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School of Veterinary and Biomedical Sciences: Faculty Publications

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Articles 361 - 390 of 454

Full-Text Articles in Veterinary Medicine

Mycobacterium Smegmatis L-Alanine Dehydrogenase (Ald) Is Required For Proficient Utilization Of Alanine As A Sole Nitrogen Source And Sustained Anaerobic Growth, Zhengyu Feng, Nancy E. Caceres, Gautam Sarath, Raul G. Barletta Sep 2002

Mycobacterium Smegmatis L-Alanine Dehydrogenase (Ald) Is Required For Proficient Utilization Of Alanine As A Sole Nitrogen Source And Sustained Anaerobic Growth, Zhengyu Feng, Nancy E. Caceres, Gautam Sarath, Raul G. Barletta

School of Veterinary and Biomedical Sciences: Faculty Publications

NAD(H)-dependent L-alanine dehydrogenase (EC 1.4.1.1) (Ald) catalyzes the oxidative deamination of L-alanine and the reductive amination of pyruvate. To assess the physiological role of Ald in Mycobacterium smegmatis, we cloned the ald gene, identified its promoter, determined the protein expression levels, and analyzed the combined effects of nutrient supplementation, oxygen availability, and growth stage on enzyme activity. High Ald activities were observed in cells grown in the presence of L- or D-alanine regardless of the oxygen availability and growth stage. In exponentially growing cells under aerobic conditions, supplementation with alanine resulted in a 25- to 50-fold increase in the …

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A Novel Herpes Simplex Virus Type 1 Transcript (Al-Rna) Antisense To The 5′ End Of The Latency-Associated Transcript Produces A Protein In Infected Rabbits, Guey-Chuen Perng, Barak Maguen, Ling Jin, Kevin R. Mott, John Kurylo, Lbachir Benmohamed, Ada Yukht, Nelson Osorio, Anthony B. Nesburn, Gail A. Henderson, Melissa Inman, Clinton J. Jones, Steven L. Wechsler Aug 2002

A Novel Herpes Simplex Virus Type 1 Transcript (Al-Rna) Antisense To The 5′ End Of The Latency-Associated Transcript Produces A Protein In Infected Rabbits, Guey-Chuen Perng, Barak Maguen, Ling Jin, Kevin R. Mott, John Kurylo, Lbachir Benmohamed, Ada Yukht, Nelson Osorio, Anthony B. Nesburn, Gail A. Henderson, Melissa Inman, Clinton J. Jones, Steven L. Wechsler

School of Veterinary and Biomedical Sciences: Faculty Publications

Following primary ocular infection, herpes simplex virus type 1 (HSV-1) establishes a lifelong latent infection in sensory neurons of the trigeminal ganglia. Latency-associated transcript (LAT), the only known viral gene abundantly transcribed during HSV-1 neuronal latency, is required for high levels of reactivation. Recently we showed that three different mutants that do not alter the LAT promoter but contain deletions within the 5′ end of the primary LAT transcript affect viral virulence (G. C. Perng et al., J. Virol. 75:9018-9028, 2001). In contrast, in LAT-null mutants viral virulence appears unaltered (T. M. Block et al., Virology 192:618-630, 1993; D. C. …

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A Mutation In The Latency-Related Gene Of Bovine Herpesvirus 1 Disrupts The Latency Reactivation Cycle In Calves, Melissa Inman, Luciane Lovato, Alan R. Doster, Clinton J. Jones Jul 2002

A Mutation In The Latency-Related Gene Of Bovine Herpesvirus 1 Disrupts The Latency Reactivation Cycle In Calves, Melissa Inman, Luciane Lovato, Alan R. Doster, Clinton J. Jones

School of Veterinary and Biomedical Sciences: Faculty Publications

Bovine herpesvirus 1 (BHV-1) is an important pathogen of cattle, and infection is usually initiated via the ocular or nasal cavity. Following acute infection, the primary site for BHV-1 latency is the sensory neuron. Reactivation from latency occurs sporadically, resulting in virus shedding and transmission to uninfected cattle. The only abundant viral transcript expressed during latency is the latency-related (LR) RNA, suggesting that it mediates some aspect of latency. An LR mutant was constructed by inserting three stop codons near the beginning of the LR-RNA, suggesting that expression of LR proteins would be altered. The LR mutant grew with wild-type …

