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Articles 1231 - 1260 of 1400

Full-Text Articles in Medicine and Health Sciences

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 Jul 1997

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 …

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Analysis Of Enhancer Function Of The Hs-40 Core Sequence Of The Human Alpha-Globin Cluster, Hsiaoli Chen, Christopher H. Lowrey, George Stamatoyannopoulos Jul 1997

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 …

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The Glucose Transporter Glut4 And The Aminopeptidase Vp165 Colocalise In Tubulo-Vesicular Elements In Adipocytes And Cardiomyocytes, Sally Martin, Jacqueline E. Rice, Gwyn W. Gould, Susanna R. Keller Jun 1997

The Glucose Transporter Glut4 And The Aminopeptidase Vp165 Colocalise In Tubulo-Vesicular Elements In Adipocytes And Cardiomyocytes, Sally Martin, Jacqueline E. Rice, Gwyn W. Gould, Susanna R. Keller

Dartmouth Scholarship

The aminopeptidase vp165 is one of the major polypeptides enriched in GLUT4-containing vesicles immuno-isolated from adipocytes. In the present study we have confirmed and quantified the high degree of colocalisation between GLUT4 and vp165 using double label immuno-electron microscopy on vesicles isolated from adipocytes and heart. The percentage of vp165-containing vesicles that also contained GLUT4 was 91%, 76%, and 86% in rat adipocytes, 3T3-L1 adipocytes, and rat heart, respectively. Internalisation of a transferrin/HRP (Tf/HRP) conjugate by 3T3-L1 adipocytes, followed by diaminobenzidine treatment in intact cells, resulted in ablation of only 41% and 45% of GLUT4 and vp165, respectively, whereas endosomal …

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Identification Of A Novel Antiapoptotic Functional Domain In Simian Virus 40 Large T Antigen., Suzanne D. Conzen, Christine A. Snay, Charles N. Cole Jun 1997

Identification Of A Novel Antiapoptotic Functional Domain In Simian Virus 40 Large T Antigen., Suzanne D. Conzen, Christine A. Snay, Charles N. Cole

Dartmouth Scholarship

The ability of DNA tumor virus proteins to trigger apoptosis in mammalian cells is well established. For example, transgenic expression of a simian virus 40 (SV40) T-antigen N-terminal fragment (N-termTag) is known to induce apoptosis in choroid plexus epithelial cells. SV40 T-antigen-induced apoptosis has generally been considered to be a p53-dependent event because cell death in the brain is greatly diminished in a p53-/- background strain and is abrogated by expression of wild-type (p53-binding) SV40 T antigen. We now show that while N-termTags triggered apoptosis in rat embryo fibroblasts cultured in low serum, expression of full-length T antigens unable to …

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Human Immunodeficiency Virus Type 1 Infection Of Cells And Tissues From The Upper And Lower Human Female Reproductive Tract, Alexandra L. Howell, Robert D. Edkins, Sherry E. Rier, Grant R. Yeaman, Judy E. Stern, Michael W. Fanger, Charles R. Wira May 1997

Human Immunodeficiency Virus Type 1 Infection Of Cells And Tissues From The Upper And Lower Human Female Reproductive Tract, Alexandra L. Howell, Robert D. Edkins, Sherry E. Rier, Grant R. Yeaman, Judy E. Stern, Michael W. Fanger, Charles R. Wira

Dartmouth Scholarship

Viable tissue sections and isolated cell cultures from the human fallopian tube, uterus, cervix, and vaginal mucosa were examined for susceptibility to infection with human immunodeficiency virus type 1 (HIV-1). We examined infectivity by using the monocytotropic strain HIV-1JR-FLand several primary isolates of HIV-1 obtained from infected neonates. HIV-1 infection was measured by p24 production in short-term culture and by immunofluorescence detection of HIV-1 Nef and p24 proteins by laser scanning confocal microscopy. Three-color immunofluorescence was used to phenotype HIV-infected cells within tissue sections from each site. Our findings indicate that epithelial, stromal, and dendritic cells and cells …

