Clotting Time Test Research Articles

Modified acid polysaccharide derived from Salvia przewalskii with excellent wound healing and enhanced bioactivity

Acid polysaccharide was extracted from Salvia przewalskii root powders (PSP), purified by diethylaminoethyl cellulose column (DEAE-52) and molecular sieve (PSP2). PSPm1 was obtained by modifying PSP2 with nitrite and phosphoric acid. The chemical structure of PSP2 and PSPm1 exhibited notable distinctions, primarily due to the absence of arabinose and promotion of glucuronic acid (GlcA). The structure of PSPm1 was deduced through the utilization of 1H, 13C, and 2-D NMR. The main chain was linked by α-D-Galp(1 → 3)-α-Glcp-(1 → fragments and →6)-β-D-Galp fragments, with the presence of →4)-α-D-GlcpA-(1 → 6)-β-D-Galp-(1 → ， → 4)-α-D-GalAp-(1 → 2,4)-α-D-Rhap-(1 → fragments and →6)-α-Glcp-(1 → 2,4)-β-D-Manp-(1 → fragments. PSPm1 exhibited different immunoregulatory bioactivity in vitro, including haemostatic effects indicated by activated clotting time of 55.5 % reduction by the activated clotting time (ACT) test and wound healing function in vivo. PSPm1 also displayed better anti-tumor biological effects than unmodified. The structure-activity dissimilarity between PSP2 and PSPm1 primarily stems from variations in molecular weight (Mw), monosaccharide composition, and branching patterns. The modification of polysaccharides from the extract residues of Chinese medicinal materials may be a new form of drug supplements.

Variability in Contemporary Heparin Prescription and Activated Clotting Time Monitoring During Percutaneous Coronary Intervention: Call for Up-To-Date Evidence-Based Guidelines

Unfractionated heparin (UFH) is the preferred anticoagulant agent in percutaneous coronary intervention (PCI) procedures for minimising the risk of thrombotic complications. Because of the narrow therapeutic range of UFH, some society guidelines have advocated the use of the activated clotting time (ACT) test to monitor anticoagulation intensity during PCI to reduce thrombotic and bleeding complications. We aimed to assess the current practice of UFH prescription and its monitoring in Australia and New Zealand (ANZ). We conducted an anonymous voluntary cross-sectional survey of interventional cardiologists (ICs) who were members of the Cardiac Society of Australia and New Zealand in 2022. The survey included 10 questions pertaining to the current practice of anticoagulation during PCI. Of 430 ICs surveyed, 148 responded (response rate, 34.4%). Most ICs (84.4%) prescribed 70-100 IU/kg of UFH for PCI. Over half of ICs (58.7%) routinely measured ACT during PCI, whereas only 22.2% routinely measured ACT after PCI to guide additional UFH prescription. Among ICs who prescribed additional UFH, approximately half (48%) aimed for ACT ≥250 seconds. Factors that influenced post-PCI UFH prescription included vascular access site and concomitant antiplatelet or anticoagulant therapy. The contemporary practice of UFH prescription during PCI and ACT monitoring in ANZ is variable and based on outdated evidence preceding current drug-eluting stents, antiplatelet therapies, and radial-first practice. Current society guideline recommendations lack clarity and agreement, reflecting the quality of the available evidence. Up-to-date clinical trials evaluating UFH prescription and ACT monitoring are needed to optimise clinical outcomes in contemporary PCI procedures.

International council for standardisation in haematology recommendations on fibrinogen assays, thrombin clotting time and related tests in the investigation of bleeding disorders.

