DiaPharma Group, Inc.

A

a2 antiplasmin

Major inhibitor of plasmin produced and secreted by hepatocytes and stored in platelet alpha granules.

ACA

Anti-cardiolipin antibodies

Acquired Platelet Function Defect

Non-hereditary diseases or associated conditions that cause the platelets to not function properly. MEDLINEplus

Activated Partial Thromboplastin Time ( APTT)

Time in seconds required for clot formation in recalcified blood plasma after the addition of contact activators and platelet substitutes (phospholipids). APTT is used to monitor therapy with heparin and other anticoagulants.see also PTT

Activated Protein C (APC) Resistance

An acquired or inherited condition associated with an increased risk of venous thrombosis and most commonly associated with a mutation in the factor V gene. Patients with APC resistance have limited anticoagulant response to APC.

Activated Prothrombin Complex Concentrates

Two prothrombin complex concentrates are purposely "activated" so that they contain some FIX, FX, etc. in active form (FIXa, FXa, etc.).

Afibrinogenemia

The absence of fibrinogen in the blood.

Aggregometry

A quantitative assessment of platelet cohesion in a photometer by the detection of changes in light transmission through a suspension of platelets in plasma. The light transmission pattern is analyzed in response to a variety of agonists.

ALP

Alkaline Phosphatase

Alpha granule

A platelet storage organelle that contains hemostatic proteins.

Amino Acid

An organic compound containing an amino group (NH2), a carboxylic acid group (COOH), and any of various side groups, especially any of the 20 compounds that have the basic formula NH2CHRCOOH, and that link together by peptide bonds to form proteins or that function as chemical messengers and as intermediates in metabolism.

Angiology

The study of blood and lymph vessels. Gray's Anatomy

Antibody

A protein produced by the immune system in response to the presence of an antigen. It defends the body against substances identified by the immune system as potentially harmful. MEDLINEplus

Anticoagulant

A substance that prevents the clotting of blood also used in the prophylaxis and treatment of clotting disorders. see also oral anticoagulants

Antifibrinolytic

Inhibiting the breakdown of fibrin.

Antiphospholipid

Plasma IgG, IgM, or IgA antibodies against protein phospholipid complexes.

Antithrombin (AT)

Naturally occurring anticoagulant that inactivates thrombin, factors Xa, IXa, XIa, XIIa, and kallikrein, also enhanced by heparin. Also called Antithrombin III, ATIII. MEDLINEplus

Antigen

A substance that induces the formation of antibodies because it is recognized by the immune system as a threat. It may be a foreign (nonnative) substance from the environment (such as chemicals) or formed within the body (such as bacterial or viral toxins). MEDLINEplus

Antiphospholipid Syndrome

A disorder that is characterized by hypercoagulability due to the presence of antibodies against phospholipids.

Aorta

The main trunk of the systemic arteries, carrying blood from the left side of the heart to the arteries of all limbs and organs except the lungs. Gray's Anatomy

Apolipoprotein (Apo)

Any of various proteins that combine with a lipid to form a lipoprotein and are a constituent of chylomicrons, HDL, LDL, and VLDL.

Apoptosis

Disintegration of cells into membrane-bound particles that are then eliminated by phagocytosis or by shedding.

Arteriole

One of the small terminal branches of an artery, especially one that connects with a capillary.

Arteriosclerosis

A chronic disease in which thickening, hardening, and loss of elasticity of the arterial walls result in impaired blood circulation. It develops with aging, and in hypertension, diabetes, hyperlipidemia, and other conditions.

Atherosclerosis

A form of arteriosclerosis characterized by the deposition of atheromatous plaques containing cholesterol and lipids on the innermost layer of the walls of large and medium-sized arteries.

Artery

Any of the muscular elastic tubes that form a branching system and that carry blood away from the heart to the cells, tissues, and organs of the body. Gray's Anatomy

B

b thromboglobulin

Platelet specific alpha granule protein that can neutralize heparin, used to monitor early platelet activation.

B Cell

B Lymphocyte. Any of the lymphocytes that mature in the bone marrow and, when stimulated by a particular antigen, differentiate into plasma cells.

Basophil

A specific type of white blood cell. These cells are readily stained with basic dyes (this is where the name comes from). Basophils make up only a small portion of the number of white blood cells but are important parts of the body?s immune response. They release histamine and other chemicals that act on the blood vessels when the immune response is triggered. MEDLINEplusBloodline

Bernard-Soulier syndrome

A rare inherited disorder in which platelets are unable to respond to von Willebrand factor. Platelets aggregate normally in response to most stimulation but do not aggregate in response to ristocetin. The response to collagen is blunted.MEDLINEplus

BIA

Bio-immunoassay.

Biochemistry

The study of the chemical processes and substances of living matter.

Biology

The science of life and all its manifestations: an area of study concerned with living organisms, their form and structure, their behavior, their function, their origin, development, and growth and their relationship to their environment and to like and unlike organisms, both living and extinct.

Biotin

A water-soluble vitamin, generally classified as a B-complex vitamin essential for the metabolism of proteins and carbohydrates (like the other B vitamins), and in the synthesis of hormones and cholesterol.

Bleeding Time

A test that measures the speed in which small blood vessels close off to stop bleeding. This test is an initial screen of platelet function, capillary integrity and von Willebrand factor function. MEDLINEplus

Blood

Fluid consisting of plasma, blood cells, and platelets that is circulated by the heart through the vertebrate vascular system, carrying oxygen and nutrients to and waste materials away from all body tissues. Gray's Anatomy

Bloodstream

The flow of blood through the circulatory system of an organism.

Blood Clot

Blood clots (fibrin clots) are the clumps that results when blood coagulates. See also thrombus and embolism.

Thrombi or emboli can lodge in a blood vessel and block the flow of blood in that location. This blockage deprives the tissues in that location of normal blood flow and oxygen (ischemia). This can result in damage, destruction (infarction), or even death of the tissues (necrosis) in that area.

Sometimes, a piece of atherosclerotic plaque (see atherosclerosis), small pieces of tumor, fat globules, air, amniotic fluid or other materials can act in the same manner as a blood clot. MEDLINEplus

Blood Vessel

An elastic tubular channel, such as an artery, a vein, or a capillary, through which the blood circulates.

C

C1 Inhibiting Factor Test

C1 esterase Inhibitor. Complement activity (CH50, CH100, terminal complement component, or individual complement proteins) is measured to determine if complement is involved in the development of a number of diseases. Complement activity is also measured to monitor severity of a disease or determine efficiency of treatment. Patients with hereditary angioedema are often depleted of C1 esterase inhibitor. MEDLINEplus

Capillary

One of the minute blood vessels that connect arterioles and venules. These blood vessels form an intricate network throughout the body for the interchange of various substances, such as oxygen and carbon dioxide, between blood and tissue cells.

Carbohydrate

Any of a group of organic compounds that includes sugars, starches, celluloses, and gums and serves as a major energy source in the diet of animals. These compounds are produced by photosynthetic plants and contain only carbon, hydrogen, and oxygen, usually in the ratio 1:2:1.

