(n.) A conductor, conduit, or artificial channel for conveying water, especially one for supplying large cities with water.
(n.) A canal or passage; as, the aqueduct of Sylvius, a channel connecting the third and fourth ventricles of the brain.
Example Sentences:
(1) In addition to the aqueduct other associated inner ear anomalies have been identified in 60% of this population including: enlarged vestibule (14); enlarged vestibule and lateral semicircular canal (7); enlarged vestibule and hypoplastic cochlea (4); and hypoplastic cochlea (4).
(2) When histamine (5 micrograms) was injected into three different levels of the ventricular system, the magnitude and duration of the resulting increases in plasma epinephrine and glucose were in the following rank order: the third ventricle greater than aqueduct much greater than fourth ventricle.
(3) The majority of the responsive neurons were located in regions surrounding the aqueduct and the medial part of PAG.
(4) When outcome was examined in patients who were stuporous or comatose on admission, a significant increase in septal shift was found among patients with a poor outcome, but there was no significant relationship between outcome and degree of pineal or aqueductal shift.
(5) This is the first case of a fulminant phase of mumps ventriculitis leading to aqueductal stenosis, which has been treated using a ventriculoscope for the first time.
(6) A series of 55 cases is described in which hydrocephalus associated with non-neoplastic narrowing of the Sylvian aqueduct produced symptoms for the first time in adult life.
(7) With systole there is downward (caudal) flow of CSF in the aqueduct of Sylvius, the foramen of Magendie, the basal cisterns and the dorsal and ventral subarachnoid spaces while during diastole, upward (cranial) flow of CSF in these same structures is seen.
(8) A patent cochlear aqueduct indicated on computed tomography scan was found and repaired through a posterior cranial fossa approach.
(9) Rats from the H-Tx strain develop hydrocephalus through a developmental obstruction of the cerebral aqueduct.
(10) In group A, kaolin was present in the fourth ventricle and Sylvian aqueduct.
(11) SE images obtained with gradient moment nulling did not allow confident distinction between patent and obstructed aqueducts.
(12) The signal intensity of the cerebrospinal fluid (CSF) in the cerebral aqueduct and lateral ventricles on magnetic resonance (MR) images was evaluated in 16 healthy individuals and in 32 patients with various forms of hydrocephalus (20 with chronic normal pressure hydrocephalus [NPH], seven with acute communicating hydrocephalus, and five with hydrocephalus ex vacuo [atrophy]).
(13) Tentorial herniation secondary to supratentorial mass lesions will cause aqueductal compression and raised intraventricular pressure.
(14) However, these cytoplasmic edema of the ependymal and glial cells totally subsided by day 30 postinjection, leaving an obliterated aqueduct with a few remnants of ependymal cells without reactive gliosis.
(15) The effect of intracranial pressure on cerebrospinal fluid formation has been studied in cats by ventricular perfusion with the aqueduct of Sylvius blocked (isolated ventricular perfusion).
(16) The disappearance of patency in the cochlear aqueduct is a progressive phenomenon reflecting the biological process of aging in the organism.
(17) The results suggest that under physiological conditions the CSF also flows through the cochleae aqueduct and the protein concentration in the Scala tympani decreases especially in the basal winding.
(18) We demonstrate that the stenosis of the aqueduct is a secondary phenomenon, not causally related to the pathogenesis of hydrocephalus, and discuss the significance of this finding to human aqueduct stenosis.
(19) In the other 71%, the pars rugosa in the vestibular aqueduct was surrounded by dura more commonly than normal.
(20) In this paper we attempted MR visualization of the vestibular aqueduct (VA) with a surface coil.
Channel
Definition:
(n.) The hollow bed where a stream of water runs or may run.
(n.) The deeper part of a river, harbor, strait, etc., where the main current flows, or which affords the best and safest passage for vessels.
(n.) A strait, or narrow sea, between two portions of lands; as, the British Channel.
(n.) That through which anything passes; means of passing, conveying, or transmitting; as, the news was conveyed to us by different channels.