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Phylogenetic Analysis Of Brazilian Bovine Viral Diarrhea Virus Type 2 (Bvdv-2) Isolates: Evidence For A Subgenotype Within Bvdv-2, Eduardo F. Flores, Julia F. Ridpath, Rudi Weiblen, Fernanda S. F. Vogel, Laura H.V.G. Gil Jun 2002

Phylogenetic Analysis Of Brazilian Bovine Viral Diarrhea Virus Type 2 (Bvdv-2) Isolates: Evidence For A Subgenotype Within Bvdv-2, Eduardo F. Flores, Julia F. Ridpath, Rudi Weiblen, Fernanda S. F. Vogel, Laura H.V.G. Gil

School of Veterinary and Biomedical Sciences: Faculty Publications

Phylogenetic analysis divides bovine viral diarrhea viruses (BVDV) into two different genotypes (BVDV1 and BVDV2). BVDV1 strains have been further subdivided into two to 11 subgenotypes. Phylogenetic analysis of BVDV2 isolates, however, has not been able to identify discrete subgenotypes. In this study, we identified six South American BVDV2 strains and one North American BVDV2 strain that cluster to a separate genetic group within BVDV2, thus representing a distinct subgenotype. The 5’ untranslated region (UTR) sequence homology between these six strains and other BVDV2 from North America, Europe and Asia (81.7%) is lower than the homology used to segregate BVDV1 …

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Isolation And Characterization Of Endophytic Colonizing Bacteria From Agronomic Crops And Prairie Plants, Denise K. Zinniel, Patricia A. Lambrecht, N. Beth Harris, Zhengyu Feng, Daniel Kuczmarski, Phyllis Higley, Carol A. Ishimaru, Alahari Arunakumari, Raul G. Barletta, Anne K. Vidaver May 2002

Isolation And Characterization Of Endophytic Colonizing Bacteria From Agronomic Crops And Prairie Plants, Denise K. Zinniel, Patricia A. Lambrecht, N. Beth Harris, Zhengyu Feng, Daniel Kuczmarski, Phyllis Higley, Carol A. Ishimaru, Alahari Arunakumari, Raul G. Barletta, Anne K. Vidaver

School of Veterinary and Biomedical Sciences: Faculty Publications

Endophytic bacteria reside within plant hosts without causing disease symptoms. In this study, 853 endophytic strains were isolated from aerial tissues of four agronomic crop species and 27 prairie plant species. We determined several phenotypic properties and found approximately equal numbers of gram-negative and gram-positive isolates. In a greenhouse study, 28 of 86 prairie plant endophytes were found to colonize their original hosts at 42 days postinoculation at levels of 3.5 to 7.7 log10 CFU/g (fresh weight). More comprehensive colonization studies were conducted with 373 corn and sorghum endophytes. In growth room studies, none of the isolates displayed pathogenicity, …

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Composition And Method For The Prevention And Treatment Of Oxidative Damage In Ocular Tissues, Marjorie F. Lou, Nalini Raghavachari;, Fengyu Qiao Apr 2002

Composition And Method For The Prevention And Treatment Of Oxidative Damage In Ocular Tissues, Marjorie F. Lou, Nalini Raghavachari;, Fengyu Qiao

School of Veterinary and Biomedical Sciences: Faculty Publications

Thioltransferase and derivatives thereof are provided. Methods of treating or preventing cataract formation comprosing administering thioltransferase or a derivative thereof are also provided. Thioltransferase or derivatives thereof are also useful for treating or preventing diseases resulting from or associated with oxidative stress. Human lens thioltransferase and a DNA sequence encoding the same are also provided.

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A Gene Capable Of Blocking Apoptosis Can Substitute For The Herpes Simplex Virus Type 1 Latency-Associated Transcript Gene And Restore Wild-Type Reactivation Levels, Guey-Chuen Perng, Barak Maguen, Ling Jin, Kevin R. Mott, Nelson Osorio, Susan M. Slanina, Ada Yukht, Homayon Ghiasi, Anthony B. Nesburn, Melissa Inman, Gail A. Henderson, Clinton J. Jones, Steven L. Wechsler Feb 2002

A Gene Capable Of Blocking Apoptosis Can Substitute For The Herpes Simplex Virus Type 1 Latency-Associated Transcript Gene And Restore Wild-Type Reactivation Levels, Guey-Chuen Perng, Barak Maguen, Ling Jin, Kevin R. Mott, Nelson Osorio, Susan M. Slanina, Ada Yukht, Homayon Ghiasi, Anthony B. Nesburn, Melissa Inman, Gail A. Henderson, Clinton J. Jones, Steven L. Wechsler

