Veterinary Pathology and Pathobiology | Open Access Articles

Light-Evoked Calcium Responses Of Isolated Melanopsin- Expressing Retinal Ganglion Cells, Andrew T. E. Hartwick, Jayne R. Bramley, Jianing Yu, Kelly T. Stevens, Charles N. Allen, William H. Baldridge, Patricia J. Sollars, Gary E. Pickard

School of Veterinary and Biomedical Sciences: Faculty Publications

A small number (<2%) of mammalian retinal ganglion cells express the photopigment melanopsin and are intrinsically photosensitive (ipRGCs). Light depolarizes ipRGCs and increases intracellular calcium levels ( [Ca²⁺]_i) but the signaling cascades underlying these responses have yet to be elucidated. To facilitate physiological studies on these rare photoreceptors, highly enriched ipRGC cultures from neonatal rats were generated using anti-melanopsin-mediated plate adhesion (immunopanning). This novel approach enabled experiments on isolated ipRGCs, eliminating the potential confounding influence of rod/cone-driven input. Light induced a rise in [Ca²⁺]_i (monitored using fura-2 imaging) in the immunopanned ipRGCs and the source of this Ca²⁺ signal was investigated. The Ca²⁺ responses were inhibited by 2-aminoethoxydiphenyl borate, SKF-96365 (1–2-(4-methoxyphenyl)-2-[3-(4-methoxyphenyl)propoxy]ethyl-1H-imidazole), flufenamic acid, …

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Enhancement Of Efficacy Of Prrsv Vaccines By Altering The Glycosylation Pattern Of Viral Glycoproteins, Asit K. Pattnaik

School of Veterinary and Biomedical Sciences: Faculty Publications

PRRSV, the causative agent of PRRS is of major economic significance to the pork industry in the USA and around the world. Current commercial vaccine does not provide adequate protection against PRRSV outbreaks. Therefore, there is an urgent need for development of more efficacious vaccine to combat PRRS. Our previous studies have suggested that (i) induction of neutralizing antibody response is an important correlate of evaluating the efficacy of a vaccine; (ii) neutralizing antibodies can be enhanced by hypoglycosylation of the major surface glycoprotein (GP5). While it is known that GP5 plays a prominent role in neutralizing antibody induction, it …

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Low Molecular Weight Protein Tyrosine Phosphatase (Lmw-Ptp) And Its Possible Physiological Functions Of Redox Signaling In The Eye Lens, Kuiyi Xing, Ashraf Raza, Stefan Lofgren, M. Rohan Fernando, Ye-Shih Ho, Marjorie F. Lou

School of Veterinary and Biomedical Sciences: Faculty Publications

Low molecular weight protein tyrosine phosphatase (LMW-PTP) was cloned from human lens epithelial B3 cells (HLE B3) and the recombinant enzyme was purified to homogeneity. The pure enzyme reacted positively with anti-LMW-PTP antibody, displayed tyrosine-specific phosphatase activity and was extremely sensitive to H2O2. The inactivated LMW-PTP could be regenerated by thioltransferase (TTase)/GSH system as demonstrated by both activity assay and by mass spectrometry (MS). The MS study also showed that an intramolecular disulfide bond was formed between C13 and C18 at the active site, and was reduced by the TTase/GSH system. The putative role of LMW-PTP in regulating platelet derived …

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Characterization Of A Virulence Related Hypothetical Protein In Edwardsiella Ictaluri, Ildiko Katalin Polyak

LSU Master's Theses

Although the biochemical characterization of E. ictaluri, the subsequent disease progression of enteric septicemia of catfish (ESC), and the associated pathologic lesions are well characterized, the mechanism of invasion of E. ictaluri into a susceptible host is poorly understood. Identification and confirmation of virulence factors and associated genes of E. ictaluri is crucial to elucidating the pathogenesis of this important disease. A signature tagged mutagenesis (STM) study conducted by Thune et al. (2006) identified 50 E. ictaluri clones with transposon insertions in genes potentially involved in pathogenesis. A specific STM mutant, 233PR, carrying a transposon insertion in a gene encoding …

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Evaluation Of Selected Immune Response To Haemonchus Contortus In Gulf Coast Native Compared To Suffolk Lambs, Krishna P. Shakya

LSU Doctoral Dissertations

Haemonchus contortus is one of the major nematode parasites causing substantial economic losses in small ruminant farming worldwide. Recently, effect of anthelmintic treatment has decreased due to an increasing problem of nematode populations that have developed resistance to anthelmintics. There are certain breeds of sheep that are identified as being relatively resistant to the parasite including Gulf Coast Native (Native) sheep. Understanding the mode of immune response that helps these breeds of sheep control infection could help design vaccines and enhance control programs. This experiment was designed to evaluate the immunological responses of Native, compared with susceptible Suffolk sheep that …

