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Articles 691 - 720 of 875

Full-Text Articles in Microbiology

Human Herpesvirus 8 Can Be Transmitted Through Blood In Drug Addicts, Carlos Sosa, Jorge Benetucci, Colleen Hanna, Laura Sieczkowski, Gabriel Deluchi, Ana Maria Canizal, Hamakwa Mantina, Winslow Klaskala, Marianna Baum, Charles Wood Jan 2001

Human Herpesvirus 8 Can Be Transmitted Through Blood In Drug Addicts, Carlos Sosa, Jorge Benetucci, Colleen Hanna, Laura Sieczkowski, Gabriel Deluchi, Ana Maria Canizal, Hamakwa Mantina, Winslow Klaskala, Marianna Baum, Charles Wood

Nebraska Center for Virology: Faculty Publications

Human Herpes virus type-8 (HHV-8) seroprevalence was studied in a population of HIV positive intravenous drug users (IVDUs) from Argentina. Analysis of this population also indirectly made it possible to study HHV-8 blood transmission, because these individuals frequently engage in needle sharing behavior and are capable of acquiring a broad array of blood borne pathogens, including Hepatitis B/C virus. The seroprevalence of HHV-8 in IVDUs was compared to a group of non-IVDUs and HIV negative individuals. Of the 223 individuals tested, 13.45% were HHV-8 positive, 16.99% in the IVDUs group, and 5.71% in the non-IVDUs. Among HIV positive IVDUs, 25/144 …

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Interferon Regulatory Factor 7 Mediates Activation Of Tap-2 By Epstein-Barr Virus Latent Membrane Protein 1, Luwen Zhang, Joseph S. Pagano Jan 2001

Interferon Regulatory Factor 7 Mediates Activation Of Tap-2 By Epstein-Barr Virus Latent Membrane Protein 1, Luwen Zhang, Joseph S. Pagano

Nebraska Center for Virology: Faculty Publications

Transporter associated with antigen processing 2 (Tap-2) is responsible for ATP-dependent transport of peptides from the cytosol to the endoplasmic reticulum, where peptides bind to newly synthesized human leukocyte antigen (HLA) class I molecules, which are essential for cellular immune responses. Epstein-Barr virus (EBV) latent membrane protein 1 (LMP-1) has been shown to induce the expression of Tap-2. In this study, the induction of endogenous Tap-2 by LMP-1 is shown to be associated with and requires the expression of interferon regulatory factor 7 (IRF-7). In DG75 Burkitt’s lymphoma (BL) cells, in which LMP-1 induces the expression of IRF-7, LMP-1 induced …

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Giant Vacuoles Observed In Dictyostelium Discoideum, Aidong Yuan, Catherine P. Chia Jan 2001

Giant Vacuoles Observed In Dictyostelium Discoideum, Aidong Yuan, Catherine P. Chia

Papers in Microbiology

Large intracellular vacuoles, >4 μm in diameter and either round or oval-shaped, were observed infrequently in Dictyostelium discoideum amoebae of axenically-grown strain AX2 (only 1 in 106–108 cells). These previously unreported single or multiple “giant” vacuoles were more common, however, in newly germinated KAX3 cells (0.55% of the population) and AT-Kneg, a strain that lacks an esterase (0.47% of the population). A vacuolar H+-ATPase was enriched in their membranes of intracellular giant vacuoles, indicating that the vacuoles were related possibly to both endosomes and the contractile vacuole compartment. When monitored over time, giant …

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Influence Of Infected Cell Growth State On Bacteriophage Reactivation Levels, Dana R. Kadavy, Julie J. Shaffer, Susan E. Lott, Thomas A. Wolf, Cathy E. Bolton, William H. Gallimore, Eugene L. Martin, Kenneth W. Nickerson, Tyler A. Kokjohn Dec 2000

Influence Of Infected Cell Growth State On Bacteriophage Reactivation Levels, Dana R. Kadavy, Julie J. Shaffer, Susan E. Lott, Thomas A. Wolf, Cathy E. Bolton, William H. Gallimore, Eugene L. Martin, Kenneth W. Nickerson, Tyler A. Kokjohn

