Short-duration peripherally inserted central catheters do not alter viscoelastic parameters in healthy dogs.

Objective: To determine if short-duration peripherally inserted central catheters (PICCs) cause a hypercoagulable state in healthy dogs, based on point-of-care viscoelastic coagulation monitor (VCM). Animals: Ten beagle dogs were randomly and equally allocated into control and PICC groups. Procedure: Control dogs had VCM analysis on whole blood following direct venipuncture before sedation (T0) and 2 h after sedation (T2). In the experimental group, a PICC was placed (medial saphenous or femoral vein) under sedation and removed after 4 h, with measurements before placement (T0) and 2 and 6 h after placement (T2 and T6, respectively). Parametric data were analyzed using 1-way ANOVA with Holm-Sídák test for multiple comparisons and paired or unpaired Student's t-test. Nonparametric data were analyzed using Friedman test with Dunn multiple comparison test for Wilcoxon matched-pairs signed-rank test, and Mann-Whitney U test for PICC group, control group, and to compare PICC versus control groups, respectively. Results: Clot formation time was longer at T2 versus T6 (P = 0.0342, but not clinically relevant) in the PICC group, with no significant differences between the PICC and control groups. Conclusion and clinical relevance: Short-term placement of a PICC line did not alter viscoelastic endpoints in healthy beagles.

L'utilisation de courte durée d'un cathéter central inséré par voie périphérique n'affecte pas les paramètres viscoélastiques chez les chiens sains. Objectif: Déterminer si les cathéters centraux insérés par voie périphérique (CCIP) pour une courte durée provoque un état d'hypercoagulabilité chez des chiens en bonne santé sur la base des mesures du Viscoelastic Coagulation Monitor (VCM) au point de soins. Animaux: Dix chiens sains de race beagle ont été choisis et répartis de façon égale et aléatoire dans un groupe témoin et un groupe de CCIP. Procédure: Les chiens témoins ont eu une prise de sang et analyse par VCM avant sédation (T0) et 2 heures après la sédation (T2). Dans le groupe expérimental, un CCIP a été mis en place (veines saphènes ou fémorales médiales) sous sédation et retiré après 4 heures. Les mesures viscoélastiques sur le sang frais ont été effectuées avant la pose du CCIP (T0), 2 heures après la pose (T2) et 2 heures après le retrait/6 heures après la pose du cathéter (T6). L'analyse statistique des données paramétriques a été faite par le test ANOVA à un facteur avec un test de comparaisons multiples de Holm-Sídák pour le groupe CCIP, un test t de Student apparié pour le groupe témoin, et un test t de Student non apparié pour comparer les groupes CCIP et témoin. Les données non paramétriques ont été analysées à l'aide du test de Friedman avec un test de comparaison multiple de Dunn pour le groupe CCIP, du test de rang signé de Wilcoxon pour le groupe témoin et du test de Mann-Whitney U pour comparer les groupes CCIP et témoin. Résultats: Pour le groupe CCIP, le temps de formation du caillot à T2 était plus long mais non cliniquement pertinent. comparativement à T6 (P = 0,0342) et il n'y avait aucune différence significative entre les groupes CCIP et témoin. Conclusion et pertinence clinique: La pose d'un CCIP pour une courte durée n'a pas modifié les variables viscoélastiques chez les chiens beagle en bonne santé.(Traduit par les auteurs).

New Findings Regarding the Effects of Selected Blue Food Colorants (Genipin, Patent Blue V, and Brilliant Blue FCF) on the Hemostatic Properties of Blood Components In Vitro.

