Affect Blood Coagulation Research Articles

Self-Crosslinked Ellipsoidal Poly(Tannic Acid) Particles for Bio-Medical Applications

Self-crosslinking of Tannic acid (TA) was accomplished to obtain poly(tannic acid) (p(TA)) particles in single step, surfactant free media using sodium periodate (NaIO4) as an oxidizing agent. Almost monodisperse p(TA) particles with 981 ± 76 nm sizes and −22 ± 4 mV zeta potential value with ellipsoidal shape was obtained. Only slight degradation of p(TA) particles with 6.8 ± 0.2% was observed at pH 7.4 in PBS up to 15 days because of the irreversible covalent formation between TA units, suggesting that hydrolytic degradation is independent from the used amounts of oxidation agents. p(TA) particles were found to be non-hemolytic up to 0.5 mg/mL concentration and found not to affect blood clotting mechanism up to 2 mg/mL concentration. Antioxidant activity of p(TA) particles was investigated by total phenol content (TPC), ferric reducing antioxidant potential (FRAP), trolox equivalent antioxidant capacity (TEAC), total flavanoid content (TFC), and Fe (II) chelating activity. p(TA) particles showed strong antioxidant capability in comparison to TA molecules, except FRAP assay. The antibacterial activity of p(TA) particles was investigated by micro-dilution technique on E. coli as Gram‑negative and S. aureus as Gram-positive bacteria and found that p(TA) particles are more effective on S. aureus with over 50% inhibition at 20 mg/mL concentration attained.

Effect of anticoagulant therapy on the course of COVID-19 in comorbid patients

Analysis of the pathogenesis of coronavirus infection caused SARS-CoV-2 indicates a significant impact of hemorheological disorders on its course and outcomes. It is known that chronic cardiovascular diseases are associated with the risk of severe course and lethal outcomes both in COVID-19 and other infectious diseases. Therefore, in each case it is necessary to study the interaction and mutual influence of different components of the treatment program prescribed to such patients.The purpose of this work was to evaluate the effect of coagulation activity on the course of a novel coronavirus infection (COVID-19) and to justify the management of comorbid patients having been received novel oral anticoagulants (NOACs) in previously selected doses according to indications in concomitant somatic diseases. Total 76 cases of confirmed coronavirus infection in patients who had been received initial therapy on an outpatient basis were analyzed. 26 patients who received NOACs (rivaroxaban, apixaban, dabigatran) made up the main group and 50 - the comparison (control) group in which patients had not been administered any drugs that affect blood clotting until the episode of COVID-19. All patients have been prescribed therapy following the Provisional guidelines «Prevention, diagnosis and treatment of coronavirus infection (COVID-19)» (https://static-0.minzdrav.gov.ru/system/attachments/attaches/). The number of hospitalizations was significantly fewer in the group of patients who had been received NOACs (19 vs. 66% in the control group). No deaths or cases of severe respiratory and/or renal failure were observed in the main group, while adverse outcomes were noted in 14% of patients who had not been administered these drugs. Taking NOACs reduces the probability of severe course and adverse outcomes in the development of coronavirus infection caused by SARS-CoV-2, which indicates a significant contribution of coagulation mechanisms to the pathogenesis in COVID-19. There were no indications for drug replacement and correction of anticoagulant therapy regimens in patients who received adequate therapy with oral anticoagulants for treating a non-severe form of coronavirus infection in ambulatory patient settings.

Plasmatic and cell-based enhancement by microparticles originated from platelets and endothelial cells under simulated in vitro conditions of a dilutional coagulopathy

