ORCID Profile
0000-0001-5313-3438
Current Organisations
Guy's and St Thomas' NHS Foundation Trust
,
University of Warwick
,
University of Nottingham
,
Aston University
,
University of Melbourne
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Publisher: S. Karger AG
Date: 14-12-2020
DOI: 10.1159/000511135
Abstract: b i Aim: /i /b To assess the current opinion on the effects of hearing loss treatment by hearing aids (HAs) and the benefits of HA use on imbalance. b i Methods: /i /b PRISMA-compliant systematic review was done, including observational studies in patients affected by mild to severe sensorineural hearing loss with HAs, investigating the benefits of HAs on balance. Electronic searches were performed through Medline, Cochrane, Embase, Web of Science, and Scopus. b i Results: /i /b A total of 200 patients in 8 studies were included in this systematic review. Four studies were cross-sectional, 3 cross-sectional controlled and 1 prospective nonrandomized study. Static and dynamic balance in the aided condition improved in patients assessed using clinical investigations including Romberg test and Functional Ambulation Performance/mini-BESTest, respectively. Variable outcomes were found measuring static and dynamic balance during the aided condition with objective tests (computerized posturography, Mobility Lab device). Improved quality of life outcomes and self-confidence were noted, while subjective measurements of balance had conflicting results. b i Conclusion: /i /b Although an improvement in balance in patients with HAs has been shown in certain conditions, the overall benefit is still unclear and it is only possible to speculate that HAs may also improve static, dynamic, or subjective perception of balance function in adults affected by hearing loss.
Publisher: Ovid Technologies (Wolters Kluwer Health)
Date: 02-04-2021
DOI: 10.1097/AUD.0000000000001010
Abstract: The primary objective of this study was to establish the reproducibility of cochlear microphonic (CM) recordings obtained from a cochlear implant (CI) electrode contact during and immediately after insertion. This was achieved by evaluating the insertion angle and calculating the position of the apical electrode contact during insertion, using postoperative cone beam computed tomography (CBCT). The secondary objective was to create in idualized patient maps of electrode contacts located within acoustically sensitive regions by correlating the CM litude to the electrode position determined using CBCT. CMs were recorded from a CI electrode contact during and immediately after insertion in 12 patients ( n = 14 ears). Intraoperative recordings were made for a 0.5 kHz tone burst stimulus and were recorded from the apical electrode contact. Postinsertion recordings were made from the odd-numbered electrode contacts (1–15) along the array, using a range of stimulus frequencies (from 0.125 to 2 kHz). The time point at which each electrode contact passed through the round window was noted throughout the insertion, and the CM litude at this point was correlated to postoperative CBCT. This correlation was then used to estimate the CM litude at particular points within the cochlea, which was in turn compared with the litudes recorded from each electrode postoperatively to assess the reproducibility of the recordings. Significant correlation was shown between intraoperative insertion and postinsertion angles at two litude events (maximum litude: 29° mean absolute error, r = 0.77, p = 0.006 10% of maximum litude: 52° mean absolute error, r = 0.85, p = 0.002). We have developed a novel method to demonstrate the reproducibility of the CM responses recorded from a CI electrode during insertion. By correlating the CM litude with the postoperative CBCT, we have also been able to create in idualized maps of CM responses, categorizing the cochlea into acoustically responsive and unresponsive regions. If the electrode contacts within the acoustically sensitive regions are shown to be associated with improved loudness discrimination, it could have implications for optimal electrode mapping and placement.
Publisher: Informa UK Limited
Date: 24-08-2021
DOI: 10.1080/14670100.2021.1961364
Abstract: To Review the benefit of the GAST questionnaire (Tilston, S. 2003. Assessing the quality of life in adult cochlear implant users. MSc dissertation. London: City University.) to measure hearing related quality of life for adults pre and post-cochlear implantation. To develop a scoring methodology as to what score constitutes a significantly 'good' or 'poor' change to better target rehabilitation to those most in need. The GAST Questionnaire was developed using a robust cycle of validation and reliability analyses using the Statistical Package for the Social Sciences (Norusis, M. 1993. The GAST questionnaire design was deemed robust. The scoring methodology used led to the 20th percentile score highlighting in iduals requiring further support and the 80th percentiles for those suitable for partial booking. The GAST questionnaire is a useful way of identifying the patients in need of support as well as to measure patient reported quality of life improvements following cochlear implantation.
