Digital Commons Network^™

Cysteine Scanning Of The Surroundings Of An Alkali-Ion Binding Site Of The Glutamate Transporter Glt-1 Reveals A Conformationally Sensitive Residue, Ruth Zarbiv, Myriam Grunewald, Michael Kavanaugh, Baruch I. Kanner

Biomedical and Pharmaceutical Sciences Faculty Publications

Glutamate transporters remove this transmitter from the extracellular space by cotransport with three sodium ions and a proton. The cycle is completed by translocation of a potassium ion in the opposite direction. Recently we have identified two adjacent amino acid residues of the glutamate transporter GLT-1 that influence potassium coupling. Using the scanning cysteine accessibility method we have now explored the highly conserved region surrounding them. Replacement of each of the five consecutive residues 396–400 by cysteine abolished transport activity but at several other positions the substitution is tolerated. One residue, tyrosine 403, was identified where cysteine substitution renders the …

Significance Of The Kccl Cytoplasmic Cooh-Terminal Fragment For The Ph Dependence Of K-Cl Cotransport In Transfected Human Embryonic Kidney Cells, Norma C. Adragna, Jin Zhang, Peter K. Lauf

Pharmacology and Toxicology Faculty Publications

No abstract provided.

The Role Of Serum On The Adhesion Of Culturedchinese Hamster Lung (Chl) Cells, Ali Yildirim

Turkish Journal of Medical Sciences

The roles of serum on the initial attachment and adhesion strength of CHL cells, which is gained following initial attachment, spreading and growth, on tissue culture polystyrene dish were determined by using a convergent Microflow chamber. In the presence of 10% fetal calf serum 98%±2% of cells were attaching within 2 hours at 37°C. While only 74%±3% of cells were attaching during the same period of incubation in serum free medium. The critical shear stresses of detachment of CHL cells were 3.01±0.25 Nm -2 , 5.38±0.55 Nm -2 , 7.22±0.54 Nm -2 , 9.47±0.43 Nm -2 , and 9.54±1.15 Nm …

The Inhibitory Effect Of Zinc On Imipenem Andmeropenem Susceptibility Of Pseudomonasaeruginosa, Selahattin Atmaca, Ramazan Çiçek, Kadri Gül

Turkish Journal of Medical Sciences

In this study we have showed that zinc ion has an inhibitory activity on imipenem and meropenem suspectibility of Pseudomonas aeruginosa. When zinc ion concentration of Mueller-Hinthon agar (MHA) media was gradually increased the zone diameters of imipenem and meropenem gradually decreased. So we concluded that zinc concentration in the media might effect imipenem and meropenem susceptibility of Pseudomonas aeruginosa and might indicate false resistance to imipenem and meropenem. Therefore the use of these antipseudomonal antibiotics in Pseudomonas infections may be restricted.

A Systematic Evaluation Of Methods To Separate X- And Y- Bearing Sperm, Jacquelyn Irving

Theses: Doctorates and Masters

This project was initiated to determine if was possible to enrich either X- or Y- bearing sperm, and hence to preselect the sex of a child. Two of the possible reasons why couple might want to select the sex of a child are firstly because of a family history of an X-linked recessive genetic disorder, which usually only affect sons, and secondly families who have had several children of one sex. For this study, men with three or more children of the same sex were recruited following the publication of an article in The West Australian newspaper. The percentage of …

The Effect Of Systemic Doxycycline On Alveolar Bone Loss Following Periradicular Surgery, G. Reed Cummings

Loma Linda University Electronic Theses, Dissertations & Projects

Studies have shown an average of 0.5 mm to over 1.0 mm of bone loss following full thickness flap reflection. Recent investigations have revealed that the tetracycline family of antibiotics can prevent bone loss. The purpose of this study was to determine the effect of systemic Doxycycline on crestal alveolar bone loss following periradicular surgery in Beagle dogs.

