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Articles 61 - 90 of 142

Full-Text Articles in Medicine and Health Sciences

Structure And Thermodynamics Of A Conserved U2 Snrna Domain From Yeast And Human, Dipali G. Sashital, Vincenzo Venditti, Courtney G. Angers, Gabriel Cornilescu, Samuel E. Butcher Jan 2007

Structure And Thermodynamics Of A Conserved U2 Snrna Domain From Yeast And Human, Dipali G. Sashital, Vincenzo Venditti, Courtney G. Angers, Gabriel Cornilescu, Samuel E. Butcher

Vincenzo Venditti

The spliceosome is a dynamic ribonucleoprotein complex responsible for the removal of intron sequences from pre-messenger RNA. The highly conserved 5′ end of the U2 small nuclear RNA (snRNA) makes key base-pairing interactions with the intron branch point sequence and U6 snRNA. U2 stem I, a stem–loop located in the 5′ region of U2, has been implicated in spliceosome assembly and may modulate the folding of the U2 and U6 snRNAs in the spliceosome active site. Here we present the NMR structures of U2 stem I from human and Saccharomyces cerevisiae. These sequences represent the two major classes of U2 …

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Distinct Glycan Structures Of Uroplakins Ia And Ib, Bo Xie, Ge Zhou, Shiu-Yung Chan, Ellen Shapiro, Xiant-Peng Kong, Xue-Ru Wu, Tung-Tien Sun, Catherine E. Costello May 2006

Distinct Glycan Structures Of Uroplakins Ia And Ib, Bo Xie, Ge Zhou, Shiu-Yung Chan, Ellen Shapiro, Xiant-Peng Kong, Xue-Ru Wu, Tung-Tien Sun, Catherine E. Costello

Bo Xie

Although it has been shown that mouse uroplakin (UP) Ia, a major glycoprotein of urothelial apical surface, can serve as the receptor for the FimH lectin adhesin of type 1-fimbriated Escherichia coli, the organism that causes a great majority of urinary tract infections, the glycan structure of this native receptor was unknown. Using a sensitive approach that combines in-gel glycosidase and protease digestions, permethylation of released glycans, and mass spectrometry, we have elucidated for the first time the native glycoform structures of the mouse UPIa receptor and those of its non-binding homolog, UPIb, and have determined the glycosylation site occupancy. …

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Keratinizing Ameloblastoma In A 9-Month-Old Llama (Lama Glama), Karyn E. Bird, Jill E. Parker, Claire B. Andreasen, Barbara J. Watrous, Jerry R. Heidel Jan 2004

Keratinizing Ameloblastoma In A 9-Month-Old Llama (Lama Glama), Karyn E. Bird, Jill E. Parker, Claire B. Andreasen, Barbara J. Watrous, Jerry R. Heidel

Claire B. Andreasen

A 9-month-old male llama (Lama glama) was presented because of a rapidly growing mass on the right side of the face. Radiographs revealed a marked expansion of the right caudal face region with bone lysis involving the maxilla and the nasal, lacrimal, zygomatic, and palatine bones. Cytologically, the mass consisted of atypical round to polygonal cells with round nuclei and basophilic cytoplasms that formed acini and rows. Histologically, the mass consisted of anastomosing cords and sheets of neoplastic odontogenic epithelial cells embedded in a loose fibrovascular connective tissue. Single layers of peripheral, polarized, palisading, columnar epithelial cells were seen at …

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Prediction Of Chicken Embryo Lethality With The Avian Escherichia Coli Traits Complement Resistance, Colicin V Production, And Presence Of The Increased Serum Survival Gene Cluster (Iss), Penelope S. Gibbs, John J. Maurer, Lisa K. Nolan, Richard E. Wooley Apr 2003

Prediction Of Chicken Embryo Lethality With The Avian Escherichia Coli Traits Complement Resistance, Colicin V Production, And Presence Of The Increased Serum Survival Gene Cluster (Iss), Penelope S. Gibbs, John J. Maurer, Lisa K. Nolan, Richard E. Wooley

Lisa K. Nolan

Differentiating between virulent and avirulent avian Escherichia coli isolates continues to be a problem for poultry diagnostic laboratories and the study of colibacillosis in poultry. The ability of a laboratory to conduct one simple test that correlates with virulence would simplify studies in these areas; however, previous studies have not enabled researchers to establish such a test. In this study, the occurrence of certain phenotypic and genotypic traits purported to contribute to avian E. coli virulence in 20 avian E. coli isolates was correlated with the results of embryo challenge studies. This analysis was undertaken in an effort to determine …

