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Miron M, Meng W, Rosenfeld AM, Dvorkin S, Poon MML, Lam N, Kumar BV, Louzoun Y, Luning Prak ET, Farber DL. Maintenance of the human memory T cell repertoire by subset and tissue site. Genome Med 2021; 13:100. [PMID: 34127056 PMCID: PMC8204429 DOI: 10.1186/s13073-021-00918-7] [Citation(s) in RCA: 26] [Impact Index Per Article: 8.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/03/2021] [Accepted: 06/01/2021] [Indexed: 01/13/2023] Open
Abstract
BACKGROUND Immune-mediated protection is mediated by T cells expressing pathogen-specific T cell antigen receptors (TCR) that are maintained at diverse sites of infection as tissue-resident memory T cells (TRM) or that disseminate as circulating effector-memory (TEM), central memory (TCM), or terminal effector (TEMRA) subsets in blood and tissues. The relationship between circulating and tissue resident T cell subsets in humans remains elusive, and is important for promoting site-specific protective immunity. METHODS We analyzed the TCR repertoire of the major memory CD4+ and CD8+T cell subsets (TEM, TCM, TEMRA, and TRM) isolated from blood and/or lymphoid organs (spleen, lymph nodes, bone marrow) and lungs of nine organ donors, and blood of three living individuals spanning five decades of life. High-throughput sequencing of the variable (V) portion of individual TCR genes for each subset, tissue, and individual were analyzed for clonal diversity, expansion and overlap between lineage, T cell subsets, and anatomic sites. TCR repertoires were further analyzed for TRBV gene usage and CDR3 edit distance. RESULTS Across blood, lymphoid organs, and lungs, human memory, and effector CD8+T cells exhibit greater clonal expansion and distinct TRBV usage compared to CD4+T cell subsets. Extensive sharing of clones between tissues was observed for CD8+T cells; large clones specific to TEMRA cells were present in all sites, while TEM cells contained clones shared between sites and with TRM. For CD4+T cells, TEM clones exhibited the most sharing between sites, followed by TRM, while TCM clones were diverse with minimal sharing between sites and subsets. Within sites, TRM clones exhibited tissue-specific expansions, and maintained clonal diversity with age, compared to age-associated clonal expansions in circulating memory subsets. Edit distance analysis revealed tissue-specific biases in clonal similarity. CONCLUSIONS Our results show that the human memory T cell repertoire comprises clones which persist across sites and subsets, along with clones that are more restricted to certain subsets and/or tissue sites. We also provide evidence that the tissue plays a key role in maintaining memory T cells over age, bolstering the rationale for site-specific targeting of memory reservoirs in vaccines and immunotherapies.
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Affiliation(s)
- Michelle Miron
- Department of Microbiology and Immunology, Columbia University, New York, NY, USA
- Columbia Center for Translational Immunology, Columbia University, New York, NY, USA
| | - Wenzhao Meng
- Department of Pathology and Laboratory Medicine, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA, USA
| | - Aaron M Rosenfeld
- Department of Pathology and Laboratory Medicine, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA, USA
| | - Shirit Dvorkin
- Department of Mathematics, Bar Ilan University, Ramat Gan, Israel
| | - Maya Meimei Li Poon
- Department of Microbiology and Immunology, Columbia University, New York, NY, USA
| | - Nora Lam
- Department of Microbiology and Immunology, Columbia University, New York, NY, USA
- Department of Pathology and Cell Biology, Columbia University, New York, NY, USA
| | - Brahma V Kumar
- Columbia Center for Translational Immunology, Columbia University, New York, NY, USA
| | - Yoram Louzoun
- Department of Mathematics, Bar Ilan University, Ramat Gan, Israel
| | - Eline T Luning Prak
- Department of Pathology and Laboratory Medicine, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA, USA.
| | - Donna L Farber
- Department of Microbiology and Immunology, Columbia University, New York, NY, USA.
- Department of Surgery, Columbia University, New York, NY, USA.
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Kumar BV, Kratchmarov R, Miron M, Carpenter DJ, Senda T, Lerner H, Friedman A, Reiner SL, Farber DL. Functional heterogeneity of human tissue-resident memory T cells based on dye efflux capacities. JCI Insight 2018; 3:123568. [PMID: 30429372 DOI: 10.1172/jci.insight.123568] [Citation(s) in RCA: 40] [Impact Index Per Article: 6.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/13/2018] [Accepted: 10/16/2018] [Indexed: 12/13/2022] Open
Abstract
Tissue-resident memory T cells (TRMs) accelerate pathogen clearance through rapid and enhanced functional responses in situ. TRMs are prevalent in diverse anatomic sites throughout the human lifespan, yet their phenotypic and functional diversity has not been fully described. Here, we identify subpopulations of human TRMs based on the ability to efflux fluorescent dyes [efflux(+) TRMs] located within mucosal and lymphoid sites with distinct transcriptional profiles, turnover, and functional capacities. Compared with efflux(-) TRMs, efflux(+) TRMs showed transcriptional and phenotypic features of quiescence including reduced turnover, decreased expression of exhaustion markers, and increased proliferative capacity and signaling in response to homeostatic cytokines. Moreover, upon activation, efflux(+) TRMs secreted lower levels of inflammatory cytokines such as IFN-γ and IL-2 and underwent reduced degranulation. Interestingly, analysis of TRM subsets following activation revealed that both efflux(+) and efflux(-) TRMs undergo extensive transcriptional changes following TCR ligation but retain core TRM transcriptional properties including retention markers, suggesting that TRMs carry out effector function in situ. Overall, our results suggest a model for tissue-resident immunity wherein heterogeneous subsets have differential capacities for longevity and effector function.
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Affiliation(s)
| | | | - Michelle Miron
- Columbia Center for Translational Immunology.,Department of Microbiology and Immunology, and
| | - Dustin J Carpenter
- Columbia Center for Translational Immunology.,Department of Surgery, Columbia University Medical Center, New York, New York, USA
| | | | | | | | - Steven L Reiner
- Department of Microbiology and Immunology, and.,Department of Pediatrics, Columbia University Medical Center, New York, New York, USA
| | - Donna L Farber
- Columbia Center for Translational Immunology.,Department of Microbiology and Immunology, and.,Department of Surgery, Columbia University Medical Center, New York, New York, USA
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Miron M, Kumar BV, Meng W, Granot T, Carpenter DJ, Senda T, Chen D, Rosenfeld AM, Zhang B, Lerner H, Friedman AL, Hershberg U, Shen Y, Rahman A, Luning Prak ET, Farber DL. Human Lymph Nodes Maintain TCF-1 hi Memory T Cells with High Functional Potential and Clonal Diversity throughout Life. J Immunol 2018; 201:2132-2140. [PMID: 30111633 DOI: 10.4049/jimmunol.1800716] [Citation(s) in RCA: 59] [Impact Index Per Article: 9.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/30/2018] [Accepted: 07/23/2018] [Indexed: 11/19/2022]
Abstract
Translating studies on T cell function and modulation from mouse models to humans requires extrapolating in vivo results on mouse T cell responses in lymphoid organs (spleen and lymph nodes [LN]) to human peripheral blood T cells. However, our understanding of T cell responses in human lymphoid sites and their relation to peripheral blood remains sparse. In this study, we used a unique human tissue resource to study human T cells in different anatomical compartments within individual donors and identify a subset of memory CD8+ T cells in LN, which maintain a distinct differentiation and functional profile compared with memory CD8+ T cells in blood, spleen, bone marrow, and lungs. Whole-transcriptome and high-dimensional cytometry by time-of-flight profiling reveals that LN memory CD8+ T cells express signatures of quiescence and self-renewal compared with corresponding populations in blood, spleen, bone marrow, and lung. LN memory T cells exhibit a distinct transcriptional signature, including expression of stem cell-associated transcription factors TCF-1 and LEF-1, T follicular helper cell markers CXCR5 and CXCR4, and reduced expression of effector molecules. LN memory T cells display high homology to a subset of mouse CD8+ T cells identified in chronic infection models that respond to checkpoint blockade immunotherapy. Functionally, human LN memory T cells exhibit increased proliferation to TCR-mediated stimulation and maintain higher TCR clonal diversity compared with memory T cells from blood and other sites. These findings establish human LN as reservoirs for memory T cells with high capacities for expansion and diverse recognition and important targets for immunotherapies.
