fibrin and Hemolysis

Following protein adsorption/activation which is the first step after the contact of material surfaces and whole blood (part 2), fibrinogen is converted to fibrin and platelets become activated and assembled in the form of a thrombus. This thrombus formation is the key feature that needs to be minimized in the creation of materials with low thrombogenicity. Further aspects of blood compatibility that are important on their own are complement and leukocyte activation which are also important drivers of thrombus formation. Hence this review summarizes the state of knowledge on all of these cascades and cells and their interactions. For each cascade or cell type, the chapter distinguishes statements which are in widespread agreement from statements where there is less of a consensus. STATEMENT OF SIGNIFICANCE: This paper is part 3 of a series of 4 reviews discussing the problem of biomaterial associated thrombogenicity. The objective was to highlight features of broad agreement and provide commentary on those aspects of the problem that were subject to dispute. We hope that future investigators will update these reviews as new scholarship resolves the uncertainties of today.

Topics: Adsorption; Animals; Biocompatible Materials; Blood Coagulation; Blood Platelets; Complement System Proteins; Fibrin; Fibrinogen; Hemolysis; Humans; Inflammation; Leukocytes; Materials Testing; Microspheres; Platelet Adhesiveness; Surface Properties; Thrombosis

Topics: Alloys; Animals; Anticoagulants; Aorta; Blood Vessel Prosthesis; Cattle; Collagen; Embolism; Fibrin; Granulation Tissue; Heart Valve Prosthesis; Heart Valves; Hemolysis; Humans; Plastics; Prosthesis Design; Silicone Elastomers; Thrombosis; Time Factors

Case-control and observational studies have provided a plausible mechanistic link between clot structure and thrombosis. We aimed to identify lifestyle, demographic, biochemical, and genetic factors that influence changes in total fibrinogen concentration and clot properties over a 10-year period in 2,010 black South Africans. Clot properties were assessed with turbidimetry and included lag time, slope, maximum absorbance, and clot lysis time. Linear mixed models with restricted maximum likelihood were used to determine whether (1) outcome variables changed over the 10-year period; (2) demographic and lifestyle variables, biochemical variables, and fibrinogen single-nucleotide polymorphisms influenced the change in outcome variables over the 10-year period; and (3) there was an interaction between the exposures and time in predicting the outcomes. A procoagulant risk score was furthermore created, and multinomial logistic regression was used to determine the exposures that were associated with the different risk score categories. In this population setting, female gender, obesity, poor glycemic control, increased low-density lipoprotein cholesterol, and decreased high-density lipoprotein cholesterol contributed to the enhanced progression to prothrombotic clot properties with increasing age. Alcohol consumption on the other hand, offered a protective effect. The above evidence suggest that the appropriate lifestyle changes can improve fibrin clot properties on a population level, decreasing cardiovascular disease risk and thus alleviate the strain on the medical health care system.

Topics: Adult; Case-Control Studies; Cell-Derived Microparticles; Female; Fibrin; Hemolysis; Humans; Iron; Male; Middle Aged; Risk Reduction Behavior; Thrombosis

The distribution of metals across the environment is increasingly becoming a major concern as they not only pollute the environment but also pose a danger to humans and animals. Human exposure to heavy metals often occurs as a combination of metals the synergistic effects of which can be more toxic than a single metal. The aim of this study was to investigate the effects that the metals mercury (Hg), nickel (Ni) and manganese (Mn) alone and in combination have on erythrocyte morphology and other components of the coagulation system using the haemolysis assay, scanning electron microscopy (SEM), and confocal laser scanning microscopy. Human blood was exposed to the heavy metals

Topics: Blood Platelets; Erythrocytes; Fibrin; Hemolysis; Humans; Male; Metals, Heavy

Snakebite envenomation causes over 140,000 deaths every year, predominantly in developing countries. As a result, it is one of the most lethal neglected tropical diseases. It is associated with incredibly complex pathophysiology due to the vast number of unique toxins/proteins present in the venoms of diverse snake species found worldwide. Here, we report the purification and functional characteristics of a Group I (PI) metalloprotease (CAMP-2) from the venom of the western diamondback rattlesnake,

Topics: Animals; Antineoplastic Agents; Antivenins; Binding Sites; Blood Platelets; Catalytic Domain; Collagen; Crotalid Venoms; Crotalus; Drug Repositioning; Erythrocytes; Fibrin; Fibrinolysis; Hemolysis; Humans; Hydroxamic Acids; Matrix Metalloproteinase Inhibitors; Matrix Metalloproteinases; Molecular Docking Simulation; Phenylalanine; Protein Binding; Protein Conformation; Structure-Activity Relationship; Substrate Specificity; Thiophenes

A fibrinolytic enzyme was produced by microalga Chlorella vulgaris cultivated in autotrophic and mixotrophic conditions added corn steep liquor, purified by a single chromatographic step, then biochemical characterization and in vitro thrombolytic activity was performed. Maximum cell concentration (1637.45 ± 15 mg L

Topics: Chlorella vulgaris; Chromatography, Ion Exchange; Erythrocytes; Fibrin; Fibrinolytic Agents; Hemolysis; Humans; Plant Proteins

Essentials An international collaboration provides a consensus for clinical definitions. This concerns thrombotic microangiopathies and thrombotic thrombocytopenic purpura (TTP). The consensus defines diagnosis, disease monitoring and response to treatment. Requirements for ADAMTS-13 are given.. Background Thrombotic thrombocytopenic purpura (TTP) and hemolytic-uremic syndrome (HUS) are two important acute conditions to diagnose. Thrombotic microangiopathy (TMA) is a broad pathophysiologic process that leads to microangiopathic hemolytic anemia and thrombocytopenia, and involves capillary and small-vessel platelet aggregates. The most common cause is disseminated intravascular coagulation, which may be differentiated by abnormal coagulation. Clinically, a number of conditions present with microangiopathic hemolytic anemia and thrombocytopenia, including cancer, infection, transplantation, drug use, autoimmune disease, and pre-eclampsia and hemolysis, elevated liver enzymes and low platelet count syndrome in pregnancy. Despite overlapping clinical presentations, TTP and HUS have distinct pathophysiologies and treatment pathways. Objectives To present a consensus document from an International Working Group on TTP and associated thrombotic microangiopathies (TMAs). Methods The International Working Group has proposed definitions and terminology based on published information and consensus-based recommendations. Conclusion The consensus aims to aid clinical decisions, but also future studies and trials, utilizing standardized definitions. It presents a classification of the causes of TMA, and criteria for clinical response, remission and relapse of congenital and immune-mediated TTP.