Natural and synthetic colorants present in food can modulate hemostasis, which includes the coagulation process and blood platelet activation. Some colorants have cardioprotective activity as well. However, the effect of genipin (a natural blue colorant) and synthetic blue colorants (including patent blue V and brilliant blue FCF) on hemostasis is not clear. In this study, we aimed to investigate the effects of three blue colorants-genipin, patent blue V, and brilliant blue FCF-on selected parameters of hemostasis in vitro. The anti- or pro-coagulant potential was assessed in human plasma by measuring the following coagulation times: thrombin time (TT), prothrombin time (PT), and activated partial thromboplastin time (APTT). Moreover, we used the Total Thrombus formation Analysis System (T-TAS, PL-chip) to evaluate the anti-platelet potential of the colorants in whole blood. We also measured their effect on the adhesion of washed blood platelets to fibrinogen and collagen. Lastly, the cytotoxicity of the colorants against blood platelets was assessed based on the activity of extracellular lactate dehydrogenase (LDH). We observed that genipin (at all concentrations (1-200 µM)) did not have a significant effect on the coagulation times (PT, APTT, and TT). However, genipin at the highest concentration (200 µM) and patent blue V at the concentrations of 1 and 10 µM significantly prolonged the time of occlusion measured using the T-TAS, which demonstrated their anti-platelet activity. We also observed that genipin decreased the adhesion of platelets to fibrinogen and collagen. Only patent blue V and brilliant blue FCF significantly shortened the APTT (at the concentration of 10 µM) and TT (at concentrations of 1 and 10 µM), demonstrating pro-coagulant activity. These synthetic blue colorants also modulated the process of human blood platelet adhesion, stimulating the adhesion to fibrinogen and inhibiting the adhesion to collagen. The results demonstrate that genipin is not toxic. In addition, because of its ability to reduce blood platelet activation, genipin holds promise as a novel and valuable agent that improves the health of the cardiovascular system and reduces the risk of cardiovascular diseases. However, the mechanism of its anti-platelet activity remains unclear and requires further studies. Its in vivo activity and interaction with various anti-coagulant and anti-thrombotic drugs, including aspirin and its derivatives, should be examined as well.

Antithrombotic Effect of Oil from the Pulp of Bocaiúva-Acrocomia aculeata (Jacq.) Lodd. ex Mart. (Arecaceae).

The study aimed to evaluate the antithrombotic action of Acrocomia aculeata pulp oil (AAPO) in natura, in an in vitro experimental model. AAPO was obtained by solvent extraction, and its chemical characterization was performed by gas chromatography coupled to a mass spectrometer (GC-MS). In vitro toxicity was evaluated with the Trypan Blue exclusion test and in vivo by the Galleria mellonella model. ADP/epinephrine-induced platelet aggregation after treatment with AAPO (50, 100, 200, 400, and 800 µg/mL) was evaluated by turbidimetry, and coagulation was determined by prothrombin activity time (PT) and activated partial thromboplastin time (aPTT). Platelet activation was measured by expression of P-selectin on the platelet surface by flow cytometry and intraplatelet content of reactive oxygen species (ROS) by fluorimetry. The results showed that AAPO has as major components such as oleic acid, palmitic acid, lauric acid, caprylic acid, and squalene. AAPO showed no toxicity in vitro or in vivo. Platelet aggregation decreased against agonists using treatment with different concentrations of AAPO. Oil did not interfere in PT and aPTT. Moreover, it expressively decreased ROS-induced platelet activation and P-selectin expression. Therefore, AAPO showed antiplatelet action since it decreased platelet activation verified by the decrease in P-selectin expression as well as in ROS production.

Tannic acid coating gauze immobilized with thrombin with ultra-high coagulation activity and antimicrobial property for uncontrollable hemorrhage.

Rapid and safe hemostasis is crucial for the survival of bleeding patients in prehospital care. It is urgent to develop high performance hemostatic material to control the massive hemorrhage in the military field and accidental trauma. In this work, an efficient protein hemostat of thrombin was immobilized onto commercial gauze, which was mediated by self-polymerization and anchoring of tannic acid (TA). Through TA treatment, the efficient immobilization of thrombin was achieved, preserving both the biological activity of thrombin and the physical properties of the dressing, including absorbency, breathability, and mechanical performance. Moreover, in the presence of TA coating and thrombin, Gau@TA/Thr could obviously shortened clotting time and enriched blood components such as plasma proteins, platelets, and red blood cells, thereby exhibiting an enhanced in vitro coagulation effect. In SD rat liver volume defect and artery transection hemorrhage models, Gau@TA/Thr still had outstanding hemostatic performance. Besides, the Gau@TA/Thr gauze had inherent antibacterial property and demonstrated excellent biocompatibility. All results suggested that Gau@TA/Thr would be a potential candidate for treating uncontrollable hemorrhage in prehospital care.

