Mechanisms Of Hemostasis Research Articles

Functional Alterations Involved in Increased Bleeding in Hereditary Hemorrhagic Telangiectasia Mouse Models.

Hereditary Hemorrhagic Telangiectasia (HHT) is an autosomal-dominant genetic disorder involving defects in two predominant genes known as endoglin (ENG; HHT-1) and activin receptor-like kinase 1 (ACVRL1/ALK1; HHT-2). It is characterized by mucocutaneous telangiectases that, due to their fragility, frequently break causing recurrent epistaxis and gastrointestinal bleeding. Because of the severity of hemorrhages, the study of the hemostasis involved in these vascular ruptures is critical to find therapies for this disease. Our results demonstrate that HHT patients with high bleeding, as determined by a high Epistaxis Severity Score (ESS), do not have prolonged clotting times or alterations in clotting factors. Considering that coagulation is only one of the processes involved in hemostasis, the main objective of this study was to investigate the overall mechanisms of hemostasis in HHT-1 (Eng+/−) and HHT-2 (Alk1+/−) mouse models, which do not show HHT vascular phenotypes in the meaning of spontaneous bleeding. In Eng+/− mice, the results of in vivo and in vitro assays suggest deficient platelet-endothelium interactions that impair a robust and stable thrombus formation. Consequently, the thrombus could be torn off and dragged by the mechanical force exerted by the bloodstream, leading to the reappearance of hemorrhages. In Alk1+/− mice, an overactivation of the fibrinolysis system was observed. These results support the idea that endoglin and Alk1 haploinsufficiency leads to a common phenotype of impaired hemostasis, but through different mechanisms. This contribution opens new therapeutic approaches to HHT patients' epistaxis.

Assessment of Hemostasis

Hemostasis is the collection of biological mechanisms responsible for bleeding cessation following surgical procedures or trauma. Congenital and acquired disorders affecting any element of the hemostatic system can result in a spectrum of bleeding pathologies ranging from inability to form stable blood clot to the pathologic propagation of blood clot outside the area of injury. Assessing the hemostatic system in an accurate and timely fashion is critical for detection of these disorders. This review briefly covers the mechanisms of primary and secondary hemostasis before comprehensively exploring the approach to preoperative evaluation of hemostasis, the strengths and weaknesses of commonly used laboratory tests of coagulation, the interpretation of test results, and the management of patients found to have abnormal hemostatic systems. Figures detail the mechanisms of hemostasis and the important features of viscoelastic testing. Tables explain the parameters frequently measured in viscoelastic testing and propose potential treatment plans based on test findings. This review contains 5 figures, 9 tables and 72 references Keywords: coagulation, conventional coagulation tests, hemostasis, thromboelastography, thromboelastometry

Assessment of Hemostasis

Hemostasis is the collection of biological mechanisms responsible for bleeding cessation following surgical procedures or trauma. Congenital and acquired disorders affecting any element of the hemostatic system can result in a spectrum of bleeding pathologies ranging from inability to form stable blood clot to the pathologic propagation of blood clot outside the area of injury. Assessing the hemostatic system in an accurate and timely fashion is critical for detection of these disorders. This review briefly covers the mechanisms of primary and secondary hemostasis before comprehensively exploring the approach to preoperative evaluation of hemostasis, the strengths and weaknesses of commonly used laboratory tests of coagulation, the interpretation of test results, and the management of patients found to have abnormal hemostatic systems. Figures detail the mechanisms of hemostasis and the important features of viscoelastic testing. Tables explain the parameters frequently measured in viscoelastic testing and propose potential treatment plans based on test findings. Key words: coagulation; conventional coagulation tests; hemostasis; thromboelastography; thromboelastometry

Overview of Anti-platelet Drug Use in Ischemic Stroke Patients at UKI General Hospital in 2015

Stroke is an acute neuro-deficit disease that occurs when there is a disturbance of cerebral blood flow. There are two kinds of stroke, hemorrhagic stroke and ischemic stroke. Ischemic stroke is a stroke that occurs due to the formation of thrombosis and emboli. Thrombosis and emboli block the bloodstream in small blood vessels or prominent blood vessels. Drugs that can cause disturbance to the hemostasis mechanism, such as antiplatelets, are usually used on stroke management. This study aims to know the types and amounts of antiplatelet drugs used on stroke ischemic patients in UKI General Hospital from January to December 2015. This research showed that stroke ischemic occurs more often at age 61 -70 (43%). There are no significant differences between both genders, the most common drugs are Aspilet 80 mg (22 times). For combination drugs, Clopidogrel with Aspilet is used more often than Clopidogrel with Ascardia.
 Keywords: stroke, thrombosis, antiplatelet

Biomaterials as Haemostatic Agents in Cardiovascular Surgery: Review of Current Situation and Future Trends.

