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Yao H, Wu Z, Gao SS, Guymer RH, Steffen V, Chen H, Hejrati M, Zhang M. Deep Learning Approaches for Detecting of Nascent Geographic Atrophy in Age-Related Macular Degeneration. Ophthalmol Sci 2024; 4:100428. [PMID: 38284101 PMCID: PMC10818248 DOI: 10.1016/j.xops.2023.100428] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 05/15/2023] [Revised: 10/31/2023] [Accepted: 11/08/2023] [Indexed: 01/30/2024]
Abstract
Purpose Nascent geographic atrophy (nGA) refers to specific features seen on OCT B-scans, which are strongly associated with the future development of geographic atrophy (GA). This study sought to develop a deep learning model to screen OCT B-scans for nGA that warrant further manual review (an artificial intelligence [AI]-assisted approach), and to determine the extent of reduction in OCT B-scan load requiring manual review while maintaining near-perfect nGA detection performance. Design Development and evaluation of a deep learning model. Participants One thousand eight hundred and eighty four OCT volume scans (49 B-scans per volume) without neovascular age-related macular degeneration from 280 eyes of 140 participants with bilateral large drusen at baseline, seen at 6-monthly intervals up to a 36-month period (from which 40 eyes developed nGA). Methods OCT volume and B-scans were labeled for the presence of nGA. Their presence at the volume scan level provided the ground truth for training a deep learning model to identify OCT B-scans that potentially showed nGA requiring manual review. Using a threshold that provided a sensitivity of 0.99, the B-scans identified were assigned the ground truth label with the AI-assisted approach. The performance of this approach for detecting nGA across all visits, or at the visit of nGA onset, was evaluated using fivefold cross-validation. Main Outcome Measures Sensitivity for detecting nGA, and proportion of OCT B-scans requiring manual review. Results The AI-assisted approach (utilizing outputs from the deep learning model to guide manual review) had a sensitivity of 0.97 (95% confidence interval [CI] = 0.93-1.00) and 0.95 (95% CI = 0.87-1.00) for detecting nGA across all visits and at the visit of nGA onset, respectively, when requiring manual review of only 2.7% and 1.9% of selected OCT B-scans, respectively. Conclusions A deep learning model could be used to enable near-perfect detection of nGA onset while reducing the number of OCT B-scans requiring manual review by over 50-fold. This AI-assisted approach shows promise for substantially reducing the current burden of manual review of OCT B-scans to detect this crucial feature that portends future development of GA. Financial Disclosures Proprietary or commercial disclosure may be found in the Footnotes and Disclosures at the end of this article.
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Affiliation(s)
- Heming Yao
- gRED Computational Science, Genentech, Inc., South San Francisco, California
| | - Zhichao Wu
- Centre for Eye Research Australia, Royal Victorian Eye and Ear Hospital, East Melbourne, Victoria, Australia
- Ophthalmology Division, Department of Surgery, The University of Melbourne, Melbourne, Victoria, Australia
| | - Simon S. Gao
- gRED Computational Science, Genentech, Inc., South San Francisco, California
| | - Robyn H. Guymer
- Centre for Eye Research Australia, Royal Victorian Eye and Ear Hospital, East Melbourne, Victoria, Australia
- Ophthalmology Division, Department of Surgery, The University of Melbourne, Melbourne, Victoria, Australia
| | - Verena Steffen
- gRED Computational Science, Genentech, Inc., South San Francisco, California
| | - Hao Chen
- gRED Computational Science, Genentech, Inc., South San Francisco, California
| | - Mohsen Hejrati
- gRED Computational Science, Genentech, Inc., South San Francisco, California
| | - Miao Zhang
- gRED Computational Science, Genentech, Inc., South San Francisco, California
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Chang DS, Callaway NF, Steffen V, Csaky K, Guymer RH, Birch DG, Patel PJ, Ip M, Gao SS, Briggs J, Honigberg L, Lai P, Ferrara D, Sepah YJ. Macular Sensitivity Endpoints in Geographic Atrophy: Exploratory Analysis of Chroma and Spectri Clinical Trials. Ophthalmol Sci 2024; 4:100351. [PMID: 37869030 PMCID: PMC10587617 DOI: 10.1016/j.xops.2023.100351] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 12/13/2022] [Revised: 06/02/2023] [Accepted: 06/06/2023] [Indexed: 10/24/2023]
Abstract
Purpose To assess different microperimetry (MP) macular sensitivity outcome measures capturing functional deterioration in eyes with geographic atrophy (GA) secondary to age-related macular degeneration (AMD). Design Patients were included from 2 identically designed, phase III, double-masked, randomized controlled clinical trials, Chroma (NCT02247479) and Spectri (NCT02247531). Participants Patients enrolled were aged ≥ 50 years with bilateral GA and no evidence of previous or active neovascular AMD. Methods Patients were randomized 2:1:2:1 to receive through 96 weeks intravitreal lampalizumab 10 mg every 4 weeks (LQ4W), every 6 weeks (LQ6W), or corresponding sham procedures. For this study, mesopic macular sensitivity of the central 20° was assessed using MP-1 microperimeter at selected sites. Main Outcome Measures Two exploratory endpoints were developed, namely perilesional sensitivity (average of points adjacent to absolute scotomatous points) and responding sensitivity (average of all nonscotomatous points; > 0 dB at baseline) by using customized masks for each patient. These were compared with conventional MP endpoints (mean macular sensitivity and number of absolute scotomatous points). Results Of 1881 Chroma and Spectri participants, 277 agreed to participate in the present study. Of these, 197 (LQ4W, n = 63; LQ6W, n = 68; pooled sham, n = 66) had reliable MP results. Enlargement of GA lesion area by approximately 2 mm2/year across treatment groups was accompanied by deterioration in all MP parameters. There was no difference in worsening of macular sensitivity or absolute scotomatous points among treatment groups. Perilesional and responding sensitivities showed greater decline over time than mean macular sensitivity. Change in GA lesion area at week 48 showed better correlation with perilesional sensitivity (r = -0.17) and responding sensitivity (r = -0.20) than mean macular sensitivity (r = -0.03), while the correlation was highest with the number of absolute scotomatous points (r = 0.37). Conclusions Perilesional or responding macular sensitivity measured by MP should be considered more sensitive endpoints than mean macular sensitivity for monitoring functional decline over time in GA. Although perilesional, responding, and mean macular sensitivity had weak correlation with GA lesion area, the number of absolute scotomatous points may provide additional information on the anatomic/functional correlation. Financial Disclosures Proprietary or commercial disclosure may be found after the references.
