The physiologically active form of vitamin D. It is formed primarily in the kidney by enzymatic hydroxylation of 25-hydroxycholecalciferol (CALCIFEDIOL). Its production is stimulated by low blood calcium levels and parathyroid hormone. Calcitriol increases intestinal absorption of calcium and phosphorus, and in concert with parathyroid hormone increases bone resorption.
Proteins, usually found in the cytoplasm, that specifically bind calcitriol, migrate to the nucleus, and regulate transcription of specific segments of DNA with the participation of D receptor interacting proteins (called DRIP). Vitamin D is converted in the liver and kidney to calcitriol and ultimately acts through these receptors.
A vitamin that includes both CHOLECALCIFEROLS and ERGOCALCIFEROLS, which have the common effect of preventing or curing RICKETS in animals. It can also be viewed as a hormone since it can be formed in SKIN by action of ULTRAVIOLET RAYS upon the precursors, 7-dehydrocholesterol and ERGOSTEROL, and acts on VITAMIN D RECEPTORS to regulate CALCIUM in opposition to PARATHYROID HORMONE.
Agents that increase calcium influx into calcium channels of excitable tissues. This causes vasoconstriction in VASCULAR SMOOTH MUSCLE and/or CARDIAC MUSCLE cells as well as stimulation of insulin release from pancreatic islets. Therefore, tissue-selective calcium agonists have the potential to combat cardiac failure and endocrinological disorders. They have been used primarily in experimental studies in cell and tissue culture.
Abnormally elevated PARATHYROID HORMONE secretion as a response to HYPOCALCEMIA. It is caused by chronic KIDNEY FAILURE or other abnormalities in the controls of bone and mineral metabolism, leading to various BONE DISEASES, such as RENAL OSTEODYSTROPHY.
A polypeptide hormone (84 amino acid residues) secreted by the PARATHYROID GLANDS which performs the essential role of maintaining intracellular CALCIUM levels in the body. Parathyroid hormone increases intracellular calcium by promoting the release of CALCIUM from BONE, increases the intestinal absorption of calcium, increases the renal tubular reabsorption of calcium, and increases the renal excretion of phosphates.
Organic substances that are required in small amounts for maintenance and growth, but which cannot be manufactured by the human body.
Any codon that signals the termination of genetic translation (TRANSLATION, GENETIC). PEPTIDE TERMINATION FACTORS bind to the stop codon and trigger the hydrolysis of the aminoacyl bond connecting the completed polypeptide to the tRNA. Terminator codons do not specify amino acids.
A directed change in translational READING FRAMES that allows the production of a single protein from two or more OVERLAPPING GENES. The process is programmed by the nucleotide sequence of the MRNA and is sometimes also affected by the secondary or tertiary mRNA structure. It has been described mainly in VIRUSES (especially RETROVIRUSES); RETROTRANSPOSONS; and bacterial insertion elements but also in some cellular genes.
A process of GENETIC TRANSLATION whereby the terminal amino acid is added to a lengthening polypeptide. This termination process is signaled from the MESSENGER RNA, by one of three termination codons (CODON, TERMINATOR) that immediately follows the last amino acid-specifying CODON.
A type I keratin that is found associated with the KERATIN-5 in the internal stratified EPITHELIUM. Mutations in the gene for keratin-14 are associated with EPIDERMOLYSIS BULLOSA SIMPLEX.
Absence of hair from areas where it is normally present.
Specific molecular sites or structures on cell membranes that react with FIBROBLAST GROWTH FACTORS (both the basic and acidic forms), their analogs, or their antagonists to elicit or to inhibit the specific response of the cell to these factors. These receptors frequently possess tyrosine kinase activity.
A family of small polypeptide growth factors that share several common features including a strong affinity for HEPARIN, and a central barrel-shaped core region of 140 amino acids that is highly homologous between family members. Although originally studied as proteins that stimulate the growth of fibroblasts this distinction is no longer a requirement for membership in the fibroblast growth factor family.
