Epidermal Growth Factor Receptor: From 1 Different Sources
(EGFR) a protein on the surface of cells (see receptor) that binds with epidermal *growth factor and is therefore involved in cell division. EGFR is expressed at increased levels in numerous tumours, particularly of the head and neck, and in colorectal cancer, in which it can be a target for antibody therapy with *cetuximab. *Tyrosine kinase inhibitors acting specifically on the EGFR include gefitinib and erlotinib in lung and pancreatic cancer.
An aspect of personal behaviour or lifestyle, an environmental exposure, or an inborn or inherited characteristic, which, on the basis of scientific evidence, is known to be associated with health-related condition(s) considered important to prevent.... risk factor
One of two proteins secreted from the lining of the stomach whose sole purpose is (it seems) to cradle B12 in a pre-fitted styrofoam mold and (A) carry it through the Seven Levels of Digestive Hell until it reaches those few absorption sites in the last foot of small intestine that understand its “Special Needs” (sounds either sexually kinky or the airplane dinner label on kosher food for flying Hassidim jewelers) and finally (B) slip it from one protein to the other, and thence into the cell membranes where its is turn handed over to (C) the specialized blood protein that can carry it safely to the final target tissues (3 times out of 4, the bone marrow). Cyanocobalamin (B12) has parts that fall off, radicals that twirl around in five directions on three charge potentials, and is as durable as a 49¢ water pistol. And, if we have an ulcer, chronic enteritis or long-standing steatorrhea, we either get B12 shots (and hope the liver still makes that blood carrier) or walk around with pernicious anemia and a hematocrit of 16.... intrinsic factor
A coagulative blood protein that is a constituent of the COAGULATION cascade – an essential component in the clotting of blood. Those people with the inherited disorder, HAEMOPHILIA, have abnormally low amounts of factor VIII and so bleed more when cut. They are treated with a concentrated version to reduce the tendency to bleed.... factor viii
A popular term applied to any new formation in any part of the body. (See CANCER; CYSTS; GANGLION; TUMOUR.) For growth of children, see WEIGHT AND HEIGHT.... growth
A site on the membrane surrounding a cell (see CELLS) that binds to the hormone OESTROGENS. This activates the cell’s reaction to the hormone. Anti-oestrogen drugs such as TAMOXIFEN used to treat breast cancer (see BREASTS, DISEASES OF) prevent the oestrogen from binding to these receptors.... oestrogen receptor
See BLOOD GROUPS.... rh factor
See BLOOD GROUPS.... rhesus factor
A protein in blood that plays an important role in the clotting mechanism. A deficiency of factor causes a rare genetic bleeding disorder known as Christmas disease.... factor ix
These are drugs that block the action of HISTAMINE at the H2 receptor (which mediates the gastric and some of the cardiovascular effects of histamine). By reducing the production of acid by the stomach, these drugs – chie?y cimetidine, ranitidine, famotidine and nizatidine – are valuable in the treatment of peptic ulcers (healing when used in high dose; preventing relapse when used as maintenance therapy in reduced dose), re?ux oesophagitis (see OESOPHAGUS, DISEASES OF), and the ZOLLINGERELLISON SYNDROME. These drugs are now being supplanted by PROTON-PUMP INHIBITORS and HELICOBACTER PYLORI eradication therapy. (See also DUODENAL ULCER.)... h2 receptor antagonists
A chemical, psychological, physiological, social, environmental or genetic factor or conditions that predisposes an individual to the development of a disease or injury.... health risk factor
The study of the interrelationships between humans, the tools they use, and the environment in which they live and work.... human-factor research
An agent involved in the clotting mechanism of the blood. It helps in the activation of THROMBOPLASTIN in the blood PLASMA (see COAGULATION).... lipoid factor
The increase in height and weight as a child develops. The period of most rapid growth occurs before birth. After birth, although growth is still rapid in the first few years of life, especially in the first year, the rate of
growth steadily decreases. Puberty marks another major period of growth, which continues until adult height and weight are reached, usually at about age 16–17 in girls and 19–21 in boys.
