Morphometric Analysis Of Normal Airway Structure In Childhood And The Influence Of A History Of Asthma On This Structure
Funder
National Health and Medical Research Council
Funding Amount
$186,113.00
Summary
The architectural structure of the airways of the lung is thought to have profound effects on airway function. Changes in this structure are believed to be partly responsible for limiting the flow of air into the lung in conditions such as constant wheezing, bronchitis and asthma. Pathological studies carried out on adult lungs have shown that the structure of the airways is indeed altered in patients with lung disease when compared with patients with no history of breathing difficulties. For ex ....The architectural structure of the airways of the lung is thought to have profound effects on airway function. Changes in this structure are believed to be partly responsible for limiting the flow of air into the lung in conditions such as constant wheezing, bronchitis and asthma. Pathological studies carried out on adult lungs have shown that the structure of the airways is indeed altered in patients with lung disease when compared with patients with no history of breathing difficulties. For example, the walls of the airways are much thicker in patients with lung disease. This thickening means that the airways are much narrower and therefore not able to carry as much air as in people with healthy lungs. In addition, the muscle within the airway wall, which is normally very sparse, is much denser in people with asthma and bronchitis. Thus, the airways can be squeezed closed more easily. It is not known if these changes are present in children who have lung disease. X-rays and sophisticated breathing tests suggest that these children may also have thicker walls and more muscle in their airways. The major difficulties in assessing whether such changes are present in children, is the lack of information on the normal structure in infants; how this changes as they grow to adulthood; or if there are any gender differences. This project aims to obtain this information from the airways of male and female children from 0-18 years. This information can then be used as a basis for comparison with the structure found in children with lung disease, in particular asthma, and therefore assist in making assessments as to the cause of their breathing difficulties. With more knowledge about these causes, we will be in a better position to design new and better treatments and produce ways of preventing them ever occurring.Read moreRead less
Mechanisms By Which Chromatin Modulates Gene Expression.
Funder
National Health and Medical Research Council
Funding Amount
$267,750.00
Summary
Gene expression in a cell occurs in the nucleus where genes are stored. In the nucleus, DNA is not in a free form but is covered with an equivalent weight of protein to form a structure known as chromatin. Chromatin is a periodic structure made up of repeating, regularly spaced subunits, the subunit being the nucleosome. A nucleosome consists of a group of proteins (histones) wrapped around with DNA. A nucleosome is both capable of blocking and activating gene expression. Therefore one important ....Gene expression in a cell occurs in the nucleus where genes are stored. In the nucleus, DNA is not in a free form but is covered with an equivalent weight of protein to form a structure known as chromatin. Chromatin is a periodic structure made up of repeating, regularly spaced subunits, the subunit being the nucleosome. A nucleosome consists of a group of proteins (histones) wrapped around with DNA. A nucleosome is both capable of blocking and activating gene expression. Therefore one important function of chromatin is to tightly regulate gene expression which is essential to allow an organism to develop properly. When gene expression is not accurately controlled by chromatin developmental defects or cancer can result from the production of incorrect proteins. To control correct gene expression, highly specific mechanisms must operate in the cell to remove, or modify, nucleosomes at certain genes at a precise time during development. One mechanism that we believe to be important is changing the make-up of a nucleosome. This can be achieved in the cell by the replacement of histones with different specialized forms of these histones (variants). We believe that these histone variants can specifically generate chromosomal domains which could in some cases expose or in other cases hide certain genes and thereby turn them on or off. Employing a new approach, we will study one of these histone variants to discover the role it plays in determining the type of chromosomal domain made and the role of this domain has in turning genes on or off at precise times in early development during the formation of different specialized cell types. This new information may define targets for the prevention of incorrect gene expression during cancer progression or abnormal development.Read moreRead less
Spatial Arrangement And Three-dimensional Structure Of Human Centromeres
Funder
National Health and Medical Research Council
Funding Amount
$283,000.00
Summary
Centromeres occur at the main constriction of chromosomes. They allow duplicated chromosomes to divide, control cell division and are involved in the control of gene expression. Faulty centromeres are found in many types of cancer and in other genetic diseases. They are also implicated in extra-chromosome disorders such as Down syndrome. Centromeres have a different structure to the rest of the chromosome and it is this structure we wish to study. We want to see how centromere DNA folds up tight ....Centromeres occur at the main constriction of chromosomes. They allow duplicated chromosomes to divide, control cell division and are involved in the control of gene expression. Faulty centromeres are found in many types of cancer and in other genetic diseases. They are also implicated in extra-chromosome disorders such as Down syndrome. Centromeres have a different structure to the rest of the chromosome and it is this structure we wish to study. We want to see how centromere DNA folds up tightly at the centromere. We also want to find out why centromeres locate in certain regions of the nucleus, because this may influence how the centromere works and how they regulate genes. Human centromeres come in many sizes and forms; by looking at a wide range of human centromeres, common structural and spatial properties will emerge. We have discovered very small centromeres - neocentromeres - which are much easier to study than other centromeres. We have used these centromeres to construct human minichromosomes, which we believe represent the main, all-human way forward to treat people with gene therapy. One way to help us achieve our aims is to stretch out centromeres in a controlled way to make it easier to visualise their structure. Our tools will be antibodies, fluorescently-labelled proteins and high resolution microscopes. These include an electron microscope, and microscopes that can produce optical sections and in turn a 3D image. One of these is the confocal laser scanning microscope; the other involves removal of out-of-focus light from images using deconvolution software to achieve the same goal. We will detect different centromere proteins with different fluorochromes for fluorescence microscopes and different sizes of gold particles for the electron microscope. Using these microscopes we have already been able to find out where one of our neocentromeres is located within the nucleus. We have also started to look at centromeres with the electron microscope.Read moreRead less
Dissecting The Divisome: Development Of Antibacterial Agents That Inhibit Bacterial Cytokinesis
Funder
National Health and Medical Research Council
Funding Amount
$504,097.00
Summary
Infectious diseases accounted for 25-30% of the estimated 54 million deaths worldwide in 1998. Unfortunately, the recent spread of antibiotic resistant bacteria from hospitals into the community has coincided with a marked downturn in the rate of development of new antibiotics. Thus, there is an urgent need to develop new antimicrobial agents. The aim of this project is to provide essential groundwork for the development of new antimicrobials that inhibit bacterial cell division.