Search Results (316)

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

Coagulation testing is commonly used in the intensive care unit (ICU) to monitor and manage the hemostatic balance, assess bleeding risk, and guide anticoagulant therapy. Routine tests used for this purpose include prothrombin time, activated partial thromboplastin time, fibrinogen, and anti-Xa assays. Some of the drugs commonly used in critically ill patients may influence coagulation assays by interacting in vitro with reagents or in vivo with coagulation pathways, thus altering the coagulation cascade and the fibrinolytic pathway. While the pharmacological effects of drugs on coagulation are usually documented, to our knowledge, no comprehensive review article has been published to date. In this review, we have conducted a critical analysis of the literature to define: (1) the impact of hydroxocobalamin, intravenous lipid emulsion, and propofol on chromogenic assays; (2) the impact of PEGylated compounds, emicizumab, recombinant activated factor VII, antibiotics, and sugammadex on chronometric assays; (3) the challenges associated with bridging anticoagulation in the ICU as well as the effect of N-acetylcystein, serotonin reuptake inhibitors, and tramadol on the hemostasis system. For each drug, we specify the routine coagulation assay that is impacted, whether this is linked to an in vitro interference or an in vivo effect, and the potential consequences on patient management. 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

Cardiovascular diseases, including thrombosis, are the leading cause of mortality worldwide. The generation of monoclonal antibodies (mAb) targeting specific coagulation factors could provide more targeted and safer anticoagulant therapies. Factor V (FV) is a critical cofactor in the prothrombinase complex, which catalyzes the conversion of prothrombin to thrombin, a key enzyme in the coagulation cascade. We isolated a novel human antibody specific to FV by using phage display technology. The selection occurred by panning a large repertoire of phages expressing human antibody fragments (scFv) in parallel on the purified recombinant protein in its native form (FV) or activated by proteolytic maturation (Factor Va (FVa)). Through ELISA screening, we identified the clone with the highest binding affinity for both targets, and it was successfully converted into IgG1. The novel human mAb, called D9, was found capable of binding to Factor V with a low nM affinity both by ELISA and BLI assays, whereas its cross-reactivity with some other coagulation factors was found null or very poor. Furthermore, when tested in blood clotting tests, it was found able to prolong activated partial thromboplastin time (aPTT). Thus, D9 could become not only a potential therapeutic agent as a specific anticoagulant but also a precious tool for diagnostic and research applications. Full article

Sericin has been characterized as demonstrating a variety of bioactivities, establishing it as a valuable resource for biomedical and pharmaceutical applications. The diverse biological activities of sericin are likely linked to its unique biochemical composition and properties. This study aimed to assess the effect of origin, seasonality, and amino acid composition on the bioactivity of sericin samples from two Portuguese regions compared to commercial sericin. The amino acid profile was analyzed using HPLC-FLD. Moreover, several bioactivities were assessed through in vitro assays, including antiproliferative effects, cell migration, antimicrobial activity, anticoagulant properties, antioxidant capacity, and anti-inflammatory effects. The results obtained in this work revealed that the origin and season affect the sericin amino acid profile. In its pure state, sericin exhibited a low content of free amino acids, with tyrosine being the most abundant (53.42–84.99%). In contrast, hydrolyzed sericin displayed a higher amino acid content dominated by serine (54.05–59.48%). Regarding bioactivities, the sericin tested did not demonstrate antioxidant or anti-inflammatory potential in the conducted tests. Notwithstanding, it showed antiproliferative activity in contact with human tumor cell lines at a minimum concentration of 0.52 mg/mL. Regarding antimicrobial activity, sericin had the capacity to inhibit the growth of the bacteria and fungi tested at concentrations between 5 and 10 mg/mL. Additionally, sericin demonstrated its capacity to prolong the coagulation time in pooled human plasma, indicating a potential anticoagulant activity. In addition, the origin and season also revealed their impact on biological activities, and sericin collected in Bragança in 2021 (S3) and 2022 (S4) demonstrated higher antiproliferative, antibacterial, and anticoagulant potentials. Future studies should focus on optimizing sericin’s bioactivities and elucidating its molecular mechanisms for clinical and therapeutic applications. Full article

