Blood Coagulation

Background: Warfarin, which is a widely used oral anticoagulant, has a narrow therapeutic window and requires regular international normalized ratio (INR) monitoring to maintain optimal anticoagulation. Recently, several portable coagulometers have been developed to measure INR levels. Objective: To compare the INR results obtained by a portable coagulometer (CoaguChek XS) and a standard laboratory method (STAGO STA-R). Methods: Overall, 433 consecutive patients (male: 191, median age: 61 [44-86] years) who were admitted to outpatient anticoagulation clinic were enrolled in this study. Each patient was tested for INR using portable CoaguChek XS and STAGO STA-R automatic laboratory coagulometer. Correlation between methods was assessed using the Pearson correlation test and Cohen k test. Bland-Altman plot was used to identify mean difference and 95% limits of agreement. Results: The mean INR values for CoaguChek XS and STAGO STA-R were 2.54 + 1.17 and 2.79 + 1.39, respectively. There was a strong positive correlation between the 2 methods (r ¼ .966; 95% confidence interval [CI]: 0.95-0.97, P < .001). The Bland-Altman analysis gave a mean difference of 0.26 + 0.40 between the 2 methods, with a 95% limit of agreement of À0.54 to 1.05. In patients with INR values >5.0, there was only a moderate correlation (r ¼ .676; 95% CI: 0.38-0.89, P ¼ .002), and the mean difference of INR tended to increase as mean INR values increased. There was a high overall agreement between the 2 methods (k ¼ .751; 95% CI: 0.69-0.80; P < .001). Conclusion: There was good consistency between traditional laboratory testing and CoaguChek XS coagulometer, which provides rapid and reliable INR analysis.

Recombinant mouse protein C was cloned, expressed, purified, and activated by Protac or thrombin. The anticoagulant activities of mouse and human activated protein C (APC) were compared using mouse and human plasma and the neuroprotective properties of murine APC were studied in an ischemic stroke model. Both human APC and mouse APC prolonged the activated partial thromboplastin time in a dose-dependent manner, but mouse APC was sixfold more effective than human APC as an anticoagulant in mouse plasma. Human protein S enhanced prolongation of the APTT clotting time of human plasma by human APC, but not by mouse APC. Hydrolysis of the S-2366 chromogenic substrate by murine APC was essentially identical to human APC. Mouse plasma contains 75 nM protein C. In a murine ischemic stroke model based on middle cerebral artery occlusion, murine APC was highly neuroprotective. The results show that recombinant murine APC is functionally similar to human APC both in vitro and in vivo and that it displays significant species specificity. The results imply that murine APC is notably superior to human APC for studies of murine disease models, including thrombosis and ischemic brain injury.

Multi-organic failure in the context of autoimmune diseases is a multi-factorial condition where different pathways concur to produce a global system breakdown. Some of these pathways include the coagulation, fibrinolysis, kinin and complement cascades which in normal conditions work together to provide a comprehensive response to injury. In pathologic conditions these regulatory mechanisms are replaced by positive feed-back loops. The common response pattern is the activation of the immune system via endothelium activation. Furthermore, these different plasma-driven mechanisms may induce standardised endothelial cell responses of which the most relevant are the activation of p38, JNK, NF-kβ and IRF-3 pathways. In this paper we review the common points between these major pathways and how they become activated, contributing to a global clinical picture. We present two examples of apparently different clinical settings, caused by the same global dysfunction: the Macrophage Activation Syndrome and the iatrogenic "cytokine storm" triggered by the administration of anti-CD28 monoclonal antibody TGN1412 in a phase 1 trial.

