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Machetanz K, Roegele M, Liebsch M, Oberle L, Weinbrenner E, Gorbachuk M, Wang SS, Tatagiba M, Naros G. Predictive value of facial motor-evoked potential and electromyography for facial motor function in vestibular schwannoma surgery. Acta Neurochir (Wien) 2024; 166:23. [PMID: 38240816 PMCID: PMC10799139 DOI: 10.1007/s00701-024-05927-0] [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] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/06/2023] [Accepted: 01/02/2024] [Indexed: 01/22/2024]
Abstract
PURPOSE Intraoperative neuromonitoring (IONM) aims to preserve facial nerve (FN) function during vestibular schwannoma (VS) surgery. However, current techniques such as facial nerve motor evoked potentials (FNMEP) or electromyography (fEMG) alone are limited in predicting postoperative facial palsy (FP). The objective of this study was to analyze a compound fEMG/FNMEP approach. METHODS Intraoperative FNMEP amplitude and the occurrence of fEMG-based A-trains were prospectively determined for the orbicularis oris (ORI) and oculi (OCU) muscle in 322 VS patients. Sensitivity and specificity of techniques to predict postoperative FN function were calculated. Confounding factors as tumor size, volume of intracranial air, or IONM duration were analyzed. RESULTS A relevant immediate postoperative FP was captured in 105/322 patients with a significant higher risk in large VS. While fEMG demonstrated a high sensitivity (77% and 86% immediately and 15 month postoperative, respectively) for identifying relevant FP, specificity was low. In contrast, FNMEP have a significantly higher specificity of 80.8% for predicting postoperative FP, whereas the sensitivity is low. A retrospective combination of techniques demonstrated still an incorrect prediction of FP in ~ 1/3 of patients. CONCLUSIONS FNMEP and fEMG differ in sensitivity and specificity to predict postoperative FP. Although a combination of IONM techniques during VS surgery may improve prediction of FN function, current techniques are still inaccurate. Further development is necessary to improve IONM approaches for FP prediction.
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Affiliation(s)
- Kathrin Machetanz
- Department of Neurosurgery and Neurotechnology, Eberhard Karls University, Hoppe-Seyler-Straße 3, 72076, Tuebingen, Germany.
| | - Martin Roegele
- Department of Neurosurgery and Neurotechnology, Eberhard Karls University, Hoppe-Seyler-Straße 3, 72076, Tuebingen, Germany
| | - Marina Liebsch
- Department of Neurosurgery and Neurotechnology, Eberhard Karls University, Hoppe-Seyler-Straße 3, 72076, Tuebingen, Germany
| | - Linda Oberle
- Department of Neurosurgery and Neurotechnology, Eberhard Karls University, Hoppe-Seyler-Straße 3, 72076, Tuebingen, Germany
| | - Eliane Weinbrenner
- Department of Neurosurgery and Neurotechnology, Eberhard Karls University, Hoppe-Seyler-Straße 3, 72076, Tuebingen, Germany
| | - Mykola Gorbachuk
- Department of Neurosurgery and Neurotechnology, Eberhard Karls University, Hoppe-Seyler-Straße 3, 72076, Tuebingen, Germany
| | - Sophie S Wang
- Department of Neurosurgery and Neurotechnology, Eberhard Karls University, Hoppe-Seyler-Straße 3, 72076, Tuebingen, Germany
| | - Marcos Tatagiba
- Department of Neurosurgery and Neurotechnology, Eberhard Karls University, Hoppe-Seyler-Straße 3, 72076, Tuebingen, Germany
| | - Georgios Naros
- Department of Neurosurgery and Neurotechnology, Eberhard Karls University, Hoppe-Seyler-Straße 3, 72076, Tuebingen, Germany
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Pinto V, Liebsch M. Technical note: pre-positioning lower limb SSEP during semi-sitting positioning in posterior fossa surgery- does it matter? J Clin Monit Comput 2023; 37:1627-1633. [PMID: 37351761 DOI: 10.1007/s10877-023-01041-1] [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: 09/07/2022] [Accepted: 05/30/2023] [Indexed: 06/24/2023]
Abstract
Intra-operative monitoring has been a crucial tool in modern neurosurgery as it allows to optimize surgical outcome whilst reducing neurological deficits. Somatosensory evoked potentials are routinely monitored in most spinal and brain surgeries due to providing invaluable information regarding the functional integrity of sensory pathways. The use of this neurophysiological technique is particular useful when positioning patients in semi-sitting position during posterior fossa surgery. However, there is general agreement within the intra-operative neuromonitoring community that either upper or lower limb SSEPs monitoring typically suffice. Nonetheless, we report a case study of a patient in whom lower limb SSEPs were independently affected from upper limb SSEPs during positioning. In this respect, we suggest that both upper and lower limb SSEPs monitoring should be considered during semi-sitting positioning in patients undergoing posterior fossa surgery.
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Affiliation(s)
- Vania Pinto
- Neurological Institute, Cleveland Clinic Abu Dhabi, Al Maryah Island, P.O. Box 112412, Abu Dhabi, UAE.
| | - Marina Liebsch
- Neurosurgery Department, Tübingen University Hospital, Tübingen, Germany
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3
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Machetanz K, Wiesinger L, Leao MT, Liebsch M, Trakolis L, Wang S, Gharabaghi A, Tatagiba M, Naros G. Interhemispheric differences in time-frequency representation of motor evoked potentials in brain tumor patients. Clin Neurophysiol 2021; 132:2780-2788. [PMID: 34583121 DOI: 10.1016/j.clinph.2021.07.024] [Citation(s) in RCA: 4] [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] [Received: 03/29/2021] [Revised: 07/10/2021] [Accepted: 07/27/2021] [Indexed: 10/20/2022]
Abstract
OBJECTIVE Conventional time-series parameters are unreliable descriptors of motor-evoked potentials (MEPs) in brain tumor patients. Frequency domain analysis is suggested to provide additional information about the status of the cortico-spinal motor system. Aim of the present study was to describe the time-frequency representation of MEPs and its relation to the motor performance. METHODS This study enrolled 17 consecutive brain tumor patients with impaired dexterity. After brain mapping of the affected (AH) and non-affected (NAH) hemisphere, TMS was applied to the hotspots of the abductor pollicis brevis muscles (APB). Using a Morlet wavelet approach, event-related spectral perturbation (ERSP) and inter-trial coherence (ITC) of the MEPs were calculated and compared to the Grooved Pegboard Test (GPT). Additionally, inter- and intra-subject reliability was assessed by the intraclass correlation coefficient (ICC). RESULTS MEPs were projecting to a frequency band between 30 and 400 Hz with a local maximum between 100 and 150 Hz. There was a significant ERSP and ITC reduction of the AH in comparison to the NAH. In contrast, no interhemispheric differences were depicted in the conventional time-series analysis. ERSP and ITC values correlated significantly with GPT results (r = 0.35 and r = 0.50). Time-frequency MEP description had good inter-and intra-subject reliability (ICC = 0.63). CONCLUSIONS Brain tumors affect corticospinal transmission resulting in a reduction of temporal and spectral MEP synchronization correlating with the dexterity performance. SIGNIFICANCE Time-frequency representation of MEPs provide additional information beyond conventional time-domain features.
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Affiliation(s)
- Kathrin Machetanz
- Neurosurgical Clinic, Department of Neurosurgery and Neurotechnology, Eberhard Karls University, Tuebingen, Germany; Institute for Neuromodulation and Neurotechnology, Department of Neurosurgery and Neurotechnology, Eberhard Karls University Tuebingen, Germany
| | - Lasse Wiesinger
- Neurosurgical Clinic, Department of Neurosurgery and Neurotechnology, Eberhard Karls University, Tuebingen, Germany
| | - Maria Teresa Leao
- Neurosurgical Clinic, Department of Neurosurgery and Neurotechnology, Eberhard Karls University, Tuebingen, Germany
| | - Marina Liebsch
- Neurosurgical Clinic, Department of Neurosurgery and Neurotechnology, Eberhard Karls University, Tuebingen, Germany
| | - Leonidas Trakolis
- Neurosurgical Clinic, Department of Neurosurgery and Neurotechnology, Eberhard Karls University, Tuebingen, Germany
| | - Sophie Wang
- Neurosurgical Clinic, Department of Neurosurgery and Neurotechnology, Eberhard Karls University, Tuebingen, Germany
| | - Alireza Gharabaghi
- Institute for Neuromodulation and Neurotechnology, Department of Neurosurgery and Neurotechnology, Eberhard Karls University Tuebingen, Germany
| | - Marcos Tatagiba
- Neurosurgical Clinic, Department of Neurosurgery and Neurotechnology, Eberhard Karls University, Tuebingen, Germany
| | - Georgios Naros
- Neurosurgical Clinic, Department of Neurosurgery and Neurotechnology, Eberhard Karls University, Tuebingen, Germany; Institute for Neuromodulation and Neurotechnology, Department of Neurosurgery and Neurotechnology, Eberhard Karls University Tuebingen, Germany.
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Maul K, Fieblinger D, Heppenheimer A, Kreutz J, Liebsch M, Luch A, Pirow R, Poth A, Strauch P, Dony E, Schulz M, Wolf T, Reisinger K. Validation of the hen's egg test for micronucleus induction (HETMN): Detailed protocol including scoring atlas, historical control data and statistical analysis. Mutagenesis 2021; 37:76-88. [PMID: 34313790 PMCID: PMC9071076 DOI: 10.1093/mutage/geab026] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/01/2021] [Accepted: 08/03/2021] [Indexed: 11/14/2022] Open
Abstract
A validation exercise of the hen's egg test for micronucleus induction (HET-MN) was finalised with a very good predictivity based on the analysis of micronuclei in peripheral erythrocytes of fertilised chicken eggs [1]. For transparency reasons this complementary publication provides further details on the assay especially as this was the first validation study in the field of genotoxicity testing involving the use of chicken eggs. Thus, the experimental protocol is described in detail and is complemented by a scoring atlas for microscopic analysis of blood cells. In addition, general characteristics of the test system, which is able to mirror the systemic availability of test compounds, are delineated: the test compound passes the egg membrane and is taken up by the blood vessels of the underlying chorioallantoic membrane. Subsequently, it is distributed by the circulating blood, metabolised by the developing liver and the yolk sac membrane, and finally excreted into the allantois, a bladder equivalent. In specific, the suitability of the test system for genotoxicity testing is shown by, inter alia, a low background DNA damage in a comprehensive historical control database. In addition, the state-of-the-art statistical method used to evaluate obtained data is delineated. It combines laboratory-specific effect threshold with the Umbrella-Williams test a statistical model also of interest for other genotoxicity test methods.