Topics: ADAMTS13 Protein; Adult; Blood Platelets; Child; Complement System Proteins; Consensus; Diagnosis, Differential; Erythrocytes; Female; Fibrin; Hematology; Hemolysis; Hemolytic-Uremic Syndrome; Humans; Inflammation; Platelet Aggregation; Platelet Count; Pregnancy; Purpura, Thrombotic Thrombocytopenic; Recurrence; Remission Induction; Societies, Medical; Terminology as Topic; Thrombotic Microangiopathies; Treatment Outcome; von Willebrand Factor

Although many attempts have been made to design advanced hemoglobin-based oxygen carriers (HBOCs), no clinically viable product has been widely approved, because they do not perform normal blood functions, such as coagulation, hematologic reactions and stability. Additionally, the in vivo oxygenation of hemoglobin-loaded nanoparticles (HbPs) encapsulated with polymers has seldom been proved. Herein, HbPs of approximately 200nm with good stability were successfully fabricated and exhibited oxygen-carrying capacity. The HbPs preserve the biological and structure features of hemoglobin according to UV-vis spectrophotometry, Fourier transform infrared (FTIR) spectroscopy and circular dichroism (CD) spectral analysis. In vitro, the HbPs showed a viscosity comparable to that of blood with no obvious effects on red blood cell aggregation. At the same time, blood compatibility was characterized in terms of platelet function, clot strength, speed of clot formation, degree of fibrin cross-linking and hemolysis rate. After intravenous administration of HbPs to mice with controlled hemorrhages, blood flow recovery and maintenance of systemic oxygenation were observed.

Topics: Administration, Intravenous; Animals; Blood Platelets; Blood Substitutes; Cattle; Erythrocyte Aggregation; Fibrin; Hemoglobins; Hemolysis; Hemorrhage; Male; Mice; Mice, Inbred BALB C; Nanoparticles; Oxygen; Particle Size; Rabbits; Rats; Rats, Wistar; Viscosity; Whole Blood Coagulation Time

Recently, bioretention and toxicity of injected nanoparticles in the body has drawn much attention in biomedical research. In the present study, 5 mg Fe per kg body weight of magnetic fibrin nanoparticles (MFNPs) were injected into mice intravenously and investigated for their blood clearance profile, biodistribution, haematology and pathology studies for a time period of 28 days. Moderately long circulation of MFNPs in blood was observed with probable degradation and excretion into the bloodstream via monoatomic iron forms. Inductively coupled plasma optical emission spectrometry (ICP-OES) and Prussian blue staining results showed increased accumulation of MFNPs in the liver, followed by spleen and other organs. Body weight, spleen/thymus indexes, haematology, serum biochemistry and histopathology studies demonstrated that MFNPs were biocompatible. These results suggest the feasibility of using MFNPs for drug delivery and imaging applications.

Topics: Animals; Biocompatible Materials; Body Weight; Dynamic Light Scattering; Female; Fibrin; Hemolysis; Liver; Magnetite Nanoparticles; Mice; Mice, Inbred BALB C; Spleen; Time Factors; Tissue Distribution

In the present study, nanosized hydroxyapatite (nHAp) was formed on iron-fibrin substrates and its physico-chemical properties were characterized. The prepared iron-fibrin-nanohydroxyapatite (IF-nHAp) composite was needle shaped with an average width of about 30nm and length of 80nm. The vibrating sample magnetometer (VSM) was used to evaluate the superparamagnetic behavior of the nanocomposite, IF-nHAp. Hemolysis and ELISA (enzyme linked immunosorbent assay) were performed to evaluate the its bio/immunocompatibility and MTT (3-(4,5-dimethylazol-2-yl)-2,5-diphenyl-tetrazolium bromide) assay using osteoblast cells was performed to scrutinize its proliferative potential. Alkaline phosphatase activity (ALP) and calcium deposition were studied to investigate the osteogenic property of the nanocomposite. RT-PCR (real time-polymerase chain reaction) was used to quantify the mRNA levels of ALP, OC (osteocalcin), and OPN (osteopontin) genes involved in the osteogenic differentiation and matrix mineralization. Further, the bone bonding ability of IF-nHAp was observed by the deposition of apatite layers on the composite incubated in simulated body fluid (SBF).

Topics: Alkaline Phosphatase; Animals; Biocompatible Materials; Cattle; Cell Death; Cell Line, Tumor; Cell Survival; Durapatite; Enzyme-Linked Immunosorbent Assay; Fibrin; Gene Expression Regulation; Hemolysis; Humans; Iron; Magnetite Nanoparticles; Magnetometry; Spectroscopy, Fourier Transform Infrared; Staining and Labeling

Fibrin used for biomedical applications is prepared by mixing concentrated solutions of fibrinogen and thrombin in presence of cross-linking agents such as Factor XIII or glutaraldehyde. The main drawbacks associated with this procedure include cost, complexity and time required for fibrin preparation. Hence, present study deals with the characterization of physiologically clotted fibrin (PF) for bone tissue engineering and drug delivery applications. For this the physico-chemical properties of PF were compared with those of the conventionally prepared fibrin (CF). Further MTT and haemolytic assays were performed for both PF and CF to compare their biocompatibility. The amount of alkaline phosphatase produced and calcium secreted by MG-63 cells in the presence of PF and CF were used to relate the osteogenic potency of PF with that of CF. Gallic acid, an anti-cancer drug was loaded within PF and CF and their role in drug delivery was compared.

