Acid-base Balance: From 2 Different Sources
The balance between the acid and alkaline elements present in the blood and body ?uids.
The normal hydrogen ion concentration of the PLASMA is a constant pH 7·4, and the lungs and kidneys have a crucial function in maintaining this ?gure. Changes in pH value will cause ACIDOSIS or ALKALOSIS.
the balance between the amount of carbonic acid and bicarbonate in the blood, which must be maintained at a constant ratio of 1:20 in order to keep the hydrogen ion concentration of the plasma at a constant value (pH 7.4). Any alteration in this ratio will disturb the acid-base balance of the blood and tissues and cause either *acidosis or *alkalosis. The lungs and the kidneys play an important role in the regulation of the acid-base balance.
A colourless, pungent, fuming liquid. Secreted by the parietal cells in the lining of the stomach, it aids in the digestion of the food.... hydrochloric acid
The final end product of certain native or dietary proteins, especially the nucleoproteins found in the nucleus of cells. Unlike the much smaller nitrogenous waste product urea, which is mostly recycled to form many amino acids, uric acid is an unrecyclable metabolite. It is a bent nail that won’t restraighten, and it must be excreted: nucleoprotein to purine to uric acid to the outside in the urine or the sweat. (See GOUT, PURINES.)... uric acid
Ascorbic acid, or vitamin C (see APPENDIX 5: VITAMINS), is a simple sugar found in living tissues – its highest concentrations being in the adrenal cortex (see ADRENAL GLANDS) and the eye. Stress and CORTICOTROPIN lead to a loss of ascorbic acid from the adrenal cortex. Fresh fruit and vegetables, particularly blackcurrants, citrus fruits, berries and green vegetables, are the richest dietary sources; it may also be synthetically prepared. Ascorbic acid is easily eliminated from the diet by traditional methods of cooking, being very soluble in water and easily destroyed by heat, alkalis, traces of copper or by an oxidase released by damage to plant tissues. De?ciency may lead to SCURVY, traditionally associated with sailors, among elderly people living alone or in poor communities living at subsistence level. It has been claimed that large doses (1–2 g daily) will prevent the common cold, but few large controlled trials have been carried out and it is inadvisable for people to dose themselves with large quantities of ascorbic acid, which may result in the formation of oxalate stones in the urinary tract. (See also VITAMIN.)... ascorbic acid
See DNA.... deoxyribonucleic acid
A valuable antistaphylococcal antibiotic used both orally and topically. It is particularly useful in osteomyelitis (see BONE, DISORDERS OF).... fusidic acid
One of the NON-STEROIDAL ANTIINFLAMMATORY DRUGS (NSAIDS) that is an analgesic (see ANALGESICS) for mild to moderate pain in RHEUMATOID ARTHRITIS, OSTEOARTHRITIS and other musculoskeletal disorders. Also used for DYSMENNORRHOEA and MENORRHAGIA. It must be used with care as it has several side-effects, in particular diarrhoea and occasional haemolytic ANAEMIA. It must not be used in patients with INFLAMMATORY BOWEL DISEASE (IBD).... mefenamic acid
An antibiotic drug, active against gram-negative (see GRAM’S STAIN) micro-organisms, used to treat and prevent infections of the URINARY TRACT.... nalidixic acid
Nicotinic acid is a member of the vitamin B complex. It is essential for human nutrition, the normal daily requirement for an adult being about 15–20 mg. A de?ciency of nicotinic acid is one of the factors in the etiology of PELLAGRA, and either nicotine acid or NICOTINAMIDE is used in the treatment of this condition. Nicotinic acid also reduces the concentration of blood lipids (see HYPERLIPIDAEMIA).... nicotinic acid
Group of chemicals found in cells and which carry biochemical codes for heredity and day-to-dayfunctioning of cells.... nucleic acid
This is an irritant poison that is used domestically for cleaning purposes. It is also found in many plants including rhubarb and sorrel. Oxalic acid, when swallowed, produces burning of the mouth and throat, vomiting of blood, breathlessness and circulatory collapse. Calcium salts, lime water or milk should be given by mouth. An injection of calcium gluconate is an antidote.... oxalic acid
A crystalline substance sparingly soluble in water that is used externally in ointments and pastes. It has antifungal properties and helps to loosen and remove scales. In high concentrations it is useful in treatment of verrucae (WARTS) and corns (see CORNS AND BUNIONS).... salicylic acid
