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)

Streptococcus pneumoniae is an important cause of upper and lower respiratory tract infections, meningitis, peritonitis, bacterial arthritis, and sepsis. Here we have studied a novel immune evasion mechanism of serotype 3 pneumococci, which are particularly resistant to phagocytosis. On their surfaces the bacteria express the factor H-binding inhibitor of complement (Hic), a protein of the pneumococcal surface protein C family. Using radioligand binding, microtiter plate assays, surface plasmon resonance analysis, and recombinant constructs of factor H, we located the binding site of Hic to short consensus repeats (SCRs) 8-11 in the middle part of factor H. This represents a novel microbial interaction region on factor H. The only other ligand known so far for SCRs 8-11 of factor H is C-reactive protein (CRP), an acute phase protein that binds to the pneumococcal C-polysaccharide. The binding sites of Hic and CRP within the SCR8-11 region were different, however, because CRP did not inhibit the binding of Hic and required calcium for binding. Binding of factor H to Hic-expressing pneumococci promoted factor I-mediated cleavage of C3b and restricted phagocytosis of pneumococci. Thus, virulent pneumococci avoid complement attack and opsonophagocytosis by recruiting functionally active factor H with the Hic surface protein. Hic binds to a previously unrecognized microbial interaction site in the middle part of factor H.
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PMID:Streptococcus pneumoniae evades complement attack and opsonophagocytosis by expressing the pspC locus-encoded Hic protein that binds to short consensus repeats 8-11 of factor H. 1182 23

Beriplex, a prothrombin complex concentrate (PCC), was administered to 42 patients requiring immediate reversal of their oral anticoagulant therapy. The dose administered was determined using the pretreatment International Normalized Ratio (INR). Blood samples were obtained before treatment and at 20, 60 and 120 min after treatment. The following investigations were performed on all samples - INR, clotting factors II, VII, IX and X, coagulation inhibitors protein C (PC) and antithrombin (AT), and other markers of disseminated intravascular coagulation, plasma fibrinogen, D-dimer and platelet count. Immediate reversal of the INR, the vitamin K-dependent clotting factors and PC was achieved in virtually all patients. Reduced AT levels were present in 18 patients before treatment. Further slight AT reductions occurred in four patients, but other associated abnormalities of haemostasis were observed in only one of the four patients. One patient with severe peripheral vascular disease, sepsis and renal and cardiac failure died of a thrombotic stroke following leg amputation, 48 h after receiving Beriplex. No other arterial and no venous thromboembolic events occurred within 7 d of treatment. Beriplex is effective in rapidly reversing the anticoagulant effects of warfarin, including PC deficiency, without inducing coagulation activation. Caution should continue to be exercised in the use of these products in patients with disseminated intravascular coagulation, sepsis or liver disease.
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PMID:Rapid reversal of oral anticoagulation with warfarin by a prothrombin complex concentrate (Beriplex): efficacy and safety in 42 patients. 1184 21

This article provides a description of the clinical disorders associated with the development of acute noncardiogenic pulmonary edema, better known as clinical acute lung injury (ALI) or the acute respiratory distress syndrome (ARDS). Much has been learned about the mechanisms by which the lung is injured in patients with sepsis, pneumonia, aspiration of gastric contents, and following major trauma. In the last 5 years, major progress has been made in the treatment of patients with ALI/ARDS. A lung protective ventilatory strategy with a low tidal volume (6 mL/kg/predicted body weight) in conjunction with a plateau pressure limit of 30 cm H(2)0 attenuated the severity of clinical lung injury and reduced mortality by 22%. Ironically, after years of searching for anti-inflammatory treatments for ALI/ARDS, it turns out that a lung protective ventilatory strategy has proven to be the most efficacious anti-inflammatory treatment ever discovered for ALI/ARDS. However, it is still possible that pharmacologic treatments also may enhance survival. For example, a recent report that activated protein C reduces mortality in patients with sepsis raises hope that the incidence and severity of sepsis-induced ALI/ARDS may be reduced by treatment with this agent that has both anti-inflammatory and anticoagulant properties. Also, therapy directed at hastening the resolution of lung injury by increasing the functional recovery of the alveolar epithelium may be of value, both in diminishing the fibroproliferative phase of ALI/ARDS as well as accelerating the resolution of alveolar edema.
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PMID:Clinical Acute Lung Injury and Acute Respiratory Distress Syndrome. 1185 76