Compare Select FEC Forward Error Correction FSM Finite State Machine FER Frame Error Rate FPGA Field-Programmable Gate Array LLR Logarithmic Likelihood Ratio LUTs Look Up Tables MAP Maximum a Posteriori ML Maximum Likelihood PCM Parity Check Matrix PN Permutation Network RAM Random Access Memory RU Recursion Unit SISO Soft-Input Soft-Output SNR Signal to Noise Ratio TS Trellis States VA Viterbi Algorithm VHDL VHSIC Hardware Description Language VHSIC Very High Speed Integrated Circuit

Background and objectives: A bicarbonate dialysate acidified with citrate (CD) has been reported to have local anticoagulant effect. This study examines the effect of CD on dialysis efficiency, measured as eKt/Vurea, and predialysis concentrations of BUN, creatinine, phosphate, and ␤-2 microglobulin in chronic dialysis units. Design, settings, participants, & measurements: Three outpatient chronic hemodialysis units with 142 patients were switched to CD for 6 mo. Using each patient's prior 6 mo on regular bicarbonate dialysate acidified by acetate (AD) as control, eKt/Vurea was compared with that of CD. Follow-up data for 7 mo after the study were collected from about one-half of the participants remaining on CD and the others returned to AD. Results: eKt/Vurea, increased (P < 0.0001) from pre-CD value of 1.51 ؎ 0.01 to 1.57 ؎ 0.01 with CD. During CD use ␤-2 microglobulin levels declined (P ‫؍‬ 0.0001) from 28.1 ؎ 10.0 to 25.9 ؎ 10.0. Similarly, the concentrations of BUN, creatinine, and phosphate also decreased on CD (P < 0.008). In the poststudy period, eKt/Vurea for the patients staying on CD remained unchanged at 1.60 ؎ 0.17 versus 1.59 ؎ 0.18 (P ‫؍‬ NS), whereas in those returning to AD the eKt/Vurea decreased from 1.55 ؎ 0.20 to 1.52 ؎ 0.17 (P < 0.0001). Conclusions: Data suggest that CD use is associated with increased solute removal.

The immunoblotting technique was applied to the study of Factor XII (F.XII) in plasma. Sodium dodecyl sulfate polyacrylamide gel electrophoresis (SDS-PAGE) of whole plasma followed by electroblotting of the electropheroqrams to nitrocellulose (NC) membranes and immunologic detection by a double antibody technique was used. 1251-F.XII was transferred to the NC membrane in amounts proportional to the amount applied to the gel provided that a constant amount of carrier protein was pesent. Based on this, a quantitative assay was developed using either normal plasma or F.XII dilutions in F.XII-deficient plasma as standards. The measurement of F.XII antiqen by immunoblotting was reproducible and qave values similar to those obtained hy radial immunodiffusion. Two normal plasma pools contained 26 and 29 ug/ml of F.XII according to the immunoblottinu assay. Compared to other immunoassays, immunoblotting has the advantaae of directly estimating the apparent molecular weiqht (MN) of the protein of interest. Thus, we could confirm the normal apparent MN (80,000) of a F.XII-like molecule previously isolated from a cross reactinq material (CRM)-positive F.XII-deficient plasma. None of eight CRM-neqative F.XII-deficient plasmas showed an 80,000 MN immunoreactive molecule. However, five of these eight plasmas had a faint autoradiographic band at 115,000 &W that was similarly seen in only three out of 43 individual normal plasmas. The nature to be defined. of this 115,000 MN band remains INTRODUCTION Gel electrophoretic separation of proteins followed by transfer and immobilization of the resolved polypeptides to a solid matrix and immunologic

The stability of interleukin 6 (IL-6), its soluble receptor (sIL-6R), IL-10 and CC16 or uteroglobin (an endogenous cytokine inhibitor) in human serum was examined using an accelerated stability testing protocol according to the Arrhenius equation. Further, the effect of time delay between blood sampling and sample processing, clotting temperature and repeated freeze-thaw cycles on serum levels of these proteins were determined. Paired serum samples were stored at 4 C, 20 C, 30 C and 40 C for 1 to 21 days. We found that IL-6 and CC16 concentrations did not change at 4 C, 20 C and 30 C. Interleukin-6 concentrations significantly declined after 11 days at 40 C. The concentrations of sIL-6R and IL-10 did not change at 4 C but significantly decreased at 20 C (after 21 and 14 days respectively), 30 C and 40 C (after 1 day at both temperatures for both cytokines). Arrhenius-plots indicated that sIL-6R and IL-10 are stable for at least several years at 20 C and 70 C, respectively. Since their relative stability, no Arrhenius-plot could be calculated for IL-6 and CC16. The concentrations of the proteins examined were not significantly altered by repeated freeze-thaw cycles, nor by extended clotting times at 4 C or 20 C. We conclude that serum samples for the determination of IL-6, sIL-6R and CC16 can be stored at 20 C for several years, but for IL-10 determinations, storage at 70 C is recommended.

