|Medical Dictionary - Dictionary of Medicine and Human Biology|
θ, upper case Θ
Tonsillectomy and adenoidectomy
any of several proteins that are produced by some tumorigenic DNA viruses (as simian virus 40) when they infect cells and that function in the transformation of normal cells into tumor cells or into tumor-forming cells and in the unwinding and replication of the DNA of the virus
any of several lymphocytes (as a helper T cell) that differentiate in the thymus, possess highly specific cell-surface antigen receptors, and include some that control the initiation or suppression of cell-mediated and humoral immunity (as by the regulation of T and B cell maturation and proliferation) and others that lyse antigen-bearing cells. Also called T lymphocyte
T suppressor cell
Suppressor T cell
the system of T tubules in striated muscle
t-butoxycarbonyl (BOC, t-BOC, Boc) (bu-toks-e-kar′bon-il)
An amino-protecting group used in peptide synthesis. SYN: tert-butyloxycarbonyl.
tert-butyloxycarbonyl (tBoc) (bu′til-oks′e-kar′bon-il)
In magnetic resonance, the time for 63% of longitudinal relaxation to occur; the value is a function of magnetic field strength and the chemical environment of the hydrogen nucleus; for protons in fat and in water, in a 1.5T magnet, about 250 msec and 3000 msec, respectively. A T.-weighted image will have a bright fat signal.
In magnetic resonance, the time for 63% of transverse relaxation to occur; the value is a function of magnetic field strength and the chemical environment of the hydrogen nucleus; for protons in fat and in water, in a 1.5T magnet, about 60 msec and 250 msec respectively. A T.-weighted image will have a bright water signal.
Abbreviation for (2,4,5-trichlorophenoxy)acetic acid.
Symbol for temperature midpoint (kelvin); melting point.
Symbol for 3,5,3′-triiodothyronine.
Symbol for thyroxine.
Abbreviation for metric ton; time.
Symbol for temperature (Celsius); tritium.
Symbol for temperature midpoint (Celsius).
Abbreviation for Terminologia Anatomica.
Symbol for tantalum.
Common name for flies of the family Tabanidae. [L. tabanus, gadfly]
A family of bloodsucking flies that includes the genera Tabanus (horsefly) and Chrysops (deerfly and mango fly), which are involved in transmission of several blood-borne parasites. [L. tabanus, gadfly]
The gadflies and horseflies; a genus of biting flies, some species of which transmit surra, infectious equine anemia, anthrax, and other diseases. [L. a gadfly]
Mexican term for typhus. [Sp., fr. L.L. tabardilii, pustules]
tabatière anatomique (tab-ah-te-ar′ an-ah-to-mek′)
SYN: anatomic snuffbox. [Fr. snuffbox]
tabella, pl .tabellae (ta-bel′la, -le)
A medicated tablet or lozenge. [L. dim. of tabula, tablet]
Progressive wasting or emaciation. [L. a wasting away] t. infantum t. in infants with congenital syphilis. t. mesenterica tuberculosis of the mesenteric and retroperitoneal lymph nodes.
The state of progressive wasting away.
Characteristic of tabes. [L. tabesco, to waste away, fr. tabes, a wasting away]
Relating to or suffering from tabes, especially tabes dorsalis. SYN: tabic, tabid.
Resembling tabes, especially tabes dorsalis. [irreg. formed fr. L. tabes, a wasting, + forma, form]
SYN: tabetic. [L. tabidus, wasting away]
The state of division of the cranial bones into two plates separated by the diploë. [L. tabula, tablet]
A large spoon, used as a measure of the dose of a medicine, equivalent to about 4 fluidrams or 12 fluidounce or 15 ml.
taboo, tabu (ta-boo′)
Restricted, prohibited, or forbidden; set apart for religious or ceremonial purposes. [Tongan, set apart]
1. Tablelike. 2. Arranged in the form of a table (2). [L. tabularis, fr. tabula, table]
SYN: tablet. [L. tabula]
An extremely potent cholinesterase inhibitor; the lethal dose for humans is believed to be as low as 0.01 mg/kg; median lethal dosage (respiratory) is about 40 mg/min/m3 for resting persons.