(n.) A gutter; a groove, as in a fluted column.
(n.) Flat ledges of heavy plank bolted edgewise to the outside of a vessel, to increase the spread of the shrouds and carry them clear of the bulwarks.
(v. t.) To form a channel in; to cut or wear a channel or channels in; to groove.
(v. t.) To course through or over, as in a channel.
Example Sentences:
(1) These channels may, at least in some cases, be responsible for the generation of pacemaker depolarizations, thereby regulating firing behaviour.
(2) The influence of the various concepts for the induction of lateral structure formation in lipid membranes on integral functional units like ionophores is demonstrated by analysing the single channel current fluctuations of gramicidin in bimolecular lipid membranes.
(3) RNAs encoding a wild-type (RBK1) and a mutant (RBK1(Y379V,V381T); RBK1*) subunit of voltage-dependent potassium channels were injected into Xenopus oocytes.
(4) The dramas are part of the BBC2 controller Janice Hadlow's plans for her "unashamedly intelligent" channel over the coming months.
(5) This was unlike the action of the calcium channel blocker, cadmium, which reduced the calcium action potential and the a.h.p.
(6) Circuitry has been developed to feed the output of an ear densitogram pickup into one channel of a two-channel Holter monitor.
(7) It is concluded the decrease in cellular volume associated with substitution of serosal gluconate for Cl results in a loss of highly specific Ba2+-sensitive K+ conductance channels from the basolateral plasma membrane.
(8) Stimulation of atrial H1-receptors is suggested to directly cause an increase in Ca-channel conductance independent of intracellular cAMP content.
(9) Similarly, 50 microM D-600, a Ca+2 channel antagonist, significantly (P less than 0.01) reduced basal and 5-HETE-induced PRL release.
(10) The purpose of the present study was to analyze the effects of cromakalim (BRL 34915), a potent drug from a new class of drugs characterized as "K+ channel openers", on the electrical activity of human skeletal muscle.
(11) This promotion of repetitive activity by the introduction of additional potassium channels occurred up to an "optimal" value beyond which a further increase in paranodal potassium permeability narrowed the range of currents with a repetitive response.
(12) Channel activation persists through the process of platelet isolation and washing and is manifested in higher measured values of [Ca2+]cyt and [Ca2+]dt in the "resting state."
(13) At 100 microM-ACh the apparent open time became shorter probably due to channel blockade by ACh molecules.
(14) The effects of low doses of dihydropyridine (DHP) calcium channel antagonists nimodipine, nifedipine, (-)-R-202-791, and amlodipine, the DHP calcium channel agonist BAY K 8644 were investigated on clonic convulsions to pentylenetetrazole (PTZ) in mice.
(15) The following model is suggested: exogenous ATP interacts with a membrane receptor in the presence of Ca2+, a cascade of events occurs which mobilizes intracellular calcium, thereby increasing the cytosolic free Ca2+ concentration which consequently opens the calcium-activated K+ channels, which then leads to a change in membrane potential.
(16) SDS-PAGE analysis of the immunoprecipitates under reducing conditions revealed that the cardiac channel is mainly composed of two large polypeptides of 190 and 150 kDa, and five smaller polypeptides of 60, 55, 35, 30, and 25 kDa.
(17) In the presence of high external Cl, a component of outward current that was inhibited by the anion channel blocker diphenylamine-2-carboxylate (DPC) appeared in 70% of the cells.
(18) In vitro studies in cardiac Purkinje fibers suggested that reversal of amitriptyline-induced cardiac membrane effects by sodium bicarbonate may be attributed not only to alkalinization but also to increased in extracellular sodium concentration, diminishing the local anesthetic action of amitriptyline and resulting in less sodium channel block.
(19) The Ca2+ channel current recorded under identical conditions in rat dorsal root ganglion neurones was less sensitive to blockade by PCP (IC50, 90 microM).
(20) In voltage-clamp experiments the ion current flowing through the channels was homogeneous indicating a defined conformation and a uniform size.