Control Of Alveolar Epithelial Cell Differentiation Before And After Birth
Funder
National Health and Medical Research Council
Funding Amount
$376,980.00
Summary
In the lung, gas exchange takes place in small terminal airsacs called alveoli. The internal surface of the alveoli are lined with 2 types of specialist cells, the type-I and type-II cells, which are essential for the normal functioning of the lung. Although both cell types look completely different and have very different functions, they are derived from the same precursor cell. However, it is not known what determines whether these cells will become a type-I or a type-II cell. This application ....In the lung, gas exchange takes place in small terminal airsacs called alveoli. The internal surface of the alveoli are lined with 2 types of specialist cells, the type-I and type-II cells, which are essential for the normal functioning of the lung. Although both cell types look completely different and have very different functions, they are derived from the same precursor cell. However, it is not known what determines whether these cells will become a type-I or a type-II cell. This application is directed towards understanding the mechanisms which determine the fate of these cells. This is critical information as the lung must have the correct proportions of both cell types to function properly as a gas exchange organ.Read moreRead less
Alveolar Epithelial Cell Differentiation And Apoptosis: Effects Of Preterm Birth, Corticosteroids And Stretch.
Funder
National Health and Medical Research Council
Funding Amount
$484,500.00
Summary
In the lung, gas exchange takes place in small terminal airsacs called alveoli. The internal surface of the alveoli are lined with 2 types of specialist cells, the type-I and type-II cells. Both cells are essential for the normal functioning of the lung; type-I cells provide a thin barrier for the gas exchange, whereas type-II cells produce the surface-active material, surfactant. In order to survive after birth, the lungs of the newborn must have appropriate numbers of each of these cell types. ....In the lung, gas exchange takes place in small terminal airsacs called alveoli. The internal surface of the alveoli are lined with 2 types of specialist cells, the type-I and type-II cells. Both cells are essential for the normal functioning of the lung; type-I cells provide a thin barrier for the gas exchange, whereas type-II cells produce the surface-active material, surfactant. In order to survive after birth, the lungs of the newborn must have appropriate numbers of each of these cell types. However, babies that are born very prematurely have few, if any, mature cells as most are non-specialised cells that possess none of the characteristics of mature type-I and type-II cells. Therefore, the lungs of very preterm babies have low levels of surfactant, are prone to injury and infection and are not efficient in the exchange of oxygen and carbon dioxide. As such, these infants are at high risk of developing chronic lung disease which is a serious debilitating disease that has long term health implications. We believe that the non-specialised cells are more prone to injury and cell death than mature cells which makes the very premature infant more susceptible to the development of chronic lung disease. As the survival and respiratory health of these infants depends upon most type-I and type-II cells maturing after birth, it is critical to understand the factors that regulate their maturation. This information will allow the development of treatments that can enhance the maturation of these cell types. This application is focused towards understanding the factors that control maturation of type-I and type-II cells, as well as the role of the non-specialised cells in the development of chronic lung disease in babies that are born very prematurely.Read moreRead less
The survival of a baby at birth is crtically dependent upon the ability of the lungs to successfully take over the role of exchanging oxygen and carbon dioxide between the air and blood. To perform this task, during fetal life the lung must have grown properly and near the end of gestation it must mature both structurally and biochemically. Thus, babies that are born early, before the expected time of birth, are born before the lungs have had the opportunity to mature. It is not surprising, ther ....The survival of a baby at birth is crtically dependent upon the ability of the lungs to successfully take over the role of exchanging oxygen and carbon dioxide between the air and blood. To perform this task, during fetal life the lung must have grown properly and near the end of gestation it must mature both structurally and biochemically. Thus, babies that are born early, before the expected time of birth, are born before the lungs have had the opportunity to mature. It is not surprising, therefore, that an inability to breathe is one of the primary problems faced by a prematurely born infant. During late gestation the lung changes dramatically in order to increase its ability to exchange gases. There is an increase in surface area and a reduction in the barrier thickness between the airspace and the blood stream. The molecular mechanisms involved in this remodelling are unknown, but it is known that the administration of corticosteroids to women at risk of preterm labour causes a large decrease in this barrier thickness and increases the distensibility of the lung. This project seeks to understand how the structure of the lung matures in late gestation and to determine whether corticosteroids regulate these changes by altering the structure of a specialised molecule, called versican. Versican resides in the tissue space outside of cells and has special properties that allow it to retain water and help organise the surrounding matrix. We propose that alterations in the structure of versican will reduce its ability to retain water, thereby reducing the tissue volume and contributing to a reduction in the air-blood tissue barrier within the lung.Read moreRead less
Postnatal Dexamethasone In Tiny Babies: Does It Do More Good Than Harm?
