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Frontiers in Bioscience (Landmark... Jun 2016Heparin, a sulfated polysaccharide, has been used as a clinical anticoagulant for over 90 years. Newer anticoagulants, introduced for certain specialized applications,... (Review)
Review
Heparin, a sulfated polysaccharide, has been used as a clinical anticoagulant for over 90 years. Newer anticoagulants, introduced for certain specialized applications, have not significantly displaced heparin and newer heparin-based anticoagulants in most medical procedures. This chapter, while reviewing anticoagulation and these newer anticoagulants, focuses on heparin-based anticoagulants, including unfractionated heparin, low molecular weight heparins and ultra-low molecular weight heparins. Heparin's structures and its biological and therapeutic roles are discussed. Particular emphasis is placed on heparin's therapeutic application and its adverse effects. The future prospects are excellent for new heparins and new heparin-based therapeutics with improved properties.
Topics: Anticoagulants; Blood Coagulation; Disseminated Intravascular Coagulation; Extracorporeal Circulation; Heparin; Humans; Venous Thromboembolism
PubMed: 27100512
DOI: 10.2741/4462 -
Blood Mar 2022Disseminated intravascular coagulation (DIC) is a syndrome triggered by infectious and noninfectious pathologies characterized by excessive generation of thrombin within...
Disseminated intravascular coagulation (DIC) is a syndrome triggered by infectious and noninfectious pathologies characterized by excessive generation of thrombin within the vasculature and widespread proteolytic conversion of fibrinogen. Despite diverse clinical manifestations ranging from thrombo-occlusive damage to bleeding diathesis, DIC etiology commonly involves excessive activation of blood coagulation and overlapping dysregulation of anticoagulants and fibrinolysis. Initiation of blood coagulation follows intravascular expression of tissue factor or activation of the contact pathway in response to pathogen-associated or host-derived, damage-associated molecular patterns. The process is further amplified through inflammatory and immunothrombotic mechanisms. Consumption of anticoagulants and disruption of endothelial homeostasis lower the regulatory control and disseminate microvascular thrombosis. Clinical DIC development in patients is associated with worsening morbidities and increased mortality, regardless of the underlying pathology; therefore, timely recognition of DIC is critical for reducing the pathologic burden. Due to the diversity of triggers and pathogenic mechanisms leading to DIC, diagnosis is based on algorithms that quantify hemostatic imbalance, thrombocytopenia, and fibrinogen conversion. Because current diagnosis primarily assesses overt consumptive coagulopathies, there is a critical need for better recognition of nonovert DIC and/or pre-DIC states. Therapeutic strategies for patients with DIC involve resolution of the eliciting triggers and supportive care for the hemostatic imbalance. Despite medical care, mortality in patients with DIC remains high, and new strategies, tailored to the underlying pathologic mechanisms, are needed.
Topics: Blood Coagulation; Disseminated Intravascular Coagulation; Fibrinolysis; Hemostasis; Humans; Thrombosis
PubMed: 34428280
DOI: 10.1182/blood.2020007208 -
American Journal of Health-system... Feb 2022To provide an overview of current literature on the pathophysiology of sepsis, with a focus on mediators of endothelial injury and organ dysfunction. (Review)
Review
PURPOSE
To provide an overview of current literature on the pathophysiology of sepsis, with a focus on mediators of endothelial injury and organ dysfunction.
SUMMARY
Sepsis is a dysregulated response to infection that triggers cascades of interconnected systems. Sepsis has been a significant cause of mortality worldwide, and the recent viral pandemic that may produce severe sepsis and septic shock has been a major contributor to sepsis-related mortality. Understanding of the pathophysiology of sepsis has changed dramatically over the last several decades. Significant insight into the components of the inflammatory response that contribute to endothelial injury and trigger coagulation pathways has been achieved. Similarly, characterization of anti-inflammatory pathways that may lead to secondary infections and poor outcome has illustrated opportunities for improved therapies. Description of an increasing number of important mediators and pathways has occurred and may point the way to novel therapies to address immune dysregulation. Pharmacists will need a fundamental understanding of the overlapping pathways of the immune response to fully prepare for use of novel treatment options. While pharmacists typically understand coagulation cascade how to utilize anticoagulants, the issues in sepsis related coagulopathy and role of mediators such as cytokines and complement and role of activated platelets and neutrophils require a different perspective.
CONCLUSION
Pharmacists can benefit from understanding both the cellular and organ system issues in sepsis to facilitate assessment of potential therapies for risk and benefit.
