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Articles 721 - 750 of 875

Full-Text Articles in Microbiology

Multicenter Comparison Of Pcr Assays For Detection Of Human Herpesvirus 8 Dna In Semen, Philip E. Pellett, Thomas J. Spira, Omar Bagasra, Chris Boshoff, Lawrence Corey, Laura De Lellis, Meei-Li Huang, Jung-Chung Lin, Steve Matthews, Paolo Monini, Paola Romessi, Carlos Sosa, Charles Wood, John A. Stewart May 1999

Multicenter Comparison Of Pcr Assays For Detection Of Human Herpesvirus 8 Dna In Semen, Philip E. Pellett, Thomas J. Spira, Omar Bagasra, Chris Boshoff, Lawrence Corey, Laura De Lellis, Meei-Li Huang, Jung-Chung Lin, Steve Matthews, Paolo Monini, Paola Romessi, Carlos Sosa, Charles Wood, John A. Stewart

Nebraska Center for Virology: Faculty Publications

Reported prevalences of human herpesvirus 8 (HHV-8) (Kaposi’s sarcoma-associated herpesvirus) in semen have ranged widely. This is possibly due to differences in assay sensitivity, geographic or population-based differences in the true presence of the virus in semen, and PCR contamination. This study assessed interlaboratory sensitivity and reproducibility in the analysis of blinded experimental panels, each consisting of 48 specimens and being composed of semen specimens from different healthy artificial-insemination donors (n = 30) and human immunodeficiency virus (HIV)-infected patients (n= 7) plus positive (n = 4) and negative (n = 7) controls. The experimental panels analyzed in each laboratory were …

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Pyoveridine Production By Pseudomonas Aeruginosa Exposed To Metals Or An Oxidative Stress Agent, Kim-Hien Thi Dao, Katherine E. Hamer, Christine L. Clark, Lawrence G. Harshman May 1999

Pyoveridine Production By Pseudomonas Aeruginosa Exposed To Metals Or An Oxidative Stress Agent, Kim-Hien Thi Dao, Katherine E. Hamer, Christine L. Clark, Lawrence G. Harshman

School of Biological Sciences: Faculty Publications

Siderophores are low molecular mass compounds used by many microorganisms to scavenge dissolved iron, which is typically rare in environments. Pseudomonas aeruginosa (PAO1) was exposed to metals and methyl viologen in low-iron medium in order to monitor the abundance of a specific siderophore (pyoverdine) and monitor growth over time. In this study it was discovered that cadmium can stimulate pyoverdine abundance. Cadmium may interact with and sequester the Fur regulatory protein, which represses siderophore synthesis under conditions of iron sufficiency. Mercury did not stimulate pyoverdine production at concentrations that strongly inhibited bacterial growth, suggesting that pyoverdine production is not governed …

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Interferon Regulatory Factor 2 Represses The Epstein-Barr Virus BamHi Q Latency Promoter In Type Iii Latency, Luwen Zhang, Joseph S. Pagano Apr 1999

Interferon Regulatory Factor 2 Represses The Epstein-Barr Virus BamHi Q Latency Promoter In Type Iii Latency, Luwen Zhang, Joseph S. Pagano

Nebraska Center for Virology: Faculty Publications

Epstein-Barr virus (EBV) nuclear antigen 1 (EBNA-1) is the essential protein for maintenance of the EBV episome and establishment of latency. The BamHI Q promoter (Qp) is used for the transcription of EBNA-1 mRNA in type I and type II latency, which are EBV infection states exemplified by Burkitt’s lymphoma and nasopharyngeal carcinoma. However, Qp is inactive in type III latency, and other promoters (the BamHI C promoter and/or the BamHI W promoter) are used for EBNA-1. The involvement of interferon regulatory factors (IRFs) in the regulation of Qp is suggested by the presence of an essential interferon-stimulated response element …

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Microbiology Of The Oil Fly, Helaeomyia Petrolei, Dana R. Kadavy, Bradley A. Plantz, Christopher A. Shaw, Jill Myatt, Tyler A. Kokjohn, Kenneth Nickerson Apr 1999

Microbiology Of The Oil Fly, Helaeomyia Petrolei, Dana R. Kadavy, Bradley A. Plantz, Christopher A. Shaw, Jill Myatt, Tyler A. Kokjohn, Kenneth Nickerson

