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Bolon B, Gary JM. Toxicologic Pathology Forum Opinion: Apoptosis/Single Cell Necrosis as a Possible Procedural Effect in Primate Brain Following Ice-Cold Saline Perfusion. Toxicol Pathol 2024:1926233241247044. [PMID: 38661106 DOI: 10.1177/01926233241247044] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 04/26/2024]
Abstract
Nonclinical studies of test articles (TAs) in nonhuman primates are often designed to assess both biodistribution and toxicity. For this purpose, studies commonly use intravenous perfusion of ice-cold (2°C-8°C) saline to facilitate measurements of TA-associated nucleic acids and proteins, after which tissues undergo later fixation by immersion for histological processing and microscopic evaluation. Intriguingly, minimal apoptosis/single cell necrosis (A/SCN) of randomly distributed neural cells is evident in the cerebral cortex and less often the hippocampus in animals from all groups, including vehicle-treated controls. Affected cells exhibit end-stage features such as cytoplasmic hypereosinophilia, nuclear condensation or fragmentation, and shape distortions, so their lineage(s) generally cannot be defined; classical apoptotic bodies are exceedingly rare. In addition, A/SCN is not accompanied by glial reactions, leukocyte infiltration/inflammation, or other parenchymal changes. The severity is minimal in controls but may be slightly exacerbated (to mild) by TA that accumulate in neural cells. One plausible hypothesis explaining this A/SCN exacerbation is that cold shock (perhaps complicated by concurrent tissue acidity and hypoxia) drives still-viable but TA-stressed cells to launch a self-directed death program. Taken together, these observations indicate that A/SCN in brain processed by cold saline perfusion with delayed immersion fixation represents a procedural artifact and not a TA-related lesion.
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Mirizzi G, Jelke F, Pilot M, Klein K, Klamminger GG, Gérardy JJ, Theodoropoulou M, Mombaerts L, Husch A, Mittelbronn M, Hertel F, Kleine Borgmann FB. Impact of Formalin- and Cryofixation on Raman Spectra of Human Tissues and Strategies for Tumor Bank Inclusion. Molecules 2024; 29:1167. [PMID: 38474679 DOI: 10.3390/molecules29051167] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/28/2024] [Revised: 02/25/2024] [Accepted: 03/02/2024] [Indexed: 03/14/2024] Open
Abstract
Reliable training of Raman spectra-based tumor classifiers relies on a substantial sample pool. This study explores the impact of cryofixation (CF) and formalin fixation (FF) on Raman spectra using samples from surgery sites and a tumor bank. A robotic Raman spectrometer scans samples prior to the neuropathological analysis. CF samples showed no significant spectral deviations, appearance, or disappearance of peaks, but an intensity reduction during freezing and subsequent recovery during the thawing process. In contrast, FF induces sustained spectral alterations depending on molecular composition, albeit with good signal-to-noise ratio preservation. These observations are also reflected in the varying dual-class classifier performance, initially trained on native, unfixed samples: The Matthews correlation coefficient is 81.0% for CF and 58.6% for FF meningioma and dura mater. Training on spectral differences between original FF and pure formalin spectra substantially improves FF samples' classifier performance (74.2%). CF is suitable for training global multiclass classifiers due to its consistent spectrum shape despite intensity reduction. FF introduces changes in peak relationships while preserving the signal-to-noise ratio, making it more suitable for dual-class classification, such as distinguishing between healthy and malignant tissues. Pure formalin spectrum subtraction represents a possible method for mathematical elimination of the FF influence. These findings enable retrospective analysis of processed samples, enhancing pathological work and expanding machine learning techniques.
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Affiliation(s)
- Giulia Mirizzi
- National Department of Neurosurgery, Centre Hospitalier de Luxembourg (CHL), 1210 Luxembourg, Luxembourg
- Saarland University Medical Center and Faculty of Medicine, 66421 Homburg, Germany
| | - Finn Jelke
- National Department of Neurosurgery, Centre Hospitalier de Luxembourg (CHL), 1210 Luxembourg, Luxembourg
- Saarland University Medical Center and Faculty of Medicine, 66421 Homburg, Germany
- Department of Cancer Research (DoCR), Luxembourg Institute of Health (LIH), 1445 Strassen, Luxembourg
| | - Michel Pilot
- Department of Medicine IV, LMU University Hospital, LMU Munich, 80539 Munich, Germany
| | - Karoline Klein
- Saarland University Medical Center and Faculty of Medicine, 66421 Homburg, Germany
| | - Gilbert Georg Klamminger
- Department of General and Special Pathology, Saarland University Medical Center (UKS), Saarland University (USAAR), 66424 Homburg, Germany
- National Center of Pathology (NCP), Laboratoire National de Santé (LNS), 3555 Dudelange, Luxembourg
| | - Jean-Jacques Gérardy
- National Center of Pathology (NCP), Laboratoire National de Santé (LNS), 3555 Dudelange, Luxembourg
- Luxembourg Center of Neuropathology (LCNP), 3555 Dudelange, Luxembourg
| | - Marily Theodoropoulou
- Department of Medicine IV, LMU University Hospital, LMU Munich, 80539 Munich, Germany
| | - Laurent Mombaerts
- National Department of Neurosurgery, Centre Hospitalier de Luxembourg (CHL), 1210 Luxembourg, Luxembourg
- Luxembourg Centre for Systems Biomedicine (LCSB), University of Luxembourg (UL), 4365 Esch-sur-Alzette, Luxembourg
| | - Andreas Husch
- Luxembourg Centre for Systems Biomedicine (LCSB), University of Luxembourg (UL), 4365 Esch-sur-Alzette, Luxembourg
| | - Michel Mittelbronn
- Department of Cancer Research (DoCR), Luxembourg Institute of Health (LIH), 1445 Strassen, Luxembourg
- National Center of Pathology (NCP), Laboratoire National de Santé (LNS), 3555 Dudelange, Luxembourg
- Luxembourg Center of Neuropathology (LCNP), 3555 Dudelange, Luxembourg
- Luxembourg Centre for Systems Biomedicine (LCSB), University of Luxembourg (UL), 4365 Esch-sur-Alzette, Luxembourg
- Department of Life Science and Medicine (DLSM), University of Luxembourg (UL), 4365 Esch-sur-Alzette, Luxembourg
| | - Frank Hertel
- National Department of Neurosurgery, Centre Hospitalier de Luxembourg (CHL), 1210 Luxembourg, Luxembourg
- Saarland University Medical Center and Faculty of Medicine, 66421 Homburg, Germany
| | - Felix Bruno Kleine Borgmann
- Saarland University Medical Center and Faculty of Medicine, 66421 Homburg, Germany
- Department of Cancer Research (DoCR), Luxembourg Institute of Health (LIH), 1445 Strassen, Luxembourg
- Hôpitaux Robert Schuman, 2540 Luxembourg, Luxembourg
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Bolon B. Toxicologic Pathology Forum Opinion: Rational Approaches to Expanded Neurohistopathology Evaluation for Nonclinical General Toxicity Studies and Juvenile Animal Studies. Toxicol Pathol 2023; 51:363-374. [PMID: 38288942 DOI: 10.1177/01926233231225239] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/10/2024]
Abstract
Existing nervous system sampling and processing "best practices" for nonclinical general toxicity studies (GTS) were designed to assess test articles with unknown, no known, or well-known neurotoxic potential. Similar practices are applicable to juvenile animal studies (JAS). In GTS and JAS, the recommended baseline sampling for all species includes brain (7 sections), spinal cord (cervical and lumbar divisions [cross and longitudinal sections for each]), and 1 nerve (sciatic or tibial [cross and longitudinal sections]) in hematoxylin and eosin-stained sections. Extra sampling and processing (ie, an "expanded neurohistopathology evaluation" [ENHP]) are used for agents with anticipated neuroactivity (toxic ± therapeutic) of incompletely characterized location and degree. Expanded sampling incorporates additional brain (usually 8-15 sections total), spinal cord (thoracic ± sacral divisions), ganglia (somatic ± autonomic, often 2-8 total), and/or nerves (2-6 total) depending on the species and study objectives. Expanded processing typically adds special neurohistological procedures (usually 1-4 for selected samples) to characterize glial reactions, myelin integrity, and/or neuroaxonal damage. In my view, GTS and JAS designs should sample neural tissues at necropsy as if ENHP will be needed eventually, and when warranted ENHP may incorporate expanded sampling and/or expanded processing depending on the study objective(s).
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Olech M. Conventional and State-of-the-Art Detection Methods of Bovine Spongiform Encephalopathy (BSE). Int J Mol Sci 2023; 24:ijms24087135. [PMID: 37108297 PMCID: PMC10139118 DOI: 10.3390/ijms24087135] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/16/2023] [Revised: 04/08/2023] [Accepted: 04/09/2023] [Indexed: 04/29/2023] Open
Abstract
Bovine spongiform encephalopathy (BSE) is a fatal neurodegenerative disease that belongs to a group of diseases known as transmissible spongiform encephalopathies (TSEs). It is believed that the infectious agent responsible for prion diseases is abnormally folded prion protein (PrPSc), which derives from a normal cellular protein (PrPC), which is a cell surface glycoprotein predominantly expressed in neurons. There are three different types of BSE, the classical BSE (C-type) strain and two atypical strains (H-type and L-type). BSE is primarily a disease of cattle; however, sheep and goats also can be infected with BSE strains and develop a disease clinically and pathogenically indistinguishable from scrapie. Therefore, TSE cases in cattle and small ruminants require discriminatory testing to determine whether the TSE is BSE or scrapie and to discriminate classical BSE from the atypical H- or L-type strains. Many methods have been developed for the detection of BSE and have been reported in numerous studies. Detection of BSE is mainly based on the identification of characteristic lesions or detection of the PrPSc in the brain, often by use of their partial proteinase K resistance properties. The objective of this paper was to summarize the currently available methods, highlight their diagnostic performance, and emphasize the advantages and drawbacks of the application of individual tests.
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Affiliation(s)
- Monika Olech
- Department of Pathology, National Veterinary Research Institute, 24-100 Puławy, Poland
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Vaz A, Teixeira BCDA, Bertholdo DB. Incomplete hippocampal inversion: diagnostic criteria and effect on epilepsy, seizure localization and therapeutic outcome in children. Seizure 2022; 100:67-75. [PMID: 35779435 DOI: 10.1016/j.seizure.2022.06.003] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/14/2022] [Revised: 05/26/2022] [Accepted: 06/12/2022] [Indexed: 10/18/2022] Open
Abstract
PURPOSE Elaborate a simple Magnetic Resonance Imaging (MRI)-based score to define Incomplete Hippocampal Inversion (IHI) in children (Phase 1), and evaluate the relation of IHI with (A) epilepsy, (B) seizure localization and (C) therapeutic response in a paediatric population (Phase 2). METHODS In Phase 1, incompletely inverted hippocampi were matched to completely inverted hippocampi. Multiple qualitative and quantitative hippocampal and extra-hippocampal features were evaluated in coronal-oblique T1-weighted (T1W) and coronal T2-weighted (T2W) images. Multivariate analysis was performed to elaborate the MRI-based score to define IHI. In Phase 2, epilepsy patients were matched to controls, and the T1W and T2W scores were applied. Multivariate analysis was performed to assess the relation of IHI and epilepsy, seizure localization and therapeutic response. RESULTS The hippocampal diameter ratio and parahippocampal angle in the coronal-oblique T1-weighted images, and the hippocampal diameter ratio and collateral sulcus depth in the coronal T2-weighted images predicted IHI in Phase 1. Simple and practical imaging-based scores were developed and are available on the website: https://ihiscore.netlify.app/. The Area Under the Receiver Operating Characteristic Curve of the T1W and T2W scores were, respectively, 0.965 and 0.983. In Phase 2, IHI independently predicted epilepsy (OR = 3.144, 95% CI = 1.981-4.991, p < 0.001), temporal lobe epilepsy (OR = 4.237, 95% CI = 1.586-11.318, p = 0.004), and drug resistant epilepsy (OR = 7.000, 95% CI = 2.800-17.500, p < 0.001). CONCLUSION The association between IHI and temporal lobe epilepsy (and the lack of association with extra-temporal epilepsy) favours the possibility of a relation between IHI and the pathophysiology of seizures in epileptic patients. Furthermore, IHI is a potential prognostic marker for therapeutic response in epilepsy.