In vivo effects of balanced, low molecular 6% and 10% hydroxyethyl starch compared with crystalloid volume replacement on the coagulation system in major pancreatic surgery-a sub-analysis of a prospective double-blinded, randomized controlled trial.

BACKGROUND: The outcome of patients undergoing major surgery treated with HES for hemodynamic optimization is unclear. This post-hoc analysis of a randomized clinical pilot trial investigated the impact of low-molecular balanced HES solutions on the coagulation system, blood loss and transfusion requirements. METHODS: The Trial was registered: EudraCT 2008-004175-22 and ethical approval was provided by the ethics committee of Berlin. Patients were randomized into three groups receiving either a 10% HES 130/0.42 solution, a 6% HES 130/0.42 solution or a crystalloid following a goal-directed hemodynamic algorithm. Endpoints were parameters of standard and viscoelastic coagulation laboratory, blood loss and transfusion requirements at baseline, at the end of surgery (EOS) and the first postoperative day (POD 1). RESULTS: Fifty-two patients were included in the analysis (HES 10% (n = 15), HES 6% (n = 17) and crystalloid (n = 20)). Fibrinogen decreased in all groups at EOS (HES 10% 338 [298;378] to 192 [163;234] mg dl-1, p<0.01, HES 6% 385 [302;442] to 174 [163;224] mg dl-1, p<0.01, crystalloids 408 [325;458] to 313 [248;370] mg dl-1, p = 0.01). MCF FIBTEM was decreased for both HES groups at EOS (HES 10%: 20.5 [16.0;24.8] to 6.5 [5.0;10.8] mm, p = <0.01; HES 6% 27.0 [18.8;35.2] to 7.0 [5.0;19.0] mm, p = <0.01). These changes did not persist on POD 1 for HES 10% (rise to 16.0 [13.0;24.0] mm, p = 0.88). Blood loss was not different in the groups nor transfusion requirements. CONCLUSION: Our data suggest a stronger but transient effect of balanced, low-molecular HES on the coagulation system. Despite the decline of the use of artificial colloids in clinical practice, these results may help to inform clinicians who use HES solutions.

NanoGraphene Clot: A New Fibrinogen-Mimic Hemostatic Material.

Trauma is the leading cause of death for adults under the age of 44. Internal bleeding remains a significant challenge in medical emergencies, necessitating the development of effective hemostatic materials that could be administered by paramedics before a patient is in the hospital and treated by surgeons. In this study, we introduce a graphene oxide (GO)-based PEGylated synthetic hemostatic nanomaterial with an average size of 211 ± 83 nm designed to target internal bleeding by mimicking the role of fibrinogen. Functionalization of GO-g-PEG with peptides derived from the α-chain of fibrinogen, such as GRGDS, or the γ-chain of fibrinogen, such as HHLGGAKQAGDV:H12, was achieved with peptide loadings of 72 ± 6 and 68 ± 15 µM, respectively. In vitro studies with platelet-rich plasma (PRP) under confinement demonstrated aggregation enhancement of 39 and 24% for GO-g-PEG-GRGDS and GO-g-PEG-H12, respectively, compared to buffer, while adenosine diphosphate (ADP) alone induced a 5% aggregation. Compared to the same materials in the absence of ADP, GO-g-PEG-GRGDS achieved a 47% aggregation enhancement, while GO-g-PEG-H12 a 25% enhancement. This is particularly important for injectable hemostats and highlights the fact that our nanographene-based materials can only act as hemostats in the presence of agonists, reducing the possibility of unwanted clotting during circulation. Further studies on collagen-coated wells under dynamic flow revealed statistically significant augmentation of PRP fluorescence signal using GRGDS- or H12-coated GO-g-PEG compared to controls. Hemolysis studies showed <1% lysis of red blood cells (RBCs) at the highest PEGylated nanographene concentration. Finally, whole human blood coagulation studies reveal faster and more pronounced clotting using our nanohemostats vs PBS control from 3 min and below (blood is clotted with 10% CaCl2 within 4-5 min), with the biggest differences to be shown at 2 and 1 min. At 1 min, the clot weight was found to be ∼45% of that between 4 and 5 min, while no clot was formed in PBS-treated blood. Reduction of CaCl2 to 5 and 3%, or utilization of prostaglandin E1, an anticoagulant, still leads to clots but of smaller weight. The findings highlight the potential of our fibrinogen-mimic PEGylated nanographene as a promising non-hemolytic injectable scaffold for targeting internal bleeding, offering insights into its platelet aggregation capabilities under confinement and under dynamic flow as well as its pronounced coagulation abilities.