Carboxypeptidase

An enzyme that catalyzes the hydrolysis of the terminal amino acid of a polypeptide from the end that contains a free carboxyl group.

Cardiology

The medical study of the structure, function, and disorders of the heart.

Cardiovascular Disease (CVD)

Disease of the cardiovascular system.

Cardiovascular System

Circulatory System. The bodily system consisting of the heart, blood vessels, and blood that circulates blood throughout the body, delivers nutrients and other essential materials to cells, and removes waste products.

Carriers

Individuals who carry the gene for a condition but do not have the condition themselves.

Cell

The smallest structural unit of living tissue capable of functioning as an independent entity. It consists of a small mass of protoplasm often bounded by a semipermeable membrane, containing usually one or more nuclei and the various nonliving products of its activities, and able to carry on independently all the basic life functions.

CELIA

Competitive Enzyme Immuno Assay

Chemistry

The study of the composition, properties and structure of substances, and of the changes they undergo.

Christmas Disease

see FIX hemophilia.

Chromogenic Assay

Enzymes are proteins that catalyze most of the chemical reactions that take place in the body. The chemical compound upon which the enzyme exerts its catalytic activity is called a substrate. Chromogenic substrates are peptides that react with proteolytic enzymes thus forming color. Attached to the peptide part of the chromogenic substrate is a chemical group which when released after the enzyme cleavage gives rise to color. This leaving group is called a chromophore, and pNA is used in Chromogenix substrates. The color change can be followed spectrophotometrically and is proportional to the proteolytic activity.

Chromogenic Substrate

Peptides that react with proteolyticenzymes thus forming color.

Chromophore

A chemical group capable of selective light absorption resulting in the coloration of certain organic compounds.

Chromosomes

Threadlike structures inside human cells that contain thousands of genes and that are passed down through families. See X-chromosome and Y-chromosome.

Circulatory System

see Cardiovascular System

Citrate

A salt or ester of citric acid.

Clone

A gene that has been copied by chemical methods in a laboratory.

Clot

See Blood Clot

Coagulation

The process in which a liquid (blood) turns to a curdlike or jellylike consistency (congeal).

Coagulation Cascade

As a result of the coagulation process, fibrinogen is split into fibrin monomer and fibrin. Fibrin monomer polymerizes to form fibrin polymer (the clot).

Coagulation factor inhibitors and plasmin (which eventually lyses the fibrin clot) are simultaneously activated by damaged tissue, but they function more slowly and over a longer period of time than the coagulation factors. The most important of the coagulation inhibitors is antithrombin III, a protein that requires endogenous (produced by the body) heparin for its activity.

COAGULATION CASCADE ILLUSTRATIONS

Coagulation FIX Concentrate

Factor IX products which contain very little or no coagulation factors other than FIX, including AlphaNine SD and Mononine.

Coagulapathy

Bleeding disorders.

Complete Blood Count

(CBC)

Quantitates the number of red blood cells (RBCs), white blood cells (WBCs), the total amount of hemoglobin in the blood, the fraction of the blood composed of cells (hematocrit), and the size of the red blood cells (MCV, mean corpuscular volume). It also includes indices that are calculated from the other measurements. The CBC is a screening test, used to diagnose and manage numerous diseases. It can reflect problems with fluid volume (such as dehydration) or loss of blood. It can show abnormalities in the production, life span, and destruction of blood cells. It can reflect acute or chronic infection, allergies, and problems with clotting. MEDLINEplus

Contact Activation

Process that initiates the intrinsic pathway of coagulation through contact with a variety of negatively-charged surfaces.

Control Plasma

A preparation of fresh, frozen or lyophilized plasma collected from human or animal blood or artificially derived material, intended for use in the quality control process. Control plasmas are used to monitor all aspects of the laboratory test system, including the reagents, instruments, reconstituting and diluting fluids and pipettes. Normal controls should give test results within the reference interval. Abnormal control plasmas should give values within the clinically relevant abnormal range.

COOH

Coronary

Of, relating to, or being the coronary arteries or veins, or the heart. A coronary thrombosis or heart attack.

Coronary Artery

Either of two arteries that originate in the aorta and supply blood to the muscular tissue of the heart.

Coronary Vein

Any one of the veins that drains blood from the muscular tissue of the heart and empties into the coronary sinus.

Corpuscle

An unattached body cell, such as a red blood cell or lymph cell. Gray's Anatomy

Coumadin

Brand name of Warfarin.

Coumarin

A vitamin K antagonist administered orally that is routinely used in the clinical management of thrombosis.

CRP

C-reactive protein

CSE

Control Standard Endotoxin

Cytokine

Any of several regulatory proteins, such as the interleukins and lymphokines, that are released by cells of the immune system and act as intercellular mediators in the generation of an immune response.

Cytoplasm

The protoplasm outside the nucleus of a cell.

D

D-dimer

Terminal degradation product of a fibrin clot. One of several peptides released as a result of the action of plasmin on fibrin.

Deep Venous Thrombosis (DVT)

A condition where there is a blood clot in a deep vein (a vein that accompanies an artery). DVT affects mainly the veins in the lower leg and the thigh. It involves the formation of a clot (thrombus) in the larger veins of the area. This thrombus may interfere with circulation of the area, and it may break off and travel through the blood stream (embolize). The embolus thus created can lodge in the brain, lungs, heart, or other area, causing severe damage to that organ.MEDLINEplus

Deoxyribonucleic Acid (DNA)

The chemical substance that makes up genes.

Desmopressin Acetate

(DDAVP, Stimate) A synthetic analogue of the natural pituitary antidiuretic hormone, 8-arginine vasopressin. When given to persons who have the capability of producing some FVIII or vWF, the drug effects a rapid, transient increase in FVIII and vWF. It can be given intravenously, subcutaneously, or by intranasal spray. The intranasal spray form is called Stimate.

Diazo

Relating to or containing a pair of bonded nitrogen atoms, one of which is also bonded to an aromatic hydrocarbon.

Dimer

A molecule consisting of two identical simpler molecules.

Disseminated Intravascular Coagulation

(DIC)

A disorder of diffuse activation of the clotting cascade that results in depletion of clotting factors in the blood. DIC occurs when the blood clotting mechanisms are activated throughout the body instead of being localized to an area of injury. Small blood clots form throughout the body, and eventually the blood clotting factors are used up and not available to form clots at sites of tissue injury. Clot dissolving mechanisms are also increased. This disorder is variable in its clinical effects, and can result in either clotting symptoms or, more often, bleeding. Bleeding can be severe. DIC may be stimulated by many factors including infection in the blood by bacteria or fungus, severe tissue injury as in burns and head injury, cancer, reactions to blood transfusions, and obstetrical complications such as retained placenta after delivery.

