Life Sciences Commons^™

Geobacter Sulfurreducens Can Grow With Oxygen As A Terminal Electron Acceptor, W. C. Lin, Maddalena V. Coppi, Derek Lovley

Derek Lovley

Geobacter sulfurreducens, previously classified as a strict anaerobe, tolerated exposure to atmospheric oxygen for at least 24 h and grew with oxygen as the sole electron acceptor at concentrations of 10% or less in the headspace. These results help explain how Geobacter species may survive in oxic subsurface environments, being poised to rapidly take advantage of the development of anoxic conditions.

Phenotype Of The Triplo-Lethal Locus Of Drosophila Melanogaster And Its Suppression By Hyperoxia, Laura K. Smoyer, Douglas R. Dorer, Kenneth W. Nickerson, Alan C. Christensen

Papers in Microbiology

The Triplo-lethal locus (Tpl) of Drosophila is both triplo-lethal and haploinsufficient, but the function of the locus is unknown. We have examined Tpl-aneuploid embryos and find that, in both trisomics and monosomics, the midgut shows extensive cell death and the tracheae are abnormal. Shortly thereafter, all tissues die. PCR-based genotyping of individual embryos and larvae show that this phenotype occurs in the trisomics after hatching and in the monosomics before hatching. Weak alleles of the interacting gene Su(Tpl) delay the death of Tpl trisomics, but they still show the same tracheal and midgut phenotypes before dying. Hyperoxia (45% oxygen) …

Optimization Of Bacterial Luciferase For Expression In Mammalian Cells, Stacey Swiger Patterson

Doctoral Dissertations

This study describes the optimization of expression of the bacterial luciferase enzyme in mammalian cells. Previous attempts to express this heterodimeric enzyme complex in mammalian cells have been met with only modest success. In this research effort, several vector formats were evaluated to fully determine the optimal format for the expression of these genes. It was determined that the bacterial luciferase enzyme produced optimal bioluminescence in mammalian cells when the genes were cloned and expressed as a bicistronic transcript fused with an internal ribosomal entry site (IRES). To optimize the enzyme expression further, a novel approach to codon optimize the …

Transgenic Approaches To Study Nodulation In The Model Legume, Lotus Japonicus, Crystal Bickley Mcalvin

Doctoral Dissertations

The soybean apyrase, GS52, characterized as an early nodulin, was further investigated for its possible role in nodulation. GS52 is expressed in roots and localized to the plasma membrane. In addition, it is rapidly induced upon rhizobial inoculation. Treatment of soybean roots with anti-GS52 antibodies blocked nodulation by Bradyrhizobium japonicum. Transgenic Lotus japonicus plants were generated expressing gs52 and showed enhanced nodulation and infection thread formation upon inoculation with Mesorhizobium loti that correlated with expression of the transgene. Surprisingly, expression of GS52 allowed L. japonicus plants to be infected but not nodulated by B. japonicum, the natural symbiont of soybean. …

Cd43 Modulates Severity And Onset Of Experimental Autoimmune Encephalomyelitis., Thandi M. Onami, M. L. Ford, A. Sperling, R. Ahmed, B. D. Evavold

Microbiology Publications and Other Works

Experimental autoimmune encephalomyelitis (EAE) is a mouse model of multiple sclerosis characterized by infiltration of activated CD4(+) T lymphocytes into tissues of the CNS. This study investigated the role of CD43 in the induction and progression of EAE. Results demonstrate that CD43-deficient mice have reduced and delayed clinical and histological disease severity relative to CD43(+/+) mice. This reduction was characterized by decreased CD4(+) T cell infiltration of the CNS of CD43(-/-) mice but similar numbers of Ag-specific T cells in the periphery, suggesting a defect in T cell trafficking to the CNS. The absence of CD43 also affected cytokine production, …

Cd43 Modulates Severity And Onset Of Experimental Autoimmune Encephalomyelitis., Thandi M. Onami, M. L. Ford, A. Sperling, R. Ahmed, B. D. Evavold

Thandi M. Onami

Experimental autoimmune encephalomyelitis (EAE) is a mouse model of multiple sclerosis characterized by infiltration of activated CD4(+) T lymphocytes into tissues of the CNS. This study investigated the role of CD43 in the induction and progression of EAE. Results demonstrate that CD43-deficient mice have reduced and delayed clinical and histological disease severity relative to CD43(+/+) mice. This reduction was characterized by decreased CD4(+) T cell infiltration of the CNS of CD43(-/-) mice but similar numbers of Ag-specific T cells in the periphery, suggesting a defect in T cell trafficking to the CNS. The absence of CD43 also affected cytokine production, …