BackgroundAggressive fluid management and other external factors may lead to hypothermia, acidosis and hemodilution (defined as Lethal Triad, LT) contributing to a trauma-induced coagulopathy (TIC) that worsens patients’ outcomes. Procoagulant microparticles (MP) are crucial players at the interface of cellular and plasmatic coagulation. However, their functions remain largely unexplored. This study aimed to characterize effects of MP subtypes and concentrations on functional coagulation under in vitro simulated conditions.MethodsBlood from eleven volunteers were collected to simulate in vitro conditions of hemodilution (HD) and LT, respectively. HD was induced by replacing a blood volume of 33% by crystalloids and for LT, samples were further processed by reducing the temperature to 32 °C and lowering the pH to 6.8. MP were obtained either from platelet concentrates (platelet-derived MP, PDMP) or from cell culture (ECV304 cells for endothelial-derived MP, EDMP) by targeted stimulation. After introducing MP to in vitro conditions, we measured their concentration-dependent effects (1.000, 10.000 and 15.000 MP/μl blood) on coagulation compared to whole blood (WB). For each condition, coagulation was characterized by flow cytometric platelet activation and by quantification of fibrin clot propagation using Thrombodynamics® technology.ResultsMP originated from platelets and endothelial cells affected blood coagulation in a concentration-dependent manner. Particularly, high PDMP quantities (10.000 and 15.000 PDMP/μl blood) significantly induced platelet activation and fibrin clot growth and size in HD conditions. In LT conditions as well, only high PDMP concentration induced platelet activation, clot growth and size. In contrast, EDMP did not induce platelet activation, but resulted in enhanced formation of spontaneous clots, irrespective of simulated condition. With increasing EDMP concentration, the time until the onset of spontaneous clotting decreased in both HD and LT conditions.DiscussionThe study demonstrates an essential role of MP within the coagulation process under simulated coagulopathic conditions. PDMP affected platelets promoting clot formation likely by providing a surface enlargement. EDMP presumably affected clotting factors of the plasmatic coagulation resulting in an increased formation of spontaneous clots.ConclusionUnder simulated conditions of a dilutional coagulopathy, MP from different cellular origin indicate a divergent but both procoagulant mechanism within the coagulation process.

The effects of submaximal exercise and cold exposure on blood coagulation parameters in coronary artery disease patients

BackgroundBoth exercise and cold exposure increase blood coagulation potential but their combined effects are not known. The purpose of the present study was to assess blood coagulation factors in response to submaximal exercise in the cold environment among patients with stable coronary artery disease (CAD).MethodsSixteen men (61.1 ± 7.1 years) with stable CAD participated in three 30-min experimental conditions (seated rest in − 15 °C and exercise in both + 22 °C and − 15 °C) in random order. The employed exercise consisted of brisk walking (66–69% of maximal heart rate). Factor VII (FVII), fibrinogen, D-dimer and von Willebrand factor (vWF) were analyzed from blood samples obtained before, immediately and one hour after each experiment.ResultsOn average, FVII activity (95% confidence interval, CI) was 123 (108–143) %, 123 (106–140) %, 121 (103–139) % (baseline, recovery 1, recovery 2), fibrinogen concentration (95% CI) 3.81 (3.49–4.12) g/l, 3.71 (3.34–4.08) g/l, 3.65 (3.26–4.05) g/l, D-dimer concentration (95% CI) 0.42 (0.28–0.56) µg/ml, 0.42 (0.29-.55) µg/ml and 0.39 (0.29–0.49) µg/ml, and vWF activity (95% CI) 184 (135–232) %, 170 (128–212) % and 173 (129–217) % after exercise in the cold. Average FVII activity varied from 122 to 123%, fibrinogen concentration from 3.71 to 3.75 g/l, D-dimer concentration from 0.35 to 0.51 µg/ml and von Willebrand factor activity from 168 to 175% immediately after each three experimental condition.ConclusionsOur findings suggest that submaximal lower body exercise carried out in a cold environment does not significantly affect blood coagulation parameters among patients with stable CAD.

Hemodynamic efficacy and safety of using modified gelatin solution and polyhydric alcohol solution for fluid resuscitation of patients with septic shock

