Penetrating, high-energy electromagnetic radiation emitted from atomic nuclei during NUCLEAR DECAY. The range of wavelengths of emitted radiation is between 0.1 - 100 pm which overlaps the shorter, more energetic hard X-RAYS wavelengths. The distinction between gamma rays and X-rays is based on their radiation source.
Examination of any part of the body for diagnostic purposes by means of X-RAYS or GAMMA RAYS, recording the image on a sensitized surface (such as photographic film).
Identification and measurement of ELEMENTS and their location based on the fact that X-RAYS emitted by an element excited by an electron beam have a wavelength characteristic of that element and an intensity related to its concentration. It is performed with an electron microscope fitted with an x-ray spectrometer, in scanning or transmission mode.
A subclass of cartilaginous fish comprising the SHARKS; rays; skates (SKATES (FISH);), and sawfish. Elasmobranchs are typically predaceous, relying more on smell (the olfactory capsules are relatively large) than sight (the eyes are relatively small) for obtaining their food.
A diffuse parenchymal lung disease caused by inhalation of dust and by tissue reaction to their presence. These inorganic, organic, particulate, or vaporized matters usually are inhaled by workers in their occupational environment, leading to the various forms (ASBESTOSIS; BYSSINOSIS; and others). Similar air pollution can also have deleterious effects on the general population.
The common name for all members of the Rajidae family. Skates and rays are members of the same order (Rajiformes). Skates have weak electric organs.
Neutrons, the energy of which exceeds some arbitrary level, usually around one million electron volts.
Hospital department which is responsible for the administration and provision of x-ray diagnostic and therapeutic services.
The joint that is formed by the distal end of the RADIUS, the articular disc of the distal radioulnar joint, and the proximal row of CARPAL BONES; (SCAPHOID BONE; LUNATE BONE; triquetral bone).
That portion of the electromagnetic spectrum immediately below the visible range and extending into the x-ray frequencies. The longer wavelengths (near-UV or biotic or vital rays) are necessary for the endogenous synthesis of vitamin D and are also called antirachitic rays; the shorter, ionizing wavelengths (far-UV or abiotic or extravital rays) are viricidal, bactericidal, mutagenic, and carcinogenic and are used as disinfectants.
The effects of ionizing and nonionizing radiation upon living organisms, organs and tissues, and their constituents, and upon physiologic processes. It includes the effect of irradiation on food, drugs, and chemicals.
Any of the numerous types of clay which contain varying proportions of Al2O3 and SiO2. They are made synthetically by heating aluminum fluoride at 1000-2000 degrees C with silica and water vapor. (From Hawley's Condensed Chemical Dictionary, 11th ed)
Membranous appendage of fish and other aquatic organisms used for locomotion or balance.
The female sex chromosome, being the differential sex chromosome carried by half the male gametes and all female gametes in human and other male-heterogametic species.
The amount of radiation energy that is deposited in a unit mass of material, such as tissues of plants or animal. In RADIOTHERAPY, radiation dosage is expressed in gray units (Gy). In RADIOLOGIC HEALTH, the dosage is expressed by the product of absorbed dose (Gy) and quality factor (a function of linear energy transfer), and is called radiation dose equivalent in sievert units (Sv).
The region of the HAND between the WRIST and the FINGERS.
The electronic transmission of radiological images from one location to another for the purposes of interpretation and/or consultation. Users in different locations may simultaneously view images with greater access to secondary consultations and improved continuing education. (From American College of Radiology, ACR Standard for Teleradiology, 1994, p3)
The articulation between a metacarpal bone and a phalanx.
The spectrometric analysis of fluorescent X-RAYS, i.e. X-rays emitted after bombarding matter with high energy particles such as PROTONS; ELECTRONS; or higher energy X-rays. Identification of ELEMENTS by this technique is based on the specific type of X-rays that are emitted which are characteristic of the specific elements in the material being analyzed. The characteristic X-rays are distinguished and/or quantified by either wavelength dispersive or energy dispersive methods.
The relationship between the dose of administered radiation and the response of the organism or tissue to the radiation.
A vacuum tube equipped with an electron emitting CATHODE and a fluorescent screen which emits visible light when excited by the cathode ray. Cathode ray tubes are used as imaging devises for TELEVISIONS; COMPUTER TERMINALS; TEXT TELECOMMUNICATION DEVICES; oscilloscopes; and other DATA DISPLAY devices.
Unstable isotopes of cadmium that decay or disintegrate emitting radiation. Cd atoms with atomic weights 103-105, 107, 109, 115, and 117-119 are radioactive cadmium isotopes.