Papers in Microbiology

Helaeomyia petrolei larvae isolated from the asphalt seeps of Rancho La Brea in Los Angeles, Calif., were examined for microbial gut contents. Standard counts on Luria-Bertani, MacConkey, and blood agar plates indicated ca. 2 x 105 heterotrophic bacteria per larva. The culturable bacteria represented 15 to 20% of the total population as determined by acridine orange staining. The gut itself contained large amounts of the oil, had no observable ceca, and maintained a slightly acidic pH of 6.3 to 6.5. Despite the ingestion of large amounts of potentially toxic asphalt by the larvae, their guts sustained the growth of …

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Nonspecific Interactions Alter Lipopolysaccharide Patterns And Protein Mobility On Sodium Dodecyl Sulfate Polyacrylamide Gels, Aidong Yuan, R L. Pardy, Catherine P. Chia Mar 1999

Nonspecific Interactions Alter Lipopolysaccharide Patterns And Protein Mobility On Sodium Dodecyl Sulfate Polyacrylamide Gels, Aidong Yuan, R L. Pardy, Catherine P. Chia

Papers in Microbiology

In testing whether bacterial lipopolysaccharide (LPS) was a natural substrate for an esterase from the soil amebae Dictyostelium discoideum, we observed altered banding patterns of the LPS and changed protein mobility on sodium dodecyl sulfate (SDS) polyacrylamide gels after incubation of LPS with the enzyme. The initial interpretation of these results was that the enzyme had removed ester-linked acyl chains from the LPS, leading to a change in its migration on gels. However, esterase inactivated by treatment with either dithiothreitol (DTT), heat, or SDS generated the same mobility shifts. Bovine serum albumin (BSA) also induced the same change in …

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Characterization Of The Jembrana Disease Virus Tat Gene And The Cis- And Trans-Regulatory Elements In Its Long Terminal Repeats, Hexin Chen, Graham Wilcox, Gde Kertayadnya, Charles Wood Jan 1999

Characterization Of The Jembrana Disease Virus Tat Gene And The Cis- And Trans-Regulatory Elements In Its Long Terminal Repeats, Hexin Chen, Graham Wilcox, Gde Kertayadnya, Charles Wood

Nebraska Center for Virology: Faculty Publications

Jembrana disease virus (JDV) is a newly identified bovine lentivirus that is closely related to the bovine immunodeficiency virus (BIV). JDV contains a tat gene, encoded by two exons, which has potent transactivation activity. Cotransfection of the JDV tat expression plasmid with the JDV promoter chloramphenicol acetyltransferase (CAT) construct pJDV-U3R resulted in a substantial increase in the level of CAT mRNA transcribed from the JDV long terminal repeat (LTR) and a dramatic increase in the CAT protein level. Deletion analysis of the LTR sequences showed that sequences spanning nucleotides 268 to 153, including the TATA box and the predicted first …

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Chlorella Virus Pbcv-1 Encodes A Functional Homospermidine Synthase, Annette Kaiser, Michael Vollmert, Dorothea Tholl, Michael V. Graves, James Gurnon, Weimei Xing, Amber D. Lisec, Kenneth Nickerson, James L. Van Etten Jan 1999

Chlorella Virus Pbcv-1 Encodes A Functional Homospermidine Synthase, Annette Kaiser, Michael Vollmert, Dorothea Tholl, Michael V. Graves, James Gurnon, Weimei Xing, Amber D. Lisec, Kenneth Nickerson, James L. Van Etten

Kenneth Nickerson Papers

Sequence analysis of the 330-kb genome of chlorella virus Paramecium bursaria chlorella virus 1 (PBCV-1) revealed an open reading frame, A237R, that encodes a protein with 34% amino acid identity to homospermidine synthase from Rhodopseudomonas viridis. Expression of the a237r gene product in Escherichia coli established that the recombinant enzyme catalyzes the NAD+-dependent formation of homospermidine from two molecules of putrescine. The a237r gene is expressed late in PBCV-1 infection. Both uninfected and PBCV-1-infected chlorella, as well as PBCV-1 virions, contain homospermidine, along with the more common polyamines putrescine, spermidine, and cadaverine. The total number of polyamine …

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Carmoviruses (Tombusviridae), Feng Qu, Thomas Jack Morris Jan 1999

