Publications by authors named "Fiona Bright"

Cortical organoids are 3D structures derived either from human embryonic stem cells or human induced pluripotent stem cells with their use exploding in recent years due to their ability to better recapitulate the human brain in vivo in respect to organization; differentiation; and polarity. Adeno-associated viruses (AAVs) have emerged in recent years as the vectors of choice for CNS-targeted gene therapy. Here; we compare the use of AAVs as a mode of gene expression in cortical organoids; over traditional methods such as lipofectamine and electroporation and demonstrate its ease-of-use in generating quick disease models through expression of different variants of the central gene-TDP-43-implicated in amyotrophic lateral sclerosis and frontotemporal dementia.

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Frontotemporal dementia refers to a group of neurodegenerative disorders characterized by behaviour and language alterations and focal brain atrophy. Amyotrophic lateral sclerosis is a rapidly progressing neurodegenerative disease characterized by loss of motor neurons resulting in muscle wasting and paralysis. Frontotemporal dementia and amyotrophic lateral sclerosis are considered to exist on a disease spectrum given substantial overlap of genetic and molecular signatures.

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Behavioral variant frontotemporal dementia (bvFTD) is a younger onset form of neurodegeneration initiated in the frontal and/or temporal lobes with a slow clinical onset but rapid progression. bvFTD is highly complex biologically with different pathological signatures and genetic variants that can exhibit a spectrum of overlapping clinical manifestations. Although the role of innate immunity has been extensively investigated in bvFTD, the involvement of adaptive immunity in bvFTD pathogenesis is poorly understood.

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The abnormal mislocalisation and ubiquitinated protein aggregation of the TAR DNA binding protein 43 (TDP-43) within the cytoplasm of neurons and glia in the central nervous system (CNS) is a pathological hallmark of early-onset neurodegenerative disorders amyotrophic lateral sclerosis (ALS) and frontotemporal dementia (FTD). The pathomechanisms underlying abnormal mislocalisation and aggregation of TDP-43 remain unknown. However, there is a growing body of evidence implicating neuroinflammation and immune-mediated mechanisms in the pathogenesis of neurodegeneration.

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This study proposes a practical approach, using the minimum number of brain regions and stains, to consolidate previously published neuropathological criteria into one operationalized schema to differentiate subtypes of frontotemporal lobar degeneration with tau-immunopositive inclusions (FTLD-tau). This approach uses the superior frontal and precentral cortices and hippocampus stained for phosphorylated-tau, p62 and modified Bielschowsky silver, and the midbrain stained only for modified Bielschowsky silver. Accuracy of interrater reliability was determined by 10 raters in 24 FTLD-tau cases (Pick disease = 4, corticobasal degeneration = 9, progressive supranuclear palsy = 5, globular glial tauopathy = 6) including 4 with a mutation in MAPT collected with consent by Sydney Brain Bank.

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Frontotemporal dementia (FTD) and amyotrophic lateral sclerosis (ALS) are neurodegenerative diseases that are considered to be on the same disease spectrum because of overlapping genetic, pathological and clinical traits. Changes in serum proteins in FTD and ALS are poorly understood, and currently no definitive biomarkers exist for diagnosing or monitoring disease progression for either disease. Here we applied quantitative discovery proteomics to analyze protein changes in FTD (N = 72) and ALS (N = 28) patient serum compared to controls (N = 22).

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Frontotemporal dementia (FTD) refers to a group of progressive neurodegenerative disorders with different pathological signatures, genetic variability and complex disease mechanisms, for which no effective treatments exist. Despite advances in understanding the underlying pathology of FTD, sensitive and specific fluid biomarkers for this disease are lacking. As in other types of dementia, mounting evidence suggests that neuroinflammation is involved in the progression of FTD, including cortical inflammation, microglial activation, astrogliosis and differential expression of inflammation-related proteins in the periphery.

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Neuroinflammation is an inflammatory response in the brain and spinal cord, which can involve the activation of microglia and astrocytes. It is a common feature of many central nervous system disorders, including a range of neurodegenerative disorders. An overlap between activated microglia, pro-inflammatory cytokines and translocator protein (TSPO) ligand binding was shown in early animal studies of neurodegeneration.

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Victims of sudden infant death syndrome (SIDS) are believed to have an underlying dysfunction in medullary homeostatic control that impairs critical responses to life threatening challenges such as hypoxia, hypercarbia and asphyxia, often during a sleep period. This failure is thought to result from abnormalities in a network of neural pathways in the medulla oblongata that control respiration, chemosensitivity, autonomic function and arousal. Studies have mainly focused on the role of serotonin, 5-hydroxytyptamine (5HT), although the neuropeptide substance P (SP) has also been shown to play an integral role in the modulation of medullary homeostatic function, often in conjunction with 5-HT.