Individuals responsible for fabrication of dental appliances.
A subdiscipline of genetics that studies RADIATION EFFECTS on the components and processes of biological inheritance.
High-energy radiation or particles from extraterrestrial space that strike the earth, its atmosphere, or spacecraft and may create secondary radiation as a result of collisions with the atmosphere or spacecraft.
Hospital department responsible for the administration and provision of immediate medical or surgical care to the emergency patient.
A form of pneumoconiosis caused by inhalation of asbestos fibers which elicit potent inflammatory responses in the parenchyma of the lung. The disease is characterized by interstitial fibrosis of the lung, varying from scattered sites to extensive scarring of the alveolar interstitium.
The thin serous membrane enveloping the lungs (LUNG) and lining the THORACIC CAVITY. Pleura consist of two layers, the inner visceral pleura lying next to the pulmonary parenchyma and the outer parietal pleura. Between the two layers is the PLEURAL CAVITY which contains a thin film of liquid.
Quartz (SiO2). A glassy or crystalline form of silicon dioxide. Many colored varieties are semiprecious stones. (From Grant & Hackh's Chemical Dictionary, 5th ed)
Diseases caused by factors involved in one's employment.
The largest of the TARSAL BONES which is situated at the lower and back part of the FOOT, forming the HEEL.
Rapid methods of measuring the effects of an agent in a biological or chemical assay. The assay usually involves some form of automation or a way to conduct multiple assays at the same time using sample arrays.
Asbestos. Fibrous incombustible mineral composed of magnesium and calcium silicates with or without other elements. It is relatively inert chemically and used in thermal insulation and fireproofing. Inhalation of dust causes asbestosis and later lung and gastrointestinal neoplasms.
Metabolic bone diseases are a group of disorders that affect the bones' structure and strength, caused by disturbances in the normal metabolic processes involved in bone formation, resorption, or mineralization, including conditions like osteoporosis, osteomalacia, Paget's disease, and renal osteodystrophy.
The measurement of radiation by photography, as in x-ray film and film badge, by Geiger-Mueller tube, and by SCINTILLATION COUNTING.
Descriptions of specific amino acid, carbohydrate, or nucleotide sequences which have appeared in the published literature and/or are deposited in and maintained by databanks such as GENBANK, European Molecular Biology Laboratory (EMBL), National Biomedical Research Foundation (NBRF), or other sequence repositories.
The ability of some cells or tissues to survive lethal doses of IONIZING RADIATION. Tolerance depends on the species, cell type, and physical and chemical variables, including RADIATION-PROTECTIVE AGENTS and RADIATION-SENSITIZING AGENTS.
Incorrect diagnoses after clinical examination or technical diagnostic procedures.
The exposure to potentially harmful chemical, physical, or biological agents that occurs as a result of one's occupation.
A chronic systemic disease, primarily of the joints, marked by inflammatory changes in the synovial membranes and articular structures, widespread fibrinoid degeneration of the collagen fibers in mesenchymal tissues, and by atrophy and rarefaction of bony structures. Etiology is unknown, but autoimmune mechanisms have been implicated.
Traumatic injuries involving the cranium and intracranial structures (i.e., BRAIN; CRANIAL NERVES; MENINGES; and other structures). Injuries may be classified by whether or not the skull is penetrated (i.e., penetrating vs. nonpenetrating) or whether there is an associated hemorrhage.
Inanimate objects that become enclosed in the body.
Outgrowth of immature bony processes or bone spurs (OSTEOPHYTE) from the VERTEBRAE, reflecting the presence of degenerative disease and calcification. It commonly occurs in cervical and lumbar SPONDYLOSIS.
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)
Elements of limited time intervals, contributing to particular results or situations.
The science, art, or technology dealing with processes involved in the separation of metals from their ores, the technique of making or compounding the alloys, the techniques of working or heat-treating metals, and the mining of metals. It includes industrial metallurgy as well as metallurgical techniques employed in the preparation and working of metals used in dentistry, with special reference to orthodontic and prosthodontic appliances. (From Jablonski, Dictionary of Dentistry, 1992, p494)
Either of the pair of organs occupying the cavity of the thorax that effect the aeration of the blood.
Reduction of bone mass without alteration in the composition of bone, leading to fractures. Primary osteoporosis can be of two major types: postmenopausal osteoporosis (OSTEOPOROSIS, POSTMENOPAUSAL) and age-related or senile osteoporosis.
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.
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.
