Related Experiment Video
Updated: Jun 29, 2025
08:13
Tail Vein Transection Bleeding Model in Fully Anesthetized Hemophilia A Mice
Published on: September 30, 2021
6.2K
Unresolved hemostasis issues in haemophilia.
Robert F Sidonio1, John W Weisel2, Darrel Stafford3
1Hemophilia of Georgia Center for Bleeding and Clotting Disorders of CHOA, Atlanta, Georgia, USA.
Summary
Red blood cells and extravascular Factor IX (FIX) are crucial for hemostasis in hemophilia patients. Understanding these factors and myosin
Area of Science:
- Hematology
- Hemostasis
- Hemophilia A
Background:
- Despite advancements in hemophilia treatments, fundamental aspects of hemostasis remain incompletely understood.
- Current understanding of hemostasis in persons with hemophilia (PwH) overlooks critical non-factor components and extravascular processes.
- Breakthrough bleeding events, particularly muscle hematomas, persist despite available factor and non-factor therapies.
Purpose of the Study:
- To review unresolved issues in hemophilia hemostasis, highlighting the roles of red blood cells, extravascular Factor IX (FIX), and skeletal muscle myosin.
- To underscore the importance of red blood cells in hemostasis, a function often overlooked in hemophilia research.
- To examine the significance of extravascular FIX and myosin in thrombin generation and potential therapeutic strategies for hemophilia.
Main Methods:
- Review of existing literature on red blood cell function in hemostasis.
- Analysis of the role of extravascular FIX in relation to unmodified and extended half-life FIX products.
- Investigation into the contribution of skeletal muscle myosin to prothrombinase complex assembly and thrombin generation.
Main Results:
- Red blood cells play a significant, yet often forgotten, role in the complex process of hemostasis.
- Extravascular FIX is critical for effective hemostasis, influencing the efficacy of both standard and long-acting FIX concentrates.
- Skeletal muscle myosin is implicated in prothrombinase assembly, potentially offering a novel target for mitigating muscle hematomas in hemophilia.
Conclusions:
- A comprehensive understanding of hemophilia hemostasis requires acknowledging the contributions of red blood cells and extravascular FIX.
- Targeting skeletal muscle myosin may provide a new avenue for preventing and treating breakthrough bleeding, especially muscle hematomas.
- Further research into these unresolved areas is essential for developing more effective hemophilia management strategies.
Keywords:
FIX deficiencyFVIII deficiencyblood coagulationheterogeneity in treatment effectsmedically unexplained symptomsMore Related Videos
09:38A Microfluidic Flow Chamber Model for Platelet Transfusion and Hemostasis Measures Platelet Deposition and Fibrin Formation in Real-time
Published on: February 14, 2017
13.8K
09:19In Vitro Microfluidic Disease Model to Study Whole Blood-Endothelial Interactions and Blood Clot Dynamics in Real-Time
Published on: May 24, 2020
8.9K
Related Concept Videos
01:24Disorders of Hemostasis
885
Hemostasis, the process that stops bleeding after a blood vessel injury, is crucial for maintaining the integrity of the circulatory system. However, disorders of hemostasis can disrupt this delicate balance, leading to either excessive clotting or bleeding. These disorders can be broadly classified into thromboembolic disorders and bleeding disorders.
Thromboembolic Disorders
Two factors primarily cause thromboembolic conditions.
Thromboembolic Disorders
Two factors primarily cause thromboembolic conditions.
885
01:05Introduction to Hemostasis
7.6K
Hemostasis is a complex physiological process that prevents excessive bleeding when a blood vessel is injured. It's crucial for maintaining the integrity of the circulatory system, as it ensures that our blood remains fluid while still within the vascular network and yet clots to prevent blood loss upon vessel injury.
The three phases of hemostasis involve many clotting factors present in plasma and several substances released by platelets and injured tissue cells. It is a fast, localized,...
The three phases of hemostasis involve many clotting factors present in plasma and several substances released by platelets and injured tissue cells. It is a fast, localized,...
7.6K
01:30Anticoagulant Drugs: Low-Molecular-Weight Heparins
690
Hemostasis is a crucial process that prevents excessive blood loss from damaged blood vessels. It involves various mechanisms such as vasoconstriction, platelet adhesion and activation, and fibrin formation. The importance of each mechanism depends on the type of vessel injury. In contrast, thrombosis is the abnormal formation of a blood clot within the blood vessels, leading to potential complications if the clot obstructs blood flow. Thrombosis can be caused by increased coagulability of the...
690
01:20Extrinsic and Intrinsic Pathways of Hemostasis
7.5K
Blood clotting or coagulation involves extrinsic and intrinsic pathways, which ultimately merge into the common pathway, forming a fibrin clot.
The Extrinsic Pathway
The extrinsic pathway of coagulation is typically initiated by tissue damage that exposes blood to tissue factor (TF), a protein released by the damaged tissue cells outside the blood vessels—this interaction with TF triggers biochemical reactions involving specific clotting factors. The key player here is Factor VII, which...
The Extrinsic Pathway
The extrinsic pathway of coagulation is typically initiated by tissue damage that exposes blood to tissue factor (TF), a protein released by the damaged tissue cells outside the blood vessels—this interaction with TF triggers biochemical reactions involving specific clotting factors. The key player here is Factor VII, which...
7.5K
01:22Formation of the Platelet Plug
6.1K
The platelet phase, the second stage of hemostasis, commences around 15-20 seconds after an injury. It follows and overlaps with the vascular phase, during which blood vessels constrict to minimize blood loss.
As the injured blood vessel contracts, endothelial cells undergo contraction, revealing collagen fibers in the basement membrane and underlying connective tissue. Furthermore, the plasma membrane of endothelial cells becomes adhesive, preparing the site for platelet adhesion. Platelets...
As the injured blood vessel contracts, endothelial cells undergo contraction, revealing collagen fibers in the basement membrane and underlying connective tissue. Furthermore, the plasma membrane of endothelial cells becomes adhesive, preparing the site for platelet adhesion. Platelets...
6.1K
01:16Clot Retraction and Fibrinolysis
5.8K
After a fibrin clot is formed, the next step is clot retraction, a vital process facilitated by platelet contractile proteins, such as actin and myosin. These proteins pull the fibrin strands closer together and condense the clot. This action reduces the size of the clot, creating a smaller, denser structure that effectively seals off the damaged vessel. Clot retraction consolidates the clot and helps with wound healing by bringing the edges of the damaged blood vessel closer together.
5.8K