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Full-Text Articles in Molecular Biology
In Vitro Assessment Of The Toxicity Of Cocaine And Its Metabolites In The Human Umbilical Artery, Tessa L. Long
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 …
The Influence Of A Human Repetitive Dna On Genome Stability, Eugenia L. Posey
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 …
Endogenous Alkylglycerol Functions As A Mediator Of Protein Kinase C Activity And Cell Proliferation, Fritz G. Buchanan
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 …
Moraxella (Branhamella) Catarrhalis: A Molecular Epidemiology Study, Lyndell R. Gill
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 …
A Molecular Basis For Erythromycin Sensitivity And Resistance In Escherichia Coli, Harold S. Chittum
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 …
Unusual Structure Of A Human Middle Repetitive Dna, Duminda D. Ratnasinghe
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 …
Characterization Of Two Temperature-Sensitive Mutants Of Escherichia Coli Exhibiting An Altered L22 Ribosomal Protein, Bonnie A. Burnette-Vick
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 …
Mouse Mast Cell Proteases: Induction, Molecular Cloning, And Characterization, Wei Chu
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 …
A Temperature-Sensitive Mutant Of Escherichia Coli Affected In The Alpha Subunit Of Rna Polymerase, Majid Mehrpouyan
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 …
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 …
Characterization Of Kpni Interspersed, Repetitive Dna Sequence Families And Their Association With The Nuclear Matrix, Joseph A. Chimera
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 …