I am a cardiac pharmacologist investigating new therapies for the precursors of, and preventing their transition to, heart failure. My core activities focus on factors that control cardiac hypertrophy and ventricular function, in both the absence and pres
Effect Of Laparoscopic Gastric Banding And Angiotensin Converting Enzyme Inhibitor On Metabolic Myocardial Disease
Funder
National Health and Medical Research Council
Funding Amount
$210,054.00
Summary
The proposed research studies will add novel information about the effects of drug acting on Renin-Angiotensin-Aldosterone system and substantial weight reduction by key hole surgery on heart muscle stiffening and scar tissue formation due to obesity and diabetes. The knowledge gained will be essential to gain important insights into the underlying process of heart failure due to over-nutrition, high blood pressure, diabetes and define strategies aimed at reducing future heart failure.
Seminal findings within our laboratory have demonstrated that disturbances of blood flow are an important trigger for blood clot formation, promoting heart attacks and stroke. Our studies have demonstrated that specialised blood cells, termed platelets, respond rapidly to local changes in blood flow in diseased blood vessels. In the present proposal we aim to identify the mechanisms by which platelets sense and respond to blood flow disturbances with the aim of identifying new approaches to prev ....Seminal findings within our laboratory have demonstrated that disturbances of blood flow are an important trigger for blood clot formation, promoting heart attacks and stroke. Our studies have demonstrated that specialised blood cells, termed platelets, respond rapidly to local changes in blood flow in diseased blood vessels. In the present proposal we aim to identify the mechanisms by which platelets sense and respond to blood flow disturbances with the aim of identifying new approaches to prevent disease-causing blood clots.Read moreRead less
Single-Beat Preload Recruitable Stroke Work Measurement Of Cardiac Contractility In Three Mammalian Models.
Funder
National Health and Medical Research Council
Funding Amount
$241,980.00
Summary
The accurate measurement of the inherent pumping capacity of the heart muscle is difficult because (i) most measurements currently in use cannot accurately discriminate between the contribution of the heart muscle and that of the vascular system to the results obtained, and (ii) the measurements which can discriminate currently require invasive measurements and procedures that frequently restrict their use. The overall purpose of this proposal is to more rigorously validate a promising method we ....The accurate measurement of the inherent pumping capacity of the heart muscle is difficult because (i) most measurements currently in use cannot accurately discriminate between the contribution of the heart muscle and that of the vascular system to the results obtained, and (ii) the measurements which can discriminate currently require invasive measurements and procedures that frequently restrict their use. The overall purpose of this proposal is to more rigorously validate a promising method we have developed that will (i) make accurate assessment possible from a single cardiac beat in both experimental animals and human subjects; (ii) reduce the number of experimental animals required for such measurements by permitting sequential measurements in the same animals; (iii) make it possible to perform such measurements non-invasively in human subjects.Read moreRead less
Mechanically-restricted Percutaneous Gene Therapeutic Solutions For Heart Failure.
Funder
National Health and Medical Research Council
Funding Amount
$187,000.00
Summary
We have developed a novel system for the localized delivery of specialised genes to the heart in order to improve contractility and function of a failing heart. Many genes, for reasons of toxicity, clearance, or uptake, require direct delivery to the target region without spillover to the systemic circulation. Our system addresses these issues by isolating the local circulation of the target organ and directly delivering the agent with minimal systemic loss and improved delivery and uptake effic ....We have developed a novel system for the localized delivery of specialised genes to the heart in order to improve contractility and function of a failing heart. Many genes, for reasons of toxicity, clearance, or uptake, require direct delivery to the target region without spillover to the systemic circulation. Our system addresses these issues by isolating the local circulation of the target organ and directly delivering the agent with minimal systemic loss and improved delivery and uptake efficiency, while minimizing potentially dangerous and toxic systemic effects.Read moreRead less
Structural And Functional Alterations Of Sarcomeric Proteins In Reperfused Myocardium
Funder
National Health and Medical Research Council
Funding Amount
$271,786.00
Summary
