Search Results (91)

Bothrops species are responsible for the majority of envenomations in Argentina. In particular, Bothrops diporus is among the main species responsible for the majority of envenomations in Argentina and causes significant injury and coagulopathy. Given the significance of this venom, the authors sought to define the toxin responsible for coagulopathy with specialized spectrophotometric and thromboelastographic methods. Utilizing clotting time, spectrophotometry, and thromboelastography, it was determined that B. diporus venom has potent, procoagulant activity in human plasma and buffer milieu. Calcium-dependent and -independent activities consistent with serine protease activity were identified. The activity included both thrombin-generating and thrombin-like enzymatic activity. The venom cleaved the serine protease-specific chromogenic substrate β-Ala-Gly-Arg-p-nitroanilide diacetate, and its activity was inhibited in plasma by antithrombin after addition of heparin. Further, venom exposed in isolation to RuCl₃, a known inhibitor of serine protease-containing venoms, demonstrated decreased activity in human plasma. In conclusion, the present study contributes to a better understanding of B. diporus venom and may have implications for the rational design of inhibitors, antivenom formulations, or preclinical models to study venom-induced coagulopathies. Full article

During pregnancy, the maternal hemostatic system undergoes significant changes to support placental angiogenesis, maintain fetal blood flow, and ensure safe delivery. This study investigates the dysregulation of hemostasis in placental insufficiency and explores potential markers for diagnosing and managing this gestational complication. Thromboelastography, coagulation and fibrinolysis functional assays, ELISA, and immunoblotting were employed to assess hemostasis dysregulation in placental dysfunction of two cohorts of pregnant women with placental dysfunction and healthy controls. Thromboelastographic analysis revealed no significant differences in clot lysis indices between the control and placental dysfunction groups, with values remaining within normal ranges, suggesting this method’s limitations for assessing fibrinolysis in pregnancy. The placental dysfunction group demonstrated moderately increased fibrinogen levels and platelet sensitivity to ADP, indicating hemostasis reactiveness. Significantly lower D-dimer levels, decreased plasminogen activator inhibitor activity (total PAI-1 + PAI-2), and increased plasminogen activator activity, driven primarily by uPA in the placental dysfunction group, indicated abnormal fibrinolysis. Immunoblotting confirmed elevated uPA/uPA-PAI complexes and reduced tPA/tPA-PAI complexes, indicating that shutdown of tPA-mediated fibrinolysis and induction of uPA-driven vessel-wall-associated proteolysis are linked to placental dysfunction. Placental dysfunction involves fibrinolytic system dysregulation, marked by decreased PAI and tPA, uPA overproduction, and hypofibrinolysis, contributing to thrombotic risks, impaired placental flow, and complications like fetal growth retardation. PAI/PA ratio and D-dimer levels have diagnostic potential for placental-dysfunction-associated complications. Full article

Cardiac tumors are rare and linked to high mortality rates in both human and veterinary medicine. Despite their clinical significance, the effects of these tumors on coagulation and cardiac function remain poorly understood. This retrospective study assessed coagulation profiles and echocardiographic parameters in 14 dogs with cardiac tumors compared to 10 healthy controls. Tumors were identified through echocardiography, with further confirmation by computed tomography/magnetic resonance imaging. Coagulation was evaluated using conventional tests (prothrombin time (PT) and activated partial thromboplastin time (aPTT)) and thromboelastography (TEG). The employed conventional coagulation tests and echocardiographic parameters showed no significant differences between the groups. However, TEG revealed a hypercoagulable state in the majority of tumor-bearing dogs (8 out of 14), characterized by shortened reaction and clot formation times, as well as an increased α-angle and coagulation index (p < 0.05–0.001). No significant correlations were found between TEG parameters and echocardiographic indices. This study is the first to demonstrate subclinical hemostatic alterations using TEG in dogs with cardiac neoplasia. The results support the utility of TEG as a more sensitive tool than conventional tests for detecting hypercoagulability, potentially guiding individualized anticoagulant strategies in affected dogs. Full article

