An Implementation Trial Of A Telephone-based Care Management Program For Patients Following Myocardial Infarction
Funder
National Health and Medical Research Council
Funding Amount
$641,656.00
Summary
We are trialling the implementation of an innovative telephone-delivered program for managing people who have had a heart attack. Cardiac rehabilitation programs are generally based in hospitals in Australia and people have to be able to attend the programs when they are offered. Even though such programs have been shown to be very effective in improving outcomes after a heart attack, at least 85% of Australians after a heart attack are either unable to access and-or unable to attend such progra ....We are trialling the implementation of an innovative telephone-delivered program for managing people who have had a heart attack. Cardiac rehabilitation programs are generally based in hospitals in Australia and people have to be able to attend the programs when they are offered. Even though such programs have been shown to be very effective in improving outcomes after a heart attack, at least 85% of Australians after a heart attack are either unable to access and-or unable to attend such programs due to transport and many other barriers. So, there is an urgent need to identify new, effective, and affordable ways of delivering cardiac rehabilitation programs to people after a heart attack. The proposed telephone-delivered program will be particularly appropriate for disadvantaged people, such as those living in rural and remote areas as well as Indigenous Australians, who do not currently have access to hospital-based cardiac rehabilitation programs. People who have had a heart attack will be recruited from three of Brisbane's largest public teaching hospitals, and will then be randomly assigned to the telephone-delivered cardiac rehabilitation program (Care Management Intervention group) or to a control or Usual Care group. The Care Management Intervention group will receive regular telephone calls from a highly qualified 'Care Manager' based at the renowned National Heart Foundation of Australia telephone support service, 'Heartline'. The Care Manager will help people to manage their heart condition and prevent the reoccurrence of further heart problems. People will also be encouraged to make necessary lifestyle and behavioural changes with the assistance of the Care Manager and some Heart Foundation educational and interactive resources to record their progress. We expect that the program or Care Management Intervention group will have better health outcomes than the control or Usual Care group at 6 and 12 months follow up.Read moreRead less
Targeting PI3K-regulated MicroRNAs To Treat Heart Failure
Funder
National Health and Medical Research Council
Funding Amount
$532,593.00
Summary
Current therapeutics largely delay heart failure progression rather than regressing it. New therapeutic strategies with the capability of improving function of the failing heart are thus greatly needed. The primary goal of this study is to determine whether novel regulatory genes can enhance cardiac function in a setting of heart failure. Ultimately, technologies that target these genes may lead to innovative pharmacotherapies in the clinical management of heart failure.
Molecular Mechanisms Of Receptor Activation And Signalling
Funder
National Health and Medical Research Council
Funding Amount
$571,980.00
Summary
Fundamental to our ability to respond to both immediate and long-term environmental changes and stresses is the coordinated regulation of cellular functions by hormonal and neurotransmitter stimuli. The great majority of such stimuli are sensed by G-protein coupled receptors (GPCR), complex glycoprotein molecules on the surface of most cells that selectively bind and are activated by various hormones and neurotransmitters. Although GPCRs are a superfamily of proteins that now compromise several ....Fundamental to our ability to respond to both immediate and long-term environmental changes and stresses is the coordinated regulation of cellular functions by hormonal and neurotransmitter stimuli. The great majority of such stimuli are sensed by G-protein coupled receptors (GPCR), complex glycoprotein molecules on the surface of most cells that selectively bind and are activated by various hormones and neurotransmitters. Although GPCRs are a superfamily of proteins that now compromise several hundred distinct but structurally-related members, the molecular mechanisms involved in their activation and, thus, their regulation of vital cellular functions, remains unclear. Based on insights that we have gained from the development and characterisation of several alpha1-adrenergic receptor mutants, we have developed a model of receptor activation. In this application we are proposing to further test and to extend the hypotheses underlying this model. Importantly, the functions regulated by GPCR include vital responses, such as the maintenance of circulatory homeostasis by augmenting heart pump function and by constricting vascular smooth muscle to maintain blood pressure. In addition, disordered cellular regulation by GPCR has been implicated in a wide variety of diseases, including hypertension, congestive heart failure and cardiac hypertrophy. Thus, the studies detailed here to further understand the molecular mechanisms of receptor activation have broad implications for our knowledge of critical physiological control systems, and may lead to novel therapeutic approaches to treat a variety of diseases.Read moreRead less
