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

Nitric oxide (NO) is believed to play an important role in sepsis-related hypotension. We examined the effects of two pore-forming bacterial exotoxins, Escherichia coli hemolysin and Staphylococcus aureus alpha-toxin, on NO formation in cultured porcine pulmonary artery endothelial cells. NO was quantified using a difference-spectrophotometric method based on the rapid and stoichiometric reaction of NO with oxyhemoglobin. Endothelial cyclic guanosine monophosphate levels were also monitored. Both exotoxins increased NO synthesis in endothelial cells in a time- and dose-dependent manner to an extent exceeding that observed with the ionophore A23187 or thrombin. The capacity of exotoxins to induce NO formation may be relevant in patients with severe local or systemic bacterial infections.
 ...
PMID:Pore-forming bacterial toxins potently induce release of nitric oxide in porcine endothelial cells. 839 Oct 61

SK&F 107647, a novel synthetic low-molecular-weight peptide, has demonstrated potent antiinfective activities in murine models of fungal and viral infection. To determine if the hematoregulatory activities of SK&F 107647 could offer protection over conventional antibiotic therapy or as a single agent in animal models of bacterial sepsis, rats were implanted intraperitoneally with a live bacteria-containing fibrin-thrombin clot. Rats pretreated subcutaneously or orally with SK&F 107647 and then infected with either a gram-negative (Escherichia coli) or a gram-positive (Staphylococcus aureus) bacteria-containing clot demonstrated significantly improved survival over control formulation-treated animals. Treated animals showed increased effector cell activation, measured by CD11b expression on neutrophils and monocytes, and up to 1000-fold reduction in the number of E. coli recovered from blood. Thus, the hematoregulatory activities of SK&F 107647 can increase natural host resistance to infections caused by both gram-negative and gram-positive bacteria.
 ...
PMID:Treatment of experimental gram-negative and gram-positive bacterial sepsis with the hematoregulatory peptide SK&F 107647. 853 60

Various assays have been developed for quantitation of soluble fibrin or fibrin monomer in clinical plasma samples, since this parameter directly reflects in vivo thrombin action on fibrinogen. Using plasma samples from healthy blood donors, patients with cerebral ischemic insult, patients with septicemia, and patients with venous thrombosis, we compared two immunologic tests using monoclonal antibodies against fibrin-specific neo-epitopes, and two functional tests based on the cofactor activity of soluble fibrin complexes in tPA-induced plasminogen activation. Test A (Enzymun-Test FM) showed the best discriminating power among normal range and pathological samples. Test B (Fibrinostika soluble fibrin) clearly separated normal range from pathological samples, but failed to discriminate among samples from patients with low grade coagulation activation in septicemia, and massive activation in venous thrombosis. Functional test C (Fibrin monomer test Behring) displayed good discriminating power between normal and pathological range samples, and correlated with test A (r = 0.61), whereas assay D (Coa-Set Fibrin monomer) showed little discriminating power at values below 10 micrograms/ml and little correlation with other assays. Standardization of assays will require further characterization of analytes detected.
 ...
PMID:Comparison of immunological and functional assays for measurement of soluble fibrin. 858 5

