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Bilousova T, Miller CA, Poon WW, Vinters HV, Corrada M, Kawas C, Hayden EY, Teplow DB, Glabe C, Albay R, Cole GM, Teng E, Gylys KH. Synaptic Amyloid-β Oligomers Precede p-Tau and Differentiate High Pathology Control Cases. THE AMERICAN JOURNAL OF PATHOLOGY 2016; 186:185-98. [PMID: 26718979 DOI: 10.1016/j.ajpath.2015.09.018] [Citation(s) in RCA: 90] [Impact Index Per Article: 11.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/13/2015] [Revised: 08/28/2015] [Accepted: 09/01/2015] [Indexed: 01/03/2023]
Abstract
Amyloid-β (Aβ) and hyperphosphorylated tau (p-tau) aggregates form the two discrete pathologies of Alzheimer disease (AD), and oligomeric assemblies of each protein are localized to synapses. To determine the sequence by which pathology appears in synapses, Aβ and p-tau were quantified across AD disease stages in parietal cortex. Nondemented cases with high levels of AD-related pathology were included to determine factors that confer protection from clinical symptoms. Flow cytometric analysis of synaptosome preparations was used to quantify Aβ and p-tau in large populations of individual synaptic terminals. Soluble Aβ oligomers were assayed by a single antibody sandwich enzyme-linked immunosorbent assay. Total in situ Aβ was elevated in patients with early- and late-stage AD dementia, but not in high pathology nondemented controls compared with age-matched normal controls. However, soluble Aβ oligomers were highest in early AD synapses, and this assay distinguished early AD cases from high pathology controls. Overall, synapse-associated p-tau did not increase until late-stage disease in human and transgenic rat cortex, and p-tau was elevated in individual Aβ-positive synaptosomes in early AD. These results suggest that soluble oligomers in surviving neocortical synaptic terminals are associated with dementia onset and suggest an amyloid cascade hypothesis in which oligomeric Aβ drives phosphorylated tau accumulation and synaptic spread. These results indicate that antiamyloid therapies will be less effective once p-tau pathology is developed.
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Affiliation(s)
- Tina Bilousova
- University of California Los Angeles School of Nursing, Los Angeles, California; Mary S. Easton Center for Alzheimer's Research at the University of California Los Angeles, Los Angeles, California
| | - Carol A Miller
- Departments of Pathology, Neurology, and the Program in Neuroscience, University of Southern California Keck School of Medicine, Los Angeles, California
| | - Wayne W Poon
- Institute for Memory Impairments and Neurological Disorders, University of California Irvine, Irvine, California
| | - Harry V Vinters
- Department of Neurology, University of California Los Angeles School of Medicine, Los Angeles, California; Department of Pathology and Laboratory Medicine, University of California Los Angeles School of Medicine, Los Angeles, California
| | - Maria Corrada
- Institute for Memory Impairments and Neurological Disorders, University of California Irvine, Irvine, California; Department of Neurology, University of California Irvine, Irvine, California
| | - Claudia Kawas
- Institute for Memory Impairments and Neurological Disorders, University of California Irvine, Irvine, California; Department of Neurology, University of California Irvine, Irvine, California; Department of Neurobiology & Behavior, University of California Irvine, Irvine, California
| | - Eric Y Hayden
- Mary S. Easton Center for Alzheimer's Research at the University of California Los Angeles, Los Angeles, California; Department of Neurology, University of California Los Angeles School of Medicine, Los Angeles, California
| | - David B Teplow
- Mary S. Easton Center for Alzheimer's Research at the University of California Los Angeles, Los Angeles, California; Department of Neurology, University of California Los Angeles School of Medicine, Los Angeles, California
| | - Charles Glabe
- Department of Molecular Biology and Biochemistry, University of California Irvine, Irvine, California
| | - Ricardo Albay
- Department of Molecular Biology and Biochemistry, University of California Irvine, Irvine, California
| | - Gregory M Cole
- Mary S. Easton Center for Alzheimer's Research at the University of California Los Angeles, Los Angeles, California; Department of Neurology, University of California Los Angeles School of Medicine, Los Angeles, California; Department of Medicine, University of California Los Angeles School of Medicine, Los Angeles, California; Geriatric Research, Education and Clinical Center, VA Greater Los Angeles Healthcare System, Los Angeles, California
| | - Edmond Teng
- Mary S. Easton Center for Alzheimer's Research at the University of California Los Angeles, Los Angeles, California; Department of Neurology, University of California Los Angeles School of Medicine, Los Angeles, California; Geriatric Research, Education and Clinical Center, VA Greater Los Angeles Healthcare System, Los Angeles, California
| | - Karen H Gylys
- University of California Los Angeles School of Nursing, Los Angeles, California; Mary S. Easton Center for Alzheimer's Research at the University of California Los Angeles, Los Angeles, California.