Role Of Transition Metal Ions And Redox Activity In The Development Of Atherosclerotic Plaques
Funder
National Health and Medical Research Council
Funding Amount
$196,018.00
Summary
Metal ions such as iron and copper have been reproted to be present in the lesions present in diseased human arteries and it has been suggested that these metal ions contribute to the development of atherosclerosis (hardening of the arteries) via their ability to catalyse the formation of highly reactive molecualr fragments called free radicals. Though metal ions are known to catalyse such reactions in test-tube experiments, both the presence of metal ions in diseased arteries and their ability ....Metal ions such as iron and copper have been reproted to be present in the lesions present in diseased human arteries and it has been suggested that these metal ions contribute to the development of atherosclerosis (hardening of the arteries) via their ability to catalyse the formation of highly reactive molecualr fragments called free radicals. Though metal ions are known to catalyse such reactions in test-tube experiments, both the presence of metal ions in diseased arteries and their ability to generate free radicals is controversial. This study will employ a novel, minimally-invasive, technique to assess the nature and quantity of metal ions present in well-defined human and animal lesions at different stages of lesion development. The ability of these metal ions to catalyse free radical formation from components present in the artery wall will also be assessed. The release of these metal ions from the artery wall to added organic molecules will be assessed as this might minimise their potential to cause damage, and provide a possible therapeutic strategy. These studies will therefore provide valuable information as to the significance and role of reactive metal ions in the development of human artery disease and the possible prevention, or minimisation, of such processes.Read moreRead less
THE BAROREFLEX IN SNORING AND THE OBSTRUCTIVE SLEEP APNOEA HYPOPNOEA SYNDROME
Funder
National Health and Medical Research Council
Funding Amount
$436,261.00
Summary
The obstructive sleep apnoea hypopnoea syndrome (OSAHS) refers to a condition in which throat blockage occurs during sleep leading to breathing difficulties, including snoring and cessation of breathing for short periods of time. OSAHS is amongst the commonest of chronic disorders of adult males, occuring in 5% of men over the age of 45 years. It is now recognised that one of the major complications of OSAHS is the development of high blood pressure and heart disease. In the proposed studies, we ....The obstructive sleep apnoea hypopnoea syndrome (OSAHS) refers to a condition in which throat blockage occurs during sleep leading to breathing difficulties, including snoring and cessation of breathing for short periods of time. OSAHS is amongst the commonest of chronic disorders of adult males, occuring in 5% of men over the age of 45 years. It is now recognised that one of the major complications of OSAHS is the development of high blood pressure and heart disease. In the proposed studies, we will examine the proposal that snoring alone, without significant associated OSAHS, can also lead to high blood pressure in habitual snorers both awake and asleep. In particular, we will explore the hypothesis that chronic snoring transmits a pressure wave through the tissues of the neck to the carotid artery which is the main blood supply to the brain. We propose that the chronic vibration of this artery can alter pressure sensors in the artery wall, which then results in the persistance of high blood pressure. Our studies will help to prove that this is a mechanism whereby both snoring and OSAHS may contribute to the development of high blood pressure. The recognition of snoring as an independent risk factor for high blood pressure will clearly have important and wide ranging implications for the future management of snoring in the prevention of high blood pressure.Read moreRead less
Identification Of Heterogeneity In Vasodilator Function In Human And Rat Resistance Vessels: Potential Drug Targets?
