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Query: UMLS:C0243026 (sepsis)
 52,417 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Leucocytes, both polymorphs and mononuclear cells, play a variety of roles in the evolution of human response to sepsis, both local and generalised. In this study, inhibitors of plasminogen activator were measured in leucocytes from normal and septic patients. Plasminogen activator inhibitor-1 (PAI-1) was identified in polymorphs from normal individuals and levels rose significantly in polymorphs from septic patients: neutrophils from normal subjects did not contain PAI-2 but this protein was detectable in significant quantities in polymorph preparations from septic patients. In contrast, mononuclear cells from normal and septic patients contained no detectable quantities of PAI-1. Significant amounts of PAI-2 were present in normal mononuclear cells, and the levels rose significantly in monocytes from septic patients. PAI-2 is thus here identified in human subjects, distinct from those with pregnancy or malignancy, as playing a role in a pathological process. The increased levels of both inhibitors produced by leucocytes may clearly contribute directly to the persistence of fibrin, a characteristic feature of the response to infection, local or general; they may thus participate in successful localisation of infections (abscess formation etc.) and in the evolution of the major systemic complications of disseminated sepsis characterised by microvascular occlusion by fibrin such as renal failure, shock lung or digital ischaemia.
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PMID:Inhibitors of plasminogen activator in neutrophils and mononuclear cells from septic patients. 877 32

Variables of the fibrinolytic system were prospectively studied in patients with haematologic malignancies in chemotherapy-induced leukocytopenia at onset and during the course of septicemia to evaluate their prognostic value. This group of patients was chosen because of their high risk of developing severe septic complications, thus allowing serial prospective testing of fibrinolytic variables prior to and during evolving sepsis or septic shock. 62 patients with febrile infectious events were accrued to the study. Of these, 13 patients progressed to severe sepsis and an additional 13 patients to septic shock as defined according to standard diagnostic criteria. At onset of fever, plasminogen activator inhibitor (PAI) activity and PAI-1 antigen levels increased from normal baseline levels and were significantly higher in the group of patients who developed septic shock compared to those with severe sepsis (medians: 10.6 versus 1.3 U/ml, p = 0.0001; 50.0 versus 5.0 ng/ml, p = 0.0002). The increase in PAI activity and antigen in septic shock was accompanied by an increase in tissue-type plasminogen activator antigen and total fibrin(ogen) degradation products and a decrease in alpha(2)-antiplasmin activity (p < 0.006). In contrast, in the group of patients that developed severe sepsis the variables of the fibrinolytic system remained unchanged at onset of fever. These differences between septic shock and severe sepsis were sustained throughout the septic episode for all variables (p < 0.0001). PAI activity of > 5 U/ml at onset of fever predicted a lethal outcome with a sensitivity of 92% and a specificity of 100%. Thus, septic shock in leukocytopenia is associated with significant activation of the fibrinolytic system presumably as a response of the vascular endothelium to inflammatory injury. Furthermore, PAI activity measurements are sensitive markers of an unfavourable prognosis.
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PMID:Increase of plasminogen activator inhibitor levels predicts outcome of leukocytopenic patients with sepsis. 882 84

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.
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PMID:A sensitive bioimmunoassay for thrombin-cleaved two-chain urokinase-type plasminogen activator in human body fluids. 882 85

Tumor necrosis factor-alpha (TNF alpha) is a central mediator in the pathogenesis of sepsis. It also interferes with the hemostatic system and exerts and a net procoagulant effect. Since TNF alpha may contribute to thrombotic complications in sepsis patients, we determined markers of thrombin activation, parameters of the fibrinolytic system (D-dimer, tissue plasminogen activator antigen (tPA) urinary type plasminogen activator antigen (uPA), plasminogen activator inhibitor antigen (PAI-1) and von Willebrand factor antigen (vWF) in 30 patients with sepsis or septic shock. All patients were treated with standard therapy, but 14 patients were treated additionally with an anti-TNF alpha monoclonal antibody (MAK 195F); 16 patients served as historical controls. No significant effect of the antibody on the parameters of the hemostatic system could be determined. Our data speak against a modulation of coagulation or the fibrinolytic system by the monoclonal anti-TNF alpha antibody MAK 195F in this cohort of sepsis patients.
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PMID:Hemostatic parameters in sepsis patients treated with anti-TNF alpha-monoclonal antibodies. 890 37

We studied the influence of age on mortality and severity of clotting abnormalities in 79 children (median age: 3.1 years) with meningococcal sepsis. Parameters of coagulation and fibrinolysis and plasma levels of cytokines were prospectively measured on admission. The mortality rate was 27%. The age of survivors was significantly different from that of non-survivors (p = 0.013). With the exception of FVII, vWF and t-PA, parameters of coagulation and fibrinolysis, as well as plasma cytokine levels were related to outcome. Patients were divided in two groups: younger and older than median age. The mortality in children < or = 3.1 years was 40% versus 13% in children > 3.1 years (p = 0.006). In contrast to cytokine levels, which were not different between the two age groups, fibrinogen, prothrombin, factors V, VII, VIII, vWF, protein C, antithrombin, FDP, and the ratio PA1-1/t-PA were related to age, indicating a more severe coagulopathy in children < or = 3.1 years despite a similar degree of inflammatory response. A relative deficiency of coagulation factors due to an immature state of the clotting system, as well as an inadequate fibrinolytic response, both related to age may have caused this more severe coagulative response in younger children, and may have contributed to the higher mortality rate.
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PMID:Age-related differences in outcome and severity of DIC in children with septic shock and purpura. 897 13