Adult respiratory distress syndrome (ARDS) is a serious complication of disseminated intravascular coagulation (DIC) or multiple organ failure. To determine whether recombinant soluble human thrombomodulin (rsTM) may be useful in treating ARDS due to sepsis, we investigated the effect of rsTM on lipopolysaccharide (LPS)-induced pulmonary vascular injury in rats. The intravenous administration of rsTM prevented the increase in pulmonary vascular permeability induced by LPS. Neither heparin plus antithrombin III (AT III) nor dansyl Glu Gly Arg chloromethyl ketone-treated factor Xa (DEGR-Xa), a selective inhibitor of thrombin generation, prevented LPS-induced vascular injury. The agents rsTM, heparin plus AT III, and DEGR-Xa all significantly inhibited the LPS-induced intravascular coagulation. Recombinant soluble TM pretreated with a monoclonal antibody (moAb) that inhibits protein C activation by rsTM did not prevent the LPS-induced vascular injury; in contrast, rsTM pretreated with a moAb that does not affect thrombin binding or protein C activation by rsTM prevented vascular injury. Administration of activated protein C (APC) also prevented vascular injury. LPS-induced pulmonary vascular injury was significantly reduced in rats with leukopenia induced by nitrogen mustard and by ONO-5046, a potent inhibitor of granulocyte elastase. Results suggest that rsTM prevents LPS-induced pulmonary vascular injury via protein C activation and that the APC-induced prevention of vascular injury is independent of its anticoagulant activity, but dependent on its ability to inhibit leukocyte activation.
 ...
PMID:Recombinant human soluble thrombomodulin reduces endotoxin-induced pulmonary vascular injury via protein C activation in rats. 860 7

This review presents the rationale for and main results of coagulation inhibitor substitution during experimental and human sepsis. Activation of the contact system induces activation of the classical complement pathway with generation of anaphylatoxins, of the kinins pathway and of fibrinolysis. Physiologic inhibition depends on the C1-inhibitor (C1-Inh.). Septic patients exhibit a relative deficiency of biologically active C1-Inh. Substitution with concentrations of C1-Inh has been safely performed and preliminary results are consistent with a possible beneficial effect on hypotension and vasopressor requirement in septic shock. The extrinsic pathway is the main initial coagulation process involved in sepsis-induced DIC. Endothelial and monocyte generation of tissue factor (TF) is activated by bacterial products and endotoxin. Activation of TF is counteracted by a specific tissue factor pathway inhibitor (TFPI). The potential for TFPI substitution to inhibit the activation of the coagulation cascade in sepsis requires further study. Thrombin generation is inhibited by antithrombin III (AT III) and the protein C-protein S system. During sepsis, AT III is consumed and degraded by elastase. Animal studies have shown that DIC and death were prevented by high doses of AT III concentrates. Although a significant reduction in the duration of biological symptoms of DIC has been reported in most human studies, the usefulness of AT III substitution in human sepsis is still debated. None of the studies was able to document a statistically significant reduction in mortality. Protein C is activated by thrombomodulin and, with its cofactor protein S, inhibits factors Va and VIIIa. The free level of protein S depends on the level of the C4b binding protein (C4bBP), an acute-phase complement regulatory protein. During sepsis, protein C activity is significantly reduced, either by acute consumption or by thrombomodulin down-regulation, and increased levels of plasma C4bBP inhibit protein S. Infusion of activated protein C and protein S substitution both protect animals from the lethal effects of bacteria. Combining these different coagulation inhibitors should be carefully studied before its use in septic patients is recommended.
 ...
PMID:Coagulation inhibitor substitution during sepsis. 863 34

Acute inflammatory illnesses, including the sepsis syndrome, often include a component of coagulation. A human whole blood culture system was developed so that the relationship between coagulation activation and cytokine responses in the presence or absence of lipopolysaccharide (LPS) could be evaluated. In the absence of LPS stimulation, coagulation activation resulted in a novel pattern of cytokine production. During a 4-hour culture of coagulating blood, significant production of interleukin-8 (IL-8; >2,000 pg/mL) was observed, whereas other proinflammatory cytokines including IL-1 beta, IL-6, or tumor necrosis factor a were undetectable or less than 35 pg/mL. The cytokine profile was distinct from that of fully anticoagulated, LPS-stimulated blood, which showed levels of all the indicated proinflammatory cytokines > or = 2,000 pg/mL over the same time period. Over 24 to 48 hours, the coagulation-induced cytokine response was characterized by marked and sustained IL-8 production, limited IL-6 generation (with kinetics delayed relative to IL-8), and minimal or undetectable tumor necrosis factor alpha levels. The magnitude of the whole blood IL-8 response correlated with the level of coagulation activation as determined by measurement of thrombin-antithrombin III complex formation. The combined stimuli of coagulation activation and LPS challenge induced a synergistic enhancement of IL-8 production but not of IL-6. Coagulation-induced cytokine production and the synergistic production of IL-8 by coagulation and LPS could be attenuated by hirudin or tissue factor pathway inhibitor (TFPI). Studies to elucidate mechanisms implicated (1) the TFPI third Kunitz and carboxy-terminus as important structural components for TFPI regulation of coagulation activation and (2) thrombin as a candidate mediator of the mononuclear cell cytokine response to coagulation activation. In summary, a unique aspect of the crosstalk between the coagulation and cytokine cascades in whole blood is shown with the identification of IL-8 as a key proinflammatory participant.
 ...
PMID:The proinflammatory cytokine response to coagulation and endotoxin in whole blood. 865 18