School of Veterinary and Biomedical Sciences: Faculty Publications

After ocular herpes simplex virus type 1 (HSV-1) infection, the virus travels up axons and establishes a lifelong latent infection in neurons of the trigeminal ganglia. LAT (latency-associated transcript), the only known viral gene abundantly transcribed during HSV-1 neuronal latency, is required for high levels of reactivation. The LAT function responsible for this reactivation phenotype is not known. Recently, we showed that LAT can block programmed cell death (apoptosis) in neurons of the trigeminal ganglion in vivo and in tissue culture cells in vitro (G.-C. Perng et al., Science 287:1500–1503, 2000; M. Inman et al., J. Virol. 75:3636–3646, 2001). Consequently, …

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Osmosensitive Release Of Neurotransmitter Amino Acids: Relevance And Mechanisms, Herminia Pasantes-Morales, Rodrigo Franco, Lenin Ochoa, Benito Ordaz Feb 2002

Osmosensitive Release Of Neurotransmitter Amino Acids: Relevance And Mechanisms, Herminia Pasantes-Morales, Rodrigo Franco, Lenin Ochoa, Benito Ordaz

School of Veterinary and Biomedical Sciences: Faculty Publications

Hyposmolarity activates amino acid efflux as part of the corrective volume process in a variety of cells. This review discusses the mechanism of amino acid release in brain cells preparations. Results present evidence of substantial differences between the efflux of taurine and that of GABA and glu-tamate, which besides a possible role as osmolytes, have a main function as synaptic transmitters. The differences found concern the efflux time course, the sensitivity to Cl– channel blockers, the modulation by tyrosine kinases, the influence of PKC and the effect of cytoskeleton disruptive agents. While taurine efflux features fit well with the …

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Mechanisms Counteracting Swelling In Brain Cells During Hyponatremia, Herminia Pasantes-Morales, Rodrigo Franco, Benito Ordaz, Lenin D. Ochoa Jan 2002

Mechanisms Counteracting Swelling In Brain Cells During Hyponatremia, Herminia Pasantes-Morales, Rodrigo Franco, Benito Ordaz, Lenin D. Ochoa

School of Veterinary and Biomedical Sciences: Faculty Publications

Water gain in the brain consequent to hyponatremia is counteracted by mechanisms that initially include a compensatory displacement of liquid from the interstitial space to cerebrospinal fluid and systemic circulation and subsequently an active reduction in cell water accomplished by extrusion of intracellular osmolytes to reach osmotic equilibrium. Potassium (K+), chloride (Cl–), amino acids, polyalcohols, and methylamines all contribute to volume regulation, with a major contribution of ions at the early phase and of organic osmolytes at the late phase of the regulatory process. Experimental models in vitro show that osmolyte fluxes occur via leak pathways …

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Mycobacterium Smegmatis D-Alanine Racemase Mutants Are Not Dependent On D-Alanine For Growth, Ofelia Chacon, Zhengyu Feng, N. Beth Harris , Nancy E. Caceres, Garry Adams, Raul G. Barletta Jan 2002

Mycobacterium Smegmatis D-Alanine Racemase Mutants Are Not Dependent On D-Alanine For Growth, Ofelia Chacon, Zhengyu Feng, N. Beth Harris , Nancy E. Caceres, Garry Adams, Raul G. Barletta

School of Veterinary and Biomedical Sciences: Faculty Publications

Mycobacterium smegmatis is a fast-growing nonpathogenic species particularly useful in studying basic cellular processes of relevance to pathogenic mycobacteria. This study focused on the D-alanine racemase gene (alrA), which is involved in the synthesis of D-alanine, a basic component of peptidoglycan that forms the backbone of the cell wall. M. smegmatis alrA null mutants were generated by homologous recombination using a kanamycin resistance marker for insertional inactivation. Mutants were selected on Middlebrook medium supplemented with 50 mM D-alanine and 20 μg of kanamycin per ml. These mutants were also able to grow in standard and minimal media without …

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Methods And Compositions For Protection Against Bovine Viral Diseases, Subramaniam Srikumaran Jan 2002

Methods And Compositions For Protection Against Bovine Viral Diseases, Subramaniam Srikumaran

School of Veterinary and Biomedical Sciences: Faculty Publications

The present invention relates to methods and compositions for eliciting an immune response against bovine viral epitopes. The methods comprise combining at least one heat shock protein with at least one bovine viral epitope to form a purified epitope/heat shock protein complex and administration of an immune system stimulating amount of the purified epitope/heat shock protein complex. The compositions comprise, a purified epitope/heat shock protein complex comprising at least one bovine viral epitope complexed with at least one heat shock protein, and a pharmaceutically acceptable carrier, diluent or excipient.