VEGF has been proposed to participate in normal and pathological vessel formation. Surprisingly, lack of only a single VEGF allele resulted in embryonic lethality due to abnormal formation of intra- and extra-embryonic vessels. Homozygous VEGF-deficient embryos, generated by tetraploid aggregation, revealed an even more severe defect in vessel formation. These results (1) suggest a tight regulation of early vessel development by VEGF and, indirectly, the presence of other VEGF-like molecules; (2) reveal an unprecedented lethal phenotype associated with heterozygous deficiency of an autosomal gene, and (3) demonstrate that tetraploid aggregation was a valid and the only method to study the phenotype of the homozyogous VEGF-deficient embryos. The dominant and strict dose-dependent role of VEGF in vivo renders this molecule a desirable therapeutic target for promoting or preventing angiogenesis. Tissue factor (TF) is the principal cellular initiator of coagulation and its deregulated expression has been related to thrombogenesis in sepsis, cancer, and inflammation. However, TF appears to be also involved in a variety of non-hemostatic functions including inflammation, cancer, brain function, immune response, and tumor-associated angiogenesis. Surprisingly, TF deficiency resulted in embryonic lethality due to abnormal extra-embryonic vessel development and defective vitelloembryonic circulation. The abnormal yolk sac vasculature is reminiscent of that observed in embryos lacking VEGF, possibly suggesting that both gene functions are interconnected. These targeting studies extend the recently documented role of TF in tumor-associated angiogenesis and warrant further study of its role in angiogenesis during other pathological disorders. The plasminogen system, via its triggers, tissue-type plasminogen activator (t-PA) and urokinase-type plasminogen activator (u-PA) and its inhibitor, plasminogen activator inhibitor-1 (PAI-1), has been implicated in thrombosis, arterial neointima formation, and atherosclerosis. Studies in mice with targeted gene inactivation of t-PA, u-PA, PAI-1, the urokinase receptor (u-PAR), and plasminogen (Plg) revealed (1) that deficiency of t-PA or u-PA increase the susceptibility to thrombosis associated with inflammation and that combined deficiency of t-PA:u-PA or deficiency of Plg induces severe spontaneous thrombosis; (2) that vascular injury-induced neointima formation is reduced in mice lacking u-PA-mediated plasmin proteolysis, unaltered in t-PA- or u-PAR-deficient mice and accelerated in PAI-1-deficient mice, but that it can be reverted by adenoviral PAI-1 gene transfer; and (3) that atherosclerosis in mice doubly deficient in apolipoprotein E (apoE) and PAI-1 is reduced after 10 weeks of cholesterol-rich diet. Thus, the plasminogen system significantly affects thrombosis, restenosis, and atherosclerosis.
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PMID:Insights in vessel development and vascular disorders using targeted inactivation and transfer of vascular endothelial growth factor, the tissue factor receptor, and the plasminogen system. 918 98

Impaired fibrinolysis, resulting from increased plasminogen activator inhibitor-1 (PAI-1) or reduced tissue-type plasminogen activator (t-PA) plasma levels, may predispose the individual to subacute thrombosis in sepsis and inflammation. The objective of these studies was to show that adenovirus-mediated gene transfer could increase systemic plasma t-PA levels and thrombolytic capacity in animal model systems. Recombinant adenovirus vectors were constructed that express either human wild type or PAI-1-resistant t-PA from the cytomegalovirus (CMV) promoter. Both t-PA-deficient (t-PA(-/-)) and PAI-1-overexpressing transgenic mice were infected by intravenous injection of these viruses. Intravenous injection of recombinant adenovirus resulted in liver gene transfer, t-PA synthesis, and secretion into the plasma. Virus dose, human t-PA antigen, and activity concentrations in plasma and extent of lysis of a 125I-fibrin-labeled pulmonary embolism were all closely correlated. Plasma t-PA antigen and activity were increased approximately 1,000-fold above normal levels. Clot lysis was significantly increased in mice injected with a t-PA-expressing virus, but not in mice injected with saline or an irrelevant adenovirus. Comparable levels of enzyme activity and clot lysis were obtained with wild type and inhibitor-resistant t-PA viruses. Adenovirus-mediated t-PA gene transfer was found to augment clot lysis as early as 4 hours after infection, but expression levels subsided within 7 days. Adenovirus-mediated transfer of a t-PA gene can effectively increase plasma fibrinolytic activity and either restore (in t-PA-deficient mice) or augment (in PAI-1-overexpressing mice) the thrombolytic capacity in simple animal models of defective fibrinolysis.
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PMID:Adenovirus-mediated transfer of tissue-type plasminogen activator augments thrombolysis in tissue-type plasminogen activator-deficient and plasminogen activator inhibitor-1-overexpressing mice. 926 70