Risk factors are recent sepsis, recent injury or trauma, recent surgery or anesthesia, complications of labor and delivery, leukemia or disseminated cancer, recent blood transfusion reaction, and severe liver disease. MEDLINEplusBloodline

Drug-induced Immune Thrombocytopenia

A condition where the use of certain drugs leads to the formation of antibodies against platelets. If these antibodies are formed during pregnancy, they may pass from the mother to the fetus.MEDLINEplus

Drug-induced Non-immune Thrombocytopenia

A reduction in normally functioning platelets that can be caused by certain drugs. Certain drugs may decrease the number of platelets by damaging the bone marrow where platelets are made. Decreased platelets may cause easy bruising or abnormal bleeding. MEDLINEplus

Dysfibrinogenemia

Malfunction of fibrinogen in the blood.

E

Edema

An excessive accumulation of serous fluid in tissue spaces or a body cavity.

EDTA

Ethylenediarnine tetraacetate. A crystalline acid, C10H16N2O8, that acts as a strong chelating agent. The sodium salt of EDTA is used as an antidote for metal poisoning, an anticoagulant, and an ingredient in a variety of industrial reagents.

EIA

Enzyme immunoassay

ELISA

Enzyme-linked immunosorbent assay

Scientists can design ELISAs in various ways to accommodate their specific application. The initial step is to adsorb one of the reactants--either the primary antibody, in order to capture the target antigen, or the antigen itself--to the solid phase (i.e. microtiter plate wells). After the excess is washed away, the second component is added and reacts specifically with the first. The final step is the chromogenic reaction of the enzyme with its substrate that identifies the complex bound to the solid phase. The amount of colored end product is proportional to the amount of target substance in the test.

In what is called an ELISA sandwich assay, a suitable antibody is adsorbed first to the solid phase, and the excess washed away. Then the sample is applied to the wells. If the target substance is present in the sample, it will be specifically bound by the antibody on the well's surface. Unbound substances are washed away. Next, a second enzyme-labeled antibody is added, which binds to another epitope on the antigen, leaving an enzymatic tag. When the chromogenic substrate is added, the enzyme converts it to a brightly colored product that signifies the antigen's presence. Antibodies can also be detected rather than antigens in an ELISA system.

The choice of ELISA enzyme label is highly dependent on an investigator's application. The two most common enzyme choices are horseradish peroxidase (HRP) and alkaline phosphatase (ALP). MEDLINEplus

ELISpot

Enzyme-linked immuno-spot

The ELISpot assay was first described two decades ago as a useful assay for the detection of specific immune responses on a single cell level. The optimization of the assay through the introduction of specifically designed antibodies, 96-well plates, automated reader systems and other tools has broadened its application. Today, the ELISpot assay is used for a wide range of applications including monitoring of immune responses in patients undergoing immunotherapeutical treatment, or specific immunological response patterns in patients with infectious, cancerous or autoimmune diseases. It is an important tool for identifying antigenicpeptides and creating vaccination strategies.

The advantage of the ELISpot assay is the possibility to identify antigen-specific T- or B cells on a single cell level without long-term in vitro culture or addition of exogenous cytokines like IL-2. Therefore, the response measured mirrors closely in vivo conditions. The ELISpot assay exhibits an outstanding high sensitivity. Furthermore, the ELISpot assay overcomes the hurdle of working with radioactive substances or fresh cells only. The ELISpot Resource Group

Embolism

A clot that travels from the site where it formed to another location in the body. Thrombi or emboli can lodge in a blood vessel and block the flow of blood in that location depriving tissues of normal blood flow and oxygen. This can result in damage, destruction (infarction), or even death of the tissues (necrosis) in that area. MEDLINEplus

Embolus

Solid mass blocking the circulation in the blood vessel.

Endogenous

Any factor or mechanism acting or derived from the system from which the analytical sample is taken.

Endotoxin (ET)

see Sepsis

Enzyme

One of a large class of complex proteinaceous substances of high molecular weight formed in and produced by living matter which are responsible for promoting the chemical reactions upon which life depends (e.g. digestion, respiration, reproduction). They accomplish this by acting like catalysts while themselves undergoing little or no change. Their action is often specific and reversible and may be dependent upon temperature, pH, and the presence of various coenzymes and activators (metallic salts, vitamins, etc.)

Eosinophil

White blood cells active in allergic diseases, fighting parasitic infections, and other disorders. An eosinophil count may be ordered if the blood differential is abnormal, or if there is suspicion for specific types of diseases. Increased levels of eosinophils (eosinophilia) are most often associated with allergic diseases and with parasites (such as worms). MEDLINEplusBloodline

Endothelium

Thin layer of flat epithelial cells that lines serous cavities, lymph vessels, and blood vessels.

Epithelium

Membranous tissue composed of one or more layers of cells separated by very little intercellular substance and forming the covering of most internal and external surfaces of the body and its organs.

Epitope

Localized region on the surface of an antigen capable of eliciting an immune response and of combining with a specific antibody to counter that response.

Erythrocyte

see red blood cell

Extrinsic Factor Deficiency

see Factor VII deficiency

Extrinsic Pathway

Activation of the clotting mechanism that begins with an extrinsic source such as tissue factor released from traumatized endothelium. Coagulation Cascade Illustration

Exogenous

Any factor or mechanism added to the sample either in vivo or to the sample in vitro.

F

Factor I

see Fibrinogen

Factor II

see Prothrombin

Factor II Deficiency

Hypoprothrombinemia; Prothrombin deficiency. A very rare disorder of blood clotting resulting from a deficiency of prothrombin. It is inherited as an autosomal recessive trait (both parents are carriers). Acquired Factor II deficiency is common and results from Vitamin K deficiency, severe liver disease, and therapeutic use of anticoagulant drugs. MEDLINEplus

Factor II Mutation

G to A substitution at the position 20210 in the 3' untranslated region of the prothrombin gene that leads to an increased risk of thrombosis.

Factor III

see Thromboplastin, Tissue Factor

Factor IV

Calcium

Factor V

Labile Factor

Factor V Deficiency

An inherited disorder that causes abnormal blood clotting, resulting from a deficiency of the plasma protein Factor V. The disease is similar to hemophilia, except bleeding into joints is less common. Bleeding can occur almost anywhere in the body, and death from hemorrhage has occurred with this disorder. MEDLINEplus

Factor V Mutation (Leiden)

Substitution of Gln for Arg in the 506 position of the factor V gene. This results in resistance to APC and risk of thrombosis.

Factor VII

Stable Factor

Factor VII Deficiency

Extrinsic factor deficiency. An inherited disorder that causes abnormal blood clotting caused by an inherited deficiency of Factor VII, an important clotting protein. MEDLINEplus

Factor VIII

Antihemophilic Factor (AHF); antihemophilic globulin (AHG); antihemophilic factor A, Factor VIII:C. A protein substance in blood plasma that participates in and is essential for the blood-clotting process. Most cases of hemophilia are caused by a deficiency of this factor.

Factor VIII Deficiency

Hemophilia A; Classical hemophilia. A hereditary disease found only in males characterized by excessive bleeding due to delayed clotting, even after minor injury, caused by a deficient activity of plasma protein factor VIII. MEDLINEplus

Factor IX

Plasma thromboplastin component (PTC); Christmas factor; antihemophilic factor B.

