Showing papers by "University College Dublin published in 1973"

The Effect of Metronidazole on the Human Taste Threshold to Alcohol

Abstract: Summary A method is described for measuring the taste threshold to alcohol in a sample of 163 subjects whose average age was 27 years. The subjects taste ascending concentrations of alcohol in water from 0.25% up to 64% absolute alcohol. Five mls of each concentration is tasted for 20 seconds, spat out, and then the subject washes out his mouth with the diluent water. Alcohol is detected as a sweet taste at a concentration of 4.2±S.E. 0.24% alcohol. The sweet taste changes to a burning taste at a mean concentration of 21.2±S.E. 1.22% alcohol. The frequency distributions for the sweet and burning tastes of alcohol depart significantly from the unimodal normal shape. During the 20 seconds while alcohol is maintained in the mouth for appreciation of its taste, the concentration of the 4% solution falls to 2%, and the concentration of the 20% solution falls to 16%. The taste threshold for metronidazole was tested in the same subjects and found to be 149±S.E. 17 mg/litre; the frequency distribution curve is unimodal in shape but negatively skewed. The taste threshold for PTC in the same subjects was bimodal with modes at 20 and 1300 mg/litre. Oral administration of 600 mg of metronidazole as 200 mg tablets over a period of 14 hours, caused no change in the taste threshold to alcohol during the following 6 days. Administration of 800 mg metronidazole over a period of 20 hours, caused a significant elevation of both sweet and burning taste thresholds to alcohol which reached its maximum on the second day after the last tablet had been taken. The taste threshold returned to its pre-metronidazole level on the fourth day. The alcohol taste threshold was raised at concentrations of metronidazole equivalent to those excreted in the saliva. The taste threshold to alcohol is a measurable human physiological characteristic. In humans, and by implication in rats, taste threshold to alcohol is appreciated through pereipheral receptors and specific afferent taste discharges, and the taste mechanism is the primary regulator of alcohol intake. The finding of a taste threshold distribution curve with more than one mode provides evidence that there may be a genetic basis to variations in alcohol taste threshold. The action of metronidazole on the alcohol taste threshold suggests that this drug may exert psychotherapeutic effects on alcohol consumption in man not only through peripheral taste receptiors but also through central taste pathways.

Effects of divergent selection for body weight on fibre number and diameter in two mouse muscles

Abstract: The effects of selection for increased or decreased body weight in mice, at 5 or 10 weeks of age, on the fibre number, fibre diameter and weight of the m. sternomastoideus and m. anterior tibialis muscles were studied. Unselected control mice were also included. Significant effects were detected in the case of each of the traits. However, the magnitude of any particular correlated response to selection varied between muscles and between selection ages in an unsystematic fashion. Most of the changes in muscle weight resulting from selection were attributable to positively correlated changes in fibre number but they were also accompanied by changes in fibre diameter in some cases. The correlated responses described indicate the difficulty of predicting how selection for body weight changes will influence cellular structure of any given muscle. Phenotypic correlations between muscle fibre number and diameter were essentially zero. The phenotypic correlations between muscle weight and fibre number and fibre diameter were positive. Sex had no effect on fibre number but had an effect on fibre diameter which depended on the particular muscle and the age of the animal.

Ionised calcium levels in "normocalcaemic" hyperparathyroidism.

Abstract: Five subjects presenting with renal stone, hypercalciuria and normal total serum calcium showed persistent elevation of ionised plasma calcium and marginal elevation of plasma parathyroid hormone concentration. Neck exploration revealed a parathyroid adenoma in each, and parathyroidectomy has been followed by reduction in both plasma ionised calcium and urine calcium. Ionised calcium measurement is an important aid in the differential diagnosis of idiopathic hypercalciuria from ‘normo-calcaemic’ hyperparathyroidism.

Behavioural aspects of cigarette smoking in relation to arousal level.

Abstract: To test the hypothesis that cigarette smokers use smoking to control arousal level 160 habitual light and heavy cigarette smokers of both sexes smoked a standard cigarette and simulated smoking under conditions eliciting either low or high arousal. Under high arousal heavy smokers exhibited a significant reduction in rate of smoking but not in simulating smoking. From other evidence it was argued that, although this group may use smoking as a means of arousal control, it appears that smokers in general smoke at a faster rate when there is little else to do.

Three-Dimensional Theory of the Smith—Purcell Effect

Abstract: The radiation emitted when a beam of electrons passes over the surface of a perfectly conducting metal is discussed. The electrons constituting the beam all move with the same velocity in the same straight line but the charge density along the beam may vary in an arbitrary manner. The metallic surface considered is any surface which may be obtained by a small perturbation of a plane. Perturbation theory is used to derive explicit expressions for the electromagnetic field generated. The mathematical techniques employed involve the use of the angular-spectrum-of-plane-waves representation of the electromagnetic field. The results obtained go far beyond those of previous (two-dimensional) theories. The special case of a sinusoidally varying surface is treated in detail and a numerical calculation yields the physically important quantity---the number of optical photons emitted per charge per unit path length---for a particular arrangement.

LSD--an in vivo retrospective chromosome study.

