Digital Commons Network^™

The Role Of Pr Otein Synthesis In The Adhesion Ofchinese Hamster Lung Cells, Ali̇ Yildirim

Turkish Journal of Medical Sciences

In order to determine the effect of endogenous protein synthesis on CHL cell adhesion, the initial attachment of these cells to tissue culture dishes was measur ed in the pr esence of 1µgml -1 emetine, in which protein synthesis was inhibited by 97% as determined by labeling the cells with [ 3 5 S]-methio-nine. In the pr esence of this drug, 80% of cells were able to adhere after 2 hours of incubation at 37 o C, while, during the same period, 97% of the contr ol cells became attached. Cells str engthen their adhesion foll owinginitial attachment, spreading and …

Biomimetic Preparation Of Ha Powders At 37°C In Urea-And Enzyme Urease-Containing Synthetic Body Fluids, Defne Bayraktar, A. Cüneyt Taş

Turkish Journal of Medical Sciences

An important inorganic phase of synthetic bone applications, calcium hydroxyapatite (HA, Ca_10 (PO_ 4 ) 6_(OH_2 ), was prepared as a single-phase and sub-micron bioceramic powder. Carbonated HA powders were synthesized from calcium nitrate tetrahydrate and di-ammonium hydrogen phosphate salts dissolved in synthetic body fluid (SBF) solutions, containing urea (H_2 NCONH_2 ) and enzyme urease, under the biomimetic conditions of 37°C and pH 7.4, with a novel chemical precipitation technique. These powders were also found to contain trace amounts of Na and Mg ions in them, intentionally incorporated by using SBF solutions, instead of pure water, during their synthesis. The …

Production And Characterization Of Monoclonal Anti-Ovalbumin Antibodies, Mehmet Zi̇ya Doymaz, Hakan Bulut, Aykut Özdarendeli̇, Yusuf Bolat

Turkish Journal of Medical Sciences

In this study, the results of anti- ovalbumin (OVA) monoclonal antibody production and characterization are reported. Splenocytes from OVA-hyperimmune Balb/C mouse were fused with F0 myeloma cells and resulting hybridoma cells were selected in hypoxanthine-aminopterine-thymidine containing medium. A total of 37 HAT resistant hybridomas were obtained. Upon testing the hybridoma supernatants in OVA and mouse immunoglobulin G specific enzyme-linked immunosorbent assays, we observed that two of the hybridomas secreted OVA specific antibodies. The hybridomas produced IgG class antibodies. The hybridomas were grown and the supernatants from the cultures were also tested in a Western Blot assay. The results of ELISA …

Investigations Of The Absorption And Metabolismof Antioxidant Flavonols, Abdul Aziz Azlina

Student Works (2000-2009)

Flavonols are polyphenols, secondary plant metabolites commonly found in plants and foods of plant origin. They have widespread biological properties in the human body. The recent discovery of their potential antioxidant activities has prompted extensive research. Flavonols particularly quercetin are potent antioxidants with higher antioxidant properties than the well known antioxidant vitamins C and E. Several epidemiology studies have demonstrated a strong inverse association between flavonoid intake and risk of coronary heart disease. The association with cancer is less defined with only some studies showing an inverse association and others not. In view of their potential to act as antioxidants …

Isovolumic Regulation In Nervous Tissue: A Novel Mechanism Of Cell Volume Regulation, O. Quesada, R. Franco, K. Hernandez-Fonseca, K. Tuz

School of Veterinary and Biomedical Sciences: Faculty Publications

Cell volume regulation is a property present in most animal cell lineages that allows them to recover their original volume after events of swelling or shrinkage. Such events can be caused by changes in external osmolarity or to osmotic gradients generated during normal cell functioning.4,6 The mechanism of cell volume regulation involves transmembrane fluxes of osmotically active solutes in the necessary direction to counteract the net gain or loss of intracellular water.9 The process through which cells recover their normal volume after swelling is named Regulatory Volume Decrease (RVD). This consists of the efflux of inorganic osmolytes, such as K …

