Investigation Of The Influence Preterm Birth On Lung Structure And Function In School Age Children.
Funder
National Health and Medical Research Council
Funding Amount
$204,482.00
Summary
Bronchopulmonary dysplasia (BPD) remains the most significant chronic lung complication of premature birth. While some information on the long term respiratory outcomes in BPD exist there are no comprehensive studies linking lung structure, function and respiratory symptoms and relating these changes to neonatal history. Studies of this kind are essential to ensure future healthcare for these children can be planned accordingly.
Mucopolysaccharidoses (MPS) are a related group of 11 debilitating genetic disorders affecting children. They result from a reduction or total deficiency of an enzyme required for the removal of carbohydrate structures called glycosaminoglycans (gags). Gag degradation occurs inside the cell in specific organelles termed lysosomes and in the absence of the appropriate enzyme, undegraded gag accumulates in the cell. This leads to a range of clinical symptoms and multiple tissue failure. Symptoms c ....Mucopolysaccharidoses (MPS) are a related group of 11 debilitating genetic disorders affecting children. They result from a reduction or total deficiency of an enzyme required for the removal of carbohydrate structures called glycosaminoglycans (gags). Gag degradation occurs inside the cell in specific organelles termed lysosomes and in the absence of the appropriate enzyme, undegraded gag accumulates in the cell. This leads to a range of clinical symptoms and multiple tissue failure. Symptoms common to more than one MPS type include mental deterioration, blindness, abdominal organ enlargement and bone growth problems leading to short stature and bone loss. My laboratory has had a long-term interest in developing treatment for MPS and our research led to the clinical implementation of enzyme replacement therapy (ERT) for MPS VI in 2005. While providing the first effective, multi-tissue treatment for MPS, our research showed that several tissues were not responsive to ERT. These are the brain, cartilage and cornea, thus children on ERT regimens will still suffer from mental retardation, arthritis and blindness. With the goal of treating these particular tissues we have developed a new approach to MPS therapy called substrate deprivation therapy (SDT). Instead of adding back the missing enzyme, SDT acts by decreasing gag production which in turn reduces the level of accumulated gag in cells. SDT results in the correction of MPS cells in culture and reduces several key clinical symptoms in the mouse model of MPS IIIA. In this proposal we will extend our research to evaluate the effect of SDT on brain and bone-joint pathology. Evaluation of efficacy will take place in the MPS VII mouse which exhibits both brain and bone disease and in a new model of MPS IVA developed specifically for this study which exhibits a joint pathology unique amongst the MPS disorders.Read moreRead less
Skeletal disease is a major problem for children with mucopolysaccharidoses (MPS). Patients suffer from early onset osteoporosis and osteoarthritis, severely affecting their quality of life. We will evaluate a lentiviral gene therapy vector developed in-house for its capacity to transduce bone, cartilage, synovial and ligament cells in a mouse model of MPS VI. Our goal is to generate high level, sustained expression of the deficient MPS enzyme and alter the course of skeletal disease in MPS.
Lung Injury Following Resuscitation In Immature Lambs
Funder
National Health and Medical Research Council
Funding Amount
$227,036.00
Summary
The primary aim of this project is to identify techniques for resuscitating premature babies that cause little or no damage to their lungs. We also want to identify factors that enhance the clearance of liquid from the lungs so air can easily enter to deliver oxygen and remove carbon dioxide at birth. About 1% of babies are born very prematurely and many develop respiratory distress syndrome (RDS). This is the major cause of illness and death in infants born at less than 32 weeks' gestation. Mos ....The primary aim of this project is to identify techniques for resuscitating premature babies that cause little or no damage to their lungs. We also want to identify factors that enhance the clearance of liquid from the lungs so air can easily enter to deliver oxygen and remove carbon dioxide at birth. About 1% of babies are born very prematurely and many develop respiratory distress syndrome (RDS). This is the major cause of illness and death in infants born at less than 32 weeks' gestation. Most of the survivors required assisted ventilation during their first weeks of life. In 1995, 2381 premature infants were ventilated in Australia and New Zealand, requiring 36,407 days of ventilator care. Thus, this is a serious condition with a high financial and social cost. It is known that RDS is caused by damage to the very immature lung which starts an inflammatory reaction. We don't know what triggers the damage and inflammation but believe that the way babies are resuscitated may damage the lungs. Currently, babies are resuscitated with a resuscitation bag squeezed by hand, with 100% oxygen. There is no pressure to stop the lungs collapsing during expiration. As the volume of gas delivered with each breath is not measured, it is possible that the volumes are too large and damage the lungs. This project will investigate whether less damage occurs to the lungs of preterm lambs when resuscitation uses a modern neonatal ventilator where each inflation is limited to a known volume. A small distending pressure will be used to stop the lungs collapsing during expiration. We will also investigate factors that enhance the clearance of liquid from the lungs after the initiation of breathing. The failure to clear lung liquid greatly limits the ability of babies to breathe and exposes those parts of the lung that are cleared to a much greater risk of injury. The results of this study will be directly applicable to the treatment and care of prematurely born babies.Read moreRead less