Background: Fibrinolytic impairment is one of the key factors involved in the pathogenesis of hemostasis disturbances in sepsis, significantly contributing to microthrombosis, organ dysfunction, and mortality rates. While hemostatic assessment in sepsis typically focuses on coagulation activation, evaluating fibrinolytic activity remains challenging due to methodological limitations and a lack of standardization of the currently available methods. Objectives: This comprehensive review examines current methods for assessing fibrinolytic activity in bacterial sepsis, their clinical applications, strengths and limitations, and future perspectives for improved diagnostic approaches. Methods: We conducted a systematic literature search and identified 52 studies that investigated fibrinolysis assessment in adult patients with bacterial sepsis using biomarkers or global tests. Studies included mainly observational cohorts examining various fibrinolytic assessment methods. Results: Fibrinolytic shutdown, primarily mediated by the overproduction of plasminogen activator inhibitor-1 (PAI-1), occurs early in sepsis and correlates with disease severity and mortality. Current assessment methods include plasma biomarker measurements (PAI-1, plasmin-antiplasmin complexes, D-dimer), global plasma-based tests (clot lysis time, plasmin generation assays), and whole-blood viscoelastic testing (rotational thromboelastometry, ROTEM; thromboelastography, TEG). Modified viscoelastic tests incorporating tissue plasminogen activators demonstrate enhanced sensitivity for detecting fibrinolytic resistance. Despite efforts, standardization is still limited, and routine clinical implementation has not been achieved yet. Conclusions: Fibrinolytic assessment provides important prognostic information in sepsis, despite methodological challenges. The integration of point-of-care viscoelastic testing with modified protocols shows promise for real-time evaluation. Future research should focus on developing standardized, automated assays suitable for routine clinical practice, enabling personalized therapeutic interventions that target fibrinolytic dysfunction in sepsis. Full article

Background/Objectives: In the last decade, several studies revealed individual response variability to different antiplatelet agents, and patients who have no response to these drugs are considered poor responders. Some studies explored platelet function during antiplatelet treatment to identify those patients with “high on-treatment platelet reactivity” (HPR), which exposes them to increased risk of major adverse cardiovascular events (MACE). Methods: We conducted a study with patients with ST-elevation myocardial infarction (STEMI) treated with dual antiplatelet therapy (DAPT) with ticagrelor and aspirin, including long-term follow-up after 5 years. We used thromboelastography, the total thrombus formation analysis system, and vasodilator-stimulated phosphoprotein phosphorylation assay (VASP) to analyze HPR with different methods; selected laboratory parameters were measured during hospitalization to check significant correlations. Results: We identified STEMI patients treated with DAPT with HPR as a risk group for MACE in a 5-year follow-up. Additionally, we have shown that HPR is associated with atherosclerosis by analyzing lipid profile parameters. Conclusions: High on-treatment platelet reactivity (HPR) increases the risk of major adverse cardiovascular events in the long term, especially with elevated C-reactive protein or an atherogenic lipid profile. Standardizing HPR assessment is crucial for optimizing individualized antiplatelet therapy and improving patient outcomes post-STEMI. Full article

Australian elapid snakes possess potent procoagulant venoms, capable of inducing severe venom-induced consumption coagulopathy (VICC) in snakebite victims through rapid activation of the coagulation cascade by converting the FVII and prothrombin zymogens into their active forms. These venoms fall into two mechanistic categories: FXa-only venoms, which hijack host factor Va, and FXa:FVa venoms, containing a complete venom-derived prothrombinase complex. While previous studies have largely focused on human plasma, the ecological and evolutionary drivers behind prey-selective venom efficacy remain understudied. Here, thromboelastography was employed to comparatively evaluate venom coagulotoxicity across prey classes (amphibian, avian, rodent) and human plasma, using a taxonomically diverse selection of Australian snakes. The amphibian-specialist species Pseudechis porphyriacus (Red-Bellied Black Snake) exhibited significantly slower effects on rodent plasma, suggesting evolutionary refinement towards ectothermic prey. In contrast, venoms from dietary generalists retained broad efficacy across all prey types. Intriguingly, notable divergence was observed within Pseudonaja textilis (Eastern Brown Snake): Queensland populations of this species, and all other Pseudonaja (brown snake) species, formed rapid but weak clots in prey and human plasma. However, the South Australian populations of P. textilis produced strong, stable clots across prey plasmas and in human plasma. This is a trait shared with Oxyuranus species (taipans) and therefore represents an evolutionary reversion towards the prothrombinase phenotype present in the Oxyuranus and Pseudonaja last common ancestor. Clinically, this distinction has implications for the pathophysiology of human envenomation, potentially influencing clinical progression, including variations in clinical coagulopathy tests, and antivenom effectiveness. Thus, this study provides critical insight into the ecological selection pressures shaping venom function, highlights intraspecific venom variation linked to geographic and phylogenetic divergence, and underscores the importance of prey-focused research for both evolutionary toxinology and improved clinical management of snakebite. Full article