Carmoviruses (Tombusviridae), Feng Qu, Thomas Jack Morris

School of Biological Sciences: Faculty Publications

Carmovirus is one of two officially recognized genera of Tombusviridae. Members of Tombusviridae all have icosahedral virions of about 30 nm in diameter with T = 3 symmetry that consists of 180 coat protein (CP) subunits of about 38- 43 kDa and a single-stranded (ss) RNA genome ranging in size from 4.0 to 4.7 kb. Carmoviruses share recognizable sequence similarity in both the polymerase and structural genes with members of the other genus, Tombusvirus. Sequence comparisons and phylogenetic analysis of these genes support the view that the genera are distinct but closely related. In addition, the genome organization of the …

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Cytoplasmic Assembly And Accumulation Of Human Immunodeficiency Virus Types 1 And 2 In Recombinant Human Colony-Stimulating Factor-1-Treated Human Monocytes: An Ultrastructural Study, Jan Marc Orenstein, Monte S. Meltzer, Terri Phipps, Howard Gendelman Aug 1998

Cytoplasmic Assembly And Accumulation Of Human Immunodeficiency Virus Types 1 And 2 In Recombinant Human Colony-Stimulating Factor-1-Treated Human Monocytes: An Ultrastructural Study, Jan Marc Orenstein, Monte S. Meltzer, Terri Phipps, Howard Gendelman

Nebraska Center for Virology: Faculty Publications

Recombinant human colony-stimulating factor-1-treated human peripheral blood-derived monocytes-macrophages are efficient host cells for recovery of the human immunodeficiency virus (HIV) from blood leukocytes of patients with acquired immunodeficiency syndrome. These cells can be maintained as viable monolayers for intervals exceeding 3 months. Infection with HIV resulted in virus-induced cytopathic effects, accompanied by relatively high levels of released progeny virus, followed by a prolonged low-level release of virus from morphologically normal cells. In both acutely and chronically infected monocytes, viral particles were seen budding into and accumulating within cytoplasmic vacuoles. The number of intravacuolar virions far exceeded those associated with the …

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The Physiology Of Life-History Trade-Offs: Experimental Analysis Of A Hormonally Induced Life-History Trade-Off In Gryllus Assimilis, Anthony J. Zera, Jason Potts, Kari Kobus Jul 1998

The Physiology Of Life-History Trade-Offs: Experimental Analysis Of A Hormonally Induced Life-History Trade-Off In Gryllus Assimilis, Anthony J. Zera, Jason Potts, Kari Kobus

Anthony Zera Publications

Adult Gryllus assimilis given an analog of juvenile hormone exhibited reduced flight muscles and enlarged ovaries similar to those found in naturally occurring flightless individuals of species that are polymorphic for dispersal capability. Control and hormone-treated (flightless) G. assimilis did not differ in the amount of food consumed or assimilated on any of three diets that differed in nutrient quantity. Thus, enhanced ovarian growth of flightless individuals resulted from increased allocation of internal nutrients to reproduction (i.e., a trade-off) rather than from increased acquisition of nutrients. Compared with flight-capable controls, flightless G. assimilis also had reduced whole-organism respiration, reduced respiration …

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Biological Characterization Of Rev Variation In Equine Infectious Anemia Virus, Michael Belshan, Matthew E. Harris, Anne E. Shoemaker, Thomas J. Hope, Susan Carpenter May 1998

Biological Characterization Of Rev Variation In Equine Infectious Anemia Virus, Michael Belshan, Matthew E. Harris, Anne E. Shoemaker, Thomas J. Hope, Susan Carpenter

Nebraska Center for Virology: Faculty Publications

Sequence analysis identified significant variation in the second exon of equine infectious anemia virus (EIAV) rev. Functional analysis indicated that limited amino acid variation in Rev significantly altered the export activity of the protein but did not affect Rev-dependent alternative splicing. EIAV Rev can mediate export through two independent cis -acting Rev-responsive elements (RREs), and differences among Rev variants were more pronounced when both RREs were present. Variation in Rev may be an important mechanism for regulation of virus replication in vivo and may contribute to changes in clinical disease.

