|Medical Dictionary - Dictionary of Medicine and Human Biology|
Rotary displacement of the heart around its axis. [G. trochos, wheel, + kardia, heart]
Revolving; rotating; denoting a revolving or wheel-like articulation. [G. trochodes, fr. trochos, wheel, + eidos, resemblance]
Combined trochocardia and horizocardia.
An insulin sensitizer used with a sulfonylurea or insulin to improve glycemic control.
Troglotrema salmincola (trog-lo-tre′ma sal-mingk′o-la)
SYN: Nanophyetus salmincola.
Charles Émile, French physician, 1844–1919. See T. ganglion, T. node.
USAN-approved contraction for triethanolamine, N(CH2CH2OH)3.
L.T., U.S. physicist, 1889–1932. See t..
A unit of visual stimulation at the retina equal to the illumination per square millimeter of pupil received from a surface of 1 lux brightness.
Paulin, French anatomist, 1842–1910. See T. vein.
The triacetyl ester of oleandomycin, a macrolide antibiotic, with a potency of not less than 760 μg per mg; an orally effective antibiotic for infections produced by Gram-positive, penicillin-resistant bacteria. SYN: triacetyloleandomycin.
trolnitrate phosphate (trol-ni′trat)
An organic nitrate with mild but persistent vasodilator action on smooth muscle of the smaller vessels of postarteriolar vascular beds; used to prevent attacks of angina pectoris.
Anton F. von, German otologist, 1829–1890. See T. corpuscles, under corpuscle, T. pockets, under pocket, T. recesses, under recess.
The chigger mite, a genus of mites (family Trombiculidae) whose larvae (chiggers, red bugs) include pests of humans and other animals, and vectors of rickettsial diseases. T. akamushi SYN: Leptotrombidium akamushi. T. alfreddugesi a mite species common in second growth and grassy brush areas of the Americas; the larvae attack humans (as well as reptiles, birds, and wild and domestic mammals), causing an intensely itching dermatitis. T. deliensis See Leptotrombidium akamushi.
Infestation by mites of the genus Trombicula.
Common name for members of the family Trombiculidae.
A family of mites whose larvae (redbugs, rougets, harvest mites, scrub mites, or chiggers) are parasitic on vertebrates and whose nymphs and adults are bright red and free-living, living on insect eggs or minute organisms in the soil. The six-legged larvae are barely visible red or orange parasites that attach to the skin for a few days to a month, producing an exceedingly irritating reaction. In the Orient, trombiculid chiggers of the genus Leptotrombidium transmit tsutsugamushi disease, caused by Rickettsia tsutsugamushi, which is transovarially transmitted in these mites.
A family of mites that formerly included the subfamily Trombiculinae, now raised to the family Trombiculidae (including the vectors of tsutsugamushi disease). T. larvae are characteristically parasitic on insects, not on vertebrates as with the larvae of Trombiculidae.
A weakly basic compound used as an alkalizing agent and as a buffer in enzymic reactions. SYN: tris(hydroxymethyl)aminomethane, tris(hydroxymethyl)methylamine.
Ernest L.O., German neurologist, *1868. See T. reflex.
A native sodium carbonate.
tropaic acid (tro-pa′ik)
SYN: tropic acid.
1. A bicyclic hydrocarbon, the fundamental structure of tropine, atropine, and other physiologically active substances. 2. In plural form, a class of alkaloids containing the t. (1) structure.
A salt or ester of tropic acid.
tropeic acid (tro-pe′ik)
SYN: tropic acid.
An ester of tropine; either a naturally occurring alkaloid or prepared synthetically.
An antispasmodic with anticholinergic properties.
A group of azo dyes used as indicators; e.g., methyl orange. [G. tropaios, pertaining to a turning or change, fr. trope, a turn]
Outermost layer of cells in the mammalian blastodermic vesicle, which will make contact with the endometrium and take part in establishing the embryo's means of receiving nutrition; the cell layer from which the trophoblast differentiates. [troph- + ectoderm]
An unclassified, nonculturable organism, named in 1992, which has been identified by electron microscopy and defined by DNA amplification technologies; it has been proven to be the infectious agent responsible for Whipple disease.
trophic (trof′ik, tro′fik)
1. Relating to or dependent upon nutrition. 2. Resulting from interruption of nerve supply. [G. trophe, nourishment]
Nutrition. Cf.:-tropic. [G. trophe, nourishment]
A trophic influence or condition. SYN: trophism (1) .