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Bifunctional Abietadiene Synthase: Mutual Structural Dependence Of The Active Sites For Protonation-Initiated And Ionization-Initiated Cyclizations, Reuben J. Peters, Ora A. Carter, Yan Zhang, Brian W. Matthews, Rodney B. Croteau Mar 2003

Bifunctional Abietadiene Synthase: Mutual Structural Dependence Of The Active Sites For Protonation-Initiated And Ionization-Initiated Cyclizations, Reuben J. Peters, Ora A. Carter, Yan Zhang, Brian W. Matthews, Rodney B. Croteau

Reuben J. Peters

Abietadiene synthase from grand fir catalyzes two sequential, mechanistically distinct cyclizations, of geranylgeranyl diphosphate and of copalyl diphosphate, in the formation of a mixture of abietadiene isomers as the committed step of diterpenoid resin acid biosynthesis. Each reaction is independently conducted at a separate active site residing in what were considered to be structurally distinct domains typical of terpene cyclases. Despite the presence of an unusual 250-residue N-terminal insertional element, a tandem pair of charged residues distal to the insertion was shown to form a functional part of the C-terminal active site. Because abietadiene synthase resembles the ancestral plant terpene …

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Characterization Of Integron Mediated Antimicrobial Resistance In Salmonella Isolated From Diseased Swine, David G. White, Shaohua Zhao, Patrick F. Mcdermott, Sherry Ayers, Sharon Friedman, Julie Sherwood, Missy Breider-Foley, Lisa K. Nolan Jan 2003

Characterization Of Integron Mediated Antimicrobial Resistance In Salmonella Isolated From Diseased Swine, David G. White, Shaohua Zhao, Patrick F. Mcdermott, Sherry Ayers, Sharon Friedman, Julie Sherwood, Missy Breider-Foley, Lisa K. Nolan

Lisa K. Nolan

Forty-two Salmonella isolates obtained from diseased swine were genetically characterized for the presence of specific antimicrobial resistance mechanisms. Twenty of these isolates were characterized as S. Typhimurium DT104 strains. Pulsed-field gel electrophoresis was used to determine genetic relatedness and revealed 20 distinct genetic patterns among the 42 isolates. However, all DT104 isolates fell within 2 closely related genetic clusters. Other Salmonella isolates were genetically grouped together according to serotype. All DT104 isolates displayed the penta-resistance phenotype to ampicillin, chloramphenicol, streptomycin, sulfamethoxazole, and tetracycline. Resistance to sulfamethoxazole, tetracycline, streptomycin, kanamycin, and ampicillin was most common among the non-DT104 Salmonella isolates. All …

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Monoclonal Antibodies To Avian Escherichia Coli Iss, Steven L. Foley, Shelley M. Horne, Catherine W. Giddings, Thomas R. Gustad, Erick D. Handegard, Michael Robinson, Lisa K. Nolan Jan 2003

Monoclonal Antibodies To Avian Escherichia Coli Iss, Steven L. Foley, Shelley M. Horne, Catherine W. Giddings, Thomas R. Gustad, Erick D. Handegard, Michael Robinson, Lisa K. Nolan

Lisa K. Nolan

Escherichia coli infections are a major problem for the poultry industry in the United States. Yet, the virulence mechanisms operative in avian E. coli are poorly understood. In the present studies, monoclonal antibodies (MAbs) have been generated that may facilitate study of the pathogenesis of avian colibacillosis. These MAbs are directed against the Iss protein because results from our laboratory have shown that the possession of iss DNA sequences is strongly correlated with the E. coli implicated in avian colibacillosis. As part of an overall effort to explore the role of iss/Iss in colibacillosis pathogenesis, Iss protein has been purified, …

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Mechanism Of Abietadiene Synthase Catalysis: Stereochemistry And Stabilization Of The Cryptic Pimarenyl Carbocation Intermediates, Reuben J. Peters, Matthew M. Ravn, Robert M. Coates, Rodney Croteau Jun 2002

Mechanism Of Abietadiene Synthase Catalysis: Stereochemistry And Stabilization Of The Cryptic Pimarenyl Carbocation Intermediates, Reuben J. Peters, Matthew M. Ravn, Robert M. Coates, Rodney Croteau

