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2001

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Articles 1 - 30 of 62

Full-Text Articles in Microbiology

Aerobic Biodegradation Of Methyl Tert-Butyl Ether By Aquifer Bacteria From Leaking Underground Storage Tank Sites, S. R. Kane, H. R. Beller, T. C. Legler, C. J. Koester, Holly C. Pinkart, R. U. Halden, A. M. Happel Dec 2001

Aerobic Biodegradation Of Methyl Tert-Butyl Ether By Aquifer Bacteria From Leaking Underground Storage Tank Sites, S. R. Kane, H. R. Beller, T. C. Legler, C. J. Koester, Holly C. Pinkart, R. U. Halden, A. M. Happel

All Faculty Scholarship for the College of the Sciences

The potential for aerobic methyl tert-butyl ether (MTBE) degradation was investigated with microcosms containing aquifer sediment and groundwater from four MTBE-contaminated sites characterized by oxygen-limited in situ conditions. MTBE depletion was observed for sediments from two sites (e.g., 4.5 mg/liter degraded in 15 days after a 4-day lag period), whereas no consumption of MTBE was observed for sediments from the other sites after 75 days. For sediments in which MTBE was consumed, 43 to 54% of added [U-14C]MTBE was mineralized to14CO2. Molecular phylogenetic analyses of these sediments indicated the enrichment of species closely …

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Interferon Regulatory Factor 7: A Key Cellular Mediator Of Lmp-1 In Ebv Latency And Transformation, Luwen Zhang, Joseph S. Pagano Dec 2001

Interferon Regulatory Factor 7: A Key Cellular Mediator Of Lmp-1 In Ebv Latency And Transformation, Luwen Zhang, Joseph S. Pagano

Nebraska Center for Virology: Faculty Publications

Interferon regulatory factor 7 (IRF-7) was cloned within the biological context of Epstein–Barr virus (EBV) latency, and has an intimate relation with EBV. EBV latent membrane protein 1 (LMP-1) regulates IRF-7 both by inducing the expression of IRF-7 and by activating IRF-7 protein through phosphorylation and nuclear translocation in a post-translational manner. The activated IRF-7 then functions to regulate both EBV and cellular target genes involved in latency, transformation and immune regulation. IRF-7 appears to be a key cellular latency protein involved in both the pathogenesis and persistence of EBV infection.

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The Effect Of The Human Papillomavirus E5 Protein On Apoptosis In Human Foreskin Keratinocytes, Kasey Pattan Dec 2001

The Effect Of The Human Papillomavirus E5 Protein On Apoptosis In Human Foreskin Keratinocytes, Kasey Pattan

Electronic Dissertations and Theses

There are over seventy genotypes of Human Papillomaviruses (HPVs), some cause benign warts and others are risk factors for the development of carcinomas of the respiratory and genital tract. Research has proven that the high risk HPV 16 E5 protein in the presence of epidermal growth (EGF) acts as a survival factor resulting in elevated levels of activated epidermal growth factor receptor (EGFR) and activated levels of ERK 1/2 and Akt, two signaling molecules downstream of EGFR, in UVP irradiated human foreskin keratinocytes (HFKs). This leads to the protection of the cells from UVB induced apoptosis. The purpose of this …

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Intracellular Signaling Molecules Activated By Epstein-Barr Virus For Induction Of Interferon Regulatory Factor 7, Luwen Zhang, Lihong Wu, Ke Hong, Joseph S. Pagano Dec 2001

Intracellular Signaling Molecules Activated By Epstein-Barr Virus For Induction Of Interferon Regulatory Factor 7, Luwen Zhang, Lihong Wu, Ke Hong, Joseph S. Pagano