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Affiliation(s)
- Dolly S. Chang
- Genentech, Inc., South San Francisco, California
- Byers Eye Institute, Stanford University School of Medicine, Palo Alto, California
| | - Natalia F. Callaway
- Genentech, Inc., South San Francisco, California
- Byers Eye Institute, Stanford University School of Medicine, Palo Alto, California
| | | | - Karl Csaky
- Retina Foundation of the Southwest, Dallas, Texas
| | - Robyn H. Guymer
- Centre for Eye Research Australia, Royal Victorian Eye and Ear Hospital, University of Melbourne, Melbourne, Australia
| | | | - Praveen J. Patel
- NIHR Biomedical Research Centre at Moorfields Eye Hospital NHS Foundation Trust and UCL Institute of Ophthalmology, London, United Kingdom
| | - Michael Ip
- Doheny Eye Institute, University of California, Los Angeles, California
| | - Simon S. Gao
- Genentech, Inc., South San Francisco, California
| | - Jayla Briggs
- Genentech, Inc., South San Francisco, California
| | | | - Phillip Lai
- Genentech, Inc., South San Francisco, California
| | | | - Yasir J. Sepah
- Byers Eye Institute, Stanford University School of Medicine, Palo Alto, California
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Schmitz-Valckenberg S, Saßmannshausen M, Braun M, Steffen V, Gao SS, Honigberg L, Ferrara D, Pfau M, Holz FG. Interreader Agreement and Longitudinal Progression of Incomplete/Complete Retinal Pigment Epithelium and Outer Retinal Atrophy in Age-Related Macular Degeneration. Ophthalmol Retina 2023; 7:1059-1068. [PMID: 37517799 DOI: 10.1016/j.oret.2023.07.021] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/21/2023] [Revised: 07/14/2023] [Accepted: 07/24/2023] [Indexed: 08/01/2023]
Abstract
OBJECTIVE To analyze the ability to evaluate changes over time of individual lesions of incomplete or complete retinal pigment epithelium (RPE) and outer retinal atrophy (iRORA and cRORA, respectively) in patients with intermediate age-related macular degeneration (iAMD). DESIGN OCT images from patients enrolled in Proxima B clinical trial (NCT02399072) were utilized. PARTICIPANTS Patients enrolled in the Proxima B clinical trial, from the cohort with geographic atrophy (GA) in 1 eye and iAMD in the other eye at baseline, were included. METHODS Junior and senior readers analyzed OCT images for the qualitative presence of 9 distinct early atrophic features (presence of zone of choroidal hypertransmission, attenuation and/or disruption of RPE, disruption of ellipsoid zone [EZ] and external limiting membrane [ELM], outer nuclear layer [ONL] thinning, outer plexiform layer [OPL]/inner nuclear layer [INL] subsidence, and hyporeflective wedge-shaped band). If deemed "present," 7 features were quantified with a predefined tolerance level of 50 μm (diameter for the zone of choroidal hypertransmission, zone of attenuation and/or disruption of the RPE, outer retinal thickness left/right vertical diameter, outer retinal thickness thinnest vertical diameter, annotation of EZ, and ELM disruption). MAIN OUTCOME MEASURES Interreader agreements for qualitative assessments (κ-type statistics) and quantitative measurements (Bland-Altman statistics) were assessed. Progression of the lesion features over time was described. RESULTS Moderate agreement was found for presence of choroidal hypertransmission (κ = 0.54), followed by ELM disruption (κ = 0.58), OPL/INL subsidence (κ = 0.46), and a hyporeflective wedge-shaped band (κ = 0.47). Quantification measurements showed that choroidal hypertransmission had the highest agreement, whereas RPE attenuation/disruption had the lowest agreement. Longitudinal adjudicated changes for quantitative measurements of lesion progression showed that choroidal hypertransmission and ELM disruption showed significant progression, whereas EZ disruption and RPE attenuation/disruption did not. CONCLUSIONS The ability to evaluate changes over time for specific features of iRORA and cRORA was explored. The most robust biomarker was found to be choroidal hypertransmission, followed by ELM disruption and the qualitative markers of OPL/INL subsidence, as well as a wedge-shaped band. Disease progression over time could be assessed by some, but not all, spectral-domain OCT features that were explored. FINANCIAL DISCLOSURE(S) Proprietary or commercial disclosure may be found in the Footnotes and Disclosures at the end of this article.
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Affiliation(s)
- Steffen Schmitz-Valckenberg
- John A. Moran Eye Center, University of Utah, Salt Lake City, Utah; GRADE Reading Center and Department of Ophthalmology, University of Bonn, Germany.
| | | | - Martina Braun
- GRADE Reading Center and Department of Ophthalmology, University of Bonn, Germany
| | | | - Simon S Gao
- Genentech, Inc., South San Francisco, California
| | | | | | - Maximilian Pfau
- GRADE Reading Center and Department of Ophthalmology, University of Bonn, Germany; Institute of Molecular and Clinical Ophthalmology, Basel, Switzerland
| | - Frank G Holz
- GRADE Reading Center and Department of Ophthalmology, University of Bonn, Germany
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Spaide T, Jiang J, Patil J, Anegondi N, Steffen V, Kawczynski MG, Newton EM, Rabe C, Gao SS, Lee AY, Holz FG, Sadda S, Schmitz-Valckenberg S, Ferrara D. Geographic Atrophy Segmentation Using Multimodal Deep Learning. Transl Vis Sci Technol 2023; 12:10. [PMID: 37428131 DOI: 10.1167/tvst.12.7.10] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 07/11/2023] Open
Abstract
Purpose To examine deep learning (DL)-based methods for accurate segmentation of geographic atrophy (GA) lesions using fundus autofluorescence (FAF) and near-infrared (NIR) images. Methods This retrospective analysis utilized imaging data from study eyes of patients enrolled in Proxima A and B (NCT02479386; NCT02399072) natural history studies of GA. Two multimodal DL networks (UNet and YNet) were used to automatically segment GA lesions on FAF; segmentation accuracy was compared with annotations by experienced graders. The training data set comprised 940 image pairs (FAF and NIR) from 183 patients in Proxima B; the test data set comprised 497 image pairs from 154 patients in Proxima A. Dice coefficient scores, Bland-Altman plots, and Pearson correlation coefficient (r) were used to assess performance. Results On the test set, Dice scores for the DL network to grader comparison ranged from 0.89 to 0.92 for screening visit; Dice score between graders was 0.94. GA lesion area correlations (r) for YNet versus grader, UNet versus grader, and between graders were 0.981, 0.959, and 0.995, respectively. Longitudinal GA lesion area enlargement correlations (r) for screening to 12 months (n = 53) were lower (0.741, 0.622, and 0.890, respectively) compared with the cross-sectional results at screening. Longitudinal correlations (r) from screening to 6 months (n = 77) were even lower (0.294, 0.248, and 0.686, respectively). Conclusions Multimodal DL networks to segment GA lesions can produce accurate results comparable with expert graders. Translational Relevance DL-based tools may support efficient and individualized assessment of patients with GA in clinical research and practice.
