The range or frequency distribution of a measurement in a population (of organisms, organs or things) that has not been selected for the presence of disease or abnormality.

A basis of value established for the measure of quantity, weight, extent or quality, e.g. weight standards, standard solutions, methods, techniques, and procedures used in diagnosis and therapy.

Measurement of volume of air inhaled or exhaled by the lung.

The statistical reproducibility of measurements (often in a clinical context), including the testing of instrumentation or techniques to obtain reproducible results. The concept includes reproducibility of physiological measurements, which may be used to develop rules to assess probability or prognosis, or response to a stimulus; reproducibility of occurrence of a condition; and reproducibility of experimental results.

Laboratory tests demonstrating the presence of physiologically significant substances in the blood, urine, tissue, and body fluids with application to the diagnosis or therapy of disease.

Age as a constituent element or influence contributing to the production of a result. It may be applicable to the cause or the effect of a circumstance. It is used with human or animal concepts but should be differentiated from AGING, a physiological process, and TIME FACTORS which refers only to the passage of time.

Tests used in the analysis of the hemic system.

Maleness or femaleness as a constituent element or influence contributing to the production of a result. It may be applicable to the cause or effect of a circumstance. It is used with human or animal concepts but should be differentiated from SEX CHARACTERISTICS, anatomical or physiological manifestations of sex, and from SEX DISTRIBUTION, the number of males and females in given circumstances.

The distance from the sole to the crown of the head with body standing on a flat surface and fully extended.

An examination of chemicals in the blood.

The specialty of ANALYTIC CHEMISTRY applied to assays of physiologically important substances found in blood, urine, tissues, and other biological fluids for the purpose of aiding the physician in making a diagnosis or following therapy.

Methods and procedures for the diagnosis of diseases or dysfunction of the endocrine glands or demonstration of their physiological processes.

The technique that deals with the measurement of the size, weight, and proportions of the human or other primate body.

A group of corticosteroids carrying hydroxy groups, usually in the 11- or 17-positions. They comprise the bulk of the corticosteroids used systemically. As they are relatively insoluble in water, salts of various esterified forms are often used for injections or solutions.

Measurement of the various processes involved in the act of respiration: inspiration, expiration, oxygen and carbon dioxide exchange, lung volume and compliance, etc.

An infant during the first month after birth.

The amount of a gas taken up, by the pulmonary capillary blood from the alveolar gas, per minute per unit of average pressure of the gradient of the gas across the BLOOD-AIR BARRIER.

Measurement of hemoglobin concentration in blood.

Binary classification measures to assess test results. Sensitivity or recall rate is the proportion of true positives. Specificity is the probability of correctly determining the absence of a condition. (From Last, Dictionary of Epidemiology, 2d ed)

Studies in which the presence or absence of disease or other health-related variables are determined in each member of the study population or in a representative sample at one particular time. This contrasts with LONGITUDINAL STUDIES which are followed over a period of time.

The volume of air contained in the lungs at the end of a maximal inspiration. It is the equivalent to each of the following sums: VITAL CAPACITY plus RESIDUAL VOLUME; INSPIRATORY CAPACITY plus FUNCTIONAL RESIDUAL CAPACITY; TIDAL VOLUME plus INSPIRATORY RESERVE VOLUME plus functional residual capacity; or tidal volume plus inspiratory reserve volume plus EXPIRATORY RESERVE VOLUME plus residual volume.

The age of the conceptus, beginning from the time of FERTILIZATION. In clinical obstetrics, the gestational age is often estimated as the time from the last day of the last MENSTRUATION which is about 2 weeks before OVULATION and fertilization.

Increased RESPIRATORY RATE.

Procedures for finding the mathematical function which best describes the relationship between a dependent variable and one or more independent variables. In linear regression (see LINEAR MODELS) the relationship is constrained to be a straight line and LEAST-SQUARES ANALYSIS is used to determine the best fit. In logistic regression (see LOGISTIC MODELS) the dependent variable is qualitative rather than continuously variable and LIKELIHOOD FUNCTIONS are used to find the best relationship. In multiple regression, the dependent variable is considered to depend on more than a single independent variable.

Guidelines and objectives pertaining to food supply and nutrition including recommendations for healthy diet.

The volume of air that is exhaled by a maximal expiration following a maximal inspiration.