Publisher: Wiley
Date: 12-11-2020
DOI: 10.1111/COA.13659
Abstract: Percutaneous bone‐anchored hearing devices (pBAHDs) are the most commonly used bone conduction implants (BCI). Concerns surround the long‐term complications, notably skin‐related, in patients with percutaneous abutments. The active transcutaneous BCI Bonebridge system can help avoid some of these pitfalls but is often considered a second‐line option due to various factors including perceived increased overall costs. Longitudinal economic analysis of Bonebridge BCI 601 versus pBAHD over a 5‐year follow‐up period. A specialist hearing implant centre. Adult patients (≥16 years) with conductive hearing loss, mixed hearing loss or single‐sided deafness, who received a Bonebridge or pBAHD implant between 1/7/2013 and 1/12/2018 with a minimum 12‐month follow‐up. We compared the mean costs per implanted patient for both implants at 1, 3 and 5 years postoperative time points. Clinical effectiveness was evaluated using objective and patient‐reported outcome measures. The mean total cost per patient of Bonebridge was significantly higher than pBAHD at 1‐year post‐implantation (£8512 standard deviation [SD] £715 vs £5590 SD £1394, P .001) however, by 5‐years post‐implantation this difference was no longer statistically significant (£12 453 SD £2159 vs £12 575 SD £3854, P .05). The overall cost convergence was mainly accounted for by the increased long‐term complications, revision surgery rates and higher cost of the pBAHD external processor compared to Bonebridge. Long‐term costs of Bonebridge to healthcare providers are comparable to pBAHDs, whilst offering lower complication rates, comparable audiological benefit and patient satisfaction. Bonebridge should be considered as a first‐line BCI option in appropriate cases.
Publisher: Elsevier BV
Date: 2009
Publisher: American Chemical Society (ACS)
Date: 17-07-2015
DOI: 10.1007/S13361-015-1226-7
Abstract: Two-dimensional Fourier transform ion cyclotron resonance mass spectrometry is a data-independent analytical method that records the fragmentation patterns of all the compounds in a s le. This study shows the implementation of atmospheric pressure photoionization with two-dimensional (2D) Fourier transform ion cyclotron resonance mass spectrometry. In the resulting 2D mass spectrum, the fragmentation patterns of the radical and protonated species from cholesterol are differentiated. This study shows the use of fragment ion lines, precursor ion lines, and neutral loss lines in the 2D mass spectrum to determine fragmentation mechanisms of known compounds and to gain information on unknown ion species in the spectrum. In concert with high resolution mass spectrometry, 2D Fourier transform ion cyclotron resonance mass spectrometry can be a useful tool for the structural analysis of small molecules. Graphical Abstract ᅟ.
Publisher: Elsevier BV
Date: 06-2009
DOI: 10.1016/J.BBR.2008.12.037
Abstract: In the amyloid over-expressing TASTPM mouse model of Alzheimer's disease, impaired contextual fear memory occurs early, and is preceded, at 4 months of age, by a deficit in extinction of contextual fear that is resistant to improvement by repeated mild novel cage stress. The first aim of this study was thus to establish whether the extinction deficit could be prevented if the novel cage procedure was applied prior to its onset. The second aim was to establish whether the occurrence of the extinction deficit was dependent on the robustness of the conditioning protocol. We first compared 3-month-old wild-type and TASTPM mice for acquisition, retention and extinction of contextual fear and then, looked at the impact of 5 weeks of novel cage stress (4 x 1 h/week) applied from 3 months onwards, on age-related changes in these behaviours evaluated at 4.5 months of age. In another experiment, we compared 4-month-old TASTPM and wild-type mice for the impact of a 2 and 5-pairing conditioning procedure on the three phases of contextual fear conditioning. In 4.5-month-old TASTPM mice, the deficit in extinction was alleviated by repeated novel cage stress, applied from prior to its onset at 3 months. At 4 months of age, the occurrence of an extinction deficit was independent of the strength of the conditioning procedure, in TASTPM mice, which even showed an increase in aversive memory under the 2-pairing condition. The robust early impairment in the extinction of contextual fear seen in adult TASTPM mice suggests that a deficit in cognitive flexibility is the first sign of behavioural pathology in this model of Alzheimer's disease.
Publisher: Wiley
Date: 14-04-2015
DOI: 10.1002/PRO.2659
Abstract: Deamidation is a nonenzymatic post‐translational modification of asparagine to aspartic acid or glutamine to glutamic acid, converting an uncharged amino acid to a negatively charged residue. It is plausible that deamidation of asparagine and glutamine residues would result in disruption of a proteins' hydrogen bonding network and thus lead to protein unfolding. To test this hypothesis Calmodulin and B2M were deamidated and analyzed using tandem mass spectrometry on a Fourier transform ion cyclotron resonance mass spectrometer (FTICR‐MS). The gas phase hydrogen bonding networks of deamidated and nondeamidated protein isoforms were probed by varying the infra‐red multi‐photon dissociation laser power in a linear fashion and plotting the resulting electron capture dissociation fragment intensities as a melting curve at each amino acid residue. Analysis of the unfolding maps highlighted increased fragmentation at lower laser powers localized around heavily deamidated regions of the proteins. In addition fragment intensities were decreased across the rest of the proteins which we propose is because of the formation of salt‐bridges strengthening the intramolecular interactions of the central regions. These results were supported by a computational flexibility analysis of the mutant and unmodified proteins, which would suggest that deamidation can affect the global structure of a protein via modification of the hydrogen bonding network near the deamidation site and that top down FTICR‐MS is an appropriate technique for studying protein folding.
