Glossary
Starting with A for "ACE inhibitor" and continuing through to Y for "Yolk Sac Tumour", we give you succinct explanations for scientific and medical terms in clear and simple words.
- Accomodative iridoplegiaAccomodative iridoplegia means partial, or rarely total, loss of the accommodation of the eye, i.e. the eye is no longer capable of forming a sharp image of a fixed object on the retina. Accomodative iridoplegia frequently occurs together with a disturbance in the mobility of the pupils. Cf. oculomotor paralysis
Causes
Type 2 diabetes, Type 1 diabetes, inflammation of the iris or of the ciliary body, glaucoma and other diseases can cause accommodative iridoplegia.
- ACE inhibitorShort term for inhibitors of the enzyme ACE (angiotensin-converting enzyme).
Actions
ACE inhibitors lower blood pressure and heart preload and afterload. This results from inhibition of the conversion of the hormone angiotensin I into angiotensin II, which constricts blood vessels, leading to an increase in blood pressure. This results in reduced release of the hormone aldosterone, which has the function of retaining sodium and water in the kidney. The resistance of the arteries then sinks.
Uses
In essential hypertension (hypertension), heart failure and after myocardial infarction (prevention of a second infarct)
Contraindications
Pregnancy and breast feeding, constriction of both renal arteries, constriction of the aorta and other.
Side-effects
Disturbances in taste, skin reactions and other rare side-effects. Caution! A drastic reduction in blood pressure and (reversible) restriction or deterioration in renal function may develop, particularly when there has been previous renal damage. - Acetylsalicylic acidChemical compound which reduces pain, fever and inflammation. Acetylsalicylic acid also decreases the aggregation of blood platelets (thrombocytes), which can cause blood clots.
Uses
1. Pain, fever and rheumatic diseases; 2. in unstable angina pectoris or acute myocardial infarction to prevent a further infarct, after vascular surgery (particularly arterial surgery), to prevent stroke when the perfusion of the brain is inadequate and when there is constriction of the blood vessels in other organs.
Contraindications
These include abnormalities in blood formation. Caution is necessary with stomach or duodenal ulcers. There are special restrictions to use if the patient is also being treated with drugs to inhibit blood coagulation.
Side-effects
Gastrointestinal problems, particularly gastric or duodenal ulcers, asthma attacks, headache, excessive tissue fluid (oedema), abnormalities in blood formation or in liver or kidney function, hypersensitivity or shock. - AcidosisA disturbance in the acid-base balance in the body, with a drop in the arterial pH to less than 7.36. The occurrence and degree are partially dependent on the possibilities for the body to compensate biochemically.
Forms
1. Metabolic Acidosis: This develops during metabolic abnormalities, such as a lack of insulin. This is compensated for by an increase in respiration (hyperventilation), which results in increased release of carbon dioxide through the lungs and to normalisation of the pH. Symptoms: Increase in the depth of breathing (Kussmaul respiration), drop in blood pressure, shock. Therapy: Acidosis can be eliminated by treatment with substances which compensate for it. 2. Respiratory Acidosis: This arises as a result of an increase in blood carbon dioxide due to low expiration (hypoventilation). Causes: Central respiratory depression, hindrance to respiratory work (e.g. with serial rib fractures or neuromuscular disease), the Pickwick syndrome and lung diseases which disturb gas exchange. Compensation: Metabolic counterregulation through the kidneys occurs only slowly and is therefore only important in chronic respiratory acidosis. Symptoms: Blue-red colouration of the skin as a result of the decrease in the oxygen content of the blood, breathlessness, rapid heart beat and other symptoms. Therapy: Increase in respiration. Acute respiratory acidosis may be treated by controlled ventilation. - ACTHACTH is an abbreviation for adrenocorticotrophic hormone and is also known as corticotropin.
The hormone ACTH is formed in the frontal lobe of the pituitary and acts on the cortex of the adrenal glands.