This guidance was prepared on behalf of the International Council for Standardisation in Haematology (ICSH) by an international working group of clinicians and scientists. The document focuses on tests and assays used for the assessment of fibrinogen function, particularly in the scenario of bleeding disorders. Thrombin clotting time (TT) is used as a screening test in some laboratories and also has some utility when direct anticoagulants are in use. The Clauss fibrinogen assay remains the method of choice for the assessment of fibrinogen function, but there are some situations where the results may be misleading. Prothrombin time derived fibrinogen assays are frequently used, but should be interpreted with caution; the results are not interchangeable between different methods and fibrinogen can be overestimated in certain clinical scenarios. Viscoelastic point of care methods may be helpful in emergency situations, while Reptilase time (and similar tests) are useful combined with TT in distinguishing heparin contamination of samples (i.e., if an incorrect blood draw is suspected) and the presence of direct thrombin inhibitors. Fibrinogen antigen assays should be used in the investigation of functional fibrinogen abnormalities; fibrinogen antigen and genetic testing are recommended in the confirmation of congenital fibrinogen disorders. The following recommendations for fibrinogen function assessment are based on published literature and expert opinion and should supplement local regulations and standards.

Effect of emicizumab-neutralizing antibodies on activated partial thromboplastin time–based clotting time test results in patients treated with emicizumab

BackgroundEmicizumab is a bispecific humanized monoclonal antibody that shortens the activated partial thromboplastin time (aPTT), making aPTT-based tests unreliable. ObjectivesTo evaluate the efficacy of a mixture of 2 anti-idiotype monoclonal antibodies (anti-emi) in neutralizing emicizumab in samples from persons with hemophilia A treated with emicizumab. MethodsFifty samples from persons with hemophilia A treated with emicizumab were analyzed for aPTT and factor VIII procoagulant activity; FVIII inhibitor titer was measured using Nijmegen-Bethesda assay in 50 plasma samples of additional patients (positive for FVIII inhibitor) treated with emicizumab. FVIII procoagulant activity and inhibitor titer were measured using 1-stage (Actin FS, Siemens) and chromogenic assays with bovine regents (Factor VIII Chromogenic Assay, Siemens). Emicizumab concentration was measured by modified a 1-stage assay calibrated with a drug-specific calibrator (r2 Diagnostics Inc). All the tests were performed on Sysmex CS-2400 (Sysmex) before and after the addition of anti-emi (Chugai Pharmaceutical). ResultsEmicizumab concentrations measured after neutralization were <1.6 μg/mL in all samples. FVIII levels were >480 IU/dL with an aPTT of <30.8 seconds in all samples before neutralization and were <1 IU/dL with an aPTT of >70 seconds after adding anti-emi. FVIII inhibitor resulted in a false negative result in 44 of 50 samples measured with the 1-stage assay before neutralization. A good correlation (r = 0.98) was found between inhibitor titer measured using the chromogenic (insensitive to emicizumab) and 1-stage assays after neutralization. ConclusionThe anti-emi antibodies were shown to completely neutralize emicizumab, making samples pretreated with anti-emi analyzable with the 1-stage assay.

Detection of glycocalyx degradation in real time: A conceptual model of thromboelastography

BackgroundThe endothelial glycocalyx is a critical component of the vascular barrier; its disruption after shock states may contribute to coagulopathy in a variety of conditions. Measurement of glycocalyx components in plasma have been used to index glycocalyx degradation but are not available as a point of care test. Heparanoids, such as heparan sulfate, may affect coagulation which may be detected by either thromboelastography or activated clotting time. MethodsEndothelial glycocalyx components syndecan-1 and heparan sulfate were added to blood samples at clinically relevant concentrations. Thromboelastography values included clot reaction time, clot amplification and fibrinogen values, and maximum clot strength (maximum amplitude, platelets). The heparinase thromboelastography cartridge was used to detect a heparin-like effect. The activated clotting time test was performed subsequently using the heparan sulfate blood samples to compare a standard coagulation test with thromboelastography clot reaction times. ResultsBoth thromboelastography clot reaction time (with comparison to heparinase) and activated clotting time were useful to detect effects of coagulation. Thromboelastography also detected platelet and fibrinogen abnormalities at higher heparan sulfate concentrations. Studies using thromboelastography or even activated clotting time may be useful to detect glycocalyx degradation after shock states and may guide clinical decision making. ConclusionThromboelastography and or activated clotting time may be useful to detect glycocalyx degradation as a point of care test in patients in the acute setting. Additionally, these assays may detect previous undisclosed coagulopathy due to glycocalyx degradation.