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Dissection Of A Circadian Oscillation Into Discrete Domains, Martha W. Merrow, Norman Y. Garceau, Jay C. Dunlap Apr 1997

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 (frq9 …

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Sch 48973: A Potent, Broad-Spectrum, Antienterovirus Compound., Peter J. Buontempo, Stuart Cox, Jacquelyn Wright-Minogue, Jason L. Demartino, Angela M. Skelton, Eric Ferrari, Randi Albin, Edward J. Rozhon, V. Girijavallabhan, John F. Modlin, John F. O'Connell Mar 1997

Sch 48973: A Potent, Broad-Spectrum, Antienterovirus Compound., Peter J. Buontempo, Stuart Cox, Jacquelyn Wright-Minogue, Jason L. Demartino, Angela M. Skelton, Eric Ferrari, Randi Albin, Edward J. Rozhon, V. Girijavallabhan, John F. Modlin, John F. O'Connell

Dartmouth Scholarship

SCH 48973 is a novel molecule with potent, selective, antienterovirus activity. In assays of the cytopathic effect against five picornaviruses, SCH 48973 had antiviral activity (50% inhibitory concentrations [IC50s]) of 0.02 to 0.11 microg/ml, with no detectable cytotoxicity at 50 microg/ml. SCH 48973 inhibited 80% of 154 recent human enterovirus isolates at an IC50 of 0.9 microg/ml. The antiviral activity of SCH 48973 is derived from its specific interaction with viral capsid, as confirmed by competition binding studies. The affinity constant (Ki) for SCH 48973 binding to poliovirus was 8.85 x 10(-8) M. In kinetic studies, a maximum of approximately …

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Where Do Elderly Veterans Obtain Care For Acute Myocardial Infarction: Department Of Veterans Affairs Or Medicare?, S M. Wright, J Daley, E S. Fisher, G E. Thibault Feb 1997

Where Do Elderly Veterans Obtain Care For Acute Myocardial Infarction: Department Of Veterans Affairs Or Medicare?, S M. Wright, J Daley, E S. Fisher, G E. Thibault

Dartmouth Scholarship

To examine Department of Veterans Affairs (VA) and Medicare hospitalizations for elderly veterans with acute myocardial infarction (AMI), their use of cardiac procedures in both systems, and patient mortality. DATA SOURCES: Merging of inpatient discharge abstracts obtained from VA Patient Treatment Files (PTF) and Medicare MedPAR Part A files. A retrospective cohort study of male veterans 65 years or older who were prior users of the VA medical system (veteran-users) and who were initially admitted to a VA or Medicare hospital with a primary diagnosis of AMI at some time from January 1, 1988 through December 31, 1990 (N = …

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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 Feb 1997

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 …

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A Heterodimer Of Thioredoxin And Ib2 Cooperates With Sec18p (Nsf) To Promote Yeast Vacuole Inheritance, Zuoyu Xu, Andreas Mayer, Eric Muller, William Wickner Jan 1997

A Heterodimer Of Thioredoxin And Ib2 Cooperates With Sec18p (Nsf) To Promote Yeast Vacuole Inheritance, Zuoyu Xu, Andreas Mayer, Eric Muller, William Wickner

Dartmouth Scholarship

Early in S phase, the vacuole (lysosome) of Saccharomyces cerevisiae projects a stream of vesicles and membranous tubules into the bud where they fuse and establish the daughter vacuole. This inheritance reaction can be studied in vitro with isolated vacuoles. Rapid and efficient homotypic fusion between saltwashed vacuoles requires the addition of only two purified soluble proteins, Sec18p (NSF) and LMA1, a novel heterodimer with a thioredoxin subunit. We now report the identity of the second subunit of LMA1 as IB2, a previously identified cytosolic inhibitor of vacuolar proteinase B. Both subunits are needed for efficient vacuole inheritance in vivo …

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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 Jan 1997

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 …

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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 Jan 1997

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 …

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F(C)Gammari-Targeted Fusion Proteins Result In Efficient Presentation By Human Monocytes Of Antigenic And Antagonist T Cell Epitopes, Chunlei Liu, Joel Goldstein, Robert F. Graziano, Jia He, Jeremiah K. O'Shea, Yashwant Deo, Paul M. Guyre Nov 1996