Topics: Absorbable Implants; Alkaline Phosphatase; Animals; Apatites; Biocompatible Materials; Calcium; Cattle; Cell Line; Cell Proliferation; Cell Survival; Drug Delivery Systems; Fibrin; Hemolysis; Humans; Materials Testing; Mice; NIH 3T3 Cells; Osteoblasts; Osteogenesis; Tensile Strength; Tissue Engineering

A fibrinolytic enzyme isolated from marine Bacillus subtilis HQS-3 was purified to electrophoretic homogeneity using ammonium sulphate precipitation, alkaline solution treatment, membrane concentration, dialysis, ion exchange, and gel filtration chromatography. SDS-PAGE and gel filtration chromatography showed that it was a monomeric protein with an apparent molecular weight of 26 kDa. The purified enzyme was active at pH 6.0-10.0 with an optimum pH of 8.0. It was stable at temperatures ranging from 25 to 37 °C, exhibiting maximum activity between 45 °C and 50 °C. The isoelectric point of the enzyme was 9.0-9.2, which was higher than those of other known fibrinolytic enzymes from Bacillus species. PMSF, EDTA, Cu(2+), Zn(2+), and Co(2+) inhibited the enzyme activity significantly. This enzyme did not cause hemolysis in vitro and preferred direct degradation of fibrin in the following order: α, β, and γ-γ chains. Thus, these results suggest that the marine-derived enzyme is a plasmin-like serine metalloprotease, which is distinct from other fibrinolytic enzymes from genus Bacillus.

Topics: Bacillus subtilis; Enzyme Inhibitors; Fibrin; Fibrinolytic Agents; Hemolysis; Hydrogen-Ion Concentration; Metals; Molecular Weight; Temperature

In this work the effects of four different multiwalled carbon nanotubes (MWCNTs), including long carboxylated (L-COOH), short carboxylated (S-COOH), long aminated (L-NH(2)) and short aminated (S-NH(2)) ones, on the integrity of red blood cells, coagulation kinetics and activation of platelets were investigated with human whole blood. We found that the four MWCNTs induced different degrees of red blood cell damage as well as a mild level of platelet activation (10-25%). L-COOH and L-NH(2) induced a higher level of platelet activation than S-COOH and S-NH(2) respectively; meanwhile L-NH(2) caused marked reductions in platelet viability. The presence of the four MWCNTs led to earlier fibrin formation, L-NH(2) increased the clots hardness significantly, while L-COOH and S-NH(2) made the clots become softer. It was concluded that the four MWCNTs affected blood coagulation process and the clots mechanical properties; they also altered the integrity of the red blood cells and the viability of the platelets, as well as induced platelets activation. The effects of MWCNTs depended on the size and chemistry of the nanotubes and the type of cells they contacted.

Topics: Amination; Biocompatible Materials; Blood Coagulation; Blood Platelets; Carboxylic Acids; Cell Survival; Diamines; Erythrocytes; Fibrin; Hemolysis; Humans; Microscopy, Electron, Scanning; Nanotubes, Carbon; Platelet Activation; Platelet Count

Mural thrombus generation at sites of damaged vessel walls is essential for both physiological haemostasis and pathological intravascular thrombosis. While thrombi are established by the concerted action of platelet aggregation and blood coagulation, most previous in vitro coagulation assays have evaluated fibrin clot formation in a closed stirring situation that lacks blood cells including platelets. We describe here a modified flow chamber system, established originally for platelet functional studies, that enables real-time observation of intra-thrombus fibrin accumulation during platelet thrombogenesis under flow conditions. Analysis by confocal laser scanning microscopy during perfusion of whole blood anticoagulated to various extents revealed that the size and shape of mural thrombi can depend on the intra-thrombus fibrin development under high shear rate conditions. These observations were confirmed by perfusion of heparinized blood or blood from haemophilia patients with or without addition of activated factor VII. Thus, our experimental system provides visual evidence supporting the concept of "cell-based coagulation under whole blood flow", which might be the most physiologically relevant model of comprehensive thrombogenicity in vivo to date. This system promises to help formulate strategies for haemostatic management of congenital coagulation disorders as well as for antithrombotic therapy targeting fatal arterial thrombosis.

Topics: Adult; Anticoagulants; Arginine; Blood Coagulation; Blood Flow Velocity; Blood Platelets; Collagen; Dose-Response Relationship, Drug; Factor VIIa; Fibrin; Hemolysis; Hemophilia A; Hemorheology; Heparin; Humans; Male; Microscopy, Confocal; Microscopy, Electron, Scanning; Middle Aged; Perfusion; Pipecolic Acids; Sulfonamides; Surface Properties; Thrombosis

Topics: Anemia, Sickle Cell; Endothelial Cells; Fibrin; Flow Cytometry; Hemolysis; Hemostasis; Humans; Hypertension, Pulmonary; Inflammation; Models, Biological; Monocytes; Thrombophilia

Sepsis is a life-threatening disorder resulting from systemic inflammatory and coagulatory responses to infection. High-mobility group box 1 protein (HMGB1), an abundant intranuclear protein, was recently identified as a potent lethal mediator of sepsis. However, the precise mechanisms by which HMGB1 exerts its lethal effects in sepsis have yet to be confirmed. We recently reported that plasma HMGB1 levels correlated with disseminated intravascular coagulation (DIC) score, indicating that HMGB1 might play an important role in the pathogenesis of DIC.. To investigate the mechanisms responsible for the lethal effects of HMGB1, and more specifically, to explore the effects of HMGB1 on the coagulation system.. Rats were exposed to thrombin with or without HMGB1, and a survival analysis, pathologic analyses and blood tests were conducted. The effects of HMGB1 on the coagulation cascade, anticoagulant pathways and surface expression of procoagulant or anticoagulant molecules were examined in vitro.. Compared to thrombin alone, combined administration of thrombin and HMGB1 resulted in excessive fibrin deposition in glomeruli, prolonged plasma clotting times, and increased mortality. In vitro, HMGB1 did not affect clotting times, but inhibited the anticoagulant protein C pathway mediated by the thrombin-thrombomodulin complex, and stimulated tissue factor expression on monocytes.. These findings demonstrate the procoagulant role of HMGB1 in vivo and in vitro. During sepsis, massive accumulation of HMGB1 in the systemic circulation would promote the development of DIC.