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Affiliation(s)
- Theodore Spaide
- Roche Personalized Healthcare, Genentech, Inc., South San Francisco, CA, USA
| | - Jiaxiang Jiang
- Clinical Imaging Group, Genentech, Inc., South San Francisco, CA, USA
- Department of Electrical and Computer Engineering, University of California, Santa Barbara, Santa Barbara, CA, USA
| | - Jasmine Patil
- Clinical Imaging Group, Genentech, Inc., South San Francisco, CA, USA
| | - Neha Anegondi
- Roche Personalized Healthcare, Genentech, Inc., South San Francisco, CA, USA
- Clinical Imaging Group, Genentech, Inc., South San Francisco, CA, USA
| | - Verena Steffen
- Roche Personalized Healthcare, Genentech, Inc., South San Francisco, CA, USA
- Biostatistics, Genentech, Inc., South San Francisco, CA, USA
| | | | - Elizabeth M Newton
- Roche Personalized Healthcare, Genentech, Inc., South San Francisco, CA, USA
| | - Christina Rabe
- Roche Personalized Healthcare, Genentech, Inc., South San Francisco, CA, USA
- Biostatistics, Genentech, Inc., South San Francisco, CA, USA
| | - Simon S Gao
- Roche Personalized Healthcare, Genentech, Inc., South San Francisco, CA, USA
- Clinical Imaging Group, Genentech, Inc., South San Francisco, CA, USA
| | - Aaron Y Lee
- Department of Ophthalmology, University of Washington, School of Medicine, Seattle, WA, USA
| | - Frank G Holz
- Department of Ophthalmology and GRADE Reading Center, University of Bonn, Bonn, Germany
| | - SriniVas Sadda
- Doheny Eye Institute, Los Angeles, CA, USA
- Department of Ophthalmology, David Geffen School of Medicine at University of California, Los Angeles, Los Angeles, CA, USA
| | - Steffen Schmitz-Valckenberg
- Department of Ophthalmology and GRADE Reading Center, University of Bonn, Bonn, Germany
- John A. Moran Eye Center, University of Utah, Salt Lake City, UT, USA
| | - Daniela Ferrara
- Roche Personalized Healthcare, Genentech, Inc., South San Francisco, CA, USA
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Anegondi N, Gao SS, Steffen V, Spaide RF, Sadda SR, Holz FG, Rabe C, Honigberg L, Newton EM, Cluceru J, Kawczynski MG, Bengtsson T, Ferrara D, Yang Q. Deep Learning to Predict Geographic Atrophy Area and Growth Rate from Multimodal Imaging. Ophthalmol Retina 2023; 7:243-252. [PMID: 36038116 DOI: 10.1016/j.oret.2022.08.018] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/06/2022] [Revised: 08/04/2022] [Accepted: 08/22/2022] [Indexed: 11/16/2022]
Abstract
OBJECTIVE To develop deep learning models for annualized geographic atrophy (GA) growth rate prediction using fundus autofluorescence (FAF) images and spectral-domain OCT volumes from baseline visits, which can be used for prognostic covariate adjustment to increase power of clinical trials. DESIGN This retrospective analysis estimated GA growth rate as the slope of a linear fit on all available measurements of lesion area over a 2-year period. Three multitask deep learning models-FAF-only, OCT-only, and multimodal (FAF and OCT)-were developed to predict concurrent GA area and annualized growth rate. PARTICIPANTS Patients were from prospective and observational lampalizumab clinical trials. METHODS The 3 models were trained on the development data set, tested on the holdout set, and further evaluated on the independent test sets. Baseline FAF images and OCT volumes from study eyes of patients with bilateral GA (NCT02247479; NCT02247531; and NCT02479386) were split into development (1279 patients/eyes) and holdout (443 patients/eyes) sets. Baseline FAF images from study eyes of NCT01229215 (106 patients/eyes) and NCT02399072 (169 patients/eyes) were used as independent test sets. MAIN OUTCOME MEASURES Model performance was evaluated using squared Pearson correlation coefficient (r2) between observed and predicted lesion areas/growth rates. Confidence intervals were calculated by bootstrap resampling (B = 10 000). RESULTS On the holdout data set, r2 (95% confidence interval) of the FAF-only, OCT-only, and multimodal models for GA lesion area prediction was 0.96 (0.95-0.97), 0.91 (0.87-0.95), and 0.94 (0.92-0.96), respectively, and for GA growth rate prediction was 0.48 (0.41-0.55), 0.36 (0.29-0.43), and 0.47 (0.40-0.54), respectively. On the 2 independent test sets, r2 of the FAF-only model for GA lesion area was 0.98 (0.97-0.99) and 0.95 (0.93-0.96), and for GA growth rate was 0.65 (0.52-0.75) and 0.47 (0.34-0.60). CONCLUSIONS We show the feasibility of using baseline FAF images and OCT volumes to predict individual GA area and growth rates using a multitask deep learning approach. The deep learning-based growth rate predictions could be used for covariate adjustment to increase power of clinical trials. FINANCIAL DISCLOSURE(S) Proprietary or commercial disclosure may be found after the references.
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Affiliation(s)
- Neha Anegondi
- Clinical Imaging Group, Genentech, Inc., South San Francisco, California; Roche Ophthalmology Personalized Healthcare, Genentech, Inc., South San Francisco, California
| | - Simon S Gao
- Clinical Imaging Group, Genentech, Inc., South San Francisco, California; Roche Ophthalmology Personalized Healthcare, Genentech, Inc., South San Francisco, California
| | - Verena Steffen
- Roche Ophthalmology Personalized Healthcare, Genentech, Inc., South San Francisco, California; Biostatistics, Genentech, Inc., South San Francisco, California
| | - Richard F Spaide
- Vitreous Retina Macula Consultants of New York, New York, New York
| | - SriniVas R Sadda
- Doheny Eye Institute, Los Angeles, California; Department of Ophthalmology, David Geffen School of Medicine at University of California, Los Angeles, Los Angeles, California
| | - Frank G Holz
- Department of Ophthalmology and GRADE Reading Center, University of Bonn, Bonn, Germany
| | - Christina Rabe
- Roche Ophthalmology Personalized Healthcare, Genentech, Inc., South San Francisco, California; Biostatistics, Genentech, Inc., South San Francisco, California
| | - Lee Honigberg
- Roche Ophthalmology Personalized Healthcare, Genentech, Inc., South San Francisco, California; Biomarker Development, Genentech, Inc., South San Francisco, California
| | - Elizabeth M Newton
- Roche Ophthalmology Personalized Healthcare, Genentech, Inc., South San Francisco, California
| | - Julia Cluceru
- Clinical Imaging Group, Genentech, Inc., South San Francisco, California; Roche Ophthalmology Personalized Healthcare, Genentech, Inc., South San Francisco, California
| | - Michael G Kawczynski
- Roche Ophthalmology Personalized Healthcare, Genentech, Inc., South San Francisco, California; Data Science Imaging, Genentech, Inc., South San Francisco, California
| | - Thomas Bengtsson
- Roche Ophthalmology Personalized Healthcare, Genentech, Inc., South San Francisco, California; Data Science Imaging, Genentech, Inc., South San Francisco, California
| | - Daniela Ferrara
- Roche Ophthalmology Personalized Healthcare, Genentech, Inc., South San Francisco, California
| | - Qi Yang
- Roche Ophthalmology Personalized Healthcare, Genentech, Inc., South San Francisco, California; Data Science Imaging, Genentech, Inc., South San Francisco, California.
