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Tan K, Sakrikar D, Ashby J, North S, Ouverson L, Wallis G, Du Chateau B, Harding S, Barnidge D. M185 QIP-MS: A reliable method for detection of M-proteins traceable to the international serum standard DA470K. Clin Chim Acta 2022. [DOI: 10.1016/j.cca.2022.04.067] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/03/2022]
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2
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Tay W, Giles H, Wright N, Afzal M, Birtwistle J, Berlanga O, North S, Drayson M, Pratt G, Wallis G, Harding S. T043 Exent mass spectrometry allows early identification of multiclonal MGUS compared to electrophoretic methods. Clin Chim Acta 2022. [DOI: 10.1016/j.cca.2022.04.280] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022]
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Tan K, Ashby J, North S, Barnidge D, Brusseau S, Patel R, Du Chateau B, Wallis G, Harding S, Sakrikar D. T032 QIP-MS: An alternative method to standard electrophoretic techniques for the identification of intact monoclonal immunoglobulins. Clin Chim Acta 2022. [DOI: 10.1016/j.cca.2022.04.269] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
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Tan K, Lajko M, Sakrikar D, Ashby J, North S, Wallis G, Harding S, Du Chateau B, Murray D, Barnidge D. T033 QIP-MS discriminates therapeutic monoclonal antibodies from endogenous m-proteins in patients with multiple myeloma. Clin Chim Acta 2022. [DOI: 10.1016/j.cca.2022.04.270] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
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Shapiro S, Fouad Alber K, Morton J, Wallis G, Britton M, Bunn A, Cheema H, Jalilzadeh Afshari S, Lin ECZ, Madge O, Naseer S, Ng E, Pora A, Sardar A, Brent A, Lasserson D. Incidence of symptomatic image-confirmed venous thromboembolism in outpatients managed in a hospital-led COVID-19 virtual ward. EJHaem 2021; 2:794-798. [PMID: 34909766 PMCID: PMC8657537 DOI: 10.1002/jha2.305] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Key Words] [Grants] [Track Full Text] [Download PDF] [Subscribe] [Scholar Register] [Received: 09/03/2021] [Revised: 09/07/2021] [Accepted: 09/09/2021] [Indexed: 11/25/2022]
Affiliation(s)
- Susan Shapiro
- Oxford Haemophilia and Thrombosis CentreOxford University Hospitals NHS Foundation TrustOxfordUK
- Radcliffe Department of MedicineUniversity of OxfordOxfordUK
- NIHR Oxford Biomedical Research CentreOxfordUK
| | - Karim Fouad Alber
- Ambulatory Assessment UnitOxford University Hospitals NHS Foundation TrustOxfordUK
| | - Joshua Morton
- Ambulatory Assessment UnitOxford University Hospitals NHS Foundation TrustOxfordUK
| | - George Wallis
- Ambulatory Assessment UnitOxford University Hospitals NHS Foundation TrustOxfordUK
| | - Meriel Britton
- Ambulatory Assessment UnitOxford University Hospitals NHS Foundation TrustOxfordUK
| | - Alex Bunn
- Ambulatory Assessment UnitOxford University Hospitals NHS Foundation TrustOxfordUK
| | - Hashem Cheema
- Ambulatory Assessment UnitOxford University Hospitals NHS Foundation TrustOxfordUK
| | | | - Ei Chae Zun Lin
- Ambulatory Assessment UnitOxford University Hospitals NHS Foundation TrustOxfordUK
| | - Oliver Madge
- Ambulatory Assessment UnitOxford University Hospitals NHS Foundation TrustOxfordUK
| | - Saniya Naseer
- Ambulatory Assessment UnitOxford University Hospitals NHS Foundation TrustOxfordUK
| | - Esther Ng
- Ambulatory Assessment UnitOxford University Hospitals NHS Foundation TrustOxfordUK
| | - Alexander Pora
- Ambulatory Assessment UnitOxford University Hospitals NHS Foundation TrustOxfordUK
| | - Abbas Sardar
- Ambulatory Assessment UnitOxford University Hospitals NHS Foundation TrustOxfordUK
| | - Andrew Brent
- Infectious Diseases DepartmentOxford University Hospitals NHS Foundation TrustOxfordUK
- Nuffield Department of MedicineUniversity of OxfordOxfordUK
| | - Daniel Lasserson
- Ambulatory Assessment UnitOxford University Hospitals NHS Foundation TrustOxfordUK
- Warwick Medical SchoolUniversity of WarwickCoventryUK
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Cook A, Faustini S, Williams L, Cunningham A, Drayson M, Shields A, Kay D, Taylor L, Plant T, Huissoon A, Wallis G, Beck S, Jossi S, Perez-Toledo M, Newby M, Allen J, Crispin M, Harding S, Richter A. Validation of a combined ELISA to detect IgG, IgA and IgM antibody responses to SARS-CoV-2 in mild or moderate non-hospitalised patients. J Immunol Methods 2021; 494:113046. [PMID: 33775672 PMCID: PMC7997147 DOI: 10.1016/j.jim.2021.113046] [Citation(s) in RCA: 32] [Impact Index Per Article: 10.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/17/2020] [Revised: 03/18/2021] [Accepted: 03/20/2021] [Indexed: 12/16/2022]
Abstract
BACKGROUND Frequently SARS-CoV-2 results in mild or moderate disease with potentially lower concentrations of antibodies compared to those that are hospitalised. Here, we validated an ELISA using SARS-CoV-2 trimeric spike glycoprotein, with targeted detection of IgG, IgA and IgM (IgGAM) using serum and dried blood spots (DBS) from adults with mild or moderate disease. METHODS Targeting the SARS-CoV-2 trimeric spike, a combined anti-IgG, IgA and IgM serology ELISA assay was developed using 62 PCR-confirmed non-hospitalised, mild or moderate COVID-19 samples, ≥14 days post symptom onset and 624 COVID-19 negative samples. The assay was validated using 73 PCR-confirmed non-hospitalised, mild or moderate COVID-19 samples, ≥14 days post symptom onset and 359 COVID-19 negative serum samples with an additional 81 DBSs. The assay was further validated in 226 PCR-confirmed non-hospitalised, mild or moderate COVID-19 samples, ≥14 days post symptom onset and 426 COVID-19 negative clinical samples. RESULTS A sensitivity and specificity of 98.6% (95% CI, 92.6-100.0), 98.3% (95% CI, 96.4-99.4), respectively, was observed following validation of the SARS-CoV-2 ELISA. No cross-reactivities with endemic coronaviruses or other human viruses were observed, and no change in results were recorded for interfering substances. The assay was stable at temperature extremes and components were stable for 15 days once opened. A matrix comparison showed DBS to correlate with serum results. Clinical validation of the assay reported a sensitivity of 94.7% (95% CI, 90.9-97.2%) and a specificity of 98.4% (95% CI, 96.6-99.3%). CONCLUSIONS The human anti-IgGAM SARS-CoV-2 ELISA provides accurate and sensitive detection of SARS-CoV-2 antibodies in non-hospitalised adults with mild or moderate disease. The use of dried blood spots makes the assay accessible to the wider community.