Actions
ACTH mainly increases the production of the so-called stress hormones (glucocorticoids) in the adrenal cortex, stimulates fat breakdown (lipolysis) and leads indirectly to an increase in the release of insulin, the hormone which decreases blood sugar. One of the factors which inhibits the formation of ACTH is a high blood concentration of glucocorticoids; cold and stress (adrenalin) increase ACTH formation. - Acute arterial occlusionSudden displacement of an artery of (roughly) normal width, with damage to the tissue or section of the organ which is served by it, which may extend to death of the tissue. Cf. occlusive arterial disease
Causes
Mostly embolism, predominantly from the left atrium of the heart, or thrombosis
Location and symptoms
1. Arteries in the brain, mostly exhibited as stroke; 2. Vessel branches; 3. Arteries in the arms or legs, with sudden intense pain, pallor, drop in temperature and decolouration (marbling) of the skin on the far side (distal) to the vessel obstruction, numbness, pain at rest from lack of perfusion of the musculature, lack of palpable arterial pulse, shock, acidification of the blood and inundation with products from the protein metabolism on reperfusion; 4. Intestinal arteries, particularly occlusion of the mesenterial arteries, renal embolism.
Diagnosis
Angiography (X-ray imaging of the vessels with contrast medium), diagnosis by ultrasound.
Therapy
Operative removal of the embolus. Treatment with heparin to inhibit blood coagulation.
Analgaesia, blood dilution, dissolution of the blood clot with drugs; after an operation prevention of a new embolus with, for example, heparin. - acute renal failurean acute disturbance of kidney function characterised by a rapid decline (>50% reduction) in glomerular filtration rate (GFR), usually resulting in little or no urine production and the accumulation of metabolic waste products in the blood; acute renal failure can occur as a potentially fatal complication of critical illness, traumatic injury and drug toxicity; it is frequently reversible but can precipitate or exacerbate chronic kidney disease
- AdenomaGrowth on the superficial cells (epitheleal tissue) of the mucous membrane of the gastrointestinal tract or glands: Initially benign, but can degenerate to become malignant. The following forms are distinguished on the basis of appearance:
1. Tubular adenoma, in which the epithelial tissue has a tube-like structure, e.g. polyps.
2. Trabecular adenoma, in which the epithelial tissue forms bars.
3. Follicular adenoma, in which small cell bubbles are formed, in which, for example, thyroid hormones are produced or can be released.
4. Adenoma with the formation of a large cavity, e.g. in the ovaries.
5. Fibroadenoma with increased growth of connective tissue cells, particularly in the female breast. - Adenoma of the Bile DuctsBenign tumour that occurs in the liver, no larger than a cherry. Originates in the bile ducts* and is itself assembled from branched ducts.
- ADHAbbreviation for antidiuretic hormone; also known as adiuretin or vasopressin.
ADH is formed in a part of the midbrain or diencephalon (hypothalamus) and stored in the pituitary. Release of ADH is increased by thirst, by a decrease in fluid volume, by drugs and emotional influences. Release of ADH is decreased by an increase in fluid volume, by alcohol and by caffeine.
Actions
ADH decreases the elimination of water by the kidneys, which increases urine concentration. It narrows blood vessels (vasopressive action), leading to an increase in blood pressure. A lack of ADH leads to increased excretion of urine (cf. diabetes insipidus).
- Adrenal failureInadequate function of the adrenal cortex
Forms
1. Acute adrenal failure as the result of tissue death from locally inadequate perfusion, e.g. after an injury during birth, abnormalities in coagulation, thrombosis of the adrenal veins or as a result of too rapid discontinuation of long-term steroid therapy with subsequent atrophy of the adrenal cortex. 2. Chronic primary failure of the adrenal cortex (Addison's disease) 3. Chronic secondary failure of the adrenal cortex: occurs when there is deficiency of ACTH.
Symptoms
Abdominal pain, signs of intoxication, circulatory weakness, low blood sugar (hypoglycaemia), hypercholesterolaemia, hyperkalaemia, acidosis, decrease in blood sodium concentration (hyponatraemia, cf. aldosterone) and others. A potentially fatal crisis may develop (so-called Addison crisis).
Therapy
Infusion of physiological saline solution (perhaps several litres), treatment with cortisol. - Adrenal TumoursA distinction is made between tumours of the adrenal cortex and medulla. In the adrenal cortex, benign tumours may develop which form hormones or which lie in fat tissue. Malignant tumours may also develop, which are mostly metastases. Pheochromcytoma is one of the tumours of the adrenal medulla.