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Edmonds R, Steffen V, Honigberg LA, Chang MC. The Role of the Complement Pathway in Clinical Progression of Geographic Atrophy: Analysis of the Phase 3 Chroma and Spectri Trials. Ophthalmology Science 2023. [DOI: 10.1016/j.xops.2023.100301] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 03/31/2023]
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Rymut SM, Sukumaran S, Sperinde G, Bremer M, Galanter J, Yoshida K, Smith J, Banerjee P, Sverkos V, Cai F, Steffen V, Henderson LM, Rhee H, Belloni PN, Lin JH, Staton TL. Dose-dependent inactivation of airway tryptase with a novel dissociating anti-tryptase antibody (MTPS9579A) in healthy participants: A randomized trial. Clin Transl Sci 2021; 15:451-463. [PMID: 34581002 PMCID: PMC8841439 DOI: 10.1111/cts.13163] [Citation(s) in RCA: 13] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/15/2021] [Revised: 08/23/2021] [Accepted: 09/07/2021] [Indexed: 11/29/2022] Open
Abstract
Tryptase is the most abundant secretory granule protein in human lung mast cells and plays an important role in asthma pathogenesis. MTPS9579A is a novel monoclonal antibody that selectively inhibits tryptase activity by dissociating active tetramers into inactive monomers. The safety, tolerability, pharmacokinetics (PKs), and systemic and airway pharmacodynamics (PDs) of MTPS9579A were assessed in healthy participants. In this phase I single‐center, randomized, observer‐blinded, and placebo‐controlled study, single and multiple ascending doses of MTPS9579A were administered subcutaneously (s.c.) or intravenously (i.v.) in healthy participants. In addition to monitoring safety and tolerability, the concentrations of MTPS9579A, total tryptase, and active tryptase were quantified. This study included 106 healthy participants (82 on active treatment). Overall, MTPS9579A was well‐tolerated with no serious or severe adverse events. Serum MTPS9579A showed a dose‐proportional increase in maximum serum concentration (Cmax) values at high doses, and a nonlinear increase in area under the curve (AUC) values at low concentrations consistent with target‐mediated clearance were observed. Rapid and dose‐dependent reduction in nasosorption active tryptase was observed postdose, confirming activity and the PK/PD relationship of MTPS9579A in the airway. A novel biomarker assay was used to demonstrate for the first time that an investigative antibody therapeutic (MTPS9579A) can inhibit tryptase activity in the upper airway. A favorable safety and tolerability profile supports further assessment of MTPS9579A in asthma. Understanding the exposure‐response relationships using the novel PD biomarker will help inform clinical development, such as dose selection or defining patient subgroups.
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Affiliation(s)
- Sharon M Rymut
- Department of Clinical Pharmacology, Genentech, Inc., South San Francisco, California, USA
| | - Siddharth Sukumaran
- Department of Preclinical and Translational PKPD, Genentech, Inc., South San Francisco, California, USA
| | - Gizette Sperinde
- Department of BioAnalytical Sciences, Genentech, Inc., South San Francisco, California, USA
| | - Meire Bremer
- Department of Ophthalmology, Metabolism, Neurology, and Immunology Biomarker Development (OMNI-BD), Genentech, Inc., South San Francisco, California, USA
| | - Joshua Galanter
- Department of Safety Science, Genentech, Inc., South San Francisco, California, USA
| | - Kenta Yoshida
- Department of Clinical Pharmacology, Genentech, Inc., South San Francisco, California, USA
| | - Jordan Smith
- Department of Biostatistics, F. Hoffmann-La Roche, Mississauga, Ontario, Canada
| | - Prajna Banerjee
- Oncology Biomarker Development, Genentech, Inc., South San Francisco, California, USA
| | - Viyia Sverkos
- Department of BioAnalytical Sciences, Genentech, Inc., South San Francisco, California, USA
| | - Fang Cai
- Department of Ophthalmology, Metabolism, Neurology, and Immunology Biomarker Development (OMNI-BD), Genentech, Inc., South San Francisco, California, USA
| | - Verena Steffen
- Department of Biostatistics, Genentech, Inc., South San Francisco, California, USA
| | - Lindsay M Henderson
- Department of Clinical Pharmacology, Genentech, Inc., South San Francisco, California, USA
| | - Horace Rhee
- Early Clinical Development, Ophthalmology, Metabolism, Neurology, and Immunology (OMNI), Genentech, Inc., South San Francisco, California, USA
| | - Paula N Belloni
- Early Clinical Development, Ophthalmology, Metabolism, Neurology, and Immunology (OMNI), Genentech, Inc., South San Francisco, California, USA
| | - Joseph H Lin
- Early Clinical Development, Ophthalmology, Metabolism, Neurology, and Immunology (OMNI), Genentech, Inc., South San Francisco, California, USA
| | - Tracy L Staton
- Department of Ophthalmology, Metabolism, Neurology, and Immunology Biomarker Development (OMNI-BD), Genentech, Inc., South San Francisco, California, USA
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Schmitz-Valckenberg S, Braun MD, Thiele S, Ferrara D, Honigberg L, Gao SS, Chen H, Steffen V, Holz FG, Saßmannshausen M. Conversion from Intermediate Age-Related Macular Degeneration to Geographic Atrophy in a Proxima B Subcohort Using a Multimodal Approach. Ophthalmologica 2021; 244:523-534. [PMID: 34348335 DOI: 10.1159/000517881] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/10/2021] [Accepted: 06/06/2021] [Indexed: 11/19/2022]
Affiliation(s)
- Steffen Schmitz-Valckenberg
- GRADE Reading Center and Department of Ophthalmology, University of Bonn, Bonn, Germany
- John A. Moran Eye Center, University of Utah, Salt Lake City, Utah, USA
| | - Martina D Braun
- GRADE Reading Center and Department of Ophthalmology, University of Bonn, Bonn, Germany
| | - Sarah Thiele
- GRADE Reading Center and Department of Ophthalmology, University of Bonn, Bonn, Germany
| | | | - Lee Honigberg
- Genentech, Inc., South San Francisco, California, USA
| | - Simon S Gao
- Genentech, Inc., South San Francisco, California, USA
| | - Hao Chen
- Genentech, Inc., South San Francisco, California, USA
| | | | - Frank G Holz
- GRADE Reading Center and Department of Ophthalmology, University of Bonn, Bonn, Germany
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Lobato FS, Lima WJ, Borges RA, Cavalini AA, Steffen V. The solution of direct and inverse fractional advection–dispersion problems by using orthogonal collocation and differential evolution. Soft comput 2020. [DOI: 10.1007/s00500-019-04541-y] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/25/2022]
