Glossary
Use the letters below to browse the glossary:
Ablation
The removal of tissue, a part of the body, or an abnormal growth, usually by cutting at operation but can be by radiation during radiotherapy.
Absolute Neutrophil Count
(ANC)
A determination of the proportions of the different kinds of white cells (leucocytes) present in a sample of blood. Usually 100 white cells are counted and classified under the microscope or by electronic apparatus, so that the results can readily be expressed as percentages of the total number of leucocytes and the absolute numbers per litre of blood. The information often aids diagnosis of a specific disease.
Acquired ImmunoDeficiency Syndrome
(AIDS)
A disease characterised by loss of the cell mediated immune response due to decreased numbers of certain T-lymphocytes.
Actinomycin D
(ACT-D)
Actinomycin D: Dactinomycin, Cosmogen Lyovac
Action on Smoking and Health (UK)
(ASH)
www
A public health charity working to achieve a sharp reduction and eventual elimination of health problems caused by tobacco.
Acute
Describing a disease of rapid onset, severe symptoms of brief duration.
Acute Lymphoblastic Leukaemia
(ALL)
Leukaemias are classified into acute or chronic varieties depending on the rate of progression of the disease. They are also classified according to the type of white blood cell that is proliferating abnormally; for example acute lymphoblastic leukaemia.
Acute Myeloid (Myeloblastic) Leukaemia
(AML)
A variety of leukaemia in which the type of blood cell that proliferates abnormally originates in the blood-forming (myeloid) tissue of the bone marrow. Myeloid leukaemias may be acute or chronic and may involve any one of the cells produced by the marrow. Blood cells in patients with chronic myeloid leukaemia contain a reciprocal translocation between chromosomes 9 and 22, which leads to a foreshortened long arm of chromosome number 22 (this abnormal chromosome is called the Philadelphia chromosome). Molecular characterization of the translocation has led to the development of a specific drug to block the effects of this abnormality
Adjuvant
(Adj)
Any substance used in conjunction with another to enhance its activity. For example a regimen of cytotxic drugs.
Adjuvant therapy
(Adj.)
Treatment given to patients, usually after surgical removal of their primary tumour when there is known to be a high risk of future tumour recurrence. Adjuvant therapy is aimed at destroying these microscopic tumour cells either locally or systemically.
Administration of Radioactive Substances Advisory Committee
(ARSAC)
Committee which issues ARSAC certificates. Legislation stipulates that any doctor or dentist who wishes to administer radioactive medicinal products to a patient should hold a certificate issued by DoH to say that he is both qualified and has the facilities to do so. ARSAC certificates are therefore required for certain clinical trials before they can be opened.
AdrenoCorticoTropic Hormone
(ACTH)
A hormone, synthesized and stored in the anterior pituitary gland, large amounts of which are released in response to any form of stress.
Adriamycin
(A)
Adriamycin hydrochloride: Doxorubicin, 14-hydroxydaunorubicin, 3-hydroxyacetyldaunorubicin, doxorubicin rapid dissolution
Adriamycin
(Adria)
Adriamycin hydrochloride: Doxorubicin, 14-hydroxydaunorubicin, 3-hydroxyacetyldaunorubicin, doxorubicin rapid dissolution
Adriamycin + Bleomycin + Vincristine + Dacarbazine
(ABVD)
Adriamycin hydrochloride: Doxorubicin, 14-hydroxydaunorubicin, 3-hydroxyacetyldaunorubicin, doxorubicin rapid dissolution
Bleomycin: Bleomycin sulphate
Vincristine: Vincristine sulphate, Oncovin
Dacarbazine: Dacarbazine citrate, DTIC, 5-(3,3-dimethyl-1-trazeno)imidazole-4-carboxamide
Bleomycin: Bleomycin sulphate
Vincristine: Vincristine sulphate, Oncovin
Dacarbazine: Dacarbazine citrate, DTIC, 5-(3,3-dimethyl-1-trazeno)imidazole-4-carboxamide
Adriamycin + Cisplatin
(AP)
Adriamycin hydrochloride: Doxorubicin, 14-hydroxydaunorubicin, 3-hydroxyacetyldaunorubicin, doxorubicin rapid dissolution
Cisplatin: CDDP, Cis DDP, Cis diamminedichloro-platinum, Cisplatinum
Cisplatin: CDDP, Cis DDP, Cis diamminedichloro-platinum, Cisplatinum
Adriamycin + Ifosfamide
(Ai)
Adriamycin hydrochloride: Doxorubicin, 14-hydroxydaunorubicin, 3-hydroxyacetyldaunorubicin, doxorubicin rapid dissolution
Ifosfamide: Mitoxana
Ifosfamide: Mitoxana
Adverse Drug Reaction
(ADR)
A reaction to a medicine given to a patient. The reaction can range from slight to life-threatening.
