Clot Dissolution Research Articles

Thrombosis Risk Assessment in Myeloproliferative Neoplasm-Is There a Role for Viscoelastic Testing?

Philadelphia chromosome-negative myeloproliferative neoplasms include polycythemia vera, essential thrombocythemia, and myelofibrosis. They are associated with increased thrombotic events, and the primary goal of therapy, in particular those with polycythemia vera and essential thrombocythemia, is the prevention of thrombotic complications typically with antiplatelet therapy and/or cytoreduction. While several patient-, disease-, and genomic-related factors have been identified to influence thrombotic risks, there are no routine laboratory investigations to date that are sufficiently accurate to assess the underlying procoagulant state and predict the thrombotic risks. Conventional coagulation testing only measures time to clot formation and cannot reliably predict bleeding and thrombotic risks. Global coagulation assays such as thromboelastography, thrombin, and fibrin generation may provide a more thorough assessment of hemostatic function. Thromboelastography and thromboelastometry are viscoelastic tests which measure the mechanical properties of the hemostatic process, including the global dynamics of clot formation, stabilization, and dissolution. While viscoelastic testing is gaining traction in the investigations of coagulopathies and goal-directed blood product replacement in trauma and massive transfusion settings, the role of these assays in thrombosis is less well defined. Here, we provide a review of the current evidence of the role of viscoelastic testing in myeloproliferative neoplasm, particularly in the thrombotic risk assessment.

In Vitro Blood Clot Formation and Dissolution for Testing New Stroke-Treatment Devices.

Strokes are among the leading causes of death worldwide. Ischemic stroke, due to plaque or other buildup blocking blood flow to the brain, is the most common type. Although ischemic stroke is treatable, current methods have severe shortcomings with high mortality rates. Clot retrieval devices, for example, can result in physically damaged vessels and death. This study aims to create blood clots that are representative of those found in vivo and demonstrate a new method of removing them. Static blood clots were formed using a 9:1 ratio of whole sheep blood and 2.45% calcium chloride solution. This mixture was heated in a water bath at 37 °C for approximately one hour until solidified. Following clot solidification, human plasmin was introduced by various methods, including soaking, injection, and membrane perfusion, and the resulting dissolution percentages were determined. Different clot types, representative of the wide range found physiologically, were also manufactured and their dissolution characteristics evaluated. A method to reproducibly create blood clots, characteristic of those found in vivo, is essential for the production of stroke retrieval devices that can efficiently and effectively remove clots from patients with low mortality rates and little/no damage to the surrounding vessels.

A Hand-Held Magnetic Acoustic Device With Integrated Real-Time Monitoring for Targeted Drug Delivery.

Advances in magnetic materials have enabled the development of new therapeutic agents that can be localized by external magnetic fields. These agents offer a potential means of improving treatment targeting and reducing the toxicity-related side effects associated with systemic delivery. Achieving sufficiently high magnetic fields at clinically relevant depths in vivo, however, remains a challenge. Similarly, there is a need for techniques for real-time monitoring that do not rely on magnetic resonance imaging (MRI). Here, we present a hand-held device to meet these requirements, combining an array of permanent magnets and a thin 64-element capacitive micromachined ultrasonic transducer (CMUT) interfaced to a real-time imaging system. Drug carrier localization was assessed by measuring the terminal velocity of magnetic microbubbles in a column of fluid above the magnetic array. It was found that the magnetic pull force was sufficient to overcome buoyancy at equivalent tissue depths of at least 35 mm and that the median terminal velocity ranged from 0.7 to 20 [Formula: see text]/s over the distances measured. A Monte Carlo study was performed to estimate capture effectiveness in tumor microvessels over a range of different tissue depths and flow rates. Finally, B-mode and contrast-enhanced ultrasound (CEUS) imaging were demonstrated using a gel flow phantom containing a 1.6-mm diameter vessel. Real-time monitoring provided visual confirmation of retention of magnetic microbubbles along the vessel wall at a flow rate of 0.5 mL/min. These results indicate that the system can successfully retain and image magnetic microbubbles at tissue depths and flow rates relevant for clinical applications such as molecular ultrasound imaging of atherosclerosis, sonodynamic and antimetabolite cancer therapy, and clot dissolution via sonothrombolysis.