Reuben J. Peters

Abietadiene synthase (AS) catalyzes the complex cyclization-rearrangement of (E,E,E)-geranylgeranyl diphosphate (8, GGPP) to a mixture of abietadiene (1a), double bond isomers 2a-4a and pimaradienes 5a-7a as a key step in the biosynthesis of the abietane resin acid constituents (1b-4b) of conifer oleoresin. The reaction proceeds at two active sites by way of the intermediate, copalyl diphosphate (9). In the second site, a putative tricyclic pimaradiene or pimarenyl(+) carbocation intermediate of undefined C13 stereochemistry and annular double bond position is formed. Three 8-oxy-17-nor analogues of 9 (17 and 19a,b) and three isomeric 15,16-bisnorpimarenyl-N-methylamines (26a-c) were synthesized and evaluated as alternative substrates …

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Complement Resistance, As Determined By Viable Count And Flow Cytometric Methods, And Its Association With The Presence Of Iss And The Virulence Of Avian Escherichia Coli, Lisa K. Nolan, Catherine W. Giddings, Shelley M. Horne, Curt Doetkott, Penelope S. Gibbs, Richard E. Wooley, Steven L. Foley Apr 2002

Complement Resistance, As Determined By Viable Count And Flow Cytometric Methods, And Its Association With The Presence Of Iss And The Virulence Of Avian Escherichia Coli, Lisa K. Nolan, Catherine W. Giddings, Shelley M. Horne, Curt Doetkott, Penelope S. Gibbs, Richard E. Wooley, Steven L. Foley

Lisa K. Nolan

Previous work in our labs has shown that avian Escherichia coli virulence is correlated with resistance to complement. Also, our studies have revealed that the presence of the increased serum survival gene (iss), known to contribute to the complement resistance and virulence of mammalian E. coli, may predict the virulent nature of an avian E. coli isolate. This relationship warrants further research, but further clarification of the relationship among virulence, complement resistance, and iss sequences requires use of complement susceptibility assays. Such assays, unfortunately, are labor-intensive, expensive, and difficult to perform. In the present study, the results of two complement …

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Location Of Increased Serum Survival Gene And Selected Virulence Traits On A Conjugative R Plasmid In An Avian Escherichia Coli Isolate, Timothy J. Johnson, Catherine W. Giddings, Shelley M. Horne, Penelope S. Gibbs, Richard E. Wooley, Jerod Skyberg, Pam Olah, Ronda Kercher, Julie S. Sherwood, Steven L. Foley, Lisa K. Nolan Apr 2002

Location Of Increased Serum Survival Gene And Selected Virulence Traits On A Conjugative R Plasmid In An Avian Escherichia Coli Isolate, Timothy J. Johnson, Catherine W. Giddings, Shelley M. Horne, Penelope S. Gibbs, Richard E. Wooley, Jerod Skyberg, Pam Olah, Ronda Kercher, Julie S. Sherwood, Steven L. Foley, Lisa K. Nolan

Lisa K. Nolan

Avian colibacillosis is a costly disease for the poultry industry. The mechanisms of virulence employed by the etiologic agent of this disease remain ill defined. However, accumulated evidence suggests that complement resistance and the presence of the increased serum survival gene (iss) in an avian Escherichia coli isolate may be indicative of its ability to cause disease. This association of iss with the E. coli implicated in avian disease may mean that iss and/or, perhaps, the genes associated with it are important contributors to avian E. coli virulence. For this reason, we have begun a search for iss's location in …

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Abietadiene Synthase Catalysis:  Conserved Residues Involved In Protonation-Initiated Cyclization Of Geranylgeranyl Diphosphate To (+)-Copalyl Diphosphate, Reuben J. Peters, Rodney B. Croteau Feb 2002

Abietadiene Synthase Catalysis:  Conserved Residues Involved In Protonation-Initiated Cyclization Of Geranylgeranyl Diphosphate To (+)-Copalyl Diphosphate, Reuben J. Peters, Rodney B. Croteau

Reuben J. Peters

Abietadiene synthase catalyzes two sequential, mechanistically distinct cyclization reactions in the formation of a mixture of abietadiene double bond isomers as the committed step in resin acid biosynthesis. Each reaction is carried out at a separate active site residing in a structurally distinct domain, and the reactions are kinetically separable. The first cyclization reaction is initiated by protonation of the terminal double bond of the universal diterpene precursor, geranylgeranyl diphosphate. The pH dependence of the overall reaction is consistent with an acid-base catalytic mechanism, and a divalent metal ion plays a role in this reaction probably by binding the diphosphate …