A single-chain polypeptide growth factor that plays a significant role in the process of WOUND HEALING and is a potent inducer of PHYSIOLOGIC ANGIOGENESIS. Several different forms of the human protein exist ranging from 18-24 kDa in size due to the use of alternative start sites within the fgf-2 gene. It has a 55 percent amino acid residue identity to FIBROBLAST GROWTH FACTOR 1 and has potent heparin-binding activity. The growth factor is an extremely potent inducer of DNA synthesis in a variety of cell types from mesoderm and neuroectoderm lineages. It was originally named basic fibroblast growth factor based upon its chemical properties and to distinguish it from acidic fibroblast growth factor (FIBROBLAST GROWTH FACTOR 1).
A fibroblast growth factor receptor that is found in two isoforms. One receptor isoform is found in the MESENCHYME and is activated by FIBROBLAST GROWTH FACTOR 2. A second isoform of fibroblast growth factor receptor 2 is found mainly in EPITHELIAL CELLS and is activated by FIBROBLAST GROWTH FACTOR 7 and FIBROBLAST GROWTH FACTOR 10. Mutation of the gene for fibroblast growth factor receptor 2 can result in craniosynostotic syndromes (e.g., APERT SYNDROME; and CROUZON SYNDROME).
A fibroblast growth factor receptor with specificity for FIBROBLAST GROWTH FACTORS; HEPARAN SULFATE PROTEOGLYCAN; and NEURONAL CELL ADHESION MOLECULES. Several variants of the receptor exist due to multiple ALTERNATIVE SPLICING of its mRNA. Fibroblast growth factor receptor 1 is a tyrosine kinase that transmits signals through the MAP KINASE SIGNALING SYSTEM.
A fibroblast growth factor receptor that regulates CHONDROCYTE growth and CELL DIFFERENTIATION. Mutations in the gene for fibroblast growth factor receptor 3 have been associated with ACHONDROPLASIA; THANATOPHORIC DYSPLASIA and NEOPLASTIC CELL TRANSFORMATION.
Products derived from the nonenzymatic reaction of GLUCOSE and PROTEINS in vivo that exhibit a yellow-brown pigmentation and an ability to participate in protein-protein cross-linking. These substances are involved in biological processes relating to protein turnover and it is believed that their excessive accumulation contributes to the chronic complications of DIABETES MELLITUS.
Cell surface molecules on cells of the immune system that specifically bind surface molecules or messenger molecules and trigger changes in the behavior of cells. Although these receptors were first identified in the immune system, many have important functions elsewhere.
A component of NF-kappa B transcription factor. It is proteolytically processed from NF-kappa B p100 precursor protein and is important for maturation of B-LYMPHOCYTES and adaptive HUMORAL IMMUNITY.
Connective tissue cells which secrete an extracellular matrix rich in collagen and other macromolecules.
An organic compound used often as a reagent in organic synthesis, as a flavoring agent, and in tanning. It has been demonstrated as an intermediate in the metabolism of acetone and its derivatives in isolated cell preparations, in various culture media, and in vivo in certain animals.
Cytoplasmic proteins that bind estrogens and migrate to the nucleus where they regulate DNA transcription. Evaluation of the state of estrogen receptors in breast cancer patients has become clinically important.
Tumors or cancer of the human BREAST.
Breast neoplasms that do not express ESTROGEN RECEPTORS; PROGESTERONE RECEPTORS; and do not overexpress the NEU RECEPTOR/HER-2 PROTO-ONCOGENE PROTEIN.
A cell line derived from cultured tumor cells.
A cell surface protein-tyrosine kinase receptor that is overexpressed in a variety of ADENOCARCINOMAS. It has extensive homology to and heterodimerizes with the EGF RECEPTOR, the ERBB-3 RECEPTOR, and the ERBB-4 RECEPTOR. Activation of the erbB-2 receptor occurs through heterodimer formation with a ligand-bound erbB receptor family member.
One of the ESTROGEN RECEPTORS that has marked affinity for ESTRADIOL. Its expression and function differs from, and in some ways opposes, ESTROGEN RECEPTOR BETA.
A pathologic process consisting of the proliferation of blood vessels in abnormal tissues or in abnormal positions.