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Affiliation(s)
- A.M. Cook
- The Binding Site Group Ltd, 8 Calthorpe Road, Birmingham B15 1QT, UK
| | - S.E. Faustini
- Clinical Immunology Service, University of Birmingham College of Medical and Dental Sciences, Birmingham B15 2TT, UK
| | - L.J. Williams
- The Binding Site Group Ltd, 8 Calthorpe Road, Birmingham B15 1QT, UK,Corresponding author at: The Binding Site Group, 8 Calthorpe Road, Birmingham B15 1QT, UK
| | - A.F. Cunningham
- Institute of Immunology and Immunotherapy, University of Birmingham, Birmingham B15 2TT, UK
| | - M.T. Drayson
- Clinical Immunology Service, University of Birmingham College of Medical and Dental Sciences, Birmingham B15 2TT, UK
| | - A.M. Shields
- Clinical Immunology Service, University of Birmingham College of Medical and Dental Sciences, Birmingham B15 2TT, UK,University Hospitals Birmingham, NHS Foundation Trust, Birmingham B15 2GW, UK
| | - D. Kay
- The Binding Site Group Ltd, 8 Calthorpe Road, Birmingham B15 1QT, UK
| | - L. Taylor
- The Royal Wolverhampton NHS Trust, Wolverhampton Road, Wolverhampton, West Midlands WV10 0QP, UK
| | - T. Plant
- Clinical Immunology Service, University of Birmingham College of Medical and Dental Sciences, Birmingham B15 2TT, UK
| | - A. Huissoon
- Institute of Immunology and Immunotherapy, University of Birmingham, Birmingham B15 2TT, UK,University Hospitals Birmingham, NHS Foundation Trust, Birmingham B15 2GW, UK
| | - G. Wallis
- The Binding Site Group Ltd, 8 Calthorpe Road, Birmingham B15 1QT, UK
| | - S. Beck
- University Hospitals Birmingham, NHS Foundation Trust, Birmingham B15 2GW, UK
| | - S.E. Jossi
- Institute of Immunology and Immunotherapy, University of Birmingham, Birmingham B15 2TT, UK
| | - M. Perez-Toledo
- Institute of Immunology and Immunotherapy, University of Birmingham, Birmingham B15 2TT, UK
| | - M.L. Newby
- School of Biological Sciences, University of Southampton, Southampton SO17 1BJ, UK
| | - J.D. Allen
- School of Biological Sciences, University of Southampton, Southampton SO17 1BJ, UK
| | - M. Crispin
- School of Biological Sciences, University of Southampton, Southampton SO17 1BJ, UK
| | - S. Harding
- The Binding Site Group Ltd, 8 Calthorpe Road, Birmingham B15 1QT, UK
| | - A.G. Richter
- Clinical Immunology Service, University of Birmingham College of Medical and Dental Sciences, Birmingham B15 2TT, UK,University Hospitals Birmingham, NHS Foundation Trust, Birmingham B15 2GW, UK
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Pang S, D'Rozario J, Wallis G, Hisana A, Bhuvan T, Payne N, Powell D, Rautela J, Huntington N, Dewson G, Huang D, Gray D, Heng T. Is mesenchymal stromal cell apoptosis necessary for their immunomodulatory capacity? Cytotherapy 2020. [DOI: 10.1016/j.jcyt.2020.03.145] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/24/2022]
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North S, Barnidge D, Brusseau S, Patel R, Haselton M, Du Chateau B, Wallis G, Harding S, Sakrikar D, Ashby J. QIP-MS: A specific, sensitive, accurate, and quantitative alternative to electrophoresis that can identify endogenous m-proteins and distinguish them from therapeutic monoclonal antibodies in patients being treated for multiple myeloma. Clin Chim Acta 2019. [DOI: 10.1016/j.cca.2019.03.920] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022]
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9
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Pang S, Wallis G, Mendonca S, Hisana A, Chappaz S, Rautela J, Huang D, Huntington N, Kile B, Gray D, Heng T. Dissecting the molecular pathways of apoptosis in mesenchymal stromal cell therapy. Cytotherapy 2019. [DOI: 10.1016/j.jcyt.2019.03.506] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
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10
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Evans C, Bateman E, Steven R, Ponsford M, Cullinane A, Shenton C, Duthie G, Conlon C, Jolles S, Huissoon AP, Longhurst HJ, Rahman T, Scott C, Wallis G, Harding S, Parker AR, Ferry BL. Measurement of Typhi Vi antibodies can be used to assess adaptive immunity in patients with immunodeficiency. Clin Exp Immunol 2018; 192:292-301. [PMID: 29377063 PMCID: PMC5980364 DOI: 10.1111/cei.13105] [Citation(s) in RCA: 18] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 10/23/2017] [Indexed: 02/06/2023] Open
Abstract
Vaccine‐specific antibody responses are essential in the diagnosis of antibody deficiencies. Responses to Pneumovax II are used to assess the response to polysaccharide antigens, but interpretation may be complicated. Typhim Vi®, a polysaccharide vaccine for Salmonella typhoid fever, may be an additional option for assessing humoral responses in patients suspected of having an immunodeficiency. Here we report a UK multi‐centre study describing the analytical and clinical performance of a Typhi Vi immunoglobulin (Ig)G enzyme‐linked immunosorbent assay (ELISA) calibrated to an affinity‐purified Typhi Vi IgG preparation. Intra‐ and interassay imprecision was low and the assay was linear, between 7·4 and 574 U/ml (slope = 0·99–1·00; R2 > 0·99); 71% of blood donors had undetectable Typhi Vi IgG antibody concentrations. Of those with antibody concentrations > 7·4 U/ml, the concentration range was 7·7–167 U/ml. In antibody‐deficient patients receiving antibody replacement therapy the median Typhi Vi IgG antibody concentrations were < 25 U/ml. In vaccinated normal healthy volunteers, the median concentration post‐vaccination was 107 U/ml (range 31–542 U/ml). Eight of eight patients (100%) had post‐vaccination concentration increases of at least threefold and six of eight (75%) of at least 10‐fold. In an antibody‐deficient population (n = 23), only 30% had post‐vaccination concentration increases of at least threefold and 10% of at least 10‐fold. The antibody responses to Pneumovax II and Typhim Vi® correlated. We conclude that IgG responses to Typhim Vi® vaccination can be measured using the VaccZyme Salmonella typhi Vi IgG ELISA, and that measurement of these antibodies maybe a useful additional test to accompany Pneumovax II responses for the assessment of antibody deficiencies.
