Open Access. Powered by Scholars. Published by Universities.®

Medical Sciences Commons

Open Access. Powered by Scholars. Published by Universities.®

Medical Microbiology

Dartmouth Scholarship

1997

Articles 1 - 3 of 3

Full-Text Articles in Medical Sciences

A Dichotomous Role For Nitric Oxide During Acute Toxoplasma Gondii Infection In Mice, Imtiaz A. Khan, Joseph D. Schwartzman, Tadashi Matsuura, Lloyd H. Kasper Dec 1997

A Dichotomous Role For Nitric Oxide During Acute Toxoplasma Gondii Infection In Mice, Imtiaz A. Khan, Joseph D. Schwartzman, Tadashi Matsuura, Lloyd H. Kasper

Dartmouth Scholarship

Production of nitric oxide by macrophages is believed to be an important microbicidal mechanism for a variety of intracellular pathogens, including Toxoplasma gondii. Mice with a targeted disruption of the inducible nitric oxide synthase gene (iNOS) were infected orally with T. gondii tissue cysts. Time to death was prolonged compared with parental controls. Histologic analysis of tissue from infected mice showed scattered small foci of inflammation with parasites in various tissues of iNOS−/− mice, whereas tissue from the parental C57BL/6 mice had more extensive tissue inflammation with few visible parasites. In particular, extensive ulceration and necrosis of distal small …


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 …


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 …