84 results on '"Kolbe S"'
Search Results
2. An Update on the Measurement of Motor Cerebellar Dysfunction in Multiple Sclerosis
- Author
-
Kenyon, KH, Boonstra, F, Noffs, G, Butzkueven, H, Vogel, AP, Kolbe, S, van der Walt, A, Kenyon, KH, Boonstra, F, Noffs, G, Butzkueven, H, Vogel, AP, Kolbe, S, and van der Walt, A
- Abstract
Multiple sclerosis (MS) is a progressive disease that often affects the cerebellum. It is characterised by demyelination, inflammation, and neurodegeneration within the central nervous system. Damage to the cerebellum in MS is associated with increased disability and decreased quality of life. Symptoms include gait and balance problems, motor speech disorder, upper limb dysfunction, and oculomotor difficulties. Monitoring symptoms is crucial for effective management of MS. A combination of clinical, neuroimaging, and task-based measures is generally used to diagnose and monitor MS. This paper reviews the present and new tools used by clinicians and researchers to assess cerebellar impairment in people with MS (pwMS). It also describes recent advances in digital and home-based monitoring for people with MS.
- Published
- 2023
3. Process Development and Manufacturing: ENHANCEMENT OF BIOACTIVE AND CELL-LABELING PEPTIDES WITH DNA-TEMPLATED MULTIVALENCE
- Author
-
Möser, C., primary, Freitag, J., additional, Kolbe, S., additional, and Smith, D.M., additional
- Published
- 2022
- Full Text
- View/download PDF
4. Artificial intelligence extension of the OSCAR-IB criteria
- Author
-
Petzold, A., Albrecht, P., Balcer, L., Bekkers, E., Brandt, A. U., Calabresi, P. A., Deborah, O. G., Graves, J. S., Green, A., Keane, P. A., Nij Bijvank, J. A., Sander, J. W., Paul, F., Saidha, S., Villoslada, P., Wagner, S. K., Yeh, E. A., Aktas, O., Antel, J., Asgari, N., Audo, I., Avasarala, J., Avril, D., Bagnato, F. R., Banwell, B., Bar-Or, A., Behbehani, R., Manterola, A. B., Bennett, J., Benson, L., Bernard, J., Bremond-Gignac, D., Britze, J., Burton, J., Calkwood, J., Carroll, W., Chandratheva, A., Cohen, J., Comi, G., Cordano, C., Costa, S., Costello, F., Courtney, A., Cruz-Herranz, A., Cutter, G., Crabb, D., Delott, L., De Seze, J., Diem, R., Dollfuss, H., El Ayoubi, N. K., Fasser, C., Finke, C., Fischer, D., Fitzgerald, K., Fonseca, P., Frederiksen, J. L., Frohman, E., Frohman, T., Fujihara, K., Cuellar, I. G., Galetta, S., Garcia-Martin, E., Giovannoni, G., Glebauskiene, B., Suarez, I. G., Jensen, G. P., Hamann, S., Hartung, H. -P., Havla, J., Hemmer, B., Huang, S. -C., Imitola, J., Jasinskas, V., Jiang, H., Kafieh, R., Kappos, L., Kardon, R., Keegan, D., Kildebeck, E., Kim, U. S., Klistorner, S., Knier, B., Kolbe, S., Korn, T., Krupp, L., Lagreze, W., Leocani, L., Levin, N., Liskova, P., Preiningerova, J. L., Lorenz, B., May, E., Miller, D., Mikolajczak, J., Said, S. M., Montalban, X., Morrow, M., Mowry, E., Murta, J., Navas, C., Nolan, R., Nowomiejska, K., Oertel, F. C., Oh, J., Oreja-Guevara, C., Orssaud, C., Osborne, B., Outteryck, O., Paiva, C., Palace, J., Papadopoulou, A., Patsopoulos, N., Pontikos, N., Preising, M., Prince, J., Reich, D., Rejdak, R., Ringelstein, M., Rodriguez de Antonio, L., Sahel, J. -A., Sanchez-Dalmau, B., Sastre-Garriga, J., Schippling, S., Schuman, J., Shindler, K., Shin, R., Shuey, N., Soelberg, K., Specovius, S., Suppiej, A., Thompson, A., Toosy, A., Torres, R., Touitou, V., Trauzettel-Klosinski, S., van der Walt, A., Vermersch, P., Vidal-Jordana, A., Waldman, A. T., Waters, C., Wheeler, R., White, O., Wilhelm, H., Winges, K. M., Wiegerinck, N., Wiehe, L., Wisnewski, T., Wong, S., Wurfel, J., Yaghi, S., You, Y., Yu, Z., Yu-Wai-Man, P., Zemaitien≐, R., Zimmermann, H., Albrecht P., Petzold A., Balcer, L., Bekkers, E., Brandt, A. U., Calabresi, P. A., Deborah, O. G., Graves, J. S., Green, A., Keane, P. A., Nij Bijvank, J. A., Sander, J. W., Paul, F., Saidha, S., Villoslada, P., Wagner, S. K., Yeh, E. A., Aktas, O., Antel, J., Asgari, N., Audo, I., Avasarala, J., Avril, D., Bagnato, F. R., Banwell, B., Bar-Or, A., Behbehani, R., Manterola, A. B., Bennett, J., Benson, L., Bernard, J., Bremond-Gignac, D., Britze, J., Burton, J., Calkwood, J., Carroll, W., Chandratheva, A., Cohen, J., Comi, G., Cordano, C., Costa, S., Costello, F., Courtney, A., Cruz-Herranz, A., Cutter, G., Crabb, D., Delott, L., De Seze, J., Diem, R., Dollfuss, H., El Ayoubi, N. K., Fasser, C., Finke, C., Fischer, D., Fitzgerald, K., Fonseca, P., Frederiksen, J. L., Frohman, E., Frohman, T., Fujihara, K., Cuellar, I. G., Galetta, S., Garcia-Martin, E., Giovannoni, G., Glebauskiene, B., Suarez, I. G., P. , Jensen, G., Hamann, S., Hartung, H. -P., Havla, J., Hemmer, B., Huang, S. -C., Imitola, J., Jasinskas, V., Jiang, H., Kafieh, R., Kappos, L., Kardon, R., Keegan, D., Kildebeck, E., Kim, U. S., Klistorner, S., Knier, B., Kolbe, S., Korn, T., Krupp, L., Lagreze, W., Leocani, L., Levin, N., Liskova, P., Preiningerova, J. L., Lorenz, B., May, E., Miller, D., Mikolajczak, J., Said, S. M., Montalban, X., Morrow, M., Mowry, E., Murta, J., Navas, C., Nolan, R., Nowomiejska, K., Oertel, F. C., Oh, J., Oreja-Guevara, C., Orssaud, C., Osborne, B., Outteryck, O., Paiva, C., Palace, J., Papadopoulou, A., Patsopoulos, N., Pontikos, N., Preising, M., Prince, J., Reich, D., Rejdak, R., Ringelstein, M., Rodriguez de Antonio, L., Sahel, J. -A., Sanchez-Dalmau, B., Sastre-Garriga, J., Schippling, S., Schuman, J., Shindler, K., Shin, R., Shuey, N., Soelberg, K., Specovius, S., Suppiej, A., Thompson, A., Toosy, A., Torres, R., Touitou, V., Trauzettel-Klosinski, S., van der Walt, A., Vermersch, P., Vidal-Jordana, A., Waldman, A. T., Waters, C., Wheeler, R., White, O., Wilhelm, H., Winges, K. M., Wiegerinck, N., Wiehe, L., Wisnewski, T., Wong, S., Wurfel, J., Yaghi, S., You, Y., Yu, Z., Yu-Wai-Man, P., Zemaitien≐, R., and Zimmermann, H.
- Subjects
0301 basic medicine ,Big Data ,medicine.medical_specialty ,Neurology ,media_common.quotation_subject ,Big data ,MEDLINE ,Reviews ,Socio-culturale ,Neurosciences. Biological psychiatry. Neuropsychiatry ,Review ,Public domain ,Retina ,Cohort Studies ,03 medical and health sciences ,Annotation ,0302 clinical medicine ,Artificial Intelligence ,medicine ,Humans ,Quality (business) ,RC346-429 ,Tomography ,media_common ,Image pattern recognition ,business.industry ,General Neuroscience ,Nervous System Diseases ,Tomography, Optical Coherence ,Algorithms ,030104 developmental biology ,Optical Coherence ,Imaging technology ,RC0321 ,Neurology. Diseases of the nervous system ,Neurology (clinical) ,Artificial intelligence ,sense organs ,business ,030217 neurology & neurosurgery ,RC321-571 - Abstract
Artificial intelligence (AI)‐based diagnostic algorithms have achieved ambitious aims through automated image pattern recognition. For neurological disorders, this includes neurodegeneration and inflammation. Scalable imaging technology for big data in neurology is optical coherence tomography (OCT). We highlight that OCT changes observed in the retina, as a window to the brain, are small, requiring rigorous quality control pipelines. There are existing tools for this purpose. Firstly, there are human‐led validated consensus quality control criteria (OSCAR‐IB) for OCT. Secondly, these criteria are embedded into OCT reporting guidelines (APOSTEL). The use of the described annotation of failed OCT scans advances machine learning. This is illustrated through the present review of the advantages and disadvantages of AI‐based applications to OCT data. The neurological conditions reviewed here for the use of big data include Alzheimer disease, stroke, multiple sclerosis (MS), Parkinson disease, and epilepsy. It is noted that while big data is relevant for AI, ownership is complex. For this reason, we also reached out to involve representatives from patient organizations and the public domain in addition to clinical and research centers. The evidence reviewed can be grouped in a five‐point expansion of the OSCAR‐IB criteria to embrace AI (OSCAR‐AI). The review concludes by specific recommendations on how this can be achieved practically and in compliance with existing guidelines.
- Published
- 2021
5. Asymmetric distribution of enlarged perivascular spaces in centrum semiovale may be associated with epilepsy after acute ischemic stroke
- Author
-
Yu, N, Sinclair, B, Posada, LMG, Chen, Z, Di, Q, Lin, X, Kolbe, S, Hlauschek, G, Kwan, P, Law, M, Yu, N, Sinclair, B, Posada, LMG, Chen, Z, Di, Q, Lin, X, Kolbe, S, Hlauschek, G, Kwan, P, and Law, M
- Abstract
OBJECTIVE: To investigate the factors influencing enlarged perivascular space (EPVS) characteristics at the onset of acute ischemic stroke (AIS), and whether the PVS characteristics can predict later post-stroke epilepsy (PSE). METHODS: A total of 312 patients with AIS were identified, of whom 58/312 (18.6%) developed PSE. Twenty healthy participants were included as the control group. The number of PVS in the basal ganglia (BG), centrum semiovale (CS), and midbrain (MB) was manually calculated on T2 -weighted MRI. The scores and asymmetry index (AI) of EPVS in each region were compared among the enrolled participants. Other potential risk factors for PSE were also analyzed, including NIHSS at admission and stroke etiologies. RESULTS: The EPVS scores were significantly higher in the bilateral BG and CS of AIS patients compared to those of the control group (both p < 0.01). No statistical differences in EPVS scores in BG, CS, and MB were obtained between the PSE group and the nonepilepsy AIS group (all p > 0.01). However, markedly different AI scores in CS were found between the PSE group and the nonepilepsy AIS group (p = 0.004). Multivariable analysis showed that high asymmetry index of EPVS (AI≥0.2) in CS was an independent predictor for PSE (OR = 3.7, 95% confidence interval 1.5-9.1, p = 0.004). CONCLUSIONS: Asymmetric distribution of EPVS in CS may be an independent risk factor and a novel imaging biomarker for the development of PSE. Further studies to understand the mechanisms of this association and confirmation with larger patient populations are warranted.