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Human Immunodeficiency Virus Neurotropism: An Analysis Of Viral Replication And Cytopathicity For Divergent Strains In Monocytes And Microglia, Anuja Ghorpade, Adeline Nukuna, Myhanh Che, Sheryl Haggerty, Yuri Persidsky, Eboni Carter, Leeroy Carhart, Laura Shafer, Howard Gendelman Apr 1998

Human Immunodeficiency Virus Neurotropism: An Analysis Of Viral Replication And Cytopathicity For Divergent Strains In Monocytes And Microglia, Anuja Ghorpade, Adeline Nukuna, Myhanh Che, Sheryl Haggerty, Yuri Persidsky, Eboni Carter, Leeroy Carhart, Laura Shafer, Howard Gendelman

Nebraska Center for Virology: Faculty Publications

Productive replication of human immunodeficiency virus type 1 (HIV-1) in brain macrophages and microglia is a critical component of viral neuropathogenesis. However, how virus-macrophage interactions lead to neurological disease remains incompletely understood. Possibly, a differential ability of virus to replicate in brain tissue macrophages versus macrophages in other tissues underlies HIV-1 neurovirulence. To these ends, we established systems for the isolation and propagation of pure populations of human microglia and then analyzed the viral life cycles of divergent HIV-1 strains in these cells and in cultured monocytes by using identical viral inocula and indicator systems. The HIV-1 isolates included those …

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Role Of The Β-Chemokine Receptors Ccr3 And Ccr5 In Human Immunodeficiency Virus Type 1 Infection Of Monocytes And Microglia, Anuja Ghorpade, Meng Qi Xia, Bradley T. Hyman, Yuri Persidsky, Adeline Nukuna, Paul Bock, Myhanh Che, Janae Limoges, Howard Gendelman, Charles R. Mackay Apr 1998

Role Of The Β-Chemokine Receptors Ccr3 And Ccr5 In Human Immunodeficiency Virus Type 1 Infection Of Monocytes And Microglia, Anuja Ghorpade, Meng Qi Xia, Bradley T. Hyman, Yuri Persidsky, Adeline Nukuna, Paul Bock, Myhanh Che, Janae Limoges, Howard Gendelman, Charles R. Mackay

Nebraska Center for Virology: Faculty Publications

Human immunodeficiency virus type 1 (HIV-1) infection in mononuclear phagocyte lineage cells (monocytes, macrophages, and microglia) is a critical component in the pathogenesis of viral infection. Viral replication in macrophages serves as a reservoir, a site of dissemination, and an instigator for neurological sequelae during HIV-1 disease. Recent studies demonstrated that chemokine receptors are necessary coreceptors for HIV-1 entry which determine viral tropism for different cell types. To investigate the relative contribution of the β -chemokine receptors CCR3 and CCR5 to viral infection of mononuclear phagocytes we utilized a panel of macrophage-tropic HIV-1 strains (from blood and brain tissue) to …

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Localization Of Human Cytomegalovirus Structural Proteins To The Nuclear Matrix Of Infected Human Fibroblasts, V. Sanchez, Peter C. Angeletti, J. A. Engler, W. J. Britt Apr 1998

Localization Of Human Cytomegalovirus Structural Proteins To The Nuclear Matrix Of Infected Human Fibroblasts, V. Sanchez, Peter C. Angeletti, J. A. Engler, W. J. Britt

Nebraska Center for Virology: Faculty Publications

The intranuclear assembly of herpesvirus subviral particles remains an incompletely understood process. Previous studies have described the nuclear localization of capsid and tegument proteins as well as intranuclear tegumentation of capsid-like particles. The temporally and spatially regulated replication of viral DNA suggests that assembly may also be regulated by compartmentalization of structural proteins. We have investigated the intranuclear location of several structural and nonstructural proteins of human cytomegalovirus (HCMV). Tegument components including pp65 (ppUL83) and ppUL69 and capsid components including the major capsid protein (pUL86) and the small capsid protein (pUL48/49) were retained within the nuclear matrix (NM), whereas the …

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Adenovirus Preterminal Protein Binds To The Cad Enzyme At Active Sites Of Viral Dna Replication On The Nuclear Matrix, Peter C. Angeletti, Jeffrey A. Engler Apr 1998

Adenovirus Preterminal Protein Binds To The Cad Enzyme At Active Sites Of Viral Dna Replication On The Nuclear Matrix, Peter C. Angeletti, Jeffrey A. Engler

Nebraska Center for Virology: Faculty Publications

Adenovirus (Ad) replicative complexes form at discrete sites on the nuclear matrix (NM) via an interaction mediated by the precursor of the terminal protein (pTP). The identities of cellular proteins involved in these complexes have remained obscure. We present evidence that pTP binds to a multifunctional pyrimidine biosynthesis enzyme found at replication domains on the NM. Far-Western blotting identified proteins of 150 and 240 kDa that had pTP binding activity. Amino acid sequencing of the 150-kDa band revealed sequence identity to carbamyl phosphate synthetase I (CPS I) and a high degree of homology to the related trifunctional enzyme known as …