The experiment was divided into two phases. The first phase served as the control (Non-Doxycycline), the second phase as the experiment (Doxycycline). Full thickness flaps were reflected in the mandibular left or right quadrant (control side) of five Beagle dogs. Using a …

Increased Focal Adhesion Kinase- And Urokinase-Type Plasminogen Activator Receptor-Associated Cell Signaling In Endothelial Cells Exposed To Asbestos, A Barchowsky, B M. Lannon, L C. Elmore, M D. Treadwell

Dartmouth Scholarship

Exposure of low-passage endothelial cells in culture to nonlethal amounts of asbestos, but not refractory ceramic fiber-1, increases cell motility and gene expression. These changes may be initiated by the fibers mimicking matrix proteins as ligands for receptors on the cell surface. In the present study, 1- to 3-hr exposures of endothelial cells to 5 mg/cm2 of chrysotile asbestos caused marked cell elongation and motility. However, little morphological change was seen when chrysotile was added to cells pretreated with either mannosamine to prevent assembly of glycophosphatidylinositol (GPI)-anchored receptors or with herbimycin A to inhibit tyrosine kinase activity. Affinity purification of …

Qsr1p, A 60s Ribosomal Subunit Protein, Is Required For Joining Of 40s And 60s Subunits., Dominic P. Eisinger, Frederick A. Dick, Bernard L. Trumpower

Dartmouth Scholarship

QSR1 is a recently discovered, essential Saccharomyces cerevisiae gene, which encodes a 60S ribosomal subunit protein. Thirty-one unique temperature-sensitive alleles of QSR1 were generated by regional codon randomization within a conserved 20-amino-acid sequence of the QSR1-encoded protein. The temperature-sensitive mutants arrest as viable, large, unbudded cells 24 to 48 h after a shift to 37 degrees C. Polysome and ribosomal subunit analysis by velocity gradient centrifugation of lysates from temperature-sensitive qsr1 mutants and from cells in which Qsr1p was depleted by down regulation of an inducible promoter revealed the presence of half-mer polysomes and a large pool of free 60S …

Sqt1, Which Encodes An Essential Wd Domain Protein Of Saccharomyces Cerevisiae, Suppresses Dominant-Negative Mutations Of The Ribosomal Protein Gene Qsr1., Dominic P. Eisinger, Frederick A. Dick, Elke Denke, Bernard L. Trumpower

Dartmouth Scholarship

QSR1 is an essential Saccharomyces cerevisiae gene, which encodes a 60S ribosomal subunit protein required for joining of 40S and 60S subunits. Truncations of QSR1 predicted to encode C-terminally truncated forms of Qsr1p do not substitute for QSR1 but do act as dominant negative mutations, inhibiting the growth of yeast when expressed from an inducible promoter. The dominant negative mutants exhibit a polysome profile characterized by 'half-mer' polysomes, indicative of a subunit joining defect like that seen in other qsr1 mutants (D. P. Eisinger, F. A. Dick, and B. L. Trumpower, Mol. Cell. Biol. 17:5136-5145, 1997.) By screening a high-copy …

Identification Of A Gal/Galnac Lectin In The Protozoan Hartmannella Vermiformis As A Potential Receptor For Attachment And Invasion By The Legionnaires' Disease Bacterium, Chandrasekar Venkataraman, Bradley J. Haack, Subbarao Bondada, Yousef Abu Kwaik

Microbiology, Immunology, and Molecular Genetics Faculty Publications

The Legionnaire's disease bacterium, Legionella pneumophila, is a facultative intracellular pathogen which invades and replicates within two evolutionarily distant hosts, free-living protozoa and mammalian cells. Invasion and intracellular replication within protozoa are thought to be major factors in the transmission of Legionnaire's disease. Although attachment and invasion of human macrophages by L. pneumophila is mediated in part by the complement receptors CR1 and CR3, the protozoan receptor involved in bacterial attachment and invasion has not been identified. To define the molecular events involved in invasion of protozoa by L. pneumophila, we examined the role of protein tyrosine phosphorylation …

The Beneficial Effect Of Vitamin E And Selenium During Experimental Chagas' Disease, Yue Hou

Masters Theses & Specialist Projects

The present study was conducted to determine if vitamin E and selenium could have a positive synergistic effect during experimental Chagas' disease. In the first phase of the study, 25 female C3HeB/FeJ mice were infected with a Brazil strain of Trypanosoma cruzi while receiving vitamin E supplementation of 0 IU/kg, 200 IU/kg, 400 IU/kg, 600 IU/kg, 800 IU/kg in their diets. In the second phase, 20 female C3HeB/FeJ mice were infected while receiving 400 IU/kg vitamin E plus selenium supplementation of 2 ppm, 4 ppm, 8 ppm, 16 ppm in their drinking water. The results demonstrate that vitamin E does …

Assembly And Regulation Of The Cd40 Receptor Complex In Human B Cells, Michelle R. Kuhné, Michael Robbins, John E. Hambor, Matthew F. Mackey, Yoko Kosaka, Toshihide Nishimura, Jason P. Gigley, Randolph J. Noelle, David M. Calderhead

