neutrophil activation in ventilator-induced lung injury

OBJECTIVE: To investigate, in a rat model, the role of the Mac-1/ICAM-1 pathway and the anti-inflammatory activity of steroid in ventilator-induced lung injury. DESIGN: Prospective, randomized controlled study. SETTING: Animal investigation using Wistar rats. INTERVENTION: Rats in three randomly assigned groups of 18, a total of 54 animals, were subject to the following: Two groups received high peak inspiratory pressure (35 cm H2O) ventilation after pretreatment with methylprednisolone (high-methylprednisolone group) or pretreatment with methylprednisolone vehicle (high-vehicle group). The third group of animals received low peak inspiratory pressure (7 cm H2O) ventilation after pretreatment with methylprednisolone vehicle (low-vehicle group). Except for animals previously killed to establish baseline values, after 40 mins of mechanical ventilation, the animals in each group were killed. Some animals provided histological samples, and the rest received total lung lavage. MEASUREMENT: We measured flow cytometry of lavage fluid, cell counts of tissue samples, and pressure-volume curves before and after mechanical ventilation. RESULTS: In the groups that received high peak inspiratory pressure ventilation, both the number of neutrophils that infiltrated the lungs and the expression of Mac-1 and ICAM-1 on neutrophils and macrophages increased significantly more than in the low-vehicle group. Static lung compliance was reduced in the high peak inspiratory pressure groups. In the high peak inspiratory pressure groups, there were significantly fewer neutrophils in samples from the high-methylprednisolone group (0.412 +/- 0.1 x 10(5)) than from the high-vehicle group (1.10 +/- 0.1 x 10(5); p < .05). The high-vehicle group showed greater expression of CD11b on neutrophils, but this was significantly decreased by methylprednisolone (mean fluorescence intensity: high-vehicle, 118.4 +/- 34.3; high-methylprednisolone, 25.8 +/- 4.2; p < .05). The lung mechanics measured by pressure-volume curve analysis were deteriorated less in the high-methylprednisolone group. CONCLUSION: Our study suggests that a neutrophil-endothelium interaction via the Mac-1/ICAM-1 pathway is involved in the activation and recruitment of neutrophils in ventilator-induced lung injury. Activation and recruitment of neutrophils were lessened by pretreatment with methylprednisolone, which might have contributed to the improvement of lung dysfunction after mechanical ventilation.     

褪黑素对急性百草枯中毒大鼠的治疗效果

目的 观察褪黑素(MT)对急性百草枯(PQ)中毒大鼠的治疗效果.方法 选择成年SD大鼠54只,随机分为正常对照组、染毒组和治疗组(每组18只).正常对照组用生理盐水灌胃,染毒组用PQ一次性灌胃(50 mg/kg)染毒,治疗组在染毒后随即腹腔注入MT 10 mg/kg,1次/d.分别于1d、3 d和7 d测定3组大鼠血清中丙二醛(MDA)含量及超氧化物歧化酶(SOD)、谷胱甘肽过氧化物酶(GSH-Px)的活力,并观察大鼠中毒表现及肺组织病理改变.结果 PQ染毒后大鼠血清中MDA含量显著高于对照组(P＜0.01);而血清SOD及GSH-Px活力明显低于对照组(P＜0.05).与染毒组比较,治疗组大鼠血清MDA含量下降;GSH-Px和SOD活力逐渐升高,差异具有统计学意义(P＜0.05).其中毒表现及肺组织病理学改变均明显减轻.结论 MT可减轻急性PQ中毒引起的脂质过氧化反应,改善大鼠的中毒症状.     