Papers in Microbiology

Reactivation of UV-C-inactivated Pseudomonas aeruginosa bacteriophages D3C3, F116, G101, and UNL-1 was quantified in host cells infected during the exponential phase, during the stationary phase, and after starvation (1 day, 1 and 5 weeks) under conditions designed to detect dark repair and photoreactivation. Our experiments revealed that while the photoreactivation capacity of stationary-phase or starved cells remained about the same as that of exponential-phase cells, in some cases their capacity to support dark repair of UV-inactivated bacteriophages increased over 10-fold. This enhanced reactivation capacity was correlated with the ca. 30- fold-greater UV-C resistance of P. aeruginosa host cells that were …

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Characterization Of Transcripts Expressed From Human Herpesvirus 6a Strain Gs Immediate-Early Region B U16-U17 Open Reading Frames, Linda Flebbe-Rehwaldt, Charles Wood, Bala Chandran Dec 2000

Characterization Of Transcripts Expressed From Human Herpesvirus 6a Strain Gs Immediate-Early Region B U16-U17 Open Reading Frames, Linda Flebbe-Rehwaldt, Charles Wood, Bala Chandran

Nebraska Center for Virology: Faculty Publications

Several gene fragments of human herpesvirus 6 (HHV-6) have been shown to activate the human immunodeficiency virus (HIV) type 1 long terminal repeat (LTR). An open reading frame (ORF) designated B701 (Y. Geng, B. Chandran, S. F. Josephs, and C. Wood, J. Virol. 66:1564–1570, 1992), found within a 22-kb HHV-6A strain GS [HHV-6A(GS)] genomic fragment and a 3.8-kb SalI subfragment, was shown to activate the HIV LTR. B701, also known as HHV-6 U16, is located in the immediate-early B (IE-B) region of the genome. The sequence of the 3.8-kb genomic fragment of HHV-6A(GS) is nearly identical to the published …

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Cytoplasmic Filament-Deficient Mutant Of Treponema Denticola Has Pleiotropic Defects, Jacques Izard, William A. Samsonoff, Ronald J. Limberger Nov 2000

Cytoplasmic Filament-Deficient Mutant Of Treponema Denticola Has Pleiotropic Defects, Jacques Izard, William A. Samsonoff, Ronald J. Limberger

Department of Food Science and Technology: Faculty Publications

In Treponema denticola, a ribbon-like structure of cytoplasmic filaments spans the cytoplasm at all stages of the cell division process. Insertional inactivation was used as a first step to determine the function of the cytoplasmic filaments. A suicide plasmid was constructed that contained part of cfpA and a nonpolar erythromycin resistance cassette (ermF and ermAM) inserted near the beginning of the gene. The plasmid was electroporated into T. denticola, and double-crossover recombinants which had the chromosomal copy of cfpA insertionally inactivated were selected. Immunoblotting and electron microscopy confirmed the lack of cytoplasmic filaments. The mutant was further …

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Natural Antibiotic Resistance Of Bacteria Isolated From Larvae Of The Oil Fly, Helaeomyia Petrolei, Dana R. Kadavy, Jacob M. Hornby, Terry Haverkost, Kenneth W. Nickerson Nov 2000

Natural Antibiotic Resistance Of Bacteria Isolated From Larvae Of The Oil Fly, Helaeomyia Petrolei, Dana R. Kadavy, Jacob M. Hornby, Terry Haverkost, Kenneth W. Nickerson

Papers in Microbiology

Helaeomyia petrolei (oil fly) larvae inhabit the asphalt seeps of Rancho La Brea in Los Angeles, Calif. The culturable microbial gut contents of larvae collected from the viscous oil were recently examined, and the majority (9 of 14) of the strains were identified as Providencia spp. Subsequently, 12 of the bacterial strains isolated were tested for their resistance or sensitivity to 23 commonly used antibiotics. All nine strains classified as Providencia rettgeri exhibited dramatic resistance to tetracycline, vancomycin, bacitracin, erythromycin, novobiocin, polymyxin, colistin, and nitrofurantoin. Eight of nine Providencia strains showed resistance to spectinomycin, six of nine showed resistance to …

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Porcine Reproductive And Respiratory Syndrome Virus: Description Of Persistence In Individual Pigs Upon Experimental Infection, R. Allende, W. W. Laegreid, G. F. Kutish, J. A. Galeota, R. W. Wills, Fernando A. Osorio Nov 2000

Porcine Reproductive And Respiratory Syndrome Virus: Description Of Persistence In Individual Pigs Upon Experimental Infection, R. Allende, W. W. Laegreid, G. F. Kutish, J. A. Galeota, R. W. Wills, Fernando A. Osorio