Intraoperative haemostasis is of paramount importance in the practice of cardiovascular surgery. Over the past 70 years, topical haemostatic methods have advanced significantly and today we deal with various haemostatic agents with different properties and different mechanisms of action. The particularity of coagulation mechanisms after extracorporeal circulation, has encouraged the introduction of new types of topic agents to achieve haemostasis, where conventional methods prove their limits. These products have an important role in cardiac, as well as in vascular, surgery, mainly in major vascular procedures, like aortic dissections and aortic aneurysms. This article presents those agents used for topical application and the mechanism of haemostasis and offers general recommendations for their use in the operating room.

Hemoglobin Levels and Platelet Counts after Hysteroscopy Due to Abnormal Uterine Bleeding.

Abnormal uterine bleeding (AUB) is a condition defined as all uterine bleeding that differs from physiological menstruation. The etiology of AUB has been classified by the International Federation of Gynecology and Obstetrics (FIGO). It includes structural categories, such as endometrial polyps, adenomyosis, leiomyomas, hyperplasia, and malignant neoplasms, and non-structural categories, i.e., hemorrhages due to congenital and acquired coagulopathies, ovarian dysfunction, disorders of the local endometrial hemostasis mechanism with normal organ structure, iatrogenic causes, and due to other poorly defined causes. This is a retrospective study based on the medical data of a group of 543 women aged 21–88 years (52.81 ± 11.79) (p < 0.01) hospitalized at the Gynecology and Obstetrics Department in Biała Podlaska, Poland. These patients underwent an hysteroscopy procedure due to excessive uterine bleeding of varied, FIGO-divided etiology. The results show the dependence of postoperative hemoglobin and platelet count on the etiology of bleeding and the age of the women. The majority of patients had normal hemoglobin and platelet counts after the procedure, while moderate anemia was the most common disorder. It occurred most frequently in patients undergoing hysteroscopy due to heavy menstrual bleeding.

Development of Cellulose Nanofibril/Casein-Based 3D Composite Hemostasis Scaffold for Potential Wound-Healing Application.

Excessive bleeding in traumatic hemorrhage is the primary concern for natural wound healing and the main reason for trauma deaths. The three-dimensional (3D) bioprinting of bioinks offers the desired structural complexity vital for hemostasis activity and targeted cell proliferation in rapid and controlled wound healing. However, it is challenging to develop suitable bioinks to fabricate specific 3D scaffolds desirable in wound healing. In this work, a 3D composite scaffold is designed using bioprinting technology and synergistic hemostasis mechanisms of cellulose nanofibrils (TCNFs), chitosan, and casein to control blood loss in traumatic hemorrhage. Bioinks that consist of casein bioconjugated TCNF (with a casein content of 104.5 ± 34.1 mg/g) using the carbodiimide cross-linker chemistry were subjected to bioprinting for customizable 3D scaffold fabrication. Further, the 3D composite scaffolds were in situ cross-linked using a green ionic complexation approach. The covalent conjugation among TCNF, casein, and chitosan was confirmed by Fourier transform infrared (FTIR) spectroscopy, nuclear magnetic resonance (NMR), X-ray photoelectron spectroscopy (XPS), sodium dodecyl sulfate-polyacrylamide gel electrophoresis (SDS-PAGE), and X-ray diffraction (XRD) studies. The in vitro hemostasis activity of the 3D composite scaffold was analyzed by a human thrombin-antithrombin (TAT) assay and adsorption of red blood cells (RBCs) and platelets. The 3D composite scaffold had a better swelling behavior and a faster whole blood clotting rate at each time point than the 3D TCNF scaffold and commercial cellulose-based dressings. The TAT assay demonstrated that the 3D composite scaffold could form a higher content of thrombin (663.29 pg/mL) and stable blood clot compared to a cellulosic pad (580.35 pg/mL), 3D TCNF (457.78 pg/mL), and cellulosic gauze (328.92 pg/mL), which are essential for faster blood coagulation. In addition, the 3D composite scaffold had a lower blood clotting index (23.34%) than the 3D TCNF scaffold (41.93%), suggesting higher efficiencies for RBC entrapping to induce blood clotting. The in vivo cytocompatibility was evaluated by a 3D cell culture study, and results showed that the 3D composite scaffold could promote growth and proliferation of NIH 3T3 fibroblast cells, which is vital for wound healing. Cellulase-based in vitro deconstruction of the 3D composite scaffold showed significant weight loss (80 ± 5%) compared to the lysozyme hydrolysis (22 ± 5%) after 28 days of incubation, suggesting the biodegradation potential of the composite scaffold. In conclusion, this study proposes efficient prospects to develop a 3D composite scaffold from bioprinting of TCNF-based bioinks that can accelerate blood clotting and wound healing, suggesting its potential application in reducing blood loss during traumatic hemorrhage.

