Pathogenesis Of Infections With Yersinia Enterocolitica
Funder
National Health and Medical Research Council
Funding Amount
$339,634.00
Summary
Yersinia enterocolitica is a significant cause of food-poisoning, gastroenteritis and abdominal pain which may be mistaken for acute appendicitis. Y. enterocolitica is a heterogenous bacterial species only some strains of which are able to cause disease. Many of the disease-causing strains have readily identifiable virulence determinants which facilitate their detection in clinical microbiological laboratories. By contrast, other types, in particular the biotype 1A strains, lack these determinan ....Yersinia enterocolitica is a significant cause of food-poisoning, gastroenteritis and abdominal pain which may be mistaken for acute appendicitis. Y. enterocolitica is a heterogenous bacterial species only some strains of which are able to cause disease. Many of the disease-causing strains have readily identifiable virulence determinants which facilitate their detection in clinical microbiological laboratories. By contrast, other types, in particular the biotype 1A strains, lack these determinants, although many of them are significantly associated with disease. During the past few years, we have compared biotype 1A strains of Y. enterocolitica obtained from patients with those from non-clinical sources in a number of assays for virulence-associated properties. These studies have shown that clinical isolates differ from non-clinical ones in terms of their ability to (1) invade epithelial cells in vitro and intestinal absorptive cells in vivo, (2) escape from epithelial cells and macrophages they have invaded, (3) resist killing by macrophages, and (4) colonise the intestinal tracts of mice. The aim of the study is to identify the bacterial determinants responsible for these differences between clinical and non-clinical strains of Y. enterocolitica biotype 1A. This will be achieved by using genetic techniques to modify virulent strains of biotype 1A at random and then identify derivatives of these bacteria with altered virulence properties. We shall also use genetic techniques to identify genes that are specifically activated when the bacteria come into contact with animal cells and tissues. The results of this research will provide new insights into the virulence mechanisms of Y. enterocolitica and related bacteria, and will be used to develop diagnostic tests which will allow pathogenic strains to be distinguished from harmless ones.Read moreRead less
Long-lived CD8 T Cell Responses Induced By A Recombinant Cytomegalovirus Vector
Funder
National Health and Medical Research Council
Funding Amount
$234,750.00
Summary
The priming of the immune system to protect against infection and disease is an important means to alleviate these conditions. Current vaccination technologies often rely on multiple inoculations (prime-boosting). In addition, specific priming of the immune system against pathogens that target mucosal sites has been difficult and often lacks efficacy resulting in temporary or variable protection. Using a well developed mouse model for a common human virus, we have explored the potential of this ....The priming of the immune system to protect against infection and disease is an important means to alleviate these conditions. Current vaccination technologies often rely on multiple inoculations (prime-boosting). In addition, specific priming of the immune system against pathogens that target mucosal sites has been difficult and often lacks efficacy resulting in temporary or variable protection. Using a well developed mouse model for a common human virus, we have explored the potential of this agent as a vaccine agent, making use of its long term persistence in the infected host to provide continued antigenic stimulation of the immune system. We have found that very strong and long lasting responses can be elicited after a single inoculation of avirulent virus. In this study, this effect will be further explored and developed.Read moreRead less
Hospital Admission, Cerebral Palsy, Intellectual Disability And Birth Defects In Assisted Conception Infants.
Funder
National Health and Medical Research Council
Funding Amount
$115,110.00
Summary
We have recently completed a study examining the prevalence of birth defects in assisted conception infants born in Western Australia from 1993-1997. Contrary to reassuring claims by other researchers in this area, we found that assisted conception infants have a two-fold increased risk of being diagnosed with a major birth defect by one year of age. We now propose to examine other long-term health outcomes in these children. This study involves record linkage between the WA Reproductive Technol ....We have recently completed a study examining the prevalence of birth defects in assisted conception infants born in Western Australia from 1993-1997. Contrary to reassuring claims by other researchers in this area, we found that assisted conception infants have a two-fold increased risk of being diagnosed with a major birth defect by one year of age. We now propose to examine other long-term health outcomes in these children. This study involves record linkage between the WA Reproductive Technology Register and four other population-based databases. The prevalence of cerebral palsy, intellectual disability, hospital admission and birth defects in assisted conception children born in WA between 1993 and 2001 will be compared to that seen in all other Western Australian children born over the same time period. The collection of information on risks associated with assisted conception treatment is vital to allow adequate counselling of couples considering fertility treatment. Cerebral palsy, intellectual disability, birth defects and hospital admission are all serious adverse health outcomes and, despite the introduction of IVF to most Western countries twenty years ago, there are limited data in the literature concerning the occurrence of these conditions in assisted conception infants. Quantifying the contribution of assisted conception treatment to neonatal, infant and childhood morbidity and mortality is also important for the planning of health service provision. Although assisted conception births represent only a small proportion of total births in Australia, these infants may require a disproportionate level of health care services, such as neonatal intensive care treatment due to complications associated with preterm or multiple birth. The wide application of assisted conception treatment in Australia and the increased number of pregnancies achieved by these means reinforce the urgent need for valid data on the health of children born after these procedures.Read moreRead less
We propose to determine if a recently discovered biological mechanism plays crucial roles in the development of eggs and sperm. To achieve this, we will remove or mutate this pathway specifically in developing eggs and sperm , then examine the effect. Preliminary results indicate that the mechanism does play important roles mutated eggs fail to complete maturation. These studies will tell us more about what makes a healthy egg and sperm, and are relevant to female and male fertility.