- Published
- 2022
6. Long-term structural brain changes in adult rats after mild ischaemic stroke
- Author
-
Syeda, W, Ermine, CM, Khilf, MS, Wright, D, Brait, VH, Nithianantharajah, J, Kolbe, S, Johnston, LA, Thompson, LH, Brodtmann, A, Syeda, W, Ermine, CM, Khilf, MS, Wright, D, Brait, VH, Nithianantharajah, J, Kolbe, S, Johnston, LA, Thompson, LH, and Brodtmann, A
- Abstract
Preclinical studies of remote degeneration have largely focused on brain changes over the first few days or weeks after stroke. Accumulating evidence suggests that neurodegeneration occurs in other brain regions remote to the site of infarction for months and even years following ischaemic stroke. Brain atrophy appears to be driven by both axonal degeneration and widespread brain inflammation. The evolution and duration of these changes are increasingly being described in human studies, using advanced brain imaging techniques. Here, we sought to investigate long-term structural brain changes in a model of mild focal ischaemic stroke following injection of endothlin-1 in adult Long-Evans rats (n = 14) compared with sham animals (n = 10), over a clinically relevant time-frame of 48 weeks. Serial structural and diffusion-weighted MRI data were used to assess dynamic volume and white matter trajectories. We observed dynamic regional brain volume changes over the 48 weeks, reflecting both normal changes with age in sham animals and neurodegeneration in regions connected to the infarct following ischaemia. Ipsilesional cortical volume loss peaked at 24 weeks but was less prominent at 36 and 48 weeks. We found significantly reduced fractional anisotropy in both ipsi- and contralesional motor cortex and cingulum bundle regions of infarcted rats (P < 0.05) from 4 to 36 weeks, suggesting ongoing white matter degeneration in tracts connected to but distant from the stroke. We conclude that there is evidence of significant cortical atrophy and white matter degeneration up to 48 weeks following infarct, consistent with enduring, pervasive stroke-related degeneration.
- Published
- 2022
7. Fixel-based Analysis of Diffusion MRI: Methods, Applications, Challenges and Opportunities.
- Author
-
Dhollander T., Clemente A., Singh M., Boonstra F., Civier O., Duque J.D., Egorova N., Enticott P., Fuelscher I., Gajamange S., Genc S., Gottlieb E., Hyde C., Imms P., Kelly C., Kirkovski M., Kolbe S., Liang X., Malhotra A., Mito R., Poudel G., Silk T.J., Vaughan D.N., Zanin J., Raffelt D., Caeyenberghs K., Dhollander T., Clemente A., Singh M., Boonstra F., Civier O., Duque J.D., Egorova N., Enticott P., Fuelscher I., Gajamange S., Genc S., Gottlieb E., Hyde C., Imms P., Kelly C., Kirkovski M., Kolbe S., Liang X., Malhotra A., Mito R., Poudel G., Silk T.J., Vaughan D.N., Zanin J., Raffelt D., and Caeyenberghs K.
- Abstract
Diffusion MRI has provided the neuroimaging community with a powerful tool to acquire in-vivo data sensitive to microstructural features of white matter, up to 3 orders of magnitude smaller than typical voxel sizes. The key to extracting such valuable information lies in complex modelling techniques, which form the link between the rich diffusion MRI data and various metrics related to the microstructural organization. Over time, increasingly advanced techniques have been developed, up to the point where some diffusion MRI models can now provide access to properties specific to individual fibre populations in each voxel in the presence of multiple "crossing" fibre pathways. While highly valuable, such fibre-specific information poses unique challenges for typical image processing pipelines and statistical analysis. In this work, we review the "Fixel-Based Analysis" (FBA) framework, which implements bespoke solutions to this end. It has recently seen a stark increase in adoption for studies of both typical (healthy) populations as well as a wide range of clinical populations. We describe the main concepts related to Fixel-Based Analyses, as well as the methods and specific steps involved in a state-of-the-art FBA pipeline, with a focus on providing researchers with practical advice on how to interpret results. We also include an overview of the scope of all current FBA studies, categorized across a broad range of neuro-scientific domains, listing key design choices and summarizing their main results and conclusions. Finally, we critically discuss several aspects and challenges involved with the FBA framework, and outline some directions and future opportunities.Copyright © 2021
- Published
- 2021
8. Fixel-based Analysis of Diffusion MRI: Methods, Applications, Challenges and Opportunities
- Author
-
Dhollander, T, Clemente, A, Singh, M, Boonstra, F, Civier, O, Duque, JD, Egorova, N, Enticott, Peter, Fuelscher, Ian, Gajamange, S, Genc, S, Gottlieb, E, Hyde, Christian, Imms, P, Kelly, C, Kirkovski, Melissa, Kolbe, S, Liang, X, Malhotra, A, Mito, R, Poudel, G, Silk, Timothy, Vaughan, DN, Zanin, J, Raffelt, D, Caeyenberghs, Karen, Dhollander, T, Clemente, A, Singh, M, Boonstra, F, Civier, O, Duque, JD, Egorova, N, Enticott, Peter, Fuelscher, Ian, Gajamange, S, Genc, S, Gottlieb, E, Hyde, Christian, Imms, P, Kelly, C, Kirkovski, Melissa, Kolbe, S, Liang, X, Malhotra, A, Mito, R, Poudel, G, Silk, Timothy, Vaughan, DN, Zanin, J, Raffelt, D, and Caeyenberghs, Karen
- Published
- 2021
9. APOSTEL 2.0 Recommendations for Reporting Quantitative Optical Coherence Tomography Studies
- Author
-
Aytulun, A, Cruz-Herranz, A, Aktas, O, Balcer, LJ, Balk, L, Barboni, P, Blanco, AA, Calabresi, PA, Costello, F, Sanchez-Dalmau, B, DeBuc, DC, Feltgen, N, Finger, RP, Frederiksen, JL, Frohman, E, Frohman, T, Garway-Heath, D, Gabilondo, I, Graves, JS, Green, AJ, Hartung, H-P, Havla, J, Holz, FG, Imitola, J, Kenney, R, Klistorner, A, Knier, B, Korn, T, Kolbe, S, Kraemer, J, Lagreze, WA, Leocani, L, Maier, O, Martinez-Lapiscina, EH, Meuth, S, Outteryck, O, Paul, F, Petzold, A, Pihl-Jensen, G, Preiningerova, JL, Rebolleda, G, Ringelstein, M, Saidha, S, Schippling, S, Schuman, JS, Sergott, RC, Toosy, A, Villoslada, P, Wolf, S, Yeh, EA, Yu-Wai-Man, P, Zimmermann, HG, Brandt, AU, Albrecht, P, Aytulun, A, Cruz-Herranz, A, Aktas, O, Balcer, LJ, Balk, L, Barboni, P, Blanco, AA, Calabresi, PA, Costello, F, Sanchez-Dalmau, B, DeBuc, DC, Feltgen, N, Finger, RP, Frederiksen, JL, Frohman, E, Frohman, T, Garway-Heath, D, Gabilondo, I, Graves, JS, Green, AJ, Hartung, H-P, Havla, J, Holz, FG, Imitola, J, Kenney, R, Klistorner, A, Knier, B, Korn, T, Kolbe, S, Kraemer, J, Lagreze, WA, Leocani, L, Maier, O, Martinez-Lapiscina, EH, Meuth, S, Outteryck, O, Paul, F, Petzold, A, Pihl-Jensen, G, Preiningerova, JL, Rebolleda, G, Ringelstein, M, Saidha, S, Schippling, S, Schuman, JS, Sergott, RC, Toosy, A, Villoslada, P, Wolf, S, Yeh, EA, Yu-Wai-Man, P, Zimmermann, HG, Brandt, AU, and Albrecht, P
- Abstract
OBJECTIVE: To update the consensus recommendations for reporting of quantitative optical coherence tomography (OCT) study results, thus revising the previously published Advised Protocol for OCT Study Terminology and Elements (APOSTEL) recommendations. METHODS: To identify studies reporting quantitative OCT results, we performed a PubMed search for the terms "quantitative" and "optical coherence tomography" from 2015 to 2017. Corresponding authors of the identified publications were invited to provide feedback on the initial APOSTEL recommendations via online surveys following the principle of a modified Delphi method. The results were evaluated and discussed by a panel of experts and changes to the initial recommendations were proposed. A final survey was recirculated among the corresponding authors to obtain a majority vote on the proposed changes. RESULTS: A total of 116 authors participated in the surveys, resulting in 15 suggestions, of which 12 were finally accepted and incorporated into an updated 9-point checklist. We harmonized the nomenclature of the outer retinal layers, added the exact area of measurement to the description of volume scans, and suggested reporting device-specific features. We advised to address potential bias in manual segmentation or manual correction of segmentation errors. References to specific reporting guidelines and room light conditions were removed. The participants' consensus with the recommendations increased from 80% for the previous APOSTEL version to greater than 90%. CONCLUSIONS: The modified Delphi method resulted in an expert-led guideline (evidence Class III; Grading of Recommendations, Assessment, Development and Evaluations [GRADE] criteria) concerning study protocol, acquisition device, acquisition settings, scanning protocol, funduscopic imaging, postacquisition data selection, postacquisition analysis, nomenclature and abbreviations, and statistical approach. It will be essential to update these recommendations to
- Published
- 2021
10. QSMART: Quantitative susceptibility mapping artifact reduction technique
- Author
-
Yaghmaie, N, Syeda, WT, Wu, C, Zhang, Y, Zhang, TD, Burrows, EL, Brodtmann, A, Moffat, BA, Wright, DK, Glarin, R, Kolbe, S, Johnston, LA, Yaghmaie, N, Syeda, WT, Wu, C, Zhang, Y, Zhang, TD, Burrows, EL, Brodtmann, A, Moffat, BA, Wright, DK, Glarin, R, Kolbe, S, and Johnston, LA
- Abstract
PURPOSE: Quantitative susceptibility mapping (QSM) is a novel MR technique that allows mapping of tissue susceptibility values from MR phase images. QSM is an ill-conditioned inverse problem, and although several methods have been proposed in the field, in the presence of a wide range of susceptibility sources, streaking artifacts appear around high susceptibility regions and contaminate the whole QSM map. QSMART is a post-processing pipeline that uses two-stage parallel inversion to reduce the streaking artifacts and remove banding artifact at the cortical surface and around the vasculature. METHOD: Tissue and vein susceptibility values were separately estimated by generating a mask of vasculature driven from the magnitude data using a Frangi filter. Spatially dependent filtering was used for the background field removal step and the two susceptibility estimates were combined in the final QSM map. QSMART was compared to RESHARP/iLSQR and V-SHARP/iLSQR inversion in a numerical phantom, 7T in vivo single and multiple-orientation scans, 9.4T ex vivo mouse data, and 4.7T in vivo rat brain with induced focal ischemia. RESULTS: Spatially dependent filtering showed better suppression of phase artifacts near cortex compared to RESHARP and V-SHARP, while preserving voxels located within regions of interest without brain edge erosion. QSMART showed successful reduction of streaking artifacts as well as improved contrast between different brain tissues compared to the QSM maps obtained by RESHARP/iLSQR and V-SHARP/iLSQR. CONCLUSION: QSMART can reduce QSM artifacts to enable more robust estimation of susceptibility values in vivo and ex vivo.
