Absolute Poverty: a situation where the per capita income is equivalent to less than one international dollar per day.
Absorbed Dose: the energy imparted to matter by ionizing radiation per unit mass of irradiated material. The unit is gray (Gy), defined to be an energy absorption of 1 joule / kg. The old unit was the rad, which was defined as an energy absorption of 100 ergs / g.
Absorbent Products: pads and garments, either disposable, worn to contain urinary incontinence or uncontrolled urine leakage. Absorbent products include shields, guards, undergarment pads, combination pad-pant systems, diaper like garments, and bed pads.
Acceptability: degree to which a service meets the cultural needs and standards of a community. This in turn will affect utilization of that service.
Access to Social Support Networks: one of the aspects of the responsiveness of health systems whereby health care activities are integrated into community interaction in order to ensure patient welfare.
Accessible Antigen: antigens of self that are in contact with antibody-forming and to a host that is normally tolerant.
Accessibility of Health Care: a measure of the proportion of a population that reaches appropriate health services.
Accessory Cell: cell required for, but actually mediating, a specific immune response. Often used to describe antigen-presenting cells.
Accountability: the obligation to disclose periodically, in adequate detail and consistent form, to all directly and indirectly responsible or properly interested parties, the purposes, principles, procedures, relationships, results, incomes, and expenditures involved in any activity, enterprise, or assignment so that they can be evaluated by the interested parties.
Accreditation, also see Licensing: the process by which an authorized agency or organization evaluates and recognizes an institution or an individual according to a set of "standards" describing the structures and processes that contribute to desirable patient outcomes.
Acetylcholine: substance (neurotransmitter) that plays an important part in the transmission of nerve impulses in the parasympathetic nervous system. These transmitters control smooth muscles, including those of the bladder and urethra, and stimulate the bladder to contract.
Acidemia: increased concentration of hydrogen ions in the blood.
Acidemia-Pathologic: a pH level associated with adverse neurologic sequelae; the threshold for pathologic-acidemia varies among research protocols, but some investigators have suggested a pH of less than 7.
Acontractile Detrusor: detrusor muscle that cannot be demonstrated to contract during testing (urodynamic studies).
Acquired Genetic Mutation: see somatic cell genetic mutation.
Action: any measure taken with some intention.
Active Immunization: direct immunization of the intact individual or of immunocompetent cells derived from and returned to the individual.
Active Immunotherapy: may be divided into two groups: specific immunogens and non-specific adjuvants. Active specific immunotherapy is attempted by the immunization of a tumor-bearing patient with autochthonous altered (radiation, chemical) tumor cells. Non-specific immunotherapy attempts to augment antitumor immunologic activity with non-specific stimulants such as BCG or C. Parvum.
Activities of Daily Living: activities necessary to meet essential human needs, such as bathing, grooming, toileting, and social interactions.
Actuarial (Life Table) Survival: this technique uses grouped information to estimate the survival curve. The data are grouped into fixed time periods (e.g., months, years) that include the maximum follow-up. The survival curve is estimated as a continuous curve and gives an estimate of the proportions of a group of patients who will be alive at different times after the initial observation. The group includes patients with incomplete follow-up.
Acute Care (Short-Stay): hospitals with an average length of stay of 30 days or less.
Acute Incontinence: incontinence that comes on suddenly, usually caused by a new illness or condition, and is often easily reversed with appropriate treatment of the condition that caused it.
Adaptation: a process whereby protection accorded a foreign graft from the immune reaction of the recipient renders it less vulnerable to immunologic attack by the host.
Additive Genetic Effects: when the combined effects of alleles at different loci are equal to the sum of their individual effects. See also -- anticipation, complex trait.
Adenine (A): a nitrogenous base, one member of the base pair AT (adenine-thymine). See also -- base pair, nucleotide.
Adequacy: application of measures, technologies, and resources which are qualitatively and quantitatively sufficient for achieving the desired goal.
Adjusted Relative Risk: the ratio of risk of disease or death among the exposed to that of the risk among the unexposed adjusted for a specific covariate (eg, maternal age, weeks of gestation, size of gestational age).
Adjuvant: a substance that when mixed with an antigen enhances its antigenicity.
Adnexae: ovaries, fallopian tubes and supporting structures.