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Parelaphostrongylus Tenuis In Captive Pronghorn Antelope (Antilocapra Americana) In Nebraska, Heather A. Simmons, David J. Steffen, Douglas L. Armstrong, Douglas G. Rogers Jan 2002

Parelaphostrongylus Tenuis In Captive Pronghorn Antelope (Antilocapra Americana) In Nebraska, Heather A. Simmons, David J. Steffen, Douglas L. Armstrong, Douglas G. Rogers

School of Veterinary and Biomedical Sciences: Faculty Publications

Lesions in four captive pronghorn antelope (Antilocapra americana) naturally infected with Parelaphostrongylus tenuis in eastern Nebraska (USA) are described in this report. Animals were bright and alert with hind limb ataxia that progressed to sternal or lateral recumbency between July 28 and October 17, 1998. Animals were euthanized due to disease progression despite therapy. Multifocal decubital ulcers over bony prominences occurred in two animals and chronic unilateral otitis media was present in one animal. Histopathologic examination revealed severe Wallerian degeneration randomly scattered throughout the spinal cords of all four animals. Spinal cord sections from two animals contained adult …

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Influence Of Protein Tyrosine Kinases On Cell Volume Change-Induced Taurine Release, Herminia Pasantes-Morales, Rodrigo Franco Jan 2002

Influence Of Protein Tyrosine Kinases On Cell Volume Change-Induced Taurine Release, Herminia Pasantes-Morales, Rodrigo Franco

School of Veterinary and Biomedical Sciences: Faculty Publications

Taurine efflux occurs in association with cell swelling in both hyposmotic and isosmotic conditions and during cell shrinkage in apoptotic death. Release occurs through a leak pathway, is largely Ca2+-independent and is sensitive to Cl– channel blockers. Taurine efflux elicited by hyposmolarity is reduced or suppressed by tyrosine kinase blockers and increased by tyrosine phosphatase inhibitors. The specific kinases involved are still unknown and may be different in the various cell types. Non-receptor and scr-related protein kinases have been identified in some cells as elements that directly phosphorylate the taurine efflux pathway. Possible tyrosine kinase targets are …

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The Bovine Herpesvirus 1 Immediate-Early Protein (Bicp0) Associates With Histone Deacetylase 1 To Activate Transcription, Yange Zhang, Clinton J. Jones Oct 2001

The Bovine Herpesvirus 1 Immediate-Early Protein (Bicp0) Associates With Histone Deacetylase 1 To Activate Transcription, Yange Zhang, Clinton J. Jones

School of Veterinary and Biomedical Sciences: Faculty Publications

Infected-cell protein 0 encoded by bovine herpesvirus 1 (BHV-1) (bICP0) is necessary for efficient productive infection, in large part, because it activates all 3 classes of BHV-1 genes (U. V. Wirth, C. Fraefel, B. Vogt, C. Vlcek, V. Paces, and M. Schwyzer, J. Virol. 66:2763–2772, 1992). Although bICP0 is believed to be a functional homologue of herpes simplex virus type 1-encoded ICP0, the only well-conserved domain between the proteins is a zinc ring finger located near the amino terminus of both proteins. Our previous studies demonstrated that bICP0 is toxic to transfected cells but does not appear to directly induce …

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A Mutation In The Latency-Related Gene Of Bovine Herpesvirus 1 Leads To Impaired Ocular Shedding In Acutely Infected Calves, Melissa Inman, Luciane Lovato, Alan R. Doster, Clinton J. Jones Sep 2001

A Mutation In The Latency-Related Gene Of Bovine Herpesvirus 1 Leads To Impaired Ocular Shedding In Acutely Infected Calves, Melissa Inman, Luciane Lovato, Alan R. Doster, Clinton J. Jones

School of Veterinary and Biomedical Sciences: Faculty Publications

Bovine herpesvirus 1 (BHV-1) is an important pathogen of cattle, and infection is usually initiated in the ocular or nasal cavity. Like other alphaherpesviruses, BHV-1 establishes latency in sensory neurons but has the potential of reactivating from latency and spreading. The only abundant viral transcript expressed during latency is the latency-related (LR) RNA, which is alternatively spliced in trigeminal ganglia during acute infection (L. R. Devireddy and C. Jones, J. Virol. 72:7294–7301, 1998). LR gene products inhibit cell cycle progression (Y. Jiang, A. Hossain, M. T. Winkler, T. Holt, A. Doster, and C. Jones, J. Virol. 72:8133–8142, 1998) and chemically …

