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Biomedical subjects

M E Carruthers

Publications and source records attributed to M E Carruthers.

16 recordsLinked to original sources
PubMed1988

Stress/catecholamine-induced cardiac necrosis. Reduction by beta 1-selective blockade.

Catecholamine-induced cardiac necrosis is a well-described phenomenon. Patients with severe head injury are known to be in a marked hyperadrenergic state and can experience cardiac morbidity; this was confirmed in a pilot study. A further study was then undertaken to examine a possible relationship between plasma catecholamine concentration and cardiac morbidity in patients with severe head injury and to assess the effect of intervention with the beta 1-selective agent atenolol. The study involved 114 hemodynamically stable patients with acute head injury who were randomized, double blind, to either placebo or atenolol given intravenously (10 mg every six hours) for three days and then orally (100 mg once a day) for four days. Both groups were equally stressed in terms of raised arterial norepinephrine levels. In patients receiving placebo, but not in those given atenolol, there was a significant (P less than 0.01) positive correlation between arterial level of norepinephrine and plasma level of cardiac-specific isoenzyme CK-MB. Thirty percent of the placebo group, in contrast to 7.4% of the atenolol group (P less than 0.05), had pathologically elevated CK-MB levels (ie, greater than 3% of total CK, a value compatible with acute myocardial infarction). Atenolol appeared to significantly reduce the likelihood of supraventricular tachycardia and ST-segment and T-wave changes and prevented cardiac necrosis (as determined post mortem). The finding that beta 1-selective blockade significantly inhibits catecholamine-induced necrosis has possible broad clinical implications.

Adolescent↗
PubMed1987

Reduction of stress/catecholamine-induced cardiac necrosis by beta 1-selective blockade.

114 haemodynamically stable patients with acute head injury were randomised, double-blind, to either placebo or atenolol given intravenously (10 mg every 6 h) for 3 days then orally (100 mg daily) for a further 4 days. Both groups were equally stressed as shown by raised arterial noradrenaline levels. In patients receiving placebo, but not in those receiving atenolol, there was a significant (p less than 0.01) positive correlation between arterial noradrenaline and levels of the myocardial isoenzyme of creatine kinase (CKMB). 30% of the placebo group compared with 7.4% of the atenolol group (p less than 0.05) showed CKMB levels greater than 3% of total creatine kinase (compatible with myocardial damage). CKMB levels greater than 6% of total creatine kinase (compatible with acute myocardial infarction) were present in 16.7% of patients receiving placebo but in no patients receiving atenolol (p = 0.053). Atenolol appeared to reduce significantly the likelihood of supraventricular tachycardia and ST-segment and T-wave changes and prevented cardiac necrosis seen at necropsy.

Adolescent↗
PubMed1983

Psychosomatic aspects in idiopathic infertility: effects of treatment with autogenic training.

It has long been recognised that there is a relationship between emotional stress and some forms of infertility. We have endeavoured to estimate "stress' levels before and after Autogenic Training in 15 couples with infertility of at least two years' duration. Potential stress markers were: plasma prolactin, total urinary free cortisol and catecholamines, and four psychological tests: Spielberger State-Trait anxiety scale, Taylor Manifest Anxiety Scale, the Cattell 16 personality factor questionnaire, and the Eysenck Personality Questionnaire. A control group of ten normal couples was included for comparison. The biochemical finding of higher mean prolactin levels in the female patients vs their controls was of particular interest. The significant reduction of the prolactin level, in parallel with decreased anxiety scores following treatment, supports the hypothesis that the elevated prolactin levels in these patients are indeed linked with emotional stress.

Adult↗
PubMed1977

Plasma glucagon levels in haemorrhagic shock.

Eleven healthy dogs were subjected to haemorrhagic shock for 90 min. after which shed blood was reinfused. Detailed studies were made of cardiopulmonary function. Samples of blood were taken at frequent intervals for the measurement of glucagon, insulin and glucose. Three dogs had samples taken for catecholamine levels. The glucagon level rose during haemorrhagic shock but there was no relationship between this rise and the change in cardiorespiratory measurement, but there was a relationship between the plasma glucagon level, the blood glucose and the catecholamine level. It is suggested that the release of glucagon in haemorrhagic shock is mediated by sympathetic stimulation of the alpha cell and that the rise in glucagon is in part responsible for the hyperglycaemia which is found in shock.

Animals↗
PubMed1976

British pilot study of exercise therapy. I. Middle-aged men.

The physiological and biochemical effects of a carefully graduated course of vigorous gymnasium training with two or three weekly exercise sessions lasting only 15 minutes have been studied in middle-aged London business men. Activity diaries and psychological questionnaires indicated that these men had a positive attitude to exercise which was probably greater than average. The gymnasium exercises caused a large oxygen debt and considerable rises in plasma catecholamines and lactate levels. A close correlation was found between the pulse rate during exercise and the Borg scale of perceived exertion, so that both could be used to ensure that short periods of exercise were sufficiently vigorous to produce a training effect, and protect against over-exertion. The acceptability of this particular exercise regime was shown by the low fall-out and injury rate. It is suggested that this exercise training programme possesses many features which are advantageous if increased physical activity is to be more widely used as a method of reducing some of the risk factors in coronary heart disease.

Adult↗
PubMed1976

British pilot study of exercise therapy. II. Patients with cardiovascular disease.

Two groups of middle-aged men, one with and one without overt cardiovascular disease, were studied while they were taking part in a specially designed course of exercise therapy in a gymnasium. The "patients" group had at least two months pre-treatment to allow physical recovery and mental re-education before their initial very small test dose of exercise. Using short periods of progressive, mainly weight-loaded, isotonic exercises carefully regulated by control of pulse rate and avoidance of symptoms of over-exertion, both groups showed large increases in effort capacity and reductions in resting pulse rate, blood pressure and plasma lipid levels within two months. The safety of this particular form of exercise was shown in this high-risk population by the low drop-out rate and the absence of cardiovascular accidents in the gymnasium over a ten year period. It is suggested that, given suitable training of the staff and using the safeguards described, the presence of doctors and a cardiac resuscitation team is unnecessary in a gymnasium specializing in cardiac rehabilitation. This makes it possible for rehabilitation and physiotherapy departments throughout the country to carry out this effective and positive form of exercise therapy.

Adult↗
PubMed1970

Computer analysis of routine pathology work schedules using a simulation programme.

A simulation programme is described which compares the efficiency of laboratory work schedules. The number of days' delay on a sample of request forms submitted to a routine biochemistry laboratory has been calculated for each of three schedules. Analysis of the results indicated that this method of comparing existing and potential work routines is likely to lead to a significant acceleration in the return of pathology results to the clinician.

Biochemical Phenomena↗
PubMed1966

Raised serum copper and caeruloplasmin levels in subjects taking oral contraceptives.

A marked increase in the serum copper and caeruloplasmin levels in 25 female subjects taking oral contraceptives is noted. The correlation between the copper and caeruloplasmin concentrations, together with the finding of normal urine copper levels in 10 of the subjects, suggests that the increased serum copper is due to increased caeruloplasmin synthesis.

Adolescent↗