Met Health Dictionary

The sum total of changes in an organism in order to achieve a balance (homeostasis). Catabolic burns up, anabolic stores and builds up; the sum of their work is metabolism.... metabolism

Uterine, bleeding, usually of normal amount occurring at completely irregular intervals, the period of flow sometimes being prolonged... metrorrhagia

Change of a mature type of cell in a tissue to another mature type of cell usually present in another tissue; e.g., development of squamous epithelium in the trachea among the normal respiratory epithelium = squamous metaplasia.... metaplasia

The spread of cancer cells through the blood, lymphatics or directly and establishment of these newgroups of cells at locations distant from the original cancer.... metastasis

An antibiotic used widely for anaerobic bacterial infections (including pseudomembranous colitis) and also for such protozoan infections as giardiasis, trichmoniasis and amoebiasis.... metronidazole

The basic rate of combustion by a person, usually measured after sleep and while resting.... basal metabolism

A statistical procedure to combine results from different studies on a similar topic. The combination of results from multiple studies may produce a stronger conclusion than can be provided by any singular study. Meta-analysis is generally most appropriate when there are no definitive studies on a topic and non-definitive studies are in some disagreement.... meta-analysis

Pain affecting the metatarsal region of the foot. It is common in adolescents, and associated with FLAT-FOOT; in adults it may be a manifestation of RHEUMATOID ARTHRITIS. Morton’s metatarsalgia is a form associated usually with the nerve to the second toe cleft, often induced by the compression of tight shoes.... metatarsalgia

Also known as tympanites, this is a distension of the ABDOMEN from excess gas or air in the INTESTINE or peritoneal cavity. On percussion the abdomen sounds resonant, like a drum. Causes include obstruction of the intestines, aerophagy (the swallowing of air), and IRRITABLE BOWEL SYNDROME (IBS). Treatment is of the underlying condition. (See also FLATULENCE.)... meteorism

One of the BIGUANIDES, metformin lowers the blood sugar by increasing cellular uptake of glucose. It is active when taken by mouth and is used to treat some patients with DIABETES MELLITUS, usually in addition to another hypoglycaemic drug.... metformin

A variety of ALCOHOL used as a solvent to remove paint or as a constituent of some antifreeze ?uids. It is poisonous: sometimes people drink it as a substitute for ethyl (ordinary) alcohol. Symptoms appear up to 24 hours after imbibing methanol and include nausea, vomiting, dizziness, headache and sometimes unconsciousness. Treatment is to induce vomiting (in conscious victims) and to do a stomach washout (see GASTRIC LAVAGE), but such steps must be taken within two hours of ingestion. Hospital treatment is usually required, when intravenous infusion of sodium bicarbonate (and sometimes ethanol, which slows up breakdown of methanol by the liver) is administered.... methanol

A COLLOID which absorbs water to swell to about 25 times its original volume. It is used in the treatment of CONSTIPATION and also in the management of OBESITY. The rationale for its use in obesity is that by swelling up in the stomach, it reduces the appetite.... methylcellulose

A centrally acting anti-hypertensive (see HYPERTENSION) drug often used in conjunction with a diuretic (see DIURETICS). It can be e?ective in controlling high blood pressure in pregnancy. The drug is also safe to use in patients with ASTHMA or heart failure.... methyldopa

One of the ANTIMETABOLITES used to treat certain forms of malignant disease. Acting to inhibit the ENZYME dihydrofolate reductase, which is essential for purine and pyrimidine synthesis, it is given orally, intravenously, intramuscularly or intrathecally. Methotrexate is used as maintenance therapy for childhood acute lymphoblastic LEUKAEMIA, while other uses include CHORIOCARCINOMA, nonHodgkin’s LYMPHOMA, and various solid tumours. Intrathecally, it is used in the prophylaxis of childhood acute lymphoblastic leukaemia, and as treatment for established meningeal cancer or lymphoma.