Molecular Padlock Assay Of Crude Plant Leaf Extracts For Detection Of Listeria Monocytogenes, Allison L. Hurlburt

Electronic Theses and Dissertations

A molecular padlock assay was developed and assessed for detection of Listeria monocytogenes that operated in crude plant extracts. The molecular padlock assay was developed by Liu et al. (1996) and modified by Lizardi et al. (1998). We further modified and described a padlock probe that detected L. monocytogenes oligonucleotide, cDNA and genomic DNA containing a 16s rRNA sequence (GenBank Acc. No. X56 153). This technique was effective in the presence of crude potato leaf extracts in contrast to PCR, which failed to detect the presence of L. monocytogenes targets in crude leaf extracts. Sensitivity of the padlock procedure was …

Molecular Characterization Of Zebrafish Interferon, Mx, And Mx Promoter, Stephen Altmann

Electronic Theses and Dissertations

Type I interferons (IFNs) represent a family of biological molecules whose antiviral, antitumor, and immunomodulatory role is well known. IFNs were first identified in the 1950's and have since been used extensively for the treatment of various cancers, and viral infections. In order to more fully characterize the IFN response, it is often necessary to use animal models. Although the mouse has been used extensively for IFN studies, a lower order vertebrate model is also desirable, as it would provide information about the structure and function of a more ancestral IFN. To this end, herein is described the cloning and …

The Endocrine Regulation Of Wing Polymorphism In Insects: State Of The Art, Recent Surprises, And Future Directions, Anthony J. Zera

Anthony Zera Publications

The endocrine mechanisms controlling the development and reproduction of flight-capable (long-winged) and flightless (short-winged or wingless) morphs of wing-polymorphic insects have been intensively investigated. The "classical model," put forward in the early 1960s, postulates that morph-specific differences in development and reproduction are caused by variation in the titers of juvenile hormone (JH) and/or ecdysone. Despite decades of study, the importance of these hormones in regulating wing polymorphism in aphids and planthoppers remains uncertain. This uncertainly is largely a consequence of technical and size constraints which have severely limited the types of endocrine approaches that can be used in these insects. …

A Hot-Vent Gastropod With Iron Sulfide Biomineralized Dermal Sclerites, Anders Waren, Stefan Bengtson, Shana K. Goffredi, Cindy L. Van Dover

Shana Goffredi

No abstract provided.

Comprehensive Analysis Of Class I And Class Ii Hla Antigens And Chronic Hepatitis B Virus Infection, Chloe L. Thio, David L. Thomas, Peter Karacki, Xiaojiang Gao, Darlene Marti, Richard A. Kaslow, James J. Goedert, Margaret Hilgartner, Steffanie A. Strathdee, Priya Duggal, Stephen J. O'Brien, Jacquie Astemborski, Mary Carrington

Biology Faculty Articles

Following an acute hepatitis B virus (HBV) infection, clearance or persistence is determined in part by the vigor and breadth of the host immune response. Since the human leukocyte antigen system (HLA) is an integral component of the immune response, we hypothesized that the highly polymorphic HLA genes are key determinants of viral clearance. HLA class I and II genes were molecularly typed in 194 Caucasian individuals with viral persistence and 342 matched controls who had cleared the virus. A single class I allele, A*0301 (odds ratio [OR], 0.47; 95% confidence interval [CI], 0.30 to 0.72; P = 0.0005) was …

Subpopulations Of Equine Infectious Anemia Virus Rev Coexist In Vivo And Differ In Phenotype, Prasith Baccam, Robert J. Thompson, Yuxing Li, Wendy O. Sparks, Michael Belshan, Karin S. Dorman, Yvonne Wannemuehler, J. Lindsay Oaks, James L. Cornette, Susan Carpenter

Nebraska Center for Virology: Faculty Publications

Lentiviruses exist in vivo as a population of related, nonidentical genotypes, commonly referred to as quasispecies. The quasispecies structure is characteristic of complex adaptive systems and contributes to the high rate of evolution in lentiviruses that confounds efforts to develop effective vaccines and antiviral therapies. Here, we describe analyses of genetic data from longitudinal studies of genetic variation in a lentivirus regulatory protein, Rev, over the course of disease in ponies experimentally infected with equine infectious anemia virus. As observed with other lentivirus data, the Rev variants exhibited a quasispecies character. Phylogenetic and partition analyses suggested that the Rev quasispecies …