Body shape changes during childhood because different areas grow at different rates. For example, at birth, the head is already about three quarters of its adult size; it grows to almost full size during the first year. Thereafter, it becomes proportionately smaller because the body grows at a much faster rate.
Growth can be influenced by heredity and by environmental factors such as nutrition and general health. Hormones also play an important role, particularly growth hormone, thyroid hormones, and, at puberty, the sex hormones.
A chronic illness, such as cystic fibrosis, may retard growth. Even a minor illness can slow growth briefly, although the growth rate usually catches up when the child recovers. In some cases, slow growth may be the only sign that a child is ill or malnourished, in which case it is known as failure to thrive. However, short stature does not necessarily indicate poor health. Abnormally rapid growth is rare. Usually, it is a familial trait, but it may occasionally indicate an underlying disorder, such as a pituitary gland tumour causing gigantism. (See also age; child development.)... growth, childhood
See H-receptor antagonists.... histamine-receptor antagonists
a group of *growth factors that promote new bone formation. Bone morphogenic protein (BMP), a naturally occurring substance that induces *osteoblast formation, has been genetically synthesized to form bone morphogenetic protein, which stimulates new bone formation and assists with fracture healing. Other bone growth factors include a type of transforming growth factor (TGF?) and insulin-like growth factor II (IGF-II), which encourage collagen formation.... bone growth factors
(CSF) one of a group of substances (haemopoietic growth factors or hormones) that are produced in the bone marrow and stimulate the production of specific blood cells. Genetically engineered granulocyte colony-stimulating factor (G-CSF) stimulates neutrophil production and also limits bone marrow toxicity from chemotherapy.... colony-stimulating factor
n. (in biochemistry) a substance that is essential to a physiological process, often a substance the nature of which is unknown. See also coagulation factors; growth factor.... factor
an inherited mutation in the gene coding for coagulation Factor V, which results in an increased susceptibility to develop venous *thrombosis.... factor v leiden
a *coagulation factor normally present in blood. Deficiency of the factor is inherited, but rarely causes spontaneous bleeding. However, bleeding does occur after surgery or trauma to the blood vessels.... factor xi
a graph, customized to a pregnant woman’s height, weight, and other factors, that plots *fundal height and estimated fetal weight on ultrasound against weeks of gestation. The graph, which shows centile lines (see centile chart), improves prediction of a baby who is *small for gestational age.... fetal growth chart
see intrauterine growth restriction.... fetal growth restriction
a group of drugs used in the treatment of type 2 diabetes. They mimic the actions of *glucagon-like peptide-1 in regulating the rise in blood glucose levels after eating and they also enhance satiety (see incretin). As these drugs respond to a falling blood glucose level there is a reduced tendency to *hypoglycaemia compared with *sulphonylurea drugs and insulin therapy itself. They are given by subcutaneous injection and three of them are licensed for use in the UK: exenatide (Byetta; twice daily dosing), liraglutide (Victoza; once daily dosing), and lixisenatide (Lyxumia; once daily dosing).... glp-1 receptor agonists
see physis.... growth plate
(IUGR, fetal growth restriction) failure of a fetus to achieve its growth potential, resulting in the birth of a baby whose birth weight is abnormally low in relation to its gestational age (see small for gestational age). Causes include *uteroplacental insufficiency, maternal disease (e.g. infection, malnutrition, high blood pressure, smoking, and alcoholism), poor socioeconomic conditions, multiple pregnancy (e.g. twins), and fetal disease or chromosomal abnormalities. It may be associated with *preterm birth.... intrauterine growth restriction
one of a class of drugs that prevent the action of *leukotrienes by blocking their receptors on cell membranes, such as those in the airways. These drugs are used in the management of asthma for their effects in relaxing the smooth muscle of the airways and in reducing inflammation in the bronchial linings. Examples are montelukast and zafirlukast; side-effects may include headache and abdominal pain or gastrointestinal upsets.... leukotriene receptor antagonist
