Novel Regulators Of Phosphate Homeostasis In Phosphate Wasting Disorders
Funder
National Health and Medical Research Council
Funding Amount
$357,513.00
Summary
This project investigates two phosphate wasting disorders - tumour-associated osteomalacia and inherited X-linked low phosphate rickets. The active factor responsible for the tumour-associated condition remains unidentified and despite isolation of the gene responsible, the mechanism of the inherited rickets is also unexplained . The proposed outcomes of this project address both these issues. Whilst the condition of the tumour-associated osteomalacia is relatively uncommon, it continues to be a ....This project investigates two phosphate wasting disorders - tumour-associated osteomalacia and inherited X-linked low phosphate rickets. The active factor responsible for the tumour-associated condition remains unidentified and despite isolation of the gene responsible, the mechanism of the inherited rickets is also unexplained . The proposed outcomes of this project address both these issues. Whilst the condition of the tumour-associated osteomalacia is relatively uncommon, it continues to be a clinical problem because its presentation is often non-specific and the tumour is often very difficult to find. To date our studies have helped in the identification of patients likely to have the condition. Furthermore, while the phosphate wasting factor may be produced in abnormally large amounts by the tumour in this condition, it is likely that the factor and the enzyme which may be associated with it have physiological roles in maintaining normal phosphate concentrations. Looking further ahead, the phosphate wasting factor may have a clinical use in patients with renal failure and phosphate retention.Read moreRead less
In the normal process of hearing, the brain actively selects sounds of interest from competing background sounds. This normal auditory function is indispensible for children and adults to cope in non-optimal listening environments, however the mechanisms by which such performance is achieved are poorly understood. This project will investigate the nerve circuits that enable this to occur and will also investigate how these circuits malfunction in various types of partial deafness. The results wi ....In the normal process of hearing, the brain actively selects sounds of interest from competing background sounds. This normal auditory function is indispensible for children and adults to cope in non-optimal listening environments, however the mechanisms by which such performance is achieved are poorly understood. This project will investigate the nerve circuits that enable this to occur and will also investigate how these circuits malfunction in various types of partial deafness. The results will improve our understanding of how we detect sounds and the impact of hearing pathologies on this process.Read moreRead less
The Effects Of Inherent Inaccuracies In DXA In Vivo BMD Measurements On Osteopenic/Osteoporotic Diagnostics/Prognositics
Funder
National Health and Medical Research Council
Funding Amount
$411,980.00
Summary
Osteoporosis (porous bone) and consequent associated bone fractures of mainly post-menopausal women and the elderly of both genders constitutes a significant, widespread and rapidly growing public health problem. It is already a major health-cost burden in Australia and worldwide and is set to increase dramatically over the next few decades as the proportion of the population at or above the osteoporosis-prone age increases sharply. Current diagnostic evaluations of osteoporosis, bone mineral st ....Osteoporosis (porous bone) and consequent associated bone fractures of mainly post-menopausal women and the elderly of both genders constitutes a significant, widespread and rapidly growing public health problem. It is already a major health-cost burden in Australia and worldwide and is set to increase dramatically over the next few decades as the proportion of the population at or above the osteoporosis-prone age increases sharply. Current diagnostic evaluations of osteoporosis, bone mineral status of the skeleton, mechanical integrity of bone, and bone fracture risk are mainly based on X-ray absorption measurements of a given individual's bone mineral density (BMD) using Dual-energy X-ray Absorptiometric (DXA) bone densitometer instrumentation. New drugs to retard, ameliorate, or reverse the low bone mineral density condition of osteoporosis are now becoming available, but cannot be prescribed unless sufficiently low BMD is demonstrated for a given patient. The efficacy of these drugs is usually held to be greatest at the earliest stage of osteoporosis (osteopenia) and their effectiveness evaluated on the basis of DXA-measured bone mineral density. The Chief Investigator of this project has already shown by published quantitative analysis and simulation studies that such BMD measurements are inherently inaccurate; that errors of 20% and greater can readily pertain, particularly for those patients at the early stages of osteoporosis and those at or above the osteoporosis-prone age -- the very individuals for whom bone mineral density values are often of paramount interest and concern. These systematic DXA inaccuracies can be large enough to either mask the presence of osteoporosis or lead to false diagnoses and patient monitoring results. The present project, for the first time anywhere, is desiged to quantitatively establish the extent of these inaccuracies using actual DXA densitometers utilizing sophisitcated and precise methods.Read moreRead less