Digital Commons Network^™

Murine Transporter Associated With Antigen Presentation (Tap) Preferences Influence Class I-Restricted T Cell Responses., A J Yellen-Shaw, C E Laughlin, R M Metrione, Laurence C. Eisenlohr

Department of Biochemistry and Molecular Biology Faculty Papers

The transporter associated with antigen presentation (TAP) complex shuttles cytosolic peptides into the exocytic compartment for association with nascent major histocompatibility complex class I molecules. Biochemical studies of murine and human TAP have established that substrate length and COOH-terminal residue identity are strong determinants of transport efficiency. However, the existence of these specificities in the intact cell and their influences on T cell responses have not been demonstrated. We have devised a method for studying TAP- mediated transport in intact cells, using T cell activation as a readout. The approach makes use of a panel of recombinant vaccinia viruses expressing …

Role Of Egr-1 Gene Expression In B Cell Receptor-Induced Apoptosis In An Immature B Cell Lymphoma, Subramanian Muthukkumar, Seong-Su Han, Sumathi Muthukkumar, Vivek M. Rangnekar, Subbarao Bondada

Microbiology, Immunology, and Molecular Genetics Faculty Publications

Ligation of B cell receptor (BCR) on BKS-2, an immature B cell lymphoma by anti-IgM antibodies (Ab) caused apoptosis. Here we report that signaling through B cell receptor in wild type BKS-2 cells down-regulated the expression of Egr-1, a zinc finger-containing transcription factor. A reduction in the level ofEgr-1 mRNA could be demonstrated as early as 30 min after the ligation of BCR on BKS-2 cells. Immunocytochemical and Western blot analysis revealed that the expression of EGR-1 protein was also inhibited by anti-IgM treatment. Antisense oligonucleotides to Egr-1 caused growth inhibition and apoptosis in BKS-2 cells, suggesting that …

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 …

The Clastogenic Effects Of Cyclophosphamide And A Sixty Hertz Electromagnetic Field On Bone Marrow Cells Of Cd-1 Mice, Kevin K. Block

Dissertations

Extremely low frequency (ELF) electromagnetic fields (EMF) have been correlated with the induction of cancer in a number of epidemiological studies (Feychting and Ahlbom, 1993; T,m and Lee, 1994; London e t al. 1991; Lovely et al., 1994; Tomenius, 1986; Wertheimer and Leeper, 1979, 1982). Two hypothesis were tested in the present study. The first hypothesis tested was that exposure to a 7.3 G magnetic field for 24 hours would increase the frequency of clastogenic and/or mutagenic events in bone m arrow cells of mice. The second hypothesis tested was that exposure to a 7.3 G magnetic field for 24 …

Transcranial Magnetic Stimulation Of The Prefrontal Cortex Delays Contralateral Endogenous Saccades, Tony Ro, Avishai Henik, Liana Machado, Robert D. Rafal

Publications and Research

The contributions of the superior prefrontal cortex (SPFC) and the superior parietal lobule (SPL) in generating voluntary endogenous and reflexive visually guided saccades were investigated using transcranial magnetic stimulation (TMS). Subjects made choice saccades to the left or right visual field in response to a central arrowhead (endogenous go signal) or a peripheral asterisk (exogenous go signal) that were presented along with a single TMS pulse at varying temporal intervals. TMS over the SPFC increased latencies for saccades made in response to an endogenous go signal toward the contralateral hemifield. No effects were observed when the go signal was exogenous …

Analysis Of Enhancer Function Of The Hs-40 Core Sequence Of The Human Alpha-Globin Cluster, Hsiaoli Chen, Christopher H. Lowrey, George Stamatoyannopoulos

Dartmouth Scholarship

HS-40 is the major regulatory element of the human α-globin locus, located 40 kb upstream of the ζ-globin gene. To test for potential interactions between HS-40 and the β- or the γ-globin gene promoters in stable transfection assays, the HS-40 core sequence was cloned upstream of either the β promoter or the γ promoter driving the neomycin phosphotransferase gene and enhancer activity was measured using a colony assay. In K562 or in MEL cells, enhancer activity of HS-40 was higher than that of the individual core sequences of the DNase I hypersensitive sites (HS) of the β-globin locus control region …

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 …}

Drift Macroalgal Abundance In Seagrass Beds: Investigating Large-Scale Associations With Physical And Biotic Attributes, Susan S. Bell, Margaret O. Hall