Topics: Animals; Blood Coagulation; Blood Coagulation Tests; Cells, Cultured; Coagulants; Cytokines; Disease Models, Animal; Disseminated Intravascular Coagulation; Enzyme Activation; Fibrin; Hemolysis; High Mobility Group Proteins; HMGB1 Protein; Humans; Inflammation; Kidney; Lung; Male; Monocytes; Protein C; Rats; Rats, Sprague-Dawley; Repressor Proteins; Thrombin; Thromboplastin; Thrombosis

Elevated plasma fibrinogen is a well known risk factor for cardiovascular disease. The mechanistic rationale for this is not known.. These studies were carried out to determine the fibrinogen concentration dependencies of clotting and lysis times and thereby determine whether these times rationalize the correlation between an increased risk of cardiovascular disease and elevated plasma fibrinogen.. The time courses of clot formation and lysis were measured by turbidity in systems comprising a) fibrinogen, thrombin and plasmin, or b) fibrinogen, thrombin, plasminogen and t-PA, or c) plasma, thrombin and t-PA. From the lysis times, k(cat) and K(m) values for plasmin action on fibrin were determined.. The time to clot increased linearly from 2.9 to 5.6 minutes as the fibrinogen concentration increased from 1 to 9 microM and did not increase further as the fibrinogen concentration was raised to 20 microM. In contrast, the clot lysis time increased linearly over the input fibrinogen concentration range of 2 to 20 microM. A similar linear trend was found in the two systems with t-PA and plasminogen. Apparent K(m) and k(cat) values for plasmin were 1.1 +/- 0.6 microM and 28 +/- 2 min(-1), respectively. K(m) values for plasmin in experiments initiated with t-PA and plasminogen were 1.6 +/- 0.2 microM in the purified system and 2.1 +/- 0.9 microM in plasma.. As the concentration of fibrinogen increases, especially above physiologic level, the balance between fibrinolysis and clotting shifts toward the latter, providing a rationale for the increased risk of cardiovascular disease associated with elevated fibrinogen.

Topics: alpha-2-Antiplasmin; Blood Coagulation; Cardiovascular Diseases; Fibrin; Fibrinogen; Hemolysis; Humans; In Vitro Techniques; Kinetics; Models, Cardiovascular; Nephelometry and Turbidimetry; Peptide Fragments; Plasminogen; Recombinant Proteins; Tissue Plasminogen Activator

The aim of this study was to determine the influence of type 2 diabetes on fibrinolysis by assessing interactions between the regulatory components of fibrinolysis and the fibrin clot, using fibrinogen purified from 150 patients with type 2 diabetes and 50 matched controls.. Clot lysis rates were determined by confocal microscopy. Plasmin generation was measured using a plasmin-specific chromogenic substrate. Surface plasmon resonance was used to determine the binding interactions between fibrin, tissue-type plasminogen activator (t-PA) and Glu-plasminogen; cross-linkage of plasmin inhibitor to fibrin by factor XIII was determined using a microtitre plate assay.. Lysis of diabetic clots was significantly slower than that of controls (1.35 vs 2.92 microm/min, p<0.0001) and plasmin generation was significantly reduced. The equilibrium binding affinity between both t-PA and Glu-plasminogen and fibrin was reduced in diabetic subjects: t-PA, K (D)=0.91+/-0.3 micromol/l (control subjects), 1.21+/-0.5 micromol/l (diabetic subjects), p=0.001; Glu-plasminogen, K (D)=97+/-19 nmol/l (control subjects), 156+/-66 nmol/l (diabetic subjects), p=0.001. Cross-linkage of plasmin inhibitor to fibrin by factor XIII was enhanced in diabetic subjects, with the extent of in vitro cross-linkage correlating with in vivo glycaemic control (HbA(1c)) (r=0.59, p=0.001).. These results indicate that impairment of the fibrinolytic process in diabetic patients is mediated via a number of different mechanisms; these may be a consequence of post-translational modifications to fibrinogen molecules, resulting from their exposure to the abnormal metabolic milieu associated with diabetes.

Topics: Aged; Blood Glucose; Body Mass Index; Diabetes Mellitus, Type 2; Drug Resistance; Enzyme Activation; Factor XIII; Female; Fibrin; Fibrinogen; Fibrinolysin; Glycated Hemoglobin; Hemolysis; Humans; Male; Mass Spectrometry; Middle Aged; Reference Values; Surface Plasmon Resonance