Objective ‒ to compare the hemodynamic effects and safety of the infusion of succinylated gelatin solution, sorbitol-containing solution, and 0.9 % normal saline (0.9 % sodium chloride), analyze their effect on the treatment of septic shock and mortality.Materials and methods. A prospective randomized clinical trial that included 94 adult patients with an active surgical infection and septic shock was conducted. There were 34 (36.2 %) male and 60 (63.8 %) female patients aged between 19 and 96 years, mean age was (66.51 ± 17.06) years. An appropriate solution in a volume of 500 ml was used for resuscitation, then hemodynamic and other clinical and laboratory parameters were monitored.Results. There was no significant difference in mean arterial pressure (MAP) between the 3 groups until the 40th minute (p>0.05). At the 45th minute MAP in the NS group differed only from MAP in the Gel group (p=0.007). At the 50th minute MAP in the NS group did not differ from the baseline (p=0.139). From the 50th minute to 2 hours, MAP in the Gel and Sorb groups was higher than in the NS group in all measurements (p<0.05). There was no statistically significant difference in heart rate (HR) in any measurement (p>0.05). Cardiac output (CO) did not differ up to the 30th minute (p>0.05), at the 35th minute, CO differed only between Gel and NS groups (p=0.019), from the 40th minute to 2 hour CO in Gel and Sorb groups were significantly higher than in NS group in all measurements (p<0.05). Oxygen delivery (DO2) also did not differ up to the 30th minute (p>0.05), from the 35th minute to the 45th minute a significant difference was found only between Gel and NS groups (p<0.05), from the 50th minute to 2 hour DO2 in Gel and Sorb group was significantly higher than in NS group in all measurements (p<0.05). After infusion of the gelatin-containing solution and sorbitol-containing solution, the acid-base balance of the blood improved significantly. The dose of gelatin-containing and sorbitol-containing solutions applied in this study was safe for the renal function of the patients with septic shock. However, it is possible that a decrease in blood fibrinogen concentrations may be associated with the use of a gelatin-containing solution. Significant improvement in the Glasgow Coma Scale scores was observed only in patients in the group receiving the sorbitol-containing solution. The difference in 28-day mortality between the groups was not statistically significant (p=0.993).Conclusions. In our observations, when using these three types of solution in patients with septic shock, hemodynamic effects up to the 40th minute did not differ between groups. From the 40th minute to 2 hour, the volemic effect of 4 % succinylated gelatin solution and balanced polyionic solution with 6 % sorbitol was significantly better, compared to the 0.9 % sodium chloride solution. The volume of solutions used in these three groups did not affect renal function in patients with septic shock. The amount of balanced polyionic solution used with 6 % sorbitol and 0.9 % sodium chloride solution did not affect blood coagulation function. But the use of 4 % succinyl gelatin solution reduced the concentration of fibrinogen in the blood. After infusion of the gelatin-containing solution with buffer formulations and sorbitol-containing solution with buffer formulations, the acid-base status of the blood was significantly improved compared to 0.9 % sodium chloride solution. Infusion of the gelatin-containing solution and 0.9 % sodium chloride solution did not affect the Glasgow coma score in patients. After infusion of the sorbitol-containing solution, patients’ consciousness was improved by this scale. The 28-day mortality did not differ significantly between groups.

Rapid review on the use of oral fatty acid supplements in the prevention or as adjunct treatment of COVID-19

KEY FINDINGS
 There is lack of clinical evidence supporting the role of oral fatty acid supplements as prevention and adjunctive 
 therapy for COVID-19. 
 
 Long-chain polyunsaturated fatty acids (PUFAs) mediate inflammation and adaptive immune responses. Omega-3
 
 fatty acids promote anti‐inflammatory effects and reduce influenza virus replication.
 
 No clinical evidence supporting the use of oral fatty acid supplements as prevention and adjunctive therapy of
 
 COVID-19 was found.
 
 We found indirect evidence from one systematic review on acute respiratory distress syndrome (ARDS) and two
 
 longitudinal cohort studies on community-acquired pneumonia that showed non-significant and inconsistent
 results.
 
 The most common known side effects of omega-3-fatty acids are gastrointestinal in nature. They may also cause
 
 allergy and affect blood clotting if taken with other medications that affect clotting.
 
 There are 2 ongoing clinical trials on eicosapentaenoic fatty acids as an adjunctive therapy to standard oral
 
 nutrition supplements or standard of care in COVID-19 patients.
 
 WHO Interim guidelines, CDC interim guidelines, Infectious Diseases Society of America COVID-19 treatment
 
 guidelines, and the American Thoracic Society did not give any recommendation on the use of nutritional
 supplements in patients with COVID-19.

Aqueous extract of Whitmania pigra Whitman ameliorates ferric chloride-induced venous thrombosis in rats via antioxidation

Whitmania pigra Whitman (W. pigra) has been widely employed in decoction for the treatment of blood stasis syndrome for many years in China. The aim of the present study was to explore the anti-venous thrombosis (VT) mechanism of the aqueous extract of W. pigra (AEW) in rats. Rats were orally administered with AEW. A inferior vena cava (IVC) thrombosis model was established. Thrombosed IVC was weighed and histopathological analyses were performed. Blood coagulation, blood fibrinolysis, blood cell count, blood viscosity and platelet activity were evaluated. Reactive oxygen species (ROS) accumulation was analyzed. Malondialdehyde (MDA) content in thrombosed IVC and antioxidants in serum were detected. Protein expression of nuclear factor erythroid 2-related factor 2 (Nrf2) and heme oxygenase 1 (HO-1) in thrombosed IVC was determined. AEW significantly reduced thrombus weight. It did not affect blood coagulation, blood fibrinolysis, blood cell count, platelet activity, or whole blood viscosity. However, AEW remarkably alleviated vascular injury, reduced ROS accumulation and MDA content, enhanced the total antioxidant capacity and the activities of superoxide dismutase, glutathione peroxidase and glutathione reductase. It increased the glutathione/oxidized glutathione ratio and the protein expression levels of Nrf2 and HO-1. In summary, W. pigra may prevent VT via Nrf2-mediated antioxidation.