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Human Immunodeficiency Virus Neurotropism: An Analysis Of Viral Replication And Cytopathicity For Divergent Strains In Monocytes And Microglia, Anuja Ghorpade, Adeline Nukuna, Myhanh Che, Sherryl Haggerty, Yuri Persidsky, Eboni Carter, Leeroy Carhart, Laura Shafer, Howard Gendelman Apr 1998

Human Immunodeficiency Virus Neurotropism: An Analysis Of Viral Replication And Cytopathicity For Divergent Strains In Monocytes And Microglia, Anuja Ghorpade, Adeline Nukuna, Myhanh Che, Sherryl Haggerty, Yuri Persidsky, Eboni Carter, Leeroy Carhart, Laura Shafer, Howard Gendelman

Nebraska Center for Virology: Faculty Publications

Productive replication of human immunodeficiency virus type 1 (HIV-1) in brain macrophages and microglia is a critical component of viral neuropathogenesis. However, how virus-macrophage interactions lead to neurological disease remains incompletely understood. Possibly, a differential ability of virus to replicate in brain tissue macrophages versus macrophages in other tissues underlies HIV-1 neurovirulence. To these ends, we established systems for the isolation and propagation of pure populations of human microglia and then analyzed the viral life cycles of divergent HIV-1 strains in these cells and in cultured monocytes by using identical viral inocula and indicator systems. The HIV-1 isolates included those …

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Prevalence Of Broad-Host-Range Lytic Bacteriophages Of Sphaerotilus Natans, Escherichia Coli, And Pseudomonas Aeruginosa, Ellen C. Jensen, Holly S. Schrader, Brenda Rieland, Thomas L. Thompson, Kit W. Lee, Kenneth W. Nickerson, Tyler A. Kokjohn Feb 1998

Prevalence Of Broad-Host-Range Lytic Bacteriophages Of Sphaerotilus Natans, Escherichia Coli, And Pseudomonas Aeruginosa, Ellen C. Jensen, Holly S. Schrader, Brenda Rieland, Thomas L. Thompson, Kit W. Lee, Kenneth W. Nickerson, Tyler A. Kokjohn

Papers in Microbiology

Two bacteriophage collections were examined with regard to their ability to form plaques on multiple bacterial host species. Nine of 10 phages studied were found to be broad-host-range bacteriophages. These phages fell into two groups. Group 1, the SN series, was isolated from sewage treatment plant samples with Sphaerotilus natans ATCC 13338 as a host. The DNAs of these bacteriophages contained modified bases and were insensitive to cleavage by type I and II restriction endonucleases. The efficiency of plating of these bacteriophages was changed only slightly on the alternate host. Group 2, the BHR series, was isolated by a two-host …

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Human Herpesvirus 8 As A Potential Sexually Transmitted Agent In Honduras, C. Sosa, W. Klaskala, B. Chandran, R. Soto, L. Sieczkowski, M. H. Wu, M. Baum, Charles Wood Jan 1998

Human Herpesvirus 8 As A Potential Sexually Transmitted Agent In Honduras, C. Sosa, W. Klaskala, B. Chandran, R. Soto, L. Sieczkowski, M. H. Wu, M. Baum, Charles Wood

Nebraska Center for Virology: Faculty Publications

The seroprevalence of human herpesvirus 8 (HHV-8) was studied in 326 human immunodeficiency virus (HIV)–positive and –negative persons from Honduras; women constituted 77% (n = 251) of the subjects. Sera were tested for lytic HHV-8 antibodies by an IFA, and positive samples were confirmed by a radioimmunoprecipitation assay. Of the 326 persons tested, 58 (17.8%) had HHV- 8 antibodies. Among the HIV-infected women, 22.7% were seropositive; 11.3% of the HIV-negative women were seropositive. HHV-8 seroprevalence was almost four times higher in HIV-positive female commercial sex workers (36%) than in HIV-negative female non–commercial sex workers (9.9%; odds ratio = 3.8, 95% …

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Seroprevalence Of Human Herpesvirus 8 Among Zambian Women Of Childbearing Age Without Kaposi’S Sarcoma (Ks) And Mother-Child Pairs With Ks, Jun He, Ganapati Bhat, Chipepo Kankasa, Chifumbe Chintu, Charles Mitchell, Wenjing Duan, Charles Wood Jan 1998