Polyvalent (Crotalinae) and anticoral (Elapidae) antivenoms produced by Instituto Clodomiro Picado, Costa Rica, were assessed for their ability to neutralize various toxic activities of the venoms of North American snakes of the genera Crotalus, Agkistrodon and Micrurus, in assays involving preincubation of venom and antivenom. When the intraperitoneal route of injection was utilized, polyvalent (Crotalinae) antivenom was effective in the neutralization of the venoms of Crotalus atrox, Crotalus adamanteus, Crotalus viridis viridis, Crotalus horridus atricaudatus, Agkistrodon contortrix contortrix and Agkistrodon piscivorus piscivorus, whereas the venom of Crotalus scutulatus was not neutralized. When the intravenous route was used, results differed depending on the "challenge dose" of venom employed. Polyvalent antivenom neutralized all venoms when mice were challenged with 2 LD(50)s of venom. When 5 LD(50)s were used, antivenom neutralized the venoms of C. atrox, C. adamanteus, C. v. viridis and C. h. atricaudatus, being ineffective in the neutralization of C. scutulatus, A. c. contortrix and A. p. piscivorus. Polyvalent antivenom was effective in the neutralization of hemorrhagic and myotoxic activities of all venoms studied. It also neutralized coagulant activity of C. adamanteus venom, whereas most of the venoms were devoid of clotting activity on plasma in vitro. Moreover, it neutralized defibrinating activity of the only three venoms that induced this effect (i.e. C. adamanteus, A. c. contortrix and A. p. piscivorus). Anticoral (Elapidae) antivenom neutralized lethality induced by the venom of Micrurus fulvius, using either the intravenous or the intraperitoneal routes of injection. Moreover, it neutralized myotoxic effect of this venom as well. It is concluded that polyvalent antivenom neutralizes lethality and other activities of most of the crotaline venoms tested. However, since it is ineffective in neutralizing the lethal effect of C. scutulatus venom, it is suggested that a venom containing presynaptically-active neurotoxic phospholipases A(2) related to "mojave toxin" needs to be introduced in the immunizing mixture in order to increase the neutralizing scope of this product in North America. Anticoral antivenom is highly effective in the neutralization of the venom of M. fulvius.

Topics: Animals; Antivenins; Blood Coagulation; Costa Rica; Crotalid Venoms; Elapid Venoms; Fibrin; Hemolysis; Hemorrhage; Infusions, Intravenous; Injections, Intradermal; Injections, Intramuscular; Injections, Intraperitoneal; Lethal Dose 50; Mice; Neutralization Tests; Snakes; United States

Membranes made from 4 commercial poly(carbonate urethanes): Carbothane (CB), Chronoflex (CF), Corethane 80A (CT80), and Corethane 55D (CT55), and from 2 poly(ether urethanes): Tecoflex (TF) and Tecothane (TT) were prepared by solution casting and sterilized by either ethylene oxide (EO) or gamma radiation. Their biocompatibility was evaluated in vitro in terms of proliferation, cell viability, and adhesion characteristics of human umbilical veins (HUVEC), monocytes (THP-1), and skin fibroblasts, and by measuring complement activation through the generation of the C3a complex. Their hemocompatibility was determined by measuring the level of radiolabeled platelet, neutrophil, and fibrin adhesion in an ex vivo arteriovenous circuit study in piglets as well as via an in vitro hemolysis test. The results of this study showed no endothelial cell proliferation on any of the materials. The cell viability study revealed that the CB, CF, and TF membranes sterilized by EO maintained the highest percentage of monocyte viability after 72 h of incubation (>70%) while none of the gamma-sterilized membranes displayed any cell viability. The fibroblast adhesion and C3a generation assays revealed that none of the materials supported any cell adhesion or activated complement, regardless of the sterilization method. The hemolysis test also confirmed that the 4 poly(carbonate urethanes) were hemolytic while none of the poly(ether urethanes) were. Finally, the ex vivo study revealed that significantly more platelets adhered to the CB and CT55 membranes while the levels of neutrophil and fibrin deposition were observed to be similar for all 6 materials. In conclusion, the study identified the CF and TF membranes as having superior biocompatibility and hemocompatibility compared to the other polyurethanes.

Topics: Animals; Biocompatible Materials; Blood; Cell Adhesion; Cell Division; Cell Survival; Complement Activation; Complement C3a; Fibrin; Fibroblasts; Heart Ventricles; Heart, Artificial; Hemolysis; Humans; Membranes, Artificial; Monocytes; Neutrophils; Platelet Adhesiveness; Polycarboxylate Cement; Polyurethanes; Prosthesis Design; Skin; Sterilization; Swine; Umbilical Veins

This investigation compared the ability of six Latin American antivenoms (monovalent antibothropic INS, Santafé de Bogotá; polyvalent INS; polyvalent probiol, Santafé de Bogotá; antibothropic Instituto Butantan, IB, São Paulo, Brazil; polyvalent Instituto Clodomiro Picado, ICP, San José, Costa Rica; polyvalent MYN, Mexico) to neutralize various pharmacological and enzymatic effects of Bothrops atrox venom from Antioquia and Chocó, north-west of Colombia. Our results demonstrated conspicuous differences in the ability of the six antivenoms. In terms of neutralization of lethality, the highest efficacy was observed in the polyvalent INS and the lowest in the polyvalent MYN antivenom. All antivenoms were highly effective in the neutralization of hemorrhage, polyvalent INS and probiol being the highest. In the neutralization of edema-forming activity, the most effective antivenom was the polyvalent (ICP); monovalent (INS) and polyvalent (MYN) were the least effective. All antivenoms were effective in the neutralization of the myotoxic activity of B. atrox venom, the most effective being the polyvalent (INS) and antibothropic (IB). Defibrinating activity was neutralized by all antivenoms; polyvalent (MYN) showed the lowest efficiency. Polyvalent (ICP) antivenom had the highest neutralizing ability against the indirect hemolytic effect of B. atrox venom; polyvalent (MYN) did not neutralize this enzymatic activity. Overall, the polyvalent antivenom (INS) showed the highest neutralizing ability.

Topics: Animals; Antivenins; Blood Coagulation; Colombia; Crotalid Venoms; Edema; Fibrin; Hemolysis; Hemorrhage; Lethal Dose 50; Mice; Necrosis; Neutralization Tests

We investigated the tissue fibrinolytic activity in an experimental model of intracerebral hematoma was developed in the guinea pig. Intracerebral hematoma was created by stereotaxically injecting 0.2 ml autologous blood into the left frontal lobe of a total 63 anesthetized adult male albino guinea pigs (weighing 280-350 gr.). The fibrinolytic activity was studied using conventional histochemical stain techniques. 20 guinea pigs were used for developing the intracerebral hematoma model; in the 43 guinea pigs, the intracerebral hematomas were studied sequentially. Intracerebral hematoma formation failed in 10 of 43 guinea pigs. Three guinea pigs died in the immediate postoperative period. It was diagnosed histopathologically purulent meningitis and ventriculitis in four guinea pigs. Tissue fibrinolytic activity was increased in the meninges and choroid plexus. No fibrinolytic activity was observed a during the first days (1 to 3 days after hematoma production). 3 to 5 days later, fibrinolytic activity was seen in the capillary buds surrounding the hematoma and among the infiltrating mononuclear cells. This activity reached highest levels for 7-14 days following production of the hematoma and decreased after 20 days. In conclusion, tissue fibrinolytic activity associated with neovascularisation and mononuclear cell infiltration appears to be important in lysis of intracerebral hematoma.