- AdrenalineChemical messenger in nerve impulses and hormone of the adrenal cortex. The release of adrenaline from the adrenal cortex is stimulated by signals from nerves and is greatly increased during stress.
Actions
Increases pulse rate, cardiac output per minute and high blood pressure; decrease in intestinal activity; relaxation of the bronchial musculature and dilation of the bronchi and pupils. Metabolism is increased, with an increase in oxygen consumption. Blood sugar is raised (hyperglycaemia) as a result of glycogen breakdown; lipolysis is increased. This leads to increased availability of energy and "increased readiness for the alarm reaction". Cf. noradrenaline. - AdrenalsPaired glands which form hormones. They are surrounded by fat tissue and lie at the upper pole of the kidney. The left adrenal is shaped like a half moon; the right is triangular. The weight is 8-10 g. The yellowish brown cortex can be distinguished from the red brown medulla on the basis of both structure and function.
Functions
1. Adrenal cortex (abbreviated as AC): Production of more than 40 different steroid hormones (corticoids) which are classified according to their actions as: a) mineralocorticoids (e.g. aldosterone), b) Glucocorticoids (e.g. cortisol) and c) Sex hormones (e.g. androgens). 2. Adrenal medulla (abbreviated as AM): Site of production of so-called catecholamines (adrenaline, noradrenaline and dopamine).
- AfterloadResistance which the heart muscle must overcome when it empties the chamber, the so-called ejection resistance. The afterload is directly dependent on the wall tension of the heart muscle and indirectly dependent on the peripheral arterial resistance. Cf. preload.
- AIDSAbbreviation for the English name, Acquired Immune Deficiency Syndrome
A disease of the immune system which develops ca. 10 to 12 years after infection with the viruses HIV-1 and HIV-2 and which involves suppression of defences against infections and tumours. AIDS is the fourth stage of the HIV disease, with marked immune weakness and the so-called AIDS-defining diseases. The disease was first described in 1981 in the USA as acquired immune deficiency of unclear origin. For occurrence, diagnosis, therapy and prognosis see HIV disease.
- AIDS HelpAIDS Help is an educational institution which provides information about AIDS. There are international offers under http://www.unaids.org, the Joint United Nations Programme on HIV/AIDS, or the Center for Disease Control (CDC) under http://www.cdc.gov/nchstp/hiv_aids/hivinfo.htm
- AIDS-Defining DiseasesGroup of diseases of which the occurrence defines the final stage of HIV disease (AIDS). The so-called full clinical picture of AIDS is evident, as soon as diseases such as the following have developed: Pneumocystis carinii pneumonia, toxoplasma infection of the brain, fungal infection of the oesophagus or lungs with Candida albicans, cytomegalic infection which spreads over the whole body, tuberculosis or the Kaposi syndrome.
- Albers-Schönberg diseasesee marble bone disease
- AlbuminsHighly water soluble large proteins which are produced in the liver. Albumins make up about 52-62 % of the total blood protein and also occur in other body fluids (e.g. cerebral and spinal fluids and lymph), in breast milk and in muscle tissue. Albumins are particularly important for the maintenance of blood volume by binding fluids and as blood transport proteins for substances which are insoluble in water (e.g. free fatty acids).
- AlbuminuriaElimination of large water soluble proteins (albumins) in the urine. Every healthy individual excretes albumin in the urine. Increased values are called microalbuminuria; very markedly increased values are referred to as macroalbuminuria. Microalbuminuria can be a sign of diabetic glomerulosclerosis (kidney damage), as a result of type 2 diabetes or type 1 diabetes. Albuminuria may lead to a decrease in blood albumin.
- AldosteroneAldosterone is the most important of the mineral corticoids, which are hormones formed in the adrenal cortex and which regulate mineral balance. Together with the enzyme renin and the hormone angiotensin (renin-angiotensin system), it regulates electrolyte and water balance and, consequent to this, blood volume and blood pressure. Specific actions of aldosterone include an increase in sodium reuptake into the blood at the end of the passage through the kidney and increased renal excretion of potassium.
- Aldosterone antagonistsSubstances which inhibit the binding of the hormone aldosterone to its receptors. The efficacy of aldosterone antagonists depends on the concentration of aldosterone in the body.
