Showing papers by "University College Dublin published in 1975"
TL;DR: It is essential to consider not only the pharmacokinetics and pharmacodynamics of ascorbic acid itself but also the effect of its interaction with drugs administered for specific purposes, in relation to tissue ascorBic acid.
Abstract: Ascorbic acid is a vitamin. In view of the current interest in the effects produced by administration of supplements that are relatively large in comparison with the recommended daily dietary intake, the effects produced by this vitamin must be considered from a pharmacological point of view. This implies that its kinetics should be studied in the blood and tissues in relation to any clinical observations that appear to be associated with, or to succeed, its administration. As in the case of other biologically active substances, the physiological factors of age,' sex,\" and circadian, monthly, and yearly rhythms :I can all alter its pharmacokinetics and pharmacodynamics. Unlike any other exogenous medicament, however, ascorbic acid is present in the blood and tissues under normal circumstances. In consequence, the interaction of supplementary vitamin C with intrinsic ascorbic acid complicates analysis of the effects produced by its administration, and affects the pharniacokinetics of the tissue ascorbic acid. Ascorbic acid plays an essential role in many metabolic reactions,$ during which there is a rapid tissue turnover of the vitamin, with consequent potentiation or inhibition of enzymatic reactions. As a result, the metabolism of extrinsic drugs may be affected by the availability of ascorbic acid in the liver and in other I t is therefore essential to consider not only the pharmacokinetics and pharmacodynamics of ascorbic acid itself but also the effect of its interaction with drugs administered for specific purposes, in relation to tissue ascorbic acid. Some of these aspects of the clinical pharmacology of ascorbic acid are discussed bclow.
66 citations
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50 citations
TL;DR: Nitrogen reserves were found mainly to be in the protein fraction of both wood and bark, and it appears that arginine and the supplementary amino acids and amides may also make up a nitrogen reserve, especially in wood.
Abstract: SummaryNitrogen levels were measured in 1-year-old shoot wood and bark of 2-year-old Golden Delicious apple trees from January to April. Nitrogen reserves were found mainly to be in the protein fraction of both wood and bark. These reserves were hydrolysed in mid-late March resulting in a rapid increase in the soluble nitrogen levels for use in growth. Prior to hydrolysis of protein there appeared to be a significant amount of soluble nitrogen present especially in wood. Arginine composed 8-17 % of the total free amino fraction in bark and 20-30 % in wood. It appears that arginine and the supplementary amino acids and amides may also make up a nitrogen reserve, especially in wood.
45 citations
TL;DR: Histological and histochemical alterations were studied in lesions due to Sarcoptes scabiei in the ears of 14 experimentally infected and 16 naturally infected pigs.
40 citations
TL;DR: In this paper, it was shown that the corridor house appeared at the villas as early as, if not earlier than, in the towns, and that in Britain villa planning influenced town-house planning in a manner not generally found on the Continent.
Abstract: Similarities of plan between town houses and the main houses of villaestates in Roman Britain have been asserted by some, denied by others, but never considered in detail. The purpose of this paper is to put forward four suggestions: (i) that in certain areas the corridor house, winged and unwinged, appeared at the villas as early as, if not earlier than, in the towns; (ii) that in Britain villa planning influenced town-house planning in a manner not generally found on the Continent; (iii) that in construction and decoration villa-dwellings exhibit a far higher degree of Romanisation than their urban counterparts until roughly the mid second century; and that, if right, these hypotheses point to important conclusions for the economic and social development of town and country in the first hundred years of Roman rule.
38 citations
TL;DR: In this article, the lowest two members of the Worley's third Rydberg series of N2, o 3,4 1 Π u ← X 1 Σ g +, have been studied in absorption using a 6.65 m vacuum spectrograph.
38 citations
TL;DR: The use of manual restraint increased blood acidity, plasma protein, calcium and magnesium, but decreased blood glucose, and Haemoglobin and haematocrit values were higher for tail blood than for blood removed from the heart or abdominal aorta.
Abstract: When used to restrain rats while obtaining cardiac blood, there was little difference between the effects of ether, pentobarbitone sodium, and fentanyl plus droperidol on acid-base balance, haemoglobin, haematocrit, plasma protein, calcium and magnesium. The use of manual restraint increased blood acidity, plasma protein, calcium and magnesium, but decreased blood glucose. Haemoglobin and haematocrit values were higher for tail blood than for blood removed from the heart or abdominal aorta.
37 citations
TL;DR: The heartwood of Dalbergia melanoxylon has yielded new examples of known neoflavanoid types including 4-phenylcoumarins, 4-methoxydalbergiones and benzophenones which have the corresponding oxygenation pattern as mentioned in this paper.
