thromboplastin and Shock--Septic

The pathobiology of the septic process includes a complex interrelationship between inflammation and the coagulations system. Antithrombin (AT) and tissue factor are important components of the coagulation system and have potential roles in the production and amplification of sepsis. Sepsis is associated with a decrease in AT levels, and low levels are also associated with the development of multiple organ failure and death. Treatment strategies incorporating AT replacement therapy in sepsis and septic shock have not resulted in an improvement in survival or reversal of disseminated intravascular coagulation.

Topics: Antithrombin III; Critical Illness; Humans; Multiple Organ Failure; Sepsis; Shock, Septic; Thromboplastin

Severe sepsis and septic shock are among the most common causes of death in noncoronary intensive care units. The incidence of sepsis has been increasing over the past two decades, and is predicted to continue to rise over the next 20 years. While our understanding of the complex pathophysiologic alterations that occur in severe sepsis and septic shock has increased greatly asa result of recent clinical and preclinical studies, mortality associated with the disorder remains unacceptably high. Despite these new insights, the cornerstone of therapy continues to be early recognition, prompt initiation of effective antibiotic therapy, and source control, and goal-directed hemodynamic, ventilatory,and metabolic support as necessary. To date, attempts to reduce mortality with innovative, predominantly anti-inflammatory therapeutic strategies have been extremely disappointing. Observations of improved outcomes with physiologic doses of corticosteroid replacement therapy and activated protein C (drotrecogin alfa[activated]) have provided new adjuvant therapies for severe sepsis and septic shock in selected patients. This article reviews the components of sepsis management and discusses the available evidence in support of these recommendations. In addition, there is a discussion of some promising new strategies.

Topics: Anti-Infective Agents; Anti-Inflammatory Agents; Cause of Death; Critical Care; Evidence-Based Medicine; Fibrinolytic Agents; Fluid Therapy; Hemofiltration; Humans; Incidence; Plasma Exchange; Practice Guidelines as Topic; Prognosis; Protein C; Respiration, Artificial; Risk Factors; Sepsis; Shock, Septic; Survival Rate; Thromboplastin; Treatment Outcome; Tumor Necrosis Factor-alpha

Tissue factor is a transmembrane procoagulant glycoprotein and a member of the cytokine receptor superfamily. It activates the extrinsic coagulation pathway, and induces the formation of a fibrin clot. Tissue factor is important for both normal homeostasis and the development of many thrombotic diseases. A wide variety of cells are able to synthesize and express tissue factor, including monocytes, granulocytes, platelets and endothelial cells. Tissue factor expression can be induced by cell surface components of pathogenic microorganisms, proinflammatory cytokines and membrane microparticles released from activated host cells. Tissue factor plays an important role in initiating thrombosis associated with inflammation during infection, sepsis, and organ transplant rejection. Recent findings suggest that tissue factor can also function as a receptor and thus may be important in cell signaling. The present minireview will focus on the role of tissue factor in the pathogenesis of septic shock, infectious endocarditis and invasive aspergillosis, as determined by both in vivo and in vitro models.

Topics: Aspergillosis; Blood Coagulation Factors; Endocarditis, Bacterial; Endothelial Cells; Humans; Shock, Septic; Thromboplastin

Normal endothelial cells express several membrane components with anticoagulant properties, which include: 1) tissue factor pathway inhibitors (TFPI), i.e. surface molecules able to accelerate the action of antithrombin (AT) on coagulation proteases; 2) thrombomodulin (TM), a thrombin binding surface protein able to inhibit thrombin activity; the complex TM-thrombin, also, activates protein C (PC); 3) endothelium derived factors such as nitric oxide and prostacyclin, which have antiadhesive properties and activate plasminogen. Exposure to inflammatory and/or septic stimuli can rapidly lead to a procoagulant response, activated by bacterial endotoxins, and to a decrease of endothelial anticoagulant membrane components. Activation of coagulation concomitant to impaired fibrinolysis is associated with fibrin deposition, tissue ischemia and necrosis. This review presents the results of different strategies aimed at reducing organ dysfunction and mortality in septic shock by modulating coagulation activity. In various animal models and in phase II clinical studies, the treatment with TFPI, AT and activated PC reduced organ dysfunction and mortality. Two phase III trials showed no efficacy of AT and a reduction of the relative risk of death with activated PC. In animal studies, supplementation with l-arginine and administration of perindopril were able to prevent septic shock-associated endothelial injury. A marked reduction of endothelial injury and improved survival of treated animals were also seen with antiglycoprotein IIb/IIIa which attenuated the role of monocytes in the disseminated intravascular coagulation process.

Topics: Animals; Antithrombins; Blood Coagulation; Clinical Trials, Phase III as Topic; Endothelium, Vascular; Humans; Lipoproteins; Nitric Oxide; Protein C; Shock, Septic; Thrombomodulin; Thromboplastin; Tumor Necrosis Factor-alpha

Inflammation and the cytokines clearly affect the coagulation system. Less clear are the specific influences of the coagulation system on inflammation. In this chapter only some of the coagulation systems affected by the cytokines are discussed, and the influences on the fibrinolytic system, which is also downregulated by selected cytokines are not mentioned; see Schneiderman and Loskutoff (1991) for a brief review. The major focus is on possible models by which inflammation and coagulation are linked, and examples where in vitro studies have led to correct in vivo predictions and where the results remain ambiguous. Finally, this chapter is clearly a biased perspective with the primary emphasis on the components and pathways with which the author has personal experience.

Topics: Animals; Blood Coagulation Factors; Cell Adhesion Molecules; Cells, Cultured; Cytokines; Disseminated Intravascular Coagulation; Endothelium, Vascular; Humans; Inflammation; Models, Biological; Neoplasms; Papio; Protein C; Shock, Septic; Thrombomodulin; Thromboplastin; Thrombosis

Cells of monocyte lineage serve as effector cells in the cellular immune response. In addition, they respond to LPS and cytokines with activation and expression of inflammatory effector gene products similar to those elicited by the antigen driven response. The response to antigen proceeds at the T helper cell level through two independent forms of cellular collaboration, contact and lymphokine. We review the control of expression of the Tissue Factor (TF) gene and the function of the TF protein. The enhanced initiation of transcription of the TF gene appears to require engagement of a 56 bp LPS Response Element, an enhancer that is engaged by both AP-1 type heterodimeric complexes as well as NF kappa B like heterodimeric complexes. Dissociation of NF kappa B from Ig kappa B by cytokine and LPS stimulation, and possibly activated T cells, may represent a common pathway to induction of the TF and other inflammatory genes. Enhancement of expression of TF is observed upon adhesion of Mo to endothelial cells and extracellular matrix proteins, as well as upon engagement of leukocyte integrins. The biological effects that follow from expression of TF by vascular cells have been resolved by analysis of function aided by the use of recombinant full length TF and truncated surface domain of TF. The rules of assembly of the cognate ligands of TF, namely the zymogen plasma factors VII and the serine protease factor VIIa, with the soluble surface domain of TF in free solution, in the presence of phospholipid surfaces and cell surface and of the anchored TF molecule have been described. It is evident that assembly of the surface domain of TF with VIIa to form the binary TF.VIIa complex induces a significant increase in the Kcat of the catalytic domain of VIIa for small peptidyl substrates and more profoundly for protein substrate. This provides substantial evidence for an allosteric effect on the catalytic cleft of VIIa that is imparted by binding to TF, its cognate catalytic cofactor. It is also evident that the TF.VIIa complex is proteolytically active and can activate the zymogen plasma factor X to the serine protease Xa in free solution, inferring that extended substrate recognition by induced structural loci of the TF.VIIa complex are created from either or both proteins to constitute a new recognition structure. It is also evident that association of X with charged phospholipid surfaces enhances the proteolytic activation of this zymogen by increasing recognitio

