脓毒症相关性急性肺损伤发病机制研究进展

急性肺损伤/急性呼吸窘迫综合征（ALI/ARDS）是临床上常见的危重病之一,病因多、影响因素复杂、救治困难,病死率高。脓毒症是危重病最主要的死亡原因,也是引起ALI/ARDS的最常见的病因,尽管对脓毒症致ALI/ARDS的机制研究较多,其确切机制尚不完全清楚。本文就脓毒症致急性肺损伤的发病机制进行综述。     

Therapeutic inhibition of CXCR2 by Reparixin attenuates acute lung injury in mice

Background and purpose:

Acute lung injury (ALI) remains a major challenge in critical care medicine. Both neutrophils and chemokines have been proposed as key components in the development of ALI. The main chemokine receptor on neutrophils is CXCR2, which regulates neutrophil recruitment and vascular permeability, but no small molecule CXCR2 inhibitor has been demonstrated to be effective in ALI or animal models of ALI. To investigate the functional relevance of the CXCR2 inhibitor Reparixin in vivo, we determined its effects in two models of ALI, induced by either lipopolysaccharide (LPS) inhalation or acid instillation.

Experimental approach:

In two ALI models in mice, we measured vascular permeability by Evans blue and evaluated neutrophil recruitment into the lung vasculature, interstitium and airspace by flow cytometry.

Key results:

Pharmacological inhibition of CXCR2 by Reparixin reduced CXCL1-induced leukocyte arrest in the microcirculation of the cremaster muscle, but did not influence arrest in response to leukotriene B₄ (LTB₄) demonstrating specificity. Reparixin (15 μg g⁻¹) reduced neutrophil recruitment in the lung by approximately 50% in a model of LPS-induced ALI. A higher dose did not provide additional reduction of neutrophil recruitment. This dose also reduced accumulation of neutrophils in the interstitial compartment and vascular permeability in LPS-induced ALI. Furthermore, both prophylactic and therapeutic application of Reparixin improved gas exchange, and reduced neutrophil recruitment and vascular permeability in a clinically relevant model of acid-induced ALI.

Conclusions and implications:

Reparixin, a non-competitive allosteric CXCR2 inhibitor attenuates ALI by reducing neutrophil recruitment and vascular permeability.     

N-acetylcysteine abrogates acute lung injury induced by endotoxin

1. Acute lung injury (ALI) or acute respiratory distress syndrome is a serious clinical problem with high mortality. N-Acetylcysteine (NAC) is an anti-oxidant and a free radical scavenger. It has been reported recently that NAC ameliorates organ damage induced by endotoxin (lipopolysaccharide; LPS) in conscious rats. The present study was designed to evaluate the effects of NAC on LPS-induced ALI and other changes in anaesthetized rats. 2. Sprague-Dawley rats were anaesthetized with pentobarbital (40 mg/kg, i.p.). Endotracheal intubation was performed to provide artificial ventilation. Arterial pressure and heart rate were monitored. The extent of ALI was evaluated with the lung weight (LW)/bodyweight ratio, LW gain, exhaled nitric oxide (NO) and protein concentration in bronchoalveolar lavage (PCBAL). Haematocrit, white blood cells, plasma nitrate/nitrite, methyl guanidine (MG), tumour necrosis factor (TNF)-alpha and interleukin (IL)-1b were measured. Pathological changes in the lung were examined and evaluated. 3. Endotoxaemia was produced by injection of 10 mg/kg, i.v., LPS (Escherichia coli). Animals were randomly divided into three groups. In the vehicle group, rats received an i.v. drip of physiological saline solution (PSS) at a rate of 0.3 mL/h. The LPS group received an i.v. drip of PSS for 1 h, followed by LPS (10 mg/kg by slow blous injection, i.v., over 1-2 min). Rats in the LPS + NAC group received NAC by i.v. drip at a rate of 150 mg/kg per h (0.3 mL/h) for 60 min starting 10 min before LPS administration (10 mg/kg by slow blous injection, i.v., over 1-2 min). Each group was observed for a period of 6 h. 4. N-Acetylcysteine treatment improved the LPS-induced hypotension and leukocytopenia. It also reduced the extent of ALI, as evidenced by reductions in LW changes, exhaled NO, PCBAL and lung pathology. In addition, NAC diminished the LPS-induced increases in nitrate/nitrite, MG, TNF-a and IL-1b. 5. In another series of experiments, LPS increased the mortality rate compared with the vehicle group (i.v. drip of PSS at a rate of 0.3 mL/h) during a 6 h observation period. N-Acetylcysteine, given 10 min prior to LPS, significantly increased the survival rate. 6. The results of the present study suggest that NAC exerts a protective effect on the LPS-induced ALI. The mechanisms of action may be mediated through the reduction of the production of NO, free radicals and pro-inflammatory cytokines.     