Topics: Animals; Cerebral Hemorrhage; Cerebral Ventricles; Erythrocytes; Fibrin; Fibrinolysis; Frontal Lobe; Guinea Pigs; Hemolysis; Male; Neovascularization, Pathologic

The blood of patients dying suddenly possess the capacity of coagulation in vitro and then of transforming spontaneously into a liquid state, this being explained by the post-mortem fibrinolysis. Electron microscopic examination of this process allowed one to follow the dynamics of structural changes in the postmortem coagulates in the course of their spontaneous lysis and retraction in vitro. It is established that the main morphological criterion of the coagulates lysis is the destruction of fibrin fibrils and their degradation into the globular particles. Polynuclear leucocytes play an important role in the lysis of coagulates; they not only phagocytized the aggregated platelets and fibrin but seemed to release specific fibrinolytic factors into the coagulates. In the coagulates undergoing retraction, as distinct from those undergoing lysis, the destruction of platelet aggregates, strengthening and densening of the fibrin network are noted.

Topics: Blood Platelets; Clot Retraction; Death, Sudden; Erythrocytes; Fibrin; Fibrinolysis; Hemolysis; Humans; In Vitro Techniques; Microscopy, Electron; Neutrophils; Postmortem Changes

Intravascular hemolysis and ultrastructure of erythrocytes from liver sinusoids were studied during and after infusion of Escherichia coli endotoxin in Labrador retriever dogs. Endotoxin infusion caused hemoconcentration, and induced disseminated intravascular coagulation (DIC), characterized by a rapid drop of platelet numbers, a gradual consumption of coagulation factors and activation of fibrinolysis. Advanced DIC and circulatory shock gradually developed, and the animals died after 7-15 h. Plasma hemoglobin concentrations did not rise for several hours, but late in the experimental period a significant intravascular hemolysis was constantly found. Circulating adenosine diphosphate (ADP) did not appear. During shock, liver biopsies revealed accumulation of erythrocytes often disintegrated within distended sinusoidal lumina. In advanced shock the fragmented erythrocyte seemed to form occlusive masses within the vessels. A fibrin-like material frequently appeared adjacent to the red cells. However, it did not have the periodicity characteristic for fibrin, and the ultrastructure of the material was very similar to that inside the erythrocytes. None of these changes were induced by saline infusion in control animals. The lack of fibrin formation and the late development of intravascular hemolysis indicate that red cell breakdown was of little importance for the initiation and progress of DIC.

Topics: Animals; Blood Coagulation Factors; Blood Pressure; Disseminated Intravascular Coagulation; Dogs; Erythrocytes; Escherichia coli; Fibrin; Fibrinolysis; Hematocrit; Hemoglobins; Hemolysis; Microscopy, Electron; Platelet Count; Shock, Septic

Topics: Animals; Blood Platelets; Carotid Arteries; Carotid Artery Thrombosis; Erythrocytes; Female; Fibrin; Hemolysis; Leukocytes; Microscopy, Electron; Phagocytosis; Rats; Time Factors

We undertook an ultrastructural study of the dual processes of hemolysis and vitreous membrane formation during the resolution of vitreous blood clots in rabbits. Red blood cell degradation began within 24 hours before the onset of the inflammatory response and occurred mainly in the extracellular matrix. Macrophage activity was directed at clearing lysed RBC debris, rather than engulfing whole RBCs. Hemolysis in the vitreous may have been initiated by the unfavorable microenvironment. Two types of vitreous membranes occurred during vitreous clot lysis. Cellular membranes were composed of aggregates of giant macrophages enclosed within a thin collagen sheet. Acellular membranes developed from coaggregated vitreous collagen fibers. A prominent acellular membrane surrounded the blood clot as a pseudocapsule. No fibroblasts or fresh collagen deposition were observed.

Topics: Animals; Blood Coagulation; Erythrocytes; Fibrin; Hemolysis; Hemorrhage; Membranes; Rabbits; Time Factors; Vitreous Body

Hemostatic reaction in the mural thrombus formation (up to 2 hrs) was examined by scanning electron microscopy after removal of the endothelium in the rabbit carotid artery by the use of a rough-surfaced needle. The endothelium was almost completely removed leaving a network of subendothelial microfilaments which sometimes appeared half embedded in the basement membrane. Platelet adhesion occurred on this subendothelial tissue in the following steps: attachment of discoid platelets, pseudopod formation and spreading. The subendothelium was thus covered by a layer of platelets in about 10 min. During adhesion they caught the microfilaments by their pseudopods and never produced hemispherical protrusions. Loose aggregates of the rounded platelets were then formed on them but they were frequently reversible, resulting in 1-2 hrs, in coverage by only one or two layers of the adhered platelets. This platelet reaction was weaker than that to collagen in case of bleeding in the previous report. Leukocyte participation in thrombus formation began at around 30 min. Fibrin strands appeared as tiny filaments which were attached exclusively to the activated platelets and later grew into thick and long fibers forming a network. Thus activated platelets seemed to be very important as the base of development of fibrin thrombus. Many erythrocytes were demonstrated to be destroyed at the mural thrombus after attaching to either the subendothelial components or activated platelets or fibrin strands and being deformed by the blood stream. This finding supports the hypothesis of microhemolysis in the hemostatic process by HELLEM (1961). This type of hemostatic reaction was proved to be caused by a slight manipulatory pressure on the arterial wall, suggesting the occurrence of thrombus formation in our daily life.