Nebraska Center for Virology: Faculty Publications

We studied the persistence of porcine reproductive and respiratory syndrome virus (PRRSV) in individual experimentally infected pigs, during a period of up to 150 days postinfection (dpi). The results of this study suggest that the persistence of PRRSV involves continuous viral replication but that it is not a true steady-state persistent infection. The virus eventually clears the body and seems to do it in most of the animals by 150 dpi or shortly thereafter. High genetic stability was seen for several regions of the persistent PRRSV’s genome, although some consistent mutations in the genes of envelope glycoproteins and M protein …

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A Receptor-Like Glycoprotein From Dictyostelium Discoideum: Functions In Phagocytosis And Cell Adhesion?, P. Christopher Larosa, Melissa B. Meirer, Catherine P. Chia Sep 2000

A Receptor-Like Glycoprotein From Dictyostelium Discoideum: Functions In Phagocytosis And Cell Adhesion?, P. Christopher Larosa, Melissa B. Meirer, Catherine P. Chia

Papers in Microbiology

The molecular mechanisms for the initial recognition and subsequent internalization of food and unicellular pathogens by phagocytes are incompletely understood We have hypothesized that a surface-exposed, glycosylated I30 kDa protein, gp130, that 1s concentrated on the plasma membrane and found In phagosomes, has a role In phagocytosis by D. discoideum amoebae. GpI30 appears to have a cytoskeletal association and has extracellular domains susceptible to proteolytic digestion. It is tightly bound to the plasma membrane probably via a carboxyterminal hydrophobic anchor predicted from the cDNA. Gp130 may be the same as a similarly sized protein, gp126, that was implicated as a …

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A Role For Calcineurin In Dictyostelium Discoideum Phagocytosis, Aidong Yuan, Catherine P. Chia Sep 2000

A Role For Calcineurin In Dictyostelium Discoideum Phagocytosis, Aidong Yuan, Catherine P. Chia

Papers in Microbiology

The Ca2+/calmodul1n-dependent protein phosphatase calcinewin is involved in the development of the cellular slime mold Dictyostelium discoideum. Because of its interactions with Ca2+, which appear to influence D. discoideum phagocytosis (Yuan and Chia, 1999, Mol. Biol. Cell 10, 220a), we undertook studies to test whether calcineurin also plays a role in Dictyostelium phagocytosis. The immunosuppressants cyclosporin A and FK506, through the formation of cyclosporin A-cyclophilin A and FK506- FK506-binding protein complexes, respectively, inhibited calcineurin activity. These two calcineurin inhibitors suppressed phagocytosis of fluorescently labeled yeast in a dose-dependent manner. Although it inhib~ted phagocytosis, cyclosporin A had an insignificant effect …

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Integrity Of The Actin Cytoskeleton Required For Both Phagocytosis And Macropinocytosis In Dictyostelium Discoideum, Aidong Yuan, Catherine P. Chia Sep 2000

Integrity Of The Actin Cytoskeleton Required For Both Phagocytosis And Macropinocytosis In Dictyostelium Discoideum, Aidong Yuan, Catherine P. Chia

Papers in Microbiology

Filamentous (F-) actin is enriched in cellular extensions, such as phagocytic cups and macropioocytic crowns, of Dlctyostelium discoideum amebae. Previous studies of actin-disrupting agents that implicated the involvement of the actin cytoskeleton in Dictyostelium phagocytosis and pinocytosis, however, have yielded conflicting results. We show that the integrity of the actin cytoskeleton is required for both phagocytosis and macropinocytosis in D. discoideum with latrunculin A (IatA), which binds to monomeric actin, and cytochalasin A (cytA), which caps the plus end of actin filaments. Using rhodamine-phalloidin to visualize F-actin, cells treated for 30 min. with 1 to 4 pM of latA displayed …

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Nutrient Absorption And Utilization By Wing And Flight Muscle Morphs Of The Cricket Gryllus Firmus: Implications For The Trade-Off Between Flight Capability And Early Reproduction, Anthony J. Zera, Tammy Brink Aug 2000

Nutrient Absorption And Utilization By Wing And Flight Muscle Morphs Of The Cricket Gryllus Firmus: Implications For The Trade-Off Between Flight Capability And Early Reproduction, Anthony J. Zera, Tammy Brink