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Virulence Factors Of Escherichia Coli From Cellulitis Or Colisepticemia Lesions In Chickens, J. S. Jeffrey, Lisa K. Nolan, K. H. Tonooka, S. Wolfe, C. W. Giddings, S. M. Horne, S. L. Foley, A. M. Lynne, J. O. Ebert, L. M. Elijah, G. Bjorklund, S. J. Pfaff-Mcdonough, R. S. Singer, C. Doetkott Jan 2002

Virulence Factors Of Escherichia Coli From Cellulitis Or Colisepticemia Lesions In Chickens, J. S. Jeffrey, Lisa K. Nolan, K. H. Tonooka, S. Wolfe, C. W. Giddings, S. M. Horne, S. L. Foley, A. M. Lynne, J. O. Ebert, L. M. Elijah, G. Bjorklund, S. J. Pfaff-Mcdonough, R. S. Singer, C. Doetkott

Lisa K. Nolan

This study was designed to compare virulence factors of cellulitis-derived Escherichia coli to colisepticemic E. coli in order to clarify whether E. coli associated with cellulitis comprise a unique subset of pathogenic E. coli. Isolates were tested for serotype, capsule, aerobactin production, colicin production, the presence of the iss gene, and serum resistance. Untypable isolates made up the greatest percentage of each group. Serotypes O2 and O78 were the most commonly identified among both groups of isolates. No statistical differences in the distribution of aerobactin or colicin production, capsule, or iss gene were observed between groups. Cluster analysis showed that …

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Cloning And Sequencing Of The Iss Gene From A Virulent Avian Escherichia Coli, Shelley M. Horne, Samantha J. Pfaff-Mcdonough, Catherine W. Giddings, Lisa K. Nolan Mar 2000

Cloning And Sequencing Of The Iss Gene From A Virulent Avian Escherichia Coli, Shelley M. Horne, Samantha J. Pfaff-Mcdonough, Catherine W. Giddings, Lisa K. Nolan

Lisa K. Nolan

Control of colibacillosis is important to the poultry industry. We have found that the presence of a gene for increased serum survival, iss, is strongly correlated with Escherichia coli isolated from birds with colibacillosis. Therefore, the iss gene and its protein product, Iss, are potential targets for detection and control of avian colibacillosis. The iss gene was amplified from a virulent avian E. coli isolate and sequenced. The sequences of the gene and the predicted protein product were compared with those of iss from a human E. coli isolate and lambda bor. The iss gene from the avian E. coli …

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Iss From A Virulent Avian Escherichia Coli, Steven L. Foley, Shelley M. Horne, Catherine W. Giddings, Michael Robinson, Lisa K. Nolan Mar 2000

Iss From A Virulent Avian Escherichia Coli, Steven L. Foley, Shelley M. Horne, Catherine W. Giddings, Michael Robinson, Lisa K. Nolan

Lisa K. Nolan

No single characteristic of virulent avian Escherichia coli has been identified that can be exploited in colibacillosis detection protocols. Research in our lab suggests a strong association between the presence of an iss DNA sequence with an isolate's disease-causing ability. The study presented here focuses on the techniques used in the expression, purification, and characterization of avian E. coli Iss protein. In brief, iss was cloned into an expression vector, the construct was transformed into a protease-deficient E. coli, and expression was induced. The protein was expressed as a glutathione-S-transferase (GST) fusion and purified by affinity chromatography. The GST portion …

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Complement Resistance-Related Traits Among Escherichia Coli Isolates From Apparently Healthy Birds And Birds With Colibacillosis, Samantha J. Pfaff-Mcdonough, Shelley M. Horne, Catherine W. Giddings, Jessica O. Ebert, Curt Doetkott, M. Herbert Smith, Lisa K. Nolan Mar 2000

Complement Resistance-Related Traits Among Escherichia Coli Isolates From Apparently Healthy Birds And Birds With Colibacillosis, Samantha J. Pfaff-Mcdonough, Shelley M. Horne, Catherine W. Giddings, Jessica O. Ebert, Curt Doetkott, M. Herbert Smith, Lisa K. Nolan

Lisa K. Nolan

In this study, 294 Escherichia coli isolates from birds with colibacillosis were collected from disease outbreaks throughout the United States and were compared with 75 fecal E. coli isolates of apparently healthy chickens by their possession of several purported virulence genes, resistance to rough-lipopolysaccharide-specific bacteriophages (rLPSr), and elaboration of capsule. Traits were selected for study on the basis of their association with complement resistance. The genes targeted in this study included those encoding colicin V (cvaC) and the outer membrane proteins TraT (traT), OmpA (ompA), and Iss (iss). No significant differences were found between the two groups of isolates in …

