Sulfur Radioisotopes
Unstable isotopes of sulfur that decay or disintegrate spontaneously emitting radiation. S 29-31, 35, 37, and 38 are radioactive sulfur isotopes.
Sulfur
An element that is a member of the chalcogen family. It has an atomic symbol S, atomic number 16, and atomic weight [32.059; 32.076]. It is found in the amino acids cysteine and methionine.
Radioisotopes
Isotopes that exhibit radioactivity and undergo radioactive decay. (From Grant & Hackh's Chemical Dictionary, 5th ed & McGraw-Hill Dictionary of Scientific and Technical Terms, 4th ed)
Zinc Radioisotopes
Unstable isotopes of zinc that decay or disintegrate emitting radiation. Zn atoms with atomic weights 60-63, 65, 69, 71, and 72 are radioactive zinc isotopes.
Sulfur Compounds
Inorganic or organic compounds that contain sulfur as an integral part of the molecule.
Radioisotope Dilution Technique
Strontium Radioisotopes
Sulfur Dioxide
Sulfur Isotopes
Stable sulfur atoms that have the same atomic number as the element sulfur, but differ in atomic weight. S-33, 34, and 36 are stable sulfur isotopes.
Iodine Radioisotopes
Amino Acids, Sulfur
'Sulfur-containing amino acids' are a category of amino acids, the building blocks of proteins, that include methionine and cysteine, which contain sulfur atoms as part of their side chains, playing crucial roles in protein structure, enzyme function, and antioxidant defense.
Krypton Radioisotopes
Indium Radioisotopes
Sodium Radioisotopes
Radioactivity
Barium Radioisotopes
Radionuclide Imaging
The production of an image obtained by cameras that detect the radioactive emissions of an injected radionuclide as it has distributed differentially throughout tissues in the body. The image obtained from a moving detector is called a scan, while the image obtained from a stationary camera device is called a scintiphotograph.
Yttrium Radioisotopes
Tin Radioisotopes
Unstable isotopes of tin that decay or disintegrate emitting radiation. Sn atoms with atomic weights 108-111, 113, 120-121, 123 and 125-128 are tin radioisotopes.
Carbon Radioisotopes
Unstable isotopes of carbon that decay or disintegrate emitting radiation. C atoms with atomic weights 10, 11, and 14-16 are radioactive carbon isotopes.
Mustard Gas
Severe irritant and vesicant of skin, eyes, and lungs. It may cause blindness and lethal lung edema and was formerly used as a war gas. The substance has been proposed as a cytostatic and for treatment of psoriasis. It has been listed as a known carcinogen in the Fourth Annual Report on Carcinogens (NTP-85-002, 1985) (Merck, 11th ed).
Iron Radioisotopes
Technetium
The first artificially produced element and a radioactive fission product of URANIUM. Technetium has the atomic symbol Tc, atomic number 43, and atomic weight 98.91. All technetium isotopes are radioactive. Technetium 99m (m=metastable) which is the decay product of Molybdenum 99, has a half-life of about 6 hours and is used diagnostically as a radioactive imaging agent. Technetium 99 which is a decay product of technetium 99m, has a half-life of 210,000 years.
Copper Radioisotopes
Phosphorus Radioisotopes
Unstable isotopes of phosphorus that decay or disintegrate emitting radiation. P atoms with atomic weights 28-34 except 31 are radioactive phosphorus isotopes.
Sulfides
Technetium Tc 99m Sulfur Colloid
A gamma-emitting radionuclide imaging agent used for the diagnosis of diseases in many tissues, particularly in the gastrointestinal system, liver, and spleen.
Mercury Radioisotopes
Cesium Isotopes
Sulfur Oxides
Inorganic oxides of sulfur.
Cerium Radioisotopes
Cobalt Isotopes
Hafnium
Isotope Labeling
Techniques for labeling a substance with a stable or radioactive isotope. It is not used for articles involving labeled substances unless the methods of labeling are substantively discussed. Tracers that may be labeled include chemical substances, cells, or microorganisms.
Gold Radioisotopes
Lead Radioisotopes
Diagnostic Techniques, Radioisotope
Any diagnostic evaluation using radioactive (unstable) isotopes. This diagnosis includes many nuclear medicine procedures as well as radioimmunoassay tests.
