Determination Of Irradiation Dose Efficacy For Use In Impaction Grafting At Revision Joint Replacement
Funder
National Health and Medical Research Council
Funding Amount
$411,517.00
Summary
Primary hip replacement is a successful intervention for hip disease, but 10-15% of hip prostheses fail and require revision surgery within 10-15 years. At the time of revision, significant bone loss around the failed prosthesis is not uncommon. A bone reconstruction procedure, called impaction grafting, where donor bone is minced and placed in the areas of deficient bone before implanting the new prosthesis, has shown to give good results at more than ten years in some centres. A high incidence ....Primary hip replacement is a successful intervention for hip disease, but 10-15% of hip prostheses fail and require revision surgery within 10-15 years. At the time of revision, significant bone loss around the failed prosthesis is not uncommon. A bone reconstruction procedure, called impaction grafting, where donor bone is minced and placed in the areas of deficient bone before implanting the new prosthesis, has shown to give good results at more than ten years in some centres. A high incidence of early complications of this procedure have included loss of fixation within the bone. Fracture of the bone around prostheses has also reported in some centres. These events require more surgery, putting the patient at higher risk greater complications and longer rehabilitations. Recent improvements in surgical technique and donor bone preparation have improved results. A current debate questions whether the dose of irradiation can be reduced from 25 kGy, while maintaining sterility of allografts. The risk of bacterial contamination in allografts is low, and irradiation reduces the mechanical strength of the graft, contributing to complications when irradiated bone is used. The benefits of decontaminating the bone may be outweighed by the higher risk for failure due to poor bone quality and resulting prosthesis instability. We will use ISO standards to test the validity of radiation dose for sterilising bone ex vivo. In the absence of controlled human studies, our aim is also to compare the results of impaction grafting with non-irradiated bone versus bone irradiated at current doses used by Australian bone banks, and lower doses indicated by ex vivo testing. We will use a large animal model of revision hip replacement, with precise measures of prosthesis stability. The results of this study will guide clinical decisions regarding the efficacy of current bone graft preparation procedures and the use of irradiated bone in human hip replacement surgery.Read moreRead less
Role Of IGF Binding Protein-3 (IGFBP-3) And IGFBP-5 As Modulators Of Nuclear Hormone Signalling
Funder
National Health and Medical Research Council
Funding Amount
$465,750.00
Summary
The insulin-like growth factors are small proteins involved in the growth of most tissues. Their actions are regulated by binding to larger proteins (known as IGFBPs) in the bloodstream and outside the cell. However, some IGFBPs are also found inside cells, where they seem to carry out other functions. We believe that two of these binding proteins, IGFBP-3 and IGFBP-5, change the way cells respond to vitamin A and vitamin D. These two vitamins are important in cell growth and in the way certain ....The insulin-like growth factors are small proteins involved in the growth of most tissues. Their actions are regulated by binding to larger proteins (known as IGFBPs) in the bloodstream and outside the cell. However, some IGFBPs are also found inside cells, where they seem to carry out other functions. We believe that two of these binding proteins, IGFBP-3 and IGFBP-5, change the way cells respond to vitamin A and vitamin D. These two vitamins are important in cell growth and in the way certain cells perform specialised functions. In test-tube experiments, IGFBP-3 and IGFBP-5 interact directly with the receptors that regulate the effects of these hormones. If the same thing happens inside the cell, IGFBP-3 and IGFBP-5 could change the way these receptors respond to signals from outside the cell. We will investigate what effect these IGFBPs have in living cells and in whole animals and how this may relate to human disease. If we are able to understand how IGFBP-3 and IGFBP-5 affect the way cells respond to vitamin A and D, then we may be able to develop new ways to treat certain human diseases.Read moreRead less
The Clinical Value Of Serology And Molecular Tests For Diagnosing Invasive Aspergillosis In At-risk Hematology Patients
Funder
National Health and Medical Research Council
Funding Amount
$1,095,500.00
Summary
Aspergillus is a fungus found in soil, on farms and on construction sites. In those whose immune system is impaired it causes severe infection. The people who are particularly at high-risk of Aspergillus infection (called Invasive Aspergillosis) are those with acute leukaemia on chemotherapy or post bone marrow transplantation. Currently 15% of those at high-risk get Invasive Aspergillosis and 58-93% of those infected die. The main reason for this high death rate is that our current diagnostic t ....Aspergillus is a fungus found in soil, on farms and on construction sites. In those whose immune system is impaired it causes severe infection. The people who are particularly at high-risk of Aspergillus infection (called Invasive Aspergillosis) are those with acute leukaemia on chemotherapy or post bone marrow transplantation. Currently 15% of those at high-risk get Invasive Aspergillosis and 58-93% of those infected die. The main reason for this high death rate is that our current diagnostic tests are not good at detecting infection or often only detect the infection at advanced stages when treatment is ineffective. Because of the limitations of current diagnostic tests the current practice is to give empiric antifungal therapy (EAFT) early to treat Invasive Aspergillosis. However studies have demonstrated that this therapy has only resulted in a minor reduction in the mortality rates and it causes significant drug toxicity. It is a suboptimal treatment modality. New tests have been developed to diagnose Invasive Aspergillosis. These tests are for the detection of an Aspergillus protein in blood and for the detection of Aspergillus DNA in the blood. Available data suggests that these new tests are sensitive in the detection of Invasive Aspergillosis. Also other studies suggest that these new tests make an early diagnosis and seem to be able to monitor responses to treatment. However no study has been performed to date which demonstrates that the use of these tests can impact on important patient outcomes. This trial is designed to determine whether the use of the new tests to guide therapy will help improve treatment of Invasive Aspergillosis, reduce drug toxicity and reduce the death rate in the high-risk patients as compared with the current standard method of diagnosis and treatment with EAFT. If the trial is successful then this represents a significant advancement in the treatment and survival of leukaemic and bone marrow transplantation patients.Read moreRead less