The outward appearance of the individual. It is the product of interactions between genes, and between the GENOTYPE and the environment.
The order of amino acids as they occur in a polypeptide chain. This is referred to as the primary structure of proteins. It is of fundamental importance in determining PROTEIN CONFORMATION.
Breaks in bones.
Screening techniques first developed in yeast to identify genes encoding interacting proteins. Variations are used to evaluate interplay between proteins and other molecules. Two-hybrid techniques refer to analysis for protein-protein interactions, one-hybrid for DNA-protein interactions, three-hybrid interactions for RNA-protein interactions or ligand-based interactions. Reverse n-hybrid techniques refer to analysis for mutations or other small molecules that dissociate known interactions.
The scattering of x-rays by matter, especially crystals, with accompanying variation in intensity due to interference effects. Analysis of the crystal structure of materials is performed by passing x-rays through them and registering the diffraction image of the rays (CRYSTALLOGRAPHY, X-RAY). (From McGraw-Hill Dictionary of Scientific and Technical Terms, 4th ed)
Large collections of small molecules (molecular weight about 600 or less), of similar or diverse nature which are used for high-throughput screening analysis of the gene function, protein interaction, cellular processing, biochemical pathways, or other chemical interactions.
A species of nematode that is widely used in biological, biochemical, and genetic studies.
'Spinal diseases' is a broad term referring to various medical conditions that affect the structural integrity, function, or health of the spinal column, including degenerative disorders, infections, inflammatory processes, traumatic injuries, neoplasms, and congenital abnormalities.
The distal part of the arm beyond the wrist in humans and primates, that includes the palm, fingers, and thumb.
I'm sorry for any confusion, but 'England' is not a medical term and does not have a medical definition. England is a country that is part of the United Kingdom, known for its rich history, cultural heritage, and contributions to medical science. However, in a medical context, it may refer to the location of a patient, healthcare provider, or research study, but it is not a term with a specific medical meaning.
A plant genus in the family PINACEAE, order Pinales, class Pinopsida, division Coniferophyta. They are coniferous evergreen trees with long, flat, spirally arranged needles that grow directly from the branch.
The sequence of PURINES and PYRIMIDINES in nucleic acids and polynucleotides. It is also called nucleotide sequence.
Proteins from the nematode species CAENORHABDITIS ELEGANS. The proteins from this species are the subject of scientific interest in the area of multicellular organism MORPHOGENESIS.
Collective name for a group of external MECHANORECEPTORS and chemoreceptors manifesting as sensory structures in ARTHROPODS. They include cuticular projections (setae, hairs, bristles), pores, and slits.
Preclinical testing of drugs in experimental animals or in vitro for their biological and toxic effects and potential clinical applications.
Detection of a MUTATION; GENOTYPE; KARYOTYPE; or specific ALLELES associated with genetic traits, heritable diseases, or predisposition to a disease, or that may lead to the disease in descendants. It includes prenatal genetic testing.
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).
Storage-stable glycoprotein blood coagulation factor that can be activated to factor Xa by both the intrinsic and extrinsic pathways. A deficiency of factor X, sometimes called Stuart-Prower factor deficiency, may lead to a systemic coagulation disorder.
A highly vascularized extra-embryonic membrane, formed by the fusion of the CHORION and the ALLANTOIS. It is mostly found in BIRDS and REPTILES. It serves as a model for studying tumor or cell biology, such as angiogenesis and TISSUE TRANSPLANTATION.
Earth or other matter in fine, dry particles. (Random House Unabridged Dictionary, 2d ed)
Tomography using x-ray transmission and a computer algorithm to reconstruct the image.
The first seven VERTEBRAE of the SPINAL COLUMN, which correspond to the VERTEBRAE of the NECK.
Situations or conditions requiring immediate intervention to avoid serious adverse results.
Penetrating electromagnetic radiation emitted when the inner orbital electrons of an atom are excited and release radiant energy. X-ray wavelengths range from 1 pm to 10 nm. Hard X-rays are the higher energy, shorter wavelength X-rays. Soft x-rays or Grenz rays are less energetic and longer in wavelength. The short wavelength end of the X-ray spectrum overlaps the GAMMA RAYS wavelength range. The distinction between gamma rays and X-rays is based on their radiation source.
The volume of air that is exhaled by a maximal expiration following a maximal inspiration.
In anatomical terms, "tail" is not used as a medical definition to describe any part of the human body; it is however used in veterinary medicine to refer to the distal portion of the spine in animals possessing tails.