Loss of Tet2 affects platelet function but not coagulation in mice.

Ten-eleven translocation 2 (TET2) functions as a methylcytosine dioxygenase that catalyzes the iterative oxidation of 5-methylcytosine to 5-hydroxymethylcytosine, 5-formylcytosine and 5-carboxylcytosine. TET2 has been shown to be crucial for the maintenance and differentiation of hematopoietic stem cells, and its deletion and/or mutations results in the expansion of HSPCs, and leads to hematological malignancies. TET2 mutations were found in a variety of hematological disorders such as CMML (60%), MDS (30%), MPN (13%) and AML (20%). Interestingly, it was shown that CMML patients with TET2 mutation exhibited fewer platelets than CMML patients without TET2 mutation. However, the role and function of TET2 in platelet hemostasis and thrombogenesis is not well defined. Here in this study, using a genetically engineered Tet2 deletion mouse model, we found that the absence of Tet2 caused a decrease in the proportion of MEP cells and hyperploid megakaryocytes. Additionally, Tet2-deficient mice displayed impaired platelet activation and aggregation under stimulation of ADP and low concentrations of thrombin, although the modestly compromised platelet function and MEP differentiation in Tet2-deficient mice could be compensated without affecting blood coagulation function. Our study indicate that Tet2 deficiency leads to mild impairment of platelet function and thrombopoiesis in mice.

Biochemical characterization of AeD7L2 and its physiological relevance in blood feeding in the dengue mosquito vector, Aedes aegypti.

Aedes aegypti saliva facilitates blood meal acquisition through pharmacologically active compounds that prevent host hemostasis. Among these salivary proteins are the D7s, which are highly abundant and have been shown to act as scavengers of biogenic amines and eicosanoids. In this work, we performed comparative structural modeling, characterized the binding capabilities, and assessed the physiological functions of the Ae. aegypti salivary protein AeD7L2 compared to the well-characterized AeD7L1. AeD7L1 and AeD7L2 show different binding affinities to several biogenic amines and biolipids involved in host hemostasis. Interestingly, AeD7L2 tightly binds U-46619, the stable analog of thromboxane A2 (KD =69.4nm), which is an important platelet aggregation mediator, while AeD7L1 shows no binding. We tested the ability of these proteins to interfere with the three branches of hemostasis: vasoconstriction, platelet aggregation, and blood coagulation. Pressure myography experiments showed these two proteins reversed isolated resistance artery vasoconstriction induced by either norepinephrine or U-46619. These proteins also inhibited platelet aggregation induced by low doses of collagen or U-46619. However, D7 long proteins did not affect blood coagulation. The different ligand specificity and affinities of AeD7L1 and AeD7L2 matched our experimental observations from studying their effects on vasoconstriction and platelet aggregation, which confirm their role in preventing host hemostasis. This work highlights the complex yet highly specific biological activities of mosquito salivary proteins and serves as another example of the sophisticated biology underlying arthropod blood feeding.

Effect of Teaching Program on Nurses' Performance Regarding Drugs that Affect Blood Coagulation in Coronary Care Unit

Background Many patients admitted to coronary care unit(CCU) and receive several drugs, these drugs save their life at the other hand these drugs are considered threatened to their life so that nurses should ensure that is safe and effective through careful evaluation of the patient's response to therapy by direct observation of physiological measures Aim of this study: was to evaluate the effect of teaching program about drugs that affect blood coagulation on nurses' performance in CCU. Study design: Quasi experimental (pre- posttest) design was used. Setting: the study was conducted in CCU at Assuit General Hospital. Sample: (30) nurses from the previous mentioned setting. Tools; two tools: were utilized in the present study Tool (1) Knowledge assessment tool by using structure interview questionnaire for nurses was utilized, Tool (2) Assessment tool for nurses’ practice by using observational check list for nurses' practice was utilized, Results: nurses’ knowledge was improved significant from 25.8±6.48 to 60.63±1.19 and nurses practice was improved from 103.87±9.83 to 169.9±1.86 after implementation of teaching program about drugs that effect blood coagulation in CCU. Recommendation: continues nursing education and training program at CCU should be organized regarding drugs affecting blood coagulation.