Endothelial pathomechanisms in acute lung injury

Acute lung injury (ALI) and its most severe extreme the acute respiratory distress syndrome (ARDS) refer to increased-permeability pulmonary edema caused by a variety of pulmonary or systemic insults. ALI and in particular ARDS, are usually accompanied by refractory hypoxemia and the need for mechanical ventilation. In most cases, an exaggerated inflammatory and pro-thrombotic reaction to an initial stimulus, such as systemic infection, elicits disruption of the alveolo-capillary membrane and vascular fluid leak. The pulmonary endothelium is a major metabolic organ promoting adequate pulmonary and systemic vascular homeostasis, and a main target of circulating cells and humoral mediators under injury; pulmonary endothelium is therefore critically involved in the pathogenesis of ALI. In this review we will discuss mechanisms of pulmonary endothelial dysfunction and edema generation in the lung with special emphasis on the interplay between the endothelium, the immune and hemostatic systems, and highlight how these principles apply in the context of defined disorders and specific insults implicated in ALI pathogenesis.     

Potential clinical application of KGF-2 (FGF-10) for acute lung injury/acute respiratory distress syndrome

Acute lung injury (ALI)/acute respiratory distress syndrome (ARDS) is an acute life-threatening form of hypoxemic respiratory failure with a high mortality rate, and there is still a great need for more effective therapies for such a severe and lethal disease. Dysfunction of endothelial and epithelial barriers is one of the most important mechanisms in hypoxia-associated ALI/ARDS. The acceleration of the epithelial repair process in the injured lung may provide an effective therapeutic target. KGF-2, a potent alveolar epithelial cell mitogen, plays an important role in organ morphogenesis and epithelial differentiation, and modulates a variety of mechanisms recognized to be important in alveolar repair and resolution in ALI/ARDS. Preclinical and clinical studies have suggested that KGF-2 may be the candidate of novel therapies for alveolar epithelial damage during ALI/ARDS.     

Calpain-2 as a therapeutic target for acute neuronal injury

Introduction: Calpains represent a family of neutral, calcium-dependent proteases, which modify the function of their target proteins by partial truncation. These proteases have been implicated in numerous cell functions, including cell division, proliferation, migration, and death. In the CNS, where calpain-1 and calpain-2 are the main calpain isoforms, their activation has been linked to synaptic plasticity as well as to neurodegeneration. This review will focus on the role of calpain-2 in acute neuronal injury and discuss the possibility of developing selective calpain-2 inhibitors for therapeutic purposes.

Areas covered: This review covers the literature showing how calpain-2 is implicated in neuronal death in a number of pathological conditions. The possibility of developing new selective calpain-2 inhibitors for treating these conditions is discussed.

Expert opinion: As evidence accumulates that calpain-2 activation participates in acute neuronal injury, there is interest in developing therapeutic approaches using selective calpain-2 inhibitors. Recent data indicate the potential use of such inhibitors in various pathologies associated with acute neuronal death. The possibility of extending the use of such inhibitors to more chronic forms of neurodegeneration is discussed.     