Effect of norepinephrine and phenylephrine on prothrombotic response in patients undergoing cesarean section under spinal anesthesia: protocol for a randomized, double-blind, controlled study.

BACKGROUND: Norepinephrine and phenylephrine are commonly used vasoactive drugs to treat hypotension during the perioperative period. The increased release of endogenous norepinephrine elicits prothrombotic changes, while parturients are generally in a hypercoagulable state. Therefore, this trial aims to investigate whether there is a disparity between equivalent doses of prophylactic norepinephrine infusion and phenylephrine infusion on prothrombotic response in patients undergoing cesarean section under spinal anesthesia. METHODS: Sixty-six eligible parturients will be recruited for this trial and randomly assigned to the norepinephrine or phenylephrine group. The "study drug" will be administered at a rate of 15 ml/h starting from the intrathecal injection. The primary outcome are plasma coagulation factor VIII activity (FVIII: C), fibrinogen, and D-dimer levels. The secondary outcomes include hemodynamic variables and umbilical artery blood pH value. DISCUSSION: Our study is the first trial comparing the effect of norepinephrine and phenylephrine on prothrombotic response in patients undergoing cesarean section under spinal anesthesia. Positive or negative results will all help us better understand the impact of vasoactive drugs on patients. If there are any differences, this trial will provide new evidence for maternal choice of vasoactive medications in the perioperative period. TRIAL REGISTRATION: Chinese Clinical Trial Registry ChiCTR2300077164. Registered on 1 November 2023. https://www.chictr.org.cn/ .

Comparison of warfarin, rivaroxaban, and dabigatran for effectiveness and safety in atrial fibrillation patients with different CHA2DS2-VASc scores: a retrospective cohort study.

BACKGROUND: This retrospective cohort study aims to compare the effectiveness and safety of warfarin, rivaroxaban, and dabigatran in atrial fibrillation (AF) patients with different CHA2DS2-VASc scores in northern China. METHODS: A retrospective cohort study was performed to evaluate anticoagulation in AF patients at the second affiliated hospital of Harbin Medical University from September 2018 to August 2019. Patients included in this study (n = 806) received warfarin (n = 300), or rivaroxaban (n = 203), or dabigatran (n = 303). Baseline characteristics and follow-up data including adherence, bleeding events and ischemic stroke (IS) events were collected. RESULTS: Patients receiving rivaroxaban (73.9%) or dabigatran (73.6%) showed better adherence than those receiving warfarin (56.7%). Compared with warfarin-treated patients, dabigatran-treated patients had lower incidence of bleeding events (10.9% vs 19.3%, χ2 = 8.385, P = 0.004) and rivaroxaban-treated patients had lower incidence of major adverse cardiovascular events (7.4% vs 13.7%, χ2 = 4.822, P = 0.028). We classified patients into three groups based on CHA2DS2-VASc score (0-1, 2-3, ≥ 4). In dabigatran intervention, incidence of bleeding events was higher in patients with score 0-1 (20.0%) than those with score 2-3 (7.9%, χ2 = 5.772, P = 0.016) or score ≥ 4 (8.6%, χ2 = 4.682, P = 0.030). Patients with score 0-1 in warfarin or rivaroxaban therapy had a similar but not significant increase of bleeding compared with patients with score 2-3 or score ≥ 4, respectively. During the follow-up, 33 of 806 patients experienced IS and more than half (19, 57.6%) were patients with score ≥ 4. Comparing patients with score 0-1 and 2-3, the latter had an significant reduction of IS in patients prescribed warfarin and non-significant reduction in rivaroxaban and dabigatran therapy. CONCLUSION: Compared with warfarin therapy, patients with different CHA2DS2-VASc scores receiving either rivaroxaban or dabigatran were associated with higher persistence. AF patients with score ≥ 4 were more likely to experience IS events while hemorrhagic tendency preferred patients with low score 0-1.