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Korepanova N, Seibold H, Steffen V, Hothorn T. Survival forests under test: Impact of the proportional hazards assumption on prognostic and predictive forests for amyotrophic lateral sclerosis survival. Stat Methods Med Res 2020; 29:1403-1419. [PMID: 31304888 DOI: 10.1177/0962280219862586] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
Abstract
We investigate the effect of the proportional hazards assumption on prognostic and predictive models of the survival time of patients suffering from amyotrophic lateral sclerosis. We theoretically compare the underlying model formulations of several variants of survival forests and implementations thereof, including random forests for survival, conditional inference forests, Ranger, and survival forests with L1 splitting, with two novel variants, namely distributional and transformation survival forests. Theoretical considerations explain the low power of log-rank-based splitting in detecting patterns in non-proportional hazards situations in survival trees and corresponding forests. This limitation can potentially be overcome by the alternative split procedures suggested herein. We empirically investigated this effect using simulation experiments and a re-analysis of the Pooled Resource Open-Access ALS Clinical Trials database of amyotrophic lateral sclerosis survival, giving special emphasis to both prognostic and predictive models.
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Affiliation(s)
- Natalia Korepanova
- International Laboratory for Intelligent Systems and Structural Analysis, Faculty of Computer Science, National Research University Higher School of Economics, Russia
| | - Heidi Seibold
- Institut für Statistik, Ludwig-Maximilians-Universität München, Germany
| | | | - Torsten Hothorn
- Institut für Epidemiologie, Biostatistik und Prävention, Universität Zürich, Switzerland
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Yang T, Dang Y, Ostaszewski B, Mengel D, Steffen V, Rabe C, Bittner T, Walsh DM, Selkoe DJ. Target engagement in an alzheimer trial: Crenezumab lowers amyloid β oligomers in cerebrospinal fluid. Ann Neurol 2019; 86:215-224. [PMID: 31168802 PMCID: PMC6771589 DOI: 10.1002/ana.25513] [Citation(s) in RCA: 55] [Impact Index Per Article: 11.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/22/2018] [Revised: 05/29/2019] [Accepted: 05/29/2019] [Indexed: 12/27/2022]
Abstract
OBJECTIVE Oligomeric forms of amyloid β protein (oAβ) are believed to be principally responsible for neurotoxicity in Alzheimer disease (AD), but it is not known whether anti-Aβ antibodies are capable of lowering oAβ levels in humans. METHODS We developed an ultrasensitive immunoassay and used it to measure oAβ in cerebrospinal fluid (CSF) from 104 AD subjects participating in the ABBY and BLAZE phase 2 trials of the anti-Aβ antibody crenezumab. Patients received subcutaneous (SC) crenezumab (300mg) or placebo every 2 weeks, or intravenous (IV) crenezumab (15mg/kg) or placebo every 4 weeks for 68 weeks. Ninety-eight of the 104 patients had measurable baseline oAβ levels, and these were compared to levels at week 69 in placebo (n = 28), SC (n = 35), and IV (n = 35) treated patients. RESULTS Among those receiving crenezumab, 89% of SC and 86% of IV patients had lower levels of oAβ at week 69 versus baseline. The difference in the proportion of patients with decreasing levels was significant for both treatment arms: p = 0.0035 for SC and p = 0.01 for IV crenezumab versus placebo. The median percentage change was -48% in the SC arm and -43% in the IV arm. No systematic change was observed in the placebo group, with a median change of -13% and equivalent portions with negative and positive change. INTERPRETATION Crenezumab lowered CSF oAβ levels in the large majority of treated patients tested. These results support engagement of the principal pathobiological target in AD and identify CSF oAβ as a novel pharmacodynamic biomarker for use in trials of anti-Aβ agents. ANN NEUROL 2019;86:215-224.
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Affiliation(s)
- Ting Yang
- Ann Romney Center for Neurologic Diseases, Department of NeurologyBrigham and Women's Hospital and Harvard Medical SchoolBostonMA
| | - Yifan Dang
- Ann Romney Center for Neurologic Diseases, Department of NeurologyBrigham and Women's Hospital and Harvard Medical SchoolBostonMA
| | - Beth Ostaszewski
- Ann Romney Center for Neurologic Diseases, Department of NeurologyBrigham and Women's Hospital and Harvard Medical SchoolBostonMA
| | - David Mengel
- Ann Romney Center for Neurologic Diseases, Department of NeurologyBrigham and Women's Hospital and Harvard Medical SchoolBostonMA
| | - Verena Steffen
- Genentech (a member of the Roche Group)South San FranciscoCA
| | - Christina Rabe
- Genentech (a member of the Roche Group)South San FranciscoCA
| | - Tobias Bittner
- Genentech (a member of the Roche Group)South San FranciscoCA
| | - Dominic M. Walsh
- Ann Romney Center for Neurologic Diseases, Department of NeurologyBrigham and Women's Hospital and Harvard Medical SchoolBostonMA
| | - Dennis J. Selkoe
- Ann Romney Center for Neurologic Diseases, Department of NeurologyBrigham and Women's Hospital and Harvard Medical SchoolBostonMA
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Steffen V, Otten J, Radek A, Wiechert W, Noack S, Pohl M. FRET-Based Biosensors for Online Measurement of Lysine Production. CHEM-ING-TECH 2016. [DOI: 10.1002/cite.201650264] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
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13
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Otten J, Steffen V, Pohl M, Wiechert W. Development of New FRET-Based Biosensors for Extracellular Metabolite Analysis. CHEM-ING-TECH 2016. [DOI: 10.1002/cite.201650356] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
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14
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Faccio G, Bannwarth MB, Schulenburg C, Steffen V, Jankowska D, Pohl M, Rossi RM, Maniura-Weber K, Boesel LF, Richter M. Encapsulation of FRET-based glucose and maltose biosensors to develop functionalized silica nanoparticles. Analyst 2016; 141:3982-4. [DOI: 10.1039/c5an02573g] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
Silicate nanoparticles with immobilized FRET-based biosensors were developed for the detection of glucose and maltose.