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Affiliation(s)
- Michelle Miron
- Columbia Center for Translational Immunology, Columbia University Medical Center, New York, NY 10032.,Department of Microbiology and Immunology, Columbia University, New York, NY 10032
| | - Brahma V Kumar
- Columbia Center for Translational Immunology, Columbia University Medical Center, New York, NY 10032
| | - Wenzhao Meng
- Department of Pathology and Laboratory Medicine, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA 19102
| | - Tomer Granot
- Columbia Center for Translational Immunology, Columbia University Medical Center, New York, NY 10032
| | - Dustin J Carpenter
- Columbia Center for Translational Immunology, Columbia University Medical Center, New York, NY 10032
| | - Takashi Senda
- Columbia Center for Translational Immunology, Columbia University Medical Center, New York, NY 10032
| | - Dora Chen
- Department of Pathology and Laboratory Medicine, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA 19102
| | - Aaron M Rosenfeld
- School of Biomedical Engineering, Drexel University, Philadelphia, PA 19104
| | - Bochao Zhang
- School of Biomedical Engineering, Drexel University, Philadelphia, PA 19104
| | | | | | - Uri Hershberg
- School of Biomedical Engineering, Drexel University, Philadelphia, PA 19104
| | - Yufeng Shen
- Department of Systems Biology, Columbia University, New York, NY 10032.,Department of Biomedical Informatics, Columbia University, New York, NY 10032
| | - Adeeb Rahman
- Icahn School of Medicine at Mount Sinai, New York, NY 10029; and
| | - Eline T Luning Prak
- Department of Pathology and Laboratory Medicine, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA 19102
| | - Donna L Farber
- Columbia Center for Translational Immunology, Columbia University Medical Center, New York, NY 10032; .,Department of Microbiology and Immunology, Columbia University, New York, NY 10032.,Department of Surgery, Columbia University, New York, NY 10032
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Carpenter DJ, Granot T, Matsuoka N, Senda T, Kumar BV, Thome JJC, Gordon CL, Miron M, Weiner J, Connors T, Lerner H, Friedman A, Kato T, Griesemer AD, Farber DL. Human immunology studies using organ donors: Impact of clinical variations on immune parameters in tissues and circulation. Am J Transplant 2018; 18:74-88. [PMID: 28719147 PMCID: PMC5740015 DOI: 10.1111/ajt.14434] [Citation(s) in RCA: 50] [Impact Index Per Article: 8.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/02/2017] [Revised: 06/23/2017] [Accepted: 07/11/2017] [Indexed: 01/25/2023]
Abstract
Organ donors are sources of physiologically healthy organs and tissues for life-saving transplantation, and have been recently used for human immunology studies which are typically confined to the sampling of peripheral blood. Donors comprise a diverse population with different causes of death and clinical outcomes during hospitalization, and the effects of such variations on immune parameters in blood and tissues are not known. We present here a coordinate analysis of innate and adaptive immune components in blood, lymphoid (bone marrow, spleen, lymph nodes), and mucosal (lungs, intestines) sites from a population of brain-dead organ donors (2 months-93 years; n = 291) across eight clinical parameters. Overall, the blood of donors exhibited similar monocyte and lymphocyte content and low serum levels of pro-inflammatory cytokines as healthy controls; however, donor blood had increased neutrophils and serum levels of IL-8, IL-6, and MCP-1 which varied with cause of death. In tissues, the frequency and composition of monocytes, neutrophils, B lymphocytes and T cell subsets in lymphoid or mucosal sites did not vary with clinical state, and was similar in donors independent of the extent of clinical complications. Our results reveal that organ donors maintain tissue homeostasis, and are a valuable resource for fundamental studies in human immunology.
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Affiliation(s)
- D J Carpenter
- Columbia Center for Translational Immunology, Columbia University Medical Center, New York, NY, USA
- Department of Surgery, Columbia University Medical Center, New York, NY, USA
| | - T Granot
- Columbia Center for Translational Immunology, Columbia University Medical Center, New York, NY, USA
- Department of Medicine, Columbia University Medical Center, New York, NY, USA
| | - N Matsuoka
- Columbia Center for Translational Immunology, Columbia University Medical Center, New York, NY, USA
| | - T Senda
- Columbia Center for Translational Immunology, Columbia University Medical Center, New York, NY, USA
- Department of Surgery, Columbia University Medical Center, New York, NY, USA
| | - B V Kumar
- Columbia Center for Translational Immunology, Columbia University Medical Center, New York, NY, USA
- Department of Microbiology and Immunology, Columbia University Medical Center, New York, NY, USA
| | - J J C Thome
- Columbia Center for Translational Immunology, Columbia University Medical Center, New York, NY, USA
- Department of Microbiology and Immunology, Columbia University Medical Center, New York, NY, USA
| | - C L Gordon
- Columbia Center for Translational Immunology, Columbia University Medical Center, New York, NY, USA
- Department of Medicine, Columbia University Medical Center, New York, NY, USA
| | - M Miron
- Columbia Center for Translational Immunology, Columbia University Medical Center, New York, NY, USA
- Department of Microbiology and Immunology, Columbia University Medical Center, New York, NY, USA
| | - J Weiner
- Department of Surgery, Columbia University Medical Center, New York, NY, USA
| | - T Connors
- Columbia Center for Translational Immunology, Columbia University Medical Center, New York, NY, USA
- Department of Pediatrics, Columbia University Medical Center, New York, NY, USA
| | | | | | - T Kato
- Department of Surgery, Columbia University Medical Center, New York, NY, USA
| | - A D Griesemer
- Columbia Center for Translational Immunology, Columbia University Medical Center, New York, NY, USA
- Department of Surgery, Columbia University Medical Center, New York, NY, USA
| | - D L Farber
- Columbia Center for Translational Immunology, Columbia University Medical Center, New York, NY, USA
- Department of Surgery, Columbia University Medical Center, New York, NY, USA
- Department of Microbiology and Immunology, Columbia University Medical Center, New York, NY, USA
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Granot T, Senda T, Carpenter DJ, Matsuoka N, Weiner J, Gordon CL, Miron M, Kumar BV, Griesemer A, Ho SH, Lerner H, Thome JJC, Connors T, Reizis B, Farber DL. Dendritic Cells Display Subset and Tissue-Specific Maturation Dynamics over Human Life. Immunity 2017; 46:504-515. [PMID: 28329707 DOI: 10.1016/j.immuni.2017.02.019] [Citation(s) in RCA: 191] [Impact Index Per Article: 27.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/01/2016] [Revised: 12/23/2016] [Accepted: 02/27/2017] [Indexed: 12/24/2022]
Abstract
Maturation and migration to lymph nodes (LNs) constitutes a central paradigm in conventional dendritic cell (cDC) biology but remains poorly defined in humans. Using our organ donor tissue resource, we analyzed cDC subset distribution, maturation, and migration in mucosal tissues (lungs, intestines), associated lymph nodes (LNs), and other lymphoid sites from 78 individuals ranging from less than 1 year to 93 years of age. The distribution of cDC1 (CD141hiCD13hi) and cDC2 (Sirp-α+CD1c+) subsets was a function of tissue site and was conserved between donors. We identified cDC2 as the major mature (HLA-DRhi) subset in LNs with the highest frequency in lung-draining LNs. Mature cDC2 in mucosal-draining LNs expressed tissue-specific markers derived from the paired mucosal site, reflecting their tissue-migratory origin. These distribution and maturation patterns were largely maintained throughout life, with site-specific variations. Our findings provide evidence for localized DC tissue surveillance and reveal a lifelong division of labor between DC subsets, with cDC2 functioning as guardians of the mucosa.