- Published
- 2021
11. Sodium selenate as a disease-modifying treatment for progressive supranuclear palsy: protocol for a phase 2, randomised, double-blind, placebo-controlled trial
- Author
-
Vivash, L, Bertram, KL, Malpas, CB, Marotta, C, Harding, IH, Kolbe, S, Fielding, J, Clough, M, Lewis, SJG, Tisch, S, Evans, AH, O'Sullivan, JD, Kimber, T, Darby, D, Churilov, L, Law, M, Hovens, CM, Velakoulis, D, O'Brien, TJ, Vivash, L, Bertram, KL, Malpas, CB, Marotta, C, Harding, IH, Kolbe, S, Fielding, J, Clough, M, Lewis, SJG, Tisch, S, Evans, AH, O'Sullivan, JD, Kimber, T, Darby, D, Churilov, L, Law, M, Hovens, CM, Velakoulis, D, and O'Brien, TJ
- Abstract
INTRODUCTION: Progressive supranuclear palsy (PSP) is a neurodegenerative disorder for which there are currently no disease-modifying therapies. The neuropathology of PSP is associated with the accumulation of hyperphosphorylated tau in the brain. We have previously shown that protein phosphatase 2 activity in the brain is upregulated by sodium selenate, which enhances dephosphorylation. Therefore, the objective of this study is to evaluate the efficacy and safety of sodium selenate as a disease-modifying therapy for PSP. METHODS AND ANALYSIS: This will be a multi-site, phase 2b, double-blind, placebo-controlled trial of sodium selenate. 70 patients will be recruited at six Australian academic hospitals and research institutes. Following the confirmation of eligibility at screening, participants will be randomised (1:1) to receive 52 weeks of active treatment (sodium selenate; 15 mg three times a day) or matching placebo. Regular safety and efficacy visits will be completed throughout the study period. The primary study outcome is change in an MRI volume composite (frontal lobe+midbrain-3rd ventricle) over the treatment period. Analysis will be with a general linear model (GLM) with the MRI composite at 52 weeks as the dependent variable, treatment group as an independent variable and baseline MRI composite as a covariate. Secondary outcomes are change in PSP rating scale, clinical global impression of change (clinician) and change in midbrain mean diffusivity. These outcomes will also be analysed with a GLM as above, with the corresponding baseline measure entered as a covariate. Secondary safety and tolerability outcomes are frequency of serious adverse events, frequency of down-titration occurrences and frequency of study discontinuation. Additional, as yet unplanned, exploratory outcomes will include analyses of other imaging, cognitive and biospecimen measures. ETHICS AND DISSEMINATION: The study was approved by the Alfred Health Ethics Committee (594/20). Each
- Published
- 2021
12. The Energetic Particle Detector
- Author
-
Rodríguez-Pacheco, J., Wimmer-Schweingruber, R., Mason, G., Ho, G., Sánchez-Prieto, S., Prieto, M., Martín, C., Seifert, H., Andrews, G., Kulkarni, S., Panitzsch, L., Boden, S., Böttcher, S., Cernuda, I., Elftmann, R., Espinosa Lara, F., Gómez-Herrero, R., Terasa, C., Almena, J., Begley, S., Böhm, E., Blanco, J., Boogaerts, W., Carrasco, A., Castillo, R., da Silva Fariña, A., de Manuel González, V., Drews, C., Dupont, A., Eldrum, S., Gordillo, C., Gutiérrez, O., Haggerty, D., Hayes, J., Heber, B., Hill, M., Jüngling, M., Kerem, S., Knierim, V., Köhler, J., Kolbe, S., Kulemzin, A., Lario, D., Lees, W., Liang, S., Martínez Hellín, A., Meziat, D., Montalvo, A., Nelson, K., Parra, P., Paspirgilis, R., Ravanbakhsh, A., Richards, M., Rodríguez-Polo, O., Russu, A., Sánchez, I., Schlemm, C., Schuster, B., Seimetz, L., Steinhagen, J., Tammen, J., Tyagi, K., Varela, T., Yedla, M., Yu, J., Agueda, N., Aran, A., Horbury, T., Klecker, B., Klein, K.-L., Kontar, E., Krucker, S., Maksimovic, M., Malandraki, O., Owen, C., Pacheco, D., Sanahuja, B., Vainio, R., Connell, J., Dalla, S., Dröge, W., Gevin, O., Gopalswamy, N., Kartavykh, Y., Kudela, K., Limousin, O., Makela, P., Mann, G., Önel, H., Posner, A., Ryan, J., Soucek, J., Hofmeister, S., Vilmer, N., Walsh, A., Wang, L., Wiedenbeck, M., Wirth, K., Zong, Q., Universidad de Alcalá - University of Alcalá (UAH), Institut für Experimentelle und Angewandte Physik [Kiel] (IEAP), Christian-Albrechts-Universität zu Kiel (CAU), Johns Hopkins University Applied Physics Laboratory [Laurel, MD] (APL), Universidad de Tarapaca, Paul Scherrer Institute (PSI), Indian Institute of Technology Bombay (IIT Bombay), Laboratoire d'études spatiales et d'instrumentation en astrophysique (LESIA (UMR_8109)), Institut national des sciences de l'Univers (INSU - CNRS)-Observatoire de Paris, and Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Sorbonne Université (SU)-Centre National de la Recherche Scientifique (CNRS)-Université de Paris (UP)
- Subjects
[SDU]Sciences of the Universe [physics] ,Physics::Space Physics ,Astrophysics::Instrumentation and Methods for Astrophysics ,Astrophysics::Solar and Stellar Astrophysics ,Astrophysics::Earth and Planetary Astrophysics - Abstract
International audience; After decades of observations of solar energetic particles from space-based observatories, relevant questions on particle injection, transport, and acceleration remain open. To address these scientific topics, accurate measurements of the particle properties in the inner heliosphere are needed. In this paper we describe the Energetic Particle Detector (EPD), an instrument suite that is part of the scientific payload aboard the Solar Orbiter mission. Solar Orbiter will approach the Sun as close as 0.28 au and will provide extra-ecliptic measurements beyond ∼30° heliographic latitude during the later stages of the mission. The EPD will measure electrons, protons, and heavy ions with high temporal resolution over a wide energy range, from suprathermal energies up to several hundreds of megaelectronvolts/nucleons. For this purpose, EPD is composed of four units: the SupraThermal Electrons and Protons (STEP), the Electron Proton Telescope (EPT), the Suprathermal Ion Spectrograph (SIS), and the High-Energy Telescope (HET) plus the Instrument Control Unit that serves as power and data interface with the spacecraft. The low-energy population of electrons and ions will be covered by STEP and EPT, while the high-energy range will be measured by HET. Elemental and isotopic ion composition measurements will be performed by SIS and HET, allowing full particle identification from a few kiloelectronvolts up to several hundreds of megaelectronvolts/nucleons. Angular information will be provided by the separate look directions from different sensor heads, on the ecliptic plane along the Parker spiral magnetic field both forward and backwards, and out of the ecliptic plane observing both northern and southern hemispheres. The unparalleled observations of EPD will provide key insights into long-open and crucial questions about the processes that govern energetic particles in the inner heliosphere.
- Published
- 2020
13. Speech biometrics can predict cerebellar dysfunction in multiple sclerosis
- Author
-
Vogel, A, Noffs, G, Boonstra, F, Perera, T, Kolbe, S, Stankovich, J, Butzkueven, H, Evans, A, Walt, AD, Vogel, A, Noffs, G, Boonstra, F, Perera, T, Kolbe, S, Stankovich, J, Butzkueven, H, Evans, A, and Walt, AD
- Abstract
Objective: To objectively describe cerebellar mediated speech function using a multiparameter index that reflects pathology and quality of life in MS. Background: Cerebellar function plays a role in cognitive processing and motor control and is important for speech production. Multiple sclerosis (MS) can result in impaired cerebellar function, leading to speech deficits. These deficits can be detected by instrumental measurement. Speech as a marker of cerebellar impairment but is not well described. Method: The speech and clinical features of 85 people with MS (plus 21 matched controls) were assessed using objective acoustic analysis, validated questionnaires of quality of life and disease severity using the Scale for the Assessment and rating of Ataxia. Magnetic resonance imaging was used to measure cerebellar pathology. A regression model with eight speech variables were used to predict cerebellar function. A composite speech score was developed from the model and tested for prediction of fine motor function using the 9-hole peg test (9HPT), for correlations with imaging outcomes and self-assessed quality of life. Results: Speech timing metrics (eg. slow rate of syllable repetition, increased proportion of silence) were the strongest predictors of cerebellar impairment, alongside phonatory instability. The acoustic composite score accounted for 54% of variation in cerebellar dysfunction, was associated with cerebellar white matter volume (r=0.3, p=0.017), quality of life (r=0.5, p<0.001) and predicted an abnormal 9HPT with 85% accuracy. Conclusion: Motor cerebellar impairment in MS was reflected in an objective multi-feature speech metric.
- Published
- 2020
14. Lesion Volume in Relapsing Multiple Sclerosis is Associated with Perivascular Space Enlargement at the Level of the Basal Ganglia.
- Author
-
Kolbe, S. C., Garcia, L. M., Yu, N., Boonstra, F. M., Clough, M., Sinclair, B., White, O., van der Walt, A., Butzkueven, H., Fielding, J., and Law, M.
- Published
- 2022
- Full Text
- View/download PDF
15. A continuum of T-2(*) components: Flexible fast fraction mapping in sodium MRI
- Author
-
Syeda, W, Blunck, Y, Kolbe, S, Cleary, JO, Johnston, LA, Syeda, W, Blunck, Y, Kolbe, S, Cleary, JO, and Johnston, LA
- Abstract
PURPOSE: Parameter mapping in sodium MRI data is challenging due to inherently low SNR and spatial resolution, prompting the need to employ robust models and estimation techniques. This work aims to develop a continuum model of sodium T2* -decay to overcome the limitations of the commonly employed bi-exponential models. Estimates of mean T2* -decay and fast component fraction in tissue are emergent from the inferred continuum model. METHODS: A closed-form continuum model was derived assuming a gamma distribution of T2* components. Sodium MRI was performed on four healthy human subjects and a phantom consisting of closely packed vials filled with an aqueous solution of varying sodium and agarose concentrations. The continuum model was applied to the phantom and in vivo human multi-echo 7T data. Parameter maps by voxelwise model-fitting were obtained. RESULTS: The continuum model demonstrated comparable estimation performance to the bi-exponential model. The parameter maps provided improved contrast between tissue structures. The fast component fraction, an indicator of the heterogeneity of localised sodium motion regimes in tissue, was zero in CSF and high in WM structures. CONCLUSIONS: The continuum distribution model provides high quality, high contrast parameter maps, and informative voxelwise estimates of the relative weighting between fast and slow decay components.
- Published
- 2019
16. Functional correlates of cognitive dysfunction in clinically isolated syndromes
- Author
-
Paul, F, Gajamange, S, Shelton, A, Clough, M, White, O, Fielding, J, Kolbe, S, Paul, F, Gajamange, S, Shelton, A, Clough, M, White, O, Fielding, J, and Kolbe, S
- Abstract
Cognitive dysfunction can be identified in patients with clinically isolated syndromes suggestive of multiple sclerosis using ocular motor testing. This study aimed to identify the functional neural correlates of cognitive dysfunction in patients with clinically isolated syndrome using MRI. Eighteen patients with clinically isolated syndrome and 17 healthy controls were recruited. Subjects underwent standard neurological and neuropsychological testing. Subjects also underwent functional MRI (fMRI) during a cognitive ocular motor task, involving pro-saccade (direct gaze towards target) and anti-saccade (direct gaze away from target) trials. Ocular motor performance variables (averaged response time and error rate) were calculated for each subject. Patients showed a trend towards a greater rate of anti-saccade errors (p = 0.09) compared to controls. Compared to controls, patients exhibited increased activation in the right postcentral, right supramarginal gyrus, and the right parietal operculum during the anti-saccade>pro-saccade contrast. This study demonstrated that changes in functional organisation of cognitive brain networks is associated with subtle cognitive changes in patients with clinically isolated syndrome.
- Published
- 2019
17. Fibre-specific white matter changes in multiple sclerosis patients with optic neuritis
- Author
-
Gajamange, S, Raffelt, D, Dhollander, T, Lui, E, van der Walt, A, Kilpatrick, T, Fielding, J, Connelly, A, Kolbe, S, Gajamange, S, Raffelt, D, Dhollander, T, Lui, E, van der Walt, A, Kilpatrick, T, Fielding, J, Connelly, A, and Kolbe, S
- Abstract
Long term irreversible disability in multiple sclerosis (MS) is thought to be primarily driven by axonal degeneration. Axonal degeneration leads to degenerative atrophy, therefore early markers of axonal degeneration are required to predict clinical disability and treatment efficacy. Given that additional pathologies such as inflammation, demyelination and oedema are also present in MS, it is essential to develop axonal markers that are not confounded by these processes. The present study investigated a novel method for measuring axonal degeneration in MS based on high angular resolution diffusion magnetic resonance imaging. Unlike standard methods, this novel method involved advanced acquisition and modelling for improved axonal sensitivity and specificity. Recent work has developed analytical methods, two novel axonal markers, fibre density and cross-section, that can be estimated for each fibre direction in each voxel (termed a "fixel"). This technique, termed fixel-based analysis, thus simultaneously estimates axonal density and white matter atrophy from specific white matter tracts. Diffusion-weighted imaging datasets were acquired for 17 patients with a history of acute unilateral optic neuritis (35.3 ± 10.2 years, 11 females) and 14 healthy controls (32.7 ± 4.8 years, 8 females) on a 3 T scanner. Fibre density values were compared to standard diffusion tensor imaging parameters (fractional anisotropy and mean diffusivity) in lesions and normal appearing white matter. Group comparisons were performed for each fixel to assess putative differences in fibre density and fibre cross-section. Fibre density was observed to have a comparable sensitivity to fractional anisotropy for detecting white matter pathology in MS, but was not affected by crossing axonal fibres. Whole brain fixel-based analysis revealed significant reductions in fibre density and fibre cross-section in the inferior fronto-occipital fasciculus (including the optic radiations) of patients compared
- Published
- 2018
18. A comparison of human and digital speech analysis to describe and monitor cerebellar dysfunction and disease severity in multiple sclerosis.