Topics: Animals; Blood Coagulation; CD4-Positive T-Lymphocytes; Cytokines; Disseminated Intravascular Coagulation; Endothelium, Vascular; Enzyme Activation; Factor VII; Factor VIIa; Gene Expression Regulation; Humans; Immunity, Cellular; Lipid Bilayers; Lipopolysaccharides; Lymphocyte Activation; Membrane Lipids; Mice; Monocytes; NF-kappa B; Shock, Septic; Thromboplastin; Transcription, Genetic

Topics: Amino Acid Sequence; Animals; Blood Coagulation; Endothelium, Vascular; Factor VIIa; Fibroblasts; Gene Expression Regulation; Genes; Humans; Leukocytes, Mononuclear; Molecular Sequence Data; Papio; Peptide Fragments; Shock, Septic; Thromboplastin

Topics: Animals; Bacteremia; Biomarkers; Disseminated Intravascular Coagulation; Dogs; Edema; Escherichia coli Infections; Inflammation; Papio; Protein C; Rats; Shock, Septic; Thromboplastin; Tumor Necrosis Factor-alpha

In the cytokine cascade, a central position is occupied by that molecule known as "cachectin" or "tumor necrosis factor," because this molecule, more than any other, has been shown to mediate the biologic effects of LPS, and to provoke a state of wasting very similar to that observed in cancer cachexia. The history of the isolation of this factor is instructive, because it illustrates the fact that a single mediator may transduce a broad spectrum of biologic effects, and may thus present itself to investigators interested in very disparate phenomena.

Topics: Animals; Genetic Code; Humans; Lymphotoxin-alpha; Shock, Septic; Thromboplastin

Topics: Adrenal Glands; Adrenocorticotropic Hormone; Animals; Antigen-Antibody Reactions; Blood Coagulation Disorders; Blood Coagulation Factors; Blood Coagulation Tests; Catecholamines; Dibenzylchlorethamine; Endotoxins; Female; Fibrinolysis; Haplorhini; Hemolysis; Hemorrhage; Humans; Kidney; Microscopy, Electron; Mononuclear Phagocyte System; Necrosis; Phagocytosis; Phenoxybenzamine; Pregnancy; Pregnancy, Animal; Shock, Septic; Shwartzman Phenomenon; Thromboplastin

Septic shock-induced disseminated intravascular coagulopathy (DIC) contributes to multiple organ failure. Mechanisms governing vascular responses to open occurrence of DIC have not yet been established. Circulating plasma microparticles (MPs), released upon cell stress, constitute a catalytic procoagulant surface and are surrogates of vascular cell activation/injury. Herein, MPs were assessed as possible markers of haemostatic and vascular dysfunction in the DIC time course.. One hundred patients with septic shock from three ICUs were enrolled and their haemostatic status evaluated at admission (D1), D2, D3 and D7. Circulating procoagulant MPs were isolated, quantified by prothrombinase assay and their cellular origin determined. DIC diagnosis was made according to the JAAM 2006 score.. Ninety-two patients were analysed and 40 had DIC during the first 24 h. Routine clotting times and factor/inhibitor activity did not allow assessing vascular cell involvement. At admission, thrombin generation and fibrinolysis were observed in both groups while impaired fibrin polymerisation was evidenced only in DIC patients. Sustained thrombin generation persisted over time in both groups at D7. While total microparticle concentrations were in the same range regardless of DIC diagnosis, specific phenotypes were already detected at admission in DIC patients. Endothelial- and leucocyte-derived MPs were higher in DIC while an increased soluble glycoprotein V/platelet ratio was delayed, underscoring the first involvement of endothelial cells and leucocytes whereas platelet activation was delayed. Endothelium-derived CD105-MPs (OR 6.55) and CD31-MPs (OR 0.49) were strongly associated with early DIC in multivariate analysis.. Endothelial-derived microparticles are relevant biomarkers of septic shock-induced DIC and could be used to evaluate early vascular injury.

Topics: Biomarkers; Cell-Derived Microparticles; Disseminated Intravascular Coagulation; Endothelial Cells; Female; Humans; Male; Middle Aged; Multiple Organ Failure; Shock, Septic; Thromboplastin; Young Adult

As US healthcare expenditures continue to rise, there is significant pressure to reduce the cost of inpatient medical services. Studies have estimated that over 70% of routine labs may not yield clinical benefits while adding over $300 in costs per day for every inpatient. Although orthopaedic trauma patients tend to have longer inpatient stays and hip fractures have been associated with significant morbidity, there is a dearth of data examining pre-operative labs in predicting post-operative adverse events in these populations. The purpose of this study was to assess whether pre-operative labs significantly predict post-operative cardiac and septic complications in orthopaedic trauma and hip fracture patients.. Between 2006 and 2013, 56,336 (15.6%) orthopaedic trauma patients were identified and 27,441 patients (7.6%) were diagnosed with hip fractures. Pre-operative labs included sodium, BUN, creatinine, albumin, bilirubin, SGOT, alkaline phosphatase, white count, hematocrit, platelet count, prothrombin time, INR, and partial thromboplastin time. For each of these labs, patients were deemed to have normal or abnormal values. Patients were noted to have developed cardiac or septic complications if they sustained (1) myocardial infarction (MI), (2) cardiac arrest, or (3) septic shock within 30 days after surgery. Separate regressions incorporating over 40 patient characteristics including age, gender, pre-operative comorbidities, and labs were performed for orthopaedic trauma patients in order to determine whether pre-operative labs predicted adverse cardiac or septic outcomes.. 749 (1.3%) orthopaedic trauma patients developed cardiac complications and 311 (0.6%) developed septic shock. Multivariate regression demonstrated that abnormal pre-operative platelet values were significantly predictive of post-operative cardiac arrest (OR: 11.107, p=0.036), and abnormal bilirubin levels were predictive (OR: 8.487, p=0.008) of the development of septic shock in trauma patients. In the hip fracture cohort, abnormal partial thromboplastin time was significantly associated with post-operative myocardial infarction (OR: 15.083, p=0.046), and abnormal bilirubin (OR: 58.674, p=0.002) significantly predicted the onset of septic shock.. This is the first study to demonstrate the utility of pre-operative labs in predicting perioperative cardiac and septic adverse events in orthopaedic trauma and hip fracture patients. Particular attention should be paid to haematologic/coagulation labs (platelets, PTT) and bilirubin values.. Prognostic Level II.