Side-effects include suppression of myelocytes in bone marrow, in?ammation of mucous membranes, and, rarely, PNEUMONITIS. It should be avoided whenever signi?cant renal impairment is present, while signi?cant pleural e?usion or ascites is also a contraindication. Blood counts should be carefully monitored whenever intrathecal methotrexate is given. Oral or parenteral folinic acid helps to prevent, or to speed recovery from, myelosuppression or mucositis.

Methotrexate is used in dermatology, where it may be indicated for cases of severe uncontrolled PSORIASIS unresponsive to conventional therapy; it may also be indicated for severe active RHEUMATOID ARTHRITIS. Because of its potentially severe haematological, pulmonary, gastrointestinal, and other toxicities it should be used only by specialists and appropriate renal and liver function tests carried out before and during treatment. It should be avoided in pregnancy, and conception should be avoided for at least six months after stopping, as should breast feeding. Concurrent administration of aspirin or other NONSTEROIDAL ANTI-INFLAMMATORY DRUGS (NSAIDS) reduces methotrexate excretion, increasing its toxicity, and should therefore be avoided whenever possible.... methotrexate

A drug that stimulates the CENTRAL NERVOUS SYSTEM. Its action is similar to DEXAMPHETAMINE. A controlled drug, one of its trade names is Ritalin® and it is (controversially) used in the treatment of ATTENTION DEFICIT DISORDER (HYPERACTIVITY SYNDROME) in children, in conjunction with behavioural treatment and family support. Because of the potential for side-effects, its administration should be under specialist supervision.... methylphenidate

A mineralcorticoid drug (see CORTICOSTEROIDS) with an action comparable to that of PREDNISOLONE, but e?ective at a somewhat lower dose.... methylprednisolone

A thiazide-type diuretic (see THIAZIDES; DIURETICS) which is particularly e?ective when combined with a loop diuretic (see LOOP DIURETICS), when it produces profound diuresis. The drug is also useful for treating kidney stones (see under KIDNEYS, DISEASES OF).... metolazone

A beta-adrenergic-receptor blocking agent. (See ADRENERGIC RECEPTORS.)... metoprolol

This drug antagonises the actions of DOPAMINE. Given orally, intramuscularly, or intravenously, it is used to treat nausea and vomiting, particularly in gastrointestinal disorders, or when associated with cytotoxics or radiotherapy. It is useful in the early treatment of MIGRAINE.

Caution is indicated in prescribing metoclopramide for elderly and young patients, and whenever hepatic or renal impairment is present, and it should be avoided in pregnancy or cases of PORPHYRIAS. Adverse effects include extrapyramidal effects (see under EXTRAPYRAMIDAL SYSTEM) and HYPERPROLACTINAEMIA with occasional TARDIVE DYSKINESIA on prolonged administration. There have also been occasional reports of drowsiness, restlessness, diarrhoea, depression and neuroleptic malignant syndrome, with rare cardiac conduction abnormalities following intravenous administration.... metoclopramide

A method of CONTRACEPTION which attempts to prevent conception by avoiding intercourse during the fertile part of the menstrual cycle. (See MENSTRUATION; SAFE PERIOD.)... rhythm method

A collection of disorders in which some part of the body’s internal chemistry (see METABOLISM; CATABOLISM) is disrupted. Some of these disorders arise from inherited de?ciencies in which a speci?c ENZYME is absent or abnormal, or does not function properly. Other metabolic disorders occur because of malfunctions in the endocrine system (see ENDOCRINE GLANDS). There may be over- or underproduction of a hormone involved in the control of metabolic activities: a prime example is DIABETES MELLITUS – a disorder of sugar metabolism; others include CUSHING’S SYNDROME; hypothyroidism and hyperthyroidism (see THYROID GLAND, DISEASES OF); and insulinoma (an insulin-producing tumour of the pancreas). The bones can be affected by metabolic disorders such as osteoporosis, osteomalacia (rickets) and Paget’s disease (see under BONE, DISORDERS OF). PORPHYRIAS, HYPERLIPIDAEMIA, HYPERCALCAEMIA and gout are other examples of disordered metabolism.