Evolution of treatments for patients with acute lung injury

Acute lung injury (ALI) and acute respiratory distress syndrome (ARDS) are acute life-threatening forms of hypoxemic respiratory failure. ALI/ARDS patients require intensive care with prolonged mechanical ventilation. Despite advances in our understanding of the pathophysiology of ALI/ARDS, mortality rates remain > 30% and survivors suffer significant decrements in their quality of life. The evolving understanding of ALI/ARDS and the complex interactions involved in ALI/ARDS open the door for many potential targets for treatment. The condition is characterised by an acute inflammatory state that leads to increased capillary permeability and accumulation of proteinaceous pulmonary oedema. The changes that occur as a result of this inflammation clinically manifest themselves as hypoxemia, infiltrates on chest radiograph and reduced lung compliance. Many years have been dedicated to analysing the complexities involved in ALI/ARDS in order to improve current and future possibilities for treatment, with the aim of improving patient outcomes. Although some therapies have demonstrated benefits of improved oxygenation, such as surfactant and nitric oxide, these benefits have not translated into reductions in the duration of mechanical ventilation or mortality. Inflammatory mediator-targeted therapies were promising early on; however, larger trials have found therapies such as cytokine modulation, platelet-activating factor inhibition and neutrophil elastase inhibitors to be ineffective in the treatment of ALI/ARDS. Preclinical studies with β2-agonists and granulocyte macrophage colony-stimulating factor have shown promise for restoring alveolar capillary barrier integrity or reducing pulmonary oedema, and further studies are being conducted to test for true clinical benefit. Despite previous therapeutic failures, newer surfactant formulations have shown promise, particularly in patients with direct forms of lung injury, and are currently in Phase III trials. Anticoagulant therapy with activated protein C has been shown to improve survival in sepsis, the most common risk factor for the development of ALI/ARDS, and is now being studied in ALI/ARDS. Until new data emerge, the focus must remain on supportive care, including optimised mechanical ventilation, nutritional support, manipulation of fluid balance and prevention of intervening medical complications.     

炎调方对脓毒症急性肺损伤大鼠肺组织髓过氧化物酶和丙二醛水平的影响

目的 观察炎调方对脓毒症急性肺损伤(ALI)大鼠肺组织髓过氧化物酶(MPO)、丙二醛(MDA)水平的影响。方法 清洁级健康雄性SD大鼠随机分为对照组、假手术组、模型组、炎调方组、地塞米松组,炎调方组ig 9.9 g/kg炎调方,地塞米松组ig 0.45 mg/kg地塞米松,每天给药1次,连续给药3 d。末次ig 2 h后采用盲肠结扎穿孔术(CLP)制备脓毒症ALI模型,分别于造模后24 h处死动物,进行肺组织HE染色,测定各组大鼠湿/干重比(W/D),肺组织MPO、MDA水平。结果 模型组大鼠肺组织损伤程度、MPO及MDA水平较对照组及假手术组显著增高(P<0.01),炎调方组、地塞米松组肺组织损伤程度、MPO及MDA水平较模型组显著降低(P<0.05、0.01)。结论 炎调方可有效减轻脓毒症ALI大鼠的炎症及氧化应激反应。     

王不留行黄酮苷对脓毒症小鼠急性肺损伤保护作用及机制研究

目的 基于网络药理学和动物实验探究王不留行黄酮苷（VAC）对脓毒症小鼠急性肺损伤的保护作用机制。方法 通过 Swiss Target Prediction数据库收集 VAC的潜在作用靶点;利用 GeneCards数据库检索肺脓毒症相关的疾病靶点;运用Draw Venn Diagram 软件构建 VAC 和疾病的共同靶点;利用 STRING 11.5数据库和 Cytoscape 3.10.0软件构建共同靶点蛋白质-蛋白质相互作用（PPI）网络;利用 Metascape 数据库进行基因本体（GO）富集分析和京都基因与基因组百科全书（KEGG）通路分析。采用 ip 给予脂多糖（LPS）构建脓毒症模型,造模同时给予 VAC（1、5 mg·kg^-1）或地塞米松干预,取各组小鼠肺组织及血清,苏木精-伊红（HE）、Masson 及 TUNEL 染色观察肺组织形态变化、纤维化及细胞凋亡情况,ELISA 法和实时荧光定量 PCR（qRT-PCR）法分别检测血清和肺组织中炎症因子水平,免疫组织化学法和 Western blotting法检测肺组织炎症通路相关蛋白表达。结果 VAC和肺脓毒症共同靶点有44个;GO富集分析涉及生物过程（BP）823个条目、细胞组分（CC）52个条目和分子功能（MF）49个条目;KEGG分析筛选出癌症通路、PI3K-Akt、JAK-STAT信号通路等 20 条信号通路。验证实验结果显示,与对照组相比,模型组小鼠肺组织损伤且纤维化严重,肺脏指数显著增加（P＜0.05）,血清及肺组织中相关炎症因子表达升高（P＜0.01、0.001）。与模型组相比,VAC及地塞米松组肺组织病理形态得到改善,纤维化程度减轻,肺脏指数显著降低（P＜0.05）,血清中肿瘤坏死因子（TNF-α）、白细胞介素-1β（IL-1β）、白细胞介素6（IL-6）水平、肺组织炎症蛋白表达量及细胞凋亡数量降低,PI3K、Akt蛋白表达升高（P＜0.05、0.01、0.001）。动物实验结果与网络药理学结果一致。结论 VAC 对脓毒症小鼠急性肺损伤具有一定的保护作用,其机制可能与调控 PI3K-Akt、NLRP3/TNF-α等通路抑制炎症的发展有关,为VAC抗炎作用机制的深入研究提供了依据。     