Topics: Aged; Bilirubin; Cost-Benefit Analysis; Diagnostic Tests, Routine; Female; Fractures, Bone; Humans; Male; Multiple Trauma; Myocardial Infarction; Orthopedic Procedures; Orthopedics; Platelet Count; Postoperative Complications; Predictive Value of Tests; Preoperative Period; Prognosis; Shock, Septic; Surgical Wound Infection; Thromboplastin; United States; Unnecessary Procedures

Circulating microparticles play a pro-inflammatory and procoagulant detrimental role in the vascular dysfunction of septic shock. It was the objective of this study to investigate mechanisms by which a pharmacological modulation of microparticles could affect vascular dysfunction in a rat model of septic shock. Septic or sham rats were treated by activated protein C (aPC) and resuscitated during 4 hours. Their microparticles were harvested and inoculated to another set of healthy recipient rats. Haemodynamic parameters were monitored, circulating total procoagulant microparticles assessed by prothrombinase assay, and their cell origin characterised. Mesenteric resistance arteries, aorta and heart were harvested for western blotting analysis. We found that a) the amount and phenotype of circulating microparticles were altered in septic rats with an enhanced endothelial, leucocyte and platelet contribution; b) aPC treatment significantly reduced the generation of leucocyte microparticles and norepinephrine requirements to reach the mean arterial pressure target in septic rats; c) Microparticles from untreated septic rats, but not from aPC-treated ones, significantly reduced the healthy recipients' mean arterial pressure; d) Microparticle thromboxane content and aPC activity were significantly increased in aPC-treated septic rats. In inoculated naïve recipients, microparticles from aPC-treated septic rats prompted reduced NF-κB and cyclooxygenase-2 arterial activation, blunted the generation of pro-inflammatory iNOS and secondarily increased platelet and endothelial microparticles. In conclusion, in this septic shock model, increased circulating levels of procoagulant microparticles led to negative haemodynamic outcomes. Pharmacological treatment by aPC modified the cell origin and levels of circulating microparticles, thereby limiting vascular inflammation and favouring haemodynamic improvement.

Topics: Animals; Cell-Derived Microparticles; Coagulants; Cyclooxygenase 2; Hemodynamics; Humans; Inflammation; Male; NF-kappa B; Phenotype; Protein C; Rats; Rats, Wistar; Recombinant Proteins; Shock, Septic; Thromboplastin; Thromboxane A2; Time Factors; Treatment Outcome

The plasma level of bacterial lipopolysaccharides (LPS) is associated with activation of the coagulation system, inhibition of fibrinolysis and the nature of the clinical presentation and outcome in patients with meningococcal disease. Tissue factor (TF)-bearing microparticles (MPs) appear to contribute to the pathogenesis of disseminated intravascular coagulation (DIC). The aim of this study was to investigate the relationship between MP-associated TF activity and the level of bacterial LPS in plasma from patients with meningococcal septic shock and meningitis.. MPs isolated from citrated plasmas were assessed for TF-dependent activity with both a plasma-based thrombin generation assay (CAT) and whole blood-based thromboelastometry (ROTEM). The LPS level was measured using a chromogenic Limulus amebocyte lysate assay.. MPs obtained from patients with meningococcal septic shock initiated significantly more efficient and TF-dependent thrombin generation in the CAT assay compared to MPs from patients with meningococcal meningitis. Differences in MP-associated TF activity between the septic shock patients and the meningitis patients were also evident when MPs were added to whole blood using ROTEM. The level of plasma LPS in patients with septic shock (range 2-2,100 EU/mL) was correlated with thrombogram parameters in the CAT assay; lagtime (r(s)=-0.84), time to peak (rs=-0.83), peak (r(s)=0.85) and ETP (r(s)=0.83).. MPs obtained from patients with meningococcal septic shock displayed more efficient TF-dependent thrombin generation and clot formation compared to MPs from meningitis patients. MP-associated TF activity was closely associated with plasma LPS levels in the septic shock group.

Topics: Adolescent; Adult; Cell-Derived Microparticles; Child; Child, Preschool; Female; Humans; Lipopolysaccharides; Male; Meningitis, Meningococcal; Meningococcal Infections; Middle Aged; Shock, Septic; Thromboplastin; Young Adult

Tissue factor (TF), which is expressed on the surface of activated monocytes, is the major procoagulant that initiates thrombus formation in sepsis. Two endogenous neuropeptides, vasoactive intestinal peptide (VIP) and pituitary adenylate cyclase-activating polypeptide (PACAP), are attractive candidates for the development of therapies against septic shock. The purpose of this study was to examine whether VIP or PACAP inhibit the LPS-induced TF expression in monocytes. Treatment of freshly isolated human monocytes or cultured monocytic THP-1 cells with VIP or PACAP leads to reduced LPS-induced TF protein, mRNA expression and activity, as demonstrated by Western blot, real-time polymerase chain reaction, and TF activity assay, respectively. In an endotoxemic model, VIP blunts the increase of LPS-induced TF expression in blood cells at the transcriptional level, as demonstrated by real-time polymerase chain reaction. However, neither neuropeptide affects the expression of TF pathway inhibitor in monocytes. In vitro, LPS increases the migration of c-Rel/p65 into the nucleus and the phosphorylation of p38 and JNK, all of which are essential for LPS-induced TF expression. In addition, interestingly, VIP and PACAP block both the migration of c-Rel/p65 and the phosphorylation of p38 and JNK, as demonstrated by Western blot analysis. These data indicate that VIP and PACAP inhibit LPS-induced TF expression in monocytes in vitro and in vivo, confirming these peptides as candidates for the multitarget therapy of septic shock.

Topics: Animals; Dose-Response Relationship, Drug; Endotoxemia; Humans; Lipopolysaccharides; Male; MAP Kinase Kinase 4; Mice; Mice, Inbred BALB C; Monocytes; p38 Mitogen-Activated Protein Kinases; Pituitary Adenylate Cyclase-Activating Polypeptide; Shock, Septic; Thromboplastin; Vasoactive Intestinal Peptide

Lemierre's syndrome presents a classic clinical picture, the pathophysiology of which remains obscure. Attempts have been made to trace genetic predispositions that modify the host detection of pathogen or the resultant systemic reaction.. A 17-year old female, with no previous medical history, was admitted to the intensive care unit for septic shock, acute respiratory distress syndrome and Lemierre's syndrome. Her DNA was assayed for single nucleotide polymorphisms previously incriminated in the detection of the pathogen, the inflammatory response and the coagulation cascade. We observed functional variations in her Toll like 5 receptor (TLR 5) gene and two coagulation variations (Tissue Factor (TF) 603 and Plasminogen-Activator-Inhibitor-1 (PAI-1) 4G-4G homozygosity) associated with thrombotic events.. The innate immune response and the prothrombogenic mutations could explain, at least in part, the symptoms of Lemierre's syndrome. Genomic study of several patients with Lemierre's syndrome may reveal its pathophysiology.