The Global Carbon Metabolism Regulator Crc Is A Component Of A Signal Transduction Pathway Required For Biofilm Development By Pseudomonas Aeruginosa, George A. O'Toole, Karine A. Gibbs, Paul W. Hager, Paul V. Phibbs, Roberto Kolter

Dartmouth Scholarship

The transition from a planktonic (free-swimming) existence to growth attached to a surface in a biofilm occurs in response to environmental factors, including the availability of nutrients. We show that the catabolite repression control (Crc) protein, which plays a role in the regulation of carbon metabolism, is necessary for biofilm formation in Pseudomonas aeruginosa. Using phase-contrast microscopy, we found that a crc mutant only makes a dispersed monolayer of cells on a plastic surface but does not develop the dense monolayer punctuated by microcolonies typical of the wild-type strain. This is a phenotype identical to that observed in mutants …

Telomerase Activity In Human Preimplantation Embryos, Diane Lynne Wright

Theses and Dissertations in Biomedical Sciences

Telomerase, a ribonucleoprotein, has been described as an essential component of highly proliferative cells, which stabilizes the telomeres and avoids cellular senescence. Telomerase has been identified in various embryonic cell stages, hematopoietic cells, and in >85% of tumor tissue biopsies analyzed. The ability to measure the potential to proliferate successfully could provide an objective measure of an embryo's quality. The objectives of this study were to modify the telomeric repeat amplification protocol (TRAP) assay system for increased sensitivity to allow detection of telomerase activity in the single cell of an oocyte and embryo, obtain telomerase activity levels for the oocyte …

Screening For Mutants In The Output Pathway Of The Circadian Clock In Chlamydomonas Reinhardtii, Wei Yuan

Masters Theses & Specialist Projects

The circadian clock is a basic component of biological systems and has been found in many organisms. It is composed by three major components: the input pathway, the oscillator and the output pathway. The purpose of this research is to study the output pathway of the circadian clock in Chlamydomonas reinhardtii strain Carnil by screening mutants, which were generated by insertional mutagenesis via glass bead transformation. The plasmid pSP124S containing the ble marker was used to introduce mutations. The CABII-1 gene has been reported to show a circadian rhythm in expression. The reporter gene ARS2 that was transcriptionally fused to …

Enhanced Apoptosis Mediates Inhibition Of Ebv-Transformed Lymphoblastoid Cell Line Proliferation By Curcumin., D Ranjan, T D Johnston, K S Reddy, G Wu, Subbarao Bondada, C Chen

Microbiology, Immunology, and Molecular Genetics Faculty Publications

BACKGROUND: Epstein-Barr virus (EBV)-associated B-cell lymphomas occur more frequently in immunodeficient states such as organ transplantation and HIV infection. We have previously reported that B cell immortalization with EBV was promoted by cyclosporin A (CyA) and that curcumin (Cur), a natural phenol with known antioxidant and antitumor properties, blocked EBV-induced B cell immortalization. In the following experiments we show that Cur inhibits the proliferation of EBV-transformed lymphoblastoid cell lines (LCL) via enhanced apoptosis.

METHODS: LCL were generated by infecting freshly isolated human B cells with EBV (B95-8) for 12 h and coculturing with predetermined optimal concentrations of CyA (500 ng/ml) …

Differential Transcription Of The Tcpph Operon Confers Biotype-Specific Control Of The Vibrio Cholerae Toxr Virulence Regulon, Yvette M. Murley, Patricia A. Carroll, Karen Skorupski, Ronald K. Taylor, Stephen B. Calderwood

Dartmouth Scholarship

Epidemic strains of Vibrio cholerae O1 are divided into two biotypes, classical and El Tor. In both biotypes, regulation of virulence gene expression depends on a cascade in which ToxR activates expression of ToxT, and ToxT activates expression of cholera toxin and other virulence genes. In the classical biotype, maximal expression of this ToxR regulon in vitro occurs at 30 degrees C at pH 6.5 (ToxR-inducing conditions), whereas in the El Tor biotype, production of these virulence genes only occurs under very limited conditions and not in response to temperature and pH; this difference between biotypes is mediated at the …