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Affiliation(s)
- K Maul
- German Federal Institute for Risk Assessment (BfR), Department of Chemical and Product Safety, Berlin, Germany
| | - D Fieblinger
- German Federal Institute for Risk Assessment (BfR), Department of Chemical and Product Safety, Berlin, Germany
| | - A Heppenheimer
- ICCR-Roßdorf GmbH (former: Harlan Cytotest Cell Research, Envigo CRS), Roßdorf, Germany
| | - J Kreutz
- Henkel AG & Co KGaA, Duesseldorf, Germany
| | - M Liebsch
- German Federal Institute for Risk Assessment (BfR), Department of Chemical and Product Safety, Berlin, Germany
| | - A Luch
- German Federal Institute for Risk Assessment (BfR), Department of Chemical and Product Safety, Berlin, Germany
| | - R Pirow
- German Federal Institute for Risk Assessment (BfR), Department of Chemical and Product Safety, Berlin, Germany
| | - A Poth
- ICCR-Roßdorf GmbH (former: Harlan Cytotest Cell Research, Envigo CRS), Roßdorf, Germany
| | - P Strauch
- ICCR-Roßdorf GmbH (former: Harlan Cytotest Cell Research, Envigo CRS), Roßdorf, Germany
| | - E Dony
- ICCR-Roßdorf GmbH (former: Harlan Cytotest Cell Research, Envigo CRS), Roßdorf, Germany
| | - M Schulz
- ICCR-Roßdorf GmbH (former: Harlan Cytotest Cell Research, Envigo CRS), Roßdorf, Germany
| | - T Wolf
- University of Osnabrueck, Osnabrueck, Germany
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Leao MT, Machetanz K, Sandritter J, Liebsch M, Stengel A, Tatagiba M, Naros G. Repetitive Transcranial Magnetic Stimulation for Tinnitus Treatment in Vestibular Schwannoma: A Pilot Study. Front Neurol 2021; 12:646014. [PMID: 33912127 PMCID: PMC8072380 DOI: 10.3389/fneur.2021.646014] [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] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/24/2020] [Accepted: 02/23/2021] [Indexed: 11/29/2022] Open
Abstract
Background: Vestibular schwannomas (VS) are brain tumors affecting the vestibulocochlear nerve. Thus, VS patients suffer from tinnitus (TN). While the pathophysiology is mainly unclear, there is an increasing interest in repetitive transcranial magnetic stimulation (rTMS) for TN treatment. However, the results have been divergent. In addition to the methodological aspects, the heterogeneity of the patients might affect the outcome. Yet, there is no study evaluating rTMS exclusively in VS-associated tinnitus. Thus, the present pilot study evaluates low-frequency rTMS to the right dorsolateral pre-frontal cortex (DLPFC) in a VS-associated tinnitus. Methods: This prospective pilot study enrolled nine patients with a monoaural VS-associated tinnitus ipsilateral to the tumor. Patients were treated with a 10-day rTMS regime (1 Hz, 100% RMT, 1,200 pulses, right DLPFC). The primary endpoint of the study was the reduction of TN distress (according to the Tinnitus Handicap Inventory, THI). The secondary endpoint was a reduction of TN intensity (according to the Tinnitus Matching Test, TMT) and the evaluation of factors predicting tinnitus outcome (i.e., hearing impairment, TN duration, type of tinnitus). Results: No complications or side effects occurred. There was one drop-out due to a non-responsiveness of the complaint. There was a significant acute effect of rTMS on the THI and TMT. However, there was no significant long-term effect after 4 weeks. While the THI failed to detect any clinically relevant acute effect of rTMS in 56% of the patients, TMT revealed a reduction of TN intensity for more than 20 in 89% and for more than 50 in 56% of the patients. Notably, the acute effect of rTMS was influenced by the TN type and duration. In general, patients with a tonal TN and shorter TN duration showed a better response to the rTMS therapy. Conclusion: The present pilot study is the first one to exclusively evaluate the effect of low-frequency rTMS to the right DLPFC in a VS-associated tinnitus. Our results prove the feasibility and the efficacy of rTMS in this patient cohort. There is a significant acute but a limited long-term effect. In addition, there is evidence that patients with a tonal tinnitus and shorter tinnitus duration might have the strongest benefit. A larger, randomized controlled study is necessary to prove these initial findings.
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Affiliation(s)
- Maria Teresa Leao
- Department of Neurosurgery and Neurotechnology, Eberhard Karls University, Tuebingen, Germany.,Section Psychooncology, Comprehensive Cancer Center Tuebingen-Stuttgart, University Hospital Tuebingen, Tuebingen, Germany
| | - Kathrin Machetanz
- Department of Neurosurgery and Neurotechnology, Eberhard Karls University, Tuebingen, Germany
| | - Joey Sandritter
- Department of Neurosurgery and Neurotechnology, Eberhard Karls University, Tuebingen, Germany
| | - Marina Liebsch
- Department of Neurosurgery and Neurotechnology, Eberhard Karls University, Tuebingen, Germany
| | - Andreas Stengel
- Section Psychooncology, Comprehensive Cancer Center Tuebingen-Stuttgart, University Hospital Tuebingen, Tuebingen, Germany.,Department of Psychosomatic Medicine and Psychotherapy, University Hospital Tuebingen, Tuebingen, Germany.,Charité Center for Internal Medicine and Dermatology, Department for Psychosomatic Medicine, Charité-Universitätsmedizin Berlin, Corporate Member of Freie Universität Berlin, Humboldt-Universität zu Berlin and Berlin Institute of Health, Berlin, Germany
| | - Marcos Tatagiba
- Department of Neurosurgery and Neurotechnology, Eberhard Karls University, Tuebingen, Germany
| | - Georgios Naros
- Department of Neurosurgery and Neurotechnology, Eberhard Karls University, Tuebingen, Germany
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Machetanz K, Gallotti AL, Leao Tatagiba MT, Liebsch M, Trakolis L, Wang S, Tatagiba M, Gharabaghi A, Naros G. Time-Frequency Representation of Motor Evoked Potentials in Brain Tumor Patients. Front Neurol 2021; 11:633224. [PMID: 33613426 PMCID: PMC7894199 DOI: 10.3389/fneur.2020.633224] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/24/2020] [Accepted: 12/21/2020] [Indexed: 12/27/2022] Open
Abstract
Background: The integrity of the motor system can be examined by applying navigated transcranial magnetic stimulation (nTMS) to the cortex. The corresponding motor-evoked potentials (MEPs) in the target muscles are mirroring the status of the human motor system, far beyond corticospinal integrity. Commonly used time domain features of MEPs (e.g., peak-to-peak amplitudes and onset latencies) exert a high inter-subject and intra-subject variability. Frequency domain analysis might help to resolve or quantify disease-related MEP changes, e.g., in brain tumor patients. The aim of the present study was to describe the time-frequency representation of MEPs in brain tumor patients, its relation to clinical and imaging findings, and the differences to healthy subject. Methods: This prospective study compared 12 healthy subjects with 12 consecutive brain tumor patients (with and without a paresis) applying nTMS mapping. Resulting MEPs were evaluated in the time series domain (i.e., amplitudes and latencies). After transformation into the frequency domain using a Morlet wavelet approach, event-related spectral perturbation (ERSP), and inter-trial coherence (ITC) were calculated and compared to diffusion tensor imaging (DTI) results. Results: There were no significant differences in the time series characteristics between groups. MEPs were projecting to a frequency band between 30 and 300 Hz with a local maximum around 100 Hz for both healthy subjects and patients. However, there was ERSP reduction for higher frequencies (>100 Hz) in patients in contrast to healthy subjects. This deceleration was mirrored in an increase of the inter-peak MEP latencies. Patients with a paresis showed an additional disturbance in ITC in these frequencies. There was no correlation between the CST integrity (as measured by DTI) and the MEP parameters. Conclusion: Time-frequency analysis may provide additional information above and beyond classical MEP time domain features and the status of the corticospinal system in brain tumor patients. This first evaluation indicates that brain tumors might affect cortical physiology and the responsiveness of the cortex to TMS resulting in a temporal dispersion of the corticospinal transmission.