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Mycobacterium Avium Subsp. Paratuberculosis In Veterinary Medicine, N. Beth Harris, Raul G. Barletta Jul 2001

Mycobacterium Avium Subsp. Paratuberculosis In Veterinary Medicine, N. Beth Harris, Raul G. Barletta

School of Veterinary and Biomedical Sciences: Faculty Publications

Bacteria of the genus Mycobacterium are gram-positive, acid- fast organisms that include a number of significant human and animal pathogens. Mycobacterium avium subsp. paratuberculosis (basonym M. paratuberculosis) is the etiological agent of a severe gastroenteritis in ruminants, known as Johne’s disease. H. A. Johne and L. Frothingham initially reported the disease in Germany in 1894. However, it was not until 1910 that F. W. Trowt successfully fulfilled Koch’s postulates by growing M. paratuberculosis in the laboratory and reproducing the disease in experimentally infected cattle (46, 148). Johne’s disease is prevalent in domestic animals worldwide and has significant impact on …

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Evidence For Two Mechanisms Of Amino Acid Osmolyte Release From Hippocampal Slices, R. Franco, M. E. Torres-Marquez, H. Pasantes-Morales Apr 2001

Evidence For Two Mechanisms Of Amino Acid Osmolyte Release From Hippocampal Slices, R. Franco, M. E. Torres-Marquez, H. Pasantes-Morales

School of Veterinary and Biomedical Sciences: Faculty Publications

A 30% decrease in osmolarity stimulated 3H-taurine, 3H-GABA and glutamate (followed as 3H-D-aspartate) efflux from rat hippocampal slices. 3H-taurine efflux was activated rapidly but inactivated slowly. It was decreased markedly by 100 μM 5-nitro-(3-phenylpropylamino) benzoic acid (NPPB) and 600 μM niflumic acid and inhibited strongly by tyrphostins AG18, AG879 and AG112 (25–100 μM), suggesting a tyrosine kinase-mediated mechanism. Hyposmolarity activated the mitogen-activated protein kinases (MAPK) extracellular-signal-related kinase-1/2 (ERK1/ERK2) and p38, but blockade of this reaction did not affect 3H-taurine efflux. Hyposmosis also activated phosphatidyl-inositide 3-kinase (PI3K) and its prevention by wortmannin (100 nM) essentially abolished …

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Persistent Bovine Viral Diarrhea Virus Infection In Us Beef Herds, T. E. Wittum, Dale M. Grotelueschen, K. V. Brock, William G. Kvasnicka, J. G. Floyd, Clayton L. Kelling, K. G. Odde Apr 2001

Persistent Bovine Viral Diarrhea Virus Infection In Us Beef Herds, T. E. Wittum, Dale M. Grotelueschen, K. V. Brock, William G. Kvasnicka, J. G. Floyd, Clayton L. Kelling, K. G. Odde

School of Veterinary and Biomedical Sciences: Faculty Publications

In the summer of 1996, we screened 18,931 calves in 128 beef herds located in five US states for persistent bovine viral diarrhea virus (BVDV) infection. Of these, 76 herds were randomly selected from the client database of collaborating veterinary practices, and 52 herds were suspected by the collaborating veterinarians to have BVDV infection based on history or clinical signs. Serum was obtained from each calf in the cooperating herds prior to 4 months of age and tested for the presence of BVDV by microtiter virus isolation. Information about each of the herds (including management practices, vaccination history, and breeding- …

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Septicemia Associated With Stenotrophomonas Maltophilia In A West African Dwarf Crocodile (Osteolaemus Tetraspis Subsp. Tetraspis), N. Beth Harris, Douglas G. Rogers Apr 2001

Septicemia Associated With Stenotrophomonas Maltophilia In A West African Dwarf Crocodile (Osteolaemus Tetraspis Subsp. Tetraspis), N. Beth Harris, Douglas G. Rogers

School of Veterinary and Biomedical Sciences: Faculty Publications

A 17-year-old male captive West African dwarf crocodile (Osteolaemus tetraspis subsp. tetraspis) died 1 month after fighting with a penmate. Abrasions were present on the head and mandible. Necropsy revealed a vegetative valvular lesion of the left atrioventricular valve, miliary foci of necrosis in the endocardium and myocardium, multiple duodenal and rectal ulcers, and serous atrophy of body fat. Stenotrophomonas maltophilia was isolated in pure culture from lung, liver, and kidney. Gram-negative bacilli were seen histologically in the valvular lesion and in foci of necrosis in the myocardium, liver, spleen, pancreas, kidney, and intestine. Septic thrombi in multiple …