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Affiliation(s)
- C Evans
- Clinical Immunology Laboratory, Oxford University Hospitals Foundation Trust, Oxford, UK
| | - E Bateman
- Clinical Immunology Laboratory, Oxford University Hospitals Foundation Trust, Oxford, UK
| | - R Steven
- Immunodeficiency Centre for Wales, University Hospital of Wales, Cardiff, UK
| | - M Ponsford
- Immunodeficiency Centre for Wales, University Hospital of Wales, Cardiff, UK
| | - A Cullinane
- Clinical Immunology Laboratory, Oxford University Hospitals Foundation Trust, Oxford, UK
| | - C Shenton
- Clinical Immunology Laboratory, Oxford University Hospitals Foundation Trust, Oxford, UK
| | - G Duthie
- Infectious Disease Department, Oxford University Hospitals Foundation Trust, Oxford, UK
| | - C Conlon
- Infectious Disease Department, Oxford University Hospitals Foundation Trust, Oxford, UK
| | - S Jolles
- Immunodeficiency Centre for Wales, University Hospital of Wales, Cardiff, UK
| | - A P Huissoon
- West Midlands Primary Immunodeficiency Centre, Birmingham Heartlands Hospital, Birmingham, UK
| | - H J Longhurst
- Department of Immunology, Barts Health NHS Trust, London, UK
| | - T Rahman
- Department of Immunology, Barts Health NHS Trust, London, UK
| | - C Scott
- Department of Immunology, Barts Health NHS Trust, London, UK
| | - G Wallis
- Binding Site Group Limited, Birmingham, UK
| | - S Harding
- Binding Site Group Limited, Birmingham, UK
| | - A R Parker
- Binding Site Group Limited, Birmingham, UK
| | - B L Ferry
- Clinical Immunology Laboratory, Oxford University Hospitals Foundation Trust, Oxford, UK
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11
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Wallis G. Italian Psychiatric Care. J R Soc Med 2018; 82:776. [PMID: 2614781 PMCID: PMC1292443 DOI: 10.1177/014107688908201238] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022] Open
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13
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Maron E, Near J, Wallis G, Stokes M, Matthews PM, Nutt DJ. A pilot study of the effect of short-term escitalopram treatment on brain metabolites and gamma-oscillations in healthy subjects. J Psychopharmacol 2016; 30:579-80. [PMID: 27166387 DOI: 10.1177/0269881116636108] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/23/2022]
Affiliation(s)
- Eduard Maron
- Department of Psychiatry, University of Tartu, Tartu, Estonia Research and Development Service and Department of Psychiatry, North Estonia Medical Centre, Tallinn, Estonia Faculty of Medicine, Division of Brain Sciences, Imperial College London, London, UK
| | - Jamie Near
- Douglas Mental Health University Institute and Department of Psychiatry, McGill University, Montreal, QC, Canada
| | - George Wallis
- Department of Experimental Psychology, University of Oxford, Oxford, UK; Oxford Centre for Human Brain Activity, University of Oxford, Oxford, UK
| | - Mark Stokes
- Department of Experimental Psychology, University of Oxford, Oxford, UK; Oxford Centre for Human Brain Activity, University of Oxford, Oxford, UK
| | - Paul M Matthews
- Faculty of Medicine, Division of Brain Sciences, Imperial College London, London, UK
| | - David J Nutt
- Faculty of Medicine, Division of Brain Sciences, Imperial College London, London, UK
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Abstract
Working memory (WM) declines as we age and, because of its fundamental role in higher order cognition, this can have highly deleterious effects in daily life. We investigated whether older individuals benefit from flexible orienting of attention within WM to mitigate cognitive decline. We measured magnetoencephalography (MEG) in older adults performing a WM precision task with cues during the maintenance period that retroactively predicted the location of the relevant items for performance (retro-cues). WM performance of older adults significantly benefitted from retro-cues. Whereas WM maintenance declined with age, retro-cues conferred strong attentional benefits. A model-based analysis revealed an increase in the probability of recalling the target, a lowered probability of retrieving incorrect items or guessing, and an improvement in memory precision. MEG recordings showed that retro-cues induced a transient lateralization of alpha (8-14 Hz) and beta (15-30 Hz) oscillatory power. Interestingly, shorter durations of alpha/beta lateralization following retro-cues predicted larger cueing benefits, reinforcing recent ideas about the dynamic nature of access to WM representations. Our results suggest that older adults retain flexible control over WM, but individual differences in control correspond to differences in neural dynamics, possibly reflecting the degree of preservation of control in healthy aging.