Intravenous lipid emulsion interference in coagulation testing: an ex vivo analysis.

INTRODUCTION: Intravenous lipid emulsion is used in the rescue treatment of certain poisonings. A complication is interference with laboratory analyses. The aim of this study was to determine the impact of intravenous lipid emulsion on routine laboratory analysis of coagulation parameters ex vivo and determine if any of the analytical techniques remain reliable. METHODS: Samples were obtained from 19 healthy volunteers and divided in triplicate. One sample served as a control, and the other two were diluted to simulate the treatment of an average adult with Intralipid® 20 per cent Fresenius Kabi 100 mL (dilution-1) or 500 mL (dilution-2). Coagulation tests performed were prothrombin time, activated prothrombin time, D-dimer concentration and fibrinogen. Coagulation testing was performed by three techniques. Test-1 was performed on a Sysmex CN6000 analyzer. Test-2 was performed with a manual mechanical endpoint method using the semi-automated Stago KC4 Delta. Test-3 involved high-speed centrifugation before repeat testing on the Sysmex CN6000 analyzer. RESULTS: For test-1, only nine (47 per cent) samples in dilution-1 could be analyzed for coagulation tests, and no coagulation tests could be analyzed for dilution-2 because of lipaemia. For test-2 and test-3, all samples could be analyzed, and all results of both testing methods fell within the limits of the laboratory reference range. DISCUSSION: Difficulties in laboratory analysis of patients having received intravenous lipid emulsion are due to multiple factors. Most automated coagulation analyzers use optical measurements, which can be unreliable in the presence of a high intravenous lipid concentration. By altering the lipaemia in the testing solution using high-speed centrifugation or by using manual mechanical endpoint detection, we were able to obtain reliable results. These findings are limited by the use of an ex vivo method and healthy volunteers. CONCLUSIONS: This ex vivo model confirms that Intralipid® interferes with routine coagulation studies. It is important that clinicians are aware and inform their laboratories of its administration.

Citrate and low-dose heparin combined anticoagulation in pediatric continuous renal replacement therapy.

There remains no optimal anticoagulation protocol for continuous renal replacement therapy (CRRT) with regional citrate anticoagulation (RCA) in pediatric patients with elevated D-dimer levels. We aimed to assess the effects of different anticoagulation strategies on the risk of CRRT filter clotting in these patients. Pediatric patients undergoing CRRT were retrospectively grouped based on pre-CRRT D-dimer levels and anticoagulant: D-RCA group (normal D-dimer, RCA only, n = 22), D+ RCA group (elevated D-dimer, RCA only, n = 50), and D+ RCA+ systemic heparin anticoagulation (SHA) group (elevated D-dimer, RCA combined with SHA, n = 55). The risk of filter clotting and incidence of bleeding were compared among the groups. Among the groups, the D+ RCA+ SHA group had the longest filter lifespan; further, the incidence of bleeding was not increased by concurrent use of low-dose heparin for anticoagulation. Moreover, concurrent heparin anticoagulation was associated with a decreased risk of filter clotting. Contrastingly, high pre-CRRT hemoglobin and D-dimer levels and post-filter ionized calcium level > 0.4 mmol/L were associated with an increased risk of filter clotting. RCA combined with low-dose heparin anticoagulation could reduce the risk of filter clotting and prolong filter lifespan without increasing the risk of bleeding in patients with elevated D-dimer levels undergoing CRRT.