Nebraska Center for Virology: Faculty Publications

Epstein-Barr virus (EBV) latent membrane protein 1 (LMP-1) is the principal oncogenic protein in the EBV transformation process. LMP-1 induces the expression of interferon regulatory factor 7 (IRF-7) and activates IRF-7 protein by phosphorylation and nuclear translocation. LMP-1 is an integral membrane protein with two regions in its C terminus that initiate signaling processes, the C-terminal activator regions 1 (CTAR-1) and CTAR-2. Here, genetic analysis of LMP-1 has determined that the PXQXT motif that governs the interaction between LMP-1 CTAR-1 and tumor necrosis factor receptor-associated factors (TRAFs) is needed to induce the expression of IRF-7. Mutations in the PXQXT motif …

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Identification Of A Cellular Protein That Interacts And Synergizes With The Rta (Orf50) Protein Of Kaposi’S Sarcoma-Associated Herpesvirus In Transcriptional Activation, Shizhen Wang, Shuhong Liu, Ming-Hoi Wu, Yunqi Geng, Charles Wood Dec 2001

Identification Of A Cellular Protein That Interacts And Synergizes With The Rta (Orf50) Protein Of Kaposi’S Sarcoma-Associated Herpesvirus In Transcriptional Activation, Shizhen Wang, Shuhong Liu, Ming-Hoi Wu, Yunqi Geng, Charles Wood

Nebraska Center for Virology: Faculty Publications

Lytic reactivation of Kaposi’s sarcoma-associated herpesvirus (KSHV), or human herpesvirus 8, from latency requires transcriptional transactivation by the viral protein RTA encoded by the ORF50 gene. Very little is known about how RTA functions and the cellular factors that may be involved in its transactivation function. Using the yeast two-hybrid system, we have identified a human cellular protein that can interact with KSHV RTA. The cellular protein, referred to as the human hypothetical protein MGC2663 by GenBank, is encoded by human chromosome 19. This protein is 554 amino acids (aa) in size and displays sequence similarity with members of the …

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Genomic Organization Of Infectious Salmon Anemia Virus, Trent Rector Dec 2001

Genomic Organization Of Infectious Salmon Anemia Virus, Trent Rector

Electronic Theses and Dissertations

Infectious salmon anemia virus (ISAV) is an emerging pathogen of farmed Atlantic salmon (Salmo salar). The development of an effective ISA virus vaccine is a high priority for salmon producers in the U.S. and elsewhere. The process of developing a recombinant vaccine requires complete genetic characterization of the virus. Toward this end we have cloned, sequenced and determined the organization of the eight segments of single-stranded RNA from ISA virus isolate CCBB. The virus was grown in cell culture and purified by density gradient ultracentrifugation. Viral RNA was isolated from purified ISAV and used in the construction of two different …

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Polycyclic Aromatic Hydrocarbon Degradation By Novel Bacteria Isolated From Burrow Sediments Of Marine Benthic Macrofauna, Wai Ki Chung Dec 2001

Polycyclic Aromatic Hydrocarbon Degradation By Novel Bacteria Isolated From Burrow Sediments Of Marine Benthic Macrofauna, Wai Ki Chung

Electronic Theses and Dissertations

Polycyclic aromatic hydrocarbons (PAH) are significant environmental pollutants and represent a severe health threat. Many cosmopolitan areas including coastal environments are heavily impacted by PAH. This research investigates the isolation of PAH-degrading bacteria from burrow sediment of marine benthic macrofauna and their potential in bioremediation. Macrofaunal burrow sediment is biogeochemically distinct from bulk sediment and has high microbial activities. Samples were collected from a local uncontaminated cove and PAH degradation potential was measured by incubating sediment slurries with exogenous PAH. Burrow sediments from two polychaetes and a mollusc showed significantly higher PAH degradation potential than the bulk sediment. The degradation …

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Hamp Domain And Signaling Mechanism Of The Aer Protein, Qinhong Ma Dec 2001