34 citations
TL;DR: Histological, histochemical and ultrastructural studies indicated that the immediate reaction resembled a local anaphylactic response, and iron-deprived pigs, experimentally infected with S. scabiei, reacted less intensely to the intradermal inoculation of crude mite extract than similarly infected, iron-treated litter mates.
26 citations
TL;DR: In this paper, the high-temperature conductivity of pure AgCl has been re-examined with a view to establishing more precisely the mobility parameters for non-collinear interstitialcy motion of Ag+ interstitials.
Abstract: The high-temperature conductivity of pure AgCl has been re-examined with a view to establishing more precisely the mobility parameters for non-collinear interstitialcy motion of Ag+ interstitials. The possible roles of direct interstitial jumps, Schottky defects, and temperature dependent activation energies has been assessed. Fomulae are given for the activity coefficients of interstitials and vacancies evaluated to O(x2) in an approximation that uses a sphericalized Brillouin zone and inlcudes only the cycle sum contributions. These activity coefficients are compared with those evaluated from the Debye-Huckel formula and their effect on the defect parameters obtained from conductivity data is assessed.
Die Hochtemperaturleitfahigkeit von reiriem AgCl wurde im Hinblick auf eine genauere Festlegung der Beweglichkeitsparameter fur nicht-kollineare Zwischengitterbewegung von Ag+-Zwischengitterionen erneut uberpruft. Die mogliche Rolle direkter Zwischengitter-sprunge, Schottky-Defekte und temperaturabhangiger Aktivierungsenergien wurde ab-geschatzt. Es werden Gleichungen fur die Aktivitatskoeffizienten von Zwischengitterteil-chen und Leerstellen angegeben, die bis zu Ox(2) ausgewertet werden in einer Naherung, welche spharikalisierte Brillouin-Zonen benutzt und nur die Beitrage der Zyklussummen enthalt. Diese Aktivitatskoeffizienten werden mit den nach der Debye-Huckel-Gleichung ausgewerteten verglichen und ihr Einflus auf die aus den Leitfahigkeitsdaten erhaltenen Defektparameter wird abgeschatzt.
25 citations
TL;DR: Cernosvitoviella sphaerotheca and Cognettia hibernica are common and widespread in Ireland and the taxonomic relationships of the species and other members of their genus are discussed.
TL;DR: In this paper, a 10% urea spray was used on Golden Delicious apple trees in both January and February to increase the total nitrogen in the leaves of the trees, due mainly to an increase in protein nitrogen.
Abstract: SummaryFollowing the application of urea sprays in October on Golden Delicious apple trees, increased amounts of nitrogen were translocated from the leaves into storage tissues. Trees receiving 10% urea spray had significantly higher levels of total nitrogen in bark in both January and February than either those receiving soil application or control treatments. However, there was also a significant increase in total nitrogen in bark from January to February in the sprayed trees, due mainly to an increase in protein nitrogen in January. In February the soluble nitrogen increased while the protein remained constant. There were no significant differences between treatments in wood total nitrogen levels in January. In February the trees receiving the 10% urea spray had significantly higher total nitrogen levels than those receiving either the soil application or control treatments. In the sprayed trees there was an increase in wood total nitrogen from January to February due to an increase in soluble nitrogen...
TL;DR: In this article, the effects of system of production on the melting point, iodine value, and fatty acid composition of perinephric and subcutaneous carcass fat were investigated.
Abstract: SUMMARY Two surveys, involving 288 lambs, were carried out on the effects of system of production on the melting (slip) point, iodine value, and fatty acid composition of perinephric and subcutaneous carcass fat. The systems studied were: A, early Spring lambs fattened indoors on concentrates; B, early Spring lambs off grass; C, early Summer lambs off grass; D, Autumn lambs off grass, and E, Winter hoggets. The melting point of both perinephric and subcutaneous fat increased progressively during the season from mean values of 41 and 32°C respectively in group A to mean values of 48 and 42°C respectively in group E. Discolouration of the surface fat was associated with the low melting points of group A. Mean iodine values of both fats decreased progressively from group A to group E and this change was associated with a decrease in levels of oleic and palmitoleic acid and a corresponding increase in the level of stearic acid. In the fat, levels of myristic acid were highest in grass fed lambs while levels of linoleic acid were highest in the concentrate-fed lambs. Within each group, perinephric fat contained more stearic and less oleic, palmitoleic, palmitic and myristic acid than subcutaneous fat. Within animals, the levels between perinephric and subcutaneous fat of melting point, iodine value and most of the individual fatty acids were highly correlated. Within animals also, the melting point of perinephric fat was correlated in decreasing order of significance with stearic acid, oleic acid, iodine value, linoleic acid and palmitoleic acid, while melting point of subcutaneous fat was correlated in decreasing order of significance with stearic acid, oleic acid, palmitoleic acid, iodine value, linoleic acid and total branched-chain fatty acids.