Expansion-clotting chitosan fabrics based on unidirectional fast-absorption fibers for rapid hemorrhage control.

The rapid absorption of water from the blood to concentrate erythrocytes and platelets, thus triggering quick closure, is important for hemostasis. Herein, expansion-clotting chitosan fabrics are designed and fabricated by ring spinning of polylactic acid (PLA) filaments as the core layer and highly hydrophilic carboxyethyl chitosan (CECS) fibers as the sheath layer, and subsequent knitting of obtained PLA@CECS core spun yarns. Due to the unidirectional fast-absorption capacity of CECS fibers, the chitosan fabrics can achieve erythrocytes and platelets aggregate quickly by concentrating blood, thus promoting the formation of blood clots. Furthermore, the loop structure of coils formed in the knitted fabric can help them to expand by absorbing water to close their pores, providing effective sealing for bleeding. Besides, They have enough mechanical properties, anti-penetrating ability, and good tissue-adhesion ability in wet conditions, which can form a physical barrier to resist blood pressure during hemostasis and prevent them from falling off the wound, thus enhancing hemostasis synergistically. Therefore, the fabrics exhibit superior hemostatic performance in the rabbit liver, spleen, and femoral artery puncture injury model compared to the gauze group. This chitosan fabric is a promising hemostatic material for hemorrhage control.

Clot-Targeted Nanogels for Dual-Delivery of AntithrombinIII and Tissue Plasminogen Activator to Mitigate Disseminated Intravascular Coagulation Complications.

Disseminated intravascular coagulation (DIC) is a pathologic state that follows systemic injury and other diseases. Often a complication of sepsis or trauma, DIC causes coagulopathy associated with paradoxical thrombosis and hemorrhage. DIC upregulates the thrombotic pathways while simultaneously downregulating the fibrinolytic pathways that cause excessive fibrin deposition, microcirculatory thrombosis, multiorgan dysfunction, and consumptive coagulopathy with excessive bleeding. Given these opposing disease phenotypes, DIC management is challenging and includes treating the underlying disease and managing the coagulopathy. Currently, no therapies are approved for DIC. We have developed clot-targeted therapeutics that inhibit clot polymerization and activate clot fibrinolysis to manage DIC. We hypothesize that delivering both an anticoagulant and a fibrinolytic agent directly to clots will inhibit active clot polymerization while also breaking up pre-existing clots; therefore, reversing consumptive coagulopathy and restoring hemostatic balance. To test this hypothesis, we single- and dual-loaded fibrin-specific nanogels (FSNs) with antithrombinIII (ATIII) and/or tissue plasminogen activator (tPA) and evaluated their clot preventing and clot lysing abilities in vitro and in a rodent model of DIC. In vivo, single-loaded ATIII-FSNs decreased fibrin deposits in DIC organs and reduced blood loss when DIC rodents were injured. We also observed that the addition of tPA in dual-loaded ATIII-tPA-FSNs intensified the antithrombotic and fibrinolytic mechanisms, which proved advantageous for clot lysis and restoring platelet counts. However, the addition of tPA may have hindered wound healing capabilities when an injury was introduced. Our data supports the benefits of delivering both anticoagulants and fibrinolytic agents directly to clots to reduce the fibrin load and restore hemostatic balance in DIC.

Purification and Structural Analyses of Sulfated Polysaccharides from Low-Value Sea Cucumber Stichopus naso and Anticoagulant Activities of Its Oligosaccharides.

