thromboplastin and Necrosis

Filoviruses are responsible for highly lethal infections. Those viruses are found in intertropical areas of Africa and Asia where they circulate in their supposed natural reservoir, fruit bats. During filovirus outbreaks and depending on the strains, various modifications in hemostasis have been observed in patients. The disseminated intravascular coagulation identified in these infections is multicausal and involves both viral factors and abnormal physiological responses. In this review we will describe the mechanisms responsible for these disturbances and we will highlight some aspects of the basis of filovirus high pathogenicity.

Topics: Adrenal Cortex; Animals; Chiroptera; Communicable Diseases, Emerging; Cytokines; Disease Reservoirs; Disseminated Intravascular Coagulation; Endothelial Cells; Filoviridae; Filoviridae Infections; Haplorhini; Hepatocytes; Host-Pathogen Interactions; Humans; Necrosis; Recombinant Proteins; Thromboplastin; Viral Load; Viral Proteins

Glioblastoma (GBM) has explosive biologic properties with rapid clinical progression leading to death. Its distinguishing pathologic features, necrosis with surrounding pseudopalisades and microvascular hyperplasia, are believed to be instrumental to its accelerated growth. Microvascular hyperplasia arises in response to the secretion of proangiogenic factors by hypoxic pseudopalisades and allows for peripheral neoplastic expansion. Mechanisms underlying necrosis and hypoxia remain obscure, but vaso-occlusive and prothrombotic contributions could be substantial. Recent investigations on the origin of pseudopalisades suggest that this morphologic phenomenon is created by a tumor cell population actively migrating away from a central hypoxic region and that, in at least a significant subset, hypoxia-induced migration appears due to vaso-occlusion caused by intravascular thrombosis. Both vascular endothelial growth factor induced vascular permeability to plasma coagulation factors and the increased neoplastic expression of tissue factor likely contribute to a prothrombotic state favoring intravascular thrombosis. In addition to prothrombotic mechanisms, vaso-occlusion could also result from angiopoietin-2-mediated endothelial cell apoptosis and vascular regression, which follows neoplastic co-option of native vessels in animal models of gliomas. Vaso-occlusive and prothrombotic mechanisms in GBM could readily explain the presence of pseudopalisades and coagulative necrosis in tissue sections, the emergence of central contrast enhancement and its rapid peripheral expansion on neuroimaging, and the dramatic shift to an accelerated rate of clinical progression. Since the hypoxic induction of angiogenesis appears to support further neoplastic growth, therapeutic targeting of the underlying vascular pathology and thrombosis could provide a new means to prolong time to progression.

Topics: Blood Vessels; Brain Neoplasms; Cell Division; Cell Hypoxia; Glioblastoma; Humans; Necrosis; Neovascularization, Pathologic; Thromboplastin; Thrombosis

There is evidence of activation of both blood coagulation and platelets in sickle cell disease. For example, plasma samples obtained in the steady state and during painful crisis demonstrate high levels of thrombin generation, depletion of anticoagulant proteins, and abnormal activation of the fibrinolytic system. Similarly, exposure of surface markers such as CD62P and CD40L, along with increased circulating levels of thrombospondin, signal platelet activation. In addition to its effects on the cleavage of fibrinogen and its ability to activate platelets, the increase in circulating thrombin levels, with its wide-ranging effects on endothelial cells and blood vessels, may be important in the pathophysiology of sickle cell disease. Therefore, treatments that could decrease thrombin generation or platelet activation may be beneficial in both the treatment of sickle cell disease and the prevention of complications that characterize this genetic disorder. This review discusses hypercoagulability in the various forms of sickle cell disease, including homozygous sickle cell anemia, hemoglobin SC disease, hemoglobin SD disease, and sickle cell-beta-thalassemia.

Topics: Anemia, Sickle Cell; Anticoagulants; Blood Coagulation; Endothelium, Vascular; Humans; Necrosis; Platelet Activation; Platelet Aggregation Inhibitors; Thrombophilia; Thromboplastin; Thrombosis

Disseminated intravascular coagulation (DIC) of blood develops as a result of a sharp increase in the release of thromboplastic substances. The mechanism of disseminated thrombosis is switched in at the level of the microcirculatory bed with defibrination of the peripheral blood and subsequent hemorrhages and bleedings. The causes of DIC development may include complications of pregnancy and delivery, different kinds of shock including endotoxin shock, hemorrhage, hemolysis. Histomorphological findings in DIC are as follows: hemorrhagic syndrome, fibrin thrombi in capillaries, arterioles and venules of the skin, kidneys, adrenals, hypophysis, gastrointestinal tract, lungs and other organs followed by necroses and hemorrhages in these organs. Clinically, DIC is manifested by symptoms of insufficiency of the affected organs (acute renal insufficiency, Waterhouse-Fridericksen syndrome, etc).

Topics: Disseminated Intravascular Coagulation; Female; Hemolysis; Hemorrhage; Humans; Kidney; Male; Microcirculation; Necrosis; Obstetric Labor Complications; Pregnancy; Pregnancy Complications, Hematologic; Shock; Surgical Procedures, Operative; Thromboplastin; Thrombosis

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

The purpose of this study was to describe the changes in plasma levels of angiogenic and inflammatory biomarkers, specifically Ang-2 and TNF-α, in patients receiving HeartMate II (HMII) left ventricular assist device (LVAD) and correlate them with nonsurgical bleeding. It has been shown that angiopoietin-2 (Ang-2) and tissue necrosis factor-α (TNF-α) may be linked to bleeding in LVAD patients. This study utilized biobanked samples prospectively collected from the PREVENT study, a prospective, multicenter, single-arm, nonrandomized study of patients implanted with HMII. Paired serum samples were obtained in 140 patients before implantation and at 90 days postimplantation. Baseline demographics were as follows: age 57 ± 13 years, 41% had ischemic etiology, 82% male, and 75% destination therapy indication. In the 17 patients with baseline elevation of both TNF-α and Ang-2, 10 (60%) experienced a significant bleeding event within 180 days postimplant compared with 37 of 98 (38%) patients with Ang-2 and TNF-α below the mean ( p = 0.02). The hazard ratio for a bleeding event was 2.3 (95% CI: 1.2-4.6) in patients with elevated levels of both TNF-α and Ang-2. In the PREVENT multicenter study, patients with elevations in serum Angiopoietin-2 and TNF-α at baseline before LVAD implantation demonstrated increased bleeding events after LVAD implantation.