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Affiliation(s)
- Robert M Mok
- Department of Experimental Psychology and Oxford Centre for Human Brain Activity, University of Oxford, Oxford OX3 7JX, UK
| | - Nicholas E Myers
- Department of Experimental Psychology and Oxford Centre for Human Brain Activity, University of Oxford, Oxford OX3 7JX, UK
| | - George Wallis
- Department of Experimental Psychology and Oxford Centre for Human Brain Activity, University of Oxford, Oxford OX3 7JX, UK
| | - Anna Christina Nobre
- Department of Experimental Psychology and Oxford Centre for Human Brain Activity, University of Oxford, Oxford OX3 7JX, UK
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Wallis G, Stokes M, Cousijn H, Woolrich M, Nobre AC. Frontoparietal and Cingulo-opercular Networks Play Dissociable Roles in Control of Working Memory. J Cogn Neurosci 2015; 27:2019-34. [PMID: 26042457 DOI: 10.1162/jocn_a_00838] [Citation(s) in RCA: 124] [Impact Index Per Article: 13.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/18/2022]
Abstract
We used magnetoencephalography to characterize the spatiotemporal dynamics of cortical activity during top-down control of working memory (WM). fMRI studies have previously implicated both the frontoparietal and cingulo-opercular networks in control over WM, but their respective contributions are unclear. In our task, spatial cues indicating the relevant item in a WM array occurred either before the memory array or during the maintenance period, providing a direct comparison between prospective and retrospective control of WM. We found that in both cases a frontoparietal network activated following the cue, but following retrocues this activation was transient and was succeeded by a cingulo-opercular network activation. We also characterized the time course of top-down modulation of alpha activity in visual/parietal cortex. This modulation was transient following retrocues, occurring in parallel with the frontoparietal network activation. We suggest that the frontoparietal network is responsible for top-down modulation of activity in sensory cortex during both preparatory attention and orienting within memory. In contrast, the cingulo-opercular network plays a more downstream role in cognitive control, perhaps associated with output gating of memory.
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Cousijn H, Tunbridge EM, Rolinski M, Wallis G, Colclough GL, Woolrich MW, Nobre AC, Harrison PJ. Modulation of hippocampal theta and hippocampal-prefrontal cortex function by a schizophrenia risk gene. Hum Brain Mapp 2015; 36:2387-95. [PMID: 25757652 PMCID: PMC4672713 DOI: 10.1002/hbm.22778] [Citation(s) in RCA: 38] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/10/2014] [Revised: 02/19/2015] [Accepted: 02/20/2015] [Indexed: 01/30/2023] Open
Abstract
Hippocampal theta-band oscillations are thought to facilitate the co-ordination of brain activity across distributed networks, including between the hippocampus and prefrontal cortex (PFC). Impairments in hippocampus-PFC functional connectivity are implicated in schizophrenia and are associated with a polymorphism within the ZNF804A gene that shows a genome-wide significant association with schizophrenia. However, the mechanisms by which ZNF804A affects hippocampus-PFC connectivity are unknown. We used a multimodal imaging approach to investigate the impact of the ZNF804A polymorphism on hippocampal theta and hippocampal network coactivity. Healthy volunteers homozygous for the ZNF804A rs1344706 (A[risk]/C[nonrisk]) polymorphism were imaged at rest using both magnetoencephalography (MEG) and functional magnetic resonance imaging (fMRI). A dual-regression approach was used to investigate coactivations between the hippocampal network and other brain regions for both modalities, focusing on the theta band in the case of MEG. We found a significant decrease in intrahippocampal theta (using MEG) and greater coactivation of the superior frontal gyrus with the hippocampal network (using fMRI) in risk versus nonrisk homozygotes. Furthermore, these measures showed a significant negative correlation. Our demonstration of an inverse relationship between hippocampal theta and hippocampus-PFC coactivation supports a role for hippocampal theta in coordinating hippocampal-prefrontal activity. The ZNF804A-related differences that we find in hippocampus-PFC coactivation are consistent with previously reported associations with functional connectivity and with these changes lying downstream of altered hippocampal theta. Changes in hippocampal-PFC co-ordination, driven by differences in oscillatory activity, may be one mechanism by which ZNF804A impacts on brain function and risk for psychosis.
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Affiliation(s)
- Helena Cousijn
- Department of Psychiatry, University of Oxford, Warneford Hospital, Oxford,, United Kingdom; Oxford Centre for Human Brain Activity, University of Oxford, Warneford Hospital, Oxford, United Kingdom
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Myers NE, Walther L, Wallis G, Stokes MG, Nobre AC. Temporal dynamics of attention during encoding versus maintenance of working memory: complementary views from event-related potentials and alpha-band oscillations. J Cogn Neurosci 2014; 27:492-508. [PMID: 25244118 DOI: 10.1162/jocn_a_00727] [Citation(s) in RCA: 72] [Impact Index Per Article: 7.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/04/2022]
Abstract
Working memory (WM) is strongly influenced by attention. In visual WM tasks, recall performance can be improved by an attention-guiding cue presented before encoding (precue) or during maintenance (retrocue). Although precues and retrocues recruit a similar frontoparietal control network, the two are likely to exhibit some processing differences, because precues invite anticipation of upcoming information whereas retrocues may guide prioritization, protection, and selection of information already in mind. Here we explored the behavioral and electrophysiological differences between precueing and retrocueing in a new visual WM task designed to permit a direct comparison between cueing conditions. We found marked differences in ERP profiles between the precue and retrocue conditions. In line with precues primarily generating an anticipatory shift of attention toward the location of an upcoming item, we found a robust lateralization in late cue-evoked potentials associated with target anticipation. Retrocues elicited a different pattern of ERPs that was compatible with an early selection mechanism, but not with stimulus anticipation. In contrast to the distinct ERP patterns, alpha-band (8-14 Hz) lateralization was indistinguishable between cue types (reflecting, in both conditions, the location of the cued item). We speculate that, whereas alpha-band lateralization after a precue is likely to enable anticipatory attention, lateralization after a retrocue may instead enable the controlled spatiotopic access to recently encoded visual information.