Three polysaccharides (SnNG, SnFS and SnFG) were purified from the body wall of Stichopus naso. The physicochemical properties, including monosaccharide composition, molecular weight, sulfate content, and optical rotation, were analyzed, confirming that SnFS and SnFG are sulfated polysaccharides commonly found in sea cucumbers. The highly regular structure {3)-L-Fuc2S-(α1,}n of SnFS was determined via a detailed NMR analysis of its oxidative degradation product. By employing ß-elimination depolymerization of SnFG, tri-, penta-, octa-, hendeca-, tetradeca-, and heptadeca-saccharides were obtained from the low-molecular-weight product. Their well-defined structures confirmed that SnFG possessed the backbone of {D-GalNAc4S6S-ß(1,4)-D-GlcA}, and each GlcA residue was branched with Fuc2S4S. SnFS and SnFG are both structurally the simplest version of natural fucan sulfate and fucosylated glycosaminoglycan, facilitating the application of low-value sea cucumbers S. naso. Bioactivity assays showed that SnFG and its derived oligosaccharides exhibited potent anticoagulation and intrinsic factor Xase (iXase) inhibition. Moreover, a comparative analysis with the series of oligosaccharides solely branched with Fuc3S4S showed that in oligosaccharides with lower degrees of polymerization, such as octasaccharides, Fuc2S4S led to a greater increase in APTT prolongation and iXase inhibition. As the degree of polymerization increases, the influence from the sulfation pattern diminishes, until it is overshadowed by the effects of molecular weight.

Factor XI inhibition in hemodialysis patients: the safer anticoagulation?

Chronic hemodialysis patients exhibit an excessive cardiovascular risk and a marked increase in both thromboembolism and bleeding episodes. Factor XI inhibition may provide anticoagulation, with a low risk of bleeding, and several factor XI inhibitors, including fesomersen, an antisense oligonucleotide, are under development. Recently, a phase 2 study of fesomersen showed a good safety profile in chronic hemodialysis patients and suggested that clotting rates of the arteriovenous fistula and the dialysis circuit are lower.

Effect of Xe/O2 Inhalation on Hemostasis in Experimental Thromboplastin Pneumonitis.

We studied the effectiveness of Xe/O2 mixture inhalation (30% Xe and 70% O2, 20 min for 5 days) in a model of experimental thromboplastin pneumonitis. Inhalation of the studied mixture decreased the intensity of the inflammatory process in the lung tissue assessed by the temperature response of animals, changed lung weight and lung weight coefficient. At acute stage of pneumonitis, an increase in xenon consumption was recorded due to its retention in the gas exchange zone and a natural decrease in oxygen consumption due to partial alveolar/capillary block. The formation of pneumonitis was accompanied by a pronounced procoagulant shift in the regulation system of the aggregate state of blood. The Xe/O2 inhalations ensured physiologically optimal levels of prothrombin and activated partial thromboplastin time against the background of a moderate decrease in fibrinogen level throughout the experiment. At the same time, the activity of the natural anticoagulant antithrombin III increased from day 5 to day 14.

Therapeutic Potentials of Medicinal Leech in Chinese Medicine.

The use of medicinal leeches in clinical therapy has been employed for a long time, as it was originally recognized for exerting antithrombin effects. These effects were due to the ability of the leech to continuously suck blood while attached to human skin. According to Chinese Pharmacopoei, leeches used in traditional Chinese medicine mainly consist of Whitmania pigra Whitman, Hirudo nipponia Whitman, and Whitmania acranulata, but the latter two species are relatively scarce. The main constituents of leeches are protein and peptide macromolecules. They can be categorized into two categories based on their pharmacological effects. One group consists of active ingredients that directly target the coagulation system, such as hirudin, heparin, and histamine, which are widely known. The other group comprises protease inhibitor components like Decorsin and Hementin. Among these, hirudin secreted by the salivary glands of the leech is the most potent thrombin inhibitor and served as the sole remedy for preventing blood clotting until the discovery of heparin. Additionally, leeches play a significant role in various traditional Chinese medicine formulations. In recent decades, medicinal leeches have been applied in fields including anti-inflammatory treatment, cardiovascular disease management, antitumor treatment, and many other medical conditions. In this review, we present a comprehensive overview of the historical journey and medicinal applications of leeches in various medical conditions, emphasizing their pharmaceutical significance within traditional Chinese medicine. This review offers valuable insights for exploring additional therapeutic opportunities involving the use of leeches in various diseases and elucidating their underlying mechanisms for future research.