Initial State Of The Drosophila Eye Before Dorsoventral Specification Is Equivalent To Ventral, Amit Singh, Kwang-Wook Choi

Biology Faculty Publications

Dorsoventral (DV) patterning is crucial for eye development in invertebrates and higher animals. DV lineage restriction is the primary event in undifferentiated early eye primordia of Drosophila. InDrosophila eye disc, a dorsal-specific GATA family transcription factor pannier (pnr) controls Iroquois-Complex (Iro-C) genes to establish the dorsal eye fate whereas Lobe (L), which is involved in controlling a Notch ligand Serrate (Ser), is specifically required for ventral growth. However, fate of eye disc cells before the onset of dorsal expression of pnr and Iro-C is not known. We show that L/Ser …

Comparison Of Double Disc And Combined Disc Method For The Detection Of Extended Spectrum Beta Lactamases In Enterobacteriaceae, K Jabeen, A Zafar, R Hasan

Department of Pathology and Laboratory Medicine

Objective:
To compare double disc approximation and combined disc method for their ability to detect extended spectrum b lactamase (ESBL) production in enterobacteriaceae and determine the percentage of isolates which are falsely reported as sensitive in absence of ESBL detection, in a clinical microbiology laboratory of a tertiary care hospital between September-October 2002.
Methods:
Selected isolates were identified according to standard biochemical tests. Disc susceptibility tests were performed according to NCCLS. ESBL detection by combined disc [cefotaxime (30 ug) versus cefotaxime plus clavulanate (30+10 ug)] was compared with detection using double discs [amoxy-clavulanic acid (20+10 ug) and aztreonam (30 ug) …

Electron Transfer By Desulfobulbus Propionicus To Fe(Iii) And Graphite Electrodes, Derek Lovley, Dawn E. Holmes, Daniel R. Bond

Derek Lovley

Desulfobulbus propionicus was able to grow with Fe(III), the humic acids analog anthraquinone-2,6-disulfonate (AQDS), or a graphite electrode as an electron acceptor. These results provide an explanation for the enrichment of Desulfobulbaceae species on the surface of electrodes harvesting electricity from anaerobic marine sediments and further expand the diversity of microorganisms known to have the ability to use both sulfate and Fe(III) as an electron acceptor.

Morph-Dependent Fatty Acid Oxidation In A Wing-Polymorphic Cricket: Implications For The Trade-Off Between Dispersal And Reproduction, Anthony J. Zera, Zhangwu Zhao

Anthony Zera Publications

Although a considerable amount of information is available on the ecology and physiology of wing polymorphism, much less is known about the biochemical–genetic basis of morph specialization for dispersal versus reproduction. Previous studies have shown that the dispersing morph of the wing-polymorphic cricket, Gryllus firmus, prioritizes the accumulation of triglyceride flight fuel over ovarian growth, while the opposite occurs in the flightless morph during the first week of adulthood. In this study, we compared the in vivo rate of lipid oxidation between genetic stocks of flight-capable versus flightless morphs to determine the role of lipid catabolism in morph specialization …

Single-Cell Enumeration Of An Uncultivated Tm7 Subgroup In The, Cleber C. Ouverney, Gary C. Armitage, David A. Relman

Faculty Publications, Biological Sciences

Specific oligonucleotide hybridization conditions were established for single-cell enumeration of uncultivated TM7 and IO25 bacteria by using clones expressing heterologous 16S rRNA. In situ analysis of human subgingival crevice specimens revealed that a greater proportion of samples from sites of chronic periodontitis than from healthy sites contained TM7 subgroup IO25. In addition, IO25 bacterial cells from periodontitis site samples were more abundant and fourfold longer than IO25 cells from healthy site samples.

