(n.) The soft spongy substance in the center of the stems of many plants and trees, especially those of the dicotyledonous or exogenous classes. It consists of cellular tissue.
(n.) The spongy interior substance of a feather.
(n.) The spinal cord; the marrow.
(n.) Hence: The which contains the strength of life; the vital or essential part; concentrated force; vigor; strength; importance; as, the speech lacked pith.
(v. t.) To destroy the central nervous system of (an animal, as a frog), as by passing a stout wire or needle up and down the vertebral canal.
Example Sentences:
(1) Finally, fosinopril had no effect on the pressor or chronotropic effects of norepinephrine (NE) or 1,1-dimethyl-4-phenylpiperinium (DMPP) or electrical stimulation of the sympathetic ganglia of pithed rats.
(2) Relatively weaker GUS activity was also detected in pith parenchyma.
(3) Both d- and l-amphetamine were also compared for their pressor and tachycardic activity in pithed rats.
(4) Intravenous administration of T-2 to pithed rats did not alter blood pressure or heart rate at a time when, in conscious rats, both blood pressure and heart rate were increased.
(5) Monoiodo-Ang II was found to be a potent, full agonist in in vivo bioassays and a more potent (2.5-fold) pressor agent than the native hormone Ang II in the pithed rat.
(6) APP 201-533 [3-amino-6-methyl-5-phenyl-2(1H)-pyridinone] was investigated in vivo in anesthetized and unanesthetized dogs and pithed open-chest cats and in vitro in guinea pig atria and papillary muscles, skinned muscle fibers from pig hearts, and rat myocardium.
(7) The effects of quinpirole, a specific dopamine DA2 receptor agonist, on autonomic nervous control of heart rate, were studied in normotensive pithed rats, by analysing its action on the tachycardia and bradycardia evoked by electrical stimulation of the cardioaccelerator (10 V; 1 ms; 0.5, 1, 3, 6 Hz) and vagus (10 V; 1 ms; 3, 6, 9 Hz) nerves respectively.
(8) Pith cells can shift from the C- to the C+ state by a process known as habituation.
(9) The pressor actions of ET3 and arginine vasopressin (AVP) were compared with one another in pithed rats in the presence of the calcium channel activator BAY K 8644 or the calcium channel antagonist nifedipine i.a.
(10) Both human endothelin 1 (ET1) and rat endothelin 3 (ET3) produced dose-dependent pressor effects in the pithed rat.
(11) Viprostol did not antagonize the tachycardia induced by stimulation of the discrete segments at C7-T1 (cardio-accelerator) of the spinal cord in pithed SHR, suggesting that viprostol did not activate the presynaptic alpha-adrenoceptors.
(12) In pithed rats, the vasopressor response to dihydroergotoxine was reduced competitively by yohimbine, and non-competitively by nifedipine, but not by prazosin or methysergide, showing that the vasoconstriction is mediated by alpha 2-adrenoceptors.
(13) The antagonistic effects of a new inositol phosphate derivative, D-myoinositol-1,2,6-trisphosphate (PP56), on pressor responses to preganglionic sympathetic nerve stimulation and exogenously administered phenylephrine or neuropeptide Y (NPY) were investigated in vivo in the pithed rat.
(14) We conclude that in contrast to the increase in diastolic pressure elicited by B-HT 920, calcium channels are not involved in the cirazoline-induced pressor responses in the pithed cat.
(15) Acute or chronic adrenalectomy did not alter the pressor responses and chronotropic effect of angiotensin in the pithed rat.
(16) Habituated cells derived from inducible pith cells give rise to normal plants whose leaf and pith tissues require cytokinin for growth in culture.
(17) The endovenous perfusion of the splenic material in acidified and alkalinized forms caused significant increases of the mean blood pressure in normal, vagotomized and pithed rats, showing that, in contradiction to previous reports, changes in pH did not affect its hypertensive activity.
(18) The dose-response curves of three alpha-agonists noradrenaline, St 587 and B-HT 933 in pithed rats were shifted rightwards by pretreatment (i.v.
(19) In pithed rats, only pindolol produced a definite fall of blood pressure.
(20) The bradycardia was reduced but not blocked by pre-treatment with guanethidine, yohimbine, propranolol or pithing.
Stem
Definition:
(v. i.) Alt. of Steem
(n.) Alt. of Steem
(n.) The principal body of a tree, shrub, or plant, of any kind; the main stock; the part which supports the branches or the head or top.
(n.) A little branch which connects a fruit, flower, or leaf with a main branch; a peduncle, pedicel, or petiole; as, the stem of an apple or a cherry.
(n.) The stock of a family; a race or generation of progenitors.
(n.) A branch of a family.