Factor IX Hemophilia

Hemophilia B; Christmas disease. A hereditary blood coagulation disorder caused by a deficiency of a plasma protein factor IX.

The disorder is caused by an inherited sex-linked recessive trait with the defective gene located on the X chromosome. Females carry two copies of the X chromosome, so if the factor IX gene on one chromosome is defective, the other can compensate. Males, however, carry only one X chromosome, so if the factor IX gene on that chromosome is defective, they have the disease. Females with one defective factor IX gene are carriers of this trait. Fifty percent of the male offspring of female carriers will have the disease, and 50% of their female offspring will be carriers. All female children of a male hemophiliac will be carriers of the trait. MEDLINEplus

Factor X

Stuart factor; Prower factor; Stuart-Prower factor.

Factor X Deficiency

Stuart-Prower deficiency. A rare inherited disorder that causes abnormal blood clotting resulting from a deficiency of the plasma protein Factor X.MEDLINEplus

Factor XI

Plasma thromboplastin antecedent (PTA); antihemophilic factor C

Factor XII

see Hageman factor; surface factor; contact factor

Factor XII Deficiency

An inherited disorder that causes prolonged clotting (coagulation) of blood in a test tube without a clinical bleeding tendency, and results from a deficiency of the plasma protein factor XII. It is not associated with abnormal bleeding, and is a rare disorder. MEDLINEplus

Factor XIII

Fibrin stabilizing factor (FSF); fibrin stabilizing enzyme; fibri-nase

Fibrin

A white insoluble protein formed from the precursor fibrinogen by the proteolytic activity of thrombin and precipitated as a tangle of threads when blood clots.

Fibrin Degradation Products (FDP)

FDPs; FSPs; Fibrin split products; Fibrin breakdown products.

The measurement of FDPs provides a direct indication of the activity of the fibrinolytic (clot-dissolving) system. When plasmin dissolves fibrinblood clots, FDPs are formed. These degradation products, which have an anticoagulant effect and inhibit clotting, can be measured. When they are present in large amounts, they indicate increased fibrinolysis, or clot breakdown, as occurs in DIC and primary fibrinolytic disorders.MEDLINEplus

Fibrinogen

Serum fibrinogen; Plasma fibrinogen; Factor I. Fibrinogen is a protein synthesized by the liver used in the blood to form a clot. It circulates in the blood as a soluble protein and when the clotting process is triggered, the soluble fibrinogen is converted to insoluble fibrin, the major protein that maintains integrity of the clot. It is cleaved (broken) by the enzymethrombin to form fibrinpeptides (short protein fragments) during normal coagulation. MEDLINEplus

Fibrinogen Assay

Assay for fibrinogen concentration - measured by the rate at which fibrinogen is converted to fibrin by the action of thrombin.

Fibrinolysis

The process by which a fibrin clot (blood clot) breaks down, caused by the action of several enzymes. Fibrinolysis occurs continuously and naturally in the body, with continuing formation and dissolution of clots in equilibrium.

However, the rate of fibrinolysis can be abnormally high because of stressors like intense exercise, inadequate oxygenation of tissues, low blood sugar, and bacterial infections. Primary fibrinolysis occurs as an "original" condition; secondary fibrinolysis develops because of another disorder, medications, or other causes.

In some cases, doctors may wish to speed up the rate of fibrinolysis. For example, when an abnormal "clot" forms in the coronary artery vessels, leading to a heart attack, man-made fibrinolytics such as tPA, streptokinase or retavase may be given intravenously to attempt to break up the culprit clot, if catheterization facilities are not readily available. MEDLINEplus

Fibrinopeptide

A molecular marker of thrombosis. Fibrinopeptide A and B are produced by the cleavage of fibrinogen by thrombin. Fibrinopeptide levels are an early indication of clot formation.

Fletcher factor

Prekallikrein

FPA

Fibrinopeptide a

Food Guide Pyramid

The relative proportions of different foods that make up a nutritious, well-balanced diet. MEDLINEplus

FSP

see Fibrin degradation products

G

Gamma-interferon

A lymphokine produced by macrophages and T cells that is involved in regulation of the immune system and activation of phagocytes.

Gene

Units of DNA that contain all the hereditary information needed to make a product, such as a protein.

Gene Therapy

Methods to correct a gene mutation by adding an intact (normal) one or changing one that is already present.

Genetic Markers

DNA pieces that are easy to identify but that themselves have nothing to do with the gene being examined, such as the gene for hemophilia.

Genotype

1. The genetic makeup, as distinguished from the physical appearance, of an organism or a group of organisms.
2. The combination of alleles located on homologous chromosomes that determines a specific characteristic or trait.

Glanzmann?s thrombasthenia

A rare inherited disorder where platelets fail to aggregate in response to normal stimulation but do clump normally in response to ristocetin. MEDLINEplus

Glycoprotein

A protein compound that also contains carbohydrate.

Glycosaminoglycan (GSG)

Mucopolysaccharide. Any of a group of polysaccharides with high molecular weight such as heparin, heparan sulfate, chondroitin sulfate, and dermatan sulfate that contain disaccharide repeating units containing N-acetylhexosamine and hexose or hexuronic acid and often form complexes with proteins.

Granulocyte

A type of white blood cell that includes neutrophils, eosinophils, and basophils.MEDLINEplus

H

Hageman Factor

see Factor XII deficiency

Haplotype

Closely linked genetic markers that are inherited together.

Heart

The chambered muscular organ in vertebrates that pumps blood received from the veins into the arteries, thereby maintaining the flow of blood through the entire circulatory system. Gray's Anatomy

Heart Attack

Sudden interruption or insufficiency of the supply of blood to the heart, typically resulting from occlusion or obstruction of a coronary artery and often characterized by severe chest pain.

Hematology

The branch of biology which deals with blood.

Hemocrit (HCT)

The percent of whole blood that is comprised of red blood cells. The hematocrit is a compound measure of RBC number and size. MEDLINEplus

Hemocyte

A blood cell, especially of an invertebrate animal.

Hemoglobin

Hgb; Hb. The protein which carries oxygen in the blood, and it is contained in red blood cells. Abnormalities of the hemoglobin value indicate defects in red blood cell homeostasis (balance). Both low and high values can indicate disease states. MEDLINEplus

Hemophilia

A group of inherited blood coagulation disorders characterized by decreased or dysfunctional clotting factors.

Hemophilia A

see Factor VIII deficiency hemophilia.

Hemophilia B

see Factor IX hemophilia.

Hemorrhage

Excessive discharge of blood from the blood vessels; profuse bleeding.

Hemostasis

The delicate balance between bleeding and excessive coagulation.

Heparin

An anticoagulant stored in, and released from the mast cells lying beneath the vascular endothelium.

Commercial heparins are extracted from animal tissues, purified, concentrated and have molecular weights of 3,000 to 57,000. Glycosaminoglycan and anticoagulant used to decrease the clotting ability of the blood and help prevent harmful clots from forming in the blood vessels. This medicine is sometimes referred to a blood thinner, although it does not actually thin the blood. Heparin interacts with antithrombin and other activated serine proteases resulting in anticoagulant activity. Heparin will not dissolve blood clots that have already formed, but it may prevent the clots from becoming larger and causing more serious problems.