- Author
-
Noffs, G, Boonstra, F, Maldonado, F, Perera, T, Kolbe, S, Evans, A, Butzkeuven, H, Vogel, A, van der Walt, A, Noffs, G, Boonstra, F, Maldonado, F, Perera, T, Kolbe, S, Evans, A, Butzkeuven, H, Vogel, A, and van der Walt, A
- Published
- 2018
19. Objective speech marker correlates with clinical scores in non-dysarthric MS
- Author
-
Noffs, G, Boonstra, F, Kolbe, S, Perera, T, Shanahan, C, Evans, A, Butzkueven, H, Vogel, A, Van der Walt, A, Noffs, G, Boonstra, F, Kolbe, S, Perera, T, Shanahan, C, Evans, A, Butzkueven, H, Vogel, A, and Van der Walt, A
- Published
- 2017
20. Subclinical speech signs correlate with MS disease severity and differentiates patients with and without clinical cerebellar dysfunction
- Author
-
Noffs, G, Boonstra, F, Perera, T, Kolbe, S, Shanahan, C, Evans, A, Butzkueven, H, Vogel, A, van der Walt, A, Noffs, G, Boonstra, F, Perera, T, Kolbe, S, Shanahan, C, Evans, A, Butzkueven, H, Vogel, A, and van der Walt, A
- Published
- 2017
21. Pathophysiology of MS tremor: an fMRI study
- Author
-
Boonstra, F, Noffs, G, Perera, T, Shanahan, C, Vogel, A, Evans, A, Butzkueven, H, van der Walt, A, Kolbe, S, Boonstra, F, Noffs, G, Perera, T, Shanahan, C, Vogel, A, Evans, A, Butzkueven, H, van der Walt, A, and Kolbe, S
- Published
- 2017
22. Social Isolation Alters Social and Mating Behavior in the R451C Neuroligin Mouse Model of Autism
- Author
-
Burrows, E. L., primary, Eastwood, A. F., additional, May, C., additional, Kolbe, S. C., additional, Hill, T., additional, McLachlan, N. M., additional, Churilov, L., additional, and Hannan, A. J., additional
- Published
- 2017
- Full Text
- View/download PDF
23. Brain structure and intragenic DNA methylation are correlated, and predict executive dysfunction in fragile X premutation females
- Author
-
Shelton, A L, primary, Cornish, K M, additional, Kolbe, S, additional, Clough, M, additional, Slater, H R, additional, Li, X, additional, Kraan, C M, additional, Bui, Q M, additional, Godler, D E, additional, and Fielding, J, additional
- Published
- 2016
- Full Text
- View/download PDF
24. Brain structure and intragenic DNA methylation are correlated, and predict executive dysfunction in fragile X premutation females
- Author
-
Shelton, AL, Cornish, KM, Kolbe, S, Clough, M, Slater, HR, Li, X, Kraan, CM, Bui, QM, Godler, DE, Fielding, J, Shelton, AL, Cornish, KM, Kolbe, S, Clough, M, Slater, HR, Li, X, Kraan, CM, Bui, QM, Godler, DE, and Fielding, J
- Abstract
DNA methylation of the Fragile X mental retardation 1 (FMR1) exon 1/intron 1 boundary has been associated with executive dysfunction in female carriers of a FMR1 premutation (PM: 55-199 CGG repeats), whereas neuroanatomical changes have been associated with executive dysfunction in PM males. To our knowledge, this study for the first time examined the inter-relationships between executive function, neuroanatomical structure and molecular measures (DNA methylation and FMR1 mRNA levels in blood) in PM and control (<44 CGG repeats) females. In the PM group, FMR1 intron 1 methylation was positively associated with executive function and cortical thickness in middle and superior frontal gyri, and left inferior parietal gyrus. By contrast, in the control group, FMR1 intron 1 methylation was negatively associated with cortical thickness of the left middle frontal gyrus and superior frontal gyri. No significant associations were revealed for either group between FMR1 mRNA and neuroanatomical structure or executive function. In the PM group, the lack of any significant association between FMR1 mRNA levels and phenotypic measures found in this study suggests that either FMR1 expression is not well conserved between tissues, or that FMR1 intron 1 methylation is linked to neuroanatomical and cognitive phenotype in PM females via a different mechanism.
- Published
- 2016
25. Parallel Changes in Structural and Functional Measures of Optic Nerve Myelination after Optic Neuritis
- Author
-
Frishman, L, van der Walt, A, Kolbe, S, Mitchell, P, Wang, Y, Butzkueven, H, Egan, G, Yiannikas, C, Graham, S, Kilpatrick, T, Klistorner, A, Frishman, L, van der Walt, A, Kolbe, S, Mitchell, P, Wang, Y, Butzkueven, H, Egan, G, Yiannikas, C, Graham, S, Kilpatrick, T, and Klistorner, A
- Abstract
INTRODUCTION: Visual evoked potential (VEP) latency prolongation and optic nerve lesion length after acute optic neuritis (ON) corresponds to the degree of demyelination, while subsequent recovery of latency may represent optic nerve remyelination. We aimed to investigate the relationship between multifocal VEP (mfVEP) latency and optic nerve lesion length after acute ON. METHODS: Thirty acute ON patients were studied at 1, 3, 6 and 12 months using mfVEP and at 1 and 12 months with optic nerve MRI. LogMAR and low contrast visual acuity were documented. By one month, the mfVEP amplitude had recovered sufficiently for latency to be measured in 23 (76.7%) patients with seven patients having no recordable mfVEP in more than 66% of segments in at least one test. Only data from these 23 patients was analysed further. RESULTS: Both latency and lesion length showed significant recovery during the follow-up period. Lesion length and mfVEP latency were highly correlated at 1 (r = 0.94, p = <0.0001) and 12 months (r = 0.75, p < 0.001). Both measures demonstrated a similar trend of recovery. Speed of latency recovery was faster in the early follow-up period while lesion length shortening remained relatively constant. At 1 month, latency delay was worse by 1.76 ms for additional 1mm of lesion length while at 12 months, 1mm of lesion length accounted for 1.94 ms of latency delay. CONCLUSION: A strong association between two putative measures of demyelination in early and chronic ON was found. Parallel recovery of both measures could reflect optic nerve remyelination.
- Published
- 2015
26. Investigations into the synthesis, radiofluorination and conjugation of a new [18F]fluorocyclobutyl prosthetic group and its in vitro stability using a tyrosine model system
- Author
-
Franck, D., Kniess, T., Steinbach, J., Zitzmann-Kolbe, S., Friebe, M., Dinkelborg, L. M., Graham, K., Franck, D., Kniess, T., Steinbach, J., Zitzmann-Kolbe, S., Friebe, M., Dinkelborg, L. M., and Graham, K.
- Abstract
The [18F]fluorocyclobutyl group has the potential to be a metabolically stable prosthetic group for PET tracers. The synthesis of the radiolabeling precursor cis-cyclobutane-1,3-diyl bis(toluene-4-sulfonate) 8 was obtained from epibromohydrin in 7 steps (2% overall yield). The radiolabeling of this precursor 8 and its conjugation to L-tyrosine as a model system was successfully achieved to give the new nonnatural amino acid 3-[18F]fluorocyclobutyl-L-tyrosine (L-3-[18F]FCBT) [18F]17 in 8% decay-corrected yield from the non-carrier-added [18F]fluoride. L-3-[18F]FCBT was investigated in vitro in different cancer cell lines to determine the uptake and stability. The tracer [18F]17 showed a time dependent uptake into different tumor cell lines (A549, NCI-H460, DU145) with the best uptake of 5.8% injected dose per 5 105 cells after 30 min in human lung carcinoma cells A549. The stability of L-3-[18F]FCBT in human and rat plasma and the stability of the non-radioactive L-3-FCBT in rat hepatocytes were both found to be excellent. These results show that the non-natural amino acid L-3-[18F]FCBT is a promising metabolically stable radiotracer for positron emission tomography.
- Published
- 2013
27. Adolescent Toluene Inhalation in Rats Affects White Matter Maturation with the Potential for Recovery Following Abstinence
- Author
-
Homberg, J, Duncan, JR, Dick, ALW, Egan, G, Kolbe, S, Gavrilescu, M, Wright, D, Lubman, DI, Lawrence, AJ, Homberg, J, Duncan, JR, Dick, ALW, Egan, G, Kolbe, S, Gavrilescu, M, Wright, D, Lubman, DI, and Lawrence, AJ
- Abstract
Inhalant misuse is common during adolescence, with ongoing chronic misuse associated with neurobiological and cognitive abnormalities. While human imaging studies consistently report white matter abnormalities among long-term inhalant users, longitudinal studies have been lacking with limited data available regarding the progressive nature of such abnormalities, including the potential for recovery following periods of sustained abstinence. We exposed adolescent male Wistar rats (postnatal day 27) to chronic intermittent inhaled toluene (3,000 ppm) for 1 hour/day, 3 times/week for 8 weeks to model abuse patterns observed in adolescent and young adult human users. This dosing regimen resulted in a significant retardation in weight gain during the exposure period (p<0.05). In parallel, we performed longitudinal magnetic resonance imaging (T₂-weighted) and diffusion tensor imaging prior to exposure, and after 4 and 8 weeks, to examine the integrity of white matter tracts, including the anterior commissure and corpus callosum. We also conducted imaging after 8 weeks of abstinence to assess for potential recovery. Chronic intermittent toluene exposure during adolescence and early adulthood resulted in white matter abnormalities, including a decrease in axial (p<0.05) and radial (p<0.05) diffusivity. These abnormalities appeared region-specific, occurring in the anterior commissure but not the corpus callosum and were not present until after at least 4 weeks of exposure. Toluene-induced effects on both body weight and white matter parameters recovered following abstinence. Behaviourally, we observed a progressive decrease in rearing activity following toluene exposure but no difference in motor function, suggesting cognitive function may be more sensitive to the effects of toluene. Furthermore, deficits in rearing were present by 4 weeks suggesting that toluene may affect behaviour prior to detectable white matter abnormalities. Consequently, exposure to inhalants that co
- Published
- 2012
28. Fluorinated cyclobutyl group for increased metabolic stability using a tyrosine model system
- Author
-
Franck, D., Kniess, T., Steinbach, J., Zitzmann-Kolbe, S., Friebe, M., Dinkelborg, L., Graham, K., Franck, D., Kniess, T., Steinbach, J., Zitzmann-Kolbe, S., Friebe, M., Dinkelborg, L., and Graham, K.