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Depletion Of 32-Kbp Circular Plasmids From Borrelia Burgdorferi, Amanda Paige Derouen Polito

LSU Master's Theses

The Lyme disease spirochete Borrelia burgdorferi has a very unusual genome composed of one linear chromosome and up to 21 linear and circular plasmids. Several plasmids are known to be important either for mammalian infection or tick colonization. A single spirochete harbors up to 7 different cp32 plasmids; however, nothing is known about their role in mammalian infection. The plasmids in this family are well maintained during in vitro cultivation, making it difficult to study their functions. To effectively deplete the plasmids, an 8kbp fragment containing essential elements for replication and partitioning in B. burgdorferi was amplified from one of …

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Influence Of Tumor Necrosis Factor-Alpha And Minocycline On Microglia And Macrophage Activation During Polytropic Retrovirus Infection, Meryll E. Corbin

LSU Master's Theses

Microglia/macrophage activation has been associated with the pathogenesis of various neurological diseases including human immunodeficiency virus encephalitis, transmissible spongiform encephalitis, and Alzheimer's disease (AD). In vitro studies have indicated a role for TNFα in activating these cells which leads to their migration, proliferation, and secretion of proinflammatory cytokines and chemokines that may potentially damage brain tissue. In the current study, we analyzed the phenotype of microglia and macrophages enriched from wild type and TNFα deficient mice infected with a neurovirulent murine retrovirus. Although TNF receptors CD120a and CD120b were expressed on both microglia and macrophage population, unaltered by either retrovirus …

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The Role Of Toll-Like Receptor 7 In The Neuropathogenesis Of Retrovirus Infection In Neonates, Stephanie Diane Lewis

LSU Master's Theses

Viral infections of the central nervous system (CNS) in infants are rare; however, they are associated with high morbidity and mortality rates. These virus infections often induce strong innate immune responses in the brain including: the production of cytokines and chemokines, the activation of astrocytes and microglia and the recruitment of macrophages. Innate immune responses are often initiated by toll-like receptors (TLR). Several studies have demonstrated that toll-like receptor 7 (TLR7) can be stimulated by single-stranded RNA from multiple viruses. In the current study, we examined the mechanism by which TLR7 contributes to neuroinflammation in the neonatal brain using a …

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Genetics Of Herpes Simplex Virus Type-1 Tegument Proteins Involved In Virion Morphogenesis And Egress, Preston A. Fulmer

LSU Doctoral Dissertations

Herpes simplex virus type-1 (HSV-1) morphogenesis occurs in multiple stages within infected cells. Initially, the virion capsid assembles within the nucleus and buds through the nuclear membrane into the cytoplasm. Within the cytoplasm, additional tegument proteins attach to the capsid and the fully tegumented capsids bud into trans-Golgi network (TGN) derived vesicles. Enveloped virions are ultimately secreted to extracellular spaces. The process by which the cytoplasmic capsids bud into TGN-derived vesicles is not well understood. The prevalent model calls for specific interactions among viral tegument proteins and membrane proteins and glycoproteins embedded within TGN membranes. To further investigate the roles …

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Differential Engagement Of Tim-1 During Activation Can Positively Or Negatively Costimulate T Cell Expansion And Effector Function, Vijay K. Kuchroo, Sheng Xiao, Nader Najafian, Jay Reddy, Monica Albin, Chen Zhu, Eric Jensen, Jaimie Imitola, Thomas Korn, Ana C. Anderson, Zheng Zhang, Cristina Gutierrez, Thomas Moll, Raymond A. Sobel, Dale T. Umetsu, Hideo Yagita, Hisaya Akiba, Terry Strom, Mohamed H. Sayegh, Rosemarie H. Dekruyff, Samia J. Khoury

School of Veterinary and Biomedical Sciences: Faculty Publications

It has been suggested that T cell immunoglobulin mucin (Tim)-1 expressed on T cells serves to positively costimulate T cell responses. However, crosslinking of Tim-1 by its ligand Tim-4 resulted in either activation or inhibition of T cell responses, thus raising the issue of whether Tim-1 can have a dual function as a costimulator. To resolve this issue, we tested a series of monoclonal antibodies specifi c for Tim-1 and identifi ed two antibodies that showed opposite functional effects. One anti–Tim-1 antibody increased the frequency of antigen-specifi c T cells, the production of the proinfl ammatory cytokines IFN-γ and IL-17, …