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Affiliation(s)
- André Vaz
- Hospital Pequeno Príncipe (Curitiba, Brazil), and Universidade Federal do Paraná (Curitiba, Brazil). Postal address: Centro de Imagem (CEIMA), Rua Desembargador Motta, 1070, 80250-060 Curitiba, Brazil.
| | - Bernardo Corrêa de Almeida Teixeira
- Hospital Pequeno Príncipe (Curitiba, Brazil), and Universidade Federal do Paraná (Curitiba, Brazil). Postal address: Hospital Pequeno Príncipe, Centro de Imagem (CEIMA), Rua Desembargador Motta, 1070, 80250-060 Curitiba, Brazil
| | - Debora Brighente Bertholdo
- Clínica DAPI (Curitiba, Brasil), and Pontifícia Universidade Católica do Paraná (Curitiba, Brazil). Postal address: Hospital Pequeno Príncipe, Centro de Imagem (CEIMA), Rua Brg. Franco, 122, 80430-210 Curitiba, Brazil
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Snyder JM, Radaelli E, Goeken A, Businga T, Boyden AW, Karandikar NJ, Gibson-Corley KN. Perfusion with 10% neutral-buffered formalin is equivalent to 4% paraformaldehyde for histopathology and immunohistochemistry in a mouse model of experimental autoimmune encephalomyelitis. Vet Pathol 2022; 59:498-505. [PMID: 35130806 PMCID: PMC9364762 DOI: 10.1177/03009858221075588] [Citation(s) in RCA: 5] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022]
Abstract
Intravascular (IV) perfusion of tissue fixative is commonly used in the field of neuroscience as the central nervous system tissues are exquisitely sensitive to handling and fixation artifacts which can affect downstream microscopic analysis. Both 10% neutral-buffered formalin (NBF) and 4% paraformaldehyde (PFA) are used, although IV perfusion with PFA is most commonly referenced. The study objective was to compare the severity of handling and fixation artifacts, semiquantitative scores of inflammatory and neurodegenerative changes, and quantitative immunohistochemistry following terminal IV perfusion of mice with either 10% NBF or 4% PFA in a model of experimental autoimmune encephalitis (EAE). The study included 24 mice; 12 were control animals not immunized and an additional 12 were immunized with PLP139-151 subcutaneously, harvested at day 20, and fixed in the same fashion. Equal numbers (4 per group) were perfused with 10% NBF or 4% PFA, and 4 were immersion-fixed in 10% NBF. NBF-perfused mice had less severe dark neuron artifact than PFA-perfused mice (P < .001). Immersion-fixed animals had significantly higher scores for oligodendrocyte halos, dark neuron artifact, and perivascular clefts than perfusion-fixed animals. Histopathology scores in EAE mice for inflammation, demyelination, and necrosis did not differ among fixation methods. Also, no significant differences in quantitative immunohistochemistry for CD3 and Iba-1 were observed in immunized animals regardless of the method of fixation. These findings indicate that IV perfusion of mice with 10% NBF and 4% PFA are similar and adequate fixation techniques in this model.
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Affiliation(s)
| | - Enrico Radaelli
- University of Pennsylvania School of Veterinary Medicine, Philadelphia, PA
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Cervical spinal hemisection alters phrenic motor neuron glutamatergic mRNA receptor expression. Exp Neurol 2022; 353:114030. [PMID: 35247372 DOI: 10.1016/j.expneurol.2022.114030] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/12/2021] [Revised: 02/18/2022] [Accepted: 02/27/2022] [Indexed: 11/22/2022]
Abstract
Upper cervical spinal cord injuries (SCI) disrupt descending inputs to phrenic motor neurons (PhMNs), impairing respiratory function. Unilateral spinal hemisection at C2 (C2SH) results in loss of ipsilateral rhythmic diaphragm muscle (DIAm) EMG activity associated with lower force behaviors accomplished by recruitment of smaller PhMNs that recovers over time in rats. Activity during higher force, non-ventilatory behaviors that recruit larger PhMNs is minimally impaired following C2SH. We previously showed neuroplasticity in glutamatergic receptor expression in PhMN post-C2SH with changes in NMDA receptor expression reflecting functional recovery. We hypothesize that C2SH-induced changes in glutamatergic receptor (AMPA and NMDA) mRNA expression in PhMNs vary with motor neuron size, with more pronounced changes in smaller PhMNs. Retrogradely-labelled PhMNs were classified in tertiles according to somal surface area and mRNA expression was measured using single-cell, multiplex fluorescence in situ hybridization. Ipsilateral to C2SH, a pronounced reduction in NMDA mRNA expression in PhMNs was evident at 3 days post-injury with similar impact on PhMNs in the lower size tertile (~68% reduction) and upper tertile (~60%); by 21DSH, there was near complete restoration of NMDA receptor mRNA expression across all PhMNs. There were no changes in NMDA mRNA expression contralateral to C2SH. There were no changes in AMPA mRNA expression at PhMNs on either side of the spinal cord or at any time-point post-C2SH. In summary, following C2SH there is ipsilateral reduction in PhMN NMDA mRNA expression at 3DSH that is not limited to smaller PhMN recruited in the generation of lower force ventilatory behaviors. The recovery of NMDA mRNA expression by 21DSH is consistent with evidence of spontaneous recovery of ipsilateral DIAm activity at this timepoint. These findings suggest a possible role for NMDA receptor mediated glutamatergic signaling in mechanisms supporting postsynaptic neuroplasticity at the PhMN pool and recovery of DIAm activity after cervical SCI.
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8
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Schwarzmaiera SM, Knarr MR, Hu S, Ertürk A, Hellal F, Plesnila N. Perfusion pressure determines vascular integrity and histomorphological quality following perfusion fixation of the brain. J Neurosci Methods 2022; 372:109493. [DOI: 10.1016/j.jneumeth.2022.109493] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/03/2021] [Revised: 01/25/2022] [Accepted: 02/03/2022] [Indexed: 10/19/2022]
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Methodology and Neuromarkers for Cetaceans’ Brains. Vet Sci 2022; 9:vetsci9020038. [PMID: 35202291 PMCID: PMC8879147 DOI: 10.3390/vetsci9020038] [Citation(s) in RCA: 9] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/15/2021] [Revised: 01/18/2022] [Accepted: 01/19/2022] [Indexed: 02/01/2023] Open
Abstract
Cetacean brain sampling may be an arduous task due to the difficulty of collecting and histologically preparing such rare and large specimens. Thus, one of the main challenges of working with cetaceans’ brains is to establish a valid methodology for an optimal manipulation and fixation of the brain tissue, which allows the samples to be viable for neuroanatomical and neuropathological studies. With this in view, we validated a methodology in order to preserve the quality of such large brains (neuroanatomy/neuropathology) and at the same time to obtain fresh brain samples for toxicological, virological, and microbiological analysis (neuropathology). A fixation protocol adapted to brains, of equal or even three times the size of human brains, was studied and tested. Finally, we investigated the usefulness of a panel of 20 antibodies (neuromarkers) associated with the normal structure and function of the brain, pathogens, age-related, and/or functional variations. The sampling protocol and some of the 20 neuromarkers have been thought to explore neurodegenerative diseases in these long-lived animals. To conclude, many of the typical measures used to evaluate neuropathological changes do not tell us if meaningful cellular changes have occurred. Having a wide panel of antibodies and histochemical techniques available allows for delving into the specific behavior of the neuronal population of the brain nuclei and to get a “fingerprint” of their real status.
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Schifferer M, Snaidero N, Djannatian M, Kerschensteiner M, Misgeld T. Niwaki Instead of Random Forests: Targeted Serial Sectioning Scanning Electron Microscopy With Reimaging Capabilities for Exploring Central Nervous System Cell Biology and Pathology. Front Neuroanat 2021; 15:732506. [PMID: 34720890 PMCID: PMC8548362 DOI: 10.3389/fnana.2021.732506] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/29/2021] [Accepted: 09/24/2021] [Indexed: 11/13/2022] Open
Abstract
Ultrastructural analysis of discrete neurobiological structures by volume scanning electron microscopy (SEM) often constitutes a "needle-in-the-haystack" problem and therefore relies on sophisticated search strategies. The appropriate SEM approach for a given relocation task not only depends on the desired final image quality but also on the complexity and required accuracy of the screening process. Block-face SEM techniques like Focused Ion Beam or serial block-face SEM are "one-shot" imaging runs by nature and, thus, require precise relocation prior to acquisition. In contrast, "multi-shot" approaches conserve the sectioned tissue through the collection of serial sections onto solid support and allow reimaging. These tissue libraries generated by Array Tomography or Automated Tape Collecting Ultramicrotomy can be screened at low resolution to target high resolution SEM. This is particularly useful if a structure of interest is rare or has been predetermined by correlated light microscopy, which can assign molecular, dynamic and functional information to an ultrastructure. As such approaches require bridging mm to nm scales, they rely on tissue trimming at different stages of sample processing. Relocation is facilitated by endogenous or exogenous landmarks that are visible by several imaging modalities, combined with appropriate registration strategies that allow overlaying images of various sources. Here, we discuss the opportunities of using multi-shot serial sectioning SEM approaches, as well as suitable trimming and registration techniques, to slim down the high-resolution imaging volume to the actual structure of interest and hence facilitate ambitious targeted volume SEM projects.
