内源性一氧化碳对内毒素休克肺组织和肾组织保护作用的实验研究

目的：研究内毒素休克时内源性一氧化碳（CO）对肺组织和肾组织的保护作用及其机制;方法：采用盲肠结扎穿孔（CLP）的方法建立大鼠内毒素休克模型,通过免疫组化、光镜下组织形态学观察及超氧化物岐化酶活性、丙二醛含量的测定进行研究;结果：治疗组肺组织和肾组织病变明显减轻,炎症反应及脂质过氧化程度减轻;结论：内毒素休克时内源性CO对肺组织和肾组织具有保护作用,且此保护作用与其抑制炎症反应和抗氧化作用有重要关系。     

酸中毒条件下脓毒性休克大鼠胸主动脉对多巴胺反应性的变化

目的:观察不同酸中毒条件下正常大鼠和脓毒性休克大鼠胸主动脉对多巴胺反应性的变化。方法:采用离体血管灌流方法,观察对照组和脓毒性休克组大鼠胸主动脉在不同pH条件下的反应性变化。结果:pH值依次降低,对照组及脓毒性休克组离体胸主动脉对多巴胺反应性均下降,在相同pH值条件下脓毒性休克组比对照组离体血管对多巴胺反应性下降更为明显。结论:①环境pH值的下降会导致正常大鼠和脓毒性休克大鼠离体动脉对多巴胺反应性的下降。②在相同的酸性环境中脓毒性休克大鼠的血管对多巴胺刺激的反应性更差,更易失去活性。     

Oxidative stress and septic shock: metabolic aspects of oxygen-derived free radicals generated in the liver during endotoxemia

This review describes the role of oxidative stress caused by endotoxin challenge in sepsis or septic shock symptoms. We observed that endotoxin injection resulted in lipid peroxide formation and membrane damage (near 60-150 kDa) in the livers of experimental animals, causing decreased levels of scavengers or quenchers of free radicals. The administration of alpha-tocopherol completely prevented injury to the liver plasma membrane caused by endotoxin, and suggested that lipid peroxidation by free radicals might occur in a tissue ischemic state, probably by disseminated intravascular coagulation (DIC), in endotoxemia. In mice, depression of Ca(2+)-ATPase activity in the liver plasma membrane may contribute to the membrane damage caused by endotoxin, and the increase of [Ca(2+)](i) in the liver cytoplasm may partially explain the oxidative stress that occurs in endotoxemia. It seems that endotoxin-induced free radical formation is regulated by Ca(2+) mobilization. Moreover, we have suggested that the oxidative stress caused by endotoxin may be due, at least in part, to the changes in endogenous zinc or selenium regulation during endotoxemia. Interestingly, the extent of TNF-alpha-induced oxidative stress may be the result of a synergism between TNF-alpha and gut-derived endotoxin. It is likely that bacterial or endotoxin translocation plays a significant role in TNF-alpha-induced septic shock. On the other hand, although nitric oxide (NO) has been implicated in the pathogenesis of vascular hyporesponsiveness and hypotension in septic shock in our experimental model, it is unlikely that NO plays a significant role in liver injury caused by free radical generation in endotoxemia.     

A hot‐water extract of Sanguisorba officinalis ameliorates endotoxin‐induced septic shock by inhibiting inflammasome activation

The inflammasome is a multiprotein signaling complex that mediates inflammatory innate immune responses through caspase 1 activation and subsequent IL‐1β secretion. However, because its aberrant activation often leads to inflammatory diseases, targeting the inflammasome holds promise for the treatment of inflammation‐related diseases. In this study, it was found that a hot‐water extract of Sanguisorba officinalis (HSO) suppresses inflammasome activation triggered by adenosine 5′‐triphosphate, nigericin, microbial pathogens, and double stranded DNA in bone marrow‐derived macrophages. HSO was found to significantly suppress IL‐1β production in a dose‐dependent manner; this effect correlated well with small amounts of caspase 1 and little ASC pyroptosome formation in HSO‐treated cells. The anti‐inflammatory activity of HSO was further confirmed in a mouse model of endotoxin‐induced septic shock. Oral administration of HSO reduced IL‐1β titers in the serum and peritoneal cavity, increasing the survival rate. Taken together, our results suggest that HSO is an inhibits inflammasome activation through nucleotide‐binding domain and leucine‐rich repeat pyrin domain 3, nucleotide‐binding domain and leucine‐rich repeat caspase recruitment domain 4 and absent in melanoma 2 pathways, and may be useful for treatment of inflammasome‐mediated diseases.     

