Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: UMLS:C0036690 (sepsis)
 59,461 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Sepsis and major trauma are the two most common causes of disseminated intravascular coagulation (DIC) and are characterized by a sudden increase in inflammatory mediators. In general, the outcome of the patient is determined by the degree of the inflammatory response. In severe cases of sepsis and trauma, cascade systems, such as the coagulation, fibrinolytic and complement systems, are activated beyond the capacity of the autoregulatory mechanisms. During DIC, plasma levels of antithrombin (AT)--a serine protease inhibitor that acts mainly on the serine proteases of the coagulation system--decrease due to the formation and subsequent elimination of complexes between AT and activated coagulation factors. The consumption of AT may start a vicious circle by facilitating further intravascular fibrin formation, followed by ischaemic tissue injury and accelerated activation of blood coagulation. Infusion of AT has an anti-inflammatory effect through its ability to counteract microvascular thrombosis. Furthermore, AT induces the release of prostacyclin from the vessel wall by binding to glycosaminoglycans on the surface of endothelial cells. Prostacyclin has a marked anti-inflammatory effect as a result of its inhibitory effect on neutrophils, monocytes and platelets.
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PMID:The effect of antithrombin on the systemic inflammatory response in disseminated intravascular coagulation. 1010 94

The pathophysiologic events of sepsis mediated by interleukin-1 (IL-1) remain ill-defined. The purpose of this study was to identify the circulatory derangements of which IL-1 was a necessary mediator and evaluate its interactions with tumor necrosis factor (TNF) and the eicosanoids during graded bacteremia. Eleven adult female swine were anesthetized, mechanically ventilated, and monitored with pulmonary artery catheters and arterial lines; they received intravenously either saline vehicle (septic control, n = 6) or human recombinant IL-1 receptor antagonist (IL-1ra, n = 5). The animals were then infused with Aeromonas hydrophila (10(9)/mL) for 4 h at rates gradually increased from .2 mL/kg/h to 4 mL/kg/h over 3 h, then sacrificed after 4 h. Mean arterial pressure (MAP), left ventricular stroke work index (LVSWI), and systemic vascular resistance index (SVRI) were recorded at baseline and hourly thereafter, and plasma 6-keto-PGF1alpha (6-KETO), tumor necrosis factor-alpha (TNF) and leukotrienes B4(LTB4) and C4D4E4 (LTCDE), pg/mL, were measured by ELISA. MAP, LVSWI, arterial P(O2) all decreased in the septic control group to levels significantly below those of the IL-1 antagonist animals. Circulating 6-KETO, LTCDE, and TNF increased significantly in all septic animals. Plasma LTB, and TNF were reduced by IL-1 blockade, compared with septic controls. TxB2 was not affected by IL-1 inhibition. There were no intergroup differences in platelet aggregation, but the in vitro aggregation response decreased from baseline in septic controls to 54+/-27% (p < .05). IL-1 is necessary to the development of systemic hypotension impaired LVSWI, and increased intravascular platelet aggregation during graded bacteremia. Conversely, IL-1 helps to maintain stroke volume and low SVRI in graded bacteremia, possibly through increased prostacyclin release. It may contribute to impaired pulmonary gas exchange and increased tissue oxygen demands. TNF release is stimulated in the presence of unopposed IL-1 and may be synergistic with it in the adverse hemodynamic effects of endogenous IL-1. IL-1 is required for increased leukotriene and prostacyclin levels in this model, but it is not involved in thromboxane release. Whether the lack of survival benefit from IL-1ra in human sepsis is due to these mixed cardiopulmonary and mediator effects, to species differences, or to timing of IL-1ra administration is not clear from the data.
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PMID:Interleukin-1 mediates hemodynamic dysfunction and release of eicosanoids and tumor necrosis factor during graded bacteremia. 1045 32

Almost all of respiratory diseases except benign lung tumors and lung dysplasia entail acute lung injury (ALI). The many clinical conditions associated with acute lung injury include aspiration pneumonia, bacterial pneumonia and sepsis. Acute lung injury is the end results of common pathways initiated by a variety of local or systemic insults leading to diffuse damage to the pulmonary parenchyma. Despite the accumulation of abundant information regarding the physiological and cellular basis of lung injury and increasing sophisticated intensive care, an improvement in prognosis has lagged behind. It has become clear that there is not one mediator responsible for ALI, but rather a complex interplay exists between diverse proinflammatory (e.g., lipopolysaccharide, complement products, cytocains, chemocains, reactive oxygen species and arachidonic acid products) and anti-inflammatory (IL-10, IL-1-RA, PGI2) mediators. Early in the course of ALI, large numbers of neutrophils are sequestered in and emigrate from the pulmonary capillaries. The fundamental cause of ALI is pulmonary vascular hyperpermeability caused by the activated neutrophils which release oxygen radicals and proteases. In these processes several adhesion molecules play very important roles. Neutrophil elastase inhibitors become very useful therapeutic agents against acute exacerbation of idiopathic interstitial pneumonia (IIP), because this pathological conditions is a type of ALI. Similarly, N-acetyl cystein could also become a useful therapeutic agent against IIP, because it is a precursor of glutathione, which is the major antioxidant in the fluid lining of the bronchial epithelium.
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PMID:[The 74th Annual Meeting President Lecture. Pathogenesis and therapy of acute lung injury]. 1053 83