Inhibition of CD8+ T cells and elimination of myeloid cells by CD4+ Foxp3− T regulatory type 1 cells in acute respiratory distress syndrome

Acute lung injury and acute respiratory distress syndrome (ARDS) are caused by rapid‐onset bilateral pulmonary inflammation. We therefore investigated the potential role of interleukin (IL)‐10⁺CD4⁺ Tr1 cells, a regulatory T cell subset with previously identified immunosuppressive functions, in ARDS patients. We first showed that circulating Tr1 cells were upregulated in active and resolved ARDS patients compared to healthy controls and pneumonia patient controls. A significant fraction of these Tr1 cells expressed granzyme B and perforin, while most Tr1 cells did not express interferon gamma (IFN‐γ), IL‐4, IL‐17 or FOXP3, suggesting that the effector functions of these Tr1 cells were primarily mediated by IL‐10, granzyme B, and perforin. Indeed, Tr1 cells effectively suppressed CD8⁺ T cell IFN‐γ production and induced lysis of monocytes and dendritic cells in vitro. The elimination of myeloid antigen‐presenting cells depended on granzyme B production. We also discovered that Tr1 cells could be identified in the bronchoalveolar lavage fluid collected from ARDS patients. All these results suggested that Tr1 cells possessed the capacity to downregulate inflammation in ARDS. In support of this, we found that ARDS patients who resolved the inflammation and survived the syndrome contained significantly higher levels of Tr1 cells than ARDS patients who succumbed to the syndrome. Overall, this report added a novel piece of evidence that ARDS could be intervened by regulatory T cell‐mediated suppressive mechanisms.     

Characterization of a double‐hit murine model of acute respiratory distress syndrome

The aim of the present study was to characterize a murine model of acute respiratory distress syndrome (ARDS) abiding by the Berlin definition of human ARDS and guidelines for animal models of ARDS. To this end, C57BL/6NCrl mice were challenged with lipopolysaccharide (LPS; 15 mg/kg, i.p.) followed 18 h later by injection of oleic acid (OA; 0.12 mL/kg, i.v.). Controls received saline injection at both time points. Haemodynamics were monitored continuously. Arterial blood gas analyses were performed just before and every 30 min after OA challenge. Ninety minutes after OA challenge, the chest of mice was scanned using micro‐computed tomography (CT). Cytokine concentrations were measured in plasma samples. Lungs were harvested 90 min after OA challenge for histology, immunohistochemistry, lung weight measurements and tissue cytokine detection. A histological lung injury score was determined. Eighteen hours after LPS challenge, mice exhibited a severe systemic inflammatory response syndrome. Oxygenation declined significantly after OA injections (P_ao ₂/F_io ₂ 283 ± 73 and 256 ± 71 mmHg at 60 and 90 min, respectively; P < 0.001). Bilateral patchy infiltrates were present on the micro‐CT scans. Histology revealed parenchymal damage with accumulation of polymorphonuclear neutrophils, intra‐alveolar proteinacous debris and few hyaline membranes. The lung wet : dry ratio indicated damage to the alveolar capillary membrane. Cytokine patterns evidenced a severe local and systemic inflammatory state in plasma and lung tissue. In conclusion, the described two‐hit model of ARDS shows a pathological picture of ARDS closely mimicking human ARDS according to the Berlin definition and may facilitate interpretation of prospective experimental results.     