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Affiliation(s)
- Martina Schifferer
- Center for Neurodegenerative Diseases (DZNE), Munich, Germany
- Munich Cluster of Systems Neurology (SyNergy), Munich, Germany
| | - Nicolas Snaidero
- Center for Neurodegenerative Diseases (DZNE), Munich, Germany
- Institute of Neuronal Cell Biology, Technical University of Munich, Munich, Germany
- Hertie Institute for Clinical Brain Research, Tübingen, Germany
| | - Minou Djannatian
- Center for Neurodegenerative Diseases (DZNE), Munich, Germany
- Institute of Neuronal Cell Biology, Technical University of Munich, Munich, Germany
| | - Martin Kerschensteiner
- Munich Cluster of Systems Neurology (SyNergy), Munich, Germany
- Institute of Clinical Neuroimmunology, University Hospital, Ludwig-Maximilians-University Munich, Munich, Germany
- Faculty of Medicine, Biomedical Center (BMC), Ludwig-Maximilians-University Munich, Munich, Germany
| | - Thomas Misgeld
- Center for Neurodegenerative Diseases (DZNE), Munich, Germany
- Munich Cluster of Systems Neurology (SyNergy), Munich, Germany
- Institute of Neuronal Cell Biology, Technical University of Munich, Munich, Germany
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Kalisvaart ACJ, Wilkinson CM, Gu S, Kung TFC, Yager J, Winship IR, van Landeghem FKH, Colbourne F. An update to the Monro-Kellie doctrine to reflect tissue compliance after severe ischemic and hemorrhagic stroke. Sci Rep 2020; 10:22013. [PMID: 33328490 PMCID: PMC7745016 DOI: 10.1038/s41598-020-78880-4] [Citation(s) in RCA: 17] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/24/2020] [Accepted: 12/01/2020] [Indexed: 02/06/2023] Open
Abstract
High intracranial pressure (ICP) can impede cerebral blood flow resulting in secondary injury or death following severe stroke. Compensatory mechanisms include reduced cerebral blood and cerebrospinal fluid volumes, but these often fail to prevent raised ICP. Serendipitous observations in intracerebral hemorrhage (ICH) suggest that neurons far removed from a hematoma may shrink as an ICP compliance mechanism. Here, we sought to critically test this observation. We tracked the timing of distal tissue shrinkage (e.g. CA1) after collagenase-induced striatal ICH in rat; cell volume and density alterations (42% volume reduction, 34% density increase; p < 0.0001) were highest day one post-stroke, and rebounded over a week across brain regions. Similar effects were seen in the filament model of middle cerebral artery occlusion (22% volume reduction, 22% density increase; p ≤ 0.007), but not with the Vannucci-Rice model of hypoxic-ischemic encephalopathy (2.5% volume increase, 14% density increase; p ≥ 0.05). Concerningly, this 'tissue compliance' appears to cause sub-lethal damage, as revealed by electron microscopy after ICH. Our data challenge the long-held assumption that 'healthy' brain tissue outside the injured area maintains its volume. Given the magnitude of these effects, we posit that 'tissue compliance' is an important mechanism invoked after severe strokes.
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Affiliation(s)
- Anna C J Kalisvaart
- Department of Psychology, Faculty of Science, University of Alberta, Edmonton, AB, Canada
| | - Cassandra M Wilkinson
- Department of Psychology, Faculty of Science, University of Alberta, Edmonton, AB, Canada
| | - Sherry Gu
- Neuroscience and Mental Health Institute, University of Alberta, Edmonton, Canada
| | - Tiffany F C Kung
- Neuroscience and Mental Health Institute, University of Alberta, Edmonton, Canada
| | - Jerome Yager
- Department of Pediatrics, Faculty of Medicine and Dentistry, University of Alberta, Edmonton, Canada
| | - Ian R Winship
- Neuroscience and Mental Health Institute, University of Alberta, Edmonton, Canada
- Department of Psychiatry, Faculty of Medicine and Dentistry, University of Alberta, Edmonton, Canada
| | - Frank K H van Landeghem
- Neuroscience and Mental Health Institute, University of Alberta, Edmonton, Canada
- Department of Laboratory Medicine and Pathology, University of Alberta Hospital, Edmonton, Canada
| | - Frederick Colbourne
- Department of Psychology, Faculty of Science, University of Alberta, Edmonton, AB, Canada.
- Neuroscience and Mental Health Institute, University of Alberta, Edmonton, Canada.
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Kim JH, Goodrich JA, Situ R, Rapuano A, Hetherington H, Du F, Parks S, Taylor W, Westmoreland T, Ling G, Bandak FA, de Lanerolle NC. Periventricular White Matter Alterations From Explosive Blast in a Large Animal Model: Mild Traumatic Brain Injury or "Subconcussive" Injury? J Neuropathol Exp Neurol 2020; 79:605-617. [PMID: 32386412 DOI: 10.1093/jnen/nlaa026] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/22/2019] [Revised: 10/15/2019] [Accepted: 03/24/2020] [Indexed: 11/14/2022] Open
Abstract
The neuropathology of mild traumatic brain injury in humans resulting from exposure to explosive blast is poorly understood as this condition is rarely fatal. A large animal model may better reflect the injury patterns in humans. We investigated the effect of explosive blasts on the constrained head minimizing the effects of whole head motion. Anesthetized Yucatan minipigs, with body and head restrained, were placed in a 3-walled test structure and exposed to 1, 2, or 3 explosive blast shock waves of the same intensity. Axonal injury was studied 3 weeks to 8 months postblast using β-amyloid precursor protein immunohistochemistry. Injury was confined to the periventricular white matter as early as 3-5 weeks after exposure to a single blast. The pattern was also present at 8 months postblast. Animals exposed to 2 and 3 blasts had more axonal injury than those exposed to a single blast. Although such increases in axonal injury may relate to the longer postblast survival time, it may also be due to the increased number of blast exposures. It is possible that the injury observed is due to a condition akin to mild traumatic brain injury or subconcussive injury in humans, and that periventricular injury may have neuropsychiatric implications.
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Affiliation(s)
| | | | | | | | - Hoby Hetherington
- Yale School of Medicine, New Haven, Connecticut; Department of Radiology, University of Pittsburgh, Pittsburgh, Pennsylvania
| | - Fu Du
- FD NeuroTechnologies Inc., Ellicott City, Maryland
| | | | | | | | - Geoffrey Ling
- Department of Neurology, F. Edward Hébert School of Medicine, Uniformed Services University of the Health Sciences, Bethesda, Maryland
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Lanigan LG, Russell DS, Woolard KD, Pardo ID, Godfrey V, Jortner BS, Butt MT, Bolon B. Comparative Pathology of the Peripheral Nervous System. Vet Pathol 2020; 58:10-33. [PMID: 33016246 DOI: 10.1177/0300985820959231] [Citation(s) in RCA: 21] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022]
Abstract
The peripheral nervous system (PNS) relays messages between the central nervous system (brain and spinal cord) and the body. Despite this critical role and widespread distribution, the PNS is often overlooked when investigating disease in diagnostic and experimental pathology. This review highlights key features of neuroanatomy and physiology of the somatic and autonomic PNS, and appropriate PNS sampling and processing techniques. The review considers major classes of PNS lesions including neuronopathy, axonopathy, and myelinopathy, and major categories of PNS disease including toxic, metabolic, and paraneoplastic neuropathies; infectious and inflammatory diseases; and neoplasms. This review describes a broad range of common PNS lesions and their diagnostic criteria and provides many useful references for pathologists who perform PNS evaluations as a regular or occasional task in their comparative pathology practice.
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Sierra E, Fernández A, Felipe-Jiménez I, Zucca D, Díaz-Delgado J, Puig-Lozano R, Câmara N, Consoli F, Díaz-Santana P, Suárez-Santana C, Arbelo M. Histopathological Differential Diagnosis of Meningoencephalitis in Cetaceans: Morbillivirus, Herpesvirus, Toxoplasma gondii, Brucella sp., and Nasitrema sp. Front Vet Sci 2020; 7:650. [PMID: 33195505 PMCID: PMC7554640 DOI: 10.3389/fvets.2020.00650] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/15/2020] [Accepted: 08/11/2020] [Indexed: 12/18/2022] Open
Abstract
Infectious and inflammatory processes are among the most common causes of central nervous system involvement in stranded cetaceans. Meningitis and encephalitis are among the leading known natural causes of death in stranded cetaceans and may be caused by a wide range of pathogens. This study describes histopathological findings in post-mortem brain tissue specimens from stranded cetaceans associated with five relevant infectious agents: viruses [Cetacean Morbillivirus (CeMV) and Herpesvirus (HV); n = 29], bacteria (Brucella sp.; n = 7), protozoa (Toxoplasma gondii; n = 6), and helminths (Nasitrema sp.; n = 1). Aetiological diagnosis was established by molecular methods. Histopathologic evaluations of brain samples were performed in all the cases, and additional histochemical and/or immunohistochemical stains were carried out accordingly. Compared with those produced by other types of pathogens in our study, the characteristic features of viral meningoencephalitis (CeMV and HV) included the most severe and frequent presence of malacia, intranuclear, and/or intracytoplasmic inclusion bodies, neuronal necrosis and associated neuronophagia, syncytia and hemorrhages, predominantly in the cerebrum. The characteristic features of Brucella sp. meningoencephalitis included the most severe and frequent presence of meningitis, perivascular cuffing, cerebellitis, myelitis, polyradiculoneuritis, choroiditis, ventriculitis, vasculitis, and fibrinoid necrosis of vessels. The characteristic features of T. gondii meningoencephalitis included lymphocytic and granulomatous encephalitis, tissue cysts, microgliosis, and oedema. In the case of Nasitrema sp. infection, lesions are all that we describe since just one animal was available. The results of this study are expected to contribute, to a large extent, to a better understanding of brain-pathogen-associated lesions in cetaceans.
