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)

Physiological inhibitors were tested for their in vitro interaction with neutrophil proteinase 3 (PR3). The major plasma proteinase inhibitor of PR3 is alpha 1AT. We have developed a radioimmunoassay (RIA) for quantitative detection of PR3-alpha 1AT complexes formed in vivo in inflammatory exudates such as synovial fluid and plasma from patients with sepsis. Levels of PR3-alpha 1AT complexes correlated significantly with levels of human neutrophil elastase (HNE)-alpha 1AT complexes. Thus, in vivo alpha 1AT not only protects against excessive HNE activity, but also against excessive PR3 activity.
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PMID:Determination of proteinase 3-alpha 1-antitrypsin complexes in inflammatory fluids. 145 41

Recruitment of inflammatory cells to the lung capillaries has been proposed as an important step in the sequence of events that lead to acute lung injury. Frequently, in the clinical setting, bacteremia and sepsis syndrome precede the acute lung failure and endotoxin priming may represent a comparable paradigm, useful for experimental pursuit. Following addition of the chemotactic tripeptide FMLP (10(-9) to 10(-6) M) to the cell-free, salt solution perfusate of isolated rat lungs, only a small degree of vasoconstriction was observed. However, in lungs isolated from rats that received 2 mg/kg intraperitoneal Salmonella enteritidis endotoxin 2 h before lung perfusion, FMLP dose dependently caused a large, transient pulmonary pressor response, edema formation, and release of large amounts of thromboxane and leukotriene B4. Since in vitro priming with endotoxin, direct vascular injury by neutrophil elastase, nor direct stimulation with FMLP of pulmonary artery rings from endotoxin-pretreated rats, mimicked the effects of in vivo endotoxin priming, we conclude that the presence of inflammatory cells in the lung capillaries accounted for the large amount of eicosanoids produced by the lungs after FMLP stimulation. In fact, by retrograde lavage of the lung circulation with a collagenase solution, previously adherent cell clumps were mobilized and identified. These cell clumps, composed of red blood cells, neutrophils, and platelets, were not seen in the vascular lavage sediment obtained from unprimed control lungs. Indomethacin, a thromboxane antagonist, AA861, a 5-lipoxygenase inhibitor, and WEB 2086, a platelet-activating factor (PAF) antagonist, reduced the thromboxane synthesis and release after FMLP (10(-7) M) in in vivo endotoxin-primed lungs. None of the inhibitors employed exclusively inhibited only one particular eicosanoid mediator but rather affected the release of several mediators, suggesting a close link between the different synthetic arachidonic acid pathways. An inhibitor of phospholipase C (2-nitro-4-carboxyphenyl-N,N-diphenylcarbamate), NCDC, but not an inhibitor of phospholipase D (Wortmannin) or of protein kinase C (staurosporine) inhibited the FMLP-stimulated pulmonary pressure rise and eicosanoid release in endotoxin-primed lungs in vivo. Our data suggest that eicosanoids (in particular thromboxane) released from cells trapped in the lung circulation, but not from constitutive lung cells, contribute to vasoconstriction and edema formation caused by the chemoattractant FMLP in endotoxin-primed lungs.
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PMID:FMLP causes eicosanoid-dependent vasoconstriction and edema in lungs from endotoxin-primed rats. 154 53

There is considerable evidence to implicate aggressive species of oxygen in the pathogenesis of organ dysfunction consequent to sepsis and septic shock. The inflammatory process appears to participate ubiquitously in this setting. A characteristic of inflammation is the involvement of activated neutrophils and their generation of aggressive oxygen species. Such species may both directly injure cells proximal to the oxidant generating cells, and may inactivate any proteolytic mechanisms normally protective against proteolytic injury caused by neutrophil elastase and other proteolytic enzymes released during inflammation. The offending agent in sepsis is most commonly envisioned as bacterial lipopolysaccharide, or endotoxin. Infusion of endotoxin into animals can reproduce much of the pathophysiology of sepsis and septic shock. In addition, administration of endotoxin to cultured cells, particularly endothelial cells, can cause responses consistent with a sequence of events that occurs in intact animals and humans. In both experimental models, it appears that aggressive oxygen species are important actors in the scenario eventuating in cell or organ injury. Of importance, the toxic consequences of these free radicals probably occurs in relatively protected spaces, including microenvironments created by close adherence between inflammatory cells and endothelial cells and the cell interior. For those reasons, the potential for antioxidants as therapy should include consideration of the volume of distribution of such substances. It is probably important that antioxidants access excluded spaces including cell interiors in order to have their maximum effect in this setting. We have studied ina preliminary way the effects of n-acetyl-cysteine, a highly permeable free radical scavenger and anti-oxidant, in patients with established ARDS.(ABSTRACT TRUNCATED AT 250 WORDS)
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PMID:Oxygen radicals--an important mediator of sepsis and septic shock. 179 73