The endothelium plays an important role in the regulation of haemostasis by producing substances such as thrombomodulin (TM). The influence of long-term volume replacement with different types of fluid on the TM-protein C-protein S system was investigated in a prospective, randomized study. Thirty trauma patients and 30 patients suffering from sepsis after major surgery received either 10% low-molecular weight (LMW) hydroxyethylstarch solution (HES-trauma, n = 15; HES-sepsis, n = 15) or 20% human albumin (HA-trauma, n = 15; HA-sepsis, n = 15) for 5 days to maintain central venous pressure (CVP) between 12 and 16 mm Hg. Plasma concentrations of TM, protein C, (free) protein S and thrombin-antithrombin (TAT) were measured in arterial blood samples obtained on the day of admission to the intensive care unit or on the day of diagnosis of sepsis and over the next 5 days. There were no differences between HA- and HES-treated trauma patients. Protein C and protein S also did not differ between HA- and HES-treatments. At baseline, TM plasma concentrations were increased to > 40 micrograms litre-1 in both sepsis groups only. In the HA-sepsis group, TM increased significantly (from 48.1 (SD 13.9) to 68.4 (13.0) micrograms litre-1), whereas it remained almost unchanged in the HES-sepsis group. In HES-sepsis patients, protein C (from 51.0 (10.1) to 71.9 (8.9)%) and protein S (from 19.0 (6.0) to 40.8 (11.4)%) increased significantly during the study, whereas both remained reduced in HA-patients. TAT (indicating intravascular coagulation) did not differ between the two fluid groups. We conclude that in trauma patients, the type of volume therapy had no influence on the TM-protein C-protein S system. In sepsis patients, volume therapy with HES was beneficial, whereas infusion of HA had no substantial positive effect on endothelial-associated coagulation.
 ...
PMID:Does the type of volume therapy influence endothelial-related coagulation in the critically ill? 3286 9

Septic shock and multiple organ failure may be associated with coagulation activation, disseminated fibrin formation, and consumption of coagulation inhibitors such as antithrombin III. We have evaluated prospectively coagulation measurements in patients with severe chemotherapy-induced neutropenia. This group of patients was chosen because of their high risk of developing severe septic complications, thus allowing serial prospective coagulation testing before and during evolving sepsis or septic shock. Sixty-two patients with febrile infectious events were accrued to the study. Of these, 13 patients progressed to severe sepsis and 13 additional patients to septic shock as defined according to standard diagnostic criteria. At the onset of fever, factor (F) VIIa activity, FVII antigen and antithrombin III (AT III) activity decreased from normal baseline levels and were significantly lower in the group of patients who progressed to septic shock compared with those that developed severe sepsis (medians: 0.3 v 1.4 ng/mL, 21 v 86 U/dL and 45% v 95%; P < .001). The decrease of these measurements in septic shock was accompanied by an increase in prothrombin fragment 1+2 (median: 3.6 v 1.4 nmol/L; P = .05), a marker of thrombin generation. These differences were sustained throughout the septic episode (P < .0001). FVIIa and AT III levels of < 0.8 ng/mL and < 70%, respectively, at onset of fever predicted a lethal outcome with a sensitivity of 100% and 85%, and a specificity of 75% and 85%, respectively. In contrast, FXIIa-alpha antigen levels were not different between groups at onset of fever but increased modestly during the course of septic shock (P = .001). Thus, septic shock in neutropenic patients is associated with increased thrombin generation. Furthermore, both FVIIa and AT III measurements are sensitive markers of an unfavorable prognosis.
 ...
PMID:Factor VIIa and antithrombin III activity during severe sepsis and septic shock in neutropenic patients. 916 Jul 2