We will seek to address an important clinical problem in orthpaedics, namely the bone loss that commonly occurs around joint replacement prostheses. Termed peri-prosthetic osteolysis (PO), this bone loss can result in the loosening and ultimate failure and need for revision of the artificial joint components. PO is thought to be caused by the body's reaction to wear particles generated from the articulating surface of the prosthesis. However, it has not previously been possible to accurately exp ....We will seek to address an important clinical problem in orthpaedics, namely the bone loss that commonly occurs around joint replacement prostheses. Termed peri-prosthetic osteolysis (PO), this bone loss can result in the loosening and ultimate failure and need for revision of the artificial joint components. PO is thought to be caused by the body's reaction to wear particles generated from the articulating surface of the prosthesis. However, it has not previously been possible to accurately explore the relationship between prothesis wear and PO, or the progression of PO, because of a lack of techniques to image and measure the volume of PO around metal prosthesis components. We have developed a means to accurately and reproducibly measure the volume of bone loss, using CT, and will do so longitudinally in joint replacement patients to obtain the first information about the progression of PO. New computer based methods will be used concurrently to relate prosthesis wear and migration parameters to PO. Patients who come to surgery for replacement of failed prostheses will be investigated further by analysis of the tissues involved in the bone loss around prostheses. Basic science experiments will seek to understand the underlying causes of PO and the findings will be important in interpreting the clinical results. An animal model will be used to seek approaches to inhibiting the pathological response to wear particles. The significance of these studies is that they will lead to improved outcomes for joint replacement patients, increasing the interval to revision surgery, which is both extremely costly and brings an attendant morbidity and mortality.Read moreRead less
Characterisation Of Human Embryonic Stem Cell Differentiation To Haematopoietic Progenitors And Stem Cells
Funder
National Health and Medical Research Council
Funding Amount
$638,856.00
Summary
Blood stem cells, which are found in the bone marrow, are currently used for treating human blood disorders including leukemia and lymphoma. However, for the majority of bone marrow transplant candidates, suitable donors cannot be found. Using embryonic stem cells, this project aims to define the conditions required to generate blood stem cells in the laboratory. The aim of the work is to provide a new source of blood stem cells that could be used in place of donor derived bone marrow.
Regulation Of Key Pathways Causing Peri-implant Bone Loss.
Funder
National Health and Medical Research Council
Funding Amount
$403,639.00
Summary
The failure of bone prostheses is becoming a major health problem in our aging population. Despite the impressive success of joint replacement surgery, a significant number of arthroplasties fail. It is now apparent that most implants fail due to bone loss around them which leads to loosening. This project aims to obtain a better understanding of the causes of implant failure and find ways to extend the life of these implants .
Mechanisms Guiding Pathfinding And Positioning Of Cortical Interneurons
Funder
National Health and Medical Research Council
Funding Amount
$621,606.00
Summary
Brain disorders place an economic and social burden on Australia and the personal costs of these illnesses are immeasurable. Several brain abnormalities are caused from the failure of neurons to position themselves in the correct location when the brain develops. Our study aims to discover how neurons move and what factors influence this process. It provides an understanding of normal brain development, as well as providing insight into what may go wrong in the formation of brain diseases.
The Risks And Benefits Of Contemporary Total Hip Replacement
Funder
National Health and Medical Research Council
Funding Amount
$493,530.00
Summary
The number of hip replacements undertaken in Australia is steadily increasing. The most common complications of hip replacements are dislocation and loosening due to bone loss around the implant, requiring complex and expensive revision surgery. This study will investigate the incidence of dislocation and, using a new diagnostic imaging technique, the incidence and amount of bone loss around a relatively new prosthetic material, the outcomes of which are not known despite its increasing use.
Understanding How Language And Reading Problems Develop: A Population-based Longitudinal Study From Infancy To Age 7
Funder
National Health and Medical Research Council
Funding Amount
$667,507.00
Summary
Early language and reading problems are common and therefore significant public health problems. They are disabling and have life-long implications for oral and written communication skills, social and emotional well-being, cognition, behaviour, academic achievement and employment. This study will address the following three problems: 1. To date no study has documented how language and reading problems develop from infancy (8 months) through to school age (7 years). 2. Little is known about risk ....Early language and reading problems are common and therefore significant public health problems. They are disabling and have life-long implications for oral and written communication skills, social and emotional well-being, cognition, behaviour, academic achievement and employment. This study will address the following three problems: 1. To date no study has documented how language and reading problems develop from infancy (8 months) through to school age (7 years). 2. Little is known about risk factors, identified early in infancy and childhood, that can be reliably used to predict language and reading problems later in childhood. 3. The relationships between language difficulties and reading problems are poorly understood. Therefore, we currently have no satisfactory methods for reliably detecting which children at much younger ages are at risk of later language disorders or reading problems. Without this information it is impossible to develop effective prevention and early intervention programs. These programs are critical if we are to: a) Prevent language and reading problems from occurring, thereby reducing the prevalence of the problem b) Intervene early in childhood, thereby reducing in the longer term the burden and cost associated with language and reading problems. The proposed study builds on an existing substantial investment by the NHMRC in the Early Language in Victoria Study (ELVS). It will provide a world-first description of the evolution of language difficulties and reading problems from infancy through to school age within a single population cohort.Read moreRead less