Expression of angiogenic factors in the uteroplacental unit is altered at time of placentation in a porcine model of von Willebrand disease type 1

Von Willebrand disease (VWD) affects blood coagulation and correlates with angiodysplasia. Data on VWD-affected women point to slightly increased miscarriage rates. We aimed to investigate the impact of VWD on angiogenesis in the uteroplacental unit of pregnant pigs of a model of VWD type 1 (T1). Uteri, placentae, and embryos were harvested at time of placentation (day 29 to 31) from four sows (two wildtype (WT) and two heterozygous for a von Willebrand factor (VWF) mutation diagnosed with T1). T1 sows were bred to a T1 boar creating embryos of three different genotypes: WT, T1 or homozygous for the VWF mutation corresponding with VWD type 3 (T3). Uteroplacental tissues were examined histologically. Embryos were genotyped. Gene expression of angiogenic factors possibly related to VWF was determined by quantitative real-time PCR. Corresponding protein expression was analyzed by immunohistochemistry. Genotyping revealed 35.3% WT, 52.9% T1 and 5.9% T3 embryos (5.9% not classified confidently). No histological alterations were found. Gene expression of VEGF was significantly increased in T1 placentae while expression of ANG1, ANG2, TIE2, and ITGB3 was significantly reduced, confirmed on protein level for different cell types. TIE2/TIE1 ratios were significantly lower in T1 placentae. Distribution of embryo genotypes indicates selection favoring the WT. Significant expression differences of angiogenic factors in placentae suggest influence of VWF on these factors during placentation, although angiodysplasia was not observed. The alterations concerning VEGF/VEGFR-2 signaling, integrin expression and the ANG/TIE system may influence angiogenesis and vascular adaptation during placentation and thus the overall outcome of pregnancy.

From Discovery of Snake Venom Disintegrins to A Safer Therapeutic Antithrombotic Agent.

Snake venoms affect blood coagulation and platelet function in diverse ways. Some venom components inhibit platelet function, while other components induce platelet aggregation. Among the platelet aggregation inhibitors, disintegrins have been recognized as unique and potentially valuable tools for examining cell–matrix and cell–cell interactions and for the development of antithrombotic and antiangiogenic agents according to their anti-adhesive and anti-migration effect on tumor cells and antiangiogenesis activities. Disintegrins represent a family of low molecular weight, cysteine-rich, Arg-Gly-Asp(RGD)/Lys-Gly-Asp(KGD)-containing polypeptides, which inhibit fibrinogen binding to integrin αIIbβ3 (i.e., platelet glycoprotein IIb/IIIa), as well as ligand binding to integrins αvβ3, and α5β1 expressed on cells (i.e., fibroblasts, tumor cells, and endothelial cells). This review focuses on the current efforts attained from studies using disintegrins as a tool in the field of arterial thrombosis, angiogenesis, inflammation, and tumor metastasis, and briefly describes their potential therapeutic applications and side effects in integrin-related diseases. Additionally, novel R(K)GD-containing disintegrin TMV-7 mutants are being designed as safer antithrombotics without causing thrombocytopenia and bleeding.

Trends and Prospects of Plant Proteases in Therapeutics.

The main function of proteases in any living organism is the cleavage of proteins resulting in the degradation of damaged, misfolded and potentially harmful proteins and therefore providing the cell with amino acids essential for the synthesis of new proteins. Besides this main function, proteases may play an important role as signal molecules and participate in numerous protein cascades to maintain the vital processes of an organism. Plant proteases are no exception to this rule. Moreover, in contrast to humanencoded enzymes, many plant proteases possess exceptional features such as higher stability, unique substrate specificity and a wide pH range for enzymatic activity. These valuable features make plant-derived proteolytic enzymes suitable for many biomedical applications, and furthermore, the plants can serve as factories for protein production. Plant proteases are already applied in the treatment of several pathological conditions in the human organism. Some of the enzymes possess antitumour, antibacterial and antifungal activity. The collagenolytic activity of plant proteases determines important medical applications such as the healing of wounds and burn debridement. Plant proteases may affect blood coagulation processes and can be applied in the treatment of digestive disorders. The present review summarizes recent advances and possible applications for plant proteases in biomedicine, and proposes further development of plant-derived proteolytic enzymes in the biotechnology and pharmaceutical industries.