A drug used in the control of bleeding. It inhibits the activation of PLASMINOGEN and FIBRINOLYSIS, and may be useful when bleeding cannot be stopped – for instance, dental extraction in HAEMOPHILIA. The drug is also useful in MENORRHAGIA.... tranexamic acid
A preparation used in the treatment of cholesterol gall-stones when laparoscopic CHOLECYSTECTOMY and endoscopic biliary procedures cannot be used (see GALL-BLADDER, DISEASES OF).... ursodeoxycholic acid
An organic acid produced by the LIVER when it is rapidly oxidising fatty acids – a metabolic process which occurs, for example, during starvation. The acid produced is then converted to ACETONE, which is excreted.... acetoacetic acid
In our context, a substance having a pH below that of neutral water (7.0) when in solution. Most metabolic waste products are acidic. Sour. See pH... acid
The ability to balance is essential for a person to stand, walk and run. Maintaining this ability is a complex exercise of coordination dependent on the brain, sensory and motor nerves, and joints. There is a regular supply of information to the brain about the positions of various parts of the body and it responds with relevant instructions to the motor parts of the body. Eyes, the inner ear, skin and muscles all provide information. The cerebellum (part of the brain) collates all the information and initiates action. Balance may be affected by disorders in the balancing mechanism of the inner ear (semicircular canals) such as MENIERE’S DISEASE, and in?ammation of the labyrinth (labyrinthitis). Infection of the middle ear, such as otitis media (see under EAR, DISEASES OF), can also disturb the ability to balance, sometimes accompanied by dizziness or VERTIGO. If the cerebellum is affected by disease – a tumour or a stroke, for example – the result will be faulty muscular coordination leading to clumsiness and the inability to walk properly.... balance
Carbolic acid, or phenol, was the precursor of all ANTISEPTICS. It paralyses and then destroys most forms of life, particularly organisms such as bacteria. It has been superseded by less penetrative and harmful antiseptics.... carbolic acid
One of the bile acids (see BILE), used in the treatment of cholesterol gall-stones for patients with mild symptoms when other modern techniques are unsuitable. (See GALL-BLADDER, DISEASES OF.)... chenodeoxycholic acid
This is responsible for the sharp taste associated with citrus fruits, such as lemons and limes, and other fruits such as currants and raspberries. Although chemically di?erent from, it is similar in action and appearance to tartaric acid, obtained from grapes and other fruits, and similar to malic acid, found in apples and pears.... citric acid
See GABA.... gamma aminobutyric acid
An unsaturated fatty acid occurring widely in the glycerides of plants. It is an essential nutrient for mammals, including humans.... linoleic acid
The most common of naturally occurring fatty acids, being present in most fats and oils in the form of triglyceride. It is used in the preparation of OINTMENTS, but not eye ointments.... oleic acid
A yellow crystalline solid substance which is used as a ?xative for tissues being prepared for examination under a microscope; it is also used as a dye.... picric acid
See RNA.... ribonucleic acid
A bisphosphonate drug used in the treatment of osteoporosis and Paget’s disease of bone. The most common side effect is inflammation of the oesophagus, which causes heartburn or difficulty in swallowing. Other side effects can include headache and abdominal pain.... alendronic acid
One of the fatty acids in the body that are essential for growth.... arachidonic acid
A topical drug used to treat mild to moderate acne.... azelaic acid
See ASPIRIN.... acetylsalicyclic acid
A drug used to treat hereditary angio-oedema (see under URTICARIA) – a serious anaphylactic (see ANAPHYLAXIS) reaction of the skin and respiratory tract resulting from a de?ciency in the body’s immunological defence mechanisms (see IMMUNITY).... aminocaproic acid
The practice of medical practitioners, dentists and other independent practitioners to seek payment from the patient for that portion of the patient’s bill not covered by the government or other third party payers.... balance billing
Chromic acid is used in several industries, particularly in chromium plating. Unless precautions are taken it may lead to dermatitis of the hands, arms, chest and face. It may also cause deep ulcers, especially of the nasal septum and knuckles.... chromic acid
A potent diuretic, with a rapid onset, and a short duration (4–6 hours), of action. (See THIAZIDES; DIURETICS.)... ethacrynic acid
