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Platelet Storage Pool Defect
Platelet storage pool deficiency is a family of clotting disorders characterized by deficient granules in platelets. Individuals with these disorders have too few or abnormally functioning alpha granules, delta granules, or both alpha and delta granules and are therefore unable to form effective clots, which leads to prolonged bleeding. Platelet storage pool deficiency can be acquired or inherited. Symptoms and signs The symptoms individuals with platelet storage pool deficiency may experience include the following: * Easy bruising * Nose bleeds * Bleeding from gums * Heavy or prolonged menstrual bleeding (menorrhagia) or bleeding after childbirth * Abnormal bleeding after surgery, circumcision, or dental work Severity can vary widely from person to person, and individuals with platelet storage pool deficiency may not experience all of the above symptoms. Cause Platelet storage pool deficiency can be acquired or inherited. Inheritance may be autosomal dominant or autosomal rec ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Coagulopathy
Coagulopathy (also called a bleeding disorder) is a condition in which the blood's ability to coagulate (form clots) is impaired. This condition can cause a tendency toward prolonged or excessive bleeding ( bleeding diathesis), which may occur spontaneously or following an injury or medical and dental procedures. Coagulopathies are sometimes erroneously referred to as "clotting disorders", but a clotting disorder is the opposite, defined as a predisposition to excessive clot formation (thrombus), also known as a hypercoagulable state or thrombophilia. Signs and symptoms Coagulopathy may cause uncontrolled internal or external bleeding. Left untreated, uncontrolled bleeding may cause damage to joints, muscles, or internal organs and may be life-threatening. People should seek immediate medical care for serious symptoms, including heavy external bleeding, blood in the urine or stool, double vision, severe head or neck pain, repeated vomiting, difficulty walking, convulsions, or ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Bleeding Time
Bleeding time is a medical test done to assess the function of a person's platelets. It involves making a patient bleed, then timing how long it takes for them to stop bleeding using a stopwatch or other suitable devices. The term template bleeding time is used when the test is performed to standardized parameters. A newer alternative to the traditional bleeding time test is the platelet function screen performed on the PFA-100 analyzer. Usage The template bleeding time test is a method used when other more reliable and less invasive tests for determining coagulation are not available., which cites #* #* #* Historically, it was used whenever physicians needed information about platelet activation. Process The test involves cutting the underside of the subject's forearm, in an area where there is no hair or visible veins. The cut is of a standardized width and depth, and is done quickly by a template device. IVY method The IVY method is the traditional format for this test. ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Hypocoagulability
In medicine (hematology), bleeding diathesis is an unusual susceptibility to bleed (hemorrhage) mostly due to hypocoagulability (a condition of irregular and slow blood clotting), in turn caused by a coagulopathy (a defect in the system of coagulation). Therefore, this may result in the reduction of platelets being produced and leads to excessive bleeding. Several types of coagulopathy are distinguished, ranging from mild to lethal. Coagulopathy can be caused by thinning of the skin ( Cushing's syndrome), such that the skin is weakened and is bruised easily and frequently without any trauma or injury to the body. Also, coagulopathy can be contributed by impaired wound healing or impaired clot formation. Signs and symptoms Complications Following are some complications of coagulopathies, some of them caused by their treatments: Causes While there are several possible causes, they generally result in excessive bleeding and a lack of clotting. Acquired Acquired causes of c ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Antifibrinolytic
Antifibrinolytics are a class of medication that are inhibitors of fibrinolysis. Examples include aminocaproic acid (ε-aminocaproic acid) and tranexamic acid. These lysine Lysine (symbol Lys or K) is an α-amino acid that is a precursor to many proteins. Lysine contains an α-amino group (which is in the protonated form when the lysine is dissolved in water at physiological pH), an α-carboxylic acid group ( ...-like drugs interfere with the formation of the fibrinolytic enzyme plasmin from its precursor plasminogen by plasminogen activators (primarily t-PA and u-PA) which takes place mainly in lysine rich areas on the surface of fibrin. Another example, aprotinin, is a naturally-occurring broad-spectrum protease inhibitor; some countries refuse to approve this medication because it supposedly has a greater mortality rate than its alternatives (tranexamic acid and aminocaproic acid) and causes damage to the kidneys and heart. It is widely agreed that systemic aprotini ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Chédiak–Higashi Syndrome