Zinc Isotopes
Stable zinc atoms that have the same atomic number as the element zinc, but differ in atomic weight. Zn-66-68, and 70 are stable zinc isotopes.
Cadmium Radioisotopes
Astatine
Radioimmunotherapy
Radiotherapy where cytotoxic radionuclides are linked to antibodies in order to deliver toxins directly to tumor targets. Therapy with targeted radiation rather than antibody-targeted toxins (IMMUNOTOXINS) has the advantage that adjacent tumor cells, which lack the appropriate antigenic determinants, can be destroyed by radiation cross-fire. Radioimmunotherapy is sometimes called targeted radiotherapy, but this latter term can also refer to radionuclides linked to non-immune molecules (see RADIOTHERAPY).
Lutetium
Radiopharmaceuticals
Samarium
Soil Pollutants, Radioactive
Pollutants, present in soil, which exhibit radioactivity.
Bromine Radioisotopes
Chlorobi
A phylum of anoxygenic, phototrophic bacteria including the family Chlorobiaceae. They occur in aquatic sediments, sulfur springs, and hot springs and utilize reduced sulfur compounds instead of oxygen.
Scintillation Counting
Subdural Effusion
Calcium Isotopes
Stable calcium atoms that have the same atomic number as the element calcium, but differ in atomic weight. Ca-42-44, 46, and 48 are stable calcium isotopes.
Radioactive Waste
Liquid, solid, or gaseous waste resulting from mining of radioactive ore, production of reactor fuel materials, reactor operation, processing of irradiated reactor fuels, and related operations, and from use of radioactive materials in research, industry, and medicine. (McGraw-Hill Dictionary of Scientific and Technical Terms, 4th ed)
Tungsten
Tungsten. A metallic element with the atomic symbol W, atomic number 74, and atomic weight 183.85. It is used in many manufacturing applications, including increasing the hardness, toughness, and tensile strength of steel; manufacture of filaments for incandescent light bulbs; and in contact points for automotive and electrical apparatus.
Serum Albumin, Radio-Iodinated
Normal human serum albumin mildly iodinated with radioactive iodine (131-I) which has a half-life of 8 days, and emits beta and gamma rays. It is used as a diagnostic aid in blood volume determination. (from Merck Index, 11th ed)
Oxidoreductases Acting on Sulfur Group Donors
Oxidoreductases with specificity for oxidation or reduction of SULFUR COMPOUNDS.
Selenium Radioisotopes
Ruthenium Radioisotopes
Sulfur Hexafluoride
Sulfur hexafluoride. An inert gas used mainly as a test gas in respiratory physiology. Other uses include its injection in vitreoretinal surgery to restore the vitreous chamber and as a tracer in monitoring the dispersion and deposition of air pollutants.
Radiometric Dating
Techniques used to determine the age of materials, based on the content and half-lives of the RADIOACTIVE ISOTOPES they contain.
Isotopes
Alpha Particles
Positively charged particles composed of two protons and two NEUTRONS, i.e. equivalent to HELIUM nuclei, which are emitted during disintegration of heavy ISOTOPES. Alpha rays have very strong ionizing power, but weak penetrability.
Chromatiaceae
Heterocyclic Compounds, 1-Ring
Sodium Pertechnetate Tc 99m
A gamma-emitting radionuclide imaging agent used for the diagnosis of diseases in many tissues, particularly in the gastrointestinal system, cardiovascular and cerebral circulation, brain, thyroid, and joints.
Chemical Warfare Agents
Radioisotope Teletherapy
Tissue Distribution
Accumulation of a drug or chemical substance in various organs (including those not relevant to its pharmacologic or therapeutic action). This distribution depends on the blood flow or perfusion rate of the organ, the ability of the drug to penetrate organ membranes, tissue specificity, protein binding. The distribution is usually expressed as tissue to plasma ratios.
Pentetic Acid
An iron chelating agent with properties like EDETIC ACID. DTPA has also been used as a chelator for other metals, such as plutonium.
Spectrometry, Gamma
Sulfurtransferases
Enzymes which transfer sulfur atoms to various acceptor molecules. EC 2.8.1.