TL;DR: The results indicate that adrenaline, noradrenaline and isoprenaline lower the VFT by a direct action on the cardiac musculature and that this effect is mediated via β‐adrenoceptors.
Abstract: 1 The ventricular fibrillation threshold (VFT) was measured in the isolated heart of the rabbit perfused via the aorta with McEwen's solution at 37 degrees C by applying a single 10 ms pulse of current during the vulnerable period of late systole. The arrhythmia induced was either fibrillation or a rapid tachycardia. 2 The catecholamines adrenaline, noradrenaline and isoprenaline, but not dopamine, when infused at rates which produced similar moderate effects on cardiac rate and force, significantly lowered the VFT; it was reduced slightly more by adrenaline than by the other two. Phenylephrine and methoxamine were ineffective. Only those sympathomimetic amines which lowered the VFT also shortened the vulnerable time, i.e. minimal time after the R-wave of the ECG at which the pulse had to be applied to induce the arrhythmia. 3 The lowering effect of adrenaline on the VFT was not influenced by phentolamine but was blocked by propranolol and pindolol. 4 Chloroform potentiated the lowering effect of adrenaline, but not that of isoprenaline, on the VFT. Carbachol did not alter the effect of adrenaline on the VFT. 5 The results indicate that adrenaline, noradrenaline and isoprenaline lower the VFT by a direct action on the cardiac musculature and that this effect is mediated via beta-adrenoceptors.
TL;DR: In this paper, it was shown that the initial function of the nuclear substituent(s) is to sterically prevent deactivation of the carbonyl group by the phenoxide anion.
TL;DR: The FCI measurements indicated that there was no significant increase in metabolically active cortisol in women taking either the combined oestrogen/progestogen or the progestogen only type of oral contraceptive.
TL;DR: Kimberlite intrusions at three localities have been mapped in detail as mentioned in this paper, and the present thickness of dykes and sheets reflects the injection of several phases of kimberlite.
Abstract: Kimberlite intrusions at three localities have been mapped in detail. Dyke intrusion in the Nigerdlikasik area follows an en-echelon pattern maintaining a constant coast-parallel trend through Precambrian gneisses. Impersistent flat-lying sheets in the Pyramidefjeld granite complex extend beyond the granite contact into similar gneisses. On Midternaes further low-angle sheet development passes from gneissose basement across an unconformity into a Proterozoic supracrustal succession. The present thickness of dykes and sheets reflects the injection of several phases of kimberlite. Trachytic flow textures, widespread dissemination and sedimentation of deepseated xenoliths and localized carbonate metasomatism suggest a very fluid magma. Zones of pronounced platy jointing, sometimes extending up to 10 m in width are a common feature of the host rocks immediately adjacent to both the dyke and sheets and their development is associated with the kimberlite emplacement. The intrusion of the kimberlites is interpreted as being controlled by the prevailing external stress field and it is suggested that the disposition of dykes and sheets reflects the stress system generated during the early stages of continental rifting between Greenland and Canada.
TL;DR: The epithelial reaction which takes place in healing excised wounds in the thoracic and metatarsal regions of the dog is described and numerous projections or pseudo-rete pegs extend from the newly formed epidermis into the wound tissues, but disappear when epithelization is complete.
TL;DR: In this article, an assessment of the information provided by n.m.r. second moment, fourth moment and T2 measurements on oriented samples of branched and linear polyethylene is made.
TL;DR: A novel type of water-soluble phosphorylated glycosphingolipid was isolated from Aspergillus niger by a simple procedure involving precipitation, DEAE-cellulose chromatography and preparative t.l.c.
Abstract: A novel type of water-soluble phosphorylated glycosphingolipid was isolated from Aspergillus niger by a simple procedure involving precipitation, DEAE-cellulose chromatography and preparative t.l.c. Besides ceramide and phosphorus it contains inositol, galactose, mannose and small amounts of glucosamine.
TL;DR: In this article, the decay time τl ofo-Ps by the electron pickoff process has been measured in polystyrene as a function of molecular weight and the overall behavior reflects closely the dependence of free volume on
Abstract: The decay time τl ofo-Ps by the electron pickoff process has been measured in polystyrene as a function of molecular weight. For samples below their glass transition temperature τl is essentially independent of
$$\bar M_n $$
. In the low molecular weight region,
$$\bar M_n< 850$$
, τl increased with decreasing
$$\bar M_n $$
in line with earlier theoretical predictions. The overall behaviour reflects closely the dependence of free volume on
$$\bar M_n $$
. The effects of molecular motion on τl are examined and it is concluded that the decay time is insensitive to such motions in polystyrene below the melting point, in contrast to what is observed in polytetrafluoroethylene.