Topics: Anticoagulants; Blood Coagulation; Blood Coagulation Disorders; Humans; Sepsis; Shock, Septic
PubMed: 34605875
DOI: 10.1093/ajhp/zxab380 -
Journal of the American College of... Aug 2021Hemostasis and thrombosis are believed to be so intricately linked that any strategies that reduce thrombosis will have an inevitable impact on hemostasis. Consequently,... (Review)
Review
Hemostasis and thrombosis are believed to be so intricately linked that any strategies that reduce thrombosis will have an inevitable impact on hemostasis. Consequently, bleeding is viewed as an unavoidable side effect of anticoagulant therapy. Emerging evidence suggests that factor XI is important for thrombosis but has a minor role in hemostasis. This information raises the possibility that anticoagulants that target factor XI will be safer than currently available agents. The authors provide a visual representation of the coagulation pathways that distinguishes between the steps involved in thrombosis and hemostasis to explain why factor XI inhibitors may serve as hemostasis-sparing anticoagulants. A safer class of anticoagulants would provide opportunities for treatment of a wider range of patients, including those at high risk for bleeding. Ongoing clinical studies will determine the extent to which factor XI inhibitors attenuate thrombosis without disruption of hemostasis.
Topics: Blood Coagulation; Factor Xa Inhibitors; Hemostasis; Humans; Thrombosis
PubMed: 34353538
DOI: 10.1016/j.jacc.2021.06.010 -
Blood Jan 2017Despite the introduction of direct oral anticoagulants (DOACs), the search for more effective and safer antithrombotic strategies continues. Better understanding of the... (Review)
Review
Despite the introduction of direct oral anticoagulants (DOACs), the search for more effective and safer antithrombotic strategies continues. Better understanding of the pathogenesis of thrombosis has fostered 2 new approaches to achieving this goal. First, evidence that thrombin may be as important as platelets to thrombosis at sites of arterial injury and that platelets contribute to venous thrombosis has prompted trials comparing anticoagulants with aspirin for secondary prevention in arterial thrombosis and aspirin with anticoagulants for primary and secondary prevention of venous thrombosis. These studies will help identify novel treatment strategies. Second, emerging data that naturally occurring polyphosphates activate the contact system and that this system is critical for thrombus stabilization and growth have identified factor XII (FXII) and FXI as targets for new anticoagulants that may be even safer than the DOACs. Studies are needed to determine whether FXI or FXII is the better target and to compare the efficacy and safety of these new strategies with current standards of care for the prevention or treatment of thrombosis. Focusing on these advances, this article outlines how treatment strategies for thrombosis are evolving and describes the rationale and approaches to targeting FXII and FXI. These emerging anticoagulant strategies should address unmet needs and reduce the systemic underuse of anticoagulation because of the fear of bleeding.
Topics: Animals; Anticoagulants; Blood Coagulation; Factor XI; Factor XII; Humans; Thrombosis
PubMed: 27780803
DOI: 10.1182/blood-2016-09-692996 -
International Journal of Molecular... Apr 2023Trauma remains one of the leading causes of death in adults despite the implementation of preventive measures and innovations in trauma systems. The etiology of... (Review)
Review
Trauma remains one of the leading causes of death in adults despite the implementation of preventive measures and innovations in trauma systems. The etiology of coagulopathy in trauma patients is multifactorial and related to the kind of injury and nature of resuscitation. Trauma-induced coagulopathy (TIC) is a biochemical response involving dysregulated coagulation, altered fibrinolysis, systemic endothelial dysfunction, platelet dysfunction, and inflammatory responses due to trauma. The aim of this review is to report the pathophysiology, early diagnosis and treatment of TIC. A literature search was performed using different databases to identify relevant studies in indexed scientific journals. We reviewed the main pathophysiological mechanisms involved in the early development of TIC. Diagnostic methods have also been reported which allow early targeted therapy with pharmaceutical hemostatic agents such as TEG-based goal-directed resuscitation and fibrinolysis management. TIC is a result of a complex interaction between different pathophysiological processes. New evidence in the field of trauma immunology can, in part, help explain the intricacy of the processes that occur after trauma. However, although our knowledge of TIC has grown, improving outcomes for trauma patients, many questions still need to be answered by ongoing studies.
Topics: Adult; Humans; Critical Illness; Blood Coagulation Disorders; Blood Coagulation; Fibrinolysis; Hemostatics; Wounds and Injuries
PubMed: 37108280
DOI: 10.3390/ijms24087118 -
Seminars in Cell & Developmental Biology Apr 2021The ability to study the behavior of cells, proteins, and cell-cell or cell-protein interactions under dynamic forces such as shear stress under fluid flow, provides a... (Review)
Review
The ability to study the behavior of cells, proteins, and cell-cell or cell-protein interactions under dynamic forces such as shear stress under fluid flow, provides a more accurate understanding of the physiopathology of hemostasis. This review touches upon the traditional methods for studying blood coagulation and platelet aggregation and provides an overview on cellular and protein response to shear stress. We also elaborate on the biological aspects of how cells recognize mechanical forces and convert them into biochemical signals that can drive various signaling pathways. We give a detailed description of the various types of microfluidic devices that are employed to study the complex processes of platelet aggregation and blood coagulation under flow conditions as well as to investigate endothelial shear-response. We also highlight works mimicking artificial vessels as platforms to study the mechanisms of coagulation, and finish our review by describing anticipated clinical uses of microfluidics devices and their standardization.