Atriopathy and atrial fibrillation. Part I

Atrial fibrillation is the most common supraventricular tachycardia, the incidence of which increases with age. This arrhythmia is the consequenсe of multiple cardiac and noncardiac pathology. The most significant side effects of atrial fibrillation are thromboembolic complications. It is generally accepted that the source of these embolisms is a thrombus in the left atrial appendage. However, the risk of thromboembolism also occurs after the onset of atrial rhythm, which can lead to a more complex hemostasis mechanism in this disease. There is no unambiguous definition of the relationship between structural and functional changes in the atria and atrial fibrillation, which manifests itself in the appearance of treatment. Essential methods of catheter operations in patients with atrial fibrillation do not take into account the peculiarities of the rhythm mechanism, which has an influence on the treatment’s results. The first part of the review reflects the anatomy, histology, and physiology of atria, their main cellular elements, and electrophysiological features. The main experimental and clinical models of arrhythmia are described; as factors provoking atrial fibrillation and mechanisms of its stabilization. The analysis of electrophysiological and structural remodeling. The concepts of atriopathy and atrial cardiomyopathy are discussed, and classification is given. The mechanisms of hemostasis disorders and possible directions of correction are presented.

GPVI inhibition by glenzocimab synergistically inhibits atherosclerotic plaque-induced platelet activation when combined with conventional dual antiplatelet therapy

Abstract Introduction Aspirin and a potent platelet P2Y12 inhibitor, such as prasugrel or ticagrelor, are not always sufficient to prevent thrombus formation in patients with ST-elevation MI (STEMI), leading to “slow flow” or “no reflow” effects after stenting. GPIIb/IIIa inhibitors, such as eptifibatide, may help in this setting, but are not used routinely due to their bleeding risk. GPVI has critical roles in thrombosis and a minimal role in haemostasis. Here we tested whether depletion of GPVI has effects on thrombus formation after MI in an animal model and investigated the effects of a novel platelet GPVI inhibitor, glenzocimab (a Fab fragment of a monoclonal antibody), on platelet activation and thrombus formation when combined with aspirin and ticagrelor. Methods We used intravital microscopy in a murine model of ST-elevation myocardial infarction and ischaemia-reperfusion injury to investigate microvascular thrombosis. We investigated the antithrombotic effects of adding glenzocimab (previously known as ACT017) to blood from healthy donors and 20 patients with ACS treated with aspirin and ticagrelor. We compared the effect of glenzocimab with the GPIIb/IIIa inhibitor eptifibatide ex-vivo. We stimulated platelets with collagen and atherosclerotic plaque material that was sourced from patients undergoing carotid endarterectomy. We investigated effects on platelet aggregation, spreading, signalling, adhesion, thrombin generation, thrombus formation and clot stability ex vivo. Results Genetic depletion of GPVI in an animal model of myocardial infarction reduced microvascular thrombosis. Ex vivo, aspirin and ticagrelor partially inhibited atherosclerotic plaque-induced platelet aggregation (assessed by multiple electrode aggregometry) by 48% compared to control (34±3 vs. 65±4 U; P&amp;lt;0.001; Figure 1). Atherosclerotic plaque-induced platelet aggregation, adhesion, secretion and activation were critically dependent on platelet GPVI activation and were potently inhibited by glenzocimab. Glenzocimab alone reduced atherosclerotic plaque-induced platelet aggregation by 75% compared to control (16±4 vs. 65±4 U; P&amp;lt;0.001; Figure 1) and by over 95% when combined with aspirin and ticagrelor (3±1 vs 65±4 U; P&amp;lt;0.001; Figure 1). Furthermore, glenzocimab provided multiple synergistic antithrombotic effects when added to the blood of aspirin and ticagrelor-treated patients with ACS ex vivo. Glenzocimab and the GPIIb/IIIa inhibitor, eptifibatide, had many similar antithrombotic effects but glenzocimab had less effect on mechanisms of general haemostasis compared to eptifibatide, as assessed by ROTEM (Figure 2). Conclusions The addition of glenzocimab to aspirin and ticagrelor provides synergistic inhibition of multiple critical mechanisms of atherothrombosis. Glenzocimab and the GPIIb/IIIa inhibitor, eptifibatide, share many similar antithrombotic effects, although glenzocimab has less impact on mechanisms involved in haemostasis compared to eptifibatide. Funding Acknowledgement Type of funding sources: Public grant(s) – National budget only. Main funding source(s): Academy of Medical Sciences UK Clinical Lecturer Starter GrantRoyal Embassy of Saudi Arabia

