Publications by authors named "Scott Ralph"

A recent phase I-II, open-label trial of ProSavin, a lentiviral vector delivering the key enzymes in the dopamine biosynthetic pathway to non-dopaminergic striatal neurons, demonstrated safety and improved motor function in parkinsonian patients. However, the magnitude of the effect suggested that optimal levels of dopamine replacement may not have been achieved. OXB-102, a lentiviral vector with an optimized expression cassette for dopamine biosynthesis, has been shown to achieve a significantly higher dopamine yield than ProSavin.

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Parkinson's disease is typically treated with oral dopamine replacement therapies. However, long-term use is complicated by motor fluctuations from intermittent stimulation of dopamine receptors and off-target effects. ProSavin, a lentiviral vector based gene therapy that delivers local and continuous dopamine, was previously shown to be well tolerated in a Phase I/II first-in-human study, with significant improvements in motor behavior from baseline at 1 year.

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Article Synopsis
  • Our memory for events depends on understanding when and where they happened, using parts of the brain called the hippocampus and prefrontal cortex.
  • Scientists studied connections between these brain areas to see how they help with memory, using a special technique to turn off certain pathways.
  • They found that turning off one pathway affected how we remember the order of events, while turning off another pathway made it hard to remember where things happened, showing that different parts of the brain work on different kinds of memory details.
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Lwing at HM Prison Norwich is not a conventional setting for healthcare. It is home to 15 prisoners with extra and palliative care needs, including dementia and cancer.

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Pharmacological dopamine replacement therapies provide the most well-established treatments for Parkinson's disease (PD). However, these long-term treatments can lead to motor complications and off-target effects. ProSavin(®), a lentiviral vector (LV)-based gene therapy approach aimed at restoring local and continuous dopamine production, through delivery of three enzymes in the dopamine biosynthesis pathway, was demonstrated to be safe and well-tolerated in a phase I/II clinical study of patients with advanced PD.

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Background: Parkinson's disease is typically treated with oral dopamine replacement therapies; however, long-term treatment leads to motor complications and, occasionally, impulse control disorders caused by intermittent stimulation of dopamine receptors and off-target effects, respectively. We aimed to assess the safety, tolerability, and efficacy of bilateral, intrastriatal delivery of ProSavin, a lentiviral vector-based gene therapy aimed at restoring local and continuous dopamine production in patients with advanced Parkinson's disease.

Methods: We undertook a phase 1/2 open-label trial with 12-month follow-up at two study sites (France and UK) to assess the safety and efficacy of ProSavin after bilateral injection into the putamen of patients with Parkinson's disease.

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ProSavin is an equine infectious anemia virus vector-based gene therapy for Parkinson's disease for which inducible HEK293T-based producer cell lines (PCLs) have been developed. These cell lines demonstrate stringent tetracycline-regulated expression of the packaging components and yield titers comparable to the established transient production system. A prerequisite for the use of PCL-derived lentiviral vectors (LVs) in clinical applications is the thorough characterization of both the LV and respective PCL with regard to identity and genetic stability.

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In Parkinson's disease, degeneration of specific neurons in the midbrain can cause severe motor deficits, including tremors and the inability to initiate movement. The standard treatment is administration of pharmacological agents that transiently increase concentrations of brain dopamine and thereby discontinuously modulate neuronal activity in the striatum, the primary target of dopaminergic neurons. The resulting intermittent dopamine alleviates parkinsonian symptoms but is also thought to cause abnormal involuntary movements, called dyskinesias.

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Gene therapy holds great promise for the treatment of a wide range of inherited and acquired disorders. The development of viral vector systems to mediate safe and long-lasting expression of therapeutic transgenes in specific target cell populations is continually advancing. Gene therapy for the nervous system is particularly challenging due to the post-mitotic nature of neuronal cells and the restricted accessibility of the brain itself.

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Amyotrophic lateral sclerosis (ALS) is a fatal neurodegenerative disease resulting in the selective death of motor neurons in the brain and spinal cord. Some familial cases of ALS are caused by dominant mutations in the gene encoding superoxide dismutase (SOD1). The emergence of interfering RNA (RNAi) for specific gene silencing could be therapeutically beneficial for the treatment of such dominantly inherited diseases.

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The development of interfering RNA (RNAi) from a naturally occurring phenomenon to a tool for mediating highly specific gene silencing provides an exciting prospect as a novel therapeutic strategy for a wide range of disorders. Although the efficacy of RNAi as a research tool for analysing gene function has been well demonstrated in several cell types, the therapeutic potential of RNAi-mediated gene silencing has only recently started to be investigated. Several neurodegenerative disorders provide particularly suitable candidates for RNAi based therapy; however, many hurdles preclude the success of therapeutic application.

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Spinal muscular atrophy (SMA) is a frequent recessive autosomal disorder. It is caused by mutations or deletion of the telomeric copy of the survival motor neuron (SMN) gene, leading to depletion in SMN protein levels. The treatment rationale for SMA is to halt or delay the degeneration of motor neurons, but to date there are no effective drug treatments for this disease.

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Nutrient deprivation during ischemia leads to severe insult to neurons causing widespread excitotoxic damage in specific brain regions such as the hippocampus. One possible strategy for preventing neurodegeneration is to express therapeutic proteins in the brain to protect against excitotoxicity. We investigated the utility of equine infectious anemia virus (EIAV)-based vectors as genetic tools for delivery of therapeutic proteins in an in vivo excitotoxicity model.

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AMPA receptors (AMPARs) are dynamically regulated at synapses, but the time course and location of their exocytosis and endocytosis are not known. Therefore, we have used ecliptic pHluorin-tagged glutamate receptor 2 to visualize changes in AMPAR surface expression in real time. We show that synaptic and extrasynaptic AMPARs respond very differently to NMDA receptor activation; there is a rapid internalization of extrasynaptic AMPARs that precedes the delayed removal of synaptic AMPARs.

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Amyotrophic lateral sclerosis (ALS) causes adult-onset, progressive motor neuron degeneration in the brain and spinal cord, resulting in paralysis and death three to five years after onset in most patients. ALS is still incurable, in part because its complex aetiology remains insufficiently understood. Recent reports have indicated that reduced levels of vascular endothelial growth factor (VEGF), which is essential in angiogenesis and has also been implicated in neuroprotection, predispose mice and humans to ALS.

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Vectors based on lentiviruses are opening up new approaches for the treatment of neurodegenerative diseases. Currently, the equine infectious anaemia virus (EIAV) vector is one of the most attractive gene delivery systems with respect to neuronal tropism. The aim was to validate EIAV-lentiviral vectors as a gene delivery system for neurotrophic factor genes in an animal model of Parkinson's disease.

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The upregulation of TIMP-1 following an excitotoxic injury has recently been hypothesized to be part of a general neuronal response that mediates long-lasting changes involved in tissue reorganization and possibly neuroprotection. In this study we have shown for the first time that within hours of applying TIMP-1 in recombinant form or by adenovirus-mediated gene transfer, neurons are highly protected against excitotoxic injury. Neither TIMP-3 nor a nonsecretable form of TIMP-1 protected neurons.

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