Urine catecholamines in children with severe Enterovirus A71 infection: comparison with paediatric septic shock

Purpose: Hypercatecholaminemia-related heart failure has been proposed as the main cause of enterovirus A71-related (EV-A71) early mortality. The purpose of this study was to measure urine catecholamine concentrations in severe EV-A71-infected children.

Methods: A total of 35 children, aged 2.5?±?2.1 years, were divided into three groups. Group I: 15 septic shock patients, group II: 17?EV-A71-stage-2 patients, and group III: 3?EV-A71-stage-4 patients. The laboratory results, cardiac biomarkers and urine catecholamine concentrations were statistically analysed.

Results: Group I had the highest C-reactive protein (CRP) levels and group II had the lowest B-type natriuretic peptide (BNP) and its N-terminal prohormone among the groups (p?=?0.039, <0.01 and <0.01, respectively). Group III patients had significantly higher urine catecholamine and troponin-I values among the groups. If urine epinephrine (Epi) >134 ug/gCr, norepinephrine (NE) >176 ug/gCr and vanillylmandelic acid (VMA) >11.7?mg/gCr were used as the cutoff points to differentiate groups II and III, the sensitivities and specificity were all 100%.

Conclusions: The significantly elevated urine catecholamine concentrations in EV-A71-stage-4 patients support the hypothesis that hypercatecholaminemia-related heart failure is involved in severe EV-A71 infection. Urine catecholamines could be used as reliable biomarkers for differentiation of severe EV-A71 infection with or without heart failure and septic shock.     

Changes of microcirculation in healthy volunteers and patients with septic shock in Xining

Objective: The purpose of this study is to investigate the characteristic of microcirculation in healthy volunteers and patients with septic shock in both Xining(2 260 m) and Nanjing(10 m). Methods: A total of 62 cases, 33 healthy volunteers, 22 cases in Xining,(2 260 m above sea level) and 11 cases in Nanjing(10 m above sea level); and 29 septic shock, 13 cases in Xining and 16 cases in Nanjing were collected. The total vessel density(TVD), perfused vessel density(PVD), proportion of perfused vessel(PPV) and microcirculation flow index(MFI) of both healthy volunteers and septic shock had been investigated by using sidestream dark field(SDF). Analyzed and managed the image data by using AVA3.0 software. Results: In the healthy volunteers in Xining area(22 cases),the volume of TVD(15.59 ± 2.58 mm/mm~2), PVD(15.58 ± 2.58 mm/mm~2) and PPV(96.60% ± 4.63%) were significant higher than the volume of TVD(10.0 ± 2.10 mm/mm~2), PVD(10.81 ± 2.38 mm/mm~2) and PPV(84.24% ± 8.00%) of the volunteers(11 cases) in Nanjing(11 cases). But the MFI(2.17 ± 0.31) of the healthy volunteers in the Xining was significant lower(P0.05) than the MFI(3.21 ± 0.34) in the healthy volunteers of Nanjing. In the septic shock group(13 cases) in the Xining, the volume of TVD(5.44 ± 1.94 mm/mm~2), PVD(4.18 ± 1.61 mm/mm~2), PPV(42.14%± 5.38%) and MFI(1.05 ± 0.32) compared with the volume of the healthy volunteers in Xining, the TVD(15.59 ± 2.58 mm/mm~2), PVD(5.58 ± 2.58 mm/mm~2), PPV(96.60% ± 4.63%) and MFI(2.17 ± 0.30) were significant lower(P0.05). In the healthy volunteers compare with septic shock group in Nanjing area, the TVD(6.80±1.72 vs 10.00±2.10, P0.05), PVD(5.86±1.58 vs10.81±2.38,P0.05), PPV(45.42±4.86 vs 84.24±4.86, P0.05), MFI(1.28±0.28 vs 3.21±0.34 P0.05), there was significant decreased. In the septic shock group in the Xining compared with the septic shock in Nanjing, there was no significant difference. 10 of 13 patients with septic shock were survived in Xining. 13 of 16 patients with septic shock were survived in Nanjing. Conclusion: The changes of physiological and pathophysiological characteristic in microcirculation induced by hypoxia would be useful for clinical treatment of septic shock at high altitude.     