Topics: Adult; Aged; Angiopoietin-2; Female; Heart Failure; Heart-Assist Devices; Hemorrhage; Humans; Male; Middle Aged; Necrosis; Prospective Studies; Retrospective Studies; Thromboplastin; Tumor Necrosis Factor-alpha

Morbidity and mortality associated with HIV infection is immune-mediated, and an understanding of HIV immunology will be beneficial in the management of HIV infectionOBJECTIVE: The objective of this research was to measure the levels of TNF-α, IL-6 and IFN-γ in asymptomatic HIV patients and non-HIV subjects, as well as their relationship with CD4 count.. Blood samples were collected from 173 subjects, consisting of 125 asymptomatic HIV patients (44 HAART-naïve and 81 on HAART) and 48 non-HIV subjects. The IFN-, IL-6, and TNF- levels in the blood were determined using enzyme-linked immunosorbent assays, and the CD4 count of all participants was determined using flow cytometry.. Regardless of treatment status, the IFN-γ levels of non-HIV subjects were significantly higher than those of HIV patients (p< 0.001). The opposite was true for IL-6, as the levels of IL-6 in non-HIV subjects were significantly lower than those in HAART-naïve HIV patients (p< 0.001) and those on HAART (p< 0.01). TNF-α levels did not differ between HIV patients and their non-HIV counterparts. Generally, the levels of these cytokines was not affected (p> 0.05) by immunosuppression (measured by CD4 count < 200 cells/μL) and there was no significant correlation between CD4 count and these cytokines (p> 0.05).. In conclusion, asymptomatic HIV infection decreased IFN-γ, increased IL-6, and had no effect on TNF-α levels, regardless of treatment status. Immunosuppression had no impact on these cytokine levels, and there was no relationship between them and CD4 counts.

Topics: Cytokines; HIV Infections; Humans; Interferon-gamma; Interleukin-6; Necrosis; Nigeria; Thromboplastin; Tumor Necrosis Factor-alpha

Trans-metatarsal operation to diabetic foot necrosis is a common procedure although only half of the patients do not need a second amputation due to surgery wound ischemia. No current tools are available for early prediction of surgery success and the clinical decision for a second operation may take weeks. Heparanase protein is involved in inflammation, angiogenesis and coagulation activation. The aim of the study was to evaluate heparanase level and procoagulant activity as an early predictor for success or failure of diabetic foot trans-metatarsal surgery.. The study group included 40 patients with diabetic foot necrosis requiring trans-metatarsal surgical intervention. Eighteen patients designated as necrotic group, developed post-surgery necrosis at the surgery wound within the first month, requiring a second more proximal amputation. Skin biopsies from the proximal surgery edge were stained for heparanase, tissue factor (TF), TF pathway inhibitor (TFPI) and by hematoxylin and eosin. Plasma samples were drawn pre-surgery and at 1h, 1week and 1month post-surgery. Samples were tested for heparanase levels by ELISA and TF+heparanase activity, TF activity and heparanase procoagulant activity.. Skin biopsy staining did not predict subsequent necrosis. In the non-necrotic group a significant rise in TF+heparanase activity, heparanase activity and heparanase levels were observed 1h and 1week post-surgery. The most significant increase was in heparanase procoagulant activity at the time point of 1h post-surgery (P<0.0001). Pre-surgery TF activity was significantly lower in the non-necrotic group compared to the necrotic group (P<0.05).. Measuring heparanase procoagulant activity pre-surgery and 1h post-surgery could potentially serve as an early tool to predict the procedure success. The present results broaden our understanding regarding early involvement of heparanase in the wound healing process.

Topics: Aged; Aged, 80 and over; Amputation, Surgical; Blood Coagulation; Diabetic Foot; Female; Glucuronidase; Humans; Male; Middle Aged; Necrosis; Skin; Thromboplastin; Wound Healing

Culture of human pancreatic islets is now routinely carried out prior to clinical islet allotransplantation, using conditions that have been developed empirically. One of the major causes of early islet destruction after transplantation is the process termed instant blood-mediated inflammatory reaction (IBMIR). The aim of this study was to develop in vitro methods to investigate IBMIR and apply them to the culture conditions used routinely in our human islet isolation laboratory. Freshly isolated or precultured (24 h, 48 h) human islets were incubated in either ABO-compatible allogeneic human blood or Hank's buffered salt solution (HBSS) for 1 h at 37°C. Tissue factor (TF) expression and leukocyte migration were assessed by light microscopy. TF was also quantified by ELISA. To assess β-cell function, glucose-stimulated insulin secretion (GSIS) assay was carried out. The extent of islet β-cell damage was quantified using a proinsulin assay. Islets cultured for 24 h had higher GSIS when compared to freshly isolated or 48-h precultured islets. Freshly isolated islets had significantly higher TF content than 24-h and 48-h precultured islets. Incubation of freshly isolated human islets in allogeneic human blood released 6.5-fold higher level of proinsulin in comparison to freshly isolated human islets in HBSS. The high level of proinsulin released was significantly attenuated when precultured islets (24 h or 48 h) were exposed to fresh blood. Histological examination of fresh islets in blood clot showed that some islets were fragmented, showing signs of extraislet insulin leakage and extensive neutrophil infiltration and necrosis. These features were markedly reduced when the islets were cultured for 24 h. These results suggest that our standard 24-h islet culture is markedly beneficial in attenuating IBMIR, as evidenced by increased GSIS, lower content of TF, decrease islet fragmentation, and proinsulin release.

Topics: Adult; Cell Movement; Cells, Cultured; Female; Humans; Inflammation; Insulin-Secreting Cells; Islets of Langerhans Transplantation; Leukocytes; Male; Middle Aged; Necrosis; Neutrophil Infiltration; Neutrophils; Organ Culture Techniques; Proinsulin; Thromboplastin

Concanavalin A (Con A) treatment induces severe hepatitis in mice in a manner dependent on T cells, interferon (IFN)-gamma, and tumor necrosis factor (TNF). Treatment with the anticoagulant heparin protects against hepatitis, despite healthy production of IFN-γ and TNF. Here, we investigated molecular and cellular mechanisms for hypercoagulation-mediated hepatitis. After Con A challenge, liver of wild-type (WT) mice showed prompt induction of Ifnγ and Tnf, followed by messenger RNA expression of tissue factor (TF) and plasminogen activator inhibitor-1 (PAI-1), which initiate blood coagulation and inhibit clot lysis, respectively. Mice developed dense intrahepatic fibrin deposition and massive liver necrosis. In contrast, Ifnγ(-/-) mice and Ifnγ(-/-) Tnf(-/-) mice neither induced Pai1 or Tf nor developed hepatitis. In WT mice TF blockade with an anti-TF monoclonal antibody protected against Con A-induced hepatitis, whereas Pai1(-/-) mice were not protected. Both hepatic macrophages and sinusoidal endothelial cells (ECs) expressed Tf after Con A challenge. Macrophage-depleted WT mice reconstituted with hematopoietic cells, including macrophages deficient in signal transducer and activator of transcription-1 (STAT1) essential for IFN-γ signaling, exhibited substantial reduction of hepatic Tf and of liver injuries. This was also true for macrophage-depleted Stat1(-/-) mice reconstituted with WT macrophages. Exogenous IFN-γ and TNF rendered T-cell-null, Con A-resistant mice deficient in recombination-activating gene 2, highly susceptible to Con A-induced liver injury involving TF.. Collectively, these results strongly suggest that proinflammatory signals elicited by IFN-γ, TNF, and Con A in both hepatic macrophages and sinusoidal ECs are necessary and sufficient for the development of hypercoagulation-mediated hepatitis.