Publisher: Wiley
Date: 31-07-2013
DOI: 10.1002/RCM.6658
Abstract: Fourier Transform Ion Cyclotron Resonance mass spectra exhibit improved resolving power, mass accuracy and signal-to-noise ratio when presented in absorption mode a process which requires calculation of a phase correction function. Mass spectrometric images can contain many thousands of pixels hence methods of decreasing the time required to solve for a phase correction function will result in significant improvements in this application. A genetic algorithm approach for optimizing the phase correction function has been developed and compared with a previously described convergent iteration technique. The genetic algorithm method has been shown to offer a five-fold improvement in processing speed compared with the previous iterative approach used in the Autophaser algorithm, while maintaining the levels of accuracy. This translates to an 11 hour improvement in processing for a 20 000 pixel mass spectrometric image. The genetic algorithm method described in this manuscript offers significant processing speed advantages over the previously described convergent iteration technique. This improvement is key to allowing the future routine use of absorption mode mass spectrometric images.
Publisher: American Chemical Society (ACS)
Date: 30-03-2016
DOI: 10.1021/ACS.ANALCHEM.5B04878
Abstract: Two-dimensional Fourier transform ion cyclotron resonance mass spectrometry (2D FT-ICR MS) allows the correlation between precursor and fragment ions in tandem mass spectrometry without the need to isolate the precursor ion beforehand. 2D FT-ICR MS has been optimized as a data-independent method for the structural analysis of compounds in complex s les. Data processing methods and denoising algorithms have been developed to use it as an analytical tool. In the present study, the capabilities of 2D FT-ICR MS are explored with a tryptic digest of cytochrome c with both ECD and IRMPD as fragmentation modes. The 2D mass spectra showed useful fragmentation patterns of peptides over a dynamic range of almost 400. By using a quadratic calibration, fragment ion peaks could be successfully assigned. The correlation between precursor and fragment ions in the 2D mass spectra was more accurate than in MS/MS spectra after quadrupole isolation, due to the limitations of quadrupole isolation. The use of the second dimension allowed for successful fragment assignment from precursors that were separated by only m/z 0.0156. The resulting cleavage coverage of cytochrome c almost matched data provided by high-resolution FT-ICR MS/MS analysis, but the 2D FT-ICR MS method required only one experimental scan.
Publisher: Elsevier BV
Date: 12-2008
DOI: 10.1016/J.SCHRES.2008.08.003
Abstract: Decreased muscarinic M1 receptor (CHRM1) mRNA has been reported in Brodmann's area (BA) 6 from subjects with schizophrenia. We have extended this study by measuring levels of CHRM1 ([(3)H]pirenzepine binding), CHRM3 ([(3)H]4-DAMP binding), the transcription factor SP1 and the CHRM1 downstream target beta-site APP-cleaving enzyme 1 (BACE1) in BA 6 from 19 subjects with schizophrenia and 19 control subjects. Radioligand binding was quantified using either in situ radioligand binding with autoradiography or, in cohorts of 10 control subjects and 10 subjects with schizophrenia, membrane enriched fraction (MEF) CNS ([(3)H]pirenzepine binding only). Levels of SP1 and BACE1 were measured by Western blotting. [(3)H]pirenzepine binding to tissue sections was in two layers, binding to tissue sections (Binding layer 1: p<0.01 Binding layer 2: p<0.001) and MEF (p<0.05) were decreased in schizophrenia. Levels of [(3)H]4-DAMP binding, SP1 and BACE1 were not altered in subjects with the disorder. This study shows a decrease in levels of CHRM1 in BA 6 from subjects with schizophrenia as CHRM1 and BA 6 are important in maintaining normal cognitive function, these data support the hypothesis that decreased levels of cortical CHRM1 may contribute to the cognitive deficits associated with schizophrenia. Our findings on BACE1 suggest that the schizophrenia phenotype reported in BACE(-/-) mice is not simply due to lack of that protein in the cortex.
Publisher: American Chemical Society (ACS)
Date: 15-10-2014
DOI: 10.1007/S13361-014-0996-7
Abstract: Glyoxal-derived advanced glycation end-products (AGEs) are formed in physiological systems affecting protein eptide function and structure. These AGEs are generated during aging and chronic diseases such as diabetes and are considered arginine glycating agents. Thus, the study of glyoxal-derived AGEs in lysine residues and amino acid competition is addressed here using acetylated and non-acetylated undecapeptides, with one arginine and one lysine residue available for glycation. Tandem mass spectrometry results from a Fourier transform ion cyclotron resonance mass spectrometer showed glycated species at both the arginine and lysine residues. One species with the mass addition of 116.01096 Da is formed at the arginine residue. A possible structure is proposed to explain this finding (Nδ-[2-(dihydroxymethyl)-2H,3aH,4H,6aH-[1,3]dioxolo[5,6-d]imidazolin-5-yl]-L-ornithine-derived AGE). The second species corresponded to intramolecular crosslink involving the lysine residue and its presence is checked with ion-mobility mass spectrometry.
Location: United Kingdom of Great Britain and Northern Ireland
Location: United Kingdom of Great Britain and Northern Ireland
Location: United Kingdom of Great Britain and Northern Ireland
Location: United Kingdom of Great Britain and Northern Ireland
Location: No location found
No related grants have been discovered for Andrew Soulby.