A gene silencing phenomenon whereby specific dsRNAs (RNA, DOUBLE-STRANDED) trigger the degradation of homologous mRNA (RNA, MESSENGER). The specific dsRNAs are processed into SMALL INTERFERING RNA (siRNA) which serves as a guide for cleavage of the homologous mRNA in the RNA-INDUCED SILENCING COMPLEX. DNA METHYLATION may also be triggered during this process.
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.
A British colony in the western North Atlantic Ocean about 640 miles east southeast of Cape Hatteras, North Carolina. It comprises a group of about 300 islands of which only about 20 are inhabited. It is called also the Bermuda Islands or the Bermudas. It was named for the Spanish explorer Juan Bermudez who visited the islands in 1515. (From Webster's New Geographical Dictionary, 1988, p140 & Room, Brewer's Dictionary of Names, 1992, p61)
Levels within a diagnostic group which are established by various measurement criteria applied to the seriousness of a patient's disorder.
That portion of the electromagnetic spectrum usually sensed as heat. Infrared wavelengths are longer than those of visible light, extending into the microwave frequencies. They are used therapeutically as heat, and also to warm food in restaurants.
Any type of variation in the appearance of energy output of the sun. (NASA Thesaurus, 1994)
A synovial hinge connection formed between the bones of the FEMUR; TIBIA; and PATELLA.
Measurement of rate of settling of erythrocytes in anticoagulated blood.
Microscopy in which the object is examined directly by an electron beam scanning the specimen point-by-point. The image is constructed by detecting the products of specimen interactions that are projected above the plane of the sample, such as backscattered electrons. Although SCANNING TRANSMISSION ELECTRON MICROSCOPY also scans the specimen point by point with the electron beam, the image is constructed by detecting the electrons, or their interaction products that are transmitted through the sample plane, so that is a form of TRANSMISSION ELECTRON MICROSCOPY.
A plant species of the genus PINUS that contains isocupressic acid.
An exotic species of the family CYPRINIDAE, originally from Asia, that has been introduced in North America. They are used in embryological studies and to study the effects of certain chemicals on development.
A large collection of DNA fragments cloned (CLONING, MOLECULAR) from a given organism, tissue, organ, or cell type. It may contain complete genomic sequences (GENOMIC LIBRARY) or complementary DNA sequences, the latter being formed from messenger RNA and lacking intron sequences.
The practice of sending a patient to another program or practitioner for services or advice which the referring source is not prepared to provide.
A chronic transmural inflammation that may involve any part of the DIGESTIVE TRACT from MOUTH to ANUS, mostly found in the ILEUM, the CECUM, and the COLON. In Crohn disease, the inflammation, extending through the intestinal wall from the MUCOSA to the serosa, is characteristically asymmetric and segmental. Epithelioid GRANULOMAS may be seen in some patients.
Rate of energy dissipation along the path of charged particles. In radiobiology and health physics, exposure is measured in kiloelectron volts per micrometer of tissue (keV/micrometer T).
The joint that is formed by the articulation of the head of FEMUR and the ACETABULUM of the PELVIS.
Any detectable and heritable change in the genetic material that causes a change in the GENOTYPE and which is transmitted to daughter cells and to succeeding generations.
A specialized CONNECTIVE TISSUE that is the main constituent of the SKELETON. The principle cellular component of bone is comprised of OSTEOBLASTS; OSTEOCYTES; and OSTEOCLASTS, while FIBRILLAR COLLAGENS and hydroxyapatite crystals form the BONE MATRIX.
Unstable isotopes of cobalt that decay or disintegrate emitting radiation. Co atoms with atomic weights of 54-64, except 59, are radioactive cobalt isotopes.
Injuries to DNA that introduce deviations from its normal, intact structure and which may, if left unrepaired, result in a MUTATION or a block of DNA REPLICATION. These deviations may be caused by physical or chemical agents and occur by natural or unnatural, introduced circumstances. They include the introduction of illegitimate bases during replication or by deamination or other modification of bases; the loss of a base from the DNA backbone leaving an abasic site; single-strand breaks; double strand breaks; and intrastrand (PYRIMIDINE DIMERS) or interstrand crosslinking. Damage can often be repaired (DNA REPAIR). If the damage is extensive, it can induce APOPTOSIS.
Production of new arrangements of DNA by various mechanisms such as assortment and segregation, CROSSING OVER; GENE CONVERSION; GENETIC TRANSFORMATION; GENETIC CONJUGATION; GENETIC TRANSDUCTION; or mixed infection of viruses.
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.
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.