胞磷胆碱对大鼠脊髓损伤的神经保护性作用

目的:观察胞磷胆碱对大鼠脊髓损伤(SCI)的神经保护作用。方法:成年SD大鼠72只随机分为对照组、甲基强的松龙(MP)组、胞磷胆碱组及联合组,各组18只;造模后即刻腹腔注射给药1次,对照组给予等量生理盐水,MP组给予30mg/kg MP,胞磷胆碱组给予40mg/kg胞磷胆碱,联合组给予30mg/kg MP及40mg/kg胞磷胆碱;伤后8、24及72h每组各处死6只大鼠取材;HE染色观察脊髓组织的病理学变化,免疫组织化学方法观察半胱天冬氨酸酶(Caspase)-3和环氧化酶(COX)-2表达变化情况,DNA原位末端缺口标记法(TUNEL)检测神经细胞凋亡。结果:与对照组相比,MP组、胞磷胆碱组及联合组脊髓组织病理学改变明显减轻,Caspase-3和COX-2表达降低(P<0.05),凋亡细胞减少(P<0.05),MP组、胞磷胆碱组及联合组各组之间差异无统计学意义。结论:胞磷胆碱对大鼠SCI有神经保护性作用,与MP疗效相似,两者的联合应用与单独用药相比未见明显优势。     

Response to exogenous surfactant is different during open lung and conventional ventilation

OBJECTIVE: Previous studies have shown that the efficacy of exogenous surfactant is dose-dependent during conventional positive pressure ventilation (PPVCON). The present study aimed to determine whether this dose-dependent relationship is also present during open lung (OLC) ventilation. We also explored the effect of exogenous surfactant on the ventilation pressures applied during ventilation. DESIGN: Animal study. SETTING: University-affiliated research laboratory. SUBJECTS: Seventy-two newborn piglets. INTERVENTIONS: After repeated whole lung lavage, animals were randomly allocated to two surfactant groups receiving either 100 mg/kg surfactant (S100) or 25 mg/kg surfactant (S25) or to a control group receiving a bolus of air. Within each group, animals were randomly assigned to either PPVCON, open lung PPV (PPVOLC), or open lung high-frequency oscillatory ventilation (HFOVOLC) and ventilated for 5 hrs. MEASUREMENTS AND MAIN RESULTS: The ventilation pressures decreased in a dose-dependent way, showing the largest reduction in the S100 group. In both OLC groups, oxygenation, lung mechanics, and polymorphonuclear neutrophils analyzed in bronchoalveolar lavage were independent of the surfactant dose. In the PPVCON group, however, there was a clear dose-dependency, resulting in a deterioration of oxygenation and lung mechanics and an increase in polymorphonuclear neutrophils as the surfactant dose decreased. Although comparable between the three ventilation groups, bronchoalveolar lavage interleukin-8 concentrations significantly increased in all ventilation groups as the surfactant dose increased. Alveolar protein influx and conversion of large to small aggregate surfactant were higher during PPVCON compared with both OLC groups. There were no differences in the surfactant treatment response between PPVOLC and HFOVOLC. CONCLUSION: Exogenous surfactant enables a reduction in ventilation pressures. Compared with PPVCON, the efficacy of surfactant treatment is less dose-dependent during open lung ventilation. Surfactant conversion during open lung ventilation is reduced compared with PPVCON. Exogenous surfactant seems to up-regulate bronchoalveolar lavage interleukin-8 concentrations, independent of the ventilation strategy.     

血必净对急性百草枯中毒大鼠肺病理改变的作用研究

目的通过研究血必净对急性百草枯（paraquat,PQ）中毒大鼠肺病理学改变的作用,探讨血必净对PQ中毒大鼠的肺损伤是否具有保护作用。方法取sD大鼠72只,随机分为3组：中毒组、血必净组、正常对照组。中毒组及血必净组用百草枯120mg／kg灌胃,一次性染毒;血必净组从染毒后2小时开始,腹腔内注射血必净10ml／kg,每日一次,至处死前;中毒组及正常对照组用等体积无菌生理盐水腹腔内注射,每日一次,至处死前。分3个不同时间点（6、24、72小时）处死大鼠（每组每个时间点8只）并取肺组织。制备标本后分别在光镜及电镜下观察各组各时间点肺组织的病理学改变。结果中毒组大鼠肺的病理学改变为急性弥漫性肺损伤,表现为肺泡腔内出血、渗出、炎性细胞浸润,肺泡隔炎性细胞浸润及纤维组织增生,Ⅰ型和Ⅱ型上皮细胞坏死脱落。血必净组的病理学改变为局灶性肺泡隔少量炎性细胞浸润,而Ⅰ型上皮细胞完整,Ⅱ型上皮细胞也无明显损伤,未见纤维组织增生。结论从病理学角度观察,血必净对PQ中毒大鼠的肺损伤具有保护作用。     