F(C)Gammari-Targeted Fusion Proteins Result In Efficient Presentation By Human Monocytes Of Antigenic And Antagonist T Cell Epitopes, Chunlei Liu, Joel Goldstein, Robert F. Graziano, Jia He, Jeremiah K. O'Shea, Yashwant Deo, Paul M. Guyre

Dartmouth Scholarship

A major challenge for using native or modified T cell epitopes to induce or suppress immunity relates to poor localization of peptides to antigen presenting cells (APCs) in vivo. In this study, we demonstrate enhanced presentation of antigenic and antagonistic peptides by targeting them to the type I Fc receptor for IgG (F(c)gammaRI, CD64) on human monocytes. A Th epitope of tetanus toxoid, TT830, and the antagonistic peptide for TT830, TT833S, were genetically grafted into the constant region of the heavy chain of the humanized anti-CD64 mAb 22 and expressed as monovalent fusion proteins, Fab22-TT830 and Fab22-TT833S. These CD64-targeted peptides …

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The Product Of The Saccharomyces Cerevisiae Rss1 Gene, Identified As A High-Copy Suppressor Of The Rat7-1 Temperature-Sensitive Allele Of The Rat7/Nup159 Nucleoporin, Is Required For Efficient Mrna Export, Veronica Del Priore, Christine A. Snay, Andre Bahr, Charles N. Cole Oct 1996

The Product Of The Saccharomyces Cerevisiae Rss1 Gene, Identified As A High-Copy Suppressor Of The Rat7-1 Temperature-Sensitive Allele Of The Rat7/Nup159 Nucleoporin, Is Required For Efficient Mrna Export, Veronica Del Priore, Christine A. Snay, Andre Bahr, Charles N. Cole

Dartmouth Scholarship

RAT7/NUP159 was identified previously in a screen for genes whose products are important for nucleocytoplasmic export of poly(A)+ RNA and encodes an essential nucleoporin. We report here the identification of RSS1 (Rat Seven Suppressor) as a high-copy extragenic suppressor of the rat7-1 temperature-sensitive allele. Rss1p encodes a novel essential protein of 538 amino acids, which contains an extended predicted coiled-coil domain and is located both at nuclear pore complexes (NPCs) and in the cytoplasm. RSS1 is the first reported high-copy extragenic suppressor of a mutant nucleoporin. Overexpression of Rss1p partially suppresses the defects in nucleocytoplasmic export of poly(A)+ RNA, rRNA …

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Attachment Of Toxoplasma Gondii To Host Cells Is Host Cell Cycle Dependent., Jane Grimwood, Jose R. Mineo, Lloyd H. Kasper Oct 1996

Attachment Of Toxoplasma Gondii To Host Cells Is Host Cell Cycle Dependent., Jane Grimwood, Jose R. Mineo, Lloyd H. Kasper

Dartmouth Scholarship

The initial attachment of Toxoplasma tachyzoites to target host cells is an important event in the life cycle of the parasite and hence critical in the pathogenesis of this infection. The efficiency of Toxoplasma attachment to synchronized populations of Chinese hamster ovary cells and bovine kidney cells was investigated by using a glutaraldehyde-fixed host cell assay system. For both cell lines, parasite attachment increased as the synchronized host cells proceeded from the G1 phase to the mid-S phase and then decreased as the cells entered the G2-M boundary. Postulating that these differences in attachment reflect the upregulation of a specific …

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Opposing Motor Activities Are Required For The Organization Of The Mammalian Mitotic Spindle Pole, Tirso Gaglio, Alejandro Saredi, James B. Bingham, M Josh Hasbani, Steven R. Grill, Trina A. Schroer, Duane A. Compton Oct 1996

Opposing Motor Activities Are Required For The Organization Of The Mammalian Mitotic Spindle Pole, Tirso Gaglio, Alejandro Saredi, James B. Bingham, M Josh Hasbani, Steven R. Grill, Trina A. Schroer, Duane A. Compton