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Affiliation(s)
- Tomer Granot
- Columbia Center for Translational Immunology, Columbia University Medical Center, New York, NY 10032, USA; Department of Medicine, Columbia University Medical Center, New York, NY 10032, USA
| | - Takashi Senda
- Columbia Center for Translational Immunology, Columbia University Medical Center, New York, NY 10032, USA; Department of Surgery, Columbia University Medical Center, New York, NY 10032, USA
| | - Dustin J Carpenter
- Columbia Center for Translational Immunology, Columbia University Medical Center, New York, NY 10032, USA; Department of Surgery, Columbia University Medical Center, New York, NY 10032, USA
| | - Nobuhide Matsuoka
- Columbia Center for Translational Immunology, Columbia University Medical Center, New York, NY 10032, USA; Department of Surgery, Columbia University Medical Center, New York, NY 10032, USA
| | - Joshua Weiner
- Department of Surgery, Columbia University Medical Center, New York, NY 10032, USA
| | - Claire L Gordon
- Columbia Center for Translational Immunology, Columbia University Medical Center, New York, NY 10032, USA; Department of Medicine, Columbia University Medical Center, New York, NY 10032, USA
| | - Michelle Miron
- Columbia Center for Translational Immunology, Columbia University Medical Center, New York, NY 10032, USA; Department of Microbiology and Immunology, Columbia University Medical Center, New York, NY 10032, USA
| | - Brahma V Kumar
- Columbia Center for Translational Immunology, Columbia University Medical Center, New York, NY 10032, USA
| | - Adam Griesemer
- Columbia Center for Translational Immunology, Columbia University Medical Center, New York, NY 10032, USA; Department of Surgery, Columbia University Medical Center, New York, NY 10032, USA
| | - Siu-Hong Ho
- Columbia Center for Translational Immunology, Columbia University Medical Center, New York, NY 10032, USA; Department of Microbiology and Immunology, Columbia University Medical Center, New York, NY 10032, USA
| | | | - Joseph J C Thome
- Columbia Center for Translational Immunology, Columbia University Medical Center, New York, NY 10032, USA; Department of Microbiology and Immunology, Columbia University Medical Center, New York, NY 10032, USA
| | - Thomas Connors
- Columbia Center for Translational Immunology, Columbia University Medical Center, New York, NY 10032, USA; Division of Critical Care, Department of Pediatrics, Columbia University Medical Center, New York, NY 10032, USA
| | - Boris Reizis
- Department of Pathology, NYU Langone Medical Center, New York, NY 10016, USA
| | - Donna L Farber
- Columbia Center for Translational Immunology, Columbia University Medical Center, New York, NY 10032, USA; Department of Surgery, Columbia University Medical Center, New York, NY 10032, USA; Department of Microbiology and Immunology, Columbia University Medical Center, New York, NY 10032, USA.
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6
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Thome JJC, Grinshpun B, Kumar BV, Kubota M, Ohmura Y, Lerner H, Sempowski GD, Shen Y, Farber DL. Longterm maintenance of human naive T cells through in situ homeostasis in lymphoid tissue sites. Sci Immunol 2016; 1. [PMID: 28361127 DOI: 10.1126/sciimmunol.aah6506] [Citation(s) in RCA: 97] [Impact Index Per Article: 12.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022]
Abstract
Naïve T cells develop in the thymus and coordinate immune responses to new antigens; however, mechanisms for their long-term persistence over the human lifespan remain undefined. Here, we investigated human naïve T cell development and maintenance in primary and secondary lymphoid tissues obtained from individual organ donors aged 3 months-73 years. In the thymus, the frequency of double-positive thymocytes declined sharply in donors over age 40 coincident with reduced recent thymic emigrants (RTE) in lymphoid tissues, while naïve T cells were functionally maintained predominantly in lymph nodes (LN). Analysis of TCR clonal distribution by CDR3 sequencing of naïve CD4+ and CD8+ T cells in spleen and LNs reveal site-specific clonal expansions of naïve T cells from individuals >40 years of age with minimal clonal overlap between lymphoid tissues. We also identified biased naïve T cell clonal distribution within specific lymph nodes based on VJ usage. Together these results suggest prolonged maintenance of naïve T cells through in situ homeostasis and retention in lymphoid tissue.
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Affiliation(s)
- Joseph J C Thome
- Columbia Center for Translational Immunology, Columbia University Medical Center, New York, NY 10032, USA; Department of Microbiology and Immunology, Columbia University Medical Center, New York, NY 10032, USA
| | - Boris Grinshpun
- Department of Systems Biology, Columbia University Medical Center, New York, NY 10032, USA
| | - Brahma V Kumar
- Columbia Center for Translational Immunology, Columbia University Medical Center, New York, NY 10032, USA
| | - Masa Kubota
- Columbia Center for Translational Immunology, Columbia University Medical Center, New York, NY 10032, USA; Department of Surgery, Columbia University Medical Center, New York, NY 10032, USA
| | - Yoshiaki Ohmura
- Columbia Center for Translational Immunology, Columbia University Medical Center, New York, NY 10032, USA; Department of Surgery, Columbia University Medical Center, New York, NY 10032, USA
| | | | | | - Yufeng Shen
- Department of Systems Biology, Columbia University Medical Center, New York, NY 10032, USA
| | - Donna L Farber
- Columbia Center for Translational Immunology, Columbia University Medical Center, New York, NY 10032, USA; Department of Microbiology and Immunology, Columbia University Medical Center, New York, NY 10032, USA; Department of Surgery, Columbia University Medical Center, New York, NY 10032, USA
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Szabo A, Fekete T, Koncz G, Kumar BV, Pazmandi K, Foldvari Z, Hegedus B, Garay T, Bacsi A, Rajnavolgyi E, Lanyi A. RIG-I inhibits the MAPK-dependent proliferation of BRAF mutant melanoma cells via MKP-1. Cell Signal 2016; 28:335-347. [PMID: 26829212 DOI: 10.1016/j.cellsig.2016.01.012] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/14/2015] [Revised: 01/22/2016] [Accepted: 01/28/2016] [Indexed: 12/20/2022]
Abstract
BACKGROUND BRAF-mutant melanoma is characterized by aggressive metastatic potential and therapeutic resistance. The innate immune receptor RIG-I has emerged as a potential target in melanoma therapies but the contributing pathways involved in anti-cancer activity are poorly characterized. METHODS Baseline and ATRA-induced expression of RIG-I in nine (3 wild type and 6 BRAF-mutant) melanoma cell lines was measured with Q-PCR and Western blot. Ligand-specific stimulation of RIG-I was detected by Q-PCR and ELISA. Activation of the RIG-I-coupled IRF3, NF-κB and MAPK pathways was tested with protein array and Western blot. Cell proliferation and apoptosis was monitored by flow cytometry and cell counting. Down modulation of MKP-1 expression in melanoma cells was performed by specific siRNA. RESULTS Short-term ATRA pre-treatment increases the expression of RIG-I in BRAF-mutant melanoma cells. Specific activation of RIG-I by 5'ppp-dsRNA leads to increased activity of the IRF3-IFNβ pathway but does not influence NF-κB signaling. RIG-I mediates the targeted dephosphorylation of several MAPKs (p38, RSK1, GSK-3α/β, HSP27) via the endogenous regulator MKP-1 resulting in decreased melanoma cell proliferation. CONCLUSION RIG-I has the potential to exert anticancer activity in BRAF-mutant melanoma via controlling IFNβ production and MAPK signaling. This is the first study showing that RIG-I activation results in MKP-1-mediated inhibition of cell proliferation via controlling the p38-HSP27, c-Jun and rpS6 pathways thus identifying RIG-I and MKP-1 as novel and promising therapeutical targets.
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Affiliation(s)
- Attila Szabo
- Department of Immunology, Faculty of Medicine, University of Debrecen, Debrecen, Hungary; Sapientia Hungarian University of Transylvania, Department of Bioengineering, Miercurea-Ciuc, Romania.