Genome Of Bovine Herpesvirus 5, Gustavo A. Delhon, M. P. Moraes, Z. Lu, C. L. Afonso, E. F. Flores, R. Weiblen, G. F. Kutish, D. L. Rock

Nebraska Center for Virology: Faculty Publications

Here we present the complete genomic sequence of bovine herpesvirus 5 (BHV-5), an alphaherpesvirus responsible for fatal meningoencephalitis in cattle. The 138,390-bp genome encodes 70 putative proteins and resembles the α2 subgroup of herpesviruses in genomic organization and gene content. BHV-5 is very similar to BHV-1, the etiological agent of infectious bovine rhinotracheitis, as reflected by the high level of amino acid identity in their protein repertoires (average, 82%). The highest similarity to BHV-1 products (≥95% amino acid identity) is found in proteins involved in viral DNA replication and processing (UL5, UL15, UL29, and UL39) and in virion proteins (UL14, …

Renal Carcinoid Tumour, Z Ahmad, N Yaqoob, S Muzaffar, A S. Hussainy, S H. Hasan

Department of Pathology and Laboratory Medicine

No abstract provided.

Renal Teratoma: A Rare Entity, N Yaqoob, Z Ahmed, N Jafri, S Muzaffar, S H. Hasan

Department of Pathology and Laboratory Medicine

No abstract provided.

Characterization Of Spy1600 A Putative Hyaluronidase Gene In Group A Streptococci, Karin M. Berling

Biological Sciences Theses & Dissertations

Group A Streptococci (GAS), also known as Streptococcus pyogenes, can cause a variety of human diseases ranging from asymptomatic to life threatening. Exactly how a single type of organism is able to inflict such a multitude of diseases remains to be fully understood. One possibility includes the large number of secreted virulence factors expressed by the organism. The recent sequencing of three streptococcal genomes has indicated the existence of several previously unknown genes, some of which may encode possible virulence factors. Among these is Spy1600, which based on its sequence similarities has been proposed to encode a hyaluronidase, a …

Cultivation Of Tropheryma Whipplei From Cerebrospinal Fluid, Matthias Maiwald, Axel Von Herbay, David N. Fredricks, Cleber C. Ouverney, Jon C. Kosek, David A. Relman

Faculty Publications, Biological Sciences

Whipple disease (WD) is a systemic disorder caused by the bacterium Tropheryma whipplei. Since the recognition of a bacterial etiology in 1961, many attempts have been made to cultivate this bacterium in vitro. It was eventually isolated, in 2000, from an infected heart valve, in coculture with human fibroblasts. Here we report the isolation of 2 new strains of T. whipplei from cerebrospinal fluid (CSF) of 2 patients with intestinal WD but no neurological signs or symptoms. One culture-positive specimen was obtained before treatment; the other was obtained 12 months after discontinuation of therapy, at a time of intestinal remission. …

Bovine Herpes Virus Gd Protein Produced In Plants Using A Recombinant Tobacco Mosaic Virus (Tmv) Vector Possesses Authentic Antigenicity, D. M. Pérez Filgueira, P.I. Zamorano, M. G. Dominguez, O. Taboga, M. P. Del Medico Zajac, M. Puntel, S. A. Romera, Thomas Jack Morris, M. V. Borca, A. M. Sadir

Papers in Virology

A tobacco mosaic virus (TMV)-based vector was utilized for expression of a cytosolic form of the bovine herpesvirus type 1 (BHV-1) protein glycoprotein D (gDc). Nicotiana benthamiana plants were harvested 7 days after inoculation with RNA transcripts derived from the TMV-gDc recombinant virus. Recombinant gDc protein of expected electrophoretic mobility accumulated in inoculated leaves to a concentration of about 20 μg/g of fresh leaf tissue. Oil-based vaccines were formulated with crude foliar extracts to immunize mice parentally. After a single injection, animals developed a sustained and specific response to both the isolated gD and native virus particles. Cattle vaccinated with …

Spectrum Of Cutaneous Appendage Tumors At Aga Khan University Hospital, N Yaqoob, Z Ahmad, S Muzaffar, M S. Gill, I N. Soomro, S H. Hasan

Department of Pathology and Laboratory Medicine

Objective: To determine the frequency of various types of cutaneous appendage tumors in our practice.
Method: This is a partly retrospective and partly prospective study conducted at the Department of Pathology, Histopathology Section, The Aga Khan University Hospital, Karachi between 1st January 1997 and 31st December 2001.
Results: One hundred sixty six skin appendage tumors were diagnosed during the study period. 87.3% were benign, while 12.6% were malignant. Male female ratio was almost equal. Mean age was 41.72 years. 37.34% showed eccrine differentiation, 14.45% showed apocrine differentiation and 41.56% showed pilosebaceous differentiation, 6.62% exhibited mixed differentiation. The 5 commonest tumors …

Evaluation Of Microbial Inocula For Initiation Of Biological Life Support Systems For Wastewater Processing On Long Term And Deep Space Missions, Kimberly L. Cook