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Affiliation(s)
- Eva Sierra
- Veterinary Histology and Pathology, Institute of Animal Health and Food Safety, Veterinary School, University of Las Palmas de Gran Canaria, Las Palmas de Gran Canaria, Spain
| | - Antonio Fernández
- Veterinary Histology and Pathology, Institute of Animal Health and Food Safety, Veterinary School, University of Las Palmas de Gran Canaria, Las Palmas de Gran Canaria, Spain
| | - Idaira Felipe-Jiménez
- Veterinary Histology and Pathology, Institute of Animal Health and Food Safety, Veterinary School, University of Las Palmas de Gran Canaria, Las Palmas de Gran Canaria, Spain
| | - Daniele Zucca
- Veterinary Histology and Pathology, Institute of Animal Health and Food Safety, Veterinary School, University of Las Palmas de Gran Canaria, Las Palmas de Gran Canaria, Spain
| | - Josué Díaz-Delgado
- Veterinary Histology and Pathology, Institute of Animal Health and Food Safety, Veterinary School, University of Las Palmas de Gran Canaria, Las Palmas de Gran Canaria, Spain.,Texas A&M Veterinary Medical Diagnostic Laboratory, College Station, TX, United States
| | - Raquel Puig-Lozano
- Veterinary Histology and Pathology, Institute of Animal Health and Food Safety, Veterinary School, University of Las Palmas de Gran Canaria, Las Palmas de Gran Canaria, Spain
| | - Nakita Câmara
- Veterinary Histology and Pathology, Institute of Animal Health and Food Safety, Veterinary School, University of Las Palmas de Gran Canaria, Las Palmas de Gran Canaria, Spain
| | - Francesco Consoli
- Veterinary Histology and Pathology, Institute of Animal Health and Food Safety, Veterinary School, University of Las Palmas de Gran Canaria, Las Palmas de Gran Canaria, Spain.,Department of Neuroscience, Imaging and Clinical Sciences, University G. D'Annunzio, Chieti, Italy
| | - Pablo Díaz-Santana
- Veterinary Histology and Pathology, Institute of Animal Health and Food Safety, Veterinary School, University of Las Palmas de Gran Canaria, Las Palmas de Gran Canaria, Spain
| | - Cristian Suárez-Santana
- Veterinary Histology and Pathology, Institute of Animal Health and Food Safety, Veterinary School, University of Las Palmas de Gran Canaria, Las Palmas de Gran Canaria, Spain
| | - Manuel Arbelo
- Veterinary Histology and Pathology, Institute of Animal Health and Food Safety, Veterinary School, University of Las Palmas de Gran Canaria, Las Palmas de Gran Canaria, Spain
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Barbone GE, Bravin A, Mittone A, Kraiger MJ, Hrabě de Angelis M, Bossi M, Ballarini E, Rodriguez-Menendez V, Ceresa C, Cavaletti G, Coan P. Establishing sample-preparation protocols for X-ray phase-contrast CT of rodent spinal cords: Aldehyde fixations and osmium impregnation. J Neurosci Methods 2020; 339:108744. [DOI: 10.1016/j.jneumeth.2020.108744] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/10/2020] [Revised: 04/14/2020] [Accepted: 04/15/2020] [Indexed: 12/14/2022]
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Bruna J, Alberti P, Calls-Cobos A, Caillaud M, Damaj MI, Navarro X. Methods for in vivo studies in rodents of chemotherapy induced peripheral neuropathy. Exp Neurol 2020; 325:113154. [PMID: 31837318 PMCID: PMC7105293 DOI: 10.1016/j.expneurol.2019.113154] [Citation(s) in RCA: 34] [Impact Index Per Article: 8.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/01/2019] [Revised: 12/07/2019] [Accepted: 12/10/2019] [Indexed: 12/15/2022]
Abstract
Peripheral neuropathy is one of the most common, dose limiting, and long-lasting disabling adverse events of chemotherapy treatment. Unfortunately, no treatment has proven efficacy to prevent this adverse effect in patients or improve the nerve regeneration, once it is established. Experimental models, particularly using rats and mice, are useful to investigate the mechanisms related to axonal or neuronal degeneration and target loss of function induced by neurotoxic drugs, as well as to test new strategies to prevent the development of neuropathy and to improve functional restitution. Therefore, objective and reliable methods should be applied for the assessment of function and innervation in adequately designed in vivo studies of CIPN, taking into account the impact of age, sex and species/strains features. This review gives an overview of the most useful methods to assess sensory, motor and autonomic functions, electrophysiological and morphological tests in rodent models of peripheral neuropathy, focused on CIPN. We include as well a proposal of protocols that may improve the quality and comparability of studies undertaken in different laboratories. It is recommended to apply more than one functional method for each type of function, and to perform parallel morphological studies in the same targets and models.
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Affiliation(s)
- Jordi Bruna
- Unit of Neuro-Oncology, Hospital Universitari de Bellvitge, Institut Català d'Oncologia L'Hospitalet, IDIBELL, Hospitalet de Llobregat, Barcelona, Spain; Department of Cell Biology, Physiology and Immunology, Institute of Neurosciences, Universitat Autònoma de Barcelona, Bellaterra, Spain; Centro de Investigación Biomédica en Red sobre Enfermedades Neurodegenerativas (CIBERNED), Spain
| | - Paola Alberti
- Experimental Neurology Unit, School of Medicine and Surgery, University Milano Bicocca, Monza, Italy; NeuroMI (Milan Center for Neuroscience), Milan, Italy
| | - Aina Calls-Cobos
- Department of Cell Biology, Physiology and Immunology, Institute of Neurosciences, Universitat Autònoma de Barcelona, Bellaterra, Spain; Centro de Investigación Biomédica en Red sobre Enfermedades Neurodegenerativas (CIBERNED), Spain
| | - Martial Caillaud
- Department of Pharmacology and Toxicology, Medical College of Virginia Campus, Virginia Commonwealth University, Richmond, VA, USA
| | - M Imad Damaj
- Department of Pharmacology and Toxicology, Medical College of Virginia Campus, Virginia Commonwealth University, Richmond, VA, USA
| | - Xavier Navarro
- Department of Cell Biology, Physiology and Immunology, Institute of Neurosciences, Universitat Autònoma de Barcelona, Bellaterra, Spain; Centro de Investigación Biomédica en Red sobre Enfermedades Neurodegenerativas (CIBERNED), Spain.
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Bolon B, Krinke GJ, Pardo ID. Essential References for Structural Analysis of the Peripheral Nervous System for Pathologists and Toxicologists. Toxicol Pathol 2019; 48:87-95. [DOI: 10.1177/0192623319868160] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/04/2023]
Abstract
Toxicologic neuropathology for the peripheral nervous system (PNS) is a vital but often underappreciated element of basic translational research and safety assessment. Evaluation of the PNS may be complicated by unfamiliarity with normal nerve and ganglion biology, which differs to some degree among species; the presence of confounding artifacts related to suboptimal sampling and processing; and limited experience with differentiating such artifacts from genuine disease manifestations and incidental background changes. This compilation of key PNS neurobiology, neuropathology, and neurotoxicology references is designed to allow pathologists and toxicologists to readily access essential information that is needed to enhance their proficiency in evaluating and interpreting toxic changes in PNS tissues from many species.
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McFadden WC, Walsh H, Richter F, Soudant C, Bryce CH, Hof PR, Fowkes M, Crary JF, McKenzie AT. Perfusion fixation in brain banking: a systematic review. Acta Neuropathol Commun 2019; 7:146. [PMID: 31488214 PMCID: PMC6728946 DOI: 10.1186/s40478-019-0799-y] [Citation(s) in RCA: 32] [Impact Index Per Article: 6.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/25/2019] [Accepted: 08/26/2019] [Indexed: 01/12/2023] Open
Abstract
Background Perfusing fixatives through the cerebrovascular system is the gold standard approach in animals to prepare brain tissue for spatial biomolecular profiling, circuit tracing, and ultrastructural studies such as connectomics. Translating these discoveries to humans requires examination of postmortem autopsy brain tissue. Yet banked brain tissue is routinely prepared using immersion fixation, which is a significant barrier to optimal preservation of tissue architecture. The challenges involved in adopting perfusion fixation in brain banks and the extent to which it improves histology quality are not well defined. Methodology We searched four databases to identify studies that have performed perfusion fixation in human brain tissue and screened the references of the eligible studies to identify further studies. From the included studies, we extracted data about the methods that they used, as well as any data comparing perfusion fixation to immersion fixation. The protocol was preregistered at the Open Science Framework: https://osf.io/cv3ys/. Results We screened 4489 abstracts, 214 full-text publications, and identified 35 studies that met our inclusion criteria, which collectively reported on the perfusion fixation of 558 human brains. We identified a wide variety of approaches to perfusion fixation, including perfusion fixation of the brain in situ and ex situ, perfusion fixation through different sets of blood vessels, and perfusion fixation with different washout solutions, fixatives, perfusion pressures, and postfixation tissue processing methods. Through a qualitative synthesis of data comparing the outcomes of perfusion and immersion fixation, we found moderate confidence evidence showing that perfusion fixation results in equal or greater subjective histology quality compared to immersion fixation of relatively large volumes of brain tissue, in an equal or shorter amount of time. Conclusions This manuscript serves as a resource for investigators interested in building upon the methods and results of previous research in designing their own perfusion fixation studies in human brains or other large animal brains. We also suggest several future research directions, such as comparing the in situ and ex situ approaches to perfusion fixation, studying the efficacy of different washout solutions, and elucidating the types of brain donors in which perfusion fixation is likely to result in higher fixation quality than immersion fixation. Electronic supplementary material The online version of this article (10.1186/s40478-019-0799-y) contains supplementary material, which is available to authorized users.
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Mortazavi F, Stankiewicz AJ, Zhdanova IV. Looking through Brains with Fast Passive CLARITY: Zebrafish, Rodents, Non-human Primates and Humans. Bio Protoc 2019; 9:e3321. [PMID: 33654828 DOI: 10.21769/bioprotoc.3321] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/11/2019] [Revised: 07/24/2019] [Accepted: 07/16/2019] [Indexed: 12/18/2022] Open
Abstract
Recently developed CLARITY (Clear Lipid-exchanged Acrylamide-hybridized Rigid Imaging/Immunostaining/In situ-hybridization-compatible Tis-sue-hYdrogel) technique renders the tissue transparent by removing lipids in the tissue, while preserving and stabilizing the cellular and subcellular structures. This provides effective penetration of diverse labeling probes, from primary and secondary antibodies to complementary DNA and RNA strands. Followed by high-resolution 3D imaging of neuronal cells and their projections in thick sections, tissue blocks, whole brains, or whole animals, CLARITY allows for superior quantitative analysis of neuronal tissue. Here, we provide our detailed protocol for PACT (Passive Clarity Technique) in brain tissue of diverse species, including human, non-human primate, rodents, and zebrafish. We describe the six principal steps: (1) Tissue fixation and preparation, (2) Passive lipid removal, (3) Immuno-labeling, (4) Optical clearing, (5) Imaging, (6) 3D visualization and quantification.
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Affiliation(s)
- Farzad Mortazavi
- Department of Anatomy and Neurobiology, Boston University School of Medicine, Boston, MA 02118, USA
| | - Alexander J Stankiewicz
- Department of Physics, University of Connecticut, Storrs, Connecticut 06269, USA.,Department of Preclinical Research, BioChron LLC, Worcester, Massachusetts 01605, USA
| | - Irina V Zhdanova
- Department of Preclinical Research, BioChron LLC, Worcester, Massachusetts 01605, USA
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20
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Abstract
Many preclinical investigations limit the evaluation of the peripheral nervous system (PNS) to paraffin-embedded sections/hematoxylin and eosin–stained sections of the sciatic nerve. This limitation ignores several key mechanisms of toxicity and anatomic differences that may interfere with an accurate assessment of test article effects on the neurons/neurites peripheral to the brain and spinal cord. Ganglion neurons may be exposed to higher concentrations of the test article as compared to neurons in the brain or spinal cord due to differences in capillary permeability. Many peripheral neuropathies are length-dependent, meaning distal nerves may show morphological changes before they are evident in the mid-sciatic nerve. Paraffin-embedded nerves are not optimal to assess myelin changes, notably those leading to demyelination. Differentiating between axonal or myelin degeneration may not be possible from the examination of paraffin-embedded sections. A sampling strategy more consistent with known mechanisms of toxicity, atraumatic harvest of tissues, optimized fixation, and the use of resin and paraffin-embedded sections will greatly enhance the pathologist’s ability to observe and characterize effects in the PNS.
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21
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Cramer SD, Lee JS, Butt MT, Paulin J, Stoffregen WC. Neurologic Medical Device Overview for Pathologists. Toxicol Pathol 2019; 47:250-263. [PMID: 30599801 DOI: 10.1177/0192623318816685] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
Thorough morphologic evaluations of medical devices placed in or near the nervous system depend on many factors. Pathologists interpreting a neurologic device study must be familiar with the regulatory framework affecting device development, biocompatibility and safety determinants impacting nervous tissue responses, and appropriate study design, including the use of appropriate animal models, group design, device localization, euthanasia time points, tissue examination, sampling and processing, histochemistry and immunohistochemistry, and reporting. This overview contextualizes these features of neurologic medical devices for pathologists engaged in device evaluations.