Anthony Zera Publications

Absorption efficiency (AD, approximate digestibility, assimilation efficiency) of various macronutrients and conversion of absorbed nutrients to biomass (ECD) were compared among the two types of flightless morph and the flight-capable morph of the cricket, Gryllus firmus. No biologically significant phenotypic or genetic difference in AD for carbohydrate, protein or lipid was observed among morphs fed either a high-nutrient (100%) or a low-nutrient (25%) diet. Thus, previously-documented differences among adult morphs in carbohydrate and lipid content must be caused by processes other than variation in nutrient absorption by morphs during adulthood. Relative absorption efficiency of total dry mass of food …

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Cloning Of The Bovine Immunodeficiency Virus Gag Gene And Development Of A Recombinant-Protein-Based Enzyme-Linked Immunosorbent Assay, Ling Zheng, Michelle Swanson, Jinghua Liao, Charles Wood, Sanjay Kapil, Ron Snider, Thomas A. Loughin, Harish Minocha Jul 2000

Cloning Of The Bovine Immunodeficiency Virus Gag Gene And Development Of A Recombinant-Protein-Based Enzyme-Linked Immunosorbent Assay, Ling Zheng, Michelle Swanson, Jinghua Liao, Charles Wood, Sanjay Kapil, Ron Snider, Thomas A. Loughin, Harish Minocha

Nebraska Center for Virology: Faculty Publications

An enzyme-linked immunosorbent assay (ELISA) was established for the rapid detection of specific bovine immunodeficiency virus (BIV) antibodies in cattle, using recombinant Gag protein as an antigen. The gag coding region from BIV was cloned into an expression vector, pQE32, which expressed high levels of recombinant protein from Escherichia coli. The ELISA was standardized by a checkerboard titration against known BIV-positive and -negative sera from cattle and a monoclonal antibody to the Gag protein. A total of 139 cattle serum samples, from the diagnostic laboratory at Kansas State University, Manhattan, and from the Dairy Station, Louisiana State University, Baton …

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Adaptation And Selection Of Prion Protein Strain Conformations Following Interspecies Transmission Of Transmissible Mink Encephalopathy, Jason C. Bartz, Richard Bessen, Debbie Mckenzie, Richard F. Marsh, Judd M. Aiken Jun 2000

Adaptation And Selection Of Prion Protein Strain Conformations Following Interspecies Transmission Of Transmissible Mink Encephalopathy, Jason C. Bartz, Richard Bessen, Debbie Mckenzie, Richard F. Marsh, Judd M. Aiken

Nebraska Center for Virology: Faculty Publications

Interspecies transmission of the transmissible spongiform encephalopathies (TSEs), or prion diseases, can result in the adaptation and selection of TSE strains with an expanded host range and increased virulence such as in the case of bovine spongiform encephalopathy and variant Creutzfeldt-Jakob disease. To investigate TSE strain adaptation, we serially passaged a biological clone of transmissible mink encephalopathy (TME) into Syrian golden hamsters and examined the selection of distinct strain phenotypes and conformations of the disease-specific isoform of the prion protein (PrPSc). The long-incubation-period drowsy (DY) TME strain was the predominate strain, based on the presence of its strain-specific …

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Tubulin And Neurofilament Proteins Are Transported Differently In Axons Of Chicken Motoneurons, Aidong Yuan, Roland G. Mills, Catherine P. Chia, John J. Bray Jun 2000

Tubulin And Neurofilament Proteins Are Transported Differently In Axons Of Chicken Motoneurons, Aidong Yuan, Roland G. Mills, Catherine P. Chia, John J. Bray

Papers in Microbiology

1. We previously showed that actin is transported in an unassembled form with its associated proteins actin depolymerizing factor, cofilin, and profilin. Here we examine the specific activities of radioactively labeled tubulin and neurofilament proteins in subcellular fractions of the chicken sciatic nerve following injection of L-[35S]methionine into the lumbar spinal cord. 2. At intervals of 12 and 20 days after injection, nerves were cut into 1-cm segments and separated into Triton X-100-soluble and particulate fractions. Analysis of the fractions by high-resolution two-dimensional gel electrophoresis, immunoblotting, fluorography, and computer densitometry showed that tubulin was transported as a unimodal wave at …