Measure of the maximum amount of air that can be expelled in a given number of seconds during a FORCED VITAL CAPACITY determination . It is usually given as FEV followed by a subscript indicating the number of seconds over which the measurement is made, although it is sometimes given as a percentage of forced vital capacity.

The gradual irreversible changes in structure and function of an organism that occur as a result of the passage of time.

A system for verifying and maintaining a desired level of quality in a product or process by careful planning, use of proper equipment, continued inspection, and corrective action as required. (Random House Unabridged Dictionary, 2d ed)

Chemical analysis based on the phenomenon whereby light, passing through a medium with dispersed particles of a different refractive index from that of the medium, is attenuated in intensity by scattering. In turbidimetry, the intensity of light transmitted through the medium, the unscattered light, is measured. In nephelometry, the intensity of the scattered light is measured, usually, but not necessarily, at right angles to the incident light beam.

The failure by the observer to measure or identify a phenomenon accurately, which results in an error. Sources for this may be due to the observer's missing an abnormality, or to faulty technique resulting in incorrect test measurement, or to misinterpretation of the data. Two varieties are inter-observer variation (the amount observers vary from one another when reporting on the same material) and intra-observer variation (the amount one observer varies between observations when reporting more than once on the same material).

Observation of a population for a sufficient number of persons over a sufficient number of years to generate incidence or mortality rates subsequent to the selection of the study group.

Statistical models in which the value of a parameter for a given value of a factor is assumed to be equal to a + bx, where a and b are constants. The models predict a linear regression.

Facilities equipped to carry out investigative procedures.

Measurable and quantifiable biological parameters (e.g., specific enzyme concentration, specific hormone concentration, specific gene phenotype distribution in a population, presence of biological substances) which serve as indices for health- and physiology-related assessments, such as disease risk, psychiatric disorders, environmental exposure and its effects, disease diagnosis, metabolic processes, substance abuse, pregnancy, cell line development, epidemiologic studies, etc.

Physiological processes and properties of the RESPIRATORY SYSTEM as a whole or of any of its parts.

A technique using antibodies for identifying or quantifying a substance. Usually the substance being studied serves as antigen both in antibody production and in measurement of antibody by the test substance.

The visualization of tissues during pregnancy through recording of the echoes of ultrasonic waves directed into the body. The procedure may be applied with reference to the mother or the fetus and with reference to organs or the detection of maternal or fetal disease.

A country in northern Africa bordering the Mediterranean Sea, between MOROCCO and TUNISIA. Its capital is Algiers.

The status during which female mammals carry their developing young (EMBRYOS or FETUSES) in utero before birth, beginning from FERTILIZATION to BIRTH.

Those characteristics that distinguish one SEX from the other. The primary sex characteristics are the OVARIES and TESTES and their related hormones. Secondary sex characteristics are those which are masculine or feminine but not directly related to reproduction.

Examinations that evaluate and monitor hormone production in the adrenal cortex.

The science and art of collecting, summarizing, and analyzing data that are subject to random variation. The term is also applied to the data themselves and to the summarization of the data.

In screening and diagnostic tests, the probability that a person with a positive test is a true positive (i.e., has the disease), is referred to as the predictive value of a positive test; whereas, the predictive value of a negative test is the probability that the person with a negative test does not have the disease. Predictive value is related to the sensitivity and specificity of the test.

The mass or quantity of heaviness of an individual. It is expressed by units of pounds or kilograms.

Salts and esters of hippuric acid.

Form of radioimmunoassay in which excess specific labeled antibody is added directly to the test antigen being measured.

A vertical distance measured from a known level on the surface of a planet or other celestial body.

The state of the organism when it functions optimally without evidence of disease.

Echocardiography applying the Doppler effect, with velocity detection combined with range discrimination. Short bursts of ultrasound are transmitted at regular intervals and the echoes are demodulated as they return.

The monitoring of the level of toxins, chemical pollutants, microbial contaminants, or other harmful substances in the environment (soil, air, and water), workplace, or in the bodies of people and animals present in that environment.

A subspecialty of internal medicine concerned with morphology, physiology, and pathology of the blood and blood-forming tissues.