Dartmouth Scholarship

We use both in vitro and in vivo approaches to examine the roles of Eg5 (kinesin-related protein), cytoplasmic dynein, and dynactin in the organization of the microtubules and the localization of NuMA (Nu-clear protein that associates with the Mitotic Apparatus) at the polar ends of the mammalian mitotic spindle. Perturbation of the function of Eg5 through either immunodepletion from a cell free system for assembly of mitotic asters or antibody microinjection into cultured cells leads to organized astral microtubule arrays with expanded polar regions in which the minus ends of the microtubules emanate from a ring-like structure that contains NuMA. …

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Activation Of The Human Thymidine Kinase (Tk) Promoter By Simian Virus 40 Large T Antigen Requires Both The T Antigen Prb Family-Binding Domain And Tk Promoter Sequences Resembling E2f-Binding Sites., Michelle M. Anderson, Jun Chen, Charles N. Cole, Susan E. Conrad Sep 1996

Activation Of The Human Thymidine Kinase (Tk) Promoter By Simian Virus 40 Large T Antigen Requires Both The T Antigen Prb Family-Binding Domain And Tk Promoter Sequences Resembling E2f-Binding Sites., Michelle M. Anderson, Jun Chen, Charles N. Cole, Susan E. Conrad

Dartmouth Scholarship

Infection of quiescent cells with the DNA tumor virus simian virus 40 induces expression of the cellular thymidine kinase (TK) gene a minimum of 10- to 20-fold, and this induction depends upon the viral protein large T antigen (T-Ag). To define both human TK promoter elements and T-Ag functional domains required for transcriptional induction, we have established a system in which stable Rat-1 transfectants harboring TK promoter-luciferase hybrid genes are infected with recombinant adenoviruses expressing either wild-type or mutant forms of T-Ag and luciferase expression is measured as an indicator of promoter activity. The results show that (i) a 135-bp …

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Cloning Of The Mammalian Type Ii Iodothyronine Deiodinase. A Selenoprotein Differentially Expressed And Regulated In Human And Rat Brain And Other Tissues., Walburga Croteau, Jennifer C. Davey, Valerie Anne Galton, Donald L. St Germain Jul 1996

Cloning Of The Mammalian Type Ii Iodothyronine Deiodinase. A Selenoprotein Differentially Expressed And Regulated In Human And Rat Brain And Other Tissues., Walburga Croteau, Jennifer C. Davey, Valerie Anne Galton, Donald L. St Germain

Dartmouth Scholarship

The deiodination of thyroid hormones in extrathyroidal tissues plays an important role in modulating thyroid hormone action. The type II deiodinase (DII) converts thyroxine to the active hormone 3,5,3'-triiodothyronine, and in the rat is expressed in the brain, pituitary gland, and brown adipose tissue (BAT). Complementary DNAs (cDNAs) for the types I and III deiodinases (DI and DIII, respectively) have been isolated and shown to code for selenoproteins. However, information concerning the structure of the mammalian DII remains limited, and the pattern of its expression in human tissues is undefined. We report herein the identification and characterization of rat and …

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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 Jul 1996

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 …

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Toxin-Coregulated Pilus, But Not Mannose-Sensitive Hemagglutinin, Is Required For Colonization By Vibrio Cholerae O1 El Tor Biotype And O139 Strains., K Helene Thelin, Ronald K. Taylor Jul 1996

Toxin-Coregulated Pilus, But Not Mannose-Sensitive Hemagglutinin, Is Required For Colonization By Vibrio Cholerae O1 El Tor Biotype And O139 Strains., K Helene Thelin, Ronald K. Taylor

Dartmouth Scholarship

The relative contributions of toxin-coregulated pilus (TCP) and cell-associated mannose-sensitive hemagglutinin (MSHA) to the colonization ability of Vibrio cholerae O1 El Tor biotype strains and O139 Bengal strains was determined by using isogenic parental and in-frame deletion mutant pairs in the infant mouse cholera model. Both the El Tor and O139 tcpA mutant strains showed a dramatic defect in colonization as indicated by their competitive indices, whereas deletion of mshA had a negligible effect on colonization in either background.