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A wide variety of neuropathological abnormalities have been investigated in infants who have died of sudden infant death syndrome (SIDS). Issues which detracted from early studies included failure to use uniform definitions of SIDS and lack of appropriately matched control populations. Development of the triple risk model focused attention on the concept of an inherent susceptibility to unexpected death in certain infants, with research demonstrating a role for the neurotransmitter serotonin within the brainstem.

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Substance P (SP) and its tachykinin NK1 receptor (NK1R) function within key medullary nuclei to regulate cardiorespiratory and autonomic control. We examined the normative distribution of SP and NK1R in the serotonergic (5-Hydroxytryptamine, [5-HT]) network of the human infant medulla during postnatal development, to provide a baseline to facilitate future analysis of the SP/NK1R system and its interaction with 5-HT within pediatric brainstem disorders in early life. [I] labelled Bolton Hunter SP (BH-SP) tissue receptor autoradiography (n = 15), single label immunohistochemistry (IHC) and double label immunofluorescence (IF) (n = 10) were used to characterize the normative distribution profile of SP and NK1R in the 5-HT network of the human infant medulla during postnatal development.

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Article Synopsis
  • The prone sleeping position increases the risk of sudden infant death syndrome (SIDS), though the reasons remain unclear.
  • Various factors have been suggested, including airway blockage, rebreathing carbon dioxide, and impaired arousal responses.
  • Recent studies indicate a significant reduction in substance P in brain areas related to motor and sensory control, which may prevent some infants from moving their heads away from dangerous sleeping situations.
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Sudden infant death syndrome (SIDS) involves failure of arousal to potentially life threatening events, including hypoxia, during sleep. While neuronal dysfunction and abnormalities in neurotransmitter systems within the medulla oblongata have been implicated, the specific pathways associated with autonomic and cardiorespiratory failure are unknown. The neuropeptide substance P (SP) and its tachykinin neurokinin-1 receptor (NK1R) have been shown to play an integral role in the modulation of homeostatic function in the medulla, including regulation of respiratory rhythm generation, integration of cardiovascular control, and modulation of the baroreceptor reflex and mediation of the chemoreceptor reflex in response to hypoxia.

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Serotonin (5-hydroxytryptamine [5-HT]) neurons in the medulla oblongata project extensively to key autonomic and respiratory nuclei in the brainstem and spinal cord regulating critical homeostatic functions. Multiple abnormalities in markers of 5-HT function in the medulla in sudden infant death syndrome (SIDS) have been reported, informing the hypothesis that at least a subset of SIDS cases is caused by deficits in 5-HT function resulting in impaired homeostatic responses to potentially life-threatening events during sleep. To investigate medullary 5-HT defects in SIDS further, we undertook qualitative analysis immunohistochemical assessment of 5-HT neuron expression within the medulla of SIDS infants (n41) and nonSIDS controls (n = 28) in an independent cohort from Forensic Science South Australia.

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Case files from Forensic Science South Australia and the Swedish National Forensic Database were reviewed over a 6-year period from 2006 to 2011 for cases where hypothermia either caused, or significantly contributed to, death. Data were analyzed for age, sex, time of year/season, place of discovery, circumstances of death, and underlying medical conditions. Despite the considerable demographic, geographic, and climatological differences, hypothermic deaths occurred at very similar rates in South Australia (3.

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A review of hypothermic deaths was undertaken using cases from the Charité University, Berlin, Germany and Forensic Science South Australia, Australia. There were 16 cases from Berlin (age range 38-96 years; average 68 years; M:F = 13:3) Wischnewski spots were present in all 16 cases (100%), skin discolouration in nine (56%), and acute pancreatitis and muscle haemorrhage in one case each (6%). There were 62 Australian cases (age range 30-89 years; average 67 years; M:F = 13:18).

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A rodent model was used to evaluate the association between hypothermia and basal vacuolization in renal tubular epithelial cells. 28 Sprague Dawley rats were anaesthetized in non-stressful conditions and placed two at a time into a cooling chamber. Body core temperatures dropped to a minimum of 7-10 °C, causing death under anaesthesia at times varying from 120 to 240 min.

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Hypothermic fatalities in humans are characterized by a range of often subtle pathological findings that typically include superficial erosive gastritis (Wischnewski spots). Experimental studies have been successfully performed using animal models to replicate this finding, however study animals have inevitably been subjected to a variety of additional stressors including food deprivation, restraint and partial immersion in water while conscious. As it is recognised that stress on its own may cause superficial erosive gastritis, a model has been developed to enable the study of the effects of hypothermia in isolation.

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An 86-year-old woman was found dead lying on her back on the floor of an unkempt kitchen. She had last been seen four days before. Her dress was pulled up and she was not wearing underpants.

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