Seroprevalence Of Human Herpesvirus 8 Among Zambian Women Of Childbearing Age Without Kaposi’S Sarcoma (Ks) And Mother-Child Pairs With Ks, Jun He, Ganapati Bhat, Chipepo Kankasa, Chifumbe Chintu, Charles Mitchell, Wenjing Duan, Charles Wood

Nebraska Center for Virology: Faculty Publications

The seroprevalence of human herpesvirus 8 (HHV-8) among a group of Zambian women of reproductive age and among mother-child pairs in which either one of them has Kaposi’s sarcoma (KS) was determined. A cross-sectional group of 378 pregnant women was randomly recruited into the study, and 183 (48.4%) had HHV-8 antibodies. Among the human immunodeficiency virus (HIV)-1–infected women, 51.1% were HHV-8–seropositive, whereas of HIV- 1–negative women, 47.3% were HHV-8–seropositive. In addition, 21 women index patients with KS and 5 young children index patients with KS were studied. All children with KS had mothers who were HHV-8–seropositive, while not all children …

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Cytoskeletal Association Of An Esterase In Dictyostelium Discoideum, Catherine P. Chia, Lothar Bomblies, Kristy K. Taylor Jan 1998

Cytoskeletal Association Of An Esterase In Dictyostelium Discoideum, Catherine P. Chia, Lothar Bomblies, Kristy K. Taylor

Papers in Microbiology

A 70-kDa glycoprotein, gp70, was found enriched in the detergentinsoluble cytoskeletal fraction of axenically grown Dictyostelium discoideum cells. Its N-terminal amino acid sequence identified it as “crystal protein” (L. Bomblies et al., 1990, J. Cell Biol. 110, 669– 679). This finding was corroborated when antibody to crystal protein cross-reacted with gp70 and its deglycosylated form. The postulated esterase activity of gp70/crystal protein was verified through comparative enzyme assays of extracts derived from cells that either overexpressed or lacked gp70. Gp70 cosedimented with cytoskeletons on sucrose gradients, suggesting an interaction with the cytoskeleton. Coisolation of gp70 with detergent-extracted cells, observed by …

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Porcine Reproductive And Respiratory Syndrome Virus Replicates In Testicular Germ Cells, Alters Spermatogenesis, And Induces Germ Cell Death By Apoptosis, Jung-Hyang Sur, Alan R. Doster, James S. Christian, Judith A. Galeota, Robert W. Wills, Jeff J. Zimmerman, Fernando A. Osorio Dec 1997

Porcine Reproductive And Respiratory Syndrome Virus Replicates In Testicular Germ Cells, Alters Spermatogenesis, And Induces Germ Cell Death By Apoptosis, Jung-Hyang Sur, Alan R. Doster, James S. Christian, Judith A. Galeota, Robert W. Wills, Jeff J. Zimmerman, Fernando A. Osorio

Nebraska Center for Virology: Faculty Publications

Like other arteriviruses, porcine reproductive and respiratory syndrome virus (PRRSV) is shed in semen, a feature that is critical for the venereal transmission of this group of viruses. In spite of its epidemiological importance, little is known of the association of PRRSV or other arteriviruses with gonadal tissues. We experimentally infected a group of boars with PRRSV 12068-96, a virulent field strain. By combined use of in situ hybridization and immunohistochemistry, we detected infection by PRRSV in the testes of these boars. The PRRSV testicular replication in testis centers on two types of cells: (i) epithelial germ cells of the …

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Physiology And Ecology Of Dispersal Polymorphism In Insects, Anthony J. Zera, Robert F. Denno Nov 1997

Physiology And Ecology Of Dispersal Polymorphism In Insects, Anthony J. Zera, Robert F. Denno

Anthony Zera Publications

Studies of dispersal polymorphism in insects have played a pivotal role in advancing our understanding of population dynamics, life history evolution, and the physiological basis of adaptation. Comparative data on wing-dimorphic insects provide the most definitive evidence to date that habitat persistence selects for reduced dispersal capability. The increased fecundity of flightless females documents that a fitness tradeoff exists between flight capability and reproduction. However, only recently have studies of nutrient consumption and allocation provided unequivocal evidence that this fitness trade-off results from a trade-off of internal resources. Recent studies involving wing-dimorphic insects document that flight capability imposes reproductive penalties …