Heparin is often used as a treatment for certain blood vessel, heart, and lung conditions. Heparin is also used to prevent blood clotting during open-heart surgery, bypass surgery, and dialysis. It is also used in low doses to prevent the formation of blood clots in certain patients, especially those who must have certain types of surgery or who must remain in bed for a long time. MEDLINEplus

Heparin Cofactor II

A thrombin inhibitor that demonstrates activation in the presence of heparin in a manner similar to antithrombin.

Heparin-associated thrombocytopenia (HAT)

Heparin-induced thrombocytopenia. HAT may present as a non-immune, self-limiting form of thrombocytopenia or an immune-based antibody - mediated, more severe form, and may be associated with thrombosis.

Hereditary

Inherited. Passed down through families.

Hirudin

A substance secreted by the buccal glands of leeches, capable of preventing coagulation by inactivating thrombin and used in medicine as an anticoagulant.

High-density Lipoprotein (HDL)

A complex of lipids and proteins in approximately equal amounts that functions as a transporter of cholesterol in the blood. High levels are associated with a decreased risk of atherosclerosis and coronary heart disease.

HIT

Heparin induced thrombocytopenia.

Homocysteine

A thiol containing amino acid that is produced by demethlyation of methionine. Hyperhomocysteinemia is a risk factor for both arterial and venous thrombosis.

HMW

High Molecular Weight.

HMW Kininogen

Fizgerald Factor

HRP

Horseradish Peroxidase.

Hyperlipidemia

Hyperlipemia. An excess of fats or lipids in the blood.

Hypofibrinogenemia

A low or deficient level of fibrinogen in the blood.

Hypoprothrombinemia

see Factor II deficiency

I

IgA

immunoglobulin A. The class of antibodies produced predominantly against ingested antigens, found in body secretions such as saliva, sweat, or tears, and functioning to prevent attachment of viruses and bacteria to epithelial surfaces.

IgG

immunoglobulin G. The most abundant class of antibodies found in blood serum and lymph and active against bacteria, fungi, viruses, and foreign particles. IgG antibodies trigger action of the complement system.

IgM

immunoglobulin M. The class of antibodies found in circulating body fluids and the first antibodies to appear in response to an initial exposure to an antigen.

Immunology

The branch of biomedicine concerned with the structure and function of the immune system, innate and acquired immunity, the bodily distinction of self from nonself, and laboratory techniques involving the interaction of antigens with specific antibodies.

Immune System

The integrated body system of organs, tissues, cells, and cell products such as antibodies that differentiates self from nonself and neutralizes potentially pathogenic organisms or substances.

Immune Thrombocytopenia Purpura

A marked decrease in platelet number as a result of circulating antiplatelet antibodies. The disorder is acquired and may present acutely or in chronic form.

INR

International Normalized Ratio. Universal scale of reporting PT results, recommended by the World Health Organization, based on calibration of local thromboplastin against an International Reference Preparation.

Interferon

Any of a group of glycoproteins that are produced by different cell types in response to various stimuli, such as exposure to a virus, bacterium, parasite, or other antigen, and that prevent viral replication in newly infected cells and, in some cases, modulate specific cellular functions. Interferon slows the rate of growth and division of cancer cells, causing them to become sluggish and die.

Interleukin-1

IL-1. Either of two proteins, released by macrophages and other cells, that induce the production of IL-2 by helper T cells and stimulate the inflammatory response.

Interleukin-2

IL-2. A lymphokine released by helper T cells in response to an antigen and IL-1 and stimulates the proliferation of helper T cells. It has been used experimentally to treat cancer by stimulating the growth of certain disease-fighting blood cells in the immune system.

Interleukin-3

IL-3. A lymphokine, released by helper T cells in response to an antigen or mitogen, that stimulates the growth of blood stem cells and lymphoid cells such as macrophages and mast cells.

Intrinsic Pathway

The part of the coagulation cascade that initiates with factor XII activation by a negatively charged surface. Coagulation Cascade Illustration

In Vitro

In an artificial environment outside the living organism.

In Vivo

Within a living organism.

ISI

International Sensitivity Index. A numerical ratio comparing the sensitivity of commercial working thromboplastins to the International Reference Preparation. The ISI is used to determine the INR for patient specimens.

ITP

Idiopathic thrombocytopenic purpura (idiopathic means the exact cause of the disease is unknown) is a bleeding disorder characterized by low platelet numbers resulting from platelet destruction by the immune system.MEDLINEplusBloodline

IU

International Units

IVD

In vitro diagnostic

K

Killer Cell

Any of various large differentiated T cells that recognize and lyse target cells bearing a specific foreign antigen, usually by infection with a virus, and that also function in defense against cancer cells.

L

LAL

Limulus Amebocyte Lysate

Leukocyte

see white blood cellGray's Anatomy

Lipid

Any of a group of organic compounds, including the fats, oils, waxes, sterols, and triglycerides, that are insoluble in water but soluble in nonpolar organic solvents, are oily to the touch, and together with carbohydrates and proteins constitute the principal structural material of living cells.

Lipopolysaccharide

Any of a group of polysaccharides in which a lipid constitutes a portion of the molecule.

Lipoprotein

Any of a group of conjugated proteins in which at least one of the components is a lipid. Lipoproteins, classified according to their densities and chemical qualities, are the principal means by which lipids are transported in the blood.

Lipoprotein(a)

A low density lipoprotein containing structures similar to the plasminogen molecule. Increased lipoprotein(a) has been identified as a major independent risk factor for coronary disease and stroke.

LMW

Low Molecular Weight

Low Molecular Weight Heparin (LMWH)

Heparin with a mean molecular weight of about 5,000 - commercially prepared by enzymatic depolymerization of conventional porcine heparin, LMWH does not prolong the APTT as much as high-molecular weight Heparin and binds less to platelets. A low molecular weight fraction of a heparin preparation that has more anti-Xa activity and more predictable dose response than standard, unfractionated heparin.

Low-density Lipoprotein (LDL)

A complex of lipids and proteins, with greater amounts of lipid than protein, that transports cholesterol in the blood. High levels are associated with an increased risk of atherosclerosis and coronary heart disease.

Lupus Anticoagulant

Antibodies against phospholipids which inhibit blood clotting in a test tube, but may be associated with a higher risk of clotting in people who have them in their blood.

Lymph

Clear, watery, sometimes faintly yellowish fluid derived from body tissues that contains white blood cells and circulates throughout the lymphatic system, returning to the venous bloodstream through the thoracic duct. Lymph acts to remove bacteria and certain proteins from the tissues, transport fat from the small intestine, and supply mature lymphocytes to the blood.