Funder
National Health and Medical Research Council
Funding Amount
$595,330.00
Summary
The balance between the ways that blood vessels decrease in size (constrict) and increase in size (dilate) determine how blood vessels normally function. There are many differences in the ways that blood vessels control this balance in different parts of the body. Such differences are altered in vascular diseases, such as hypertension and diabetes, which are prevalent in obesity, such that constriction generally outweighs dilation. However, what these differences are and how they occur are not w ....The balance between the ways that blood vessels decrease in size (constrict) and increase in size (dilate) determine how blood vessels normally function. There are many differences in the ways that blood vessels control this balance in different parts of the body. Such differences are altered in vascular diseases, such as hypertension and diabetes, which are prevalent in obesity, such that constriction generally outweighs dilation. However, what these differences are and how they occur are not well understood. While current drugs for treating vascular disease either reduce vessel constriction or increase dilation, they are not specific for individual arteries; a situation that would allow us to control vascular diseases in a very specific manner. Recently, we have described differences between the ways that individual vessels are controlled. These changes relate to differences in the way that different vessels dilate. AIMS - To further understand normal blood vessel function and the changes that occur in blood vessels in cardiovascular disease, with a focus on the ways that blood vessels dilate in normal states and in obesity-related diseases, such as in hypertension and diabetes. - The eventual aim is to identify the specific ways that arteries function, so that artery-specific drug targets can be identified to treat disease-related changes in cardiovascular disease in a very specific manner. EXPECTED OUTCOMES This project will contribute to understanding blood vessel function in health and disease. The expected eventual outcome is the identification of the mechanisms that underlie the function of different arteries in different parts of the body, so that specific individual vessel function can be targeted to treat vascular disease. Additionally, this work will also verify the relevance of the diet-induced obesity animal model, in terms of the characteristics and causes of human obesity and related cardiovascular disease.Read moreRead less
Drug-induced Immune Thrombocytopenia: Understanding The Disease Mechanisms Is The Key To Better Treatment
Funder
National Health and Medical Research Council
Funding Amount
$509,550.00
Summary
Many very commonly used medications cause an allergic reaction in a small number of patients that receive them. The allergic reaction results in platelets being destroyed and puts the patients at risk of bleeding. The patient recovers slowly if the drug is stopped but there is no other treatment and no way to reverse the effect quickly if the patient starts to bleed. This project will try to understand the mechanism of the condition and test a potential treatment.
Mitochondrial Iron Overload And Friedreich's Ataxia: The Role Of Frataxin In Iron And Haem Metabolism
Funder
National Health and Medical Research Council
Funding Amount
$285,990.00
Summary
Friedreich's ataxia (FA) is due to the lack of a protein known as frataxin. Recent studies using Baker's yeast have shown that the deletion of frataxin results in the accumulation of toxic iron in the mitochondrion. More recently, a variety of studies have shown that FA patients have iron loading within their cells. The iron build-up may cause severe damage. At present, the role of frataxin in mammalian mitochondrial iron metabolism is unknown. Our preliminary studies demonstrate that frataxin i ....Friedreich's ataxia (FA) is due to the lack of a protein known as frataxin. Recent studies using Baker's yeast have shown that the deletion of frataxin results in the accumulation of toxic iron in the mitochondrion. More recently, a variety of studies have shown that FA patients have iron loading within their cells. The iron build-up may cause severe damage. At present, the role of frataxin in mammalian mitochondrial iron metabolism is unknown. Our preliminary studies demonstrate that frataxin is down-regulated by either erythroid differentiation or the haem precursor protoporphyrin IX (Becker and Richardson, submitted). These data strongly suggest a role for frataxin in iron metabolism. In the present study we will continue to assess if frataxin plays a role in the way cells handle iron. Using a unique model of mitochondrial iron overload developed in my lab (Richardson et al. (1996) BLOOD 87:3477), we will extensively investigate the iron metabolism of the mitochondrion in order to determine the function of frataxin and its role in Friedreich's ataxia. In addition, we have developed a series of new drugs known as iron chelators that can enter the mitochondrion due to their high lipid solubility (Becker and Richardson 1999 J. Lab. Clin. Med. 134:510). These latter drugs are far more effective than the chelator currently used to treat iron overload, desferrioxamine (DFO). Indeed, our chelators have been designed to result in high iron chelation efficacy but low toxicity (see Becker and Richardson, 1999). This exciting research may be crucial in understanding the development of FA and in creating new therapies such as the use of iron chelators.Read moreRead less