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20
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Haegens S, Cousijn H, Wallis G, Harrison PJ, Nobre AC. Inter- and intra-individual variability in alpha peak frequency. Neuroimage 2014; 92:46-55. [PMID: 24508648 PMCID: PMC4013551 DOI: 10.1016/j.neuroimage.2014.01.049] [Citation(s) in RCA: 313] [Impact Index Per Article: 31.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/26/2013] [Revised: 01/19/2014] [Accepted: 01/27/2014] [Indexed: 11/19/2022] Open
Abstract
Converging electrophysiological evidence suggests that the alpha rhythm plays an important and active role in cognitive processing. Here, we systematically studied variability in posterior alpha peak frequency both between and within subjects. We recorded brain activity using MEG in 51 healthy human subjects under three experimental conditions - rest, passive visual stimulation and an N-back working memory paradigm, using source reconstruction methods to separate alpha activity from parietal and occipital sources. We asked how alpha peak frequency differed within subjects across cognitive conditions and regions of interest, and looked at the distribution of alpha peak frequency between subjects. In both regions we observed an increase of alpha peak frequency from resting state and passive visual stimulation conditions to the N-back paradigm, with a significantly higher alpha peak frequency in the 2-back compared to the 0-back condition. There was a trend for a greater increase in alpha peak frequency during the N-back task in the occipital vs. parietal cortex. The average alpha peak frequency across all subjects, conditions, and regions of interest was 10.3 Hz with a within-subject SD of 0.9 Hz and a between-subject SD of 2.8 Hz. We also measured beta peak frequencies, and except in the parietal cortex during rest, found no indication of a strictly harmonic relationship with alpha peak frequencies. We conclude that alpha peak frequency in posterior regions increases with increasing cognitive demands, and that the alpha rhythm operates across a wider frequency range than the 8-12 Hz band many studies tend to include in their analysis. Thus, using a fixed and limited alpha frequency band might bias results against certain subjects and conditions.
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Affiliation(s)
- Saskia Haegens
- Department of Psychiatry, Columbia University College of Physicians and Surgeons, New York, USA; Cognitive Neuroscience and Schizophrenia Program, Nathan Kline Institute, Orangeburg, USA.
| | - Helena Cousijn
- Department of Psychiatry, Warneford Hospital, University of Oxford, Oxford, UK; Oxford Centre for Human Brain Activity, University of Oxford, Oxford, UK
| | - George Wallis
- Oxford Centre for Human Brain Activity, University of Oxford, Oxford, UK; Department of Experimental Psychology, University of Oxford, Oxford, UK
| | - Paul J Harrison
- Department of Psychiatry, Warneford Hospital, University of Oxford, Oxford, UK
| | - Anna C Nobre
- Oxford Centre for Human Brain Activity, University of Oxford, Oxford, UK; Department of Experimental Psychology, University of Oxford, Oxford, UK
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Adams-Bedford J, Wallis G, Backus B. The impact of intention, action, and learnt contingency on visual perception. J Vis 2013. [DOI: 10.1167/13.9.754] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022] Open
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22
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Wallis G. A multichannel model of face processing based on self-organizing principles. J Vis 2013. [DOI: 10.1167/13.9.1115] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022] Open
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24
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Cloete S, Wallis G. Rapid recruitment of extra-visual information supports heading control when visual feedback is unavailable. J Vis 2011. [DOI: 10.1167/11.11.919] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022] Open
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26
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Affiliation(s)
- George Wallis
- a Duracell Worldwide Technology Center, 37A Street, Needham, MA 02194
| | - Robert Menke
- a Duracell Worldwide Technology Center, 37A Street, Needham, MA 02194
| | - Charles Chelton
- a Duracell Worldwide Technology Center, 37A Street, Needham, MA 02194
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27
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Abstract
Evidence is presented that low concentrations of mercury and chlorine vapor in air form reaction products. At constant mercury concentration the rate of formation increases with chlorine concentration and relative humidity. The mercury-chlorine compound as well as the vapor of elemental mercury are absorbed by Hopcalite or by KMnO4-H2SO4 scrubber solution. The compound can be separated from mercury vapor by its absorption in polyurethane or by filtration by means of Millipore aerosol membranes.
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Affiliation(s)
- R Menke
- P. R. Mallory & Co., Inc., Burlington, MA 01803, USA
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28
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Burgess-Limerick R, Krupenia V, Wallis G, Pratim-Bannerjee A, Steiner L. Directional control-response relationships for mining equipment. Ergonomics 2010; 53:748-757. [PMID: 20496241 DOI: 10.1080/00140131003675109] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/29/2023]
Abstract
A variety of directional control-response relationships are currently found in mining equipment. Two experiments were conducted in a virtual environment to determine optimal direction control-response relationships in a wide variety of circumstances. Direction errors were measured as a function of control orientation (horizontal or vertical), location (left, front, right) and directional control-response relationships. The results confirm that the principles of consistent direction and visual field compatibility are applicable to the majority of situations. An exception is that fewer direction errors were observed when an upward movement of a horizontal lever or movement of a vertical lever away from the participants caused extension (lengthening) of the controlled device, regardless of whether the direction of movement of the control is consistent with the direction in which the extension occurs. Further, both the control of slew by horizontally oriented controls and the control of device movements in a frontal plane by the perpendicular movements of vertical levers were associated with relatively high rates of directional errors, regardless of the directional control-response relationship, and these situations should be avoided. STATEMENT OF RELEVANCE: The results are particularly applicable to the design of mining equipment such as drilling and bolting machines, and have been incorporated into MDG35.1 Guideline for bolting & drilling plant in mines (Industry & Investment NSW, 2010). The results are also relevant to the design of any equipment where vertical or horizontal levers are used to control the movement of equipment appendages, e.g. cranes mounted to mobile equipment and the like.