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Affiliation(s)
- Kathrin Machetanz
- Neurosurgical Clinic, Department of Neurosurgery and Neurotechnology, Eberhard Karls University of Tuebingen, Tuebingen, Germany.,Department of Neurosurgery and Neurotechnology, Institute for Neuromodulation and Neurotechnology, Eberhard Karls University of Tuebingen, Tuebingen, Germany
| | - Alberto L Gallotti
- Department of Neurosurgery and Stereotactic Radiosurgery, Vita-Salute University, Milan, Italy
| | - Maria Teresa Leao Tatagiba
- Neurosurgical Clinic, Department of Neurosurgery and Neurotechnology, Eberhard Karls University of Tuebingen, Tuebingen, Germany
| | - Marina Liebsch
- Neurosurgical Clinic, Department of Neurosurgery and Neurotechnology, Eberhard Karls University of Tuebingen, Tuebingen, Germany
| | - Leonidas Trakolis
- Neurosurgical Clinic, Department of Neurosurgery and Neurotechnology, Eberhard Karls University of Tuebingen, Tuebingen, Germany
| | - Sophie Wang
- Neurosurgical Clinic, Department of Neurosurgery and Neurotechnology, Eberhard Karls University of Tuebingen, Tuebingen, Germany
| | - Marcos Tatagiba
- Neurosurgical Clinic, Department of Neurosurgery and Neurotechnology, Eberhard Karls University of Tuebingen, Tuebingen, Germany
| | - Alireza Gharabaghi
- Department of Neurosurgery and Neurotechnology, Institute for Neuromodulation and Neurotechnology, Eberhard Karls University of Tuebingen, Tuebingen, Germany
| | - Georgios Naros
- Neurosurgical Clinic, Department of Neurosurgery and Neurotechnology, Eberhard Karls University of Tuebingen, Tuebingen, Germany.,Department of Neurosurgery and Neurotechnology, Institute for Neuromodulation and Neurotechnology, Eberhard Karls University of Tuebingen, Tuebingen, Germany
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7
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Machetanz K, Trakolis L, Leão MT, Liebsch M, Mounts K, Bender B, Ernemann U, Gharabaghi A, Tatagiba M, Naros G. Neurophysiology-Driven Parameter Selection in nTMS-Based DTI Tractography: A Multidimensional Mathematical Model. Front Neurosci 2019; 13:1373. [PMID: 31920523 PMCID: PMC6930230 DOI: 10.3389/fnins.2019.01373] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/29/2019] [Accepted: 12/04/2019] [Indexed: 01/08/2023] Open
Abstract
Object: There is an increasing interest in preoperative diffusion tensor imaging-based fiber tracking (DTI-FT) to preserve function during surgeries in motor eloquent brain regions. However, DTI tractography is challenged by inherent presumptions during particular tracking steps [e.g., deterministic vs. probabilistic DTI, fractional anisotropy (FA) and fiber length (FL) thresholding] and the missing "ground truth" information. In the present study, we intended to establish an objective, neurophysiology-driven approach for parameter selection during DTI-FT of the corticospinal tract integrating both imaging and neurophysiological information. Methods: In ten patients with lesions in eloquent motor areas, preoperative navigated transcranial magnetic stimulation (nTMS) was performed, followed by individual deterministic DTI-FT from a grid of cortical seed points. We investigated over 300 combinations of FA and FL thresholds and applied subsequently a multidimensional mathematical modeling of this empirical data. Optimal DTI parameters were determined by the relationship between DTI-FT (i.e., number of fibers, NoF) and nTMS (i.e., amplitudes of motor-evoked potentials) results. Finally, neurophysiological DTI parameters and the resulting tractography were compared to the current standard approaches of deterministic DTI fiber tracking with a 75% and 50% FA and a FL threshold of 110 mm as well as with intraoperative direct cortical and subcortical stimulation. Results: There was a good goodness-of-fit for the mathematical model (r 2 = 0.68 ± 0 13; range: 0.59-0.97; n = 8) except of two cases. Neurophysiology-driven parameter selection showed a high correlation between DTI-FT and nTMS results (r = 0.73 ± 0.16; range: 0.38-0.93). In comparison to the standard approach, the mathematically calculated thresholds resulted in a higher NoF in 75% of patients. In 50% of patients this approach helped to clarify the exact tract location or to detect additional functional tracts, which were not identified by the standard approach. This was confirmed by direct cortical or subcortical stimulation. Conclusion: The present study evaluates a novel user-independent method to extract objective DTI-FT parameters that were completely based on neurophysiological data. The findings suggest that this method may improve the specificity and sensitivity of DTI-FT and thereby overcome the disadvantages of current approaches.
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Affiliation(s)
- Kathrin Machetanz
- Department of Neurosurgery, Eberhard Karls Universität Tübingen, Tübingen, Germany
| | - Leonidas Trakolis
- Department of Neurosurgery, Eberhard Karls Universität Tübingen, Tübingen, Germany
| | - Maria Teresa Leão
- Department of Neurosurgery, Eberhard Karls Universität Tübingen, Tübingen, Germany
| | - Marina Liebsch
- Department of Neurosurgery, Eberhard Karls Universität Tübingen, Tübingen, Germany
| | - Kristin Mounts
- Department of Neurosurgery, Eberhard Karls Universität Tübingen, Tübingen, Germany
| | - Benjamin Bender
- Department of Neuroradiology, Eberhard Karls Universität Tübingen, Tübingen, Germany
| | - Ulrike Ernemann
- Department of Neuroradiology, Eberhard Karls Universität Tübingen, Tübingen, Germany
| | - Alireza Gharabaghi
- Department of Neurosurgery, Eberhard Karls Universität Tübingen, Tübingen, Germany
| | - Marcos Tatagiba
- Department of Neurosurgery, Eberhard Karls Universität Tübingen, Tübingen, Germany
| | - Georgios Naros
- Department of Neurosurgery, Eberhard Karls Universität Tübingen, Tübingen, Germany
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Naros G, Sandritter J, Liebsch M, Ofori A, Rizk AR, Del Moro G, Ebner F, Tatagiba M. Predictors of Preoperative Tinnitus in Unilateral Sporadic Vestibular Schwannoma. Front Neurol 2017; 8:378. [PMID: 28824535 PMCID: PMC5541055 DOI: 10.3389/fneur.2017.00378] [Citation(s) in RCA: 9] [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] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/02/2017] [Accepted: 07/17/2017] [Indexed: 12/12/2022] Open
Abstract
Objective Nearly two-thirds of patients with vestibular schwannoma (VS) are reporting a significantly impaired quality of life due to tinnitus. VS-associated tinnitus is attributed to an anatomical and physiological damage of the hearing nerve by displacing growth of the tumor. In contrast, the current pathophysiological concept of non-VS tinnitus hypothesizes a maladaptive neuroplasticity of the central nervous system to a (hidden) hearing impairment resulting in a subjective misperception. However, it is unclear whether this concept fits to VS-associated tinnitus. This study aims to determine the clinical predictors of VS-associated tinnitus to ascertain the compatibility of both pathophysiological concepts. Methods This retrospective study includes a group of 478 neurosurgical patients with unilateral sporadic VS evaluated preoperatively regarding the occurrence of ipsilateral tinnitus depending on different clinical factors, i.e., age, gender, tumor side, tumor size (T1–T4 according to the Hannover classification), and hearing impairment (Gardner–Robertson classification, GR1–5), using a binary logistic regression. Results 61.8% of patients complain about a preoperative tinnitus. The binary logistic regression analysis identified male gender [OR 1.90 (1.25–2.75); p = 0.002] and hearing impairment GR3 [OR 1.90 (1.08–3.35); p = 0.026] and GR4 [OR 8.21 (2.29–29.50); p = 0.001] as positive predictors. In contrast, patients with large T4 tumors [OR 0.33 (0.13–0.86); p = 0.024] and complete hearing loss GR5 [OR 0.36 (0.15–0.84); p = 0.017] were less likely to develop a tinnitus. Yet, 60% of the patients with good clinical hearing (GR1) and 25% of patients with complete hearing loss (GR5) suffered from tinnitus. Conclusion These data are good accordance with literature about non-VS tinnitus indicating hearing impairment as main risk factor. In contrast, complete hearing loss appears a negative predictor for tinnitus. For the first time, these findings indicate a non-linear relationship between hearing impairment and tinnitus in unilateral sporadic VS. Our results suggest a similar pathophysiology in VS-associated and non-VS tinnitus.
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Affiliation(s)
- Georgios Naros
- Department of Neurosurgery, Eberhard Karls University, Tuebingen, Germany
| | - Joey Sandritter
- Department of Neurosurgery, Eberhard Karls University, Tuebingen, Germany
| | - Marina Liebsch
- Department of Neurosurgery, Eberhard Karls University, Tuebingen, Germany
| | - Alex Ofori
- Department of Neurosurgery, Eberhard Karls University, Tuebingen, Germany
| | - Ahmed R Rizk
- Department of Neurosurgery, Eberhard Karls University, Tuebingen, Germany
| | - Giulia Del Moro
- Department of Neurosurgery, Eberhard Karls University, Tuebingen, Germany.,Department of Neurosurgery, University of Padova, Padova, Italy
| | - Florian Ebner
- Department of Neurosurgery, Eberhard Karls University, Tuebingen, Germany
| | - Marcos Tatagiba
- Department of Neurosurgery, Eberhard Karls University, Tuebingen, Germany
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Kullmann M, Tatagiba M, Liebsch M, Feigl GC. Evaluation of the Predictive Value of Intraoperative Changes in Motor-Evoked Potentials of Caudal Cranial Nerves for the Postoperative Functional Outcome. World Neurosurg 2016; 95:329-334. [DOI: 10.1016/j.wneu.2016.07.078] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/23/2016] [Revised: 07/20/2016] [Accepted: 07/21/2016] [Indexed: 10/21/2022]
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10
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Naros G, Moro G, Leao T, Sandritter J, Rizk A, Liebsch M, Ebner F, Tatagiba M. Electrophysiological Evidence for Central Neuroplasticity of the Contralesional Ear in Patients with Unilateral Vestibular Schwannoma. Skull Base Surg 2016. [DOI: 10.1055/s-0036-1592485] [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: 10/21/2022]
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Mewes KR, Fischer A, Zöller NN, Laubach V, Bernd A, Jacobs A, van Rompay A, Liebsch M, Pirow R, Petersohn D. Catch-up validation study of an in vitro skin irritation test method based on an open source reconstructed epidermis (phase I). Toxicol In Vitro 2016; 36:238-253. [PMID: 27432483 DOI: 10.1016/j.tiv.2016.07.007] [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] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/15/2016] [Revised: 06/30/2016] [Accepted: 07/13/2016] [Indexed: 11/19/2022]
Abstract
We have developed a new in vitro skin irritation test based on an open source reconstructed epidermis (OS-REp) with openly accessible protocols for tissue production and test performance. Due to structural, mechanistic and procedural similarity, a blinded catch-up validation study for skin irritation according to OECD Performance Standards (PS) was conducted in three laboratories to promote regulatory acceptance, with OS-REp models produced at a single production site only. While overall sensitivity and predictive capacity met the PS requirements, overall specificity was only 57%. A thorough analysis of the test results led to the assumption that some of the false-positive classifications could have been evoked by volatile skin-irritating chemicals tested in the same culture plate as the non-irritants falsely predicted as irritants. With GC/MS and biological approaches the cross-contamination effect was confirmed and the experimental set-up adapted accordingly. Retesting of the affected chemicals with the improved experimental set-up and otherwise identical protocol resulted in correct classifications as non-irritants. Taking these re-test results into account, 93% overall sensitivity, 70% specificity and 82% accuracy was achieved, which is in accordance with the OECD PS. A sufficient reliability of the method was indicated by a within-laboratory-reproducibility of 85-95% and a between-laboratory-reproducibility of 90%.