Topics: Adolescent; Female; Fusobacterium Infections; Fusobacterium necrophorum; Humans; Pharyngitis; Plasminogen Activator Inhibitor 1; Polymorphism, Single Nucleotide; Respiratory Distress Syndrome; Shock, Septic; Syndrome; Thrombophlebitis; Thromboplastin; Toll-Like Receptor 5

Endothelium plays a critical role in the pathobiology of sepsis by integrating systemic host responses and local rheological stimuli. We studied the differential expression and activation of tissue factor (TF)-dependent coagulation on linear versus branched arterial segments in a baboon sepsis model. Animals were injected intravenously with lethal doses of Escherichia coli or saline and sacrificed after 2 to 8 hours. Whole-mount arterial segments were stained for TF, TF-pathway inhibitor (TFPI), factor VII (FVII), and markers for endothelial cells (ECs), leukocytes, and platelets, followed by confocal microscopy and image analysis. In septic animals, TF localized preferentially at branches, EC surface, leukocytes, and platelet aggregates and accumulated in large amounts in the subendothelial space. FVII strongly co-localized with TF on ECs and leukocytes but less so with subendothelial TF. TFPI co-localized with TF and FVII on endothelium and leukocytes but not in the subendothelial space. Focal TF increases correlated with fibrin deposition and increased endothelial permeability to plasma proteins. Biochemical analysis confirmed that aortas of septic baboons expressed more TF mRNA and protein than controls. Branched segments contained higher TF protein levels and coagulant activity than equivalent linear areas. These data suggest that site-dependent endothelial heterogeneity and rheological factors contribute to focal procoagulant responses to E. coli.

Topics: Animals; Aorta; Arteries; Biomarkers; Blood Coagulation; Blood Platelets; Disease Models, Animal; Endothelial Cells; Escherichia coli Infections; Factor VII; Image Processing, Computer-Assisted; Leukocytes; Lipopolysaccharides; Lipoproteins; Microscopy, Confocal; Models, Biological; Papio; RNA, Messenger; Shock, Septic; Thromboplastin; Up-Regulation

Disseminated intra-vascular coagulation (DIC) is a serious and frequently fatal condition associated with gross abnormalities of thrombosis, haemostasis, vascular function and inflammation. We measured serial levels of plasma soluble E selectin (marking endothelia damage), interleukin 6 (IL-6, a marker if inflammation) and tissue factor (involved in coagulation) in two young adults with bacterially-induced DIC. Soluble E selectin and IL-6 were grossly elevated on presentation and increased as the DIC progressed. Tissue factor was normal on admission but also increased with the DIC. However, levels remained high in one of the patients who subsequently died, whilst levels resolved in the patient who survived. We suggest that both admission and evolving sE-selectin and IL-6 levels may be useful in predicting outcome, and that measurement of TF has little extra to offer.

Topics: Adult; Biomarkers; Disease Progression; Disseminated Intravascular Coagulation; E-Selectin; Endothelium, Vascular; Female; Humans; Interleukin-6; Male; Meningitis, Meningococcal; Meningococcal Infections; Prognosis; Sepsis; Shock, Septic; Thromboplastin

Streptococcal toxic shock syndrome (StrepTSS) is an invasive infection characterized by marked coagulopathy, multiple organ failure, and rapid tissue destruction and is strongly associated with M type 1 and 3 group A streptococci (GAS). Initiation of the coagulation cascade with formation of microvascular thrombi contributes to multiple organ failure in human cases of gram-negative bacteremia; however, little is known regarding the mechanism of coagulopathy in StrepTSS. Thus, we investigated the abilities of several strains of M type 1 and 3 GAS isolated from human cases of StrepTSS to stimulate production of tissue factor (TF), the principal initiator of coagulation in vivo. Washed, killed M type 1 and 3 GAS, but not M type 6 GAS, elicited high-level TF-mediated procoagulant activity from both isolated human monocytes and cultured human umbilical vein endothelial cells. M type 1 GAS consistently elicited higher levels of TF from monocytes than did M type 3 GAS. GAS-induced TF synthesis in monocytes did not correlate with production of tumor necrosis factor alpha or interleukin-8. Conversely, M type 3 GAS were consistently more potent than M type 1 GAS in stimulating endothelial cell TF synthesis. These results demonstrate that (i) M type 1 and 3 strains of GAS are potent inducers of TF synthesis, (ii) GAS-induced TF synthesis is not simply an epiphenomenon of cytokine generation, and (iii) induction of TF in endothelial cells and monocytes may be M type specific. In total, these findings suggest that a novel interaction between GAS and host cells contributes to the observed coagulopathy in StrepTSS.

Topics: Bacterial Typing Techniques; Blood Coagulation; Cells, Cultured; Cytokines; Endothelium, Vascular; Humans; Inflammation; Monocytes; Shock, Septic; Streptococcal Infections; Streptococcus pyogenes; Thromboplastin; Umbilical Veins

Topics: Animals; Apoptosis; Dendritic Cells; Hemorrhagic Fever, Ebola; Humans; Macrophages; Shock, Septic; Thromboplastin

Sepsis and septic shock are very complex and dynamic clinical syndromes. A systemic response to an infection or other triggers can induce a cascade consisting of toxins--leukocytes--cytokines--mediators of inflammation--endothelial cell dysfunction--activation of blood coagulation--intravascular fibrin deposition--alteration of microcirculation, resulting in a damage of organs. Multi organ failure and sepsis are therefore tightly connected. The associated disturbances of blood coagulation range between a simple activation of coagulation with a transient increase of activation markers (i.e. D-dimer), similar to an acute-phase reaction and full blown disseminated intravascular coagulation with consumption coagulopathy. This article summarizes these pathophysiological mechanisms, shows available diagnostic tools and differential diagnoses, and discusses therapeutic options for sepsis and multi organ failure.

Topics: Animals; Blood Coagulation Tests; Disseminated Intravascular Coagulation; Endothelium, Vascular; Fibrinolysis; Humans; Inflammation Mediators; Multiple Organ Failure; Platelet Activation; Shock, Septic; Systemic Inflammatory Response Syndrome; Thromboplastin

The enhanced extrinsic blood coagulation following septic shock often manifests cardiovascular complications. The upregulated monocytic tissue factor (mTF) was shown to be a primary contributor to the extrinsic hypercoagulation following acute bacterial endotoxin (LPS) infection. A single-stage clotting assay monitors TF-initiated coagulation. We herein demonstrate a novel anticoagulant activity of antimicrobial peptide Buforin I (BF I) in offsetting LPS-induced mTF hypercoagulation in THP-1 cells, which was confirmed in a cell-free in vitro model, showing that BF I effectively blocked rabbit brain thromboplastin (rbTF) procoagulant activity. Upon inclusion of 25 microM BF I into human plasma, the prolonged prothrombin time (PT) was consistent with the depressed TF-initiated coagulation. In a two-stage chromogenic assay monitoring S-2288 hydrolysis, BF I significantly inhibited not only mTF- but also rbTF-catalyzed FVII activation accompanied by the diminished FVIIa formation. The inhibition by BF I of FVII activation accounted for its novel anticoagulant activity in offsetting mTF-initiated hypercoagulation.