Adverse Event
(AE)
Any untoward medical occurrence in a patient or clinical trial subject administered a medicinal product. This event does not necessarily need to appear to have been caused by the treatment, but the relationship between the event and the medicine cannot be ruled out.
African Burkitt's Lymphoma
A typle of B-cell lymphoma. Also see 'Burkitt's Lymphoma'.
Age Standardisation Rate
(ASR)
The ASR for an area is the number of events, usually expressed per 100,000, that would occur in that area if it had the same age structure as the standard population and the local age-specific rates of the area applied. Normally refers to mortality as the event.
Akinesia
A loss of normal muscular tonicity or responsiveness.
Akinetic mutinism
A state of complete physical unresponsiveness although the patient's eyes remain open and appear to follow movements. It is a consequence of damage to the base of the brain and can follow surgery.
ALanine AminoTransferase
(ALT)
An enzyme involved in the transamination of amino acids. Measurement of ALT in the serum is of use in the diagnosis and study of acute liver disease. It was formerly called serum glutamic pyruvic transaminase (SGPT).
Allele
One of two or more alternative forms of a gene, only one of which can be present in a chromosome. Two alleles of a particular gene occupy the same relative positions on a pair of homologous chromosomes. If the two alleles are the same, the individual is homozygous for the gene; if they are different he is heterozygous.
Allergy
A disorder in which the body becomes hypersensitive to particular antigens (called allergens), which provoke characteristic symptoms whenever they are subsequently inhaled, ingested, injected, or otherwise contacted. Normally antibodies in the bloodstream and tissues react with and destroy specific antigens without further trouble. In an allergic person, however, the allergens provoke the release of a class of antibodies (IgE) that become bound to mast cells in the body's tissues. The subsequent reaction of allergen with tissue-bound antibody also leads, as a side-effect, to cell damage, release of histamine and serotonin, inflammation, and all the symptoms of the particular allergy. Different allergies afflict different tissues and may have either local or general effects, varying from asthma and hay fever to severe dermatitis or gastroenteritis or extremely serious shock (see anaphylaxis).
ALLOgraft
(ALLO)
A living tissue or organ graft between two members of the same species (i.e. a donor and recipient). For example, a bone marrow transplant from one person to another. Such grafts will not survive unless the recipient is treated to suppress his body's immune response to the foreign tissue.
Alopecia
Absence of hair from areas where it normally grows on the body.
Alpha Feto Protein
(AFP (aFP))
A protein that is formed in the liver and yolk sac of the fetus and is present in the amniotic fluid and secondarily in maternal blood. The level of AFP can be detected by a maternal blood test performed between the 16th and 18th weeks of pregnancy to aid prenatal diagnosis of certain foetal conditions. Levels are elevated in open neural tube defects (e.g. spina bifida), twins and triplets, open abdominal wall defects (e.g. gastroschisis), and foetal death. Levels of AFP are decreased in Down's syndrome. When levels are unexpectedly high or low, further investigations (e.g. ultrasound) are indicated. AFP is also produced by certain tumours and is therefore referred to as a tumour marker.
Alternative Hypothesis
(H1)
A statement hypothesising that there is a difference, on average, in the question of interest between the groups being compared.
Amenorrhoea
The absence or stopping of the menstrual periods. Menstrual periods can stop after establishment for a variety of reasons including disorders of the hypothalamus, ovaries and chemotherapy.
American Society of Clinical Oncology
(ASCO)
Association of American Oncology professionals involved with the multidisciplinary care of patient's with cancer.
American Society of Hematology
(ASH)
The American Society of Hematology is concerned with the causes and treatment of blood disorders.
Amino Acids
The building blocks of proteins. They are so named because all have a basic amino group (-NH2) and an acidic carboxyl group (-COOH). Peptides, polypeptides, and proteins are formed from strings of amino acids joined together by the formation of peptide bonds. All proteins are formed from combinations of only 20 different amino acids, whether the proteins derive from bacteria or from man.