Improving treatment for acute ischemic stroke-Clot busting innovation in the pipeline.

Acute ischemic stroke is a consequence of disrupted blood flow to the brain, caused by thrombosis—the pathological formation of occlusive clots within blood vessels, which can embolize distally to downstream tissues and microvasculature. The highest priority of stroke treatment is the rapid removal of occlusive clots and restoration of tissue perfusion. Intravenous thrombolysis is the pharmacological standard-of-care for the dissolution of blood clots, wherein thrombolytic drugs are administered to restore vessel patency. While the introduction of recombinant tissue-plasminogen activator (rtPA) in 1996 demonstrated the benefit of acute thrombolysis for clot removal, this was countered by severe limitations in terms of patient eligibility, lytic efficacy, rethrombosis and safety implications. Development of safer and efficacious treatment strategies to improve clot lysis has not significantly progressed over many decades, due to the challenge of maintaining the necessary efficacy-safety balance for these therapies. As such, rtPA has remained the sole approved acute therapeutic for ischemic stroke for over 25 years. Attempts to improve thrombolysis with coadministration of adjunct antithrombotics has demonstrated benefit in coronary vessels, but remain contraindicated for stroke, given all currently approved antithrombotics adversely impact hemostasis, causing bleeding. This Perspective provides a brief history of stroke drug development, as well as an overview of several groups of emerging drugs which have the potential to improve thrombolytic strategies in the future. These include inhibitors of the platelet receptor glycoprotein VI and the signaling enzyme PI3-Kinase, novel anticoagulants derived from hematophagous creatures, and proteolysis-targeting chimeras.

Efficacy and safety of edoxaban in patients with chronic thromboembolic pulmonary hypertension: protocol for a multicentre, randomised, warfarin-controlled, parallel group trial - KABUKI trial

IntroductionChronic thromboembolic pulmonary hypertension (CTEPH) is a complication of prior pulmonary thromboembolism (PE), caused by incomplete clot dissolution after PE. In patients with CTEPH, lifelong anticoagulation is mandatory to prevent...

In Vitro Antioxidant, Cytotoxic, Thrombolytic Activities and Phytochemical Evaluation of Methanol Extract of the Ampelocissus Barbata (Wall.) Leaves

Context: Oxidative stress and pertaining counterbalance mechanism are actively working in the living organisms. The overproduction of reactive oxygen species (ROS) in the ongoing equipoising process requires to be compensated by strong antioxidants. Plants as a rich source of antioxidants not only reduce oxidative stress but also possess cytotoxic, thrombolytic and phytochemical potentials. Aims: To find out the antioxidant, cytotoxic, thrombolytic and phytochemical capabilities of the methanolic extracts of Ampelocissus barbata (Wall.) leaves. Methods and Material: Assessment of the in vitro antioxidant activity of extract was carried out using DPPH radical scavenging assay, determination of reducing power capacity and total phenolic content. The thrombolytic activity was assessed by disintegration of clot and prospective phytochemical activities were by standard qualitative analysis such as Mayer’s, Dragendroff’s Wagner’s and Hager’s Reagent test for alkaloids; Libermann-Burchared and Salkowski Reagent tests for steroid and terpenoids; Molish Reagent, Benedict’s Reagent, Fehling’s Solution A & B reagent test for carbohydrates; Ferric Chloride (5%) Solution, Potassium Dichromate (10%) Solution tests for tannins; Shinoda test and Alkaline reagent test for Flavonoids; Froth tests & Haemolysis test for Saponins. Statistical analysis used: The statistical analysis was carried out using GraphPad Prism and Microsoft excel Results: Appreciable DPPH radical scavenging activity of the extract was observed with the IC50 value of 107.47±1.46 µg/ml. A significant correlation was found between the standard ascorbic acid (AA) and the plant extracts at the p˂0.05 for the reducing power assay where, the activity increased with the concentration of the extracts and the highest absorbance value was 3.025±0.15 and 1.826±0.006 for the AA and the extracts respectively. The plant also accommodates a considerable amount of polyphenols, reflected in the value of gallic acid equivalent 277.397±0.419 mg/ml. Finally, the percentage (%) of clot lysis for the thrombolytic activity was revealed to be 7.031±0.697, 35.297±1.307, and 75.083±0.599 for the water (negative control), extract, and the standard Streptokinase respectively. The study revealed the presence of phytochemicals namely alkaloids, flavonoids, tannins and glycosides. Conclusions: The study disclosed the promising in vitro activity of the plant, which necessitates the further analysis for the isolation and evaluation of the active principles.