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Affiliation(s)
| | | | - Mark T Butt
- 1 Tox Path Specialists, LLC, Frederick, Maryland, USA
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22
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Bolon B, Krinke G, Butt MT, Rao DB, Pardo ID, Jortner BS, Garman RH, Jensen K, Andrews-Jones L, Morrison JP, Sharma AK, Thibodeau MS. STP Position Paper: Recommended Best Practices for Sampling, Processing, and Analysis of the Peripheral Nervous System (Nerves and Somatic and Autonomic Ganglia) during Nonclinical Toxicity Studies. Toxicol Pathol 2018; 46:372-402. [DOI: 10.1177/0192623318772484] [Citation(s) in RCA: 39] [Impact Index Per Article: 6.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
Abstract
Peripheral nervous system (PNS) toxicity is surveyed inconsistently in nonclinical general toxicity studies. These Society of Toxicologic Pathology “best practice” recommendations are designed to ensure consistent, efficient, and effective sampling, processing, and evaluation of PNS tissues for four different situations encountered during nonclinical general toxicity (screening) and dedicated neurotoxicity studies. For toxicity studies where neurotoxicity is unknown or not anticipated (situation 1), PNS evaluation may be limited to one sensorimotor spinal nerve. If somatic PNS neurotoxicity is suspected (situation 2), analysis minimally should include three spinal nerves, multiple dorsal root ganglia, and a trigeminal ganglion. If autonomic PNS neuropathy is suspected (situation 3), parasympathetic and sympathetic ganglia should be assessed. For dedicated neurotoxicity studies where a neurotoxic effect is expected (situation 4), PNS sampling follows the strategy for situations 2 and/or 3, as dictated by functional or other compound/target-specific data. For all situations, bilateral sampling with unilateral processing is acceptable. For situations 1–3, PNS is processed conventionally (immersion in buffered formalin, paraffin embedding, and hematoxylin and eosin staining). For situation 4 (and situations 2 and 3 if resources and timing permit), perfusion fixation with methanol-free fixative is recommended. Where PNS neurotoxicity is suspected or likely, at least one (situations 2 and 3) or two (situation 4) nerve cross sections should be postfixed with glutaraldehyde and osmium before hard plastic resin embedding; soft plastic embedding is not a suitable substitute for hard plastic. Special methods may be used if warranted to further characterize PNS findings. Initial PNS analysis should be informed, not masked (“blinded”). Institutions may adapt these recommendations to fit their specific programmatic requirements but may need to explain in project documentation the rationale for their chosen PNS sampling, processing, and evaluation strategy.
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Affiliation(s)
| | | | - Mark T. Butt
- Tox Path Specialists, LLC, Frederick, Maryland, USA
| | - Deepa B. Rao
- US Food and Drug Administration, Center for Drug Evaluation and Research, Silver Spring, Maryland, USA
| | | | - Bernard S. Jortner
- Virginia Polytechnic Institute and State University, Blacksburg, Virginia, USA
| | - Robert H. Garman
- Consultants in Veterinary Pathology, Inc., Murrysville, Pennsylvania, USA
| | - Karl Jensen
- US Environmental Protection Agency, Research Triangle Park, North Carolina, USA
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Abstract
The locus coeruleus (LC) is the largest catecholaminergic nucleus and extensively projects to widespread areas of the brain and spinal cord. The LC is the largest source of noradrenaline in the brain. To date, the only examined Delphinidae species for the LC has been a bottlenose dolphin (Tursiops truncatus). In our experimental series including different Delphinidae species, the LC was composed of five subdivisions: A6d, A6v, A7, A5, and A4. The examined animals had the A4 subdivision, which had not been previously described in the only Delphinidae in which this nucleus was investigated. Moreover, the neurons had a large amount of neuromelanin in the interior of their perikarya, making this nucleus highly similar to that of humans and non-human primates. This report also presents the first description of neuromelanin in the cetaceans’ LC complex, as well as in the cetaceans’ brain.
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Hotterbeekx A, Onzivua S, Menon S, Colebunders R. Histological examination of post-mortem brains of children with nodding syndrome. ANNALS OF TRANSLATIONAL MEDICINE 2018; 6:134. [PMID: 29955594 DOI: 10.21037/atm.2018.02.04] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
Affiliation(s)
- An Hotterbeekx
- Global Health Institute, University of Antwerp, Antwerp, Belgium
| | - Sylvester Onzivua
- Department of pathology, Makerere University Medical School, Kampala, Uganda
| | - Sonia Menon
- Global Health Institute, University of Antwerp, Antwerp, Belgium
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Musigazi GU, De Vleeschauwer S, Sciot R, Verbeken E, Depreitere B. Brain perfusion fixation in male pigs using a safer closed system. Lab Anim 2018; 52:413-417. [DOI: 10.1177/0023677217752747] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
Tissue fixation methods are well established for rodents, but not for large animals. We present a simple technique for in situ brain perfusion fixation in a male porcine model, using cervical vessels for inflow and outflow and achieving a closed system. Thirty-four pigs, aged 4.7 ± 0.6 months and weighing 60.7 ± 10.9 kg, were anaesthetised and mechanically ventilated. The ipsilateral common carotid artery and external jugular vein were dissected and constituted the inflow and outflow access, respectively. The brains were perfused and fixed in situ with heparinised saline followed by buffered formaldehyde. Then, specimens (brain, cerebellum and brainstem) were extracted and processed for histology. Fixative fluid leakage was avoided, achieving a closed system. This technique minimises the exposure to toxic chemicals such as formaldehyde and associated hazards (inherent toxicity, eye irritation), thereby increasing operators’ safety. Perfusion was performed with a peristaltic pump for 20–30 minutes at an optimum rate of 0.20 l/min and required only 5 litres of the fixative. The specimens were sufficiently hardened to be extracted. High-quality tissues were available for histology analysis. This technique offers a user-friendly closed system for brain perfusion fixation which can be adapted for other tissues of the head, face and neck.
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Affiliation(s)
- Gracia U. Musigazi
- Experimental Neurosurgery and Neuroanatomy, Neurosciences, KU Leuven, Belgium
- Department of Neurosurgery, Leuven University Hospitals, Belgium
| | | | - Raf Sciot
- Department of Pathology, Leuven University Hospitals, Belgium
| | - Eric Verbeken
- Department of Pathology, Leuven University Hospitals, Belgium
| | - Bart Depreitere
- Experimental Neurosurgery and Neuroanatomy, Neurosciences, KU Leuven, Belgium
- Department of Neurosurgery, Leuven University Hospitals, Belgium
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Saliani A, Perraud B, Duval T, Stikov N, Rossignol S, Cohen-Adad J. Axon and Myelin Morphology in Animal and Human Spinal Cord. Front Neuroanat 2017; 11:129. [PMID: 29311857 PMCID: PMC5743665 DOI: 10.3389/fnana.2017.00129] [Citation(s) in RCA: 51] [Impact Index Per Article: 7.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/15/2017] [Accepted: 12/13/2017] [Indexed: 12/11/2022] Open
Abstract
Characterizing precisely the microstructure of axons, their density, size and myelination is of interest for the neuroscientific community, for example to help maximize the outcome of studies on white matter (WM) pathologies of the spinal cord (SC). The existence of a comprehensive and structured database of axonal measurements in healthy and disease models could help the validation of results obtained by different researchers. The purpose of this article is to provide such a database of healthy SC WM, to discuss the potential sources of variability and to suggest avenues for robust and accurate quantification of axon morphometry based on novel acquisition and processing techniques. The article is organized in three sections. The first section reviews morphometric results across species according to range of densities and counts of myelinated axons, axon diameter and myelin thickness, and characteristics of unmyelinated axons in different regions. The second section discusses the sources of variability across studies, such as age, sex, spinal pathways, spinal levels, statistical power and terminology in regard to tracts and protocols. The third section presents new techniques and perspectives that could benefit histology studies. For example, coherent anti-stokes Raman spectroscopy (CARS) imaging can provide sub-micrometric resolution without the need for fixation and staining, while slide scanners and stitching algorithms can provide full cross-sectional area of SC. In combination with these acquisition techniques, automatic segmentation algorithms for delineating axons and myelin sheath can help provide large-scale statistics on axon morphometry.
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Affiliation(s)
- Ariane Saliani
- NeuroPoly Lab, Institute of Biomedical Engineering, Polytechnique Montreal, Montreal, QC, Canada
| | - Blanche Perraud
- NeuroPoly Lab, Institute of Biomedical Engineering, Polytechnique Montreal, Montreal, QC, Canada
| | - Tanguy Duval
- NeuroPoly Lab, Institute of Biomedical Engineering, Polytechnique Montreal, Montreal, QC, Canada
| | - Nikola Stikov
- NeuroPoly Lab, Institute of Biomedical Engineering, Polytechnique Montreal, Montreal, QC, Canada
- Montreal Heart Institute, Montreal, QC, Canada
| | - Serge Rossignol
- Groupe de Recherche sur le Système Nerveux Central, Department of Neuroscience, Faculty of Medicine, Université de Montréal, Montreal, QC, Canada
| | - Julien Cohen-Adad
- NeuroPoly Lab, Institute of Biomedical Engineering, Polytechnique Montreal, Montreal, QC, Canada
- Functionnal Neuroimaging Unit, Centre de Recherche de l'Institut Universitaire de Gériatrie de Montréal, Université de Montréal, Montreal, QC, Canada
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27
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Mavioglu H, Tuglu I, Temiz C, Ozbilgin K, Cilaker S, Selcuki D, Selcuki M. Clinical and Histological Changes of Intrathecally Administered Gadopentate Dimeglumine (Gd-DTPA) in Normal Rats. ACTA ACUST UNITED AC 2016. [DOI: 10.1177/197140090501800501] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022]
Abstract
Objectives: This study is carried out to explore clinical and histological changes induced in rats by intrathecal administration of Gd-DTPA via suboccipital spinal injection. 2.5, 5, 10 μmol/g-brain of Gd-DTPA were injected intrathecally to 43 adult male rats and sucrose as control solution with same volume and osmolarity were injected to 18 rats. Animals were sacrificed on day 4 and 14. Sections from the cortex, brain stem, cerebellum and medulla spinalis were obtained to examine for cell loss and apoptosis. In this study, no clinical abnormalities were observed in 69.8 % of rats of Gd-DTPA group and in 83.3 % of rats of sucrose group. Transient neurological signs such as ataxia and paresis were seen in 11.6 % of rats in the Gd-DTPA group and in 5.5 % of rats in the sucrose group. They were seen more frequently in the Gd-DTPA group especially in the highest dose and volume. Histological examination did not revealed necrosis or apoptosis in both groups. This study suggests that intrathecally administered Gd-DTPA may be safe in humans when lower doses per gram of brain are used than rats.