- Abstract
Objectives: [18F]Fluoroalkyl chains are known to be potential sites for metabolic instability and can result in suboptimal PET image quality [1]. The aim of this work was to develop the [18F]fluorocyclobutyl substituent as a novel 18F-labeled prosthetic group that should have an increased metabolic stability whilst maintaining its efficacy. The well-characterized tyrosine LAT transporter system was used as a model test system. Methods: The precursors (cis-cyclobutane-1,3-diol ditosylate and tert-butyl N-(tert-butoxycarbonyl)-O-[trans-3-(tosyloxy)cyclobutyl]-L-tyrosinate) and the reference compound, 3-(cis-fluorocyclobutyl)-tyrosine, for the indirect and direct radiosyntheses of 3-(cis-[18F]fluorocyclobutyl)tyrosine (3-[18F]FCBT) were synthesized. The radiosynthesis of the 3-[18F]FCBT via indirect and direct methods were successfully established as outlined in Scheme 1. In vitro studies were performed in A549 cells after incubation with 3-[18F]FCBT at 37°C for up to 60 min with/without inhibitors FET and non-radioactive 3-FCBT. In vivo PET imaging studies were performed on mice bearing human lung cancer xenografts (A549 carcinoma). Results: 3-[18F]FCBT was synthesized via the direct method from precursor 3 in good yield (27-37% d.c.) and excellent radiochemical purity (>99%) in 57-73 minutes. In comparison, the indirect method from the precursor 1 and tyrosine gave only moderate yields (6-12% d.c.) and required longer synthesis times (140-158 minutes). The cell uptake studies showed an increase of 3-[18F]FCBT over time reaching a plateau of 5.87% at 30 min . In animal PET imaging the A549 lung carcinoma xenografts in mice were clearly visualized by the injection of 6 MBq 3-[18F]FCBT. The compound showed fast clearance from the blood and renal as well as hepatobiliary excretion. Preliminary in vitro stability investigations using 3-FCBT indicate excellent stab
- Published
- 2011
29. Investigating fluorinated cycloalkyl groups for increased metabolic stability using a Tyrosine model system
- Author
-
Franck, D., Kniess, T., Steinbach, J., Zitzmann-Kolbe, S., Friebe, M., Dinkelborg, L. M., Graham, K., Franck, D., Kniess, T., Steinbach, J., Zitzmann-Kolbe, S., Friebe, M., Dinkelborg, L. M., and Graham, K.
- Abstract
Objectives: The aim was to investigate whether fluorocyclobutyl rings can be introduced into targeting probes to improve metabolic stability, while maintaining its binding affinity, using tyrosine as a model system for the LAT transporters. Methods: The precursor, cis-cyclobutane-1,3-diol ditosylate, its corresponding F-19 reference compound trans-3-fluorocyclobutanol (FCB), along with the cis-(3-fluorocyclobutyl)-tyrosine (3FCBT), were synthesized using standard organic chemistry methodologies. The non-radioactive 3FCBT was tested in competition and efflux stimulation cell assays using A549 human lung carcinoma cells with [3H]-D-Tyrosine. The metabolic stability of reference compound 3FCBT was studied in both rat hepatocytes and human plasma. Radiosynthesis methods using standard radiofluorination of the prosthetic group [18F]FCB and its conjugation to tyrosine gave the desired 3[18F]FCBT after chromatographic purification. In vitro studies were performed in A549 cells using 3[18F]FCBT and incubated at 37°C for 10, 20, 30 and 60 minutes with and without inhibitors fluoroethyl-tyrosine (FET) and non-radioactive 3FCBT. Results: The syntheses of cis-cyclobutane-1,3-diol ditosylate, trans-3-fluorocyclobutanol (FCB), along with the cis-(3-fluorocyclobutyl)-tyrosine (3FCBT) were established. 3FCBT was shown to block the uptake of [3H]-D-tyrosine in the competition cell assay and could stimulate the release of 3H]-D-Tyrosine from the cell in an efflux stimulation cell assay. 3FCBT showed very high stability in both rat hepatocytes (> 95%) and human plasma (> 95%). The unoptimized radiosynthesis gave the desired 3[18F]FCBT, via the prosthetic group [18F]FCB, in moderate yield (12%) with high radiochemical purity (> 99%). The cell uptake showed an increase of 3[18F]FCBT over time and reached a plateau of 5.87% after 30 minutes. Conclusions: The radiosynthesis of the prosthetic
- Published
- 2011
30. A platform for distributed analysis of neuroimaging data on global Grids
- Author
-
Stockinger, H, Buyya, R, Perrott, R, Kolbe, S, Ma, TC, Liu, W, Soh, WS, Egan, G, Stockinger, H, Buyya, R, Perrott, R, Kolbe, S, Ma, TC, Liu, W, Soh, WS, and Egan, G
- Published
- 2005
31. Numerical calculations for the vibrations of a kettledrum shell
- Author
-
Kolbe, S. and Kolbe, S.
- Published
- 1989
32. 924 - Process Development and Manufacturing: ENHANCEMENT OF BIOACTIVE AND CELL-LABELING PEPTIDES WITH DNA-TEMPLATED MULTIVALENCE.
- Author
-
Möser, C., Freitag, J., Kolbe, S., and Smith, D.M.
- Subjects
- *
MANUFACTURING processes , *PEPTIDES - Published
- 2022
- Full Text
- View/download PDF
33. APOSTEL 2.0 Recommendations for Reporting Quantitative Optical Coherence Tomography Studies
- Author
-
Jennifer S. Graves, Robert P. Finger, Gema Rebolleda, Aykut Aytulun, Elliot Frohman, Ari J. Green, Peter A. Calabresi, Frank G. Holz, Bernardo Sanchez-Dalmau, Wolf A. Lagrèze, Sven G. Meuth, Lisanne J. Balk, Joachim Havla, Hanna Zimmermann, Laura J. Balcer, Patrick Yu-Wai-Man, Philipp Albrecht, Joel S. Schuman, Alexander U. Brandt, Piero Barboni, P. Villoslada, David Garway-Heath, Sven Schippling, Benjamin Knier, Friedemann Paul, Thomas Korn, Letizia Leocani, Scott Kolbe, Delia Cabrera DeBuc, Teresa Frohman, Jette Lautrup Frederiksen, Andrés Cruz-Herranz, Jaime Imitola, Robert C. Sergott, Oliver Maier, Augusto Azuara Blanco, Hans-Peter Hartung, Orhan Aktas, Julia Krämer, Marius Ringelstein, Elena H. Martinez-Lapiscina, Nicolas Feltgen, Rachel Kenney, Iñigo Gabilondo, Ahmed Toosy, E. Ann Yeh, Sebastian Wolf, Gorm Pihl-Jensen, Olivier Outteryck, Axel Petzold, Fiona Costello, Shiv Saidha, Jana Lizrova Preiningerova, Alexander Klistorner, Neurology, Ophthalmology, APH - Mental Health, APH - Methodology, Amsterdam Neuroscience - Neuroinfection & -inflammation, Aytulun, A., Cruz-Herranz, A., Aktas, O., Balcer, L. J., Balk, L., Barboni, P., Blanco, A. A., Calabresi, P. A., Costello, F., Sanchez-Dalmau, B., Debuc, D. C., Feltgen, N., Finger, R. P., Frederiksen, J. L., Frohman, E., Frohman, T., Garway-Heath, D., Gabilondo, I., Graves, J. S., Green, A. J., Hartung, H. -P., Havla, J., Holz, F. G., Imitola, J., Kenney, R., Klistorner, A., Knier, B., Korn, T., Kolbe, S., Kramer, J., Lagreze, W. A., Leocani, L., Maier, O., Martinez-Lapiscina, E. H., Meuth, S., Outteryck, O., Paul, F., Petzold, A., Pihl-Jensen, G., Preiningerova, J. L., Rebolleda, G., Ringelstein, M., Saidha, S., Schippling, S., Schuman, J. S., Sergott, R. C., Toosy, A., Villoslada, P., Wolf, S., Yeh, E. A., Yu-Wai-Man, P., Zimmermann, H. G., Brandt, A. U., and Albrecht, P.
- Subjects
Research design ,medicine.medical_specialty ,Consensus ,Delphi Technique ,Computer science ,Delphi method ,MEDLINE ,610 Medicine & health ,Terminology ,03 medical and health sciences ,0302 clinical medicine ,Retinal Diseases ,medicine ,Humans ,Medical physics ,030212 general & internal medicine ,Research Methods in Neurology ,Grading (education) ,Protocol (science) ,Guideline ,Checklist ,ddc ,Ophthalmology ,Research Design ,Neurology (clinical) ,Function and Dysfunction of the Nervous System ,030217 neurology & neurosurgery ,Tomography, Optical Coherence - Abstract
ObjectiveTo update the consensus recommendations for reporting of quantitative optical coherence tomography (OCT) study results, thus revising the previously published Advised Protocol for OCT Study Terminology and Elements (APOSTEL) recommendations.MethodsTo identify studies reporting quantitative OCT results, we performed a PubMed search for the terms “quantitative” and “optical coherence tomography” from 2015 to 2017. Corresponding authors of the identified publications were invited to provide feedback on the initial APOSTEL recommendations via online surveys following the principle of a modified Delphi method. The results were evaluated and discussed by a panel of experts and changes to the initial recommendations were proposed. A final survey was recirculated among the corresponding authors to obtain a majority vote on the proposed changes.ResultsA total of 116 authors participated in the surveys, resulting in 15 suggestions, of which 12 were finally accepted and incorporated into an updated 9-point checklist. We harmonized the nomenclature of the outer retinal layers, added the exact area of measurement to the description of volume scans, and suggested reporting device-specific features. We advised to address potential bias in manual segmentation or manual correction of segmentation errors. References to specific reporting guidelines and room light conditions were removed. The participants' consensus with the recommendations increased from 80% for the previous APOSTEL version to greater than 90%.ConclusionsThe modified Delphi method resulted in an expert-led guideline (evidence Class III; Grading of Recommendations, Assessment, Development and Evaluations [GRADE] criteria) concerning study protocol, acquisition device, acquisition settings, scanning protocol, funduscopic imaging, postacquisition data selection, postacquisition analysis, nomenclature and abbreviations, and statistical approach. It will be essential to update these recommendations to new research and practices regularly.
- Published
- 2021
34. The characteristics and reproducibility of motor speech functional neuroimaging in healthy controls.
- Author
-
Kenyon KH, Boonstra F, Noffs G, Morgan AT, Vogel AP, Kolbe S, and Van Der Walt A
- Abstract
Introduction: Functional magnetic resonance imaging (fMRI) can improve our understanding of neural processes subserving motor speech function. Yet its reproducibility remains unclear. This study aimed to evaluate the reproducibility of fMRI using a word repetition task across two time points., Methods: Imaging data from 14 healthy controls were analysed using a multi-level general linear model., Results: Significant activation was observed during the task in the right hemispheric cerebellar lobules IV-V, right putamen, and bilateral sensorimotor cortices. Activation between timepoints was found to be moderately reproducible across time in the cerebellum but not in other brain regions., Discussion: Preliminary findings highlight the involvement of the cerebellum and connected cerebral regions during a motor speech task. More work is needed to determine the degree of reproducibility of speech fMRI before this could be used as a reliable marker of changes in brain activity., Competing Interests: GN and AdV were employed by Redenlab Inc. The remaining authors declare that the research was conducted in the absence of any commercial or financial relationships that could be construed as a potential conflict of interest. The author(s) declared that they were an editorial board member of Frontiers, at the time of submission. This had no impact on the peer review process and the final decision., (Copyright © 2024 Kenyon, Boonstra, Noffs, Morgan, Vogel, Kolbe and Van Der Walt.)