Partitioning lung and plasma proteins: circulating surfactant proteins as biomarkers of alveolocapillary permeability

1. The alveolocapillary membrane faces an extraordinary task in partitioning the plasma and lung hypophase proteins, with a surface area approximately 50-fold that of the body and only 0.1-0.2 micron thick. 2. Lung permeability is compromised under a variety of circumstances and the delineation between physiological and pathological changes in permeability is not always clear. Although the tight junctions of the epithelium, rather than the endothelium, are regarded as the major barrier to fluid and protein flux, it is becoming apparent that the permeability of both are dynamically regulated. 3. Whereas increased permeability and the flux of plasma proteins into the alveolar compartment has dire consequences, fortuitously the flux of surfactant proteins from the airspaces into the circulation may provide a sensitive means of non-invasively monitoring the lung, with important implications for treatment modalities. 4. Surfactant proteins are unique in that they are present in the alveolar hypophase in high concentrations. They diffuse down their vast concentration gradients (approximately 1:1500-7000) into the circulation in a manner that reflects lung function and injury score. Surfactant proteins vary markedly in size (approximately 20-650 kDa) and changes in the relative amounts appear particularly diagnostic with regard to disease severity. Alveolar levels of surfactant proteins remain remarkably constant despite respiratory disease and, unlike the flux of plasma proteins into the alveolus, which may reach equilibrium in acute lung injury, the flux of surfactant proteins is unidirectional because of the concentration gradient and because they are rapidly cleared from the circulation. 5. Ultimately, the diagnostic usefulness of surfactant proteins as markers of alveolocapillary permeability will demand a sound understanding of their kinetics through the vascular compartment.     

Pharmacological modulation of C‐X‐C motif chemokine receptor 4 influences development of acute respiratory distress syndrome after lung ischaemia–reperfusion injury

Activation of C‐X‐C motif chemokine receptor 4 (CXCR4) has been reported to result in lung protective effects in various experimental models. The effects of pharmacological CXCR4 modulation on the development of acute respiratory distress syndrome (ARDS) after lung injury, however, are unknown. Thus, we studied whether blockade and activation of CXCR4 influences development of ARDS in a unilateral lung ischaemia–reperfusion injury rat model. Anaesthetized, mechanically ventilated animals underwent right lung ischaemia (series 1, 30 minutes; series 2, 60 minutes) followed by reperfusion for 300 minutes. In series 1, animals were treated with vehicle or 0.7 μmol/kg of AMD3100 (CXCR4 antagonist) and in series 2 with vehicle, 0.7 or 3.5 μmol/kg ubiquitin (non‐cognate CXCR4 agonist) within 5 minutes of reperfusion. AMD3100 significantly reduced PaO₂/FiO₂ ratios, converted mild ARDS with vehicle treatment into moderate ARDS (PaO₂/FiO₂ ratio<200) and increased histological lung injury. Ubiquitin dose‐dependently increased PaO₂/FiO₂ ratios, converted moderate‐to‐severe into mild‐to‐moderate ARDS and reduced protein content of bronchoalveolar lavage fluid (BALF). Measurements of cytokine levels (TNFα, IL‐6, IL‐10) in lung homogenates and BALF showed that AMD3100 reduced IL‐10 levels in homogenates from post‐ischaemic lungs, whereas ubiquitin dose‐dependently increased IL‐10 levels in BALF from post‐ischaemic lungs. Our findings establish a cause‐effect relationship for the effects of pharmacological CXCR4 modulation on the development of ARDS after lung ischaemia–reperfusion injury. These data further suggest CXCR4 as a new drug target to reduce the incidence and attenuate the severity of ARDS after lung injury.     