The efficacies of specific Bothrops atrox-Lachesis and standard Bothrops-Lachesis antivenoms were compared in the north eastern Amazon region of Brazil. The main aim was to investigate whether a specific antivenom raised against the venom of B. atrox, the most important Amazon snake species from a medical point of view, was necessary for the treatment of patients in this region. Seventy-four patients with local and systemic effects of envenoming by Bothrops or Lachesis snakes were randomly allocated to receive either specific (n = 38) or standard (n = 36) antivenoms. In 46 cases (24 in the standard antivenom group, 22 in the other) the snake was identified either by enzyme immunoassay or by examination of the dead snake, as B. atrox in 45, L. muta in one. Patients were similar in all clinical and epidemiological respects before treatment. Results indicated that both antivenoms were equally effective in reversing all signs of envenoming detected both clinically and in the laboratory. Venom-induced haemostatic abnormalities were resolved within 24 h after the Clinical trial of two antivenoms for the treatment of Bothrops and Lachesis bites 29 start of antivenom therapy in most patients. The extent of local complications, such as local skin necrosis and secondary infection, was similar in both groups. There were no deaths. The incidence of early anaphylactic reactions was 18% and 19%, respectively for specific and standard antivenoms; none was life-threatening. Measurement of serum venom concentrations by enzyme immunoassay (EIA) confirmed that both antivenoms cleared venom antigenaemia effectively. EIA also revealed that one patient had been bitten by Lachesis muta, although the clinical features in this case were not distinctive.

Surface-coated cardiopulmonary bypass (CPB) has been shown to have excellent biocompatibility during cardiac surgery in adults, but there have been only a few reports demonstrating the efficacy of this coating for congenital cardiac surgery. We tested the efficacy of poly-2-methoxyethylacrylate (PMEA) coating for CPB circuits in congenital cardiac surgery. Eleven operative cases of ventricular septal defect were studied: group C (control: no coating, n = 5) and group P (PMEA coating, n = 6). The platelet count and beta-thromboglobulin (beta TG), fibrinogen (FBG), thrombin-antithrombin complex (TAT), and neutrophil elastase levels were measured during the operation. Postoperative chest tube drainage was analyzed and the surface of the artificial lung was observed with an electron microscope. Elevation of TAT and neutrophil elastase was suppressed in group P (P &lt; 0.05). Observation of the artificial lung surface using an electron microscope clearly revealed fewer blood cells were a...

Venous thromboembolism (VTE) is a significant cause of mortality in patients with lung cancer. Despite the availability of a wide range of anticoagulants to help prevent thrombosis, thromboprophylaxis in ambulatory patients is a challenge due to its associated risk of haemorrhage. As a result, anticoagulation is only recommended in patients with a relatively high risk of VTE. Efforts have been made to develop predictive models for VTE risk assessment in cancer patients, but the availability of a reliable predictive model for ambulate patients with lung cancer is unclear. We have analysed the latest information on this topic, with a focus on the lung cancer-related risk factors for VTE, and risk prediction models developed and validated in this group of patients. The existing risk models, such as the Khorana score, the PROTECHT score and the CONKO score, have shown poor performance in external validations, failing to identify many high-risk individuals. Some of the newly developed an...

1. Blood coagulation factor levels and the normal ranges of commonly used coagulation tests were established for Sigmodon hispidus. 2. The white cell, red cell and platelet counts have been determined together with the red cell parameters as measured by the Coulter model S-plus. 3. The relationship between the results reported here and those published for related species are discussed.

