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octreotide
A potent, long-acting synthetic SOMATOSTATIN octapeptide analog that inhibits secretion of GROWTH HORMONE and is used to treat hormone-secreting tumors; DIABETES MELLITUS; HYPOTENSION, ORTHOSTATIC; HYPERINSULINISM; hypergastrinemia; and small bowel fistula.
ofloxacin
A synthetic fluoroquinolone antibacterial agent that inhibits the supercoiling activity of bacterial DNA GYRASE, halting DNA REPLICATION.
oils
Unctuous combustible substances that are liquid or easily liquefiable on warming, and are soluble in ether but insoluble in water. Such substances, depending on their origin, are classified as animal, mineral, or vegetable oils. Depending on their behavior on heating, they are volatile or fixed. (Dorland, 28th ed)
oils, volatile
Oils which evaporate readily. The volatile oils occur in aromatic plants, to which they give odor and other characteristics. Most volatile oils consist of a mixture of two or more TERPENES or of a mixture of an eleoptene (the more volatile constituent of a volatile oil) with a stearopten (the more solid constituent). T...
ointment bases
Various mixtures of fats, waxes, animal and plant oils and solid and liquid hydrocarbons; vehicles for medicinal substances intended for external application; there are four classes: hydrocarbon base, absorption base, water-removable base and water-soluble base; several are also emollients.
okadaic acid
A specific inhibitor of phosphoserine/threonine protein phosphatase 1 and 2a. It is also a potent tumor promoter. It is produced by DINOFLAGELLATES and causes diarrhetic SHELLFISH POISONING.
olanzapine
A benzodiazepine derivative that binds SEROTONIN RECEPTORS; MUSCARINIC RECEPTORS; HISTAMINE H1 RECEPTORS; ADRENERGIC ALPHA-1 RECEPTORS; and DOPAMINE RECEPTORS. It is an antipsychotic agent used in the treatment of SCHIZOPHRENIA; BIPOLAR DISORDER; and MAJOR DEPRESSIVE DISORDER; it may also reduce nausea and vomiting in ...
oleandomycin
Antibiotic macrolide produced by Streptomyces antibioticus.
oleanolic acid
A pentacyclic triterpene that occurs widely in many PLANTS as the free acid or the aglycone for many SAPONINS. It is biosynthesized from lupane. It can rearrange to the isomer, ursolic acid, or be oxidized to taraxasterol and amyrin.
oleic acid
An unsaturated fatty acid that is the most widely distributed and abundant fatty acid in nature. It is used commercially in the preparation of oleates and lotions, and as a pharmaceutical solvent. (Stedman, 26th ed)
oleic acids
A group of fatty acids that contain 18 carbon atoms and a double bond at the omega 9 carbon.
oligoclonal bands
Multiple protein bands serving as markers of specific ANTIBODIES and detected by ELECTROPHORESIS of CEREBROSPINAL FLUID or serum. The bands are most often seen during inflammatory or immune processes and are found in most patients with MULTIPLE SCLEROSIS.
oligodeoxyribonucleotides
A group of deoxyribonucleotides (up to 12) in which the phosphate residues of each deoxyribonucleotide act as bridges in forming diester linkages between the deoxyribose moieties.
oligodeoxyribonucleotides, antisense
Short fragments of DNA that are used to alter the function of target RNAs or DNAs to which they hybridize.
oligomycins
A closely related group of toxic substances elaborated by various strains of Streptomyces. They are 26-membered macrolides with lactone moieties and double bonds and inhibit various ATPases, causing uncoupling of phosphorylation from mitochondrial respiration. Used as tools in cytochemistry. Some specific oligomycins a...
oligonucleotide probes
Synthetic or natural oligonucleotides used in hybridization studies in order to identify and study specific nucleic acid fragments, e.g., DNA segments near or within a specific gene locus or gene. The probe hybridizes with a specific mRNA, if present. Conventional techniques used for testing for the hybridization produ...
oligonucleotides
Polymers made up of a few (2-20) nucleotides. In molecular genetics, they refer to a short sequence synthesized to match a region where a mutation is known to occur, and then used as a probe (OLIGONUCLEOTIDE PROBES). (Dorland, 28th ed)
oligonucleotides, antisense
Short fragments of DNA or RNA that are used to alter the function of target RNAs or DNAs to which they hybridize.
oligopeptides
Peptides composed of between two and twelve amino acids.
oligoribonucleotides
A group of ribonucleotides (up to 12) in which the phosphate residues of each ribonucleotide act as bridges in forming diester linkages between the ribose moieties.
oligoribonucleotides, antisense
Short fragments of RNA that are used to alter the function of target RNAs or DNAs to which they hybridize.
oligosaccharides
Carbohydrates consisting of between two (DISACCHARIDES) and ten MONOSACCHARIDES connected by either an alpha- or beta-glycosidic link. They are found throughout nature in both the free and bound form.