Sepsis may lead to deranged thromboxane-prostacyclin ratio with consecutive organ dysfunction. Because of the suggested role of the gut in the pathogenesis of septic shock and multiple organ failure, we investigated the effects of the novel dual thromboxane synthase inhibitor and receptor antagonist DTTX-30 (TRASI) on intestinal tissue perfusion, O2 kinetics, and energy metabolism over 24 h of hyperdynamic, normotensive porcine endotoxemia. Before, 12, 18, and 24 h after starting continuous i.v. endotoxin (LPS), we measured portal venous (PV) blood flow, intestinal oxygen extraction (iO2ER), intracapillary hemoglobin O2 saturation (HbO2%) of the ileal wall, intramucosal ileal PCO2, PV lactate-pyruvate (L-P) ratio, and plasma levels of thromboxane and prostacyclin. Treatment with TRASI (0.12 mg/kg i.v. bolus injection followed by an infusion of 0.29 mg/kg/h) initiated after 12 h of LPS infusion markedly reduced the plasma thromboxane levels and attenuated the LPS-induced fall in systemic vascular resistance, resulting in hemodynamic stabilization. TRASI did not influence the LPS-induced increase in PV blood flow nor intracapillary HbO2%, thus reflecting unchanged microcirculatory O2 availability and decreased iO2ER, possibly because of reduced O2 requirements. Nevertheless, TRASI prevented the LPS-induced increase in the PV L-P ratio, attenuated the progression of the ileal mucosal-arterial PCO2 gap, and tended to attenuate the gradual fall of PV pH. Hence, compounds like TRASI may beneficially influence LPS-related derangements of gut energy metabolism.
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PMID:Effects of the combined thromboxane receptor antagonist and synthase inhibitor DTTX-30 on intestinal O2-exchange and energy metabolism during hyperdynamic porcine endotoxemia. 1077 20

Endothelial cells have two important anticoagulant systems, heparan sulfate-antithrombin system and thrombomodulin-protein C system. Under physiological conditions, these two systems inhibit activation of coagulation on endothelial cells. However, under inflammatory conditions, tumor necrosis factor(TNF)-alpha or other cytokines produced by monocytes reduce the anticoagulant properties of endothelial cell by downregulating expression of heparan sulfate and thrombomodulin on endothelial cells. Antithrombin stimulates prostacyclin generation from endothelial cells by interacting with heparan sulfate of endothelial cells and generated prostacyclin inhibits TNF-alpha production by monocytes. Activated protein C inhibits TNF-alpha production by monocyte dependent of its protease activity. Thus, antithrombin and activated protein C might inhibit the endothelial perturbation induced by cytokines. Antithrombin regulates TNF-alpha induced tissue factor expression on endothelial cells by an unknown mechanism. Thus, antithrombin and activated protein C might be useful agents for treating coagulation abnormalities associated with sepsis or other inflammation because these agents inhibit not only coagulation but also downregulation of anticoagulant activities of endothelial cells.
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PMID:[Endothelial cells and coagulation abnormalities]. 1081 Aug 75

