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Articles 271 - 285 of 285

Full-Text Articles in Molecular Biology

Molecular Typing Of Mycobacterial Isolates Cultured From The Tissue Of Inflammatory Bowel Disease (Crohn's Disease) Patients, Leanne M. Adams Jan 2004

Molecular Typing Of Mycobacterial Isolates Cultured From The Tissue Of Inflammatory Bowel Disease (Crohn's Disease) Patients, Leanne M. Adams

Electronic Theses and Dissertations

The role of Mycobacterium avium subsp paratuberculosis (MAP) in the etiology and pathogenesis of inflammatory bowel disease (IBD) including Crohn's Disease (CD), has been investigated. The fastidious characteristics and cross reactivity of MAP with other members in Mycobacteria have produced significant challenges in their detection and identification. In this two year pilot study, an array of three PCR molecular assays based on the detection of sequences from the16S rRNA, IS1245, and IS900 genes, belonging to members of the MAC, have been developed and optimized into a common protocol to be used as a rapid and accurate diagnostic tool regarding M. …

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Cold-Temperature Adaptation Of Muscle Creatine Kinase From An Antartic Teleost (Chaenocephalus Aceratus), Paul Winnard Jr. Dec 2001

Cold-Temperature Adaptation Of Muscle Creatine Kinase From An Antartic Teleost (Chaenocephalus Aceratus), Paul Winnard Jr.

Electronic Theses and Dissertations

The white muscle of Chuenocephulus aceratus, an Antarctic teleost of the Channicthyidae family, has a compromised glycoiytic capacity and this fish cannot depend on glycolysis for rapid ATP generation For C. aceratus, creatine kinase (CK) and phosphocreatine (PCr) reserves comprise the metabolic pathway that may supplement and overcome this deficiency in energy transduction. Two conditions, low glycolytic capacity and evolution in a chronically cold habitat (-1.86°C), give us reason to believe that C. aceratus muscle CK (MMCK) has been subjected to strong selective pressure. Thus, the hypothesis of this thesis is that MMCK fiom C. aceratus white muscle …

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Detection Of Insulin Receptor, Epidermal Growth Factor Receptor, And Interleukin-6 On Individual Mouse Embryos By Immuno-Polymerase Chain Reaction, Kun Xu Dec 2001

Detection Of Insulin Receptor, Epidermal Growth Factor Receptor, And Interleukin-6 On Individual Mouse Embryos By Immuno-Polymerase Chain Reaction, Kun Xu

Electronic Theses and Dissertations

Three series of experiments were conducted to: 1) optimize the conditions for the production of pUC19 plasmid and of biotinylated pUC19 fragments; 2) optimize the conditions for the production of protein A-streptavidin chimera (chimeric protein); and 3) detect soluble antigens [bovine serum albumin (BSA) and interleukin-6 (IL-6)] and membrane-bound antigens [insulin receptor and epidermal growth factor receptor (EGFr)] of mouse embryos by immuno-polymerase chain reaction (I-PCR). The first experimental series, which included bacterial culture, chimeric protein purification, and chimeric protein functional experiments, was performed to investigate the effects of IPTG (isopropyl-β-D-thiogalactopyranoside) induction time and temperature, bacterial culture medium, and protein …

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Quinic Acid-Mediated Induction Of Hypovirulence And A Hypovirulence-Associated Double-Stranded Rna In Rhizoctonia Solani, Chunyu Liu Aug 2001

Quinic Acid-Mediated Induction Of Hypovirulence And A Hypovirulence-Associated Double-Stranded Rna In Rhizoctonia Solani, Chunyu Liu

Electronic Theses and Dissertations

This study is a part of a project focused on the relationship between dsRNA and hypovirulence in R. solani. Hypovirulence refers to a condition in which a pathogen has a drastically reduced ability to cause disease. Rhizoctonia solani is a soil-borne pathogen causing diseases in numerous plants. Phenyl acetic acid (PAA), a metabolite of phenylalanine, causes Rhizoctonia disease symptoms on potato in the absence of the pathogen itself. The amount of PAA produced by a hypovirulent isolate is 10% of that produced by virulent isolates. A 3.6 kb dsRNA (M2) has been shown to be associated with hypovirulence in …

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In Vitro Assessment Of The Toxicity Of Cocaine And Its Metabolites In The Human Umbilical Artery, Tessa L. Long Aug 1998

In Vitro Assessment Of The Toxicity Of Cocaine And Its Metabolites In The Human Umbilical Artery, Tessa L. Long

Electronic Theses and Dissertations

An in vitro model was used to assess the effect of cocaine and its metabolites on the umbilical artery. Objectives were to pharmacologically confirm the presence of adrenergic innervation using tyramine, evaluate the ability of cocaine, benzoylecgonine, norcocaine and cocaethylene to potentiate vasoconstriction by serotonin and norepinephrine, examine the ability of ketanserin to block the enhanced vasoconstriction produced by cocaine, and determine displacement of 3 H-ketanserin by serotonin, norepinephrine, tyramine and mianserin. The vasoconstrictive effect of tyramine (100 μM) was enhanced in the presence of cocaine by 257%. Vasoconstrictive effects of serotonin and norepinephrine were significantly enhanced by cocaine by …