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Cytoprotective and Antioxidant Effects of an Edible Herb, Enhydra fluctuans Lour. (Asteraceae), against Experimentally Induced Lead Acetate Intoxication. PLoS One 2016; 11:e0148757. [PMID: 26859407 PMCID: PMC4747604 DOI: 10.1371/journal.pone.0148757] [Citation(s) in RCA: 23] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/17/2015] [Accepted: 01/09/2016] [Indexed: 01/31/2023] Open
Abstract
Background Enhydra fluctuans Lour. (Asteraceae), an edible aquatic herb, is traditionally employed against toxic effects of heavy metals in India. The present study was planned to discover the protective effect of edible extract of E. fluctuans (AEEF) against Pb toxicity. Methods The cytoprotective role of AEEF was determined on murine hepatocytes employing MTT assay and Hoechst staining. The effects on lipid peroxidation, protein carbonylation, endogenous redox systems and the transcription levels of apoptotic proteins were studied after incubating the hepatocytes with AEEF (400 μg/ml) + Pb-acetate (6.8 μM). The defensive role of AEEF (100 mg/kg) against Pb-acetate (5 mg/kg) intoxication was measured in mice by in vivo assays. Biochemical, haematological and histological parameters, intracellular Pb burden and redox status were measured. Results AEEF exhibited a concentration dependent cytoprotective effect against Pb-induced cytotoxicity in vitro. Pb-acetate incubation significantly (p < 0.01) altered the extents of ROS production ↑, protein carbonylation ↑, lipid peroxidation ↑, endogenous antioxidant enzymes ↓ and GSH ↓ in vitro. Besides, Pb-acetate significantly (p < 0.01) induced apoptosis in the hepatocytes apparent from the altered expressions of apoptotic proteins viz. Apaf-1 ↑, Bad ↑, Bcl-2 ↓, Cyt C ↑, cleaved caspases↑, Bid ↑ and Fas ↑. However, AEEF (400 μg/ml) could significantly (p < 0.05–0.01) attenuate the Pb-acetate mediated toxic manifestation in vitro. In in vivo assay, Pb-acetate (5 mg/kg) treated mice exhibited significantly (p < 0.01) high intracellular Pb content. A high Pb-burden within the tissues caused significant (p < 0.05–0.01) patho-physiological alterations viz. ROS production ↑, protein carbonylation↑, lipid peroxidation ↑, DNA fragmentation ↑, ATP formation ↑, mitochondrial co-enzymes Q ↓, endogenous antioxidant enzymes ↓ and GSH ↓ within the selected tissues. The haematological and serum biochemical parameters were significantly (p < 0.05–0.01) different in the Pb-acetate treated mice. Finally, histological assessment imposed significant toxic occurrence within the organs of Pb-intoxicated animals. However, concurrent administration of AEEF (100 mg/kg) could significantly (p < 0.05–0.01) reinstate the Pb-acetate mediated toxicity. Conclusion Presence of metal chelators and phyto-antioxidants within AEEF would offer overall protection through promoting Pb clearance coupled with restoring redox balance.