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Affiliation(s)
- H. Mavioglu
- Celal Bayar University, Faculty of Medicine, Department of Neurology; Manisa
| | - I. Tuglu
- Department of Histology & Embryology; Manisa
| | - C. Temiz
- Celal Bayar University, Faculty of Medicine, Department of Neurosurgery; Manisa, Turkey
| | - K. Ozbilgin
- Department of Histology & Embryology; Manisa
| | - S. Cilaker
- Department of Histology & Embryology; Manisa
| | - D. Selcuki
- Celal Bayar University, Faculty of Medicine, Department of Neurology; Manisa
| | - M. Selcuki
- Celal Bayar University, Faculty of Medicine, Department of Neurosurgery; Manisa, Turkey
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28
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Bolon B, Garman R, Jensen K, Krinke G, Stuart B. A ‘Best Practices’ Approach to Neuropathologic Assessment in Developmental Neurotoxicity Testing—for Today. Toxicol Pathol 2016; 34:296-313. [PMID: 16698729 DOI: 10.1080/01926230600713269] [Citation(s) in RCA: 40] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/29/2022]
Abstract
A key trait of developmental neurotoxicants is their ability to cause structural lesions in the immature nervous system. Thus, neuropathologic assessment is an essential element of developmental neurotoxicity (DNT) studies that are designed to evaluate chemically-induced risk to neural substrates in young humans. The guidelines for conventional DNT assays have been established by regulatory agencies to provide a flexible scaffold for conducting such studies; recent experience has launched new efforts to update these recommendations. The present document was produced by an ad hoc subcommittee of the Society of Toxicologic Pathology (STP) tasked with examining conventional methods used in DNT neuropathology in order to define the ‘best practices’ for dealing with the diverse requirements of both national (EPA) and international (OECD) regulatory bodies. Recommendations (including citations for relevant neurobiological and technical references) address all aspects of the DNT neuropathology examination: study design; tissue fixation, collection, processing, and staining; qualitative and quantitative evaluation; statistical analysis; proper control materials; study documentation; and personnel training. If followed, these proposals will allow pathologists to meet the need for a sound risk assessment (balanced to address both regulatory issues and scientific considerations) in this field today while providing direction for the research needed to further refine DNT neuropathology ‘best practices’ in the future.
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Affiliation(s)
- Brad Bolon
- GEMpath Inc., Cedar City, Utah 84720, USA
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Rao DB, Jortner BS, Sills RC. Animal models of peripheral neuropathy due to environmental toxicants. ILAR J 2015; 54:315-23. [PMID: 24615445 DOI: 10.1093/ilar/ilt058] [Citation(s) in RCA: 25] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/30/2022] Open
Abstract
Despite the progress in our understanding of pathogeneses and the identification of etiologies of peripheral neuropathy, idiopathic neuropathy remains common. Typically, attention to peripheral neuropathies resulting from exposure to environmental agents is limited relative to more commonly diagnosed causes of peripheral neuropathy (diabetes and chemotherapeutic agents). Given that there are more than 80,000 chemicals in commerce registered with the Environmental Protection Agency and that at least 1000 chemicals are known to have neurotoxic potential, very few chemicals have been established to affect the peripheral nervous system (mainly after occupational exposures). A wide spectrum of exposures, including pesticides, metals, solvents, nutritional sources, and pharmaceutical agents, has been related, both historically and recently, to environmental toxicant-induced peripheral neuropathy. A review of the literature shows that the toxicity and pathogeneses of chemicals adversely affecting the peripheral nervous system have been studied using animal models. This article includes an overview of five prototypical environmental agents known to cause peripheral neuropathy--namely, organophosphates, carbon disulfide, pyridoxine (Vitamin B6), acrylamide, and hexacarbons (mainly n-hexane, 2,5-hexanedione, methyl n-butyl ketone). Also included is a brief introduction to the structural components of the peripheral nervous system and pointers on common methodologies for histopathologic evaluation of the peripheral nerves.
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Morrison JP, Sharma AK, Rao D, Pardo ID, Garman RH, Kaufmann W, Bolon B. Fundamentals of translational neuroscience in toxicologic pathology: optimizing the value of animal data for human risk assessment. Toxicol Pathol 2014; 43:132-9. [PMID: 25398755 DOI: 10.1177/0192623314558306] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
A half-day Society of Toxicologic Pathology continuing education course on "Fundamentals of Translational Neuroscience in Toxicologic Pathology" presented some current major issues faced when extrapolating animal data regarding potential neurological consequences to assess potential human outcomes. Two talks reviewed functional-structural correlates in rodent and nonrodent mammalian brains needed to predict behavioral consequences of morphologic changes in discrete neural cell populations. The third lecture described practical steps for ensuring that specimens from rodent developmental neurotoxicity tests will be processed correctly to produce highly homologous sections. The fourth talk detailed demographic factors (e.g., species, strain, sex, and age); physiological traits (body composition, brain circulation, pharmacokinetic/pharmacodynamic patterns, etc.); and husbandry influences (e.g., group housing) known to alter the effects of neuroactive agents. The last presentation discussed the appearance, unknown functional effects, and potential relevance to humans of polyethylene glycol (PEG)-associated vacuoles within the choroid plexus epithelium of animals. Speakers provided real-world examples of challenges with data extrapolation among species or with study design considerations that may impact the interpretability of results. Translational neuroscience will be bolstered in the future as less invasive and/or more quantitative techniques are devised for linking overt functional deficits to subtle anatomic and chemical lesions.
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Affiliation(s)
| | | | - Deepa Rao
- National Toxicology Program, National Institute of Environmental Health Sciences and Integrated Laboratory Systems, Research Triangle Park, North Carolina, USA
| | | | - Robert H Garman
- Consultants in Veterinary Pathology, Inc., Murrysville, Pennsylvania, USA
| | | | - Brad Bolon
- The Ohio State University, College of Veterinary Medicine, Columbus, Ohio, USA
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Kovacs SK, Leonessa F, Ling GSF. Blast TBI Models, Neuropathology, and Implications for Seizure Risk. Front Neurol 2014; 5:47. [PMID: 24782820 PMCID: PMC3988378 DOI: 10.3389/fneur.2014.00047] [Citation(s) in RCA: 44] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/15/2014] [Accepted: 03/26/2014] [Indexed: 12/31/2022] Open
Abstract
Traumatic brain injury (TBI) due to explosive blast exposure is a leading combat casualty. It is also implicated as a key contributor to war related mental health diseases. A clinically important consequence of all types of TBI is a high risk for development of seizures and epilepsy. Seizures have been reported in patients who have suffered blast injuries in the Global War on Terror but the exact prevalence is unknown. The occurrence of seizures supports the contention that explosive blast leads to both cellular and structural brain pathology. Unfortunately, the exact mechanism by which explosions cause brain injury is unclear, which complicates development of meaningful therapies and mitigation strategies. To help improve understanding, detailed neuropathological analysis is needed. For this, histopathological techniques are extremely valuable and indispensable. In the following we will review the pathological results, including those from immunohistochemical and special staining approaches, from recent preclinical explosive blast studies.
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Affiliation(s)
- S Krisztian Kovacs
- Laboratory of Neurotrauma, Department of Neurology, Uniformed Services University of the Health Sciences , Bethesda, MD , USA
| | - Fabio Leonessa
- Laboratory of Neurotrauma, Department of Neurology, Uniformed Services University of the Health Sciences , Bethesda, MD , USA
| | - Geoffrey S F Ling
- Laboratory of Neurotrauma, Department of Neurology, Uniformed Services University of the Health Sciences , Bethesda, MD , USA
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Bolon B, Garman RH, Pardo ID, Jensen K, Sills RC, Roulois A, Radovsky A, Bradley A, Andrews-Jones L, Butt M, Gumprecht L. STP position paper: Recommended practices for sampling and processing the nervous system (brain, spinal cord, nerve, and eye) during nonclinical general toxicity studies. Toxicol Pathol 2013; 41:1028-48. [PMID: 23475559 DOI: 10.1177/0192623312474865] [Citation(s) in RCA: 122] [Impact Index Per Article: 11.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
The Society of Toxicologic Pathology charged a Nervous System Sampling Working Group with devising recommended practices to routinely screen the central nervous system (CNS) and peripheral nervous system (PNS) in Good Laboratory Practice-type nonclinical general toxicity studies. Brains should be weighed and trimmed similarly for all animals in a study. Certain structures should be sampled regularly: caudate/putamen, cerebellum, cerebral cortex, choroid plexus, eye (with optic nerve), hippocampus, hypothalamus, medulla oblongata, midbrain, nerve, olfactory bulb (rodents only), pons, spinal cord, and thalamus. Brain regions may be sampled bilaterally in rodents using 6 to 7 coronal sections, and unilaterally in nonrodents with 6 to 7 coronal hemisections. Spinal cord and nerves should be examined in transverse and longitudinal (or oblique) orientations. Most Working Group members considered immersion fixation in formalin (for CNS or PNS) or a solution containing acetic acid (for eye), paraffin embedding, and initial evaluation limited to hematoxylin and eosin (H&E)-stained sections to be acceptable for routine microscopic evaluation during general toxicity studies; other neurohistological methods may be undertaken if needed to better characterize H&E findings. Initial microscopic analyses should be qualitative and done with foreknowledge of treatments and doses (i.e., "unblinded"). The pathology report should clearly communicate structures that were assessed and methodological details. Since neuropathologic assessment is only one aspect of general toxicity studies, institutions should retain flexibility in customizing their sampling, processing, analytical, and reporting procedures as long as major neural targets are evaluated systematically.
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Affiliation(s)
- Brad Bolon
- 1The Ohio State University, Columbus, Ohio, USA
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Rosati M, Goedde T, Steffen F, Gandini G, De Risio L, Reese S, Matiasek K. Developmental Changes in Voltage-Gated Calcium Channel α 2δ-Subunit Expression in the Canine Dorsal Root Ganglion. Dev Neurosci 2012; 34:440-8. [DOI: 10.1159/000343725] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/03/2011] [Accepted: 09/27/2012] [Indexed: 01/21/2023] Open
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Kaufmann W, Bolon B, Bradley A, Butt M, Czasch S, Garman RH, George C, Gröters S, Krinke G, Little P, McKay J, Narama I, Rao D, Shibutani M, Sills R. Proliferative and nonproliferative lesions of the rat and mouse central and peripheral nervous systems. Toxicol Pathol 2012; 40:87S-157S. [PMID: 22637737 DOI: 10.1177/0192623312439125] [Citation(s) in RCA: 90] [Impact Index Per Article: 7.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/17/2022]
Abstract
Harmonization of diagnostic nomenclature used in the pathology analysis of tissues from rodent toxicity studies will enhance the comparability and consistency of data sets from different laboratories worldwide. The INHAND Project (International Harmonization of Nomenclature and Diagnostic Criteria for Lesions in Rats and Mice) is a joint initiative of four major societies of toxicologic pathology to develop a globally recognized nomenclature for proliferative and nonproliferative lesions in rodents. This article recommends standardized terms for classifying changes observed in tissues of the mouse and rat central (CNS) and peripheral (PNS) nervous systems. Sources of material include academic, government, and industrial histopathology databases from around the world. Covered lesions include frequent, spontaneous, and aging-related changes as well as principal toxicant-induced findings. Common artifacts that might be confused with genuine lesions are also illustrated. The neural nomenclature presented in this document is also available electronically on the Internet at the goRENI website (http://www.goreni.org/).