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Affiliation(s)
- R Burgess-Limerick
- School of Human Movement Studies, The University of Queensland 4072, Australia.
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29
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Wallis G. On the spatio-temporal limits of retinal motion compensation, and why they are the undoing of temporal binding. J Vis 2010. [DOI: 10.1167/6.6.93] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022] Open
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30
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Wallis G. Breaking multiple forms of view invariance. J Vis 2010. [DOI: 10.1167/7.9.334] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022] Open
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31
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Burmester A, Wallis G. Capacity limits for the detection of changing visual features. J Vis 2010. [DOI: 10.1167/6.6.58] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022] Open
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32
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Carter O, Pettigrew J, Hasler F, Wallis G, Vollenweider F. Psilocybin slows binocular rivalry switching through serotonin modulation. J Vis 2010. [DOI: 10.1167/6.6.43] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022] Open
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33
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Pollard JS, Taylor SE, Wallis G, Panchal SN, Egun AA. Bowel obstruction in the postpartum period as a result of caecal volvulus around a large uterine leiomyoma. J OBSTET GYNAECOL 2009; 29:673. [PMID: 19757285 DOI: 10.1080/01443610903100633] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/20/2022]
Affiliation(s)
- J S Pollard
- Department of General Surgery, Royal Preston Hospital, Preston, UK
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34
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Greig C, Spreckley K, Aspinwall R, Gillaspy E, Grant M, Ollier W, John S, Doherty M, Wallis G. Linkage to nodal osteoarthritis: quantitative and qualitative analyses of data from a whole-genome screen identify trait-dependent susceptibility loci. Ann Rheum Dis 2006; 65:1131-8. [PMID: 16504993 PMCID: PMC1798305 DOI: 10.1136/ard.2005.048165] [Citation(s) in RCA: 17] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/04/2022]
Abstract
OBJECTIVE To identify susceptibility loci for nodal osteoarthritis. METHODS A genome screen at an average marker spacing of 9.29 cM was carried out on 558 people from 202 families, of whom 491 had nodal osteoarthritis. All genotyped people were graded for the incidence and severity of distal interphalangeal (DIP) nodes, and radiographs from 354 people were graded for joint-space narrowing (JSN) and osteophytes (OSTs). Age-regressed indices for DIP nodes, JSN and OSTs were calculated using these phenotypic data. Affected sibling pair (ASP) and quantitative trait analyses were carried out using MERLIN. RESULTS The data analysis identified suggestive linkage to loci on chromosomes 3 (for JSN and OST), 4 (for JSN), 8 (for DIP), 11 (for radiographic osteoarthritis) and 16 (for JSN). Both the ASP and quantitative analyses identified the loci on chromosomes 4 and 11. The loci on chromosomes 3 and 16 overlap with those previously identified for large-joint osteoarthritis. Of the loci identified by the quantitative analyses with the logarithm of the odds of linkage >1.5, two were linked to more than one trait, whereas nine were linked to single traits: one for DIP, six for JSN and two for OST. CONCLUSION The ASP and quantitative analyses of the cohort with nodal osteoarthritis suggest that multiple susceptibility loci for osteoarthritis influence the traits, which combine to form the osteoarthritis phenotype, and that these loci may not act exclusively on the joints of the hand.
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Affiliation(s)
- C Greig
- The Wellcome Trust Centre for Cell-Matrix Research, Smith Building, Oxford Road, University of Manchester, Manchester M13 9PT, UK
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35
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Eyre S, Roby P, Wolstencroft K, Spreckley K, Aspinwall R, Bayoumi R, Al-Gazali L, Ramesar R, Beighton P, Gleghorn L, Wallis G. Identification of a locus for a form of spondyloepiphyseal dysplasia on chromosome 15q26.1: exclusion of aggrecan as a candidate gene. J Med Genet 2005; 42:e34. [PMID: 15937074 PMCID: PMC1736074] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 05/02/2023]
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36
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Abstract
Despite their limitations, linear filter models continue to be used to simulate the receptive field properties of cortical simple cells. For theoreticians interested in large scale models of visual cortex, a family of self-similar filters represents a convenient way in which to characterise simple cells in one basic model. This paper reviews research on the suitability of such models, and goes on to advance biologically motivated reasons for adopting a particular group of models in preference to all others. In particular, the paper describes why the Gabor model, so often used in network simulations, should be dropped in favour of a Cauchy model, both on the grounds of frequency response and mutual filter orthogonality.
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Affiliation(s)
- G Wallis
- Max-Planck Institute for Biological Cybernetics, Tübingen, Germany.
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37
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Eyre S, Roby P, Wolstencroft K, Spreckley K, Aspinwall R, Bayoumi R, Al-Gazali L, Ramesar R, Beighton P, Wallis G. Identification of a locus for a form of spondyloepiphyseal dysplasia on chromosome 15q26.1: exclusion of aggrecan as a candidate gene. J Med Genet 2002; 39:634-8. [PMID: 12205105 PMCID: PMC1735219 DOI: 10.1136/jmg.39.9.634] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/31/2022]
Abstract
We have investigated a family with an autosomal dominant form of spondyloepiphyseal dysplasia (SED) characterised by short stature and severe premature degenerative arthropathy. Previous studies have excluded linkage between this condition and the locus for the type II collagen gene. Here we report the identification of linkage between this disorder and a locus on the long arm of chromosome 15 between markers D15S979 and D15S1004. According to current linkage maps and sequence data, this locus includes that of the aggrecan gene (AGC1). Our linkage data from the SED family show, however, that AGC1 maps to a locus that is proximal to D15S979. This proximal location for AGC1 is further supported by linkage data from a second family with an autosomal recessive form of multiple epiphyseal dysplasia that also maps to the SED locus. In both families AGC1 is therefore excluded as a candidate gene.