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Abstract
Abstract. Many organizations receive applications from people from different countries, and this is reflected in the research interest in cross-cultural differences in applicant reactions. The results of this research stream suggest only a minor role of country differences, but should be considered as preliminary in nature for several reasons. In particular, many studies have been conducted with students as hypothetical applicants, and assessment centers (ACs) have largely been neglected so far. Trying to overcome previous shortcomings, we examined applicant reactions to an AC conducted by the European Personnel Selection Office for selecting employees for European Union institutions. Applicants from eight European countries (N = 243) rated the AC on six reaction dimensions: measurement quality, face validity, controllability, absence of stress, good organization, and positive atmosphere. Reassuring for practitioners, results did again not suggest cross-cultural differences.
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16
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Steffen V, Cardozo-Filho L, Silva E, Evangelista L, Guirardello R, Mafra M. Equilibrium modeling of ion adsorption based on Poisson–Boltzmann equation. Colloids Surf A Physicochem Eng Asp 2015. [DOI: 10.1016/j.colsurfa.2014.11.065] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/24/2022]
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Yang T, Dang Y, Ostaszewski B, Mengel D, Steffen V, Rabe C, Bittner T, Walsh DM, Selkoe DJ. DT‐02‐03: TARGET ENGAGEMENT IN AN AD TRIAL: CRENEZUMAB LOWERS Aβ OLIGOMER LEVELS IN CSF. Alzheimers Dement 2006. [DOI: 10.1016/j.jalz.2018.07.012] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/28/2022]
Affiliation(s)
- Ting Yang
- Ann Romney Center for Neurologic DiseasesBrigham and Women's HospitalBostonMAUSA
| | - Yifan Dang
- Ann Romney Center for Neurologic DiseasesBrigham and Women's HospitalBostonMAUSA
| | - Beth Ostaszewski
- Ann Romney Center for Neurologic DiseasesBrigham and Women's HospitalBostonMAUSA
| | - David Mengel
- Ann Romney Center for Neurologic DiseasesBrigham and Women's HospitalBostonMAUSA
| | | | | | | | - Dominic M. Walsh
- Harvard Medical School/Ann Romney Center for Neurologic DiseasesBrigham and Women's HospitalBostonMAUSA
| | - Dennis J. Selkoe
- Harvard Medical School/Ann Romney Center for Neurologic DiseasesBrigham and Women's HospitalBostonMAUSA
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Abstract
Illness narratives have become a central issue in medical anthropology. Many researchers have made use of narratives as data in a meaning-centered approach, analysing personal illness accounts as a kind of coping strategy by which human beings ascribe cultural meaning to suffering. Often such narratives are being presented as clinical case stories or as patients' accounts told in interviews to a researcher. But apart from being methodologically created data personal stories also have their own life. They are a way of expressing experience, and as reality manifests itself as experience in us, stories are fundamental to human understanding. In many therapeutic groups personal stories are told as a way of sharing experience in order to solve common problems. This article focuses on the social and processual nature of personal narratives as they are presented in Alcoholics Anonymous (AA) groups. The article is based on a study of AA and Minnesota Model treatment of alcoholism in Denmark from 1990 to 1993. Various genres of personal narratives told at AA meetings are identified and analysed referring to individual as well as social and cultural levels. By focusing on interpersonal relationships and the creation of a shared identity in the groups, the article suggests that the ongoing telling of personal narratives in Alcoholics Anonymous takes place in a continuum between autobiography and myth. Thus, individual and collective experience are merged into the same therapeutic process.
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Affiliation(s)
- V Steffen
- Institute of Anthropology, University of Copenhagen, Denmark
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20
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de la Cruz CP, Revilla E, Steffen V, Rodríguez-Gómez JA, Cano J, Machado A. Protection of the aged substantia nigra of the rat against oxidative damage by (-)-deprenyl. Br J Pharmacol 1996; 117:1756-60. [PMID: 8732287 PMCID: PMC1909550 DOI: 10.1111/j.1476-5381.1996.tb15350.x] [Citation(s) in RCA: 23] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/01/2023] Open
Abstract
1. We have studied the effect of (-)-deprenyl on the oxidative damage that the rat substantia nigra suffers during aging. 2. (-)-Deprenyl (2 mg kg-1, three times a week) administered for two months, beginning at 22 months of age, produced a significant increase in tyrosine hydroxylase (TH) activity (2.67 +/- 0.40 and 3.64 +/- 0.38 nmol mg-1 protein h-1 in untreated aged rats and treated aged rats respectively, P < 0.05) and in TH amount (0.072 +/- 0.012 and 0.128 +/- 0.38 absorbance 405 nm in untreated aged and treated aged rats respectively, P < 0.05). 3. The proteins of aged rat substantia nigra showed a significant decrease of carbonyl groups in treated animals compared with saline-injected control rats (136.2 +/- 21.8 and 71.5 +/- 13.2 c.p.m. microgram-1 protein in untreated aged and treated aged rats respectively, P < 0.05). 4. The carbonyl groups measured in TH enzyme showed a statistically significant decrease (42.3%) after (-)-deprenyl treatment (471.4 +/- 73.0 and 271.9 +/- 50.00 c.p.m. in untreated aged and treated aged rats respectively, P < 0.001). 5. All these results suggest that oxidative damage produced during aging is prevented by (-)-deprenyl treatment and could explain the effect of this drug in Parkinson's disease (PD) and other degenerative diseases such as Alzheimer's disease.
