QUANTITATIVE ASSESSMENT OF LOOSENING IN HIP ARTHROPLASTIES USING MECHANICAL VIBRATION DIAGNOSTICS
Funder
National Health and Medical Research Council
Funding Amount
$185,665.00
Summary
Recent advances and improvements made to the mechanical design of artificial joints have led to greater strength, fatigue life and wear resistance. However, this extension to the working life of joint replacements has led to patients becoming increasingly vulnerable to the problem of joint loosening. There are over 500 000 hip joint replacements performed every year, on a worldwide basis. Of these 7 to 13% will require revision surgery because of loosening at some stage of their working life. Th ....Recent advances and improvements made to the mechanical design of artificial joints have led to greater strength, fatigue life and wear resistance. However, this extension to the working life of joint replacements has led to patients becoming increasingly vulnerable to the problem of joint loosening. There are over 500 000 hip joint replacements performed every year, on a worldwide basis. Of these 7 to 13% will require revision surgery because of loosening at some stage of their working life. This is becoming a major concern to health services around the world since revision surgery is associated with a higher risk to the patient and costs are far greater than for the primary operation. Current diagnostic techniques using radiographic imaging are both invasive and lack diagnostic accuracy. The ability to detect joint loosening and to discriminate between the various causes of joint loosening following arthroplasty is of great importance to the success of subsequent care plans. This study will be the first in the world to assess the validity of a new diagnostic test that uses low energy mechanical vibration to quantify the degree of loosening in both components of the implanted hip joint. Once the technique has been proven it could readily be extended to evaluate the degree of fixation of other implanted prostheses used to replace the knee, ankle or joints of the upper limbs.Read moreRead less
Populations of viruses in an host can be very diverse and just as the behaviour of a population of humans can be very different to the behaviour of individuals in them, populations of viruses behave differently to the behaviour of individuals in them. This diversity may provide a survival advantage to the virus and it also may regulate the severity of the symptoms in an infected host. This study will provide important new information that will drive vaccine strategies and public health policy.
Orexins As Neuroendocrine Integrators Between Nutrition And Reproduction Control Systems
Funder
National Health and Medical Research Council
Funding Amount
$332,036.00
Summary
Studies on humans and a range of animal species have shown that the effects of nutrition on reproduction are mediated at least partly by changes in the secretion of gonadotrophin releasing hormone (GnRH) and thus gonadotrophins. A number of metabolic signals must also be involved but those tested to date (glucose, insulin, leptin) do not seem to play major roles. Two exciting new candidates are orexin-A and orexin-B, a recently discovered pair of peptides that stimulate feeding behaviour. They a ....Studies on humans and a range of animal species have shown that the effects of nutrition on reproduction are mediated at least partly by changes in the secretion of gonadotrophin releasing hormone (GnRH) and thus gonadotrophins. A number of metabolic signals must also be involved but those tested to date (glucose, insulin, leptin) do not seem to play major roles. Two exciting new candidates are orexin-A and orexin-B, a recently discovered pair of peptides that stimulate feeding behaviour. They are synthesized in the brain and, in rodents, they either stimulate or inhibit gonadotrophin secretion, depending on the presence of sex steroids. In this project, we will investigate the roles of the orexins as integrators of signals about gonadal activity, nutrition and body condition, all of which affect the activity of the reproductive control centres in the brain. We will use the mature male sheep because it shows clear and repeatable reproductive responses to changes in nutrition. We will locate the orexin-producing cells and the cells that respond to the orexins, and show how orexin production is affected by diet. We will also study the ways in which the orexins affect, and are affected by, the hormone systems that control reproduction and metabolism. Finally, we will try to find out why there are two orexins by looking at how their actions differ. Ultimately, the orexin system might explain the brain processes that are behind many of the reproductive problems that are associated with metabolic disorders, such as appetite loss, excessive exercise, undernutrition, polycystic ovarian syndrome, and insulin-dependent diabetes.Read moreRead less
Respiratory Modulation Of RVLM Premotor Neurons: Role In The Sympathetic Over-activity Of Hypertension.
Funder
National Health and Medical Research Council
Funding Amount
$338,605.00
Summary
Hypertension is a common health disorder in all societies and is a major risk factor for the development of life threatening cardiovascular diseases, including heart failure and stroke. Whilst some effective therapies are available, many patients are not adequately treated or have reduced quality of life due to serious side effects. There is a great need for alternative therapies. The central nervous system is clearly involved in hypertension although the level of that involvement is not well un ....Hypertension is a common health disorder in all societies and is a major risk factor for the development of life threatening cardiovascular diseases, including heart failure and stroke. Whilst some effective therapies are available, many patients are not adequately treated or have reduced quality of life due to serious side effects. There is a great need for alternative therapies. The central nervous system is clearly involved in hypertension although the level of that involvement is not well understood- i.e. is it a causal factor or just a contributor to the maintenance of established hypertension? The experiments outlined in this application are based on the observation that modulation of nervous activity to blood vessels is more influenced by the respiratory system in people with high blood pressure, than in normotensive people. We aim to test whether this increased respiratory modulation might be involved in the generation of the high blood pressure.Read moreRead less