Minimal interference of concizumab with standard clinical coagulation laboratory assays - An in vitro study.

INTRODUCTION: Non-factor replacement therapies are emerging as prophylactic treatment options in haemophilia A or B (HA/HB) with and without inhibitors. Concizumab is an anti-tissue factor pathway inhibitor (TFPI) monoclonal antibody preventing factor (F)Xa inhibition and enhancing thrombin generation. Based on experience with other non-factor therapies and extended half-life products, there is a focus on potential interference with common clinical coagulation assays used to monitor patients treated with concizumab. AIM: To evaluate the impact of concizumab on standard clinical coagulation assays. METHODS: Plasma samples (normal, HA/HB with/without inhibitors) in the presence/absence of added concizumab (250-16,000 ng/mL) were analysed in clinical assays including activated partial thromboplastin time (aPTT), prothrombin time (PT), FVIII and FIX one-stage clot and chromogenic substrate assay, assays for detecting FVIII or FIX inhibitors and other assays for coagulation factors. RESULTS: Concizumab did not impact PT assays, but resulted in a small shortening of aPTT (up to 5 s in haemophilia plasma and 0.4 s in normal plasma). Concizumab had no, or only a minor impact on FVIII and FIX activity assays or Bethesda inhibitor assays. FXI and FXII activity in normal plasma, as measured by single factor aPTT-based assay, was significantly increased in the presence of concizumab (+11% each). This was also the case for FVII and FX measured by PT-based assays using plasma with 25% of FVII or FX (+64% and +22%, respectively). CONCLUSION: The presence of concizumab did not, or only slightly, influence the outcome of standard clinical coagulation assays relevant for HA and HB.

The Clot Thickens: Differential Coagulotoxic and Cardiotoxic Activities of Anguimorpha Lizard Venoms.

Despite their evolutionary novelty, lizard venoms are much less studied in comparison to the intense research on snake venoms. While the venoms of helodermatid lizards have long been assumed to be for defensive purposes, there is increasing evidence of toxic activities more useful for predation than defence (such as paralytic neurotoxicity). This study aimed to ascertain the effects of Heloderma, Lanthanotus, and Varanus lizard venoms on the coagulation and cardiovascular systems. Anticoagulant toxicity was demonstrated for the Varanus species studied, with the venoms prolonging clotting times in human and bird plasma due to the destructive cleavage of fibrinogen. In contrast, thromboelastographic analyses on human and bird plasmas in this study demonstrated a procoagulant bioactivity for Heloderma venoms. A previous study on Heloderma venom using factor-depleted plasmas as a proxy model suggested a procoagulant factor was present that activated either Factor XI or Factor XII, but could not ascertain the precise target. Our activation studies using purified zymogens confirmed FXII activation. Comparisons of neonate and adult H. exasperatum, revealed the neonates to be more potent in the ability to activate FXII, being more similar to the venom of the smaller species H. suspectum than the adult H. exasperatum. This suggests potent FXII activation a basal trait in the genus, present in the small bodied last common ancestor. This also indicates an ontogenetic difference in prey preferences in the larger Heloderma species paralleing the change in venom biochemistry. In addition, as birds lack Factor XII, the ability to clot avian plasma suggested an additional procoagulant site of action, which was revealed to be the activation of Factor VII, with H. horridum being the most potent. This study also examined the effects upon the cardiovascular system, including the liberation of kinins from kininogen, which contributes to hypotension induction. This form of toxicity was previously described for Heloderma venoms, and was revealed in this study was to also be a pathophysiological effect of Lanthanotus and Varanus venoms. This suggests that this toxic activity was present in the venom of the last common ancestor of the anguimorph lizards, which is consistent with kallikrein enzymes being a shared toxin trait. This study therefore uncovered novel actions of anguimorph lizard venoms, not only contributing to the evolutionary biology body of knowledge but also revealing novel activities to mine for drug design lead compounds.