I'm sorry for any confusion, but "London" is a place name and not a medical term, so it doesn't have a medical definition. It's the capital city of England and the United Kingdom, known for its rich history, culture, and landmarks. If you have any questions related to health or medicine, I'd be happy to help answer those!
Organized periodic procedures performed on large groups of people for the purpose of detecting disease.
The reconstruction of a continuous two-stranded DNA molecule without mismatch from a molecule which contained damaged regions. The major repair mechanisms are excision repair, in which defective regions in one strand are excised and resynthesized using the complementary base pairing information in the intact strand; photoreactivation repair, in which the lethal and mutagenic effects of ultraviolet light are eliminated; and post-replication repair, in which the primary lesions are not repaired, but the gaps in one daughter duplex are filled in by incorporation of portions of the other (undamaged) daughter duplex. Excision repair and post-replication repair are sometimes referred to as "dark repair" because they do not require light.
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.
A species of the genus SACCHAROMYCES, family Saccharomycetaceae, order Saccharomycetales, known as "baker's" or "brewer's" yeast. The dried form is used as a dietary supplement.
The relative amounts of various components in the body, such as percentage of body fat.
Noninflammatory degenerative disease of the knee joint consisting of three large categories: conditions that block normal synchronous movement, conditions that produce abnormal pathways of motion, and conditions that cause stress concentration resulting in changes to articular cartilage. (Crenshaw, Campbell's Operative Orthopaedics, 8th ed, p2019)
The second longest bone of the skeleton. It is located on the medial side of the lower leg, articulating with the FIBULA laterally, the TALUS distally, and the FEMUR proximally.
An infant during the first month after birth.
The insertion of recombinant DNA molecules from prokaryotic and/or eukaryotic sources into a replicating vehicle, such as a plasmid or virus vector, and the introduction of the resultant hybrid molecules into recipient cells without altering the viability of those cells.
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.
An autosomal recessive genetic disease of the EXOCRINE GLANDS. It is caused by mutations in the gene encoding the CYSTIC FIBROSIS TRANSMEMBRANE CONDUCTANCE REGULATOR expressed in several organs including the LUNG, the PANCREAS, the BILIARY SYSTEM, and the SWEAT GLANDS. Cystic fibrosis is characterized by epithelial secretory dysfunction associated with ductal obstruction resulting in AIRWAY OBSTRUCTION; chronic RESPIRATORY INFECTIONS; PANCREATIC INSUFFICIENCY; maldigestion; salt depletion; and HEAT PROSTRATION.
Any method used for determining the location of and relative distances between genes on a chromosome.
The longest and largest bone of the skeleton, it is situated between the hip and the knee.
The technique that deals with the measurement of the size, weight, and proportions of the human or other primate body.
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.
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.
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.
Proteins that originate from insect species belonging to the genus DROSOPHILA. The proteins from the most intensely studied species of Drosophila, DROSOPHILA MELANOGASTER, are the subject of much interest in the area of MORPHOGENESIS and development.
The process in which substances, either endogenous or exogenous, bind to proteins, peptides, enzymes, protein precursors, or allied compounds. Specific protein-binding measures are often used as assays in diagnostic assessments.
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.
Established cell cultures that have the potential to propagate indefinitely.
The degree of similarity between sequences of amino acids. This information is useful for the analyzing genetic relatedness of proteins and species.
The intracellular transfer of information (biological activation/inhibition) through a signal pathway. In each signal transduction system, an activation/inhibition signal from a biologically active molecule (hormone, neurotransmitter) is mediated via the coupling of a receptor/enzyme to a second messenger system or to an ion channel. Signal transduction plays an important role in activating cellular functions, cell differentiation, and cell proliferation. Examples of signal transduction systems are the GAMMA-AMINOBUTYRIC ACID-postsynaptic receptor-calcium ion channel system, the receptor-mediated T-cell activation pathway, and the receptor-mediated activation of phospholipases. Those coupled to membrane depolarization or intracellular release of calcium include the receptor-mediated activation of cytotoxic functions in granulocytes and the synaptic potentiation of protein kinase activation. Some signal transduction pathways may be part of larger signal transduction pathways; for example, protein kinase activation is part of the platelet activation signal pathway.
Endogenous substances, usually proteins, which are effective in the initiation, stimulation, or termination of the genetic transcription process.
Variant forms of the same gene, occupying the same locus on homologous CHROMOSOMES, and governing the variants in production of the same gene product.
ANIMALS whose GENOME has been altered by GENETIC ENGINEERING, or their offspring.