The appropriate balance of ?uid input and output (along with dissolved salts essential for life) over 24 hours. During this period, about 2,500 millilitres (ml) of ?uid should be taken in by a 70-kg man and the same amount excreted; of this, 1,500 ml will be drunk, 800 ml will be in the food eaten, and 200 ml produced by food metabolism. Excreted water is made up of 1,500 ml of urine, 800 ml insensible loss and 200 ml in the faeces. A 70-kg man’s total body ?uid is 42 litres – 60 per cent of body weight. Intracellular ?uid comprises 28 litres, extracellular, 14 litres and blood, 5 litres. Water is controlled mainly by the sodium concentration in the body ?uids via the release of antidiuretic hormone (ADH – see VASOPRESSIN) from the posterior part of the PITUITARY GLAND. In seriously ill people, close monitoring of ?uid intake and output, along with measurements of PLASMA sodium and calcium concentrations, is an essential factor in treatment.... fluid balance
Lysergic acid diethylamide belongs to the ergot group of ALKALOIDS. It has various effects on the brain, notably analgesic and hallucinogenic, thought to be due to its antagonism of 5hydroxytryptamine (5-HT). In small doses it induces psychic states, in which the individual may become aware of repressed memories. For this reason it may help in the treatment of certain anxiety states, if used under skilled supervision. LSD rapidly induces TOLERANCE, however, and psychological DEPENDENCE may occur, although not physical dependence. Serious side-effects include psychotic reactions, with an increased risk of suicide.... lysergic acid diethylamide (lsd)
Also known as mandelamine, a non-toxic keto-acid used in the treatment of infections of the urinary tract, especially those due to the Escherichia coli and the Streptococcus faecalis or Enterococcus. It is administered in doses of 3 grams several times daily. As it is only e?ective in an acid urine, ammonium chloride must be taken at the same time.... mandelic acid
One of the early antituberculous (see TUBERCULOSIS) antibiotics. It tended to cause DYSPEPSIA and has been replaced by newer antituberculous drugs with fewer side-effects. The ?rst-line drugs for tuberculosis are now rifampicin, isoniazid, and ethambutol.... para-amino salicylic acid
See CYANIDE POISONING.... prussic acid poisoning
Foods that produce acid when metabolised. Ash from these foods contains sulphur, phosphoric acid and chlorine, all essential for efficient metabolism. Breads, cereals, cheese, chicken, chocolate, cocoa, coffee, cranberries, eggs, fish, flour, fowl, grain products, lentils, meats (lean), nuts, oats, oatmeal, oysters, pasta, peanuts, peanut butter, pearl barley, plums, prunes, rhubarb, rabbit, rice (white), sugar, sweet corn, tea, veal, wholemeal bread, wheatgerm. ... acid foods
Associated with a number of conditions including PMT, low blood pressure, etc. Treatment: same as for MENIERE’S DISEASE. ... balance – disorders of
A polyunsaturated fatty acid; an essential ingredient in the body’s production of prostaglandins. Present naturally in mother’s milk. The body produces GLA from linoleic acid present in food as an essential fatty acid (EFA). Vital to growth, cell structure and cardiac health. Sources: Evening Primrose oil; Sunflower seed oil, Borage and Blackcurrant. Preparations from the fermentation of rotten carrots. Helps lower blood pressure and prevent cholesterol build-up in the blood. ... gamma linolenic acid (gla)
Regurgitation of acidic fluid from the stomach into the oesophagus due to inefficiency of the muscular valve at the lower end of the oesophagus. Also known as gastro-oesophageal reflux disease (GORD), acid reflux may inflame the oesophagus, resulting in heartburn due to oesophagitis. It may occur in pregnancy and often affects overweight people.... acid reflux
The active ingredient of many sunscreen preparations. Its abbreviation is.... para-aminobenzoic acid
see aspirin.... acetylsalicylic acid
a technique for creating a mechanical bond between resin-based materials and the enamel of teeth; it is used to retain and seal the margins of composite fillings, to retain brackets of fixed orthodontic appliances, and to retain resin-based *fissure sealants and adhesive bridges. Phosphoric acid is used to create a porous surface into which a bonding agent can flow.... acid-etch technique
adj. 1. describing bacteria that have been stained and continue to hold the stain after treatment with an acidic solution. For example, tuberculosis bacteria are acid-fast when stained with a *carbol fuchsin preparation. 2. describing a stain that is not removed from a specimen by washing with an acidic solution.... acid-fast