This study evaluated whether or not prostacyclin (PGI2) was necessary or sufficient by itself in a pathophysiologic concentration to mediate the cardiovascular dysfunction of septic shock. Anesthetized adult swine received anesthesia only (ANESTHESIA CONTROL, n = 6); graded Aeromonas hydrophila, 10(10)/mL, infusion at 0.2 mL/kg/h that increased to 4.0 mL/kg/h over 3 h (SEPTIC SHOCK CONTROL, n = 6); pathophysiologic prostacyclin infusion to match septic shock control plasma levels without bacteremia (PGI2 INFUSION, n = 6), or graded Aeromonas hydrophila plus anti-prostacyclin antibody infusion (ANTI-PGI2-Ab INFUSION, n = 5). This graded porcine bacteremia model was 100% lethal after 4 h. Cardiovascular hemodynamics, arterial blood gases, and plasma levels of arachidonate metabolites were measured at baseline and hourly over a 4-h period. The results showed that PGI2 was not a necessary mediator of impaired cardiovascular hemodynamics in graded bacteremia, as anti-PGI2 antibody infusion did not improve the cardiac index, systemic vascular resistance, or peripheral oxygen balance in septic animals. Also, PGI2 was not sufficient alone to cause the cardiovascular dysfunction of sepsis, as pathophysiologic infusion of PGI2 did not reproduce such changes in normal animals. PGI2 blockade during bacteremia significantly increased LTC4D4E4, and LTB4 whereas PGI2 infusion suppressed LTC4D4E4 concentration, suggesting that endogenous PGI2 may blunt leukotriene release during septic shock. These results indicate a complex dynamic equilibrium among prostacyclin and leukotrienes in septic shock.
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PMID:The cardiovascular hemodynamics and leukotriene kinetics during prostacyclin and anti-prostacyclin antibody infusions in septic shock. 1084 36

To evaluate the effect of exogenous nitric oxide (NO) and endogenous NO on the production of prostacyclin (PGI(2)) by cultured human pulmonary artery smooth muscle cells (HPASMC) treated with lipopolysaccharide (LPS), interleukin-1(beta)(IL-1(beta)), tumor necrosis factor alpha (TNF(alpha)) or interferon gamma (IFN(gamma)), HPASMC were treated with LPS and cytokines together with or without sodium nitroprusside (SNP), NO donor, N(G)-monomethyl-L-arginine (L-NMMA), NO synthetase inhibitor, and methylene blue (MeB), an inhibitor of the soluble guanylate cyclase. After incubation for 24 h, the postculture media were collected for the assay of nitrite by chemiluminescence method and the assay of PGI(2)by radioimmunoassay. The incubation of HPASMC with various concentrations of LPS, IL-1(beta)or TNF(alpha)for 24 h caused a significant increase in nitrite release and PGI(2)production. However, IFN(gamma)slightly increased the release of nitrite and had little effect on PGI(2)production. Although the incubation of these cells for 24 h with SNP did not cause a significant increase in PGI(2)production, the incubation of HPASMC with SNP and 10 microg/ml LPS, or with SNP and 100 U/ml IL-1(beta)further increase PGI(2)production and this enhancement was closely related to the concentration of SNP. However, stimulatory effect of SNP on PGI(2)production was not found in TNF(alpha)- and IFN(gamma)- treated HPASMC. Addition of L-NMMA to a medium containing LPS or IL-1(beta)reduced nitrite release and attenuated the stimulatory effect of those agents on PGI(2)production. MeB significantly suppressed the production of PGI(2)by HPASMC treated with or without LPS or IL-1(beta). The addition of SNP partly reversed the inhibitory effect of MeB on PGI(2)production by HPASMC. These experimental results suggest that NO might stimulate PGI(2)production by HPASMC. Exogenous NO together with endogenous NO induced by LPS or cytokines from smooth muscle cells might synergetically enhance PGI(2)production by these cells, possibly in clinical disorders such as sepsis and acute respiratory distress syndrome.
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PMID:Nitric oxide enhances PGI(2)production by human pulmonary artery smooth muscle cells. 1091 30

Chronic pulmonary hypertension and septic lung failure display different clinical features resulting in severe disturbances in the pulmonary circulation. In these diseases, the pulmonary bloodflow is impaired by a pathologic constriction of blood vessels that may lead to right ventricular overloading as well as serious worsening of gas exchange mainly caused by ventilation/perfusion mismatch. Various mechanisms deteriorating the vascular function may induce both an irreversible and a reversible contraction of pulmonary vessels, respectively. Two pharmacological approaches exist to reduce the vascular resistance: Reduction of the increased vascular tone by relaxation of vascular smooth muscle cells (effect of vasodilators). Inhibition of thrombus-mediated obliteration of the lung perfusion by use of anticoagulant and fibrinolytic drugs. Prevention of the structural reorganization of pulmonary vessels (vascular remodeling) by use of vasodilators with anti-inflammatory and anti-proliferative potency such as prostanoids. The systemic (intravenous or oral) application of vasodilative agents in sepsis and chronic pulmonary hypertension has, however, important side effects: Antagonism of the hypoxic pulmonary vasoconstriction aggravates the ventilation/perfusion mismatch (decrease in arterial oxygenation). Side effects of these vasodilators (systemic hypotension). The inhalative route of application is superior because of the pulmonary enrichment of the applied agent (pulmonary selectivity). Furthermore, a preferential deposition in the well-ventilated areas of the lung is achieved (intrapulmonary selectivity). Thus, the decrease in pulmonary-vascular resistance is paralleled by both optimized ventilation-perfusion matching and subsequently improved gas exchange. First clinical studies with inhaled nitric oxide and aerosolized prostacyclin have been performed in intubated and mechanically ventilated patients with septic lung failure. At present, the use of the long-acting prostacyclin analogue ilomedin for ambulant treatment of patients with chronic pulmonary hypertension is under investigation.
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PMID:[Inhalative strategies for improvement of pulmonary hemodynamics and gas exchange in sepsis and severe pulmonary hypertension]. 1092 31