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Affiliation(s)
- K R Mewes
- Henkel AG & Co. KGaA, Henkelstr. 67, 40589 Düsseldorf, Germany.
| | - A Fischer
- Henkel AG & Co. KGaA, Henkelstr. 67, 40589 Düsseldorf, Germany
| | - N N Zöller
- Goethe-University, Medical School, Department of Dermatology, Venereology and Allergology, Theodor-Stern-Kai 7, 60590 Frankfurt, Germany
| | - V Laubach
- Goethe-University, Medical School, Department of Dermatology, Venereology and Allergology, Theodor-Stern-Kai 7, 60590 Frankfurt, Germany
| | - A Bernd
- Goethe-University, Medical School, Department of Dermatology, Venereology and Allergology, Theodor-Stern-Kai 7, 60590 Frankfurt, Germany
| | - A Jacobs
- VITO NV Flemish Institute for Technological Research, Environmental Risk and Health Unit, Boeretang 200, 2400 Mol, Belgium
| | - A van Rompay
- VITO NV Flemish Institute for Technological Research, Environmental Risk and Health Unit, Boeretang 200, 2400 Mol, Belgium
| | - M Liebsch
- Bundesinstitut für Risikobewertung (BfR), Max-Dohrn-Straße 8-10, 10589 Berlin, Germany
| | - R Pirow
- Bundesinstitut für Risikobewertung (BfR), Max-Dohrn-Straße 8-10, 10589 Berlin, Germany
| | - D Petersohn
- Henkel AG & Co. KGaA, Henkelstr. 67, 40589 Düsseldorf, Germany
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12
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Affiliation(s)
- Florian Roser
- Department of Neurosurgery, Neurological Institute, Cleveland Clinic Abu Dhabi, UAE.
| | - Marina Liebsch
- Department of Neurosurgery, University Hospital Tübingen, Tübingen, Germany
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Cooper-Hannan R, Harbell JW, Coecke S, Balls M, Bowe G, Cervinka M, Clothier R, Hermann F, Klahm LK, de Lange J, Liebsch M, Vanparys P. The principles of good laboratory practice: application to in vitro toxicology studies. Altern Lab Anim 2014; 27:539-77. [PMID: 25487864 DOI: 10.1177/026119299902700410] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Affiliation(s)
- R Cooper-Hannan
- Qualitas, Danworth Lane, Hurstpierpoint, West Sussex BN6 9LN, UK
| | - J W Harbell
- Institute for In Vitro Science, 21 Firstfield Road, Suite 220, Gaithersburg, MD 20878, USA
| | - S Coecke
- ECVAM, Institute for Health and Consumer Protection, European Commission Joint Research Centre, 21020 Ispra, Italy
| | - M Balls
- ECVAM, Institute for Health and Consumer Protection, European Commission Joint Research Centre, 21020 Ispra, Italy
| | - G Bowe
- ECVAM, Institute for Health and Consumer Protection, European Commission Joint Research Centre, 21020 Ispra, Italy
| | - M Cervinka
- Charles University Faculty of Medicine, Simkova 870, Hradec Králové, Czech Republic
| | - R Clothier
- FRAME Alternatives Laboratory, University of Nottingham Medical School, Queen's Medical Centre, Nottingham NG7 2UH, UK
| | - F Hermann
- RCC Cytotest Cell Research, In den Leppsteinwiessen 19, 64380 Rossdorf, Germany
| | - L K Klahm
- Human and Environmental Safety Division, The Procter and Gamble Company, Cincinnati, OH, USA
| | - J de Lange
- ECVAM, Institute for Health and Consumer Protection, European Commission Joint Research Centre, 21020 Ispra, Italy
| | - M Liebsch
- ZEBET, BgVV, Diedersdorfer Weg 1, 12277 Berlin, Germany
| | - P Vanparys
- Genetic and In Vitro Toxicology, Janssen Pharmaceutica, Turnhoutse Weg 30, 2340 Beerse, Belgium
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Acioly MA, Liebsch M, de Aguiar PHP, Tatagiba M. Facial Nerve Monitoring During Cerebellopontine Angle and Skull Base Tumor Surgery: A Systematic Review from Description to Current Success on Function Prediction. World Neurosurg 2013; 80:e271-300. [DOI: 10.1016/j.wneu.2011.09.026] [Citation(s) in RCA: 63] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/25/2011] [Accepted: 09/06/2011] [Indexed: 11/17/2022]
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15
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Troeller S, Linsel G, Huettig N, Bauer M, Graebsch C, Smirnova L, Pirow R, Liebsch M, Berger-Preiß E, Kock H, Oertel A, Ritter D, Knebel J. Air/liquid interface (ALI) technique for toxicity testing of gaseous compounds on human lung cells. Toxicol Lett 2013. [DOI: 10.1016/j.toxlet.2013.05.271] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
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16
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Lepski G, Honegger J, Liebsch M, Sória MG, Narischat P, Ramina KF, Nägele T, Ernemann U, Tatagiba M. Safe resection of arteriovenous malformations in eloquent motor areas aided by functional imaging and intraoperative monitoring. Neurosurgery 2013; 70:276-88; discussion 288-9. [PMID: 21946511 DOI: 10.1227/neu.0b013e318237aac5] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/19/2022] Open
Abstract
BACKGROUND Arteriovenous malformations (AVMs) proximal to motor cortical areas or motor projection systems are challenging to manage because of the risk of severe sensory and motor impairment. Surgical indication in these cases therefore remains controversial. OBJECTIVE To propose a standardized approach for centrally situated AVMs based on functional imaging and intraoperative electrophysiological evaluation. METHODS We conducted a retrospective analysis of 15 patients who underwent surgical treatment for AVMs in motor cortical areas or proximal to motor projections. Preoperative assessment included functional magnetic resonance and 3-dimensional tractography. Operations were performed under continuous electrophysiological monitoring aided by direct brain stimulation. We identified critical bloody supply to the motor areas by temporary occluding the feeding vessels under electrophysiological monitoring. Clinical outcome was evaluated with the modified Rankin Scale. RESULTS Total resection was achieved in 12 cases, whereas electrophysiology limited total extirpation in 3 cases. A significant reduction of motor evoked potentials by up to 15% of the initial values was associated with good recovery of motor function; in contrast, the disappearance of potentials correlated with long-term impairment. The mean follow-up time was 13 months, and clinical assessments revealed overall functional improvement (P < .05). After surgery, 11 patients were asymptomatic or presented with only minor neurological deficits. CONCLUSION Surgical resection of AVMs in eloquent motor areas can be considered a safe option for selected cases when performed in conjunction with a detailed functional assessment. Possible selection criteria for surgical treatment are discussed in light of the presented clinical data.
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Affiliation(s)
- Guilherme Lepski
- Department of Neurosurgery, University Hospital of Tübingen, Tübingen, Baden-Württemberg, Germany.
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Lill C, Meissner E, Schjeide L, Schjeide BM, Liebsch M, Roehr J, Rouleau G, Hardiman O, Traynor B, Van den Berg L, Al-Chalabi A, Bertram L. Comprehensive Research Synopsis and Systematic Meta-Analyses in ALS Genetics: The ALSGene Database (P01.095). Neurology 2012. [DOI: 10.1212/wnl.78.1_meetingabstracts.p01.095] [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: 11/15/2022] Open
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18
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Peiser M, Tralau T, Heidler J, Api AM, Arts JHE, Basketter DA, English J, Diepgen TL, Fuhlbrigge RC, Gaspari AA, Johansen JD, Karlberg AT, Kimber I, Lepoittevin JP, Liebsch M, Maibach HI, Martin SF, Merk HF, Platzek T, Rustemeyer T, Schnuch A, Vandebriel RJ, White IR, Luch A. Allergic contact dermatitis: epidemiology, molecular mechanisms, in vitro methods and regulatory aspects. Current knowledge assembled at an international workshop at BfR, Germany. Cell Mol Life Sci 2011; 69:763-81. [PMID: 21997384 PMCID: PMC3276771 DOI: 10.1007/s00018-011-0846-8] [Citation(s) in RCA: 221] [Impact Index Per Article: 17.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/14/2011] [Revised: 08/29/2011] [Accepted: 09/20/2011] [Indexed: 12/13/2022]
Abstract
Contact allergies are complex diseases, and one of the important challenges for public health and immunology. The German ‘Federal Institute for Risk Assessment’ hosted an ‘International Workshop on Contact Dermatitis’. The scope of the workshop was to discuss new discoveries and developments in the field of contact dermatitis. This included the epidemiology and molecular biology of contact allergy, as well as the development of new in vitro methods. Furthermore, it considered regulatory aspects aiming to reduce exposure to contact sensitisers. An estimated 15–20% of the general population suffers from contact allergy. Workplace exposure, age, sex, use of consumer products and genetic predispositions were identified as the most important risk factors. Research highlights included: advances in understanding of immune responses to contact sensitisers, the importance of autoxidation or enzyme-mediated oxidation for the activation of chemicals, the mechanisms through which hapten-protein conjugates are formed and the development of novel in vitro strategies for the identification of skin-sensitising chemicals. Dendritic cell cultures and structure-activity relationships are being developed to identify potential contact allergens. However, the local lymph node assay (LLNA) presently remains the validated method of choice for hazard identification and characterisation. At the workshop the use of the LLNA for regulatory purposes and for quantitative risk assessment was also discussed.