Lymphatic System

The interconnected system of spaces and vessels between body tissues and organs by which lymph circulates throughout the body. Gray's Anatomy

Lymphocyte

Any of the nearly colorless cells found in the blood, lymph, and lymphoid tissues, constituting approximately 25 percent of white blood cells and including B cells, which function in humoral immunity, and T cells, which function in cellular immunity.Bloodline

Lymphokine

Any of various substances released by T cells that have been activated by antigens. They function in the immune response through a variety of actions, including stimulating the production of nonsensitized lymphocytes and activating macrophages.

Lyophilize

To freeze-dry (blood plasma or other biological substances).

Lysis

The dissolution or destruction of cells, such as blood cells or bacteria, as by the action of a specific lysin that disrupts the cell membrane.

M

Macrophage

Any of the large phagocytic cells of the reticuloendothelial system.Bloodline

Mannitol

A white, crystalline, water-soluble, slightly sweet alcohol, C6H8(OH)6, used as a dietary supplement and dietetic sweetener and in medical tests of renal function.

Marker

A gene with a known location on a chromosome and a clear-cut phenotype, used as a point of reference when mapping a new mutant.

Mast Cell

A cell found in connective tissue that contains numerous basophilic granules and releases substances such as heparin and histamine in response to injury or inflammation of bodily tissues.

Mitogen

An agent that induces mitosis.

Molecule

The smallest particle of a substance that retains the chemical and physical properties of the substance and is composed of two or more atoms; a group of like or different atoms held together by chemical forces.

Monoclonal Antibody (mAb)

Any of the highly specific antibodies produced in large quantity by the clones of a single hybrid cell formed in the laboratory by the fusion of a B cell with a tumor cell. They can locate and bind to cancer cells wherever they are in the body. They can be used alone, or used to deliver drugs, toxins, or radioactive material directly to the tumor cells.

Monocyte

A large, circulating, phagocyticwhite blood cell, having a single well-defined nucleus and very fine granulation in the cytoplasm. Monocytes constitute from 3 to 8 percent of the white blood cells in humans.Bloodline

Mutation

A defect or change in a gene.

Myocardial Infarction (MI)

see heart attack

N

Necrosis

Death of a portion of tissue or an organ in the body. This is caused when not enough blood is supplied to the tissue, whether from trauma, radiation, or chemicals. When larger areas of tissues are dead, the tissue is called gangrene. MEDLINEplus

Neutrophil

A cell, especially an abundant type of granular white blood cell that is highly destructive of microorganisms.Bloodline

Nonactivating Surface

A surface that does not activate coagulation factors (as indicated by lengthening or shortening of the PT or APTT).

O

Oncology

The study or science dealing with the physical, chemical, and biologic properties and features of neoplasms, including causation, pathogenesis, and treatment.

Oral Anticoagulants

Anticoagulants which inhibit synthesis of vitamin K-dependent clotting factors and parental agents such as heparin, LMW Heparin and hirudin.

P

Peptide

Any of various natural or synthetic compounds containing two or more amino acids linked by the carboxyl group of one amino acid to the amino group of another.

Peroxidase

Any of a group of enzymes that occur especially in plant cells and catalyze the oxidation of a substance by a peroxide.

Phagocyte

Any type of cell that engulfs and destroys invading organisms.

Phagocytosis

The engulfing and ingestion of bacteria or other foreign bodies by phagocytes.

Phenotype

1. The observable physical or biochemical characteristics of an organism, as determined by both genetic makeup and environmental influences.
2. The expression of a specific trait, such as stature or blood type, based on genetic and environmental influences.

Phosphatase

Any of numerous enzymes that catalyze the hydrolysis of esters of phosphoric acid and are important in the absorption and metabolism of carbohydrates, nucleotides, and phospholipids and in the calcification of bone.

Phosphate

A salt or ester of phosphoric acid.

Phosphoric Acid

A clear colorless liquid, H3PO4, used in pharmaceuticals.

Phospholipid

Amphipathic biological molecule containing a polar, hydrophilic phosphate head group, and a hydrophobic hydrocarbon tail, which allows phospholipids to self assemble in water into a bi-layer.

Plaque

A deposit of fatty material on the inner lining of an arterial wall, characteristic of atherosclerosis.

Plasma

The viscous living matter of a cell surrounding the nucleus, the protoplasm.

Plasmin

Fibrinolysin. A proteolyticenzyme that is formed from plasminogen in bloodplasma and dissolves the fibrin in blood clots.

Plasminogen

The inactive precursor to plasmin that is cleaved by plasminogen activators tor form the active serine protease plasmin.

Plasminogen Activator

A group of serine proteases that cleave plasminogen to form plasmin including tPA, streptokinase, and urokinase.

Plasminogen Activator Inhibitor (PAI)

A class of serpin glycoprotein serpins that modulate the fibrinolytic system including PAI-1, PAI-2, PAI-3, and protease nexin.

Platelet

A microscopic, noncellular disk found in large numbers in vertebrate blood, produced in bone marrow from megakaryocyte, that is involved in the activation of prothrombin. Platelets are necessary for normal blood clotting. Most importantly, they aggregate (clump) together to plug small holes in damaged vessels. They also activate factor VIII and release phospholipids necessary for the coagulation cascade.MEDLINEplusBloodlineGray's Anatomy

Platelet Activation

One of the first steps in the coagulation process. Platelet activation in vitro can occur as a result of agitation of blood in the tube, difficult phlebotomy, shear stress arising from the phlebotomy process, and from increased contact with the inner surface of the tube, if the latter is comprised of an activating material. Once activated, platelets release protein, lipid, and other mediators which lead to aggregation and can result in shortened clotting times.

Platelet Aggregation

The term that refers to the platelet's ability to clump or attach to each other.

Platelet Aggregation Test

A test of the ability of platelets to clump together (aggregate) and cause blood clotting that helps to diagnose diseases of platelet dysfunction and distinguish between inherited bleeding problems (such as hemophilia or von Willebrand disease) and acquired bleeding problems (those that occur because of such things as another disorder or medication). MEDLINEplus

Platelet Antibodies

Antibodies to platelet antigens that are IgG or IgM isotype and are called platelet associated immunoglobulin or PAIg. The presence of increased PAIg on the platelet surface is an indication of immune thrombocytopenia.

Platelet Antigen

Antibodies to platelet antigens that are located on the platelet glycoproteins GPIa/IIa, GPIb/IX, and GP IIb/IIIa. Platelet antigen PLA1 is the most common antigen seen in alloimmune thrombocytopenia and in autoimmune thrombocytopenic purpura.

Platelet Associated Antibodies

A test to identify the presence of abnormal antiplatelet antibodies in plasma. MEDLINEplus

Platelet Count

Thrombocyte count. A test that measures the number of platelets in blood.A diminished number of platelets (below the lower limit of normal) is called thrombocytopenia and an elevated number (above the upper limit of normal) is called thrombocytosis. MEDLINEplus

Platelet Factor 4 (PF4)

A high-affinity heparin-binding protein that is stored in platelet alpha granules.

Platelet Rich Plasma

The preparation of whole blood by centrifugation to produce a supernatant fraction of high platelet content.

pNA

para-nitroaniline

Polybrene®

hexadimethrine bromide

Polyclonal

Descended from more than one group of cells, especially of genetically different origins.