A-390 Implementation of the New GEM Hemochron 100 Point-of-care Coagulation System for Heparin Monitoring During Cardiopulmonary Bypass Procedures

Abstract Background The Ohio State University Wexner Medical Center has monitored the administration of unfractionated heparin (UFH) during cardiopulmonary bypass (CPB) procedures with the activated coagulation time test, using the Hemochron Signature Elite (Elite) instrument (Werfen) with the ACT+ cartridge. An assessment was conducted to evaluate the performance of the newest Hemochron model, the GEM Hemochron 100 (Werfen), to upgrade current instruments. Methods Precision and Methods Comparison studies were conducted with nine GEM Hemochron 100 systems. Each GEM Hemochron 100 instrument was analyzed with two levels of directCHECK liquid quality control, five replicates, over four days. The Method Comparison study compared the results from one Elite system's result, against the average result reported from one to three GEM Hemochron 100 systems. This methodology was repeated in multiple groups, using different Elite and GEM Hemochron 100 systems. All tests were performed with the ACT+ assay, which is sensitive to UFH from 1–6 IU/mL. Results Precision: All nine GEM Hemochron 100 instruments yielded: Level 1 CV ≤ 9.5%, and Level 2 CV ≤ 2.5%. Method Comparison: Total datasets 66; range 94–902 seconds; estimated bias at the 300, 420, and 480 second ACT+ clinical decision points were 1.6, 3.2, 4.1 seconds respectively; correlation (r) 0.97; slope 1.01; average CV across GEM Hemochron 100 systems 6.0%. Conclusion The performance of the new GEM Hemochron 100 system demonstrated acceptable agreement compared to the Elite system during CPB, maintaining existing ACT+ procedural target times. Results of system performance were consistent with the manufacturer's package insert, as well as previously published data. Based on the clinical performance, GEM Hemochron 100 systems have been implemented into our surgical suites.

Preparation of porous carbon spheres by templated self-assembly for rapid hemostasis

Porous carbon spheres (PCS) with different specific surface areas and porous structures were prepared by templated self-assembly method. The as-prepared PCS had uniform radically distributed channels, single cavity and dispersed dendritic pore structures respectively. The whole blood clotting time tests showed the good hemostatic properties of PCS, even better than Celox. It's probably the specific surface area made the difference over the hemostatic performance of PCS. The possible reason is that the higher specific surface area can increase the contact area between PCS and blood, promote blood coagulation rapidly. And the oxygen polar functional groups on the surface of PCS can rapidly stimulate platelets and red blood cells when in contact with blood. Both of the hemolysis rate and cell viability experiments proved that PCS had good biocompatibility. The hemostatic effect of PCS in vivo were preliminary validated on the mouse tail-cutting model and the rabbit liver injury model, and all PCS could efficiently control the caudal and hepatic hemorrhage. Especially, PCSF127 with a pore size of 3 nm and specific surface area of 335 m2 g−1 showed the best hemostatic efficiency, and it was expected to be an ideal candidate for rapid hemostasis in the battlefield or pre-hospital.