- Published
- 2024
- Full Text
- View/download PDF
35. Volumetric and diffusion MRI abnormalities associated with dysarthria in multiple sclerosis.
- Author
-
Kenyon KH, Strik M, Noffs G, Morgan A, Kolbe S, Harding IH, Vogel AP, Boonstra FMC, and van der Walt A
- Abstract
Up to half of all people with multiple sclerosis experience communication difficulties due to dysarthria, a disorder that impacts the motor aspects of speech production. Dysarthria in multiple sclerosis is linked to cerebellar dysfunction, disease severity and lesion load, but the neuroanatomical substrates of these symptoms remain unclear. In this study, 52 participants with multiple sclerosis and 14 age- and sex-matched healthy controls underwent structural and diffusion MRI, clinical assessment of disease severity and cerebellar dysfunction and a battery of motor speech tasks. Assessments of regional brain volume and white matter integrity, and their relationships with clinical and speech measures, were undertaken. White matter tracts of interest included the interhemispheric sensorimotor tract, cerebello-thalamo-cortical tract and arcuate fasciculus, based on their roles in motor and speech behaviours. Volumetric analyses were targeted to Broca's area, Wernicke's area, the corpus callosum, thalamus and cerebellum. Our results indicated that multiple sclerosis participants scored worse on all motor speech tasks. Fixel-based diffusion MRI analyses showed significant evidence of white matter tract atrophy in each tract of interest. Correlational analyses further indicated that higher speech naturalness-a perceptual measure of dysarthria-and lower reading rate were associated with axonal damage in the interhemispheric sensorimotor tract and left arcuate fasciculus in people with multiple sclerosis. Axonal damage in all tracts of interest also correlated with clinical scales sensitive to cerebellar dysfunction. Participants with multiple sclerosis had lower volumes of the thalamus and corpus callosum compared with controls, although no brain volumetrics correlated with measures of dysarthria. These findings indicate that axonal damage, particularly when measured using diffusion metrics, underpin dysarthria in multiple sclerosis., Competing Interests: K.H.K., F.M.C.B., M.S. and A.M. have nothing to disclose. A.v.d.W. served on advisory boards and receives unrestricted research grants from Novartis, Biogen, Merck and Roche; has received speaker’s honoraria and travel support from Novartis, Roche and Merck; and receives grant support from the National Health and Medical Research Council of Australia and MS Research Australia. A.P.V. is the chief science officer of Redenlab Inc. G.N. works in the scientific development for Redenlab Inc. S.K. received unrestricted research grants from Biogen and grant support from MS Research Australia. I.H.H receives grants from the National Health and Medical Research Council and honoraria from Steminent Biotherapeutics and PTC therapeutics., (© The Author(s) 2024. Published by Oxford University Press on behalf of the Guarantors of Brain.)
- Published
- 2024
- Full Text
- View/download PDF
36. A Targeted Thorium-227 Conjugate Demonstrates Efficacy in Preclinical Models of Acquired Drug Resistance and Combination Potential with Chemotherapeutics and Antiangiogenic Therapies.
- Author
-
Zitzmann-Kolbe S, Kristian A, Zopf D, Kamfenkel C, Politz O, Ellingsen C, Hilbig J, Juul MU, Fonslet J, Nielsen CH, Schatz CA, Bjerke RM, Cuthbertson AS, Mumberg D, and Hagemann UB
- Subjects
- Humans, Female, GPI-Linked Proteins, Cell Line, Tumor, Drug Resistance, Mesothelin
- Abstract
Targeted alpha therapies (TAT) are an innovative class of therapies for cancer treatment. The unique mode-of-action of TATs is the induction of deleterious DNA double-strand breaks. Difficult-to-treat cancers, such as gynecologic cancers upregulating the chemoresistance P-glycoprotein (p-gp) and overexpressing the membrane protein mesothelin (MSLN), are promising targets for TATs. Here, based on the previous encouraging findings with monotherapy, we investigated the efficacy of the mesothelin-targeted thorium-227 conjugate (MSLN-TTC) both as monotherapy and in combination with chemotherapies and antiangiogenic compounds in ovarian and cervical cancer models expressing p-gp. MSLN-TTC monotherapy showed equal cytotoxicity in vitro in p-gp-positive and -negative cancer cells, while chemotherapeutics dramatically lost activity on p-gp-positive cancer cells. In vivo, MSLN-TTC exhibited dose-dependent tumor growth inhibition with treatment/control ratios of 0.03-0.44 in various xenograft models irrespective of p-gp expression status. Furthermore, MSLN-TTC was more efficacious in p-gp-expressing tumors than chemotherapeutics. In the MSLN-expressing ST206B ovarian cancer patient-derived xenograft model, MSLN-TTC accumulated specifically in the tumor, which combined with pegylated liposomal doxorubicin (Doxil), docetaxel, bevacizumab, or regorafenib treatment induced additive-to-synergistic antitumor efficacy and substantially increased response rates compared with respective monotherapies. The combination treatments were well tolerated and only transient decreases in white and red blood cells were observed. In summary, we demonstrate that MSLN-TTC treatment shows efficacy in p-gp-expressing models of chemoresistance and has combination potential with chemo- and antiangiogenic therapies., (©2023 The Authors; Published by the American Association for Cancer Research.)
- Published
- 2023
- Full Text
- View/download PDF
37. Monitoring the acute and subacute recovery of cognitive ocular motor changes after a sports-related concussion.
- Author
-
Symons GF, O'Brien WT, Abel L, Chen Z, Costello DM, O'Brien TJ, Kolbe S, Fielding J, Shultz SR, and Clough M
- Subjects
- Male, Female, Humans, Saccades, Mental Recall, Cognition, Athletic Injuries, Brain Concussion
- Abstract
Identifying when recovery from a sports-related concussion (SRC) has occurred remains a challenge in clinical practice. This study investigated the utility of ocular motor (OM) assessment to monitor recovery post-SRC between sexes and compared to common clinical measures. From 139 preseason baseline assessments (i.e. before they sustained an SRC), 18 (12 males, 6 females) consequent SRCs were sustained and the longitudinal follow-ups were collected at 2, 6, and 13 days post-SRC. Participants completed visually guided, antisaccade (AS), and memory-guided saccade tasks requiring a saccade toward, away from, and to a remembered target, respectively. Changes in latency (processing speed), visual-spatial accuracy, and errors were measured. Clinical measures included The Sports Concussion Assessment Tool, King-Devick test, Stroop task, and Digit span. AS latency was significantly longer at 2 days and returned to baseline by 13-days post-SRC in females only (P < 0.001). Symptom numbers recovered from 2 to 6 days and 13 days (P < 0.05). Persistently poorer AS visual-spatial accuracy was identified at 2, 6 and 13 days post-SRC (P < 0.05) in both males and females but with differing trajectories. Clinical measures demonstrated consistent improvement reminiscent of practice effects. OM saccade assessment may have improved utility in tracking recovery compared to conventional measures and between sexes., (© The Author(s) 2022. Published by Oxford University Press. All rights reserved. For permissions, please e-mail: journals.permissions@oup.com.)
- Published
- 2023
- Full Text
- View/download PDF
38. Enhancing TreeMMoSys with a high-precision strain gauge to measure the wind-induced response of trees down to the ground.
- Author
-
Nickl J, Kolbe S, and Schindler D
- Abstract
Measuring tree response to wind loads is fundamental for the process-based analysis of wind-tree interactions. Comprehensive knowledge of wind-tree interactions enables the further development of decision support tools available for estimating the probability of wind damage to trees. The assessment of critical wind loads that lead to damage is particularly important. This paper describes the inexpensive Tree Strain Sensor (TSS) suitable for precisely measuring the response of tree parts to external loads such as pulling tests and natural wind loading. It is an addition to the recently developed Tree Motion Monitoring System (TreeMMoSys) but can also be used as a standalone device, allowing measurements necessary to estimate effective wind loads on trees., Competing Interests: The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (© 2022 The Author(s).)
- Published
- 2022
- Full Text
- View/download PDF
39. Long-term structural brain changes in adult rats after mild ischaemic stroke.
- Author
-
Syeda W, Ermine CM, Khilf MS, Wright D, Brait VH, Nithianantharajah J, Kolbe S, Johnston LA, Thompson LH, and Brodtmann A
- Abstract
Preclinical studies of remote degeneration have largely focused on brain changes over the first few days or weeks after stroke. Accumulating evidence suggests that neurodegeneration occurs in other brain regions remote to the site of infarction for months and even years following ischaemic stroke. Brain atrophy appears to be driven by both axonal degeneration and widespread brain inflammation. The evolution and duration of these changes are increasingly being described in human studies, using advanced brain imaging techniques. Here, we sought to investigate long-term structural brain changes in a model of mild focal ischaemic stroke following injection of endothlin-1 in adult Long-Evans rats ( n = 14) compared with sham animals ( n = 10), over a clinically relevant time-frame of 48 weeks. Serial structural and diffusion-weighted MRI data were used to assess dynamic volume and white matter trajectories. We observed dynamic regional brain volume changes over the 48 weeks, reflecting both normal changes with age in sham animals and neurodegeneration in regions connected to the infarct following ischaemia. Ipsilesional cortical volume loss peaked at 24 weeks but was less prominent at 36 and 48 weeks. We found significantly reduced fractional anisotropy in both ipsi- and contralesional motor cortex and cingulum bundle regions of infarcted rats ( P < 0.05) from 4 to 36 weeks, suggesting ongoing white matter degeneration in tracts connected to but distant from the stroke. We conclude that there is evidence of significant cortical atrophy and white matter degeneration up to 48 weeks following infarct, consistent with enduring, pervasive stroke-related degeneration., (© The Author(s) 2022. Published by Oxford University Press on behalf of the Guarantors of Brain.)
- Published
- 2022
- Full Text
- View/download PDF
40. Potential impacts of emerald ash borer and adaptation strategies on wildlife communities in black ash wetlands.
- Author
-
R Grinde A, B Youngquist M, A Slesak R, R Kolbe S, D Bednar J, J Palik B, and W D'Amato A
- Subjects
- Animals, Animals, Wild, Birds, Larva, Mammals, Trees, Wetlands, Coleoptera, Fraxinus
- Abstract
Black ash wetlands cover approximately 1.2 million ha of wetland forest in the western Great Lakes region, providing critical habitat for wildlife. The future of these wetlands is critically threatened by a variety of factors, including emerald ash borer (Agrilus planipennis; emerald ash borer [EAB]), which has been eliminating native populations of otherwise healthy ash throughout the Great Lakes region since it was discovered in 2002. To quantify the potential impacts of tree mortality from EAB on wildlife communities, we measured seasonal bird, mammal, and amphibian diversity in black ash wetlands using a dual approach: (1) documenting bird and amphibian species across 27 mature reference black ash wetlands in northern Minnesota, USA and (2) assessing how bird, mammal, and amphibian communities respond to experimental manipulations of black ash forests that emulate mortality and management strategies related to the potential impact of EAB. In total, 85 wildlife species were recorded for the entire study including 57 bird species, 5 amphibian species, and 23 mammal species. Results from the reference sites show that hydrologic regime, percentage of ash canopy cover, and understory cover were important habitat characteristics for bird and amphibian communities. Results from the experimental sites show there may be short-term increases in species richness for mammal and bird communities associated with changes in forest structure due to ash mortality; however, anticipated changes resulting from EAB-caused mortality, particularly the conversion of these sites to non-forested wetlands, will lead to significant shifts in bird and mammal community composition. Loss of ash may cause declines in forest-dependent species and increases in open-canopy and wetland-associated species. Additionally, whereas increased ponding extent and longer hydroperiods may be beneficial for some amphibian species, the loss of the forest canopy will result in an overall decrease in bird diversity and reduce forest connectivity for all species. Our results indicate the potential for significant large-scale impacts of black ash mortality on forest-associated wildlife. Management strategies that focus on establishing alternative trees species to maintain long-term forest cover and structural complexity in these wetlands will help to maintain and conserve wildlife diversity., (© 2022 The Ecological Society of America.)
- Published
- 2022
- Full Text
- View/download PDF
41. Asymmetric distribution of enlarged perivascular spaces in centrum semiovale may be associated with epilepsy after acute ischemic stroke.
