Temple University

About: Temple University is a education organization based out in Philadelphia, Pennsylvania, United States. It is known for research contribution in the topics: Population & Poison control. The organization has 32154 authors who have published 64375 publications receiving 2219828 citations.

Social Contracts and Marketing Ethics

Abstract: In this article, the authors describe the need and the search to date for a normative moral foundation for marketing. Social contract theory appears promising because of its clear correspondence to...

Impact of the Deepwater Horizon oil spill on a deep-water coral community in the Gulf of Mexico

Abstract: To assess the potential impact of the Deepwater Horizon oil spill on offshore ecosystems, 11 sites hosting deep-water coral communities were examined 3 to 4 mo after the well was capped. Healthy coral communities were observed at all sites >20 km from the Macondo well, including seven sites previously visited in September 2009, where the corals and communities appeared unchanged. However, at one site 11 km southwest of the Macondo well, coral colonies presented widespread signs of stress, including varying degrees of tissue loss, sclerite enlargement, excess mucous production, bleached commensal ophiuroids, and covering by brown flocculent material (floc). On the basis of these criteria the level of impact to individual colonies was ranked from 0 (least impact) to 4 (greatest impact). Of the 43 corals imaged at that site, 46% exhibited evidence of impact on more than half of the colony, whereas nearly a quarter of all of the corals showed impact to >90% of the colony. Additionally, 53% of these corals’ ophiuroid associates displayed abnormal color and/or attachment posture. Analysis of hopanoid petroleum biomarkers isolated from the floc provides strong evidence that this material contained oil from the Macondo well. The presence of recently damaged and deceased corals beneath the path of a previously documented plume emanating from the Macondo well provides compelling evidence that the oil impacted deep-water ecosystems. Our findings underscore the unprecedented nature of the spill in terms of its magnitude, release at depth, and impact to deep-water ecosystems.

Role of the Leishmania surface protease gp63 in complement fixation, cell adhesion, and resistance to complement-mediated lysis.

Abstract: The Leishmania surface protease gp63 has been identified as a parasite virulence factor. To better define the role of gp63 in Leishmania infectivity, the interaction of recombinant gp63 with complement and complement receptors was examined. On Leishmania, gp63 was not necessary for complement fixation. Complement activation occurred on transfected organisms expressing varying amounts of gp63 and on organisms expressing a mutant form of gp63 devoid of proteolytic activity. However, organisms expressing wild-type gp63 on their surface fixed only small amounts of the terminal complement components and were dramatically more resistant to lysis by complement than were those lacking functional gp63. Organisms expressing wild-type gp63 more rapidly converted C3b on their surface to a form that exhibited the neoantigen of iC3b and interacted avidly with cells expressing Mac-1, the receptor for iC3b. Complement fixation by transfected mammalian cells expressing recombinant Leishmania gp63 on their surface was also examined. The presence of Leishmania gp63 on the surface of these cells converted them into efficient activators of complement. Cells expressing gp63 on their surface fixed complement and bound avidly to the human complement receptors. The proteolytic activity of this molecule was not necessary for complement activation or adhesion to complement receptors. Thus, gp63 may contribute to parasite virulence by exerting a novel type of control over complement fixation. Organisms expressing gp63 can exploit the opsonic properties of complement while avoiding its lytic effects.