Transdisciplinary Research In Frailty: Knowledge Translation To Inform New Models of Care.

Transforming care for frail older adults requires more than rigorous research. While preventing, identifying and managing frailty are critical to reducing the personal and health systems impact of frailty worldwide, collaborative approaches to research and research application that reflect stakeholder perspectives and priorities are necessary to create meaningful solutions to frailty-related challenges. In South Australia, a new Centre for Research Excellence in Frailty was recently launched with funding from the National Health and Medical Research Council of Australia.

The preoperative management of phaeochromocytoma.

Although the preoperative use of alpha-receptor antagonist drugs is generally accepted for patients with phaeochromocytoma, evidence on the most appropriate treatment and its timing is scarce. In this retrospective study, the effectiveness of the preoperative preparation of fourteen patients who required surgical excision of a phaeochromocytoma was examined in the light of their operative stability. A simple score was developed of blood pressure stability by scoring the need for additional antihypertensive agents intraoperatively before, and blood pressure support after, tumour removal.

5-Hydroxytryptamine-induced contraction of the marmoset aorta is mediated by a 5-HT1-like receptor.

1. 5-Hydroxytryptamine (5-HT) exerts both contractile and relaxant effects in the marmoset isolated aorta, actions that are unaffected by the 5-HT2 antagonist ketanserin. The aim of the present study was to define the receptors mediating the contractile activity of 5-HT in the marmoset aorta.

Functional tolerance to alpha-adrenergic receptor blockade in the spontaneously hypertensive rat highlights the multifunctional role of vascular angiotensin II in the development of hypertension.

Treatment of spontaneously hypertensive rats (SHR) with alpha-adrenoceptor antagonists failed to alter the development of hypertension in this animal model. However, agents such as captopril (CAP) and losartan (LOS) which interfere with the renin-angiotensin system effectively prevented the development of hypertension. When tolerance occurred in the presence of doxazosin (DOX) or phenoxybenzamine, there was an enhanced sensitivity to the blood pressure lowering influence of LOS.

The influence of the renin angiotensin system on abnormal expression of nerve growth factor in the spontaneously hypertensive rat.

1. The levels of the neurotrophic factor, nerve growth factor (NGF) in the mesenteric vascular bed of the spontaneously hypertensive rat (SHR) were greater than those in the corresponding vascular bed of normotensive Wistar-Kyoto rats (WKY). 2.

Sympathetic suppression attenuates anomalous responses to morphine in unexplained pain after cholecystectomy.

Anomalous responses to morphine are common in patients with unexplained pain in the upper abdomen after cholecystectomy and may be linked to activation of the sympathetic nervous system. The hypothesis that sympathetic suppression would attenuate anomalous responses to morphine was tested by a randomized, cross-over trial using a standard challenge with morphine, with and without pretreatment with clonidine (300 micrograms orally, 1 h prior to the administration of morphine). In 13 of the 15 patients who completed the study, pre-treatment with clonidine decreased plasma concentrations of noradrenaline, dopamine and adrenaline by 56, 15 and 25% respectively.

Phaeochromocytoma: intraoperative changes in blood pressure and plasma catecholamines.

The aim of this study was to assess the relationship between changes in plasma catecholamine concentrations and intra-arterial blood pressure (BP) measured simultaneously during resection of phaeochromocytoma (n = 14). Arterial plasma concentrations of noradrenaline (NA), adrenaline (A) and dopamine (DA) were measured by a radio-enzymatic method. Arterial NA concentrations (pmol/ml; median and Wilcoxon 95% CI) were 71.

The effect of captopril treatment and its withdrawal on the gene expression of the renin-angiotensin system.

The mRNA expression of renin, angiotensinogen and angiotensin converting enzyme (ACE) was determined in the kidneys and livers from spontaneously hypertensive rats (SHR) and Wistar-Kyoto rats (WKY) during chronic treatment with captopril and following its withdrawal. Chronic captopril treatment was associated with a dramatic rise in renin mRNA in the kidney and an elevation in mRNA for ACE in the liver. The release from captopril treatment was associated with a reversal of the increase in kidney renin mRNA but no reversal of the sustained elevation of ACE mRNA in the liver.