There are also more than 200 identi?ed disorders described as inborn errors of metabolism. Some cause few problems; others are serious threats to an individual’s life. Individual disorders are, fortunately, rare – probably one child in 10,000 or 100,000; overall these inborn errors affect around one child in 1,000. Examples include GALACTOSAEMIA, PHENYLKETONURIA, porphyrias, TAY SACHS DISEASE and varieties of mucopolysaccharidosis, HOMOCYSTINURIA and hereditary fructose (a type of sugar) intolerance.... metabolic disorders

A by-product, waste product, or endotoxin produced as the result of metabolism, both normal and defensive.... metabolites

An immature granulocyte (white blood cell) usually found in the bone marrow’s blood-making tissue. It can, however, appear in the blood in a range of diseases, including infection.... metamyelocyte

The extremity of a long bone where it joins the epiphysis (see BONE – Growth of bones).... metaphysis

Metatarsus is the group name of the ?ve metatarsal bones in the foot. Metatarsus varus is the condition characterised by deviation of the forefoot towards the other foot. It is a common condition in newborn babes and almost always corrects itself spontaneously. Only in the rare cases in which it is due to some deformity of the bones or muscles of the foot is any treatment required.... metatarsus

A derivative of HAEMOGLOBIN in which the iron has been oxidised from ferrous to ferric form. It does not combine with oxygen and therefore plays no part in oxygen transport. Normal concentration of methaemoglobin in red blood cells is less than 1 per cent of the total haemoglobin. When a large concentration of the haemoglobin is in the form of methaemoglobin, the patient will suffer from HYPOXIA and will be cyanosed (see CYANOSIS). Most cases of METHAEMOGLOBINAEMIA are due to chemical agents.... methaemoglobin

An odourless, colourless, highly ?ammable gas. It occurs naturally in gas from coal mines and oil wells, where it is a hazard because of its explosive properties. ‘Natural’ gas supplied to homes and industries is almost 100 per cent methane. Unlike coal gas, it is not poisonous unless present in large amounts, when it may displace oxygen and thus asphyxiate (su?ocate) anyone exposed to it. Decomposition of organic matter produces methane.... methane

Methionine is an essential amino acid (see AMINO ACIDS; INDISPENSABLE AMINO ACIDS) that contains sulphur; it is necessary for normal growth in infants and to maintain nitrogen balance in adults.... methionine

Also called oil of Wintergreen, the liquid has analgesic (see ANALGESICS) and counter-irritant properties. Rubbed into the skin, the oil helps to relieve pain in LUMBAGO, SCIATICA and ‘rheumatic conditions’.... methyl salicylate

Methylene blue, or methylthionin chloride, is used in a dose of 75–100 mg, as a 1-per-cent intravenous injection, in the treatment of METHAEMOGLOBINAEMIA, which may occur following high doses of local anaesthetics such as prilocaine.... methylene blue

A drug used to prevent attacks of MIGRAINE. The drug requires hospital supervision, as it has to be used with care because of the toxic effects it sometimes produces – for example, nausea, drowsiness and retroperitoneal FIBROSIS.... methysergide

The basic unit of length in the modern version of the metric system, known as the International System of Units (SI). It is equivalent to 39·37 inches.... metre

In?ammation of the uterus (see UTERUS, DISEASES OF).... metritis

Metyrapone is a drug that inhibits the production of CORTISOL in the adrenal cortex, which results in an increase in ACTH production and (completing the feedback control cycle) thus greater synthesis of the chemical precursors of cortisol. Metyrapone is used to treat patients with CUSHING’S SYNDROME (a condition caused by excess amounts of corticosteroid hormones in the body) where surgery is not possible.... metyrapone

A device that measures the rate at which an individual can expel air from the LUNGS. This is an indication of the reserve in the capacity of the lungs. Narrowed airways (bronchospasm) slow the rate at which air can be expelled; the peak ?ow meter can assess the severity of the condition. ASTHMA causes bronchospasm and the device can measure the e?ectiveness of treatment with BRONCHODILATOR drugs; this should be done regularly to monitor the progress of the disease.... peak flow meter

Any substance involved in a metabolic reaction (a biochemical reaction in the body). The term metabolite is sometimes used to refer only to the products of a metabolic reaction. (See also metabolism.)... metabolite

A synthetic opioid analgesic drug that resembles morphine.