Hamp Domain And Signaling Mechanism Of The Aer Protein, Qinhong Ma

Loma Linda University Electronic Theses, Dissertations & Projects

Escherichia coli utilizes the Aer protein to sense changes in the intracellular energy level and guide the bacteria to a niche where the cellular energy level is optimal. Aer contains a PAS sensory domain and an FI fragment in the N terminus and a chemotaxis signaling domain in the C terminus, separated by a putative transmembrane region. In this dissertation, I report that the linker region of Aer (residues 205-265), which joins the transmembrane region to the signaling domain, is a conserved signal transduction module in numerous methyl-accepting chemoreceptors, histidine kinases, adenylyl cyclases, and other sensory proteins in all three …

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Development Of A Model For Infective Endocarditis Via Intravenous Injection And Tooth Infection Of Rats Using Pathogenic Bacteria, Shahrokh Shabahang Dec 2001

Development Of A Model For Infective Endocarditis Via Intravenous Injection And Tooth Infection Of Rats Using Pathogenic Bacteria, Shahrokh Shabahang

Loma Linda University Electronic Theses, Dissertations & Projects

Historically, focal areas of infection have been linked to a number of systemic ailments. During the early part of the 20th century, patients who were suffering from inexplicable diseases and who were suspected of having infected teeth were referred to the dentist for multiple extraction of their dentition. The discovery of antibiotics provided a false sense of security that the war against microorganisms is no longer a concern for mankind. However, more recently, it has become common belief that increasing numbers of systemic diseases are linked to chronic infections. Recovery of bacteria from representative tissues has led investigators to believe …

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Enzymological And Radiotracer Studies Of Lipid Metabolism In The Flight-Capable And Flightless Morphs Of The Wing-Polymorphic Cricket, Gryllus Firmus, Z. Zhao, Anthony J. Zera Nov 2001

Enzymological And Radiotracer Studies Of Lipid Metabolism In The Flight-Capable And Flightless Morphs Of The Wing-Polymorphic Cricket, Gryllus Firmus, Z. Zhao, Anthony J. Zera

Anthony Zera Publications

The flight-capable morph of the wing-polymorphic cricket, Gryllus firmus, exhibited significantly higher activities of each of five lipogenic enzymes compared with the obligately flightless morph on a standard and a high-carbohydrate diet during early adulthood. Similarly, the rate of incorporation of [14C]-acetate into total lipid was higher in the flight-capable morph during this time. By contrast, activities of lipogenic enzymes and rates of lipid biosynthesis, in general, did not differ between morphs on a low nutrient diet during early adulthood. Differences in lipid biosynthesis account for previously documented differences in lipid reserves between morphs on some, but …

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Extended Tailing Of Bacteria Following Breakthrough At The Narrow Channel Focus Area, Oyster, Virginia, Pengfei Zhang, William P. Johnson, Timothy D. Scheibe, Keun-Hyung Choi, Fred C. Dobbs, Brian J. Mailloux Nov 2001

Extended Tailing Of Bacteria Following Breakthrough At The Narrow Channel Focus Area, Oyster, Virginia, Pengfei Zhang, William P. Johnson, Timothy D. Scheibe, Keun-Hyung Choi, Fred C. Dobbs, Brian J. Mailloux

OES Faculty Publications

Extended tailing of low bacterial concentrations following breakthrough at the Narrow Channel focus area was observed for 4 months. Bacterial attachment and detachment kinetics associated with breakthrough and extended tailing were determined by fitting a one-dimensional transport model to the field breakthrough-tailing data. Spatial variations in attachment rate coefficient (k(f)) were observed under forced gradient conditions (i.e., k(f) decreased as travel, distance increased), possibly because of decreased bacterial adhesion with increased transport distance. When pore water velocity decreased by an order of magnitude at 9 days following injection, apparent bacterial attachment rate coefficients did not decrease with velocity as expected …

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Microbial Loop Carbon Cycling In Ocean Environments Studied Using A Simple Steady-State Model, T. R. Anderson, H. W. Ducklow Oct 2001

Microbial Loop Carbon Cycling In Ocean Environments Studied Using A Simple Steady-State Model, T. R. Anderson, H. W. Ducklow