Therapeutic uses
When there is excessive release of aldosterone, high blood pressure (hypertension) or when there is deficiency of potassium in the blood as a result of drug treatment. Caution! Aldosterone antagonists may cause an excessive increase in blood potassium concentration.
- allogeneicforeign to the body
- Alpha-calcidolIntermediate product of vitamin D metabolism. Alpha-calcidol is converted in the liver into 1, 25-dihydroxycalciferol (calcitriol), which is the compound which is actually active. It is used for the prevention and treatment of osteoporosis and renal osteopathy.
- Alpha-Glucosidase inhibitorsSubstance which inhibits the breakdown of certain sugars (disaccharides) in the mucous membrane of the small intestine by inhibiting the enzymes which split disaccharides into monosaccharides. Only monosaccharides can be absorbed in the intestine, which means that alpha-glucosidase inhibitors decrease the uptake of glucose from the intestine into blood. alpha-Glucosidase inhibitors are used in type 2 diabetes. Cf. antidiabetic drugs
- alpha-InterferonAlso described as natural human leukocyte interferon or alpha-IFN
Group of endogenous proteins which are formed by cells and released into the circulation after an infection by viruses, bacteria or other microorganisms. alpha-Interferon is made in the white blood cells. When this protein is to be used as a drug, it can either be isolated from donated blood or prepared by genetic engineering. alpha-Interferon is used in the treatment of severe viral diseases (e.g. AIDS, Chronic Hepatitis), certain forms of cancer and herpes infections. Interferons can block viral replication. At the moment, they are only available as solutions for injection. There are several possible reasons why interferons may not be used (contraindications). These should be discussed with the physician. One reason is protein allergy.
Symptoms like flu are frequently one of the side effects after an injection of interferon. There may also be skin reactions at the site of injection. It is particularly important to check blood parameters at the start of the treatment.
Apart from alpha-interferon, the body produces ß-interferon in certain connective tissue cells and gamma-interferon in T-cells. - AlveoliAlveoli are the so-called air sacs, in which gas exchange occurs during respiration. An alveolus has a diameter of 100-300 micometers. The total surface of all alveoli of the human lung comes to 70-80 m2. Alveoli are surrounded by a scaffolding of elastic fibres and the capillary network of the pulmonary arteries. They are connected to each other by pores in the alveolar wall. In the alveoli, oxygen is taken up by diffusion into the blood through the so-called alveolocapillary membrane and carbon dioxide is released.
- AminoacidsBuilding blocks of the proteins, the 20 alpha-aminocarboxylic acids from which proteins are made up. Aminoacids are classified according to their chemical structure, their properties, their functions and the metabolic products they form.
- AmylasesAmylases are enzymes, which break down starch and glycogen. Break down products can be taken up by the body. Cf. digestion of carbohydrates.
Classification
1. Alpha-amylases (also known as endoamylases) split the carbohydrate molecule within the polyglucose chain. Polysaccharides with a variable number of glucose units are formed, together with maltose and isomaltose. Amylases occur in man, particularly in the secretions of the pancreas and the parotid. 2. Beta-amylases only occur in plants and microorganisms. 3. Gamma-amylases split glucose residues from the end of the carbohydrate molecule. They occur particularly in liver and kidney cells. - Amylosesee starch
- Anabolic drugsSubstances which increase the formation of protein in the body, for example in the muscles, and which accelerate growth. 1. Strictly defined, anabolic drugs are steroids which are derived from androgens (male sex hormones); 2. Aromatase inhibitors inhibit the production of oestrogens; Beta-sympathomimetic drugs: substances which stimulate the beta-receptors in the sympathetic arm of the vegetative nervous system (cf. receptors).
Uses
Anabolic steroids may be used for example for anaemia due to a pathological reduction in blood-forming bone marrow and osteoporosis. Anabolic steroids are frequently misused to build up muscle (so-called doping).
Contraindications
Pregnancy, prostatic cancer, disturbances in liver function
Side-Effects
Development of secondary male sexual characteristics in women (virilisation), decrease in the size of the testicles and lack of mature sperm in men, disturbances in liver function, aggressiveness. - AnalgesicsDrugs which alleviate pain. They may act in the brain or spinal chord (centrally active analgesics) or on the nerves outside the brain and spinal chord (peripherally active analgesics).