Adoptive Immunization: the transfer of immunity from one individual to another by means of specifically immune lymphoid cells or materials derived from such cells that are capable of transferring specific immunologic information to the recipient's lymphocytes.
Adverse Selection: a situation where individuals are able to purchase insurance at rates which are below actuarially fair rates, because information known to them is not available to insurers (asymmetric information).
Affected Relative Pair: individuals related by blood, each of whom is affected with the same trait. Examples are affected sibling, cousin, and avuncular pairs. See also -- avuncular relationship.
Affinity: a measure of the binding constant of a single antigen-combining site with a monovalent antigenic determinant.
Affordability: extent to which the intended clients of a service can pay for it.
AFP: see α-fetoprotein.
Age-Rating: technique for adjusting insurance premiums according to the age of the insured.
Age Specific Rates: these are calculated by dividing the number of cases of deaths or other health variable occurring in each specified age group by the corresponding population or survey sample in the same age group. Sometimes, this is expressed as a rate per 100,000 population; other times as a percent of sampled population. This rate may be calculated for a particular age and sex grouping to show how a risk factor, occurrence of death or incidence of a disease changes with age and sex.
Age Standardization: rates are adjusted for age to facilitate comparisons between populations which have different age structures. (There are two different methods commonly used to adjust for age, direct or indirect. We use direct standardization in which age-specific rates are multiplied againsta constant population, the WHO standard population EIP 1999).
Agency Principle: the process of having one party (the agent) make decisions on behalf of another (the principal).
Agglutinin: any antibody that produces aggregation or agglutination of a particular or insoluble antigen.
Aggregation Technique: a technique used in model organism studies in which embryos at the 8-cell stage of development are pushed together to yield a single embryo (used as an alternative to microinjection). See also -- model organisms.
AIDS: acquired immune deficiency syndrome.
AIDS Incidence: the number of new cases registered from Acquired Immunodeficiency Syndrome (AIDS) for a given sex, in a specific year, expressed per 1,000,000 population, for a given country, territory, or geographic area.
Algorithm: a sequence of logical steps that should be taken when dealing with a given task.
Allele: one of two or more alternate forms of a gene. Alternative form of a genetic locus; a single allele for each locus is inherited from each parent (e.g., at a locus for eye color the allele might result in blue or brown eyes). See also -- locus, gene expression.
Allele Specific Oligonucleotides: synthetic oligonucleotide designed to hybridize to a specific sequence, and under the right conditions, to fail to hybridize to a related sequence. Allele specific oligonucleotides also are use as PCR primers in several methods similarly designed to distinguish between closely related alleles.
Allelic Exclusion: the ability of heterozygous lymphoid cell to produce only an allelic form of an antigen-specific receptor (immunoglobulin or T cell receptor) when they have the genetic endowment to produce both.
Allergen: a substance (antigen or hapten) that incites allergy.
Allergy: a state of specific increased reactivity to an antigen or hapten such as occurs in hay fever. The term is used to designate states of delayed sensitivity caused by contact allergens.
Alloantibody (Isoantibody): any antibody produced by one individual that reacts specifically with an antigen present in another individual of the same species. The isoantibody is commonly used in hematology; the alloantibody is used in tissue transplantation.
Allogeneic: variation in alleles among members of the same species. Referring to genetically dissimilar individuals of the same species.
Allogeneic Disease: any systemic illness resulting from a graft-vs-host response when the graft contains immunologically competent cells and the host is immunologically competent cells and the host is immunologically incompetent (e.g., runt disease).
Allograft (Homograft): a graft derived from an allogeneic donor.
Alloimmune: specifically immune to an allogeneic antigen.
Alpha Error: the error of rejecting a true null hypothesis, i.e. declaring that a difference exists when it does not. The rejection of the null hypothesis when it is, in fact, correct. Also called a Type I error.
Alternative Complement Pathway: the mechanism of complement activation that does not involve activation of the C1-C4-C2 pathway by antigen-antibody complexes and begins with the activation of C3.
Alternative Splicing: different ways of combining a gene's exons to make variants of the complete protein
Ambulatory Care: all types of health services provided to patients who are not confined to an institutional bed as inpatients during the time services are rendered.