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Dewanjee S, Dua TK, Khanra R, Das S, Barma S, Joardar S, Bhattacharjee N, Zia-Ul-Haq M, Jaafar HZE. Water Spinach, Ipomoea aquatic (Convolvulaceae), Ameliorates Lead Toxicity by Inhibiting Oxidative Stress and Apoptosis. PLoS One 2015; 10:e0139831. [PMID: 26473485 PMCID: PMC4608788 DOI: 10.1371/journal.pone.0139831] [Citation(s) in RCA: 30] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/13/2015] [Accepted: 09/17/2015] [Indexed: 12/13/2022] Open
Abstract
BACKGROUND Ipomoea aquatica (Convolvulaceae), an aquatic edible plant, is traditionally used against heavy metal toxicity in India. The current study intended to explore the protective role of edible (aqueous) extract of I. aquatica (AEIA) against experimentally induced Pb-intoxication. METHODS The cytoprotective role of AEIA was measured on mouse hepatocytes by cell viability assay followed by Hoechst staining and flow cytometric assay. The effect on ROS production, lipid peroxidation, protein carbonylation, intracellular redox status were measured after incubating the hepatocytes with Pb-acetate (6.8 μM) along with AEIA (400 μg/ml). The effects on the expressions of apoptotic signal proteins were estimated by western blotting. The protective role of AEIA was measured by in vivo assay in mice. Haematological, serum biochemical, tissue redox status, Pb bioaccumulation and histological parameters were evaluated to estimate the protective role of AEIA (100 mg/kg) against Pb-acetate (5 mg/kg) intoxication. RESULTS Pb-acetate treated hepatocytes showed a gradual reduction of cell viability dose-dependently with an IC50 value of 6.8 μM. Pb-acetate treated hepatocytes exhibited significantly enhanced levels (p < 0.01) of ROS production, lipid peroxidation, protein carbonylation with concomitant depletion (p < 0.01) of antioxidant enzymes and GSH. However, AEIA treatment could significantly restore the aforementioned parameters in murine hepatocytes near to normalcy. Besides, AEIA significantly reversed (p < 0.05-0.01) the alterations of transcription levels of apoptotic proteins viz. Bcl 2, Bad, Cyt C, Apaf-1, cleaved caspases [caspase 3, caspase 8 and caspase 9], Fas and Bid. In in vivo bioassay, Pb-acetate treatment caused significantly high intracellular Pb burden and oxidative pressure in the kidney, liver, heart, brain and testes in mice. In addition, the haematological and serum biochemical factors were changed significantly in Pb-acetate-treated animals. AEIA treatment restored significantly the evaluated-parameters to the near-normal position. CONCLUSION The extract may offer the protective effect via counteracting with Pb mediated oxidative stress and/or promoting the elimination of Pb by chelating. The presence of substantial quantities of flavonoids, phenolics and saponins would be responsible for the overall protective effect.
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Affiliation(s)
- Saikat Dewanjee
- Advanced Pharmacognosy Research Laboratory, Department of Pharmaceutical Technology, Jadavpur University, Kolkata, 700032, India
| | - Tarun K. Dua
- Advanced Pharmacognosy Research Laboratory, Department of Pharmaceutical Technology, Jadavpur University, Kolkata, 700032, India
| | - Ritu Khanra
- Advanced Pharmacognosy Research Laboratory, Department of Pharmaceutical Technology, Jadavpur University, Kolkata, 700032, India
| | - Shilpa Das
- Advanced Pharmacognosy Research Laboratory, Department of Pharmaceutical Technology, Jadavpur University, Kolkata, 700032, India
| | - Sujata Barma
- Advanced Pharmacognosy Research Laboratory, Department of Pharmaceutical Technology, Jadavpur University, Kolkata, 700032, India
| | - Swarnalata Joardar
- Advanced Pharmacognosy Research Laboratory, Department of Pharmaceutical Technology, Jadavpur University, Kolkata, 700032, India
| | - Niloy Bhattacharjee
- Advanced Pharmacognosy Research Laboratory, Department of Pharmaceutical Technology, Jadavpur University, Kolkata, 700032, India
| | - M. Zia-Ul-Haq
- Department of Pharmacognosy, University of Karachi, Karachi, 75270, Pakistan
| | - Hawa Z. E. Jaafar
- Department of Crop Science, Faculty of Agriculture, Universiti Putra, Selangor, 43400, Malaysia
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Byrne UTE, Ross JM, Faull RLM, Dragunow M. High-throughput quantification of Alzheimer's disease pathological markers in the post-mortem human brain. J Neurosci Methods 2008; 176:298-309. [PMID: 18835409 DOI: 10.1016/j.jneumeth.2008.09.008] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/04/2008] [Revised: 09/03/2008] [Accepted: 09/05/2008] [Indexed: 01/03/2023]
