Arise the systems physician.

Healthcare in Australia faces significant challenges. Variations in care, suboptimal safety and reliability, fragmentation of care and unsustainable cost increases are compounded by substantial overuse and underuse of clinical interventions. These problems arise not from intentional actions of individual clinicians, but from deficiencies in the design, operations and governance of systems of care. Physicians play an important role in optimising systems of care and, in doing so, must rely on enhanced skills in a range of domains. These include: how to evaluate and improve quality and safety of clinical processes; analyse and interpret clinical and administrative data in ways that can be used to enhance care delivery; build and lead cohesive multidisciplinary teams capable of solving operational defects and inefficient workarounds; and implement new and effective innovations in clinical service delivery. While clinical skills are essential in individual patient care, skills that improve systems of care targeting whole patient populations will become increasingly desirable and recognised as core skills.

Effects of adrenalectomy and corticosterone administration on hypothalamic obesity in rats.

The present experiment was designed to assess the role of adrenal hormones in hypothalamic hyperphagia and obesity. Ventromedial hypothalamic (VMH) or sham lesions were produced either 15 days before or after adrenalectomy (ADX) or sham adrenalectomy in rats in a completely counterbalanced design (experiment 1). Body weight and food intake were recorded for 30 days after the second surgery. Adrenalectomy in obese VMH animals eliminated all excess weight gain and decreased food intake to below the level of all control groups. VMH lesions in ADX animals did not produce the characteristic weight gain associated with ventromedial hypothalamic damage, and this group was not significantly different from animals with sham lesions in body weight or food intake. In experiment 2, the administration of corticosterone resulted in a marked increase in the rate of weight gain in ADX-VMH animals, and the withdrawal of the hormones was followed by weight loss. It is concluded that adrenal glucocorticoid hormones are necessary for the development and maintenance of VMH hyperphagia and obesity.

Hypothalamic obesity in female rats in absence of vagally mediated hyperinsulinemia.

In order to assess the role of vagally mediated hyperinsulinemia in hypothalamic obesity, plasma insulin and glucose levels were assayed in vagotomized and sham-vagotomized female rats after a 6-h fast and after a measured glucose meal both before and 10-14 days after ventromedial hypothalamic (VMH) lesions. Both groups displayed similar gains in body weight in the first 10 days after VMH lesions, but only the sham-vagotomized VMH-lesioned animals displayed elevated fasting insulin levels. Fasting glucose levels did not differ either before or after the lesion. The insulin response to oral glucose was increased in VMH rats, both in vagotomized and sham-vagotomized animals, and it is concluded that the hyperresponsiveness to oral glucose is independent of vagal mediation. Vagotomy markedly exaggerated the glucose and insulin response to oral glucose loading in both intact rats and rats with VMH lesions, probably as a result of more rapid absorption of glucose from the intestine. It is concluded that the fasting hyperinsulinemia that is characteristic of VMH animals is under vagal control and that its elimination does not prevent the development of obesity.