- Author
-
Yu N, Sinclair B, Posada LMG, Chen Z, Di Q, Lin X, Kolbe S, Hlauschek G, Kwan P, and Law M
- Subjects
- Basal Ganglia, Corpus Callosum, Humans, Magnetic Resonance Imaging, Epilepsy diagnostic imaging, Epilepsy etiology, Glymphatic System, Ischemic Stroke, Stroke complications, Stroke diagnostic imaging
- Abstract
Objective: To investigate the factors influencing enlarged perivascular space (EPVS) characteristics at the onset of acute ischemic stroke (AIS), and whether the PVS characteristics can predict later post-stroke epilepsy (PSE)., Methods: A total of 312 patients with AIS were identified, of whom 58/312 (18.6%) developed PSE. Twenty healthy participants were included as the control group. The number of PVS in the basal ganglia (BG), centrum semiovale (CS), and midbrain (MB) was manually calculated on T
2 -weighted MRI. The scores and asymmetry index (AI) of EPVS in each region were compared among the enrolled participants. Other potential risk factors for PSE were also analyzed, including NIHSS at admission and stroke etiologies., Results: The EPVS scores were significantly higher in the bilateral BG and CS of AIS patients compared to those of the control group (both p < 0.01). No statistical differences in EPVS scores in BG, CS, and MB were obtained between the PSE group and the nonepilepsy AIS group (all p > 0.01). However, markedly different AI scores in CS were found between the PSE group and the nonepilepsy AIS group (p = 0.004). Multivariable analysis showed that high asymmetry index of EPVS (AI≥0.2) in CS was an independent predictor for PSE (OR = 3.7, 95% confidence interval 1.5-9.1, p = 0.004)., Conclusions: Asymmetric distribution of EPVS in CS may be an independent risk factor and a novel imaging biomarker for the development of PSE. Further studies to understand the mechanisms of this association and confirmation with larger patient populations are warranted., (© 2022 The Authors. CNS Neuroscience & Therapeutics published by John Wiley & Sons Ltd.)- Published
- 2022
- Full Text
- View/download PDF
42. Exploiting mesothelin in thymic carcinoma as a drug delivery target for anetumab ravtansine.
- Author
-
Chen V, Umemura S, Han Y, Raman R, Tucker R, Chahine J, Kim IK, Schatz C, Zitzmann-Kolbe S, Sommer A, Onda M, Lee T, He Y, and Giaccone G
- Subjects
- Animals, Cell Line, Tumor, Cell Proliferation drug effects, Cell Survival drug effects, Cisplatin administration & dosage, Cisplatin pharmacology, Drug Synergism, Female, Gene Expression Regulation, Neoplastic drug effects, HT29 Cells, Humans, Immunoconjugates pharmacology, Maytansine administration & dosage, Maytansine pharmacology, Mice, Neoplasms, Glandular and Epithelial genetics, Neoplasms, Glandular and Epithelial metabolism, Thymoma genetics, Thymoma metabolism, Thymus Neoplasms genetics, Thymus Neoplasms metabolism, Up-Regulation drug effects, Xenograft Model Antitumor Assays, Immunoconjugates administration & dosage, Maytansine analogs & derivatives, Mesothelin genetics, Mesothelin metabolism, Neoplasms, Glandular and Epithelial drug therapy, Thymoma drug therapy, Thymus Neoplasms drug therapy
- Abstract
Background: Thymic epithelial tumours (TETs) are rare tumours comprised of thymomas and thymic carcinoma. Novel therapies are needed, especially in thymic carcinoma where the 5-year survival rate hovers at 30%. Mesothelin (MSLN), a surface glycoprotein that is cleaved to produce mature MSLN (mMSLN) and megakaryocyte potentiating factor (MPF), is expressed in limited tissues. However, its expression is present in various cancers, including thymic carcinoma, where it is expressed in 79% of cases., Methods: We utilised flow cytometry, in vitro cytotoxicity assays, and an in vivo xenograft model in order to demonstrate the ability of the MSLN targeting antibody-drug conjugate (ADC) anetumab ravtansine (ARav) in inhibiting the growth of thymic carcinoma., Results: Thymoma and thymic carcinoma cell lines express MSLN, and anetumab, the antibody moiety of ARav, was capable of binding MSLN expressing thymic carcinoma cells and internalising. ARav was effective at inhibiting the growth of thymic carcinoma cells stably transfected with mMSLN in vitro. In vivo, 15 mg/kg ARav inhibited T1889 xenograft tumour growth, while combining 7.5 mg/kg ARav with 4 mg/kg cisplatin yielded an additive effect on inhibiting tumour growth., Conclusions: These data demonstrate that anetumab ravtansine inhibits the growth of MSLN positive thymic carcinoma cells in vitro and in vivo., (© 2021. The Author(s), under exclusive licence to Springer Nature Limited.)
- Published
- 2022
- Full Text
- View/download PDF
43. Lesion Volume in Relapsing Multiple Sclerosis is Associated with Perivascular Space Enlargement at the Level of the Basal Ganglia.
- Author
-
Kolbe SC, Garcia LM, Yu N, Boonstra FM, Clough M, Sinclair B, White O, van der Walt A, Butzkueven H, Fielding J, and Law M
- Subjects
- Basal Ganglia diagnostic imaging, Basal Ganglia pathology, Brain diagnostic imaging, Brain pathology, Humans, Magnetic Resonance Imaging methods, Glymphatic System diagnostic imaging, Glymphatic System pathology, Multiple Sclerosis pathology, Multiple Sclerosis, Relapsing-Remitting diagnostic imaging, Multiple Sclerosis, Relapsing-Remitting pathology
- Abstract
Background and Purpose: Perivascular spaces surround the blood vessels of the brain and are involved in neuroimmune functions and clearance of metabolites via the glymphatic system of the brain. Enlarged perivascular spaces could be a marker of dysfunction in these processes and, therefore, are highly relevant to monitoring disease activity in MS. This study aimed to compare the number of enlarged perivascular spaces in people with relapsing MS with MR imaging markers of inflammation and brain atrophy., Materials and Methods: Fifty-nine patients (18 with clinically isolated syndrome, 22 with early and 19 with late relapsing-remitting MS) were scanned longitudinally (mean follow-up duration = 19.6 [SD, 0.5] months) using T2-weighted, T1-weighted, and FLAIR MR imaging. Two expert raters identified and counted enlarged perivascular spaces on T2-weighted MR images from 3 ROIs (the centrum semiovale, basal ganglia, and midbrain). Baseline and change with time in the number of enlarged perivascular spaces were correlated with demographics and lesion and brain volumes., Results: Late relapsing-remitting MS had a greater average number of enlarged perivascular spaces at baseline at the level of the basal ganglia (72.3) compared with early relapsing-remitting MS (60.5) and clinically isolated syndrome (54.7) ( F = 3.4, P = .042), and this finding correlated with lesion volume ( R = 0.44, P = .0004) but not brain atrophy ( R = -0.16). Enlarged perivascular spaces increased in number with time in all regions, and the rate of increase did not differ among clinical groups., Conclusions: Enlarged perivascular spaces at the level of the basal ganglia are associated with greater neuroinflammatory burden, and the rate of enlargement appears constant in patients with relapsing-remitting disease phenotypes., (© 2022 by American Journal of Neuroradiology.)
- Published
- 2022
- Full Text
- View/download PDF
44. Sodium selenate as a disease-modifying treatment for progressive supranuclear palsy: protocol for a phase 2, randomised, double-blind, placebo-controlled trial.
- Author
-
Vivash L, Bertram KL, Malpas CB, Marotta C, Harding IH, Kolbe S, Fielding J, Clough M, Lewis SJG, Tisch S, Evans AH, O'Sullivan JD, Kimber T, Darby D, Churilov L, Law M, Hovens CM, Velakoulis D, and O'Brien TJ
- Subjects
- Australia, Clinical Trials, Phase II as Topic, Double-Blind Method, Humans, Randomized Controlled Trials as Topic, Selenic Acid therapeutic use, Treatment Outcome, Supranuclear Palsy, Progressive drug therapy
- Abstract
Introduction: Progressive supranuclear palsy (PSP) is a neurodegenerative disorder for which there are currently no disease-modifying therapies. The neuropathology of PSP is associated with the accumulation of hyperphosphorylated tau in the brain. We have previously shown that protein phosphatase 2 activity in the brain is upregulated by sodium selenate, which enhances dephosphorylation. Therefore, the objective of this study is to evaluate the efficacy and safety of sodium selenate as a disease-modifying therapy for PSP., Methods and Analysis: This will be a multi-site, phase 2b, double-blind, placebo-controlled trial of sodium selenate. 70 patients will be recruited at six Australian academic hospitals and research institutes. Following the confirmation of eligibility at screening, participants will be randomised (1:1) to receive 52 weeks of active treatment (sodium selenate; 15 mg three times a day) or matching placebo. Regular safety and efficacy visits will be completed throughout the study period. The primary study outcome is change in an MRI volume composite (frontal lobe+midbrain-3rd ventricle) over the treatment period. Analysis will be with a general linear model (GLM) with the MRI composite at 52 weeks as the dependent variable, treatment group as an independent variable and baseline MRI composite as a covariate. Secondary outcomes are change in PSP rating scale, clinical global impression of change (clinician) and change in midbrain mean diffusivity. These outcomes will also be analysed with a GLM as above, with the corresponding baseline measure entered as a covariate. Secondary safety and tolerability outcomes are frequency of serious adverse events, frequency of down-titration occurrences and frequency of study discontinuation. Additional, as yet unplanned, exploratory outcomes will include analyses of other imaging, cognitive and biospecimen measures., Ethics and Dissemination: The study was approved by the Alfred Health Ethics Committee (594/20). Each participant or their legally authorised representative and their study partner will provide written informed consent at trial commencement. The results of the study will be presented at national and international conferences and published in peer-reviewed journals., Trial Registration Number: Australian New Zealand Clinical Trials Registry (ACTRN12620001254987)., Competing Interests: Competing interests: All authors report a grant from the NHMRC to support this study. The authors report the following disclosures outside of this study: LV reports personal fees from Biogen Australia, and research funding from Biogen, Eisai and LMI. AHE reports honoraria for presentations from Merck, Allergan, Ipsen, Teva, UCB, Abbott, AbbVie, STADA, participation in scientific advisory board meetings with Allergan, AbbVie, Ipsen and STADA and shares in GKC and CSL. DD reports consultancy fees from Biogen, Novartis. KLB, CMalpas, CMarotta, IHH, SK, JF, MC, SJGL, ST, JDOS, TK, LC, ML, CMH and DV report no disclosures., (© Author(s) (or their employer(s)) 2021. Re-use permitted under CC BY-NC. No commercial re-use. See rights and permissions. Published by BMJ.)
- Published
- 2021
- Full Text
- View/download PDF
45. DNA repair inhibitors sensitize cells differently to high and low LET radiation.
- Author
-
Bannik K, Madas B, Jarke S, Sutter A, Siemeister G, Schatz C, Mumberg D, and Zitzmann-Kolbe S
- Subjects
- Alpha Particles, Cell Cycle drug effects, Cell Cycle radiation effects, Cell Cycle Checkpoints drug effects, Cell Line, Tumor, Cell Survival drug effects, HEK293 Cells, Histones metabolism, Humans, Linear Energy Transfer, Micronucleus Tests, Radiation, Ionizing, Radiometry, X-Rays, Ataxia Telangiectasia Mutated Proteins pharmacology, DNA Breaks, Double-Stranded drug effects, DNA Repair drug effects, DNA Repair radiation effects, DNA-Activated Protein Kinase pharmacology, Radiation Tolerance drug effects, Radiation-Sensitizing Agents pharmacology
- Abstract
The aim of this study was to investigate effects of high LET α-radiation in combination with inhibitors of DDR (DNA-PK and ATM) and to compare the effect with the radiosensitizing effect of low LET X-ray radiation. The various cell lines were irradiated with α-radiation and with X-ray. Clonogenic survival, the formation of micronuclei and cell cycle distribution were studied after combining of radiation with DDR inhibitors. The inhibitors sensitized different cancer cell lines to radiation. DNA-PKi affected survival rates in combination with α-radiation in selected cell lines. The sensitization enhancement ratios were in the range of 1.6-1.85 in cancer cells. ATMi sensitized H460 cells and significantly increased the micronucleus frequency for both radiation qualities. ATMi in combination with α-radiation reduced survival of HEK293. A significantly elicited cell cycle arrest in G
2 /M phase after co-treatment of ATMi with α-radiation and X-ray. The most prominent treatment effect was observed in the HEK293 by combining α-radiation and inhibitions. ATMi preferentially sensitized cancer cells and normal HEK293 cells to α-radiation. DNA-PKi and ATMi can sensitize cancer cells to X-ray, but the effectiveness was dependent on cancer cells itself. α-radiation reduced proliferation in primary fibroblast without G2 /M arrest., (© 2021. The Author(s).)- Published
- 2021
- Full Text
- View/download PDF
46. Fixel-based Analysis of Diffusion MRI: Methods, Applications, Challenges and Opportunities.
- Author
-
Dhollander T, Clemente A, Singh M, Boonstra F, Civier O, Duque JD, Egorova N, Enticott P, Fuelscher I, Gajamange S, Genc S, Gottlieb E, Hyde C, Imms P, Kelly C, Kirkovski M, Kolbe S, Liang X, Malhotra A, Mito R, Poudel G, Silk TJ, Vaughan DN, Zanin J, Raffelt D, and Caeyenberghs K
- Subjects
- Brain physiology, Diffusion Magnetic Resonance Imaging trends, Humans, Image Processing, Computer-Assisted trends, Nerve Fibers physiology, White Matter physiology, Brain cytology, Brain diagnostic imaging, Diffusion Magnetic Resonance Imaging methods, Image Processing, Computer-Assisted methods, White Matter diagnostic imaging
- Abstract
Diffusion MRI has provided the neuroimaging community with a powerful tool to acquire in-vivo data sensitive to microstructural features of white matter, up to 3 orders of magnitude smaller than typical voxel sizes. The key to extracting such valuable information lies in complex modelling techniques, which form the link between the rich diffusion MRI data and various metrics related to the microstructural organization. Over time, increasingly advanced techniques have been developed, up to the point where some diffusion MRI models can now provide access to properties specific to individual fibre populations in each voxel in the presence of multiple "crossing" fibre pathways. While highly valuable, such fibre-specific information poses unique challenges for typical image processing pipelines and statistical analysis. In this work, we review the "Fixel-Based Analysis" (FBA) framework, which implements bespoke solutions to this end. It has recently seen a stark increase in adoption for studies of both typical (healthy) populations as well as a wide range of clinical populations. We describe the main concepts related to Fixel-Based Analyses, as well as the methods and specific steps involved in a state-of-the-art FBA pipeline, with a focus on providing researchers with practical advice on how to interpret results. We also include an overview of the scope of all current FBA studies, categorized across a broad range of neuro-scientific domains, listing key design choices and summarizing their main results and conclusions. Finally, we critically discuss several aspects and challenges involved with the FBA framework, and outline some directions and future opportunities., (Copyright © 2021. Published by Elsevier Inc.)