Classification
1. Opioid analgesics act through opioid receptors (cf. receptors), which is the same way as natural opiate-like substances act. Opioid analgesics are used for cancer pain or for intense pain after an operation. Caution is called for, because of the danger of drug dependency! The opioid analgesics include: a) natural components of opium, the so-called opium alkaloids; b) semi- and fully synthetic morphine-like substances.
2. Non-opioid analgesics, which may also reduce fever and inflammation: a) aniline derivatives; b) non-steroidal anti-inflammatory drugs; c) other non-opioid analgesics. - Analysable patient-level dataThis is the raw data collected on each patient at each doctor visit. Patient level analysable data are in databases that allow analysis by computer programmes and statistical tests.
- anaphylaxisa severe, sometimes fatal allergic reaction to a substance; symptoms include difficulty breathing, low blood pressure and rash, sometimes with blisters or urticaria
- AndrogensCollective term for male sexual hormones which are formed in the testicles, adrenals and (in small quantities) ovaries. The most important androgens are testosterone (highest blood concentration) and its metabolic products dihydrotestosterone (active form), androstendione and androsterone. In the blood, about 98% of androgens are bound to a transport protein. The actions of androgens include the following: Stimulation of specific metabolic pathways; Male genitals: influence on the development of the penis, seminal duct, seminal vesicles and prostate, support certain stages in the development of sperms; skin, hair: development of the male pattern of hair growth, influence on acne and other skin diseases; Skeleton: at high doses increase longitudinal growth; Enzymes: expression of sex-specific enzyme pattern in various organs.
- anemiaa deficiency of red blood cells and/or hemoglobin, the protein that carries oxygen from the lungs and distributes it to the bodys tissues; anemia can be measured by hemoglobin concentration, red blood cell volume (also called hematocrit) or red blood cell count
- Angina abdominalisalso known as angina intestinalis, Ortner syndrome, claudication intermittens abdominalsi or dysbasia intestinalis
Syndrome connected with chronic abnormalities in intestinal perfusion, mostly due to arteriosclerosis of the arteries which serve the intestine. Cf. occlusion of the mesenteric arteries.
Symptoms
1. Without symptoms, discovered by chance; 2. pain after eating; 3. alternating continuous pain with enhanced intestinal movements, wind and loss of weight; 4. acute abdominal pain, abnormal intestinal movement with problems in defecation, intestinal obstruction, inflammation of the diaphragm and death of intestinal tissue. - Angina intestinalissee angina abdominalis
- Angina pectorisalso known as stenocardia
Name for the typical symptoms of acutely inadequate perfusion of the coronary arteries (coronary insufficiency), with sudden pain in the chest (mostly behind the breastbone), which may last for seconds or minutes. The pain radiates into the left (more rarely right) shoulder-arm-hand region , into the neck-lower jaw region or into the back. There is often a feeling of narrowness in a belt-shaped area round the chest and loss of breath, which can extend to fear of death. An attack may be triggered by physical exertion, excitement, cold or perhaps a heavy meal.
Causes
Imbalance between availability and requirement for oxygen in patients with coronary heart disease, spasm of the coronary vessels (Prinzmetal angina) or, more rarely, disturbances in the normal conditions for blood flow (high or low blood pressure, cardiac arrythmia).
Classification
1. Stable angina pectoris with pain only during exercise and of which the severity remains constant over months; 2. Unstable angina pectoris with newly occurring pain which changes or increases and which develops on mild physical exertion or even at rest; potential precursor of a myocardial infarction; 3. Prinzmetal angina. This form of angina pectoris is not the expression of the beginning of coronary disease, but usually the sign of critical constriction of the coronary vessels which is already present (more than 70 % reduction in cross-section).
Therapy
Nitroglycerin (frequently causes prompt improvement, see organic nitrates),
beta-receptor blockers, calcium antagonists, operation: see coronary heart disease
- angiogenesisthe development of new blood vessels
- AngiographyX-Ray imaging of the blood vessels after injection of an X-ray contrast medium by direct or (more often) indirect punctation of a vessel (cf. X-rays).
Contraindications
Angiography may not be performed if the patient is allergic to contrast medium or suffers from renal failure or some forms of heart failure.