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Protostrongylid Parasites And Pneumonia In Captive And Wild Thinhorn Sheep (Ovis Dalli), Emily J. Jenkins, A. M. Veitch, Susan J. Kutz, T. K. Bollinger, J. M. Chirino-Trejo, B. T. Elkin, K. H. West, Eric P. Hoberg, L. Polley

Harold W. Manter Laboratory of Parasitology: Faculty Publications

We describe health significance of protostrongylid parasites (Parelaphostrongylus odocoilei and Protostrongylus stilesi) and other respiratory pathogens in more than 50 naturally infected Dall’s sheep (Ovis dalli dalli) from the Mackenzie Mountains, Northwest Territories (1998–2002) as well as in three Stone’s sheep (O. d. stonei) experimentally infected with P. odocoilei (2000–2002). Histological lesions in the brain and distribution of P. odocoilei in the muscles of experimentally and naturally infected sheep were consistent with a previously hypothesized ‘‘central nervous system to muscle’’ pattern of migration for P. odocoilei. Dimensions of granulomas associated with eggs of …

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Brucella Melitensis: The Evaluation Of A Putative Hemagglutinin Gene's Effect On Virulence In The Caprine Model, Quinesha Laticia Perry

LSU Doctoral Dissertations

Brucella melitensis is a facultative intracellular bacterial pathogen that causes abortions in goats and sheep and Malta fever in humans. The zoonotic disease brucellosis causes severe economic losses in the Mediterranean region and parts of Africa, Asia, and Latin America. With the completion of the genomic sequences of B. abortus 2308 and B. melitensis 16M, no classical virulence factors were found; and the chromosomes were virtually identical. However, in B. melitensis, a putative hemagglutinin gene was identified which is absent in B. abortus. The possibility of the hemagglutinin gene being a potential virulence factor was evaluated via gene replacement/deletion in …

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Full-Text Articles in Veterinary Pathology and Pathobiology

Light-Evoked Calcium Responses Of Isolated Melanopsin- Expressing Retinal Ganglion Cells, Andrew T. E. Hartwick, Jayne R. Bramley, Jianing Yu, Kelly T. Stevens, Charles N. Allen, William H. Baldridge, Patricia J. Sollars, Gary E. Pickard

School of Veterinary and Biomedical Sciences: Faculty Publications

Enhancement Of Efficacy Of Prrsv Vaccines By Altering The Glycosylation Pattern Of Viral Glycoproteins, Asit K. Pattnaik

School of Veterinary and Biomedical Sciences: Faculty Publications

Low Molecular Weight Protein Tyrosine Phosphatase (Lmw-Ptp) And Its Possible Physiological Functions Of Redox Signaling In The Eye Lens, Kuiyi Xing, Ashraf Raza, Stefan Lofgren, M. Rohan Fernando, Ye-Shih Ho, Marjorie F. Lou

School of Veterinary and Biomedical Sciences: Faculty Publications

Characterization Of A Virulence Related Hypothetical Protein In Edwardsiella Ictaluri, Ildiko Katalin Polyak

LSU Master's Theses

Evaluation Of Selected Immune Response To Haemonchus Contortus In Gulf Coast Native Compared To Suffolk Lambs, Krishna P. Shakya

LSU Doctoral Dissertations

Depletion Of 32-Kbp Circular Plasmids From Borrelia Burgdorferi, Amanda Paige Derouen Polito

LSU Master's Theses

Influence Of Tumor Necrosis Factor-Alpha And Minocycline On Microglia And Macrophage Activation During Polytropic Retrovirus Infection, Meryll E. Corbin

LSU Master's Theses

The Role Of Toll-Like Receptor 7 In The Neuropathogenesis Of Retrovirus Infection In Neonates, Stephanie Diane Lewis

LSU Master's Theses

Genetics Of Herpes Simplex Virus Type-1 Tegument Proteins Involved In Virion Morphogenesis And Egress, Preston A. Fulmer

LSU Doctoral Dissertations

School of Veterinary and Biomedical Sciences: Faculty Publications

Protostrongylid Parasites And Pneumonia In Captive And Wild Thinhorn Sheep (Ovis Dalli), Emily J. Jenkins, A. M. Veitch, Susan J. Kutz, T. K. Bollinger, J. M. Chirino-Trejo, B. T. Elkin, K. H. West, Eric P. Hoberg, L. Polley

Harold W. Manter Laboratory of Parasitology: Faculty Publications

Brucella Melitensis: The Evaluation Of A Putative Hemagglutinin Gene's Effect On Virulence In The Caprine Model, Quinesha Laticia Perry

LSU Doctoral Dissertations