Phosphoinositide-Ap-2 Interactions Required For Targeting To Plasma Membrane Clathrin-Coated Pits., I Gaidarov, James H. Keen

Department of Microbiology and Immunology Faculty Papers

The clathrin-associated AP-2 adaptor protein is a major polyphosphoinositide-binding protein in mammalian cells. A high affinity binding site has previously been localized to the NH(2)-terminal region of the AP-2 alpha subunit (Gaidarov et al. 1996. J. Biol. Chem. 271:20922-20929). Here we used deletion and site- directed mutagenesis to determine that alpha residues 21-80 comprise a discrete folding and inositide-binding domain. Further, positively charged residues located within this region are involved in binding, with a lysine triad at positions 55-57 particularly critical. Mutant peptides and protein in which these residues were changed to glutamine retained wild-type structural and functional characteristics by …

Genetic And Structural Analyses Of Cytoplasmic Filaments Of Wild-Type Treponema Phagedenis And A Flagellar Filament-Deficient Mutant, Jacques Izard, William A. Samsonoff, Mary Beth Kinoshita, Ronald J. Limberger

Department of Food Science and Technology: Faculty Publications

Unique cytoplasmic filaments are found in the treponeme genus of spirochete bacteria. Their function is unknown, but their location underneath the periplasmic flagellar filaments (PFF) suggests a role in motility and/or cell structure. To better understand these unique structures, the gene coding for the cytoplasmic filaments, cfpA, was identified in various treponemal species. Treponema phagedenis cfpA was 2,037 nucleotides long, and the encoded polypeptide showed 78 to 100% amino acid sequence identity with the partial sequence of CfpA from T. denticola, T. vincentii, and T. pallidum subsp. pertenue. Wild-type T. phagedenis and a …

Global Cns Gene Transfer For A Childhood Neurogenetic Enzyme Deficiency: Canavan Disease., Paola Leone, Christopher G Janson, Scott J Mcphee, Matthew J During

Department of Neurosurgery Faculty Papers

The neurogenetic prototypic disease on which we chose to test our gene therapy strategy is Canavan disease (CD). CD is an autosomal recessive leukodystrophy associated with spongiform degeneration of the brain. At present the disease is uniformly fatal in affected probands. CD is characterized by mutations in the aspartoacylase (ASPA) gene, resulting in loss of enzyme activity. In this review, recent evidence is summarized on the etiology and possible treatments for CD. In particular, we discuss two gene delivery systems representing recent advances in both viral and liposome technology: a novel cationic liposome-polymer-DNA (LPD) complex, DCChol/DOPE-protamine, as well as recombinant …

A Vibrio Cholerae Lysr Homolog, Aphb, Cooperates With Apha At The Tcpph Promoter To Activate Expression Of The Toxr Virulence Cascade, Gabriela Kovacikova, Karen Skorupski

Dartmouth Scholarship

We describe here a new member of the LysR family of transcriptional regulators, AphB, which is required for activation of the Vibrio cholerae ToxR virulence cascade. AphB activates the transcription of the tcpPH operon in response to environmental stimuli, and this process requires cooperation with a second protein, AphA. The expression of neither aphA or aphB is strongly regulated by environmental stimuli, raising the possibility that the activities of the proteins themselves may be influenced under various conditions. Strains of the El Tor biotype of V. cholerae typically exhibit lower expression of ToxR-regulated virulence genes in vitro than classical strains …

Interaction Between Fgf And Bmp Signaling Pathways Regulates Development Of Metanephric Mesenchyme., Andrew T. Dudley, R. E. Godin, E. J. Robertson

Journal Articles: Genetics, Cell Biology & Anatomy

Nephrogenesis in the mouse kidney begins at embryonic day 11 and ends approximately 10 days postpartum. During this period, new nephrons are continually being generated from a stem-cell population-the nephrogenic mesenchyme-in response to signals emanating from the tips of the branching ureter. Relatively little is known about the mechanism by which the nephrogenic mesenchyme cell population is maintained at the tips of the ureter in the presence of signals promoting tubulogenesis. Previous studies have shown that a loss of Bmp7 function leads to kidney defects that are a likely result of progressive loss of nephrogenic mesenchyme by apoptosis. The studies …