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Wohlsein P, Deschl U, Baumgärtner W. Nonlesions, unusual cell types, and postmortem artifacts in the central nervous system of domestic animals. Vet Pathol 2012; 50:122-43. [PMID: 22692622 DOI: 10.1177/0300985812450719] [Citation(s) in RCA: 32] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
In the central nervous system (CNS) of domestic animals, numerous specialized normal structures, unusual cell types, findings of uncertain or no significance, artifacts, and various postmortem alterations can be observed. They may cause confusion for inexperienced pathologists and those not specialized in neuropathology, leading to misinterpretations and wrong diagnoses. Alternatively, changes may mask underlying neuropathological processes. "Specialized structures" comprising the hippocampus and the circumventricular organs, including the vascular organ of the lamina terminalis, subfornical organ, subcommissural organ, pineal gland, median eminence/neurohypophyseal complex, choroid plexus, and area postrema, are displayed. Unusual cell types, including cerebellar external germinal cells, CNS progenitor cells, and Kolmer cells, are presented. In addition, some newly recognized cell types as of yet incompletely understood significance and functionality, such as synantocytes and aldynoglia, are introduced and described. Unusual reactive astrocytes in cats, central chromatolysis, neuronal vacuolation, spheroids, spongiosis, satellitosis, melanosis, neuromelanin, lipofuscin, polyglucosan bodies, and psammoma bodies may represent incidental findings of uncertain or no significance and should not be confused with significant microscopic changes. Auto- and heterolysis as well as handling and histotechnological processing may cause postmortem morphological changes of the CNS, including vacuolization, cerebellar conglutination, dark neurons, Buscaino bodies, freezing, and shrinkage artifacts, all of which have to be differentiated from genuine lesions. Postmortem invasion of micro-organisms should not be confused with intravital infections. Awareness of these different changes and their recognition are a prerequisite for identifying genuine lesions and may help to formulate a professional morphological and etiological diagnosis.
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Affiliation(s)
- P Wohlsein
- Department of Pathology, University of Veterinary Medicine Hannover, Bünteweg 17, D-30559 Hannover, Germany.
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Bolon B, Couto S, Fiette L, Perle KL. Internet and Print Resources to Facilitate Pathology Analysis When Phenotyping Genetically Engineered Rodents. Vet Pathol 2011; 49:224-35. [DOI: 10.1177/0300985811415709] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022]
Abstract
Genetically engineered mice and rats are increasingly used as models for exploring disease progression and mechanisms. The full spectrum of anatomic, biochemical, and functional changes that develop in novel, genetically engineered mouse and rat lines must be cataloged before predictions regarding the significance of the mutation may be extrapolated to diseases in other vertebrate species, including humans. A growing list of reference materials, including books, journal articles, and websites, has been produced in the last 2 decades to assist researchers in phenotyping newly engineered rodent lines. This compilation provides an extensive register of materials related to the pathology component of rodent phenotypic analysis. In this article, the authors annotate the resources they use most often, to allow for quick determination of their relevance to research projects.
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Affiliation(s)
- B. Bolon
- The Ohio State University, Columbus, Ohio
| | - S. Couto
- Genentech, Inc., South San Francisco, California
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Hale SL, Andrews-Jones L, Jordan WH, Jortner BS, Boyce RW, Boyce JT, III RCS, Butt MT, Garman RH, Jensen K, Krinke G, Little PB. Modern Pathology Methods for Neural Investigations. Toxicol Pathol 2011; 39:52-7. [DOI: 10.1177/0192623310394213] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
Abstract
This session at the 2010 joint symposium of the Society of Toxicologic Pathology (STP) and the International Federation of Societies of Toxicologic Pathologists (IFSTP) explored modern neuropathology methods for assessing the neurotoxicologic potential of xenobiotics. Conventional techniques to optimally prepare and evaluate the central and peripheral neural tissues while minimizing artifact were reviewed, and optimal schemes were set forth for evaluation of the nervous system during both routine (i.e., general toxicity) studies and enhanced (i.e., specialized neurotoxicity) studies. Stereology was introduced as the most appropriate means of examining the possible impact of toxicants on neural cell numbers. A focused discussion on brain sampling took place among a panel of expert neuroscientists (anatomists and pathologists) and the audience regarding the proper balance between sufficient sampling and cost- and time-effectiveness of the analysis. No consensus was reached on section orientation (coronal sections of both sides vs. a parasagittal longitudinal section with several unilateral hemisections from the contralateral side), but most panelists favored sampling at least 8 sections (or approximately double to triple the current complement) in routine toxicity studies.
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Affiliation(s)
| | | | | | - Bernard S. Jortner
- Virginia-Maryland Regional College of Veterinary Medicine, Blacksburg, VA, USA
| | | | | | | | - Mark T. Butt
- Tox Path Specialists, LLC, Walkersville, MD, USA
| | | | - Karl Jensen
- U.S. Environmental Protection Agency, Research Triangle Park, NC, USA
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Jordan WH, Young JK, Hyten MJ, Hall DG. Preparation and Analysis of the Central Nervous System. Toxicol Pathol 2010; 39:58-65. [PMID: 21139057 DOI: 10.1177/0192623310391480] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022]
Abstract
For many pathologists, neuropathology is intimidating. Practical approaches for nervous tissue histologic evaluations to meet both routine and advanced study designs can lead to rewarding neuropathology efforts. Cost-effective, high-quality histologic evaluations can occur if animals are exsanguinated quickly, brains removed carefully to maintain structural integrity and avoid dark neuron artifact, immersion-fixed quickly and thoroughly, and trimmed and processed to consistently survey multiple areas. While brightfield examination of H&E-stained sections is generally sufficient for survey evaluations, epifluorescent assessment of neuronal autofluorescence facilitates recognition of neurodegeneration in H&E-stained sections. Fluoro-Jade B or specialized immunohistochemical stains may be required to answer specific questions. Evaluations require that both technical staff and pathologists have a working knowledge of a few easily identified neuroanatomic landmarks and familiarity with use of a detailed brain atlas. At least four coronal sections should be routinely surveyed from young adult rats, with evaluation of comparable areas in other laboratory animal species. This number should be at least doubled if there is reason to suspect morphologic changes in the CNS. This article focuses on technical details of efficient specimen preparation for neuropathologic evaluations involving relatively large numbers of rodents, as well as a practical approach to basic neuroanatomic site identification.
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Affiliation(s)
| | | | | | - D. Greg Hall
- Lilly Research Laboratories, Indianapolis, Indiana, USA
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Abstract
This article is from a presentation at the 2010 STP/IFSTP Symposium on Neuropathology. The organization and basic structure of the peripheral nervous system is reviewed. Examples of toxicant-induced peripheral nerve injury such as neuronopathy, axonopathy, and myelinapathy are discussed, as are contemporary methods for examination of these tissues.
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Bolon B, Bradley A, Garman RH, Krinke GJ. Useful Toxicologic Neuropathology References for Pathologists and Toxicologists. Toxicol Pathol 2010; 39:234-9. [DOI: 10.1177/0192623310385142] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
Investigations in toxicologic neuropathology are complex undertakings because of the intricate spatial and temporal diversity in the anatomic, functional, and molecular organization of the central and peripheral nervous systems. This compilation of toxicologic neuropathology resources has been designed to consolidate a broad range of useful neurobiology, neuropathology, and neurotoxicology resources in a single reference. This collection will increase familiarity with the basic knowledge, skills, and tools required for the proficient practice of toxicologic neuropathology and should help to improve the analysis and interpretation of pathology data sets from neural tissues in toxicology studies.
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Affiliation(s)
| | - Alys Bradley
- Charles River Laboratories, Preclinical Services, Edinburgh EH33 2NE, Scotland, United Kingdom
| | - Robert H. Garman
- Consultants in Veterinary Pathology, Inc., Murrysville, Pennsylvania, USA
| | - Georg J. Krinke
- Pathology Evaluations (PATHEV), 4402 Frenkendorf, Switzerland
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Bolon B, Anthony DC, Butt M, Dorman D, Green MV, Little PB, Valentine WM, Weinstock D, Yan J, Sills RC. “Current Pathology Techniques” Symposium Review: Advances and Issues in Neuropathology. Toxicol Pathol 2008. [DOI: 10.1177/0192623308322313] [Citation(s) in RCA: 15] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/22/2023]
Abstract
Our understanding of the mechanisms that incite neurological diseases has progressed rapidly in recent years, mainly owing to the advent of new research instruments and our increasingly facile ability to assemble large, complex data sets acquired across several disciplines into an integrated representation of neural function at the molecular, cellular, and systemic levels. This mini-review has been designed to communicate the principal technical advances and current issues of importance in neuropathology research today in the context of our traditional neuropathology practices. Specific topics briefly addressed in this paper include correlative biology of the many facets of the nervous system; conventional and novel methods for investigating neural structure and function; theoretical and technical issues associated with investigating neuropathology end points in emerging areas of concern (developmental neurotoxicity, neurodegenerative conditions); and challenges and opportunities that will face pathologists in this field in the foreseeable future. We have organized this information in a manner that we hope will be of interest not only to professionals with a career focus in neuropathology, but also to general pathologists who occasionally face neuropathology questions.
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Affiliation(s)
| | - Douglas C. Anthony
- University of Missouri, Department of Pathology and Anatomical Sciences, Columbia, Missouri, USA
| | - Mark Butt
- Tox Path Specialists, Walkersville, Maryland, USA
| | - David Dorman
- North Carolina State University, College of Veterinary Medicine, Raleigh, North Carolina, USA
| | | | - Peter B. Little
- Charles River Laboratories, Research Triangle Park, North Carolina, USA
| | | | | | - James Yan
- Hospira Inc., Lake Forest, Illinois, USA
| | - Robert C. Sills
- National Institute of Environmental Health Sciences, Research Triangle Park, North Carolina, USA
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Hubbs AF, Benkovic SA, Miller DB, O'Callaghan JP, Battelli L, Schwegler-Berry D, Ma Q. Vacuolar leukoencephalopathy with widespread astrogliosis in mice lacking transcription factor Nrf2. THE AMERICAN JOURNAL OF PATHOLOGY 2007; 170:2068-76. [PMID: 17525273 PMCID: PMC1899457 DOI: 10.2353/ajpath.2007.060898] [Citation(s) in RCA: 93] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
Abstract
NFE2-related factor 2 (Nrf2), an oxidant-activated CNC bZip transcription factor, has been implicated in defense against oxidative stress and chemical insults in a range of cell and tissue types, including the central nervous system. Here, we report that deletion of the Nrf2 gene in mice caused vacuolar (spongiform) leukoencephalopathy with widespread astrogliosis. The leukoencephalopathy was present in all Nrf2-null mice more than 10 months of age, was characterized by vacuolar degeneration involving all major brain regions, and was most apparent in the white tracts of the cerebellum and pons. Vacuolar degeneration in white tracts was attributable to myelin unwinding and intramyelinic cysts, and double-label immunofluorescence for 4-hydroxy-2-nonenal and myelin basic protein localized free-radical-induced oxidative damage to the myelin sheath. Moreover, the brains of Nrf2-null mice exhibited widespread astrocyte activation with profusion of glial fibrillary acidic protein-immunoreactive glial processes. The study uncovered a possible physiological role for Nrf2 in maintaining central nervous system myelin. If this role is confirmed, it may suggest new approaches to treating genetically and chemically induced myelin degenerative diseases.
