FETAL BRAIN INJURY RESULTING FROM INTRAUTERINE INFECTION: LONG TERM CONSEQUENCES AND THE POTENTIAL FOR INTERVENTION
Funder
National Health and Medical Research Council
Funding Amount
$452,640.00
Summary
Brain damage during fetal life is a significant cause of later neurological problems such as cerebral palsy. Recent studies have shown that brain injury detected in infants is usually caused by adverse conditions within the uterus prior to labour, but the exact causes are poorly understood. It is also apparent that babies born prematurely are at increased risk of suffering serious brain damage. Unfortunately, at present, it is not possible to prevent or effectively treat brain damage in the fetu ....Brain damage during fetal life is a significant cause of later neurological problems such as cerebral palsy. Recent studies have shown that brain injury detected in infants is usually caused by adverse conditions within the uterus prior to labour, but the exact causes are poorly understood. It is also apparent that babies born prematurely are at increased risk of suffering serious brain damage. Unfortunately, at present, it is not possible to prevent or effectively treat brain damage in the fetus or newborn, partly due to ignorance about how and when the damage is occurring. In recent years it has become evident that infections in the mother, may be linked to both premature birth and brain damage. It has been proposed that the certain chemicals (cytokines) which are released during an infection can across the placenta to the fetus, causing inflammatory changes that lead to brain damage. However, although associations have been shown in studies of women, there is little evidence that infections actually cause brain damage in the fetus. This project will define the effects of an inflammation inducing chemical (bacterial endotoxin) on the fetal brain and the pattern of inflammation it sets up in the fetus. We will also examine the effects of brain damage caused by endotoxin in the newborn lamb, and relate this to alterations in behaviour. Once we have defined the effects of endotoxin on brain structure, we will test the effects of chemicals that are known to block the actions of inflammatory cytokines. We hope that by blocking the chemical pathway that leads to the production of harmful cytokines we may be able to prevent brain injury from occurring when the fetus is exposed to an infection in the mother. It is expected that this project will provide important information that helps us to understand how infection in the mother can cause brain injury in the fetus. This information is vital if strategies to prevent or treat brain injury are to be developed.Read moreRead less
Cerebrovascular Effects Of Intrauterine Hypoxia: Contribution To Perinatal Brain Injury
Funder
National Health and Medical Research Council
Funding Amount
$579,138.00
Summary
During pregnancy, delivery of oxygen and nutrients to the growing fetus is sometimes disturbed, and can lead to injury of the developing brain. In this project we investigate the idea that low oxygen (hypoxia) causes brain demage to blood vessels in the fetal brain, and new blood vessesl produced in an attempt to repair this damage are fragile and prone to rupture, explaining the high incidence of bleeding in the brain of prematurely-born and full term infants that experience birth hypoxia.
Neuroactive Steroids In The Developing Brain: Potential For Preventing Perinatal Brain Damage
Funder
National Health and Medical Research Council
Funding Amount
$481,500.00
Summary
Complications during pregnancy, birth asphyxia or premature birth can lead to serious neurological impairment in the newborn. Despite excellent neonatal care many of these babies go on to have serious handicaps. Neuroactive steroids are a group of neuromodulators that are derived from the hormone progesterone. These steroids fall into two groups, those that appear to protect brain cells from damage caused by an inadequate supply of oxygen and those that may increase cell death. We have shown tha ....Complications during pregnancy, birth asphyxia or premature birth can lead to serious neurological impairment in the newborn. Despite excellent neonatal care many of these babies go on to have serious handicaps. Neuroactive steroids are a group of neuromodulators that are derived from the hormone progesterone. These steroids fall into two groups, those that appear to protect brain cells from damage caused by an inadequate supply of oxygen and those that may increase cell death. We have shown that protective neuroactive steroids are present in very large amounts in the fetal brain. Steroids produced by the placenta are converted to these neuroactive products by enzymes in the brain leading to the high levels that are seen during fetal life. Certain adverse conditions during pregnancy as well as preterm birth may cause marked changes in the balance of steroids that could increase susceptibility to brain injury. We have found that areas of the brain, where damage most often occurs, normally contain the highest amount of protective steroids, but only in late pregnancy. This suggests that disturbances that lower steroid production in these areas could contribute to the death of cells, particularly in mid-pregnancy and after premature birth. In the proposed studies, we will examine whether a toxic balance of steroids develops following adverse events in pregnancy as well as the areas of the brain where this is most pronounced. We will examine the changes in the expression of enzymes that can potentially cause the accumulation of protective steroids in the brain. We will then examine treatments that can raise the concentration of steroids and determine which combination of steroids best reduces cell death and brain injury following complications during pregnancy. The findings of this work will indicate the best therapeutic approach that may be adopted to modify the concentration of certain steroids so as to reduce the risk of brain damage in the fetus and neonate.Read moreRead less
Impact Of Chronic Intrauterine Inflammation On Neurodevelopmental & Physiological Responses To Fetal Hypoxia.