Characterizing Erythrocyte Motions In Flowing Blood, Markos Leggas

Theses and Dissertations (ETD)

Characterizing the probabilistic motions of cells is a prerequisite for the development of a general model of transport and surface deposition of white cells and platelets (WBC/P). These phenomena differ greatly when red blood cells (RBC) are present at normal levels, but follow convective diffusion in dilute suspensions. A critical need is to understand and characterize dispersion and diffusion as they apply to red cells in suspension flow. The dispersive motions of
0.5-micrometer beads and fluorescently labeled human RBC flowing in dilute (0.003%) and concentrated (25%) RBC suspensions, respectively, were characterized using fluorescence videomicroscopy methods, and times for individual tracer …

Insertional Inactivation Of Treponema Denticola Tap1 Results In A Nonmotile Mutant With Elongated Flagellar Hooks, Ronald J. Limberger, Linda L. Slivienski, Jacques Izard, William A. Samsonoff

Department of Food Science and Technology: Faculty Publications

The treponemal fla operon is comprised of numerous motility-related genes; however, the initial gene of this operon, tap1, has no known function. A recently developed system to generate specific mutants in Treponema denticola was utilized to determine if Tap1 was essential for motility. T. denticola tap1 and flanking DNA were identified, cloned, and sequenced, and a suicide plasmid that contained tap1 interrupted with an erythromycin resistance cassette (ermF and ermAM) was constructed. Because of potential polar effects from this cassette, a second plasmid that contained tap1 interrupted with a modified erythromycin resistance cassette that lacked the putative ermF transcription …

Interruption Of Multiple Cellular Processes In Ht-29 Epithelial Cells By Pseudomonas Aeruginosa Exoenzyme S, Joan C. Olson, Jennifer E. Fraylick, Eileen M. Mcguffie, Katherine M. Dolan, Timothy L. Yahr, Dara W. Frank, Timothy S. Vincent

Dartmouth Scholarship

Exoenzyme S (ExoS), an ADP-ribosylating enzyme produced by the opportunistic pathogen Pseudomonas aeruginosa, is directly translocated into eukaryotic cells by bacterial contact. Within the cell, ExoS ADP-ribosylates the cell signaling protein Ras and causes inhibition of DNA synthesis and alterations in cytoskeletal structure. To further understand the interrelationship of the different cellular effects of ExoS, functional analyses were performed on HT-29 epithelial cells after exposure to ExoS-producing P. aeruginosa 388 and the non-ExoS-producing strain 388DeltaS. Two different mechanisms of morphological alteration were identified: (i) a more-transient and less-severe cell rounding caused by the non-ExoS-producing strain 388DeltaS and (ii) a more-severe, …

Study Of The Baig Gene In Bile Acid 7Α-Dehydroxylating Bacteria, Michael David

Masters Theses & Specialist Projects

Recently, intestinal bile acid 7α-dehydroxylating bacteria have been implicated in cholesterol gallstone disease. Eubacterium sp. strain V.P.I. 12708, a bile acid 7α-dehydroxylating bacteria, contains multiple bile acid inducible (bai) genes which are located on a large bai operon. Genes of this operon encode the enzymes responsible for bile acid 7α-dehydroxylation. The baiG gene encodes a bile acid transporter in Eubacterium sp. strain V.P.I. 12708. Utilizing the polymerase chain reaction I determined the presence or absence of baiG-like genes in six bile acid 7α-dehydroxylating strains: Clostridium sp. Strain TN-271, Eubacterium sp. strain 1-10, Clostridium bifermentans strain 1-55, Clostridium sordellii strain Y67, …

Genetic And Transcriptional Analyses Of The Vibrio Cholerae Mannose-Sensitive Hemagglutinin Type 4 Pilus Gene Locus, Jane W. Marsh, Ronald K. Taylor