Amino Acid: any of a class of 20 molecules that are combined to form proteins in living things. The sequence of amino acids in a protein and hence protein function are determined by the genetic code.
Amplification: an increase in the number of copies of a specific DNA fragment; can be in vivo or in vitro. See also -- cloning, polymerase chain reaction.
Anal Sphincters: two rings of muscles surrounding the rectum and anus, which help control passage of bowel movements.
Anamnestic Response (Recall Phenomenon, Memory Phenomenon): an accelerated response of antibody production to an antigen that occurs in an animal that has previously responded to the antigen.
Anaphylaxis, Acute: systemic shock (often fatal) that develops in a minutes after subsequent exposure to a specific foreign antigen to which the host has already reacted.
Anergy: absence of a hypersensitivity reaction that would be expected in other similarly sensitized individuals.
Aneuploidy: in this condition there is an extra or missing chromosome.
Animal Model: see -- model organisms.
Anonymous: presented without identity; anonymity is an ethical practice whereby research results cannot be linked to any particular individual.
Annotation: adding pertinent information such as gene coded for, amino acid sequence, or other commentary to the database entry of raw sequence of DNA bases. See also -- bioinformatics.
Annual Birth Average: total number of live births expected in a specific year, for a given country, territory, or geographic area. Technical Note: The annual births average corresponds to an estimated value, consistent with the corresponding United Nations fertility medium-variant quinquennial population projections.
Annual Death Average: total number of deaths expected in a specific year, for a given country, territory, or geographic area. Technical Note: The annual deaths average corresponds to an estimated value, consistent with the corresponding United Nations fertility medium-variant quinquennial population projections.
Annual GDP Growth Rate: the annual average rate of change of the gross domestic product (GDP) at market prices based on constant local currency, for a given national economy, during a specified period of time. It expresses the difference between GDP values from one period to the next as a proportion of the GDP from the earlier period, usually multiplied by 100. Technical Note: GDP average annual growth rates are those estimated by the World Bank from the corresponding data in the United Nations' Systems of National Accounts expressed in 1995 US dollars constant prices, using the least-squares method. The least-squares growth rate is estimated by fitting a linear regression trend line to the logarithmic annual values of the variable in the relevant period. The calculated growth rate is an average rate that is representative of the available observations over the entire period. It does not necessarily match the actual growth rate between any two periods.
Annual Growth Rate: indicator used in population studies to assess average change in the size of a population from one year to the next.
Annual National Health Expenditure as a Proportion of The Gross Domestic Product (GDP): estimates of public expenditure corresponds to expenditures of the institutions of General Government in the function of Health (Division 07) of the international classification of Government Expenditures by functions or purposes of the Systems of National Accounts of United Nations (SCN 1993); derived from the Government Financial Statistical Yearbook 2002 (GSF 2002) from the International Monetary Fund or country's health account studies. Estimates of private expenditure in health corresponds to the expenditures by the Household Sector in the function of Health or Health or Health Personal Care of the international classification of Individual Consumption by Purposes of the SCN 1993; derived from data from the Consumer Price Index, household surveys, and/or national studies on health accounts.
Annual Number of Registered Deaths Under-5 due to Diphtheria: the number of deaths in children under 5 years of age from diphtheria (ICD-9 code 032 ; ICD-10 code A36) as the underlying cause of death, as registered in their death certificates, for a given year, in a given country, territory, or geographic area.
Annual Number of Registered Deaths Under-5 due to Pertussis: the number of deaths in children under 5 years of age from whooping cough (ICD-9 code 033; ICD-10 code A37) as the underlying cause of death, as registered in their death certificates, for a given year, in a given country, territory, or geographic area.
Annual Number of Registered Deaths Under-5 due to Tetanus: the number of deaths in children under 5 years of age from tetanus (ICD-9 code 037; ICD-10 code A35) as the underlying cause of death, as registered in their death certificates, for a given year, in a given country, territory, or geographic area.
Annual Parasite Index: the number of confirmed new cases from malaria registered in a specific year, expressed per 1,000 individuals under surveillance, for a given country, territory, or geographic area. Annual parasite index (API) refers to high and moderate malaria transmission risk areas.