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Measuring Hospital Use Without Claims: A Comparison Of Patient And Provider Reports., R E. Clark, S K. Ricketts, G J. Mchugo Jun 1996

Measuring Hospital Use Without Claims: A Comparison Of Patient And Provider Reports., R E. Clark, S K. Ricketts, G J. Mchugo

Dartmouth Scholarship

We compared the validity of hospital admission and length of stay reports from patients, outpatient providers, and hospitals, and we examined possible sources of error. Data were collected from people enrolled in a randomized trial of treatment for severe mental illness and substance use disorders, from community mental health centers (CMHCs), and from hospitals. Reports for each of the 74 study participants covered two-year time periods beginning and ending at various times between 1989 and 1993. We compared reports from the various sources and constructed a hybrid with data from all three sources. Using parametric and non-parametric statistics, we compared …

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Toxoplasma Gondii-Induced Immune Suppression By Human Peripheral Blood Monocytes: Role Of Gamma Interferon., Jacqueline Y. Channon, Lloyd H. Kasper Apr 1996

Toxoplasma Gondii-Induced Immune Suppression By Human Peripheral Blood Monocytes: Role Of Gamma Interferon., Jacqueline Y. Channon, Lloyd H. Kasper

Dartmouth Scholarship

The ability of Toxoplasma gondii to evade the host immune response during primary infection in humans is poorly understood. In murine toxoplasmosis, infected spleen macrophages release soluble factors that mediate a transient immunosuppression, which may allow the parasite to become established. When an enriched population of human monocytes from seronegative individuals was incubated with toxoplasmas in vitro, soluble factors that mediated market suppression of mitogen-induced lymphocyte DNA synthesis were released. Irradiated tachyzoites that do not undergo replication were sufficient stimuli for near-maximal soluble factor release. Up to 50% of the soluble factor-mediated suppression is attributable to a gamma interferon (IFN-gamma)-dependent …

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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 Apr 1996

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 …

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Disruption Of The Cbfa2 Gene Causes Necrosis And Hemorrhaging In The Central Nervous System And Blocks Definitive Hematopoiesis., Qing Wang, Terryl Stacy, Michael M Binder, Miguel Marin-Padilla, Arlene H. Sharpe, Nancy A. Speck Apr 1996

Disruption Of The Cbfa2 Gene Causes Necrosis And Hemorrhaging In The Central Nervous System And Blocks Definitive Hematopoiesis., Qing Wang, Terryl Stacy, Michael M Binder, Miguel Marin-Padilla, Arlene H. Sharpe, Nancy A. Speck

Dartmouth Scholarship

The CBFA2 (AML1) gene encodes a DNA-binding subunit of the heterodimeric core-binding factor. The CBFA2 gene is disrupted by the (8;21), (3;21), and (12;21) chromosomal translocations associated with leukemias and myelodysplasias in humans. Mice lacking a CBF alpha 2 protein capable of binding DNA die between embryonic days 11.5 and 12.5 due to hemorrhaging in the central nervous system (CNS), at the nerve/CNS interfaces of cranial and spinal nerves, and in somitic/intersomitic regions along the presumptive spinal cord. Hemorrhaging is preceded by symmetric, bilateral necrosis in these regions. Definitive erythropoiesis and myelopoiesis do not occur in Cbfa2-deficient embryos, and disruption …

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Cd40-Cd40 Ligand Interactions In Experimental Allergic Encephalomyelitis And Multiple Sclerosis., Koen Gerritse, Jon D. Laman, Randolph J. Noelle, Alejandro Aruffo Mar 1996

Cd40-Cd40 Ligand Interactions In Experimental Allergic Encephalomyelitis And Multiple Sclerosis., Koen Gerritse, Jon D. Laman, Randolph J. Noelle, Alejandro Aruffo