Obesity is a risk factor for thrombosis-related diseases and a condition that leads to vitamin D deficiency. Furthermore, orthopedic conditions are also at risk for diseases associated with coagulation and endothelial function. This study aimed to assess whether vitamin D supplementation in patients with acute (AOCs) and chronic orthopedic conditions (COCs) and coexisting obesity could affect coagulation and endothelial function. Thirty-three obese individuals with AOCs or COCs were included in the study. Patients were supplemented with vitamin D at 4000 IU/day for 3 months. An enzyme-linked immunosorbent assay (ELISA) was used to measure the concentrations of alpha 2-antiplasmin (α2AP), vascular cell adhesion molecule 1 (VCAM-1), plasminogen activator inhibitor-1 (PAI-1), tissue factor pathway inhibitor (TFPI), and vitamin D, which were examined at two time points—before and after supplementation. Regardless of the increase in serum vitamin D levels in both groups after supplementation, there was a statistically significant increase in VCAM-1 and PAI-1 levels in the group with AOCs, whereas only VCAM-1 increased statistically significantly in the second group. For obese patients with COCs, vitamin D does not appear to have a potentially beneficial effect on coagulation and the endothelium. Full article

Transport by unmanned aerial systems (UASs) (e.g., drones) could save time and personnel. Our study aimed to assess the effect of drone transportation on the clinical laboratory results of biological samples by examining its impact on pre-analytical and analytical processes. We performed a cross-sectional study of healthy volunteers from Sha’ar Menashe Mental Health Center between July and November 2022. Blood and urine samples were transferred to the central laboratory at Hillel Yaffe Medical Center. Overall, 40 healthcare workers aged 21–67 years (57.5% females) with a mean age of 45.8 (SD = 11.3) years from Sha’ar Menashe Mental Health Center were recruited in the study. There were no significant differences between transportation modes in the complete blood count levels. We found a significant difference between the transportation modes for GGT (p = 0.01) and PT (p = 0.04), despite the very similar mean results of these tests. In Bland–Altman plots, GGT and PT samples fell within the 95% limits of agreement and were indicated as not clinically relevant; however, glucose and LDH did not meet the 95% acceptance criterion and showed a potential clinical effect. There was full agreement between the two types of transportation for urine glucose, nitrites, and urine cultures. UAS transport is an appropriate method for maintaining the quality of most routine clinical laboratory specimens, similar to the routine procedure of using a vehicle. For the 34 biochemistry, hematology, and coagulation assay parameters, only glucose and LDH did not meet the 95% acceptance criterion and showed a potential clinical effect. Full article

Background: Patients with cancer often develop a prothrombotic state that can evolve into venous and arterial thrombosis, which is associated with poor clinical outcomes. Glioblastoma multiforme (GBM) is the most frequently associated with thrombosis, but the underlying causes of this prothrombotic state are poorly defined. Objectives: We designed a study to characterize the expression of coagulation factor X (FX) and its alternatively spliced transcripts in glioblastoma tissues surgically removed from patients and in clonal cell lines. Methods: The F10 mRNA and FX protein were quantified in tissues surgically removed from seven patients with glioblastoma (glioma grade 3–4) and those from non-tumor patients. Glioblastoma cells from three human clonal lines were examined for the expression and secretion of FX at baseline and after the cells were stimulated with lipopolysaccharide (LPS) or subjected to oxygen/glucose starvation in culture. PCR products were subjected to Sanger sequencing and amplicon sequencing to identify F10 isoforms and their ratios. A chromogenic assay was performed to assess FX activity. Results: Glioblastoma tissue and cell lines expressed high levels of the full-length and an alternatively spliced F10 mRNA. The latter produced a C-terminal truncated FX. The ratio of full-length to truncated F10 transcripts was significantly higher in normal brain tissues than in glioblastoma tissue. In cultured cells from the glioblastoma cell lines, FX was secreted to the conditioned medium and was active in cleaving a chemical substrate. The FX expression and secretion were upregulated in cells stimulated with LPS or subjected to oxygen/glucose starvation. Discussion: Glioblastoma cells synthesize and secrete FX that was active in promoting thrombin generation. These findings provide a new underlying mechanism to explain why glioblastoma patients are prone to developing thrombosis. Full article

