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Full-Text Articles in Medicine and Health Sciences

Genomic Structure Of Murine Mitochondrial Dna Polymerase-Gamma., Justin L. Mott, Grace Denniger, Steve J. Zullo, H. Peter Zassenhaus Oct 2000

Genomic Structure Of Murine Mitochondrial Dna Polymerase-Gamma., Justin L. Mott, Grace Denniger, Steve J. Zullo, H. Peter Zassenhaus

Journal Articles: Biochemistry & Molecular Biology

We have sequenced a genomic clone of the gene encoding the mouse mitochondrial DNA polymerase. The gene consists of 23 exons, which span approximately 13.2 kb, with exons ranging in size from 53 to 768 bp. All intron-exon boundaries conform to the GT-AG rule. By comparison with the human genomic sequence, we found remarkable conservation of the gene structure; the intron-exon borders are in almost identical locations for the 22 introns. The 5' upstream region contains approximately 300 bp of homology between the mouse and human sequences that presumably contain the promoter element. This region lacks any obvious TATA domain …


Immunologic Effects Of Gliotoxin In Rats: Mechanisms For Prevention Of Autoimmune Diabetes Mellitus, Honggang Liu, Susan H. Jackman, Henry Driscoll, Bryan Larsen Oct 2000

Immunologic Effects Of Gliotoxin In Rats: Mechanisms For Prevention Of Autoimmune Diabetes Mellitus, Honggang Liu, Susan H. Jackman, Henry Driscoll, Bryan Larsen

Biochemistry and Microbiology

Various fungal products, such as gliotoxin (GT), have immunomodulating activity, a fact exploited previously by our group for prevention of autoimmune diabetes mellitus in BB/Wor rats. To understand better the immunologic effects in GT-treated rats, splenocytes from 65-day-old prediabetic diabetes-prone rats were phenotypically characterized after chronic treatment with GT. A parallel study examined the direct effects of GT on splenocyte preparations incubated with the mycotoxin. In vitro treatment of splenocytes with GT revealed relative decreases in CD4+ and increases in CD8+ T-cell subsets, whereas in vivo treatment with GT did not result in detectable alterations in relative CD4+ and CD8+ …


Helicobacter Pylori Serology And The Diagnosis Of H. Pylori Infection In Children, Yoram Elitsur, Rafah Aflak, Cheryl Neace, W. E. Triest Sep 2000

Helicobacter Pylori Serology And The Diagnosis Of H. Pylori Infection In Children, Yoram Elitsur, Rafah Aflak, Cheryl Neace, W. E. Triest

Biochemistry and Microbiology

Serological screening accuracy rate may be dependent on clinical and pathological determinants. The aim of this study was to evaluate the accuracy of Hp serology test (Roche Biomedical Lab., Labcorp), In the diagnosis of Hp infection in 121 children who were seen in the Pediatric Gastoenterology Clinic at the Marshall University Joan C. Edwards School of Medicine In Huntington. Positive serology detected children with Hpassociated gastritis with a sensitivity of 51.6%. Positive serology significantly correlated with the degree of gastric inflammation and density of Hp organisms in the gastric mucosa (ANOVA p < 0.001). The Labcorp. Hp-ELISA test had a poor accuracy rate for the detection of Hp-gastritis in children. Gastric biopsies should always be performed to establish the diagnosis of Hp infection in children.


A Ypt/Rab Effector Complex Containing The Sec1 Homolog Vps33p Is Required For Homotypic Vacuole Fusion, Darren F. Seals, Gary Eitzen, Nathan Margolis, William T. Wickner, Albert Price Aug 2000

A Ypt/Rab Effector Complex Containing The Sec1 Homolog Vps33p Is Required For Homotypic Vacuole Fusion, Darren F. Seals, Gary Eitzen, Nathan Margolis, William T. Wickner, Albert Price

Dartmouth Scholarship

Yeast vacuoles undergo priming, docking, and homotypic fusion, although little has been known of the connections between these reactions. Vacuole-associated Vam2p and Vam6p (Vam2/6p) are components of a 65S complex containing SNARE proteins. Upon priming by Sec18p/NSF and ATP, Vam2/6p is released as a 38S subcomplex that binds Ypt7p to initiate docking. We now report that the 38S complex consists of both Vam2/6p and the class C Vps proteins [Reider, S. E. and Emr, S. D. (1997) Mol. Biol. Cell 8, 2307-2327]. This complex includes Vps33p, a member of the Sec1 family of proteins that bind t-SNAREs. We term this …