Background/Objectives: Platelet activity contributes to myocardial infarction; inadequate inhibition is a risk factor for stent thrombosis and mortality. Inadequate platelet inhibition during treatment is an important risk factor for stent thrombosis and may be associated with increased mortality. This study assessed platelet and coagulation activity in post-MI patients, identifying parameters associated with adverse ST-elevation myocardial infarction (STEMI) outcomes over 3 years, to identify patients needing intensive secondary prevention. Methods: From 57 admitted patients, 19 STEMI patients were analyzed. Thromboelastography (TEG) and Total Thrombus Formation Analysis System (T-TAS) were used to assess hemostasis and coagulation. Selected laboratory parameters were measured for correlations. Major adverse cardiovascular events (MACEs) were defined as ischemic stroke, myocardial infarction, ischemic heart disease, thrombosis, and death from cardiovascular causes. Results: The group with MACEs was characterized by a faster time to initial clot formation and greater reflection of clot strength. T-TAS parameters, such as area under the curve at 10 min (T-TAS AUC10), showed lower values in the same group of patients. A moderate positive correlation suggested that as white blood cell count increases, T-TAS AUC10 values also tend to increase. A strong negative correlation (rho = −1.000, p < 0.01) was observed between low-density lipoprotein and kinetics in the TEG using the kaolin test at baseline in patients with MACEs. Conclusions: Some of the parameters suggest they are associated with adverse outcomes of STEMI, indicate the existence of an inflammatory state, and may contribute to risk stratification of STEMI patients and identify who will require ongoing monitoring. Full article

Patient blood management (PBM) is a multidisciplinary approach aimed at improving patient outcomes through targeted anemia treatment that minimizes allogeneic blood transfusions, employs blood conservation techniques, and avoids inappropriate use of blood product transfusions. Viscoelastic testing (VET) techniques, such as thromboelastography (TEG) and rotational thromboelastometry (ROTEM), have led to significant advancements in PBM. These techniques offer real-time whole-blood assessment of hemostatic function. This provides the clinician with a more complete hemostasis perspective compared to that provided by conventional coagulation tests (CCTs), such as the prothrombin time (PT) and the activated partial thromboplastin time (aPTT), which only assess plasma-based coagulation. VET does this by mapping the complex processes of clot formation, stability, and breakdown (i.e., fibrinolysis). As a result of real-time whole-blood coagulation assessment during hemorrhage, hemostasis can be achieved through targeted transfusion therapy. This approach helps fulfill an objective of PBM by helping to reduce unnecessary transfusions. However, challenges remain that limit broader adoption of VET, particularly in hospital settings. Of these, standardization and the high cost of the devices are those that are faced the most. This discussion highlights the potential of VET application in PBM to guide blood-clotting therapies and improve outcomes in patients with coagulopathies from various causes that result in hemorrhage. Another aim of this discussion is to highlight the limitations of implementing these technologies so that appropriate measures can be taken toward their wider integration into clinical use. Full article

A series of new isatin hydrazones bearing phosphorus-containing moiety was synthesized through a simple, high-yield and easy work-up reaction of phosphine oxide (Phosenazide) or phosphinate (2-chloroethyl (4-(dimethylamino)phenyl)(2-hydrazinyl-2-oxoethyl)phosphinate, CAPAH) hydrazides with aryl-substituted isatins. The ³¹P NMR technique showed that, in most cases, out of 12 examples in solution, the ratio of the two spatial isomers varied from 1:1 to 1:3. Quantum chemical calculations confirmed the predominance of Z,syn form both in the gas phase and in solution. According to X-ray analysis data in crystals, they exist only in Z,syn form too. Most of the phosphine oxide derivatives and 5-methoxy- and 5-bromoaryl phosphinate analogs exhibit anti-aggregant activity at the level of acetylsalicylic acid but inhibit platelet activation processes more effectively. The 5-chloro type phosphinate derivative exhibits anti-aggregant properties more effectively than acetylsalicylic acid under the conditions of the tissue factor (TF)-activated thromboelastography (TEG) model, the ex vivo thrombosis model. Thus, all the obtained results can become the basis for future pharmaceutical developments to create effective anti-aggregation drugs with broad antithrombotic potential. Full article