The etiology of acute pancreatitis is based on several causes, among which idiopathic nature (< 30%) is second to biliary stone disease (60-70%). It is still under debate whether alcohol as the main cause of chronic pancreatitic disease can cause acute pancreatitis. Based on Opie's "obstruction theory" of 1901 and experimental data, it is now widely accepted that the gallstone passage into or through the terminal biliopancreatic ductal system triggers acute (necrotizing) pancreatitis by causing pancreatic ductal obstruction. However, the sequential intracellular mechanisms in the pathogenesis of acute pancreatitis remain unclear. A co-localization hypothesis has been proposed to explain the premature intracellular activation of trypsinogen to trypsin: due to a yet unknown defect in the intracellular protein transport and sorting system within the acinar cell, lysosomal hydrolases (i.e. cathepsin B) and secretory proteins (i.e. trypsinogen) co-localize in a fragile postgolgi vacuole where activation can occur. In addition, alterations of exo- and endocytosis at the apical pole exist (i.e. secretion block). The pathophysiological events are characterized by local and systemic hypovolemia and (micro)circulatory failure aggravating necrosis, followed by ARDS, renal failure and several other severe complications (i.e. sepsis and DIC). The systemic overflow of proteolytic enzymes (i.e. PLA-2) and kinins plays a major role as mediating factor in severe cases, resulting in multiorgan failure.
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PMID:[Etiology, pathogenesis and pathophysiology of acute pancreatitis]. 928 10

In patients with sepsis and septic shock, both coagulation and fibrinolysis are activated frequently leading to the syndrome of diffuse intravascular coagulation (DIC). The different mechanisms leading to abnormalities in coagulation and fibrinolysis are discussed in detail. The coagulation and fibrinolytic system appear to be influenced by the septic process largely independently, leading to a procoagulant imbalance between these systems. Coagulation is initiated by mediator-induced expression of tissue factor and is associated with consumption of the natural coagulation inhibitors antithrombin III, protein C, and protein S. As a result, high plasma levels of thrombin-antithrombin complex (TAT) can be found. The effects on fibrinolysis are dominated by (highly) increased levels of plasminogen activator inhibitor type 1 (PAI-1), leading to inadequate fibrinolysis. Although levels of plasminogen activator antigen are increased, its activity is almost completely inhibited by PAI-1. The resulting effects predispose to a procoagulant state, with widespread fibrin deposition, which may be an important mechanism contributing to multiple organ failure. A thorough understanding of the pathophysiological mechanisms underlying the DIC-syndrome is a prerequisite for a rational approach and future therapy for this severe complication of sepsis.
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PMID:Derangements of coagulation and fibrinolysis in critically ill patients with sepsis and septic shock. 951 78

We describe here the broad spectrum of acute renal insufficiency occurring in the course of human immunoinsufficiency virus infection. In our renal unit in Tenon hospital, 90 human immunoinsufficiency virus-infected adult patients were admitted for acute renal insufficiency between June 1988 and December 1996. Sixty out of them had a pathological diagnosis. The remaining patients did not have renal biopsy because of obstructive renal failure (n = 2), bleeding risk (n = 11), or clinically evident hypovolemic and/or sepsis-related acute tubular necrosis (n = 17). Nine different causes of acute renal insufficiency were listed. Human immunoinsufficiency virus-associated nephropathy, the most specific human immunoinsufficiency virus-related renal disease, which was diagnosed in 14 patients, is characterized by focal and segmental glomerulosclerosis with an important hyperplasia and/or proliferation of podocytes and huge tubular distension. The rapid progression to end-stage renal failure was not a constant feature since 10/14 patients had a partial renal recovery. Hemolytic-uremic syndrome was the other major cause of acute renal failure in these patients (32 cases) and was found to be associated with active cytomegalovirus infection. Cytomegalovirus-infected cells were present in half of the renal biopsies performed in this group of patients. Furthermore, these patients had an increased plasma tissue-type plasminogen activator activity whereas its type 1 inhibitor was not significantly increased, as opposed to non human immunoinsufficiency virus-associated hemolytic-uremic syndrome. Half of the patients had a complete renal recovery. The other causes of acute renal insufficiency were 1) intratubular deposition of either drugs (Adiazine, Foscavir, Indinavir) in 13 patients, or monoclonal light chain in one patient with B cell-lymphoma; 2) lupus-like glomerulonephritis characterized in one case by a complete clinical remission after 6 month-treatment by antiproteases; 3) acute tubular necrosis. In this setting, rhabdomyolysis could reveal HIV infection. The heterogeneity of renal diseases could be explained by the variation of human immunoinsufficiency virus-associated infections along time and by the different drugs which permit a better survival. We can hypothesize that new HIV-associated diseases will occur with the long term use of antiproteases.
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PMID:[Human immunodeficiency virus and acute renal insufficiency]. 961 98


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