Abstract
Quantitative analysis of amyloid plaques and neurofibrillary tangles is central to many Alzheimer's disease studies. A novel approach for quantitative immunohistochemistry of plaques and tangles has arisen from the need to account for the heterogeneous expression pattern of these markers in the human brain. This approach aims to overcome the human bias inherent to many sampling strategies, to account for the effects of tissue shrinkage resulting from antigen-retrieval procedures, and to accelerate the analysis of large sample sets by using a high-throughput quantification system. The procedure entailed three coordinated steps: acquisition of montaged images of entire tissue sections, randomised sampling across the cortex, and automated quantification of the selected samples with morphometric image analysis software. Two-dimensional estimates of plaque and tangle densities were obtained from the superior temporal gyrus and middle temporal gyrus of Alzheimer's disease and normal human brains. Results showed a robust correlation between the numbers of plaques and tangles quantified by automated image analysis and those acquired by manual counting. Correction for antigen-retrieval tissue shrinkage ensured that density measurements were not over-estimated. The value and applicability of this assay was demonstrated by the statistically significant differences observed between the averaged densities of plaques and tangles within different investigational groups. We report an accurate and objective approach to the quantification of plaques and tangles in human brain tissue. Implementation of a randomised sampling strategy coupled with a reproducible automated quantification system will facilitate more rigorous comparison of quantitative data derived from different immunohistochemical studies.
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Affiliation(s)
- Ursula T E Byrne
- Department of Anatomy with Radiology, Faculty of Medical and Health Sciences, The University of Auckland, Auckland, New Zealand
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Teboul O, Feki A, Dubois A, Bozon B, Faure A, Hantraye P, Dhenain M, Delatour B, Delzescaux T. A standardized method to automatically segment amyloid plaques in Congo Red stained sections from Alzheimer transgenic mice. ACTA ACUST UNITED AC 2008; 2007:5593-6. [PMID: 18003280 DOI: 10.1109/iembs.2007.4353614] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022]
Abstract
Automated detection of amyloid plaques (AP) in post mortem brain sections of patients with Alzheimer disease (AD) or in mouse models of the disease is a major issue to improve quantitative, standardized and accurate assessment of neuropathological lesions as well as of their modulation by treatment. We propose a new segmentation method to automatically detect amyloid plaques in Congo Red stained sections based on adaptive thresholds and a dedicated amyloid plaque/tissue modelling. A set of histological sections focusing on anatomical structures was used to validate the method in comparison to expert segmentation.
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Affiliation(s)
- Olivier Teboul
- Medical Image Research Center, URA CEA-CNRS 2210, 4 place du Général Leclerc, 914006 Orsay Cedex, France
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Fully automated and adaptive detection of amyloid plaques in stained brain sections of Alzheimer transgenic mice. MEDICAL IMAGE COMPUTING AND COMPUTER-ASSISTED INTERVENTION : MICCAI ... INTERNATIONAL CONFERENCE ON MEDICAL IMAGE COMPUTING AND COMPUTER-ASSISTED INTERVENTION 2008. [PMID: 18044661 DOI: 10.1007/978-3-540-75759-7_116] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register]
Abstract
Automated detection of amyloid plaques (AP) in post mortem brain sections of patients with Alzheimer disease (AD) or in mouse models of the disease is a major issue to improve quantitative, standardized and accurate assessment of neuropathological lesions as well as of their modulation by treatment. We propose a new segmentation method to automatically detect amyloid plaques in Congo Red stained sections based on adaptive thresholds and a dedicated amyloid plaque/tissue modelling. A set of histological sections focusing on anatomical structures was used to validate the method in comparison to expert segmentation. Original information concerning global amyloid load have been derived from 6 mouse brains which opens new perspectives for the extensive analysis of such a data in 3-D and the possibility to integrate in vivo-post mortem information for diagnosis purposes.