Doctoral Dissertations

A fundamental goal of ecological research is to better understand the relationship between structural diversity, functional diversity and ecosystem stability. Insight into the mechanisms that regulate microbial ecosystem function should provide important new information to improve system control for ecological, agricultural and biotechnological applications that depend on microbial processes. For example, defined microbial consortia have been employed to improve plant growth through enhanced nutrient uptake, production of plant growth promoting hormones or control of pathogens. However, a lack of consistency of results in field application has limited the widespread use of microbial inoculants. A major goal in rhizosphere studies, therefore, …

The Virulence Activator Apha Links Quorum Sensing To Pathogenesis And Physiology In Vibrio Cholerae By Repressing The Expression Of A Penicillin Amidase Gene On The Small Chromosome, Gabriela Kovacikova, Wei Lin, Karen Skorupski

Dartmouth Scholarship

Activation of the tcpPH promoter on the Vibrio pathogenicity island by AphA and AphB initiates the Vibrio cholerae virulence cascade and is regulated by quorum sensing through the repressive action of HapR on aphA expression. To further understand how the chromosomally encoded AphA protein activates tcpPH expression, site-directed mutagenesis was used to identify the base pairs critical for AphA binding and transcriptional activation. This analysis revealed a region of partial dyad symmetry, TATGCA-N6-TNCNNA, that is important for both of these activities. Searching the V. cholerae genome for this binding site permitted the identification of a second one upstream of a …

Quorum Sensing In Candida Albicans: Probing Farnesol’S Mode Of Action With 40 Natural And Synthetic Farnesol Analogs, Roman Shchepin, Jacob M. Hornby, Erin Burger, Timothy Niessen, Patrick H. Dussault, Kenneth Nickerson

Kenneth Nickerson Papers

The dimorphic fungus Candida albicans produces extracellular farnesol (3,7, 11-trimethyl-2,6,10-dodecatriene- 1-ol) which acts as a quorum-sensing molecule (QSM) to suppress filamentation. Of four possible geometric isomers of farnesol, only the E,E isomer possesses QSM activity. We tested 40 natural and synthetic analogs of farnesol for their activity in an N-acetylglucosamine-induced differentiation assay for germ tube formation (GTF). Modified structural features include the head group, chain length, presence or absence of the three double bonds, substitution of a backbone carbon by S, O, N, and Se heteroatoms, presence or absence of a 3-methyl branch, and the bulkiness of the hydrophobic …

Expression Of Luxi In Bacillus Thuringiensis For The Development Of A Bacteriophage-Based Bioreporter System For The Detection Of Anthrax, Amy Tomaszewski

Masters Theses

In light of the recent anthrax attacks of 2001in the United States, the need for a rapid, sensitive, and real-time surveillance system for detecting pathogenic bacteria has become readily apparent. A proof-of-principle study involving development of a bacteriophage-based bioreporter system for the detection of Bacillus anthracis spores has been initiated in the surrogate strain Bacillus thuringiensis 4Q7. The final goal of the project is to develop an engineered bacteriophage with the luxI gene from Vibrio fischeri, which upon infection of the target organism, would produce the signal molecule, N-(3-oxohexanoyl)-L-homoserine lactone (OHHL), capable of inducing bioluminescence in a neighboring …

Plasmepsin 4, The Food Vacuole Aspartic Proteinase Found In All Plasmodium Spp. Infecting Man, John B. Dame, Charles A. Yowell, Levi Omara-Opyene, Jane M. Carlton, Roland A. Cooper, Tang Li

Roland A. Cooper

Isolation And Characterization Of Thermophilic, Calcium-Precipitating Bacteria Form Calcite Deposits At Yucca Mountain, Terry Ann Else, Curtis R. Pantle, Penny S. Amy, Mark P. Buttner, Amy J. Smiecinski

Publications (YM)

Calcite deposits, composed of a mixture of calcium carbonate and silicon dioxide, were found in fractures and small cavities within the welded tuff of Yucca Mountain. This research investigation involves determining the presence of thermophilic, calciumprecipitating bacteria within these deposits. The possible existence of thermophilic bacteria may help to resolve the issue of whether these calcite deposits formed from precipitation of dissolved calcium carbonate in rain water transported from the overlying soil environment or as a result of upwelling of geothermally-heated waters transported from below the mountain. Evidence for microbially-influenced calcite precipitation in these deposits is indicated by the presence …