乌司他丁对急性百草枯中毒大鼠肺病理改变的作用研究

目的通过研究乌司他丁（utinastatin,UTI）对急性百草枯（paraquat,PQ）中毒大鼠肺病理学改变的作用研究,探讨乌司他丁对PQ中毒大鼠的肺损伤是否具有保护作用。方法取SD大鼠72只,随机均分为三组,中毒组、乌司他丁组和正常对照组。中毒组及乌司他丁组用百草枯120mg/kg灌胃,一次性染毒;乌司他丁组从染毒后2h开始,腹腔内注射乌司他丁7.5万U/kg,1次/d,至处死前;中毒组及正常对照组用等体积无菌生理盐水腹腔内注射,1次/d,至处死前。分三个不同时间点（6、24、72h）处死大鼠（每组每个时间点8只）,并取肺组织制备标本后分别在光镜及电镜下观察肺组织的病理学改变。结果中毒组大鼠肺的病理学改变为急性弥漫性肺损伤,表现为肺泡腔内出血、渗出,炎性细胞浸润、肺泡隔炎性细胞浸润及纤维组织增生,Ⅰ型和Ⅱ型上皮细胞坏死脱落;乌司他丁组大鼠的病理学改变为局灶性肺泡隔少量炎性细胞浸润,而Ⅰ型上皮细胞完整,Ⅱ型上皮细胞也无明显损伤,未见纤维组织增生。结论从病理学角度观察,乌司他丁对百草枯中毒大鼠的肺损伤具有保护作用。     

Lidocaine attenuates acute lung injury induced by a combination of phospholipase A2 and trypsin

OBJECTIVE: Acute severe pancreatitis is often associated with acute lung injury, including acute respiratory distress syndrome. Acute lung injury induced by phospholipase A2 (PLA2) or trypsin, a pancreatic enzyme, is an experimental model resembling acute respiratory distress syndrome. Neutrophils and platelets are thought to play a pivotal role in the pathogenesis of acute respiratory failure. Lidocaine inhibits some aspects of neutrophil and platelet functions. We conducted the current study to assess the effects of pretreatment with lidocaine on acute lung injury induced by a combination of PLA2 and trypsin. DESIGN: Prospective, randomized animal study. SETTING: University research laboratory. SUBJECTS: Twenty-one adult male Japanese White rabbits (weight range, 2.0-2.4 kg). INTERVENTIONS: The animals were mechanically ventilated with a tidal volume of 10 mL/kg and an Fio2 of 0.4, and thereafter, they were randomly assigned to three groups. Acute lung injury was induced by a combination of PLA2 (1000 units/kg/hr) and trypsin (5000 units/kg/hr) infused intravenously for 4 hrs. Immediately before induction of the acute lung injury, the lidocaine treatment group received intravenous lidocaine (2 mg/kg bolus followed by 2 mg/kg/hr) until they were killed. In the nontreatment group, saline was given instead of lidocaine. Rabbits in the nonlung-injury group received saline infusion instead of the pancreatic enzymes. MEASUREMENTS AND MAIN RESULTS: During the experimental period (4 hrs), arterial blood gases, lung mechanics, and peripheral neutrophil and platelet counts were measured. Immediately after killing, the wet weight/dry weight ratio of the lung was recorded. Light microscopic findings (lung injury score and number of neutrophils) were compared between the three groups. The combination of PLA2 and trypsin decreased Pao2, lung compliance, and peripheral counts of neutrophils and platelets and increased alveolar/arterial oxygen tension difference, lung resistance, wet weight/dry weight ratio, and the number of neutrophils in the lung. Lidocaine treatment attenuated these changes. The two pancreatic enzymes caused extensive morphologic lung damage, which was lessened by lidocaine. CONCLUSIONS: We conclude that pretreatment with intravenous lidocaine attenuated the lung injury induced by the pancreatic enzymes. However, further studies are required to determine whether this drug has a therapeutic effect once the lung injury has developed.