microRNA-125b在脓毒症急性肺损伤中的表达及其与炎症因子水平相关性

摘要：目的探讨microRNA-125b（miR-125b）在脓毒症急性肺损伤中的表达及其与炎症因子的相关性。方法 腹腔注射脂多糖（LPS）诱导急性肺损伤大鼠模型,对照组注射等量的生理盐水（n=20）;各模型组（n=20）大鼠注射LPS 4、8、12及24 h后取其肺组织,HE染色观察病理学变化;PCR检测各组各时点肺组织中miR-125b、肿瘤坏死因子-α（TNF-α）与白细胞介素-6（IL-6）变化。Pearson相关性分析实验组肺组织中miR-125b的表达与TNF-α、IL-6水平的相关性。NR8383细胞培养后分组,对照组不进行LPS刺激,实验组加入LPS刺激4 h、8 h、12 h及24 h时收集细胞,检测各组miR-125b、TNF-α与IL-6的含量变化。另NR8383细胞设3组,阴性对照组只转染空表达质粒,miR-125b mimic组转染miR-125b mimic表达质粒,miR-125b inhibitor组转染miR-125b inhibitor质粒。PCR测各组细胞中miR-125b 表达情况,Western blot测Notch1的表达情况。结果LPS各处理组大鼠模型肺组织严重出血、水肿及大量炎症细胞浸润。与对照组比较,在注射LPS 4、8、12以24 h后,实验组大鼠肺组织中miR-125b显著降低;而肺组织中TNF-α与IL-6水平则升高,其中在LPS注射4 h后,TNF-α与IL-6的表达水平达到峰值（P＜0.05）。实验组肺组织中miR-125b的表达与TNF-α及IL-6呈负相关（r 分别为-0.599、-0.580;P＜0.05）。在LPS诱导的第4、8、12、24 h,实验组NR8383细胞系miR-125b表达水平均低于对照组,而TNF-α、IL-6的表达水平均高于对照组（P＜0.05）。与阴性对照组比较,miR-125b mimic组miR-125b 相对表达量升高、Notch1蛋白相对表达量则降低（P＜0.05）,miR-125binhibitor组miR-125b 相对表达量降低、Notch1蛋白相对表达量升高（P＜0.05）;与miR-125b mimic组比较,miR-125binhibitor组miR-125b 相对表达量降低、Notch1蛋白相对表达量升高（P＜0.05）。结论在脓毒症急性肺损伤中,microRNA-125b可能通过调控Notch1蛋白的表达,影响炎症因子TNF-α与IL-6的表达,参与其免疫炎症调控过程。     

L6H9 attenuates LPS-induced acute lung injury in rats through targeting MD2

Acute lung injury (ALI) is a clinical syndrome characterized by respiratory failure and acute inflammatory response. Myeloid differentiation protein 2 (MD2) has been reported to play a pivotal role in the recognition of LPS and LPS-mediates inflammatory response. There have been no clinically effective therapeutic drugs for ALI. L6H9, an inhibitor of MD2, showed anti-inflammatory effects and cardiac protective activity. However, its effect on ALI has not been elucidated. In this study, intratracheal instillation of LPS was employed to induce ALI in rats. L6H9 pretreatment attenuates LPS-induced pathological variations in lung tissue and pulmonary edema. LPS instillation enhanced lung microvascular permeability, thereby causing inflammatory cells flow into bronchoalveolar lavage fluid (BALF). However, L6H9 inhibited the LPS-induced upregulation of total protein concentration and the number of inflammatory cells in BALF. In the meantime, macrophages infiltration in lung tissue induced by LPS was also mitigated by L6H9 treatment. Furthermore, L6H9 suppressed LPS-induced inflammatory cytokines expression in BALF, serum, and lung tissue. It is noteworthy that LPS-induced MD2/TLR4 complex formation was inhibited by L6H9 in lung tissue. On the whole, these results show that L6H9 can attenuate LPS-induced ALI in vivo by targeting MD2. Our study provide new candidate for the treatment of ALI.     