Dartmouth Scholarship

The mannose-sensitive hemagglutinin (MSHA) of the Vibrio cholerae O1 El Tor biotype is a member of the family of type 4 pili. Type 4 pili are found on the surface of a variety of gram-negative bacteria and have demonstrated importance as host colonization factors, bacteriophage receptors, and mediators of DNA transfer. The gene locus required for the assembly and secretion of the MSHA pilus has been localized to a 16.7-kb region of the V. cholerae chromosome. Sixteen genes required for hemagglutination, including five that encode prepilin or prepilin-like proteins, have been identified. Examination of MSHA-specific cDNAs has localized two promoters …

Transgenic Mice Which Overexpress Neurotrophin-3 (Nt-3) And Method Of Use, Kathryn M. Albers, Brian M. Davis

Neuroscience Faculty Patents

Transgenic mice express increased levels of neurotrophin-3 (NT-3) in epithelium when their ancestors are microinjected with the NT-3 gene. The NT-3 growth factor expressing transgenic mice are useful in the study of neurodegenerative disorders of the brain such as Parkinson's syndrome and Alzheimer's disease, of the spinal cord motor neurons such as amyotrophic lateral sclerosis, and for testing drug candidates for the treatment of these diseases.

Genetic Monitoring In The Workplace: A Tool Not A Solution, Lillian Trettin, Catherine Musham, Richard Jablonski

RISK: Health, Safety & Environment (1990-2002)

The authors differentiate between genetic monitoring and screening, and discuss the potential risks and benefits of predictive testing technologies.

The Dermatophytic Flora Ratio Of Dermatophytes, Hüseyi̇n Taniş, Gürbüz Aksoy, Zülal Aşçi

Turkish Journal of Medical Sciences

This paper describes the mycological examination of patients admitted to the department of dermatology of Kahramanmaras State Hospital. One hundred and seventy samples of finger nails, hairs and skin were collected from patients suspected of having fungal diseases and were examined under a light microscope after being treated with 15-20% KOH solution. It was observed that 68 of the 170 samples contained fungal hyphae and arthrospores, while 62 samples were free of these. Forty samples were observed to have Malasezia furfur. The samples containing M. furfur were not subjected to a culture medium. Of the 130 cultured samples, 68 had …

Infectious Diseases Concomitant With Urinary Tract Infections In Children, Ayşe Balat, L. Leighton Hill

Turkish Journal of Medical Sciences

Urinary-tract infection (UTI) is one of the most common infectious diseases in children; however, the significance of combined infection in the pathogenesis of UTI remains uncertain. Of 48,382 patients discharged from Texas Children's Hospital from July 1, 1991, to June 30, 1994, 1,221 (2.5%) were discharged with a diagnosis of UTI. We retrospectively reviewed the files of these 1,221 patients to assess for concomitant infections and causative microorganisms in patients with first-time UTI, no urologic abnormalities, and no other major diagnoses. Of the 1,221 patients, 511 (42%) had first-time UTI with no urological abnormalities or other major diagnoses, of which …

The “Spot 14” Gene Resides On The Telomeric End Of The 11q13 Amplicon And Is Expressed In Lipogenic Breast Cancers: Implications For Control Of Tumor Metabolism, Joel T. Moncur, Jonathan P. Park, Vincent A. Memoli, T. K. Mohandas, William B. Kinlaw

Dartmouth Scholarship

Enhanced long chain fatty acid synthesis may occur in breast cancer, where it is necessary for tumor growth and predicts a poor prognosis. “Spot 14” (S14) is a carbohydrate- and thyroid hormone-inducible nuclear protein specific to liver, adipose, and lactating mammary tissues that functions to activate genes encoding the enzymes of fatty acid synthesis. Amplification of chromosome region 11q13, where the S14 gene (THRSP) resides, also predicts a poor prognosis in breast tumors. We localized the S14 gene between markers D11S906 and D11S937, at the telomeric end of the amplified region at 11q13, and found that it was …