Topics: Amino Acid Sequence; Animals; Anti-Infective Agents; Blood Coagulation; Cell Line; Factor VII; Humans; In Vitro Techniques; Lipopolysaccharides; Molecular Sequence Data; Proteins; Rabbits; Shock, Septic; Thromboplastin; Thrombosis

Hemorrhagic shock due to major trauma predisposes to the development of acute respiratory distress syndrome. Because lung fibrin deposition is one of the hallmarks of this syndrome, we hypothesized that resuscitated shock might predispose to the development of a net procoagulant state in the lung. A rodent model of shock/resuscitation followed by low-dose intratracheal lipopolysaccharide (LPS), a clinically relevant "two-hit" model, was used to test this hypothesis. Resuscitated shock primed the lungs for an increased tissue factor and plasminogen activator (PA) inhibitor-1 gene expression in response to LPS, while the fibrinolytic PA was reduced. These alterations were recapitulated in isolated alveolar macrophages, suggesting their role in the process. LPS-induced tumor necrosis factor (TNF) was also augmented in animals after antecedent shock/resuscitation, and studies using anti-TNF antibodies revealed that TNF expression was critical to the induction of the procoagulant molecules and the reduction in PA. By contrast, TNF did not appear to play an important role in neutrophil sequestration in this model, inasmuch as anti-TNF had no effect on lung neutrophil accumulation or chemokine expression. However, treatment prevented albumin leak by preventing alveolar neutrophil activation. The inclusion of the antioxidant N-acetyl-cysteine in the resuscitation fluid resulted in prevention of both the development of the net procoagulant state and lung neutrophil sequestration, suggesting a role for upstream oxidant effects in the priming process. These studies provide a cellular and molecular basis for lung fibrin deposition after resuscitated shock and demonstrate a divergence of pathways responsible for fibrin generation and neutrophil accumulation.

Topics: Acetylcysteine; Animals; Antioxidants; Blood Coagulation Disorders; Bronchoalveolar Lavage Fluid; Capillary Leak Syndrome; Disseminated Intravascular Coagulation; Fibrin; Fibrinolysis; Gene Expression Regulation; Lipopolysaccharides; Lipoproteins; Macrophage Activation; Macrophages, Alveolar; Male; Models, Biological; Neutrophils; NF-kappa B; Oxidative Stress; Plasminogen Activator Inhibitor 1; Pulmonary Alveoli; Rats; Rats, Sprague-Dawley; Reactive Oxygen Species; Respiratory Distress Syndrome; Shock, Hemorrhagic; Shock, Septic; Thromboplastin; Transcription, Genetic; Tumor Necrosis Factor-alpha

Recently published studies suggest that the procoagulant receptor protein tissue factor (TF) is involved in vitro in cell adhesion and migration, via an interaction of its cytoplasmic domain with cytoskeletal proteins. Interestingly, TF is abundantly expressed in myocardium, but not in skeletal muscle. To elucidate the possible roles of TF in the myocardium, this study examined the cellular distribution of TF in relation to cytoskeletal proteins, as well as its relative amounts in different segments of premature, mature, and pathologically altered cardiac muscle. In juvenile and adult hearts, TF was predominantly detectable in the transverse part of the intercalated discs, where it co-localized with cytoskeletal proteins such as desmin and vinculin. The lowest amount of TF was observed in right atrial and the highest in left ventricular myocardium, which correlated with the number of contact sites of cardiomyocytes in these segments of the cardiac muscle. Lower levels of TF were present in structurally altered myocardium from patients with hypertension or ventricular hypertrophy. In addition, TF expression was decreased in human heart during sepsis and transiently decreased in rabbit heart in an endotoxaemia model, which indicates that a reduction in TF may contribute to cardiac failure in sepsis. The microtopography of TF at cardiomyocyte contact sites indicates that TF may play a structural role in the maintenance of cardiac muscle.

Topics: Adolescent; Adult; Aged; Aged, 80 and over; Aging; Animals; Cell Communication; Child; Child, Preschool; Cytoskeletal Proteins; Female; Humans; Hypertrophy, Left Ventricular; Infant; Infant, Newborn; Infant, Premature; Male; Mice; Mice, Inbred BALB C; Middle Aged; Myocardium; Sex Characteristics; Shock, Septic; Thromboplastin

To investigate whether impaired endothelial function was related to alteration of nitric oxide (NO) formation during endotoxic shock, we studied the effects of supplementation of L-arginine (L-Arg), D-arginine (D-Arg), and N(G)-nitro-L-arginine methyl ester (L-NAME), on endothelial function and structure in a rabbit model. Endotoxic shock was induced by a single lipopolysaccharide bolus (0.5 mg/kg i.v., Escherichia coli endotoxin). Coagulation factors and expression of monocyte tissue factor were determined by functional assays. Endothelium-dependent vascular relaxation was assessed by in vitro vascular reactivity. Immunohistochemical staining (CD31) was performed to assess damaged endothelial cell surface of the abdominal aorta. These parameters were studied 5 days after the onset of endotoxic shock and were compared under three conditions: in absence of treatment, with L-Arg or D-Arg supplementation, or with L-NAME. Both L-Arg and D-Arg significantly improved endothelium-dependent relaxation and endothelial morphological injury. L-NAME did not alter endothelial histological injury induced by lipopolysaccharide. These data indicate that arginine supplementation nonspecifically prevents endothelial dysfunction and histological injury in rabbit endotoxic shock. Moreover, L-Arg has no effect on coagulation activation and expression of monocyte tissue factor induced by endotoxic shock.

Topics: Acetylcholine; Animals; Arginine; Blood Gas Analysis; Calcimycin; Disease Models, Animal; Endothelium, Vascular; Enzyme Inhibitors; Hemostasis; Ionophores; Lipopolysaccharides; Male; Monocytes; NG-Nitroarginine Methyl Ester; Nitroprusside; Phenylephrine; Rabbits; Shock, Septic; Thromboplastin; Vasoconstriction; Vasoconstrictor Agents; Vasodilation; Vasodilator Agents; Weight Loss