Acute cholangitis due to haemobilia complicating percutaneous cholecystostomy: First literature case report.

BackgroundLaparoscopic cholecystectomy is the standard treatment for acute cholecystitis. Cholecystostomy is a good option in patients with significant comorbidities. We report a case of a patient having had a percutaneous cholecystostomy for acute cholecystitis complicated with haemobilia and acute cholangitis.Presentation of a caseA woman aged 64 years old, with a history of diabetes, arterial hypertension, and chronic obstructive pulmonary disease was admitted to our institution with acute cholecystitis.We opted for transhepatic percutaneous cholecystostomy (PC) and antibiotics.On the fourth day, the patient had acute cholangitis due to haemobilia.We injected physiologic saline serum through the drain of cholecystostomy to dissolve the blood clot. There was a clinical improvement.We performed laparoscopic cholecystectomy two months later. The patient had an uneventful recovery with a follow-up of five months.DiscussionWe report the first literature report of acute cholangitis due to haemobilia complicating percutaneous cholecystostomy in a patient admitted for cholecystitis.We highlight the importance of the injection of saline physiologic serum from the catheter. Medical treatment with antibiotics may be enough knowing that blood clots can disappear spontaneously. In case of failure, ERCP with sphincterotomy should be performed.ConclusionHaemobilia causing acute cholangitis is a rare complication of percutaneous cholecystostomy. Conservative treatment with antibiotics and injection of saline physiologic serum from the catheter is a good treatment option. In case of failure, ERCP should not be delayed.

Novel Inhibitors and Activity-Based Probes Targeting Trypsin-Like Serine Proteases.

The trypsin-like proteases (TLPs) play widespread and diverse roles, in a host of physiological and pathological processes including clot dissolution, extracellular matrix remodelling, infection, angiogenesis, wound healing and tumour invasion/metastasis. Moreover, these enzymes are involved in the disruption of normal lung function in a range of respiratory diseases including allergic asthma where several allergenic proteases have been identified. Here, we report the synthesis of a series of peptide derivatives containing an N-alkyl glycine analogue of arginine, bearing differing electrophilic leaving groups (carbamate and triazole urea), and demonstrate their function as potent, irreversible inhibitors of trypsin and TLPs, to include activities from cockroach extract. As such, these inhibitors are suitable for use as activity probes (APs) in activity-based profiling (ABP) applications.