The plasmin/plasminogen system of enzymes may be involved in leukocyte migration through the endothelial cell layer of the vascular wall during inflammatory processes associated with vascular injury, atherosclerosis, and sepsis. Synthesis of plasminogen activator inhibitor type 1 (PAI-1) by the endothelium may protect these cells and the subendothelial cell matrix from excessive degradation and retard leukocyte migration. We report in this work for the first time the down-regulation of both basal and thrombin- or endotoxin-induced PAI-1 in cultured human endothelial cells by the activated T cell product, IFN-gamma. Down-regulation of basal and thrombin- or endotoxin-induced endothelial PAI-1 protein by IFN-gamma was found to be both time and dose dependent. Decreases of up to 71% relative to thrombin- or endotoxin-treated controls, using an optimal IFN-gamma concentration of between 20 and 200 U/ml, were found for human macrovascular and microvascular endothelial cells. However, IFN-gamma did not appear to affect IL-1 alpha- and TNF-alpha-induced levels of PAI-1 protein or mRNA in these cells. Northern blot analysis paralleled protein results, showing decreases in specific endothelial cell thrombin- or LPS-induced PAI-1 mRNA expression, respectively, after incubation with IFN-gamma for 24 h. These results suggest a means by which the migration of circulating leukocytes through endothelial cell layers during inflammation may be facilitated.
 ...
PMID:IFN-gamma inhibits thrombin- and endotoxin-induced plasminogen activator inhibitor type 1 in human endothelial cells. 880 64

Thrombin cleaves single-chain urokinase-type plasminogen activator (scu-PA) into a two-chain form (tcu-PA/T), which is virtually inactive in plasminogen activator assays. Little is known about the physiological importance of tcu-PA/T. To examine the occurrence of tcu-PA/T in vivo, we developed a sensitive and specific bioimmunoassay (BIA) for the assessment of tcu-PA/T in human body fluids. In this BIA, urokinase antigen was immuno-immobilized in microtiter plates and treated with cathepsin C, a specific activator of tcu-PA/T, after which plasminogen activator activity was measured. The occurrence of tcu-PA/T was examined in the plasma of 27 healthy individuals and of 17 sepsis patients, and in the synovial fluid of 16 rheumatoid arthritis patients. In addition, the concentration of urokinase antigen and scu-PA were measured in all three groups. In the plasma of the healthy individuals no measurable amounts of tcu-PA/T could be found(< detection limit of 0.2 ng/ml). In the plasma of almost all sepsis patients tcu-PA/T could be detected (median value 0.4 ng/ml). The amount of tcu-PA/T was 12% of the amount of scu-PA and accounted for about 9% of urokinase antigen. In the synovial fluid of all rheumatoid arthritis patients tcu-PA/T could be measured (median value 5.4 ng/ml) at a concentration which was twofold higher than the concentration found for scu-PA. In this group tcu-PA/T contributed to about 47% of the urokinase antigen. From these data we conclude that inactivation of scu-PA by thrombin can take place in vivo under pathological conditions which involve the production of large amounts of thrombin. This way thrombin may regulate fibrinolysis and extracellular proteolysis. The BIA for tcu-PA/T can be of use for further research on the physiological role of tcu-PA/T.
 ...
PMID:A sensitive bioimmunoassay for thrombin-cleaved two-chain urokinase-type plasminogen activator in human body fluids. 882 85


<< Previous 1 2 3 4 5 6 7 8 9 10 Next >>