Integrative Biology Faculty and Staff Publications

The relationship between a suite of physical and biological factors and drift macroalgal abundance was examined in 12 seagrass sites spanning a distance of over 50 km within Tampa Bay, Florida, USA. Field sampling was conducted in December 1991, and drift algal abundance was determined by recording algal percent cover from 25 quadrants at each site. Additionally, drift macroalgae were collected from gridded plots and dry weight biomass measured. Sediment characteristics and seagrass biomass, shoot density, blade length and percent cover at each site were also determined. Likewise, position of site within Tampa Bay was categorized by spatial coordinates. Step-wise …

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 …

Aspartate 19 And Glutamate 121 Are Critical For Transport Function Of The Myo-Inositol/H+ Symporter From Leishmania Donovani, Andreas Seyfang, Michael Kavanaugh, Scott M. Landfear

Biomedical and Pharmaceutical Sciences Faculty Publications

The protozoan flagellate Leishmania donovani has an active myo-inositol/proton symporter (MIT), which is driven by a proton gradient across the parasite membrane. We have used site-directed mutagenesis in combination with functional expression of transporter mutants in Xenopusoocytes and overexpression in Leishmania transfectants to investigate the significance of acidic transmembrane residues for proton relay and inositol transport. MIT has only three charged amino acids within predicted transmembrane domains. Two of these residues, Asp¹⁹ (TM1) and Glu¹²¹ (TM4), appeared to be critical for transport function of MIT, with a reduction of inositol transport to about 2% of wild-type …

Tyrosine 140 Of The Γ-Aminobutyric Acid Transporter Gat-1 Plays A Critical Role In Neurotransmitter Recognition, Yona Bismuth, Michael Kavanaugh, Baruch I. Kanner

Biomedical and Pharmaceutical Sciences Faculty Publications

The γ-aminobutyric acid (GABA) transporter GAT-1 is located in nerve terminals and catalyzes the electrogenic reuptake of the neurotransmitter with two sodium ions and one chloride. We now identify a single tyrosine residue that is critical for GABA recognition and transport. It is completely conserved throughout the superfamily, and even substitution to the other aromatic amino acids, phenylalanine (Y140F) and tryptophan (Y140W), results in completely inactive transporters. Electrophysiological characterization reveals that both mutant transporters exhibit the sodium-dependent transient currents associated with sodium binding as well as the chloride-dependent lithium leak currents characteristic of GAT-1. On the other hand, in both …

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 …

Regulation Of The Ncx1 Gene In The Normal And Hypertrophied Myocardium, Kimberly Victoria Barnes

MUSC Theses and Dissertations

The sodium-calcium exchanger (NCX1) plays a major role in calcium efflux, and therefore, in calcium homeostasis in the heart. The exchanger mRNA and protein is rapidly upregulated within one hour of pressure overload. In this work, the exchanger has been shown to be upregulated by persistent pressure overload for at least one to two weeks. The 5' end of the NCX1 gene has been characterized in order to examine transcriptional regulation of the cardiac promoter. Four feline NCX1 isoforms of the 5' untranslated region have been cloned: one from brain (Br1), one from kidney (K1), and two from heart (H1 …

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 …

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 …

Cellular Basis Of Decreased Immune Responses To Pneumococcal Vaccines In Aged Mice, Manju Garg, Wei Luo, Alan M. Kaplan, Subbarao Bondada

Microbiology, Immunology, and Molecular Genetics Faculty Publications

Previously, model systems were developed in our laboratory to study murine immune responses to the 23-valent pneumococcal polysaccharide vaccine Pnu-Imune, both in vivo and in vitro (M. Garg and B. Subbarao, Infect. Immun. 60:2329-2336, 1992; M. Garg, A. M. Kaplan, and S. Bondada, J. Immunol. 152: 1589-1596, 1994). Using these systems, we found that aged mice did not respond to the vaccine in vivo or in vitro. Cell separation studies showed that the unresponsiveness of the aged spleen cells to the vaccine was not due to an intrinsic B-cell defect or to T-cell-mediated immunosuppression but resulted from an accessory cell …

Identification And Characterization Of The Thrombin Binding Sites On Fibrin, David A. Meh, Kevin R. Siebenlist, Michael W. Mosesson

Biomedical Sciences Faculty Research and Publications

Thrombin binds to fibrin at two classes of non-substrate sites, one of high affinity and the other of low affinity. We investigated the location of these thrombin binding sites by assessing the binding of thrombin to fibrin lacking or containing γ′ chains, which are fibrinogen γ chain variants that contain a highly anionic carboxyl-terminal sequence. We found the high affinity thrombin binding site to be located exclusively in D domains on γ′ chains (K_a, 4.9 × 10⁶⁻¹; n, 1.05 per γ′ chain), whereas the low affinity thrombin binding site was in the fibrin E …