Despite the strong association between antiphospholipid antibodies (aPL) and thrombosis, the pathogenic role of aPL in the development of thrombosis has not been fully elucidated. Proposed pathophysiological mechanisms may be categorized into two types. First, aPL may act in vivo by disrupting the kinetics of the normal procoagulant and anticoagulant reactions occurring on cell membranes. Second, aPL may stimulate certain cells thereby altering the expression and secretion of various molecules. In this article, we review the mechanisms by which aPL may develop thrombotic events. ᮊ

Estrogens have been associated with thromboembolic events. Our group has described the anticoagulant effect of 17β-aminoestrogens in rodents, potentially new alternative estrogenic agents without thrombogenic risk. This work compares the contrasting effects of estradiol and the 17β-aminoestrogens (prolame, butolame, and pentolame) on blood clotting time. Ovariectomized CD1 mice received a single injection of 17β-aminoestrogens, estradiol (20 to 80 mg/kg), or

Objective: To demonstrate the effects of 2-year transdermal continuous combined low-dose estradiol (0.025 mg/day) and norethisterone acetate (0.125 mg/day) on lipid/lipoprotein profile and coagulation/fibrinolysis. Methods: A double-blind, randomized, multicenter, parallel, 1-year trial enrolled 266 healthy women at least 2 years post menopause. Patients received either 0.025 mg estradiol and 0.125 mg norethisterone acetate daily or placebo transdermally. One hundred and thirty five women completed a second year open follow-up (96 had used Estragest TTS, 39 placebo during the first year), where all women had the estradiol/norethisterone patch. Lipid/lipoprotein profile and coagulation/fibrinolysis parameters were studied at 0, 24, 48, 72 and 96 weeks. Results: In women on estradiol/norethisterone total cholesterol, Lp(a) and VLDL cholesterol decreased significantly more than in the placebo group after 24 weeks and LDL cholesterol after 48 weeks. Women on estradiol/norethisterone had no change in HDL, triglycerides or Lp(a), an increased HDL/total cholestrol ratio and decreased LDL, VLDL and total cholesterol at 48 weeks compared to placebo. Women with active treatment also showed a significant reduction compared with the placebo group of Factor VII and antithrombin III at 24 and 48 weeks and a reduction of fibrinogen at 24 weeks. These changes persisted over the second year. Conclusions: A continuous combined low-dose transdermal patch daily delivering 0.025 mg estradiol and 0.125 mg norethisterone acetate provided beneficial effects on lipid/lipoprotein profile and coagulation/fibrinolysis. The changes were similar to those previously described after higher dose oral and transdermal estrogen/progestogen regimens.

The work focused on the penultimate enzyme, prothrombin, in the coagulation cascade. Prothrombin was purified and characterized from ostrich plasma. The results obtained contribute to a better understanding of blood coagulation in the ostrich and the evolution of prothrombin and the coagulation cascade. Prothrombin was purified from ostrich plasma by barium chloride precipitation, ammonium sulfate fractionation, and DEAE-cellulose and Cu 2 + -chelate Sepharose chromatography. Ostrich prothrombin exhibited a M r of 72 800 and a pI of 6.9 using SDS-PAGE and PAG-isoelectrofocusing, respectively. The N-terminal sequence of ostrich prothrombin showed 78 and 87% identity with human and bovine, respectively. The cDNA was isolated from ostrich liver and the predicted amino acid sequence compared with those from other species. Ostrich prothrombin shares sequence identity with chicken (84%), human (60%), bovine (59%), rat (60%), mouse (59%) and hagfish (50%) prothrombin, suggesting a common function of prothrombin in these vertebrates. Amino acid sequence identities indicate that the thrombin b-chain (62%) and the propeptide-Gla (75%) domains are the regions most constrained for the common functions of vertebrate prothrombins. Ostrich prothrombin, therefore, shows similarity in structure to other vertebrate prothrombins.

Atherosclerotic plaque rupture and erosions precipitate thrombus formation and may lead to an acute ischemic syndrome. Lipids and lipoproteins modulate the expression and/or function of thrombotic, fibrinolytic and rheologic factors, and thereby influence hemostasis and potential tissue damage resulting from vascular injury. Triglyceride-enriched lipoproteins are accompanied by elevations in factor VII clotting activity, plasminogen activator inhibitor (PAI-1) and viscosity of blood and plasma. Low density lipoprotein (LDL) promotes platelet activation and tissue factor expression and LDL levels correlate with levels of vitamin K dependent coagulation factors and fibrinogen. Conversely, LDL inhibits tissue factor pathway inhibitor (TFPI) which limits activation of the extrinsic coagulation pathway. High density lipoprotein (HDL) has anti-atherothrombotic properties that result from inhibition of platelet and erythrocyte aggregation, reduced blood viscosity and suppression of tissue factor activity and PAI-1 activity and antigen levels. The effects of lipids and lipoproteins on hemostasis and rheology may have important implications for the clinical sequelae following plaque disruption and erosion.