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Enhanced Adhesion Of Pasteurella Multocida To Cultured Turkey Peripheral Blood Monocytes, Ingrid M. Pruimbroom, Richard B. Rimler, Mark R. Ackermann Mar 1999

Enhanced Adhesion Of Pasteurella Multocida To Cultured Turkey Peripheral Blood Monocytes, Ingrid M. Pruimbroom, Richard B. Rimler, Mark R. Ackermann

Mark R. Ackermann

Capsular hyaluronic acid (HA) mediates adhesion of serogroup A strains of Pasteurella multocida to elicited turkey air sac macrophages (TASM). In contrast, freshly isolated turkey peripheral blood monocytes (TPBM) do not bind serogroup A strains. Following culture of TPBM for 6 days in chamber slides, adhesion of the bacteria to TPBM increased gradually. Incubation in chamber slides coated with entactin-collagen IV-laminin (ECL) attachment matrix or exposure to phorbol myristate acetate (PMA) further enhanced the adhesion ofP. multocida to TPBM. Addition of HA, but not Arg-Gly-Asp peptide, to TPBM culture inhibited bacterial adherence similarly to the inhibition previously reported for TASM. …

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Magnetic Resonance Imaging Analysis Of Molecular Mobility During Dissolution Of Poly(Vinyl Alcohol) In Water, Balaji Narasimhan, J. E.M. Snaar, R. W. Bowtell, S. Morgan, C. D. Melia, N. A. Peppas Jan 1999

Magnetic Resonance Imaging Analysis Of Molecular Mobility During Dissolution Of Poly(Vinyl Alcohol) In Water, Balaji Narasimhan, J. E.M. Snaar, R. W. Bowtell, S. Morgan, C. D. Melia, N. A. Peppas

Balaji Narasimhan

Magnetic resonance imaging is used to study changing microstructure and molecular motion during dissolution of poly(vinyl alcohol) (PVA) in water. One-dimensional water concentration profiles were measured as a function of distance from the polymer-solvent interface. Diffusion-weighted profiles were used to calculate the spatial variation of the self-diffusion coefficient of water. The results indicate that diffusion coefficient values decrease toward the glassy core of the polymer. Self-diffusion coefficient values within the dissolving polymer increase with increasing dissolution time, while those near the polymer-solvent interface remain fairly constant. The effect of PVA molecular weight on the dissolution mechanism was investigated, with MÌ„n …

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Normal Reference Intervals And The Effects Of Time And Feeding On Serum Bile Acid Concentrations In Llamas, Claire B. Andreasen, Erwin G. Pearson, Brad B. Smith, Terry C. Gerros, Duane Lassen Apr 1998

Normal Reference Intervals And The Effects Of Time And Feeding On Serum Bile Acid Concentrations In Llamas, Claire B. Andreasen, Erwin G. Pearson, Brad B. Smith, Terry C. Gerros, Duane Lassen

Claire B. Andreasen

Fifty clinically healthy llamas, 0.5–13 years of age (22 intact males, 10 neutered males, 18 females), with no biochemical evidence of liver disease or hematologic abnormalities, were selected to establish serum bile acid reference intervals. Serum samples submitted to the clinical pathology laboratory were analyzed using a colorimetric enzymatic assay to establish bile acid reference intervals. A nonparametric distribution of llama bile acid concentrations was 1–23 mmol/liter for llamas .1 year of age and 10–44 mmol/liter for llamas #1 year of age. A significant difference was found between these 2 age groups. No correlation was detected between gender and bile …

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A Comparison Of Iron Absorption In Adults And Infants Consuming Identical Infant Formulas, Richard F. Hurrell, Lena Davidsson, Manju B. Reddy, Peter Kastenmayer, James D. Cook Jan 1998

A Comparison Of Iron Absorption In Adults And Infants Consuming Identical Infant Formulas, Richard F. Hurrell, Lena Davidsson, Manju B. Reddy, Peter Kastenmayer, James D. Cook