A recent large trial has shown that recombinant activated protein C reduced mortality in severe sepsis. This is the first real advance in the pharmacotherapy of sepsis since the introduction of antibiotics in the last century.
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PMID:Activated protein C in severe sepsis. 1186 88

The role of activated protein C (APC) in coagulation, inflammation, and fibrinolysis and the pharmacology, pharmacokinetics, and trials of recombinant human activated protein C (rhAPC), or drotrecogin alfa (activated), in sepsis are described. Protein C, a naturally occurring vitamin K-dependent serine protease in the blood, remains inactive until exposed to the thrombin-thrombomodulin complex. This change between the inactive and active forms occurs constantly in humans and serves to balance the coagulation cascade. APC functions in concert with protein S as an anticoagulant, a fibrinolytic agent, and an antiinflammatory agent. In response to serious infection, a procoagulant process is activated leading to thrombin and fibrin deposition in small vessels that results in decreased blood flow, decreased oxygen delivery, and organ failure. The body's natural defense during severe sepsis is to activate protein C through the thrombin-thrombomodulin complex in an attempt to restore the imbalance of the hemostatic systems. However, APC has a short half-life, and the pool of circulating protein C is rapidly depleted in severe sepsis. Low protein C levels have been correlated with poor outcome in patients with severe sepsis and in animal models. These observations led to a Phase III safety and efficacy trial of drotrecogin alfa (activated) that demonstrated a significant improvement in mortality compared with placebo (24.7% versus 30.8%). This 6.1% absolute difference in mortality translates to a 19.4% reduction in relative risk of death in the treated patients. The proper use of drotrecogin alfa (activated) will require careful consideration of appropriate patients to treat and further studies in patient populations that were excluded from the Phase III trial, as well as possible modification of dosing schemes on the basis of patient response.
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PMID:Recombinant human activated protein C in severe sepsis. 1188 9

The roles of inflammation and coagulation in the pathophysiology of sepsis are described. Sepsis results when an infectious insult triggers a localized inflammatory reaction that then spills over to cause systemic symptoms of fever or hypothermia, tachycardia, tachypnea, and either leukocytosis or leukopenia. These clinical symptoms are called the systemic inflammatory response syndrome. Severe sepsis is defined by dysfunction of one of the major organ systems or unexplained metabolic acidosis. The inflammatory reaction is mediated by the release of cytokines, including tumor necrosis factor-alpha, interleukins, and prostaglandins, from neutrophils and macrophages. The cytokines activate the extrinsic coagulation cascade and inhibit fibrinolysis. These overlapping processes result in microvascular thrombosis; thrombosis is one potential factor producing organ dysfunction. Activation of the coagulation system leads to consumption of endogenous anticoagulants (e.g., protein C and antithrombin); this may be an important factor in the development of microvascular coagulation. Antiinflammatory mediators as well as inflammatory mediators have a role in sepsis, and an excess of either can result in poor patient outcomes. Sepsis is a complex syndrome involving activation of a variety of systems.
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PMID:Pathophysiology of sepsis. 1188 12

Severe bacterial sepsis, particularly secondary to meningococcaemia, is a well-recognized cause of purpura fulminans resulting from severe acquired protein C (PC) deficiency. Recently, PC and activated protein C (APC) concentrate replacement therapy has been shown to improve outcome in patients with meningococcaemia- associated purpura fulminans and severe sepsis respectively. Despite these impressive findings, PC and APC concentrates are not currently widely available. We describe a 31-year-old patient with pneumococcal septic shock, purpura fulminans (PF) and severe acquired PC deficiency, whom we successfully treated with conventional therapy and high-volume plasma exchange as a source of PC.
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PMID:Plasma exchange as a source of protein C for acute onset protein C pathway failure. 1249 94

