Modelling The Impact Of Global Climate Change On The Epidemiology Of Infectious Diseases In Bangladesh
Funder
National Health and Medical Research Council
Funding Amount
$118,988.00
Summary
Climate change may impact on human health via a change in the distribution and pathogenicity of infectious diseases, particularly in the South Asian region. This study will use high quality environmental and clinical data from an established time-series collated in Bangladesh, to better inform mathematical models which may predict future changes in infectious diseases epidemiology. Accurate and valid modelling can be valuable in guiding future public health policy for vulnerable populations.
An Investigation Of Vibrio Cholerae Sialidase As A Target For Drug Discovery
Funder
National Health and Medical Research Council
Funding Amount
$227,036.00
Summary
The prevalence of the disease Cholera still causes significant human mortality, in particular in underdevloped countries. The process that enables the cholera toxin to cause signficant damage is now partly understood. This research project will provide a range of chemical entities (probes) that have the potential of intervening in this process . These probes will be the basis for a drug discovery programme that targets toxin binding. Through molecular modelling based on protein structural inform ....The prevalence of the disease Cholera still causes significant human mortality, in particular in underdevloped countries. The process that enables the cholera toxin to cause signficant damage is now partly understood. This research project will provide a range of chemical entities (probes) that have the potential of intervening in this process . These probes will be the basis for a drug discovery programme that targets toxin binding. Through molecular modelling based on protein structural information, drug candidate synthesis and evaluation of these compounds in relevant test tube (in vitro) assays it is envisaged that a number of candidate compounds will be then further optimised for eventual pre-clinical investigation. The technology to be used in this project is comparable to that we have used in the discovery of the recently approved influenza drug, Relenza .Read moreRead less
Neural Mechanisms Mediating Hypersecretion And Motility Patterns Induced By Enterotoxins
Funder
National Health and Medical Research Council
Funding Amount
$415,250.00
Summary
This project aims to identify the nerve cells that are responsible for the massive oversecretion of water and salt seen with cholera and other diseases producing diarrhoea. Many of these disease act through specific toxins and, although the biochemical targets of these toxins are reasonably well understood, the nerve cells on which they act have never been identified. Furthermore, the mechanisms that couple the oversecretion with a massive increase in the propulsive activity of the intestine are ....This project aims to identify the nerve cells that are responsible for the massive oversecretion of water and salt seen with cholera and other diseases producing diarrhoea. Many of these disease act through specific toxins and, although the biochemical targets of these toxins are reasonably well understood, the nerve cells on which they act have never been identified. Furthermore, the mechanisms that couple the oversecretion with a massive increase in the propulsive activity of the intestine are also unknown. We will investigate each of these questions using the small intestine of the guinea-pig, because the nerve circuit in this preparation is better understood than that of any other. Nerve cells that respond to three specific toxins, each known to activate the nervous system via different mechanisms, will be determined using intracellular recording methods, injection of marker dyes and methods that allow the identification of their neurochemistry. This will allow the functions of responsive nerve cells to be identified and their places in the circuits that control secretion and propulsion to be determined. This information will be correlated with studies in whole animals being undertaken in Sweden so that potential sites for intervention can be identified.Read moreRead less
Cholera Toxin Co-receptor Interaction In The Prevention Of Inflammatory Autoimmune Disorders
Funder
National Health and Medical Research Council
Funding Amount
$359,577.00
Summary
Vaccination is undoubtedly one of mankind's greatest achievements. While infections continue to be the major cause of morbidity and mortality in the developing world, heart disease, cancer, chronic allergies and autoimmune disorders are taking their toll in advanced societies. Our expanding knowledge of these 'modern diseases' shows that the immune system plays a central role and hence it is important to learn if new immunologically-based therapies can be developed for such chronic human disorde ....Vaccination is undoubtedly one of mankind's greatest achievements. While infections continue to be the major cause of morbidity and mortality in the developing world, heart disease, cancer, chronic allergies and autoimmune disorders are taking their toll in advanced