| | - Tunde Fekete
- Department of Immunology, Faculty of Medicine, University of Debrecen, Debrecen, Hungary
| | - Gabor Koncz
- Department of Immunology, Faculty of Medicine, University of Debrecen, Debrecen, Hungary; Sapientia Hungarian University of Transylvania, Department of Bioengineering, Miercurea-Ciuc, Romania
| | - Brahma V Kumar
- Department of Immunology, Faculty of Medicine, University of Debrecen, Debrecen, Hungary
| | - Kitti Pazmandi
- Department of Immunology, Faculty of Medicine, University of Debrecen, Debrecen, Hungary
| | - Zsofia Foldvari
- Department of Immunology, Faculty of Medicine, University of Debrecen, Debrecen, Hungary
| | - Balazs Hegedus
- 2nd Institute of Pathology, Semmelweis University, Budapest, Hungary; MTA-SE Molecular Oncology Research Group, Hungarian Academy of Sciences, Budapest, Hungary
| | - Tamas Garay
- 2nd Institute of Pathology, Semmelweis University, Budapest, Hungary; MTA-SE Molecular Oncology Research Group, Hungarian Academy of Sciences, Budapest, Hungary
| | - Attila Bacsi
- Department of Immunology, Faculty of Medicine, University of Debrecen, Debrecen, Hungary; Sapientia Hungarian University of Transylvania, Department of Bioengineering, Miercurea-Ciuc, Romania
| | - Eva Rajnavolgyi
- Department of Immunology, Faculty of Medicine, University of Debrecen, Debrecen, Hungary; Sapientia Hungarian University of Transylvania, Department of Bioengineering, Miercurea-Ciuc, Romania
| | - Arpad Lanyi
- Department of Immunology, Faculty of Medicine, University of Debrecen, Debrecen, Hungary; Sapientia Hungarian University of Transylvania, Department of Bioengineering, Miercurea-Ciuc, Romania
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Khanam PS, Sangeetha B, Kumar BV, Kiran U, Priyadarshini PI, Ram R, Sridhar MS, Kumar VS. Gloriosa superba ingestion: Hair loss and acute renal failure. Indian J Nephrol 2015; 25:174-6. [PMID: 26060369 PMCID: PMC4446924 DOI: 10.4103/0971-4065.145423] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022] Open
Abstract
Gloriosa superba is a plant that grows wild in several parts of South India. Tubers of this plant contain several alkaloids. Acute intoxication following the ingestion of G. superba results in gastrointestinal and haematological abnormalities, hepatic and renal insufficiency, cardiotoxicity and hair loss. We present a case with typical features of G superba toxicity.
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Affiliation(s)
- P S Khanam
- Department of General Medicine, Sri Venkateswara Medical College, Tirupati, Andhra Pradesh, India
| | - B Sangeetha
- Department of Nephrology, Sri Venkateswara Institute of Medical Sciences, Tirupati, Andhra Pradesh, India
| | - B V Kumar
- Department of General Medicine, Sri Venkateswara Medical College, Tirupati, Andhra Pradesh, India
| | - U Kiran
- Department of General Medicine, Sri Venkateswara Medical College, Tirupati, Andhra Pradesh, India
| | - P I Priyadarshini
- Department of General Medicine, Sri Venkateswara Medical College, Tirupati, Andhra Pradesh, India
| | - R Ram
- Department of Nephrology, Sri Venkateswara Institute of Medical Sciences, Tirupati, Andhra Pradesh, India
| | - M S Sridhar
- Department of General Medicine, Sri Venkateswara Medical College, Tirupati, Andhra Pradesh, India
| | - V S Kumar
- Department of Nephrology, Sri Venkateswara Institute of Medical Sciences, Tirupati, Andhra Pradesh, India
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Pazmandi K, Agod Z, Kumar BV, Szabo A, Fekete T, Sogor V, Veres A, Boldogh I, Rajnavolgyi E, Lanyi A, Bacsi A. Oxidative modification enhances the immunostimulatory effects of extracellular mitochondrial DNA on plasmacytoid dendritic cells. Free Radic Biol Med 2014; 77:281-90. [PMID: 25301097 DOI: 10.1016/j.freeradbiomed.2014.09.028] [Citation(s) in RCA: 52] [Impact Index Per Article: 5.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/07/2014] [Revised: 09/03/2014] [Accepted: 09/26/2014] [Indexed: 12/14/2022]
Abstract
Inflammation is associated with oxidative stress and characterized by elevated levels of damage-associated molecular pattern (DAMP) molecules released from injured or even living cells into the surrounding microenvironment. One of these endogenous danger signals is the extracellular mitochondrial DNA (mtDNA) containing evolutionary conserved unmethylated CpG repeats. Increased levels of reactive oxygen species (ROS) generated by recruited inflammatory cells modify mtDNA oxidatively, resulting primarily in accumulation of 8-oxo-7,8-dihydroguanine (8-oxoG) lesions. In this study, we examined the impact of native and oxidatively modified mtDNAs on the phenotypic and functional properties of plasmacytoid dendritic cells (pDCs), which possess a fundamental role in the regulation of inflammation and T cell immunity. Treatment of human primary pDCs with native mtDNA up-regulated the expression of a costimulatory molecule (CD86), a specific maturation marker (CD83), and a main antigen-presenting molecule (HLA-DQ) on the cell surface, as well as increased TNF-α and IL-8 production from the cells. These effects were more apparent when pDCs were exposed to oxidatively modified mtDNA. Neither native nor oxidized mtDNA molecules were able to induce interferon (IFN)-α secretion from pDCs unless they formed a complex with human cathelicidin LL-37, an antimicrobial peptide. Interestingly, simultaneous administration of a Toll-like receptor (TLR)9 antagonist abrogated the effects of both native and oxidized mtDNAs on human pDCs. In a murine model, oxidized mtDNA also proved a more potent activator of pDCs compared to the native form, except for induction of IFN-α production. Collectively, we demonstrate here for the first time that elevated levels of 8-oxoG bases in the extracellular mtDNA induced by oxidative stress increase the immunostimulatory capacity of mtDNA on pDCs.
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Affiliation(s)
- Kitti Pazmandi
- Department of Immunology, Faculty of Medicine, University of Debrecen, 98 Nagyerdei Blvd., Debrecen H-4012, Hungary
| | - Zsofia Agod
- Department of Immunology, Faculty of Medicine, University of Debrecen, 98 Nagyerdei Blvd., Debrecen H-4012, Hungary
| | - Brahma V Kumar
- Department of Immunology, Faculty of Medicine, University of Debrecen, 98 Nagyerdei Blvd., Debrecen H-4012, Hungary
| | - Attila Szabo
- Department of Immunology, Faculty of Medicine, University of Debrecen, 98 Nagyerdei Blvd., Debrecen H-4012, Hungary
| | - Tunde Fekete
- Department of Immunology, Faculty of Medicine, University of Debrecen, 98 Nagyerdei Blvd., Debrecen H-4012, Hungary
| | - Viktoria Sogor
- Department of Immunology, Faculty of Medicine, University of Debrecen, 98 Nagyerdei Blvd., Debrecen H-4012, Hungary
| | - Agota Veres
- Department of Immunology, Faculty of Medicine, University of Debrecen, 98 Nagyerdei Blvd., Debrecen H-4012, Hungary
| | - Istvan Boldogh
- Department of Microbiology and Immunology, University of Texas Medical Branch at Galveston, 301 University Blvd., Galveston, TX 77555, USA
| | - Eva Rajnavolgyi
- Department of Immunology, Faculty of Medicine, University of Debrecen, 98 Nagyerdei Blvd., Debrecen H-4012, Hungary
| | - Arpad Lanyi
- Department of Immunology, Faculty of Medicine, University of Debrecen, 98 Nagyerdei Blvd., Debrecen H-4012, Hungary
| | - Attila Bacsi
- Department of Immunology, Faculty of Medicine, University of Debrecen, 98 Nagyerdei Blvd., Debrecen H-4012, Hungary.
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Csillag A, Kumar BV, Szabó K, Szilasi M, Papp Z, Szilasi ME, Pázmándi K, Boldogh I, Rajnavölgyi É, Bácsi A, László JF. Exposure to inhomogeneous static magnetic field beneficially affects allergic inflammation in a murine model. J R Soc Interface 2014; 11:20140097. [PMID: 24647908 DOI: 10.1098/rsif.2014.0097] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/25/2022] Open
Abstract
Previous observations suggest that static magnetic field (SMF)-exposure acts on living organisms partly through reactive oxygen species (ROS) reactions. In this study, we aimed to define the impact of SMF-exposure on ragweed pollen extract (RWPE)-induced allergic inflammation closely associated with oxidative stress. Inhomogeneous SMF was generated with an apparatus validated previously providing a peak-to-peak magnetic induction of the dominant SMF component 389 mT by 39 T m(-1) lateral gradient in the in vivo and in vitro experiments, and 192 mT by 19 T m(-1) in the human study at the 3 mm target distance. Effects of SMF-exposure were studied in a murine model of allergic inflammation and also in human provoked skin allergy. We found that even a single 30-min exposure of mice to SMF immediately following intranasal RWPE challenge significantly lowered the increase in the total antioxidant capacity of the airways and decreased allergic inflammation. Repeated (on 3 consecutive days) or prolonged (60 min) exposure to SMF after RWPE challenge decreased the severity of allergic responses more efficiently than a single 30-min treatment. SMF-exposure did not alter ROS production by RWPE under cell-free conditions, while diminished RWPE-induced increase in the ROS levels in A549 epithelial cells. Results of the human skin prick tests indicated that SMF-exposure had no significant direct effect on provoked mast cell degranulation. The observed beneficial effects of SMF are likely owing to the mobilization of cellular ROS-eliminating mechanisms rather than direct modulation of ROS production by pollen NAD(P)H oxidases.