Rosaniline Dyes
Nuclear Medicine
Technetium Tc 99m Pentetate
A technetium imaging agent used in renal scintigraphy, computed tomography, lung ventilation imaging, gastrointestinal scintigraphy, and many other procedures which employ radionuclide imaging agents.
Sulfur Acids
Inorganic or organic acids that contain sulfur as an integral part of the molecule.
Tritium
Tritium is an isotope of hydrogen (specifically, hydrogen-3) that contains one proton and two neutrons in its nucleus, making it radioactive with a half-life of about 12.3 years, and is used in various applications including nuclear research, illumination, and dating techniques due to its low energy beta decay.
Radiometry
The measurement of radiation by photography, as in x-ray film and film badge, by Geiger-Mueller tube, and by SCINTILLATION COUNTING.
Carbon Isotopes
Nostoc commune
A form species of spore-producing CYANOBACTERIA, in the family Nostocaceae, order Nostocales. It is an important source of fixed NITROGEN in nutrient-depleted soils. When wet, it appears as a jelly-like mass.
Cysteine
A thiol-containing non-essential amino acid that is oxidized to form CYSTINE.
Whole-Body Counting
Measurement of radioactivity in the entire human body.
Chlorobium
Potassium Radioisotopes
Hydrogen Sulfide
Oxidation-Reduction
A chemical reaction in which an electron is transferred from one molecule to another. The electron-donating molecule is the reducing agent or reductant; the electron-accepting molecule is the oxidizing agent or oxidant. Reducing and oxidizing agents function as conjugate reductant-oxidant pairs or redox pairs (Lehninger, Principles of Biochemistry, 1982, p471).
Iodohippuric Acid
Chromatium
A genus of gram-negative, ovoid to rod-shaped bacteria that is phototrophic. All species use ammonia as a nitrogen source. Some strains are found only in sulfide-containing freshwater habitats exposed to light while others may occur in marine, estuarine, and freshwater environments.
Organometallic Compounds
Iron
Radiation Dosage
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).
Positron-Emission Tomography
An imaging technique using compounds labelled with short-lived positron-emitting radionuclides (such as carbon-11, nitrogen-13, oxygen-15 and fluorine-18) to measure cell metabolism. It has been useful in study of soft tissues such as CANCER; CARDIOVASCULAR SYSTEM; and brain. SINGLE-PHOTON EMISSION-COMPUTED TOMOGRAPHY is closely related to positron emission tomography, but uses isotopes with longer half-lives and resolution is lower.
Acidithiobacillus
A genus of gram-negative rod-shaped bacteria in the class GAMMAPROTEOBACTERIA. They are obligately acidophilic and aerobic, using reduced SULFUR COMPOUNDS to support AUTOTROPHIC GROWTH.
Sentinel Lymph Node Biopsy
Vitamin B 12
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.
Molecular Sequence Data
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.
Sulfonium Compounds
Sulfur compounds in which the sulfur atom is attached to three organic radicals and an electronegative element or radical.
Absorption
Cysteine Synthase
An enzyme that catalyzes the biosynthesis of cysteine in microorganisms and plants from O-acetyl-L-serine and hydrogen sulfide. This enzyme was formerly listed as EC 4.2.99.8.
Technetium Tc 99m Medronate
A gamma-emitting radionuclide imaging agent used primarily in skeletal scintigraphy. Because of its absorption by a variety of tumors, it is useful for the detection of neoplasms.
Sulfur-Reducing Bacteria
A group of gram-negative, anaerobic bacteria that is able to oxidize acetate completely to carbon dioxide using elemental sulfur as the electron acceptor.
Phosphorus Isotopes
Avidin
Iron-Sulfur Proteins
A group of proteins possessing only the iron-sulfur complex as the prosthetic group. These proteins participate in all major pathways of electron transport: photosynthesis, respiration, hydroxylation and bacterial hydrogen and nitrogen fixation.
Cesium Radioisotopes
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.
Brachytherapy
Thiosulfate Sulfurtransferase
An enzyme that catalyzes the transfer of the planetary sulfur atom of thiosulfate ion to cyanide ion to form thiocyanate ion. EC 2.8.1.1.
Iridium Radioisotopes
Autoradiography
Hydrogensulfite Reductase
An enzyme found primarily in SULFUR-REDUCING BACTERIA where it plays an important role in the anaerobic carbon oxidation pathway.