Trauma-induced coagulopathy: prospective observation study

Coagulopathy remains the leading cause of illness and death in people with severe trauma.&#x0D; The aim was to study the indicators of vascular-platelet hemostasis in severe trauma and to establish changes in the main pathophysiological mechanisms of primary hemostasis that occur in patients with trauma-induced coagulopathy, compared with almost healthy individuals of the same age.&#x0D; Materials and methods. The study included 44 patients aged 19 to 55 years (36.1 [28.7; 43.2] years). The control group included 20 patients of the therapeutic department without preconditions for changes in the hemostasis system, and the main group - 24 patients with diagnosis of “severe trauma” who were treated in the anesthesiology and intensive care department.&#x0D; Results and discussion. We studied indicators of intravascular platelet activation. Patients had a normal number of platelets in the venous blood, but the level of spherocytes and spheroechinocytes increased. On the 3rd day after the injury, number of platelets in the venous blood was normal, however the level of discocytes decreased, and the level of discochinocytes, spheroechinocytes and the sum of active forms of platelets increased. On the fifth day, the level of discochinocytes and active forms of platelets, significantly higher (p&lt;0.05) among patients of the main group, and spherocytes, spheroechinocytes and platelets involved in the aggregates, were significantly lower than in the control group of patients (p&lt;0.05).&#x0D; Conclusions. Indicators of vascular-platelet hemostasis in patients with polytrauma had significant differences from those of the control group. This may be evidence of activation of the vascular-platelet system of the hemostasis system and may be a prerequisite for late thrombotic complications in patients with polytrauma

ГЕМОСТАЗКОНТРОЛИРУЮЩАЯ АКТИВНОСТЬ И ВОДНЫЙ БАЛАНС ЛЕГКИХ В ДИНАМИКЕ ЭКСПЕРИМЕНТАЛЬНОЙ ИШЕМИИ МОЗГА

The study aims to investigate the system of hemostasis and fibrinolysis in venous and arterial blood, the features of blood filling and lung water balance, as well as the activity of lipid peroxidation (LPO) processes in the lung tissue iduring the acute cerebral ischemia. Material and methods. The experiments were performed on non-pedigree male rats, including control and sham operated ones. Acute cerebral ischemia was modeled by the bilateral occlusion of the common carotid arteries. Survived animals were assessed according to the degree of neurological deficit using the McGraw scale. Complex studies included determination of activated partial thromboplastin time, prothrombin time, time of XIIa-dependent fibrinolysis of arterial and venous blood, LPO intensity by the content of thiobarbituric acid active products and catalase activity in the lung tissue, the number of circulating endothelial cells; assessment of the lung blood filling and water balance by the gravimetric method. Results. In 24 hours after cerebral ischemia we found that the coagulation potential of blood increased in the systemic circulation and the pulmonary circulation affected by inhibition of the fibrinolysis system. On the 21st day of cerebral ischemia, dysregulation of hemostasis mechanisms in the pulmonary bloodstream was revealed in the form of hypercoagulation of blood and hyperfibrinolysis. At the same time the increase of malondialdehyde, blood circulation, and the content of the extravascular fluid in the lungs were noted. The correlation between the intensification of LPO processes with an imbalance of pro- and anticoagulants and hyperhydration of the lung tissue has been shown. The obtained results indicate a progressive course of disorders of the non-gas exchange functions of the lungs in the dynamics of acute experimental cerebral ischemia.