A nutritional condition produced by a deficiency of VITAMIN D in the diet, insufficient production of vitamin D in the skin, inadequate absorption of vitamin D from the diet, or abnormal conversion of vitamin D to its bioactive metabolites. It is manifested clinically as RICKETS in children and OSTEOMALACIA in adults. (From Cecil Textbook of Medicine, 19th ed, p1406)
Derivative of 7-dehydroxycholesterol formed by ULTRAVIOLET RAYS breaking of the C9-C10 bond. It differs from ERGOCALCIFEROL in having a single bond between C22 and C23 and lacking a methyl group at C24.
A diphosphonate which affects calcium metabolism. It inhibits ectopic calcification and slows down bone resorption and bone turnover.
The constricted portion of the thigh bone between the femur head and the trochanters.
The amount of mineral per square centimeter of BONE. This is the definition used in clinical practice. Actual bone density would be expressed in grams per milliliter. It is most frequently measured by X-RAY ABSORPTIOMETRY or TOMOGRAPHY, X RAY COMPUTED. Bone density is an important predictor for OSTEOPOROSIS.
Reduction of bone mass without alteration in the composition of bone, leading to fractures. Primary osteoporosis can be of two major types: postmenopausal osteoporosis (OSTEOPOROSIS, POSTMENOPAUSAL) and age-related or senile osteoporosis.
VERTEBRAE in the region of the lower BACK below the THORACIC VERTEBRAE and above the SACRAL VERTEBRAE.
Fractures of the FEMUR HEAD; the FEMUR NECK; (FEMORAL NECK FRACTURES); the trochanters; or the inter- or subtrochanteric region. Excludes fractures of the acetabulum and fractures of the femoral shaft below the subtrochanteric region (FEMORAL FRACTURES).
Breaks in bones.
Assistance in managing and monitoring drug therapy for patients receiving treatment for cancer or chronic conditions such as asthma and diabetes, consulting with patients and their families on the proper use of medication; conducting wellness and disease prevention programs to improve public health; overseeing medication use in a variety of settings.
In glycogen or amylopectin synthesis, the enzyme that catalyzes the transfer of a segment of a 1,4-alpha-glucan chain to a primary hydroxy group in a similar glucan chain. EC
A gland in males that surrounds the neck of the URINARY BLADDER and the URETHRA. It secretes a substance that liquefies coagulated semen. It is situated in the pelvic cavity behind the lower part of the PUBIC SYMPHYSIS, above the deep layer of the triangular ligament, and rests upon the RECTUM.
Tumors or cancer of the PROSTATE.
Provision of physical and biological barriers to the dissemination of potentially hazardous biologically active agents (bacteria, viruses, recombinant DNA, etc.). Physical containment involves the use of special equipment, facilities, and procedures to prevent the escape of the agent. Biological containment includes use of immune personnel and the selection of agents and hosts that will minimize the risk should the agent escape the containment facility.
A glycoprotein that is a kallikrein-like serine proteinase and an esterase, produced by epithelial cells of both normal and malignant prostate tissue. It is an important marker for the diagnosis of prostate cancer.
Proteins, generally found in the CYTOPLASM, that specifically bind ANDROGENS and mediate their cellular actions. The complex of the androgen and receptor migrates to the CELL NUCLEUS where it induces transcription of specific segments of DNA.
Disorders caused by interruption of BONE MINERALIZATION manifesting as OSTEOMALACIA in adults and characteristic deformities in infancy and childhood due to disturbances in normal BONE FORMATION. The mineralization process may be interrupted by disruption of VITAMIN D; PHOSPHORUS; or CALCIUM homeostasis, resulting from dietary deficiencies, or acquired, or inherited metabolic, or hormonal disturbances.
Coloration of the skin.
Irradiation directly from the sun.
Works containing information articles on subjects in every field of knowledge, usually arranged in alphabetical order, or a similar work limited to a special field or subject. (From The ALA Glossary of Library and Information Science, 1983)
That portion of the electromagnetic spectrum immediately below the visible range and extending into the x-ray frequencies. The longer wavelengths (near-UV or biotic or vital rays) are necessary for the endogenous synthesis of vitamin D and are also called antirachitic rays; the shorter, ionizing wavelengths (far-UV or abiotic or extravital rays) are viricidal, bactericidal, mutagenic, and carcinogenic and are used as disinfectants.