COVID-19 infection as a new risk factor for penile Mondor disease

BackgroundPenile Mondor disease is a superficial dorsal vein thrombophlebitis of the penis, which mainly affects young and middle-aged men. It generally manifests as a visible painful cord located along the dorsal surface of the penis with signs of skin inflammation. The condition is usually self-limiting, but in severe cases a surgical procedure may be necessary in addition to pharmacological treatment. Coronavirus disease 2019 (COVID-19) caused by SARS-CoV-2 is associated with a frequent incidence of thrombophilia; therefore, such a prothrombotic state during infection may be a significant risk factor for penile Mondor disease.Case presentationThe 34-year-old patient reported moderate pain felt on the surface of the penis. During the medical interview, the patient did not admit significant risk factors for Mondor Disease, apart from the previous, a month earlier COVID-19 disease. Examination revealed swelling erythema and a thick indurated cord on the surface of the penis. Color Doppler ultrasound was performed to confirm assumptions and exclude thrombosis of other penile vessels. Based on visible clots in the course of the superficial penile vein and after exclusion of vasculitis due to autoimmune disease the diagnosis of penile Mondor disease was made. Pharmacological therapy was implemented to further break down the clot and prevent rethrombosis in the penile vessels. The patient did not report any treatment complications and returned for a control visit, which revealed complete clot dissolution on ultrasound; therefore, complete recovery was stated.ConclusionsThis case report presents the correlation between SARS-Cov-2 infection and penile Mondor disease, based on the confirmed influence of COVID-19 on the pathophysiology of thrombosis. It can be concluded that COVID- 19 is a risk factor for Mondor disease, as in the presented case the virus was the only prothrombotic risk factor for the patient. Consequently, the possibility of developing thrombosis in the form of penile Mondor disease should be taken into account among patients with post-COVID-19 and active SARS-Cov-2 infection.

Fibrin Strands Will Grow from Soluble Fibrin and Hang Up in an In Vitro Microcirculatory Viscoelastic Model: Is This a Major Cause of COVID-19 Associated Coagulopathy?

Viscoelastic testing (VET) by both TEG and ROTEM has demonstrated hypercoagulability early in corona virus disease 2019 (COVID-19) associated coagulopathy (CAC). Additional VET studies demonstrated fibrinolytic shutdown late in a majority of severely ill COVID-19 patients with an associated elevation of d-dimer. Elevated d-dimer confirms that coagulation, followed by fibrinolysis, has occurred. These findings imply that, during CAC, three enzymes—thrombin, Factor XIIIa and plasmin—must have acted in sequence. However, limitations in standard VET analyses preclude exploration of the earliest phases of clot induction, as well as clot formation and clot dissolution in flowing blood. Herein, we describe a novel method illuminating aspects of this unexplored area. In addition, we created an in vitro blood flow model in which the interactions of thrombin, Factor XIII and plasmin with fibrinogen can be studied, allowing the determination of soluble fibrin (SF), the highly unstable form of fibrin that precedes the appearance of a visible clot. This model allows the determination of the SF level at which fibrin microclots begin to form.

Potential effects and relevant lead compounds of Vigna mungo (L.) Hepper seeds against bacterial infection, helminthiasis, thrombosis and neuropharmacological disorders

Multidrug-resistant bacterial infections, helminthiasis, thrombosis, anxiety and insomnia are some of the major global health concerns. Vigna mungo (L.) Hepper (VM) has been used traditionally to treat microbial infection, helminthic disorder, schizophrenia, memory loss, and blood circulatory problem. This research aims to discover antibacterial, anthelmintic, thrombolytic and neuropharmacological effects of the methanol extract of Vigna mungo seeds (MESVM), and also in-silico prediction of relevant lead compounds by molecular docking and ADME/T analysis. The crude extracts and subsequent fractions of MESVM were investigated for antibacterial activity by disc diffusion method, anthelmintic activity by paralysis and death test on earthworms, and thrombolytic activity by in vitro blood clot dissolution test. Open-field test and elevated plus maze test were performed for evaluating anxiolytic activity of the extracts. Using molecular docking, ligand poses of selected VM seeds’ phytoconstituents were predicted targeting tubulin, GlcN-6-P synthase, and human tissue plasminogen activator proteins for anthelmintic, antibacterial, and thrombolytic activity, respectively. In the antibacterial activity test, the MESVM at 10000 μg/mL concentration created highest and significant (P < 0.001) zone of inhibition against Staphylococcus aureus (15.42 mm) and Escherichia coli (12 mm) compared with tetracycline. The MESVM exhibited remarkable anthelmintic activity at 50 mg/mL concentration with 35.4 min paralysis time, 75.2 min death time and were closer to the durations of standard drug albendazole. No test extract showed anxiolytic activity. In thrombolytic activity test, all concentrations of MESVM produced clot lytic activity with high significance (P < 0.001) in comparison with the blank. In docking, 2′-hydroxygenistein, cyclokievitone hydrate, and aureol displayed maximum affinity to the target proteins for anthelmintic, antibacterial, and thrombolytic activity, respectively. This research revealed that the MESVM demonstrated potential anthelmintic, antibacterial and thrombolytic effects that confirmed the folkloric uses of VM and the found relevant lead compounds might be further optimized in future drug development.