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The Influence Of A Human Repetitive Dna On Genome Stability, Eugenia L. Posey May 1998

The Influence Of A Human Repetitive Dna On Genome Stability, Eugenia L. Posey

Electronic Theses and Dissertations

A uniquely human interspersed repetitive DNA sequence family, the L2Hs, are highly polymorphic in human genomes. Several features of interspersed repeated DNA may contribute to the instability observed. Certain motifs (direct repeats, palindromes, and inverted repeats) comprising L2Hs elements may adopt unusual secondary structures such as cruciforms or hairpins. These motifs have been associated with features of genome instability in recombination, insertions and deletions. The L2Hs elements also are AT-rich (76%) compared to the bulk of human DNA (52%). That their dynamic nature (i.e. polymorphisms) may arise from recombination, insertions and deletions has led to the hypothesis that the L2Hs …

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Endogenous Alkylglycerol Functions As A Mediator Of Protein Kinase C Activity And Cell Proliferation, Fritz G. Buchanan May 1997

Endogenous Alkylglycerol Functions As A Mediator Of Protein Kinase C Activity And Cell Proliferation, Fritz G. Buchanan

Electronic Theses and Dissertations

To explore the possibility that 1-O-alkyl-sn-glycerol (alkylglycerol) may serve a regulatory role in the control of cell proliferation or PKC activity, we examined the ability of alkylglycerol to influence PKC activity and subcellular distribution as well as the ability of alkylglycerol to effect cell proliferation. MDCK cells grown to confluence show a loss of PKC activity associated with the membrane, as reported in fibroblasts. Preconfluent cultures of MDCK cells have a high level of PKC activity associated with the membrane. However, treatment of preconfluent cultures with alkylglycerol causes a reduction of PKC activity. A similar inhibition was observed with alkylglycerol …

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Moraxella (Branhamella) Catarrhalis: A Molecular Epidemiology Study, Lyndell R. Gill May 1995

Moraxella (Branhamella) Catarrhalis: A Molecular Epidemiology Study, Lyndell R. Gill

Electronic Theses and Dissertations

Moraxella (Branhamella) catarrhalis is the third-most-frequently isolated microorganism associated with acute exacerbations of chronic bronchitis in patients during their stay at the Mountain Home VA Medical Center (MHVAMC). In order to develop a practical, epidemiologically-meaningful typing method for M. (B.) catarrhalis, we tested two methods based on analysis of chromosomal DNA for typeability, reproducibility, and ability to differentiate between unrelated strains (discriminatory power, D). M. (B.) catarrhalis isolants from MHVAMC from 7/1/87-6/30/88 were grown overnight in broth and embedded in agarose. DNA was isolated by standard methods. The DNA was subjected to: (1) restriction endonuclease digestion (with either Bgl II …

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A Molecular Basis For Erythromycin Sensitivity And Resistance In Escherichia Coli, Harold S. Chittum Dec 1993

A Molecular Basis For Erythromycin Sensitivity And Resistance In Escherichia Coli, Harold S. Chittum

Electronic Theses and Dissertations

The effect of erythromycin on the 50S ribosomal subunit during cell growth has been extensively investigated. Sucrose density gradient analysis of ribosomes formed in the presence and absence of the drug revealed a 50S specific assembly defect is partially responsible for erythromycin's inhibitory effects on wild type cells. Examination of two erythromycin-resistant mutants of E. coli (N281 and N282) revealed that mutant N281 (L22 mutant) but not N282 (L4 mutant) was assembly defective in the presence of the drug, although only at much higher drug concentrations (300 ug/ml vs. 75 ug/ml for wild type cells). The altered genes from each …

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Unusual Structure Of A Human Middle Repetitive Dna, Duminda D. Ratnasinghe Dec 1993

Unusual Structure Of A Human Middle Repetitive Dna, Duminda D. Ratnasinghe

Electronic Theses and Dissertations

The L2Hs sequences are a polymorphic, interspersed, middle repetitive DNA family unique to human genomes. Genomic fingerprinting indicates that these DNAs vary from one individual to another and between tissues of the same individual. Sequence analysis reveals that they are AT-rich (76%) and contain many unusual sequence arrangements (palindromes, inverted and direct repeats). These sequence properties confer on the L2Hs elements the potential to fold into non-B-form structures, a characteristic of recombination hot spots. To test this hypothesis carbodiimide, osmium tetroxide and S$\sb1$ nuclease were used as single-strand specific probes to study a recombinant plasmid, pN6.4.39, containing a single L2Hs …