1. SYN: trophicity. 2. SYN: nutrition (1) . [G. trophe, nourishment]
Food, nutrition. [G. trophe, nourishment]
trophoblast (trof′o-blast, tro′fo-blast)
The mesectodermal cell layer covering the blastocyst that erodes the uterine mucosa and through which the embryo receives nourishment from the mother; the cells do not enter into the formation of the embryo itself, but contribute to the formation of the placenta. The t. develops processes that later receive a core of vascular mesoderm and are then known as the chorionic villi; the t. soon becomes two-layered, differentiating into the syncytiotrophoblast, an outer layer consisting of a multinucleated protoplasmic mass (syncytium), and the cytotrophoblast, the inner layer next to the mesoderm in which the cells retain their membranes. SYN: chorionic ectoderm. [tropho- + G. blastos, germ] plasmodial t. SYN: syncytiotrophoblast. syncytial t. SYN: syncytiotrophoblast.
Relating to the trophoblast.
SYN: trophochromidia. [tropho- + G. chroma, color]
Nongerminal or vegetative extranuclear masses of chromatin, found in certain protozoan forms; e.g., the macronucleus of certain ciliates, such as Paramecium. SYN: trophochromatin.
A cell that supplies nourishment; e.g., Sertoli cells in the seminiferous tubules. SYN: trephocyte. [tropho- + G. kytos, cell]
The trophectoderm, or trophoblast, together with the vascular mesodermal layer underlying it. SEE ALSO: serosa (2) . [tropho- + G. derma, skin]
Cutaneous trophic changes due to neural involvement.
The dynamics of nutrition or metabolism. SYN: nutritional energy. [tropho- + G. dynamis, power]
A trophic disorder, such as atrophy, hypertrophy, or a skin eruption, occurring as a consequence of disease or injury of the nerves of the part. [tropho- + G. neuron, nerve, + -osis, condition]
Relating to a trophoneurosis.
SYN: macronucleus (2) .
SYN: plastid (1) . [tropho- + G. plastos, formed]
1. Canalicular structures described by A.F. Holmgren in the protoplasm of certain cells. 2. Vascular endometrium of the uterus between the myometrium and the trophoblast. [tropho- + G. spongia, a sponge]
SYN: trophotropism. [tropho- + G. taxis, arrangement]
Relating to trophotropism.
Chemotaxis of living cells in relation to nutritive material; it may be positive (toward nutritive material) or negative (away from nutritive material). SYN: trophotaxis. [tropho- + G. trope, a turning]
The ameboid, vegetative, asexual form of certain Sporozoea, such as the schizont of the plasmodia of malaria and related parasites. [tropho- + G. zoon, animal]
Food, nutrition. [G. trophe, nourishment]
Abnormal deviation of the eye. See strabismus. [G. trope, a turning]
A turning toward, having an affinity for. Cf.:-trophic. [G. trope, a turning]
tropic acid (trop′ik)
A constituent of atropine and of scopolamine, in which it is esterified through its COOH to the 3-CHOH of tropine. SYN: tropaic acid, tropeic acid.
An anticholinergic agent used to effect a rapid and brief mydriasis for eye examinations.
The major constituent of atropine and scopolamine, from which it is obtained on hydrolysis. t. mandelate SYN: homatropine. t. tropate SYN: atropine.
The phenomenon, observed in living organisms, of moving toward (positive t.) or away from (negative t.) a focus of light, heat, or other stimulus; usually applied to the movement of a portion of the organism as opposed to taxis, the movement of an entire organism. [G. trope, a turning] viral t. the specificity of a virus for a particular host tissue, determined in part by the interaction of viral surface structures with host cell-surface receptors.
tropocollagen (tro-po-kol′a-jen, trop′o-)
The fundamental units of collagen fibrils, consisting of three helically arranged polypeptide chains.
The precursor to elastin; t. does not contain desmosine or isodesmosine cross-links.
Any instrument for measuring the degree of rotation or torsion, as of the eyeball or the shaft of a long bone. [G. trope, a turning, + metron, measure]
A fibrous protein extractable from muscle; sometimes specified as t. B to distinguish it from t. A (paramyosin) prominent in mollusks.
A globular protein of muscle that binds to tropomyosin and has considerable affinity for calcium ions; a central regulatory protein of muscle contraction. T. T binds to tropomyosin; t. I inhibits F-actin-myosin interactions; t. C is a calcium-binding protein and has a key role in muscle contraction.
A long, narrow, shallow channel or depression. gingival t. the formation of a crater as a result of destruction of interdental tissues so that, in effect, there exists a labial and lingual curtain of gingiva with no interproximal connection at all. Langmuir t. a t. with a movable surface barrier for studying the compression of surface films. synaptic t. the depression of the surface of the striated muscle fiber that accommodates the motor endplate.
Armand, French physician, 1801–1867. See T. point, T. sign, T. spot, T. syndrome, T.-Lallemand bodies, under body.
Used for treatment of venous disorders.
Symbol for tryptophan and its radicals.
Relating to the trunk of the body or to any arterial or nerve trunk, etc.
. . . Feedback