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Chubb C, Inagaki Y, Sheu P, Cummings B, Wasserman A, Head E, Cotman C. BioVision: An application for the automated image analysis of histological sections. Neurobiol Aging 2006; 27:1462-76. [PMID: 16271803 DOI: 10.1016/j.neurobiolaging.2005.08.023] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/21/2005] [Revised: 08/12/2005] [Accepted: 08/22/2005] [Indexed: 10/25/2022]
Abstract
We describe a computer application, "BioVision", that can be trained to quickly and effectively classify and quantify user definable histological objects (e.g., senile plaques, neurofibrillary tangles) within single or double-labeled immunocytochemically stained sections. For a given image population, BioVision is interactively trained (in Independent User Mode) by an investigator to perform the desired classifications. This training yields a statistical model of the different types of objects occurring in the target image population. The resulting model can then be used (in Automated User Mode) to classify all objects in any image or images from the target population. BioVision simplifies the quantification of complex visual objects and improves inter-rater reliability. The program accomplishes classification in two major stages: pixel classification and blob classification. In pixel classification, each pixel is assigned to one of some number of substance classes, based on its chromatic properties and local context, reflecting basic histological distinctions of interest. In the blob classification phase, the image's pixels are first partitioned into "blobs": maximal connected sets of pixels assigned to the same substance class. Then, based on its size, shape, textural and contextual properties, each blob is assigned to a histological object class. A Bayesian classifier is used in each of the pixel and blob classification stages. We report several tests of BioVision. First, we applied BioVision to classify senile plaques and neurofibrillary tangles in several test cases of Alzheimer's brain immunostained for beta-amyloid and PHF-tau and compared the results to those produced by experienced investigators. BioVision was trained to classify Plaque-type blobs as either plaques or plaque-type nonentities, and tangle-type blobs as either tangles or tangle-type nonentities. BioVision classified the objects with an accuracy comparable to the trained investigator. Next, we applied BioVision to the task of counting all the tangles in hippocampal images from 22 Alzheimer's disease (AD) cases selected to span a broad range of dementia levels from the tissue repository of UC Irvine's Center for the study of Brain Aging and Dementia. The tangle counts produced by BioVision proved to be significantly better predictors of the cases' adjusted MMSE scores than any of tangle load, age at death, post mortem interval or the interval between the last MMSE score and death.
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Affiliation(s)
- Charles Chubb
- Department of Cognitive Sciences, and Institute for Mathematical Behavioral Sciences, University of California, Irvine, USA.
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Underwood RA, Gibran NS, Muffley LA, Usui ML, Olerud JE. Color subtractive-computer-assisted image analysis for quantification of cutaneous nerves in a diabetic mouse model. J Histochem Cytochem 2001; 49:1285-91. [PMID: 11561013 DOI: 10.1177/002215540104901011] [Citation(s) in RCA: 52] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022] Open
Abstract
Immunohistochemistry (IHC) is a valuable tool for labeling structures in tissue samples. Quantification of immunolabeled structures using traditional approaches has proved to be difficult. Manual counts of IHC-stained structures are inherently biased, require multiple observers, and generate qualitative data. Stereological methods provide accurate quantification but are complex and labor-intensive when staining must be compared among large numbers of samples. In an effort to quickly, objectively, and reproducibly quantify cutaneous innervation in a large number of counterstained tissue sections, we developed a color subtractive-computer-assisted image analysis (CS-CAIA) system. To develop and test the CS-CAIA method, tissue sections of diabetic (db/db) mouse skin and their wild-type (db/-) littermates were stained by IHC for the neural marker PGP 9.5. The brown-red PGP 9.5 peroxidase stain was colorimetrically isolated through a scripted process of color background removal. The remaining stain was thresholded and binarized for computer determination of nerve profile counts (number of stained regions), area fraction (total area of nerve profiles per unit area of tissue), and area density (total number of nerve profiles per unit area of tissue). Using CS-CAIA, epidermal nerve profile counts, area fraction, and area density were significantly lower in db/db compared to db/- mice.