A New Role For A Snare Protein As A Regulator Of The Ypt7/Rab-Dependent Stage Of Docking, Christian Ungermann, Albert Price, William Wickner Aug 2000

A New Role For A Snare Protein As A Regulator Of The Ypt7/Rab-Dependent Stage Of Docking, Christian Ungermann, Albert Price, William Wickner

Dartmouth Scholarship

The homotypic fusion of yeast vacuoles occurs in an ordered cascade of priming, docking, and fusion. The linkage between these steps has so far remained unclear. We now report that Vam7p (the vacuolar SNAP-23/25 homolog) signals from the cis-SNARE complex to Ypt7p (the vacuolar Rab/Ypt) to initiate the docking process. After Vam7p has been released from the cis-SNARE complex by Sec18p-mediated priming, it is still required for Ypt7p-dependent docking and it needs Ypt7p to remain on the vacuole.


Vitamin A And Cancer, Richard M. Niles Jul 2000

Vitamin A And Cancer, Richard M. Niles

Biochemistry and Microbiology

Vitamin A, its physiological metabolites and synthetic derivatives (retinoids) have been shown to have protective effects against the development of certain types of cancer. In addition, pharmacological amounts of retinoids have been used with some success in the treatment of a few human tumors. The chemoprevention effect of retinoids is most likely exerted at the tumor promotion phase of carcinogenesis. Retinoids block tumor promotion by either inhibiting proliferation, inducing apoptosis, inducing differentiation, or a combination of these actions. Clinically, isotretinoin (13-cis-retinoic acid) significantly decreases the incidence of second primary tumors in patients with head and neck cancer and also reduces …


Effect Of Receptor-Selective Retinoids On Growth And Differentiation Pathways In Mouse Melanoma Cells, Sejal H. Desai, Goran Boskovic, Linda L. Eastham, Marcia Dawson, Richard M. Niles May 2000

Effect Of Receptor-Selective Retinoids On Growth And Differentiation Pathways In Mouse Melanoma Cells, Sejal H. Desai, Goran Boskovic, Linda L. Eastham, Marcia Dawson, Richard M. Niles

Biochemistry and Microbiology

Treatment of B16 mouse melanoma cells with all-trans-retinoic acid (ATRA) results in inhibition of cell proliferation and induction of differentiation. Accompanying these events is an induction of retinoic acid receptor β (RARβ) expression, an increase in protein kinase Cα (PKCα) expression, and enhanced activator protein-1 (AP-1) transcriptional activity. These cells express nuclear RARα and RARγ and nuclear retinoid X receptors (RXR) α and β constitutively. We tested the ability of receptor-selective retinoids to induce the biochemical changes found in ATRA-treated melanoma cells and also tested their effectiveness in decreasing anchorage-dependent and -independent growth. The RXR-selective ligand (2E,4E)-6-(5,6,7,8-tetrahydro-3,5,5,8,8-pentamethyl-2-naphthalenyl)-3,7-dimethyl-2,4,6-octatrienoic acid (SR11246) was …


Asymmetric Requirements For A Rab Gtpase And Snare Proteins In Fusion Of Copii Vesicles With Acceptor Membranes, Xiaochun Cao, Charles Barlowe Apr 2000

Asymmetric Requirements For A Rab Gtpase And Snare Proteins In Fusion Of Copii Vesicles With Acceptor Membranes, Xiaochun Cao, Charles Barlowe

Dartmouth Scholarship

Soluble NSF attachment protein receptor (SNARE) proteins are essential for membrane fusion in transport between the yeast ER and Golgi compartments. Subcellular fractionation experiments demonstrate that the ER/Golgi SNAREs Bos1p, Sec22p, Bet1p, Sed5p, and the Rab protein, Ypt1p, are distributed similarly but localize primarily with Golgi membranes. All of these SNARE proteins are efficiently packaged into COPII vesicles and suggest a dynamic cycling of SNARE machinery between ER and Golgi compartments. Ypt1p is not efficiently packaged into vesicles under these conditions. To determine in which membranes protein function is required, temperature-sensitive alleles of BOS1, BET1, SED5, SLY1, and YPT1 that …