polyurethanes have been shown to have excellent blood contacting properties. In this paper, similar polyurethanes which are water soluble have been investigated to determine their influence on thrombus formation. These polymers were shown to delay clotting times in the following ways: by direct complex formation between the polymer and thrombin; by interference with fibrin polymerization;

To identify optimum international normalized ratio (INR) levels and required warfarin doses and anticoagulation-related complications in patients following mechanical prosthetic valve replacement. Five hundred and seven patients were prospectively followed up for 10 years (2008.5 patient-years). Anticoagulation-related complications were classified into hemorrhage and thromboembolism. Two hundred and ninety-two (57.6%) were males and 215 (42.4%) were females with a mean age of 29.5 +/- 11.32 years. A total of 268 (52.9%) patients had mitral, 96 (18.9%) had aortic and mitral, and 76 (15%) had aortic valve replacement (AVR). Valves implanted totaled 345 (68%) ball and cage, 126 (24.9%) bileaflet, and 36 (7.1%) single disc. There were 10,669 total visits, with mean INR 2.6 +/- 0.59 and mean warfarin 5.17 +/- 1.6 mg. Sixty-four (3.2% per patient-years) events occurred during follow-up, of which 23 (1.13% per patient-years) events were due to thromboembolism and 41 (2.04% per patient-yea...

The genus Citrus of the family Rutaceae includes many species e.g. Citrus indica, Citrus aurantifolia and Citrus limon, among which Citrus limon L. Burm. f. has been reported to have highest antimicrobial activity. It is used as antidote against certain venom, due to its platelet inhibitory effect and also reported to have hypocholesterolemic effect. However its anticoagulant and thrombolytic effect were not been investigated, hence a prospective in-vitro/in-vivo study was designed to determine the effect of Citrus limon on blood parameters, coagulation and anticoagulation factors. In-vitro tests revealed highly significant increase in thrombin time and activated partial thromboplastin time by Citrus limon, whereas fibrinogen concentration was significantly reduced in comparison to control, however prothrombin time was not affected significantly. In-vivo testing of Citrus limon was done at three different doses i.e. 0.2ml/kg, 0.4ml/kg and 0.6ml/kg in healthy rabbits. Significant cha...

Efforts to develop long circulating polymeric nanoparticles have propelled many strategies in nanoparticle surface modification to bypass immune surveillance and systemic clearance. In this context, our present study reports on the preparation and evaluation of mucin functionalized poly lactic-co-glycolic acid (PLGA) nanoparticles as hemocompatible, cell penetrating nanoparticulate drug delivery system. Amino groups of mucin were conjugated to the terminal carboxylic acid groups on PLGA to be followed by nanoparticle synthesis via standard solvent evaporation technique. Detailed in vitro experiments were performed to illustrate the significance of alternating copolymer structured mucin modified PLGA nanoparticles in terms of enhanced hemocompatibility and cellular uptake. Mucylation proved promising in controlling PLGA nanoparticle-interaction with plasma proteins (opsonins) and blood components via hemolysis, thrombogenecity and complement activation. Besides hemocompatibility, the modified and unmodified nanoparticles were also found to be cytocompatible with L929 and C6 cell lines. The fluorescent and confocal image analysis evaluated the extent of cellular uptake of nanoparticles into C6 cells. Specifically the combination of stealth properties and cellular internalization capacity of mucin modified PLGA nanoparticle (PLGA-Mucin) lead us to propose it as a safe, efficient and multifunctional nanoplatform for disease specific intravenous drug delivery applications as far as in vitro experiments are concerned.