Characterisation Of The Pathways Leading To DNA Demethylation In The Embryo.
Funder
National Health and Medical Research Council
Funding Amount
$634,573.00
Summary
Complex living creatures like humans have specialised cells that co-operate to form important organs like brains and reproductive organs. Specialised cells have specific genes locked on or off. When a sperm fertilises an egg, all the switches of the genes that are locked on or off get reset to neutral so that the fertilised egg can divide and grow into all cell types in the body. We do not know how this resetting happens in the egg. This project seeks to discover the mechanism involved.
The Role Of Transcription Factors In Regulating The First Round Of Gene Expression In The Early Embryo.
Funder
National Health and Medical Research Council
Funding Amount
$348,931.00
Summary
Assisted reproductive technologies result in a high incidence of multiple births. This is and adverse outcome that requires correction. It stems from the common transfer of several embryos due to the low chance of an individual embryo made by IVF resulting in a baby. This project will determine the normal pattern of gene expression in the embryo and define: (1) how it is adversely changed as a consequence of IVF; and (2) the extent that these changes are a cause of the low embryo viability.
Mechanisms Of P53 Induced Embryopathy After In Vitro Fertilisation.
Funder
National Health and Medical Research Council
Funding Amount
$483,737.00
Summary
Assisted reproductive technologies (ART) cause many embryos not to survive to birth. We have shown that IVF causes increased expression of protein normally involved in stopping cells from dividing. This is a major cause of embryo death after IVF. This project will determine how this protein acts to cause embryonic death and assess strategies to prevent it.
Functional Genomic Analysis Of The Role Of P53 In Early Embryo Death After Assisted Reproductive Technologies (ART).
Funder
National Health and Medical Research Council
Funding Amount
$227,036.00
Summary
Assisted reproductive technologies (ART, such as IVF and related techniques) are successful treatments for most forms of infertility. ART are expensive therapies and much of this cost is related to the relative inefficiency of the technology. Much of this is due to the high mortality of the resulting embryos. Typically, 45-80% of embryos produced by ART do not survive the first week. Consequently the chance of any individual embryo resulting in a successful birth is not high. There has been only ....Assisted reproductive technologies (ART, such as IVF and related techniques) are successful treatments for most forms of infertility. ART are expensive therapies and much of this cost is related to the relative inefficiency of the technology. Much of this is due to the high mortality of the resulting embryos. Typically, 45-80% of embryos produced by ART do not survive the first week. Consequently the chance of any individual embryo resulting in a successful birth is not high. There has been only modest increments in embryo survival in recent years. The low cahnce of individual embryos resulting in a baby means that: (1) generally several treatment cycles are required; (2) superovulation is used to maximise the number of embryos produced giving an accumulation of unwanted cryopreserved embryos; (3) more than one embryo is generally transferred resulting in a significant incidence of multiple pregancies. The high mortality of the early embryo seems to be a general feature of IVF but its causes and effectors are not known. It has recently been established that it largely occurs due to a form of cell 'suicide' known as apoptosis. This form of cell death has important normal functions: its activation allows for cells that are no longer required to be removed, allowing the remodelling of tissues and it also serves to remove cells that are irreversibly damaged. p53 is a protein that has the ability to 'sense' cell stress and damage and to direct the cell to undergo apoptosis if the stress is severe. This project will examine if ART cause increased expression of p53 and whether this elevation of p53 causes embryonic cell death. We will examine the factirs that control p53 expression in the embryo. using mice with mutations that stop the function of p53 and several of its regulatory proteins. Experiments will determine the susceptibility of embryos possessing these mutations and will therefore allow us to define the proteins causing apoptosis after ART.Read moreRead less