Annual Population Growth Rate: the annual average rate of change of population size, for a given country, territory, or geographic area, during a specified period. It expresses the ratio between the annual increase in the population size and the total population for that year, usually multiplied by 100. The annual increase in the population size is defined as a sum of differences: the difference between births less deaths and the difference between immigrants less emigrants, in a given country, territory or geographic area at a given year.
Annual Proportion of Registered Deaths Under 5 Years of Age due to Intestinal Infectious Diseases (ADD): proportion of deaths in children under 5 years of age for which the underlying cause of death was an intestinal infectious disease (ICD-9 codes 001-009; ICD-10 codes A00-A09) for a given year, in a given country, territory, or geographic area.
Annual Proportion of Registered Deaths Under 5 Years of Age due to Acute Respiratory Infections (ARI): proportion of deaths in children under 5 years of age for which the underlying cause of death was an acute respiratory infection (ICD-9 codes 460-466, 480-487; ICD-10 codes J00-J22) for a given year, in a given country, territory, or geographic area.
Antibiotics: substances that inhibit the growth of or kill microorganisms (bacteria and viruses); used to treat infections.
Antibody (Ab): a substance (usually a gamma globulin) that can be incited in an animal by an antigen or by a hapten combined in an animal by an antigen or by a hapten combined with a carrier and that reacts specifically with the antigen or hapten. Some antibodies can occur naturally without known antigen stimulation.
Antibody-dependent Cell-mediated Cytotoxicity: a phenomenon in which target cells, coated with antibody, are destroyed by specialized killer cells (NK cells and macrophages), which bear receptors for the Fc portion on the coating antibody.
Antibody Reaction Site (Antigen-binding Site, Antibody-combining Site): the inverted surface site on antibody that reacts with the antigen determinant site on the antigen.
Antibody Response: the production of antibody in response to stimulation by specific antigen.
Anticholinergic: drug that interferes with the effects of acetylcholine, thus impeding the action of the parasympathetic nervous system. An anticholinergic drug will facilitate storage of urine by increasing bladder capacity and decreasing bladder overactivity.
Anticipation: each generation of offspring has increased severity of a genetic disorder; e.g., a grandchild may have earlier onset and more severe symptoms than the parent, who had earlier onset than the grandparent. See also -- additive genetic effects, complex trait.
Antigen: a substance that can react specifically with antibodies and under certain conditions can incite an animal to form specific antibodies. Extrinsic: an antigen that is not a constituent or product of the cell. Intrinsic: an antigen that is a constituent or product of the cell.
Antigen Determinant: a small, three-dimensional everted surface configuration on the antigen molecule that specifically reacts with the antibody reaction site on the antibody molecule.
Antigen-presenting Cell: a specialized type of cell, bearing cell antigen-presenting cell surface class II major histocompatibility complex molecules, and involved in the processing and presentation of antigen to inducer or helper T cells.
Antigen Receptor: the specific antigen-binding receptor on T or B lymphocytes; these receptors are transcribed and translated from rearrangements of V genes.
Antigenic Modulation: loss of antigenicity or change in antigenic markers by which tumor cells may avoid immunologic identification or destruction.
Antigenic Paralysis: see immunologic tolerance.
Antioncogene: see tumor suppressor gene.
Antisense: nucleic acid that has a sequence exactly opposite to an mRNA molecule made by the body; binds to the mRNA molecule to prevent a protein from being made. See also -- transcription.
Anus: final two inches of the rectum, surrounded by the internal anal sphincter and the external sphincter.
Apoptosis: programmed cell death, the body's normal method of disposing of damaged, unwanted, or unneeded cells. A form of programmed cell death caused by activation of endogenous molecules leading to the fragmentation of DNA. See also -- cell.
Appraisal (Assessment): appraisal or assessment follows on from the scoping stage of a HIA, where the potential health impacts which have been identified are assessed and evaluated using the available evidence base.
Appropriate (ness): if an expected health benefit exceeds the expected negative consequences by a large enough margin to justify performing the procedure rather than other alternatives.
Arrayed Library: individual primary recombinant clones (hosted in phage, cosmid, YAC, or other vector) that are placed in two-dimensional arrays in microtiter dishes. Each primary clone can be identified by the identity of the plate and the clone location (row and column) on that plate. Arrayed libraries of clones can be used for many applications, including screening for a specific gene or genomic region of interest. See also -- library, genomic library, gene chip technology.