Topics: Animals; Concanavalin A; Endothelial Cells; Fibrin; Hepatitis, Animal; Interferon-gamma; Liver; Macrophages; Mice; Mice, Knockout; Mitogens; Necrosis; Plasminogen Activator Inhibitor 1; Signal Transduction; STAT1 Transcription Factor; T-Lymphocytes; Thrombophilia; Thromboplastin; Tumor Necrosis Factor-alpha

Acyl-CoA:cholesterol acyltransferase (ACAT) converts cholesterol to cholesteryl esters in plaque foam cells. Complete deficiency of macrophage ACAT has been shown to increase atherosclerosis in hypercholesterolemic mice because of cytotoxicity from free cholesterol accumulation, whereas we previously showed that partial ACAT inhibition by Fujirebio compound F1394 decreased early atherosclerosis development. In this report, we tested F1394 effects on preestablished, advanced lesions of apolipoprotein-E-deficient mice.. Apolipoprotein-E-deficient mice on Western diet for 14 weeks developed advanced plaques, and were either euthanized (Baseline), or continued on Western diet with or without F1394 and euthanized after 14 more weeks. F1394 was not associated with systemic toxicity. Compared with the baseline group, lesion size progressed in both groups; however, F1394 significantly retarded plaque progression and reduced plaque macrophage, free and esterified cholesterol, and tissue factor contents compared with the untreated group. Apoptosis of plaque cells was not increased, consistent with the decrease in lesional free cholesterol. There was no increase in plaque necrosis and unimpaired efferocytosis (phagocytic clearance of apoptotic cells). The effects of F1394 were independent of changes in plasma cholesterol levels.. Partial ACAT inhibition by F1394 lowered plaque cholesterol content and had other antiatherogenic effects in advanced lesions in apolipoprotein-E-deficient mice without overt systemic or plaque toxicity, suggesting the continued potential of ACAT inhibition for the clinical treatment of atherosclerosis, in spite of recent trial data.

Topics: Acetyl-CoA C-Acyltransferase; Animals; Aorta; Aortic Diseases; Apolipoproteins E; Apoptosis; Atherosclerosis; Cholesterol; Cyclohexanes; Diet, Atherogenic; Dioxanes; Disease Models, Animal; Disease Progression; Enzyme Inhibitors; Foam Cells; Male; Mice; Mice, Knockout; Necrosis; Plaque, Atherosclerotic; Thromboplastin

Duramycin is a polypeptide that binds specifically to phosphatidylethanolamine (PE) on cell surfaces with high affinity, and has been shown to disrupt tumour cell surface-based coagulation and exhibit weak antimicrobial activity. The aim of the present study was to characterize the effect of duramycin on tumour cell proliferation and viability. Duramycin was used to detect phosphatidylethanolamine expression on cell lines by flow cytometry. Cells were cultured in the presence of duramycin and proliferation and cell viability assessed. Electron microscopy and confocal microscopy were utilized to investigate cell membrane structure after duramycin treatment. Pancreatic tumour cells were shown to express phosphatidylethanolamine on their cell surfaces by specific labelling with duramycin. Phosphatidylethanolamine expression was generally increased in apoptotic cells and more so in necrotic cells. Cells cultured in the presence of duramycin showed increasing levels of apoptosis and ultimately necrosis with increasing duramycin concentrations, and cell proliferation was reduced in a duramycin dose-dependent manner between 0.125 and 12.5 μmol/l. Tissue factor expression was also reduced when cells were cultured in the presence of duramycin. Cells imaged by electron microscopy were fragile, suggesting that membrane integrity was compromised by duramycin, although no obvious differences in membrane structure were observed by live cell confocal imaging. Duramycin induced apoptosis and exhibited antiproliferative and anticoagulant effects on pancreatic tumour cells, most probably by disrupting cell membrane structure and/or function.

Topics: Antineoplastic Agents; Apoptosis; Bacteriocins; Cell Adhesion; Cell Line, Tumor; Cell Membrane; Cell Proliferation; Dose-Response Relationship, Drug; Humans; Microscopy, Confocal; Microscopy, Electron; Necrosis; Peptides; Phosphatidylethanolamines; Thromboplastin

Atherosclerotic coronary arteries are more calcified in patients with than without chronic kidney disease (CKD). We addressed the potential for coronary microvascular obstruction in patients with and without CKD during stenting for saphenous vein aorto-coronary graft (SVG) stenosis under protection with a distal occlusion/aspiration device. In patients with and without CKD (n = 20/20), SVG plaque composition was analyzed from virtual histology using intravascular ultrasound analysis before stent implantation. There was more dense calcium and more necrotic core in patients with than without CKD (14 ± 3 vs. 3 ± 1 % and 21 ± 3 vs. 12 ± 2 % of plaque volume, respectively). Coronary aspirate was retrieved during stent implantation and divided into particulate debris and plasma. Patients with CKD had more particulate debris and calcium release than patients without CKD. In contrast, the release of serotonin was less in patients with than without CKD (0.4 ± 0.1 vs. 1.2 ± 0.3 μmol/L), whereas that of catecholamines, endothelin, tissue factor, thromboxane, tumor necrosis factor α, and C reactive protein was not significantly different. Confirming the biochemical results, aspirate plasma from patients with CKD induced less vasoconstriction of rat mesenteric arteries than that from patients without CKD (with endothelium (+E), 26 ± 7 %; without endothelium (-E): 28 ± 7 % vs. +E, 68 ± 12 %; -E: 95 ± 16 % of maximum KCl-induced vasoconstriction). Graft atherosclerosis of patients with CKD is more degenerated and releases more particulate debris and calcium, but the aspirate has surprisingly less serotonin and vasoconstrictor potential.

Topics: Adult; Aged; Aged, 80 and over; alpha-2-HS-Glycoprotein; Animals; Atherosclerosis; Blood Vessel Prosthesis Implantation; C-Reactive Protein; Calcium; Coronary Artery Disease; Graft Occlusion, Vascular; Humans; Male; Middle Aged; Necrosis; Plaque, Atherosclerotic; Rats; Renal Insufficiency, Chronic; Saphenous Vein; Stents; Thromboplastin; Tumor Necrosis Factor-alpha; Ultrasonography, Interventional; Vascular Calcification; Vasoconstriction