During pregnancy and the peripartum period in women, hypofibrinolysis and hypercoagulation minimize excessive hemorrhage risk during parturition. While hypercoagulation is documented in peripartum mares, hypofibrinolysis is not. This study aimed to characterize and compare the fibrinolytic potential of healthy, non-pregnant mares and peripartum mares using tissue-factor (TF)-activated, tissue-plasminogen-activator (tPA)-modified thromboelastography (TEG). TF-activated TEG modified with tPA (500 and 650 U/mL) was performed on plasma samples from 9 pregnant mares at 3, 2, and 1 month pre-partum and 1, 7, and 30 days post-partum, as well as on time-matched samples from 6 non-pregnant mares. At both tPA concentrations, there were relative increases in clot strength [MA] and changes in lysis parameters consistent with hypofibrinolysis (increased CL30 and decreased Ly30) in the pregnant mares compared to the non-pregnant mares. The differences were most frequently detected 1 month pre-partum and at 1 and 7 days post-partum, providing preliminary evidence suggesting pregnant mares are hypofibrinolytic during late gestation and the early post-partum period. However, our small sample size, the unexpected changes in fibrinolysis in the non-pregnant mares over time, and the inconsistent performance of the assay indicate a need for a larger study after further assay optimization to confirm the results. Further investigations of the tPA-modified TEG assay and fibrinolysis in clinical cases are warranted. Full article

Ortho-R (ChitogenX Inc., Kirkland, QC, Canada) is a lyophilized chitosan formulation that also contains calcium chloride and trehalose. Ortho-R was designed to be solubilized in autologous platelet-rich plasma (PRP), a blood-derived component, in order to become an injectable implant that augments the surgical repair of soft tissues. The Ortho-R/PRP formulation coagulates post-application, similarly to blood. Having the ability to predict the speed of coagulation of an Ortho-R/PRP mixture prepared with PRP isolated from a specific patient would be an advantage in the operating room. The purpose of this study was to investigate whether human donor characteristics (age, sex, body mass index, habits) and autologous PRP properties would have an impact on Ortho-R/PRP mixture coagulation. Clot maximal amplitude and shear elastic modulus were significantly positively correlated with body mass index and platelet concentration in the isolated PRPs. Clot formation time, maximal amplitude and shear elastic modulus were all negatively correlated with PRP red blood cell concentration (and associated hemoglobin and hematocrit content). Donor characteristics were not good predictors of coagulation kinetics in Ortho-R/PRP mixtures. Some of the isolated PRP properties were better predictors of Ortho-R/PRP coagulation kinetics. However, predicting how an Ortho-R/PRP mixture from a particular patient will coagulate is very difficult since all PRP isolation devices yield heterogeneous PRPs and analysis of the isolated PRPs occurs post-administration. Full article

Background: Thromboelastography-6s (TEG^®6s), a novel device developed to assess coagulation status, presents advantages such as less frequent calibration, ease of use, and greater stability against movements compared to the previous system (TEG5000). This is the first study in the literature to compare coagulation profiles in the early postoperative period of liver resection (LR) using conventional coagulation tests (CCTs) and TEG^®6s. Methods: Forty-six adult patients admitted to the ICU post-surgery after elective LR for malignancy were included. CCTs were used to classify patients into hypocoagulable (HCG) (platelet count < 80 × 10⁹/L, international normalized ratio ≥ 1.4, or activated partial thromboplastin time > 38 s) and normocoagulable (all other cases) groups. Mann–Whitney tests, Spearman’s correlation, and linear regression were used. Results: On ICU admission, nineteen (41.3%) patients had a hypocoagulable profile based on CCTs, but only two (10.5%) of them were rated as hypocoagulable by TEG (p = 0.165). Intraoperatively, HCG patients experienced higher estimated blood loss (EBL) (p = 0.002); they required more fluids (p = 0.019), and more of them received red blood cell transfusions (p = 0.025). They also had higher postoperative arterial lactate levels (p = 0.036). Postoperative 12 h EBL was similar in the two groups (around 150 mL). The ICU stay was longer for HCG group (p = 0.010). Weak associations were observed between TEG/CCTs measures of coagulation initiation [e.g., between R time citrated rapid TEG, and international normalized ratio (r² = 0.448; p < 0.001)], clot formation [i.e., between conventional fibrinogen value using Clauss method and α-angle citrated rapid TEG (r² = 0.542; p < 0.001)], and clot strength [e.g., between conventional fibrinogen and citrated kaolin maximum amplitude (r² = 0.484; p < 0.001)]. Conclusions: CCTs revealed hypocoagulability that was not confirmed by TEG^®6s. However, the thromboelastography coagulation profile was more consistent with the detected non-relevant postoperative bleeding. Full article