Topics: Blood Coagulation; Hemostasis; Humans; Lab-On-A-Chip Devices; Platelet Aggregation; Signal Transduction; Thrombosis
PubMed: 32563678
DOI: 10.1016/j.semcdb.2020.06.002 -
Blood Reviews Sep 2016Blood flow regulates coagulation and fibrin formation by controlling the transport, or mass transfer, of zymogens, co-factors, enzymes, and inhibitors to, from, and... (Review)
Review
Blood flow regulates coagulation and fibrin formation by controlling the transport, or mass transfer, of zymogens, co-factors, enzymes, and inhibitors to, from, and within a growing thrombus. The rate of mass transfer of these solutes relative to their consumption or production by coagulation reactions determines, in part, the rate of thrombin generation, fibrin deposition, and thrombi growth. Experimental studies on the influence of blood flow on specific coagulation reactions are reviewed here, along with a theoretical framework that predicts how flow influences surface-bound coagulation binding and enzymatic reactions. These flow-mediated transport mechanisms are also used to interpret the role of binding site densities and injury size on initiating coagulation and fibrin deposition. The importance of transport of coagulation proteins within the interstitial spaces of thrombi is shown to influence thrombi architecture, growth, and arrest.
Topics: Blood Coagulation; Humans; Regional Blood Flow; Rheology
PubMed: 27133256
DOI: 10.1016/j.blre.2016.04.004 -
Immunobiology Nov 2023The immune complement and the coagulation systems are blood-based proteolytic cascades that are activated by pathway-specific triggers, based on protein-protein... (Review)
Review
The immune complement and the coagulation systems are blood-based proteolytic cascades that are activated by pathway-specific triggers, based on protein-protein interactions and enzymatic cleavage reactions. Activation of these systems is finely balanced and controlled through specific regulatory mechanisms. The complement and coagulation systems are generally viewed as distinct, but have common evolutionary origins, and several interactions between these homologous systems have been reported. This complement and coagulation crosstalk can affect activation, amplification and regulatory functions in both systems. In this review, we summarize the literature on coagulation factors contributing to complement alternative pathway activation and regulation and highlight molecular interactions of the complement alternative pathway regulator factor H with several coagulation factors. We propose a mechanism where factor H interactions with coagulation factors may contribute to both complement and coagulation activation and regulation within the haemostatic system and fibrin clot microenvironment and introduce the emerging role of factor H as a modulator of coagulation. Finally, we discuss the potential impact of these protein interactions in diseases associated with factor H dysregulation or deficiency as well as evidence of coagulation dysfunction.
Topics: Humans; Complement Factor H; Blood Coagulation; Blood Coagulation Factors; Complement System Proteins; Thrombosis; Complement Activation
PubMed: 37633063
DOI: 10.1016/j.imbio.2023.152707 -
Nanomedicine (London, England) Jun 2013Nanoparticle interactions with the blood coagulation system can be beneficial or adverse depending on the intended use of a nanomaterial. Nanoparticles can be engineered... (Review)
Review
Nanoparticle interactions with the blood coagulation system can be beneficial or adverse depending on the intended use of a nanomaterial. Nanoparticles can be engineered to be procoagulant or to carry coagulation-initiating factors to treat certain disorders. Likewise, they can be designed to be anticoagulant or to carry anticoagulant drugs to intervene in other pathological conditions in which coagulation is a concern. An overview of the coagulation system was given and a discussion of a desirable interface between this system and engineered nanomaterials was assessed in part I, which was published in the May 2013 issue of Nanomedicine. Unwanted pro- and anti-coagulant properties of nanoparticles represent significant concerns in the field of nanomedicine, and often hamper the development and transition into the clinic of many promising engineered nanocarriers. This part will focus on the undesirable effects of engineered nanomaterials on the blood coagulation system. We will discuss the relationship between the physicochemical properties of nanoparticles (e.g., size, charge and hydrophobicity) that determine their negative effects on the blood coagulation system in order to understand how manipulation of these properties can help to overcome unwanted side effects.
Topics: Animals; Blood Coagulation; Humans; Nanomedicine; Nanoparticles
PubMed: 23730696
DOI: 10.2217/nnm.13.49