Amsacrine
(Amsacrine)
Amsacrine: M-AMSA, AMSA, Amsidine, Acridinyl anisidide
Amsacrine
(M-AMSA)
Amsacrine: M-AMSA, AMSA, Amsidine, Acridinyl anisidide
Anaemia
(A)
A reduction in the quantity of the oxygen-carrying pigment haemoglobin in the blood. There are a variety of causes of anaemia from acute haemorrhage (e.g. accident or surgical operation), lack of iron, and leukaemia when red cell production in the bone marrow is suppressed. Anaemia can also be caused by toxic chemicals (e.g. cytotoxic drugs).
Anaesthetic
(A)
An agent that reduces or abolishes sensation, affecting either the whole body (general anaesthetic) or a particular area or region of the body (local anaesthetic). General anaesthetics, used for surgical procedures, depress activity of the central nervous system and produce a loss of consciousness. Anaesthesia is induced by short-acting barbiturates (such as Thiopental) and maintained by inhalation anaesthetics (such as Halothane). Local anaesthetics inhibit conduction of impulses in sensory nerves in the region where they are injected or applied; they include Tetracaine, Bupivacaine, and Lidocaine.
Analgesic
A drug that relieves pain.
Analysis of Covariance
(ANCOVA)
A statistical method to compare the mean question of interest between several groups, taking account of factors such as age, sex etc.
Analysis of Variance
(ANOVA)
A statistical method to compare the mean question of interest between several groups.
Anaphylactic shock
An acute extreme and generalised reaction in which widespread antihistamine release causes swelling (oedema), constriction of the bronchioles, heart failure, circulatory collapse and can result in death due to the sudden overwhelming effect on the body.
Anaphylaxis
An abnormal reaction to a particular antigen in which histamine is released from tissues and causes either local or widespread symptoms. An allergic reaction is an example of localized anaphylaxis.
Anaplasia
A loss of normal cell characteristics or differentiation, which may be to such a degree that it is impossible to define the origin of the cells. Typical of malignant tumours.
Angiography
X-ray examination of blood vessels. A dye that is opaque to x-rays is injected into the artery and a rapid series of X-rays are taken.
Aniridia
Congenital absence of the iris of the eye.
Anomaly
Any deviation from the normal, especially a congenital or developmental defect.
Anorexia
Loss of appetite.
Anosmia
A loss of the sense of smell. May be caused by a frontal brain tumour.
Anterior
(Ant.)
Describing or relating to the front (ventral) portion of the body, limbs or any part of any organ.
Anthony Nolan Registry
Part of the Anthony Nolan Trust this organisation provides a bone marrow register as well as undertaking research into improving the safety and effectiveness of bone marrow transplants.
Antibiotic(s)
(ANT(S))
A substance, produced by or derived from a micro-organism that destroys or inhibits the growth of other micro-organisms. Antibiotics are used to treat infections caused by organisms that are sensitive to them. They may alter the normal microbial content of the body (e.g. in the intestine, bladder or lungs) by destroying one or more groups of harmless organisms. Some antibiotics may cause allergic reactions.
Antibody
A special kind of blood protein that is synthesized in the lymphoid tissue in response to the presence of a particular antigen and circulates in the plasma to attack the antigen and render it harmless. This attack is the basis of both immunity and allergy. Antibody formation is also responsible for tissue or organ rejection following transplant.
Antiemetic
A drug that prevents nausea or vomiting.
Antifungal
A drug that kills or inactivates fungi and is used to treat fungal (including yeast) infections. Antifungal drugs include Amphotericin, Itraconazole and Nystatin.
Antigen
Any substance that the body regards as foreign or potentially dangerous and against which it produces an antibody. Antigens are usually proteins.
Antimetabolite
A drug that interferes with the normal metabolic processes within cells by combining with the enzymes responsible for them. For example Fluorouracil, Methotrexate and Mercaptopurine prevent cell growth by interfering with enzyme reactions essential for nucleic acid synthesis. Their side effects involve blood cell disorders and digestive disturbances.
Antimitotic
A drug that inhibits cell division (mitosis) and growth. For example Procarbazine.
Antipyretic
A drug that reduces fever (pyrexia) by lowering the body temperature. For example Paracetamol.
Antiseptic
A chemical that destroys or inhibits the growth of disease causing bacteria and other micro-organisms and is sufficiently non-toxic to be applied to the skin or to mucous membranes to cleanse wounds and prevent infections.
Anuria
The failure of the kidneys to produce urine and is associated with increasing uraemia.
Aperient
A mild laxative.
Apex
The tip or summit of an organ (e.g. describing the heart or lung).