Methadone is used under supervision to relieve withdrawal symptoms in people undergoing a heroin or morphine detoxification programme.

Side effects may include nausea, vomiting, constipation, dizziness, and dry mouth.... methadone

An alternative name for methanol.... methyl alcohol

Linn.

Synonym: D. fastuosa Linn.

Family: Solanaceae.

Habitat: Throughout India, particularly in waste place.

English: Thornapple, Downy Datura.

Ayurvedic: Dhattuura, Dhuurta, Dhastura, Unmatta, Shivapriya, Harapriya, Hema, Haatta, Dhustuu- ra, Dhustuuraka, Kanaka, Maatula. Also equated with Raaj-dhatuura. (white var.)

Unani: Dhaturaa.

Siddha/Tamil: Oomatthai, Karu- voomatthai.

Action: Various plant parts are used in headache, hemiplegia, epilepsy, delirium, convulsions, cramps, rigid thigh muscles, rheumatism. Leaf— antitumour, antirheumatic. Leaf and corolla—anti-inflammatory. Flower—antiasthmatic. Seed, leaf and root—anticatarrhal, febrifuge, antidiarrhoeal, antidermatosis; also used in cerebral complications. Seeds—used in asthma. Limited use in kinetosis (excessive salivation, nausea and vomiting).

Along with other therapeutic applications, The Ayurvedic Pharmacopoeia ofIndia indicated the use of the whole plant in dysuria and alopecia.

The plant accumulates more hyos- cine than hyoscyamine. Hyoscine content of dried leaves and flowering tops—between 0.02-0.55%. Alkaloid content of leaves—0.55%; stem—0.4%; seeds—0.19%; pericarps—0.8%; root at flowering of the plant—0.77%.

Hyoscine in large doses causes delirium and coma.

Dosage: Seed—30-60 mg. (API Vol. III.)... datura metel

A process by which the body destroys and excretes drugs, so limiting their duration of action. Phase 1 metabolism consists of transformation by oxidation, reduction, or hydrolysis. In phase 2 this transformed product is conjugated (joined up) with another molecule to produce a water-soluble product which is easier to excrete.... drug metabolism

Research based on critical evaluation through observation or experimentation, not opinion or speculation.... empirical methods

(German / Latin) Form of Margaret, meaning “resembling a pearl / the child of light” / one who is ambitious Metah, Metta, Mettah... meta

The ?ve long bones which occupy the HAND between the carpal bones at the wrist and the phalanges of the ?ngers. The large rounded ‘knuckles’ at the root of the ?ngers are formed by the heads of these bones.... metacarpal bones

See METASTASIS.... metastatic

The ?ve bones in the foot which correspond to the METACARPAL BONES in the hand, lying between the tarsal bones, at the ankle, and the toes.... metatarsal bones

That division of the animal kingdom which embraces all animals whose cells become differentiated to form tissues. It includes all animals except the protozoa.... metazoa

(Greek) A gentle woman Meteah, Metia, Metiah... metea

Also known as Physeptone®, this is a synthetic drug structurally similar to MORPHINE, one of many opioid drugs used to treat severe pain. Methadone is, however, less sedating and has a longer half-life. Furthermore, it is more reliable when taken orally. Although vomiting is common, this is generally less severe than with morphine.