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Affiliation(s)
- M. Peiser
- Department of Product Safety, German Federal Institute for Risk Assessment (BfR), Thielallee 88-92, 14195 Berlin, Germany
| | - T. Tralau
- Department of Product Safety, German Federal Institute for Risk Assessment (BfR), Thielallee 88-92, 14195 Berlin, Germany
| | - J. Heidler
- Department of Product Safety, German Federal Institute for Risk Assessment (BfR), Thielallee 88-92, 14195 Berlin, Germany
| | - A. M. Api
- Research Institute for Fragrance Materials, Hackensack, NJ USA
| | | | | | - J. English
- Nottingham University Hospitals, Nottingham, UK
| | - T. L. Diepgen
- Department of Social Medicine, Occupational and Environmental Dermatology, University of Heidelberg, Heidelberg, Germany
| | | | - A. A. Gaspari
- School of Medicine, University of Maryland, Baltimore, MD USA
| | - J. D. Johansen
- Department of Derma-allergology, Gentofte Hospital, University of Copenhagen, Copenhagen, Denmark
| | - A. T. Karlberg
- Department of Chemistry, Dermatochemistry and Skin Allergy, University of Gothenburg, Gothenburg, Sweden
| | - I. Kimber
- Faculty of Life Sciences, University of Manchester, Manchester, UK
| | | | - M. Liebsch
- Department of Experimental Toxicology and ZEBET, Center for Alternatives to Animal Testing, German Federal Institute for Risk Assessment (BfR), Berlin, Germany
| | - H. I. Maibach
- Department of Dermatology, University of California San Francisco, San Francisco, CA USA
| | - S. F. Martin
- Allergy Research Group, Department of Dermatology, University Medical Center Freiburg, Freiburg, Germany
| | - H. F. Merk
- Department of Dermatology and Allergology, University Hospitals Aachen, Aachen, Germany
| | - T. Platzek
- Department of Product Safety, German Federal Institute for Risk Assessment (BfR), Thielallee 88-92, 14195 Berlin, Germany
| | - T. Rustemeyer
- VU University Medical Center, Amsterdam, The Netherlands
| | - A. Schnuch
- Department of Dermatology, University of Göttingen, Göttingen, Germany
| | - R. J. Vandebriel
- National Institute for Public Health and the Environment, Bilthoven, The Netherlands
| | - I. R. White
- St. John’s Institute of Dermatology, St. Thomas’ Hospital, London, UK
| | - A. Luch
- Department of Product Safety, German Federal Institute for Risk Assessment (BfR), Thielallee 88-92, 14195 Berlin, Germany
- Department of Experimental Toxicology and ZEBET, Center for Alternatives to Animal Testing, German Federal Institute for Risk Assessment (BfR), Berlin, Germany
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19
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Feigl GC, Ritz R, Moraes M, Klein J, Ramina K, Gharabaghi A, Krischek B, Danz S, Bornemann A, Liebsch M, Tatagiba MS. Resection of malignant brain tumors in eloquent cortical areas: a new multimodal approach combining 5-aminolevulinic acid and intraoperative monitoring. J Neurosurg 2010; 113:352-7. [PMID: 19911888 DOI: 10.3171/2009.10.jns09447] [Citation(s) in RCA: 94] [Impact Index Per Article: 6.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
Abstract
OBJECT Several studies have revealed that the gross-total resection (GTR) of malignant brain tumors has a significant influence on patient survival. Frequently, however, GTR cannot be achieved because the borders between healthy brain and diseased tissue are blurred in the infiltration zones of malignant brain tumors. Especially in eloquent cortical areas, resection is frequently stopped before total removal is achieved to avoid causing neurological deficits. Interestingly, 5-aminolevulinic acid (5-ALA) has been shown to help visualize tumor tissue intraoperatively and, thus, can significantly improve the possibility of achieving GTR of primary malignant brain tumors. The aim of this study was to go one step further and evaluate the utility and limitations of fluorescence-guided resections of primary malignant brain tumors in eloquent cortical areas in combination with intraoperative monitoring based on multimodal functional imaging data. METHODS Eighteen patients with primary malignant brain tumors in eloquent areas were included in this prospective study. Preoperative neuroradiological examinations included MR imaging with magnetization-prepared rapid gradient echo (MPRAGE), functional MR, and diffusion tensor imaging sequences to visualize functional areas and fiber tracts. Imaging data were analyzed offline, loaded into a neuronavigational system, and used intraoperatively during resections. All patients received 5-ALA 6 hours before surgery. Fluorescence-guided tumor resections were combined with intraoperative monitoring and cortical as well as subcortical stimulation to localize functional areas and fiber tracts during surgery. RESULTS Twenty-five procedures were performed in 18 consecutive patients. In 24% of all surgeries, resection was stopped because a functional area or cortical tract was identified in the resection area or because motor evoked potential amplitudes were reduced in an area where fluorescent tumor cells were still seen intraoperatively. Grosstotal resection could be achieved in 16 (64%) of the surgeries with preservation of all functional areas and fiber tracts. In 2 patients presurgical hemiparesis became accentuated postoperatively, and 1 of these patients also suffered from a new homonymous hemianopia following a second resection. CONCLUSIONS The authors' first results show that tumor resections with 5-ALA in combination with intraoperative cortical stimulation have the advantages of both methods and, thus, provide additional safety for the neurosurgeon during resections of primary malignant brain tumors in eloquent areas. Nonetheless, more cases and additional studies are necessary to further prove the advantages of this multimodal strategy.
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Affiliation(s)
- Guenther C Feigl
- Department of Neurosurgery, University of Tuebingen Medical Center, Tuebingen, Germany.
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20
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Trauer S, Lademann J, Knorr F, Richter H, Liebsch M, Rozycki C, Balizs G, Büttemeyer R, Linscheid M, Patzelt A. Development of an in vitro modified skin absorption test for the investigation of the follicular penetration pathway of caffeine. Skin Pharmacol Physiol 2010; 23:320-7. [PMID: 20588083 DOI: 10.1159/000313514] [Citation(s) in RCA: 30] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/30/2009] [Accepted: 03/24/2010] [Indexed: 11/19/2022]
Abstract
The Organization for Economic Cooperation and Development (OECD) recommends caffeine as a reference substance for in vitro skin absorption tests using Franz diffusion cells (FDC). However, it has not been possible to investigate the follicular penetration pathway using this method until now. The aim of this study was to develop a technique to allow the examination of the follicular penetration pathway of a substance penetrating into the skin. The OECD standard method was therefore combined with the follicle closing technique (FCT), an established in vivo method. By using test skin of varying follicular densities, different penetration values were obtained for the test substance caffeine. The follicular penetration rate was determined by an indirect calculation after modifying the in vivo FCT for use in the in vitro FDC. This method is the first to allow the differentiation of penetration pathways by combining the OECD standard method (using the FDC) and the FCT. Caffeine showed a surprisingly high rate of penetration through the follicular shunts in vitro.
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Affiliation(s)
- S Trauer
- Center of Experimental and Applied Cutaneous Physiology, Department of Dermatology, Charité - Universitätsmedizin Berlin, Berlin, Germany
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21
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Acioly MA, Liebsch M, Carvalho CH, Gharabaghi A, Tatagiba M. Transcranial Electrocortical Stimulation to Monitor the Facial Nerve Motor Function During Cerebellopontine Angle Surgery. Oper Neurosurg (Hagerstown) 2010; 66:354-61; discussion 362. [DOI: 10.1227/01.neu.0000369654.41677.b7] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/19/2022] Open
Abstract
Abstract
OBJECTIVE
This study was conducted to investigate the success rate of using the facial motor evoked potential (FMEP) of orbicularis oculi and oris muscles for facial nerve function monitoring with use of a stepwise protocol, and its usefulness in predicting facial nerve outcome during cerebellopontine angle (CPA) surgeries.
METHODS
FMEPs were recorded intraoperatively from 60 patients undergoing CPA surgeries. Transcranial electrocortical stimulation (TES) was performed using corkscrew electrodes positioned at hemispheric montage (C3/C4 and CZ). The contralateral abductor pollicis brevis muscle was used as the control response. Stimulation was always applied contralaterally to the affected side using 1, 3, or 5 rectangular pulses ranging from 200 to 600 V with 50 μs of pulse duration and an interstimulus interval of 2 ms. Facial potentials were recorded from needles placed in the orbicularis oculi and oris muscles.
RESULTS
FMEP from the orbicularis oris and oculi muscles could be reliably monitored in 86.7% and 85% of the patients, respectively. The immediate postoperative facial function correlated significantly with the FMEP ratio in the orbicularis oculi muscle at 80% amplitude ratio (P = .037) and orbicularis oris muscle at 35% ratio (P = .000). FMEP loss was always related to postoperative facial paresis, although in different degrees.
CONCLUSION
FMEPs can be obtained reliably by using TES with 3 to 5 train pulses. Stable intraoperative FMEPs can predict a good postoperative outcome of facial function. However, further refinements of this technique are necessary to minimize artifacts and to make this method more reliable.
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Affiliation(s)
- Marcus André Acioly
- Department of Neurosurgery, University of Tübingen, Tübingen, Germany, and Department of Neurology, University of São Paulo, São Paulo, Brazil
| | - Marina Liebsch
- Department of Neurosurgery, University of Tübingen, Tübingen, Germany
| | | | | | - Marcos Tatagiba
- Department of Neurosurgery, University of Tübingen, Tübingen, Germany
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Abstract
Object
The current neurophysiological assessment of syringomyelia is inadequate. Early-stage syringomyelia is anatomically predisposed to affect decussating spinothalamic fibers that convey pain and sensation primarily. Silent periods have been proven to be a sensitive tool for detecting alterations in this pathway.
Methods
Thirty-seven patients with syringomyelia were included in this prospective study. Routine electrophysiological measurements were applied including somatosensory evoked potential (SSEP) and motor evoked potential (MEP) recordings for all extremities. The silent periods were recorded from the pollicis brevis muscle, and electrical stimuli were applied to the ipsilateral digiti II. To establish baseline values, the authors had 28 healthy controls undergo monitoring. Sensitivity and specificity values were statistically evaluated according to the main clinical symptoms (paresis, dissociative syndrome, and pain).
Results
All control individuals had normal silent periods in voluntarily activated muscle. In syringomyelia patients, the affected limb showed pathological silent periods with all symptoms (sensitivity 30–50%). Pain was the most specific symptom (90%), despite SSEP and MEP values that were within the normal range.
Conclusions
Silent period testing is a sensitive neurophysiological technique and an invaluable tool for preoperative assessment of syringomyelia. Silent periods are associated with early dysfunction of thin myelinated spinothalamic tract fibers, even when routine electrophysiological measurements still reveal normal values. Conduction abnormalities that selectively abolish the silent periods can distinguish between hydromyelia (a physiologically dilated central canal) and space-occupying syringomyelia.