Aphasia
(Dysphasia) A disorder of language affecting the generation of speech and its understanding. It can be caused by a tumour in the left half of the brain (the dominant hemisphere) in a right handed person. It is commonly accompanied by difficulties in reading and writing.
Aplasia
Total or partial failure of development of an organ or tissue or cell.
Aplastic Anaemia
(AA)
Aplastic anaemia is characterized by a failure of blood cell production resulting in pancytopenia and reduced bone marrow cellularity.
Apraxia
(Dyspraxia) An inability to make skilled movements with accuracy. This is a disorder of the cerebral cortex resulting in the patient's inability to organize the movements rather than clumsiness due to weakness. Indicates there may be a tumour in the parietal or frontal lobes of the brain.
Arachnoid mater
The middle of the three membranes covering the brain and spinal cord.
Arachnoid villi
Thin walled projections outwards of the arachnoid membrane into the blood filled sinuses of the dura. Acts as a one way valve for CSF from the arachnoid space to the bloodstream.
Area Under the Curve
(AUC)
Used to summarise the information from a series of measurements on one subject. Consecutive data points are joined together by a straight line and the AUC calculated normally using the trapezoidal rule.
Area Under the Curve
(AUC)
Used to summarise the information from a series of measurements on one subject. Consecutive data points are joined together by a straight line and the AUC calculated normally using the trapezoidal rule.
Ascites
The accumulation of fluid in the peritoneal cavity causing abdominal swelling.
Asparaginase
(Asp)
Asparaginase: L-Asparaginase, Crisantapase, Erwinase, e coli Asparaginase
ASpartate AminoTransferase
(AST)
An enzyme involved in the transamination of amino acids. Measurement of AST in the serum may be used in the diagnosis of acute myocardial infarction and acute liver disease. It was formerly called serum glutamic oxaloacetic transaminase (SGOT).
Aspergillosis
A disease in which the fungus Aspergillus fumigatus grows freely in pre-existing lesions in the lungs and bronchioles. The fungus can attack the mucous membranes, lungs, liver and kidneys.
Aspergillus
(Asp)
A genus of fungi, including many common moulds, which cause infections of the respiratory system.
Aspiration
(A /Asp)
The withdrawal of fluid from the body by means of suction through an instrument such as a hollow needle. This technique is used for removing fluid from a cyst or tumour cavity and is a method of obtaining a bone marrow sample.
Association for Clinical Data Management
(ACDM)
Professional association for the data management professional.
Astrocyte
A type of cell with numerous sheet-like processes extending from its cell body, found throughout the CNS. It is one type of cell which make up the glia. Astrocytes provide the nutrients for neurones and take part in information storage processes.
Astrocytoma
A brain tumour derived from non-nervous cells (glia), which, unlike the neurones, retain the ability to reproduce themselves by mitosis. All grades of malignancy occur from slow-growing tumours whose histological structure resembles normal glial cells, to rapidly growing highly invasive tumours whose cell structure is poorly differentiated.
Ataxia
The shaky movements and unsteady gait that result from the brain's failure to regulate the body's posture and the strength and direction of limb movements. The patient presents with inco-ordination.
Atelectasis
The failure of part of the lung to expand.
Ateriovenous malformation
A knot of distended bloodvessels overlying and compressing the surface of the brain. It commonly causes epilepsy. If one of the bloodvesssels bursts this causes a subarachnoid haemorrhage.
Atrophy
The wasting away of a normally developed organ or tissue due to degeneration of cells. Reported effect of chemotherapy upon tumour cells.
Audiology
Study of hearing.
Audiometry
(AUDIO)
Measurement of hearing at different sound frequencies; therefore helping in the diagnosis of hearing loss.
Audit
(AUDIT)
A systematic and independent examination of trial related activities and documents to determine whether the evaluated trial related activities were conducted, the data recorded, analysed and accurately reported according to the protocol and GCP.
AUTOgraft
(AUTO)
Tissue taken from one part of the body and transferred to another part of the same individual. In the example of bone marrow, it is harvested and stored for later use.
Autonomic Nervous System
(ANS)
The part of the nervous system responsible for the control of bodily functions that are not consciously directed (e.g. heart beat, bladder control, intestinal movements, sweating, salivation). The ANS is subdivided into the sympathetic and parasympathetic systems.
Autonomic neuropathy
Weakness causing dysfunction of the ANS. For example paralytic ileus (stasis of the ileum), urinary retention (bladder dysfunction)
Azoospermia
The absence of sperm.