Coronary artery disease remains the major cause of mortality for the adult population in our society. Despite the advances of coronary artery bypass surgery and medical treatment for reperfusion of occluded coronary arteries, the problem of impaired pump function of the heart remains a major obstacle. Although blood flow can be restored to the jeopardised heart muscle by either clot dissolving drugs, balloon angioplasty, or coronary artery surgery, the heart muscle may not regain pump function f ....Coronary artery disease remains the major cause of mortality for the adult population in our society. Despite the advances of coronary artery bypass surgery and medical treatment for reperfusion of occluded coronary arteries, the problem of impaired pump function of the heart remains a major obstacle. Although blood flow can be restored to the jeopardised heart muscle by either clot dissolving drugs, balloon angioplasty, or coronary artery surgery, the heart muscle may not regain pump function for days to weeks after the event. This delayed recovery of pump function, known as myocardial stunning, can lead to heart failure and slow down a patient's recovery from heart surgery or heart attack. The cause of this myocardial stunning is unknown. We suggest that stunning results from damage to essential proteins in the contractile apparatus of the heart, which requires a prolonged time period for repair. This project aims to identify the site and extent of protein damage occurring in the heart following interruption and subsequent restoration of cardiac blood flow. In concert with this, we seek to determine the mechanism of protein damage. The findings of this project should allow us to subsequently investigate new treatment approaches for acute pump dysfunction in patients with ischaemic heart disease.Read moreRead less
Contractile And Relaxant Effects Of B2- And B1-adrenoceptors In Human Heart: Blockade By A Third Generation B-blocker
Funder
National Health and Medical Research Council
Funding Amount
$136,320.00
Summary
The force and the duration of each heart beat can be modified in disease states affecting the heart. They can also be modified by chemicals which occur naturally in the body. Two of the most important naturally occurring chemicals which affect the function of the heart are (-)-noradrenaline and (-)-adrenaline. These chemicals and others which have been synthesized and optimized can also be used therapeutically. They work by activating proteins which occur on the cell surface, called b-adrenocept ....The force and the duration of each heart beat can be modified in disease states affecting the heart. They can also be modified by chemicals which occur naturally in the body. Two of the most important naturally occurring chemicals which affect the function of the heart are (-)-noradrenaline and (-)-adrenaline. These chemicals and others which have been synthesized and optimized can also be used therapeutically. They work by activating proteins which occur on the cell surface, called b-adrenoceptors. When activated, b-adrenoceptors cause an increase in the force of each heart beat and a reduction in the duration of each heart beat. This may be an advantage in conditions where the heart beat is too long. In this study we propose to map the biochemical pathways through which b-adrenoceptors affect each heart beat. The therapeutic management of heart failure has been revolutionized by the use of compounds which block b-adrenoceptors. One such drug, carvedilol is currently used in this country. The way in which it works may not be fully understood. In preliminary experiments we have identified a novel mechanism for carvedilol directly in human heart in which it may work and contribute to it's beneficial effects in the management of heart failure. Our studies will focus on this finding.Read moreRead less
Cardiac Arrhythmias And Cardiac Contractility During Stress: Regulation By Brainstem Medullary Raph Neurons
Funder
National Health and Medical Research Council
Funding Amount
$425,250.00
Summary
Life is stressful, and in subjects with predisposed hearts stressful events may provoke sudden life-threatening or fatal disturbances of the heart rhythm (arrhythmias). Activity in nerves that control the heart is the main trigger of arrhythmias. This activity is initiated in the brain, when, for example, we have a sudden emotional shock. At present, the neurochemistry and connections of the brain neurons responsible for arrhythmias, have not been identified. Our project is designed to find answ ....Life is stressful, and in subjects with predisposed hearts stressful events may provoke sudden life-threatening or fatal disturbances of the heart rhythm (arrhythmias). Activity in nerves that control the heart is the main trigger of arrhythmias. This activity is initiated in the brain, when, for example, we have a sudden emotional shock. At present, the neurochemistry and connections of the brain neurons responsible for arrhythmias, have not been identified. Our project is designed to find answers to these questions. Our hypothesis is that the responsible neurons are located in the midline portion of the medulla oblongata (the lower part of the brain); that activation of these neurons will increase cardiac function in a manner that may provoke arrhythmias; and, conversely, that their inhibition will protect the heart during stressful events by suppressing potentially arrhythmogenic neural signals. We hypothesise that cardiac-controlling neurons possess receptors for serotonin (one of the brain neurotransmitters), and that the neurons can be inhibited by drugs that selectively activate a specific subtype of these receptors. Our results will increase our understanding of the causes of cardiac arrhythmias by elucidating the link between emotional-psychological events in the brain and stress-induced cardiac events. Our findings could contribute to the identification of new drugs that will protect the heart during stress.Read moreRead less
Understanding The Myometrial Transition At Term And Preterm Labour To Guide Tocolysis
Funder
National Health and Medical Research Council
Funding Amount
$808,447.00
Summary
This grant seeks to understand how the muscle cells of the uterus transform at the time of labour. We propose that this transformation is organised by enzymes that modify the histones around key genes. We will test if a similar pathway operates in cases of preterm labour. The results will guide the development of new ways of treating premature labour that will use targeted nanoparticles to deliver siRNA directly to the muscle cells of the uterus.