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Affiliation(s)
- Anikó Csillag
- Department of Immunology, Faculty of Medicine, University of Debrecen, , 98 Nagyerdei Boulevard, Debrecen 4012, Hungary
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Pazmandi K, Kumar BV, Szabo K, Boldogh I, Szoor A, Vereb G, Veres A, Lanyi A, Rajnavolgyi E, Bacsi A. Ragweed subpollen particles of respirable size activate human dendritic cells. PLoS One 2012; 7:e52085. [PMID: 23251688 PMCID: PMC3522620 DOI: 10.1371/journal.pone.0052085] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/14/2012] [Accepted: 11/09/2012] [Indexed: 12/21/2022] Open
Abstract
Ragweed (Ambrosia artemisiifolia) pollen grains, which are generally considered too large to reach the lower respiratory tract, release subpollen particles (SPPs) of respirable size upon hydration. These SPPs contain allergenic proteins and functional NAD(P)H oxidases. In this study, we examined whether exposure to SPPs initiates the activation of human monocyte-derived dendritic cells (moDCs). We found that treatment with freshly isolated ragweed SPPs increased the intracellular levels of reactive oxygen species (ROS) in moDCs. Phagocytosis of SPPs by moDCs, as demonstrated by confocal laser-scanning microscopy, led to an up-regulation of the cell surface expression of CD40, CD80, CD86, and HLA-DQ and an increase in the production of IL-6, TNF-α, IL-8, and IL-10. Furthermore, SPP-treated moDCs had an increased capacity to stimulate the proliferation of naïve T cells. Co-culture of SPP-treated moDCs with allogeneic CD3+ pan-T cells resulted in increased secretion of IFN-γ and IL-17 by T cells of both allergic and non-allergic subjects, but induced the production of IL-4 exclusively from the T cells of allergic individuals. Addition of exogenous NADPH further increased, while heat-inactivation or pre-treatment with diphenyleneiodonium (DPI), an inhibitor of NADPH oxidases, strongly diminished, the ability of SPPs to induce phenotypic and functional changes in moDCs, indicating that these processes were mediated, at least partly, by the intrinsic NAD(P)H oxidase activity of SPPs. Collectively, our data suggest that inhaled ragweed SPPs are fully capable of activating dendritic cells (DCs) in the airways and SPPs' NAD(P)H oxidase activity is involved in initiation of adaptive immune responses against innocuous pollen proteins.
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Affiliation(s)
- Kitti Pazmandi
- Department of Immunology, Medical and Health Science Center, University of Debrecen, Debrecen, Hungary
| | - Brahma V. Kumar
- Department of Immunology, Medical and Health Science Center, University of Debrecen, Debrecen, Hungary
| | - Krisztina Szabo
- Department of Immunology, Medical and Health Science Center, University of Debrecen, Debrecen, Hungary
| | - Istvan Boldogh
- Department of Microbiology and Immunology, University of Texas Medical Branch at Galveston, Galveston, Texas, United States of America
| | - Arpad Szoor
- Department of Biophysics and Cell Biology, Medical and Health Science Center, University of Debrecen, Debrecen, Hungary
| | - Gyorgy Vereb
- Department of Biophysics and Cell Biology, Medical and Health Science Center, University of Debrecen, Debrecen, Hungary
| | - Agota Veres
- Department of Immunology, Medical and Health Science Center, University of Debrecen, Debrecen, Hungary
| | - Arpad Lanyi
- Department of Immunology, Medical and Health Science Center, University of Debrecen, Debrecen, Hungary
| | - Eva Rajnavolgyi
- Department of Immunology, Medical and Health Science Center, University of Debrecen, Debrecen, Hungary
| | - Attila Bacsi
- Department of Immunology, Medical and Health Science Center, University of Debrecen, Debrecen, Hungary
- * E-mail:
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Rosenblatt A, Kumar BV, Mo A, Welsh CS, Margolis RL, Ross CA. Age, CAG repeat length, and clinical progression in Huntington's disease. Mov Disord 2011; 27:272-6. [PMID: 22173986 DOI: 10.1002/mds.24024] [Citation(s) in RCA: 78] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/10/2011] [Revised: 09/23/2011] [Accepted: 10/12/2011] [Indexed: 11/08/2022] Open
Abstract
The objective of this study was to further explore the effect of CAG repeat length on the rate of clinical progression in patients with Huntington's disease. The dataset included records for 569 subjects followed prospectively at the Baltimore Huntington's Disease Center. Participants were seen for a mean of 7.1 visits, with a mean follow-up of 8.2 years. Subjects were evaluated using the Quantified Neurologic Examination and its Motor Impairment subscale, the Mini-Mental State Examination, and the Huntington's disease Activities of Daily Living Scale. By itself, CAG repeat length showed a statistically significant but small effect on the progression of all clinical measures. Contrary to our previous expectations, controlling for age of onset increased the correlation between CAG repeat length and progression of all variables by 69% to 159%. Graphical models further supported the idea that individuals with smaller triplet expansions experience a more gradual decline. CAG repeat length becomes an important determinant of clinical prognosis when accounting for age of onset. This suggests that the aging process itself influences clinical outcomes in Huntington's disease. Inconsistent results in prior studies examining CAG repeat length and progression may indeed reflect a lack of age adjustment.
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Affiliation(s)
- Adam Rosenblatt
- Department of Psychiatry and Behavioral Sciences, Johns Hopkins University School of Medicine, Baltimore, Maryland, USA.
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Rosenblatt A, Kumar BV, Margolis RL, Welsh CS, Ross CA. Factors contributing to institutionalization in patients with Huntington's disease. Mov Disord 2011; 26:1711-6. [DOI: 10.1002/mds.23716] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/08/2010] [Revised: 02/09/2011] [Accepted: 02/22/2011] [Indexed: 11/11/2022] Open
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15
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Affiliation(s)
- B V Kumar
- Department of Ophthalmology, A-Floor, Royal Hallamshire Hospital, Glossop Road, Sheffield, S10 2JF, England, UK.
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Affiliation(s)
- B V Kumar
- Department of Ophthalmology, A-Floor, Royal Hallamshire Hospital, Glossop Road, Sheffield, S10 2JF, UK.
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Kumar BV, Padshetty NS, Bai KY, Rao MS. Prevalence of Candida in the oral cavity of diabetic subjects. J Assoc Physicians India 2005; 53:599-602. [PMID: 16190127] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 05/04/2023]
Abstract
OBJECTIVE Estimation of prevalence of Candida in the oral cavity of diabetic and non-diabetic subjects. MATERIAL AND METHODS One hundred and three subjects of diabetes mellitus (49 Type 1 diabetes mellitus and 54 Type 2 diabetes mellitus) and one hundred non-diabetic subjects (control) were studied. RESULTS 41(83.67%) out of 49 Type 1 diabetes mellitus, 37(68.52%) out of 54 Type 2 diabetes mellitus and 27(27%) out of 100 in non-diabetic subjects were found to carry Candida in their oral cavity. Colony Forming Unit (CFU) of Candida in the oral cavity ranking in groups was Type 1 diabetes mellitus > Type 2 diabetes mellitus > non-diabetic subjects. CONCLUSION Colonization and carriage of Candida in the oral cavity was found to be higher in diabetic subjects than in non-diabetic subjects. However anti-diabetic therapy and glycaemic control in diabetes were found to bear no relation with carriage of Candida in the oral cavity.