VIMS Articles

A simple steady-state model is used to examine the microbial loop as a pathway for organic C in marine systems, constrained by observed estimates of bacterial to primary production ratio (BP:PP) and bacterial growth efficiency (BGE). Carbon sources (primary production including extracellular release of dissolved organic carbon, DOC), cycling via zooplankton grazing and viral lysis, and sinks (bacterial and zooplankton respiration) are represented. Model solutions indicate that, at least under near steady-state conditions, recent estimates of BP:PP of about 0.1 to 0.15 are consistent with reasonable scenarios of C cycling (low BGE and phytoplankton extracellular release) at open ocean sites …

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The Metabolic Basis Of Life History Variation: Genetic And Phenotypic Differences In Lipid Reserves Among Life History Morphs Of The Wing-Polymorphic Cricket, Gryllus Firmus, Anthony J. Zera, A. Larsen Sep 2001

The Metabolic Basis Of Life History Variation: Genetic And Phenotypic Differences In Lipid Reserves Among Life History Morphs Of The Wing-Polymorphic Cricket, Gryllus Firmus, Anthony J. Zera, A. Larsen

Anthony Zera Publications

The flight-capable morph of the wing-polymorphic cricket, Gryllus firmus, accumulated a substantially greater quantity of total lipid and triglyceride, compared with the obligately flightless morph, during the first five days of adulthood. Increased lipid accumulation in the flight-capable morph was genetically based, and was produced when ovarian growth is substantially reduced in that morph. Temporal changes in lipid levels suggest that the higher triglyceride reserves in the flight-capable morph fed a high-nutrient diet were produced by elevated lipid biosynthesis. By contrast, on a low-nutrient or high carbohydrate diet, increased lipid levels in the flight-capable morph appeared to result primarily …

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Membrane Glycoprotein Gp130 Of Dictyostelium Discoideum Is Lipid-Linked And Its Fate Altered In The Presence Of Tunicamycin, Betsy L. Barent, Catherine P. Chia Sep 2001

Membrane Glycoprotein Gp130 Of Dictyostelium Discoideum Is Lipid-Linked And Its Fate Altered In The Presence Of Tunicamycin, Betsy L. Barent, Catherine P. Chia

Papers in Microbiology

We are studying the structure and role in phagocytosis of gp130, a glycoprotein located on the extracellular surface of D. discoideum amoebae. Predictions from the protein sequence of gp130 deduced from the cDNA indicate its attachment to the membrane via a glycosylphosphatidylinositol (GP1)-anchor. This was confirmed when radiolabeled palmitic acid was incorporated into gp130 of axenically grown cells, and when nitrous acid deamination released gp130 from purified membranes. The GPI-anchor of gp130 resisted cleavage by bacterial and mammalian phosphoinositol-specific phospholipases. However, in the presence of protease inhibitors, we detected in vitro a time-dependent cleavage of gp 130 that was effectively …

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Problem Based Learning In The 3rd World Context, V Zaman Aug 2001

Problem Based Learning In The 3rd World Context, V Zaman

Department of Pathology and Laboratory Medicine

No abstract provided.

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A Novel Strategy Utilizing Co-Expression Of Murine Il-12 And Antisense Tgf-Pl Against H238 Tumor Formation, Craig A. Seheult Aug 2001

A Novel Strategy Utilizing Co-Expression Of Murine Il-12 And Antisense Tgf-Pl Against H238 Tumor Formation, Craig A. Seheult

Loma Linda University Electronic Theses, Dissertations & Projects

Cytokines have a profound effect on immune modulation, thus playing a significant role in cancer gene therapy. A variety of human carcinomas secrete transforming growth factor-beta (TGF-β), a cytokine with potent immunosuppressive properties. Suppressing TGF-β could be a key to successfully combating malignancies, such as gliomas, mammary, and colon cancers, that over-express TGF-β. Conversely, interleukin-12 (IL-12) is a potent immunostimulatory cytokine capable of regulating T and NK cell-mediated cytotoxic responses (Trinchieri, 1994) during an anti-tumor response. Activation of the immune system with such immunostimulatory cytokines renders it inert to the suppressive effects of TGF-β. To better understand these processes our …