Alterations or deviations from normal shape or size which result in a disfigurement of the foot occurring at or before birth.
A species of fruit fly much used in genetics because of the large size of its chromosomes.
The worsening of a disease over time. This concept is most often used for chronic and incurable diseases where the stage of the disease is an important determinant of therapy and prognosis.
Process of generating a genetic MUTATION. It may occur spontaneously or be induced by MUTAGENS.
The transmission and reproduction of transient images of fixed or moving objects. An electronic system of transmitting such images together with sound over a wire or through space by apparatus that converts light and sound into electrical waves and reconverts them into visible light rays and audible sound. (From Webster, 3rd ed)
Input/output devices designed to receive data in an environment associated with the job to be performed, and capable of transmitting entries to, and obtaining output from, the system of which it is a part. (Computer Dictionary, 4th ed.)
Any of the processes by which nuclear, cytoplasmic, or intercellular factors influence the differential control of gene action during the developmental stages of an organism.
A product of hard secondary xylem composed of CELLULOSE, hemicellulose, and LIGNANS, that is under the bark of trees and shrubs. It is used in construction and as a source of CHARCOAL and many other products.
Tumors or cancer of the LUNG.
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 articulation between a metatarsal bone (METATARSAL BONES) and a phalanx.
A genus of small, two-winged flies containing approximately 900 described species. These organisms are the most extensively studied of all genera from the standpoint of genetics and cytology.
Proteins obtained from the species SACCHAROMYCES CEREVISIAE. The function of specific proteins from this organism are the subject of intense scientific interest and have been used to derive basic understanding of the functioning similar proteins in higher eukaryotes.
The ratio of radiation dosages required to produce identical change based on a formula comparing other types of radiation with that of gamma or roentgen rays.
A test used to determine whether or not complementation (compensation in the form of dominance) will occur in a cell with a given mutant phenotype when another mutant genome, encoding the same mutant phenotype, is introduced into that cell.
A group of elongate elasmobranchs. Sharks are mostly marine fish, with certain species large and voracious.
Deliberate breeding of two different individuals that results in offspring that carry part of the genetic material of each parent. The parent organisms must be genetically compatible and may be from different varieties or closely related species.
Electrically neutral elementary particles found in all atomic nuclei except light hydrogen; the mass is equal to that of the proton and electron combined and they are unstable when isolated from the nucleus, undergoing beta decay. Slow, thermal, epithermal, and fast neutrons refer to the energy levels with which the neutrons are ejected from heavier nuclei during their decay.
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.
In vitro method for producing large amounts of specific DNA or RNA fragments of defined length and sequence from small amounts of short oligonucleotide flanking sequences (primers). The essential steps include thermal denaturation of the double-stranded target molecules, annealing of the primers to their complementary sequences, and extension of the annealed primers by enzymatic synthesis with DNA polymerase. The reaction is efficient, specific, and extremely sensitive. Uses for the reaction include disease diagnosis, detection of difficult-to-isolate pathogens, mutation analysis, genetic testing, DNA sequencing, and analyzing evolutionary relationships.
Single-stranded complementary DNA synthesized from an RNA template by the action of RNA-dependent DNA polymerase. cDNA (i.e., complementary DNA, not circular DNA, not C-DNA) is used in a variety of molecular cloning experiments as well as serving as a specific hybridization probe.
The most diversified of all fish orders and the largest vertebrate order. It includes many of the commonly known fish such as porgies, croakers, sunfishes, dolphin fish, mackerels, TUNA, etc.
Genes whose loss of function or gain of function MUTATION leads to the death of the carrier prior to maturity. They may be essential genes (GENES, ESSENTIAL) required for viability, or genes which cause a block of function of an essential gene at a time when the essential gene function is required for viability.
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.
Proteins which bind to DNA. The family includes proteins which bind to both double- and single-stranded DNA and also includes specific DNA binding proteins in serum which can be used as markers for malignant diseases.
The functional hereditary units of HELMINTHS.
A multistage process that includes cloning, physical mapping, subcloning, determination of the DNA SEQUENCE, and information analysis.
Mutagenesis where the mutation is caused by the introduction of foreign DNA sequences into a gene or extragenic sequence. This may occur spontaneously in vivo or be experimentally induced in vivo or in vitro. Proviral DNA insertions into or adjacent to a cellular proto-oncogene can interrupt GENETIC TRANSLATION of the coding sequences or interfere with recognition of regulatory elements and cause unregulated expression of the proto-oncogene resulting in tumor formation.