血管紧张素转换酶2在SARS病理途径中的作用

人类严重急性呼吸综合征(SARS)相关冠状病毒(SARS-CoV)感染导致的严重急性呼吸系统病变,其临床肺部病理损害特征与急性肺损伤和急性呼吸窘迫病变相似。SARS-CoV可以结合人血管紧张素转换酶(ACE)2,二者结合效率与病毒感染复制能力相关。ACE2与ACE1共同调控肾素-血管紧张素系统,二者的功能平衡维持肺的正常功能。SARS-CoV感染时,其棘突蛋白与ACE2结合,下调人体ACE2水平,肺内ACE2和ACE1功能失衡,血管紧张素Ⅱ过度激活AT1受体,导致肺部毛细血管通透性增加,随之出现肺水肿和急性肺损伤。ACE2是SARS病理途径中的关键因子,在SARS临床治疗和SARS药物研制中有重要意义。     

血必净注射液治疗脓毒症伴轻度急性呼吸窘迫综合征疗效及对多配体蛋白聚糖-1和氧化应激指标的影响

目的 探讨血必净注射液对脓毒症伴轻度急性呼吸窘迫综合征（ARDS）患者的治疗效果及对多配体蛋白聚糖-1（SDC-1）和氧化应激相关指标的影响。方法 选取2021年1月—2022年9月河北医科大学哈励逊国际和平医院收治的84例脓毒症伴轻度ARDS患者,按照随机数字表法将患者分为对照组和试验组,每组各42例。对照组患者给予早期复苏、抗感染、营养支持及对症治疗。试验组在对照组基础上加用血必净注射液,每次取血必净注射液100 mL加0.9%氯化钠注射液100 mL,静脉滴注,每天2次,连续治疗3 d。分别于治疗前后,检测两组患者外周血C反应蛋白（CRP）、白细胞介素6（IL-6）、白细胞介素8（IL-8）、肿瘤坏死因子-α（TNF-α）、丙二醛（MDA）、超氧化物歧化酶（SOD）、透明质酸（HA）、SDC-1、硫酸乙酰肝素（HS）水平;比较两组治疗前后Murray肺损伤评分（MLIS）、全身性感染相关性器官功能衰竭（SOFA）评分、急性生理学及慢性健康状况Ⅱ（APACHE Ⅱ）评分,随访两组患者出院1个月生存情况。结果 试验组治疗总有效率（85.71%）高于对照组（66.67%）,两组差异有统计学意义（P<0.05）。治疗前,两组IL-8、IL-6、TNF-α、CRP、MDA、SOD、HA、SDC-1、HS比较,差异无统计学意义（P>0.05）。治疗后,两组IL-8、IL-6、TNF-α、CRP、MDA、HA、SDC-1、HS水平均较本组治疗前显著降低（P<0.05）,SOD较治疗前显著升高（P<0.05）;且试验组IL-8、IL-6、TNF-α、CRP、MDA、HA、SDC-1、HS水平较对照组明显降低（P<0.05）,SOD较对照组明显升高（P<0.05）。治疗前,两组SOFA、APACHE Ⅱ、MLIS评分均无显著差异（P>0.05）。治疗后,两组SOFA、APACHE Ⅱ、MLIS评分均较本组治疗前显著降低（P<0.05）,且试验组SOFA、APACHE Ⅱ、MLIS评分较对照组明显降低（P<0.05）。出院后1个月,试验组死亡率（30.95%）明显低于对照组（52.38%）,差异有统计学意义（P<0.05）。脓毒症伴轻度ARDS患者血管内皮糖萼（EG）降解物HA、SDC-1、HS水平与MLIS评分间呈正相关（r＝0.733,P=0.036;r＝0.831,P=0.011;r＝0.826,P=0.013）。受试者工作特征（ROC）曲线显示,SDC-1联合氧化应激指标检测对脓毒症伴轻度ARDS患者短期的预后预测价值更大。结论 血必净注射液通过减轻脓毒症伴轻度ARDS患者肺血管内皮EG的降解,明显缓解ARDS,有效改善患者短期预后。     