an organic compound containing an amino group (–NH2) and a carboxyl group (–COOH). Amino acids are fundamental constituents of all *proteins. They are classified as *essential amino acids, i.e. those that cannot be synthesized by the body, and nonessential amino acids, which can be synthesized by the body. Certain amino acids present in the body are not found in proteins; these include *citrulline, *ornithine, *taurine, and *gamma-aminobutyric acid.... amino acid
(aspartate) see amino acid.... aspartic acid
(BSS) a solution containing physiological concentrations of sodium chloride, potassium chloride, calcium chloride, magnesium chloride, sodium acetate, and sodium citrate. Such fluids are isotonic to eye tissue; they are used during intraocular surgery and to replace intraocular fluids.... balanced salt solution
the linking of the two strands of a DNA molecule by means of hydrogen bonds between the bases of the nucleotides. Adenine always pairs with thymine and cytosine with guanine. See DNA.... base pairing
an antiseptic, active against fungi and bacteria, used as a preservative in foods and pharmaceutical preparations and, combined with salicylic acid, in the form of an ointment (Whitfield’s ointment) for the treatment of ringworm.... benzoic acid
(cholalic acid) see bile acids.... cholic acid
see Krebs cycle.... citric acid cycle
a drug that interferes with the *penicillinases that inactivate *beta-lactam antibiotics, such as *amoxicillin or *ticarcillin. Combined with the antibiotic, clavulanic acid can overcome drug resistance.... clavulanic acid
see bile acids.... deoxycholic acid
an *amino acid that is essential for normal growth and development but cannot be synthesized by the body. Essential amino acids are obtained from protein-rich foods in the diet, such as meat, fish, eggs, and dairy products. Adults require eight essential amino acids: leucine, isoleucine, valine, phenylalanine, threonine, methionine, tryptophan, and lysine. Children require an additional nine, as their body’s requirement is greater than can be synthesised by it: tyrosine, glycine, cysteine, arginine, proline, histidine, glutamine, serine, and asparagine.... essential amino acid
an organic acid with a long straight hydrocarbon chain and an even number of carbon atoms. Fatty acids are the fundamental constituents of many important lipids, including *triglycerides. Some fatty acids can be synthesized by the body; others, the *essential fatty acids, must be obtained from the diet. Examples of fatty acids are palmitic acid, oleic acid, and stearic acid. See also fat; saturated fatty acid; unsaturated fatty acid.... fatty acid
a derivative of folic acid involved in purine synthesis. It is used to reverse the biological effects of methotrexate and other *dihydrofolate reductase inhibitors and so to prevent excessive toxicity. This action is termed folinic acid rescue. Folinic acid has a potentiating effect with *fluorouracil, with which it is often used.... folinic acid
a sugar acid derived from glucose. Glucuronic acid is an important constituent of *chondroitin sulphate (found in cartilage) and *hyaluronic acid (found in synovial fluid).... glucuronic acid
(glutamate) see amino acid; neurotransmitter.... glutamic acid
(GAD) a common enzyme that, because of similarities to certain bacterial proteins, can provoke an autoimmune reaction against the beta cells of the pancreas (see islet cell antibodies) progressing to type 1 *diabetes mellitus.... glutamic acid decarboxylase
see bile acids.... glycocholic acid
a derivative of *histamine that was formerly used to test for acid secretion in the stomach in conditions involving abnormal gastric acid secretion, such as *Zollinger-Ellison syndrome.... histamine acid phosphate
a product formed during the metabolism of the amino acids phenylalanine and tyrosine. In normal individuals homogentisic acid is oxidized by the enzyme homogentisic acid oxidase. In rare cases this enzyme is lacking and a condition known as *alcaptonuria, in which large amounts of homogentisic acid are excreted in the urine, results.... homogentisic acid
an acid *mucopolysaccharide that acts as the binding and protective agent of the ground substance of connective tissue. It is also present in the synovial fluid around joints and in the vitreous and aqueous humours of the eye.... hyaluronic acid
(prussic acid) an intensely poisonous volatile acid that can cause death within a minute if inhaled. It has a smell of bitter almonds. See cyanide.... hydrocyanic acid
(5-HIAA) a metabolite of *serotonin, the most common secretion product of *carcinoid tumours. Measured over 24 hours in the urine, this is the most reliable screening test for such tumours.... 5-hydroxyindoleacetic acid