#4431 PREPARATION OF IMIDAZOLE QUATERNARY AMMONIUM SALT MICROSPHERES WITH HIGH BILIRUBIN ADSORPTION PERFORMANCE AND SELF-ANTICOAGULATION ABILITY

Abstract Background and Aims Bilirubin is a crucial toxin in liver metabolism. Increase of bilirubin is one of common manifestations in patients with abnormal liver function, and large accumulation of bilirubin in the blood can lead to more severe hepatic dysfunction and even death. Due to the poor therapy effect and the shortage of available donor organs, the artificial liver support system has been introduced to maintain the liver function and bridge patients to transplantation. Previous studies have found that imidazole quaternary ammonium salts have great potential to adsorb bilirubin. This work is to develop a novel bilirubin adsorption column by simple and general method, and evaluate the removal efficiency, anticoagulant property and biocompatibility of the bilirubin adsorption column. Method Multifunctional microspheres were fabricated by in situ co-polymerization of 1-vinylimidazole and divinylbenzene. Nuclear magnetic resonance (NMR), thermo-gravimetric analysis and X-ray photoelectron spectroscopy (XPS) etc. were performed to characterize the chemical compositions of the microspheres. Meanwhile, hemolysis test, blood routine test and clotting time test etc. were leveraged to evaluate the biocompatibility of the microspheres. Both static adsorption test and dynamic adsorption test were performed in vitro to evaluate adsorption performance. Results A variety of methods had proved successful synthesis of the adsorption performance. The hemolysis ratios of microspheres were less than 5%. Compared with BS330 microspheres and PES microspheres, the activated partial thromboplastin time (APTT) and thrombin time (TT) were longer in this work. Moreover, the microspheres showed a high adsorption clearance. In PBS solution of bilirubin, the adsorbent could decrease bilirubin from 200 mg/L to 45-55 mg/L. Conclusion The results suggested that the multifunctional microspheres can significantly reduce bilirubin concentration without obvious adverse interactions and could exhibit anticoagulation activity.

Unfractionated heparin and the activated clotting time in non-cardiac arterial procedures.

Unfractionated heparin is administered during non-cardiac arterial procedures (NCAP) to prevent thromboembolic complications. In order to achieve a safe level of anticoagulation, the effect of heparin can be measured. The aim of this review was to provide an overview on what is known about heparin, suggested tests to monitor the effect of heparin, including the activated clotting time (ACT), and the factors that could influence that ACT. A literature search in PubMed was performed. Articles reporting on heparin, clotting time tests (including thrombin time, activated partial thromboplastin time, anti-activated factor X and ACT), and ACT measurement devices were selected. Heparin has a non-predictable effect in the individual patient, which could be measured using the ACT. However, ACT values can be influenced by many factors, such as hemodilution, hypothermia and thrombocytopenia. In addition, a high variation in ACT outcomes is found between measurement devices of different brands. In the sparse literature on the role of ACT during NCAP, no consensus has been reached on optimal target ACT values. An ACT >250 seconds leads to more bleeding complications. Females have a longer ACT after heparin administration, with a higher risk of bleeding complications. The effect of heparin is unpredictable. ACT can be used to monitor the effect of heparin and achieve individualized anticoagulation, tailored to the patient and the specifics of the operative procedure. However, the ACT itself can be affected by several factors and caution must be present, as measured ACT values differ between measurement devices.

Reference interval for the C-ACT activated clotting time test in healthy dogs using a water bath and manual assessment of clot formation

ABSTRACT Aims To establish a reference range for the canine C-ACT activated clotting time (ACT) test using a water bath and visual clot assessment technique. Methods Healthy, privately owned dogs (n = 48) were prospectively recruited to the study. Blood samples were collected via direct jugular venipuncture for complete blood count, serum biochemistry analysis and measurement of prothrombin time (PT) and activated partial thromboplastin time (aPTT). Five animals with major abnormalities or who became agitated during phlebotomy were excluded. For the 43 remaining animals, 2 mL of blood was collected via the cephalic vein and added directly to a C-ACT tube that was shaken vigorously before being placed in a water bath at 37°C. Tubes were visually assessed for clot formation and C-ACT was recorded in seconds when the magnet within the tube lodged in the clot. Results The nonparametric reference interval (capturing the central 95% of the data) was 50–80 seconds, with a 90% CI for the lower limit of 50–55 seconds and a 90% CI for the upper limit of 75–80 seconds. The C-ACT ACT test had a positive correlation with aPTT (0.42; 95% CI = 0.13–0.64). There was no evidence of a correlation between C-ACT ACT and age, weight, PT, haematocrit, white blood cell count, platelet count or total protein. Conclusions and clinical relevance The results of this study suggest that the normal reference interval for ACT in dogs using C-ACT tubes in a 37°C water bath is 50–80 seconds. Care should be taken extrapolating the results of this study to the general population, as the smaller study design had less control for confounders than a larger study. However, when using the described analytical methods, C-ACT tube ACT test results >80 seconds should be considered prolonged in dogs and should prompt further investigation. Abbreviations: ACT: Activated clotting time; aPTT: Activated partial thromboplastin time; EDTA: Ethylenediaminetetraacetic acid; Hct: Haematocrit; PT: Prothrombin time