Subacute stent thrombosis, caused by undesired interactions between blood and the stent surface, is a major concern in the first few weeks following coronary artery stent implantation. The aim of this study was to establish a novel in vitro model for hemocompatibility testing of coronary artery stents according to ISO 10993-4. The model consists of a modified Chandler-Loop design with closed heparin-coated PVC Loops and a thermostated water bath. The tests were performed with anticoagulated human whole blood. After incubation in the loop, blood was analyzed for coagulation and inflammatory activation markers (TAT, β-TG, sP-selectin, SC5b-9 and PMN-elastase). Three different stent types with varying thrombogenicity were tested; statistically significant differences were found between the three stent types in measures of coagulation and platelet activation. The new Chandler-Loop model can be used as an alternative to animal and current in vitro models, especially for the determination of early events after stent implantation.

A systematic survey was made of some 25 amines, including several newly synthesized ones, to assess their inhibitory effect in the enzymatic crosslinking of fibrin. Compounds were selected from the point of view of different basicities and side-chain substitutions.

An acidic polysaccharide with anticoagulant activity was isolated from the edible mushroom Auricularia auricula using water, alkali or acid extracts. The alkali extract showed the highest anticoagulant activity and was thereby further purified using gel filtration chromatography. Specific anticoagulant activity of the purified polysaccharide was 2 IU/mg and its average mass was ∼160 kDa. The polysaccharide from this species of mushroom contains mainly mannose, glucose, glucuronic acid and xylose but no sulfate esters. Its anticoagulant activity was due to catalysis of thrombin inhibition by antithrombin but not by heparin cofactor II. Inhibition of Factor Xa by antithrombin was not catalyzed by the polysaccharide. The glucuronic acid residues were essential for the anticoagulant action of the mushroom polysaccharide since the activity disappeared after reduction of its carboxyl groups. In ex vivo tests using rats orally fed with the polysaccharide, we observed an inhibitory effect on platelet aggregation as observed with aspirin, a well-known antiplatelet agent. The polysaccharides from these mushrooms may constitute a new source of compounds with action on coagulation, platelet aggregation and, perhaps, on thrombosis.

Electrostatic interactions between negatively charged polymer surfaces and factor XII (FXII), a blood coagulation factor, were investigated by sum frequency generation (SFG) vibrational spectroscopy, supplemented by several analytical techniques including attenuated total reflection Fourier transform infrared spectroscopy (ATR-FTIR), quartz crystal microbalance (QCM), ζ-potential measurement, and chromogenic assay. A series of sulfonated polystyrenes (sPS) with different sulfonation levels were synthesized as model surfaces with different surface charge densities. SFG spectra collected from FXII adsorbed onto PS and sPS surfaces with different surface charge densities showed remarkable differences in spectral features and especially in spectral intensity. Chromogenic assay experi-ments showed that highly charged sPS surfaces induced FXII autoactivation. ATR-FTIR and QCM results indicated that adsorption amounts on the PS and sPS surfaces were similar even though the surface charge densities were different. No significant conformational change was observed from FXII adsorbed onto surfaces studied. Using theoretical calculations, the possible contribution from the third-order nonlinear optical effect induced by the surface electric field was evaluated, and it was found to be unable to yield the SFG signal enhancement observed. Therefore it was concluded that the adsorbed FXII orientation and ordering were the main reasons for the remarkable SFG amide I signal increase on sPS surfaces. These investigations indicate that negatively charged surfaces facilitate or induce FXII autoactivation on the molecular level by imposing specific orientation and ordering on the adsorbed protein molecules.

Background Buerger's disease (BD) is a segmental occlusive vascular disease. The aim of this study was to detect functional changes in brachial artery and asymptomatic morphological changes in extra-cranial carotid arteries not affected by the disease process and to assess markers of inflammation and endothelial damage.

The cardiopulmonary bypass (CPB) used in heart surgery has a deleterious effect on hemostasis. The aim of our study was to assess by means of standard laboratory and point-of-care methods changes induced by CPB in coagulation parameters, particularly in platelet function, and to determine whether these changes differ depending on the type of heart-lung machine (HLM) used: minimal extracorporeal circulation system (MECC) and standard HLM. The study enrolled 88 patients scheduled for coronary artery bypass surgery performed on pump. Forty-four interventions were performed with MECC and 44 with standard HLM. Blood was sampled preoperatively, after 30 min on CPB, after weaning from CPB, and 24 h postoperatively. Coagulation and platelet function were assessed using multiple electrode aggregometry (MEA), rotation thromboelastometry, as well as standard laboratory tests. Rotation thromboelastometry and standard

The extract of Marsypianthes chamaedrys, a plant used against snakebites, in the present study was shown to inhibit fibrinoclotting induced by several Brazilian snake venoms or thrombin. These data indicate that this extract affected thrombinlike enzymes. In this first report we determine some features of the components present in the extract regarding the antifibrinoclotting action. Our results show that active components responsible for those effects are thermo-resistant and are concentrated in the methanolic fraction.