Polymorphism

The occurrence of different forms, stages, or types in individual organisms or in organisms of the same species, independent of sexual variations. A genetic mutation with a frequency in the population of at least 1%

Polypeptide

A peptide, such as a small protein, containing many molecules of amino acids, typically between 10 and 100.

Prekallikrein

Fletcher factor

Primary Thrombocythemia

Primary thrombocythemia is a condition of overproduction of the platelet cells without a recognizable cause. MEDLINEplus

Protease (Proteolytic Enzymes)

Enzymes that degrade proteins into smaller peptides or amino acids to be used either as an energy source or as building blocks for resynthesis of proteins. See Proteolysis

Protein

Any of a class of naturally occurring, usually colloidal, complex combinations of amino acids (containing carbon, hydrogen, oxygen, nitrogen, usually sulfur, occasionally phosphorus) which are essential constituents of all living cells, being responsible for growth and maintenance of all tissue, and the essential nitrogenous constituent of the food of animals. They can be synthesized from inorganic nitrogenous material by plants, but apparently not by animals.

Protein C

A vitamin K-dependent protein produced in the liver that, when enzymatically converted to activated protein C, cleaves factors Va and VIIIa, and inactivates factors V and VIII. Deficient protein C can result in excessive clotting. These clots tend to form in veins, not arteries. MEDLINEplus

Protein C Deficiency

Protein C deficiency can be either inherited or acquired in association with other conditions. Liver disease, DIC, warfarin, and chemotherapy can result in decreased protein C levels. MEDLINEplus

Protein S

A vitamin K-dependent glycoprotein produced in the liver that serves as a cofactor to the activities of protein C. It inactivates factors V and VIII. MEDLINEplus

Protein S Deficiency

Deficient protein S can result in excessive clotting tendencies. These are usually vein clots, such as DVT, but occasionally this disorder can be associated with arterial clots. Deficiency may be inherited or acquired due to other conditions. This can be due to oral contraceptive use or pregnancy, and diseases such as DIC and HIV infection may also be associated with decreased levels of this protein. MEDLINEplus

Proteolysis

The hydrolytic breakdown of proteins into simpler, soluble substances such as peptides and amino acids, as occurs during digestion.

Prothrombin

Factor II. A carbohydrate-proteincompound in plasma that is converted by thromboplastin into thrombin during blood clotting.

Prothrombin Complex Concentrate (PCC)

PCC are plasma-derived and can be used to treat patients with deficiencies of factors II, VII and X as well as certain patients with inhibitors to factors VIII and IX.

Prothrombin Deficiency

see Factor II deficiency

Prothrombin Time (PT)

Prothrombin time; Pro-time. A test used for evaluation of the extrinsic and common coagulation pathway. The PT is the time in seconds required for a fibrin clot to form after tissue thromboplastin and an optimal amount of calcium chloride have been added to the sample (citrated plasma). Because it is sensitive to deficiencies of factor II, VII, and IX, the PT is the most common assay used to monitor warfarin therapy. MEDLINEplus

PTT

APTT; Partial thromboplastin time; Activated partial thromboplastin time. A test that measures the intrinsic clotting time in plasma.MEDLINEplus

Pulmonary Embolism

Sudden occlusion of the pulmonary artery or its branches by an embolus.

Q

R

Reagent

Substance employed to produce a chemical reaction in order to measure quantities, pertaining to other substances.

Recombinant Factor VIIa (rVIIa)

Refers to genetically engineered or cloned FVIIa that is not derived from human or animal plasma. Currently licensed rFVIIa products include NovoSeven.

Recombinant Factor VIII (rFVIII)

Recombinant (r) FVIII refers to genetically engineered or cloned FVIII that is not derived from human or animal plasma. Currently licensed rFVIII products include Recombinate (Bioclate), Kogenate (Helixate) and ReFacto (a deletion rFVIII product that lacks the B domain and contains no albumin stabilizer).

Recombinant Factor VIX (rFVIX)

Recombinant (r) FVIX refers to genetically engineered or cloned FVIII that is not derived from human or animal plasma. Currently licensed rFVIX products include BeneFix.

Red Blood Cell (RBC)

RBCs transport hemoglobin which, in turn, transport oxygen. The amount of oxygen received by tissue is dependent on the amount and function of RBCs and hemoglobin. RBCs normally survive for about 120 days in the blood; they are then removed by phagocytic cells in the spleen or Kupffer cells in the liver. MEDLINEplusGray's Anatomy

Ribonucleic Acid

(RNA)

A polymeric constituent of all living cells and many viruses, consisting of a long, usually single-stranded chain of alternating phosphate and ribose units with the bases adenine, guanine, cytosine, and uracil bonded to the ribose. The structure and base sequence of RNA are determinants of protein synthesis and the transmission of genetic information.

Russell's Viper Venom (RVV)

Stypven. Tissue thromboplastin derived from snake venom that can activate the coagulation cascade at factor X. This reagent is used to detect deficiency of factor X.

S

Secondary Fibrinolysis

The process by which a fibrin clot (blood clot) breaks down because of disorder, medications, or other causes. MEDLINEplus

Sepsis

Septic Shock

Systemic Inflammatory Response Syndrome (SIRS)

Sepsis is a serious, severe illness caused by infection of the bloodstream. Illness is a result of toxins produced by bacteria, and the body's response to these toxins.

Sepsis occurs in 2 of every 100 hospital admissions. It is a result of a bacterial infection that can originate anywhere in the body. Common sites are the kidneys (upper urinary tract infection), the liver or gall bladder, the bowel (usually seen with peritonitis), the skin (cellulitis) and the lungs (bacterial pneumonia).

Meningitis may also be accompanied by sepsis. In children, sepsis may accompany infection of the bone (osteomyelitis). In hospitalized patients, common sites of infection include intravenous lines, surgical wounds, surgical drains, and sites of skin breakdown known as decubitus ulcers or bedsores. MEDLINEplusBloodline

Septicemia

Blood poisoning; Bacteremia with sepsis. The presence of bacteria in the blood (bacteremia) and is often associated with severe disease. Septicemia is a serious, rapidly progressive, life-threatening infection that can arise from infections throughout the body, including infections in the lungs, abdomen, and urinary tract. It may precede or coincide with infections of the bone (osteomyelitis), central nervous system (meningitis), or other tissues. Septicemia can rapidly lead to septic shock and death. Septicemia associated with some organisms such as meningococci can lead to shock, adrenal collapse and DIC, a condition called Waterhouse-Friderichsen syndrome. MEDLINEplus

Serine Protease

Proteolyticenzyme with a reactive seryl amino acid residue in its active site. Selectively hydrolyzes peptide bonds containing arginine or lysine. Typically, these enzyme circulate in a precursor or zymogen form, being regulated by specific activators and inhibitors.

Serology

The study of serums and their reactions, especially the behavior of antibodies and antigens.

Serpin

Serine protease inhibitor

Serum

The clear yellowish fluid obtained upon separating whole blood into its solid and liquid components after it has been allowed to clot.