To determine the duration of vascular blood vessel dysfunction and coagulation abnormalities after administration of endotoxin in a nonlethal septic rabbit model.. Randomized, controlled, interventional trial.. University animal laboratory.. A total of 30 male New Zealand White rabbits, randomly assigned to one of two groups.. Male New Zealand White rabbits were randomly divided into control or lipopolysaccharide (LPS) (0.5 mg/kg iv bolus Escherichia coli endotoxin)-treated groups. Metabolic acidosis and coagulation activation confirmed the presence of septic shock. The abdominal aorta was removed at 24 hrs (day 1), day 5, or day 21 after LPS injection. Immunohistochemical staining for an endothelial cell marker (PECAM-1/CD31) was performed to assess endothelial injury. Endothelium-dependent vascular relaxation was analyzed by in vitro vascular reactivity studies. Responses to acetylcholine, to calcium ionophore (A-23187), and to sodium nitroprusside were studied. In addition, arterial blood samples were collected on day 1, day 5, and day 21 for measurement of clotting factors and tissue factor activity.. LPS injection resulted in endothelial injury, with loss of approximately 25% of the endothelial area on day 5, which disappeared on day 21. LPS injection also caused a significantly reduced relaxation response to acetylcholine (44.9% +/-9.9% vs. 76.5%+/-5.4% for the control group; p < .005), which was restored on day 21. In contrast, vascular relaxation in response to A-23187 and sodium nitroprusside was not altered. A significant decrease in the platelet count was observed on day 1, associated with a decrease in factors II and V. On day 5, platelet count and factors II and V were corrected in conjunction with an elevated monocyte tissue factor activity in LPS-injected rabbits. On day 21, coagulation abnormalities were corrected.. A single endotoxin injection in the rabbit was responsible for prolonged aortic endothelial cell dysfunction, as well as a prolonged procoagulant state. The latter is a potential trigger for disseminated intravascular coagulation. Importantly, these features are associated with normalization of conventional biological evidence of septic shock.

Topics: Animals; Blood Coagulation Factors; Disseminated Intravascular Coagulation; Endothelium, Vascular; Endotoxins; Escherichia coli; Male; Rabbits; Shock, Septic; Thrombophilia; Thromboplastin; Vascular Resistance

Monocyte activation in response to recombinant human granulocyte-macrophage colony-stimulating factor (GM-CSF) was examined in vitro in septic shock patients. These monocytes exhibited a greater respiratory burst activity than monocytes from healthy subjects; the response to secondary stimulation with bacterial stimuli was attenuated. GM-CSF restored the ability of monocytes to respond appropriately to secondary stimulation. Expression of certain integrin adhesion molecules, L-selectin, and Fcgamma receptors was increased on monocytes of septic shock patients; expression of CD11c was reduced. GM-CSF up-regulated integrin expression and decreased L-selectin, FcgammaRII, and FcgammaRIII expression. Septic patients exhibited greater biologic activity of monocyte tissue factor than did healthy subjects. Priming monocytes with GM-CSF accelerated tissue factor activation following stimulation with lipopolysaccharide and bacterial culture supernatant. Certain parameters of monocyte function may be restored by exposure to GM-CSF. This benefit may be offset by an increase in monocyte procoagulant activity.

Topics: Adult; Aged; Antigens, CD; Culture Media, Conditioned; Female; Granulocyte-Macrophage Colony-Stimulating Factor; Humans; Integrin alphaXbeta2; Integrins; L-Selectin; Leukocytes, Mononuclear; Lipopolysaccharides; Male; Middle Aged; Monocytes; Receptors, Fc; Receptors, IgG; Respiratory Burst; Shock, Septic; Thromboplastin; Up-Regulation

To determine whether treatment with recombinant human tissue factor pathway inhibitor (TFPI), an inhibitor of the extrinsic coagulation pathway, can improve survival in a clinically relevant model of gram-negative sepsis, rabbits were given an intraperitoneal inoculation of a suspension containing hemoglobin (40 microg/mL), porcine mucin (150 microg/mL), and viable Escherichia coli O18:K1 (1.0 +/- 0.5 x 10(5) cfu/kg). Treatment with gentamicin (5 mg/kg every 12 h for five doses) was instituted 4 h after induction of peritonitis. At the same time point, rabbits were randomized to receive a 24-h infusion of vehicle or one of three different doses of TFPI. Treatment groups, 7-day survival rates, and significance versus control were as follows: control, 1 of 20; TFPI(LOW DOSE) (0.1 mg/kg, then 1 microg/kg/min), 3 of 12 (P = .14); TFPI(MID DOSE), (0.5 mg/kg, then 5 microg/kg/min), 7 of 12 (P = .002); TFPI(HIGH DOSE) (10 mg/kg, then 10 microg/kg/min), 4 of 13 (P = .04). Thus, delayed treatment with TFPI improves survival in septic rabbits.

Topics: Animals; Anti-Bacterial Agents; Anticoagulants; Blood Coagulation; Blood Pressure; Dose-Response Relationship, Drug; Drug Therapy, Combination; Escherichia coli Infections; Gentamicins; Humans; Lipoproteins; Oxygen; Peritonitis; Rabbits; Recombinant Proteins; Shock, Septic; Thromboplastin

To obtain systematic information on the extrinsic coagulation pathway, as well as to investigate the time course of the coagulation abnormalities in sepsis.. Prospective observational study.. General intensive care unit.. Nineteen patients with the diagnosis of severe sepsis or septic shock and nine control patients.. None.. Tissue factor antigen concentration (tissue factor antigen), prothrombin fragment F1+2, thrombin antithrombin III complex, fibrinopeptide A, D-dimer, and antithrombin III concentrations were measured on the day of diagnosis of severe sepsis and septic shock, and on days 1, 2, 3, and 4 after diagnosis. The concentrations of tissue factor antigen, prothrombin fragment F1+2, fibrinopeptide A, and D-dimer were significantly increased in patients with severe sepsis and septic shock compared with control subjects. However, the concentrations of thrombin antithrombin III complex showed no statistical differences between the septic patients and the control subjects. Significantly, low antithrombin III concentrations were observed in the septic patient groups compared with control subjects. With the exception of D-dimer, the concentrations of the hemostatic markers were similar between severe sepsis and septic shock patients. Significant correlations were noted between tissue factor antigen and the disseminated intravascular coagulation score (r2=.236, p< .0001) and the number of dysfunctioning organs (r2=.229, p=.035).. We systematically elucidated coagulation disorders in newly defined sepsis. The extrinsic coagulation pathway is activated in patients with severe sepsis and septic shock. In these patients, enhanced thrombin generation and activation, and fibrin formation were demonstrated when compared with the control subjects. Furthermore, the thrombin generated appears not to be fully neutralized by antithrombin III.

Topics: Adult; Aged; Antithrombin III; Biomarkers; Blood Coagulation; Blood Coagulation Disorders; Case-Control Studies; Female; Fibrin Fibrinogen Degradation Products; Fibrinopeptide A; Humans; Male; Middle Aged; Peptide Fragments; Peptide Hydrolases; Prospective Studies; Protein Precursors; Prothrombin; Sepsis; Shock, Septic; Thromboplastin

The procoagulant activity of mononuclear cells (MNCs) may play an important role in the disseminated intravascular coagulation seen in septic shock. This study compares the capacity of Escherichia coli (E. coli) and recombinant human TNF-alpha (rhTNF-alpha) to induce procoagulant activity by baboon MNCs. In vivo studies showed that MNC procoagulant activity was significantly increased at T + 120 min after LD100 E. coli infusion into baboons. Most of this procoagulant activity was attributable to tissue factor. In contrast, a bolus infusion of rhTNF-alpha (150 micrograms/kg) and a monoclonal antibody to activated protein C (2 mg/kg) did not induce any increase of MNC procoagulant activity at T + 120 min even though the plasma TNF-alpha level was 10 times higher than that seen following infusion of E. coli. In vitro studies showed that E. coli at concentrations comparable to that observed in the vivo study and LPS at a concentration of 2.5 ng/mL induced more intense tissue factor expression by both human and baboon monocytes than rhTNF-alpha in the concentrations ranging from 10 to 1,000 ng/mL. These results suggest that TNF-alpha alone is not sufficient to induced noticeable MNC procoagulant activity, at least, in the early stage of this septic shock model.

