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Biomedical subjects

J Bligh

Publications and source records attributed to J Bligh.

At least 19 recordsLinked to original sources
PubMed1995

Problem-based learning in medicine: an introduction.

Problem-based learning is an innovative and challenging approach to medical education--innovative because it is a new way of using clinical material to help students learn, and challenging because it requires the medical teacher to use facilitating and supporting skills rather than didactic, directive ones. For the student, problem-based learning emphasises the application of knowledge and skills to the solution of problems rather than the recall of facts. It is an approach much favoured by curriculum planners in new and more progressive medical schools. This paper describes the educational basis of problem-based learning and gives an example of how it operates in undergraduate medical education.

Education, Medical, Undergraduate↗
PubMed1995

The changing context of undergraduate medical education.

It has long been recognised that intensive efforts are needed to reform medical education in order to meet the future needs of populations worldwide. Pressure for changes to the organisation, content and delivery of both undergraduate and postgraduate medical education has greatly increased in the last two decades. The experience of innovative medical schools, the emergence of learner-centred teaching methods and the implications of health-care reforms in North America and Britain are major factors influencing calls for change. The pace of change has accelerated to such an extent in recent years that progress towards widespread reform appears to be more attainable than ever before. This article provides an overview of the changing context of health-care, some patterns of existing medical education and some strategies for change.

Curriculum↗
PubMed1995

Oncocytic metaplasia of bile duct epithelium in hepatic GVHD.

A 15-year-old female underwent matched unrelated BMT for chemotherapy resistant ALL. She died 3 months later from septicaemia complicating grade IV GVHD. Light and electron microscopic examination of the post-mortem liver confirmed GVHD and showed oncocytic metaplasia of interlobular bile duct epithelium. We report that oncocytic metaplasia of bile duct epithelium is part of the pathological spectrum of hepatic GVHD.

Adolescent↗
PubMed1989

The increased oxygen uptake upon immersion. The raised external pressure could be a causative factor.

The principal cause of the immediate transient elevation in ventilation (VE, L.min-1) and oxygen uptake (VO2, L.min-1), when a human subject is immersed in cold water is considered to be the stimulation of cutaneous cold receptors. The present study demonstrates that the initial VE and VO2 responses are comprised of a thermogenic and a hydrostatic component. The peak values in VE reached (mean +/- SD) 66.8 +/- 22.3, 53.9 +/- 38.1, 32.2 +/- 15.4, 22.5 +/- 3.6, 19.5 +/- 4.6 L.min-1 during the first minute of immersion in 10 degrees, 15 degrees, 20 degrees, 28 degrees and 40 degrees C water, respectively. Similarly, peaks (mean +/- SD) in VO2 of 1.22 +/- 0.25, 1.01 +/- 0.32, 0.98 +/- 0.39, 0.81 +/- 0.09, and 0.78 +/- 0.26 L.O2.min-1, were reached when subjects were immersed in 10 degrees, 15 degrees, 20 degrees, 28 degrees, and 40 degrees C water. It is concluded that the observed increases in VO2 during the first minute of immersion are partly due to the increased hydrostatic pressure causing a shift of venous blood towards the thoracic region, and a transient increase in the uptake of oxygen into the blood.

Body Temperature↗
PubMed1989

Core threshold temperatures for sweating.

To detect shifts in the threshold core temperature (Tc) for sweating caused by particular nonthermal stresses, it is necessary to stabilize or standardize all other environmental and physiological variables which cause such shifts. It is, however, difficult to cause progressive changes in Tc without also causing changes in skin temperature (Tsk). This study compares the technique of body warming by immersion in water at 40 degrees C, and subsequent body cooling in water at 28 degrees C, to determine the core threshold for sweating, with one by which Tc was raised by cycling exercise in air at 20 degrees C, and then lowered by immersion in water at 28 degrees C. The first of these procedures involved considerable shifts in Tsk upon immersion in water at 40 degrees C, and again upon transfer to water at 28 degrees C; the second procedure caused only small changes in Tsk. The onset of sweating at a lower esophageal temperature (Tes) during immersion in water at 40 degrees C (36.9 +/- 0.1 degrees C) than during exercise (37.4 +/- 0.3 degree C) is attributed to the high Tsk since Tes was then unchanged. Likewise, the rapid decline in the sweat rate during immersion at 28 degrees C had the same time course to extinction after the pretreatments. This related more to the Tsk, which was common, than to the levels or rates of change of Tes, which both differed between techniques. Tes fell most rapidly, and thus sweating was extinguished at a lower Tes, following 40 degrees C immersion than following exercise.(ABSTRACT TRUNCATED AT 250 WORDS)

Air↗
PubMed1981

Amino acids as central synaptic transmitters or modulators in mammalian thermoregulation.

