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Biomedical subjects

D Ballantyne

Publications and source records attributed to D Ballantyne.

At least 91 records · Page 5Linked to original sources
PubMed1983

Coronary care in the elderly.

Over a five-year period (1974-78), 2947 patients were admitted to the Coronary Care Unit, Victoria Infirmary, Glasgow, and it was confirmed that 1474 of these patients had had a myocardial infarction. Over 70% were of state pensionable age, that is women over the age of 60 years and men over 65 years. No difference was found in the incidence of successful resuscitation from primary ventricular fibrillation following acute myocardial infarction between the under-60-year-old and over-70-year-old age groups. Further, this study did not show any rise in mortality, with age, following acute myocardial infarction.

Aged↗
PubMed1983

Ambulatory electrocardiography in squash players.

Ambulatory electrocardiography was carried out in 21 healthy, fit, male squash players (aged 23-43 years) before, during, and after match play. Resulting electrocardiograms were analysed with respect to heart rate and changes in rhythm. The results indicate that squash increases the heart rate to 80% of an individual's predicted maximum heart rate for the duration of a game. Ventricular arrhythmias were detected in seven of the subjects during play and in seven in the immediate post-exercise period, an incidence which was not reproduced on subsequent maximal treadmill exercise testing. This study indicates that squash is a physiologically demanding sport which places a severe strain on the myocardium for considerable periods of time and is capable of generating cardiac arrhythmias. These findings are particularly important for an individual already at risk of sudden death from coronary artery disease or structural cardiovascular abnormalities. Medical advice before participation in the game will identify those at high risk of cardiovascular disease. Subjects in this study who developed arrhythmias were not, however, identified by history, examination, or exercise electrocardiography. Thus, it seems unwise to begin playing squash after the age of 40 years. Whether subjects in this age group already participating in the game should continue to play remains a matter for individual judgment.

Adult↗
PubMed1983

Thiazides, beta blockers and lipoproteins.

Some of the more important recent studies on the effect of thiazides and beta-adrenoceptor blocking agents is conflicting, possibly because of differences in patient compliance and in lipoprotein methodology and quality assurance between studies. It is likely that in the short-term, thiazide diuretics produce an increase in plasma triglyceride and cholesterol and in LDL-cholesterol. No consistent effect of monotherapy with beta-adrenoceptor blocking agents was seen. Further long-term studies of monotherapy with both of these classes of drugs are required. Combined therapy with thiazides or beta-adrenoceptor blocking agents consistently increased plasma triglyceride concentrations, but their effect on VLDL, LDL and HDL concentrations is uncertain. Further research required into the effect of these drugs on apolipoproteins which may be useful discriminators for patients with coronary heart disease (Avogaro et al., 1979) and on HDL subfractions.

Adrenergic beta-Antagonists↗
PubMed1982

High density and low density lipoprotein subfractions in survivors of myocardial infarction and in control subjects.

The major lipoprotein classes (very low, low and high density lipoproteins, VLDL, LDL and HDL) and three lipoprotein subfractions (HDL2, HDL3 and LDL2) of 31 male survivors of myocardial infarction (MI) have been compared with those of 24 ostensibly normal subjects. The two groups had similar ages, relative weights, smoking and dietary habits, and physical activities. The MI survivors had significantly higher concentrations of total and VLDL-triglyceride and total and LDL-cholesterol than the control subjects. The differences in HDL-cholesterol, and total apolipoproteins A-1 and B were of borderline significance. HDL2 was significantly lower and LDL2 was higher in the MI survivors. There was no difference in HDL3. The differences in lipoprotein subfractions could be ascribed to differences in cholesterol, phospholipid and proteins, but not in triglyceride. The data suggest that the minor HDL2 subfraction shows a closer association with established coronary heart disease than does total HDL-cholesterol. The increased LDL-cholesterol concentration in the MI survivors can be ascribed at least partly to an increase in the major subfraction, LDL2.

Aged↗
PubMed1982

Critical closing pressure, local perfusion pressure, and the failing skin flap.