Topics: Animals; Blood Platelets; Carotid Arteries; Endothelium; Erythrocytes; Fibrin; Hemolysis; Hemostasis; Microscopy, Electron, Scanning; Platelet Adhesiveness; Platelet Aggregation; Rabbits

Radially oriented acicular crystalline aggregates could be induced by incubating heparinised blood with bacterial endotoxins. These aggregates did not appear in the blood of 37 healthy volunteers but were observed in the blood of 130 patients, predominantly those with vasculitis, psoriasis, and bacterial infections. Study of these asteroid structures, which resemble 'sunbursts', led to the view that they are oriented crystals of fibrin radiating from a central platelet mass undergoing lysis.

Topics: Bacterial Infections; Blood Platelets; Crystallization; Dermatitis; Endotoxins; Enterobacteriaceae; Fibrin; Hemolysis; Humans; Hypersensitivity; In Vitro Techniques; Pseudomonas aeruginosa; Psoriasis; Streptococcus; Vascular Diseases

Alternations in the coagulation mechanism were looked for in a population of eclamptic women, most of when were young, nulliparous, and without evidence of chronic vascular disease, and all of whom survived. Thrombocytopenia was identified in 29% of these women. A prolonged plasma thrombin time was demonstrated in 51% yet elevated fibrinogen-fibrin degradation products in serum were uncommon, as was fibrin monomer in plasma. Overt microangiopathic hemolysis was rare. It is concluded that disseminated intravascular coagulation, when it does occur in eclampsia, is the consequence of the disease rather than the cause. Moreover, endothelial damage, rather contents, probably initiates the thrombocytopenia and other coagulation changes.

Topics: Adolescent; Blood Cell Count; Blood Coagulation; Blood Platelets; Eclampsia; Female; Fibrin; Fibrin Fibrinogen Degradation Products; Fibrinogen; Hemolysis; Humans; Pregnancy; Thrombin

The maternal coagulation mechanism has been investigated in an effort to identify its role, if any, in the pathogenesis of eclampsia. Thrombocytopenia was identified in 28 of 95 cases (29 per cent), a prolonged thrombin time in 19 of 38 (50 per cent), abnormally elevated serum fibrinogen-fibrin degradation products in two of 65 (3 per cent), and circulating fibrin monomer in one out of 20 (5 per cent). Overt hemolysis was rare (2 per cent). Thus the pattern as well as the degree of change in the maternal coagulation mechanism differed remarkably from that typical of severe abruptio placentae and of prolonged retention of a dead fetus, the classic obstetric models of fast and slow disseminated intravascular coagulation. It is concluded that the coagulation changes when present in eclampsia are effect rather than cause. Moreover, the changes may evolve primarily from platelet adherence at sites of vascular endothelial damage as the consequence of segmental vasospasm and vasodilatation rather than be triggered by the escape of thromboplastin from the placenta into the maternal circulation.

Topics: Abruptio Placentae; Adolescent; Blood Cell Count; Blood Platelets; Disseminated Intravascular Coagulation; Eclampsia; Female; Fibrin; Fibrin Fibrinogen Degradation Products; Fibrinogen; Hemolysis; Humans; Pregnancy; Thrombin; Thrombocytopenia; Time Factors

Topics: Animals; Eye Diseases; Fibrin; Fibrin Fibrinogen Degradation Products; Fibrinolysis; Hemolysis; Hemorrhage; Plasminogen Activators; Rabbits; Vitreous Body

Evidence of disseminated intravascular coagulation (DIC) was dought in normal baboons infused with autologous hemolyzed whole blood, preceded or followed by infusion of dextran (molecular weight, 70,000). Mean peak plasma hemoglobin following a rapid single injection was 370 mg/100 ml in 2 animals and 1,236 mg/100 ml in 1 animal, while levels during continuous 5 hour infusion in 2 animals averaged 326 and 474 mg/100 ml, respectively. Dextran infusion immediately preceded hemoglobin injection in 2 baboons and followed hemoglobin injection by 1 1/2 and 2 1/2 hours, respectively, in 2 baboons. Coagulation studies showed a moderate although significant fall in platelet count with prolongation of the partial thromboplastin time following hemoglobin infusion, and shortening of the thrombin time after dextran. Fibrin degradation products developed in four of five experiments after hemolysate injection. The induction of acute experimental hemoglobinemia results, therefore, in the development of coagulation changes consistent with milk DIC. Preliminary infusion of dextran (molecular weight, 70,000) may facilitate this response by either initiating the development or impeding the clearance of fibrin degradation products.

Topics: Acute Disease; Animals; Blood Cell Count; Blood Coagulation; Blood Platelets; Dextrans; Disseminated Intravascular Coagulation; Fibrin; Fibrinogen; Haplorhini; Hemoglobins; Hemolysis; Molecular Weight; Papio; Prothrombin Time; Thrombin; Thromboplastin; Time Factors

In summary, in contrast to a blood-membrane interphase system (artificial kidney), the use of a blood-gas interphase system (bubble oxygenator), even at a low flow rate of 400 ml/min, leads to severe changes in platelet function and number, to a temporary delay in fibrin formation and to a prolonged bleeding time. A definite bleeding tendency expresses the disturbance in hemostatic balance, as predominantly effected by the changes in platelet function. Hemolysis is apparently a minor symptom, and does not express the gravity of this damaging situation.

Topics: Adenosine Diphosphate; Animals; Blood Cell Count; Blood Coagulation; Blood Platelets; Dogs; Extracorporeal Circulation; Fibrin; Hemoglobins; Hemolysis; Kidneys, Artificial; Oxygenators; Platelet Aggregation; Prothrombin Time; Thrombocytopenia; Time Factors

Changes in the clotting system, as well as morphological and functional alterations corresponding to that of the pathologic phenomenon of disseminated intravascular coagulation (DIC) or consumption coagulopathy, were produced by thrombin infusion (550 NIH U X kg-1 X h-1) in rats and simultaneous inhibition of fibrinolysis by PAMBA (100 mg/kg). Changes in the fibrinogen level and platelet count as well as the appearances of fibrin monomers and the formation of microthrombi in several organs were evaluated. Simultaneously, the function of the respiratory system was investigated by continuous measurement of oxygen consumption as well as elasticity and water content of the lung. From the time course of the alterations in the several parameters, conclusions can be drawn for the pathogenesis and the possible therapeutic influence on DIC.