Mass Spectrometry
Thiobacillus
A genus of gram-negative, rod-shaped bacteria that derives energy from the oxidation of one or more reduced sulfur compounds. Many former species have been reclassified to other classes of PROTEOBACTERIA.
Sulfur Group Transferases
Zinc
A metallic element of atomic number 30 and atomic weight 65.38. It is a necessary trace element in the diet, forming an essential part of many enzymes, and playing an important role in protein synthesis and in cell division. Zinc deficiency is associated with ANEMIA, short stature, HYPOGONADISM, impaired WOUND HEALING, and geophagia. It is known by the symbol Zn.
Evaluation Studies as Topic
Air Pollutants
Thiotrichaceae
Cystine
Epsilonproteobacteria
Sulfate Adenylyltransferase
Cystathionine gamma-Lyase
Half-Life
Octreotide
Gammaproteobacteria
Acidianus
A genus of facultatively anaerobic coccoid ARCHAEA, in the family SULFOLOBACEAE. Cells are highly irregular in shape and thermoacidophilic. Lithotrophic growth occurs aerobically via sulfur oxidation in some species. Distribution includes solfataric springs and fields, mudholes, and geothermically heated acidic marine environments.
Sensitivity and Specificity
Cobalt Radioisotopes
Unstable isotopes of cobalt that decay or disintegrate emitting radiation. Co atoms with atomic weights of 54-64, except 59, are radioactive cobalt isotopes.
Liver
Tomography, Emission-Computed
Air Pollution
The presence of contaminants or pollutant substances in the air (AIR POLLUTANTS) that interfere with human health or welfare, or produce other harmful environmental effects. The substances may include GASES; PARTICULATE MATTER; or volatile ORGANIC CHEMICALS.
Phototrophic Processes
Processes by which phototrophic organisms use sunlight as their primary energy source. Contrasts with chemotrophic processes which do not depend on light and function in deriving energy from exogenous chemical sources. Photoautotrophy (or photolithotrophy) is the ability to use sunlight as energy to fix inorganic nutrients to be used for other organic requirements. Photoautotrophs include all GREEN PLANTS; GREEN ALGAE; CYANOBACTERIA; and green and PURPLE SULFUR BACTERIA. Photoheterotrophs or photoorganotrophs require a supply of organic nutrients for their organic requirements but use sunlight as their primary energy source; examples include certain PURPLE NONSULFUR BACTERIA. Depending on environmental conditions some organisms can switch between different nutritional modes (AUTOTROPHY; HETEROTROPHY; chemotrophy; or phototrophy) to utilize different sources to meet their nutrients and energy requirements.
Nitrogen
An element with the atomic symbol N, atomic number 7, and atomic weight [14.00643; 14.00728]. Nitrogen exists as a diatomic gas and makes up about 78% of the earth's atmosphere by volume. It is a constituent of proteins and nucleic acids and found in all living cells.
Molybdenum
Geologic Sediments
A mass of organic or inorganic solid fragmented material, or the solid fragment itself, that comes from the weathering of rock and is carried by, suspended in, or dropped by air, water, or ice. It refers also to a mass that is accumulated by any other natural agent and that forms in layers on the earth's surface, such as sand, gravel, silt, mud, fill, or loess. (McGraw-Hill Dictionary of Scientific and Technical Terms, 4th ed, p1689)
RNA, Ribosomal, 16S
Receptors, Somatostatin
Cell surface proteins that bind somatostatin and trigger intracellular changes which influence the behavior of cells. Somatostatin is a hypothalamic hormone, a pancreatic hormone, and a central and peripheral neurotransmitter. Activated somatostatin receptors on pituitary cells inhibit the release of growth hormone; those on endocrine and gastrointestinal cells regulate the absorption and utilization of nutrients; and those on neurons mediate somatostatin's role as a neurotransmitter.
Lyases
Arylsulfatases
Enzymes that catalyze the hydrolysis of a phenol sulfate to yield a phenol and sulfate. Arylsulfatase A, B, and C have been separated. A deficiency of arylsulfatases is one of the causes of metachromatic leukodystrophy (LEUKODYSTROPHY, METACHROMATIC). EC 3.1.6.1.