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Region Of Herpes Simplex Virus Type 1 Latency-Associated Transcript Sufficient For Wild-Type Spontaneous Reactivation Promotes Cell Survival In Tissue Culture, Melissa Inman, Guey-Chuen Perng, Gail A. Henderson, Homayon Ghiasi, Anthony B. Nesburn, Steven L. Wechsler, Clinton J. Jones Apr 2001

Region Of Herpes Simplex Virus Type 1 Latency-Associated Transcript Sufficient For Wild-Type Spontaneous Reactivation Promotes Cell Survival In Tissue Culture, Melissa Inman, Guey-Chuen Perng, Gail A. Henderson, Homayon Ghiasi, Anthony B. Nesburn, Steven L. Wechsler, Clinton J. Jones

School of Veterinary and Biomedical Sciences: Faculty Publications

The latency-associated transcript (LAT) is the only abundant herpes simplex virus type 1 (HSV-1) transcript expressed during latency. In the rabbit eye model, LAT null mutants do not reactivate efficiently from latency. We recently demonstrated that the LAT null mutant dLAT2903 induces increased levels of apoptosis in trigeminal ganglia of infected rabbits compared to LAT+ strains (G.-C. Perng, C. Jones, J. Ciacci-Zarella, M. Stone, G. Henderson, A. Yokht, S. M. Slanina, F. M. Hoffman, H. Ghiasi, A. B. Nesburn, and C. S. Wechsler, Science 287:1500–1503, 2000).The same study also demonstrated that a plasmid expressing LAT nucleotides 301 to …

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Legionella Pneumophila Entry Gene Rtxa Is Involved In Virulence, Suat L. G. Cirillo, Luis E. Bermudez, Sahar H. El-Etr, Gerald Duhamel, Jeffrey D. Cirillo Jan 2001

Legionella Pneumophila Entry Gene Rtxa Is Involved In Virulence, Suat L. G. Cirillo, Luis E. Bermudez, Sahar H. El-Etr, Gerald Duhamel, Jeffrey D. Cirillo

School of Veterinary and Biomedical Sciences: Faculty Publications

Successful parasitism of host cells by intracellular pathogens involves adherence, entry, survival, intracellular replication, and cell-to-cell spread. Our laboratory has been examining the role of early events, adherence and entry, in the pathogenesis of the facultative intracellular pathogen Legionella pneumophila. Currently, the mechanisms used by L. pneumophila to gain access to the intracellular environment are not well understood. We have recently isolated three loci, designated enh1, enh2, and enh3, that are involved in the ability of L. pneumophila to enter host cells. One of the genes present in the enh1 locus, rtxA, is homologous to repeats …

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Amino Acid Osmolytes In Regulatory Volume Decrease And Isovolumetric Regulation In Brain Cells: Contribution And Mechanisms, Herminia Pasantes-Morales, Rodrigo Franco, M. Eugenia Torres-Marquez, Karla Hernandez-Fonseca, Arturo Ortega Oct 2000

Amino Acid Osmolytes In Regulatory Volume Decrease And Isovolumetric Regulation In Brain Cells: Contribution And Mechanisms, Herminia Pasantes-Morales, Rodrigo Franco, M. Eugenia Torres-Marquez, Karla Hernandez-Fonseca, Arturo Ortega

School of Veterinary and Biomedical Sciences: Faculty Publications

Brain adaptation to hyposmolarity is accomplished by loss of both electrolytes and organic osmolytes, including amino acids, polyalcohols and methylamines. In brain in vivo, the organic osmolytes account for about 35% of the total solute loss. This review focus on the role of amino acids in cell volume regulation, in conditions of sudden hyposmosis, when cells respond by active regulatory volume decrease (RVD) or after gradual exposure to hyposmotic solutions, a condition where cell volume remains unchanged, named isovolumetric regulation (IVR). The amino acid efflux pathway during RVD is passive and is similar in many respects to the volume-activated anion …

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Clinical, Pathological And Antigenic Aspects Of Bovine Viral Diarrhea Virus (Bvdv) Type 2 Isolates Identified In Brazil, E. F. Flores, L. H. G. V. Gil, S. A. Botton, R. Weiblen, J. F. Ridpath, L. C. Kreutz, C. Pilati, D. Driemeyer, V. Moojen, A. C. Wendelstein Oct 2000