Methadone is valuable as a suppressant for non-productive cough, acting on the medullary ‘cough centre’ in the central nervous system. It is also helpful in weaning addicts o? morphine and heroin, having a slower onset of DEPENDENCE and a less severe withdrawal syndrome. When used for prolonged periods, methadone should not be given more often than twice daily, to avoid the risks of accumulation and opioid overdosage.... methadone hydrochloride

Methaemoglobinaemia is a condition due to the presence in the blood of METHAEMOGLOBIN. It is characterised by CYANOSIS which turns the skin and lips a blue colour, shortness of breath, headache, fatigue and sickness. There are two main forms: a hereditary form and a toxic form. The latter is caused by certain drugs, including acetanilide, phenacetin, the sulphonamides and benzocaine. The treatment of the toxic form is the withdrawal of the causative drug. In the more severe cases the administration of methylene blue or ascorbic acid may also be needed, and these are the drugs used in the hereditary form.... methaemoglobinaemia

The scientific study of methods.... methodology

See TOLUENE.... methylbenzene

Most staphylococci (see STAPHYLOCOCCUS) have now evolved resistance to benzylpenicillin (see PENICILLIN) because of their ability to produce PENICILLINASE. Cloxacillin and ?ucloxacillin are antibiotics still e?ective against most staphylococci; at one time methicillin was used to combat resistant strains, but in hospital environments bacteria acquired immunity to this powerful drug (now withdrawn from use) and to cloxacillin. RIFAMPICIN, VANCOMYCIN, TEICOPLANIN and temocillin are still active against most penicillinase-producing gram-negative bacteria (see GRAM’S STAIN). There is, however, a growing threat to health because of the rise in the number of antibiotic-resistant bacteria, particularly in hospitals. The bacteria themselves are not more virulent than others, but the di?culty in treating them with a safe and e?ective antibiotic mean that they are more dangerous. It is likely that lapses in normal hygienic practice – such as frequent hand-washing – has resulted in an increase in MRSA disease.... methicillin-resistant staphylococcus aureus (mrsa)

Methyl is an organic radical whose chemical formula is CH3, and which forms the centre of a wide group of substances known as the methyl group. For example, methyl alcohol is obtained as a by-product in the manufacture of beet-sugar, or by distillation of wood; methyl salicylate is the active constituent in oil of wintergreen; methyl hydride is better known as marsh gas.

Methyl alcohol, or wood spirit (see METHANOL), is distilled from wood and is thus a cheap form of alcohol. It has actions similar to, but much more toxic than, those of ethyl alcohol. It has a specially pronounced action on the nervous system, and in large doses is apt to cause neuritis, especially of the optic nerves, leading to blindness, partial or complete.... methyl

(Greek) A wise counselor Metine, Metyn, Metyne... metin

(Greek) One who is industrious Metiss, Metisse, Metys, Metyss, Metysse... metis

A disorder characterised by irregular bouts of uterine (see UTERUS) bleeding – without previous OVULATION – due to excessive oestrogenic activity. It is associated with endometrial hyperplasia and cysts of the ovary.... metropathia haemorrhagica

Any uterine disease... metropathy

Prolapse of the uterus... metroptosis

Abnormal uterine discharge... metrorrhea

(Finnish) Woman of the forest Metsah... metsa

(Hebrew) Favored by God Mettabell, Mettabele, Mettabelle, Mettabela, Mettabella... mettabel

(Danish) As graceful as a pearl Metalise, Mettalisse, Mettalisa, Mettalissa... mettalise

Pollution of the blood and tissues by environmental poisons and traces of chemicals is a source of chronic disease. The most common toxic metals are lead, aluminium, cadmium, mercury and arsenic in that order. Copper is also toxic but is essential in small amounts.

Lead disrupts neurotransmitters in the brain and disposes to nervous excitability, aggression and hyperactivity. Aluminium is associated with senile dementia and Alzheimer’s disease, accumulating in the brain. Cadmium induces changes in behaviour with reduced mental ability. Mercury is present in the amalgam used in dental surgery as part-filling for teeth. Arsenical poisoning may occur in food contamination or paints.

An internal chelating or cleansing of tissues of the lungs, urinary system, blood and lymph may be assisted by a combination of relative expectorants, diuretics, hepatics and adaptogens among which are: Barberry, Blue Flag root, Chaparral, Burdock, Echinacea, Red Clover, Yellow Dock. To bind with metals and assist their passage through the intestinal canal to the outside of the body: Irish Moss, Iceland Moss or Slippery Elm. Garlic.