The purpose of this study was to test a novel, dual tumour vascular endothelial cell (VEC)- and tumour cell-targeting factor VII-targeted Sn(IV) chlorin e6 photodynamic therapy (fVII-tPDT) by targeting a receptor tissue factor (TF) as an alternative treatment for chemoresistant breast cancer using a multidrug resistant (MDR) breast cancer line MCF-7/MDR.. The TF expression by the MCF-7/MDR breast cancer cells and tumour VECs in MCF-7/MDR tumours from mice was determined separately by flow cytometry and immunohistochemistry using anti-human or anti-murine TF antibodies. The efficacy of fVII-tPDT was tested in vitro and in vivo and was compared with non-targeted PDT for treatment of chemoresistant breast cancer. The in vitro efficacy was determined by a non-clonogenic assay using crystal violet staining for monolayers, and apoptosis and necrosis were assayed to elucidate the underlying mechanisms. The in vivo efficacy of fVII-tPDT was determined in a nude mouse model of subcutaneous MCF-7/MDR tumour xenograft by measuring tumour volume.. To our knowledge, this is the first presentation showing that TF was expressed on tumour VECs in chemoresistant breast tumours from mice. The in vitro efficacy of fVII-tPDT was 12-fold stronger than that of ntPDT for MCF-7/MDR cancer cells, and the mechanism of action involved induction of apoptosis and necrosis. Moreover, fVII-tPDT was effective and safe for the treatment of chemoresistant breast tumours in the nude mouse model.. We conclude that fVII-tPDT is effective and safe for the treatment of chemoresistant breast cancer, presumably by simultaneously targeting both the tumour neovasculature and chemoresistant cancer cells. Thus, this dual-targeting fVII-tPDT could also have therapeutic potential for the treatment of other chemoresistant cancers.

Topics: Adult; Aged; Animals; Apoptosis; Blotting, Western; Breast Neoplasms; Cell Line, Tumor; Chlorophyllides; CHO Cells; Cricetinae; Cricetulus; Drug Resistance, Neoplasm; Endothelial Cells; Factor VII; Female; Flow Cytometry; Gene Expression Regulation, Neoplastic; Humans; Immunohistochemistry; Mammary Neoplasms, Experimental; Mice; Mice, Nude; Middle Aged; Necrosis; Neovascularization, Pathologic; Photochemotherapy; Photosensitizing Agents; Porphyrins; Thromboplastin; Treatment Outcome; Tumor Burden; Xenograft Model Antitumor Assays

Alpha-naphthylisothiocyanate (ANIT) causes cholestatic hepatitis characterized by intrahepatic bile duct epithelial cell injury and periportal hepatocellular necrosis. The progression of ANIT-induced hepatocyte injury is reported to involve extrahepatic cells including platelets. We showed recently that the procoagulant protein tissue factor (TF) is essential for ANIT-induced coagulation and contributes to ANIT-induced liver necrosis. Platelets have been shown to express TF and can contribute to coagulation cascade activation. To this end, we tested the hypothesis that platelet-dependent coagulation contributes to ANIT-induced liver injury. In ANIT (60 mg/kg)-treated mice, activation of the coagulation cascade occurred prior to a decrease of platelets in the blood. Immunostaining for glycoprotein IIb (CD41) revealed platelet accumulation along the borders of necrotic foci in livers of ANIT-treated mice. Antibody-mediated platelet depletion did not affect coagulation but markedly affected liver histopathology in ANIT-treated mice. Platelet depletion induced marked pooling of blood within necrotic lesions consistent with parenchymal-type peliosis as early as 24 h after ANIT treatment. In contrast, treatment with the P2Y(12) inhibitor clopidogrel significantly reduced ANIT-induced hepatocyte necrosis and serum alanine aminotransferase activity but did not exaggerate bleeding into necrotic foci. Clopidogrel also reduced hepatic neutrophil accumulation but did not affect induction of Intercellular adhesion molecule-1 or chemokine CxC motif ligand-1 messenger RNA expression in liver. The data indicate that ANIT-induced coagulation is platelet independent and that platelets contribute to ANIT-induced hepatocyte necrosis by promoting neutrophil accumulation. In contrast, severe thrombocytopenia induces parenchymal-type peliosis in the livers of ANIT-treated mice, a rare hepatic lesion associated with pooling of blood in the liver.

Topics: 1-Naphthylisothiocyanate; Animals; Antibodies, Monoclonal; Biomarkers; Blood Coagulation; Blood Platelets; Cholestasis, Intrahepatic; Clopidogrel; Gene Expression; Hepatocytes; Liver; Male; Mice; Mice, Inbred C57BL; Necrosis; Platelet Aggregation Inhibitors; Platelet Membrane Glycoprotein IIb; Thromboplastin; Ticlopidine

The objective of this study was to develop a ligand-targeted photodynamic therapy (tPDT) by conjugating factor VII (fVII) protein with photosensitiser verteporfin in order to overcome the poor selectivity and enhance the effect of non-targeted PDT (ntPDT) for cancer. fVII is a natural ligand for receptor tissue factor (TF) with high affinity and specificity. The reason for targeting receptor TF for the development of tPDT is that TF is a common but specific target on angiogenic tumour vascular endothelial cells (VEC) and many types of tumour cells, including solid tumours and leukaemia.. Murine factor VII protein (mfVII) containing a mutation (Lys341Ala) was covalently conjugated via a cross linker EDC with Veterporfin (VP) that was extracted from liposomal Visudyne, and then free VP was separated by Sephadex G50 spin columns. fVII-tPDT using mfVII-VP conjugate, compared to ntPDT, was tested in vitro for the killing of breast cancer cells and VEGF-stimulated VEC and in vivo for inhibiting the tumour growth of breast tumours in a mouse xenograft model.. We showed that: (i) fVII protein could be conjugated with VP without affecting its binding activity; (ii) fVII-tPDT could selectively kill TF-expressing breast cancer cells and VEGF-stimulated angiogenic HUVECs but had no side effects on non-TF expressing unstimulated HUVEC, CHO-K1 and 293 cells; (iii) fVII targeting enhanced the effect of VP PDT by three to four fold; (iii) fVII-tPDT induced significantly stronger levels of apoptosis and necrosis than ntPDT; and (iv) fVII-tPDT had a significantly stronger effect on inhibiting breast tumour growth in mice than ntPDT.. We conclude that the fVII-targeted VP PDT that we report here is a novel and effective therapeutic with improved selectivity for the treatment of breast cancer. Since TF is expressed on many types of cancer cells including leukaemic cells and selectively on angiogenic tumour VECs, fVII-tPDT could have broad therapeutic applications for other solid cancers and leukaemia.