Mitochondrial Iron Overload And Friedreich's Ataxia: The Role Of Frataxin In Iron And Haem Metabolism
Funder
National Health and Medical Research Council
Funding Amount
$606,000.00
Summary
Friedreich's ataxia (FA) is due to the lack of a protein known as frataxin. A variety of studies using Baker's yeast and conditional frataxin knockout (KO) mice have shown that deletion of frataxin leads to the accumulation of toxic iron in their mitochondrion. More recently, a variety of studies have shown that FA patients have iron-loading within their mitochondrion. Iron in the highly redox active environment of the mitochondrion could contribute to the generation of cytotoxic radicals that c ....Friedreich's ataxia (FA) is due to the lack of a protein known as frataxin. A variety of studies using Baker's yeast and conditional frataxin knockout (KO) mice have shown that deletion of frataxin leads to the accumulation of toxic iron in their mitochondrion. More recently, a variety of studies have shown that FA patients have iron-loading within their mitochondrion. Iron in the highly redox active environment of the mitochondrion could contribute to the generation of cytotoxic radicals that cause severe damage. Further, cells deficient in frataxin are sensitive to oxidant stress and Fe chelators rescue oxidant-mediated death of cells from FA patients. Indeed, free radical scavengers have shown to be of use in the treatment of this disease. Studies in DR's lab during this NHMRC grant have shown that frataxin is down-regulated by erythroid differentiation or the haem precursor, protoporphyrin IX (BLOOD 2002;99:3813-22). These data indicate a role for frataxin in Fe metabolism and the pathogenesis of FA. In this study we will continue to examine the role of frataxin in the way cells handle Fe using experimental models developed under the current NHMRC grant. These include transfected cell lines with low frataxin expression generated using an expression vector containing anti-sense frataxin cDNA. Further we obtained the frataxin conditional KO mouse and generated a breeding colony. These animals display many of the pathological features of FA and are the best current model of the disease. Indeed, they will be critical for assessing the role of frataxin in Fe metabolism and as a model to test the ability of Fe-binding drugs to prevent the pathology observed. We designed lipid-soluble chelators that can enter the mitochondrion to bind Fe (Biochim Biophys Acta 2001;1536:133-140) and these ligands will be tested to prevent disease progression in the KO mice. This exciting research is crucial for understanding the pathogenesis of FA and in creating new therapies.Read moreRead less
A NOVEL MOUSE MODEL TO INVESTIGATE THE MECHANISMS OF VIRUS-INDUCED ARTHRITIS
Funder
National Health and Medical Research Council
Funding Amount
$336,000.00
Summary
We have developed a novel animal model by which to study arthritic disease caused by insect-transmitted viruses known as arboviruses. The existence of this model and novel reagents provides an excellent opportunity to further explore the basic mechanisms of infectious disease in a complete functioning animal, rather than specific cultured cells. The study will use modern approaches in molecular and cellular biology to achieve this goal. The production by our immune systems of soluble mediators ( ....We have developed a novel animal model by which to study arthritic disease caused by insect-transmitted viruses known as arboviruses. The existence of this model and novel reagents provides an excellent opportunity to further explore the basic mechanisms of infectious disease in a complete functioning animal, rather than specific cultured cells. The study will use modern approaches in molecular and cellular biology to achieve this goal. The production by our immune systems of soluble mediators (cytokines-chemokines) and antibodies is an overwhelming positive aspect of our physiological response to infection by microbes. Protection from disease by these immune compounds can happen naturally, or the body's ability to produce these factors can be exploited to our benefit via the administration of vaccines. However, these factors can also be detrimental to the host contributing to severe disease. For instance, work performed almost 40 years ago showed for the first time that under particular conditions, antibodies against viruses can enhance infection, instead of inhibiting infection as normally seen. In the intervening years work by scientists all over the world has associated antibody-dependent enhancement (ADE) of infection to many types of viruses; ADE is even thought to be a risk factor to serious disease with dengue virus, and has been shown in vitro for the AIDS virus and Ebola virus. We have recently discovered a molecular mechanism which explains how antibody enhances viral infection in vitro. In studies on immune cells infected with Ross River Virus (RRV) we found that infection helped by antibody resulted in the specific disruption to the production of cellular chemicals which are toxic to viruses. Are these mechanisms of antibody-enhanced infection also found in animals? Will such mode of infection cause enhanced disease and tissue pathology (arthritis) in animals?Read moreRead less