Dissolution Effect of Alteplase on Arterial Blood Clot Model of Hypertensive Intracerebral Hemorrhage Patients in vitro.

ObjectiveTo explore the dissolution effect of alteplase (rt-PA) on arterial blood clots of patients with hypertensive cerebral hemorrhage in vitro and analyze the optimal concentration and action time of rt-PA for intracranial hematomas.MethodsThe arterial blood of 35 patients with confirmed hypertensive cerebral hemorrhage were collected, centrifuged, and the serum was aspirated to prepare the blood clot model. The 0.125, 0.25, 0.5, 1, 2, and 3 mg t-PA, 20,000 U, and 40,000 U urokinase (u-PA) were taken for the corresponding blood clot for dissolution test. The blood clot volume and dissolution volume was measured at 0, 30, 60, 90, 120, and 150 min.ResultsWithout intervention, the blood clot volume of men was higher than that of women at 0, 30, 60, and 90 min (P < 0.05). Without intervention, hematocrit (HCT) was correlated with blood clot volume and the correlation decreased with time. The 30, 60, and 90 min dissolution curves of each group showed an upward trend (P < 0.05), and the dissolution curves tended to be flat at 120 min and 150 min. The dissolution volume of.125 mg/3 ml, 0.25 mg/3 ml, 0.5 mg/3 ml rt-PA, 20,000 U, 40,000 U u-PA was higher than that of 1, 2, 3 mg/ml rt-PA (P < 0.05). The dissolution volume of.125 mg/3 ml, 0.25 mg/3 ml, 0.5 mg/3 ml rt-PA was not significantly different from 20,000 and 40,000 U u-PA (P > 0.05). Gender differences did not affect the effects of the above drugs.ConclusionIn vitro, low-concentration rt-PA has a better dissolution effect, and it shows a time-dependent effect, reaching the highest effect in 90 min.

Microbial Fibrinolytic Enzymes as Anti-Thrombotics: Production, Characterisation and Prodigious Biopharmaceutical Applications.

Cardiac disorders such as acute myocardial infarction, embolism and stroke are primarily attributed to excessive fibrin accumulation in the blood vessels, usually consequential in thrombosis. Numerous methodologies including the use of anti-coagulants, anti-platelet drugs, surgical operations and fibrinolytic enzymes are employed for the dissolution of fibrin clots and hence ameliorate thrombosis. Microbial fibrinolytic enzymes have attracted much more attention in the management of cardiovascular disorders than typical anti-thrombotic strategies because of the undesirable after-effects and high expense of the latter. Fibrinolytic enzymes such as plasminogen activators and plasmin-like proteins hydrolyse thrombi with high efficacy with no significant after-effects and can be cost effectively produced on a large scale with a short generation time. However, the hunt for novel fibrinolytic enzymes necessitates complex purification stages, physiochemical and structural-functional attributes, which provide an insight into their mechanism of action. Besides, strain improvement and molecular technologies such as cloning, overexpression and the construction of genetically modified strains for the enhanced production of fibrinolytic enzymes significantly improve their thrombolytic potential. In addition, the unconventional applicability of some fibrinolytic enzymes paves their way for protein hydrolysis in addition to fibrin/thrombi, blood pressure regulation, anti-microbials, detergent additives for blood stain removal, preventing dental caries, anti-inflammatory and mucolytic expectorant agents. Therefore, this review article encompasses the production, biochemical/structure-function properties, thrombolytic potential and other surplus applications of microbial fibrinolytic enzymes.