Topics: Animals; Blood Pressure; Coagulants; Disseminated Intravascular Coagulation; Escherichia coli; Escherichia coli Infections; Fibrinogen; Humans; Lethal Dose 50; Leukocytes; Leukocytes, Mononuclear; Lipopolysaccharides; Papio; Platelet Count; Recombinant Proteins; Shock, Septic; Thromboplastin; Tumor Necrosis Factor-alpha

Tissue factor pathway inhibitor (TFPI) plays a key role in modulating tissue factor-dependent blood coagulation. This study was done to determine not only the inhibitory effects of recombinant human TFPI (rTFPI) on thrombus formation in rat models with disseminated intravascular coagulation (DIC), but also to identify the distribution of exogenous TFPI in vivo. Disseminated intravascular coagulation was induced by administering a priming dose of carrageenan 10 mg/kg body weight and was followed 24 hours later by a provocative dose of lipopolysaccharide (LPS) 500 mg/kg body weight. The rTFPI was administered intravenously at a dose of either 1 or 4 mg/kg body weight immediately after LPS treatment. Exogenous rTFPI at a dose of 4 mg/kg significantly inhibited the consumption of fibrinogen, platelets and factor VIIa (P < .05) and also reduced the number of fibrin thrombi formed in the liver, lungs, kidneys, and spleen (P < .05), whereas rTFPI at a dose of 1 mg/kg had no significant inhibitory effect on these DIC parameters. Recombinant human rTFPI activity was rapidly cleared from the plasma; however, a significant amount of the inhibitor was still present in tissues even 3 to 6 hours after intravenous administration. Exogenous TFPI was mainly identified in Kupffer cells, macrophages, and on the microvascular endothelial lining of different organs. In the kidney, rTFPI was identified on both the abluminal surface of the renal tubules and the luminal surface of the proximal convoluted tubules. No rTFPI, however, was detected in the hepatocytes. Tissue factor was mainly expressed by monocytes/macrophages. These findings suggest that TFPI plays an important role in modulating TF-dependent thrombogenesis. The elucidation of the rTFPI distribution and interactions in vivo might thus provide valuable insight into its inhibitory mechanisms as well as its therapeutic implications in DIC.

Topics: Animals; Anticoagulants; Carrageenan; Disease Models, Animal; Disseminated Intravascular Coagulation; Fibrin; Humans; Immunohistochemistry; Lipoproteins; Male; Rats; Rats, Wistar; Recombinant Proteins; Shock, Septic; Survival Rate; Thromboplastin; Thrombosis; Tissue Distribution

Microvascular thrombosis with intravascular fibrin deposition is a characteristic pathologic alteration during endotoxic shock. This effect is predominantly mediated by expression of the cellular procoagulant tissue factor by endothelial cells and cells of monocyte or macrophage lineage, resulting in acceleration of the coagulation cascade and fibrin deposition.. To determine whether modulation of this response by treatment with an antitissue factor antibody might have beneficial effects.. A polyclonal antibody to murine tissue factor was prepared by injecting rabbits with a synthesized peptide sequence of murine tissue factor. To determine the activity of the antibody, elicited murine peritoneal macrophages were treated for 4 hours with 10-micrograms/mL lipopolysaccharide (LPS), and procoagulant activity was determined via a clotting assay (milliunits of activity per 10(6) macrophages).. The tissue factor antibody abrogated LPS-induced macrophage procoagulant activity, confirming activity of the antibody (macrophages, 236 +/- 28 mU/10(6) macrophages; macrophages/LPS, 3801 +/- 190* mU/10(6) macrophages; macrophages/LPS/alpha-tissue factor, 753 +/- 92* mU/10(6) macrophages; n = 3; the asterisk indicates P < .05 by an analysis of variance). Additionally, antibody-protein affinity was confirmed by Western blot analysis. Having determined the activity of the antibody in vitro, we tested its efficacy in vivo in a lethal endotoxemia model. Mice were immunized with 200 microL of antiserum intraperitoneally 2 hours before injection with 250 micrograms of LPS intraperitoneally and 24 hours later. Control animals received 200 microL of saline solution. All animals initially exhibited lethargy and piloerection, characteristic of the predicted response to LPS. However, immunized animals had a significantly (P < .05) reduced mortality compared with control animals. Fibrinogen levels were significantly (P < .05) higher in the immunized mice, suggesting decreased consumption of coagulation factors, a finding consistent with an antitissue factor effect. Further, plasma tumor necrosis factor levels 90 minutes after LPS injection were similar in both groups, suggesting normal induction of the cytokine cascade.. Modulation of microvascular fibrin deposition by abrogating tissue factor-mediated coagulation significantly (P < .05) improved survival in this model without attenuating the initiation of the cytokine cascade. These findings suggest a pathogenic role for coagulation in the induction of acute organ injury during sepsis.

Topics: Amino Acid Sequence; Animals; Antibodies, Monoclonal; Disseminated Intravascular Coagulation; Female; Immunization; Mice; Molecular Sequence Data; Shock, Septic; Thromboplastin; Thrombosis

Disseminated intravascular thrombosis is a frequent complication of endotoxic shock, and modulation of endothelial cell hemostatic properties has been proposed to play a role in its pathogenesis based on studies of endothelial cells in culture. This study examined the in vivo expression of tissue factor (TF) and thrombomodulin (TM) in a baboon model of lethal Escherichia coli sepsis using immunohistochemistry with monospecific antibodies. Expression of E-selectin (E-sel) was also determined as a marker of endothelial cell activation. Correlation of immunoreactivity with procoagulant activity in lipopolysaccharide-stimulated cultured human endothelial cells showed that immunohistochemistry was sufficiently sensitive to detect as little as 5% of the maximum in vitro endothelial cell TF response. Vascular endothelium of control animals expressed TM but had no detectable TF or E-sel. Following E. coli infusion, widespread E-sel expression and microvascular fibrin deposition was evident within 6 hours. However, expression of TF by endothelial cells became detectable only in the splenic microvasculature, where endothelial specificity of TF expression was confirmed by dual immunofluorescence of TF with von Willebrand's factor and with TM. In the spleen, there was a dissociation of expression of TF and E-sel, with marginal zone vessels being TF-positive and E-sel-negative, whereas sinusoidal endothelium was E-sel-positive but TF-negative. TM expression was unchanged from controls. Additionally, expression of TF by lung alveolar epithelial cells, splenic macrophages, and epithelial cells of the renal glomeruli was observed to be enhanced in septic animals. This study documents endothelial cell expression of TF in vivo in a relevant pathological setting. At the same time, compared with endothelial cells in culture, there is in vivo both significantly greater control of TF expression than expected, given the strong positive stimuli present in lethal E. coli septic shock and an unpredicted heterogeneity of activation responses.