Activated platelets bind numerous adhesive and procoagulant proteins by receptor-mediated processes. Although there is little evidence to suggest that these processes are heterogeneous in platelets, we previously found that platelets co-stimulated with collagen and thrombin express functional alpha-granule factor V only on a subpopulation of cells. Here we show that these cells, referred to as &#39;COAT-platelets&#39;, bind additional alpha-granule proteins, including fibrinogen, von Willebrand factor, thrombospondin, fibronectin and alpha2-antiplasmin. These proteins are all transglutaminase substrates, and inhibitors of transglutaminase prevent the production of COAT-platelets. A synthetic transglutaminase substrate (CP15) also binds to COAT-platelets, and analysis by high performance liquid chromatography/mass spectrometry shows that a product is formed with a relative molecular mass (Mr) equal to CP15 plus 176. Serotonin, an abundant component of platelet-dense granules, has an ...

Cardiovascular diseases remain to be the leading cause of death in Western societies. Despite major findings in vascular biology that lead to a better understanding of the pathomechanisms involved in atherosclerosis, treatment of the disease has only changed slightly within the last years. A big body of evidence suggests that atherosclerosis is a chronic inflammatory disease of the vessel wall. Accumulation and peroxidation of LDL-particles within the vessel wall trigger a strong inflammatory response, causing macrophage and T-cell accumulation within the vessel wall. Additionally, B-cells and specific antibodies against LDL-particles, as well as the complement system are implicated in atherogenesis. Besides data from clinical trials and autopsy studies it was the implementation of mouse models of atherosclerosis and the emerging field of direct gen-modification that lead to a thorough description of the pathophysiological mechanisms involved in the disease and created overwhelming ...

The efficacy of oral aspirin treatment in the secondary prevention of cardio and cerebro vascular disease is well known. However oral administration is often associated with abdominal discomfort. The feasibility of delivering aspirin transdermally from eudragit and polyvinyl acetate (PVA) matrix-type patches to enhance its antithrombotic efficiency of aspirin was investigated. Transdermal films containing mixture of eudragit RL: eudragit RS and polyvinyl acetate were fabricated. Eudragit RL: eudragit RS (5:1) films containing 30 mg/ transdermal patch aspirin showed maximum release (11.891.1g/cm 2 ) after 24 hrs as compared to PVA films. With regards to appearance eudragit films were also wrinkle free, uniform, flexible and transparent with good adhesion property to skin. The effect of turpentine oil and lemon oil at different concentrations on the in vitro percutaneous absorption of aspirin from eudragit copolymer patches through rat skin was investigated. Two formulation containing 50 mg/transdermal patch ASA with 0.042 ml turpentine oil and 0.042 ml lemon oil showed a significantly higher flux of ASA 4.22 g/cm 2 /hr and 38.52 g/cm 2 /hr respectively. The optimized formulations influenced the blood coagulation parameters (bleeding time, prothrombin time, Activated partial prothrombin time) significantly by means of affecting both the extrinsic coagulation system and the intrinsic coagulation system as compared to orally administered and control gel formulations.

The purpose of the present study was to investigate if diclofenac administration interferes with the time course of alveolar wound healing in rats. Forty-two Wistar rats were used, 21 rats received 10 mg/kg/day of diclofenac one day before and 4 days after extraction of the right maxillary incisors and 21 rats received saline. The animals were sacrificed 7, 14 and 21 days after tooth extraction. Progressive new bone formation and a decrease in the volume fraction of blood clot and connective tissue from 1 to 3 weeks after tooth extraction was quantified using the histometric point-counting method. Diclofenac treatment caused a significant delay in new bone formation in association with an impairment of blood clot remission/organization.