新型特异性磷脂酶A2抑制剂对急性胰腺炎肺损伤的疗效研究

目的探讨一种新型磷脂酶A2（PLA2）抑制剂对重症急性胰腺炎（SAP）并发急性肺损伤（ALI）的保护作用。方法24只Wistar大鼠随机分为3组：假手术组（SO组）、SAP模型组（SAP组）、抑制剂预处理组（抑制剂组）。采用5％牛磺胆酸钠逆行胰胆管注射的方法制备SAP模型,抑制剂组在术前30min经股静脉注射特异性PLA2抑制剂（5mg／kg）。3组于手术后12h处死大鼠并收集标本,测定3组血清淀粉酶、肺干湿比、大鼠血清和肺组织sPLA2活性,聚合酶链反应（PCR）法检测肺组织Ⅱ型分泌型PLA2抑制剂（sPLA2-ⅡA）mRNA的表达,光镜下观察胰腺和肺脏的病理变化并计算病理评分。结果SAP组血清淀粉酶、肺干湿比、血清和肺组织sPLA2-ⅡA、肺组织sPLA2-ⅡA mRNA表达、胰腺和肺组织病理评分明显高于其他2组（P〈0．01）;抑制剂组上述指标均低于SAP组（P〈0．01）,但仍高于SO组（P〈0．01）。结论该新型特异性PLA2抑制剂通过降低血清和肺组织PLA2的活性,对大鼠SAP并发肺损伤有一定的保护作用。     

靶器官保护策略对急性肺损伤的防护作用

目的探讨靶器官保护策略对急性肺损伤的防护作用。方法将急性肺损伤患者85例完全随机分为对照组（42例）和研究组（43例）。2组给予常规治疗,研究组为保护炎症靶器官（肠道、肺脏）加用①生大黄30g,水煎成200ml溶液（水煎15min）,分2次／d口服或管饲;②静脉滴注盐酸氨溴索60mg,2次／d;③静脉注射乌司他丁40万U,1次／8h,疗程7d。监测患者治疗前后呼吸频率、PaO2、氧合指数、血清中肿瘤坏死因子-α（TNF-α）、白细胞介素6（IL-6）、IL一8水平、7d后全身炎症反应综合征（SIRS）评分及预后情况。结果2组治疗前各项监测指标差异无统计学意义,治疗后研究组患者呼吸频率、PaO,、氧合指数、SIRS评分明显优于对照组（P〈0．05）;研究组TNF一仅、IL-6、IL一8于治疗第3天明显下降,改善均优于对照组（P〈0．05）。研究组7d后SIRS评分低于对照组,但差异无统计学意义[（1．7±1．3）分比（2．64-1．3）分,P〉0．05];ARDS发生率低于对照组[29．2％（12／43）比59．5％（25／42）,P〈0．05];病死率虽低于对照组,但差异无统计学意义[18．6％（8／43）比25．6％（11／42）,P〉0．05]。结论注重炎症靶器官保护可抑制炎症介质产生、释放和体内炎症反应的放大,提供肺保护作用。     

Prostaglandin E2 synthase inhibition as a therapeutic target

Background: Most NSAIDs function by inhibiting biosynthesis of PGE₂ by inhibition of COX-1 and/or COX-2. Since COX-1 has a protective function in the gastro-intestinal tract (GIT), non-selective inhibition of both cycloxy genases leads to moderate to severe gastro-intestinal intolerance. Attempts to identify selective inhibitors of COX-2, led to the identification of celecoxib and rofecoxib. However, long-term use of these drugs has serious adverse effects of sudden myocardial infarction and thrombosis. Drug-mediated imbalance in the levels of prostaglandin I₂ (PGI₂) and thromboxane A₂ (TXA₂) with a bias towards TXA₂ may be the primary reason for these events. This resulted in the drugs being withdrawn from the market, leaving a need for an effective and safe anti-inflammatory drug. Methods: Recently, the focus of research has shifted to enzymes downstream of COX in the prosta glandin biosynthetic pathway such as prostaglandin E₂ synthases. Microsomal prostaglandin E₂ synthase-1 (mPGES-1) specifically isomerizes PGH₂ to PGE₂, under inflammatory conditions. In this review, we examine the biology of mPGES-1 and its role in disease. Progress in designing molecules that can selectively inhibit mPGES-1 is reviewed. Conclusion: mPGES-1 has the potential to be a target for anti-inflammatory therapy, devoid of adverse GIT and cardiac effects and warrants further investigation.