Joanne O. Davidson

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Brain damage resulting from cerebral ischemia remains a significant problem at all stages of life. In adults, ischemic stroke is the third leading cause of death and the leading cause of disability in the developed world. In term newborns, moderate to severe brain damage after hypoxia-ischemia (HI) occurs in 1-3 per 1000 live births. One of the most(More)
OBJECTIVE Connexin hemichannels can open during ischemia, resulting in loss of membrane potential, calcium influx, and release of glutamate. In this study, we tested the hypothesis that opening of hemichannels after cerebral ischemia may contribute to delayed evolution of injury. METHODS We infused a mimetic peptide that blocks connexin 43 hemichannels(More)
Alterations in Connexin43 (Cx43) expression levels have been shown to play a role in inflammatory processes including skin wounding and neuroinflammation. Cx43 protein levels increase following a skin wound and can inhibit wound healing. Increased Cx43 has been observed following stroke, epilepsy, ischemia, optic nerve damage, and spinal cord injury with(More)
Cerebral palsy is one of the most devastating consequences of brain injury around the time of birth, and nearly a third of cases are now associated with premature birth. Compared with term babies, preterm babies have an increased incidence of complications that may increase the risk of disability, such as intraventricular hemorrhage, periventricular(More)
Melatonin is a naturally occurring indolamine with mild antioxidant properties that is neuroprotective in perinatal animals. There is limited information on its effects on preterm brain injury. In this study, 23 chronically instrumented fetal sheep received 25 minutes of complete umbilical cord occlusion at 101 to 104 days gestation (term is 147 days).(More)
There is increasing evidence that connexin hemichannels, the half gap junctions that sit unopposed in the cell membrane, can open during ischemia and that blockade of connexin43 hemichannels after cerebral ischemia can improve neural outcomes. However, it is unclear whether connexin blockade during ischemia is protective. In the present study global(More)
Magnesium sulphate is a standard therapy for eclampsia in pregnancy and is widely recommended for perinatal neuroprotection during threatened preterm labour. MgSO4 is a vasodilator and negative inotrope. Therefore the aim of this study was to investigate the effect of MgSO4 on the cardiovascular and cerebrovascular responses of the preterm fetus to(More)
Asphyxia around the time of preterm birth is associated with neurodevelopmental disability. In this study, we tested the hypothesis that blockade of connexin hemichannels would improve recovery of brain activity and reduce cell loss after asphyxia in preterm fetal sheep. Asphyxia was induced by 25 min of complete umbilical cord occlusion in preterm fetal(More)
Preterm born infants have high rates of brain injury, leading to motor and neurocognitive problems in later life. Infection and resulting inflammation of the fetus and newborn are highly associated with these disabilities. However, there are no established neuroprotective therapies. Microglial activation and expression of many cytokines play a key role in(More)
Hypoxia-ischemia before or around the time of birth occurs in approximately 2/1000 live births and is associated with a high risk of death or lifelong disability. Therapeutic hypothermia is now well established as standard treatment for infants with moderate to severe hypoxic-ischemic encephalopathy but is only partially effective. There is compelling(More)