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
Postviral Wheezing In Childhood: Disregulation Of Airway Tone?
Funder
National Health and Medical Research Council
Funding Amount
$577,040.00
Summary
Asthma is a very common childhood condition that is becoming increasingly more common. Wheezing is common in infants and young children following viral infections and is often thought of as the first manifestation of asthma. However, many children and infants who wheeze with viral infections appear to grow out of asthma in their teenage years. Asthma that persists into adult life is usually associated with allergies to common environmental allergens, such as house dust mite and grass pollens. Ho ....Asthma is a very common childhood condition that is becoming increasingly more common. Wheezing is common in infants and young children following viral infections and is often thought of as the first manifestation of asthma. However, many children and infants who wheeze with viral infections appear to grow out of asthma in their teenage years. Asthma that persists into adult life is usually associated with allergies to common environmental allergens, such as house dust mite and grass pollens. However, many infants who wheeze with viral infections, especially in the first year of life, do not develop allergies in later life, raising the possibility that they did not have the same type of asthma as those whose symptoms persist. This project will study the effects of viral infections on lung function to determine whether particular types of virus can have detrimental effects of lung function lasting for years. We will also examine whether the age at which the infection occurs and the severity of the infection influence the long-term outcome. The project involves studying infants during the recovery phase of respiratory viral infections, older children years after documented infections and experimental animal models that have been infected under controlled conditions. By determining whether respiratory viral infections can have long-term effects on lung function that can mimic asthma, we will advance our understanding of how asthma develops. In addition, specific treatment and preventative strategies could then be developed to prevent these long-term abnormalities, instead of relying on asthma medication (especially inhaled corticosteroids) as is the current practice. Preventative strategies could include encouraging the development of specific vaccines.Read moreRead less
Anaphylaxis To Australian Native Ant Venoms; Major Allergens, Cross-reactivity, Diagnosis And Risk Assessment.
Funder
National Health and Medical Research Council
Funding Amount
$345,813.00
Summary
Insect venom allergy is a major cause of life-threatening allergy (anaphylaxis) in this country, and native ants are the most frequent cause in some regions. For introduced insects (bees and wasps), venom extracts are widely available for diagnostic and therapeutic use, but this is not yet the case for native ants. As many as 50,000 Australians may be affected by allergy to stings from ants in the native genus Myrmecia. This project will provide an in-depth understanding of the ant species respo ....Insect venom allergy is a major cause of life-threatening allergy (anaphylaxis) in this country, and native ants are the most frequent cause in some regions. For introduced insects (bees and wasps), venom extracts are widely available for diagnostic and therapeutic use, but this is not yet the case for native ants. As many as 50,000 Australians may be affected by allergy to stings from ants in the native genus Myrmecia. This project will provide an in-depth understanding of the ant species responsible for anaphylaxis in Australia. We will develop a range of diagnostic test modules, a detailed national map of causative species, and a panel of reference venoms and allergic sera, so that accurate diagnostic tests can be assured, and so that high quality venom extracts can be provided for human use (immunotherapy). We will also study allergic volunteers for up to five years, so as to determine which people are at the highest risk of repeated stings and reactions and thus most likely to benefit from desensitisation. Current evidence suggests that the commonest cause of native insect venom allergy may be the jack jumper ant Myrmecia pilosula, for which a desensitising venom extract has been developed and shown to be highly effective in preventing life threatening reactions. The research described in this application will enable doctors to ensure an accurate diagnosis, which is an essential step before desensitising treatment can be offered for jack jumper allergy. Another large group of people are probably allergic to larger Myrmecia known as bull dog ants or inch ants. Our results with regard to cross-reactivity patterns and venom similarities will enable us to determine an optimum therapeutic mixture of bull dog ant venoms and thus enable us to provide treatment for people allergic to these ants as well.Read moreRead less
Cysteine-rich Secretory Protein Regulation Of Ion Channels In Male Fertility And Prostate Cancer
Funder
National Health and Medical Research Council
Funding Amount
$474,309.00
Summary
Diagnosis of the precise causes of male infertility and the development of male contraceptives requires improved understanding of sperm function. The Cysteine-Rich Secretory Proteins (CRISPs) are produced in the male reproductive tract where they regulate sperm function. Our project will demonstrate the essential requirement for CRISPs in sperm function and investigate their role in other tissues of the reproductive tract, including the prostate where they may be involved in prostate cancer.