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Flight-Muscle Polymorphism In The Cricket Gryllus Firmus: Muscle Characteristics And Their Influence On The Evolution Of Flightlessness, Anthony J. Zera, Jeffry Sall, Kimberly Grudzinski Oct 1997

Flight-Muscle Polymorphism In The Cricket Gryllus Firmus: Muscle Characteristics And Their Influence On The Evolution Of Flightlessness, Anthony J. Zera, Jeffry Sall, Kimberly Grudzinski

Anthony Zera Publications

Flight muscles of the cricket Gryllus firmus are polymorphic, existing as pink or white phenotypes. White muscles are smaller in size, have reduced number and size of muscle fibers, and have reduced in vitro enzyme activities and respiration rates relative to pink muscles of newly molted, fully winged adults. G. firmus is also polymorphic for wing length. All newly molted long-winged adults exhibited the pink-muscle phenotype, while most newly molted short-winged adults exhibited the white-muscle phenotype, which resulted from arrested muscle growth. As long-winged adults aged, fully grown pink muscle was transformed into white muscle via histolysis. The substantially higher …

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Irf-7, A New Interferon Regulatory Factor Associated With Epstein-Barr Virus Latency, Luwen Zhang, Joseph S. Pagano Oct 1997

Irf-7, A New Interferon Regulatory Factor Associated With Epstein-Barr Virus Latency, Luwen Zhang, Joseph S. Pagano

Nebraska Center for Virology: Faculty Publications

The Epstein-Barr virus (EBV) BamHI Q promoter (Qp) is the only promoter used for the transcription of Epstein-Barr virus nuclear antigen 1 (EBNA-1) mRNA in cells in the most restricted (type I) latent infection state. However, Qp is inactive in type III latency. With the use of the yeast one-hybrid system, a new cellular gene has been identified that encodes proteins which bind to sequence in Qp. The deduced amino acid sequence of the gene has significant homology to the interferon regulatory factors (IRFs). This new gene and products including two splicing variants are designated IRF-7A, IRF-7B, and IRF-7C. The …

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Phagosomal Proteins Of Dictyostelium Discoideum, Betsy L. Rezabek, Juan M. Rodriguez-Paris, James A. Cardelli, Catherine P. Chia Jul 1997

Phagosomal Proteins Of Dictyostelium Discoideum, Betsy L. Rezabek, Juan M. Rodriguez-Paris, James A. Cardelli, Catherine P. Chia

Papers in Microbiology

In recognizing food particles, Dictyostelium cell-surface molecules initiate cytoskeletal rearrangements that result in phagosome formation. After feeding D. discoideum cells latex beads, early phagosomes were isolated on sucrose step gradients. Protein analyses of these vesicles showed that they contained glycoproteins and surface-labeled species corresponding to integral plasma membrane proteins. Cytoskeletal proteins also were associated with phagosomes, including myosin II, actin and a 30 kDa-actin bundling protein. As seen by the acridine orange fluorescence of vesicles containing bacteria, phagosomes were acidified rapidly by a vacuolar H+-ATPase that was detected by immunoblotting. Except for the loss of cytoskeletal proteins, few other changes …

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Transcriptional Patterns Of The Pcd41 (U27) Locus Of Human Herpesvirus 6, Yi Zhou, Bala Chandran, Charles Wood May 1997

Transcriptional Patterns Of The Pcd41 (U27) Locus Of Human Herpesvirus 6, Yi Zhou, Bala Chandran, Charles Wood

Nebraska Center for Virology: Faculty Publications

Human herpesvirus 6 (HHV-6) is a lymphotropic herpesvirus, and in vitro, it can productively infect many of the same cell types that human immunodeficiency virus (HIV) infects. Simultaneous infection of T cells by HIV and HHV-6 can lead to both activation of the HIV promoter and acceleration of the cytopathic effects. Several HHV-6 genes have been demonstrated to activate HIV promoter expression. Among them is a cDNA clone, pCD41 (U27), which codes for the HHV-6 DNA polymerase accessory protein. We have now further characterized the transcription pattern in the pCD41 locus and identified at least six RNA species, ranging in …

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Immune Suppression In Calves With Bovine Immunodeficiency Virus, Shucheng Zhang, Charles Wood, Wenzhi Xue, Samuel Krukenberg, Qimin Chen, Harish Minocha Mar 1997