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Affiliation(s)
| | | | | | - Klaus Dietz
- 2Medical Biometry, University of Tübingen, Germany
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Acioly de Sousa MA, Feigl G, Liebsch M, Tatagiba M. Monitoring of Facial Nerve Motor Function during Skull Base Surgery using Transcranial Electrocortical Stimulation. KLIN NEUROPHYSIOL 2008. [DOI: 10.1055/s-2008-1072972] [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: 10/21/2022]
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Kejlová K, Jírová D, Bendová H, Kandárová H, Weidenhoffer Z, Kolárová H, Liebsch M. Phototoxicity of bergamot oil assessed by in vitro techniques in combination with human patch tests. Toxicol In Vitro 2007; 21:1298-303. [PMID: 17669618 DOI: 10.1016/j.tiv.2007.05.016] [Citation(s) in RCA: 26] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/29/2006] [Accepted: 05/29/2007] [Indexed: 11/24/2022]
Abstract
The aim of this study was to clarify the differences in the phototoxicity of bergamot oil obtained from four different suppliers. Spectral and chemical analyses were performed to identify presence of photoactive compounds in the test samples. The phototoxicity was assessed in vitro by the 3T3 NRU phototoxicity test (PT) and subsequently in a phototoxicity test on reconstructed human skin model (H3D PT). Confirmatory photopatch tests in a group of volunteers were performed using the first non-phototoxic concentration determined in the H3D PT. The spectral and chemical analyses revealed, that two samples of bergamot oil exhibited a potential for photoactivation. These oils were subsequently classified as phototoxic in the 3T3 NRU PT, however, only on the basis of borderline results and depending on the solvent used. H3D PT revealed clear classifications, correlating well with the findings of spectral and chemical analysis. The test was, however, not yet capable of precise prediction of safe, non-phototoxic concentrations. Additional endpoints, e.g. interleukin determination might be employed to increase the sensitivity of the test. Although the study showed the usefulness of the tiered testing strategy, currently, the extrapolation of in vitro results to human situation may be performed only to a limited extent.
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Affiliation(s)
- K Kejlová
- National Reference Center for Cosmetics, National Institute of Public Health, Srobárova 48, 100 42 Prague 10, Czech Republic.
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Kandárová H, Richter H, Liebsch M, Lademann J. Stratum corneum architecture of reconstructed human skin models monitored by fluorescent confocal laser scanning microscopy. Laser Phys Lett 2007; 4:308-311. [DOI: 10.1002/lapl.200610107] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/17/2024]
Abstract
Fluorescence confocal scanning laser microscopy (CLSM) using a handheld scanner, was performed to visualize the microscopic architecture of stratum corneum (SC) of the three reconstructed human epidermal (RHE) models: EpiDermTM (MatTek Corporation, Ashland, MA), EPISKIN® (EPISKIN SNC, Lyon, France) and SkinEthic® (SkinEthic Laboratories, Nice, France). To compare the differences between the SC structure of the RHE models and human SC, experiments were also performed on normal human epidermis in vivo. Sodium fluorescein stained skin cultures and human skin were imaged continuously using the confocal laser microscope Stratum, Optiscan. Fluorescein was excited at 488 nm and the fluorescent emission was detected at > 505 nm. In each experiment, a series of representative images of each visualized layer of the RHE models and human SC was collected. Our early observations confirmed that the reconstructed human skin models closely resemble human SC. After improving the experimental conditions, the method might be used for studying the effects of topically applied compounds e.g. pharmaceuticals and cosmetic to the SC.
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Schreiber S, Mahmoud A, Vuia A, Rübbelke MK, Schmidt E, Schaller M, Kandárová H, Haberland A, Schäfer UF, Bock U, Korting HC, Liebsch M, Schäfer-Korting M. Reconstructed epidermis versus human and animal skin in skin absorption studies. Toxicol In Vitro 2005; 19:813-22. [PMID: 15913948 DOI: 10.1016/j.tiv.2005.04.004] [Citation(s) in RCA: 80] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/11/2004] [Revised: 04/06/2005] [Accepted: 04/08/2005] [Indexed: 11/16/2022]
Abstract
European chemical policy in general and the REACH initiative in particular will increase the number of chemical substances submitted to toxicological evaluation by several orders of magnitude compared to the current status. To limit animal exposure the resulting enormous increase in testing, however, asks for validated in vitro test systems. While the OECD favours in vitro testing for cutaneous absorption using viable human and animal skin (Guideline 428) the availability of viable human skin is already limited today. We present a comparison of various in vitro techniques suitable for routine skin absorption studies including commercially available reconstructed human epidermis which may be a reliable alternative to excised human and animal skin. In order to develop a protocol for the subsequent transfer to partner laboratories the experimental set-up was analysed stepwise using the OECD reference compounds caffeine and testosterone. Franz cell type, the donor and receptor media for hydrophilic/lipophilic substances, albumin and tensid addition, and storage conditions of the excised skins were systematically varied. A protocol has been developed which now allows to proceed to the pre-validation process.
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Affiliation(s)
- S Schreiber
- Institut für Pharmazie, Abteilung Pharmakologie und Toxikologie, Freie Universität Berlin, Königin-Luise-Str. 2+4, D-14195 Berlin, Germany
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Gerner I, Spielmann H, Hoefer T, Liebsch M, Herzler M. Regulatory use of (Q)SARs in toxicological hazard assessment strategies. SAR QSAR Environ Res 2004; 15:359-366. [PMID: 15669695 DOI: 10.1080/10629360412331297335] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/24/2023]
Abstract
In 2001, the European Commission published a policy statement ("White Paper") on future chemicals regulation and risk reduction that proposed the use of non-animal test systems and tailor-made testing approaches, including (Q)SARs, to reduce financial costs and the number of test animals employed. The authors have compiled a database containing data submitted within the EU chemicals notification procedure. From these data, (Q)SARs for the prediction of local irritation/corrosion and/or sensitisation potential were developed and published. These (Q)SARs, together with an expert system supporting their use, will be submitted for official validation and application within regulatory hazard assessment strategies. The main features are: two sets of structural alerts for the prediction of skin sensitisation hazard classification as defined by the European risk phrase R43, comprising 15 rules for chemical substructures deemed to be sensitising by direct action with cells or proteins, and three rules for substructures acting indirectly, i.e., requiring biochemical transformation; a decision support system (DSS) for the prediction of skin and/or eye lesion potential built from information extracted from our database. This DSS combines SARs defining reactive chemical substructures relevant for local lesions to be classified, and QSARs for the prediction of the absence of such a potential. The role of the BfR database, and (Q)SARs derived from it, in the use of current and future (EU) testing strategies for irritation and sensitisation is discussed.
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Affiliation(s)
- I Gerner
- Federal Institute for Risk Assessment (BfR), Thielallee 88-92, D-14195 Berlin, Germany
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Genschow E, Liebsch M, Halle W, Spielmann H. [Report on the ICCVAM workshop on in vitro methods for assessing acute systemic toxicity]. ALTEX 2001; 18:115-6. [PMID: 11378685] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 02/20/2023]
Abstract
It was suggested in the ICCVAM workshop that the Register of Cytotoxicity (RC), using in vitro cytotoxicity data to predict the in vivo starting doses, should be implemented into acute toxicity testing as soon as possible. The validity of the in vitro cytotoxicity data to establish appropriate starting doses for acute toxicity testing will be assessed experimentally. Secondly, in order to replace the use of animals in acute lethality testing a formal validation will be conducted in which the ability to predict rodent LD50 values and toxicity classes from cytotoxicity data will be evaluated.
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Klemm M, Genschow E, Pohl I, Barrabas C, Liebsch M, Spielmann H. [Permanent embryonic mouse germ cell-lines, an in vitro alternative to in vivo germ cell mutagenicity tests]. ALTEX 2001; 18:127-30. [PMID: 11378688] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 02/20/2023]
Abstract
Germ cell mutagenesis is required by the 7th amendment of the directive 67/548 EEC into the national regulations on existing chemicals. Officially accepted in vivo test systems for stage specific mutagenicity are the dominant lethal (DL) test and the specific locus test (SLT) in mice. An acceptable in vitro alternative designed to address germ cell mutagenesis and discriminate between male and female specific effects is not available at present. In order to offer a sensitive and predictive in vitro method to assess the genotoxic potential of chemical agents on male and female reproduction, we established primordial germ (PG) cell-derived permanent embryonic germ (EG) cell lines of the mouse (strain BALB/cJ). The differences in developmental sensitivity of the EG(3) cell line and differentiated fibroblast cells 3T3 were comparatively tested with cytotoxicity assay (MTT test ) and genotoxic studies (SCE-assay) under identical test conditions. The concentration-response curves reflected the female cell line EG(3) to be extremely sensitive concerning cytotoxic and genotoxic endpoints. Therefore this cell line was used to classify in vivo genotoxic and non-genotoxic test substances with different potential endpoints. Applying linear discriminant analysis three endpoints were identified for the correct classification (100%) of all test chemicals, namely the SCE(200) value (increase of 200% in the mean number of SCEs per metaphase spread) for EG(3) (3 hrs and 24 hrs assay) and the IC(5)0 value for EG(3) after 3 hrs of exposure to test chemicals.
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Affiliation(s)
- M Klemm
- ZEBET/ Bundesinstitut für gesundheitlichen Verbraucherschutz und Veterinärmedizin (BgVV), D-Berlin
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Abstract
As no scientific approach or regulatory guidelines existed for the experimental validation of in vitro toxicity tests, in 1990 a US/European validation workshop agreed in Amden (Switzerland) on a simple definition of the validation process. Several international validation studies failed, although they were conducted according to these recommendations. Taking into account the lessons learned from this experience, a second validation workshop was held by ECVAM in Amden in 1994 to develop a more precisely defined validation concept. Prevalidation and the development of biostatistically defined prediction models were added as essential elements to the validation process. In 1995/1996 the ECVAM validation procedure was officially accepted by EU member countries and at the international level by the US regulatory agencies and the OECD. The improved validation concept was immediately introduced into ongoing validation studies. In 1996 the ECVAM/COLIPA validation study of the in vitro phototoxicity test, which was conducted according to the ECVAM/OECD validation concept, was finished successfully and in 1998 a supporting study on UV-filter chemicals was undertaken. In 1998 the 3T3 NRU PT in vitro phototoxicity test was the first experimentally validated in vitro toxicity test that was recommended for regulatory purposes by ESAC, the ECVAM Scientific Advisory Committee, and by the DG ENV of the EU Commission. Meanwhile, two in vitro skin corrosivity tests have successfully been validated by ECVAM. Finally, in June 2000 the three experimentally validated tests were accepted by EU member states for regulatory purposes as the first in vitro toxicity tests. In addition, ECVAM has funded a successful validation study of three in vitro embryotoxicity tests, which was conducted in 12 European laboratories and finished in July 2000. The three tests validated in this study were the whole embryo culture (WEC) test applied to rat embryos, the micromass (MM) test employing primary cultures of dissociated mouse limb bud cells and the mouse embryonic stem cell test (EST). Examples will be given of successful validation studies during the past decade with particular reference to in vitro toxicity tests that were evaluated for regulatory purposes either by the US validation centre ICCVAM or ECVAM in the fields of sensitisation, phototoxicity and embryotoxicity
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Affiliation(s)
- H Spielmann
- National Centre for Documentation and Evaluation of Alternative Methods to Animal Experiments (ZEBET), Federal Institute for Health Protection of Consumers and Veterinary Medicine (BgVV), Berlin, Germany.