A simple apparatus was devised to perfuse the rat groin flap to study the relationship between perfusion pressure and flow. Results demonstrate that a relatively high intraarterial pressure must be applied to this skin flap before blood flow will commence. Results suggest that this critical closing phenomenon is the result of surface tension, blood rheology, venous pressure, tissue pressure, and vascular smooth muscle tone. Correlating the experiments of Milton and Landis reveals that, beyond a certain distance, local perfusion pressure in a skin flap gradually decreases with increasing distance from the flap base. These observations suggest that the perfusion boundary in a skin flap forms at the point where perfusion pressure has fallen to the level of the critical closing pressure. Methods of increasing survival length of a flap by decreasing critical closing pressure are discussed. The effects of edema and pressure dressings on flap and replant survival are examined in terms of the closing pressure concept.

Animals↗
PubMed1982

The effect of moderate physical exercise on the plasma lipoprotein subfractions of male survivors of myocardial infarction.

The effect of regular, moderate exercise on the lipoprotein subfractions of male survivors of myocardial infarction was studied. Nineteen men were randomly allocated to an incremental exercise program and 23 to a control group. Both groups were studied for 6 months. No change occurred in any lipoprotein class in the control group. In the trained group, total triglyceride and low-density lipoprotein (LDL) cholesterol concentrations decreased significantly (0.01 greater than p greater than 0.001 and 0.05 greater than p greater than 0.01, respectively) and high-density lipoprotein (HDL) cholesterol and apolipoprotein A-1 rose (both p less than 0.001). The concentration of the HDL2 subfraction increased with training (0.01 greater than p greater than 0.001) and HDL2 did not change. No relationship was found between changes in lipoproteins and treadmill exercise test performance. Thus, in survivors of myocardial infarction, exercise may alter plasma lipoprotein values beneficially.

Apolipoproteins↗
PubMed1981

Effect of slow oxprenolol and a combination of slow oxprenolol and cyclopenthiazide on plasma lipoproteins.

The effect of slow oxprenolol on plasma lipoprotein concentrations was compared to that of combined therapy with slow oxprenolol and cyclopenthiazide. The design of the study was a double blind between patient investigation in which 9 subjects with mild hypertension received slow oxprenolol and 11 slow oxprenolol and cyclopenthiazide. Plasma lipoproteins were analysed at 0, 2, 4, 8, 12 and 16 weeks. Slow oxprenolol given alone resulted in a significant rise in plasma and low density lipoprotein (LDL) cholesterol concentration whereas combined therapy with slow oxprenolol and cyclopenthiazide produced significant rises in plasma and very low density lipoprotein (VLDL) triglyceride. If one accepts that a rise in plasma or LDL cholesterol increases atherogenic risk more than a rise in plasma or VLDL triglyceride combined therapy is preferable.

Adult↗
PubMed1981

Combined vasodilator therapy in the treatment of chronic heart failure.

Treatment of resistant congestive cardiac faiure by vasodilators is now well accepted. Twelve such patients were started on Isosorbide Dinitrate and Hydralazine therapy and monitored for 24 hours. Oral treatment was then continued indefinitely. This group responded well to combined therapy and four had their regimes altered in the light of haemodynamic observations. It was then concluded that this type of treatment can be tailored to the individual patient to produce the best effects on preload and afterload.

Blood Pressure↗
PubMed1980

A prospective randomized trial of tocainide in patients following myocardial infarction.

One hundred forty-six patients with recent acute myocardial infarction were grouped at random into those treated with tocainide, an oral analogue of lignocaine, or placebo and followed up for 6 months. In addition to standard investigations, a 24-hour ambulatory taped ECG recording was obtained prior to randomization and thereafter at 2, 8, 16, and 24 hours after discharge. The ECGs were analyzed by means of an automated, computerized reporting system. Forty-two patients had significant ventricular arrhythmias, 10 of whom had effective plasma levels of tocainide compared with 27 patients on placebo (P < 0.005). In the placebo patients with increasing mobilization there was a consistent rise in the number of ventricular ectopic beats per day. There was no such increase in the tocainide patients (P < 0.01). Side effects were few and the incidence of central nervous system side effects was similar in both the tocainide and placebo groups. There was no conclusive evidence of myocardial depression, heart rate and blood pressure being unchanged over the 6-month period. Although ventricular arrhythmias were suppressed, the number of patients in the study was too small to draw conclusions regarding the mortality rate.