Differential Expression Of Chemokines In A Mouse Model Of Wound Healing, Susan H. Jackman, Matthew B. Yoak, Shivaleela Keerthy, Bonnie L. Beaver Apr 2000

Differential Expression Of Chemokines In A Mouse Model Of Wound Healing, Susan H. Jackman, Matthew B. Yoak, Shivaleela Keerthy, Bonnie L. Beaver

Biochemistry and Microbiology

Macrophages have a multifaceted role in wound healing. While their initial activity may be in the degradation and elimination of damaged tissue, macrophages also produce and secrete a variety of mediators that can participate in the repair process as well. To perform these functions, macrophages must be recruited to a wound site. Our purpose was to examine the temporal and spatial expression of macrophage chemoattracting cytokines (chemokines) at a surgical wound site. A surgical wound was prepared on the dorsal aspect of B6AFI/J mice. Biopsies were obtained from the wound and a comparable nonwounded area between 6 and 72 hr …


Membrane Cholesterol Content Modulates Activation Of Volume-Regulated Anion Current In Bovine Endothelial Cells., I Levitan, A E Christian, T N Tulenko, G H Rothblat Apr 2000

Membrane Cholesterol Content Modulates Activation Of Volume-Regulated Anion Current In Bovine Endothelial Cells., I Levitan, A E Christian, T N Tulenko, G H Rothblat

Department of Biochemistry and Molecular Biology Faculty Papers

Activation of volume-regulated anion current (VRAC) plays a key role in the maintenance of cellular volume homeostasis. The mechanisms, however, that regulate VRAC activity are not fully understood. We have examined whether VRAC activation is modulated by the cholesterol content of the membrane bilayer. The cholesterol content of bovine aortic endothelial cells was increased by two independent methods: (a) exposure to a methyl-beta-cyclodextrin saturated with cholesterol, or (b) exposure to cholesterol-enriched lipid dispersions. Enrichment of bovine aortic endothelial cells with cholesterol resulted in a suppression of VRAC activation in response to a mild osmotic gradient, but not to a strong …


Fungal Ipc Synthase Assay, Jeffery Radding, Robert C. Dickson, Robert L. Lester Feb 2000

Fungal Ipc Synthase Assay, Jeffery Radding, Robert C. Dickson, Robert L. Lester

Molecular and Cellular Biochemistry Faculty Patents

The presently-disclosed IPC synthase-inhibitor assays comprise the steps of: (1) expression of the IPC1 gene in a cell; (2) introducing labeled starting substrates for ceramide conversion as well as potential inhibitor(s) of such conversion to the expressed gene product in an environment which allows time and conditions for conversion, and (3) identifying those potential inhibitors which actually inhibit conversion. The present invention also provides methods to determine the ability of a test compound to inhibit fungal growth, comprising the steps of (1) presenting active inositolphosophotidylceramide synthase in a manner such that synthesis of inositolphosphotidylceramide can occur; (2) introducing ceramide and …


Auto-Inhibition Of Ets-1 Is Counteracted By Dna Binding Cooperativity With Core-Binding Factor Α2, Tamara L. Goetz, Ting-Lei Gu, Nancy A. Speck, Barbara J. Graves Jan 2000

Auto-Inhibition Of Ets-1 Is Counteracted By Dna Binding Cooperativity With Core-Binding Factor Α2, Tamara L. Goetz, Ting-Lei Gu, Nancy A. Speck, Barbara J. Graves

Dartmouth Scholarship

Auto-inhibition is a common transcriptional control mechanism that is well characterized in the regulatory transcription factor Ets-1. Autoinhibition of Ets-1 DNA binding works through an inhibitory module that exists in two conformations. DNA binding requires a change in the inhibitory module from the packed to disrupted conformation. This structural switch provides a mechanism to tightly regulate Ets-1 DNA binding. We report that the Ets-1 partner protein core-binding factor α2 (CBFα2; also known as AML1 or PEBP2) stimulates Ets-1 DNA binding and counteracts auto-inhibition. Support for this conclusion came from three observations. First, the level of cooperative DNA binding (10-fold) was …