oligosaccharides, branched-chain
Oligosaccharides containing various types of glycosidic linkages that yield branching or antennae. The number of antennae (such as bi-, tri-, tetra-, or penta-antennary) in the oligosaccharides on the PROTEOGLYCANS; GLYCOPROTEINS; or LIPOPOLYSACCHARIDES contribute to their biological activities, such as receptor bindin...
olive oil
Oil extracted from fruit of the OLIVE TREE (genus Olea).
olivomycins
A mixture of several closely related glycosidic antibiotics obtained from Actinomyces (or Streptomyces) olivoreticuli. They are used as fluorescent dyes that bind to DNA and prevent both RNA and protein synthesis and are also used as antineoplastic agents.
olmesartan medoxomil
An ANGIOTENSIN II TYPE 1 RECEPTOR BLOCKER that is used to manage HYPERTENSION.
olopatadine hydrochloride
An antihistamine with mast-cell stabilizing properties used as eye drops in the treatment of ALLERGIC CONJUNCTIVITIS.
omega-agatoxin iva
A neuropeptide toxin from the venom of the funnel web spider, Agelenopsis aperta. It inhibits CALCIUM CHANNELS, P-TYPE by altering the voltage-dependent gating so that very large depolarizations are needed for channel opening. It also inhibits CALCIUM CHANNELS, Q-TYPE.
omega-chloroacetophenone
A potent eye, throat, and skin irritant. One of its uses is as a riot control agent.
omega-conotoxin gvia
A neurotoxic peptide, which is a cleavage product (VIa) of the omega-Conotoxin precursor protein contained in venom from the marine snail, CONUS geographus. It is an antagonist of CALCIUM CHANNELS, N-TYPE.
omega-conotoxins
A family of structurally related neurotoxic peptides from mollusk venom that inhibit voltage-activated entry of calcium into the presynaptic membrane. They selectively inhibit N-, P-, and Q-type calcium channels.
omega-n-methylarginine
A competitive inhibitor of nitric oxide synthetase.
omeprazole
A 4-methoxy-3,5-dimethylpyridyl, 5-methoxybenzimidazole derivative of timoprazole that is used in the therapy of STOMACH ULCERS and ZOLLINGER-ELLISON SYNDROME. The drug inhibits an H(+)-K(+)-EXCHANGING ATPASE which is found in GASTRIC PARIETAL CELLS.
oncostatin m
A cytokine with both pro- and anti-inflammatory actions that depend upon the cellular microenvironment. Oncostatin M is a 28 kDa monomeric glycoprotein that is similar in structure to LEUKEMIA INHIBITORY FACTOR. Its name derives from the the observation that it inhibited the growth of tumor cells and augmented the grow...
ondansetron
A competitive serotonin type 3 receptor antagonist. It is effective in the treatment of nausea and vomiting caused by cytotoxic chemotherapy drugs, including cisplatin, and has reported anxiolytic and neuroleptic properties.
onium compounds
Ions with the suffix -onium, indicating cations with coordination number 4 of the type RxA+ which are analogous to QUATERNARY AMMONIUM COMPOUNDS (H4N+). Ions include phosphonium R4P+, oxonium R3O+, sulfonium R3S+, chloronium R2Cl+
o-phthalaldehyde
A reagent that forms fluorescent conjugation products with primary amines. It is used for the detection of many biogenic amines, peptides, and proteins in nanogram quantities in body fluids.
ophthalmic solutions
Sterile solutions that are intended for instillation into the eye. It does not include solutions for cleaning eyeglasses or CONTACT LENS SOLUTIONS.
opiate alkaloids
Alkaloids found in OPIUM from PAPAVER and their derivatives that induce analgesic and narcotic effects by action upon OPIOID RECEPTORS.
opioid peptides
The endogenous peptides with opiate-like activity. The three major classes currently recognized are the ENKEPHALINS, the DYNORPHINS, and the ENDORPHINS. Each of these families derives from different precursors, proenkephalin, prodynorphin, and PRO-OPIOMELANOCORTIN, respectively. There are also at least three classes of...
opipramol
A tricyclic antidepressant with actions similar to AMITRIPTYLINE.
opium
The air-dried exudate from the unripe seed capsule of the opium poppy, Papaver somniferum, or its variant, P. album. It contains a number of alkaloids, but only a few - MORPHINE; CODEINE; and PAPAVERINE - have clinical significance. Opium has been used as an analgesic, antitussive, antidiarrheal, and antispasmodic.
opsins
Photosensitive proteins in the membranes of PHOTORECEPTOR CELLS such as the rods and the cones. Opsins have varied light absorption properties and are members of the G-PROTEIN-COUPLED RECEPTORS family. Their ligands are VITAMIN A-based chromophores.