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Effects Of Liposome-Encapsulated Tnf-Alpha And Radiation Against Colon Cancer, Dong Won Kim Aug 2001

Effects Of Liposome-Encapsulated Tnf-Alpha And Radiation Against Colon Cancer, Dong Won Kim

Loma Linda University Electronic Theses, Dissertations & Projects

Previous studies have shown that tumor necrosis factor-α (TNF-α) can augment the antitumor effects of radiation, inhibiting tumor progression to a greater extent than either modality alone. However, nonspecific toxicities associated with TNF-α have limited its use as an adjuvant. This limitation is potentially resolved with the encapsulation of TNF-α in sterically stabilized, PEGylated liposomes (STEALTH®). Thus, the overall hypothesis of the research was that the combination of radiation with STEALTH® liposome encapsulated TNF-α (SL-TNF-α) will have greater efficacy and fewer dose-limiting side effects in the LS174T human colorectal tumor xenograft model compared to the combination of free TNF-α and …

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Mononuclear Phagocyte Differentiation, Activation, And Viral Infection Regulate Matrix Metalloproteinase Expression: Implications For Human Immunodeficiency Virus Type 1-Associated Dementia, Anuja Ghorpade, Raisa Persidskaia, Radhika Suryadevara, Myhanh Che, Xiao Juan Liu, Yuri Persidsky, Howard Gendelman Jul 2001

Mononuclear Phagocyte Differentiation, Activation, And Viral Infection Regulate Matrix Metalloproteinase Expression: Implications For Human Immunodeficiency Virus Type 1-Associated Dementia, Anuja Ghorpade, Raisa Persidskaia, Radhika Suryadevara, Myhanh Che, Xiao Juan Liu, Yuri Persidsky, Howard Gendelman

Nebraska Center for Virology: Faculty Publications

The pathogenesis of human immunodeficiency virus type 1 (HIV-1)-associated dementia (HAD) is mediated mainly by mononuclear phagocyte (MP) secretory products and their interactions with neural cells. Viral infection and MP immune activation may affect leukocyte entry into the brain. One factor that influences central nervous system (CNS) monocyte migration is matrix metalloproteinases (MMPs). In the CNS, MMPs are synthesized by resident glial cells and affect the integrity of the neuropil extracellular matrix (ECM). To ascertain how MMPs influence HAD pathogenesis, we studied their secretion following MP differentiation, viral infection, and cellular activation. HIV-1-infected and/or immune-activated monocyte-derived macrophages (MDM) and human …

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Reductive Presipitation Of Gold By Dissimilatory Fe(Iii)-Reducing Bacteria And Archaea, Kazem Kashefi, Jason M. Tor, Kelly P. Nevin, Derek Lovley Jul 2001

Reductive Presipitation Of Gold By Dissimilatory Fe(Iii)-Reducing Bacteria And Archaea, Kazem Kashefi, Jason M. Tor, Kelly P. Nevin, Derek Lovley

Kelly Nevin

Studies with a diversity of hyperthermophilic and mesophilic dissimilatory Fe(III)-reducing Bacteria andArchaea demonstrated that some of these organisms are capable of precipitating gold by reducing Au(III) to Au(0) with hydrogen as the electron donor. These studies suggest that models for the formation of gold deposits in both hydrothermal and cooler environments should consider the possibility that dissimilatory metal-reducing microorganisms can reductively precipitate gold from solution.