Analysis of peripheral blood lymphocyte subsets and prognosis in patients with septic shock

The purpose of the study is to study the relationship between peripheral blood lymphocyte subset proportion and prognosis in patients with septic shock. Fifty‐two patients with septic shock, admitted to the intensive care unit between March 2007 and December 2010, were enrolled in this study. Peripheral blood lymphocyte subset proportions were measured using flow cytometry. The percentage of CD3⁺CD4⁺ T lymphocytes and CD19⁺ lymphocytes, CD4⁺/CD8⁺ T cell ratio were substantially lower in patients with septic shock compared to the control group (P < 0.01). The percentage of CD3⁺CD8⁺ T lymphocytes did not differ significantly between the two groups (P > 0.05). The percentage of CD16⁺CD56⁺ lymphocytes was higher in patients with septic shock than in the control group (P < 0.01). Compared with the survivor group, the percentage of CD3⁺CD4⁺ T lymphocytes and CD19⁺ lymphocytes, CD4⁺/CD8⁺ T cell ratio were clearly lower in the non‐survivor group (P < 0.01). There was no difference in the percentage of CD3⁺CD8⁺ T lymphocytes between the non‐survivor and survivor groups (P > 0.05). The percentage of CD16⁺CD56⁺ lymphocytes was higher in the non‐survivor group than in the survivor group (P < 0.05). The total maximum SOFA score and the delta SOFA score were much higher in the non‐survivor group than in the survivor group (P < 0.01). Immune imbalance occurs in patients with septic shock. Peripheral blood lymphocyte subset proportion and SOFA scores can be used to assess the treatment and prognosis of septic shock.     

两种败血症休克模型大鼠心肌细胞一氧化氮合酶活性的改变

目的：观察两种败血症休克模型大鼠的血流动力学及心肌细胞一氧化氮合酶活性变化的异同,探讨一氧化氮合酶参与败血症休克性心肌抑制的机制。方法：采用注射脂多糖（LPS）诱导及盲肠结扎穿孔（CLP）致腹膜炎诱导败血症休克模型,测定血流动力学指标以及心肌细胞胞浆一氧化氮合酶（NOS）活性。结果：①CLP模型大鼠的血流动力学指标随时间呈先上升后下降的趋势,LPS模型直接表现为类似于CLP模型晚期的动力学状态。在使用NOS抑制剂N-硝基-L精氨酸甲酯（L-NAME）后,CLP模型晚期及LPS模型的心室动力学指标均有明显改善。②CLP模型大鼠心肌细胞胞浆NOS活性在败血症中期达到最大。与假手术组相比,LPS模型、CLP模型晚期心肌细胞胞浆NOS活性均有明显增加,但是LPS模型与CLP模型晚期两组之间无明显差异。③使用L-NAME后,CLP晚期组与LPS组亚硝基及硝基化合物生成量均明显降低（P〈0.01）。其中,LPS组与CLP晚期组相比,前者固定表达型NOS生成亚硝基及硝基化合物生成量明显高于后者（P〈0．01）。结论：在LPS与CLP诱导的败血症休克模型中,心肌NOS是引起心室动力学变化的主要因素;在两种模型,心肌NOS亚型的表达不同,在LPS模型中主要为iNOS,而在CLP模型中则可能是cNOS和iNOS共同发挥作用。     

Towards a rational development of anti-endotoxin agents: novel approaches to sequestration of bacterial endotoxins with small molecules.

Endotoxins, or lipopolysaccharides (LPS), present on the surface of Gram-negative bacteria, play a key role in the pathogenesis of septic shock, a common clinical problem and a leading cause of mortality in critically ill patients, for which no specific therapeutic modalities are available at the present time. The toxic moiety of LPS is a glycolipid called 'lipid A', which is composed of a bisphosphorylated diglucosamine backbone bearing up to seven acyl chains in ester and amide linkages. Lipid A is structurally highly conserved in Gram-negative bacteria, and is therefore an attractive target for developing anti-endotoxin molecules designed to sequester, and thereby neutralize, the deleterious effects of endotoxins. The anionic and amphipathic nature of lipid A enables the interaction of a wide variety of cationic amphiphiles with the toxin. This review describes the systematic evaluation of several structural classes of cationic amphiphiles, both peptides and non-peptidic small molecules, in the broader context of recent efforts aimed at developing novel anti-endotoxin strategies. The derivation of a pharmacophore for LPS recognition has led to the identification of novel, nontoxic, structurally simple small molecules, the lipopolyamines. The lipopolyamines bind and neutralize LPS in in vitro experiments as well as in animal models of endotoxicity, and thus present novel and exciting leads for rational, structure-based development of LPS-sequestering agents of potential clinical value.     