The effects of medium cut-off and high-flux membranes on activated clotting time of patients on hemodialysis.

The interaction between blood and dialysis membrane increases the risk of clot formation. Membrane properties can interfere with coagulation activation during dialysis. Heparin is usually used to ensure anticoagulation, which can be monitored by the Activated Clotting Time (ACT) test. The purpose of this study was to compare the ACT of patients with chronic kidney disease (CKD) undergoing hemodialysis with high-flux (HF) and medium cut-off (MCO) membranes. This is a prospective, randomized, crossover study in which 32 CKD patients were dialyzed for 12 weeks with each membrane. Blood clotting measured by ACT was evaluated at the beginning, 2nd, and 4th hour of the dialysis session. Throughout the study, there were no changes in the dose or administration method of heparin. Patients mainly were middle-aged, non-black males on hemodialysis for eight years. Before randomization, ACT values were 132 ± 56, 195 ± 60, and 128 ± 32 seconds at pre-heparinization, 2nd and 4th hour, respectively. After 12 weeks, ACT values in HF and MCO groups were 129 ± 17, 205 ± 65 and 139 ± 38 seconds, and 143 ± 54, 219 ± 68 and 142 ± 45 seconds, respectively. An ANOVA model adjusted and unadjusted for repeated measures showed a significant time but no treatment or interaction effects. In an additional paired-sample analysis, no difference between ACT values of HF and MCO Groups was observed. There was no difference regarding the ACT test during dialysis therapy using HF or MCO membranes. This data suggests that no adjustment in the dose or administration method of heparin is necessary with the use of MCO dialysis membranes.

Gelatin/calcium chloride electrospun nanofibers for rapid hemostasis.

Blood coagulation is the body's main defense to bleeding caused by trauma and is divided into endogenous and exogenous pathways. Calcium ions play a very important role in the process of blood coagulation, as the ions activate the many enzymes that are required for coagulation. In this paper, gelatin hemostatic membranes containing calcium ions were prepared by electrospinning. The fibers were characterized with scanning electron microscopy, Fourier transform infrared spectroscopy, and X-ray diffraction. The biocompatibility and coagulation processes using the calcium ion-containing gelatin fibrous membranes were evaluated in vitro with dynamic whole-blood coagulation tests, hemolysis tests, coagulation time tests, and platelet adhesion tests. It was demonstrated that the calcium ion-containing gelatin membranes had lower hemolysis rates and shorter clotting times than commercially available hemostatic sponges and hemostatic gauzes. In vivo hemostasis experiments were also conducted on the tail vein and liver of mice. Animal experiments demonstrated that the incorporation of calcium ions into the electrospun gelatin membranes promoted platelet aggregation, ensured adhesion of the electrospun membrane to the wound and reduced the bleeding volume and hemostasis time. The composite calcium ion-gelatin electrospun membranes exhibited good in vivo and in vitro hemostatic abilities and accelerated blood clotting by stimulating the coagulation pathway to promote platelet aggregation at the wounds and the formation of mature blood clots for a new approach for acute trauma treatment.

