Publications by authors named "Joseph Walton"

The auditory system is constantly tasked with detecting acoustic cues in complex auditory environments. Difficulty hearing speech in noise, largely a result of energetic masking, is a major communication complaint of the elderly, which impacts a third of the global population over 65. The neural mechanisms responsible for processing sound in background noise and subsequently achieving release from energetic masking remain obscure.

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In addition to the ubiquitous loss of the VHL gene in clear cell renal cell carcinoma (ccRCC), co-deletions of chromatin-regulating genes are common drivers of tumorigenesis, suggesting potential vulnerability to epigenetic manipulation. A library of chemical probes targeting a spectrum of epigenetic regulators is screened using a panel of ccRCC models. MS023, a type I protein arginine methyltransferase (PRMT) inhibitor, is identified as an antitumorigenic agent.

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Introduction: Cases of nitrous oxide (NO)-induced myeloneuropathy are increasing at UK hospitals. At our centre, a dedicated ambulatory care pathway, endorsed nationally, was established to treat and monitor patients with NO-myeloneuropathy in 2021 and refined through three audit cycles. We analysed the outcomes of patients on this pathway to better understand factors associated with non-engagement.

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Background: The study aimed to elucidate the prevalence of nitrous oxide (N2O) usage in patients with unexplained venous thromboembolism (VTE), highlighting the potential association with hyperhomocysteinaemia (HHcy).

Methods: We conducted a retrospective study at the Royal London Hospital, examining cases of N2O-related VTE from March to August 2023. Among 50 patients identified, four (8%) had recent unprovoked VTE.

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The naturally occurring amino acid, l-ergothioneine (EGT), has immense potential as a therapeutic, having shown promise in the treatment of other disease models, including neurological disorders. EGT is naturally uptaken into cells via its specific receptor, OCTN1, to be utilized by cells as an antioxidant and anti-inflammatory. In our current study, EGT was administered over a period of 6 months to 25-26-month-old CBA/CaJ mice as a possible treatment for age-related hearing loss (ARHL), since presbycusis has been linked to higher levels of cochlear oxidative stress, apoptosis, and chronic inflammation.

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The inbred mouse strain CBA/CaJ is a frequently used animal model of age-related hearing loss in humans. These mice display significant hearing loss at a relatively advanced age, similar to most humans, with progressive loss of hearing as the mouse continues to age. While important descriptions of hearing loss in this mouse strain at multiple ages have previously been published, shortcomings persist in the data for hearing over the lifespan of the mouse.

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Recreational use of nitrous oxide (NO) has increased rapidly in recent years and is now the second most commonly used recreational drug among young people in the UK. There has been a corresponding rise in cases of nitrous oxide-induced subacute combined degeneration of the cord (NO-SACD), a pattern of myeloneuropathy usually associated with severe vitamin B deficiency. This can cause serious and permanent disability in young people but, if recognised early, may be effectively treated.

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The startle reflex (SR), a robust, motor response elicited by an intense auditory, visual, or somatosensory stimulus has been widely used as a tool to assess psychophysiology in humans and animals for almost a century in diverse fields such as schizophrenia, bipolar disorder, hearing loss, and tinnitus. Previously, SR waveforms have been ignored, or assessed with basic statistical techniques and/or simple template matching paradigms. This has led to considerable variability in SR studies from different laboratories, and species.

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Biallelic inactivation of the tumour suppressor gene Von Hippel-Lindau (VHL) occurs in the vast majority of clear cell renal cell carcinoma (ccRCC) instances, disrupting cellular oxygen-sensing mechanisms to yield a state of persistent pseudo-hypoxia, defined as a continued hypoxic response despite the presence of adequate oxygen levels. However, loss of VHL alone is often insufficient to drive oncogenesis. Results from genomic studies have shown that co-deletions of VHL with one (or more) of three genes encoding proteins involved in chromatin modification and remodelling, polybromo-1 gene (PBRM1), BRCA1-associated protein 1 (BAP1) and SET domain-containing 2 (SETD2), are common and important co-drivers of tumorigenesis.

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Tinnitus is the phantom perception of sound that has no external source. A neurological signature of tinnitus, and the frequently associated hyperacusis, is an imbalance between excitatory and inhibitory activity in the central auditory system (CAS), leading to dysregulated network excitability. The large conductance, calcium-activated potassium (BK) channel is a key player in pre- and post-synaptic excitability through its mediation of K currents.

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Recent evidence suggests that modulation of the large-conductance, calcium-activated potassium (BK) channel regulates auditory processing in the brain. Because ion channel expression often changes during aging, this could be a factor in age-related hearing loss. The current study explored how the novel BK channel modulator LS3 shapes central auditory processing in young and old adult mice.

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Here we present a 3D-printed, wirelessly controlled microsystem for drug delivery, comprising a refillable microreservoir and a phase-change peristaltic micropump. The micropump structure was inkjet-printed on the back of a printed circuit board around a catheter microtubing. The enclosure of the microsystem was fabricated using stereolithography 3D printing, with an embedded microreservoir structure and integrated micropump.