Immune Suppression In Calves With Bovine Immunodeficiency Virus, Shucheng Zhang, Charles Wood, Wenzhi Xue, Samuel Krukenberg, Qimin Chen, Harish Minocha

Nebraska Center for Virology: Faculty Publications

The present study was designed to evaluate the effect of bovine immunodeficiency virus (BIV) infection on immune functions and possible interactions between BIV and other bovine viruses in calves. Ten calves were inoculated intravenously with BIV, and five served as controls. An increased lymphocyte proliferation to BIV gag protein was demonstrated 2 to 6 weeks after BIV inoculation (P < 0.05). Lymphocyte subset differentiation revealed a decreased CD4/CD8 ratio (P < 0.05) during weeks 2 to 7, suggesting a possible immune dysfunction in BIV-infected calves. When the calves were inoculated with bovine herpesvirus type 1 (BHV-1), the antibody response to BHV-1 in BIV-infected calves was delayed and the antibody titers were significantly lower (P < 0.05). Injection of bovine viral diarrhea virus vaccine also elicited a lower neutralizing antibody response in BIV-infected calves. The results indicated that immune suppression occurred in BIV-infected calves.

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Encapsidation Of Turnip Crinkle Virus Is Defined By A Specific Packaging Signal And Rna Size, Feng Qu, Thomas Jack Morris Feb 1997

Encapsidation Of Turnip Crinkle Virus Is Defined By A Specific Packaging Signal And Rna Size, Feng Qu, Thomas Jack Morris

Nebraska Center for Virology: Faculty Publications

A protoplast infection assay has been used to reliably examine the viral RNA encapsidation of turnip crinkle virus (TCV). Analysis of the encapsidation of various mutant viral RNAs revealed that a 186-nucleotide (nt) region at the 3’ end of the coat protein (CP) gene, with a bulged hairpin loop of 28 nt as its most essential element, was indispensable for TCV RNA encapsidation. When RNA fragments containing the 186-nt region were used to replace the CP gene of a different virus, tomato bushy stunt virus, the resulting chimeric viral RNAs were encapsidated into TCV virions. Furthermore, analysis of the encapsidated …

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Detection Of Bovine Immunodeficiency Virus Antibodies In Cattle By Western Blot Assay With Recombinant Gag Protein, Shucheng Zhang, Wenzhi Xue, Charles Wood, Qi-Min Chen, Sanjay Capil, Harish Minocha Jan 1997

Detection Of Bovine Immunodeficiency Virus Antibodies In Cattle By Western Blot Assay With Recombinant Gag Protein, Shucheng Zhang, Wenzhi Xue, Charles Wood, Qi-Min Chen, Sanjay Capil, Harish Minocha

Nebraska Center for Virology: Faculty Publications

A western blot assay using purified recombinant bovine immunodeficiency virus gag protein has been developed for detection of bovine immunodeficiency virus antibodies in bovine serum samples. The test was standardized with known bovine immunodeficiency virus positive and negative bovine serum samples and the monoclonal antibody to gag protein. Both naturally and experimentally infected cattle sera demonstrated positive test results. The result of western blot assay was compared with polymerase chain reaction test results in 134 blood samples collected from Kansas. Twenty-six samples tested positive for bovine immunodeficiency virus DNA with polymerase chain reaction (18.7%) and 25 were positive for the …

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About The Cellular Tropism Of The Gammaherpesvirus Bovine Herpesvirus Type 4, Fernando A. Osorio, J. A. Galeota-Wheeler, D. E. Reed, O. Lopez Dec 1996

About The Cellular Tropism Of The Gammaherpesvirus Bovine Herpesvirus Type 4, Fernando A. Osorio, J. A. Galeota-Wheeler, D. E. Reed, O. Lopez

Nebraska Center for Virology: Faculty Publications

We read with interest the recent report by Egyed et al. (4) about the distribution in tissue, in the natural host, of bovine herpesvirus type 4 (BHV-4), a member of the gammaherpesvirus group. Using PCR, those authors were able to trace BHV-4 (Movar strain) in several tissues of experimentally infected cattle (mostly spleen, lung, trachea, and nasal epithelium tissues) at different times, ranging from 3 to 48 days postinfection. The authors also report consistent detection of BHV-4 DNA in what they consider to be a pure population of lymphocytes obtained from peripheral blood of the BHV-4- infected cattle, and then …

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