Although the hemodynamic response to polymicrobial sepsis is characterized by an early, hyperdynamic phase followed by a late, hypodynamic phase, the factors responsible for producing the transition from the hyperdynamic to the hypodynamic stage are not fully understood. The failure to recognize or prevent this transition may lead to progressive deteriorations in cell and organ functions and ultimately result in multiple organ failure. Despite the fact that several vasoactive mediators (i.e., nitric oxide, prostacyclin, calcitonin gene-related peptide) have been implicated in producing cardiovascular alterations during sepsis, recent studies have indicated that adrenomedullin (AM), a novel vasodilatory peptide, plays an important role in initiating the hyperdynamic response during the early stage of polymicrobial sepsis. In addition, the reduced vascular responsiveness appears to be responsible for producing the transition from the early, hyperdynamic phase to the late, hypodynamic phase of sepsis. Moreover, modulation of AM vascular responsiveness reduces sepsis-induced mortality. In this review the physiological effects of AM, mechanisms of its action, and regulation of its production under various pathophysiological conditions will be discussed. Furthermore, the role of AM in producing the biphasic hemodynamic responses observed during polymicrobial sepsis and approaches for pharmacologically modulating vascular responsiveness and hemodynamic stability under such conditions will be described.
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PMID:The role of adrenomedullin in producing differential hemodynamic responses during sepsis. 1455 33

Sepsis and septic shock are the most frequent cause of mortality in non cardiologic intensive care units. Mortality of the severe form is still elevated in spite of the progress in the antibiotic therapy and in the hemodynamic and respiratory support. The most frequent cause of death is the Multi Organ Dysfunction Syndrome (MODS). The excessive inflammatory reaction and the damage of the microvascular bed secondary to the inflammation and to the disseminated intravascular coagulation (DIC) are important pathogenetic factors. In the sepsis a complex system of cellular activation initiates the release and the interaction of activators and inhibitors of the inflammation (cytokines), the activation of the enzymatic cascade systems (coagulation, fibrinolytic and complement systems) and the synthesis of proteases and anti proteases. The activation of the coagulation system, uncontrolled by the fibrinolytic system with formation of fibrin in the micro vascular bed, has an important role in the MODS. Experimental data and clinical observations suggest a possible therapeutic role of antithrombin III (AT) in sepsis; its plasma concentration is constantly decreased in patients with sepsis or septic shock and the entity of the decrease is correlated with the severity of the clinical picture and the outcome. At has a double function: regulation of the coagulation system and anti inflammatory properties. The anti inflammatory properties depend in part on the binding to the glycosaminoglycans of the endothelial cells and the consequent release of prostacyclin (PGI2). The anti inflammatory effect is independent from the anticoagulant one. The preliminary studies on the clinical use of AT were carried out in small groups of patients with DIC associated with pathologies of different etiology and often in very critical conditions. In general the evaluation criteria were the improvement or the normalization of the laboratory data. The interpretation of the therapeutic effect of AT is difficult because the dysomogeneity of these studies. The effect on mortality is controversial. Recently three prospective, randomized, double blind studies have been published in patients with severe sepsis and septic shock. The results of the single studies are inconclusive but the limited number of patients included in each study may explain the results. A meta-analysis of the data referring to the patients with severe sepsis and septic shock evidenced an odd ratio (OR) of 0.43 with 95% confidential interval of 0.20-0.92 (p = 0.029). The preliminary analysis of the results of a phase III study is unconclusive. Time, dosage and duration of treatment are still open to question. In perspective AT may be used in other clinical conditions associated with activation of the hemostatic system (cardiac surgery, stem cell transplantation, burns) even though the preliminary results must be confirmed by prospective studies. All these data suggest severe sepsis and septic shock as main criteria for treatment.
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PMID:[Antithrombin III concentrates in the treatmetn of sepsis and septic shock: indictions, limits and future prospects] . 1121 42


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