Topics: Animals; Apoptosis; Breast Neoplasms; Cell Line, Tumor; Cell Proliferation; CHO Cells; Cricetinae; Cricetulus; Dose-Response Relationship, Drug; Drug Carriers; Endothelial Cells; Factor VII; Female; Humans; Ligands; Mice; Mice, Inbred BALB C; Mutation; Necrosis; Photochemotherapy; Photosensitizing Agents; Porphyrins; Thromboplastin; Time Factors; Transfection; Tumor Burden; Verteporfin; Xenograft Model Antitumor Assays

In acute pancreatitis (AP), disorders of the coagulation-fibrinolysis system are closely related to the severity of the AP and to organ dysfunctions. We previously reported that plasma tissue factor (TF) levels were elevated in patients with AP, particularly in cases of alcoholic AP with pancreatic necrosis. Tissue factor pathway inhibitor (TFPI) is a key regulator of the extrinsic coagulation pathway, but plasma TFPI levels in AP have not yet been determined.. Plasma TFPI concentrations were measured by enzyme-linked immunosorbent assay in 44 patients with AP on admission. The relationships between AP severity, pancreatic necrosis, organ dysfunction, infection, and prognosis were analyzed.. Plasma TFPI levels were increased in AP patients compared with healthy volunteers. Plasma TFPI levels in severe AP were greater than those in mild AP. Plasma TFPI levels significantly correlated with Ranson score, APACHE II score, and Japanese severity score. Plasma TFPI levels in patients with pancreatic necrosis were greater than those in patients without pancreatic necrosis. Plasma TFPI levels in patients with organ dysfunction were greater than those in patients without organ dysfunction. In patients with pancreatic necrosis, the TF/TFPI ratios in non-survivors were lower than those in survivors. Moreover, the mortality rates in patients with TF/TFPI ratios > or = 2.0 were lower than those in patients with TF/TFPI ratios < 2.0.. Plasma TFPI levels were significantly increased in patients with AP, and the elevation was markedly related to the severity, pancreatic necrosis and organ dysfunctions. The imbalance of TF and TFPI may influence the disease state and thereby the prognosis in AP.

Topics: Acute Disease; APACHE; Biomarkers; Blood Coagulation; Case-Control Studies; Female; Humans; Lipoproteins; Male; Middle Aged; Multiple Organ Failure; Necrosis; Pancreatitis; Prognosis; Severity of Illness Index; Thromboplastin

Focal necrosis is a key pathologic feature that distinguishes glioblastoma from lower grade glioma. The presence of necrosis in a glioblastoma could promote its rapid growth and clinical progression. Focal necrosis of glioblastoma seems to be associated with thrombosis that result from hyper-coagulability. In the present study, we found that glioblastoma cells had a high level of constitutive nuclear factor (NF)-kappaB activity, which was directly correlated with necrosis in glioblastomas. We also found a direct correlation between NF-kappaB activity and the expression of tissue factor (TF), a potent procoagulant factor in gliomas. Inhibition of TF by an inhibitory antibody prevented the procoagulant activity of glioblastoma cells, indicating a TF-dependent mechanism. Blockade of NF-kappaB activation significantly inhibited TF expression and the procoagulant activity of glioblastoma cells in vitro. Blockade of NF-kappaB activation also significantly inhibited in vivo expression of TF, which was directly correlated with decreased necrosis formation and tumor growth of glioblastoma cells in nude mice. Collectively, these results suggest that elevated NF-kappaB activity in glioblastomas cells plays a critical role in necrosis formation of glioblastoma and that inhibition of NF-kappaB activity in glioblastoma can suppress necrosis formation and progressive growth.

Topics: Cell Line, Tumor; Glioblastoma; Humans; I-kappa B Proteins; Immunohistochemistry; Interleukin-8; Necrosis; NF-kappa B; NF-KappaB Inhibitor alpha; Thromboplastin; Transfection; Vascular Endothelial Growth Factor A

We have previously shown that part of the heparin-binding domain of the vascular endothelial growth factor (VEGF), designated HBDt, localizes very selectively to surfaces of the endothelial cells of i.t blood vessels. Here, we have coupled the HBDt to the extracellular domain of tissue factor (TFt), to locally initiate the thrombogenic cascade. In tumor-bearing mice, infusion of this HBDt.TFt results in rapid occlusive thrombosis selective only for tumor microvasculature with resultant infarctive destruction of tumors. We now show that infusion of an optimal combination of this HBDt.TFt and its requisite cofactor (factor VIIa) in tumor models results in significant tumor eradication. Binding studies and confocal microscopy indicate that the target for the HBDt.TFt seems to be a trimolecular complex of chondroitin C sulfate proteoglycan, neuropilin-1, and VEGF receptor-2, overexpressed together only in highly angiogenic sites of the tumor microenvironment. The HBDt.TFt was also colocalized with the trimolecular receptor complex in endothelial sprouts from tumor tissues, and its binding inhibited the growth of such sprouts. In vitro, we show that the HBDt structure has its highest affinity for chondroitin 6 sulfate. We show the potential of this HBDt.TFt as a candidate therapeutic and elucidate its target in vivo.

Topics: Animals; Endothelium, Vascular; Heparin; Male; Mice; Mice, Inbred BALB C; Necrosis; Neoplasms, Experimental; Neovascularization, Pathologic; Peptide Fragments; Protein Structure, Tertiary; Recombinant Fusion Proteins; Spheroids, Cellular; Thrombin; Thromboplastin; Thrombosis

Tissue factor (TF), the main initiator of blood coagulation, contributes to the manifestation of disseminated intravascular coagulation following septic shock in meningococcal infection. Since a direct relationship between disease severity and lipopolysaccharide (LPS) concentration in the circulation has been shown, we hypothesized that the procoagulant and cytotoxic effects of endotoxin also in vitro were related to its concentration. In vitro studies, however, have frequently used much higher LPS concentrations than those observed in clinical samples. Using elutriation-purified human monocytes, we observed that LPS up to 1000 ng/ml exerted a concentration-dependent increase in TF activity (tenase activity, fibrin formation in plasma). Although there was a dose-dependent increase in TF activity, there was not a concomitant increase in TF expression at LPS concentrations above 1 ng/ml (flow cytometry, Western blotting, TF mRNA). Flow cytometry revealed that this discrepancy between TF activity and TF expression at endotoxin concentrations above 1 ng/ml, coincided with an LPS dose-dependent increase in cell surface phosphatidylserine (PS), considered to promote coagulation. The increased PS expression was associated with an increased number of 7-AAD-positive cells indicating cell death. We conclude that enhancement of monocyte procoagulant activity in vitro by high concentrations of LPS may result from increased PS exposure due to apoptosis and necrosis. Therefore, the LPS concentrations used to examine monocyte procoagulant activity in vitro, should be carefully chosen.

Topics: Annexin A5; Antibodies, Monoclonal; Apoptosis; Blood Coagulation; Cells, Cultured; Cysteine Endopeptidases; Dose-Response Relationship, Drug; Fibrinopeptide A; Humans; Lipopolysaccharides; Monocytes; Necrosis; Neoplasm Proteins; Phosphatidylserines; RNA, Messenger; Thromboplastin

Previous studies have emphasized the role of ischemia in inducing vascular thrombosis.. Using a skin flap model of acute ischemia in the rat, we studied the effect of active-site inactivated factor VIIa (FVIIai), an inhibitor of tissue factor (TF), on tissue survival during acute ischemia.. Ribonuclease protection analysis revealed an increase in TF in ischemic parts of the flap, and in situ hybridization localized this increase mainly to perivascular cells. A decrease in vascular thrombosis, as determined by fibrin immunostaining, was observed in FVIIai-treated animals. Intravenous administration of FVIIai had a positive impact on survival of the flap. Laser Doppler flowmetry revealed an increase in blood flow in the FVIIai-treated group. In treated animals, prothrombin time (PT) was increased (P < 0.01), whereas partial thromboplastin time (APTT) was unaltered; no significant impairment in systemic hemostasis (peri- and postoperative bleeding) was observed.. These findings demonstrate that TF expression is increased in perivascular cells in ischemic skin flaps and that FVIIai, by inhibiting TF, increases flap survival.