Of the amino acids that affect the activity of central neurons, aspartate and glutamate (which exert generally excitatory influences) and glycine, taurine, and gamma-aminobutyric acid (GABA) (which generally exert inhibitory influences) are the strongest neurotransmitter candidates. As with other putative transmitter substances, their effects on body temperature when injected into the cerebral ventricles or the preoptic hypothalamus tend to vary within and between species. These effects are uninterpretable without accompanying information regarding effector activity changes and the influences of dose and ambient temperature. Observations necessary for analysis of apparent action have been made in studies of the effects of intracerebroventricular injections of these amino acids into sheep. Aspartate and glutamate have similar excitatory effects on the neural pathways that activate both heat production and heat loss effectors. Glycine appears to be without effect.

Amino Acids↗
PubMed1980

Diuretic effect of intraventricular and intravenous infusions of noradrenaline in conscious sheep.

Infusion of noradrenaline at rates between 32-160 nmol.min-1 for 30 min into one lateral cerebral ventricle of conscious sheep caused a diuresis which was accompanied by negative solute-free water reabsorption and which lasted for 90-120 min. The range of noradrenaline infusion rates used reflects differences between individual animals in the rate of infusion necessry to cause diuresis. Intracerebroventricular (ICV) infusion of noradrenaline at half the diuretic rate caused no significant changes in urine flow. The diuresis induced by ICV noradrenaline infusion was prevented by concurrent ICV administration of the alpha-adrenergic antagonist, phentolamine, but was not prevented by concurrent ICV administration of the beta antagonist, propranolol, or by concurrent intravenous infusion of phentolamine. Intravenous infusion of noradrenaline at rates that were diuretic by ICV infusion caused a diuresis of approximately 30 min duration which coincided with the period of intravenous noradrenaline infusion. This diuresis was prevented by concurrent intravenous infusion of phentolamine. These results were interpreted as indicating that the higher rates of ICV infusion of noradrenaline caused the prolonged water diuresis by acting at a site in the brain and, thereby, inhibiting the release of endogenous vasopressin. ICV infusion of noradrenaline at all rates was followed by a reduction in mean arterial blood pressure and pulse pressure with variable changes in heart rate and by depression of the rates of renal clearance of PAH, potassium and total solute.

Animals↗
PubMed1979

Effect of intraventricular injection of transmitter substances and temperature on autonomic functions of conscious sheep.

1. Changes in cardiovascular and renal functions following injection of noradrenaline, 5-hydroxytryptamine and carbachol into one lateral cerebral ventricle were investigated in conscious sheep at ambient air temperatures of 0 and 40 degrees C. The dose rates used were known to produce predictable changes in thermoregulation in sheep. 2. The changes in body temperature, respiratory frequency and shivering caused by the intracerebroventricular (I.C.V.) injections of noradrenaline, 5-hydroxytryptamine and carbachol were as reported previously. 3. The cardiovascular and renal responses of the sheep at both high and low ambient temperatures were consistent for each transmitter indicating that these activities had no major dependence on the type of thermoregulatory response. 4. I.C.V. injection of noradrenaline increased heart rate and decreased pulse pressure but caused no change in mean arterial blood pressure (B.P.). Urine flow rate, sodium clearance, potassium clearance and osmolal clearance were decreased whereas solute-free water reabsorption was unaltered. 5. I.C.V. injection of 5-hydroxytryptamine caused no significant alterations in either cardiovascular or renal function. 6. I.C.V. injection of carbachol increased systolic and diastolic B.P., heart rate and haematocrit. Sodium, potassium and osmolal clearances were increased after administration of carbachol. 7. The changes in renal function after noradrenaline and carbachol injection could be explained by the concurrent changes in cardiovascular function.

Animals↗
PubMed1979

Aspects of thermoregulatory physiology pertinent to hyperthermic treatment of cancer.

Local hyperthermia is relatively safe, while whole-body hyperthermia is potentially dangerous because the therapeutically effective elevation of body temperature is close to the tolerable limit to hyperthermia beyond which permanent damage may be caused. Here consideration is given to the most reliable index of body temperature during hyperthermia and the techniques for raising body temperature. The possibility of effecting local brain cooling and thereby increasing the margin of safety during whole-body hyperthermia is also considered.

Animals↗