Complications
Anaphylactic shock (as a result of allergy), bleeding, injury to the blood vessel wall, thromboembolismsm. - Angiotensin II blockeralso known as angiotensin II receptor antagonists
Name for antagonists of the hormone angiotensin II, which lower blood pressure. Cf. antihypertensive drugs, ACE inhibitors
- Anion exchangerssee lipid sinkers
- AntibioticsDrugs which are used for the treatment of bacterial infections. Antibiotics were originally metabolic products from moulds, bacteria and other micro- and macroorganisms (plants). Today they are also produced artificially. The prototype is penicillin G which was used under the name "antibiotic" by A. Fleming in 1928 for the first time and which comes from the penicillium mould, Penicillium notatum.
Mechanism of action
Various, e.g. by inhibiting the synthesis of the bacterial cell wall or of bacterial proteins. Antibiotics have (relatively) specific areas of action. A distinction is made between antibiotics which kill bacteria (bactericidal) or which inhibit their growth (bacteriostatic). The effective use of bacteriostatic drugs requires intact immune defence. The activity of the antibiotics is impaired if the microorganisms to be treated are resistant to the antibiotic. The combination of different antibiotics can give good efficacy even with only moderately sensitive bacteria. - AntibodiesA group of glycoproteins (immunoglobulins) which are formed by lymphocytes and plasma cells in the immune system after contact with antigens from white blood cells of the immune system (so-called B-lymphocytes) and plasma cells and which react exclusively with the corresponding antigen (antigen-antibody reaction). Antibodies may bind to both foreign antigens, such as microorganisms which cause disease, and to native antigens, such as tumour cells.
- Antibodies, Monoclonalalso MCAb
Identical antibodies formed from a group of genetically identical plasma cells (so-called plasma cell clone). These are either formed reactively during an immune response or as a result of malignant degeneration of the plasma cell. Monoclonal antibodies can also be produced in large quantities under laboratory conditions.
Antibodies can be examined diagnostically in blood, if it is suspected that there is a tumour which is producing these antibodies. Artificially produced monoclonal antibodies are used in various laboratory tests to detect specific proteins.
Radioactively labelled artificial monoclonal antibodies can be used to localise tumour tissue in living patients. Artificially produced monoclonal antibodies are being used experimentally in the treatment of various sorts of cancer (e.g. colorectal carcinoma,breast cancer, malignant melanoma). The idea is that they bind to specific components of the cancer cells and destroy them as a result. They can also be used to inhibit the immune system. - Antidiabetic drugsDrugs which reduce blood sugar and which are used in the treatment of type 2 diabetes and type 1 diabetes. 1. Insulin; 2. oral antidiabetic drugs: sulphonylureas, alpha-glucosidase inhibitors, biguanides, thiazolidindiones, glinides
- antidiuretic hormone (ADH)a hormone released by the pituitary gland that increases water reabsorption
- AntigenAn antigen is a substance which is recognised as foreign by an organism and which evokes a specific immune response, with the formation of antibodies, where the word "specific" means that the response is only against this antigen. Bacteria, viruses, other microorganisms and foreign proteins can all act as antigens. Cf. Influenza virus.
- Antigenic DriftGradual changes over the years in an antigen, which are mostly only slight. As a result of this, antibodies which are formed in the human body during immunisation against the original antigen can lose their protective activity. For example, new variants of the subtype of the influenza virus arises by changes (mutations) in the genes which bear the information for the virus antigens haemagglutinin and neuraminidases. Cf. antigenic shift
- Antigenic ShiftA sudden and usually considerable change in the properties of an antigen of a microorganism (particularly a virus), as a result of which new subtypes may arise. For example, an antigenic shift is caused in the influenza virus (type A) by exchange of genetic material between two subtypes. This usually leads to a new pandemic, as the antibodies which are present in man are no longer active against the new subtype of the influenza virus. Cf. antigenic drift.
- Antihypertensive drugsalso known as antihypertensives
Drugs used to reduce abnormally increased blood pressure (see hypertension). They include diuretic drugs, which mostly increase the renal excretion of water and dissolved sodium chloride, sympatholytic drugs, including alpha-receptor blockers and beta-receptor blockers, which inhibit the activity of the sympathetic nervous system, ACE inhibitors, angiotensin II blockers, which counteract the ability of angiotensin II to constrict blood vessels, calcium antagonists and other drugs which widen blood vessels. - Antilipidaemic drugssee lipid sinkers
- AntiserumDesignation for a blood serum which contains antibodies to one or more defined antigens. Antisera are isolated from animals or people who have either been specially immunised for this purpose or who have suffered from a certain disease and who have therefore produced these antibodies. Because of the many ways in which the reactions of immune defence may occur, the antiserum contains different antibodies to the antigen. Antisera are used, for example, for the identification of pathogens. Cf. Serogroup, Serotype.