Metal-organic framework (UiO-66 and UiO-66-NH2)-based adsorbents for bilirubin removal used in hemoperfusion.

Excessive accumulation of bilirubin in patients with hyperbilirubinemia can lead to tissue and organ damage and neurological diseases, and is even life-threatening in severe cases. Hemoperfusion is an effective method for removing bilirubin, but clinically used hemoperfusion adsorbents have unsatisfactory adsorption capacity and kinetics. In order to obtain a safe and efficient bilirubin adsorbent, Zr-based Metal-Organic Framework (MOF) material UiO-66 with high specific surface area and aqueous medium stability was prepared and modified with varying degrees of amination to improve its adsorption capacity. According to adsorption experiments in aqueous solution and simulated plasma, it was confirmed that the unsaturated coordinated zirconium in UiO-66 can effectively induce the aggregation and precipitation of free bilirubin unbound to albumin and the amino group on UiO-66-NH2 has a strong affinity for albumin bound bilirubin. The adsorption effect of UiO-66-NH2 with a high degree of amino modification is significantly stronger than that of UiO-66-NH2 with a low degree of modification. In simulated plasma with a bilirubin concentration of 40 mg dL-1, the adsorption capacities of UiO-66 and UiO-66-NH2-1.9 can reach 69.08 mg g-1 and 81.13 mg g-1. The adsorption isotherm fitting and adsorption kinetics fitting results also show that UiO-66 and UiO-66-NH2 are good adsorbents for bilirubin. In dynamic adsorption, the adsorbents also showed good performance and did not affect the protein in the plasma. The hemolysis test, coagulation time test, and cytotoxicity test confirmed that the bilirubin adsorbents based on UiO-66 and UiO-66-NH2 have good blood compatibility and biocompatibility. This study provides new ideas for the development of a novel bilirubin adsorbent and a theoretical basis for the study of bilirubin adsorption mechanisms.

In Vivo Coagulation Effects of Thymus vulgaris Leaves Extract in Mice

Background: In addition to current therapies, herbal medicine is still used as an effective method for the treatment of some diseases such as bleeding disorders. Thymus vulgaris has been employed as traditional remedy in the treatment of bleeding disorders, although its clinical effects have not been investigated yet. Accordingly, this study evaluated the effects of the T. vulgaris extract on coagulation parameters, including bleeding time (BT), clotting time (CT), prothrombin time (PT), activated partial thromboplastin time (aPTT), and the number of platelets (PLT). Methods: Forty male mice were randomly divided into 5 groups (n=8). The treated groups were administered with 100, 200, or 300 mg/kg/daily of the hydroalcoholic extract, as well as negative and positive control groups. Blood samples were taken from animals on the 13th and 14th day after treatment, and then coagulation indices were determined finally. Results: The results demonstrated a significant reduction in the BT and CT tests while a significant increase in PT, aPTT, and platelet numbers. Phenolic and flavonoid compounds in the hydro-alcoholic extract of T. vulgaris are the most affecting compounds confirmed by gas chromatography-mass spectrometry and phytochemical experiments. Conclusion: In general, the results indicated the coagulation effect of the T. vulgaris extract through primary homeostasis and a common pathway of secondary hemostasis.

Binding of Gamma-Glutamyl Transferase to TLR4 Signalling Allows Tissue Factor Activation in Monocytes.