ITRAQ-based quantitative proteomics and network pharmacology revealing hemostatic mechanism mediated by Zingiberis Rhizome Carbonisata in deficiency-cold and Hemorrhagic Syndrome rat models

Zingiberis Rhizome Carbonisata (ZRC) has been used as a hemostatic agent in traditional Chinese medicine (TCM). However, the underlying molecular mechanism remains unclear. In this study, network pharmacology method was used to predict the potential mechanism of ZRC on hemostasis, based on the structures of the main compounds. Then, iTRAQ-based quantitative proteomics analysis was used for verification of the candidate target proteins and pathways to illustrate the underlying mechanisms. Furthermore, the differentially expressed proteins (DEPs) in the enriched pathways were validated by Enzyme-linked immunosorbent assay. The results showed that the hemostasis mechanism of ZRC may be related to Platelet activation, Rap1 signaling pathway and Complement and coagulation cascades. And 10 proteins (Fermt3, ACTB, Talin, αIIbβ3, Fga, Fgb, Fgg, FXIIIb, Kng and PLC-β were identified as the target DEPs) are considered as the key factors related to hemostatic efficacy of ZRC. Thus, integrated network pharmacology and quantitative proteomics technology were applied for the effective illuminating the molecular mechanisms of Chinese material medica.

The hemostatic mechanism of "Treated the Spleen" therapy on immune thrombocytopenia based on the characteristics of vasoactive factors.

To explore the effect mechanism of "treat the spleen" therapy on immune thrombocytopenia (ITP) based on the characteristics of vasoactive factors. The ITP mice model was established by passive immunomodeling. 120 successfully modeled BALB/c mice were randomly divided into 6 groups: normal group, model group, prednisone group, Guipi Decoction group, Jianpi Yiqi group, and Jianpi Shexue group. These mice were treated with medicine for 16 days. After treatment, the platelet (PLT) counts and the degree of bleeding were evaluated, and the serum ET-1, NO, NOS3, TXA2, PGI2, vWF, VCAM-1, and TM contents of the model mice were detected by enzyme-linked immunosorbent assay (ELISA). The PLT counts in peripheral blood of mice in each experimental group significantly decreased compared with that in the normal group (P<0.01). On the 8th day after commencing administration, compared with the model group, PLT counts of mice in each experimental group significantly increased (P<0.01). Before administration, all groups had different bleeding tendencies except for the normal group. On the 6th and 8th day of drug intervention, compared with the model group, the bleeding grade of treated groups was significantly decreased (P<0.01). The values of ET-1, vWF, and VCAM-1 in each experimental group significantly decreased compared with that in the normal group, while the TXA2 values were up-regulated compared with that in the normal and model groups (P<0.01). The values of NO and TM in each experimental group significantly decreased compared with that in the normal group (P<0.05). In addition to the Guipi Decoction group, the NOS3 values in each group were significantly decreased compared with that in the normal group (P<0.05). The PGI2 values of the "treat the spleen" groups were significantly decreased compared to the normal group (P<0.01). In addition to increasing the PLT counts in peripheral blood of ITP model mice to achieve a hemostatic effect, the "treat the spleen" recipes up-regulated the levels of TXA2 and VCAM-1, while down-regulating the levels of PGI2 and TM. Therefore, balancing the procoagulant and anticoagulant factors might be one of the effective mechanisms of hemostasis.

A microfluidic bleeding model to investigate the effects of blood flow shear on microvascular hemostasis

Hemorrhage is the phenomenon of blood loss caused by vascular trauma or other pathological reasons, which is life-threatening in severe cases. Because microhemorrhage is difficult to visually monitor and pre-treat in vivo, it is necessary to establish in vitro prediction methods to study the hemostasis mechanism in different physiological environments. In this study, a microfluidic bleeding model was developed to investigate the effect of blood flow shear on microvascular hemostasis. The results indicated that the regulation of blood shear rate on platelet aggregation affected the growth and morphology of hemostatic thrombus, and finally regulated the process of hemostasis. This in vitro model is significant to studies on hemostatic mechanisms, a reliable prediction of microhemorrhages, and an adjustment of the treatment scheme.