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Binding Of Equine Infectious Anemia Virus Rev To An Exon Splicing Enhancer Mediates Alternative Splicing And Nuclear Export Of Viral Mrnas, Michael Belshan, Gregory S. Park, Patricia Bilodeau, C. Martin Stoltzfus, Susan Carpenter May 2000

Binding Of Equine Infectious Anemia Virus Rev To An Exon Splicing Enhancer Mediates Alternative Splicing And Nuclear Export Of Viral Mrnas, Michael Belshan, Gregory S. Park, Patricia Bilodeau, C. Martin Stoltzfus, Susan Carpenter

Nebraska Center for Virology: Faculty Publications

In addition to facilitating the nuclear export of incompletely spliced viral mRNAs, equine infectious anemia virus (EIAV) Rev regulates alternative splicing of the third exon of the tat/rev mRNA. In the presence of Rev, this exon of the bicistronic RNA is skipped in a fraction of the spliced mRNAs. In this report, the cis-acting requirements for exon 3 usage were correlated with sequences necessary for Rev binding and transport of incompletely spliced RNA. The presence of a purine-rich exon splicing enhancer (ESE) was required for exon 3 recognition, and the addition of Rev inhibited exon 3 splicing. Glutathione-S-transferase (GST)-Rev bound …

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Juvenile Hormone Titer And Morph-Specific Reproduction In The Wing-Polymorphic Cricket, Gryllus Firmus, Gretchen Cisper, Anthony J. Zera, David W. Borst Apr 2000

Juvenile Hormone Titer And Morph-Specific Reproduction In The Wing-Polymorphic Cricket, Gryllus Firmus, Gretchen Cisper, Anthony J. Zera, David W. Borst

Anthony Zera Publications

Juvenile hormone titers and reproductive characteristics were measured in adult wing and flight-muscle morphs of the wing-polymorphic cricket, Gryllus firmus, during the first week of adulthood. This species has three morphs: one flight capable morph with fully-developed wings and fully-developed flight muscles [LW(F)], one flightless morph with fully-developed wings and histolyzed (non-functional) flight muscles [LW(H)], and another flightless morph with underdeveloped (short) wings and underdeveloped flight muscles (SW). Both flightless morphs [LW(H) and SW] had larger ovaries which contained a greater number of postvitellogenic eggs compared with the flight capable [LW(F)] morph. The juvenile hormone titer was significantly higher …

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Jembrana Disease Virus Tat Can Regulate Human Immunodeficiency Virus (Hiv) Long Terminal Repeat-Directed Gene Expression And Can Substitute For Hiv Tat In Viral Replication, Hexin Chen, Jun He, Steven Fong, Graham Wilcox, Charles Wood Mar 2000

Jembrana Disease Virus Tat Can Regulate Human Immunodeficiency Virus (Hiv) Long Terminal Repeat-Directed Gene Expression And Can Substitute For Hiv Tat In Viral Replication, Hexin Chen, Jun He, Steven Fong, Graham Wilcox, Charles Wood

Nebraska Center for Virology: Faculty Publications

Jembrana disease virus (JDV) is a bovine lentivirus genetically similar to bovine immunodeficiency virus; it causes an acute and sometimes fatal disease in infected animals. This virus carries a very potent Tat that can strongly activate not only its own long terminal repeat (LTR) but also the human immunodeficiency virus (HIV) LTR. In contrast, HIV Tat cannot reciprocally activate the JDV LTR (H. Chen, G. E. Wilcox, G. Kertayadnya, and C. Wood, J. Virol. 73:658–666, 1999). This indicates that in transactivation JDV Tat may utilize a mechanism similar to but not the same as that of the HIV Tat. To …

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Interferon Regulatory Factor 7 Is Induced By Epstein-Barr Virus Latent Membrane Protein 1, Luwen Zhang, Joseph S. Pagono Feb 2000

Interferon Regulatory Factor 7 Is Induced By Epstein-Barr Virus Latent Membrane Protein 1, Luwen Zhang, Joseph S. Pagono

Nebraska Center for Virology: Faculty Publications

Infection by Epstein-Barr virus (EBV) generates several types of latency with different profiles of gene expression but with expression of Epstein-Barr nuclear antigen 1 (EBNA-1) in common. The BamHI Q promoter (Qp) is used for the transcription of EBNA-1 mRNA in type I latency, which is an EBV infection state exemplified by Burkitt’s lymphoma (BL). However, Qp is inactive in type III latency, and other promoters (C/Wp) are used for transcription of EBNA-1, which raises the question of how usage of these promoters is governed. Interferon (IFN) regulatory factor 7 (IRF-7) was identified first as a negative regulator of …