An indicator of body density as determined by the relationship of BODY WEIGHT to BODY HEIGHT. BMI=weight (kg)/height squared (m2). BMI correlates with body fat (ADIPOSE TISSUE). Their relationship varies with age and gender. For adults, BMI falls into these categories: below 18.5 (underweight); 18.5-24.9 (normal); 25.0-29.9 (overweight); 30.0 and above (obese). (National Center for Health Statistics, Centers for Disease Control and Prevention)

Measurement of the amount of air that the lungs may contain at various points in the respiratory cycle.

The quality of SEMEN, an indicator of male fertility, can be determined by semen volume, pH, sperm concentration (SPERM COUNT), total sperm number, sperm viability, sperm vigor (SPERM MOTILITY), normal sperm morphology, ACROSOME integrity, and the concentration of WHITE BLOOD CELLS.

State of the body in relation to the consumption and utilization of nutrients.

Country located in EUROPE. It is bordered by the NORTH SEA, BELGIUM, and GERMANY. Constituent areas are Aruba, Curacao, Sint Maarten, formerly included in the NETHERLANDS ANTILLES.

Determination, by measurement or comparison with a standard, of the correct value of each scale reading on a meter or other measuring instrument; or determination of the settings of a control device that correspond to particular values of voltage, current, frequency or other output.

A statistical technique that isolates and assesses the contributions of categorical independent variables to variation in the mean of a continuous dependent variable.

The exposure to potentially harmful chemical, physical, or biological agents that occurs as a result of one's occupation.

A value equal to the total volume flow divided by the cross-sectional area of the vascular bed.

Individuals classified according to their sex, racial origin, religion, common place of living, financial or social status, or some other cultural or behavioral attribute. (UMLS, 2003)

The volume of the HEART, usually relating to the volume of BLOOD contained within it at various periods of the cardiac cycle. The amount of blood ejected from a ventricle at each beat is STROKE VOLUME.

Echocardiography amplified by the addition of depth to the conventional two-dimensional ECHOCARDIOGRAPHY visualizing only the length and width of the heart. Three-dimensional ultrasound imaging was first described in 1961 but its application to echocardiography did not take place until 1974. (Mayo Clin Proc 1993;68:221-40)

A country spanning from central Asia to the Pacific Ocean.

Elements of limited time intervals, contributing to particular results or situations.

The taking of a blood sample to determine its character as a whole, to identify levels of its component cells, chemicals, gases, or other constituents, to perform pathological examination, etc.

The oxygen-carrying proteins of ERYTHROCYTES. They are found in all vertebrates and some invertebrates. The number of globin subunits in the hemoglobin quaternary structure differs between species. Structures range from monomeric to a variety of multimeric arrangements.

Controlled physical activity which is performed in order to allow assessment of physiological functions, particularly cardiovascular and pulmonary, but also aerobic capacity. Maximal (most intense) exercise is usually required but submaximal exercise is also used.

Studies in which subsets of a defined population are identified. These groups may or may not be exposed to factors hypothesized to influence the probability of the occurrence of a particular disease or other outcome. Cohorts are defined populations which, as a whole, are followed in an attempt to determine distinguishing subgroup characteristics.

Either of the pair of organs occupying the cavity of the thorax that effect the aeration of the blood.

The relative amounts of various components in the body, such as percentage of body fat.

Any technique by which an unknown color is evaluated in terms of standard colors. The technique may be visual, photoelectric, or indirect by means of spectrophotometry. It is used in chemistry and physics. (McGraw-Hill Dictionary of Scientific and Technical Terms, 4th ed)

The capability of the LUNGS to distend under pressure as measured by pulmonary volume change per unit pressure change. While not a complete description of the pressure-volume properties of the lung, it is nevertheless useful in practice as a measure of the comparative stiffness of the lung. (From Best & Taylor's Physiological Basis of Medical Practice, 12th ed, p562)

The amounts of various substances in food needed by an organism to sustain healthy life.

The number of LEUKOCYTES and ERYTHROCYTES per unit volume in a sample of venous BLOOD. A complete blood count (CBC) also includes measurement of the HEMOGLOBIN; HEMATOCRIT; and ERYTHROCYTE INDICES.

Physiologically, the opposition to flow of air caused by the forces of friction. As a part of pulmonary function testing, it is the ratio of driving pressure to the rate of air flow.