Coagulation, deformability, and aggregation of RBCs and platelets following exposure to dielectric barrier discharge plasma with the use of different feeding gases

There are several applications for non-thermal plasma at atmospheric pressure, such as the sterilization of infected tissues, wound healing, and delicate surgery. Non-thermal plasma generates reactive oxygen/nitrogen species (RONS). In this study, we examined human red blood cells (RBCs), platelet function, and blood coagulation, following treatments with different feeding gases (air, nitrogen (N2), and argon (Ar)) of the dielectric barrier discharge plasma (DBDP) at different exposure times. This is the first study to evaluate the effects of DBDP on hemolysis, deformability, aggregation, and morphology of RBCs, as well as platelet function and blood coagulation at three doses (5, 10 and 15 min exposure). In comparison to N2 and Ar DBDP, air DBDP at more than 10 min exposure to RBC in culture plate with 2 ml liquid solution caused hemolysis and alterations in RBC deformability and aggregation owing to the higher levels of hydrogen peroxide, hydroxyl oxidants and other RONS. Moreover, air DBDP affected platelet function at high doses (more than 10 min exposure). Consequently, the air DBDP at, or more, than 10 min exposure affects blood coagulation and blood cells. The proposed method is useful for assessing the performances and dose optimization of various non-thermal plasma types used with different type of gases in biological applications.

Treating Tissue Factor-Positive Cancers with Antibody-Drug Conjugates That Do Not Affect Blood Clotting.

The primary function of tissue factor (TF) resides in the vasculature as a cofactor of blood clotting; however, multiple solid tumors aberrantly express this transmembrane receptor on the cell surface. Here, we developed anti-TF antibody-drug conjugates (ADC) that did not interfere with the coagulation cascade and benchmarked them against previously developed anti-TF ADCs. After screening an affinity-matured antibody panel of diverse paratopes and affinities, we identified one primary paratope family that did not inhibit conversion of Factor X (FX) to activated Factor X (FXa) and did not affect conversion of prothrombin to thrombin. The rest of the antibody panel and previously developed anti-TF antibodies were found to perturb coagulation to varying degrees. To compare the anticancer activity of coagulation-inert and -inhibitory antibodies as ADCs, a selection of antibodies was conjugated to the prototypic cytotoxic agent monomethyl auristatin E (MMAE) through a protease-cleavable linker. The coagulation-inert and -inhibitory anti-TF ADCs both killed cancer cells effectively. Importantly, the coagulation-inert ADCs were as efficacious as tisotumab vedotin, a clinical stage ADC that affected blood clotting, including in patient-derived xenografts from three solid tumor indications with a need for new therapeutic treatments-squamous cell carcinoma of the head and neck (SCCHN), ovarian, and gastric adenocarcinoma. Furthermore, a subset of the anti-TF antibodies could also be considered for the treatment of other diseases associated with upregulation of membranous TF expression, such as macular degeneration. Mol Cancer Ther; 17(11); 2412-26. ©2018 AACR.

Potential Applications of Venom Peptides as Anti-Thrombotic Agents for Management of Arterial and Deep-Vein Thrombosis

Thrombus is composed of two main substances i.e. red blood cells and aggregated platelets which make a web of inter-connected fibrin proteins. During injury it prevents bleeding, so it is very useful but it can be very dangerous if it is produced in healthy blood vessels and block the blood flow through it. Mural thrombi attaches with the blood vessels but in most cases do not block it completely. Venoms are an incredible source of peptides having amazing bioactivities with varying number of amino acid residues. Anticoagulant venom peptides however inhibit the enzyme taking part in coagulation like factor Xa and thrombin. The anticoagulant potential of venom peptides have also been reported by the degradation of the fibrin or fibrinogen related to serine or metalloproteases. Designing and development of numerous therapeutic agents or lead molecules mostly for cardiovascular diseases have been motivated from toxins/proteins from snake venoms. For example, disintegrins, a large family of platelet aggregation inhibitors found in viperid and crotalid snake venoms were the basis for designing of platelet aggregation inhibitors such as eptifibatide and tirofiban. Ancrod isolated from Malayan pit viper venom can cause reduction in level of blood fibrinogen and has been effectively tried in various ischemic conditions, including stroke. In order to search for novel lead molecules, the emphasis should be on isolation and characterization of pharmacologically active snake venoms proteins affecting blood coagulation and platelet aggregation. In this review an attempt has been made to recapitulates and discuss venoms of different animals and arthropod having anticoagulant peptides for their potential use in therapeutics and diagnostics.

Injection testosterone and adverse cardiovascular events: Acase-crossover analysis.