- aplastic anemiaanemia that is characterised by defective function of the blood-forming organs (i.e. bone marrow) and is caused by toxic agents (e.g. chemicals or X-rays) or is idiopathic in origin
- Apoplexysee stroke
- apoptosisprogrammed cell death, a normal process whereby the body disposes of unneeded or damaged cells
- apoptoticpertaining to apoptosis or programmed cell death, a natural process in which the body eliminates unneeded or damaged cells
- AppetiteDesire to eat certain foods, which is evoked in phylogenetically old parts of the brain (hypothalamus) and which is influenced by both external factors, such as smell, taste and appearance) and internal factors, such as gastric filling, blood sugar concentration and individual state. Appetite is based on knowledge and experience of the corresponding meals and is a psychological urge which should not be equated with hunger.
- Appetite suppressantsIndirectly acting sympathomimetic drugs and similar substances, which are presumed to inhibit the centres in the brain which control appetite.
Use
In cases of pathological overweight, generally short term (3-4 weeks) for the introduction or support of a program to reduce body weight, with the aim of long term alteration in nutritional and behavioural habits.
Drug side-effects
Dry mouth, sweating, headache, insomnia. Depending on the dose, there may be a euphoric effect, which can lead to dependence and an increase in blood pressure. - ArteriesBlood vessels which lead blood away from the heart. In the systemic circulation, arteries contain oxygen-rich blood. In the pulmonary circulation they contain oxygen-poor blood. Cf. circulation of the blood, arteries.
- ArteriolosclerosisThe changes in the finest arteries (arterioles) which correspond to arteriosclerosis.
Occurrence
In the genuine arteriolosclerotic shrunken kidney and in the finest arteries in the brain, the pancreas, the spleen, the retina of the eye and peripheral arteries.
- Arteriosclerosisalso known as atherosclerosis or (colloquially) as hardening of the arteries
Most important and most frequent pathological change in the arteries, with hardening, thickening, loss of elasticity and reduction in free cross-section.
Causes
Partly as a result of animal experiments, of clinical studies and of observations of the general population, numerous toxins and diseases have been seen as responsible for the triggering or development of arteriosclerosis. These include high blood pressure (hypertension), high blood fat (particularly hypercholesterolaemia), diabetes mellitus (type 2 diabetes, type 1 diabetes), nicotine, antigen-antibody complexes, inflammation, low tissue levels of oxygen, psychological stress, age and family background.
Origin of the Disease (Theories)
1. Changes in the contents of the vessel, such as pressure, turbulence, increases in blood fat, etc., cause injuries to the inner layer of the vessel, which then lead to increased influx of material and to metabolic and cellular reactions in the vessel wall. The results include deposition of fluid in the innermost layer of the vessel, increased formation of certain polysaccharides, precipitation of fat-protein complexes, proliferation of connective tissue and muscle cells, with increased fibre formation, possibly hyalinosis (deposition of substances in connective tissue), increased fat deposition, often tissue death, tearing open of sections of the internal tissue wall and calcification. 2. Primary changes in the innermost layer of the blood vessel (intima) or cell layer of the blood vessels (epithelium), with deposition of blood platelets and fibrin, cause proliferation of connective tissue. The consequences include stationary blood clots (thrombi), fat deposits in the vessel wall and others. 3. Arteriosclerosis is seen as the result of an original abnormal predisposition of the blood vessel wall, which is intensified by high blood pressure or high levels of blood fat. The muscle and connective tissue cells in the innermost layer of the blood vessel wall proliferate for unknown reasons, with increased formation of connective tissue fibres and ground substance and of fats. 4. Recent studies suggest that the interaction between blood platelets and the vessel wall plays a decisive role in the development of arteriosclerosis.
Prevention
Or regression of early stage arteriosclerosis, by removal or by reducing the levels of toxins to the vessel wall, such as nicotine.