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Affiliation(s)
- R A Underwood
- Department of Medicine (Dermatology), University of Washington, Seattle, Washington, USA
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Egensperger R, Kösel S, von Eitzen U, Graeber MB. Microglial activation in Alzheimer disease: Association with APOE genotype. Brain Pathol 1998; 8:439-47. [PMID: 9669695 PMCID: PMC8098510 DOI: 10.1111/j.1750-3639.1998.tb00166.x] [Citation(s) in RCA: 105] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/19/2022] Open
Abstract
Microglial cells are considered to play an important role in the pathogenesis of Alzheimer disease. Apart from producing the Alzheimer amyloid precursor (APP) as an acute phase protein, microglial cells seem to be involved in the deposition of its amyloidogenic cleavage product, the amyloid-beta peptide (Abeta). Abeta is bound by apolipoprotein E (APOE) in an isoform-specific manner, and it has been demonstrated that inheritance of the AD susceptibility allele, APOE epsilon4, is associated with increased deposition of Abeta in the cerebral cortex. However, the relationship between APOE epsilon4 gene dose and microglial activation is unknown. Using microglial expression of major histocompatibility complex class II molecules as a marker, we have performed a quantitative genotype-phenotype analysis on microglial activation in frontal and temporal cortices of 20 APOE genotyped AD brains. The number of activated microglia and the tissue area occupied by these cells increased significantly with APOE epsilon4 gene dose. When a model of multiple linear regression was used to compare the relative influence of APOE genotype, sex, disease duration, age at death, diffuse and neuritic plaques as well as neurofibrillary tangles on microglial activation, only APOE genotype was found to have a significant effect. Thus, the APOE gene product represents an important determinant of microglial activity in AD. Since microglial activation by APP has been shown to be modulated by apoE in vitro, a direct role of microglia in AD pathogenesis is conceivable.
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Affiliation(s)
- Rupert Egensperger
- Molecular Neuropathology Laboratory, Institute of Neuropathology, Hannover Medical School, Hannover, Germany
| | - Siegfried Kösel
- Molecular Neuropathology Laboratory, Institute of Neuropathology, Ludwig Maximilians University, Munich, Germany
| | - Ulrich von Eitzen
- Molecular Neuropathology Laboratory, Institute of Neuropathology, Ludwig Maximilians University, Munich, Germany
| | - Manuel B. Graeber
- Molecular Neuropathology Laboratory, Department of Neuromorphology, Max Planck Institute of Neurobiology (formerly Max Planck Institute of Psychiatry, Basic Sciences Institute), Martinsried, Germany
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Farkas DL, Du C, Fisher GW, Lau C, Niu W, Wachman ES, Levenson RM. Non-invasive image acquisition and advanced processing in optical bioimaging. Comput Med Imaging Graph 1998; 22:89-102. [PMID: 9719850 DOI: 10.1016/s0895-6111(98)00011-1] [Citation(s) in RCA: 83] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
Light is a most versatile tool for investigating biological systems and phenomena; the range, non-destructiveness, spatial discrimination and speed of optical imaging are all important for investigating structure and function at the cellular, tissue or even whole organism level. In live biological imaging, where the technological requirements are heightened, other features of light, such as coherence and wavelength, are used to generate the additional contrast and resolution needed. We report here recent improvements in our ability to image biological specimens optically, focusing on (a) spectral resolution and the related image processing issues, and (b) tomographic three-dimensional fluorescence imaging in vivo.