Gamma-glutamyl transferase (GGT) is involved in the progression of atherosclerosis, since its enzymatic activity promotes the generation of reactive oxygen species (ROS). Besides, GGT may act as a prothrombotic factor by inducing tissue factor (TF) expression, independently of its enzymatic activity. The aim of this study was to assess whether GGT-induced TF stimulation was a consequence of binding to toll-like receptor 4 (TLR4) expressed on monocytes, the precursors of macrophages and foam cells which colocalize with GGT activity within atherosclerotic plaques. Experiments were performed in human peripheral blood mononuclear cells (PBMCs), THP-1 cells (a monocytic cellular model), and HEK293 cells, which were genetically modified to study the activation of TLR4. TF procoagulant activity was assessed by a one-stage clotting time test, and TF protein expression was estimated by western blot. Human recombinant (hr) GGT protein increased TF procoagulant activity and protein expression in both PBMCs and THP-1 cells. The GGT-induced TF stimulation was prevented by cellular pretreatment with TLR4/NF-κB inhibitors (LPS-Rs, CLI-095, and BAY-11-7082), and HEK293 cells lacking TLR4 confirmed that TLR4 is essential for GGT-induced activation of NF-κB. In conclusion, hrGGT induced TF expression in monocytes through a cytokine-like mechanism that involved the activation of TLR4/NF-κB signaling.

Magnetic Nanosorbents for Adsorption of Blood Mercury

AbstractMercury enters the human body through the food chain and various ways and exists in blood, kidney and other organs, which will cause great harm. Therefore, it is important to design a safe and effective mercury remover for the removal of blood mercury. In this work, we modified a layer of amino‐rich hyperbranched polyamide nanomaterials (HPN) on the surface of Fe3O4 nanoparticles (Fe/HPN‐NH2 NPs). Among them, tetraethylenepentamine was crosslinked with hyperbranched polyamide by methyl acrylate, which effectively increased the number of amino functional groups in the material. The morphology, structural characteristics and composition of Fe/HPN‐NH2 NPs were characterized. The results of adsorption experiments showed that Fe/HPN‐NH2 NPs had good adsorption ability for inorganic mercury and methylmercury in water. Series of in vitro biocompatibility evaluation tests such as coagulation time tests, erythrocyte morphology observation, blood routine test, complement activation and immune factor test at the molecular level showed that the synthesized Fe/HPN‐NH2 NPs had good biocompatibility. When the initial concentration of lead was 1 ppm and the concentration of adsorbent was 10 mg/mL, the removal efficiency of blood mercury can reach up to 65 % without changing the amount of other commonly existing ions. This blood mercury removal strategy provides the possibility for blood purification.

Anticoagulation Strategies in Pediatric Cardiopulmonary Bypass, Weight-Based vs. Concentration-Based Approaches

Pediatric patients undergoing cardiopulmonary bypass (CPB) require adequate anticoagulation to combat hemostatic activation. Heparin is used to bind and catalyze antithrombin III (ATIII) that works to inhibit clot formation. To dose heparin, a weight-based (WB) or patient-specific concentration-based (PSCB) method can be used. The WB protocol calculates the dose based on the patients’ weight and uses an activated clotting time (ACT) test to ensure anticoagulation. The ACT has limitations during CPB especially for pediatric patients who have immature hemostatic systems. The PSCB method predicts the patients’ response to heparin by projecting a heparin dose–response (HDR) curve. Some investigators have found benefit to using the PSCB method but further investigation into how well the HDR predicts the heparin response is needed. A literature review was conducted for studies that looked at heparin management strategies in pediatric CPB patients between 1992 and 2020. Articles that focused on pediatric physiology, heparin management strategies, and anticoagulation were included. Articles older than 1990 were excluded. The literature review highlights that utilizing the PSCB approach more adequately anticoagulated patients. The WB protocol was found to have several flaws due to its reliance on the ACT, especially in infants. The results show that further investigation is needed to understand why there is benefit to using the PSCB approach. Observing the association between the HDR curve and subsequent heparin concentrations could determine how accurately it predicts the patients’ response to heparin and why there is benefit to using this method.

Anticoagulation Strategies in Pediatric Cardiopulmonary Bypass, Weight-Based vs. Concentration-Based Approaches.