Funder
National Health and Medical Research Council
Funding Amount
$280,750.00
Summary
Careful examination of records from hundreds of pregnancies has indicated that low-grade infection or inflammation within the uterus during pregnancy is associated with an increase in the likelihood that the newborn baby will suffer from cerebral palsy. This strong association suggests that inflammation during pregnancy can cause damage to the developing baby's brain. Similar studies have also identified an association betwen events that result in a lack of oxygen supply to the developing brain ....Careful examination of records from hundreds of pregnancies has indicated that low-grade infection or inflammation within the uterus during pregnancy is associated with an increase in the likelihood that the newborn baby will suffer from cerebral palsy. This strong association suggests that inflammation during pregnancy can cause damage to the developing baby's brain. Similar studies have also identified an association betwen events that result in a lack of oxygen supply to the developing brain and cerebral palsy. However the studies that have identified these associations are incapable of determining the mechanisms by which these factors affect brain development. Even though inflammation during pregnancy is common, and is often associated with diseases after birth, experimental studies of the effects of this type of inflammation on the wellbeing of the unborn baby have not been performed. Our research group has developed a unique experimental model, using sheep, which is particularly suitable for determining how inflammation and a lack of oxygen may affect the unborn baby and cause brain damage. By continuously giving a sterile bacterial cell wall preparation (endotoxin) into the amniotic fluid of pregnant sheep we can cause prolonged inflammation with characteristics that are similar to those that accompany inflammation during human pregnancy but different to other models of inflammation within the uterus. We intend to use our model to determine how prolonged inflammation and a lack of oxygen affect the well-being of the developing lamb before birth and how these factors affect brain development. Our proposed study will provide valuable information about how inflammation and a lack of oxygen interact to affect brain development. We expect that when inflammation is present the fetus becomes more vulnerable to the effects of a lack of oxygen, resulting in more severe brain damage occuring than when either factor is experienced alone.Read moreRead less
The Fetal Response To Infection, With Particular Reference To Alterations Of Tryptophan Metabolism
Funder
National Health and Medical Research Council
Funding Amount
$410,616.00
Summary
Infection in pregnancy has long been known to be associated with a high risk for brain damage in the baby. There is now good evidence that the brain can be damaged before birth, and in other babies where the brain is damaged after birth there is reason to say that these infants were factors associated with the pregnancy that rendered them vulnerable to risk factors postnatally. Very little is known about the effects of infection on the fetus. Some recent work has shown that substances released f ....Infection in pregnancy has long been known to be associated with a high risk for brain damage in the baby. There is now good evidence that the brain can be damaged before birth, and in other babies where the brain is damaged after birth there is reason to say that these infants were factors associated with the pregnancy that rendered them vulnerable to risk factors postnatally. Very little is known about the effects of infection on the fetus. Some recent work has shown that substances released from bacteria induce cells in the uterus and placenta to produce inflammatory chemicals that can damage the brain. In this project we propose the following model: 1), infection causes the release of substances from the uterus and placenta that disrupt the blood-brain barrier in the fetal brain; and, 2), infection alters the metabolism of the essential amino acid tryptophan in the fetus, causing greater production of metabolites that have toxic effects on the developing brain. We have preliminary evidence to support these two proposals. If the idea is proven correct, it should be possible to administer simple analogues of tryptophan to prevent the toxic metabolites of this amino acid from increasing in the fetus when either the mother or the uterus becomes infected. Because these substances can be given by mouth, this would allow a simple treatment to be developed for women at risk of infection, or who are already infected. This would be particularly useful wherever medical services and resources are limited, as for under-priviledged groups and in Third World countries.Read moreRead less
Preventing Prenatal Brain Injury In Fetal Growth Restriction
Funder
National Health and Medical Research Council
Funding Amount
$511,294.00
Summary
Intrauterine fetal growth restriction (IUGR) is a serious complication of pregnancy associated with increased perinatal morbidity and mortality. In particular, IUGR infants have a high risk of perinatal brain injury which is likely to arise from damage before birth. Our aim is to use an ovine model of IUGR to define the causes of that brain injury and to develop new therapies that could be offered to women to protect their unborn baby.