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Klemm M, Genschow E, Pohl I, Barrabas C, Liebsch M, Spielmann H. Permanent embryonic germ cell lines of BALB/cJ mice--an in vitro alternative for in vivo germ cell mutagenicity tests. Toxicol In Vitro 2001; 15:447-53. [PMID: 11566577 DOI: 10.1016/s0887-2333(01)00050-9] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
To offer a sensitive and predictive in vitro method to assess germ cell mutagenicity, we established primordial germ (PG) cell-derived permanent female and male embryonic germ (EG) cell lines of the mouse (strain BALB/cJ). The differences in developmental sensitivity of EG cells and differentiated fibroblast cells of the mouse cell line 3T3 to genotoxicants were tested comparatively under identical test conditions. Cytotoxicity assay was measured by the MTT test and genotoxic effects were determined by sister chromatid exchanges (SCE) rates induced by standard reference mutagens. Both methods are used to assign the chemicals to two classes of in vivo reproductive toxicity, non- and strongly genotoxic to germ cells. Applying linear discriminant analysis, a biostatistical prediction model (PM) was developed for the female cell line EG(3). This procedure identified a single variable, the Ig(SCE(200)EG(3)) as the statistically significant concentration related increase of 200% in the mean number of SCEs per metaphase spread after 3 h of exposure to be sufficient for separation into the classes: non- and strongly genotoxic to germ cells. Applying this PM to the training set of five genotoxic and three non-genotoxic test chemicals, 100% correct classifications were obtained.
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Affiliation(s)
- M Klemm
- Center for Documentation and Evaluation of Alternative Methods to Animal Experiments (ZEBET), Federal Institute for Health Protection of Consumers and Veterinary Medicine (BgVV), Berlin, Germany
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Halle W, Spielmann H, Liebsch M. [Prediction of human lethal concentrations by cytotoxicity data from 50 MEIC chemicals]. ALTEX 2001; 17:75-9. [PMID: 11085862] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 02/18/2023]
Abstract
Procedures for predicting human toxicity on the basis of cytotoxicity data for different chemicals are of current interest. The study was designed to clarify the possibility of predicting human toxicity by using the cytotoxicity values IC(50x) of the 50 MEIC chemicals listed in the Registry of Cytotoxicity (RC). All calculations with the data of cytotoxicity and in vivo toxicity were carried out uniformly by using standardised methods with the aim of comparing the results in the literature with each other. The following results were achieved: Firstly, the IC(50x) values in the RC are suited better for predicting human toxicity than IC(50) values determined in cell culture experiments with one cell type and one cytotoxic endpoint. This result is correct for the values of linear regression parameters as well as for the values of the prediction error (PE) defined by Ponsoda et al. (1997). Secondly, by using the geometrical mean of four lethal concentrations (LCx) - calculated from the tabulated lethal concentration (LC), lethal plasma concentration (LPC), clinical lethal concentration (CLC) and forensic lethal concentration (FLC) - the parameters for predicting the human toxicity were slightly improved. Moreover, these comparative examinations demonstrate that in all cases the cytotoxicity data are suited better for predicting acute animal toxicity than for predicting acute human toxicity. The results confirm, once more, the reliability and general validity of RC cytotoxicity data for examinations of different problems in cytotoxicology.
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Affiliation(s)
- W Halle
- Zentralstelle zur Erfassung und Bewertung von Ersatz- und Ergänzungsmethoden zum Tierversuch (ZEBET) im Bundesinstitut für gesundheitlichen Verbraucherschutz und Veterinärmedizin (BgVV), D-Berlin.
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Spielmann H, Müller L, Averbeck D, Balls M, Brendler-Schwaab S, Castell JV, Curren R, Gibbs NK, Liebsch M, Lovell WW, Merk HF, Nash JF, Neumann NJ, Pape WJ, Ulrich P, Vohr HW. The second ECVAM workshop on phototoxicity testing. The report and recommendations of ECVAM workshop 42. Altern Lab Anim 2000; 28:777-814. [PMID: 11105201 DOI: 10.1177/026119290002800603] [Citation(s) in RCA: 46] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Affiliation(s)
- H Spielmann
- ZEBET, BgVV, Diedersdorfer Weg 1, 12277 Berlin, Germany.
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Balls M, Berg N, Bruner LH, Curren RD, de Silva O, Earl LK, Esdaile DJ, Fentem JH, Liebsch M, Ohno Y, Prinsen MK, Spielmann H, Worth AP. Eye Irritation Testing: The Way Forward. The Report and Recommendations of ECVAM Workshop 34. Altern Lab Anim 1999; 27:53-77. [PMID: 25423402] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/04/2023]
Abstract
This is the report of the thirty-fourth of a series of workshops organised by the European Centre for the Validation of Alternative Methods (ECVAM). ECVAM's main goal, as defined in 1993 by its Scientific Advisory Committee, is to promote the scientific and regulatory acceptance of alternative methods which are of importance to the biosciences and which reduce, refine or replace the use of laboratory animals. One of the first priorities set by ECVAM was the implementation of procedures which would enable it to become well-informed about the state-of-the-art of non-animal test development and validation, and the potential for the possible incorporation of alternative tests into regulatory procedures. It was decided that this would be best achieved by the organisation of ECVAM workshops on specific topics, at which small groups of invited experts would review the current status of various types of in vitro tests and their potential uses, and make recommendations about the best ways forward (1). The workshop on Eye Irritation Testing: The Way Forward was held in Egham, UK, on 15-17 June 1998, under the chairmanship of Michael Balls (ECVAM, Italy). The workshop had two aims, the first of which was to review some of the previous multi-laboratory validation studies on alternatives to the Draize eye test and assess why many promising alternative methods were not successful in these studies. The second aim was to discuss strategies for making progress toward the short-term reduction, refinement, and eventual replacement, of the Draize test, including: a new approach to the validation of in vitro tests for eye irritancy, based on the use of reference standards, which promises to overcome some of the problems encountered in previous studies; the use of stepwise testing strategies which reduce and refine the use of animals in eye irritation testing; the use of multivariate and other statistical techniques for the further analysis of data generated in previous validation studies; and a programme of research aimed at understanding the underlying mechanisms of eye irritation.
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Affiliation(s)
- M Balls
- ECVAM, JRC Environment Institute, 21020 Ispra, Italy
| | - N Berg
- Novo Nordisk, Novo Alle, 2880 Bagsvaerd, Denmark
| | - L H Bruner
- Procter & Gamble (Health and Beauty Care), Lovett House, Lovett Road, Staines, Middlesex TW18 3AZ, UK
| | - R D Curren
- Institute for In Vitro Sciences, 21 Firstfield Road, Gaithersburg, MD 20878, USA
| | - O de Silva
- L'Oréal Recherche Avancée - Sciences du Vivant, 1 Avenue Eugène Schueller, 93601 Aulnay-sous-Bois Cedex, France
| | - L K Earl
- SEAC Toxicology Unit, Unilever Research, Colworth House, Sharnbrook, Bedford MK44 1LQ, UK
| | - D J Esdaile
- Rhône-Poulenc, 355 rue Dostoievski, 06903 Sophia Antipolis Cedex, France
| | - J H Fentem
- ECVAM, JRC Environment Institute, 21020 Ispra, Italy
| | - M Liebsch
- ZEBET, BgVV, Diedersdorfer Weg 1, 12277 Berlin, Germany
| | - Y Ohno
- Division of Pharmacology, Biological Safety Research Centre, National Institute of Health Sciences, 1-18-1 Kamiyoga, Setakaya-ku, Tokyo 158, Japan
| | - M K Prinsen
- TNO Nutrition and Food Research Institute, Division of Toxicology, 3700 AJ Zeist, The Netherlands
| | - H Spielmann
- ZEBET, BgVV, Diedersdorfer Weg 1, 12277 Berlin, Germany
| | - A P Worth
- ECVAM, JRC Environment Institute, 21020 Ispra, Italy
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Spielmann H, Balls M, Dupuis J, Pape WJ, de Silva O, Holzhütter HG, Gerberick F, Liebsch M, Lovell WW, Pfannenbecker U. A Study on UV Filter Chemicals from Annex VII of European Union Directive 76/768/EEC, in the In Vitro 3T3 NRU Phototoxicity Test. Altern Lab Anim 1998; 26:679-708. [PMID: 26042493] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/04/2023]
Abstract
In 1996, the Scientific Committee on Cosmetology of DGXXIV of the European Commission asked the European Centre for the Validation of Alternative Methods to test eight UV filter chemicals from the 1995 edition of Annex VII of Directive 76/768/EEC in a blind trial in the in vitro 3T3 cell neutral red uptake phototoxicity (3T3 NRU PT) test, which had been scientifically validated between 1992 and 1996. Since all the UV filter chemicals on the positive list of EU Directive 76/768/EEC have been shown not to be phototoxic in vivo in humans under use conditions, only negative effects would be expected in the 3T3 NRU PT test. To balance the number of positive and negative chemicals, ten phototoxic and ten non-phototoxic chemicals were tested under blind conditions in four laboratories. Moreover, to assess the optimum concentration range for testing, information was provided on appropriate solvents and on the solubility of the coded chemicals. In this study, the phototoxic potential of test chemicals was evaluated in a prediction model in which either the Photoirritation Factor (PIF) or the Mean Photo Effect (MPE) were determined. The results obtained with both PIF and MPE were highly reproducible in the four laboratories, and the correlation between in vitro and in vivo data was almost perfect. All the phototoxic test chemicals provided a positive result at concentrations of 1μ/ml, while nine of the ten non-phototoxic chemicals gave clear negative results, even at the highest test concentrations. One of the UV filter chemicals gave positive results in three of the four laboratories only at concentrations greater than 100μ/ml; the other laboratory correctly identified all 20 of the test chemicals. An analysis of the impact that exposure concentrations had on the performance of the test revealed that the optimum concentration range in the 3T3 NRU PT test for determining the phototoxic potential of chemicals is between 0.1μg/ml and 10μg/ml, and that false positive results can be obtained at concentrations greater than 100μg/ml. Therefore, the positive results obtained with some of the UV filter chemicals only at concentrations greater than 100μg/ml do not indicate a phototoxic potential in vivo. When this information was taken into account during calculation of the overall predictivity of the 3T3 NRU PT test in the present study, an almost perfect correlation of in vitro versus in vivo results was obtained (between 95% and 100%), when either PIF or MPE were used to predict the phototoxic potential. The management team and participants therefore conclude that the 3T3 NRU PT test is a valid test for correctly assessing the phototoxic potential of UV filter chemicals, if the defined concentration limits are taken into account.