Pediatric patients undergoing cardiopulmonary bypass (CPB) require adequate anticoagulation to combat hemostatic activation. Heparin is used to bind and catalyze antithrombin III (ATIII) that works to inhibit clot formation. To dose heparin, a weight-based (WB) or patient-specific concentration-based (PSCB) method can be used. The WB protocol calculates the dose based on the patients' weight and uses an activated clotting time (ACT) test to ensure anticoagulation. The ACT has limitations during CPB especially for pediatric patients who have immature hemostatic systems. The PSCB method predicts the patients' response to heparin by projecting a heparin dose-response (HDR) curve. Some investigators have found benefit to using the PSCB method but further investigation into how well the HDR predicts the heparin response is needed. A literature review was conducted for studies that looked at heparin management strategies in pediatric CPB patients between 1992 and 2020. Articles that focused on pediatric physiology, heparin management strategies, and anticoagulation were included. Articles older than 1990 were excluded. The literature review highlights that utilizing the PSCB approach more adequately anticoagulated patients. The WB protocol was found to have several flaws due to its reliance on the ACT, especially in infants. The results show that further investigation is needed to understand why there is benefit to using the PSCB approach. Observing the association between the HDR curve and subsequent heparin concentrations could determine how accurately it predicts the patients' response to heparin and why there is benefit to using this method.

Detecting Alterations in Fractal Fibrin Patterns using Light Microscopy

Fibrin is produced from the polymerization of fibrinogen at the completion of the coagulation cascade. Alterations in the structure and pattern of fibrin in plasma clots have been associated with various disease states such as pulmonary embolism, myocardial infarction, and hemophilia. Assessing these structural changes often requires confocal microscopy with fluorescently labeled fibrinogen or electron microscopy. Here, we demonstrate a novel method whereby pathophysiological alterations in fibrin patterns can be detected using light microscopy. Images of plasma clots from the partial thromboplastin time test were analyzed for alterations in fractal patterns using The Workflow of Matrix Biology Informatics. Factor VIII and Factor IX deficiencies showed significant changes in lacunarity, branchpoints, and total pattern area. We also detected significant changes in fibrin patterns altered by hyperglycemia, a known risk factor for thrombosis and embolisms. This work has direct clinical relevance as it utilizes readily available technology that can be applied in the clinical laboratory to screen patient samples for fibrin alterations when clotting time tests are prolonged. This diagnostic information could be utilized in the identification of various diseases that affect blood clot formation.

Evaluation Of The Anticoagulant Effect Of Phenolic Extracts Of Two Olive Mill By-products: Olive Mill Wastewater And Olive Mill Pomace

In the Mediterranean basin, olive oil production represents an important economic sector for some countries. Currently, production is constantly growing and is done at the expense of the environment. In addition to its main product, which is virgin olive oil, it generates two by-products, olive mill pomace (OMP) and olive mill wastewater (OMW). These by-products have heretofore little economic value despite their large constitutions of polyphenols that are of great importance in the pharmaceutical industry. This study aimed to assess the anticoagulant effect of the phenolic extract of OMP and OMW from cold extraction in the region of Khenchela, northeastern Algeria. This activity was chosen for its essential role in the prevention and treatment of cardiovascular diseases and their serious complications, which threaten public health and constitute the leading cause of death worldwide. The extraction of the polyphenols was done by the maceration method. The content of total polyphenols was estimated by the Folin-Ciocalteu method. The amount of flavonoids was determined by the aluminum chloride method. The anticoagulant activity of the polyphenols was evaluated in vitro using the Kaolin-cephalin coagulation time (KCT) and prothrombin time (PT) tests. The coagulation times obtained in normal plasma in the presence of these polyphenols indicated that they exert a great anticoagulant activity. It was very highly significant on both endogenous and exogenous coagulation pathways for OMW extracts and significant for OMP extracts. This activity was observed more for the endogenous pathway of coagulation than the exogenous pathway. In conclusion, the polyphenols of olive oil pomace and olive mill wastewater can be used in the pharmaceutical field as an anticoagulant against the complications of thrombotic diseases.