Xylans, polysaccharides abundantly derived from agricultural byproducts, have shown potential pharmacological properties, making them a subject of increasing research interest. This study aimed to expand the understanding of xylans’ pharmacological properties and relate them to their composition. A method combining ultrasound and alkaline media for xylan extraction from corn cobs (ERX) was used, resulting in a significant increase in final yield compared to other methodologies. The physicochemical characterization of ERX was carried out, and its antioxidant, cytotoxic, anticoagulant, and immunomodulatory properties were evaluated. ERX demonstrated significant antioxidant activity with metal-chelating properties and induced apoptosis in HeLa tumor cells (p < 0.0001). It also reduced nitric oxide (NO) production by activated macrophages and extended the blood coagulation time, as assessed by the APTT assay (p < 0.0001). Further fractionation of ERX using various organic solvents resulted in multiple xylan subfractions. Among them, the ethanol-derived subfraction E1.4 exhibited remarkable pharmacological activities, including metal-chelation, cytotoxicity against HeLa cells via apoptosis, reduced NO production (p < 0.0001), and prolonged coagulation times (p < 0.0001). E1.4 is heteroxylan with a molecular weight of approximately 100 kDa. These findings suggest that corn cobs could be a promising source of pharmacologically significant molecules, particularly the heteroxylan E1.4. Future studies should focus on the structural characterization of this xylan to understand the relationship between structure and biological activity and explore the therapeutic potential of E1.4 in vivo models. Full article

Schisandra chinensis Turcz. (Baill.) is a dioecious vine belonging to the Schisandraceae family. Its berries show beneficial activities, including cardioprotective, antioxidant, and anti-inflammatory. We examined the chemical content of S. chinensis berry extract and its antiplatelet potential in vitro. The antiplatelet activity assays included measurements of thrombus formation in full blood (with Total Thrombus-formation Analysis System) and platelet activation and adhesion. We also assessed the extract’s effect on coagulation times in human plasma and its cytotoxicity toward blood platelets based on extracellular lactate dehydrogenase activity. The most important constituents of the extract were dibenzocyclooctadiene lignans; schisandrin was the dominant compound. S. chinensis berry extract at the concentration of 50 μg/mL inhibited thrombus formation by approximately 15%. The adhesion of unstimulated and thrombin-activated blood platelets to collagen was inhibited by all used concentrations of the extract (0.5–50 μg/mL), while the adhesion of adenosine diphosphate (ADP)-activated platelets to fibrinogen was inhibited only by the concentrations of 10 and 50 μg/mL. The extract also inhibited the exposition of the active form of GPIIb/IIIa on the surface of platelets stimulated with 10 μM ADP (at 0.5–50 μg/mL) and 20 μM ADP (at 50 μg/mL). The exposition of P-selectin was inhibited only by the extract at the concentrations of 5–50 μg/mL in platelets stimulated with 10 μg/mL collagen. Moreover, the extract was not cytotoxic toward blood platelets. This indicates that S. chinensis berries hold promise as new antiplatelet agents, but more studies are needed to determine their mechanisms of action and in vivo efficiency. Full article