- arteriovenous fistulaa channel or passage that has been surgically created between an artery and a vein
- arteriovenous grafta passage between an artery and a vein created using a synthetic tube
- arthralgiajoint pain
- Arthrosisalso known as Arthrosis deformans
Degenerative disease of the joints, which is predominantly the result of an imbalance between the wear and tear and the composition or capacity of the individual joint sections or tissues.
Symptoms
At first there is a feeling of tension or stiffness in the affected joints, then pain at the start of a movement, pain during stress and finally permanent pain. There may be joint noises during movement, joint instability and muscular dystrophy.
Diagnosis
x-ray examination.
Therapy
Stressful factors such as wetness, cold and overweight should be avoided. Exercise and physiotherapy, massage and perhaps treatment with warmth, alleviate the disease and can prevent its progression. There are also drugs to reduce pain and so-called cartilage regeneration preparations. Orthopaedic assistance, such as a walking stick or raised shoes, alleviate the symptoms. There are also operative methods available, extending to total replacement of the joint. - Ascitessee Ascites.
- AscitesAlso hydroperitoneum or abdominal dropsy.
Accumulation of water in the free abdominal cavity. A distinction is made between inflammatory forms, such as peritonitis, from non-inflammatory forms, for example, during high blood pressure in the hepatic circulation or in liver cirrhosis. There are also cases in which the liquid is contaminated with blood or lymph.
Diagnosis: The disease is diagnosed by measuring the increase in the circumference of the abdomen. Diagnosis on the basis of an ultrasound investigation is also possible. The ascites fluid can also be removed with a syringe to assist the diagnosis (punctation).
Therapy: In cases of liver cirrhosis, only low levels of salt and fluid should be taken. Drug treatment with diuretics can be helpful, as can removal of the ascites fluid by punctation. If none of these measures is helpful, there is the possibility of draining the fluid into the blood with a direct connection between the abdominal cavity and the vascular system (shunt). - Ascorbic Acidsee Vitamin C
- asparaginean amino acid (C4H8N2O3) that is synthesised in the body from aspartate, which is also an amino acid ; asparagine is important in the biosynthesis of glycoproteins
- AssayAn assay is a procedure where a property or concentration of a substance in a sample is measured.
- asterixisan abnormal tremor consisting of involuntary jerking movements, especially of the hands, frequently occurring with impending hepatic coma and other forms of metabolic brain disorders
- asthenialack or loss of strength
- Atherosclerosissee arteriosclerosis
- atrial natriuretic peptidea hormone produced by heart cells that causes increased sodium excretion
- Autoimmune DiseaseAlso Autoaggressive Disease.
Disease which is triggered by a reaction to the endogenous substances in the body. Diseases of this sort occur particularly frequently in some families. There are autoimmune diseases which react against a specific organ, such as chronic gastritis or diabetes. Other autoimmune diseases do not involve a reaction against a specific organ, for example, rheumatic diseases. The transition between these two forms is not sharp, as can, for example, be seen in chronic aggressive hepatitis (see Chronic Hepatitis).
Therapy: Replacement (e.g. injection of insulin) or transplantation (e.g. of a kidney) are often helpful in organ-specific diseases. Otherwise, the symptoms are treated and drugs may be prescribed which suppress the immune system. - autoimmune hemolytic anemiaa form of anemia caused by antibodies that react with red blood cells, leading to their destruction
- Autoimmune Hepatitissee chronic hepatitis.
- AutointoxicationSelf-poisoning with metabolic products from your own body, e.g. during severe liver or kidney failure or diabetic coma.
- autosomal dominantrefers to a genetic trait or mutation that occurs on one of the non-sex chromosomes (autosomes) and that is always expressed, even if only one copy is present; i.e. dominant inheritance occurs when an abnormal gene from one parent is capable of causing disease even though the matching gene from the other parent is normal
- autosomal recessiverefers to a genetic trait or mutation that occurs on one of the non-sex chromosomes (autosomes) and that is only expressed when two copies are present, i.e. recessive inheritance occurs when both genes of a pair must be abnormal to produce disease
- azotemiahigh concentration of nitrogenous waste products in the blood
Glossary entries: Roche and Walter de Gruyter, Berlin