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The Wasp-Like Protein Scar Regulates Macropinocytosis, Phagocytosis And Endosomal Membrane Flow In Dictyostelium, David J. Seastone, Ed Harris, Lesly A. Temesvari, James E. Bear, Charles L. Saxe, James Cardelli Jul 2001

The Wasp-Like Protein Scar Regulates Macropinocytosis, Phagocytosis And Endosomal Membrane Flow In Dictyostelium, David J. Seastone, Ed Harris, Lesly A. Temesvari, James E. Bear, Charles L. Saxe, James Cardelli

Publications

Scar, a member of the WASp protein family, was discovered in Dictyostelium discoideum during a genetic screen for second-site mutations that suppressed a developmental defect. Disruption of the scar gene reduced the levels of cellular F-actin by 50%. To investigate the role of Scar in endocytosis, phagocytosis and endocytic membrane trafficking, processes that depend on actin polymerization, we have analyzed a Dictyostelium cell line that is genetically null for Scar. Rates of fluid phase macropinocytosis and phagocytosis are significantly reduced in the scar- cell-line. In addition, exocytosis of fluid phase is delayed in these cells and movement of fluid phase …

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Interactions Among Murine Cytomegalovirus Us22 Family Gene Products That Influence Viral Pathogenesis, Zaruhi Karabekian Jul 2001

Interactions Among Murine Cytomegalovirus Us22 Family Gene Products That Influence Viral Pathogenesis, Zaruhi Karabekian

Theses and Dissertations in Biomedical Sciences

Cytomegalovirus (CMV) is a complex, ubiquitous herpesvirus that is characterized by acute, chronic, and latent infections. Monocytes-macrophages are the key target cell type involved in pathogenesis, which is most effectively studied using the murine model of CMV infection. Previously three murine CMV (MCMV) genes (M139, M140, and M141) were identified to regulate viral expression in cultured macrophages and in mice. These genes are members of the US22 gene family with respect to HCMV homology. There is no function assigned to the proteins encoded by these genes. However, deletion of M139, M140, and M141 significantly curtails growth of MCMV in macrophages …

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The Physiology Of Life History Trade-Offs In Animals, Anthony J. Zera, Lawrence G. Harshman Jun 2001

The Physiology Of Life History Trade-Offs In Animals, Anthony J. Zera, Lawrence G. Harshman

Anthony Zera Publications

The functional causes of life history trade-offs have been a topic of interest to evolutionary biologists for over six decades. Our review of life history trade-offs discusses conceptual issues associated with physiological aspects of trade-offs, and it describes recent advances on this topic. We focus on studies of four model systems: wing polymorphic insects, Drosophila, lizards, and birds. The most significant recent advances have been: (a) incorporation of genetics in physiological studies of trade-offs, (b) integration of investigations of nutrient input with nutrient allocation, (c) development of more sophisticated models of resource acquisition and allocation, (d) a shift to more …

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Salivary Acinar Cells From Aquaporin 5-Deficient Mice Have Decreased Membrane Water Permeability And Altered Cell Volume Regulation, Carissa M. Krane, James E. Melvin, Ha-Van Nguyen, Linda Richardson, Jennifer E. Towne, Thomas Doetschman, Anil G. Menon Jun 2001

Salivary Acinar Cells From Aquaporin 5-Deficient Mice Have Decreased Membrane Water Permeability And Altered Cell Volume Regulation, Carissa M. Krane, James E. Melvin, Ha-Van Nguyen, Linda Richardson, Jennifer E. Towne, Thomas Doetschman, Anil G. Menon

Biology Faculty Publications

Aquaporins (AQPs) are channel proteins that regulate the movement of water through the plasma membrane of secretory and absorptive cells in response to osmotic gradients. In the salivary gland, AQP5 is the major aquaporin expressed on the apical membrane of acinar cells. Previous studies have shown that the volume of saliva secreted by AQP5-deficient mice is decreased, indicating a role for AQP5 in saliva secretion; however, the mechanism by which AQP5 regulates water transport in salivary acinar cells remains to be determined. Here we show that the decreased salivary flow rate and increased tonicity of the saliva secreted byAqp5 …

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Combined, Functional Genomic-Biochemical Approach To Intermediary Metabolism: Interaction Of Acivicin, A Glutamine Amidotransferase Inhibitor, With Escherichia Coli K-12, D. R. Smulski, L. L. Huang, M. P. Mccluskey, M. J. Gladnick Reeve, Amy Cheng Vollmer, T. K. Van Dyk, R. A. Larossa Jun 2001