Cancer is characterized by chronic inflammation and hypercoagulability, with an excess of venous thromboembolism (VTE). Tissue factor, the initiator of blood coagulation, circulates associated with extracellular vesicles (EV-TF). Studies investigating EV-TF between cancer-associated and non-cancer-associated VTE are lacking. We therefore compared EV-TF in unprovoked VTE (U-VTE), cancer-associated VTE (C-VTE), and cancer without VTE (C-w/o VTE). We also investigated interleukin-6 (IL-6) levels between the same groups. The final population included 68 patients (U-VTE: n = 15; C-VTE: n = 24; C-w/o VTE: n = 29). All patients with VTE were enrolled within 48 h of diagnosis; non-VTE patients were recruited in the oncologic outpatient services. EV were isolated by differential centrifugation from 4 mL of peripheral blood; the final EV pellet (16,000× g for 45 min) was resuspended in 100 μL saline and tested for TF using a one-step clotting assay. There was a statistically significant difference for higher EV-TF in C-VTE and C-w/o VTE compared to U-VTE (p = 0.024; Kruskal–Wallis test). There was no significant difference between C-VTE and C-w/o VTE. Moreover, we did not find any difference in IL-6 levels. These preliminary data suggest that cancer represents, per se, a strong driver of EV-TF generation. Full article

Background: We compared the enzymatic, coagulant, and neuromuscular activities of two variants (yellow—CDRy and white—CDRw) of Crotalus durissus ruruima venom with a sample of C. d. terrificus (CDT) venom and examined their neutralization by antivenom against CDT venom. Methods: The venoms were screened for enzymatic and coagulant activities using standard assays, and electrophoretic profiles were compared by SDS-PAGE. Neutralization was assessed by preincubating venoms with crotalic antivenom and assaying the residual activity. Results: SDS-PAGE showed that the venoms had similar electrophoretic profiles, with the main bands being phospholipase A₂ (PLA₂), serine proteinases, L-amino acid oxidase (LAAO), and phosphodiesterase. CDRy venom had the highest proteolytic and LAAO activities, CDRw venom had greater PLA₂ and esterolytic activities at the highest quantity tested, and CDT had greater PLA₂ activity than CDRy. CDRw and CDT venoms had similar proteolytic and LAAO activities, and CDRy and CDT venoms had comparable esterolytic activity. None of the venoms altered the prothrombin time (PT), but all of them decreased the activated partial thromboplastin time (aPPT); this activity was neutralized by antivenom. The minimum coagulant dose potency was CDRw >> CDRy > CDT. All venoms had thrombin-like activity that was attenuated by antivenom. CDRy and CDRw venoms showed α-fibrinogenolytic activity. All venoms partially cleaved the β-chain. CDRy and CDT venoms caused neuromuscular facilitation (enhanced muscle contractions) followed by complete blockade, whereas CDRw venom caused only blockade. Antivenom neutralized the neuromuscular activity to varying degrees. Conclusions: These findings indicate that while CDR and CDT venoms share similarities, they also differ in some enzymatic and biological activities and in neutralization by antivenom. Some of these differences could influence the clinical manifestations of envenomation by C. d. ruruima and their neutralization by the currently used therapeutic antivenom. Full article