TL;DR: Geometry optimized ab initio calculations for cyclopropenone (I) and its dimethyl derivative (II) are reported in this paper, where the effect of the methyl substituents in this strained ring system with an exocyclic heteroatom is to increase the bond lengths and the electronic delocalisation.
TL;DR: An acid brown podzolic (pH 4.0) soil of wide distribution in Ireland was limed with Ca(OH)2 to pH values of 5.2 and 7.4 as discussed by the authors.
Abstract: An acid brown podzolic (pH 4.0) soil of wide distribution in Ireland was limed with Ca(OH)2 to pH values of 5.2 and 7.4. With each increment of lime significant increases in growth and F uptake by Italian ryegrass occurred, the increases being greatest with the first increment. Increasing soil pH resulted in decreased extractable aluminum and iron as well as exchangeable hydrogen. Available P as measured by various extractants increased with increasing soil pH. The relative performance of three P fertilizers, superphosphate, phospal and basic slag was affected by liming. Basic slag was more effective than superphosphate at pH 4.0, was as effective at pH 5.2 and was less effective at pH 7.4. Phospal was poorest at each pH level. While growth and P uptake increased with increasing P levels the relative responses to the three fertilizers decreased with increasing soil pH.
TL;DR: In this article, a scheme for refining crude copper to cathode copper without casting anodes is proposed, in which a diaphragm is necessary if cuprous sulphate is allowed to concentrate in the cell.
TL;DR: No evidence of hydatid infection was detected at post mortem examination of sheep which had been inoculated intraperitoneally with protoscoleces of Echinococcus granulosus equinus.
TL;DR: Investigations of the relationship between symptoms of the natural common cold and administration of supplementary vitamin C must record and take into account the following factors: 1.
Abstract: Investigations of the relationship between symptoms of the natural common cold and administration of supplementary vitamin C must record and take into account the following factors: 1. Definition of the cold syndrome in terms of incidence (number of colds per person in unit time, generally taken as duration of study); duration of syndrome (number of days during which a defined number of symptoms persist in individual patients); and severity of symptoms (recorded subjectively on a daily basis for individual symptoms on a graded scale of which the lowest value records absence of the symptom). Days of absence from work provide a general measure arising from cold disability. Integrated morbidity is defined as the product of incidence of colds, and severity of individual colds. The two values for incidence and integrated morbidity are not independent of one another. Integrated morbidity provides a general measure of intensity of the syndrome as opposed to the disability it produces. Total symptom intensity provides a similar measure to integrated morbidity. The Total Intensity Score is defined as the total severity of any symptoms of the cold syndrome present on each day of reporting, divided by the total number of days of reporting. Variation in symptom quality can be evaluated by measuring the degree of association between symptom pairs. If viral diagnostic tests, or antibody measurement, are not included in the investigation, a screening process is necessary to exclude upper respiratory allergic disease. Local respiratory symptoms of an allergic nature, those produced by mental stress in subjects prone to vasomotor rhinitis, and those arising from chronic infection of the nasal passages, are eliminated from the data on the cold syndrome by excluding syndromes that exceeded 21 days in duration. 2. Measurement of plasma and leukocyte ascorbic acid concentrations in the subjects. Correlation of these measurements with the cold symptomatology enables the relationship between tissue ascorbic acid and the cold syndrome to be measured directly. Administration of exogenous supplementary vitamin C during the cold syndrome only allows indirect assumptions to be made about the relationship between the cold syndrome and the effect associated with vitamin C administration. 3. The preliminary decision as to whether supplementary vitamin C will be administered on a prophylactic or a therapeutic basis. If it is decided that a prophylactic investigation will be carried out, it is essential that the period of administration of supplementary vitamin C is sufficiently long to ensure that tissue concentrations of ascorbic acid have been elevated in the subjects when they are included in the trial. Factors such as sex, age, dietary intake of vitamin C, and initial ascorbic acid status of the tissues can all have profound effects on
TL;DR: In this article, the effect of nitriles on the cell voltage, optimum current density and role of additives is considered and optimum electrolyte compositions and cell arrangements are proposed for aqueous cupric sulphate electrolytes.
TL;DR: In this article, a poly(propylene sulphide) initiated by cadmium bis(phenyl allyl thiolate) was fractionated from benzene-methanol, and the fractions were examined by viscosity, osmotic pressure and light scattering determinations.