Interleukin-10 rs2227307 and CXCR2 rs1126579 polymorphisms modulate the predisposition to septic shock

Despite major improvements in its treatment and diagnosis, sepsis is still a leading cause of death and admittance to the intensive care unit (ICU). Failure to identify patients at high risk of developing septic shock contributes to an increase in the sepsis burden and rapid molecular tests are currently the most promising avenue to aid in patient risk determination and therapeutic anticipation. The primary goal of this study was to evaluate the genetic susceptibility that affects sepsis outcome in 72 sepsis patients admitted to the ICU. Seven polymorphisms were genotyped in key inflammatory response genes in sepsis, including tumour necrosis factor-α, interlelukin (IL)-1β, IL-10, IL-8, Toll-like receptor 4, CXCR1 and CXCR2. The primary finding showed that patients who were homozygous for the major A allele in IL-10 rs1800896 had almost five times higher chance to develop septic shock compared to heterozygotes. Similarly, selected clinical features and CXCR2 rs1126579 single nucleotide polymorphisms modulated septic shock susceptibility without affecting survival. These data support the hypothesis that molecular testing has clinical usefulness to improve sepsis prognostic models. Therefore, enrichment of the ICU portfolio by including these biomarkers will aid in the early identification of sepsis patients who may develop septic shock.     

Plasma levels of F-actin and F:G-actin ratio as potential new biomarkers in patients with septic shock

Objective: To compare plasma levels of F-actin, G-actin and thymosin beta 4 (TB4) in humans with septic shock, noninfectious systemic inflammatory response syndrome (SIRS) and healthy controls.

Results: F-actin was significantly elevated in septic shock as compared with noninfectious SIRS and healthy controls. G-actin levels were greatest in the noninfectious SIRS group but significantly elevated in septic shock as compared with healthy controls. TB4 was not detectable in the septic shock or noninfectious SIRS group above the assay’s lowest detection range (78?ng/ml).

Conclusions: F-actin is significantly elevated in patients with septic shock as compared with noninfectious SIRS. F-actin and the F:G-actin ratio are potential biomarkers for the diagnosis of septic shock.     

EGFR kinase activity is required for TLR4 signaling and the septic shock response

Mammalian Toll-like receptors (TLR) recognize microbial products and elicit transient immune responses that protect the infected host from disease. TLR4—which signals from both plasma and endosomal membranes—is activated by bacterial lipopolysaccharides (LPS) and induces many cytokine genes, the prolonged expression of which causes septic shock in mice. We report here that the expression of some TLR4-induced genes in myeloid cells requires the protein kinase activity of the epidermal growth factor receptor (EGFR). EGFR inhibition affects TLR4-induced responses differently depending on the target gene. The induction of interferon-β (IFN-β) and IFN-inducible genes is strongly inhibited, whereas TNF-α induction is enhanced. Inhibition is specific to the IFN-regulatory factor (IRF)-driven genes because EGFR is required for IRF activation downstream of TLR—as is IRF co-activator β-catenin—through the PI3 kinase/AKT pathway. Administration of an EGFR inhibitor to mice protects them from LPS-induced septic shock and death by selectively blocking the IFN branch of TLR4 signaling. These results demonstrate a selective regulation of TLR4 signaling by EGFR and highlight the potential use of EGFR inhibitors to treat septic shock syndrome.     

Soluble TREM-1 as a diagnostic and prognostic biomarker in patients with septic shock: an observational clinical study

Objectives: The impact of TREM-1-mediated inflammation was investigated in different inflammatory settings.

Methods: Secondary analyses of an observational clinical pilot study, including 60 patients with septic shock, 30 postoperative controls and 30 healthy volunteers.

Results: Plasma levels of sTREM-1 were found to identify patients with septic shock more effectively than procalcitonin and C-reactive protein. Moreover, sTREM-1 was identified to be an early predictor for survival in patients with septic shock.

Conclusion: Due to its diagnostic as well as prognostic value in sepsis syndrome, implementation of sTREM-1 measurements in routine diagnostics should be taken into account.     