Anilides↗
PubMed1979

Response of plasma lipoproteins and acute phase proteins to myocardial infarction.

Plasma concentrations of lipoprotein-lipids, apolipoprotein B (apoB) and of seven other proteins have been estimated serially in 27 patients up to three months following myocardial infarction. Results were compared with those from age- and sex-matched control subjects. At three months the mean total, low density lipoprotein (LDL) and high density lipoprotein (HDL) cholesterol concentrations were higher than those of the control subjects, whereas very low density lipoprotein (VLDL) cholesterol, total and VLDL triglyceride, and total and LDL apolipoprotein B concentrations were not significantly different. Relative to concentrations at three months total and LDL cholesterol and apolipoprotein B concentrations fell markedly, and a slight fall occurred in HDL cholesterol following infarction. VLDL cholesterol and total and VLDL triglyceride were decreased only on day one. Albumin and transferrin concentrations were higher and alpha 1-acid glycoprotein was lower at three months than in the control subjects; alpha 2-macroglobulin, caeruloplasmin, haptoglobin and immunoglobulin IgM were not significantly different. Following infarction albumin and transferrin fell, alpha 2-macroglobulin did not change, and alpha 1-acid glycoprotein, caeruloplasmin, haptoglobin and IgM rose. The changes in both lipids and protein are probably part of the general metabolic response to trauma.

Acute Disease↗
PubMed1978

Plasma protein concentrations in hypertriglyceridaemic subjects. Effect of clofibrate and comparison with normal subjects.

Clofibrate, a widely used hypolipidaemic agent was given for twelve weeks to ten subjects with hypertriglyceridaemia. Its effect on lipoprotein-lipids and caeruloplasmin, IgA, IgM, alpha2-microglobulin and transferrin was assessed by comparing analyses at 4, 8 and 12 weeks on therapy with the means of values at two weeks before and at the start of treatment. The normal variation in plasma proteins was assessed in six healthy volunteers during the same period of time. On clofibrate, very low density lipoprotein (VLDL) cholesterol and triglyceride concentrations fell, but the concentrations of cholesterol in low density (LDL) and high density (HDL) lipoproteins showed no consistent change. Caeruloplasmin and IgM concentrations decreased significantly, IgA showed a limited falls (significant only at 8 weeks) and alpha2-macroglobulin did not change. The concentration of transferrin increased on therapy. No relationships were found between the falls in VLDL-lipid concentrations and the alterations in other plasma proteins. No significant variation occurred in the concentrations of lipids or proteins in the normal subjects during the period of study. The results indicate that clofibrate exerts general effects on protein metabolism.

Adult↗
PubMed1978

Interrelation of age, obesity, cigarette smoking, and blood pressure in hypertensive patients.

The relations between age, obesity, cigarette smoking, and blood pressure were investigated in 637 men and 835 women who had attended the Glasgow Blood Pressure Clinic with untreated hypertension. In contrast to results of population surveys of mainly normotensive people no relation was found between cigarette consumption and either systolic or diastolic blood pressure. Moreover, contrary to results of epidemiological studies a relation between adiposity and blood pressure was found in only male non-smokers. Thus the relations established for largely normotensive populations do not apply to hypertensive patients.

Adult↗
PubMed1978

Effect of clofibrate on the composition of very low and low density lipoprotein subfractions in type III hyperlipoproteinaemia.

The effect of clofibrate on the lipid and protein composition of very low and low density lipoprotein subfractions (VLDL of SF greater than 100, 60-100 and 20-60; LDL of Sf 10.4-20, 5.7-12 and 3.5-6.5), was investigated in 6 patients with type III hyperlipoproteinaemia (HLP). After four weeks of therapy significant reductions occurred in the concentration of cholesterol in each VLDL fraction, and of triglycerides in Sf greater than 100 and Sf 60-100 VLDL. No changes were found in the concentrations of apolipoprotein B or of the total tetramethylurea (TMU) soluble proteins, but in four patients in whom polyacrylamide disc gel electrophoresis of the TMU soluble proteins was carried out, it was found that arginine-rich peptide (ARP) had largely disappeared on therapy. These findings would be in keeping with increased catabolism of VLDL in response to clofibrate. No significant changes were observed in LDL lipid or protein concentrations.

Apolipoproteins↗