Peroxide-Induced Damage to Plasminogen Molecules.

Plasminogen is a zymogenic form of plasmin, an enzyme that plays a fundamental role in the dissolution of fibrin clots as well as in many other physiological processes. For the first time, by the method of gas chromatography-mass spectrometry, post-translational modifications in the primary structure of plasminogen treated with physiologically relevant amounts of hydrogen peroxide were identified. It was found that methionine and tryptophan residues located in different structural regions of plasminogen served as targets of the oxidant. Plasminogen oxidation caused a dose-dependent effect in decreasing the fibrinogenolytic activity of plasmin evidenced by the formation of fibrinogen degradation products. The possible antioxidant role of methionines in the oxidative modification of plasminogen is discussed.

Tocilizumab mitigates hypercoagulability after out-of-hospital cardiac arrest – results from a randomized controlled trial (IMICA)

Abstract Background Systemic inflammation constitutes a key element of the post cardiac arrest syndrome (PCAS) which affects initially comatose resuscitated cardiac arrest patients. We have recently shown that treatment with tocilizumab, an IL-6 receptor antagonist, reduces systemic inflammation and myocardial injury after out-of-hospital cardiac arrest (OHCA). Inflammation and coagulation are interconnected, and changes in coagulation often accompany inflammatory states. Purpose To investigate if conventional coagulation parameters or a viscoelastic hemostatic assay differ in patients treated with tocilizumab compared to placebo. Methods Eighty comatose OHCA patients were randomized 1:1 in a double-blinded placebo-controlled trial to a single infusion of tocilizumab or placebo in addition to standard of care including targeted temperature management. Trial registration: Clinicaltrials.gov NCT03863015. Endpoints were plasma fibrinogen, platelet count, and Thrombelastography (TEG) variables. TEG analysis was performed utilizing whole blood in a citrated kaolin assay with heparinase (to neutralize any unfractionated or low molecular weight heparin that had been administered), and the following variables were analyzed: reaction time (R), angle, maximum amplitude (MA), and lysis at 30 minutes (Ly30) which represents clot initiation, propagation, strength and dissolution respectively. Data reported as median (Q1; Q3), statistical analysis performed by constrained linear mixed models, and a p&amp;lt;0.05 was considered statistically significant. Results Admission median levels of the investigated coagulation parameters were within normal levels for both the tocilizumab and placebo group. At 48 hours, for the placebo group, fibrinogen levels (figure 1) had risen to supra-normal levels, TEG angle had increased from 64 (10; 67) till 72 (69; 74), and TEG MA (figure 2) had increased to the hypercoagulable range (all p&amp;lt;0.05), while for the tocilizumab group fibrinogen levels and TEG MA remained within normal values. Both groups had a significant fall in platelet count from admission till 48h [placebo: from 252 109/L (208; 282) till 151 (126; 189); tocilizumab from 217 (183; 260) till 152 (127; 183)], with no group differences. Also for both groups there was significant shortening of the TEG R time [placebo: from 8 min (6; 10) till 6 (6; 8); tocilizumab from 8 (6; 9) till 7 (6; 8)], again with no difference between groups. Ly30 did not change over time or differ between groups. Conclusion Treatment with tocilizumab following resuscitated OHCA aids in maintaining a normo-coagulable state, whereas placebo patients developed supra-normal fibrinogen levels and a hypercoagulable TEG clot strength. Funding Acknowledgement Type of funding sources: Private grant(s) and/or Sponsorship. Main funding source(s): The Danish Heart Foundation (Reference no. 19-R135-A9302-22125); Region Hovedstadens Forskningsfond til sundhedsforskning (CapitalRegion Research Foundation, Denmark; reference no. A6030) Figure 1. FibrinogenFigure 2. Thrombelastography MA