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Affiliation(s)
- D L Farkas
- Center for Light Microscope Imaging and Biotechnology, Carnegie Mellon University, Pittsburgh, PA 15213, USA. farkas+@cmu.edu
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Abstract
Recent evidence suggests that AD is associated with the development of cerebral amyloid angiopathy and with significant changes in the blood-brain barrier glucose transporter and basement membrane protein alterations. It is likely that these changes significantly contribute to chronic cerebral hypoperfusion, possibly resulting in progressive neural death in AD. To investigate the etiology of these changes, we have analyzed postmortem tissue sections of frontal cortex of moderately demented AD cases, stained using both single-label and double-label immunocytochemistry to detect vessels and beta-amyloid. The resultant color images are analyzed using HSV (hue-saturation-value) color image analysis, shape analysis, and histogram analysis techniques. These analyses let us segment the tissue images for further statistical analyses.
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Affiliation(s)
- R J de Figueiredo
- Department of Electrical and Computer Engineering, University of California, Irvine 92697, USA
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Ball MJ, Murdoch GH. Neuropathological criteria for the diagnosis of Alzheimer's disease: are we really ready yet? Neurobiol Aging 1997; 18:S3-12. [PMID: 9330979 DOI: 10.1016/s0197-4580(97)00074-2] [Citation(s) in RCA: 16] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/05/2023]
Abstract
The specific diagnosis of AD as a particular dementia from which a patient suffered assumes, debatably, a reasonably pure clinicopathological entity in which the same concatenation of lesions will not be encountered in others dying with a similar clinical disorder. Statistically complex computations such as multivariate analyses of morphometric data from our laboratory and similar attempts in Swedish and British series may not prove pragmatic for pathological confirmation. The Braaks' schema posits six stages in the evolution of AD. Unfortunately, application of this model to 50 British autopsies cannot reliably identify those cases clinically diagnosed as demented. Furthermore, lack of universal definition for each of the probable lesional subtypes augments the difficulty devising a quantitative consensus. Disease stage refers to a progressive increase in anatomical (geographic) extent of involvement, whereas, grade refers to a progressive increase in severity of affliction within any one site. There is only a tendency for stage and grade to progress in parallel. Nor is it obligatory that either always does progress. More energies should be concentrated upon determining which histopathological abnormality is most injurious to neuronal integrity. Dutch workers opine that in both normal aging and AD, claims of massive, neocortical nerve cell loss may have been based on inadequate morphometry and/or a loss of markers. Requiring urgent resolution is whether cellular changes seen in brains of aging normals represent merely the earliest phase of typical AD (and therefore a good model for Alzheimer pathogenesis), or rather reflect a totally different aging syndrome distinct from AD. We have proposed that abnormalities in the hippocampal formation (with or without neocortical neuronal lesions) may underlie a decline of all higher cognitive functions in senile dementia Alzheimer type. West and colleagues optical disector approach likewise shows that neurodegeneration associated within aging individuals' hippocampi is quantitatively and qualitatively distinct from the neuronal loss in AD. Clinical confreres' imprecision whether or when to term subtle cognitive loss "incipient AD" is understandably mirrored by residual neuropathological struggles to dichotomize such brains as "normative aging" distinct from "putative AD."
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Affiliation(s)
- M J Ball
- Section of Neuropathology, Oregon Health Sciences University, Portland 97201, USA
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Abstract
The study of relationships between neuropathological characteristics and behavioral, structural, chemical, and molecular variables offers immense promise for understanding the basic pathophysiology of Alzheimer's disease. This position paper examines the need for standardized procedures and quantitation if neuropathological data are to be optimally useful among laboratories investigating the biology of Alzheimer's disease. These requirements include standardized fixation, embedding, sectioning, staining, brain regions and sampling methods. In addition, the definition of the structures to be quantified, such as plaque type(s), needs to be rigorously specified. Unbiased stereological methods for quantification should be used. These needs for optimal research utility exceed the needs and practicality for diagnostic purposes, suggesting a two-tiered approach to the neuropathology of Alzheimer's disease: diagnostic and research.
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Affiliation(s)
- P D Coleman
- Department of Neurobiology and Anatomy, University of Rochester Medical Center, NY 14642, USA
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Cummings BJ, Pike CJ, Cotman CW. Author's response to commentaries. Neurobiol Aging 1996. [DOI: 10.1016/s0197-4580(96)00171-6] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
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