oral sprays
Pharmacologic agents in the form of a mist or spray delivered into the body through the mouth.
orexin receptor antagonists
Substances that bind to and inhibit the action of OREXIN RECEPTORS. Drugs in this class have been used as SLEEP AIDS, PHARMACEUTICAL.
orexins
Neuropeptide hormones that play a role in regulating a variety of behavioral and physiological processes in response to motivational stimuli.
organically modified ceramics
Organic-inorganic hybrid polymers developed primarily for DENTAL RESTORATION. They typically contain a defined mixture of ORGANOSILICON COMPOUNDS; CERAMICS; and organic POLYMERS.
organic chemicals
A broad class of substances containing carbon and its derivatives. Many of these chemicals will frequently contain hydrogen with or without oxygen, nitrogen, sulfur, phosphorus, and other elements. They exist in either carbon chain or carbon ring form.
organocopper compounds
Organic compounds that contain COPPER as an integral part on the molecule.
organofluorophosphonates
A subclass of organophosphates that have a FLUORINE atom substituted for one of the OXYGEN atoms.
organogold compounds
Organic compounds that contain GOLD as an integral part of the molecule. Some are used as ANTIRHEUMATIC AGENTS. The term chrysotherapy derives from an ancient Greek term for gold.
organoiron compounds
Organic compounds that contain iron in carbon-to-iron chemical bond.
organomercury compounds
Organic compounds which contain mercury as an integral part of the molecule.
organometallic compounds
A class of compounds of the type R-M, where a C atom is joined directly to any other element except H, C, N, O, F, Cl, Br, I, or At. (Grant & Hackh's Chemical Dictionary, 5th ed)
organophosphates
Carbon-containing phosphoric acid derivatives. Included under this heading are compounds that have CARBON atoms bound to one or more OXYGEN atoms of the P(=O)(O)3 structure. Note that several specific classes of endogenous phosphorus-containing compounds such as NUCLEOTIDES; PHOSPHOLIPIDS; and PHOSPHOPROTEINS are liste...
organophosphonates
Carbon-containing phosphonic acid compounds. Included under this heading are compounds that have carbon bound to either OXYGEN atom or the PHOSPHOROUS atom of the (P=O)O2 structure.
organophosphorus compounds
Organic compounds that contain phosphorus as an integral part of the molecule. Included under this heading is broad array of synthetic compounds that are used as PESTICIDES and DRUGS.
organoplatinum compounds
Organic compounds which contain platinum as an integral part of the molecule.
organoselenium compounds
Organic compounds which contain selenium as an integral part of the molecule.
organosilicon compounds
Organic compounds that contain silicon as an integral part of the molecule.
organotechnetium compounds
Organic compounds that contain technetium as an integral part of the molecule. These compounds are often used as radionuclide imaging agents.
organothiophosphates
Carbon-containing thiophosphoric acid derivatives. Included under this heading are compounds that have carbon bound to either SULFUR atom, or the OXYGEN atom of the SPO3 core structure.
organothiophosphonates
Carbon-containing thiophosphonic acid compounds. Included under this heading are compounds that have carbon bound to either SULFUR atom, PHOSPHOROUS atom, or the OXYGEN atom of the SPO2 core structure.
organothiophosphorus compounds
Compounds containing carbon-phosphorus bonds in which the phosphorus component is also bonded to one or more sulfur atoms. Many of these compounds function as CHOLINERGIC AGENTS and as INSECTICIDES.
organotin compounds
Organic compounds which contain tin in the molecule. Used widely in industry and agriculture.
orlistat
A lactone derivative of LEUCINE that acts as a pancreatic lipase inhibitor to limit the absorption of dietary fat; it is used in the management of obesity.
ornidazole
A nitroimidazole antiprotozoal agent used in ameba and trichomonas infections. It is partially plasma-bound and also has radiation-sensitizing action.
ornipressin
A synthetic analog of vasopressin with ORNITHINE substitution at residue 8 of the cyclic nonapeptide. It is used as a local vasoconstrictor and hemostatic.
ornithine
An amino acid produced in the urea cycle by the splitting off of urea from arginine.
ornithine decarboxylase inhibitors
Substances and drugs that inhibit or block the activity of ORNITHINE DECARBOXYLASE.
orotic acid
An intermediate product in PYRIMIDINE synthesis which plays a role in chemical conversions between DIHYDROFOLATE and TETRAHYDROFOLATE.
orphenadrine
A muscarinic antagonist used to treat drug-induced parkinsonism and to relieve pain from muscle spasm.
ortho-aminobenzoates
Benzoic acids, salts, or esters that contain an amino group attached to carbon number 2 or 6 of the benzene ring structure.
oseltamivir
An acetamido cyclohexene that is a structural homolog of SIALIC ACID and inhibits NEURAMINIDASE.