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Characterization Of Two Temperature-Sensitive Mutants Of Escherichia Coli Exhibiting An Altered L22 Ribosomal Protein, Bonnie A. Burnette-Vick Aug 1991

Characterization Of Two Temperature-Sensitive Mutants Of Escherichia Coli Exhibiting An Altered L22 Ribosomal Protein, Bonnie A. Burnette-Vick

Electronic Theses and Dissertations

Analysis of E. coli strains SK1047 and SK1048 have shown them to be temperature-sensitive, protein-synthesis deficient. An alteration in ribosomal protein L22 was detected in both strains using two dimensional gel electrophoresis. Protein L22 was purified from both strains by reversed phase high performance liquid chromatography and from two dimensional electrophoretic gels. Purified ribosomal protein L22 was labeled by reductive methylation and used in 23S RNA binding assays with and without ribosomal protein L4. At the permissive temperature, protein L22 from SK1047 bound less efficiently than the control while protein L22 from SK1048 bound as efficiently as the control. At …

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Mouse Mast Cell Proteases: Induction, Molecular Cloning, And Characterization, Wei Chu May 1991

Mouse Mast Cell Proteases: Induction, Molecular Cloning, And Characterization, Wei Chu

Electronic Theses and Dissertations

Tryptase, a mast cell-specific serine protease with trypsin-like specificity, has been identified in a mouse mast cell line (ABFTL-6) based on it's enzymatic activity, inhibition properties, and cross-reactivity to a human mast cell tryptase antibody. The effects of fibroblast-conditioned medium and sodium butyrate on ABFTL-6 mast cell differentiation and tryptase expression have been examined. ABFTL-6 mouse mast cells undergo phenotypic changes upon culturing in media supplemented with fibroblast-conditioned media at 50% or 1 mM sodium butyrate. The induced cells increased in size, had larger and more metachromatic cytoplasmic granules, and increased their total cellular protein about four-fold. Tryptase activity increased …

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A Temperature-Sensitive Mutant Of Escherichia Coli Affected In The Alpha Subunit Of Rna Polymerase, Majid Mehrpouyan Dec 1990

A Temperature-Sensitive Mutant Of Escherichia Coli Affected In The Alpha Subunit Of Rna Polymerase, Majid Mehrpouyan

Electronic Theses and Dissertations

A temperature-sensitive mutant of Escherichia coli affected in the alpha subunit of RNA polymerase has been investigated. Gene mapping and complementation experiments placed the mutation to temperature-sensitivity within the alpha operon at 72 min on the bacterial chromosome. The rate of RNA synthesis in vivo and the accumulation of ribosomal RNA were significantly reduced in the mutant at 44$\sp\circ$C. The thermostability at 44$\sp\circ$C of the purified holoenzyme from mutant cells was about 20% of that of the normal enzyme. Assays with T7 DNA as a template showed that the fraction of active enzyme competent for transcription was reduced as a …

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Isolation And Characterization Of Temperature-Sensitive Protein Synthesis Mutants Of Escherichia Coli By Directed Mutagenesis Of The Defective Bacteriophage Lambda Fus2, Kenton L. Lohman Dec 1985

Isolation And Characterization Of Temperature-Sensitive Protein Synthesis Mutants Of Escherichia Coli By Directed Mutagenesis Of The Defective Bacteriophage Lambda Fus2, Kenton L. Lohman

Electronic Theses and Dissertations

Mutagenesis of the defective transducing bacteriophage lambda fus2 was used to isolate a collection of temperature-sensitive mutants of E. coli in the major ribosomal protein gene cluster. Four mutants were examined in detail. Two of the mutants were resistant to the ribosomal antibiotics neamine and spectinomycin. Another mutant was defective in 50S ribosomal subunit assembly at 42(DEGREES)C. The 30S subunit proteins S17 and S19 were changed in two different mutants. Each protein migrated as a more basic species in two-dimensional gels of ribosomal proteins. Ribosomes from each of the four mutants examined showed a temperature-dependent reduction in translational activity in …

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Characterization Of Kpni Interspersed, Repetitive Dna Sequence Families And Their Association With The Nuclear Matrix, Joseph A. Chimera Dec 1984

Characterization Of Kpni Interspersed, Repetitive Dna Sequence Families And Their Association With The Nuclear Matrix, Joseph A. Chimera

Electronic Theses and Dissertations

The KpnI, 1.2 and 1.5 kb families of interspersed repetitive DNAs from the African green monkey genome were isolated and characterized. Each family contains three populations of segments based on their sequence lengths and susceptibility to cleavage by the restriction enzymes KpnI and RsaI. The first population contains the smallest segments which are susceptible to both KpnI and RsaI cleavage and have fragment lengths of 1.2 kb (1.2 kb family) and 1.5 kb (1.5 kb family) respectively. The members in this population are referred to as KpnI-sensitive segments. The second population contains longer segments (> 2 kb) which represent fusions …

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