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Affiliation(s)
- B V Kumar
- Dept. of Microbiology, MR Medical College
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19
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Battaner E, Kumar BV. Rifampin: inhibition of ribonucleic acid synthesis after potentiation by amphotericin B in Saccharomyces cerevisiae. Antimicrob Agents Chemother 2005; 5:371-6. [PMID: 15825390 PMCID: PMC428977 DOI: 10.1128/aac.5.4.371] [Citation(s) in RCA: 17] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
The inhibition of Saccharomyces cerevisiae growth by amphotericin B and rifampin was studied. Rifampin alone had no effect on growth or macromolecular syntheses. Lethal amounts of amphotericin B produced a late inhibition of ribonucleic acid (RNA) synthesis simultaneous with the arrest of growth and protein synthesis. In contrast, low doses of amphotericin B along with rifampin caused an early arrest of RNA synthesis, followed by a later arrest of growth and protein synthesis. Used with rifampin, amphotericin B thus appears to increase cell permeability for rifampin, which in turn inhibits RNA synthesis; such results are consistent with some reports of inhibition of yeast RNA polymerase function by rifampin. Experiments with petite mutants ruled out any special effect of the antibiotics on mitochondrial RNA synthesis, so that nuclear RNA synthesis is affected. Acrylamide gel analyses of RNA pulse-labeled after addition of the two antibiotics in synergy showed that synthesis of all major classes of RNA was progressively and uniformly inhibited.
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Srinivasan S, Kumar BV, Prasad S, Hiscott P. Partial posterior capsulectomy through an anterior approach: an intraocular lens retaining technique in the management of presumed Propionibacterium acnes endophthalmitis. Eye (Lond) 2005; 20:382-4. [PMID: 15746949 DOI: 10.1038/sj.eye.6701850] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [What about the content of this article? (0)] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022] Open
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Ashraff NN, Kumar BV, Das A, Moriarty AP. Correction of pseudophakic anisometropia in a patient with pseudoexfoliation using an implantable contact lens. Br J Ophthalmol 2004; 88:309. [PMID: 14736803 PMCID: PMC1771982 DOI: 10.1136/bjo.2003.021915] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [What about the content of this article? (0)] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/04/2022]
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Keskinoz M, Kumar BV. Application of linear minimum mean-squared-error equalization for volume holographic data storage. Appl Opt 1999; 38:4387-4393. [PMID: 18323925 DOI: 10.1364/ao.38.004387] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/26/2023]
Abstract
When target densities of volume holographic data storage systems are increased, the systems experience increased interference from adjacent pixels and noise. Here we present a method for designing and applying linear minimum mean-squared-error (LMMSE) equalization to improve the bit error rates (BER's) and hence the storage densities achievable. Numerical results with five defocused data pages indicate that a significant improvement in the BER is possible with LMMSE equalization.
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Affiliation(s)
- M Keskinoz
- Department of Electrical and Computer Engineering, Carnegie Mellon University, Data Storage Systems Center, Pittsburgh, Pennsylvania 15213, USA
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23
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Vadde V, Kumar BV. Channel modeling and estimation for intrapage equalization in pixel-matched volume holographic data storage. Appl Opt 1999; 38:4374-4386. [PMID: 18323924 DOI: 10.1364/ao.38.004374] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/26/2023]
Abstract
We present two different channel models (the magnitude model and the intensity model) for a pixel-matched volume holographic data storage system that employs the 4-focal-length architecture. First, a framework to describe the channel models is developed. We evaluate the linearity of the channel models by comparing data values obtained from diffraction-limited interference with data values predicted by the channel models. The models are evaluated for linearity and equalization gain under different storage and read-back conditions, such as fill factors, apertures, and contrast ratios. Bit error rate results obtained by use of linear equalization methods in conjunction with the channel models developed are also presented. Our results suggest that the magnitude model leads to better performance when the fill factors are small, whereas the intensity model appears to be more appropriate for the high-fill-factor cases. The magnitude model, when suitable, appears to provide a storage density improvement of as great as 65%, whereas the intensity model seems capable of providing as much as 15% density gain through deconvolution. The optimum aperture for storage seems to be close to the Nyquist aperture.
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Affiliation(s)
- V Vadde
- Electrical and Computer Engineering Department, Carnegie Mellon University, Data Storage Systems Center, Pittsburgh, Pennsylvania 15213, USA
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Geetha N, Ankathil R, Ramachandran V, Kumar BV, Ramachandran K, Nair AR, Rajan B. Near-tetraploid acute lymphoblastic leukaemia with skeletal lesions: a unique entity? Med Pediatr Oncol 1999; 32:461-3. [PMID: 10358712 DOI: 10.1002/(sici)1096-911x(199906)32:6<461::aid-mpo18>3.0.co;2-k] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
Affiliation(s)
- N Geetha
- Regional Cancer Centre, Trivandrum, Kerala, India.
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Abstract
A new form of modulation coding for page-oriented memories (POM's) based on parity is introduced. The parity-based codes are evaluated by use of simulated POM data pages. It is illustrated that the proposed parity codes can outperform balanced modulation codes in the presence of fixed-pattern noise and additive white Gaussian noise.
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Kumar BV, Hafeez M. A study on the prevalence of Toxocora spp eggs at public places in Andhra Pradesh. J Commun Dis 1998; 30:197-8. [PMID: 10093429] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 02/11/2023]
Affiliation(s)
- B V Kumar
- College of Veterinary Science, Tirupati, Andhra Pradesh
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Kumar BV, Ng TK. Multiple circular-harmonic-function correlation filter providing specified response to in-plane rotation. Appl Opt 1996; 35:1871-1878. [PMID: 21085311 DOI: 10.1364/ao.35.001871] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/30/2023]
Abstract
The circular-harmonic-function correlation filter originally proposed by Hsu and Arsenault [Appl. Opt. 21, 4016 (1982)] for in-plane rotation invariance uses only one harmonic, which results in poor discrimination capability of the filter. Various methods to use multiple harmonics were explored previously by different researchers. We present a new method to combine multiple circular harmonics into a single filter that can provide the desired correlation response to in-plane rotation while minimizing the correlation-plane energy. Since multiple harmonics are included, the filter can discriminate well, and since correlation-plane energy is minimized, correlation peaks tend to be sharp. Since the designer can specify the desired in-plane rotation response, a variety of filter behaviors (including complete invariance to input rotations) can be obtained. Underlying theory is discussed, and simulation results are presented.
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Abstract
A numerical simulation of hemodynamics in blood vessels with 0-75% dilation is made. A transient UVP finite element method (FEM) and a stable time integration scheme, based on a predictor-corrector strategy, with constant error monitoring are employed in the flow analysis. The pulsatile flow is analyzed without any assumptions in nonlinear terms and is characterized by thoroughly analyzing the flow, pressure, and stress fields. The central axis velocity, central axis and wall pressures, pressure gradient history, and wall shear stress are influenced by the presence of aneurysm. Time-dependent recirculation regions which are sensitive to the degree of dilation of the vessel are seen in the concavity of the dilation. The transverse velocities and their variations with time are found to be too significant to be neglected. The effects of nonlinear convective terms and the nonlinear geometry of the vessel are clearly depicted through the transverse velocity and pressure profiles.
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Affiliation(s)
- B V Kumar
- Department of Mathematics & Scientific Computing, Indian Institute of Technology, Kanpur, U.P.-India
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Abstract
Cholesterol esterase (CEases; E.C. 3.1.13) has been purified to homogeneity from rabbit pancreas. The method of purification consists of homogenization of total pancreas, high speed centrifugation, anion exchange column chromatography on S-Sepharose, size exclusion on Sephacryl followed by affinity chromatography on heparin agarose. During the purification procedure, two distinct isoforms of CEases have been identified. Both forms are similar in their molecular weights, bile salt requirement and pH optima but differ in their sensitivity to heparin. Isoform-I is resistant and isoform-II is sensitive to heparin. In the normal pancreas of the adult rabbit, the amount of each of the enzymes appears to be in equimolar concentrations. Physiological significance of the existence of heparin sensitive and resistant forms by the same tissue is unclear. In view of the significant role played by heparin in the modulation of CEase activity and several other physiological functions, these two isoforms may have different mechanisms of action on the hydrolysis of carboxyl esters of cholesterol and vitamins.