Quantile‐specific heritability of plasminogen activator inhibitor type‐1 (PAI‐1, aka SERPINE1) and other hemostatic factors

BackgroundPlasminogen activator inhibitor type‐1 (PAI‐1, aka SERPINE1) is a moderately heritable glycoprotein that regulates fibrin clot dissolution (fibrinolysis). ObjectivesTest whether the heritabilities (h2) of PAI‐1 and other hemostatic factors are constant throughout their distribution or whether they are quantile‐specific (i.e., a larger or smaller h2 depending on whether their concentrations are high or low). MethodsQuantile regression was applied to 5606 parent‐offspring pairs and 5310 full siblings of the Framingham Heart Study. Quantile‐specific heritability was estimated from the parent‐offspring regression slope (βPO, h2 = 2βPO/(1+rspouse)) and the full‐sib regression slope (βFS, h2 = {(1+8rspouseβFS)0.5–1}/(2rspouse)). ResultsHeritability (h2 ± SE) increased significantly with increasing percentiles of the offspring's age‐ and sex‐adjusted PAI‐1 distribution when estimated from βPO (plinear trend = 0.0001): 0.09 ± 0.02 at the 10th, 0.09 ± 0.02 at the 25th, 0.16 ± 0.02 at the 50th, 0.29 ± 0.04 at the 75th, and 0.26 ± 0.08 at the 90th percentile of the PAI‐1 distribution, and when estimated from βFS (plinear trend = 6.5x10−7). There was no significant evidence for quantile‐specific heritability for factor VII (plinear trend = 0.35), D‐dimer (plinear trend = 0.08), tPA (plinear trend = 0.74), or von Willebrand factor (plinear trend = 0.79). ConclusionHigher mean plasma PAI‐1 antigen concentrations tend to accentuate genetic effects (quantile‐dependent expressivity), which is consistent with the greater reported differences in PAI‐1 concentrations between rs1799889 SERPINE1 (4G/5G) genotypes in patients with osteonecrosis, meningococcal sepsis, obesity, prior myocardial infarction, deep vein thrombosis, and polycystic ovarian syndrome than in healthy controls. It is also consistent with the greater increases in PAI‐1 concentrations in 4G‐allele carriers than 5G/5G homozygotes following fibrinolytic treatment, low‐salt intake, and high saturated fat intake.

Isolation and Purification of Thrombolytic Enzyme Extracted from Earthworm Punjab, Pakistan

The Cardiovascular disease due to thrombus (clot) formation is the major factor of death throughout the world. Earthworms being the eco engineers has thrombolytic enzyme that can be used for thrombolysis. The thrombolytic enzyme was isolated and purified from supernatant of earthworm Apporectodea longa by column chromatography. Six Strain BKT 11, BKT 15, BKT 17, BKT 26, BKT 27 and BKT 28 shows the thrombolytic activity 791.64 U/mg, 1362.39 U/mg, 1205.4 U/mg, 710.63 U/mg, 529.66 U/mg and 625.00 U/mg respectively. Thrombolytic activity was confirmed by blood clot lysis method. Different concentrations 50 ?l,100 ?l, 150 ?l, 200 ?l and 250 ?l of extracted enzyme were applied on 25mg of wet blood clot along with control where distill water used. These fractions of extracted enzymes represent the dissolution of clot (thrombolysis). The molecular weight 32 KDa was determined by sodium dodecyl sulphate gel electrophoresis (SDS-PAGE). Results show that extracted elute have potential of fibrinolytic activity in this specie of earthworm and it can serve as a suitable therapeutic agent. Keywords: Thrombolytic activity, Casein plate assay, Blood clot lysis, spectrophotometry, Gel electrophoresis.