(n.) A curved piece of timber to which the two sides of a ship are united at the fore end. The lower end of it is scarfed to the keel, and the bowsprit rests upon its upper end. Hence, the forward part of a vessel; the bow.
(n.) Fig.: An advanced or leading position; the lookout.
(n.) Anything resembling a stem or stalk; as, the stem of a tobacco pipe; the stem of a watch case, or that part to which the ring, by which it is suspended, is attached.
(n.) That part of a plant which bears leaves, or rudiments of leaves, whether rising above ground or wholly subterranean.
(n.) The entire central axis of a feather.
(n.) The basal portion of the body of one of the Pennatulacea, or of a gorgonian.
(n.) The short perpendicular line added to the body of a note; the tail of a crotchet, quaver, semiquaver, etc.
(n.) The part of an inflected word which remains unchanged (except by euphonic variations) throughout a given inflection; theme; base.
(v. t.) To remove the stem or stems from; as, to stem cherries; to remove the stem and its appendages (ribs and veins) from; as, to stem tobacco leaves.
(v. t.) To ram, as clay, into a blasting hole.
(v. t.) To oppose or cut with, or as with, the stem of a vessel; to resist, or make progress against; to stop or check the flow of, as a current.
(v. i.) To move forward against an obstacle, as a vessel against a current.
Example Sentences:
(1) However, CT will be insensitive in the detection of the more cephalic proximal lesions, especially those in the brain stem, basal cisterns, and skull base.
(2) Based on our results, we propose the following hypotheses for the neurochemical mechanisms of motion sickness: (1) the histaminergic neuron system is involved in the signs and symptoms of motion sickness, including vomiting; (2) the acetylcholinergic neuron system is involved in the processes of habituation to motion sickness, including neural store mechanisms; and (3) the catecholaminergic neuron system in the brain stem is not related to the development of motion sickness.
(3) The examination of the standard waves' amplitude and latency of the brain stem auditory evoked response (BAEP) was performed in 20 guinea pigs (males and females, weighing 250 to 300 g).
(4) A previous trial into the safety and feasibility of using bone marrow stem cells to treat MS, led by Neil Scolding, a clinical neuroscientist at Bristol University, was deemed a success last year.
(5) Proliferation of quiescent hematopoietic stem cells, purified by cell sorting and evaluated by spleen colony assay (CFU-S), was investigated by measuring the total cell number and CFU-S content and the DNA histogram at 20 and 48 hours of liquid culture.
(6) The last stems from trends such as declining birth rate, an increasingly mobile society, diminished importance of the nuclear family, and the diminishing attractiveness of professions involved with providing maintenance care.
(7) Following BHT administration, the alveolar stem cells (type II pneumocytes) proliferate and differentiate according to a biphasic pattern, with proliferative peaks at d 3 and 7.
(8) In testing the contribution of the long, curved stem to the torsional stability of uncemented prostheses by comparing it with other stems, the long, curved stem was the most stable, followed by a shorter straight stem, and a short, proximally curved stem.
(9) For example, stem pairing with a sequence other than wild-type resulted in normal protein binding in vitro but derepression of protein synthesis in vivo.
(10) These results indicate that this population (approximately 0.1% of bone marrow) may contain the pluripotent hematopoietic stem cell.
(11) Brain-stem CBF varied the most but did not correlate with clinical signs of brain-stem dysfunction.
(12) We infer from these results that endotoxin ameliorates the cyclical changes in blood cell counts by regulating hematopoietic proliferative activity at the stem cell level.
(13) The effects of inhibitors of aldehyde dehydrogenase activity on the sensitivity of murine pluripotent hematopoietic stem cells to oxazaphosphorine anticancer agents, e.g.
(14) Three strains of fluorescent pseudomonads (IS-1, IS-2, and IS-3) isolated from potato underground stems with roots showed in vitro antibiosis against 30 strains of the ring rot bacterium Clavibacter michiganensis subsp.
(15) This has stemmed from an inadequate understanding of the mechanisms involved in the formation and propagation of this condition.
(16) We therefore think that the detailed examination of CALLA(-) non-T non-B ALL cells using myeloid specific antibodies is helpful in clarifying the characteristics of myeloid precursors and the common bipotential stem cell of lymphoid and myeloid progenitors.
(17) Imaging studies had shown no change in his brain stem lesion, which at autopsy was found to be a focal collection of fibrillary astrocytes.
(18) These cells were hypothesized to be the stem cells for the corneal epithelium.
(19) Auditory brain stem potentials (ABP) were recorded in 27 patients with Bell's palsy during the early phase of the disease and 1-3 months later.
(20) The results indicate that stimulation of trigeminal subnucleus caudalis, a brain stem region that processes nociceptor afferent information, evokes a prompt increase in plasma ACTH.