Clinical, Pathological And Antigenic Aspects Of Bovine Viral Diarrhea Virus (Bvdv) Type 2 Isolates Identified In Brazil, E. F. Flores, L. H. G. V. Gil, S. A. Botton, R. Weiblen, J. F. Ridpath, L. C. Kreutz, C. Pilati, D. Driemeyer, V. Moojen, A. C. Wendelstein

School of Veterinary and Biomedical Sciences: Faculty Publications

Nucleotide sequencing and phylogenetic analysis of Brazilian bovine viral diarrhea virus (BVDV) field isolates identified four viruses belonging to the genotype 2. Comparison of 5’ UTR sequences from these isolates to those of North American BVDV type 2 revealed genomic variations that correlated with the geographic origins of the isolates. Two of the Brazilian type 2 viruses were isolated from clinical cases of gastroenteric/respiratory disease and two were isolated from healthy bovine fetuses. The clinical cases affected young animals (8- and 18-months-old) and were characterized by diarrhea, respiratory signs, extensive oral and digestive tract erosions, conjunctival and vulvar congestion, occasional …

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Hsv Latency-Associated Transcript And Neuronal Apoptosis, Anthony B. Nesburn, Clinton J. Jones Sep 2000

Hsv Latency-Associated Transcript And Neuronal Apoptosis, Anthony B. Nesburn, Clinton J. Jones

School of Veterinary and Biomedical Sciences: Faculty Publications

Thompson and Sawtell report that the Promega Anti-PARP p85 antibody did not recognize cleaved PARP in mouse or rabbit cells in their experiments, and conclude that the results reported with this antibody by Perng et al. (1) are an artifact. The Promega antibody was generated against a peptide based on the sequence of human p85. Although the corresponding bovine sequence differs by two amino acids, the antibody reacts with both human and bovine p85 (2). The mouse and rat sequences for this region of p85 differ from the human sequence by a single amino acid that corresponds to one of …

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Intestinal Lesions Caused By A Strain Of Chlamydia Suis In Weanling Pigs Infected At 21 Days Of Age, Douglas G. Rogers, Arthur A. Andersen Sep 2000

Intestinal Lesions Caused By A Strain Of Chlamydia Suis In Weanling Pigs Infected At 21 Days Of Age, Douglas G. Rogers, Arthur A. Andersen

School of Veterinary and Biomedical Sciences: Faculty Publications

The objective of this study was to determine whether a strain of Chlamydia suis shown previously to be an intestinal pathogen in gnotobiotic piglets could cause diarrhea and intestinal lesions in young weanling pigs. Pigs from 2 sows were randomly assigned to 2 groups. Group 1 included 13 pigs that were weaned at 24 hours of age and then housed in isolator units and fed milk replacer and unmedicated starter ration. Group 2 included 8 pigs that nursed their respective sows, consumed unmedicated starter ration, and were weaned at 21 days of age. Ten pigs in group 1 and 6 …

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Efflux Of Osmolyte Amino Acids During Isovolumic Regulation In Hippocampal Slices, Rodrigo Franco, Octavio Quesada, Herminia Pasantes-Morales May 2000

Efflux Of Osmolyte Amino Acids During Isovolumic Regulation In Hippocampal Slices, Rodrigo Franco, Octavio Quesada, Herminia Pasantes-Morales

School of Veterinary and Biomedical Sciences: Faculty Publications

The efflux of potassium (K+) and amino acids from hippocampal slices was measured after sudden exposure to 10% (270 mOsm), 25% (225 mOsm) or 50% (150 mOsm) hyposmotic solutions or after gradual decrease (22.5 mOsm/min) in external osmolarity. In slices suddenly exposed to 50% hyposmotic solutions, swelling was followed by partial (74%) cell volume recovery, suggesting regulatory volume decrease (RVD). With gradual hyposmotic changes, no increase in cell water content was observed even when the solution at the end of the experiment was 50% hyposmotic, showing the occurrence of isovolumic regulation (IVR). The gradual decrease in osmolarity elicited …

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Virus-Induced Neuronal Apoptosis Blocked By The Herpes Simplex Virus Latency-Associated Transcript, Guey-Chuen Perng, Clinton J. Jones, Janice Ciacci-Zanella, Melissa Stone, Gail A. Henderson, Ada Yukht, Susan M. Slanina, Florence M. Hofman, Homayon Ghiasi, Anthony B. Nesburn, Steven L. Wechsler Feb 2000