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Cap-Independent Translational Enhancement Of Turnip Crinkle Virus Genomic And Subgenomic Rnas, Feng Qu, Thomas Jack Morris Feb 2000

Cap-Independent Translational Enhancement Of Turnip Crinkle Virus Genomic And Subgenomic Rnas, Feng Qu, Thomas Jack Morris

Nebraska Center for Virology: Faculty Publications

The presence of translational control elements and cap structures has not been carefully investigated for members of the Carmovirus genus, a group of small icosahedral plant viruses with positive-sense RNA genomes. In this study, we examined both the 5’ and 3’ untranslated regions (UTRs) of the turnip crinkle carmovirus (TCV) genomic RNA (4 kb) as well as the 5’ UTR of the coat protein subgenomic RNA (1.45 kb) for their roles in translational regulation. All three UTRs enhanced translation of the firefly luciferase reporter gene to different extents. Optimal translational efficiency was achieved when mRNAs contained both 5’ and 3’ …

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Identification Of The Transactivation Domain Of The Transcription Factor Sox-2 And An Associated Co-Activator, Tamara K. Nowling, Lance R. Johnson, Matthew S. Wiebe, Angie Rizzino Jan 2000

Identification Of The Transactivation Domain Of The Transcription Factor Sox-2 And An Associated Co-Activator, Tamara K. Nowling, Lance R. Johnson, Matthew S. Wiebe, Angie Rizzino

Nebraska Center for Virology: Faculty Publications

The importance of interactions between Sox and POU transcription factors in the regulation of gene expression is becoming increasingly apparent. Recently, many examples of the involvement of Sox-POU partnerships in transcription have been discovered, including a partnership between Sox-2 and Oct-3. Little is known about the mechanisms by which these factors modulate transcription. To better understand the molecular interactions involved, we mapped the location of the transactivation do-main of Sox-2. This was done in the context of its interaction with Oct-3, as well as its ability to transactivate as a fusion protein linked to the DNA-binding domain of Gal4. Both …

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Quantitative Image Analysis Of Simian Immunodeficiency Virus Replication In Macrophages Coinfected With Mycobacterium Avium Complex, Qingsheng Li, Keith G. Mansfield, Andrew Lackner, Ashley T. Haase Jan 2000

Quantitative Image Analysis Of Simian Immunodeficiency Virus Replication In Macrophages Coinfected With Mycobacterium Avium Complex, Qingsheng Li, Keith G. Mansfield, Andrew Lackner, Ashley T. Haase

Qingsheng Li Publications

Mycobacterium avium is the most frequent cause of disseminated bacterial infection in patients with human immunodeficiency virus type 1 infection and in rhesus macaques with simian immunodeficiency virus (SIV) infection. This animal model of AIDS was used to test the hypothesis that this frequent association is the result of reciprocal enhancement of replication of both microorganisms. The replication of M. avium and SIV was analyzed in lymphatic tissues obtained from rhesus macaques experimentally inoculated with SIVmac who developed or remained free of overt M. avium infection. In situ hybridization, quantitative image analysis, and staining of M. avium and of macrophages …

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Role Of Esterase Gp70 And Its Influence On Growth And Development Of Dictyostelium Discoideum, Aidong Yuan, Catherine P. Chia Jan 2000

Role Of Esterase Gp70 And Its Influence On Growth And Development Of Dictyostelium Discoideum, Aidong Yuan, Catherine P. Chia

Papers in Microbiology

Gp70 is an esterase originally called crystal protein because of its presence in crystalline structures in aggregation-competent Dictyostelium discoideum cells. Although postulated to break down spore coats, the function of gp70 in vivo was incompletely investigated. Our immunolocalization and biochemical studies of vegetative D. discoideum amoebae show that gp70 was recruited to phagosomes and found in lysosomes. Purified gp70 was effective at hydrolyzing naphthyl substrates with acyl chains typical of lipids and lipopolysaccharides, indicating that the gp70 was involved in digesting endocytosed molecules. The activity of purified gp70 was inhibited by reductants that retarded its electrophoretic mobility and verified the …