The Protective Role Of Manganese Superoxide Dismutase Against Adriamycin-Induced Acute Cardiac Toxicity In Transgenic Mice, Hsiu-Chuan Yen, Terry D. Oberley, Satit Vichitbandha, Ye-Shih Ho, Daret K. St. Clair

Toxicology and Cancer Biology Faculty Publications

Adriamycin (ADR) is a potent anticancer drug known to cause severe cardiac toxicity. Although ADR generates free radicals, the role of free radicals in the development of cardiac toxicity and the intracellular target for ADR-induced cardiac toxicity are still not well understood. We produced three transgenic mice lines expressing increased levels of human manganese superoxide dismutase (MnSOD), a mitochondrial enzyme, as an animal model to investigate the role of ADR-mediated free radical generation in mitochondria. The human MnSOD was expressed, functionally active, and properly transported into mitochondria in the heart of transgenic mice. The levels of copper-zinc SOD, catalase, and …

Antibody Response To Heat Shock Proteins Of Trypanosoma Cruzi And Histopathology In Mice Infected And Maintained At Elevated Environmental Temperature, Ahmed Arif

Masters Theses & Specialist Projects

Trypanosoma cruzi is an obligate intracellular parasite infecting 18-20 million people in Latin America. It is the causative agent of Chagas' disease, commonly referred to as American Trypanosomiasis. The C3H murine model is widely used to study experimental Chagas' disease. It is well documented that when these highly susceptible mice are infected with the Brazil strain of T. cruzi and maintained at room temperature (RT), mice die between day 35-45 of infection. However, when held at an elevated temperature of 36°C, C3H mice survive an otherwise lethal infection with T. cruzi. When held at 36°C, the body temperature of the …

The Relationship Between The Fibrinogen D Domain Self-Association/Cross-Linking Site (Gammaxl) And The Fibrinogen Dusart Abnormality (Aalpha R554c-Albumin): Clues To Thrombophilia In The "Dusart Syndrome", Michael W. Mosesson, Kevin R. Siebenlist, James F. Hainfeld, J. S. Wall, C. Soria, J. P. Caen

Biomedical Sciences Faculty Research and Publications

Cross-linking of fibrinogen at its COOH-terminal gamma chain cross-linking site occurs in the presence of factor XIIIa due to self-association at a constitutive D domain site ("gammaXL"). We investigated the contribution of COOH-terminal regions of fibrinogen Aalpha chains to the gammaXL site by comparing the gamma chain cross-linking rate of intact fibrinogen (fraction I-2) with that of plasma fraction I-9, plasmic fraction I-9D, and plasmic fragment D1, which lack COOH-terminal Aalpha chain regions comprising approximately 100, approximately 390, and 413 residues, respectively. The cross-linking rates were I-2 > I-9 > 1-9D = D1, and indicated that the terminal 100 or more Aalpha …

2,4-Disulfonyl Phenyl Butyl Nitrone, Its Salt And Their Use As Pharmaceuticals, John M. Carney

Pharmacology and Nutritional Sciences Faculty Patents

2,4-disulfonyl α-phenyl-tert-butyl nitrone and its pharmaceutically acceptable salts are disclosed. These materials are useful as pharmaceutical agents for oral or parenteral, e.g. intravenous administration to patients suffering from acute central nervous system oxidation as occurs in a stroke or from gradual central nervous system oxidation which can exhibit itself as progressive central nervous system function loss. The materials are also used to ameliorate the side effects of oxidative-damage causing antineoplastic disease treatments.

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 …

Update - February 1996, Loma Linda University Center For Christian Bioethics

Update

In this issue:

-- Adventism and Assisted Procreation: Excerpts from a panel discussion at LLU
-- Adventist Guidelines on Assisted Procreation
-- LLU offers Masters of Arts in Biomedical and Clinical Ethics

2,4-Disulfonyl Phenyl Butyl Nitrone, Its Salt And Their Use As Pharmaceuticals Free Radical Traps, John M. Carney

Pharmacology and Nutritional Sciences Faculty Patents

2,4-disulfonyl α-phenyl-tert-butyl nitrone and its pharmaceutically acceptable salts are disclosed. These materials are useful as pharmaceutical agents for oral or intravenous administration to patients suffering from acute central nervous system oxidation as occurs in a stroke or from gradual central nervous system oxidation which can exhibit itself as progressive central nervous system function loss.