Topics: Aminobenzoates; Animals; Antifibrinolytic Agents; Blood Cell Count; Blood Platelets; Blood Vessels; Disease Models, Animal; Disseminated Intravascular Coagulation; Endothelium; Fibrin; Fibrinogen; Hemoglobins; Hemolysis; Lung; Lung Volume Measurements; Male; Pulmonary Edema; Rats; Respiration; Thrombin; Thrombosis

Topics: Adenosine Diphosphate; Blood Cell Count; Blood Coagulation; Blood Platelets; Blood Viscosity; Calcium; Clot Retraction; Collagen; Elasticity; Fibrin; Fibrinogen; Hemolysis; Humans; Platelet Adhesiveness

Topics: Animals; Biopsy; Disseminated Intravascular Coagulation; Fibrin; Fibrinolysis; Fluorescent Antibody Technique; Freund's Adjuvant; Hemolysis; Immunization; Isoantibodies; Isoantigens; Kidney; Kidney Glomerulus; Kidney Tubules, Proximal; Macaca fascicularis; Microscopy, Electron

Topics: Anemia, Hemolytic; Fibrin; Fibrinolysis; Heart Valve Prosthesis; Hemolysis; Humans

Topics: Adolescent; Adult; Blood Cell Count; Blood Coagulation Tests; Blood Platelets; Factor VIII; Female; Fibrin; Hemolysis; Humans; Leukemia, Myeloid, Acute; Male; Methods

Topics: Acute Kidney Injury; Anemia, Hemolytic; Anuria; Blood Cell Count; Blood Coagulation Factors; Blood Transfusion; Central Nervous System Diseases; Disseminated Intravascular Coagulation; Erythrocytes, Abnormal; Fibrin; Hematuria; Hemoglobins; Hemolysis; Heparin; Humans; Hyperkalemia; Infant; Kidney; Kidney Glomerulus; Peritoneal Dialysis; Thrombocytopenia

Topics: Animals; Assisted Circulation; Blood Volume; Cattle; Chromium Isotopes; Erythrocyte Aging; Erythrocytes; Fibrin; Fibroblasts; Hemolysis; Polymers; Serum Albumin, Radio-Iodinated; Surface Properties

Topics: Adipose Tissue; Aminocaproates; Animals; Blood Coagulation; Blood Coagulation Factors; Blood Coagulation Tests; Embolism, Fat; Female; Femoral Fractures; Fibrin; Fibrinolysis; Hemoglobinometry; Hemolysis; Phagocytosis; Plasminogen; Premedication; Pulmonary Embolism; Rats; Serum Albumin, Radio-Iodinated; Trypan Blue

Topics: Fibrin; Hemolysis; Humans; Hydrogen-Ion Concentration; Lymphocytes; Methods; Neutrophils

Topics: Animals; Blood Coagulation Disorders; Blood Platelets; Busulfan; Fibrin; Fibrinogen; Hemolysis; Injections, Intravenous; Kidney Glomerulus; Models, Biological; Neoplasms; Platelet Adhesiveness; Purpura; Rabbits; Sepsis; Shock; Shwartzman Phenomenon; Sulfonic Acids; Thrombocytopenia

Topics: Adult; Anemia, Hemolytic; Blood Coagulation; Blood Flow Velocity; Cell Membrane; Erythrocytes; Fibrin; Glass; Hemodynamics; Hemolysis; Humans; In Vitro Techniques; Methods; Microscopy, Phase-Contrast; Motion Pictures; Nylons

Topics: Abruptio Placentae; Adult; Animals; Anuria; Bilirubin; Blood Coagulation Disorders; Dogs; Erythrocytes; Female; Fibrin; Fibrinolysis; Hematologic Diseases; Hemolysis; Humans; Mice; Pregnancy; Rabbits; Rats; Shock, Hemorrhagic; Thrombin; Thromboplastin

Topics: Blood Chemical Analysis; Erythrocytes; Fibrin; Hemolysis; Humans; Hydrogen-Ion Concentration; Leukocytes; Lymphocytes; Methods; Neutrophils

Topics: Aminocaproates; Anemia, Hemolytic; Animals; Blood Cell Count; Erythrocytes; Fibrin; Fibrinogen; Fibrinolysis; Hemoglobinometry; Hemolysis; Heparin; Iodine Isotopes; Iron Isotopes; Male; Plasma; Rabbits; Thrombosis; Trypsin Inhibitors; Venoms; Warfarin

Topics: Afibrinogenemia; Animals; Erythrocytes; Fibrin; Fibrinogen; Hemoglobinometry; Hemolysis; Iodine Isotopes; Iron Isotopes; Rabbits; Thrombosis

Topics: Animals; Blood Coagulation; Blood Coagulation Factors; Buffers; Calcium Chloride; Cattle; Cysteine; Fibrin; Fibrinogen; Hemoglobins; Hemolysis; Sulfhydryl Compounds; Thrombelastography; Thrombin

Topics: Animals; Blood Cell Count; Blood Coagulation; Blood Platelets; Erythrocytes; Fibrin; Hemolysis; Radiation Injuries, Experimental; Rats

Topics: Blood Coagulation; Cell Death; Erythrocytes; Fibrin; Fibrinolysis; Hemolysis; Humans; Thrombolytic Therapy; Thromboplastin

Topics: Blood Coagulation; Cysteine; Erythrocytes; Fibrin; Hemolysis; In Vitro Techniques; Sulfhydryl Compounds