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Azidothymidine And Interferon-Α Induce Apoptosis In Herpesvirus-Associated Lymphomas, Richard K. Lee, Jian-Ping Cai, Vadim Deyev, Parkash Gill, Lisa Cabral, Charles Wood, Ram Agarwal, Wenle Xia, Lawrence Boise, Eckhard Podack, William Harrington Jr. Nov 1999

Azidothymidine And Interferon-Α Induce Apoptosis In Herpesvirus-Associated Lymphomas, Richard K. Lee, Jian-Ping Cai, Vadim Deyev, Parkash Gill, Lisa Cabral, Charles Wood, Ram Agarwal, Wenle Xia, Lawrence Boise, Eckhard Podack, William Harrington Jr.

Nebraska Center for Virology: Faculty Publications

Lymphoproliferative diseases that occur in immunocompromised patients are frequently associated with herpesviruses. These patients often fare poorly after treatment with conventional chemotherapy. We reported previously that patients with AIDS-related Burkitt’s lymphoma (BL) responded to parenteral azidothymidine (AZT) and IFN-α. We found that EBV-positive lymphoma cells derived from these patients cultured with AZT express CD95 and undergo apoptosis. AZT-mediated apoptosis was caspase dependent and occurred despite Fas receptor blockade. In contrast, EBV-negative lymphomas were resistant to AZT-induced apoptosis, as were EBV-positive lymphomas that expressed high levels of bcl-2. Primary effusion lymphoma (PEL) cell lines infected with human herpesvirus type 8 required …

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Lymphotropic Virions Affect Chemokine Receptor-Mediated Neural Signaling And Apoptosis: Implications For Human Immunodeficiency Virus Type 1-Associated Dementia, Jialin Zheng, Anuja Ghorpade, Douglas Niemann, Robin L. Cotter, Michael R. Thylin, Leon Epstein, Jennifer Swartz, Robin B. Shepard, Xiaojuan Liu, Adeline Nukuna, Howard E. Gendelman Oct 1999

Lymphotropic Virions Affect Chemokine Receptor-Mediated Neural Signaling And Apoptosis: Implications For Human Immunodeficiency Virus Type 1-Associated Dementia, Jialin Zheng, Anuja Ghorpade, Douglas Niemann, Robin L. Cotter, Michael R. Thylin, Leon Epstein, Jennifer Swartz, Robin B. Shepard, Xiaojuan Liu, Adeline Nukuna, Howard E. Gendelman

Nebraska Center for Virology: Faculty Publications

Chemokine receptors pivotal for human immunodeficiency virus type 1 (HIV-1) infection in lymphocytes and macrophages (CCR3, CCR5, and CXCR4) are expressed on neural cells (microglia, astrocytes, and/or neurons). It is these cells which are damaged during progressive HIV-1 infection of the central nervous system. We theorize that viral coreceptors could effect neural cell damage during HIV-1-associated dementia (HAD) without simultaneously affecting viral replication. To these ends, we studied the ability of diverse viral strains to affect intracellular signaling and apoptosis of neurons, astrocytes, and monocyte-derived macrophages. Inhibition of cyclic AMP, activation of inositol 1,4,5-trisphosphate, and apoptosis were induced by diverse …

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Evolutionary Endocrinology Of Juvenile Hormone Esterase: Functional Relationship With Wing Polymorphism In The Cricket, Gryllus Firmus, Anthony J. Zera, Yuan Huang Aug 1999

Evolutionary Endocrinology Of Juvenile Hormone Esterase: Functional Relationship With Wing Polymorphism In The Cricket, Gryllus Firmus, Anthony J. Zera, Yuan Huang

Anthony Zera Publications

The existence, nature, and physiological consequences of genetic variation for juvenile hormone esterase (JHE) activity was studied in the wing-polymorphic cricket, Gryllus firmus. Hemolymph (blood) JHE activity was sixfold lower in nascent short-winged (SW) females, relative to nascent long-winged (LW) females, during the last juvenile stadium (stage). Morph-associated genetic variation for JHE activity had two causes, variation in loci: (1) regulating whole-organism enzyme activity; and (2) controlling the degree to which JHE is secreted into the blood. Reduced JHE activity in nascent SW-selected individuals was associated with reduced in vivo juvenile hormone catabolism. This suggests that variation in JHE …

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The Endocrine Genetics Of Wing Polymorphism In Gryllus: Critique Of Recent Studies And State Of The Art, Anthony J. Zera Aug 1999