The Medicines Control Agency of the Ministry of Health (UK) has given consideration to the content of heavy metal impurities and rules that a limit of 75 micrograms of total heavy metals shall be the acceptable maximum daily intake.

Licence-holders are required to carry out tests on all incoming material. Some seaweeds may be heavily polluted with mercury, arsenic and radioactive particles as a result of micro-biological contamination. The MCA requires Bladderwrack and other seaweeds to contain minimum levels. ... heavy metal toxicity

A method of preventing pregnancy by blocking the passage of sperm to the uterus, for example by using a condom or a diaphragm. (See also contraception, barrier methods of.)... barrier method

Also called the mucus inspection method, a technique in which a woman notes changes in the characteristics of mucus produced by the cervix in order to predict ovulation for the purposes of contraception or family planning.... billings’ method

A method of contraception, also called the rhythm method, based on abstaining from sexual intercourse around the time of ovulation (calculated by a woman’s menstrual cycles). The method is unreliable because the menstrual cycle may vary (see contraception, natural methods).... calendar method

A form of contraception based on identifying periods for abstinence from intercourse according to the changes in the mucus secreted by a woman’s cervix (see contraception, natural methods of).... cervical mucus method

The use by women of synthetic progestogen drugs, which are often combined with synthetic oestrogens, to prevent pregnancy.

These drugs suppress ovulation and make cervical mucus thick and impenetrable to sperm.

They also cause thinning of the endometrium (lining of the uterus), which reduces the chance of a fertilized egg implanting successfully.

The best-known form of hormonal contraception is the contraceptive pill (see oral contraceptives).

The hormones can also be given as contraceptive implants under the skin, by injection (see contraceptives, injectable), or be released by IUDs.... contraception, hormonal methods of

Methods of avoiding conception based on attempts to pinpoint a woman’s fertile period around the time of ovulation, so that sexual intercourse can be avoided at this time. The calendar method is based on the assumption that ovulation occurs around 14 days before menstruation. Because of its high failure rate, it has been largely superseded by other methods. The temperature method is based on the normal rise of a woman’s body temperature in the second half of the menstrual cycle, after ovulation has occurred. The woman takes her temperature daily using an ovulation thermometer. Sex is considered to be only safe after there has been a sustained temperature rise for at least 3 days.

The cervical mucus method attempts to pinpoint the fertile period by observing and charting the amount and appearance of cervical mucus during the menstrual cycle.

Recognized changes in the mucus occur before and often at ovulation.

The symptothermal method combines the temperature and cervical mucus methods.... contraception, natural methods of

See coitus interruptus.... contraception, withdrawal method of

Inherited defects of body chemistry. Inborn errors of metabolism are caused by single gene defects, which lead to abnormal functioning of an enzyme.

Some of these gene defects are harmless, but others are severe enough to result in death or physical or mental handicap. Examples include Tay–Sachs disease, phenylketonuria, Hurler’s syndrome, and Lesch–Nyhan syndrome. Collectively, inborn errors of metabolism affect around 1 child in 5,000.

Symptoms are usually present at or soon after birth. They may include unexplained illness or failure to thrive, developmental delay, floppiness, persistent vomiting, or seizures.

Routine tests are performed on newborn babies for some genetic disorders, such as phenylketonuria.

Treatment is not needed for some inborn errors of metabolism. For others, avoidance of a specific environmental factor may be sufficient. In some cases, the missing enzyme or the protein that it produces can be manufactured using genetic engineering techniques, or a vitamin supplement can help compensate for the defective enzyme. If the enzyme is made in blood cells, a bone marrow transplant may provide a cure.

