Publications by authors named "Marcella J Wyatt"

Background: Diffuse intrinsic pontine glioma (DIPG) is a lethal type of pediatric brain tumor that is resistant to conventional chemotherapies. Palbociclib is a putative novel DIPG treatment that restricts the proliferation of rapidly dividing cancer cells via selective inhibition of cyclin-dependent kinase (CDK) 4 and CDK6. However, implementing palbociclib as a monotherapy for DIPG is unfeasible, as CDK4/6 inhibitor resistance is commonplace and palbociclib does not readily cross the blood-brain barrier (BBB) or persist in the central nervous system.

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OBJECTIVE The pan-histone deacetylase inhibitor panobinostat has preclinical efficacy against diffuse intrinsic pontine glioma (DIPG), and the oral formulation has entered a Phase I clinical trial. However, panobinostat does not cross the blood-brain barrier in humans. Convection-enhanced delivery (CED) is a novel neurosurgical drug delivery technique that bypasses the blood-brain barrier and is of considerable clinical interest in the treatment of DIPG.

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Targeting epigenetic changes in diffuse intrinsic pontine glioma (DIPG) may provide a novel treatment option for patients. This report demonstrates that sodium valproate, a histone deacetylase inhibitor (HDACi), can increase the cytotoxicity of carboplatin in an additive and synergistic manner in DIPG cells in vitro. Sodium valproate causes a dose-dependent decrease in DIPG cell viability in three independent ex vivo cell lines.

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We currently use Convection-Enhanced Delivery (CED) of the platinum-based drug, carboplatin as a novel treatment strategy for high grade glioblastoma in adults and children. Although initial results show promise, carboplatin is not specifically toxic to tumour cells and has been associated with neurotoxicity at high infused concentrations in pre-clinical studies. Our treatment strategy requires intermittent infusions due to rapid clearance of carboplatin from the brain.

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Context: Inadequate penetration of the blood-brain barrier (BBB) by systemically administered chemotherapies including carboplatin is implicated in their failure to improve prognosis for patients with glioblastoma. Convection-enhanced delivery (CED) of carboplatin has the potential to improve outcomes by facilitating bypass of the BBB.

Objective: We report the first use of an implantable CED system incorporating a novel transcutaneous bone-anchored port (TBAP) for intermittent CED of carboplatin in a patient with recurrent glioblastoma.

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Non-viral vector formulations comprise typically complexes of nucleic acids with cationic polymers or lipids. However, for in vivo applications cationic formulations suffer from problems of poor tissue penetration, non-specific binding to cells, interaction with serum proteins and cell adhesion molecules and can lead to inflammatory responses. Anionic formulations may provide a solution to these problems but they have not been developed to the same extent as cationic formulations due to difficulties of nucleic acid packaging and poor transfection efficiency.

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Enzymatic degradation contributes to the control of intracerebral amyloid-β (Aβ) peptide levels. Previous studies have demonstrated the therapeutic potential of viral vector-mediated neprilysin (NEP) gene therapy in mouse models of Alzheimer's disease (AD). However, clinical translation of NEP gene therapy is limited by ethical and practical considerations.

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Background: Convection-enhanced delivery (CED), a direct method for drug delivery to the brain through intraparenchymal microcatheters, is a promising strategy for intracerebral pharmacological therapy. By establishing a pressure gradient at the tip of the catheter, drugs can be delivered in uniform concentration throughout a large volume of interstitial fluid. However, the variables affecting perivascular distribution of drugs delivered by CED are not fully understood.

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Vein grafts are used to bypass coronary arterial stenosis, but many grafts thrombose soon after surgery. A model was developed in the pig to allow continuous measurement of blood flow and production of flow-restricting thrombi (cyclic flow reductions; CFRs). Saphenous vein lumen was exposed to adenovirus ex vivo, to over-express human tissue plasminogen activator (h-tPA), with beta-galactosidase adenovirus as a control.

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