The Endocrine Genetics Of Wing Polymorphism In Gryllus: Critique Of Recent Studies And State Of The Art, Anthony J. Zera

Anthony Zera Publications

In a series of papers, the most recent of which was published in Evolution, quantitative-genetic experiments were undertaken on reproductive and physiological correlates of wing polymorphism in the sand cricket, Gryllus firmus (Fairbairn 1994; Fairbairn and Yadlowski 1997; Roff et al. 1997). A goal of these studies was to determine the physiological causes underlying: (1) genetic variation for an ecologically important threshold trait (wing polymorphism); and (2) genetic correlations between wing morph and other reproductive and migratory features, such as fecundity and flight muscle histolysis. These authors concluded that genetic variation for the activity of the endocrine regulator, juvenile hormone …

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Genetic And Structural Analyses Of Cytoplasmic Filaments Of Wild-Type Treponema Phagedenis And A Flagellar Filament-Deficient Mutant, Jacques Izard, William A. Samsonoff, Mary Beth Kinoshita, Ronald J. Limberger Aug 1999

Genetic And Structural Analyses Of Cytoplasmic Filaments Of Wild-Type Treponema Phagedenis And A Flagellar Filament-Deficient Mutant, Jacques Izard, William A. Samsonoff, Mary Beth Kinoshita, Ronald J. Limberger

Department of Food Science and Technology: Faculty Publications

Unique cytoplasmic filaments are found in the treponeme genus of spirochete bacteria. Their function is unknown, but their location underneath the periplasmic flagellar filaments (PFF) suggests a role in motility and/or cell structure. To better understand these unique structures, the gene coding for the cytoplasmic filaments, cfpA, was identified in various treponemal species. Treponema phagedenis cfpA was 2,037 nucleotides long, and the encoded polypeptide showed 78 to 100% amino acid sequence identity with the partial sequence of CfpA from T. denticola, T. vincentii, and T. pallidum subsp. pertenue. Wild-type T. phagedenis and a …

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Broad-Spectrum Protection Against Tombusviruses Elicited By Defective Interfering Rnas In Transgenic Plants, Teresa Rubio, Marise Borja, Herman Scholthof, Paul A. Feldstein, Thomas Jack Morris, Andrew O. Jackson Jun 1999

Broad-Spectrum Protection Against Tombusviruses Elicited By Defective Interfering Rnas In Transgenic Plants, Teresa Rubio, Marise Borja, Herman Scholthof, Paul A. Feldstein, Thomas Jack Morris, Andrew O. Jackson

Nebraska Center for Virology: Faculty Publications

We have designed a DNA cassette to transcribe defective interfering (DI) RNAs of tomato bushy stunt virus (TBSV) and have investigated their potential to protect transgenic Nicotiana benthamiana plants from tombusvirus infections. To produce RNAs with authentic 5’ and 3’ termini identical to those of the native B10 DI RNA, the DI RNA sequences were flanked by ribozymes (RzDI). When RzDI RNAs transcribed in vitro were mixed with parental TBSV transcripts and inoculated into protoplasts or plants, they became amplified, reduced the accumulation of the parental RNA, and mediated attenuation of the lethal syndrome characteristic of TBSV infections. Analysis of …

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Insertional Inactivation Of Treponema Denticola Tap1 Results In A Nonmotile Mutant With Elongated Flagellar Hooks, Ronald J. Limberger, Linda L. Slivienski, Jacques Izard, William A. Samsonoff Jun 1999

Insertional Inactivation Of Treponema Denticola Tap1 Results In A Nonmotile Mutant With Elongated Flagellar Hooks, Ronald J. Limberger, Linda L. Slivienski, Jacques Izard, William A. Samsonoff

Department of Food Science and Technology: Faculty Publications

The treponemal fla operon is comprised of numerous motility-related genes; however, the initial gene of this operon, tap1, has no known function. A recently developed system to generate specific mutants in Treponema denticola was utilized to determine if Tap1 was essential for motility. T. denticola tap1 and flanking DNA were identified, cloned, and sequenced, and a suicide plasmid that contained tap1 interrupted with an erythromycin resistance cassette (ermF and ermAM) was constructed. Because of potential polar effects from this cassette, a second plasmid that contained tap1 interrupted with a modified erythromycin resistance cassette that lacked the putative ermF transcription …

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