Topics: Acute Disease; Animals; Blood Coagulation; Factor VIIa; Female; Ischemia; Necrosis; Rats; Rats, Wistar; Regional Blood Flow; Skin; Surgical Flaps; Thromboplastin; Thrombosis; Time Factors; Tissue Survival

Tissue factor is the prime initiator of blood coagulation. Expression of tissue factor in tumor endothelial cells leads to thrombus formation, occlusion of vessels and development of hemorrhagic infarctions in the tumor tissue, often followed by regression of the tumor. Tumor cells produce endogenous vascular endothelial growth factor (VEGF), which sensitizes endothelial cells for systemically administered tumor necrosis factor alpha (TNF alpha) and synergistically enhances the TNF-induced expression of tissue factor. We have analyzed the pathways involved in the induction of tissue factor in human umbilical cord vein endothelial cells (HUVECs) after combined stimulation with TNF and VEGF. By using specific low molecular weight inhibitors, we demonstrated that protein kinase C (PKC), p44/42 and p38 mitogen-activated protein (MAP) kinases, and stress-activated protein kinase (JNK) are essentially involved in the induction of tissue factor. In contrast, the application of wortmannin, an inhibitor of phosphatidylinositol 3 (PI3)-kinase, led to strongly enhanced expression of tissue factor in TNF- and VEGF-treated cells, implicating a negative regulatory role for PI3-kinase. In vivo, the application of wortmannin promoted the formation of TNF-induced hemorrhages and intratumoral necroses in murine meth A tumors. The co-injection of wortmannin lowered the effective dose of applied TNF. Therefore, it is conceivable that the treatment of TNF-sensitive tumors with a combination of TNF and wortmannin will ensure the selective damage of the tumor endothelium and minimize the risk of systemic toxicity of TNF. TNF-treatment in combination with specific inhibition of PI3-kinase is a novel concept in anti-cancer therapy.

Topics: Androstadienes; Animals; Blotting, Western; Endothelial Growth Factors; Endothelium, Vascular; Enzyme Inhibitors; Fibrosarcoma; Flow Cytometry; Intercellular Signaling Peptides and Proteins; JNK Mitogen-Activated Protein Kinases; Lymphokines; MAP Kinase Kinase 4; Methylcholanthrene; Mice; Mice, Inbred C57BL; Mitogen-Activated Protein Kinase 1; Mitogen-Activated Protein Kinase 3; Mitogen-Activated Protein Kinase Kinases; Mitogen-Activated Protein Kinases; Necrosis; p38 Mitogen-Activated Protein Kinases; Phosphatidylinositol 3-Kinases; Phosphoinositide-3 Kinase Inhibitors; Phosphorylation; Protein Kinase C; Sarcoma, Experimental; Thromboplastin; Tumor Necrosis Factor-alpha; Vascular Endothelial Growth Factor A; Vascular Endothelial Growth Factors; Wortmannin

Topics: Animals; Kidney; Male; Necrosis; Oligodeoxyribonucleotides, Antisense; Rats; Rats, Inbred Lew; Renal Circulation; Reperfusion Injury; Thionucleotides; Thromboplastin

A cascade of inflammatory reactions characterize acute vascular rejection after heart transplantation. This study was undertaken to test the hypothesis that acute vascular rejection is associated with up-regulation of vitronectin receptor (alphavbeta3), increased expression of tissue factor, and activation of the extracellular matrix metalloproteinase induction system.. Acute vascular rejection developed in 14 heart transplant recipients within 2 weeks of transplantation, confirmed by immunofluorescence (AVR group). We compared these patients with 10 transplant recipients who had no evidence of acute vascular rejection or peritransplant ischemic injury (control group). We evaluated endomyocardial biopsy specimens for alphavbeta3, tissue factor, and extracellular matrix metalloproteinase inducer (EMMPRIN).. Compared with the control group, the AVR group demonstrated evidence of significantly increased expression of alphavbeta3 (1.9-fold, p < 0.001), tissue factor (1.8-fold, p < 0.001), and EMMPRIN (1.5-fold, p < 0.001). All patients in the AVR group received plasmapheresis; 11 of 14 patients had evidence of ischemic necrosis on biopsy specimens, and 3 of 14 patients experienced hemodynamic compromise and graft dysfunction and died within 3 weeks of transplant. Another patient died at 10 months after transplant.. Acute vascular rejection is associated with up-regulation of alphavbeta3, tissue factor, and activation of the matrix metalloproteinase induction system, which may contribute to the lethal morbidity associated with this disease.

Topics: Acute Disease; Adult; Antigens, CD; Antigens, Neoplasm; Basigin; Endothelium, Vascular; Female; Graft Rejection; Heart Transplantation; Humans; Male; Membrane Glycoproteins; Myocardium; Necrosis; Receptors, Vitronectin; Thromboplastin; Up-Regulation

The influence of xenogeneic humoral immunoreaction on hepatic nonparenchymal cells (NPCs) was evaluated ex situ in xenoperfused rat livers.. Isolated rat livers were perfused via the portal vein (PV) for 240 min. The perfusates consisted of fresh rat blood (group 1), fresh human blood (group 2), and fresh human blood containing 5 microg/mL soluble complement receptor type 1 (Group 3).. Deposition of human IgM and C(5b-9) complement was observed in group 2, although only human IgM deposition was detected in group 3. Portal vein pressure in group 2 rose drastically during the first 10 min. Creatine kinase BB component gradually increased in all groups, followed by an elevation in alanine aminotransferase and both parameters were significantly higher in group 2 than in groups 1 and 3. In group 2, platelet thrombi in the peripheral PVs and periportal hemorrhage were observed after 10 min, and massive necrosis around the central veins after 240 min; these changes were not observed in group 1 or 3. Production of tumor necrosis factor alpha and alpha interferon and expression of intercellular adhesion molecule 1 (ICAM-1) were lower in group 2 than in groups 1 and 3. In group 2, there were negative areas for ICAM-1 and tumor necrosis factor alpha staining around the central veins after 240 min, which were consistent with necrotic areas.. In xenoperfused rat livers, humoral mediators initially caused the disturbance of microcirculation, which would induce long ischemia in the pericentral areas, resulting in massive necrosis. NPC necrosis may be responsible for less production of cytokines and adhesion molecules in the xenoperfused livers.