Background and Objectives: Serotonin modulates platelet aggregation and secretion, but its role in hemostasis remains controversial. This study hypothesized that the 5-HT₃ receptor antagonist palonosetron may inhibit platelet function and aimed to evaluate its effects on blood coagulation using thromboelastography (TEG). Materials and Methods: Blood samples from 11 healthy volunteers were treated with palonosetron at concentrations of 25, 250, and 2500 ng/mL. Untreated samples served as controls. Coagulation parameters were assessed using global hemostasis (citrated kaolin, citrated rapid TEG, citrated kaolin with heparinase, and citrated functional fibrinogen) and PlateletMapping (adenosine diphosphate [ADP], arachidonic acid, and others) assays. Results: In the global hemostasis assay, maximum amplitude values, reflecting clot strength, decreased with increasing palonosetron concentrations in all tests, including citrated kaolin (p = 0.031), citrated rapid TEG (p = 0.001), citrated kaolin with heparinase (p = 0.033), and citrated functional fibrinogen (p = 0.011). The PlateletMapping assay showed significant reductions in ADP-induced platelet aggregation (p = 0.001), with the largest inhibition observed at 2500 ng/mL (p = 0.007). Despite these changes, all values remained within normal reference ranges. Conclusions: Palonosetron induces hypocoagulable trends in vitro by inhibiting platelet function and fibrinogen-mediated clot strength. However, these changes are unlikely to result in clinically significant hemostatic impairment when used within therapeutic doses. Further research is warranted to confirm these findings and explore their clinical relevance. Full article

The Philippines has a high diversity of venomous snake species, but there is minimal information on their envenomation effects. This is evidenced by the small number of case reports, the poor reporting of envenomation cases, and the absence of specific antivenoms apart from one against the Philippine cobra (Naja philippinensis). This study sought to profile the action of selected Philippine pit viper venoms on blood coagulation and to investigate whether commercially available non-specific antivenoms can provide adequate protection against these venoms. Venom from the pit vipers Trimeresurus flavomaculatus and Trimeresurus mcgregori were subjected to coagulation assays, antivenom cross-neutralization tests, and thromboelastography. Venoms from both species were able to clot human plasma and isolated human fibrinogen. Consistent with pseudo-procoagulant/thrombin-like activity, the resulting fibrin clots were weak and transient, thereby contributing to net anticoagulation through the depletion of fibrinogen levels. Clotting factors fIXa and fXa were also inhibited by the venoms, further contributing to the net anticoagulant activity. Monovalent and polyvalent antivenoms from the Thai Red Cross Society were effective against both venoms, indicating cross-neutralization of venom toxins; the polyvalent antivenom was able to rescue fibrinogen clotting to a greater degree than the monovalent antivenom. Our findings highlight the coagulopathic effects of these pit viper venoms and suggest the utility of procuring the non-specific antivenoms for areas in the Philippines with a high risk for pit viper envenomation. Full article

Blood coagulation tests are crucial in the clinical management of cardiovascular diseases and preoperative diagnostics. However, the widespread adoption of existing detection devices, such as thromboelastography (TEG) instruments, is hindered by their bulky size, prohibitive cost, and lengthy detection times. In contrast, magnetoelastic sensors, known for their low cost and rapid response, have garnered attention for their potential application in various coagulation tests. These sensors function by detecting resonant frequency shifts in response to changes in blood viscosity during coagulation. Nevertheless, the frequency-based detection approach necessitates continuous and precise frequency scanning, imposing stringent demands on equipment design, processing, and analytical techniques. In contrast, amplitude-based detection methods offer superior applicability in many sensing scenarios. This paper presents a comprehensive study on signal acquisition from magnetoelastic sensors. We elucidate the mathematical relationship between the resonant amplitude of the response signal and liquid viscosity, propose a quantitative viscosity measurement method based on the maximum amplitude of the signal, and construct a corresponding sensing device. The proposed method was validated using glycerol solutions, demonstrating a sensitivity of 13.83 V⁻¹/Pa^0.5s^0.5Kg^0.5m^−1.5 and a detection limit of 0.0817 Pa^0.5s^0.5Kg^0.5m^−1.5. When applied to real-time monitoring of the coagulation process, the resulting coagulation curves and maximum amplitude (MA) parameters exhibited excellent consistency with standard TEG results (R² values of 0.9552 and 0.9615, respectively). Additionally, other TEG parameters, such as R-time, K-time, and α-angle, were successfully obtained, effectively reflecting viscosity changes during blood coagulation. Full article