Virus-Induced Neuronal Apoptosis Blocked By The Herpes Simplex Virus Latency-Associated Transcript, Guey-Chuen Perng, Clinton J. Jones, Janice Ciacci-Zanella, Melissa Stone, Gail A. Henderson, Ada Yukht, Susan M. Slanina, Florence M. Hofman, Homayon Ghiasi, Anthony B. Nesburn, Steven L. Wechsler

School of Veterinary and Biomedical Sciences: Faculty Publications

Latent infections with periodic reactivation are a common outcome after acute infection with many viruses. The latency-associated transcript (LAT) gene is required for wild-type reactivation of herpes simplex virus (HSV). However, the underlying mechanisms remain unclear. In rabbit trigeminal ganglia, extensive apoptosis occurred with LAT- virus but not with LAT+ viruses. In addition, a plasmid expressing LAT blocked apoptosis in cultured cells. Thus, LAT promotes neuronal survival after HSV-1 infection by reducing apoptosis.

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Isovolumic Regulation In Nervous Tissue: A Novel Mechanism Of Cell Volume Regulation, O. Quesada, R. Franco, K. Hernandez-Fonseca, K. Tuz Jan 2000

Isovolumic Regulation In Nervous Tissue: A Novel Mechanism Of Cell Volume Regulation, O. Quesada, R. Franco, K. Hernandez-Fonseca, K. Tuz

School of Veterinary and Biomedical Sciences: Faculty Publications

Cell volume regulation is a property present in most animal cell lineages that allows them to recover their original volume after events of swelling or shrinkage. Such events can be caused by changes in external osmolarity or to osmotic gradients generated during normal cell functioning.4,6 The mechanism of cell volume regulation involves transmembrane fluxes of osmotically active solutes in the necessary direction to counteract the net gain or loss of intracellular water.9 The process through which cells recover their normal volume after swelling is named Regulatory Volume Decrease (RVD). This consists of the efflux of inorganic osmolytes, such as K …

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The Latency-Related Gene Of Bovine Herpesvirus 1 Inhibits Programmed Cell Death, Janice Ciacci-Zanella, Melissa Stone, Gail A. Henderson, Clinton J. Jones Dec 1999

The Latency-Related Gene Of Bovine Herpesvirus 1 Inhibits Programmed Cell Death, Janice Ciacci-Zanella, Melissa Stone, Gail A. Henderson, Clinton J. Jones

School of Veterinary and Biomedical Sciences: Faculty Publications

Although viral gene expression occurs in the peripheral nervous system during acute infection, bovine herpesvirus 1 (BHV-1) gene expression is extinguished, many neurons survive, and latency ensues. The only abundant viral transcript expressed during latency is the latency-related (LR) RNA, which is alternatively spliced in trigeminal ganglia during acute infection (L. Devireddy and C. Jones, J. Virol. 72:7294–7301, 1998). A subset of neurons express a protein encoded by the LR gene and the LR protein (LRP) is associated with cyclin-dependent kinase 2 (Cdk2)/cyclin complexes during productive infection (Y. Jiang, A. Hossain, M. T. Winkler, T. Holt, A. Doster, and C. …

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Bovine Herpesvirus 1 Can Infect Cd4+ T Lymphocytes And Induce Programmed Cell Death During Acute Infection Of Cattle, M. T. C. Winkler, Alan R. Doster, Clinton J. Jones Oct 1999

Bovine Herpesvirus 1 Can Infect Cd4+ T Lymphocytes And Induce Programmed Cell Death During Acute Infection Of Cattle, M. T. C. Winkler, Alan R. Doster, Clinton J. Jones

School of Veterinary and Biomedical Sciences: Faculty Publications

Acute infection of cattle with bovine herpesvirus 1 (BHV-1) represses cell-mediated immunity, which can lead to secondary bacterial infections. Since BHV-1 can induce apoptosis of cultured lymphocytes, we hypothesized that these virus-host interactions occur in cattle. To test this hypothesis, we analyzed lymph nodes and peripheral blood mononuclear cells (PBMC) after calves were infected with BHV-1. In situ terminal deoxynucleotidyltransferase- mediated dUTP nick end-labeling (TUNEL) staining of lymphoid tissues (pharyngeal tonsil, cervical, retropharyngeal, and inguinal) was used to detect apoptotic cells. Calves infected with BHV-1 for 7 days revealed increased apoptotic cells near the corticomedullary junction in lymphoid follicles and …

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