Interactions between 5-hydroxytryptamine, noradrenaline and the thromboxane-A2 mimetic U44069 in the marmoset isolated aorta.

1. The effects of 5-hydroxytryptamine (5-HT) in the absence and presence of noradrenaline (NA) or the thromboxane-A2 mimetic, U44069, were investigated in ring preparations of marmoset aorta. 2.

The expression and localisation of the angiotensin-converting enzyme mRNA in human adipose tissue.

Recent evidence in rats has indicated that angiotensinogen may be synthesised in adipose tissue surrounding blood vessels and that a local renin-angiotensin system may regulate adipose tissue blood supply and the efflux of fatty acids from fat in that species. This hypothesis is critically dependent on the local expression of the angiotensin converting enzyme gene in adipocytes. Thus the current study set out to examine whether the angiotensin converting enzyme gene was expressed in human adipose tissue and, if it was present, to localise the individual sites of that expression.

Identification of a nonendothelial cell thromboxane-like constrictor response and its interaction with the renin-angiotensin system in the aorta of spontaneously hypertensive rats.

Aortic ring preparations from spontaneously hypertensive rats (SHR) and normotensive Wistar Kyoto (WKY) rats were treated with N omega-nitro-L-arginine (NOLA, 10(-4) M). This produced a sustained contraction in preparations from SHR but not WKY rats. A similar contraction in aortic ring preparations from the SHR was produced with methylene blue (10(-5) M) and NG-monomethyl-L-arginine (10(-5) M).

Angiotensin II-mediated facilitation of sympathetic neurotransmission in the spontaneously hypertensive rat is not associated with neuronal uptake of the peptide.

Evidence suggests that angiotensin II (AII) can modulate neuroeffector responses in the vasculature of spontaneously hypertensive rats (SHR). Included in this modulation is an action of AII in facilitating release of neurotransmitter from sympathetic nerves by a mechanism involving prejunctional angiotensin receptors. In addition, AII may be a substrate for the carrier processes that operate within sympathetic nerves.

Influence of alpha 1- and alpha 2-adrenoceptor antagonist therapy on the development of hypertension in spontaneously hypertensive rats.

There is general agreement that the sympathetic nervous system is involved in the development of hypertension in spontaneously hypertensive rats (SHR). However, in a previous study we established that chronic administration of the selective alpha 1-adrenoceptor antagonist terazosin to SHR failed to prevent this phenomenon. In the present study, we extended that investigation further by examining the effects of another selective alpha 1-antagonist (doxazosin), an alpha 2-adrenoceptor antagonist (yohimbine), and a combination of these agents.

Plasma catecholamine levels during exposure to an environment of hyperbaric oxygen.

Plasma catecholamine levels were measured before, during and after hyperbaric oxygen therapy in nine subjects. Adrenaline levels were elevated immediately prior to hyperbaric oxygen therapy, but then fell and stabilized once treatment commenced. No significant fluctuations in plasma dopamine or noradrenaline levels were noted during the treatment period.

The use of calcium channel blockers in general practice.

Over the past decade the calcium antagonist drugs, also known as calcium channel blockers, have become established for use in a variety of cardiovascular diseases. A bewildering (and ever-growing) number of drugs in this class now becoming available. This article summarises the important characteristics of the calcium antagonists and discusses their practical use in hypertension, angina and other conditions in general practice.

The influence of chronic captopril treatment and its withdrawal on endothelium-dependent relaxation.

The current experiments were designed to explore the relationship between the renin angiotensin system (RAS) and prostanoid formation in aortic ring preparations from spontaneously hypertensive rats (SHR). A further aim was to examine the mechanisms responsible for the reversal of the impaired acetylcholine (ACh) mediated relaxation induced by chronic administration of the angiotensin converting enzyme inhibitor captopril and the relationship of the ACh response to blood pressure. Rats were administered captopril (100 mg/kg/day) and their blood pressures monitored from 5 to 17 weeks of age.