Babassu is the popular name of Orbignya phalerata Mart. (Arecaceae). The mesocarp flour obtained from their fruits has been used in Brazil as medicine in the treatment of pains, constipation, obesity, leukemia, rheumatism, ulcerations, tumors, inflammations and venous diseases. The effect of the chronic oral treatment with aqueous extract of babassu mesocarp (500 mg/kg day) on the number of platelets, the prothrombin time (PT), the activated partial thromboplastin time (aPTT), the nitric oxide (NO) production and the carrageenin-induced thrombosis was evaluated, using C57Bl/6 mice. The chronic oral treatment with babassu mesocarp induced an anti-thrombotic effect. There was a 88.9% reduction in the necrosis of the tail. This effect seems to be related to an increase in the ability of the macrophage to produce NO and to a slow coagulation process associated to an increase of 12.0 and 13.9% in PT and aPTT, respectively. However, the anti-thrombotic effect seems to be not related to alterations in the number of platelets. It is possible to conclude that the oral treatment with babassu mesocarp has a significant anti-thrombotic effect, which could justify the popular use of babassu mesocarp in the treatment of venous diseases. Meanwhile, this study suggests a potential use of babassu mesocarp as a prophylactic agent to avoid thrombosis events.

Aqueous extracts, prepared from dried or fresh roots, stems or leaves of Mikania glomerata, a plant found in Mata Atlântica in Southeastern Brazil, were able to efficiently neutralize different toxic, pharmacological, and enzymatic effects induced by venoms from Bothrops and Crotalus snakes. Phospholipase A2 activity and the edema induced by Crotalus durissus terrificus venom were inhibited around 100 and ∼40%, respectively, although this inhibition was only partial for Bothrops venoms. The hemorrhagic activity of Bothrops venoms (Bothrops altenatus, Bothrops moojeni, Bothrops neuwiedi, and Bothrops jararacussu) was significantly inhibited by this vegetal species, while the clotting activity of Crotalus durissus terrificus, Bothrops jararacussu, and Bothrops neuwiedi venoms was totally inhibited. Although, the mechanism of action of Mikania glomerata extract is still unknown, the finding that no visible change was detected in the electrophoretic pattern of snake venom after incubation with the extract excludes proteolytic degradation as a potential mechanism. Since the extract of Mikania glomerata significantly inhibited the studied snake venoms, it may be used as an alternative treatment to serumtherapy and, in addition, as a rich source of potential inhibitors of PLA2s, metalloproteases and serineproteases, enzymes involved in several physiopathological human and animal diseases.

In a study of 20 patients with hypercholesterolemia (type IIa) the effects of lovastatin (20-80 mg/ day) on various clotting and thrombosis parameters were monitored for 12 months. On 11 occasions various cholesterol fractions and clotting parameters were determined in each patient. In additon, the clotting inhibitors AT III, protein C, protein S, and C 1-esterase inhibitor and the fibrinolysis parameters plasminogen and a2-antiplasmin were examined. Platelet function was monitored on the basis of spontaneous and induced (collagen, ADP, epinephrine, ristocetin) aggregation. Lovastatin in the above dosage brought about a 66 mg/dl (from 320 ___ 12.6 to 254 _+ 12.0 mg/dl) reduction in the total cholesterol level and a 56 mg/dl (from 244 + 11.4 to 188 _+ 12.1 mg/dl) reduction in LDL cholesterol at the end of the study. Fibrinogen showed a significance decrease during the study period, whereas PT and aPTT remained unaffected. The initial slopes of the ADP-induced platelet aggregation revealed a significant decrease. C-reactive protein and platelet count remained within the normal range, indicating no significant change. Thrombin clotting time, AT III, Cl-esterase inhibitor, plasminogen, and ~t2-antiplasmin were not modified. Protein C and S behaved in a contradictory way, but remained within the normal range. Long-term treatment with lovastatin was associated with a significant reduction of fibrinogen levels and platelet aggregation induced by ADP in type-II a hypercholesterolemic patients. These alterations, as well as their role in cardiovascular disease, should be the subject of further investigations.