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Affiliation(s)
- W Jamry
- Division of Geriatric Research Education and Clinical Center, VA Medical Center, St. Louis, MO 63125, USA
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Abstract
A nonlinear pulsatile suspension flow in a dilated vessel is numerically analysed. Two sets of highly coupled nonlinear partial differential equations governing the suspension flow are numerically solved, to simulate the suspension flow dynamics. A transient velocity-pressure (UVP) finite element method (FEM) and a stable time integration scheme, based on a predictor-corrector strategy, with constant error monitoring are employed in the flow analysis. The pulsatile suspension flow is characterized by analysing the flow, pressure and stress fields. Effects of the nonlinear particulate phase on the nonlinear suspending fluid phase are brought out by comparing the suspension flow results with those of homogeneous flow. Particles are seen to dampen the flow velocity, wall and central axis pressure, pressure gradient and wall shear stress. time-dependent recirculation regions which are sensitive to the presence of particles are seen in the dilated portion of the vessel. These recirculation regions favour thrombogenesis. The nonlinear effects due to the vessel geometry and those due to the convective terms dominate the dampening effect of the particles. These nonlinear effects are depicted through the transverse velocity and pressure plots. Wall shear stresses of suspension flow are not only high but also alternate in direction.
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Affiliation(s)
- B V Kumar
- Department of Mathematics and Computer Science, Sri Sathya Sai Institute of Higher Learning, India
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Kumar BV, Carlson DW, Mahalanobis A. Optimal trade-off synthetic discriminant function filters for arbitrary devices. Opt Lett 1994; 19:1556-1558. [PMID: 19855582 DOI: 10.1364/ol.19.001556] [Citation(s) in RCA: 16] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/28/2023]
Abstract
A new correlation-filter design methodology is presented for achieving two objectives: synthetic discriminant function filters that can be implemented on arbitrary various criteria of interest. devices and that can provide optimal trade-off among various criteria of interest.
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Affiliation(s)
- S H Nizamie
- Central Institute of Psychiatry, Kanke, Ranchi, India
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Rajalakshmi M, Kumar BV, Kapur MM, Pal PC. Ultrastructural changes in the efferent duct and epididymis of men with obstructive infertility. Anat Rec (Hoboken) 1993; 237:199-207. [PMID: 8238971 DOI: 10.1002/ar.1092370207] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/29/2023]
Abstract
Ultrastructural changes in the efferent duct and in different regions of the epididymis in men with obstructive azoospermia were compared with corresponding tissues collected from men of proven fertility who underwent castration due to malignancy of the prostate. Major degenerative changes were seen in the efferent duct and the caput epididymidis of men with obstruction at the caput epididymidis which may have been induced by fluid pressure due to defective absorption of testicular fluid in the caput epididymidis. These degenerative changes included decrease in tubular and lumen diameter of the caput and the cauda epididymides, decrease in height of the stereocilia, reduction in rough endoplasmic reticulum and Golgi material, and presence of lipofuscin and osmiophilic dense bodies. The degenerative changes were less when the site of obstruction was in the cauda epididymidis since fluid reabsorption would continue to take place normally in the caput epididymidis. In men who had undergone vasoepididymostomy (VEA), the ejaculated spermatozoa showed a high percentage of morphological abnormalities which may have occurred due to adverse effects of long-term obstruction on spermatogenesis.
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Affiliation(s)
- M Rajalakshmi
- Department of Reproductive Biology, All India Institute of Medical Sciences, New Delhi
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Abstract
Rabbit pancreatic cholesterol esterase (CEase, carboxyl ester lipase, EC 3.1.1.3) has been cloned from a lambda gt11 library of adult rabbit pancreatic cDNA. The open reading frame consists of 1788 nucleotides which encodes 576 amino acids of the functional protein and a 20 amino acid leader peptide. When compared to other species, the greatest homology is observed between residues 82-248 with little or no homology at the C-terminal end where proline-glutamate-serine-threonine (PEST) segments are a characteristic feature of the human CEase. Rabbit CEase (RCEase) retains the active-site serine (gxsxg), the active-site histidine and the tentative heparin binding site (KKRCLQ) at similar positions in comparison to pancreatic CEases of other species. When rabbit CEase cDNA is expressed in monkey kidney (COS-7) cells, enzymatic hydrolytic activity is detected in the growth medium as is a 67 kDa protein by Western blotting with polyclonal anti-CEase antibody. Northern blot analysis shows two mRNA (2.2 and 3.2 kb) species.
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Affiliation(s)
- N S Colwell
- Geriatric Research Education and Clinical Center, V.A. Medical Center, St. Louis, MO
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Abstract
Pleiotrophin (PTN), midkine (MK), and retinoic acid-induced heparin-binding (RI-HB) protein are members of a recently discovered family of developmentally regulated cytokines. We report here the cloning, sequencing, chromosomal localization, and structural organization of the genomic version of the human PTN gene and its comparison to the mouse MK gene. The PTN gene was found to be arranged in five exons and four introns, in a fashion similar to that of the mouse MK gene. Exon 1, as for MK, does not appear to encode amino acid sequence. As in the case of the MK gene, exon 2 encodes the hydrophobic leader sequence of PTN, which constitutes the beginning of gene translation. The signal peptide cleavage site of both genes lies toward the 3' end of exon 2. Exons 3 and 4 of PTN were most closely related to exons 3 and 4 of the MK gene; in particular, six of the ten cysteine residues were coded for in exon 3 and the remaining 4 in exon 4. The intron-exon splice junctions of both genes occurred through the same residues. The two genes were found to be less closely related in the fifth exon which encodes the highly basic C-terminal domains, the translation termination codon, and the polyadenylation signal of both cDNAs. We also report approximately 2000 bp of the 5' untranslated sequence of the PTN gene and the site of initiation of transcription in human placenta. PTN was localized to human chromosome 7q33-34 by fluorescence in situ hybridization. These data confirm the existence of a new gene family of developmentally regulated cytokines.
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Affiliation(s)
- P G Milner
- Department of Medicine, Washington University Medical Center, St. Louis, Missouri 63110
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36
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Abstract
A tutorial survey is presented of the many composite filter designs proposed for distortion-invariant optical pattern recognition. Remarks are made throughout regarding areas for further investigation.
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37
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Kumar BV, Aleman-Gomez JA, Colwell N, Lopez-Candales A, Bosner MS, Spilburg CA, Lowe M, Lange LG. Structure of the human pancreatic cholesterol esterase gene. Biochemistry 1992; 31:6077-81. [PMID: 1627550 DOI: 10.1021/bi00141a017] [Citation(s) in RCA: 34] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/27/2022]
Abstract
The gene for human pancreatic cholesterol esterase consists of 11 exons and 10 introns and is 9.2 kb in length. The last and longest exon (841 nucleotides) is unique to the human gene. Functional amino acids are encoded on separate exons. The leader sequence is encoded by a single exon which carries two additional N-terminal amino acids of the mature functional protein. A positive TATA element is identified 43 nucleotides from the start codon. Pulse-field gel electrophoresis and hybridization with various cDNA probes and direct sequence data revealed the existence of a CEase-like gene. Partial sequence analysis of this gene from a human cosmid library and human genomic DNA showed a premature stop signal in exon 10, shortly after the codon for the active-site histidine. Both the functional gene and the CEase-like gene have a polyadenylation signal in the 3'-untranslated region. Thus, the complex gene structure for this intestinally active enzyme may provide in part a potential molecular explanation for the well-known heterogeneity of the intestinal absorption of cholesterol.
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Affiliation(s)
- B V Kumar
- Department of Medicine, Jewish Hospital of St. Louis, Washington University Medical Center, Missouri 63110
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38
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Abstract
Eighteen corpora striata from normal human foetal brains ranging in gestational age from 16 to 40 weeks and five from post natal brains ranging from 23 days to 42 years were analysed for the ontogeny of dopamine receptors using [3H]spiperone as the ligand and 10 mM dopamine hydrochloride was used in blanks. Spiperone binding sites were characterized in a 40-week-old foetal brain to be dopamine receptors by the following criteria: (1) It was localized in a crude mitochondrial pellet that included synaptosomes; (2) binding was saturable at 0.8 nM concentration; (3) dopaminergic antagonists spiperone, haloperidol, pimozide, trifluperazine and chlorpromazine competed for the binding with IC50 values in the range of 0.3-14 nM while agonists--apomorphine and dopamine gave IC50 values of 2.5 and 10 microM, respectively suggesting a D2 type receptor. Epinephrine and norepinephrine inhibited the binding much less efficiently while mianserin at 10 microM and serotonin at 1 mM concentration did not inhibit the binding. Bimolecular association and dissociation rate constants for the reversible binding were 5.7 x 10(8) M-1 min-1 and 5.0 x 10(-2) min-1, respectively. Equilibrium dissociation constant was 87 pM and the KD obtained by saturation binding was 73 pM. During the foetal age 16 to 40 weeks, the receptor concentration remained in the range of 38-60 fmol/mg protein or 570-1080 fmol/g striatum but it increased two-fold postnatally reaching a maximum at 5 years.(ABSTRACT TRUNCATED AT 250 WORDS)
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Affiliation(s)
- B V Kumar
- Department of Biochemistry, Indian Institute of Science, Bangalore
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39
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Abstract
Competitive learning paradigms are usually defined with winner-take-all (WTA) activation rules. The paper develops a mathematical model for competitive learning paradigms using a generalization of the WTA activation rule (g-WTA). The model is a partial differential equation (PDE) relating the time rate of change in the ;density' of weight vectors to the divergence of a vector field called the neural flux. Characteristic trajectories are used to study solutions of the PDE model over scalar weight spaces. These solutions show how the model can be used to design competitive learning algorithms which estimate the modes of unknown probability density functions.