The arrangement of two or more amino acid or base sequences from an organism or organisms in such a way as to align areas of the sequences sharing common properties. The degree of relatedness or homology between the sequences is predicted computationally or statistically based on weights assigned to the elements aligned between the sequences. This in turn can serve as a potential indicator of the genetic relatedness between the organisms.
Inhaling and exhaling the smoke of burning TOBACCO.
A nitrosourea compound with alkylating, carcinogenic, and mutagenic properties.
Proteins which are found in membranes including cellular and intracellular membranes. They consist of two types, peripheral and integral proteins. They include most membrane-associated enzymes, antigenic proteins, transport proteins, and drug, hormone, and lectin receptors.
RNA sequences that serve as templates for protein synthesis. Bacterial mRNAs are generally primary transcripts in that they do not require post-transcriptional processing. Eukaryotic mRNA is synthesized in the nucleus and must be exported to the cytoplasm for translation. Most eukaryotic mRNAs have a sequence of polyadenylic acid at the 3' end, referred to as the poly(A) tail. The function of this tail is not known for certain, but it may play a role in the export of mature mRNA from the nucleus as well as in helping stabilize some mRNA molecules by retarding their degradation in the cytoplasm.
A form of interactive entertainment in which the player controls electronically generated images that appear on a video display screen. This includes video games played in the home on special machines or home computers, and those played in arcades.
A prediction of the probable outcome of a disease based on a individual's condition and the usual course of the disease as seen in similar situations.
The five long bones of the METATARSUS, articulating with the TARSAL BONES proximally and the PHALANGES OF TOES distally.
Proteins found in the nucleus of a cell. Do not confuse with NUCLEOPROTEINS which are proteins conjugated with nucleic acids, that are not necessarily present in the nucleus.
A layer of living cells between the bark and hardwood that each year produces additional wood and bark cells, forming concentric growth rings.
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)
Organs and other anatomical structures of non-human vertebrate and invertebrate animals.
Treatment of food with RADIATION.
The visual display of data in a man-machine system. An example is when data is called from the computer and transmitted to a CATHODE RAY TUBE DISPLAY or LIQUID CRYSTAL display.
Protein analogs and derivatives of the Aequorea victoria green fluorescent protein that emit light (FLUORESCENCE) when excited with ULTRAVIOLET RAYS. They are used in REPORTER GENES in doing GENETIC TECHNIQUES. Numerous mutants have been made to emit other colors or be sensitive to pH.
Alterations or deviations from normal shape or size which result in a disfigurement of the hand occurring at or before birth.
A genus of small free-living nematodes. Two species, CAENORHABDITIS ELEGANS and C. briggsae are much used in studies of genetics, development, aging, muscle chemistry, and neuroanatomy.
A genus of the Torpedinidae family consisting of several species. Members of this family have powerful electric organs and are commonly called electric rays.
The functional hereditary units of INSECTS.
Small double-stranded, non-protein coding RNAs (21-31 nucleotides) involved in GENE SILENCING functions, especially RNA INTERFERENCE (RNAi). Endogenously, siRNAs are generated from dsRNAs (RNA, DOUBLE-STRANDED) by the same ribonuclease, Dicer, that generates miRNAs (MICRORNAS). The perfect match of the siRNAs' antisense strand to their target RNAs mediates RNAi by siRNA-guided RNA cleavage. siRNAs fall into different classes including trans-acting siRNA (tasiRNA), repeat-associated RNA (rasiRNA), small-scan RNA (scnRNA), and Piwi protein-interacting RNA (piRNA) and have different specific gene silencing functions.
The restriction of a characteristic behavior, anatomical structure or physical system, such as immune response; metabolic response, or gene or gene variant to the members of one species. It refers to that property which differentiates one species from another but it is also used for phylogenetic levels higher or lower than the species.
The level of protein structure in which combinations of secondary protein structures (alpha helices, beta sheets, loop regions, and motifs) pack together to form folded shapes called domains. Disulfide bridges between cysteines in two different parts of the polypeptide chain along with other interactions between the chains play a role in the formation and stabilization of tertiary structure. Small proteins usually consist of only one domain but larger proteins may contain a number of domains connected by segments of polypeptide chain which lack regular secondary structure.
Devices, manned and unmanned, which are designed to be placed into an orbit about the Earth or into a trajectory to another celestial body. (NASA Thesaurus, 1988)
A cell line derived from cultured tumor cells.
Genes whose expression is easily detectable and therefore used to study promoter activity at many positions in a target genome. In recombinant DNA technology, these genes may be attached to a promoter region of interest.