(NGF) a protein (see growth factor), consisting of two polypeptide chains, that is required for the development and longevity of some neurons, including those in the sympathetic nervous system and some central nervous system and sensory neurons. Nerve growth factor is necessary for axon growth and also for initiating new neuronal connections with other cells. The role of NGFs in preventing the degeneration of brain cells is being explored in research into Alzheimer’s disease.... nerve growth factor
a receptor on synapses that binds the *neurotransmitter glutamate and also binds its *agonist NMDA (N-methyl-D-aspartate). This receptor is involved in learning, memory, mood, and cognition; its overactivity is associated with chronic pain. NMDA-receptor antibodies are associated with an *encephalitis preceded by psychiatric symptoms, often in patients with ovarian malignancy (teratoma). NMDA-receptor antagonists (e.g. *amantadine, *memantine hydrochloride, *riluzole) are used in the treatment of (among other conditions) epilepsy, Alzheimer’s disease, and chronic pain syndromes.... nmda receptor
see anti-oestrogen.... oestrogen-receptor antagonist
(PDGF) see growth factor.... platelet-derived growth factor
a cell or group of cells found between muscle fibres that responds to stretching of the muscle by transmitting impulses to the central nervous system through the sensory nerves. Stretch receptors are part of the *proprioceptor system necessary for the performance of coordinated muscular activity.... stretch receptor
(TGF) a protein – a *cytokine – that controls growth, proliferation, and other functions in most cells. It plays a role in asthma and other respiratory diseases and is also involved in diseases elsewhere in the body. There are two classes: TGF-? and TGF-?.... transforming growth factor
autoantibodies targeted against the *thyroid-stimulating hormone (TSH) receptor of the thyroid cells. They can activate the TSH receptor, leading to the hyperthyroidism of *Graves’ disease, or they can block the TSH receptor, causing *hypothyroidism.... tsh receptor antibodies
(PRRT) a type of radiotherapy used to treat neuroendocrine tumours (NETs; see neuroendocrine system). A *radionuclide is combined with a relevant *peptide to create a so-called radiopeptide, which is injected into the patient’s bloodstream. Because NETs have an overexpression of peptide receptors, the radiopeptide binds to the tumour, delivering a high dose of radiation directly to the cancer cells. The chief merit of PRRT is this ability to target delivery of radionuclides for highly localized treatment. A similar technique, using a gamma emitter as the radionuclide, can be used for locating and imaging NETs.... peptide receptor radionuclide therapy
(TEN, Lyell’s syndrome) a severe reaction to medications with a high mortality rate. Medications causing TEN include sulfonamides, anticonvulsants, antiretrovirals, and allopurinol. Widespread separation of the dead epidermal layer from underlying skin occurs, with consequent problems due to skin failure: impaired temperature regulation, infection risk, severe pain, etc. Mucous membranes are commonly affected, including the eyes (sometimes leading to blindness), mouth, and genitalia. Multi-organ failure may occur. Treatments include stopping the offending medication, good supportive nursing (usually in an ITU or HDU setting), antibiotics where appropriate, and intravenous immunoglobulin or ciclosporin.... toxic epidermal necrolysis
(TNF) either of two proteins, TNF-? or TNF-?, that function as *cytokines. Produced by macrophages, monocytes, T lymphocytes, and various other cells, they mediate many responses, including inflammation, and have a marked action against tumour cells. Anti-TNF drugs (see cytokine inhibitor) are used in the treatment of several disorders, especially rheumatoid arthritis and ankylosing spondylitis.... tumour necrosis factor
(VEGF) a *growth factor made by both normal cells and their abnormal or malignant counterparts to stimulate new blood vessel formation (see angiogenesis). It can be targeted by a family of drugs known as *angiogenesis inhibitors, which include *bevacizumab.... vascular endothelial growth factor
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