Quercetin but not luteolin suppresses the induction of lethal shock upon infection of mice with Salmonella typhimurium

Tumor necrosis factor-alpha (TNF-alpha) is important for the induction of systemic inflammatory responses that lead to lethal shock. Quercetin and luteolin, which differ by one hydroxyl group, are known to suppress the lipopolysaccharide-induced production of TNF-alpha in vitro. We show differing inhibitory effects of quercetin and luteolin on the induction of lethal shock in Salmonella typhimurium aroA-infected mice. In a time- and dose-dependent manner, quercetin reduced the plasma levels of TNF-alpha, lowered bacterial titers in livers, prevented liver damage and prolonged survival, while luteolin had little or no effect. Compared with luteolin, quercetin increased the infiltration of Gr-1(+)CD69(+) neutrophils into the peritoneal cavity and lowered heat shock protein 70 expression. Obviously, the additional hydroxyl group in quercetin is important for suppressing infection-induced lethal shock in mice.     

Synthesis and biological activity of novel MIF antagonists

Two series of novel furan and indole compounds were synthesized and probed for inhibition of macrophage migration inhibitory factor (MIF) activity. Several compounds from both series inhibited the enzymatic activity of MIF at levels equal to or significantly better than ISO-1 (an early MIF inhibitor). The majority of the compounds that robustly inhibited the spontaneous secretion/release/recognition of MIF from freshly isolated human peripheral blood mononuclear cells were from the furan series (compounds 5, 9, 13, 15, and 16). In contrast, compounds that markedly inhibited the MIF-induced production of pro-inflammatory cytokines were predominantly from the indole series (compounds 26, 29, and 32).     

人MIF基因启动子多态性与结核病易感性的关系

为了研究巨噬细胞移动抑制因子(MIF)与结核病易感性的关系,分析了肺结核病人和正常人MIF基因启动子多态性。DNA测序分析的结果显示,正常人MIF基因启动子-794区CATT序列重复次数存在明显的差异,5、6和7个拷贝的几率分别是22.2%、44.4%和33.3%。7个肺结核病人中6人有6个拷贝,1人有7个拷贝,出现的频率分别为85.6%和14.3%。对比分析提示,肺结核病人MIF基因启动子区CATT低拷贝数(低于或等于6个)出现的频率明显高于正常人(85.6%比66.6%),可能同结核病的致病相关。     

Tetralone derivatives are MIF tautomerase inhibitors and attenuate macrophage activation and amplify the hypothermic response in endotoxemic mice

Macrophage migration inhibitory factor (MIF) is a pro-inflammatory cytokine playing crucial role in immunity. MIF exerts a unique tautomerase enzymatic activity that has relevance concerning its multiple functions and its small molecule inhibitors have been proven to block its pro-inflammatory effects. Here we demonstrate that some of the E-2-arylmethylene-1-tetralones and their heteroanalogues efficiently bind to MIF’s active site and inhibit MIF tautomeric (enolase, ketolase activity) functions. A small set of the synthesised derivatives, namely compounds (4), (23), (24), (26) and (32), reduced inflammatory macrophage activation. Two of the selected compounds (24) and (26), however, markedly inhibited ROS and nitrite production, NF-κB activation, TNF-α, IL-6 and CCL-2 cytokine expression. Pre-treatment of mice with compound (24) exaggerated the hypothermic response to high dose of bacterial endotoxin. Our experiments suggest that tetralones and their derivatives inhibit MIF’s tautomeric functions and regulate macrophage activation and thermal changes in severe forms of systemic inflammation.     

The role of mitochondrial nitric oxide synthase in inflammation and septic shock

Nitric oxide and cytokines constitute the molecular markers and the intercellular messengers of inflammation and septic shock. Septic shock occurs with an exacerbated inflammatory response that damages tissue mitochondria. Skeletal muscle appears as one of the main target organs in septic shock, showing an increased nitric oxide (NO) production, an early oxidative stress, and contractile failure. Mitochondria isolated from rat and human skeletal muscle in septic shock show a markedly increased NO generation and a decreased state 3 respiration, more marked with nicotinamide adenine dinucleotide (NAD)-linked substrates than with succinate, without uncoupling or impairment of phosphorylation. One of the current hypothesis for the molecular mechanisms of septic shock is that the enhanced NO production by mitochondrial nitric oxide synthase (mtNOS) leads to excessive peroxynitrite (ONOO(-)) production and protein nitration in the mitochondrial matrix, to mitochondrial dysfunction and to contractile failure. Surface chemiluminescence is a useful assay to assess inflammation and oxidative stress in in situ liver and skeletal muscle. Liver chemiluminescence in inflammatory processes and phagocyte chemiluminescence have been found spectrally different from spontaneous liver chemiluminescence with increased 440-600 nm emission, likely due to NO and ONOO(-) participation in the reactions leading to the formation of excited species.