Topics: Alanine Transaminase; Animals; Antibodies, Heterophile; Antibody Formation; Creatine Kinase; Creatine Kinase, BB Form; E-Selectin; Gene Expression; Graft Rejection; In Vitro Techniques; Intercellular Adhesion Molecule-1; Interferon-gamma; Interleukin-1; Isoenzymes; Liver; Liver Circulation; Male; Microcirculation; Necrosis; Rats; Rats, Wistar; Receptors, Complement; RNA, Messenger; Thromboplastin; Transcription, Genetic; Transplantation, Heterologous; Tumor Necrosis Factor-alpha

The present series of experiments provide evidence that FVII is synthesized outside of the liver and is found in a variety of cells in normal and atherosclerotic vessels. In normal vessels FVII was localized to the endothelial cell layer and in adventitial fibroblasts at sites where tissue factor (TF) is also found. In early and advanced atherosclerotic lesions, FVII was mostly found in macrophage- rich regions colocalized with TF. Foam cells and macrophages in the necrotic core adjacent to the cholesterol clefts and foamy macrophages in early intimal thickenings all showed strong cytoplasmic staining with FVII antibodies. Although it is possible that FVII protein staining found in normal and atherosclerotic vessels originated from the blood, the finding of FVII mRNA by both in situ hybridization and RT-PCR suggests that these tissues are sites of FVII synthesis. Additional work demonstrated synthesis of FVII in a variety of tissues and smooth muscle cells and fibroblasts in vitro. The distribution of FVII synthesis in extrahepatic tissues and more recent data regarding thrombin-independent signaling as a consequence of FVII/TF binding may suggest the possibility of other cellular functions for this coagulation factor.

Topics: Aorta; Arteriosclerosis; Factor VII; Factor X; Humans; Liver; Muscle, Smooth, Vascular; Necrosis; Organ Specificity; Reference Values; Thromboplastin

Vascular changes are considered the major histopathological indicator of chronic allograft dysfunction. These changes are characterized by intimal thickening caused by accumulation of primarily smooth muscle cells. Contributing factors may be of both immunological and nonimmunological origin. Cold ischemia has been shown to trigger intimal proliferation in the absence of alloantigen in an isogenic rat aortic transplant model. We have used this model to investigate the impact of inhibition of tissue factor (TF) signalling on the progression of intimal thickening. Group 1 was treated with recombinant FVIIa inhibited in its active site (rFVIIai), and group 2 served as untreated controls. At 8 weeks the intimal area was measured with image analysis. Medial areas and the proportion of medial necrosis were determined. Animals treated with rFVIIai showed significantly less intimal thickening compared with controls: median 0.147 vs. 0.256 mm2, respectively (p = 0.008). A positive correlation between intimal hyperplasia and medial necrosis (r(s) = 0.79, p = 0.01), as well as adventitial inflammation (r(s) = 0.83, p = 0.009), was found. TF mRNA was not detected in the neointima at 8 weeks, as determined by in situ hybridization. We conclude that active site inhibited FVIIa (rFVIIai) given prior to and directly after implantation of aortic transplants significantly reduces intimal hyperplasia caused by nonimmunological factors in this model.

Topics: Animals; Aorta, Abdominal; Factor VIIa; Necrosis; Rats; Recombinant Proteins; Signal Transduction; Thromboplastin; Transplantation, Isogeneic; Tunica Intima

In the present studies, we report the cloning and structural characterization of the HFGL2 gene and its functional role in human fulminant hepatitis. The HFGL2 gene is approximately 7 kb in length with 2 exons. The putative promoter contains cis element consensus sequences that strongly suggest the inducibility of its expression. From the nucleotide sequence of the human gene, a 439-amino acid long protein is predicted. The overall identity between the murine fgl2 and hfgl2 coded proteins is over 70%. About 225 amino acids at the carboxyl end of these molecules are almost 90% identical, and correspond to a well-conserved fibrinogen-related domain. Both HFGL2 and FGL2 encode a type II transmembrane protein with a predicted catalytic domain toward the amino terminus of the protein. Transient transfection of Chinese hamster ovary (CHO) cells with a full-length cDNA of HFGL2 coding region resulted in high levels of prothrombinase activity. Livers from 8 patients transplanted for fulminant viral hepatitis were examined for extent of necrosis, inflammation, fibrin deposition, and HFGL2 induction. In situ hybridization showed positive staining of macrophages in areas of active hepatocellular necrosis. Fibrin stained positively in these areas and was confirmed by electron microscopy. These studies define a unique prothrombinase gene (HFGL2) and implicate its importance in the pathogenesis of fulminant viral hepatitis.

Topics: Adolescent; Adult; Amino Acid Sequence; Animals; Child, Preschool; CHO Cells; Cloning, Molecular; Consensus Sequence; Cricetinae; Female; Fibrin; Fibrinogen; Hepatitis, Viral, Human; Humans; Infant; Liver; Male; Middle Aged; Molecular Sequence Data; Necrosis; Promoter Regions, Genetic; Thromboplastin; Transfection

Activated Kupffer cells provoke massive liver necrosis after endotoxin stimulation through microcirculatory disturbance caused by sinusoidal fibrin deposition in rats undergoing 70% hepatectomy. In these rats, serum activities of purine nucleoside phosphorylase (PNP) and alanine transaminase (ALT) were increased at 1 and 5 hours, respectively, following endotoxin administration. When 70% resected liver was perfused with Dulbecco's modified Eagle medium (DMEM) containing heat-inactivated fetal calf serum, the increase in both enzyme activities was not affected by addition of endotoxin during perfusion, suggesting that activated Kupffer cells injured neither sinusoidal endothelial cells nor hepatocytes. The activity of tissue factor, an initiator of blood coagulation cascade, was much higher in Kupffer cells isolated from partially hepatectomized rats than in those from normal rats. In contrast, mRNA expressions of tissue factor pathway inhibitor (TFPI) as well as thrombomodulin were almost undetectable in normal and partially resected livers. When recombinant human TFPI was injected intravenously in 70% hepatectomized rats, TFPI was markedly stained on the surfaces of sinusoidal endothelial cells and microvilli of hepatocytes on immunohistochemistry. In these rats, endotoxin-induced liver injury was significantly attenuated compared with rats given no TFPI. Similar attenuation was also found in rats receiving recombinant human thrombomodulin. These results suggest that fibrin deposition developing in 70% hepatectomized rats after endotoxin administration may be caused by deranged blood coagulation in the hepatic sinusoids through increasing tissue factor activity in Kupffer cells and minimal TFPI and thrombomodulin in endothelial cells. The destruction of sinusoidal endothelial cells as well as hepatocytes may occur as a result of microcirculatory disturbance caused by such sinusoidal fibrin deposition.