Exogenous testosterone administration may affect blood clotting, polycythaemia, and may increase atherosclerosis, though any association with cardiovascular events is unclear. While the literature is inconclusive, some studies have suggested testosterone use may increase short-term risk of cardiovascular events and stroke, and injection testosterone may convey higher risks than other dosage forms. We sought to evaluate the short-term cardiovascular risk of receiving injection testosterone. We conducted a case-crossover analysis comparing injection testosterone exposure in the 7days prior to an outcome event to referent windows in the past to estimate the acute association of cardiovascular outcomes with the receipt of testosterone injections. We identified adult male testosterone users hospitalized with myocardial infarction (MI), stroke or a composite of MI, stroke or unstable angina in US commercial claims (2000-2013) or Medicare (2007-2010) databases. We identified testosterone use for the patients from pharmacy dispensing claims or in-office procedure codes in the insurance billing data. We identified 2898 commercially insured men with events and recent testosterone use, and 339 from Medicare. Injected testosterone was associated with an increased risk of adverse events (composite outcome of myocardial infarction, stroke or unstable angina) in the immediate postinjection period for the older, Medicare population only: commercial insurance, odds ratios (OR)=0.98 (95% confidence intervals [CI]: 0.86-1.12); Medicare, OR=1.45 (1.07, 1.98). This association was either greatly attenuated or not present when evaluating receipt of any testosterone dosage forms (injection, gel, patch, implant): commercial insurance, OR=1.01 (0.92, 1.11); Medicare, OR=1.26 (95% CI: 0.98-1.63). Testosterone injections were uniquely associated with short-term risk of acute cardio- and cerebrovascular events in older adult men following injection receipt.

Genetic risk factors in thrombotic primary antiphospholipid syndrome: A systematic review with bioinformatic analyses.

Antiphospholipid Syndrome (APS) is an autoimmune multifactorial disorder. Genetics is believed to play a contributory role in the pathogenesis of APS, especially in thrombosis development and pregnancy morbidity. In the last 20 years, extensive research on genetic contribution on APS indicates that APS is a polygenic disorder, where a number of genes are involved in the development of its clinical manifestations. The aim of this systematic review is to evaluate the genetic risk factors in thrombotic primary APS. Additionally, to assess the common molecular functions, biological processes, pathways, interrelations with the gene encoded proteins and RNA-Seq-derived expression patterns over different organs of the associated genes via bioinformatic analyses. Without restricting the year, a systematic search of English articles was conducted (up to 4th September 2017) using Web of Science, PubMed, Scopus, ScienceDirect and Google Scholar databases. Eligible studies were selected based on the inclusion criteria. Two researchers independently extracted the data from the included studies. Quality assessment of the included studies was carried out using a modified New-Castle Ottawa scale (NOS). From an initial search result of 2673 articles, 22 studies were included (1268 primary APS patients and 1649 healthy controls). Twenty-two genes were identified in which 16 were significantly associated with thrombosis in primary APS whereas six genes showed no significant association with thrombosis. Based on the NOS, 14 studies were of high quality while 6 were low quality studies. From the bioinformatic analyses, thrombin-activated receptor activity (q = 6.77 × 10-7), blood coagulation (q = 2.63 × 10-15), formation of fibrin clot (q = 9.76 × 10-10) were the top hit for molecular function, biological process and pathway categories, respectively. With the highest confidence interaction score of 0.900, all of the thrombosis-associated gene encoded proteins of APS were found to be interconnected except for two. Based on the pathway analysis, cumulatively all the genes affect haemostasis [false discovery rate (FDR) = 1.01 × 10-8] and the immune system [FDR = 9.93 × 10-2]. Gene expression analysis from RNA-Seq data revealed that almost all the genes were expressed in 32 different tissues in the human body. According to our systematic review, 16 genes contribute significantly in patients with thrombotic primary APS when compared with controls. Bioinformatic analyses of these genes revealed their molecular interconnectivity in protein levels largely by affecting blood coagulation and immune system. These genes are expressed in 32 different organs and may pose higher risk of developing thrombosis anywhere in the body of primary APS patients.