Combined, Functional Genomic-Biochemical Approach To Intermediary Metabolism: Interaction Of Acivicin, A Glutamine Amidotransferase Inhibitor, With Escherichia Coli K-12, D. R. Smulski, L. L. Huang, M. P. Mccluskey, M. J. Gladnick Reeve, Amy Cheng Vollmer, T. K. Van Dyk, R. A. Larossa

Biology Faculty Works

Acivicin, a modified amino acid natural product, is a glutamine analog. Thus, it might interfere with metabolism by hindering glutamine transport, formation, or usage in processes such as transamidation and translation. This molecule prevented the growth of Escherichia coli in minimal medium unless the medium was supplemented with a purine or histidine, suggesting that the HisHF enzyme, a glutamine amidotransferase, was the target of acivicin action. This enzyme, purified from E. coli, was inhibited by low concentrations of acivicin. Acivicin inhibition was overcome by the presence of three distinct genetic regions when harbored on multicopy plasmids. Comprehensive transcript profiling using …

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Il-2 And Antisense Tgf-B1 Gene Therapy Of The H238 Tumor And Analysis Of Tgf-B Receptors, Azim Moiz Mohamedali Jun 2001

Il-2 And Antisense Tgf-B1 Gene Therapy Of The H238 Tumor And Analysis Of Tgf-B Receptors, Azim Moiz Mohamedali

Loma Linda University Electronic Theses, Dissertations & Projects

Transforming growth factor-beta (TGF-p) belongs to a family of immunosuppressive cytokines, capable of regulating macrophages, T, B and NK cells. We have detected the TGF-p transcript being synthesized by H238 cells. This is herpes simplex-Type2 transformed murine fibrosarcoma cell line. The amount of TGF-p formed/106 cells was >2000pg/ml. Previous attempts to control H238 tumorigenicity had sub-optimal efficacies. In addition, studies had shown that the FI238 cell line was not responsive to TGF-p. This project was an attempt to develop an improved modality to reduce H238 tumorigenicity and investigate potential abnormalities in expression of TGF-p receptors in the H238 cell line. …

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Identification Of The Polar Flagellum Genes In Azospirillum Brasilense, Enid Thanna Mckinley Jun 2001

Identification Of The Polar Flagellum Genes In Azospirillum Brasilense, Enid Thanna Mckinley

Loma Linda University Electronic Theses, Dissertations & Projects

Azospirillum brasilenser, a nitrogen fixing rhizobacterium, can colonize plant roots and increase the yield of economically important cereals, such as rice and grasses. This organism has a mixed pattern of flagellation: a single polar flagellum for motility in liquid medium and lateral flagella which might be involved in motility across the root surface and or attachment to the root hairs of plants. Flagella dictate A. brasilense chemotactic ability and motility, which plays an important role in colonization of plant roots. However, nothing is known about the genes that code for the polar flagellum. To study the polar flagellum, different mutants …

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Isolation And Characterization Of A Soluble Nadph-Dependant Fe(Iii) Reductase From Geobacter Sulfurreducens, Franz Kaufmann, Derek Lovley May 2001

Isolation And Characterization Of A Soluble Nadph-Dependant Fe(Iii) Reductase From Geobacter Sulfurreducens, Franz Kaufmann, Derek Lovley

Derek Lovley

NADPH is an intermediate in the oxidation of organic compounds coupled to Fe(III) reduction in Geobacter species, but Fe(III) reduction with NADPH as the electron donor has not been studied in these organisms. Crude extracts of Geobacter sulfurreducens catalyzed the NADPH-dependent reduction of Fe(III)-nitrilotriacetic acid (NTA). The responsible enzyme, which was recovered in the soluble protein fraction, was purified to apparent homogeneity in a four-step procedure. Its specific activity for Fe(III) reduction was 65 micromol. min(-1). mg(-1). The soluble Fe(III) reductase was specific for NADPH and did not utilize NADH as an electron donor. Although the enzyme reduced several forms …

