A clinical syndrome characterized by repeated spontaneous hemorrhages and a remarkable increase in the number of circulating platelets.
A myeloproliferative disorder of unknown etiology, characterized by abnormal proliferation of all hematopoietic bone marrow elements and an absolute increase in red cell mass and total blood volume, associated frequently with splenomegaly, leukocytosis, and thrombocythemia. Hematopoiesis is also reactive in extramedullary sites (liver and spleen). In time myelofibrosis occurs.
Increased numbers of platelets in the peripheral blood. (Dorland, 27th ed)
A Janus kinase subtype that is involved in signaling from GROWTH HORMONE RECEPTORS; PROLACTIN RECEPTORS; and a variety of CYTOKINE RECEPTORS such as ERYTHROPOIETIN RECEPTORS and INTERLEUKIN RECEPTORS. Dysregulation of Janus kinase 2 due to GENETIC TRANSLOCATIONS have been associated with a variety of MYELOPROLIFERATIVE DISORDERS.
Conditions which cause proliferation of hemopoietically active tissue or of tissue which has embryonic hemopoietic potential. They all involve dysregulation of multipotent MYELOID PROGENITOR CELLS, most often caused by a mutation in the JAK2 PROTEIN TYROSINE KINASE.
A de novo myeloproliferation arising from an abnormal stem cell. It is characterized by the replacement of bone marrow by fibrous tissue, a process that is mediated by CYTOKINES arising from the abnormal clone.
Cell surface receptors that are specific for THROMBOPOIETIN. They signal through interaction with JANUS KINASES such as JANUS KINASE 2.
The number of PLATELETS per unit volume in a sample of venous BLOOD.
A humoral factor that stimulates the production of thrombocytes (BLOOD PLATELETS). Thrombopoietin stimulates the proliferation of bone marrow MEGAKARYOCYTES and their release of blood platelets. The process is called THROMBOPOIESIS.
Formation and development of a thrombus or blood clot in the blood vessel.
An alkylating agent structurally similar to MITOMYCIN and found to be effective in the treatment of leukemia and various other neoplasms in mice. It causes leukemia and thrombocytopenia in almost all human patients.
Very large BONE MARROW CELLS which release mature BLOOD PLATELETS.
An antineoplastic agent that inhibits DNA synthesis through the inhibition of ribonucleoside diphosphate reductase.
An antineoplastic agent that acts by alkylation.
A transient increase in the number of leukocytes in a body fluid.
Leukocytes with abundant granules in the cytoplasm. They are divided into three groups according to the staining properties of the granules: neutrophilic, eosinophilic, and basophilic. Mature granulocytes are the NEUTROPHILS; EOSINOPHILS; and BASOPHILS.
A mutation in which a codon is mutated to one directing the incorporation of a different amino acid. This substitution may result in an inactive or unstable product. (From A Dictionary of Genetics, King & Stansfield, 5th ed)
The process of generating thrombocytes (BLOOD PLATELETS) from the pluripotent HEMATOPOIETIC STEM CELLS in the BONE MARROW via the MEGAKARYOCYTES. The humoral factor with thrombopoiesis-stimulating activity is designated THROMBOPOIETIN.
Pathologic inclusions occurring in erythrocytes.
Enlargement of the spleen.
An increase in the total red cell mass of the blood. (Dorland, 27th ed)
Non-nucleated disk-shaped cells formed in the megakaryocyte and found in the blood of all mammals. They are mainly involved in blood coagulation.
A severe sometimes chronic anemia, usually macrocytic in type, that does not respond to ordinary antianemic therapy.
Any detectable and heritable change in the genetic material that causes a change in the GENOTYPE and which is transmitted to daughter cells and to succeeding generations.
Agents that cause clotting.
A disorder of HEMOSTASIS in which there is a tendency for the occurrence of THROMBOSIS.
A myelodysplastic/myeloproliferative disorder characterized by myelodysplasia associated with bone marrow and peripheral blood patterns similar to CHRONIC MYELOID LEUKEMIA, but cytogenetically lacking a PHILADELPHIA CHROMOSOME or bcr/abl fusion gene (GENES, ABL).
The naturally occurring or experimentally induced replacement of one or more AMINO ACIDS in a protein with another. If a functionally equivalent amino acid is substituted, the protein may retain wild-type activity. Substitution may also diminish, enhance, or eliminate protein function. Experimentally induced substitution is often used to study enzyme activities and binding site properties.
The co-occurrence of pregnancy and a blood disease (HEMATOLOGIC DISEASES) which involves BLOOD CELLS or COAGULATION FACTORS. The hematologic disease may precede or follow FERTILIZATION and it may or may not have a deleterious effect on the pregnant woman or FETUS.
The soft tissue filling the cavities of bones. Bone marrow exists in two types, yellow and red. Yellow marrow is found in the large cavities of large bones and consists mostly of fat cells and a few primitive blood cells. Red marrow is a hematopoietic tissue and is the site of production of erythrocytes and granular leukocytes. Bone marrow is made up of a framework of connective tissue containing branching fibers with the frame being filled with marrow cells.
Drugs or agents which antagonize or impair any mechanism leading to blood platelet aggregation, whether during the phases of activation and shape change or following the dense-granule release reaction and stimulation of the prostaglandin-thromboxane system.
Bleeding or escape of blood from a vessel.
A specialized agency of the United Nations designed as a coordinating authority on international health work; its aim is to promote the attainment of the highest possible level of health by all peoples.
A subclass of lipid-linked proteins that contain a GLYCOSYLPHOSPHATIDYLINOSITOL LINKAGE which holds them to the CELL MEMBRANE.
A subnormal level of BLOOD PLATELETS.
A vascular anomaly that is a collection of tortuous BLOOD VESSELS and connective tissue. This tumor-like mass with the large vascular space is filled with blood and usually appears as a strawberry-like lesion in the subcutaneous areas of the face, extremities, or other regions of the body including the central nervous system.
Quinazolines are heterocyclic aromatic organic compounds consisting of a benzene ring fused to a pyrazine ring, which are synthesized and used as intermediates in pharmaceuticals, particularly in the production of various drugs such as antimalarials, antihypertensives, and antitumor agents.
Cell surface proteins that bind cytokines and trigger intracellular changes influencing the behavior of cells.
Antigens that exist in alternative (allelic) forms in a single species. When an isoantigen is encountered by species members who lack it, an immune response is induced. Typical isoantigens are the BLOOD GROUP ANTIGENS.