Manju B. Reddy

Fe absorption was estimated in adults and infants from the erythrocyte incorporation of Fe isotopes added to infant formula. Fe absorption was measured in adults using radioisotopes, and in infants with a stable-isotope technique. In adults, the geometric mean Fe absorption from a ready-to-feed soya formula with its native phytic acid content was 2.4%. This increased to 6.0 % (P < 0.05) after almost complete dephytinization. In infants, mean Fe absorption values were 3.9 and 8.7% respectively from the same products (P(O.05). In adults, mean Fe absorption from a spray-dried soya formula containing 110 mg ascorbic acid was 4.1 %, increasing to 5.3 % (P < 0.05) when ascorbic acid was doubled to 220 mgfl. In infants, mean Fe absorption values were 5.7 and 9.5 % (P < 0.05) from the same products. Mean Fe absorption from a milk-based formula was 6.5 % in adults compared with 6.7 % in infants. All meals in the adult and infant studies were fed using an identical meal size of 217 g. Increasing the meal size threefold in adults did not change fractional Fe absorption. Mean Fe absorption values for each meal were lower in adults than in infants, but the relative inhibitory effect of phytic acid and the enhancing effect of ascorbic acid were similar. We conclude that Fe absorption studies in adults can be used to assess the influence of enhancers and inhibitors of Fe absorption in infant formulas fed to infants. Further studies, however, are required to extend these findings to weaning foods and complete meals.

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Further Characterization Of A Complement-Sensitive Mutant Of A Virulent Avian Escherichia Coli Isolate, Theodore J. Kottom, Lisa K. Nolan, Michael Robinson, John Brown, Tom Gustad, Shelley M. Horne, Catherine W. Giddings Dec 1997

Further Characterization Of A Complement-Sensitive Mutant Of A Virulent Avian Escherichia Coli Isolate, Theodore J. Kottom, Lisa K. Nolan, Michael Robinson, John Brown, Tom Gustad, Shelley M. Horne, Catherine W. Giddings

Lisa K. Nolan

An attempt was made to characterize the mechanism of complement resistance operating in a virulent avian Escherichia coli isolate. Using flow cytometry to detect antibody to C3, we found that there was significantly more antibody bound to a complement-sensitive mutant of this wild type than to the parent organism, suggesting that more C3 subunits were bound to the wild type. Neither the wild type nor the mutant degraded C3. Further, the mutant was phagocytosed to a significantly greater degree than the wild type by cultured phagocytes in the presence of C5-deficient serum. These data suggest that the wild type is …

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A Highly Adherent Phenotype Associated With Virulent Bvg+-Phase Swine Isolates Of Bordetella Bronchiseptica Grown Under Modulating Conditions, Karen B. Register, Mark R. Ackermann Dec 1997

A Highly Adherent Phenotype Associated With Virulent Bvg+-Phase Swine Isolates Of Bordetella Bronchiseptica Grown Under Modulating Conditions, Karen B. Register, Mark R. Ackermann

Mark R. Ackermann

The ability of Bvg(-)-phase and Bvg(+)-phase Bordetella bronchiseptica swine isolates, grown under modulating or nonmodulating conditions, to adhere to swine ciliated nasal epithelial cells was determined. When virulent strains were cultivated at 37 degrees C in the Bvg+ phase, numerous adherent bacteria (approximately eight per cell, depending on the strain used) were observed. However, when such strains were grown under modulating conditions (23 degrees C), a significant increase in the level of attachment was seen, suggesting that B. bronchiseptica produces a Bvg-repressed adhesin under these conditions. bvg mutant strains, including an isogenic bvgS mutant, adhered minimally. Western blots indicated that …

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Effects Of Pasteurella Multocida Toxin On Porcine Bone Marrow Cell Differentiation Into Osteoclasts And Osteoblasts, S. M. Gwaltney, R. J. S. Galvin, K. B. Register, R. B. Rimler, Mark R. Ackermann Sep 1997

Effects Of Pasteurella Multocida Toxin On Porcine Bone Marrow Cell Differentiation Into Osteoclasts And Osteoblasts, S. M. Gwaltney, R. J. S. Galvin, K. B. Register, R. B. Rimler, Mark R. Ackermann

Mark R. Ackermann

The effect of Pasteurella multocida toxin (PMT) on porcine osteoclast and osteoblast differentiation was studied using in vitro cell culture systems. When grown in the presence of Vitamin D3, isolated porcine bone marrow cells formed multinucleated cells with features characteristic of osteoclasts. Exposure of bone marrow cells to Vitamin D3 and PMT during growth resulted in formation of increased numbers and earlier appearance of osteoclasts compared to controls. Ultrafiltered medium from PMT-treated cells likewise increased osteoclast numbers, suggesting that a soluble mediator may be involved in the action of PMT. When cell cultures were treated with fluorescein-labeled PMT, fluorescence was …

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Iron Regulatory Protein 1 Is Not Required For The Modulation Of Ferritin And Transferrin Receptor Expression By Iron In A Murine Pro-B Lymphocyte Cell Line, Kevin Schalinske, Kenneth P. Blemings, Daniel W. Steffen, Opal S. Chen, Richard S. Eisenstein Sep 1997