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Affiliation(s)
- S Eyre
- The Wellcome Trust Centre for Cell-Matrix Research, University of Manchester, Manchester, UK
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38
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Pace JM, Atkinson M, Willing MC, Wallis G, Byers PH. Deletions and duplications of Gly-Xaa-Yaa triplet repeats in the triple helical domains of type I collagen chains disrupt helix formation and result in several types of osteogenesis imperfecta. Hum Mutat 2001; 18:319-26. [PMID: 11668615 DOI: 10.1002/humu.1193] [Citation(s) in RCA: 31] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022]
Abstract
Triple helix formation is a prerequisite for the passage of type I procollagen from the endoplasmic reticulum and secretion from the cell to form extracellular fibrils that will support mineral deposition in bone. Analysis of cDNA from 11 unrelated individuals with osteogenesis imperfecta (OI) revealed the presence of 11 novel, short in-frame deletions or duplications of three, nine, or 18 nucleotides in the helical coding regions of the COL1A1 and COL1A2 collagen genes. Triple helix formation was impaired, type I collagen alpha chains were post-translationally overmodified, and extracellular secretion was markedly reduced. With one exception, the obligate Gly-Xaa-Yaa repeat pattern of amino acids in the helical domains was not altered, but the Xaa- and Yaa position residues were out of register relative to the amino acid sequences of adjacent chains in the triple helix. Thus, the identity of these amino acids, in addition to third position glycines, is important for normal helix formation. These findings expand the known repertoire of uncommon in-frame deletions and duplications in OI, and provide insight into normal collagen biosynthesis and collagen triple helix formation.
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Affiliation(s)
- J M Pace
- Department of Pathology, University of Washington, Seattle, Washington, USA
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39
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Wiebe MG, Karandikar A, Robson GD, Trinci AP, Candia JL, Trappe S, Wallis G, Rinas U, Derkx PM, Madrid SM, Sisniega H, Faus I, Montijn R, van den Hondel CA, Punt PJ. Production of tissue plasminogen activator (t-PA) in Aspergillus niger. Biotechnol Bioeng 2001; 76:164-74. [PMID: 11505386 DOI: 10.1002/bit.1156] [Citation(s) in RCA: 52] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022]
Abstract
A protease-deficient strain of Aspergillus niger has been used as a host for the production of human tissue plasminogen activator (t-PA). In defined medium, up to 0.07 mg t-PA (g biomass)(-1) was produced in batch and fed-batch cultures and production was increased two- to threefold in two-phase batch cultures in which additional glucose was provided as a single pulse at the end of the first batch growth phase. Production was increased [up to 1.9 mg t-PA (g biomass)(-1)] by the addition of soy peptone to the defined medium. The rate of t-PA production in batch cultures supplemented with soy peptone (0.2 to 0.6 mg t-PA L(-1) h(-1)) was comparable to rates observed previously in high-producing mammalian or insect cell cultures. In glucose-limited chemostat culture supplemented with soy peptone, t-PA was produced at a rate of 0.7 mg t-PA L(-1) h(-1). Expression of t-PA in A. niger resulted in increased expression of genes (bipA, pdiA, and cypB) involved in the unfolded protein response (UPR). However, when cypB was overexpressed in a t-PA-producing strain, t-PA production was not increased. The t-PA produced in A. niger was cleaved into two chains of similar molecular weight to two-chain human melanoma t-PA. The two chains appeared to be stable for at least 16 h in culture supernatant of the host strain. However, in general, <1% of the t-PA produced in A. niger was active, and active t-PA disappeared from the culture supernatant during the stationary phase of batch cultures, suggesting that the two-chain t-PA may have been incorrectly processed or that initial proteolytic cleavage occurred within the proteolytic domain of the protein. Total t-PA (detected by enzyme-linked immunoassay) also eventually disappeared from culture supernatants, confirming significant extracellular proteolytic activity, even though the host strain was protease-deficient.
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Affiliation(s)
- M G Wiebe
- School of Biological Sciences, University of Manchester, Manchester, UK.
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40
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Affiliation(s)
- A White
- 2.205 Stopford Building, School of Biological Sciences, University of Manchester, Oxford Road, Manchester, M13 9PT, UK
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41
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Wallis G. β-Galactofuranoside glycoconjugates on conidia and conidiophores of Aspergillus niger. FEMS Microbiol Lett 2001. [DOI: 10.1016/s0378-1097(01)00219-1] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022] Open
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42
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Abstract
The influence of temporal association on the representation and recognition of objects was investigated. Observers were shown sequences of novel faces in which the identity of the face changed as the head rotated. As a result, observers showed a tendency to treat the views as if they were of the same person. Additional experiments revealed that this was only true if the training sequences depicted head rotations rather than jumbled views; in other words, the sequence had to be spatially as well as temporally smooth. Results suggest that we are continuously associating views of objects to support later recognition, and that we do so not only on the basis of the physical similarity, but also the correlated appearance in time of the objects.
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Affiliation(s)
- G Wallis
- Department of Human Movement Studies, University of Queensland, St. Lucia 4072, Queensland, Australia.
