Proteins that are present in blood serum, including SERUM ALBUMIN; BLOOD COAGULATION FACTORS; and many other types of proteins.

The narrow tube connecting the YOLK SAC with the midgut of the EMBRYO; persistence of all or part of it in post-fetal life produces abnormalities, of which the commonest is MECKEL DIVERTICULUM.

'Blood Protein Disorders' refer to conditions characterized by an abnormal amount, structure, or function of proteins present in the blood, including immunoglobulins, coagulation factors, complement components, and transport proteins, which can lead to various clinical manifestations such as immune dysfunction, bleeding disorders, or metabolic imbalances.

Non-nucleated disk-shaped cells formed in the megakaryocyte and found in the blood of all mammals. They are mainly involved in blood coagulation.

The attachment of PLATELETS to one another. This clumping together can be induced by a number of agents (e.g., THROMBIN; COLLAGEN) and is part of the mechanism leading to the formation of a THROMBUS.

A major protein in the BLOOD. It is important in maintaining the colloidal osmotic pressure and transporting large organic molecules.

The oxygen-carrying proteins of ERYTHROCYTES. They are found in all vertebrates and some invertebrates. The number of globin subunits in the hemoglobin quaternary structure differs between species. Structures range from monomeric to a variety of multimeric arrangements.

The number of PLATELETS per unit volume in a sample of venous BLOOD.

Electrophoresis applied to BLOOD PROTEINS.

The process whereby PLATELETS adhere to something other than platelets, e.g., COLLAGEN; BASEMENT MEMBRANE; MICROFIBRILS; or other "foreign" surfaces.

Surface glycoproteins on platelets which have a key role in hemostasis and thrombosis such as platelet adhesion and aggregation. Many of these are receptors.

A CXC chemokine that is found in the alpha granules of PLATELETS. The protein has a molecular size of 7800 kDa and can occur as a monomer, a dimer or a tetramer depending upon its concentration in solution. Platelet factor 4 has a high affinity for HEPARIN and is often found complexed with GLYCOPROTEINS such as PROTEIN C.

The transfer of blood platelets from a donor to a recipient or reinfusion to the donor.

A phospholipid derivative formed by PLATELETS; BASOPHILS; NEUTROPHILS; MONOCYTES; and MACROPHAGES. It is a potent platelet aggregating agent and inducer of systemic anaphylactic symptoms, including HYPOTENSION; THROMBOCYTOPENIA; NEUTROPENIA; and BRONCHOCONSTRICTION.

Laboratory examination used to monitor and evaluate platelet function in a patient's blood.

Platelet membrane glycoprotein complex important for platelet adhesion and aggregation. It is an integrin complex containing INTEGRIN ALPHAIIB and INTEGRIN BETA3 which recognizes the arginine-glycine-aspartic acid (RGD) sequence present on several adhesive proteins. As such, it is a receptor for FIBRINOGEN; VON WILLEBRAND FACTOR; FIBRONECTIN; VITRONECTIN; and THROMBOSPONDINS. A deficiency of GPIIb-IIIa results in GLANZMANN THROMBASTHENIA.

Platelet membrane glycoprotein complex essential for normal platelet adhesion and clot formation at sites of vascular injury. It is composed of three polypeptides, GPIb alpha, GPIb beta, and GPIX. Glycoprotein Ib functions as a receptor for von Willebrand factor and for thrombin. Congenital deficiency of the GPIb-IX complex results in Bernard-Soulier syndrome. The platelet glycoprotein GPV associates with GPIb-IX and is also absent in Bernard-Soulier syndrome.

An enzyme formed from PROTHROMBIN that converts FIBRINOGEN to FIBRIN.

Adenosine 5'-(trihydrogen diphosphate). An adenine nucleotide containing two phosphate groups esterified to the sugar moiety at the 5'-position.

Human alloantigens expressed only on platelets, specifically on platelet membrane glycoproteins. These platelet-specific antigens are immunogenic and can result in pathological reactions to transfusion therapy.

A subnormal level of BLOOD PLATELETS.

Plasma glycoprotein clotted by thrombin, composed of a dimer of three non-identical pairs of polypeptide chains (alpha, beta, gamma) held together by disulfide bonds. Fibrinogen clotting is a sol-gel change involving complex molecular arrangements: whereas fibrinogen is cleaved by thrombin to form polypeptides A and B, the proteolytic action of other enzymes yields different fibrinogen degradation products.

Cell adhesion molecule and CD antigen that mediates the adhesion of neutrophils and monocytes to activated platelets and endothelial cells.

Very large BONE MARROW CELLS which release mature BLOOD PLATELETS.

Duration of blood flow after skin puncture. This test is used as a measure of capillary and platelet function.