- Published
- 2021
- Full Text
- View/download PDF
47. White and Gray Matter Abnormalities in Australian Footballers With a History of Sports-Related Concussion: An MRI Study.
- Author
-
Major B, Symons GF, Sinclair B, O'Brien WT, Costello D, Wright DK, Clough M, Mutimer S, Sun M, Yamakawa GR, Brady RD, O'Sullivan MJ, Mychasiuk R, McDonald SJ, O'Brien TJ, Law M, Kolbe S, and Shultz SR
- Subjects
- Australia, Diffusion Tensor Imaging, Gray Matter diagnostic imaging, Humans, Magnetic Resonance Imaging, Male, Athletic Injuries diagnostic imaging, Brain Concussion diagnostic imaging, White Matter diagnostic imaging
- Abstract
Sports-related concussion (SRC) is a form of mild traumatic brain injury that has been linked to long-term neurological abnormalities. Australian rules football is a collision sport with wide national participation and is growing in popularity worldwide. However, the chronic neurological consequences of SRC in Australian footballers remain poorly understood. This study investigated the presence of brain abnormalities in Australian footballers with a history of sports-related concussion (HoC) using multimodal MRI. Male Australian footballers with HoC (n = 26), as well as noncollision sport athletes with no HoC (n = 27), were recruited to the study. None of the footballers had sustained a concussion in the preceding 6 months, and all players were asymptomatic. Data were acquired using a 3T MRI scanner. White matter integrity was assessed using diffusion tensor imaging. Cortical thickness, subcortical volumes, and cavum septum pellucidum (CSP) were analyzed using structural MRI. Australian footballers had evidence of widespread microstructural white matter damage and cortical thinning. No significant differences were found regarding subcortical volumes or CSP. These novel findings provide evidence of persisting white and gray matter abnormalities in Australian footballers with HoC, and raise concerns related to the long-term neurological health of these athletes., (© The Author(s) 2021. Published by Oxford University Press. All rights reserved. For permissions, please e-mail: journals.permission@oup.com.)
- Published
- 2021
- Full Text
- View/download PDF
48. Novel Prediction of Diagnosis Effectiveness for Adaptation of the Spectral Kurtosis Technology to Varying Operating Conditions.
- Author
-
Kolbe S, Gelman L, and Ball A
- Subjects
- Technology, Vibration, Algorithms, Machine Learning
- Abstract
In this paper, two novel consistency vectors are proposed, which when combined with appropriate machine learning algorithms, can be used to adapt the Spectral Kurtosis technology for optimum gearbox damage diagnosis in varying operating conditions. Much of the existing research in the field is limited to test apparatus run in constant and carefully controlled operating conditions, and the authors have previously publicised that the Spectral Kurtosis technology requires adaptation to achieve the highest possible probabilities of correct diagnosis when a gearbox is run in non-stationary conditions of speed and load. However, the authors' previous adaptation has been computationally heavy using a brute-force approach unsuited to online use, and therefore, created the requirement to develop these two newly proposed vectors and allow computationally lighter techniques more suited to online condition monitoring. The new vectors are demonstrated and experimentally validated on vibration data collected from a gearbox run in multiple combinations of operating conditions; for the first time, the two consistency vectors are used to predict diagnosis effectiveness, with the comparison and proof of relative gains between the traditional and novel techniques discussed. Consistency calculations are computationally light and thus, many combinations of Spectral Kurtosis technology parameters can be evaluated on a dataset in a very short time. This study shows that machine learning can predict the total probability of correct diagnosis from the consistency values and this can quickly provide pre-adaptation/prediction of optimum Spectral Kurtosis technology parameters for a dataset. The full adaptation and damage evaluation process, which is computationally heavier, can then be undertaken on a much lower number of combinations of Spectral Kurtosis resolution and threshold.
- Published
- 2021
- Full Text
- View/download PDF
49. Immunostimulatory effects of targeted thorium-227 conjugates as single agent and in combination with anti-PD-L1 therapy.
- Author
-
Lejeune P, Cruciani V, Berg-Larsen A, Schlicker A, Mobergslien A, Bartnitzky L, Berndt S, Zitzmann-Kolbe S, Kamfenkel C, Stargard S, Hammer S, Jørgensen JS, Jackerott M, Nielsen CH, Schatz CA, Hennekes H, Karlsson J, Cuthbertson AS, Mumberg D, and Hagemann UB
- Subjects
- Animals, Gene Expression Profiling, Immunoconjugates pharmacology, Immunotherapy, Mice, Thorium pharmacology, Transfection, Xenograft Model Antitumor Assays, B7-H1 Antigen antagonists & inhibitors, Immunoconjugates therapeutic use, Thorium therapeutic use
- Abstract
Background: Targeted thorium-227 conjugates (TTCs) are an emerging class of targeted alpha therapies (TATs). Their unique mode of action (MoA) is the induction of difficult-to-repair clustered DNA double-strand breaks. However, thus far, their effects on the immune system are largely unknown. Here, we investigated the immunostimulatory effects of the mesothelin-targeted thorium-227 conjugate (MSLN-TTC) in vitro and in vivo in monotherapy and in combination with an inhibitor of the immune checkpoint programmed death receptor ligand 1 (PD-L1) in immunocompetent mice., Methods: The murine cell line MC38 was transfected with the human gene encoding for MSLN (hMSLN) to enable binding of the non-cross-reactive MSLN-TTC. The immunostimulatory effects of MSLN-TTC were studied in vitro on human cancer cell lines and MC38-hMSLN cells. The efficacy and MoA of MSLN-TTC were studied in vivo as monotherapy or in combination with anti-PD-L1 in MC38-hMSLN tumor-bearing immunocompetent C57BL/6 mice. Experiments were supported by RNA sequencing, flow cytometry, immunohistochemistry, mesoscale, and TaqMan PCR analyses to study the underlying immunostimulatory effects. In vivo depletion of CD8+ T cells and studies with Rag2/Il2Rg double knockout C57BL/6 mice were conducted to investigate the importance of immune cells to the efficacy of MSLN-TTC., Results: MSLN-TTC treatment induced upregulation of DNA sensing pathway transcripts ( IL-6 , CCL20 , CXCL10 , and stimulator of interferon genes ( STING )-related genes) in vitro as determined by RNASeq analysis. The results, including phospho-STING activation, were confirmed on the protein level. Danger-associated molecular pattern molecules were upregulated in parallel, leading to dendritic cell (DC) activation in vitro . MSLN-TTC showed strong antitumor activity (T:C 0.38, p<0.05) as a single agent in human MSLN-expressing MC38 tumor-bearing immunocompetent mice. Combining MSLN-TTC with anti-PD-L1 further enhanced the efficacy (T:C 0.08, p<0.001) as evidenced by the increased number of tumor-free surviving animals. MSLN-TTC monotherapy caused migration of CD103+ cDC1 DCs and infiltration of CD8+ T cells into tumors, which was enhanced on combination with anti-PD-L1. Intriguingly, CD8+ T-cell depletion decreased antitumor efficacy., Conclusions: These in vitro and in vivo data on MSLN-TTC demonstrate that the MoA of TTCs involves activation of the immune system. The findings are of relevance for other targeted radiotherapies and may guide clinical combination strategies., Competing Interests: Competing interests: PL, VC, ABL, AS, AM, LB, SB, SZK, CK, SS, SH, CS, HH, JK, AC, DM, and UH are employees of Bayer AG or Bayer AS. AS, SB, SH, CS, HH, and DM are shareholders of Bayer AG. PL, SH, JK, AC, and UH hold patents on targeted thorium-227 conjugates., (© Author(s) (or their employer(s)) 2021. Re-use permitted under CC BY-NC. No commercial re-use. See rights and permissions. Published by BMJ.)
- Published
- 2021
- Full Text
- View/download PDF
50. Darolutamide Potentiates the Antitumor Efficacy of a PSMA-targeted Thorium-227 Conjugate by a Dual Mode of Action in Prostate Cancer Models.
- Author
-
Hammer S, Schlicker A, Zitzmann-Kolbe S, Baumgart S, Hagemann UB, Scholz A, Haendler B, Lejeune P, Karlsson J, Ellingsen C, Hennekes H, Nielsen CH, Juul MU, Mumberg D, and Schatz CA
- Subjects
- Animals, Humans, Male, Mice, Drug Combinations, Models, Biological, Androgen Receptor Antagonists therapeutic use, Antigens, Surface drug effects, Glutamate Carboxypeptidase II drug effects, Prostatic Neoplasms drug therapy, Pyrazoles therapeutic use, Thorium therapeutic use
- Abstract
Purpose: Androgen receptor (AR) inhibitors are well established in the treatment of castration-resistant prostate cancer and have recently shown efficacy also in castration-sensitive prostate cancer. Although most patients respond well to initial therapy, resistance eventually develops, and thus, more effective therapeutic approaches are needed. Prostate-specific membrane antigen (PSMA) is highly expressed in prostate cancer and presents an attractive target for radionuclide therapy. Here, we evaluated the efficacy and explored the mode of action of the PSMA-targeted thorium-227 conjugate (PSMA-TTC) BAY 2315497, an antibody-based targeted alpha-therapy, in combination with the AR inhibitor darolutamide., Experimental Design: The in vitro and in vivo antitumor efficacy and mode of action of the combination treatment were investigated in preclinical cell line-derived and patient-derived prostate cancer xenograft models with different levels of PSMA expression., Results: Darolutamide induced the expression of PSMA in androgen-sensitive VCaP and LNCaP cells in vitro , and the efficacy of darolutamide in combination with PSMA-TTC was synergistic in these cells. In vivo , the combination treatment showed synergistic antitumor efficacy in the low PSMA-expressing VCaP and in the high PSMA-expressing ST1273 prostate cancer models, and enhanced efficacy in the enzalutamide-resistant KUCaP-1 model. The treatments were well tolerated. Mode-of-action studies revealed that darolutamide induced PSMA expression, resulting in higher tumor uptake of PSMA-TTC, and consequently, higher antitumor efficacy, and impaired PSMA-TTC-mediated induction of DNA damage repair genes, potentially contributing to increased DNA damage., Conclusions: These results provide a strong rationale to investigate PSMA-TTC in combination with AR inhibitors in patients with prostate cancer., (©2021 The Authors; Published by the American Association for Cancer Research.)
- Published
- 2021
- Full Text
- View/download PDF
Catalog
Discovery Service for Jio Institute Digital Library
For full access to our library's resources, please sign in.