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Affiliation(s)
| | - M Balls
- ECVAM, JRC Insitute of Health and Consumer Protection, Ispra, Italy
| | | | | | | | - H G Holzhütter
- Humboldt University Medical School, Institute of Biochemistry, Berlin, Germany
| | - F Gerberick
- The Procter and Gamble Company, Cincinnati, OH, USA
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Fentem J, Archer G, Balls M, Botham P, Curren R, Earl L, Esdaile D, Holzhütter HG, Liebsch M. The ECVAM International Validation Study on In Vitro Tests for Skin Corrosivity. 2. Results and Evaluation by the Management Team. Toxicol In Vitro 1998; 12:483-524. [DOI: 10.1016/s0887-2333(98)00019-8] [Citation(s) in RCA: 103] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 02/15/1998] [Indexed: 10/16/2022]
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Spielmann H, Balls M, Dupuis J, Pape W, Pechovitch G, de Silva O, Holzhütter HG, Clothier R, Desolle P, Gerberick F, Liebsch M, Lovell W, Maurer T, Pfannenbecker U, Potthast J, Csato M, Sladowski D, Steiling W, Brantom P. The International EU/COLIPA In Vitro Phototoxicity Validation Study: Results of Phase II (Blind Trial). Part 1: The 3T3 NRU Phototoxicity Test. Toxicol In Vitro 1998; 12:305-27. [DOI: 10.1016/s0887-2333(98)00006-x] [Citation(s) in RCA: 162] [Impact Index Per Article: 6.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 12/20/1997] [Indexed: 10/17/2022]
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Spielmann H, Liebsch M, Moldenhauer F, Holzhütter HG, Bagley DM, Lipman JM, Pape WJ, Miltenburger H, de Silva O, Hofer H, Steiling W. IRAG working group 2. CAM-based assays. Interagency Regulatory Alternatives Group. Food Chem Toxicol 1997; 35:39-66. [PMID: 9100814 DOI: 10.1016/s0278-6915(96)00103-2] [Citation(s) in RCA: 32] [Impact Index Per Article: 1.2] [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: 02/04/2023]
Abstract
CAM-based assays, in which test material is applied to the chorion allantoic membrane (CAM) of embryonated chicken eggs, were assessed as alternatives to the Draize eye irritation test. Two general types of CAM-based assays are currently in use, the HET-CAM test and the CAMVA assay. Evaluations were made of five data sets produced with three different modifications of the HET-CAM test and two data sets obtained with the same CAMVA protocol. Data sets consisted of 9-133 test chemicals, usually from the sponsor's product line, and also from a validation trial. Each data set and assay protocol were analysed for quality of data, purpose and proposed use of the assay, range of responses covered, range of test materials amenable, current use in safety and risk assessment both in-house and for regulatory purposes. Since the MMAS Draize score was not available for all in vivo data sets, the sigma MMMIS, which correlates well with the MMAS, was used instead. In vitro/in vivo correlations calculated with Pearson's linear coefficient ranged from r = 0.6 to r = 0.9 for six of seven data sets. Corneal opacity and inflammation of the iris showed the best correlation to in vitro data. Prediction rates were significantly improved when partial linear regression was used, and the predictivity of three different HET-CAM protocols was almost the same. HET-CAM assays showed the best prediction with surfactants and surfactant-based formulations, whereas the CAMVA assay provided the best performance with alcohols.
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Affiliation(s)
- H Spielmann
- ZEBET (National Centre for Documentation and Validation of Alternatives to Animal Experiments), BgVV (Federal Institute for Health Protection of Consumers and Veterinary Medicine), Berlin, Germany
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Spielmann H, Liebsch M, Moldenhauer F, Holzhutter HG, de Silva O. Modern biostatistical methods for assessing in vitro/in vivo correlation of severely eye irritating chemicals in a validation study of in vitro alternatives to the Draize eye test. Toxicol In Vitro 1995; 9:549-56. [DOI: 10.1016/0887-2333(95)00043-8] [Citation(s) in RCA: 17] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022]
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Liebsch M, Döring B, Donelly T, Logemann P, Rheins L, Spielmann H. application of the human dermal model skin2 ZK 1350 to phototoxicity and skin corrosivity testing. Toxicol In Vitro 1995; 9:557-62. [DOI: 10.1016/0887-2333(95)00042-7] [Citation(s) in RCA: 34] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022]
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Spielmann H, Liebsch M, Pape WJ, Balls M, Dupuis J, Klecak G, Lovell WW, Maurer T, De Silva O, Steiling W. EEC/COLIPA in vitro photoirritancy program: results of the first stage of validation. Curr Probl Dermatol 1995; 23:256-64. [PMID: 9035920 DOI: 10.1159/000424321] [Citation(s) in RCA: 18] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/03/2023]
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Edwards SM, Donnelly TA, Sayre RM, Rheins LA, Spielmann H, Liebsch M. Quantitative in vitro assessment of phototoxicity using a human skin model, Skin2. Photodermatol Photoimmunol Photomed 1994; 10:111-7. [PMID: 7947190] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 01/28/2023]
Abstract
The ability to accurately predict the phototoxic potential of personal and skin care products remains a key element in assessing the safety of premarketed products. To find a reliable in vitro alternative test for photoirritancy, the European Commission and the European Cosmetic Association are conducting a 3-year, European validation study. Based on the results of this study, an in vitro photoirritancy method will be selected for incorporation into new international guidelines for photoirritancy testing. As a part of this study, Skin2, a cultured human skin system, was used to evaluate the phototoxic potential of chemicals with known photoirritative properties. The Skin2 ZK1351, a 3-dimensional co-culture system, consists of dermal fibroblasts and a multilayered epidermis comprising differentiated keratinocytes. This product line has previously been used to evaluate the irritative potential of topically applied ingredients and products. In this study, various concentrations of the test chemicals were applied to the epidermal side of the Skin2 tissue for contact times of 1 h or 24 h and then the tissue was exposed to 2.9 J/cm2 of ultraviolet A (UVA) radiation. Treated but nonirradiated tissues were also assayed to predict the cytotoxic potential of the test chemicals, which could mask the phototoxic reaction. After exposure, the tissue substrates were rinsed free of test chemicals and allowed to recover for 24 h. Following this incubation, the MTT reduction assay was used to assess cytotoxicity.(ABSTRACT TRUNCATED AT 250 WORDS)
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Affiliation(s)
- S M Edwards
- Advanced Tissue Sciences, Inc., La Jolla, California 92037-1005
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Spielmann H, Kalweit S, Liebsch M, Wirnsberger T, Gerner I, Bertram-Neis E, Krauser K, Kreiling R, Miltenburger H, Pape W, Steiling W. Validation study of alternatives to the Draize eye irritation test in Germany: Cytotoxicity testing and HET-CAM test with 136 industrial chemicals. Toxicol In Vitro 1993; 7:505-10. [DOI: 10.1016/0887-2333(93)90055-a] [Citation(s) in RCA: 79] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
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Liebsch M, Becker W. Comparative glucose tolerance studies in the freshwater snail Biomphalaria glabrata: influence of starvation and infection with the trematode Schistosoma mansoni. J Comp Physiol B 1990; 160:41-50. [PMID: 2355116 DOI: 10.1007/bf00258761] [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: 12/31/2022]
Abstract
The dynamic reactions of B. glabrata on intravasal loads of 20-1000 micrograms glucose.g live fresh wt-1 were studied in standard fed snails (SFS). Starved snails (SS) and snails infected with S. mansoni (IS) were given 100-500 micrograms glucose.g fresh live wt-1. Mean hemolymph glucose level was 12.1 mg.100 ml-1 in SFS. It was not significantly lower in SS (10.7 mg.100 ml-1), but significantly reduced in IS (8.5 mg.100 ml-1). Since hemolymph volumes were significantly increased in SS, the amount of circulating glucose (pool) did not change (75 micrograms.g body weight-1) compared to SFS (62 micrograms.g-1). It was, however, reduced to 41 micrograms.g-1 in IS. In SFS the circulating glucose pool had to be doubled to induce significantly elimination of the injected glucose. Tripled pools were eliminated with half-times of 45 min, whereas lower and higher glucose loads were eliminated significantly slower (half-times: 80-105 min). Glucose tolerance of SS was reduced: half-times were doubled, and metabolization of injected glucose was reduced. Since tissue fresh weights were lowered by 40%, absolute incorporation of 14C from labeled glucose was lowered, but specific incorporation (per mg) was higher than in SFS and IS. Glucose tolerance of IS was increased: metabolic clearance rates rose by 70% and half-times were shortened by 30%, though absolute and specific rates of 14C incorporation were lowered. However, IS lost 25% of the label to the water, whereas SFS lost 12% and SS only lost 8%. Using the antimetabolite 2-deoxyglucose, 80% of the losses proved to be glucose in IS, and 50% in SFS. The present results suggest the existence of a glucostatic regulation in B. glabrata with lower sensitivity and capacity than in mammals. As to glucose tolerance, the often reported parallelism in metabolic shifts induced by starvation and parasitic infection was not confirmed.
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Affiliation(s)
- M Liebsch
- Zoologisches Institut und Museum der Universität Hamburg, Federal Republic of Germany
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