Regulation Of Eicosanoid Production In The Fetal Placenta In Preterm Labour
Funder
National Health and Medical Research Council
Funding Amount
$256,980.00
Summary
Prostaglandins are fatty substances made within the body and they are what causes the pregnant uterus to contract and push out the fetus. At present we can't control preterm birth because we don't understand well enough how prostaglandin synthesis is controlled. New discoveries in our lab have suggested an exciting new possibility- that prostaglandins partially regulate their own synthesis. If we find this is so, there may be far-reaching implications for the ways in which anti-inflammatory drug ....Prostaglandins are fatty substances made within the body and they are what causes the pregnant uterus to contract and push out the fetus. At present we can't control preterm birth because we don't understand well enough how prostaglandin synthesis is controlled. New discoveries in our lab have suggested an exciting new possibility- that prostaglandins partially regulate their own synthesis. If we find this is so, there may be far-reaching implications for the ways in which anti-inflammatory drugs are used, not only in prevention of premature birth, but in inflammatory diseases too. Most research in this area has been directed toward understanding what controls the overall synthesis of prostaglandins, but there are several types of prostaglandins with different functions. we are now in a position to study, for the first time, how the synthesis of the specific prostaglandins is regulated in the pregnant uterus and how this changes during normal and preterm birth.Read moreRead less
The Effects Of Maternal Health On Fetal Kidney Development And Its Function
Funder
National Health and Medical Research Council
Funding Amount
$297,338.00
Summary
There is an epidemic of renal disease among Australian aborigines. While much of this could have been prevented by effective control of Group A streptococcal skin infections, there is also evidence that the high susceptibility to end-stage renal disease is related to poor intrauterine development of the kidney as low- birth weight is a predisposing factor. Mothers, whose renal function is impaired, tend to have babies which are low birth weight. There is no knowledge about the effects of materna ....There is an epidemic of renal disease among Australian aborigines. While much of this could have been prevented by effective control of Group A streptococcal skin infections, there is also evidence that the high susceptibility to end-stage renal disease is related to poor intrauterine development of the kidney as low- birth weight is a predisposing factor. Mothers, whose renal function is impaired, tend to have babies which are low birth weight. There is no knowledge about the effects of maternal renal dysfunction on development of the fetal kidney. We have recently developed an animal model in which we can study the effects of maternal renal dysfunction on the development of the kidney of her offspring. Human beings form 60% of the functional units (nephrons) in the kidney in the last trimester. Sheep, like human beings (and unlike rats), completely form all the nephrons that they will ever have, during intrauterine life. While the fetal kidneys play an essential role in the formation of amniotic fluid, regulation of fetal fluid and electrolyte homeostasis depends on maternal renal function via transplacental transfer. If maternal renal function is reduced, it is likely that the fetal kidneys will be exposed to a greater volume and solute load through transplacental equilibration. This may have a profund effect on renal development especially if coupled with an inadequate maternal diet and a high maternal salt intake. Under these conditions we predict that development of the fetal kidney will be impaired and renal capacity after birth, reduced. This means that the kidney will 'age' more rapidly. Thus the affected individual would be predisposed to renal disease in adult life. In our animal model we will study the effects and interactions of maternal renal insufficiency, poor fetal nutrition and a high maternal salt intake on fetal kidney development and function.Read moreRead less
Leptin And Development: A Role In The Transition At Birth
Funder
National Health and Medical Research Council
Funding Amount
$100,380.00
Summary
A series of epidemiological studies have demonstrated that life expectancy and the risk of developing a range of adult diseases such as heart disease, diabetes mellitus and obesity, are related to weight and size at birth. It appears that genetic and environmental factors interact during pregnancy to determine the growth rate of the embryo and fetus and result in a permanent programming of the development of fetal organs and tissues which may result in the onset of disease in adult life. It is w ....A series of epidemiological studies have demonstrated that life expectancy and the risk of developing a range of adult diseases such as heart disease, diabetes mellitus and obesity, are related to weight and size at birth. It appears that genetic and environmental factors interact during pregnancy to determine the growth rate of the embryo and fetus and result in a permanent programming of the development of fetal organs and tissues which may result in the onset of disease in adult life. It is well established that babies born to mothers who develop diabetes in pregnancy are bigger at birth and are at greater risk of developing obesity in childhood. Paradoxically several major studies of human populations exposed to deprivation during pregnancy have shown that children born to mothers who experience undernutrition in pregnancy may also develop obesity in adult life. A new hormone has recently been identified which acts as a signal of fat mass and which plays a major role in the regulation of body weight and energy expenditure in the adult. We propose to define the role of this hormone before birth and to determine whether its production or action is altered by an increase or a decrease in fetal nutrition. In particular, we will investigate whether perturbations in the metabolic environment of the fetus program an increased production of this hormone or resistance to its actions after birth. These studies will increase our understanding of what adaptive changes before birth may relate to an increased likelihood of obesity after birth.Read moreRead less