Arthus Reaction: an inflammatory reaction characterized by edema, hemorrhage, and necrosis that follows the administration of antigen to an animal that already possesses precipitating antibody to that antigen.
Artificial Urinary Sphincter: mechanical device surgically implanted into the patient that consists of a cuff placed around the bulbar urethra or bladder neck, a pressure-regulating balloon, and a pump. The device is used to control opening and closing of the urethra manually and is the most commonly used surgical procedure for the treatment of male urethral insufficiency.
Asphyxia: a clinical situation of damaging acidemia, hypoxia, and metabolic acidosis. This definition, although traditional, is not specific to cause. A more complete definition of birth asphyxia includes a requirement for a recognizable sentinel event capable of interrupting oxygen supply to the fetus or infant. This definition fails to include conditions that are not readily recognized clinically, such as occult abruption, but is probably correct in a majority of cases.
Assembly: putting sequenced fragments of DNA into their correct chromosomal positions.
Atonic Bladder: often caused by peripheral neuropathies, such as diabetes mellitus. The bladder is flaccid and overdistended with urine. Overflow incontinence may occur. Also referred to as a lower motor neuron bladder.
Atopy: a hereditary predisposition of various individuals to develop immediate-type hypersensitivity on contact with certain antigens.
Attributable Risk: the difference in actual incidence between exposed and unexposed groups, providing a realistic estimate of the change in incidence in a given population. A modest increase in relative risk will produce only a small number of cases when clinical events are rare, such as venous thromboembolism and arterial thrombosis in young women.
Audit Trail: documentation that allows reconstruction of the course of events (from ICH E6). In relation to trial registration applies to the ability to monitor changes made to the trial registration data set after the time of initial registration.
Auto- : self or same.
Autoantibodies: antibodies produced by an animal that react with the animal's own antigens. The stimulus is not known but could be the animal's own antigens or cross-reacting foreign antigens.
Autoantigen: a self-antigen that incites the formation of autoantibodies.
Autochthonous (Indigenous): found in the same individual in which it originates, as in the case of a neoplasm; autochthonous tumor is a tumor borne by the host of origin.
Autograft: a graft derived from the same individual to whom it is transplanted.
Autoimmune: condition in which the body produces antibodies to its own tissue.
Autologous: derived from the recipient itself.
Autonomy: one of the aspects of the responsiveness of health systems whereby one enjoys the freedom to decide for oneself on alternative treatment, testing and care options, including the decision to refuse treatment, if of sound mind. It literally means self-rule. In medical practice, the principle of autonomy implies personal rule of the self that is free both from controlling interferences by others and from personal limitations that prevent meaningful choice, such as inadequate understanding. Autonomy provides a strong moral foundation for informed consent, in which a patient, fully informed about his/her medical condition and available therapies, freely chooses to be a willing participant in any treatment or non-treatment.
Autoradiography: a technique that uses X-ray film to visualize radioactively labeled molecules or fragments of molecules; used in analyzing length and number of DNA fragments after they are separated by gel electrophoresis.
Autosomal Dominant: an allele located on an autosome (non-sex chromosome) that express itself phenotypically in the presence of the same or a different allele (ie, in a homozygous or heterozygous condition). A gene on one of the non-sex chromosomes that is always expressed, even if only one copy is present. The chance of passing the gene to offspring is 50% for each pregnancy. See also -- autosome, dominant, gene.
Autosomal Recessive: an allele located on an autosome that does not express itself phenotypically in the presence of a dominant allele (ie, in a heterozygous condition). It is only phenotypically expressed in a homozygous condition.
Autosome: a chromosome not involved in sex determination. The diploid human genome consists of a total of 46 chromosomes: 22 pairs of autosomes, and 1 pair of sex chromosomes (the X and Y chromosomes). See also -- sex chromosome.
Availability: identifies the presence or absence of needed health care services.
Average Length of Stay: average length of stay is computed by dividing the (total) number of days in inpatient or acute care institutions by the number of discharges (or admissions).
Avuncular Relationship: the genetic relationship between nieces and nephews and their aunts and uncles.
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