Liquid chromatographic techniques which feature high inlet pressures, high sensitivity, and high speed.

A group of chemical elements that are needed in minute quantities for the proper growth, development, and physiology of an organism. (From McGraw-Hill Dictionary of Scientific and Technical Terms, 4th ed)

The frequency of different ages or age groups in a given population. The distribution may refer to either how many or what proportion of the group. The population is usually patients with a specific disease but the concept is not restricted to humans and is not restricted to medicine.

A specialized agency of the United Nations designed as a coordinating authority on international health work; its aim is to promote the attainment of the highest possible level of health by all peoples.

Measurement of rate of settling of erythrocytes in anticoagulated blood.

A procedure consisting of a sequence of algebraic formulas and/or logical steps to calculate or determine a given task.

Commercially prepared reagent sets, with accessory devices, containing all of the major components and literature necessary to perform one or more designated diagnostic tests or procedures. They may be for laboratory or personal use.

The Arctic Ocean and the lands in it and adjacent to it. It includes Point Barrow, Alaska, most of the Franklin District in Canada, two thirds of Greenland, Svalbard, Franz Josef Land, Lapland, Novaya Zemlya, and Northern Siberia. (Webster's New Geographical Dictionary, 1988, p66)

In utero measurement corresponding to the sitting height (crown to rump) of the fetus. Length is considered a more accurate criterion of the age of the fetus than is the weight. The average crown-rump length of the fetus at term is 36 cm. (From Williams Obstetrics, 18th ed, p91)

ERYTHROCYTE size and HEMOGLOBIN content or concentration, usually derived from ERYTHROCYTE COUNT; BLOOD hemoglobin concentration; and HEMATOCRIT. The indices include the mean corpuscular volume (MCV), the mean corpuscular hemoglobin (MCH), and the mean corpuscular hemoglobin concentration (MCHC).

Spectrophotometric techniques by which the absorption or emmision spectra of radiation from atoms are produced and analyzed.

Individuals whose ancestral origins are in the continent of Europe.

A period in the human life in which the development of the hypothalamic-pituitary-gonadal system takes place and reaches full maturity. The onset of synchronized endocrine events in puberty lead to the capacity for reproduction (FERTILITY), development of secondary SEX CHARACTERISTICS, and other changes seen in ADOLESCENT DEVELOPMENT.

The resistance to the flow of either alternating or direct electrical current.

A nonmetallic element of the halogen group that is represented by the atomic symbol I, atomic number 53, and atomic weight of 126.90. It is a nutritionally essential element, especially important in thyroid hormone synthesis. In solution, it has anti-infective properties and is used topically.

Techniques used to carry out clinical investigative procedures in the diagnosis and therapy of disease.

The number of LYMPHOCYTES per unit volume of BLOOD.

Studies to determine the advantages or disadvantages, practicability, or capability of accomplishing a projected plan, study, or project.

Any tests done on exhaled air.

The largest of the TARSAL BONES which is situated at the lower and back part of the FOOT, forming the HEEL.

Gradual increase in the number, the size, and the complexity of cells of an individual. Growth generally results in increase in ORGAN WEIGHT; BODY WEIGHT; and BODY HEIGHT.

Examination of urine by chemical, physical, or microscopic means. Routine urinalysis usually includes performing chemical screening tests, determining specific gravity, observing any unusual color or odor, screening for bacteriuria, and examining the sediment microscopically.

The number of males and females in a given population. The distribution may refer to how many men or women or what proportion of either in the group. The population is usually patients with a specific disease but the concept is not restricted to humans and is not restricted to medicine.

The residual portion of BLOOD that is left after removal of BLOOD CELLS by CENTRIFUGATION without prior BLOOD COAGULATION.

The continuous measurement of physiological processes, blood pressure, heart rate, renal output, reflexes, respiration, etc., in a patient or experimental animal; includes pharmacologic monitoring, the measurement of administered drugs or their metabolites in the blood, tissues, or urine.

Application of statistical procedures to analyze specific observed or assumed facts from a particular study.

Individuals whose ancestral origins are in the southeastern and eastern areas of the Asian continent.

The exposure to potentially harmful chemical, physical, or biological agents in the environment or to environmental factors that may include ionizing radiation, pathogenic organisms, or toxic chemicals.