Single Nucleotide Polymorphism

A common genetic mutation involving a single nucleotide and therefore altering the amino acid encoded.

Sodium Citrate

Anticoagulant contained in the standard evacuated tubes used for coagulation testing. When evacuated tubes are filled to proper volume, they contain the recommended ratio of 9 parts blood to 1 part anticoagulant. Usually present at 3.2% or 3.8% concentration. A 3.2% concentration is generally recommended.

Stability

Ability of a system, when kept under specified conditions, to maintain a stated property value within specified limits for a specified period of time.

Streptavidin

A tetrameric protein which binds very tightly to the small molecule, biotin.

Streptococcus

Round to ovoid, gram-positive, often pathogenic bacterium of the genus Streptococcus that occurs in pairs or chains, many species of which destroy red blood cells and cause various diseases in humans, including erysipelas, scarlet fever, and strep throat.

Streptokinase

Proteolyticenzymethat is produced by hemolytic streptococci, is capable of converting plasminogen to plasmin, and is used medically to dissolve blood clots.

Storage Pool Disease

A group of disorders characterized by defective stimulation by materials, especially ADP, which trigger platelet aggregation.MEDLINEplus

Stuart-Prower Deficiency

see Factor X deficiency

Substrate

The substance upon which an enzyme acts.

suPAR

Soluble uPAR

Superficial Thrombophlebitis

An inflammation of a vein just below the surface of the skin, which results from a blood clot. MEDLINEplus

T

TAFI

Thrombin Activatable Fibrinolysis Inhibitor (plasma procarboxypeptidase B or U).

T Cell

T Lymphocyte. Any of the lymphocytes that mature in the thymus and have the ability to recognize specific peptideantigens through the receptors on their cell surface.

Thrombin

A potent coagulation enzyme derived from the precursor prothrombin which circulates in the blood and enables fibrinogen to form fibrin, causing blood clots.

Thrombin Time Test (TT)

A test used to evaluate the final steps of the coagulation pathway. The TT is the time in seconds required for a fibrin clot to form in a sample after a known amount of thrombin has been added.

Thrombogen

A blood clot (prothrombin).

Thrombocyte

see platelet

Thrombocytopenia

A disorder of where the number of platelets is low, typically below 150,000/mm3, which is sometimes associated with abnormal bleeding. MEDLINEplus

Thromboembolism

An obstruction of a vessel formed by a thrombus carried by the blood stream from the site of origin.

Thrombolysis

The lysing of thrombi by a series of events, most significantly involving the action of plasmin of the thrombus.

Thrombophlebitis

Avein inflammation related to a blood clot.Common causes of vein inflammation include local irritation (for example, because of an IV line), infection in or near a vein, and blood clots. Specific disorders associated with thrombophlebitis include superficial thrombophlebitis, DVT and pelvic vein thrombophlebitis. MEDLINEplus

Thromboplastin

Thrombokinase; Protease that converts prothrombin to thrombin in the early stages of blood clotting.

Thrombosis

The formation of a clot inside a blood vessel, especially in the coronary or cerebral arteries. Thrombosis in a coronary artery, which supplies the heart, results in a myocardial infarction. If this process occurs in the brain, the patient experiences a stroke.

Thrombotic Thrombocytopenic Purpura (TTP)

A disorder of the blood characterized by low platelets, low red blood cell count (caused by premature breakdown of the cells), and neurological abnormalities. MEDLINEplusBloodline

Thromboxane

A potent aggregating substance formed from arachidonic acid through the cyclo-oxygenase pathway.

Thrombus

A fibrinous clot formed in a blood vessel by the aggregation of platelets and fibrin which may also contain other elements including red blood cells. Thrombi commonly cause vascular obstruction at the point of formation and remain where they are formed.

Tissue Plasminogen Activator (tPA)

A clot-dissolving enzyme that is produced naturally by cells in the walls of blood vessels and catalyzes the conversion of plasminogen to plasmin.

TMB

Tetramethylbenzidine

TNF

Tumor Necrosis Factor

Trypsin

A pancreatic enzyme that catalyzes the hydrolysis of proteins to form smaller polypeptide units.

TUNEL

Terminal deoxynucleotidyl transferase nick-end labeling

U

uPAR

Urokinaseplasminogen activator receptor

Urokinase

An enzyme in human urine that catalyzes the conversion of plasminogen to plasmin and is used in medicine to dissolve blood clots.

UF

Unfractionated.

Unfractionated Heparin

An anticoagulant stored in, and released from the mast cells lying beneath the vascular endothelium. UF heparin may be further processed by enzymatic digestion and other methods to yield low molecular weight heparin, also used as an anticoagulant.

V

Vascular

Of, characterized by, or containing vessels that carry or circulate fluids, such as blood. Gray's Anatomy

Vein

Any of the membranous blood vessels that form a branching system and carry blood to the heart. Gray's Anatomy

Venule

A small vein, especially one joining capillaries to larger veins.

Vessel

see blood vessel

Vitamin K

A fat-soluble vitamin that plays an important role in blood clotting. MEDLINEplus

Vitamin K Deficiency

An inability to absorb the vitamin from the intestinal tract. It can also occur after prolonged treatment with oral antibiotics. MEDLINEplus

Von Willebrand Factor

A protein that carries factor VIII in the blood and helps platelets to stick to the blood vessel wall and to each other, which is necessary for normal blood clotting. MEDLINEplus

Von Willebrand?s Disease

The most common hereditary, autosomal bleeding disorder characterized by quantitative decreases in von Willebrand factor. The typical hemorrhagic manifestation is bleeding from mucous membranes. MEDLINEplus

W

Warfarin

A coumarin derivative, such as Coumadin, administered orally to prevent blood clots from forming or growing larger. Often prescribed for patients with certain types of irregular heartbeat and after a heart attack or heart valve replacement surgery. It works by stopping the formation of substances that cause clots. MEDLINEplus

White Blood Cell

(WBC)

Any of several types of microscopic, white, amorphous, nucleated blood cells that help defend the body from infection such asneutrophils (polymorphonuclear leukocytes; PMNs), band cells (slightly immature neutrophils), T-type lymphocytes (T cells), B-type lymphocytes (B cells), monocytes, eosinophils, and basophils. The different mature forms have different functions, including ingesting bacteria, protozoans, or infected or dead body cells; producing antibodies. Any infection or acute stress will result in an increased production of WBCs. This usually entails increased numbers of cells and an increase in the percentage of immature cells (mainly band cells) in the blood. This change is referred to as a "shift to the left". Blood normally contains 5,000-10,000 leukocytes per cu mm. MEDLINEplusBloodline

Whole Blood

Blood drawn from the body from which no constituent, such as plasma or platelets, has been removed.

X

X-chromosome

Sex chromosome associated with female characteristics in mammals, occurring paired in the female and single in the male.

Y

Y-chromosome

Sex chromosome associated with male characteristics in mammals, not occurring in females and occurring with one X-chromosome in the male sex-chromosome pair.

Z