Dartmouth Scholarship

CD40 is a member of the tumor necrosis factor (TNF) receptor superfamily. Studies with human B cells show that the binding of CD154 (gp39, CD40L) to CD40 recruits TNF receptor– associated factor 2 (TRAF2) and TRAF3 to the receptor complex, induces the downregulation of the nonreceptor-associated TRAFs in the cell and induces an increased expression of Fas on the cell surface. Combined signaling through the interluekin 4 receptor and CD40 induces an increased expression of Fas with a commensurate increase in the level of TRAF2, but not TRAF3, that is recruited to the receptor complex. In contrast, engagement of the …

Cellular Responses In Escherichia Coli To Lethal And Sublethal Doses Of Ozone, Indira Ruth Komanapalli

Loma Linda University Electronic Theses, Dissertations & Projects

Ozone is a major component of photochemical smog. High levels of this pollutant, sufficient to affect human health are found in many urban areas worldwide. Though limited studies in humans are supported by extensive findings from animal experiments, a difficulty in interpreting the results of these experiments has lead to an ambiguity on the biochemical mechanism of ozone toxicity. To elucidate the mechanism by which ozone causes cell damage and eventual cell death we conducted a comprehensive study using Escherichia coli K-12 as a model.

Studies on the comparative inactivation of bacteriophage lambda (λ), Escherichia coli, and Candida albicans …

Dissection Of A Circadian Oscillation Into Discrete Domains, Martha W. Merrow, Norman Y. Garceau, Jay C. Dunlap

Dartmouth Scholarship

The circadian oscillator in Neurospora is a negative feedback loop involving as principal players the products of the frequency (frq) locus. frq encodes multiple forms of its protein product FRQ, which act to depress the amounts of frq transcript. In this scheme there are two discrete and separable steps to the circadian cycle, negative feedback itself (repression) in which FRQ acts to decrease the levels of its own transcript, and recovery from repression (derepression) in which frq transcript levels return to peak amounts. By introducing an exogenously regulatable frq transgene into a frq loss-of-function strain (frq^{9 …}

Anti-Idiotype Monoclonal Antibody 1a7 And Use For The Treatment Of Melanoma And Small Cell Carcinoma, Malaya Chatterjee, Kenneth A. Foon

Microbiology, Immunology and Molecular Genetics Faculty Patents

The present invention relates isolation of anti-idiotypic antibody 1A7 raised against anti-GD2 mAb 14G2a and its use for the treatment of melanoma and small cell carcinoma. The antibody may be used as a substitute for isolated purified GD2 antigen in any appropriate application.

C-Terminal Truncations Of The Yeast Nucleoporin Nup145p Produce A Rapid Temperature-Conditional Mrna Export Defect And Alterations To Nuclear Structure., Thomas C. Dockendorff, Catherine V. Heath, Alan L. Goldstein, Christine A. Snay, C N. Cole

Dartmouth Scholarship

A screen for temperature-sensitive mutants of Saccharomyces cerevisiae defective in nucleocytoplasmic trafficking of poly(A)+ RNA has identified an allele of the NUP145 gene, which encodes an essential nucleoporin. NUP145 was previously identified by using a genetic synthetic lethal screen (E. Fabre, W. C. Boelens, C. Wimmer, I. W. Mattaj, and E. C. Hurt, Cell 78:275-289, 1994) and by using a monoclonal antibody which recognizes the GLFG family of vertebrate and yeast nucleoporins (S. R. Wente and G. Blobel, J. Cell Biol. 125:955-969, 1994). Cells carrying the new allele, nup145-10, grew at 23 and 30 degrees C but were unable to …

Proton (H) Modulation Of K-Cl Cotransport Through Both Internal And External Sites In Dids-Ph-Clamped Low Magnesium Lk Sheep Erythrocytes, Peter K. Lauf, Norma C. Adragna

Pharmacology and Toxicology Faculty Publications

No abstract provided.

Mutation Of An Amino Acid Residue Influencing Potassium Coupling In The Glutamate Transporter Glt-1 Induces Obligate Exchange, Michael Kavanaugh, Annie Bendahan, Noa Zerangue, Yumin Zhang, Baruch I. Kanner

Biomedical and Pharmaceutical Sciences Faculty Publications

Glutamate transporters maintain low synaptic concentrations of neurotransmitter by coupling uptake to flux of other ions. After cotransport of glutamic acid with Na⁺, the cycle is completed by countertransport of K⁺. We have identified an amino acid residue (glutamate 404) influencing ion coupling in a domain of the transporter implicated previously in kainate binding. Mutation of this residue to aspartate (E404D) prevents both forward and reverse transport induced by K⁺. Sodium-dependent transmitter exchange and a transporter-mediated chloride conductance are unaffected by the mutation, indicating that this residue selectively influences potassium flux coupling. The results …

The Isolation And Characterization Of Plv22a, A Mobilizable Plasmid From Bacteroides Fragilis, Thomas Joseph Novicki

Dissertations

No abstract provided.