People with a child or a close relative who is affected may benefit from genetic counselling before planning a pregnancy.... metabolism, inborn errors of

One of 5 long, cylindrical bones within the hand. The bones run from the wrist to the base of each digit, with the heads of the bones forming the knuckles.... metacarpal bone

One of 5 long, cylindrical bones within the foot. The bones make up the central skeleton of the foot and are held in an arch by the surrounding ligaments.... metatarsal bone

The joint between each metatarsal bone and its adjoining toe bone (see phalanges). The metatarsophalangeal joint at the base of the big toe is commonly affected by gout and by hallux rigidus.... metatarsophalangeal joint

See MRSA.... methicillin-resistant staphylococcus aureus

See

Ecstasy.... methylenedioxymethamfetamine

See contraception, natural methods of.... mucus method of contraception

See contraception, natural methods of.... symptothermal method

See contraception, natural methods of.... temperature method

See coitus interruptus.... withdrawal method

a method of planning pregnancy involving the daily examination of cervical mucus, which varies in consistency and colour throughout the menstrual cycle. Use of a Billings mucus observation chart to help identify the type of mucus enables the woman to have six days’ warning of impending ovulation. [J. and E. Billings (20th century), Australian physicians]... billings method

a technique for expelling the placenta from the uterus. Upward pressure is applied to the uterus through the abdominal wall while holding the umbilical cord taut. When the uterus is elevated in this way, the placenta will be in the cervix or upper vagina and is then expelled by applying pressure below the base of the uterus. [T. Brandt (1819–95), Swedish obstetrician; H. R. Andrews (1872–1942), British gynaecologist]... brandt–andrews method

a process in which a drug administered by mouth is absorbed from the gastrointestinal tract and transported via the portal vein to the liver, where it is metabolized. As a result, in some cases only a small proportion of the active drug reaches the systemic circulation and its intended target tissue. First-pass metabolism can be bypassed by giving the drug via sublingual or buccal routes.... first-pass metabolism

a method of staining for the demonstration of enzymes, especially phosphatases and lipases, in histological specimens. [G. Gomori (1904–57), Hungarian histochemist]... gomori’s method

any one of a group of inherited conditions in which there is a disturbance in either the structure, synthesis, function, or transport of protein molecules. There are over 1500 inborn errors of metabolism; examples are *phenylketonuria, *homocystinuria, and *hypogammaglobulinaemia.... inborn error of metabolism

(MMP) any one of a group of zinc-containing proteases capable of digesting the extracellular tissue matrix. These enzymes play an important role in cell division, cell migration, inflammation, neoplastic invasion (*metastasis), and *angiogenesis.... matrix metalloproteinase

(insulin resistance syndrome, syndrome X) a very common condition in which impaired glucose tolerance, impaired fasting glucose, or type 2 diabetes (see glucose tolerance test) is combined with central obesity (increased fat within the abdomen), raised blood pressure (*hypertension), and *hyperlipidaemia. It is associated with a risk of premature vascular disease (heart attack and stroke). The principal underlying cause is *insulin resistance, which is genetically determined.... metabolic syndrome

1. adj. relating to the bones of the hand (*metacarpus). 2. n. any of the bones forming the metacarpus.... metacarpal

n. the five bones of the hand that connect the *carpus (wrist) to the *phalanges (digits).... metacarpus

n. a chromosome in which the centromere is at or near the centre of the chromosome. —metacentric adj.... metacentric

n. (pl. metacercariae) a mature form of the *cercaria larva of a fluke. Liver fluke metacercariae are enveloped by thin cysts and develop on various kinds of vegetation.... metacercaria

(metachromatism) n. 1. the property of a dye of staining certain tissues or cells a colour that is different from that of the stain itself. 2. the variation in colour produced in certain tissue elements that are stained with the same dye. 3. abnormal coloration of a tissue produced by a particular stain. —metachromatic adj.... metachromasia

n. philosophical study of the theoretical foundations of *ethics, as opposed to practical ethics.... metaethics

n. a genus of small flukes, usually less than 3 mm in length, that are common as parasites of dogs and cats in the Far East, N Siberia, and the Balkan States. Adult flukes of M. yokogawai occasionally infect the human duodenum if undercooked fish (the intermediate host) is eaten. They may cause inflammation and some ulceration of the intestinal lining, which produces a mild diarrhoea. Flukes can be easily removed with tetrachloroethylene.... metagonimus