Coagulation factor XIa is a new serine-protease family drug target for next-generation anticoagulants. With the snake venom Kunitz-type peptide BF9 as the scaffold, we obtained a highly active XIa inhibitor BF9-N17K in our previous work, but it also inhibited the hemostatic target plasmin. Here, in order to enhance the selectivity of BF9-N17K toward XIa, four mutants, BF9-N17K-L19A, BF9-N17K-L19S, BF9-N17K-L19D, and BF9-N17K-L19K, were further designed using the P2′ amino acid classification scanning strategy. The anticoagulation assay showed that the four P2′ single-point mutants still had apparent inhibitory anticoagulation activity that selectively inhibited the human intrinsic coagulation pathway and had no influence on the extrinsic coagulation pathway or common coagulation pathway, which indicated that the single-point mutants had minimal effects on the anticoagulation activity of BF9-N17K. Interestingly, the enzyme inhibitor assay experiments showed that the XIa and plasmin inhibitory activities were significantly changed by the P2′ amino acid replacements. The XIa inhibitory activity of BF9-N17K-L19D was apparently enhanced, with an IC₅₀ of 19.28 ± 2.53 nM, and its plasmin inhibitory was significantly weakened, with an IC₅₀ of 459.33 ± 337.40 nM. BF9-N17K-L19K was the opposite to BF9-N17K-L19D, which had enhanced plasmin inhibitory activity and reduced XIa inhibitory activity. For BF9-N17K-L19A and BF9-N17K-L19S, no apparent changes were found in the serine protease inhibitory activity, and they had similar XIa and plasmin inhibitory activities to the template peptide BF9-N17K. These results suggested that the characteristics of the charge of the P2′ site might be associated with the drug selectivity between the anticoagulant target XIa and hemostatic target plasmin. In addition, according to the molecular diversity and sequence conservation, a common motif GR/PCR/KA/SXIP-XYGGC is proposed in the XIa-inhibitory Kunitz-type peptides, which might provide a new clue for further peptide engineering. In conclusion, through P2′ amino acid classification scanning with the snake venom Kunitz-type peptide scaffold, a new potent and selective XIa inhibitor, BF9-N17K-L19D, was discovered, which provides a new XIa-targeting lead drug template for the treatment of thrombotic-related diseases. Full article

Splanchnic vein thrombosis (SVT), which is particularly prevalent in myeloproliferative neoplasms (MPNs), has a multifactorial pathomechanism involving the anticoagulant protein C (PC) pathway. To better characterize the hypercoagulable state in SVT we assessed its key enzymes thrombin and activated PC (APC). The study population included 73 patients with SVT, thereof 36 MPN+, confirmed by bone marrow biopsy, 37 MPN−, and 30 healthy controls. Direct measurement of the active enzyme forms of thrombin and APC in the circulation was achieved by using oligonucleotide-based enzyme capture assays (OECA). Additionally, activation markers of coagulation and fibrinolysis were measured. Plasma levels of free thrombin and APC were higher in the MPN+ than in the MPN− cohort, with 0.49 vs. <0.46 pmol/L (p = 0.0057), respectively, 1.23 vs. 0.58 pmol/L (p = 0.0122), and in healthy controls (vs. <0.46 pmol/L, p = 0.0012; vs. 0.54 pmol/L, p = 0.0035). The indirect activation markers prothrombin fragment 1+2, thrombin-antithrombin complex, and D-dimer did not differ between groups. Receiver operating characteristic analysis suggested that SVT patients with MPN can be better distinguished by APC than by conventional indirect thrombin markers. A potential application of these biomarkers to guide anticoagulant therapy and to investigate the role of the PC pathway in MPN-associated hypercoagulability should be further studied. Full article

Echis ocellatus envenomings are a public health problem in West Africa, leading to bleeding and hypocoagulability. The aim of this study was to assess the hemostasis disorders associated with E. ocellatus envenoming. Envenomed patients with an abnormal whole blood clotting test (WBCT) were prospectively included at Tanguiéta, Benin. A WBCT with a sequential reading (i.e., at 20, 30, and 60 min), viscoelastic analysis (VA) using the Quantra analyzer, and blood count were performed on admission. VA and the WBCT were also assessed at 4, 8, 12, 24, 48, and 72 h after antivenom administration. Nineteen patients were included. On admission, the main results were an absence of a clot on VA and a slight decrease in platelets. Clot time gradually decreased over time while clot stiffness, fibrinogen, and platelet contributions to stiffness increased. Sequential reading improved the sensitivity of the WBCT. At H48, all patients with recurrence bleeding after antivenom administration had an abnormal WBCT while patients with a normal WBCT never had bleeding during their follow-up. VA allows the identification of various hemostasis disorders. Hypofibrinogenemia was the main disorder that persisted for several days after treatment. A WBCT with a sequential reading is an effective alternative for monitoring hypocoagulability in the absence of a laboratory. Full article