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Full-Text Articles in Medicine and Health Sciences

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 …


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 …


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. …


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 …


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 …


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 …


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 …


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.


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 …


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 …


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 …


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 …


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 …


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 …


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 …


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 …


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 …