societies. Our expanding knowledge of these 'modern diseases' shows that the immune system plays a central role and hence it is important to learn if new immunologically-based therapies can be developed for such chronic human disorders. This project takes advantage of our recent discoveries on the immunological properties of a hitherto feared molecule - cholera toxin. We have shown that one portion of the toxin, the B-subunit, responsible for binding to cell membranes, possesses remarkable immunomodulatory properties that prevent the development of inflammatory autoimmune disorders such as rheumatoid arthritis in animal models. The B-subunit, in contrast to the whole cholera toxin, is non-toxic and has no adverse effects in humans. This has sparked considerable interest in the development of such molecules as novel anti-inflammatory agents and highlighted the necessity to better understand the B-subunit's mode of action. Current theory specifies that the B-subunit mediates its immunomodulatory effects by binding and cross-linking a ubiquitous plasma membrane glycosphingolipid, GM1 ganglioside. The essential role of GM1-interaction was recently challenged by our discovery that a mutant B-subunit (H57A) was unable to modulate the immune system even though it still bound to GM1; suggesting that the B-subunits interact with another receptor (or co-receptor), and that it is this second interaction that directs the immune system to prevent development of autoimmune disease. The primary aims are to characterize the nature of B-subunit interaction with the cell membrane and to identify the co-receptor. This work has the potential to provide a new target for drug discovery and development of immunotherapeutics.Read moreRead less
Neurogenic Diarrhoea: Lessons From Cholera Toxin And Related Bacterial Exotoxins
Funder
National Health and Medical Research Council
Funding Amount
$543,818.00
Summary
Many bacteria that cause diarrhoea act via the gut’s own nervous system to massively increase the transport of water and salt into the lumen of the intestine. In this project we will investigate mechanisms that lead to this over-excitation of the gut’s nervous system to test the idea that this is due to a change in the properties of the final nerve cells in the normal pathway that controls water transport. This will identify novel sites for drug treatments of diarrhoea.
Integrons, Mobile Gene Cassettes And Pathogencity In Vibrio Cholerae
Funder
National Health and Medical Research Council
Funding Amount
$550,285.00
Summary
Bacteria are remarkably adaptive and evolve in ways that plants and animals do not. One of these ways is Lateral Gene Transfer or LGT, which is a process allowing bacterial cells to share genes. Such mobile genes can greatly influence the extent to which pathogenic bacteria can cause disease. One notable example is Vibrio cholerae where many strains can be benign but some can give rise to cholera pandemics. Here, we will investigate this phenomenon in this important bacterium.
Neural Coordination Of Intestinal Motility And Mucosal Secretion Of Water And Salt - Role In Toxin Induced Diarrhoea
Funder
National Health and Medical Research Council
Funding Amount
$490,020.00
Summary
This project deals with some of the basic mechanisms underlying disorders of gastrointestinal function and in particular with the mechanisms responsible for diarrhoea. Whenever there is a natural disaster (the recent tsunami for example) or a war, the breakdown of medical services leads to concern about outbreaks of cholera and other diarrhoea causing diseases, so understanding the mechanisms by which the cholera bacterium cause diarrhoea remains a major imperative. It is known that the diarrhoe ....This project deals with some of the basic mechanisms underlying disorders of gastrointestinal function and in particular with the mechanisms responsible for diarrhoea. Whenever there is a natural disaster (the recent tsunami for example) or a war, the breakdown of medical services leads to concern about outbreaks of cholera and other diarrhoea causing diseases, so understanding the mechanisms by which the cholera bacterium cause diarrhoea remains a major imperative. It is known that the diarrhoea resulting from cholera infection is produced by an enterotoxin, which acts to produce a massive over-secretion of water and salt through the intestinal wall, which if it is not controlled causes death by dehydration. This effect requires the activity of the nerve cells within the gut wall, the enteric nervous system (ENS). Other bacterial toxins have similar effects and also require activity of the ENS for these effects to be manifested. This project will identify how these toxins alter the activity of the ENS and the effects that they have on intestinal movements which are also regulated by the ENS. We already know that the movements and secretion of water are related to each other and that this relationship is disturbed in some more subtle diseases like irritable bowel syndrome. This project will characterise this relationship, thereby shedding light on the physiology underlying a variety of gastrointestinal disorders.Read moreRead less