A systematic collection of factual data pertaining to the nutritional status of a human population within a given geographic area. Data from these surveys are used in preparing NUTRITION ASSESSMENTS.

A graphic means for assessing the ability of a screening test to discriminate between healthy and diseased persons; may also be used in other studies, e.g., distinguishing stimuli responses as to a faint stimuli or nonstimuli.

The lower right and left chambers of the heart. The right ventricle pumps venous BLOOD into the LUNGS and the left ventricle pumps oxygenated blood into the systemic arterial circulation.

The number of RED BLOOD CELLS per unit volume in a sample of venous BLOOD.

Studies used to test etiologic hypotheses in which inferences about an exposure to putative causal factors are derived from data relating to characteristics of persons under study or to events or experiences in their past. The essential feature is that some of the persons under study have the disease or outcome of interest and their characteristics are compared with those of unaffected persons.

An aspect of personal behavior or lifestyle, environmental exposure, or inborn or inherited characteristic, which, on the basis of epidemiologic evidence, is known to be associated with a health-related condition considered important to prevent.

The middle third of a human PREGNANCY, from the beginning of the 15th through the 28th completed week (99 to 196 days) of gestation.

A count of SPERM in the ejaculum, expressed as number per milliliter.

A cobalt-containing coordination compound produced by intestinal micro-organisms and found also in soil and water. Higher plants do not concentrate vitamin B 12 from the soil and so are a poor source of the substance as compared with animal tissues. INTRINSIC FACTOR is important for the assimilation of vitamin B 12.

Air pollutants found in the work area. They are usually produced by the specific nature of the occupation.

Glucose in blood.

The exercise capacity of an individual as measured by endurance (maximal exercise duration and/or maximal attained work load) during an EXERCISE TEST.

A noninvasive method for assessing BODY COMPOSITION. It is based on the differential absorption of X-RAYS (or GAMMA RAYS) by different tissues such as bone, fat and other soft tissues. The source of (X-ray or gamma-ray) photon beam is generated either from radioisotopes such as GADOLINIUM 153, IODINE 125, or Americanium 241 which emit GAMMA RAYS in the appropriate range; or from an X-ray tube which produces X-RAYS in the desired range. It is primarily used for quantitating BONE MINERAL CONTENT, especially for the diagnosis of OSTEOPOROSIS, and also in measuring BONE MINERALIZATION.

Parliamentary democracy located between France on the northeast and Portugual on the west and bordered by the Atlantic Ocean and the Mediterranean Sea.

The process of generating three-dimensional images by electronic, photographic, or other methods. For example, three-dimensional images can be generated by assembling multiple tomographic images with the aid of a computer, while photographic 3-D images (HOLOGRAPHY) can be made by exposing film to the interference pattern created when two laser light sources shine on an object.

Regular course of eating and drinking adopted by a person or animal.

A class of statistical methods applicable to a large set of probability distributions used to test for correlation, location, independence, etc. In most nonparametric statistical tests, the original scores or observations are replaced by another variable containing less information. An important class of nonparametric tests employs the ordinal properties of the data. Another class of tests uses information about whether an observation is above or below some fixed value such as the median, and a third class is based on the frequency of the occurrence of runs in the data. (From McGraw-Hill Dictionary of Scientific and Technical Terms, 4th ed, p1284; Corsini, Concise Encyclopedia of Psychology, 1987, p764-5)

A human infant born before 37 weeks of GESTATION.

The number of WHITE BLOOD CELLS per unit volume in venous BLOOD. A differential leukocyte count measures the relative numbers of the different types of white cells.

The number of times the HEART VENTRICLES contract per unit of time, usually per minute.

The hemodynamic and electrophysiological action of the left HEART VENTRICLE. Its measurement is an important aspect of the clinical evaluation of patients with heart disease to determine the effects of the disease on cardiac performance.

Pathological processes involving any part of the LUNG.

The volume of packed RED BLOOD CELLS in a blood specimen. The volume is measured by centrifugation in a tube with graduated markings, or with automated blood cell counters. It is an indicator of erythrocyte status in disease. For example, ANEMIA shows a low value; POLYCYTHEMIA, a high value.

Proteins that are present in blood serum, including SERUM ALBUMIN; BLOOD COAGULATION FACTORS; and many other types of proteins.