A 55-kD polypeptide that is the one of the two chains that comprise the IL-2 receptor.
A circumscribed discoloration of the skin or mucous membrane, such as a macule or freckle. [Fr. spot] t. blanche SYN: macula albida. t. laiteuse 1. SYN: milk spots, under spot. 2. SYN: macula albida. [Fr., milky spot]
An instrument to determine the shortest time an object must be exposed in order to be perceived. [G. tachistos, very rapid, fr. tachys, rapid, + skopeo, to view]
Record made by a tachometer. [G. tachos, speed, + gramma, mark]
A tachometer designed to provide a continuous record of speed or rate. [G. tachos, speed, + grapho, to write]
The recording of speed or rate. [G. tachos, speed, + grapho, to write]
An instrument for measuring speed or rate; e.g., revolutions of a shaft, heart rate (cardiotachometer), arterial blood flow (hemotachometer), respiratory gas flow (pneumotachometer). [G. tachos, speed, + metron, measure]
Rapid. [G. tachys, quick]
Any disturbance of the heart's rhythm, regular or irregular, resulting by convention in a rate over 100 beats/min during physical examination. [tachy- + G. a- priv. + rhythmos, rhythm]
Type of growth in which a part grows more rapidly than the whole. [tachy- + G. auxo, to increase]
Relating to or suffering from excessively rapid action of the heart.
Relating to rapid heart rate.
Relating to, causing, or characterized by a rapid pulse. [tachy- + G. krotos, a striking]
Any member of a group of polypeptides, widely scattered in vertebrate and invertebrate tissues, that have in common four of the five terminal amino acids: Phe–Xaa–Gly–Leu–Met–NH2; pharmacologically, they all cause hypotension in mammals, contraction of gut and bladder smooth muscle, and secretion of saliva. [G. tachys, swift, + kineo, to move, + -in]
Rapid pacing of the heart by an artificial electronic pacemaker operating faster than the basic cardiac rate.
Rapid appearance of progressive decrease in response to a given dose following repetitive administration of a pharmacologically or physiologically active substance. [tachy- + G. phylaxis, protection]
Rapid breathing. SYN: polypnea. [tachy- + G. pnoe (pnoie), breathing] transient t. of the newborn a syndrome of generally mild t. in otherwise healthy newborns, lasting usually only about 3 days. SYN: respiratory distress syndrome type II.
SYN: tachycardia. [tachy- + G. rhythmos, rhythm]
Sterol(s) formed by ultraviolet irradiation of any 5,7-diene-3β-sterol, which breaks the 9,10 bond, but usually from either or both of ergosterol and lumisterol to produce t.2 (ertacalciol, (6E,22E)-9,10-secoergosta-5(10),6,8,22-tetraen-3β-ol) and from 7-dehydrocholesterol to produce t.3 (tacalciol, (6E,3S)-9,10-secocholesta-5(10),6,8-trien-3β-ol). When reduced to the 5,7-diene (or 5,7,22-triene) form, dihydrotachysterol3 (10,19-dihydrocalciol) or dihydrotachysterol2 (10,19-dihydroercalciol), antirachitic action appears. This property has been of therapeutic interest, but t. is being replaced by the true vitamin D hormone (calcitriol) and its derivatives.
SYN: tachycardia. [tachy- + G. systole, contracting]
A rapidly multiplying stage in the development of the tissue phase of certain coccidial infections, as in Toxoplasma gondii development in acute infections of toxoplasmosis. [tachy- + G. zoon, animal]
An anticholinesterase agent with nonspecific central nervous system stimulatory effects; used in early stages of Alzheimer disease.
Relating to touch or to the sense of touch. [L. tactilis, fr. tango, pp. tactus, to touch]
1. The sense of touch. 2. The act of touching. [L. tactio, fr. tango, pp. tactus, to touch]
SYN: esthesiometer. [L. tactus, touch, + G. metron, measure]
tactor (tak′tar, -tor)
A tactile end organ. [L. one who or that which touches]
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