n. a condition in which objects appear distorted. It is usually due to a disorder of the retina affecting the *macula (the most sensitive part).... metamorphopsia

metabolites of the hormones adrenaline and noradrenaline, respectively. Both hormones are released in excess from a *phaeochromocytoma, and measurement of their metabolites is the most reliable screening test for this rare but potentially lethal condition. The test is best carried out on a complete 24-hour urine collection.... metanephrine and normetanephrine

n. the excretory organ of the fetus, which develops into the kidney and is formed from the rear portion of the *nephrogenic cord. It does not become functional until birth, since urea is transferred across the placenta to the mother.... metanephros

n. the second stage of *mitosis and of each division of *meiosis, in which the chromosomes line up at the centre of the *spindle, with their centromeres attached to the spindle fibres.... metaphase

n. a *sympathomimetic drug that stimulates alpha receptors and is used as a *vasoconstrictor to treat acute *hypotension.... metaraminol

vb. (of a malignant tumour) to spread by *metastasis.... metastasize

the calcification of otherwise normal tissues in patients with *hypercalcaemia. Compare dystrophic calcification.... metastatic calcification

1. adj. relating to the bones of the foot (*metatarsus). 2. n. any of the bones forming the metatarsus.... metatarsal

n. a part of the *thalamus consisting of two nuclei through which impulses pass from the eyes and ears to be distributed to the cerebral cortex.... metathalamus

n. part of the hindbrain, formed by the pons and the cerebellum and continuous below with the medulla oblongata. See brain.... metencephalon

combining form denoting an instrument for measuring. Example: perimeter (instrument for measuring the field of vision).... meter

n. a chemical complex of the pigment portion of haemoglobin (haem) with the plasma protein *albumin. It is formed in the blood in such conditions as *blackwater fever or paroxysmal nocturnal haemoglobinuria, in which red blood cells are destroyed and free haemoglobin is released into the plasma. In such conditions methaemalbumin can be detected in both the blood and urine.... methaemalbumin

(hexamine) n. a drug used for the prevention and treatment of chronic or recurrent lower urinary tract infections. High doses may cause irritation of the stomach or bladder.... methenamine

n. see meticillin.... methicillin

n. see levomepromazine.... methotrimeprazine

a mixture consisting mainly of ethyl alcohol with *methyl alcohol and petroleum hydrocarbons. The addition of pyridine gives it an objectionable smell, and the dye methyl violet is added to make it recognizable as unfit to drink. It is used as a solvent, cleaning fluid, and fuel.... methylated spirits

a basic dye used for colouring the stainable part of the cell nucleus (chromatin) and – with pyronin – for the differential staining of RNA and DNA, which give a red and a green colour respectively.... methyl green

n. a preservative chemical commonly used in water-based products, such as cosmetics and toiletries. It is responsible for an epidemic of allergic contact *dermatitis, with intermittent facial dermatitis being the commonest presentation.... methylisothiazolinone

(methylmalonic acidaemia, aminoacidopathy) a defect of amino acid metabolism causing an excess of methylmalonic acid in the urine and blood. There are two types: one is an *inborn error of metabolism due to a deficiency of the enzyme methylmalonyl-CoA mutase; the other is an acquired type due to deficiency of vitamin B12, which results in defective synthesis of adenosylcobalamin (a cofactor in this metabolic process).... methylmalonic aciduria

(gentian violet) a dye used mainly for staining protozoans.... methyl violet

(methicillin) n. a semisynthetic penicillin that was originally used to treat infections by penicillin-resistant staphylococci. It has been superseded for this purpose by *flucloxacillin but continues to be used to test the drug sensitivity of staphylococci. Meticillin-resistant staphylococci (MRS) can be responsible for increasing rates of infection in hospitals. Until recently, such infections have responded to *vancomycin, but strains of bacilli have emerged that are resistant to vancomycin, giving rise to infections that are very difficult to treat. See also superinfection.... meticillin

(metro-) combining form denoting the uterus.... metr

combining form denoting measuring or measurement.... metry