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Congenital sensorineural hearing loss (SNHL) affects thousands of infants each year and results in significant delays in speech and language development. Previous studies have shown that early exposure to a simple augmented acoustic environment (AAE) can limit the effects of progressive SNHL on hearing sensitivity. However, SNHL is also accompanied by hearing loss that is not assessed on standard audiological examinations, such as reduced temporal processing acuity.

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The acoustic startle response (ASR) is an involuntary muscle reflex that occurs in response to a transient loud sound and is a highly-utilized method of assessing hearing status in animal models. Currently, a high level of variability exists in the recording and interpretation of ASRs due to the lack of standardization for collecting and analyzing these measures. An ensembled machine learning model was trained to predict whether an ASR waveform is a startle or non-startle using highly-predictive features extracted from normalized ASR waveforms collected from young adult CBA/CaJ mice.

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Na-K-2Cl Cotransporter (NKCC1) is a protein that aids in the active transport of sodium, potassium, and chloride ions across cell membranes. It has been shown that long-term systemic treatment with aldosterone (ALD) can enhance NKCC1 protein expression and activity in the aging cochlea resulting in improved hearing. In the present work, we used a cell line with confirmed NKCC1 expression to demonstrate that in vitro application of ALD increased outward voltage-gated potassium currents significantly, and simultaneously upregulated whole lysate and membrane portion NKCC1 protein expression.

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Background: The acoustic startle response (ASR) is a simple reflex that results in a whole body motor response after animals hear a brief loud sound and is used as a multisensory tool across many disciplines. Unfortunately, a method of how to record, process, and analyze ASRs has yet to be standardized, leading to high variability in the collection, analysis, and interpretation of ASRs within and between laboratories.

New Method: ASR waveforms collected from young adult CBA/CaJ mice were normalized with features extracted from the waveform, the resulting power spectral density estimates, and the continuous wavelet transforms.

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Reservoir-based drug delivery microsystems have enabled novel and effective drug delivery concepts in recent decades. These systems typically comprise integrated storing and pumping components. Here we present a stand-alone, modular, thin, scalable, and refillable microreservoir platform as a storing component of these microsystems for implantable and transdermal drug delivery.

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This article was migrated. The article was marked as recommended. The initial history and examination is a fundamental aspect of clinical practice.

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Inner ear disorders such as sensorineural deafness and genetic diseases may one day be treated with local drug delivery to the inner ear. Current pharmacokinetic models have been based on invasive methods to measure drug concentrations, limiting them in spatial resolution, and restricting the research to larger rodents. We developed an intracochlear pharmacokinetic model based on an imaging, learning-prediction (LP) paradigm for learning transport parameters in the murine cochlea.

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Objective: High doses of sodium salicylate (SS) are known to induce tinnitus, general hyperexcitability in the central auditory system, and to cause mild hearing loss. We used the auditory brainstem response (ABR) to assess the effects of SS on auditory sensitivity and temporal processing in the auditory nerve and brainstem. ABRs were evoked using tone burst stimuli varying in frequency and intensity with presentation rates from 11/s to 81/s.

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Advances in protective and restorative biotherapies have created new opportunities to use site-directed, programmable drug delivery systems to treat auditory and vestibular disorders. Successful therapy development that leverages the transgenic, knock-in, and knock-out variants of mouse models of human disease requires advanced microsystems specifically designed to function with nanoliter precision and with system volumes suitable for implantation. Here we present results for a novel biocompatible, implantable, scalable, and wirelessly controlled peristaltic micropump.

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Acoustic trauma can induce temporary or permanent noise-induced hearing loss (NIHL). Noise exposed animal models allow us to study the effects of various noise trauma insults on the cochlea and auditory pathways. Here we studied the short-term and long-term functional changes occurring in the auditory system following exposure to two different noise traumas.

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Active mechanical amplification of sound occurs in cochlear outer hair cells (OHCs) that change their length with oscillations of their membrane potential. Such length changes are the proposed cellular source of the cochlear amplifier, and prestin is the motor protein responsible for OHC electromotility. Previous findings have shown that mice lacking prestin displayed a loss of OHC electromotility, subsequent loss of distortion-product otoacoustic emissions, and a 40-60 dB increase in hearing thresholds.

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Due to the critical role of cochlear ion channels for hearing, the focus of the present study was to examine age-related changes of Na, K-ATPase (NKA) subunits in the lateral wall of mouse cochlea. We combined qRT-PCR, western blot and immunocytochemistry methodologies in order to determine gene and protein expression levels in the lateral wall of young and aged CBA/CaJ mice. Of the seven NKA subunits, only the mRNA expressions of α1, β1 and β2 subunit isoforms were detected in the lateral wall of CBA/CaJ mice.

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There is a compelling need for the development of new sensory and neural prosthetic devices which are capable of more precise point stimulation. Current prosthetic devices suffer from the limitation of low spatial resolution due to the non-specific stimulation characteristics of electrical stimulation, i.e.

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