Funder
National Health and Medical Research Council
Funding Amount
$394,688.00
Summary
The survival rate for tiny or very premature babies has improved dramatically in recent times, from below 10% in the 1960s to greater than 70% in the 1990s. However, some of these babies require prolonged periods of help with breathing and oxygen treatment to survive, and many develop a form of chronic lung disease in the newborn period. A powerful group of drugs, known as corticosteroids, have been used to treat or prevent this chronic lung disease in newborn babies, with some success in shorte ....The survival rate for tiny or very premature babies has improved dramatically in recent times, from below 10% in the 1960s to greater than 70% in the 1990s. However, some of these babies require prolonged periods of help with breathing and oxygen treatment to survive, and many develop a form of chronic lung disease in the newborn period. A powerful group of drugs, known as corticosteroids, have been used to treat or prevent this chronic lung disease in newborn babies, with some success in shortening the time that the babies need help with breathing. However, corticosteroids have the potential to cause long-term harm to the developing baby's brain, and may cause lifelong problems with thinking, walking, talking, seeing or hearing. We want to test in a clinical trial if corticosteroids, specifically dexamethasone, can reduce the need for help with breathing and the rate of chronic lung disease without causing long-term problems to the developing baby's brain. Babies who are very tiny (born weighing less than 1000 g), or born very early (born before 28 weeks of pregnancy, or more than 12 weeks premature) will be eligible for this study if they still need help with their breathing after one week of age from a machine called a respirator, and their doctor considers that corticosteroids might be helpful to the baby's breathing. Some babies will receive dexamethasone and other babies will be treated with a harmless placebo - chance will decide which treatment the baby receives. All other aspects of the babies' care will continue as normally. Children who survive to 2 years of age will be assessed fully to determine if they have any problems with their health, including problems with their thinking, walking, talking, seeing or hearing. We will determine if dexamethasone is helpful or not for very tiny or very premature babies who have breathing problems after the first week of life. We will also measure the economic impact of dexamethasone treatment in these babies.Read moreRead less
SCHOOL-AGE OUTCOME FOR VERY TINY/PRETERM CHILDREN BORN IN VICTORIA IN 1991-92
Funder
National Health and Medical Research Council
Funding Amount
$252,956.00
Summary
The survival rate for tiny or very premature babies has improved dramatically in recent times, from below 10% in the 1960s to greater than 70% in the 1990s. Several new treatments have helped to improve their survival rate, but some have the potential to cause long-term harm to the developing baby's brain or lung, and may cause lifelong problems with thinking, walking, talking, seeing, hearing, growth or breathing. Babies who are very tiny (born weighing less than 1000 g), or born very early (bo ....The survival rate for tiny or very premature babies has improved dramatically in recent times, from below 10% in the 1960s to greater than 70% in the 1990s. Several new treatments have helped to improve their survival rate, but some have the potential to cause long-term harm to the developing baby's brain or lung, and may cause lifelong problems with thinking, walking, talking, seeing, hearing, growth or breathing. Babies who are very tiny (born weighing less than 1000 g), or born very early (born before 28 weeks of pregnancy, or more than 12 weeks premature) will be assessed long term (to 8-9 years of age), as broadly as possible, and in comparison with normal birthweight (NBW, birthweight >2499 g) children. Outcomes will encompass academic progress and behaviour, brain function, general health, growth, and respiratory health. We will compare the outcomes for very tiny-preterm children who were treated with several of these new therapies with those who were not so treated. We will assess whether alternative measures of long term outcome that assess the quality of life are applicable to very tiny-preterm children. If so, these measures could be used much more widely, since they are cheaper and less time-consuming.Read moreRead less
I am a developmental lung physiologist who specialises in understanding the factors regulating normal and abnormal lung development as well as the physiological transformation of the lung into an efficient gas-exchange organ at birth.