Search results for "otas"
showing 10 items of 1136 documents
Reactivity of isolated human chorionic vessels: analysis of some influencing variables
2003
The aim of the study was to determine whether 24 h of cold storage of samples, mode of delivery, and gestational age influenced in vitro human chorionic vascular reactivity (35 arteries and 34 veins). The following groups were compared: (i) fresh versus 24-h cold-stored (4 °C in Krebs–Henseleit solution) chorionic vascular rings from normal term placentas, (ii) fresh chorionic vascular rings from normal term placentas obtained after vaginal delivery versus those obtained after elective caesarean section, and (iii) fresh chorionic vascular rings from normal term placentas versus those obtained from preterm deliveries. Isometric recording of the concentration–response curve to KCl (5–120 mM)…
PSYCHIATRIC DISTURBANCE LEADING TO POTASSIUM DEPLETION, SODIUM DEPLETION, RAISED PLASMA-RENIN CONCENTRATION, AND SECONDARY HYPERALDOSTERONISM
1968
Abstract Nine psychiatrically disturbed women were studied, variously suffering from the effects of anorexia nervosa, vomiting, and abuse of diuretics and purgatives. Each had more than one source of electrolyte depletion, and each deliberately concealed at least one of these. All were potassium-depleted, and in all but one sodium depletion was also evident. During exacerbations plasma-renin concentration was raised, secretion-rate and plasma concentration of aldosterone were increased, and the metabolic clearance of aldosterone was diminished. It is suggested that in combined sodium and potassium deficiency, conservation of sodium may be relatively more effective than that of potassium, an…
Abscess of the orbit arising 48 h after root canal treatment of a maxillary first molar
2006
Aim To discuss a rare, but severe complication arising following routine root canal treatment. Summary An orbital abscess is reported that occurred following routine root canal treatment. A young, healthy female patient, with no history of chronic paranasal infection had undergone root canal treatment of the right maxillary first molar. On hospital admission, she presented with extensive periorbital swelling and discreet diplopia. Computed tomography imaging identified massive purulent sinusitis and subsequent involvement of the orbit via the inferior and medial orbital wall within 48 h after completion of root canal treatment. Immediate surgical drainage of the maxillary sinus and the or…
Influence of Duration of Experiment on Rate of Uptake of Radioactive Potassium in Smooth Muscle
1963
THE rates of uptake and loss of radioactive tracers by excitable tissues can often be described by a function involving one exponential term1–3, but over relatively long periods deviations have been observed from such a simple course4–7. The rates of exchange towards the end of such periods are commonly slower than would be predicted from the initial rates and two general causes for this behaviour have been suggested: either the rates are, in fact, diminishing during the course of an experiment or the tissue is not behaving uniformly. This latter possibility has been extensively investigated1,8–15, because biological material shows an obvious lack of uniformity, and because deviations from …
Inhibition of human detrusor contraction by a urothelium derived factor.
2003
Stimulating muscarinic receptors in pig bladder urothelium causes the release of a diffusable factor that inhibits contractions of the underlying detrusor muscle. We investigated whether the contractions of human detrusor strips elicited by the muscarinic agonist carbachol, electrical field stimulation, KCl or the neurokinin receptor agonist neurokinin A are affected by the urothelium.Paired intact and urothelium denuded muscle strips were placed in modified gassed Tyrode's solution at 37C. Cumulative concentration-response curves to carbachol or KCl were constructed. In other tissues the strips were stimulated electrically (1 to 40 Hz) with trains of square wave pulses 20 seconds in durati…
Effect of divalent cations on KCl- and noradrenaline-induced contractile responses in rat aorta after nifedipine treatment.
1999
Abstract Nifedipine (1 μM) relaxed the sustained contractile responses induced by 1 μM noradrenaline or 60 mM KCl in rat aortic strips. After washing, a second addition of the spasmogens gave smaller tonic contractions than the first one. Even more, a third addition of KCl also gave a smaller contraction than the first one, but a complete recovery of the contractile response to noradrenaline was obtained by a third addition of this agonist. Application of cumulative amounts of Ca2+ or Ba2+ (2.4–24 mM) on the residual contraction in response to these agents after nifedipine treatment, but in the absence of the blocker, restored the magnitude of the contractile responses. Addition of cumulati…
DIFFERENT ABILITY OF TRIFLUOPERAZINE TO INHIBIT AGONIST-INDUCED CONTRACTION OF LUNG PARENCHYMA STRIPS FROM CONTROL AND SENSITIZED GUINEA-PIGS
1988
Abstract There is increasing interest in the therapeutic potential of calcium antagonists in asthma. Among them the use of calmodulin antagonists deserves consideration. In the present work the effect of trifluoperazine on contractions generated by different mechanisms (CaCl2, KCl, acetylcholine, histamine and 5-hydroxytryptamine) in lung parenchyma strip isolated from control and actively sensitized guinea-pigs has been studied. Trifluoperazine produced both in unsensitized and sensitized lung strips, a concentration-dependent, right, downward displacement of the concentration-response curves to the agonists used, although the sensitization procedure resulted in a potentiation in the abili…
Voltage- and Agonist-Induced Activation of Smooth Muscle of the Human Upper Urinary Tract: Different Mechanisms
1985
Smooth muscles are such a remarkably diverse group of tissues that the difference in properties between any two of them may be as great as between a smooth muscle and a striated muscle. With this diversity it is not surprising that the ways in which different stimuli initiate contraction are also extremely varied and interesting although we still know very little about the details of the mechanisms involved. In an attempt to shed some light on the cellular contraction cycle of smooth muscle of the human upper urinary tract, this article will focus on two topics: 1. Previous findings in smooth muscle research will be summarized and discussed briefly as they are pertinent to an understanding …
Influence of hormonal treatment on the response of the rat isolated uterus to histamine and histamine receptor agonists.
1992
The response of the isolated uterus to histamine and histamine agonists was investigated in progesterone- and oestrogen-treated rats. The uterine inhibitory responses to histamine and 4-methylhistamine (a histamine H2 receptor agonist) were similar in KCl-contracted uteri from progesterone- and oestrogen-treated rats. The histamine H1 receptor agonist, 2-pyridyl-ethylamine, produced a relaxant response only in progesterone dominant uterus. This was inhibited by the histamine H1 receptor antagonist. In the rat isolated uterus which was not preconstricted by KCl, neither histamine, 4-methylhistamine, nor 2-pyridyl-ethylamine produced any effect in the presence or absence of ranitidine. Raniti…
Macronutrient leaching in a fertilized juvenile hybrid aspen (Populus tremula L. × P. tremuloides Michx.) plantation cultivated in an agroforestry sy…
2017
Abstract Leaching of macronutrients such as nitrogen, phosphorus and potassium from soils is of particular interest in the Baltic Sea region because of its adverse effects on water quality. The objective of this study was to evaluate macronutrient leaching in a juvenile hybrid aspen (Populus tremula L. × P. tremuloides Michx.) plantation cultivated in an agroforestry system and fertilized with biogas production residues, wastewater sludge and wood ash in hemi-boreal climate conditions. Analysis of macronutrient concentrations in the soil solution showed that annual macronutrient leaching decreased over time after the establishment of the plantation and application of fertilizers. Moreover, …