Iron Regulatory Protein 1 Is Not Required For The Modulation Of Ferritin And Transferrin Receptor Expression By Iron In A Murine Pro-B Lymphocyte Cell Line, Kevin Schalinske, Kenneth P. Blemings, Daniel W. Steffen, Opal S. Chen, Richard S. Eisenstein

Kevin Schalinske

Iron regulatory proteins (IRPs) are cytoplasmic RNA binding proteins that are central components of a sensory and regulatory network that modulates vertebrate iron homeostasis. IRPs regulate iron metabolism by binding to iron responsive element(s) (IREs) in the 5* or 3* untranslated region of ferritin or transferrin receptor (TfR) mRNAs. Two IRPs, IRP1 and IRP2, have been identified previously. IRP1 exhibits two mutually exclusive functions as an RNA binding protein or as the cytosolic isoform of aconitase. We demonstrate that the BayF3 family of murine pro-B lymphocytes represents the first example of a mammalian cell line that fails to express IRP1 …

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Decreased Intracellular Survival Of An Fkpa Mutant Of Salmonella Typhimurium Copenhagen, Shelley M. Horne, Theodore J. Kottom, Lisa K. Nolan, Kevin D. Young Feb 1997

Decreased Intracellular Survival Of An Fkpa Mutant Of Salmonella Typhimurium Copenhagen, Shelley M. Horne, Theodore J. Kottom, Lisa K. Nolan, Kevin D. Young

Lisa K. Nolan

The fkpA gene of Salmonella typhimurium encodes a protein similar to the macrophage infectivity potentiator (Mip) proteins of Legionella pneumophila and Chlamydia trachomatis. Because Mip proteins enhance the ability of these intracellular pathogens to survive within macrophages and epithelial cells, we tested whether the product of the fkpA gene would have the same effect on the intracellular growth of a virulent strain of S. typhimurium. By a series of P22 transductions, the fkpA gene of S. typhimurium Copenhagen was replaced with the inactive fkpA1::omega-Cm gene from Escherichia coli, creating the mutant S. typhimurium KY32H1. The Copenhagen and KY32H1 strains were …

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A Porcine Model For The Evaluation Of Virulence Of Bordetella Bronchiseptica, Mark R. Ackermann, K. B. Register, C. Gentry-Weeks, S. M. Gwaltney, T. Magyar Jan 1997

A Porcine Model For The Evaluation Of Virulence Of Bordetella Bronchiseptica, Mark R. Ackermann, K. B. Register, C. Gentry-Weeks, S. M. Gwaltney, T. Magyar

Mark R. Ackermann

Studies of virulence factors of Bordetella bronchiseptica require a suitable system. Such a system was devised in colostrum-deprived, caesarean-derived pigs, aged 7 d. In two different experiments, pigs (n=11) were inoculated intranasally with 106 colony-forming units of the virulent strain 4609. In the same way, further pigs (n=11) were inoculated with a strain (B133) of unknown virulence. No significant differences between 4609 and B133 colonization were seen. However, colonization of the turbinates was significantly higher than that of the trachea, lung and tonsil, and a significantly higher degree of colonization was present at 11 d post-inoculation (PI) than at 15 …

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Large Plasmids Of Avian Escherichia Coli Isolates, Dawn M. Doetkott, Lisa K. Nolan, Catherine W. Giddings, David L. Berryhill Dec 1996

Large Plasmids Of Avian Escherichia Coli Isolates, Dawn M. Doetkott, Lisa K. Nolan, Catherine W. Giddings, David L. Berryhill

Lisa K. Nolan

The plasmid DNA of 30 Escherichia coli isolates from chickens was extracted and examined using techniques designed to isolate large plasmids. This plasmid DNA was examined for the presence of certain known virulence-related genes including cvaC, tra7 and some aerobactin-related sequences. Seventeen of the 30 isolates contained from one to four plasmids greater than 50 kb in size. Eleven of these 17 strains possessed plasmids greater than 100 kb in size. Therefore, E. coli isolates of chickens frequently contain large plasmids, and many of these plasmids are likely to contain virulence related sequences.