Selected Aspects of Camel Immune System and Immune Responses

The camel economy is of considerable importance for arid countries. In the last decade, studies about camel immune system and immune responses have recorded increasing interest. However, drawing a comprehensive picture of the camel immune system remains far from reached. A major part of this review is to cover the studies of the primary and secondary immune organs and the markers of the camel immune cells and certain lymphoid tissues. At the same time, immune responses to different diseases and the nature of effective immunity were included, with an emphasis on the most important zoonotic diseases in camels such as MERS CoV; brucellosis. New findings on the diversity mechanisms of camel immunoglobulin genes were addressed. However, detail of the mechanism of MHC-restricted cellular immunity and the mechanism of B lymphocyte activation in camels await further attention. Interestingly, the gross and the histological structure of the lymphoid tissues of the camel’s thymus, tonsils, and peyer’s patches have indicated significant differences from other animals in terms of structure and function. The most peculiar CD expression, such as LPAM-I, MAdCAM-1 and CX3CR1, in certain camel cells and tissues refers to possible extraordinary mechanisms of immune hemostasis in camel in comparison to other ruminants. The widely applied immunodiagnostic techniques to control camel diseases and to assist in improving the camel resistance were considered. Extensive studies of the camel immune system were greatly hampered by lack of specific reagents to camel markers and low funds in the field of camel immunology.

Изменение функциональной активности тромбоцитов при длительном световом воздействии в эксперименте

We studied the effect of intensive light exposure on the aggregation activity of white male rats' platelets using the experimental Light-Dark (18:6) lighting model. Analysis of platelet aggregation activity was carried out using a computerized 230LA "Biola" aggregation analyzer using the method of V.A. Gabbasov. It was established that in case of prolonged light exposure in the body of laboratory animals there was a disturbance of aggregation activity accompanied by an increase in the parameters of the curve of the average weighted radius of platelets and the parameters of the light transmittance curve. Violation of the daytime regime in the form of artificial prolongation of illumination causes increase of platelet aggregation activity and provokes development of microcirculatory disturbances. Forming changes in the hemostasis system increase in proportion to the duration of the experiment. The most pronounced changes in the vascular-platelet mechanism of hemostasis are formed on the 21st day of the experiment, indicating the development of processes of maladaptation followed by exhaustion of the organism.

Hemostasis Efficacy and Mechanism of Cold Atmospheric Air Plasma

The capacity of a cold atmospheric-pressure air plasma (CAAP) device for advanced first aid is presented. Using swine as an animal model, two trials: 1) a large, curved cut in hindquarters area and 2) amputation of a front leg, were performed. Cold atmospheric-pressure air plasma effluent, which carries reactive oxygen species (ROS) atomic oxygen (OI), is applied for wound treatments. Swift hemostasis of the wounds by the CAAP treatment was demonstrated. The pressure applied by a finger on the cut arteries in trial 1 and the tourniquet applied in trial 2 could be removed immediately after the treatment and there was no re-bleed in both cases. CAAP hemostasis mechanism was explored via in-vitro tests. The tests on sodium citrate mixed blood-droplet samples show that 1) the heat delivered by the CAAP has no impact on the observed clot formation, 2) plasma effluent activates platelets to promote coagulation state and cascade, and 3) the degree of clotting increases with the total amount of applied OI by means of the CAAP effluent. It took only 16 s of the CAAP treatment to reach full clotting, which was considerably shortened from the natural clotting time of about 25 minutes. The tests on smeared blood samples show that the reduction of the platelet count and the increase of RBC count are proportional to the amount of applied OI. A plausible CAAP hemostasis mechanism is concluded from the in vitro test results and the animal model trials.

Pathogenetic basis of venous thromboembolic complications as deuteropathies of COVID-19

Аt present, it can be noted without exaggeration that COVID-19 is the most serious challenge to the international system of practical health care in its recent history. Extremely high rates of morbidity and mortality dictate the need for a more detailed study of the pathogenetic aspects of the developing infectious disaster. In addition to respiratory distress syndrome, and systemic inflammatory response syndrome, COVID-19 is characterized by polyvalent disorders of the mechanisms of systemic hemostasis, which is reflected in the increase in the number of venous thromboembolic complications in the overall structure of morbidity and mortality. This literature review summarizes information on Covid-associated coagulopathy and its impact on changes in the clinical and epidemiological characteristics of venous thromboembolic complications.