Abstract: In 1967 it was first shown that the addition of d-lysergic acid diethylamide (d-LSD 25) to cultures of human leucocytes caused extensive in vitro chromosome damage (Cohen, Marinello & Back, 1967). Other in vitro studies (Jarvik, Kato & Moralishvili, 1968; Cohen, Hirschhorn & Frosch, 1967; Corey et al. 1970) supported these findings. Results of in vivo studies have been somewhat contradictory. The studies of three groups of investigators (Cohenet al. 1 9 6 7 ~ ; Irwin & Egozcue, 1967; Egozcue, Irwin & Maruffo, 1968; Cohen et al. 1968 ; Nielsen et al. 1968 ; Nielsen, Freidrich & Tsuboi, 1969) presented evidence in favour of an elevated breakage rate, while other studies (Loughman, Sargent & Isrealstam, 1967 ; Sparkes, Melnyk & Bozzetti, 1968; Judd, Brandkamp and McGlothlin, 1969; Stenchever & Jarvis, 1970; Hulten et al. 1968; Dorrance, Janeger & Teplitz, 1970; Lucas & Lehanbecker, 1969; Jarvik, 1969) did not support these findings. In a number of these in vivo studies important variables (e.g. the potency and purity of LSD used, the frequency of and dose per exposure, the time interval between exposure and sampling, the concomitant exposure to other drugs and many other variables) were not controlled. Controlled in vivo studies (Corey et al. 1970; Sparkes, Melnyk & Bozzetti, 1968; Bender & Siva Sankar, 1968; Siva Sankar, Rozsa & Giesler, 1969; Tjio, Pahnke and Kurland, 1969) have shown no significant increase in chromosome damage and one report (Hungerford et al. 1968) has suggested a slight transient increase. The carcinogenic potential of LSD has been suggested (Cohen et al. 19672,; Irwin & Egozcue, 1967; Egozcue et al. 1968; Cohen et al. 1968) and a number of studies (Irwin & Egozcue, 1967; Egozcue et al. 1968; Grossbard et al. 1968) have reported the presence of centric fragments resembling the Phl chromosome often associated with chronic granulocytic leukaemia. I n addition, two cases of leukaemia have been recorded in patients treated with pure LSD (Tylden, 1968; Garson & Robson, 1969). In an attempt to clarify some of these unexplained putative effects of LSD, a retrospective in vivo study was carried out, using as experimental subjects psychiatric patients who were treated under clinical conditions with known amounts of pure d-LSD 25. This report deals with the results of cytogenetic studies performed on 32 experimental subjects and on 32 controls.

Growth and enzyme production by Bacillus subtilis and Flavobacterium pectinovorum in Picea sitchensis

Abstract: When Sitka spruce (Picea sitchensis) is stored in water, an increase takes place in the permeability of the wood. This increase is due to bacterial degradation of the tori and bordered pit membranes and partial degradation of the crossfield pits. It has been demonstrated that two bacteria—Bacillus subtilis and Flavobacterium pectinovorum—isolated from this water stored wood, grow and produce amylase, xylanase and pectinase in sapwood blocks suspended in sterile pond water. Since these organisms have also been shown to increase the permeability of sapwood blocks, it has been concluded that they are primarily responsible for the permeability changes that occur when spruce poles are stored in lake water.

In the British Museum, London

Abstract: There is a collection entitled the Berkeley Papers, Additional MSS 39304–I6 (39312–16 contain nothing by B), which contains by far the largest and most important part of B’s manuscript remains It includes those private papers of the Bishop which passed to his son Dr George Berkeley, and thence to the latter’s son George Monck Berkeley, with whom the line ended Southey mentions them in his Omniana (1812, Lond, vol 1, p 251, sec 133): “A journal of his travels in Italy, and many other of his papers, remain unpublished His grandson, George Monck Berkeley, had he lived, would have given them to the public I know not what is become of them since the family has been extinct, but of such a man not a relick should be lost” They passed through the Grimston family to the Rose family The first public use made of them was when the widow of the Rev Hugh James Rose (Principal of King’s College, Lond; d 1838) lent them to J S M Anderson for his Hist of the Church of England in the Colonies (entry above, 275); see vol 3, p 176, n 10, p 461, p 488, n 23 Rose’s brother, Archdeacon Henry John Rose, later placed them at the disposal of Fraser when the latter was preparing his 1871 ed of the Works They were presented to the Brit Mus in 1916 by Mrs W F Rose For further particulars see B M Cat of Additions to the MSS 1916–20 (1933) and LL, pp xiff

Witch Hunting in Southwestern Germany, 1562–1684: The Social and Intellectual Foundations . By H. C. Erik Midelfort. Stanford: Stanford University Press, 1972. viii + 306 pp. $11.50.

Abstract: sion of Christianity in the period, one different from both the Church of Rome and mainstream Protestantism. Thus, Gastaldi sees the Anabaptists as more radical than other Christians because they wanted to rid the church of 1500 years of accumulated cultural baggage and restore it (restitutio) to New Testament purity. Moreover, like Williams, Littell and most other current historians of the topic, Gastaldi distinguishes between peaceful, mainstream Anabaptists and fanatical aberrations of the movement such as the one at Münster.

Lateral Distribution of u.h.f. Radio Emission associated with Cosmic Ray Showers

Abstract: A NUMBER of measurements have been made on the lateral distribution of radio emission from cosmic ray showers, in the frequency band 22.25 MHz to 178 MHz (refs. 1–6). These results have shown that near the air shower core the radio pulse amplitude falls off rapidly with distance, h the distribution at distances > 100 m being flatter. It has also been shown that the lower the observational frequency, the broader the lateral distribution for a given shower. Experiments by the Dublin group7,8 have indicated an upper limit of ≤100 m for the lateral distribution at 550 MHz. Here we report an extension of lateral distribution studies at two different u.h.f. frequencies.

The Single Atom Spectrometer and its Application in Chemistry and Biology

Abstract: MUCH work has been done on damage in solids caused by particulate and non-particulate radiation; however, the subsequent effect on the environment has been neglected. I have demonstrated1–3 that material can be transferred to an emitter whose electrons bombard a solid, and that single atoms and complexes liberated can be detected by the fluctuations they cause in the field emission when they impinge on the emitter. The present work was directed to detecting, recording and identifying these entities; in short, to the design of a single atom spectrometer.