osmium
A very hard, gray, toxic, and nearly infusible metal element, atomic number 76, atomic weight 190.2, symbol Os.
osmium compounds
Inorganic compounds that contain osmium as an integral part of the molecule.
osmium tetroxide
(T-4)-Osmium oxide (OsO4). A highly toxic and volatile oxide of osmium used in industry as an oxidizing agent. It is also used as a histological fixative and stain and as a synovectomy agent in arthritic joints. Its vapor can cause eye, skin, and lung damage.
osteopontin
A negatively-charged extracellular matrix protein that plays a role in the regulation of BONE metabolism and a variety of other biological functions. Cell signaling by osteopontin may occur through a cell adhesion sequence that recognizes INTEGRIN ALPHA-V BETA-3.
ouabain
A cardioactive glycoside consisting of rhamnose and ouabagenin, obtained from the seeds of Strophanthus gratus and other plants of the Apocynaceae; used like DIGITALIS. It is commonly used in cell biological studies as an inhibitor of the NA(+)-K(+)-EXCHANGING ATPASE.
ovalbumin
An albumin obtained from the white of eggs. It is a member of the serpin superfamily.
ox40 ligand
A membrane-bound tumor necrosis family member that is expressed on activated antigen-presenting cells such as B-LYMPHOCYTES and MACROPHAGES. It signals T-LYMPHOCYTES by binding the OX40 RECEPTOR.
oxacillin
An antibiotic similar to FLUCLOXACILLIN used in resistant staphylococci infections.
oxadiazoles
Compounds containing five-membered heteroaromatic rings containing two carbons, two nitrogens, and one oxygen atom which exist in various regioisomeric forms.
oxalates
Derivatives of OXALIC ACID. Included under this heading are a broad variety of acid forms, salts, esters, and amides that are derived from the ethanedioic acid structure.
oxalic acid
A strong dicarboxylic acid occurring in many plants and vegetables. It is produced in the body by metabolism of glyoxylic acid or ascorbic acid. It is not metabolized but excreted in the urine. It is used as an analytical reagent and general reducing agent.
oxaliplatin
An organoplatinum complex in which the platinum atom is complexed with 1,2-diaminocyclohexane, and with an oxalate ligand which is displaced to yield active oxaliplatin derivatives. These derivatives form inter- and intra-strand DNA crosslinks that inhibit DNA replication and transcription. Oxaliplatin is an antineopla...
oxaloacetates
Derivatives of OXALOACETIC ACID. Included under this heading are a broad variety of acid forms, salts, esters, and amides that include a 2-keto-1,4-carboxy aliphatic structure.
oxaloacetic acid
A dicarboxylic acid ketone that is an important metabolic intermediate of the CITRIC ACID CYCLE. It can be converted to ASPARTIC ACID by ASPARTATE TRANSAMINASE.
oxamic acid
Amino-substituted glyoxylic acid derivative.
oxamniquine
An anthelmintic with schistosomicidal activity against Schistosoma mansoni, but not against other Schistosoma spp. Oxamniquine causes worms to shift from the mesenteric veins to the liver where the male worms are retained; the female worms return to the mesentery, but can no longer release eggs. (From Martindale, The E...
oxandrolone
A synthetic hormone with anabolic and androgenic properties.
oxaprozin
An oxazole-propionic acid derivative, cyclooxygenase inhibitor, and non-steroidal anti-inflammatory drug that is used in the treatment of pain and inflammation associated with of OSTEOARTHRITIS; RHEUMATOID ARTHRITIS; and ARTHRITIS, JUVENILE.
oxazepam
A benzodiazepine used in the treatment of anxiety, alcohol withdrawal, and insomnia.
oxazines
Six-membered heterocycles containing an oxygen and a nitrogen.
oxazocines
One ring heterocyclic compounds defined by C6H7NO. Permitted are any degree of hydrogenation, any substituents and any ortho-fused or ortho-peri-fused ring systems.
oxazoles
Five-membered heterocyclic ring structures containing an oxygen in the 1-position and a nitrogen in the 3-position, in distinction from ISOXAZOLES where they are at the 1,2 positions.
oxazolidinones
Derivatives of oxazolidin-2-one. They represent an important class of synthetic antibiotic agents.
oxazolone
Immunologic adjuvant and sensitizing agent.
oxcarbazepine
A carbamazepine derivative that acts as a voltage-gated sodium channel blocker. It is used for the treatment of PARTIAL SEIZURES with or without secondary generalization. It is also an inducer of CYTOCHROME P-450 CYP3A4.
oxepins
Compounds based on a 7-membered heterocyclic ring including an oxygen. They can be considered a medium ring ether. A natural source is the MONTANOA plant genus. Some dibenzo-dioxepins, called depsidones, are found in GARCINIA plants.