Dartmouth Scholarship

We investigated the role of CD40-CD40 ligand (CD40L) interactions in multiple sclerosis (MS) and experimental allergic encephalomyelitis (EAE). Activated helper T cells expressing CD40L (gp39) surface protein were found in MS patient brain sections, but not in brain tissue sections of normal controls or patients with other neurological disease. CD40L-positive cells were co-localized with CD40-bearing cells in active lesions (perivascular infiltrates). Most of these CD40-bearing cells proved to be of the monocytic lineage (macrophages or microglial cells), and relatively few were B cells. To functionally evaluate CD40-CD40L interactions, EAE was elicited in mice by means of proteolipid-peptide immunization. Treatment with …

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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 Mar 1996

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 …

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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 Feb 1996

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 …

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Gtpase-Deficient G Alpha 16 And G Alpha Q Induce Pc12 Cell Differentiation And Persistent Activation Of Cjun Nh2-Terminal Kinases., Lynn E. Heasley, Brooke Storey, Gary R. Fanger, Laura Butterfield, J Zamarripa, D Blumberg, R A. Maue Feb 1996

Gtpase-Deficient G Alpha 16 And G Alpha Q Induce Pc12 Cell Differentiation And Persistent Activation Of Cjun Nh2-Terminal Kinases., Lynn E. Heasley, Brooke Storey, Gary R. Fanger, Laura Butterfield, J Zamarripa, D Blumberg, R A. Maue

Dartmouth Scholarship

Persistent stimulation of specific protein kinase pathways has been proposed as a key feature of receptor tyrosine kinases and intracellular oncoproteins that signal neuronal differentiation of rat pheochromocytoma (PC12) cells. Among the protein serine/threonine kinases identified to date, the p42/44 mitogen-activated protein (MAP) kinases have been highlighted for their potential role in signalling PC12 cell differentiation. We report here that retrovirus-mediated expression of GTPase-deficient, constitutively active forms of the heterotrimeric Gq family members, G alpha qQ209L and G alpha 16Q212L, in PC12 cells induces neuronal differentiation as indicated by neurite outgrowth and the increased expression of voltage-dependent sodium channels. Differentiation …

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Physical Linkage Of The Vibrio Cholerae Mannose-Sensitive Hemagglutinin Secretory And Structural Subunit Gene Loci: Identification Of The Mshg Coding Sequence., Jane W. Marsh, Daxi Sun, Ronald K. Taylor Jan 1996

Physical Linkage Of The Vibrio Cholerae Mannose-Sensitive Hemagglutinin Secretory And Structural Subunit Gene Loci: Identification Of The Mshg Coding Sequence., Jane W. Marsh, Daxi Sun, Ronald K. Taylor

Dartmouth Scholarship

Vibrio cholerae O1 expresses a variety of cell surface factors which mediate bacterial adherence and colonization at the intestinal epithelium. The mannose-sensitive hemagglutinin (MSHA), a type IV pilus, is a potential attachment factor of the V. cholerae El Tor biotype. We describe a TnphoA mutant that is defective in its ability to hemagglutinate mouse erythrocytes. The TnphoA insertion maps to a recently identified genetic locus that encodes products that are predicted to be essential for assembly and export of the MSHA pilus. Insertional disruption at this locus in a mshA-phoA reporter strain provides evidence for a role of this locus …

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Gas1-Induced Growth Suppression Requires A Transactivation-Independent P53 Function., Giannino Del Sal, Elisabetta M. Ruaro, Rene Utrera, Charles N. Cole Dec 1995

Gas1-Induced Growth Suppression Requires A Transactivation-Independent P53 Function., Giannino Del Sal, Elisabetta M. Ruaro, Rene Utrera, Charles N. Cole

Dartmouth Scholarship

In normal cells, induction of quiescence is accompanied by the increased expression of growth arrest-specific genes (gas). One of them, gas1, is regulated at the transcriptional level and codes for a membrane-associated protein (Gas1) which is down regulated during the G0-to-S phase transition in serum-stimulated cells. Gas1 is not expressed in growing or transformed cells, and when overexpressed in normal fibroblasts, it blocks the G0-to-S phase transition. Moreover, Gas1 blocks cell proliferation in several transformed cells with the exception of simian virus 40- or adenovirus-transformed cell lines. In this paper, we demonstrate that overexpression of Gas1 blocks cell proliferation in …

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