Identification and verification of effective components of Huanghuai for dysfunctional uterine bleeding based on network pharmacology and molecular docking

ObjectiveThe Huanghuai (HH), which is made from the dried roots of Scutellaria baicalensis (Huangqin in Chinese) and the dried flowers and buds of Sophora japonica (Huaihua in Chinese), is a traditional Chinese formula used to treat dysfunctional uterine bleeding (DUB) (Benglou in Chinese) and proven to treat hemostasis effectively in our previous study. Network pharmacology and molecule docking were performed to study the underlying mechanism of Huanghuai (HH), and pharmacodynamic experiments were conducted to verify its curative effect. MethodsTCMSP, UniProt, GeneCards, STRING, DAVID databases, and Cytoscape 3.7.2 were utilized for the construction of a compound-target-pathway network. Docking the potential effective components with potential targets. The HPLC analysis of the potential effective components was performed. In vivo, the hot plate test model was used to study the analgesic activity, the egg white was used to study the swollen reaction in the sole in mice, and the hemostasis effect was studied by the capillary method, tail-breaking method and abortion uterus test. ResultsThe results showed that six compounds (acacetin, beta-sitosterol, wogonin, baicalein, kaempferol and quercetin) and four potential targets (PTGS2, AKT1, TP53 and TNF) in the compound-target-pathway network were the potential material basis for HH to treat DUB. It can be seen that the binding energy of the acacetin, wogonin, baicalein, beta-sitosterol, kaempferol and quercetin in HH docked with the receptor proteins PTGS2, AKT1, TP53, and TNF were far less than −5.0 kJ/mol, which means the molecules have low conformational energy, stable structure and high binding activity. And the result of HPLC analysis showed that acacetin, wogonin, baicalein, kaempferol and quercetin were the potential effective components of the hemostasis mechanism of HH, beta-sitosterol was removed due to low content. In vivo testing of the potential effective components, it revealed that the group of potential effective components identified by HPLC could increase the pain threshold, inhibit the swelling hind paws of mice induced by egg white, reduce the bleeding time and clotting time, reduce uterine bleeding, decrease the uterine weight, increase the content of Ca and ET-1, and reduce the content of NO in uterine homogenate tissue, and decrease of E2 and P content in uterine serum in aborted rats, whose efficacy was equal to HH. ConclusionThe results indicated that HH and potential active ingredient groups obtained from network pharmacology can treat DUB and play a hemostatic effect. The results obtained by network pharmacology have certain reliability. This study provides new indications for further mechanism research of HH on DUB and the development of HH or its components as an alternative therapy for patients with DUB. At the same time, the application of network pharmacology strategy may provide a powerful tool for exploring the mechanism of traditional Chinese medicine and discovering new biologically active ingredients.

The Role of Epigenetics in the Regulation of Hemostatic Balance.

Epigenetics, a term conventionally used to explain the intricate interplay between genes and the environment, is now regarded as the fundament of developmental biology. Several lines of evidence garnered over the past decades suggest that epigenetic alterations, mostly encompassing DNA methylation, histone tail modifications, and generation of microRNAs, play an important, though still incompletely explored, role in both primary and secondary hemostasis. Epigenetic variations may interplay with platelet functions and their responsiveness to antiplatelet drugs, and they may also exert a substantial contribution in modulating the production and release into the bloodstream of proteins involved in blood coagulation and fibrinolysis. This emerging evidence may have substantial biological and clinical implications. An enhanced understanding of posttranscriptional mechanisms would help to clarify some remaining enigmatic issues in primary and secondary hemostasis, which cannot be thoughtfully explained by genetics or biochemistry alone. Increased understanding would also pave the way to developing innovative tests for better assessment of individual risk of bleeding or thrombosis. The accurate recognition of key epigenetic mechanisms in hemostasis would then contribute to identify new putative therapeutic targets, and develop innovative agents that could be helpful for preventing or managing a vast array of hemostasis disturbances.