Norf1, A Putative Human Group I Rna Helicase That Regulates Nonsense Mrna Levels, Steven E. Applequist

Dissertations

No abstract provided.

Role Of Tgf-† In Heart Development: Analysis Of The Type Ii Tgf-† Receptor, Patricia S. Grutkoski

Dissertations

No abstract provided.

Cyclic Amp And Its Receptor Protein Negatively Regulate The Coordinate Expression Of Cholera Toxin And Toxin-Coregulated Pilus In Vibrio Cholerae, Karen Skorupski, Ronald K. Taylor

Dartmouth Scholarship

Insertion mutations in two Vibrio cholerae genes, cya and crp, which encode adenylate cyclase and the cyclic AMP (cAMP) receptor protein (CRP), respectively, derepressed the expression of a chromosomal cholera toxin (CT) promoter-lacZ fusion at the nonpermissive temperature of 37 degrees C. In the classical biotype strain O395, the crp mutation increased the production of both CT and toxin-coregulated pilus (TCP) in vitro under a variety of growth conditions not normally permissive for their expression. The most dramatic increase in CT and TCP was observed with the crp mutant in Luria-Bertani (LB) medium pH 8.5, at 30 degrees C. El …

Analysis Of Mutant Platelet-Derived Growth Factor Receptors Expressed In Pc12 Cells Identifies Signals Governing Sodium Channel Induction During Neuronal Differentiation., Gary R. Fanger, Richard R. Vaillancourt, Lynn E. Heasley, Jean-Pierre P. Montmayeur, Gary L. Johnson, Robert A. Maue

Dartmouth Scholarship

The mechanisms governing neuronal differentiation, including the signals underlying the induction of voltage-dependent sodium (Na+) channel expression by neurotrophic factors, which occurs independent of Ras activity, are not well understood. Therefore, Na+ channel induction was analyzed in sublines of PC12 cells stably expressing platelet-derived growth factor (PDGF) beta receptors with mutations that eliminate activation of specific signalling molecules. Mutations eliminating activation of phosphatidylinositol 3-kinase (PI3K), phospholipase C gamma (PLC gamma), the GTPase-activating protein (GAP), and Syp phosphatase failed to diminish the induction of type II Na+ channel alpha-subunit mRNA and functional Na+ channel expression by PDGF, as determined by RNase …

Method For Obtaining Antifungal And Herbicidal Compounds That Target The First Committed Step In Shingolipid Long-Chain Base Biosynthesis, Robert C. Dickson, Robert L. Lester

Molecular and Cellular Biochemistry Faculty Patents

The invention provides the LCB1 and LCB2 genes of the yeast Saccharomyces cerevisiae that encode subunits of the enzyme serine palmitoyltransferase (SPT), the first enzyme leading to synthesis of the long-base component of the sphingolipids. The present specification describes the isolation of the LCB1 and LCB2 genes. The invention further relates to methods of using these genes to either inhibit SPT activity or to inhibit synthesis of the enzyme. Furthermore, the invention relates to methods for constructing strains of S. cerevisiae or other organisms that can be used to select and to test for compounds that either inhibit SPT activity …

Differential Expression Of The Toxr Regulon In Classical And E1 Tor Biotypes Of Vibrio Cholerae Is Due To Biotype-Specific Control Over Toxt Expression., Victor J. Dirita, Melody Neely, Ronald K. Taylor, Paul M. Bruss

Dartmouth Scholarship

The two major disease-causing biotypes of Vibrio cholerae, classical and El Tor, exhibit differences in their epidemic nature. Their behavior in the laboratory also differs in that El Tor strains produce two major virulence factors, cholera toxin (CT) and the toxin coregulated pilus (TCP), only under very restricted growth conditions, whereas classical strains do so in standard laboratory medium. Expression of toxin and TCP is controlled by two activator proteins, ToxR and ToxT, that operate in cascade fashion with ToxR controlling the synthesis of ToxT. Both biotypes express equivalent levels of ToxR, but only classical strains appear to express ToxT …