Topics: Animals; Cell Adhesion Molecules; E-Selectin; Endothelium, Vascular; Escherichia coli Infections; Immunohistochemistry; Lipopolysaccharides; Membrane Glycoproteins; Microcirculation; Papio; Receptors, Cell Surface; Receptors, Thrombin; Shock, Septic; Thrombin; Thromboplastin; Tissue Distribution

Exposure of cultured endothelial cells to bacterial endotoxin induces an enhancement of cell procoagulant activity (PCA) and a simultaneous reduction of thrombomodulin activity (TM). We evaluated the effect of endotoxin on the expression of both endothelial PCA and TM in vivo, in rabbits. Animals were given a single i.v. injection of endotoxin (E. coli 0111:B4 LPS, W, 10-200 micrograms/kg); the thoracic aorta was harvested after 2 or 4 hours and placed in an ad hoc device to expose the endothelial surface only. Endotoxin treatment resulted in a dose-dependent increase of endothelial PCA (p < 0.001, at 100 micrograms/kg or more), which was totally dependent on factor VII and thus identified as tissue factor. In contrast, endothelial TM activity, as measured by the rate of thrombin-induced protein C activation, was similar in control and endotoxemic rabbits, even when the animals were given two injections (50 micrograms/kg, 24 h apart), or a continuous infusion (40 micrograms/kg/h during 4 hours) of endotoxin. To explore the effect of endotoxin on TM activity at the microcirculation level, we measured the extent of protein C activation in vivo, induced by a continuous infusion of low doses of thrombin (1 NIH U/kg/min for 60 min). Again, endotoxin administration was not associated with significant changes in TM-dependent protein C activation, as assessed by the anticoagulant activity present in a barium citrate plasma eluate obtained at the end of thrombin infusion. Although reduction of TM during persistent endotoxemia cannot be definitively excluded, our data support a major role of endothelial PCA in LPS-induced coagulative changes.

Topics: Animals; Aorta, Thoracic; Blood Coagulation Factors; Endothelium, Vascular; Endotoxins; Enzyme Activation; Factor VII; Gene Expression Regulation; Male; Protein C; Rabbits; Shock, Septic; Thrombomodulin; Thromboplastin

Gram-negative bacteremia poses a major health problem, causing one-half of cases of lethal septic shock acquired during hospitalization. Bacterial lipopolysaccharide (LPS) and the inflammatory cytokines, tumor necrosis factor (TNF) and interleukin-1 (IL-1), have been shown to be essential mediators of septic shock. Among the effects of these mediators is a coagulopathy that may be triggered by induced expression of tissue factor (TF) on macrophages and endothelial cells. We now report that 500 micrograms/kg of either immunoglobulin G (IgG) or Fab fragments of a monoclonal antibody against TF administered to baboons as a pretreatment attenuates the coagulopathy and protects against LD100 Escherichia coli. This study provides direct evidence of an essential effector role for TF in septic shock.

Topics: Adrenal Glands; Animals; Antibodies, Monoclonal; Blood Pressure; Creatinine; Escherichia coli Infections; Factor VII; Fibrinogen; Kidney; Liver; Lung; Papio; Shock, Septic; Spleen; Thromboplastin

Topics: Animals; Blood Coagulation; Brain; Escherichia coli; Extracellular Space; Homeostasis; Intracellular Fluid; Rats; Shock, Septic; Thromboplastin; Tissue Extracts; Transplantation, Heterologous; Transplantation, Homologous

Topics: Animals; Blood Coagulation Disorders; Blood Platelets; Blood Pressure; Cardiac Output; Disseminated Intravascular Coagulation; Escherichia coli Infections; Fibrinolysis; Hematocrit; Hydrogen-Ion Concentration; Male; Oxygen; Papio; Prothrombin Time; Sepsis; Shock, Septic; Thromboplastin; Vascular Resistance

Topics: Acute Kidney Injury; Anti-Bacterial Agents; Blood Coagulation Disorders; Endotoxins; Histamine Release; Humans; Hypotension; Hypoxia; Intestinal Absorption; Ischemia; Mononuclear Phagocyte System; Pulmonary Atelectasis; Shock; Shock, Septic; Thromboplastin

Topics: Acute Kidney Injury; Anemia, Hemolytic; Blood Coagulation Disorders; Blood Coagulation Factors; Blood Transfusion; Coronary Disease; Female; Heart Arrest; Hemorrhagic Disorders; Humans; Hyaline Membrane Disease; Infant, Newborn; Ischemia; Kidney Transplantation; Male; Obstetric Labor Complications; Pregnancy; Shock, Septic; Shwartzman Phenomenon; Thrombocytopenia; Thromboembolism; Thromboplastin; Toxemia; Wounds and Injuries

Topics: Abortion, Septic; Blood Coagulation Disorders; Embolism, Amniotic Fluid; Female; Fetal Death; Fibrinolysis; Gelatin; Hemorrhagic Disorders; Humans; Hydrogen-Ion Concentration; Placenta; Placenta Diseases; Plasma Substitutes; Pregnancy; Pregnancy Complications; Pulmonary Embolism; Shock, Hemorrhagic; Shock, Septic; Streptokinase; Thrombophlebitis; Thromboplastin; Thrombosis

Topics: Animals; Blood Coagulation; Blood Platelets; Catecholamines; Humans; Hypoxia; Microscopy, Electron; Shock; Shock, Septic; Thromboembolism; Thromboplastin; Wounds and Injuries

Topics: Blood Cell Count; Blood Coagulation Disorders; Blood Coagulation Factors; Blood Coagulation Tests; Blood Platelets; Blood Pressure; Child; Child, Preschool; Factor V; Fibrinogen; Heparin; Humans; Hypotension; Infant; Infant, Newborn; Prothrombin Time; Rocky Mountain Spotted Fever; Sepsis; Shock, Septic; Thrombocytopenia; Thromboplastin

Topics: Animals; Anticoagulants; Blood Coagulation Disorders; Dogs; Endotoxins; Escherichia coli; Fibrinolysin; Prothrombin Time; Shock, Hemorrhagic; Shock, Septic; Thromboplastin

Topics: Adolescent; Adult; Aged; Anticoagulants; Blood Coagulation Disorders; Blood Coagulation Factors; Child; Child, Preschool; Female; Fibrinogen; Histocytochemistry; Humans; Infant; Male; Meningitis; Meningococcal Infections; Middle Aged; Neisseria meningitidis; Prothrombin Time; Sepsis; Shock, Septic; Skin Manifestations; Thrombocytopenia; Thromboplastin