Ultrasonic recording of the size, motion, and composition of the heart and surrounding tissues. The standard approach is transthoracic.

Theoretical representations that simulate the behavior or activity of biological processes or diseases. For disease models in living animals, DISEASE MODELS, ANIMAL is available. Biological models include the use of mathematical equations, computers, and other electronic equipment.

A soft, grayish metal with poisonous salts; atomic number 82, atomic weight 207.19, symbol Pb. (Dorland, 28th)

Studies which start with the identification of persons with a disease of interest and a control (comparison, referent) group without the disease. The relationship of an attribute to the disease is examined by comparing diseased and non-diseased persons with regard to the frequency or levels of the attribute in each group.

A 191-amino acid polypeptide hormone secreted by the human adenohypophysis (PITUITARY GLAND, ANTERIOR), also known as GH or somatotropin. Synthetic growth hormone, termed somatropin, has replaced the natural form in therapeutic usage such as treatment of dwarfism in children with growth hormone deficiency.

Ratio of T-LYMPHOCYTES that express the CD4 ANTIGEN to those that express the CD8 ANTIGEN. This value is commonly assessed in the diagnosis and staging of diseases affecting the IMMUNE SYSTEM including HIV INFECTIONS.

A technique of inputting two-dimensional images into a computer and then enhancing or analyzing the imagery into a form that is more useful to the human observer.

Measurement of the maximum rate of airflow attained during a FORCED VITAL CAPACITY determination. Common abbreviations are PEFR and PFR.

Processes and properties of the CARDIOVASCULAR SYSTEM as a whole or of any of its parts.

An activity in which the body advances at a slow to moderate pace by moving the feet in a coordinated fashion. This includes recreational walking, walking for fitness, and competitive race-walking.

A bile pigment that is a degradation product of HEME.

The rate at which oxygen is used by a tissue; microliters of oxygen STPD used per milligram of tissue per hour; the rate at which oxygen enters the blood from alveolar gas, equal in the steady state to the consumption of oxygen by tissue metabolism throughout the body. (Stedman, 25th ed, p346)

Measurement of intracardiac blood flow using an M-mode and/or two-dimensional (2-D) echocardiogram while simultaneously recording the spectrum of the audible Doppler signal (e.g., velocity, direction, amplitude, intensity, timing) reflected from the moving column of red blood cells.

Classic quantitative assay for detection of antigen-antibody reactions using a radioactively labeled substance (radioligand) either directly or indirectly to measure the binding of the unlabeled substance to a specific antibody or other receptor system. Non-immunogenic substances (e.g., haptens) can be measured if coupled to larger carrier proteins (e.g., bovine gamma-globulin or human serum albumin) capable of inducing antibody formation.

The measurement of frequency or oscillation changes.

Studies in which individuals or populations are followed to assess the outcome of exposures, procedures, or effects of a characteristic, e.g., occurrence of disease.

A widely used industrial solvent.

Studies determining the effectiveness or value of processes, personnel, and equipment, or the material on conducting such studies. For drugs and devices, CLINICAL TRIALS AS TOPIC; DRUG EVALUATION; and DRUG EVALUATION, PRECLINICAL are available.

A country in western Europe bordered by the Atlantic Ocean, the English Channel, the Mediterranean Sea, and the countries of Belgium, Germany, Italy, Spain, Switzerland, the principalities of Andorra and Monaco, and by the duchy of Luxembourg. Its capital is Paris.

The ability to carry out daily tasks and perform physical activities in a highly functional state, often as a result of physical conditioning.

The amount of force generated by MUSCLE CONTRACTION. Muscle strength can be measured during isometric, isotonic, or isokinetic contraction, either manually or using a device such as a MUSCLE STRENGTH DYNAMOMETER.

The amount of mineral per square centimeter of BONE. This is the definition used in clinical practice. Actual bone density would be expressed in grams per milliliter. It is most frequently measured by X-RAY ABSORPTIOMETRY or TOMOGRAPHY, X RAY COMPUTED. Bone density is an important predictor for OSTEOPOROSIS.

The continuous sequential physiological and psychological maturing of an individual from birth up to but not including ADOLESCENCE.

Predetermined sets of questions used to collect data - clinical data, social status, occupational group, etc. The term is often applied to a self-completed survey instrument.