A hyperdynamic sepsis model was set up in seven adult baboons to evaluate neutrophil-activating peptide-1/interleukin (IL)-8 (NAP-1/IL-8), IL-1 beta, IL-6, tumor necrosis factor-alpha (TNF alpha), and IFN-gamma in plasma. By continuous intravenous administration of 10(10) cfu/kg live Escherichia coli over 8 h with additional infusion therapy (less than or equal to 50 ml/kg/h), endotoxin plasma levels of 2.7-22.3 ng/ml were observed. In plasma the kinetics of NAP-1/IL-8 and IL-6 were similar to those of IL-1 at the end of the experiment (8 h) (peak median values, 34, 4197, and 230 ng/ml, respectively). Differences were greatest for IL-6. Monocyte activation during sepsis was confirmed by elevated plasma neopterin levels (91-139 mumol/mmol of creatine). Granulocyte activation was evident from both incipient neutropenia and the massive release of neutrophil elastase into the plasma as measured by a new immunoassay (peak level, 374 ng/ml). Thus, in primate bacteremia, early TNF release is followed by a concomitant increase of NAP-1/IL-8 with plasma kinetics similar to those of IL-6 and IL-1 and accompanied by massive activation of neutrophils.
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PMID:Plasma neutrophil-activating peptide-1/interleukin-8 and neutrophil elastase in a primate bacteremia model. 190 12

Gram-negative bacterial sepsis is frequently associated with acute renal failure but the specific effects of lipopolysaccharide (LPS) and other bacterial products on kidney function are not known. Since either LPS or formyl-methionyl-leucyl-phenylalanine (FMLP)--a chemotactic peptide from bacterial cell walls--activate neutrophils (PMN) to release a number of potentially toxic factors in vitro, we determined the effect of adding PMN with LPS and/or FMLP to isolated perfused rat kidneys. Isolated rat kidneys perfused with LPS alone or LPS and normal PMN had normal glomerular filtration rates (GFR) and tubular Na reabsorption (TNa). Kidneys perfused with FMLP alone or FMLP and normal PMN also had normal GFR and TNa. In contrast, addition of PMN with both FMLP and LPS caused progressive renal dysfunction. For example, after 60 minutes of perfusion, GFR was reduced from 610 +/- 31 to 147 +/- 17 microliters/min/g and TNa from 97 +/- 1 to 72 +/- 2%, both P less than 0.01. Perfusion with the O2 metabolite scavengers catalase or dimethylthiourea afforded no protection while perfusion with the neutrophil elastase inhibitor Eglin C conferred substantial, but not complete, protection: GFR 492 +/- 34 microliters/min/g; TNa 91 +/- 3%. However, perfusion with both Eglin C and catalase completely prevented the toxic effects of LPS and FMLP-treated PMN on renal function. We conclude that in isolated kidneys, 1) the toxic effects of LPS requires FMLP-treated PMN and that 2) LPS and FMLP treated PMN cause progressive renal injury which is mediated by both O2 metabolites and neutrophil elastase.
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PMID:Role of neutrophil derived oxidants and elastase in lipopolysaccharide-mediated renal injury. 205 18

In human blood, cortisol is transported by a plasma protein known as corticosteroid-binding globulin (CBG). As anticipated from primary structure comparisons of CBG and alpha 1-proteinase inhibitor (A1-PI), CBG acts as a substrate for neutrophil elastase. However, unlike A1-PI, CBG does not alter the activity of this enzyme, but is cleaved by it at a single location close to its carboxy-terminus, and this reduces its molecular size by 5 kDa with the concomitant release of more than 80% of CBG-bound cortisol. Three small molecular size fragments are detected after elastase cleavage, and carbohydrate analysis of these fragments suggests that they represent the same polypeptide fragment which has been differentially glycosylated. To assess the biological significance of these observations, CBG was incubated with either mononuclear cells or granulocytes obtained from patients with acute inflammation (sepsis) and from a normal volunteer. Only granulocytes from septic patients reduced the mol wt of CBG by about 5 kDa and destroyed its steroid-binding activity. Preincubation with A1-PI prevented this, which demonstrates that neutrophil elastase plays a key role in this event. These results suggest a physiological role for CBG in the delivery of cortisol to sites of inflammation.
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PMID:A role for corticosteroid-binding globulin in delivery of cortisol to activated neutrophils. 237 Feb 99