Chédiak–Higashi syndrome (CHS) is a rare autosomal recessive disorder that arises from a mutation of a lysosomal trafficking regulator protein, which leads to a decrease in phagocytosis. The decrease in phagocytosis results in recurrent pyogenic infections, albinism, and peripheral neuropathy. In Chédiak–Higashi syndrome, the lysosomal trafficking regulator (LYST) gene is mutated, leading to disruption of protein synthesis as well as the storage and secretory function of lysosomal granules in white blood cells. This results in defective white blood cell function with enlarged vesicles. This syndrome also leads to neutropenia and phagocyte bactericidal dysfunction due to impaired chemotaxis. Deficiency in serotonin and adenosine-phosphate-containing granules in platelets causes impaired platelet aggregation, leading to prolonged bleeding time. Thus, patients are susceptible to infections and often present with oculo-cutaneous albinism and coagulation defects. Patients often p ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Hermansky–Pudlak Syndrome
Heřmanský–Pudlák syndrome (often written Hermansky–Pudlak syndrome or abbreviated HPS) is an extremely rare autosomal recessive disorder which results in Albinism, oculocutaneous albinism (decreased pigmentation), bleeding problems due to a platelet abnormality (platelet storage pool defect), and storage of an abnormal fat-protein compound (lysosome, lysosomal accumulation of ceroid lipofuscin). It is thought to affect around 1 in 500,000 people worldwide, with a significantly higher occurrence in Puerto Rico, Puerto Ricans, with a prevalence of 1 in 1800. Many of the clinical research studies on the disease have been conducted in Puerto Rico. There are eight classic forms of the disorder, based on the genetic mutation from which the disorder stems. It is named for František Heřmanský (1916–1980) and Pavel Pudlák (1927–1993). Signs and symptoms There are three main disorders caused by Hermansky–Pudlak syndrome, which result in these symptoms: * Albinism and eye ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Quebec Platelet Disorder
Quebec platelet disorder (QPD) is a rare autosomal dominant bleeding disorder first described in a family from the province of Quebec, Canada. The disorder is characterized by large amounts of the fibrinolytic enzyme urokinase-type plasminogen activator (uPA) in platelets. This causes accelerated fibrinolysis (blood clot breakdown) which can result in bleeding. Signs and symptoms Individuals with QPD are at risk for experiencing a number of bleeding symptoms, including joint bleeds, hematuria, and large bruising. Pathophysiology The disorder is characterized by large amounts of uPA in platelets.Kahr, 2001 Consequently, stored platelet plasminogen is converted to plasmin, which is thought to play a role in degrading a number of proteins stored in platelet α-granules. These proteins include platelet factor V, von Willebrand factor, fibrinogen, thrombospondin-1, and osteonectin. There is also a quantitative deficiency in the platelet protein multimerin 1 ( MMRN1). Furthermore, u ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Gray Platelet Syndrome
Gray platelet syndrome (GPS), or platelet alpha-granule deficiency, is a rare congenital autosomal recessive bleeding disorder caused by a reduction or absence of alpha-granules in blood platelets, and the release of proteins normally contained in these granules into the marrow, causing myelofibrosis. The name derives from the initial observation of gray appearance of platelets with a paucity of granules on blood films from a patient with a lifelong bleeding disorder. Signs and symptoms Signs of GPS typically arise at birth or in childhood, these signs and symptoms include thrombocytopenia, bruising susceptibility, and Nosebleed, epistaxis. Typically, the observed low platelet count in individuals is progressive, this can result in fatal hemorrhages later in life. Additionally, females who are affected may experience irregular menstrual cycles and heavy menstrual bleeding. Another common effect of GPS is myelofibrosis, where scar tissue builds up in the bone marrow causing it to b ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Platelet Alpha-granule
Alpha granules, (α-granules) also known as platelet alpha-granules are a cellular component of platelets. Platelets contain different types of granules that perform different functions, and include alpha granules, dense granules, and lysosomes. Of these, alpha granules are the most common, making up 50% to 80% of the secretory granules. Alpha granules contain several growth factors. Contents Contents include insulin-like growth factor 1, platelet-derived growth factors, TGF beta, platelet factor 4 (which is a heparin-binding chemokine) and other clotting proteins (such as thrombospondin, fibronectin, factor V, and von Willebrand factor). The alpha granules express the adhesion molecule P-selectin and CD63. These are transferred to the membrane after synthesis. The other type of granules within platelets are called dense granules. Clinical significance A deficiency of alpha granules is known as gray platelet syndrome Gray platelet syndrome (GPS), or platelet alpha-granule ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Platelet Aggregation Function
Platelets or thrombocytes () are a part of blood whose function (along with the coagulation factors) is to react to bleeding from blood vessel injury by clumping to form a blood clot. Platelets have no cell nucleus; they are fragments of cytoplasm from megakaryocytes which reside in bone marrow or lung tissue, and then enter the circulation. Platelets are found only in mammals, whereas in other vertebrates (e.g. birds, amphibians), thrombocytes circulate as intact mononuclear cells. One major function of platelets is to contribute to hemostasis: the process of stopping bleeding at the site where the lining of vessels (endothelium) has been interrupted. Platelets gather at the site and, unless the interruption is physically too large, they plug the hole. First, platelets attach to substances outside the interrupted endothelium: ''adhesion''. Second, they change shape, turn on receptors and secrete chemical messengers: ''activation''. Third, they connect to each other through r ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