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Passage Of Cd18- And Cd18+ Bovine Neutrophils Into Pulmonary Alveoli During Acute Pasteurella Haemolytica Pneumonia, Mark R. Ackermann, M. E. Kehrli Jr., K. A. Brogden Nov 1996

Passage Of Cd18- And Cd18+ Bovine Neutrophils Into Pulmonary Alveoli During Acute Pasteurella Haemolytica Pneumonia, Mark R. Ackermann, M. E. Kehrli Jr., K. A. Brogden

Mark R. Ackermann

CD18 is a subunit for three β2 integrin molecules (Mac-1, p150, 95, LFA-1), which are expressed on the plasma membrane of neutrophils. These molecules mediate passage of neutrophils into sites of infection. In children and animals that lack CD18 expression, neutrophil infiltration is impaired in most tissues. However, in lung, CD18-neutrophils have been identified in the airway spaces during spontaneous episodes of pneumonia. To determine whether CD18 is vital for passage through the pulmonary alveolar wall, lung lobes of cattle with neutrophils that were deficient in CD18 expression (CD18-) and cattle with normal CD18 expression (CD18+) were inoculated with Pasteurella …

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Capsular Hyaluronic Acid-Mediated Adhesion Of Pasteurella Multocida To Turkey Air Sac Macrophages, Ingrid M. Pruimboom, Richard B. Rimler, Mark R. Ackermann, Kim A. Brogden Oct 1996

Capsular Hyaluronic Acid-Mediated Adhesion Of Pasteurella Multocida To Turkey Air Sac Macrophages, Ingrid M. Pruimboom, Richard B. Rimler, Mark R. Ackermann, Kim A. Brogden

Mark R. Ackermann

Serogroup A strains of Pasteurella multocida, the major cause of fowl cholera, are resistant to phagocytosis in nonimmunized birds. Adherence studies with a capsulated strain of P multocida (serotype A:3) and turkey air sac macrophages in culture showed that the bacteria were capable of adhering in large numbers to the macrophages but were not internalized. A noncapsulated variant of the bacteria (serotype -:3) showed little or no adherence and was not internalized. These data indicated that the adhesive properties were caused by the presence of a capsule on the bacteria. The role of capsular hyaluronic acid in adherence to macrophages …

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Comparison Of Polyclonal Antibodies To Three Different Preparations Of Mycobacterium Paratuberculosis In Immunohistochemical Diagnosis Of Johne's Disease In Cattle, Judith R. Stabel, Mark R. Ackermann, Jesse P. Goff Oct 1996

Comparison Of Polyclonal Antibodies To Three Different Preparations Of Mycobacterium Paratuberculosis In Immunohistochemical Diagnosis Of Johne's Disease In Cattle, Judith R. Stabel, Mark R. Ackermann, Jesse P. Goff

Mark R. Ackermann

Polyclonal antisera were raised in rabbits against preparations of live and heat-killed Mycobac-terium paratuberculosis and cell-wall proteins of M. paratuberculosis and were evaluated as diagnostic tools in immunohistochemical staining of bovine tissue. Live preparations of M. paratuberculosis (LMp) were inoculated intraperitoneally or intravenously at 109/ml. Heat-killed M. paratuberculosis (HKMp) was prepared by treatment of bacteria at 85 C for 10 minutes. Cell-wall proteins were isolated from M. paratuberculosis and conjugated to keyhole limpet hemocyanin to improve antigenicity (KLH-CWPMp). The HKMp and KLH-CWPMp preparations were emulsified in incomplete Freund's adjuvant before subcutaneous inoculation of rabbits. Antibody titers in the terminal blood …

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Analysis Of Plasmids Cloned From A Virulent Avian Escherichia Coli And Transformed Into Escherichia Coli Dh5Α, Richard E. Wooley, Penelope S. Gibbs, Harry W. Dickerson, John Brown, Lisa K. Nolan Sep 1996

Analysis Of Plasmids Cloned From A Virulent Avian Escherichia Coli And Transformed Into Escherichia Coli Dh5Α, Richard E. Wooley, Penelope S. Gibbs, Harry W. Dickerson, John Brown, Lisa K. Nolan

Lisa K. Nolan

Three of four plasmids from a virulent wild-type avian Escherichia coli were cloned or transformed into an avirulent laboratory recipient E. coli DH5a and tested for the ability to confer a virulence phenotype. The three plasmids transformed into E. coli DH5a were 5, 6, and 56 kb. A fourth plasmid of 64 kb was not successfully transformed. Parameters used to measure virulence included presence of type 1 pili and a smooth lipopolysaccharide (LPS) layer, motility, production of Colicin V, resistance to host complement, and embryo lethality. The 5-kb plasmid encoded for ampicillin resistance, whereas the 6-kb plasmid encoded for tetracycline …

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