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Affiliation(s)
- Ann F Hubbs
- Experimental Pathology Laboratory, Toxicology and Molecular Biology Branch, Health Effects Laboratory Division, National Institute for Occupational Safety and Health/CDC, 1095 Willowdale Road, Morgantown, WV 26505, USA
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Kaufmann W, Gröters S. Developmental neuropathology in DNT-studies—A sensitive tool for the detection and characterization of developmental neurotoxicants. Reprod Toxicol 2006; 22:196-213. [PMID: 16781841 DOI: 10.1016/j.reprotox.2006.04.021] [Citation(s) in RCA: 16] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/27/2006] [Revised: 04/10/2006] [Accepted: 04/10/2006] [Indexed: 11/18/2022]
Abstract
Developmental neurotoxicity (DNT-) studies are the first reproduction toxicity studies for which an extended histopathological examination of developing structures is required by the current EPA and OECD guidelines. The morphological screening includes a macroscopic evaluation of the brain and nervous tissue, brain weight parameters, gross morphometry of the brain, neurohistological examinations and a quantitative analysis of major brain areas. This review is intended to give an overview about the needs according to guideline requirements, practical approaches for a successful developmental neuropathology and its preconditions and does include examples of background data on the value and functional meaning of morphological data. A selection of experimental data from literature is also presented in the light of their contribution for the understanding of important, neurodevelopmental disorders in humans.
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Affiliation(s)
- Wolfgang Kaufmann
- Department of Product Safety, Regulations, Experimental Toxicology and Ecology, BASF AG, Ludwigshafen, Germany.
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Hancock SK, Hinckley J, Ehrich M, Jortner BS. Morphological measurement of neurotoxic injury in the peripheral nervous system: preparation of material for light and transmission electron microscopic evaluation. CURRENT PROTOCOLS IN TOXICOLOGY 2005; Chapter 12:Unit12.12. [PMID: 23045109 DOI: 10.1002/0471140856.tx1212s22] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/01/2023]
Abstract
An important method of assessing experimental neurotoxic injury is the pathologic examination of the nervous system. Methods for fixation, sampling, and preparation of peripheral nervous system tissues for critical pathological neurotoxicology studies are presented. Fixation of tissue is carried out using either perfusion-fixation of laboratory animals or immersion-fixation of dissected nerve segments. Dissection of the peripheral nervous system (from perfusion-fixed animals) is done to allow for multilevel sampling. Focus is on use of epoxy resin embedding tissue sections for optimal light microscopic resolution. Protocols for processing, sectioning, and staining for light and transmission electron microscopy are provided. A protocol for teasing and microscopic study of individual myelinated fibers is provided.
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Affiliation(s)
- S K Hancock
- Virginia Polytechnic Institute and State University, Blacksburg, VA, USA
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Gill S, Murphy M, Clausen J, Richard D, Quilliam M, MacKinnon S, LaBlanc P, Mueller R, Pulido O. Neural injury biomarkers of novel shellfish toxins, spirolides: a pilot study using immunochemical and transcriptional analysis. Neurotoxicology 2003; 24:593-604. [PMID: 12900072 DOI: 10.1016/s0161-813x(03)00014-7] [Citation(s) in RCA: 62] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/27/2022]
Abstract
In 1991, routine biotoxin monitoring of bivalve molluscs at aquaculture sites along the eastern shore of Nova Scotia, Canada revealed a group of novel seafood toxins called spirolides, whose origin was the dinoflagellate Alexandrium ostenfeldii. Result from this preliminary study in rodents demonstrates a highly toxic lethal response in rats and mice after intraperitoneal injections of lipophilic extracts. To elucidate the modes of action and toxicologic pathology, brain and internal organs were examined by histology and various biomarkers of neural injury were monitored by immunohistochemistry (IH) and/or transcriptional analysis. The histological and transcriptional data showed that the effects of spirolides are species dependent for mice and rats. Histopathology showed that in the mouse brain, the hippocampus and brain stem appeared to be the major target regions but no histological changes were observed in the rat. Transcriptional analysis in the mouse brain showed no alterations in the biomarkers whereas in the rat brain there were major changes in the markers of neuronal injury. These biomarkers included the early injury markers HSP-72, c-jun and c-fos which are essential for converting stimuli into intracellular changes within neurons. The potential effects of spirolides were also evaluated with respect to different subtypes of the acetylcholine receptors (AChRs) since earlier reports showed these as putative targets. Both the muscarinic and nicotinic AChRs were found to be upregulated. Hence, transcriptional and immunohistochemical analysis does provide insight to the molecular mechanisms of this novel group of shellfish toxins. No histological changes were observed in other tissues.
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Affiliation(s)
- Santokh Gill
- Health Canada, Pathology Section, TRD, Bureau Chemical Safety, HPFB, Ottawa, Ontario, Canada K1A 0L2.
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Abstract
Sampling of large-sized brains (eg, dog, primate) for microscopic examination is frequently inadequate to detect localized neurotoxic injury. Furthermore, the examination of H&E-stained sections alone will often be insufficient for the detection of subtle neuropathogic alteration. It is imperative for any pathologist evaluating brain sections to have knowledge of microscopic neuroanatomy and to also have some understanding of basic neurochemistry. When a focus of degeneration is detected within the brain, the pathologist needs to ascertain not only the specific anatomic location of this focus but also the neuroanatomic regions that project to and receive output from the injured focus. Because of the complexity of brain circuitry and the fact that the brain contains many distinctive neuron populations, many more brain sections are required for adequate microscopic evaluation than for any other body organ. Deciding which and how many areas should be examined, microscopically, from a large size brain is often problematic. Although any sampling protocol will be influenced by what is known about the test chemical, it has been well established that certain regions of the brain (eg, hippocampus and other components of the limbic system, basal ganglia, Purkinje neurons) are more susceptible than others to a variety of physical, metabolic, and chemical insults. Knowledge of these regional sensitivities will assist in guiding the pathologist in the development of an adequate sampling protocol.
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Affiliation(s)
- Robert H Garman
- Consultants in Veterinary Pathology, Inc, Murrysville, Pennsylvania 15668-0068, USA
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Monleón E, Monzón M, Hortells P, Vargas A, Badiola JJ. Detection of PrP(sc) in samples presenting a very advanced degree of autolysis (BSE liquid state) by immunocytochemistry. J Histochem Cytochem 2003; 51:15-8. [PMID: 12502750 DOI: 10.1177/002215540305100103] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022] Open
Abstract
Although detection of the abnormal isoform of prion protein (PrP(sc)), the specific feature of transmissable spongiform encephalopathies (TSEs), has been previously demonstrated on formalin-fixed autolytic tissue, no samples with autolysis as severe as tested here (i.e., liquid state) have previously been tested. It is inevitable that a small but significant proportion of brains, especially in summer due to delays in postmortem examination, undergo an extremely severe autolysis that makes samples unsuitable for diagnosis by conventional techniques. In this study, 25 bovine samples were diagnosed by applying immunocytochemistry on the corresponding liquid fraction. Four additional portions of brainstem (positive and negative sheep and cattle) were subjected to one of the autolysis regimens at 56C or environmental conditions for up to 80 days and were analyzed with the same methodology. No abnormal protein could be detected in any of the control animals. PrP(sc) accumulation was observed by immunocytochemistry in all cases that were positive by either immunohistochemistry on the corresponding filtrates or by Prionics Western blotting, showing an excellent agreement between the methodology assessed and these routine techniques. The results of this study demonstrate immunocytochemistry as a useful tool for diagnosis in liquid-state samples, solving a most relevant problem in BSE and scrapie epidemiology.
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Affiliation(s)
- Eva Monleón
- National Reference Centre for Transmissible Spongiform Encephalopathies, University of Zaragoza, Zorgoza, Spain
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49
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Debeer SOS, Baron TGM, Bencsik AA. Transmissible spongiform encephalopathy diagnosis using PrPsc immunohistochemistry on fixed but previously frozen brain samples. J Histochem Cytochem 2002; 50:611-6. [PMID: 11967272 DOI: 10.1177/002215540205000502] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022] Open
Abstract
The histological diagnosis of transmissible spongiform encephalopathies (TSEs), such as scrapie and bovine spongiform encephalopathy (BSE), relies on identification in the brain of spongiosis, gliosis, and neuron loss without inflammatory lesions. Because of its sensitivity, immunohistochemistry of abnormal prion protein (PrPsc) is of great help in this diagnosis and can be used on its own or complementary to the biochemical detection of PrPsc. However, in some cases no formalin-fixed material is available, rendering its use as a complementary method impossible. For that purpose, we studied the possibility of detecting PrPsc immunohistochemically in fixed brain samples that had been previously frozen and used for Western blotting analysis. We compared freshly and fixed-frozen brain samples originating from the same sheep, either affected or unaffected with scrapie. We also studied fixed-frozen brain samples from scrapie-affected goats and from cows showing BSE. We showed that in all the species tested, despite damage to the histological structures, PrPsc was still detectable in the fixed-frozen brain sections without unspecific background staining. Notwithstanding the limited number of cases thus far analyzed, we have already demonstrated the possibility of using PrPsc immunohistochemistry on fixed-frozen brain samples with very good efficacy, thus rendering possible its use for diagnostic purposes in TSEs.
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Affiliation(s)
- Sabine O S Debeer
- AFSSA, Laboratoire d'Etudes et de Recherches en Pathologie Bovine et Hygiène des Viandes, Unité Virologie-ATNC, Lyon, France
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50
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Debeer SO, Baron TG, Bencsik AA. Immunohistochemistry of PrPsc within bovine spongiform encephalopathy brain samples with graded autolysis. J Histochem Cytochem 2001; 49:1519-24. [PMID: 11724899 DOI: 10.1177/002215540104901205] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/25/2022] Open
Abstract
Bovine spongiform encephalopathy (BSE) is a transmissible neurodegenerative disease of cattle. Clinical diagnosis can be confirmed by investigation of both spongiform changes and abnormal prion protein (PrPsc), a marker considered specific for the disease. Tissue autolysis, often unavoidable in routine field cases, is not compatible with histological examination of the brain even though PrPsc is still detectable by immunoblotting. To determine how autolysis might affect accurate diagnosis using PrPsc immunohistochemistry, we studied 50 field samples of BSE brainstem (obex) with various degrees of autolysis. We demonstrated that the antigen-unmasking pretreatments necessary for PrPsc immunohistochemistry were compatible with the preservation of autolyzed brain sections and that PrPsc detection was unaffected by autolysis, even though anatomic markers were sometimes lost. In tissue samples in which anatomic sites were still recognizable, PrPsc accumulation was detected in specific gray matter nuclei. In samples with advanced autolysis, PrPsc deposits were still observed, at least at the cellular level, as an intraneuronal pattern. We found that the sensitivity of PrPsc immunohistochemistry as a diagnostic method for BSE was undiminished even by severe tissue autolysis.
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Affiliation(s)
- S O Debeer
- AFSSA, Laboratoire d'Etudes et de Recherches en Pathologie Bovine et Hygiène des Viandes, Unité Virologie-ATNC, Lyon, France.
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