The prognosis of septicaemia depends on the occurrence of complications such as shock and coagulation defects. The damage to haemostasis is usually explained by the action of the main coagulation and fibrinolysis enzymes, thrombin and plasmin. This paper presents data concerning the role of a third protease, granulocytic elastase. 82 patients who had been admitted to our hospital with suspected septicaemia were examined. Septicaemia was proven in 22 patients by the growth of microorganisms in blood cultures, and was clinically diagnosed in 9 patients. The plasma levels of neutrophil elastase-like protease complexed to a1antitrypsin (a1AT-ELP) were measured by zone immunoelectrophoresis assay (ZIA). The a1AT-ELP values were significantly increased in the 31 septic as compared to the 51 non-septic patients. In patients with complicated septicaemia, negative correlations of a1AT-ELP with factor XIII and the coagulation inhibitor antithrombin III were demonstrable. Among the patients with septic complications, the 3 who survived exhibited a dramatic decrease of a1AT-ELP, whereas in the other 16 patients who died the levels remained elevated. It might be of therapeutic significance that in 9 patients receiving fresh plasma and AT III-concentrate substitution for DIC the a1AT-ELP levels dropped, whereas they remained high in the other septicaemia patients. There were no correlations between a1AT-ELP and the a2antiplasmin-plasmin complexes (a2AP-P1), but strong correlations with signs of coagulation. The data suggest an interaction of coagulation and elastase release, probably involving the Hageman factor.
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PMID:Participation and interactions of neutrophil elastase in haemostatic disorders of patients with severe infections. 329 74

Staphylococcus aureus is known to produce three very active extracellular proteinases. One of these enzymes, a cysteine proteinase, after purification to homogeneity was found to degrade insoluble bovine lung elastin at a rate comparable to human neutrophil elastase. This enzyme had no detectable activity against a range of synthetic substrates normally utilized by elastase, chymotrypsin, or trypsin-like proteinases. However, it did hydrolyze the synthetic substrate carbobenzoxy-phenylalanyl-leucyl-glutamyl-p-nitroanilide (Km = 0.5 mM, kcat = 0.16 s-1). The proteolytic activity of the cysteine proteinase was rapidly and efficiently inhibited by alpha 2-macroglobulin and also by the cysteine-specific inhibitor rat T-kininogen (Ki = 5.2 X 10(-7) M). Human kininogens, however, did not inhibit. Human plasma apparently contains other inhibitors of this enzyme, since plasma depleted of alpha 2-macroglobulin retained significant inhibitory capacity. The elastolytic activity of this S. aureus proteinase and its lack of control by human kininogens or cystatin C may explain some of the connective tissue destruction seen in bacterial infections due to this and related organisms such as may occur in septicemia, septic arthritis, and otitis.
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PMID:Degradation of elastin by a cysteine proteinase from Staphylococcus aureus. 342 37

The interaction of three proteinases (seryl, cysteinyl, and metallo-) from Staphylococcus aureus with human plasma alpha 1-proteinase inhibitor has been investigated. As expected, none of the enzymes was inactivated by this protein, each, instead causing the conversion of the native inhibitor into an inactive form of decreased molecular weight. Amino-terminal sequence analysis indicated that inhibitor inactivation had occurred by peptide bond cleavage near the reactive center of this protein. When the inhibitor was modified by this treatment, it became resistant to both pH and temperature denaturation and, in contrast to the intact denatured protein, did not undergo further proteolytic degradation. This process of inactivation of alpha 1-proteinase inhibitor by pathogenic proteinases could result in a deregulation of its target enzyme, neutrophil elastase, and, therefore, may be important in the consumption of some plasma proteins by this enzyme during septicemia.
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PMID:The inactivation of human plasma alpha 1-proteinase inhibitor by proteinases from Staphylococcus aureus. 353 18

Previous studies investigated the effects of neutrophil elastase on isolated factors in the hemostatic process. Some of these reported effects are, however, procoagulative and others anticoagulative. The aim of this study was to ascertain the effect of elastase on the in vivo hemostatic competency. The effect of elastase activity on the hemostatic competency was determined in a group of 50 surgical intensive care unit patients and 23 control subjects. Surgical intensive care unit patients were subgrouped into a surgery, a trauma, and a sepsis-multiple organ failure group. Elastase activity was assessed by elastase-alpha 1-proteinase inhibitor levels and hemostatic competency by thromboelastography. Thromboelastography results showed a relatively normal coagulative ability in the surgery group, a varying degree of thromboelastographic hypocoagulability in the trauma group, and pronounced thromboelastographic instability in the sepsis-multiple organ failure group. Increases in elastase-alpha 1-proteinase inhibitor levels up to 200 micrograms/L were accompanied by a compromised coagulative ability as seen in a prolongation of both the first and second phases of the clotting time, as well as a decrease in the maximal clot elasticity.
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PMID:Hemostatic competency and elastase-alpha 1-proteinase inhibitor levels in surgery, trauma, and sepsis. 767 12


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