Study the effect of static magnetic field intensity on drug delivery by magnetic nanoparticles

Employing the magnets in therapy has a long history of treating diseases, and currently new applications such as drug delivery by magnetic nanoparticles are gaining more attention. This research tried to study the effect of static magnetic field intensity on drug delivery by magnetic nanoparticles carrying thrombolytic agents. In this research, Fe3O4@SiO2 nanoparticles carrying streptokinase were applied. The efficiency of thrombolysis and micro-CT-scan images are utilized to study the effect of different magnetic fields (0.1, 0.2, 0.3 and 0.5 T) on thrombolysis. The results confirm that increasing the static magnetic field intensity accelerated the thrombolysis. Increasing the intensity of the magnetic field from 0.1 to 0.3 T leads to an increase in clot dissolution rate from 55 to 89%, respectively. Moreover, micro-CT-scan images revealed that magnetic nanoparticles carrying a thrombolytic agent penetrated deeper into the mesh-like structure of clot as the magnetic field intensities increased, which could lead to further dissolution of the clot.

The association of anticoagulation therapy characteristics with left atrial thrombus lysis in patients with nonvalvular persistent atrial fibrillation

Purpose. The aim of this study was to reveal the effect of the duration and characteristics of anticoagulant therapy on the clot dissolution in the left atrial appendage (LAA) in patients with persistent atrial fibrillation (AF).Material and methods. The repeat transesophageal echocardiography was performed in 68 patients with persistent AF, because the thrombus was detected in the LAA during the first examination. Of these, 37 (54.4%) patients started or continued to receive warfarin and 31 (45.6%) patients continued to receive the direct oral anticoagulants. Transesophageal echocardiography was repeated after 3-5 weeks. One follow-up examination was for 53 patients, two follow-up examination was for 11 patients and three follow-up examination was for 4 patients. Cox regression analysis was performed to identify factors affecting the likelihood of clot dissolution and Kaplan-Meier survival analyses with log-rank tests were used to compare the clot dissolution time.Results. The chance of the LAA thrombus lysis is 50% after 35.0 ± 3.7 days of receiving anticoagulants. This time is reduced to 30.0 ± 1.4 days for small thrombus (no more than 18 mm), and it increases to 45.0 ± 7.4 days (p = 0.038) for large thrombus. The dissolution time of small thrombus depends on the characteristics of the treatment: the median of the dissolution curve is 24.0 ± 3.7 days when the patients received the direct oral anticoagulants, and the median of the dissolution curve is 40.0 ± 7.2 days (p = 0.009), if the patients received warfarin. The dependence of the dissolution time of large thrombus on the characteristics of treatment did not found.Conclusion. The LAA thrombus dissolution time in patients with atrial fibrillation depends on their size, and the dissolution time of small thrombi depends on the characteristics of anticoagulant therapy.

Clot Degradation Under the Action of Histotripsy Bubble Activity and a Lytic Drug.

Deep vein thrombosis is a major source of morbidity worldwide. For critical obstructions, catheter-directed thrombolytics are the frontline therapy to achieve vessel recanalization. Techniques that aid lytic therapy are under development to improve treatment efficacy and reduce procedure-related complications. Histotripsy is one such adjuvant under development that relies on focused ultrasound for in situ nucleation of bubble clouds. Prior studies have demonstrated synergistic effects for clot dissolution when histotripsy is combined with lytic therapy. The success of this combination approach is hypothesized to promote thrombolytic efficacy via two mechanisms: erythrocyte fractionation (hemolysis) and increased lytic activity (fibrinolysis). In this study, the contributions of hemolysis and fibrinolysis to clot degradation under histotripsy and a lytic were quantified with measurements of hemoglobin and D-dimer, respectively. A linear regression analysis was used to determine the relationship between hemoglobin, D-dimer, and the overall treatment efficacy (clot mass loss). A similar analysis was conducted to gauge the role of bubble activity, which was assessed with passive cavitation imaging, on hemolysis and fibrinolysis. Tabulation of these data demonstrated hemolysis and fibrinolysis contributed equally to clot mass loss. Furthermore, bubble cloud activity promoted the generation of hemoglobin and D-dimer in equal proportion. These studies indicate a multifactorial process for clot degradation under the action of histotripsy and a lytic therapy.