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43
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44
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Stewart CA, Hyam K, Wallis G, Sang H, Robinson KA, Floyd RA, Kotake Y, Hensley K. Phenyl-N-tert-butylnitrone demonstrates broad-spectrum inhibition of apoptosis-associated gene expression in endotoxin-treated rats. Arch Biochem Biophys 1999; 365:71-4. [PMID: 10222040 DOI: 10.1006/abbi.1999.1159] [Citation(s) in RCA: 18] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
Systemic exposure to gram-negative bacterial substances such as lipopolysaccharide (LPS, or endotoxin) induces an uncontrolled, massive inflammatory reaction which culminates in multiple system organ failure and death. Septic shock often does not respond to corticosteroids; however, certain low-molecular-weight antioxidant compounds have been discovered to possess potent anti-inflammatory action, and some of these novel compounds can rescue animals from experimentally induced septic shock. Phenyl-N-tert-butylnitrone (PBN) is the archetype of the nitrone class of antioxidants which we have previously shown to suppress LPS-induced cytokine biosynthesis in vivo. Using a multiprobe ribonuclease protection assay, we now demonstrate the ability of PBN to suppress proapoptotic gene expression in the LPS-induced model of endotoxic shock. The broad-spectrum gene-suppressive affects of PBN are discussed in the context of inflammatory signal transduction and models are proposed to explain why certain antioxidants may also possess anti-inflammatory and antiapoptotic properties.
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Affiliation(s)
- C A Stewart
- Free Radical Biology and Aging Research Program, Oklahoma Medical Research Foundation, 825 Northeast 13th Street, Oklahoma City, Oklahoma 73104, USA
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45
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Roby P, Eyre S, Worthington J, Ramesar R, Cilliers H, Beighton P, Grant M, Wallis G. Autosomal dominant (Beukes) premature degenerative osteoarthropathy of the hip joint maps to an 11-cM region on chromosome 4q35. Am J Hum Genet 1999; 64:904-8. [PMID: 10053028 PMCID: PMC1377811 DOI: 10.1086/302291] [Citation(s) in RCA: 42] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [What about the content of this article? (0)] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/03/2022] Open
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46
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Abstract
OBJECTIVE Evidence was sought for genetic anticipation (disease occurring at an earlier age in subsequent generations, with increasing severity) in nodal osteoarthritis (NOA). METHODS Age at symptom onset and disease severity was compared within 30 parent/offspring pairs with NOA. Correlation between the offspring age of disease onset and the parental age at conception was also assessed. RESULTS The age at onset of nodal symptoms was earlier in the offspring (43 years (95% confidence intervals (CI) 38 to 47) v 61 (CI 58 to 65); mean difference 18 years (CI 13 to 22): p < 0.001) as was larger joint symptom onset (48 years (CI 41 to 55) v 67 (CI 61 to 73); mean difference 20 years (CI 13 to 27): p < 0.01). A negative correlation existed between age of offspring symptom onset and parental age at conception. Fifteen (50%) offspring had similar or more extensive disease than their parents. CONCLUSIONS These results suggest genetic anticipation occurs in NOA and if confirmed a search for trinucleotide repeats is warranted.
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Affiliation(s)
- G D Wright
- Department of Rheumatology, City Hospital, Nottingham
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47
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Wallis G. Spatio-temporal influences at the neural level of object recognition. Network 1998; 9:265-278. [PMID: 9861989] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 05/22/2023]
Abstract
In late 1988, Miyashita published work reporting recordings of single cells in the inferotemporal cortex of the macaque monkey (Miyashita 1988 Nature 335 817-20). He described the responses of neurons to a sequence of random fractal pattern images, and how many of the neurons tested were seen to respond strongly to a subset of the images on the basis of sequence presentation order, i.e. appearance in time, rather than their spatial similarity. In this work, I describe a local Hebb-like learning rule which in conjunction with a simple feedforward neural architecture is capable of replicating the type of temporal-order association apparent in the cells from which he made recordings. The paper also advances reasons for requiring such learning by describing its possible role in establishing transformation invariant representations of objects.
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Affiliation(s)
- G Wallis
- Max-Planck-Institut für biologische Kybernetik, Tübingen, Germany
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48
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Affiliation(s)
- D J Brackett
- Department of Surgery, College of Medicine, University of Oklahoma Health Sciences Center, Oklahoma City, USA
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49
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Abstract
A means for establishing transformation-invariant representations of objects is proposed and analyzed, in which different views are associated on the basis of the temporal order of the presentation of these views, as well as their spatial similarity. Assuming knowledge of the distribution of presentation times, an optimal linear learning rule is derived. Simulations of a competitive network trained on a character recognition task are then used t highlight the success of this learning rule in relation to simple Hebbian learning and to show that the theory can give accurate quantitative predictions for the optimal parameters for such networks.
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50
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Tabatabaie T, Kotake Y, Wallis G, Jacob JM, Floyd RA. Spin trapping agent phenyl N-tert-butylnitrone protects against the onset of drug-induced insulin-dependent diabetes mellitus. FEBS Lett 1997; 407:148-52. [PMID: 9166889 DOI: 10.1016/s0014-5793(97)00327-x] [Citation(s) in RCA: 26] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/04/2023]
Abstract
Insulin-dependent diabetes mellitus is an autoimmune disease believed to be caused by an inflammatory process in the pancreas leading to selective destruction of the beta-cells. Cytokines and nitric oxide (NO) have been shown to be involved in this destruction. Phenyl N-tert-butylnitrone (PBN) has demonstrated protective effects against several pathological conditions including ischemia-reperfusion injury and endotoxin-induced shock. We report here that PBN co-administration can prevent the onset of the STZ-induced diabetes in mice. PBN co-treatment inhibited the streptozotocin (STZ)-induced hyperglycemia, the elevation in the level of glycated hemoglobin and weight loss in the treated mice. Histological observations indicated destruction of B-cells in the STZ-treated animals and its prevention by PBN co-treatment. EPR spin trapping experiments in the pancreas indicated the in vivo formation of NO in STZ-treated animals and its attenuation by PBN treatment.
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Affiliation(s)
- T Tabatabaie
- Free Radical Biology and Aging Research Program, Oklahoma Medical Research Foundation, Oklahoma City 73104, USA.
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