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Human Papillomavirus Virus-Like Particles Are Efficient Oral Immunogens When Coadministered With Escherichia Coli Heat-Labile Enterotoxin Mutant R192g Or Cpg Dna, S. Gerber, C. Lane, Deborah M. Brown, E. Lord, M. Dilorenzo, J. D. Clements, E. Rybicki, A.-L. Williamson, R. C. Rose May 2001

Human Papillomavirus Virus-Like Particles Are Efficient Oral Immunogens When Coadministered With Escherichia Coli Heat-Labile Enterotoxin Mutant R192g Or Cpg Dna, S. Gerber, C. Lane, Deborah M. Brown, E. Lord, M. Dilorenzo, J. D. Clements, E. Rybicki, A.-L. Williamson, R. C. Rose

Nebraska Center for Virology: Faculty Publications

Certain human papillomaviruses (HPVs) cause most cervical cancer, which remains a significant source of morbidity and mortality among women worldwide. HPV recombinant virus-like particles (VLPs) are promising vaccine candidates for controlling anogenital HPV disease and are now being evaluated as a parenteral vaccine modality in human subjects. Vaccines formulated for injection generally are more costly, more difficult to administer, and less acceptable to recipients than are mucosally administered vaccines. Since oral delivery represents an attractive alternative to parenteral injection for large-scale human vaccination, the oral immunogenicity of HPV type 11 (HPV-11) VLPs in mice was previously investigated; it was found …

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Regulation Of Human Immunodeficiency Virus Type 1 Infection, Β-Chemokine Production, And Ccr5 Expression In Cd40l-Stimulated Macrophages: Immune Control Of Viral Entry, Robin L. Cutter, Jialin Zheng, Myhanh Che, Douglas Niemann, Ying Liu, Johnny He, Elaine Thomas, Howard Gendelman May 2001

Regulation Of Human Immunodeficiency Virus Type 1 Infection, Β-Chemokine Production, And Ccr5 Expression In Cd40l-Stimulated Macrophages: Immune Control Of Viral Entry, Robin L. Cutter, Jialin Zheng, Myhanh Che, Douglas Niemann, Ying Liu, Johnny He, Elaine Thomas, Howard Gendelman

Nebraska Center for Virology: Faculty Publications

Mononuclear phagocytes (MP) and T lymphocytes play a pivotal role in the host immune response to human immunodeficiency virus type 1 (HIV-1) infection. Regulation of such immune responses can be mediated, in part, through the interaction of the T-lymphocyte-expressed molecule CD40 ligand (CD40L) with its receptor on MP, CD40. Upregulation of CD40L on CD4+ peripheral blood mononuclear cells during advanced HIV-1 disease has previously been reported. Based on this observation, we studied the influence of CD40L-CD40 interactions on MP effector function and viral regulation in vitro. We monitored productive viral infection, cytokine and β -chemokine production, and β-chemokine receptor …

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Development Of A Genetic System For Geobacter Sulfurreducens, Maddalena V. Coppi, Ching Leang, Steven J. Sandler, Derek Lovley Apr 2001

Development Of A Genetic System For Geobacter Sulfurreducens, Maddalena V. Coppi, Ching Leang, Steven J. Sandler, Derek Lovley

Derek Lovley

Members of the genus Geobacter are the dominant metal-reducing microorganisms in a variety of anaerobic subsurface environments and have been shown to be involved in the bioremediation of both organic and metal contaminants. To facilitate the study of the physiology of these organisms, a genetic system was developed forGeobacter sulfurreducens. The antibiotic sensitivity of this organism was characterized, and optimal conditions for plating it at high efficiency were established. A protocol for the introduction of foreign DNA into G. sulfurreducens by electroporation was also developed. Two classes of broad-host-range vectors, IncQ and pBBR1, were found to be capable of replication …

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