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Biomedical subjects

A McDonald

Publications and source records attributed to A McDonald.

At least 127 records · Page 7Linked to original sources
PubMed1984

Body cooling in human males by cold-water immersion after vigorous exercise.

Five male subjects were immersed to neck level in a whole-body water calorimeter (water temperature 19 degrees C) on two occasions. One immersion was preceded by 30 min of exercise on a treadmill at 80% of the subjects' maximum heart rate, while the other was preceded by no exercise (control). Ventilation, oxygen consumption, hand-grip strength, and heat loss (measured by calorimetry) results showed no significant differences between resting and exercise trials. Minute ventilation and oxygen consumption increased during the immersion but the magnitude of the increase varied among subjects. There was a significant decrease is isometric hand-grip strength after 30 min of immersion. Rectal temperatures fell faster (0.031 degree C +/- 0.004 degree C/min) for exercised subjects than for controls (0.019 degree C +/- 0.005 degree C/min) between 10 and 45 min of immersion (P less than 0.01). It appears that vigorous preimmersion exercise may shorten survival time in cold water due to an increase in cooling rate.

Adult↗
PubMed1983

A probable case of Chromobacterium violaceum infection in Australia.

A case of a north-Queensland Aboriginal child, who died of a septicaemic illness probably caused by Chromobacterium violaceum, is reported. This organism is a Gram-negative bacillus found in soil and water. Human and animal infections are very rare, but have been reported from various tropical and subtropical areas of the world. Most of these have been fatal, although survival after recognition, appropriate antibiotic therapy, and surgical intervention has also been reported.

Australia↗
PubMed1983

Predicting coliform concentrations in upland impoundments: design and calibration of a multivariate model.

This paper reports on the calibration and use of a multiple regression model designed to predict concentrations of Escherichia coli and total coliforms in two upland British impoundments. The multivariate approach has improved predictive capability over previous univariate linear models because it includes predictor variables for the timing and magnitude of hydrological input to the reservoirs and physiochemical parameters of water quality. The significance of these results for catchment management research is considered.

Enterobacteriaceae↗
PubMed1982

Cerebral palsy and severe educational subnormality in low-birthweight children: a comparison of births in 1951-53 and 1970-73.

The prevalence at school age of cerebral palsy and severe education subnormality in children of low birthweight (less than or equal to 4 lb=1814 g) born to residents in the region served by the South East Thames Regional Health Authority in the early 1970s was compared with that in children of the same birthweight born in 1950-53. The prevalence of one or both of these defects was lower in the 1970s cohort; this was due to both a fall in the incidence of extreme gestational immaturity among children of low birthweight and a reduction in risk of defects to the gestationally immature births that occurred. The decreased risk of these defects in children of low birthweight was approximately counter-balanced by the increased likelihood of their survival; among children of all birthweights the prevalence of these defects attributable to children of very low birthweight changed little.

Cerebral Palsy↗
PubMed1982

Generation of fecal and total coliform surges by stream flow manipulation in the absence of normal hydrometeorological stimuli.

The response of Escherichia coli and total coliform concentration to increases in river discharge was investigated. Artificial hydrographs were generated on eight occasions between 21 October 1979 and 3 March 1981 by releasing water from Thruscross Reservoir in North Yorkshire into Fewston Reservoir. The majority of the releases were made after rainless periods to isolate the effects of stream channel entrainment from those induced by rainfall on the land surface. In the absence of rainfall, bacterial concentrations are shown to increase more than 10-fold in response to stage increases. It is suggested that two stores of bacteria must exist on the catchment, the first being a land store and the second a channel or near-channel store. Movement from the land to the channel store must relate to hill slope hydrological processes, whereas movement between stores in the channel fluvial system may be closely allied to sedimentary processes. Some consideration is given to bacterial levels in relation to European Economic Communities guidelines for contact recreation.

England↗
PubMed1981

A study of homicide: the validity of predictive test factors.

This study is a retrospective comparison of the psychological test findings within four groups, including 61 murderers, 42 assaulters, 71 perpetrators of theft, and 24 unemployed non-criminal controls. Psychological test findings did not discriminate very well among these groups. Some purported hostility scales, such as the Elizur Hostility Scale, the DeVos Hostility Scale, and Megargee's Overcontrolled-Hostility Scale, did not discriminate at all. The 16 Personality-Factor Questionnaire was particularly unhelpful, rating all four groups as having above-average emotional stability, One must conclude that individual psychological test factors are of little value in predicting violent behaviour. Further research is being undertaken to separate the murder group into motivational sub-categories.

Adult↗
PubMed1980

Mushrooms and madness. Hallucinogenic mushrooms and some psychopharmacological implications.

This article reviews the major hallucinogenic fungi both for their historical as well as neurochemical import. Despite voluminous literature on them, relatively little study has focused on psilocybin related substances that could relate to forms of psychotic illness. Some metabolic pathways are reviewed which illustrate the need for more study of indole compounds such as baeocystin.

Amanita↗
PubMed1979

Tension pneumoperitoneum complicating cardiac resuscitation.

A case of gastric rupture and tension pneumonperitoneum following cardiac resuscitation is presented. Respiratory embarrassment necessitated emergency decompression by needle puncture of the peritoneal cavity, followed by laparotomy and repair of the gastric tear. The post-operative course has been satisfactory. The aetiology of the gastric rupture is discussed and recommendations are made for the prevention and treatment of this unusual complication of combined mouth to mouth respiration and external cardiac massage.

Humans↗
PubMed1979

The limits of Munchausen's syndrome.

The authors review the literature on Munchausen's syndrome and speculate about possible underlying psychological mechanisms. The proposed DSM III classification of factitious illnesses suggests a continuum from hysteria on one end of the spectrum to malingering on the other. Two case studies are presented which represent variants of this syndrome. Both patients were given a sodium amytal interview, a procedure not previously reported in the Munchausen's literature. The procedure was helpful in eliciting a more accurate history and a clearer sense of the underlying dynamics. Some suggestions for further research are made.

Adult↗
PubMed1978

Mystical seven.

Explore the source record for details and available documents.

Female↗
PubMed1976

Analog computer assisted beat-by-beat measurement of stroke volume and related variables in man.

A technique for the beat-by-beat measurement of stroke volume is described. Aortic blood velocity signals are obtained from a catheter-mounted electromagnetic velocity transducer and analysed by a purpose-built analog computer. The stroke volume is computed by integration of each period of systolic forward flow using the velocity signal as its sole input. Automatic compensation of flowmeter drift is incorporated and inappropriate triggering of integration by diastolic artefact is prevented by applying both amplitude and duration criteria for the recognition of systolic forward flow. Early diastolic reverse flow is excluded from integration. The cardiac output, mean aortic flow per beat, and interbeat interval are also computed from the velocity signal. With aortic pressure as an additional input signal the mean arterial pressure per beat and systemic vascular resistance can be computed. The computer outputs are calibrated by a manual method. Preliminary studies comparing values for the cardiac output measured by this system and the direct Fick technique have indicated an excellent correlation between the two methods.

Aorta↗
PubMed1975

Colchicine inhibition of the heparin-stimulated release of clearing-factor lipase from isolated fat-cells.

When isolated fat-cells are incubated at 25 degrees C in serum-based media containing glucose, insulin and heparin, the rise that occurs in the clearing-factor lipase activity of the incubation medium is inhibited by colchicine. The rise in the fat-cell clearing-factor lipase activity that occurs during similar incubations in the absence of heparin is not affected by colchicine.

Adipose Tissue↗