Non-invasive method of demonstrating internal anatomy based on the principle that atomic nuclei in a strong magnetic field absorb pulses of radiofrequency energy and emit them as radiowaves which can be reconstructed into computerized images. The concept includes proton spin tomographic techniques.

A major protein in the BLOOD. It is important in maintaining the colloidal osmotic pressure and transporting large organic molecules.

Carbon monoxide (CO). A poisonous colorless, odorless, tasteless gas. It combines with hemoglobin to form carboxyhemoglobin, which has no oxygen carrying capacity. The resultant oxygen deprivation causes headache, dizziness, decreased pulse and respiratory rates, unconsciousness, and death. (From Merck Index, 11th ed)

The thick, yellowish-white, viscid fluid secretion of male reproductive organs discharged upon ejaculation. In addition to reproductive organ secretions, it contains SPERMATOZOA and their nutrient plasma.

Devices or objects in various imaging techniques used to visualize or enhance visualization by simulating conditions encountered in the procedure. Phantoms are used very often in procedures employing or measuring x-irradiation or radioactive material to evaluate performance. Phantoms often have properties similar to human tissue. Water demonstrates absorbing properties similar to normal tissue, hence water-filled phantoms are used to map radiation levels. Phantoms are used also as teaching aids to simulate real conditions with x-ray or ultrasonic machines. (From Iturralde, Dictionary and Handbook of Nuclear Medicine and Clinical Imaging, 1990)

A status with BODY WEIGHT that is grossly above the acceptable or desirable weight, usually due to accumulation of excess FATS in the body. The standards may vary with age, sex, genetic or cultural background. In the BODY MASS INDEX, a BMI greater than 30.0 kg/m2 is considered obese, and a BMI greater than 40.0 kg/m2 is considered morbidly obese (MORBID OBESITY).

Total number of calories taken in daily whether ingested or by parenteral routes.

Red blood cells. Mature erythrocytes are non-nucleated, biconcave disks containing HEMOGLOBIN whose function is to transport OXYGEN.

Tomography using x-ray transmission and a computer algorithm to reconstruct the image.

PRESSURE of the BLOOD on the ARTERIES and other BLOOD VESSELS.

The hemodynamic and electrophysiological action of the right HEART VENTRICLE.

A group of people with a common cultural heritage that sets them apart from others in a variety of social relationships.

Blood of the fetus. Exchange of nutrients and waste between the fetal and maternal blood occurs via the PLACENTA. The cord blood is blood contained in the umbilical vessels (UMBILICAL CORD) at the time of delivery.

The total number of cases of a given disease in a specified population at a designated time. It is differentiated from INCIDENCE, which refers to the number of new cases in the population at a given time.

Period of contraction of the HEART, especially of the HEART VENTRICLES.

A classification of lymphocytes based on structurally or functionally different populations of cells.

A member of the vitamin B family that stimulates the hematopoietic system. It is present in the liver and kidney and is found in mushrooms, spinach, yeast, green leaves, and grasses (POACEAE). Folic acid is used in the treatment and prevention of folate deficiencies and megaloblastic anemia.

The qualitative or quantitative estimation of the likelihood of adverse effects that may result from exposure to specified health hazards or from the absence of beneficial influences. (Last, Dictionary of Epidemiology, 1988)

Research techniques that focus on study designs and data gathering methods in human and animal populations.

Ultrasonography applying the Doppler effect, with frequency-shifted ultrasound reflections produced by moving targets (usually red blood cells) in the bloodstream along the ultrasound axis in direct proportion to the velocity of movement of the targets, to determine both direction and velocity of blood flow. (Stedman, 25th ed)

The measurement of an organ in volume, mass, or heaviness.

The science dealing with the earth and its life, especially the description of land, sea, and air and the distribution of plant and animal life, including humanity and human industries with reference to the mutual relations of these elements. (From Webster, 3d ed)

An analytical method used in determining the identity of a chemical based on its mass using mass analyzers/mass spectrometers.

Levels within a diagnostic group which are established by various measurement criteria applied to the seriousness of a patient's disorder.

Inhaling and exhaling the smoke of burning TOBACCO.

The principal sterol of all higher animals, distributed in body tissues, especially the brain and spinal cord, and in animal fats and oils.