A deoxyribonucleotide polymer that is the primary genetic material of all cells. Eukaryotic and prokaryotic organisms normally contain DNA in a double-stranded state, yet several important biological processes transiently involve single-stranded regions. DNA, which consists of a polysugar-phosphate backbone possessing projections of purines (adenine and guanine) and pyrimidines (thymine and cytosine), forms a double helix that is held together by hydrogen bonds between these purines and pyrimidines (adenine to thymine and guanine to cytosine).
Screens which absorb the energy in the x-ray beam that has penetrated the patient and convert this energy into a light pattern which has as nearly as possible the same information as the original x-ray beam. The more light a screen produces for a given input of x-radiation, the less x-ray exposure and thus shorter exposure time are needed to expose the film. In most film-screen systems, the film is sandwiched between two screens in a cassette so that the emulsion on each side is exposed to the light from its contiguous screen.
Short sequences (generally about 10 base pairs) of DNA that are complementary to sequences of messenger RNA and allow reverse transcriptases to start copying the adjacent sequences of mRNA. Primers are used extensively in genetic and molecular biology techniques.
Unstable isotopes of cesium that decay or disintegrate emitting radiation. Cs atoms with atomic weights of 123, 125-132, and 134-145 are radioactive cesium isotopes.
The development of anatomical structures to create the form of a single- or multi-cell organism. Morphogenesis provides form changes of a part, parts, or the whole organism.
Positively-charged atomic nuclei that have been stripped of their electrons. These particles have one or more units of electric charge and a mass exceeding that of the Helium-4 nucleus (alpha particle).
Gross hypo- or aplasia of one or more long bones of one or more limbs. The concept includes amelia, hemimelia, phocomelia, and sirenomelia.
The developmental entity of a fertilized egg (ZYGOTE) in animal species other than MAMMALS. For chickens, use CHICK EMBRYO.
A genetic rearrangement through loss of segments of DNA or RNA, bringing sequences which are normally separated into close proximity. This deletion may be detected using cytogenetic techniques and can also be inferred from the phenotype, indicating a deletion at one specific locus.
Stable cobalt atoms that have the same atomic number as the element cobalt, but differ in atomic weight. Co-59 is a stable cobalt isotope.
Linear POLYPEPTIDES that are synthesized on RIBOSOMES and may be further modified, crosslinked, cleaved, or assembled into complex proteins with several subunits. The specific sequence of AMINO ACIDS determines the shape the polypeptide will take, during PROTEIN FOLDING, and the function of the protein.
Parts of plants that usually grow vertically upwards towards the light and support the leaves, buds, and reproductive structures. (From Concise Dictionary of Biology, 1990)
Proteins obtained from the ZEBRAFISH. Many of the proteins in this species have been the subject of studies involving basic embryological development (EMBRYOLOGY).
Lateral displacement of the great toe (HALLUX), producing deformity of the first METATARSOPHALANGEAL JOINT with callous, bursa, or bunion formation over the bony prominence.
Chromosomal, biochemical, intracellular, and other methods used in the study of genetics.
A species of gram-negative, facultatively anaerobic, rod-shaped bacteria (GRAM-NEGATIVE FACULTATIVELY ANAEROBIC RODS) commonly found in the lower part of the intestine of warm-blooded animals. It is usually nonpathogenic, but some strains are known to produce DIARRHEA and pyogenic infections. Pathogenic strains (virotypes) are classified by their specific pathogenic mechanisms such as toxins (ENTEROTOXIGENIC ESCHERICHIA COLI), etc.
A procedure consisting of a sequence of algebraic formulas and/or logical steps to calculate or determine a given task.
Transport proteins that carry specific substances in the blood or across cell membranes.
Theoretical representations that simulate the behavior or activity of genetic processes or phenomena. They include the use of mathematical equations, computers, and other electronic equipment.
A plant species of the genus CHRYSANTHEMUM, family ASTERACEAE. The flowers contain PYRETHRINS, cinerolones, and chrysanthemines which are powerful contact insecticides. Most in the old Pyrethrum genus are reclassified to TANACETUM; some to other ASTERACEAE genera.
The process of finding chemicals for potential therapeutic use.
Determination of the energy distribution of gamma rays emitted by nuclei. (McGraw-Hill Dictionary of Scientific and Technical Terms, 4th ed)
Any of the processes by which nuclear, cytoplasmic, or intercellular factors influence the differential control (induction or repression) of gene action at the level of transcription or translation.