Knowledge, Attitudes And Behavior Of African American Undergraduate College Students Concerning Primary Preventative Health, Lionas Mayes

McCabe Thesis Collection

African Americans' knowledge about primary preventive health and their attitudes toward primary preventive health influence their health behavior. Primary preventive health behavior is also affected by the individuals' definition of health and the significance they ascribe to their health status. Attitudes toward primary preventive health determine whether health assessment is important in preventing disease. African Americans have a myriad of views about health and general well being. The purpose of this study is to determine the relationship between primary preventive health knowledge, primary preventive health attitudes and primary preventive health behavior in African American undergraduate students. A survey will be …

Evaluation Of The Success Of Adoptive Versus Passive Transfer Of Immunity Against Trypanosoma Cruzi, Karen Powell

Masters Theses & Specialist Projects

Several investigators have demonstrated an increased resistance to the protozoal parasite Trypanosoma cruzi (the causative agent of Chagas' disease) in highly susceptible C3H mice when maintained at an environmental temperature of 36°C. This increased resistance is manifested as delay in onset of parasitemia, decreased parasitemia, decreased pathology, and increased longevity with eventual clearing of the parasite from the bloodstream. In addition, this enhanced resistance has been shown to be an immunologic phenomenon and not due to the direct effects of elevated temperature on the parasite itself. To ascertain the possible contributions of humoral vs. cellular immunity to the above phenomenon, …

Ca2+ Signaling Modulates Cytolytic T Lymphocyte Effector Functions, Mark T. Esser, Doris M. Haverstick, Claudette L. Fuller, Charles A. Gullo Phd, Vivian Lam Braciale

Biochemistry and Microbiology

Cytolytic T cells use two mechanisms to kill virally infected cells, tumor cells, or other potentially autoreactive T cells in short-term in vitro assays. The perforin/granule exocytosis mechanism uses preformed cytolytic granules that are delivered to the target cell to induce apoptosis and eventual lysis. FasL/Fas (CD95 ligand/CD95)–mediated cytolysis requires de novo protein synthesis of FasL by the CTL and the presence of the death receptor Fas on the target cell to induce apoptosis. Using a CD8⁺ CTL clone that kills via both the perforin/granule exocytosis and FasL/Fas mechanisms, and a clone that kills via the FasL/Fas mechanism only, …

Subcellular Localization Of Mineralocorticoid Receptors In Living Cells: Effects Of Receptor Agonists And Antagonists, Géza Fejes-Tóth, David Pearce, Anikó Náray-Fejes-Tóth

Dartmouth Scholarship

Results on the subcellular localization of the mineralocorticoid receptor (MR) have been controversial. To determine the subcellular distribution and trafficking of the MR in living cells after binding of agonists and antagonists, we expressed a MR-green fluorescent protein (GFP) chimera in mammalian cells lacking endogenous MR. The GFP-tagged MR (GFP-MR) remained transcriptionally active, as determined in cotransfection experiments with the MR-responsive reporter, TAT3-LUC. The subcellular localization of GFP-MR was monitored by fluorescence time-lapse microscopy. In the absence of hormone, MR was present both in the cytoplasm and nucleus. Aldosterone induced a rapid nuclear accumulation of the MR. Aldosterone-bound GFP-MR was …

Characterization Of The Promoter And Upstream Activation Sequences Of Sporulation-Specific Genes Spr1 (Ssg1) And Spr2 In Saccharomyces Cerevisiae, Sharmini S. Soosaithasan

Theses, Dissertations and Capstones

Sporulation is a developmental process in which temporally distinct sets of genes regulate the processes of meiosis and ascospore formation. Sporulation-specific genes are classified into early, middle, and late genes based on their peak time of expression during sporulation. Regulation of two late genes, SPR1 and SPR2, was studied. The function of SPR2 is unknown. Its regulatory region contains two Mid Sporulation Elements (MSE) repeated in tandem that are sufficient to confer sporulation-specific regulation to a CYCl-lacZ reporter. These sequences have UAS (upstream activation sequence) properties, as each 14 base pair element is sufficient to confer sporulation-specific regulation …