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Affiliation(s)
- C P de la Cruz
- Departamento de Bioquímica, Bromatología y Toxicología, Facultad de Farmacia, Universidad de Sevilla, Spain
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21
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Steffen V, Santiago M, de la Cruz CP, Revilla E, Machado A, Cano J. Effect of intraventricular injection of 1-methyl-4-phenylpyridinium: protection by acetyl-L-carnitine. Hum Exp Toxicol 1995; 14:865-71. [PMID: 8588946 DOI: 10.1177/096032719501401102] [Citation(s) in RCA: 16] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/31/2023]
Abstract
1-methyl-4-phenylpyridinium (MPP+) is the bioactivated product of 1-methyl-4-phenyl- 1, 2, 3, 6-tetrahydropyridine (MPTP). The neurotoxic action of MPP+ injected intracerebroventricularly (ICV) in the rat has been studied, using dopaminergic systems in the substantia nigra, striatum, olfactory bulb, median eminence and hypophysis. The following results were obtained: (1) Rats with ICV administration of 1 microliter MPP+ solution (62.5 micrograms of MPP+ rat) showed 50% mortality; (2) The ICV administration of MPP+ produced a decrease in dopamine (DA) concentration in different areas of rat CNS studied: striatum (83%), hypophysis (95%) and median eminence (70%). However, olfactory bulb and substantia nigra were not affected; (3) MPP+ by ICV administration produced neurotoxic effect on the dopaminergic system. We also studied the possible protective action of acetyl-L-carnitine (ALC) against the neurotoxic action of MPP+. Rats were intraperitoneally injected daily for 8 days with 100 mg kg-1 of ALC and 3 days from the beginning of the MPP+ treatment; (4) We found that the ALC treatment significantly protected against mortality produced by the ICV injection of MPP+. Rats treated with ALC showed no mortality; (5) We did not find a protective effect on the dopaminergic system studying either catecholamine concentration or measuring tyrosine hydroxylase, neurofilament or glial fibrillary acid protein; (6) The results suggest that the ALC protective action could be related to energy metabolism.
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Affiliation(s)
- V Steffen
- Departamento de Bioquímica, Bromatología y Toxicología, Facultad de Farmacia, Universidad de Sevilla, Spain
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22
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Vizuete ML, Steffen V, Machado A, Cano J. 1-Methyl-4-phenylpyridinium has greater neurotoxic effect after selenium deficiency than after vitamin E deficiency in rat striatum. Eur J Pharmacol 1994; 270:183-7. [PMID: 8039547 DOI: 10.1016/0926-6917(94)90061-2] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/28/2023]
Abstract
The present study was designed to assess the extent of the protective effect of antioxidative capacity of dopaminergic neurons against the possible oxidative stress produced by 1-methyl-4-phenylpyridinium. We have studied the direct effect of 1-methyl-4-phenylpyridinium on striatum slices from rats fed with selenium-deficient or vitamin E-deficient diets for 30 days. Glutathione peroxidase activity decreased significantly after selenium dietary restriction. Our results showed that the effect of 1-methyl-4-phenylpyridinium on dopamine and its metabolites 3,4-dihydroxyphenylacetic acid, homovanillic homovanillic acid and 3-methoxytyramine in animals with both restriction diets was higher than in controls. However, this effect was significantly greater in animals with low selenium diets than with vitamin E-deficient diets in terms of dopamine, 3,4-dihydroxyphenylacetic acid and homovanillic acid, which were all significantly more depleted by 1-methyl-4-phenylpyridinium in selenium-deficient rats than in vitamin E-deficient rats. Therefore, considering changes in the levels of dopamine and its metabolites as an index of 1-methyl-4-phenylpyridinium toxicity, our results seem to indicate that the glutathione-glutathione peroxidase system has a greater protector effect than vitamin E.
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Affiliation(s)
- M L Vizuete
- Departamento de Bioquimica, Bromatologia y Toxicologia, Facultad de Farmacia, Sevilla, Spain
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23
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Steffen V, Vizuete ML, Machado A, Cano J. The effect of a vitamin E-deficient diet on amino acid levels in the substantia nigra, striatum and hippocampus of rats. Life Sci 1994; 54:375-9. [PMID: 8289599 DOI: 10.1016/0024-3205(94)00794-2] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/29/2023]
Abstract
The effects of a vitamin E deficiency diet for 15 days on amino acid concentrations have been studied in the substantia nigra, striatum and hippocampus of the rat. The substantia nigra showed an increase in glutamate and GABA and a decrease of tryptophan concentration compared with controls. In the striatum, aspartate and glycine decreased, no changes were found in the amino acid concentrations in the hippocampus. The substantia nigra and striatum showed opposite results-an increase and decrease of amino acids respectively. The increase of glutamate found in substantia nigra is particularly interesting as it may suggest possible links to degenerative processes. These results suggest that vitamin E could play a crucial role in substantia nigra degeneration and that the substantia nigra could be more sensitive to an oxidative stress than other brain structures.
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Affiliation(s)
- V Steffen
- Departamento de Bioquimica, Bromatologia y Toxicologia, Facultad de Farmacia, Universidad de Sevilla, Spain
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24
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Vizuete ML, de la Roza C, Steffen V, Machado A, Cano J. Changes in neurotransmitters in superior colliculus after neonatal enucleation: biochemical and immunocytochemical studies. Neuroscience 1993; 56:165-76. [PMID: 7901805 DOI: 10.1016/0306-4522(93)90571-v] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/27/2023]
Abstract
The turnover rate of dopamine and serotonin and the level of glutamate in superior colliculus are increased in adult, neonatally enucleated rats compared with normal control adult animals. Moreover, immunocytochemical data showed that the stratum zonale and the stratum griseum superficiale of the superior colliculus, specifically of bienucleated rats, display a dense network of serotonin-immunoreactive fibres, suggesting an increase in serotoninergic innervation. At the electron microscope level, serotonin-immunoreactive fibres and large postsynaptic serotonin-immunoreactive profiles exhibiting microtubules could be observed in the stratum zonale and the stratum griseum superficiale of the bienucleated rat. These results suggest that neonatal enucleation produces reorganization of serotoninergic and glutamatergic inputs. It is possible that serotonin may exert a profound influence upon collicular function.
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Affiliation(s)
- M L Vizuete
- Departamento de Bioquimica, Facultad de Farmacia, Universidad de Sevilla, Madrid
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25
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Abstract
Rats were treated with deprenyl for 3 weeks. Afterwards, slices of the corpus striatum were incubated with 1-methyl-4-phenylpyridinium ion (MPP+). Concentrations of dopamine and its metabolite concentrations were assayed. The effect of MPP+ in animals treated with deprenyl was smaller than in controls, indicating that deprenyl protects against MPP+. We also measured superoxide dismutase (SOD) and catalase activities and carbonyl group content of the proteins. Both activities increased in deprenyl-treated rats, and the amount of carbonyl groups was unchanged. These results suggest that the protective effect of deprenyl is independent of the monoamine oxidase-B inhibitor and of the induction of SOD and catalase activities.