DEVELOPMENT OF CARDIOVASCULAR CONTROL DURING SLEEP IN HUMAN INFANTS AFTER PRETERM BIRTH
Funder
National Health and Medical Research Council
Funding Amount
$358,537.00
Summary
Infants spend the major part of their life in sleep, and the period between birth and 6 months of age sees dramatic changes in their sleep organisation. Coincidently, there are dramatic developmental changes in the infant's heart and blood pressure control systems, and the ability to compensate for stress such as falls of blood pressure (hypotension) or in the level of oxygen in the blood (hypoxaemia). In infants born preterm, the risks of hypoxaemia, and even death are significantly greater dur ....Infants spend the major part of their life in sleep, and the period between birth and 6 months of age sees dramatic changes in their sleep organisation. Coincidently, there are dramatic developmental changes in the infant's heart and blood pressure control systems, and the ability to compensate for stress such as falls of blood pressure (hypotension) or in the level of oxygen in the blood (hypoxaemia). In infants born preterm, the risks of hypoxaemia, and even death are significantly greater during sleep than during wakefulness, but why this is so is uncertain. This study will examine the ability of infants to respond to stress during sleep. Four groups of infants will be examined: healthy infants born at normal gestation; healthy infants born prematurely (preterm); preterm infants who have experienced mild hypoxaemia soon after birth; and preterm infants who have suffered more severe hypoxaemia because of lung disease. Infants will be studied in a sleep laboratory during day-time sleep, and their ability to control blood pressure will be determined. By contrasting the effectiveness of blood pressure control between the infant groups we aim to determine whether preterm infants have lasting problems as a result of their premature birth, or their exposure to hypoxaemia. By contrasting infants in sleep and wakefulness, we aim to assess whether the risks of poorer blood pressure control are greater in sleep.Read moreRead less
Nasal CPAP For Very Preterm Infants At Birth: Does It Improve Outcome? A Randomised Controlled Trial
Funder
National Health and Medical Research Council
Funding Amount
$460,604.00
Summary
Neonatal respiratory distress syndrome (RDS) is the major cause of morbidity and mortality in preterm infants. Many of these infants need ventilatory support to keep them alive. In 1996 and 1997, 10,471 infants in Australia and New Zealand needed ventilatory support for a total of 72,544 days. This treatment is a great physical burden for the infants and an enormous emotional stress for their parents. Each day of treatment costs about A$2000 so their hospital treatment costs about $72 million a ....Neonatal respiratory distress syndrome (RDS) is the major cause of morbidity and mortality in preterm infants. Many of these infants need ventilatory support to keep them alive. In 1996 and 1997, 10,471 infants in Australia and New Zealand needed ventilatory support for a total of 72,544 days. This treatment is a great physical burden for the infants and an enormous emotional stress for their parents. Each day of treatment costs about A$2000 so their hospital treatment costs about $72 million a year. Of infants born less than 29 weeks' gestational age, about 40% of the survivors subsequently developed chronic lung disease (CLD). This condition is defined as prolonged dependence on supplementary oxygen therapy. CLD is associated with further costs and increased lung problems and readmissions to hospital in the first year of life. Thus, CLD is an expensive and time-consuming condition that has a high social cost. This project will determine whether treating these very premature babies from birth simply by applying oxygen under a low continuous positive pressure (CPAP) into their nose rather than the present treatment of placing a tube in the windpipe (known as intubation) and ventilation will reduce the incidence and severity of neonatal respiratory distress syndrome and subsequent chronic lung disease. The project will involve 600 babies from different, high quality neonatal intensive care units. Babies who are born at less than 29 weeks' gestation and who show signs of breathing at birth will be randomly allocated to be treated with either nasal CPAP or intubation and ventilation. This project will determine whether CPAP treatment at birth improves survival and reduces the severity of the RDS and subsequent CLD, or has no long term beneficial effect. If the trial is successful, this will be one of the most useful new treatments in neonatal medicine because it is simple to use, easier for the babies, and cheaper than ventilation.Read moreRead less