Drotrecogin alfa (activated), recombinant human activated protein C, inhibits coagulation and inflammation and promotes fibrinolysis in patients with severe sepsis. 850 patients with severe sepsis treated with intravenous drotrecogin alfa (activated) 24 microg/kg/h for 96 hours had a significantly greater reduction in 28-day all-cause mortality (24.7%) than 840 placebo recipients (30.8%) in a randomised, double-blind, placebo-controlled study. The drug was associated with a 19.4% reduction in the relative risk of death at 28 days compared with placebo. Baseline characteristics of and pre-existing conditions in patients with sepsis appeared to have no effect on the efficacy of drotrecogin alfa (activated). A significantly greater reduction in median percentage change from baseline plasma D-dimer levels (a coagulation marker) was seen with drotrecogin alfa (activated) treatment than with placebo on study days 1 to 7 in patients with severe sepsis. On study days 1, 4, 5, 6 and 7, a significantly greater median reduction in interleukin-6 levels (an inflammation marker) from baseline was seen with drotrecogin alfa (activated) treatment than placebo. Drotrecogin alfa (activated) was associated with an increased incidence of serious bleeding events during the infusion period [2.4% vs 1.0% with placebo; p = 0.024] and the 28-day study period (3.5 vs 2.0%; p = 0.06) of the efficacy trial. This increase was primarily related to procedure-related events; there were no significant differences between the treatment groups in nonprocedure-related serious bleeding events. The most frequent site of bleeding was the gastrointestinal tract. With the exception of bleeding events, there were no clinically significant differences between treatment groups in the efficacy trial in the incidence of adverse events. Of the 210 deaths in patients with severe sepsis treated with drotrecogin alfa (activated) 24 microg/kg/h in the efficacy trial, four deaths due to haemorrhage and one due to cerebral oedema were possibly related to the study drug.
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PMID:Drotrecogin alfa (activated). 1189 30

Protein C is a vitamin-K dependent zymogen of the anti-coagulant serine protease activated protein C (APC). In this paper, we report four lines of evidence that APC can activate protein C in pooled normal plasma, and purified protein C. First, the addition of APC to protein C-deficient plasma supplemented with protein C produces a prolongation of the clotting time of plasma that is proportional to the amount of protein C. This behavior was observed with APC from the Chromogenix APC resistance kit (Dia Pharm, Franklin, OH, USA) and from APC derived from the thrombin activation of human protein C (Enzyme Research Laboratories, South Bend, IN, USA). Secondly, using immunoblotting after gel electrophoresis, the disappearance of epitopes for monoclonal antibodies that recognize protein C but not APC indicates a time course for the activation by APC of protein C in pooled normal plasma and protein C purified from plasma. Thirdly, the same time course for the disappearance of protein C specific epitope can be followed using ELISA. Finally, protein C can be activated by APC as indicated by the increase in APC specific synthetic substrate Tryp-Arg-Arg-p nitroaniline hydrolysis. Kinetic data indicate a value of 4.7+/-0.4 mM(-1) s(-1) for the activation of protein C by APC under physiological conditions and in the presence of calcium. These observations document that APC must function not only in the inactivation of activated factors V and VIII, but also in the activation of protein C. This additional action of APC may be important to consider more broadly because of APC in the treatment of sepsis.
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PMID:Proteolysis of protein C in pooled normal plasma and purified protein C by activated protein C (APC). 1189 50

The dendritic cell (DC) is the most potent APC of the immune system, capable of stimulating naive T cells to proliferate and differentiate into effector T cells. Recombinant adenovirus (Adv) readily transduces DCs in vitro allowing directed delivery of transgenes that modify DC function and immune responses. In this study we demonstrate that footpad injection of a recombinant Adv readily targets transduction of myeloid and lymphoid DCs in the draining popliteal lymph node, but not in other lymphoid organs. Popliteal DCs transduced with an empty recombinant Adv undergo maturation, as determined by high MHC class II and CD86 expression. However, transduction with vectors expressing human IL-10 limit DC maturation and associated T cell activation in the draining lymph node. The extent of IL-10 expression is dose dependent; transduction with low particle numbers (10(5)) yields only local expression, while transduction with higher particle numbers (10(7) and 10(10)) leads additionally to IL-10 appearance in the circulation. Furthermore, local DC expression of human IL-10 following in vivo transduction with low particle numbers (10(5)) significantly improves survival following cecal ligation and puncture, suggesting that compartmental modulation of DC function profoundly alters the sepsis-induced immune response.
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PMID:Increased survival in sepsis by in vivo adenovirus-induced expression of IL-10 in dendritic cells. 1190 99


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