see essential fatty acid.... linolenic acid
a sulphur-containing compound that can be readily interconverted to and from its reduced form, dihydrolipoic acid. Lipoic acid functions in carbohydrate metabolism as one of the *coenzymes in the oxidative decarboxylation of pyruvate and other ?-keto acids.... lipoic acid
(LSD) an illegal hallucinogenic drug that was formerly used to aid treatment of certain psychological disorders. Side-effects include digestive upsets, dizziness, tingling, anxiety, sweating, dilated pupils, muscle incoordination and tremor. Alterations in sight, hearing, and other senses occur, psychotic effects, depression, and confusion are common, and tolerance to the drug develops rapidly. Because of these toxic effects, LSD is no longer used clinically. See Appendix 12 for a list of street names for illicit drugs.... lysergic acid diethylamide
a strong corrosive mineral acid, HNO3, the concentrated form of which is capable of producing severe burns of the skin. Swallowing the acid leads to intense burning pain and ulceration of the mouth and throat. Treatment is by immediate administration of alkaline solutions, followed by milk or olive oil.... nitric acid
the relationship between the nitrogen taken into the body and that excreted, denoting the balance between the manufacture and breakdown of the body mass. A negative nitrogen balance, when excretion exceeds intake, is usual after injury or operations as the energy requirements of the body are met disproportionately from endogenous sources.... nitrogen balance
see osmium tetroxide.... osmic acid
see fatty acid.... palmitic acid
(PAS reaction) a test for the presence of glycoproteins, polysaccharides, certain mucopolysaccharides, glycolipids, and certain fatty acids in tissue sections. The tissue is treated with periodic acid, followed by *Schiff’s reagent. A positive reaction is the development of a red or magenta coloration.... periodic acid–schiff reaction
see hydrocyanic acid.... prussic acid
see folate.... pteroylglutamic acid
(pyruvate) a compound, derived from carbohydrates, that may be oxidized via a complex series of reactions in the *Krebs cycle to yield carbon dioxide and energy in the form of ATP.... pyruvic acid
a *fatty acid in which all the carbon atoms are linked by single bonds and the molecule is unable to accept additional atoms (i.e. it cannot undergo addition reactions with other molecules). These fats occur mainly in animal and dairy products, and a diet high in these foods may contribute to a high serum cholesterol level, which may increase the risk of *coronary artery disease. Compare unsaturated fatty acid.... saturated fatty acid
an amino sugar. Sialic acid is a component of some *glycoproteins, *gangliosides, and bacterial cell walls.... sialic acid
see fatty acid.... stearic acid
a powerful corrosive acid, H2SO4, widely used in industry. Swallowing the acid causes severe burning of the mouth and throat and difficulty in breathing, speaking, and swallowing. The patient should drink large quantities of milk or water or white of egg; gastric lavage should not be delayed. Skin or eye contact should be treated by flooding the area with water.... sulphuric acid
see bile acids.... taurocholic acid
an *astringent used for a variety of skin conditions. It is also applied topically to produce sloughing, especially for the removal of warts.... trichloracetic acid
an antifungal agent, applied to the skin for the treatment of athlete’s foot.... undecenoic acid
a *fatty acid in which one (monounsaturated) or many (polyunsaturated) of the carbon atoms are linked by double bonds that are easily split in chemical reactions so that other substances can connect to them. These fats occur in fish and plant-derived foods, and a diet high in unsaturated fats is associated with low serum cholesterol levels. Compare saturated fatty acid.... unsaturated fatty acid
see sodium valproate.... valproic acid
(VMA) a metabolite of *catecholamines excreted in abnormal amounts in the urine in conditions of excess catecholamine production, such as *phaeochromocytoma. The measurement of VMA levels in a 24-hour urine sample was formerly used as a screening test for this condition, but in the UK it has been largely superseded by the urinary metanephrine test (see metanephrine and normetanephrine).... vanillylmandelic acid
(zolendronate) a *bisphosphonate drug that is used to treat Paget’s disease and malignant *hypercalcaemia and is also establishing a role in treating bone metastases, both in terms of symptom relief and preventing bone fractures.... zoledronic acid
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