Topics: Alanine Transaminase; Animals; Blood Coagulation Disorders; Endotoxins; Hepatectomy; Humans; Injections, Intravenous; Kupffer Cells; Lipoproteins; Liver; Male; Necrosis; Purine-Nucleoside Phosphorylase; Rats; Rats, Inbred F344; Recombinant Proteins; Thrombomodulin; Thromboplastin; Tissue Distribution

The mechanisms by which tumor necrosis factor (TNF) exerts its necrotic effects are somewhat obscure. We hypothesize that TNF, by monocyte activation, produces the procoagulant tissue factor, thus leading to a state of hypercoagulability with resultant thrombotic vascular occlusion and tissue necrosis. To test this hypothesis, modified recalcification time values (in minutes +/- standard deviation) were obtained on aliquots of blood with A) 20 microL of albumin, B) 20 microL of saline containing endotoxin, and C) 20 microL of albumin with 450 units of TNF. No differences were noted if the samples were not incubated. We conclude that TNF, can cause tumor (tissue) necrosis, and since incubation is required, TNF alone (without monocyte activation) has no procoagulant activity.

Topics: Blood Coagulation; Endotoxins; Escherichia coli; Humans; Monocytes; Necrosis; Serum Albumin; Thromboplastin; Thrombosis; Tumor Necrosis Factor-alpha

Endothelial cell activation and alterations of intravascular coagulation were investigated in 27 cases of Hodgkin's disease (HD), in five cases of anaplastic large cell lymphoma (ALCL), and in ten reactive lymph nodes. Lymph node sections were immunostained for E-selectin, a molecule present on cytokine-activated endothelial cells; for tissue factor (TF), a cellular initiator of the coagulation cascade; for glycoprotein (gp) II/III, a platelet-specific antigen; and for fibrin. In HD, vascular activation was particularly prominent in the nodular sclerosis subtype, as indicated by a larger number of E-selectin-positive blood vessels (72 +/- 49) compared with mixed cellularity (22 +/- 37). High expression of E-selectin was associated with alterations of intravascular coagulation, as indicated by immunostaining of some vascular endothelial cells for TF, by a higher incidence of intravascular thrombi, and by the extensive presence of areas of fibrin exudation and necrosis. In ALCL, the levels of endothelial cell activation and intravascular coagulation were comparable to those of HD nodular sclerosis. In reactive nodes, some E-selectin-positive blood vessels were observed only in 3/10 cases; immunostaining for TF was not detected on endothelial cells; and alterations of intravascular coagulation were rarely observed.

Topics: Adolescent; Adult; Aged; Cell Adhesion Molecules; E-Selectin; Endothelium, Vascular; Female; Fibrin; Hodgkin Disease; Humans; Lymph Nodes; Male; Middle Aged; Necrosis; Neoplasm Proteins; Regional Blood Flow; Thromboplastin; Thrombosis

We have reported earlier that immunodepletion of extrinsic pathway inhibitor (EPI) sensitizes rabbits to disseminated intravascular coagulation (DIC) induced by infusing a low concentration of tissue factor (TF). We now describe the effect of immunodepletion of EPI in rabbits administered endotoxin. Cortisone-treated rabbits were administered anti-rabbit EPI immunoglobulin (IgG) or Fab fragments or were administered control nonimmune material before an injection of endotoxin. In four of seven rabbits administered anti-EPI, plasma EPI activity levels were reduced by 70% to 80% of initial levels for 6 to 8 hours. In these rabbits the endotoxin induced extensive DIC, as evidenced by substantial decreases in fibrinogen, factor V, factor VIII, and platelets, and gross hemorrhagic necrosis of the kidneys due to massive deposition of fibrin in the glomerular microcirculation (the generalized Shwartzman reaction). In three rabbits administered anti-EPI, plasma EPI levels were only transiently reduced. In these rabbits and in four rabbits administered nonimmune IgG or Fab, endotoxin induced minimal to moderate intravascular clotting and deposits of fibrin were not found in the glomerular capillaries. Because it is believed that TF expressed on monocytes triggers endotoxin-induced coagulation, these data are taken as evidence that EPI functions as a natural anticoagulant that can regulate factor VIIa/TF activity expressed on cell surfaces in vivo. They support a hypothesis that EPI prevents thrombotic complications that might otherwise result from exposure of blood to cytokine-induced generation of small amounts of TF on cell surfaces in many inflammatory and infectious disease states.

Topics: Animals; Disseminated Intravascular Coagulation; Endotoxins; Factor V; Factor VII; Factor VIII; Fibrinogen; Kidney; Lipoproteins; Necrosis; Rabbits; Thromboplastin

Successful prevention of the progression of incipient hemorrhagic skin necrosis by timely administration of vitamin K1 in a woman treated with phenprocoumon is presented. From a critical review of the literature strong evidence emerges that coumarin necrosis does only occur in cases with severe initial drug induced hypocoagulability. Non- recognition thusfar of its importance is due to insufficient knowledge of the biological activities of thromboplastin preparations presently used in the laboratory control of oral anticoagulation. All well documented cases with apparently adequate Quick values were monitored with Faktor VIII insensitive thromboplastin. Therefore, such preparations should no longer be used in anticoagulant control.

Topics: 4-Hydroxycoumarins; Female; Hemorrhage; Humans; Middle Aged; Necrosis; Phenprocoumon; Skin; Skin Diseases; Thromboplastin; Vitamin K 1

Topics: Alanine Transaminase; Animals; Aspartate Aminotransferases; Blood Platelets; Blood Proteins; Blood Urea Nitrogen; Cryosurgery; Disseminated Intravascular Coagulation; Dogs; Fibrinogen; Hemostasis; Liver; Necrosis; Postoperative Complications; Shock, Hemorrhagic; Thromboplastin

Topics: Adult; Aged; Arthritis; Blood Coagulation Disorders; Blood Coagulation Tests; Blood Platelets; Carcinoma; Factor VIII; Female; Fibrinolysin; Hepatitis; Humans; Liver Diseases; Male; Middle Aged; Necrosis; Rectal Neoplasms; Thrombin; Thromboplastin; Vaginal Neoplasms

Topics: Breast Neoplasms; Female; Humans; Lung Neoplasms; Middle Aged; Necrosis; Neoplasm Metastasis; Neoplasm Seeding; Neoplasms, Radiation-Induced; Radiotherapy; Skin Neoplasms; Thromboplastin

Topics: Adult; Alanine Transaminase; Aminocaproates; Angioedema; Animals; Aspartate Aminotransferases; Bilirubin; Blood Cell Count; Blood Coagulation Disorders; Blood Coagulation Tests; Blood Platelets; Creatine Kinase; Creatinine; Dogs; Factor V; Factor VIII; Fibrinogen; Haplorhini; Hemolysis; Humans; Hyperbilirubinemia, Hereditary; Male; Methyltestosterone; Muscular Diseases; Myoglobinuria; Necrosis; Norepinephrine; Plasminogen; Rats; Spectrophotometry; Thromboembolism; Thromboplastin

Topics: Coumarins; Drug Hypersensitivity; Female; Humans; Male; Necrosis; Skin Diseases; Thromboplastin

Topics: Aminocaproates; Aminocaproic Acid; Animals; Anticoagulants; Electrons; Fibrin; Kidney Diseases; Kidney Glomerulus; Necrosis; Nephrosclerosis; Pathology; Rabbits; Research; Thrombin; Thromboplastin; Thrombosis