Abstract 2246: Anti-proliferative activities of lipid fraction of extract from the skin of the catfish Arius Bilineatus, Valenciennes

Abstract The catfish (Arius bilineatus, Val.) secretes a gelatinous substance composed of biochemically active lipids and proteins from its skin upon stress or injury. Preparations from the skin have previously been shown to affect blood clotting and accelerates healing of non-healing diabetic foot ulcers in man. We have reported previously fish skin preparation (CSP) derived from the skin of the Catfish and it’s lipid fraction exerted anti-inflammatory activity in the in vitro cells and in vivo animal models. Here anti-proliferative effect of a lipid fraction of fish skin preparation (CSP-L) derived from the skin of the catfish and its plausible mechanism were investigated in human hepatocellular carcinoma (HCC) Hep3B and human pancreatic cancer Panc-1 cells. Cells were treated with CSP-L (0 to 100 μg/ml) for 72 hrs and cell proliferation was measured by the MTT assay. The results showed much stronger inhibition by CSP-L in Panc-1 cells than that of Hep3B cells with IC50 of 5.5 ± 1.4 μg/ml and 19.5 ± 7.7 μg/ml, respectively. Cell cycle analysis with PI staining suggested that CSP-L (25 - 100 μg/ml) led to G1 phase arrest in Hep3B cells whereas S phase arrest was observed in Panc-1 cells, suggesting the differential molecular mechanisms responsible for CSP-L induced cell growth suppression in Hep3B and Panc-1 cells. The alteration of cell cycle was concentration dependent. Additionally, CSP-L concentration dependently suppressed the invasion of Hep3B and Panc-1 cells. The molecular mechanism associated with CSP-L’s anti-proliferative effect was examined by Western blotting in both Hep3B and Panc-1 cells. Intriguingly, CSP-L (50 and 100 μg/ml) notably decreased protein levels of cyclin D, Stat3, pRB and pERk in Hep3 B cells in a concentration dependent manner. In contrast, only pRB and pERK protein expression were reduced in CSP-L treated Panc-1 cells. These again suggest that CSP-L inhibited the proliferation of Hep3B and Panc-1 cells by different molecular mechanisms. Collectively, our preliminary data suggest that CSP-L has a great potential to be developed as an anticancer or preventive agent for both HCC or pancreatic cancer and warrants further investigation. This study was support by a grant from Kuwait Foundation for the Advancement of Science No. KFAS 2013-120701A-D, and Kuwait University Research Grant No. SL03/14. Citation Format: Peiying Yang, Jibin Ding, Yong Pan, Yan Jiang, Mohammad Afzal, Bincy M. Paul, Sosamma O. George, Jassim M. Al-Hassan. Anti-proliferative activities of lipid fraction of extract from the skin of the catfish Arius Bilineatus, Valenciennes [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2017; 2017 Apr 1-5; Washington, DC. Philadelphia (PA): AACR; Cancer Res 2017;77(13 Suppl):Abstract nr 2246. doi:10.1158/1538-7445.AM2017-2246

Role of heterotrimeric G proteins in platelet activation and clot formation in platelets treated with integrin αIIbβ3 inhibitor

Mechanisms of platelet activation are triggered by thrombin, adenosine diphosphate (ADP), epinephrine, thromboxane A2, and other soluble agonists which induce signaling via heterotrimeric Gαq, Gαi, and Gα12/13 proteins. We have undertaken a study addressing the contribution of these G proteins to platelet activation and clot formation in the presence of eptifibatide, thus excluding outside-in signaling provided by integrin αIIbβ3–fibrinogen engagement.Selective and combined activation of the G proteins was achieved by using combinations of platelet agonists and inhibitors. Platelet activation in platelet-rich plasma was evaluated by P-selectin expression using flow cytometry. Contribution of platelets to whole blood clotting was assessed by rotation thromboelastometry (ROTEM).Selective signaling of Gαq or Gαi but not Gα12/13 promoted P-selectin expression. Further enhancement of P-selectin expression was achieved by ADP-induced combined signaling of Gαq and Gαi, and to more extent by U46619 at high concentration (1.5 μM) induced combined signaling of Gαq and Gα12/13 while maximal P-selectin expression was achieved by thrombin receptor-activating peptide (TRAP)-induced combined signaling of Gαq, Gαi, and Gα12/13. In ROTEM, selective activation of Gαq, Gαi, or Gα12/13 failed to affect blood clotting. Combined signaling of Gαq and Gαi or Gαq and Gα12/13 or all three G proteins shortened the clotting time and stimulated clot strength. Pretreatment of platelets with acetylsalicylic acid did not change the effect of ADP but inhibited the effect of TRAP. Signaling of Gαq and Gα12/13 triggered by U46619 also stimulated clot formation.Combined signaling of either Gαq and Gαi or Gαq and Gα12/13 is sufficient to stimulate maximal platelet activation and enhanced clot formation in platelets treated with inhibitor of integrin αIIbβ3. It could be suggested that outside-in signaling is not necessarily required to fulfill these platelet functions.