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Affiliation(s)
- M Lemmon
- Dept. of Electr. and Comput. Eng., Carnegie Mellon Univ., Pittsburg, PA
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40
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Vasantha S, Kumar BV, Roopashree SD, Das S, Shankar SK. Neuroanatomy of Cysticercus cellulosae (Cestoda) as revealed by acetylcholinesterase and nonspecific esterase histochemistry. Parasitol Res 1992; 78:581-6. [PMID: 1438150 DOI: 10.1007/bf00936456] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/27/2022]
Abstract
The nervous system of Cysticercus cellulosae, the metacestode stage of the tapeworm Taenia solium, was delineated using histochemical methods for the localization of the enzyme markers; nonspecific esterase and acetylcholinesterase. The main features of the nervous system include a pair of cerebral ganglia, a circumcerebral nerve ring, a rostellar nerve ring, and anterior and posterior nerves and their branches. The posterior nerves form a subtegumental network in the strobila and the bladder wall. A nerve network around excretory tubules could also be demonstrated, suggesting neuronal control of excretion in the metacestode. No sheath was observed around the nervous system. The morphological features described suggest "cephalization" of the nervous system in this parasite.
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Affiliation(s)
- S Vasantha
- Astra Research Centre India, Malleswaram, Bangalore
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41
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Kumar BV, Juday RD. Design of phase-only, binary phase-only, and complex ternary matched filters with increased signal-to-noise ratios for colored noise. Opt Lett 1991; 16:1025-1027. [PMID: 19776864 DOI: 10.1364/ol.16.001025] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/28/2023]
Abstract
An algorithm is provided for treating nonwhite additive noise in determining regions of support for phase-only filters, binary phase-only filters, and complex ternary matched filters. It is analytically shown to be optimal in the signal-to-noise ratio sense. It extends earlier research that assumed white noise.
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42
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Abstract
Expressions are derived for real filters that have a maximum correlation signal to noise ratio. Both continuous and discrete cases are treated and shown to have similar forms. The signal can be complex, and the case of a real signal is considered and related to previous results.
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43
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Kumar BV, Shi W, Hendrix C. Phase-only filters with maximally sharp correlation peaks. Opt Lett 1990; 15:807-809. [PMID: 19768085] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Subscribe] [Scholar Register] [Indexed: 05/28/2023]
Abstract
A performance measure called the peak-to-correlation energy is used to characterize the sharpness of correlation outputs. This measure is then used to determine the phase-only filter with maximally sharp correlation peaks.
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44
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Abstract
Several performance criteria are described to enable a fair comparison among the various correlation filter designs: signal-to-noise ratio, peak sharpness, peak location, light efficiency, discriminability, and distortion invariance. The trade-offs resulting between some of these criteria are illustrated with the help of a new family of filters called fractional power filters (FPFs). The classical matched filter, phase-only filter (POF), and inverse filter are special cases of FPFs. Using examples, we show that the POF appears to provide a good compromise between noise tolerance and peak sharpness.
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45
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Bahri Z, Kumar BV. Fast algorithms for designing optical phase-only filters (POFs) and binary phase-only filters (BPOFs). Appl Opt 1990; 29:2992-2996. [PMID: 20567366 DOI: 10.1364/ao.29.002992] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/29/2023]
Abstract
Very efficient suboptimal algorithms for the design of phase-only filters and binary phase-only filters are presented. A reduction of 2- to 3-orders of magnitude in computer time is obtained over previous algorithms. The loss in signal-to-noise ratio is negligible (<0.001 dB).
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46
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Abstract
The histology of different regions of human epididymis in men undergoing vasoepididymostomy to correct epididymal obstruction was studied. The data indicate major degenerative changes in intertubular connective tissue and in the epididymal epithelium. These include increase in connective tissue thickness and its infiltration by leucocytes in some cases, decrease in tubular diameter, degeneration and/or vacuolation of cytoplasm of nonciliated cells of efferent duct and principal cells of epididymis and presence of multinucleate giant cells in the epididymal lumen. These histological abnormalities are discussed in relation to the role such epididymis can play in sperm maturation following vasoepididymostomy.
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Affiliation(s)
- M Rajalakshmi
- Department of Reproductive Biology, All India Institute of Medical Sciences, New Delhi
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47
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Kumar BV, Shipstone AC, Setty BS. Effect of vasectomy on the ultrastructure of epididymal epithelium in rhesus monkey. Int J Fertil 1990; 35:180-91. [PMID: 1973925] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Subscribe] [Scholar Register] [Indexed: 12/29/2022]
Abstract
Ultrastructural changes in the epididymal epithelium and the fate of accumulating spermatozoa were examined in the vasectomized rhesus monkey (Macaca mulatta). Accumulation of spermatozoa resulted in an increase in the diameter of the tubule and its lumen. Ultrastructure of principal cells revealed that they continue to perform both secretory and absorptive functions after vasectomy. The rough endoplasmic reticulum, Golgi complex, and mitochondria were well developed in the principal cell. Bulging of the apical portion of principal cells and membrane-bound structures in the lumen suggests an increase in apocrine secretion. An increase in the number of vesicles, vacuoles, and multivesicular bodies in the principal cells indicates an increased absorptive activity. Increased absorptive function was also evident in the apical cells. Macrophages with sperm remnants were seen in the lumen, and occasionally in the connective tissue. The principal or only mechanism of sperm disposal after vasectomy appeared to be intraluminal endocytosis by macrophages.
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Affiliation(s)
- B V Kumar
- Division of Endocrinology, Central Drug Research Institute, Lucknow, India
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48
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Kumar BV. Signal to noise ratio loss in correlators using real filters. Appl Opt 1989; 28:3287-3288. [PMID: 20555689 DOI: 10.1364/ao.28.003287] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/29/2023]
Abstract
Simple expressions are derived for the loss in signal-tonoise ratio when a real filter is used instead of a complex filter in an optical correlator.
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49
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Kumar BV, Casasent DP, Mahalanobis A. Correlation filters for target detection in a Markov model background clutter. Appl Opt 1989; 28:3112-3119. [PMID: 20555659 DOI: 10.1364/ao.28.003112] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/29/2023]
Abstract
The performance of distortion-invariant correlation filters in the presence of background clutter is addressed. Background images are modeled as Markov noise processes, and a synthesis procedure for the optimal filter is described. It is shown that spatially filtering the training set images eliminates the need for the inversion of large noise covariance matrices, thus leading to a computationally efficient filter realization. The effect of errors (in the estimation of clutter correlation coefficient) on filter performance is theoretically analyzed, and a bound on the relative degradation of the SNR due to such errors is presented.
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50
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Kumar BV, Bahri Z. Efficient algorithm for designing a ternary valued filter yielding maximum signal to noise ratio. Appl Opt 1989; 28:1919-1925. [PMID: 20548767 DOI: 10.1364/ao.28.001919] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/29/2023]
Abstract
An efficient algorithm for designing a ternary valued filter yielding the highest signal to noise ratio (SNR) is utlined. Numerical evaluations using the image of a tank indicate that using such a filter can provide an improvement in SNR of ~5 dB over the conventional binary phase-only filter (BPOF). This is superior to the 1-dB improvement obtained for that image by varying the threshold line angle (TLA) in filter binarization. Simulation results are presented. They agree with the numerically computed SNRs.
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