The Effect Of Acute Low Ph On Feeding And Locomotor Activity Of Larval Fathead Minnows, Pimephales Promelas, Sharon Ore

Masters Theses & Specialist Projects

Lowered pH conditions in aquatic environments can have a negative impact on many aquatic organisms. In fish it has been shown that acidic water conditions may result in altered gill morphology, reduced reproductive success, changes in locomotor and feeding behavior and even death. Juveniles and adults have been the primary focus of research. However, the larval stage is potentially the most sensitive to toxicity. It is also important ontogenetically as several crucial development thresholds, such as first feeding, occur during this period. The impact of acute low pH on feeding performance was investigated in larval fathead minnows one to fifteen …

Phenylbutyl Nitrone Compositions And Methods For Prevention Of Gastric Ulceration, John M. Carney, Robert A. Floyd

Pharmacology and Nutritional Sciences Faculty Patents

Compositions containing PBN, or active derivatives thereof, in a suitable pharmaceutical carrier for administration to a patient, are disclosed for treating or preventing gastric ulceration caused by ingestion of non-steroidal anti-inflammatories. Based on animal studies, the dosage is in the range of 3 to 300 mg/kg and is administered prior to, simultaneously, or shortly after ingestion of the NSAID compounds(s). In the preferred embodiment, the range is between 10 and 30 mg/kg, depending on the dosage unit required to protect the mucosa. The preferred method of administration is orally, alone or in combination with the non-steroidal anti-inflammatory. It is believed …

Antibody To The Ligand For Cd40 (Gp39) Inhibits Murine Aids-Associated Splenomegaly, Hypergammaglobulinemia, And Immunodeficiency In Disease-Susceptible C57bl/6 Mice., Kathy A. Green, Karen M. Crassi, Jon D. Laman, Arjan Schoneveld, Rendall R. Strawbridge, Teresa M. Foy, Randolph J. Noelle, William R. Green

Dartmouth Scholarship

Infection of genetically susceptible C57BL/6 mice with the LP-BM5 isolate of murine retroviruses cause profound splenomegaly, hypergammaglobulinemia, lymphadenopathy, and an immunodeficiency syndrome which includes the development of terminal B-cell lymphomas. Because many of these and the other manifestations of LP-BM5 virus-induced disease are similar to those seen in AIDS, this syndrome has been named murine AIDS, or MAIDS. Previous reports have shown that the onset of MAIDS depends on the presence of both CD41 T cells and B cells and have suggested that CD41 T-cell-B-cell interactions are important to disease pathogenesis. Here, we assessed the possibility that interactions between CD40 …

Antisense Oligodeoxynucleotide Inhibition Of A Swelling-Activated Cation Channel In Osteoblast-Like Osteosarcoma Cells., Randall L. Duncan, Neil Kizer, Elizabeth L. Barry, Peter P A Friedman, Keith A. Hruska

Dartmouth Scholarship

By patch-clamp analysis, we have shown that chronic, intermittent mechanical strain (CMS) increases the activity of stretch-activated cation channels of osteoblast-like UMR-106.01 cells. CMS also produces a swelling-activated whole-cell conductance (Gm) regulated by varying strain levels. We questioned whether the swelling-activated conductance was produced by stretch-activated cation channel activity. We have identified a gene involved in the increase in conductance by using antisense oligodeoxynucleotides (ODN) derived from the alpha 1-subunit genes of calcium channels found in UMR-106.01 cells (alpha1S, alpha1C, and alpha1D). We demonstrate that alpha 1C antisense ODNs abolish the increase in Gm in response to hypotonic swelling following …

Distinct Cis-Acting Elements Mediate Clock, Light, And Developmental Regulation Of The Neurospora Crassa Eas (Ccg-2) Gene., Deborah Bell-Pedersen, Jay C. Dunlap, Jennifer J. Loros

Dartmouth Scholarship

The Neurospora crassa eas (ccg-2) gene, which encodes a fungal hydrophobin, is transcriptionally regulated by the circadian clock. In addition, eas (ccg-2) is positively regulated by light and transcripts accumulate during asexual development. To sort out the basis of this complex regulation, deletion analyses of the eas (ccg-2) promoter were carried out to localize the cis-acting elements mediating clock, light, and developmental control. The primary sequence determinants of a positive activating clock element (ACE) were found to reside in a 45-bp region, just upstream from the TATA box. Using a novel unregulated promoter/reporter system developed for this study, we show …