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Affiliation(s)
- M L Vizuete
- Departamento de Bioquimica, Bromatologia y Toxicologia, Facultad de Farmacia, Universidad de Sevilla, Spain
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Vizuete ML, Steffen V, Machado A, Cano J. Effects of neonatal enucleation on catecholamine and serotonin turnover and amino acid levels in lateral geniculate nucleus and visual cortex of the adult rat. Brain Res 1992; 575:231-7. [PMID: 1373983 DOI: 10.1016/0006-8993(92)90084-m] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/26/2022]
Abstract
Changes in turnover of dopamine (DA), noradrenaline (NA) and serotonin (5-hydroxytryptamine (5-HT)) and their metabolites, together with amino acid content, have been studied in dorsal lateral geniculate nucleus (LGNd) and visual cortex (VC) of neonatal enucleated rats. Enucleation increases the 5-HT turnover in LGNd and catecholamine turnover in VC. In contrast, enucleation decreases glutamate (and/or aspartate) content in LGNd and gamma-aminobutyric acid (GABA) in VC. These changes suggest an increase of the inhibitory action of the biogenic amines in LGNd after neonatal enucleation. The decrease of GABA in VC may reflect the importance of GABA in intracortical circuitry.
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Affiliation(s)
- M L Vizuete
- Departamento de Bioquimica, Bromatologia y Toxicologia, Universidad de Sevilla, Spain
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Steffen V, Gordillo E, Castaño A, Cano J, Machado A. Age-dependent changes in the activity and isoenzymatic pattern of the phosphofructokinase in different areas of the central nervous systems. Neurosci Lett 1991; 125:15-8. [PMID: 1830378 DOI: 10.1016/0304-3940(91)90118-d] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/29/2022]
Abstract
Regional activity of phosphofructokinase enzyme and the amount of the isoenzyme C in 7 areas of young, adult and aged rats brain have been studied. The phosphofructokinase activity in substantia nigra decreased in adult and aged rats, but the maximum decrease was found in the septum of aged rats. There is a regional distribution of the isoenzyme C in the different areas studied. There was a general decrease in the amount of this isoenzyme in the areas studied with the exception of the hippocampus and the amygdala. The highest decrease was found in the septal area and in the diagonal band of Broca. These results are discussed in relation to the aging in different regions.
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Affiliation(s)
- V Steffen
- Departamento de Bioquimica, Bromatologia y Toxicologia, Facultad de Farmacia, Universidad de Sevilla, Spain
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Steffen V. [Illness and suffering. There is a way of saying--and understanding it]. Sygeplejersken 1988; 88:10-2. [PMID: 3252506] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 01/04/2023]
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Steffen V. [Incidence and value of extracardiac-induced cardiac arrhythmias and ECG changes]. Z Arztl Fortbild (Jena) 1982; 76:633-6. [PMID: 7180030] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 01/23/2023]
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Steffen V. [Incidence and significance of extracardially caused heart rhythm disorders and ECG changes]. Z Arztl Fortbild (Jena) 1982; 76:585-8. [PMID: 7136035] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 01/23/2023]
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Steffen V. [Incidence and significance of extracardially induced heart rhythm disorders and ECG changes. 1]. Z Arztl Fortbild (Jena) 1982; 76:533-7. [PMID: 7124019] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 01/23/2023]
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Steffen V, Fiehring H. [Bretylium tosylate as an anti-arrhythmic drug]. Z Gesamte Inn Med 1976; 31:913-9. [PMID: 798429] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 12/24/2022]
Abstract
With the help of an analysis of the world literature pharmacological, pharmacokinetic and electrophysiological properties as well as the possibilities of the clinico-therapeutic use of Bretylium tosylat are demonstrated. The pharmacon is of increasing interest as antiarrhytmic, especially in the commandment of otherwise therapy-refractory ventricular disturbances of rhythm. A positively inotropic effect is proved. More severe side effects, such as arterial hypotension and increase of the pulmonary vascular resistance have an objection to routine application. The antifibrillatory effect needs particular consideration. This effect might promote this pharmacon to the "chemical defibrillator" in the emergency situation.
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Steffen V, Assmann I, Fiehring H. [Clinical experiences with bretylium tosylate]. Z Gesamte Inn Med 1976; 31:684-8. [PMID: 793213] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 12/24/2022]
Abstract
Because of its antiarrhythmic and antifibrillatory qualities as well as its positively inotropic effect bretylium tosylate increasingly finds interest. The first results of a clinical and haemodynamical mechanocardiographic investigation with bretylium tosylate are presented. In doses between 1.6 and 6.2 mg/kg body weight intravenously and intramuscularly after an initial increase of blood pressure a clear decrease of the systolic system blood pressure develops. The resistance of the peripheral vessels decreases by 10 to 20%. It is an increase of the heart index and the stroke volume index by 10 to 30% to be proved as an expression of a positively inotropic effect. In orientating investigations the antiarrhythmic effect could be confirmed. The side-effects observed cause us to give a strong indication and to observe the patients carefully. The main area of application of bretylium tosylate might be seen in the possibility to achieve a pharmacological defibrillation of the ventricles.
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Steffen V, Fiehring H, Kulick B, Schaedel H. [Possibilities of a routine prevention of arrhythmia in the early phase of acute myocardial infarct]. Z Gesamte Inn Med 1975; 30:193-4 concl. [PMID: 1202763] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 12/26/2022]
Abstract
The frequency of the electric heart death in the early phase of the acute myocardial infarction demands a prophylactic use of antiarrhythmic remedies. In a guarded ward for coronary diseases since 1972 all patients with a fresh myocardial infarction or suspicion of infarction were treated with a continuous intravenous lidocain drip in a dosage of 100 mg/per hour for 48 hours. In 266 patients in a certain examination period ventricular fibrillation was observed only once and ventricular tachycardias twice. In accordance with literary data the prophylatic medication of lidocain gives an effective defence against threatening disturbances of the ventricular rhythm. The indications for a passagere electrostimulation in bradycardiac disturbances of rhythm associated with acute myocardial infarction are demonstrated.
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Teichmann W, Krosch H, Rikirsch P, Weser C, Steffen V. [Forms of organization of the medical care and therapy choices in the prehospital phase of acute myocardial infarct]. Z Arztl Fortbild (Jena) 1975; 69:373-5. [PMID: 1221645] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 12/26/2022]
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Steffen V, Fiehring H. [Prevention and treatment of drug-induced arrhythmia in acute myocardial infarct]. Z Gesamte Inn Med 1972; 27:875-81. [PMID: 4405247] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 01/10/2023]
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Assmann I, Fiehring H, Dittrich P, Steffen V, Assmann H. [Diastolic murmurs in idiopathic hypertrophic subaortal stenosis]. Dtsch Gesundheitsw 1972; 27:1788-91. [PMID: 4673790] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 01/11/2023]
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