Job Accommodation In The Automobile Industry : Addressing The Problem Of Lateral Epicondylitis, Thanigaivel Ashwin Raj

Theses and Dissertations (ETD)

Cumulative trauma disorders are musculoskeletal problems such as carpal tunnel syndrome, rotator cuff tendinitis, and epicondylitis which can affect assembly line workers. The injuries are thought to result from repetitive motions performed under excessive loads in anomalous postures. The project aimed to design, build, install, and evaluate worksite accommodation at the Saturn plant for a worker with right lateral epicondylitis. The goal was to make her fully functional in her original team which required addressing the injurious aspects of the task that caused or aggravated her injury.

A process of observation, interview, and analysis identified “the door mount” operation on …

Asct-1 Is A Neutral Amino Acid Exchanger With Chloride Channel Activity, Noa Zerangue, Michael Kavanaugh

Biomedical and Pharmaceutical Sciences Faculty Publications

The ubiquitous transport activity known as system ASC is characterized by a preference for small neutral amino acids including alanine, serine, and cysteine. ASCT-1 and ASCT-2, recently cloned transporters exhibiting system ASC-like selectivity, are members of a major amino acid transporter family that includes a number of glutamate transporters. Here we show that ASCT1 functions as an electroneutral exchanger that mediates negligible net amino acid flux. The electrical currents previously shown to be associated with ASCT1-mediated transport result from activation of a thermodynamically uncoupled chloride conductance with permeation properties similar to those described for the glutamate transporter subfamily. Like glutamate …

Kinetics And Stoichiometry Of A Proton/Myo-Inositol Cotransporter, Elizabeth M. Klamo, Mark E. Drew, Scott M. Landfear, Michael Kavanaugh

Biomedical and Pharmaceutical Sciences Faculty Publications

Voltage clamp recording was used to measure steady-state and presteady-state currents mediated by a myo-inositol transporter cloned from Leishmania donovani and expressed in Xenopus oocytes. Application of myo-inositol resulted in inward currents, which did not require external sodium and which were increased by increasing the extracellular proton concentration and by membrane hyperpolarization. Alkalinization of the extracellular space occurred concomitantly with myo-inositol influx. Correlation of membrane currents with radiolabeled myo-inositol flux revealed that one positive charge is translocated with each molecule of myo-inositol, consistent with cotransport of one proton. The transport concentration dependence on both species …

Top-Down Cascade From A Bitrophic Predator In An Old-Field Community, Matthew D. Moran, Thomas P. Rooney, L. E. Hurd

Biological Sciences Faculty Publications

We tested the hypothesis that a bitrophic (third and fourth level) arthropod predator can exert a cascading, top-down influence on other arthropods and plants in an early successional old field. First-stadium mantids, Tenodera sinensis, were added to replicated open-field plots in numbers corresponding to naturally occurring egg hatch density and allowed to remain for ≈ 2 mo. Sticky-trap dispersal barriers around both control and mantid-addition plots allowed us to monitor emigration of arthropods continuously during the experiment. Biomass of herbivores, carnivores, and plants, and abundances of arthropod taxa within plots were determined at the beginning, middle, and end of …

A Thermodynamic Study Of Electroneutral K-Cl Cotransport In Ph- And Volume-Clamped Low K Sheep Erythrocytes With Normal And Low Internal Magnesium, Peter K. Lauf, Norma C. Adragna

Pharmacology and Toxicology Faculty Publications

Swelling-Induced human erythrocyte K-Cl cotransport is membrane potential independent and capable of uphill transport. However, a complete thermodynamic analysis of basal and stimulated K-Cl cotransport, at constant cell volume, is missing, This study was performed in low K sheep red blood cells before and after reducing cellular free Mg into the nanomolar range with the divalent cation ionophore A23187 and a chelator, an intervention known to stimulate K-Cl cotransport. The anion exchange inhibitor 4,4'diisothiocyanato-2,2'disulfonic stilbene was used to clamp intracellular pH and Cl or NO3 concentrations. Cell volume was maintained constant as external and internal pH differed by more than …

Microevolutionary Patterns And Molecular Markers: The Genetics Of Geographic Variation In Ascaris Suum, Steven A. Nadler

Harold W. Manter Laboratory of Parasitology: Faculty Publications

Molecular markers have been used only rarely to characterize the population genetic structure of nematodes. Published studies have suggested that different taxa may show distinct genetic architectures. Isoenzyme and RAPD markers have been used to investigate geographic variation of Ascaris suum at the level of infrapopulations (nematodes within individual hosts), within localities, and among geographic regions. Independent estimates of genetic differentiation among population samples based on isoenzyme and RAPD data showed similar patterns and substantial correlation. Heterozygote deficiencies within infrapopulations and large values for inbreeding coefficients among infrapopulations suggested that the composition of these populations was not consistent with a …