Streptococcus suis intranasal challenge model and identification of a potential anti-phagocytic virulence factor in S. suis supernatant

Streptococcus suis (S. suis) colonizes the tonsils of most healthy pigs. However, in some pigs the bacteria invade causing a septicemia resulting in meningitis, arthritis, serositis, and/or pneumonia. The interaction between S. suis and neutrophils has been reported to be important, but factors involved in the S. suis/neutrophil interaction are unknown. In addition, there are no published models of experimentally induced S. suis disease using exposure of pigs to S. suis alone via the natural route of infection (oral/nasal). A model of this nature is important for the evaluation of virulence factors, vaccines, and treatment regimens. Two studies are presented in this dissertation;The first study was designed to develop a reproducible intranasal S. suis challenge model and to use the model to better understand S. suis-induced disease. Pigs were exposed to S. suis serotype 2, isolate ISU VDL #40634/94, by aerosolization or by intranasal inoculation. The exposure to S. suis was with or without preexposure to a nasal mucosal irritant, ammonia. The results of these experiments indicated that the ammonia pretreatment did not change the pathogenesis of the disease or disease incidence when compared to S. suis alone. Intranasal inoculation resulted in a higher number of animals developing S. suis-induced disease compared to aerosolized S. suis. The outcome following intranasal inoculation of S. suis did not change after the S. suis serotype 2 isolate was passaged in vitro 20 times. Streptococcus porcinus avirulent live vaccine was evaluated for efficacy against S. suis-induced disease using this model. The S. porcinus vaccine reduced S. suis-induced disease incidence, but not significantly (p \u3e 0.05), and was not pursued further;The second study was designed to characterize S. suis factors secreted by S. suis serotype 2 during incubation in saline for two hours. A porcine neutrophil suppressive factor that passed through a 1000 dalton filter was identified. Reverse phase high performance liquid chromatography was used to purify the factor. The suppressive fraction contained guanine and at least two other unknown components that may be other bases and/or nucleosides. The factor suppresses neutrophil iodination, but does not inhibit neutrophil ingestion of Staphylococcus aureus, cytochrome C reduction, or random migration

Molecular aspects of persistent bovine viral diarrhea virus infection on bovine neutrophils

http://www.worldcat.org/oclc/2085995

Gardner-Webb Review, Volume 5, 2004

Annual publication associated with the Life of the Scholar Multidisciplinary Conference. This publication presents selected essays written by undergraduate students at Gardner-Webb University

Evaluation of the microstructure of Al-Cu-Li-Ag-Mg Weldalite (tm) alloys, part 4

Weldalite (trademark) 049 is an Al-Cu-Li-Ag-Mg alloy designed to have ultrahigh strength and to serve in aerospace applications. The alloy displays significantly higher strength than competitive alloys in both naturally aged and artificially aged tempers. The strengthening phases in such tempers have been identified to, in part, explain the mechanical properties attained. In general, the alloy is strengthened by delta prime Al3Li and Guinier-Preston (GP) zones in the naturally aged tempers. In artificially aged tempers in slightly underaged conditions, strengthening is provided by several phases including GP zones, theta prime Al2Cu, S prime Al2CuMg, T(sub 1) Al2CuLi, and possibly a new phase. In the peak strength artificially aged tempers, T(sub 1) is the predominant strengthening phase

High school students' perceptions of and attitudes toward globalization: an analysis of international baccalaureate students in Estado de Mexico, Mexico, and Texas, U.S.A.

As the last few decades have seen a proliferation of debate concerning todayâÂÂs international system referred to as âÂÂglobalization,â education has seen an exponential rise in curriculum (such as that promoted by global education, international education, and the International Baccalaureate Organization) that instills students with âÂÂinternational understandingâ and âÂÂglobal perspectives.â Through a two-site, interpretive study, this dissertation explored the nature of 15 studentsâ international understanding and their grasp of globalization. Qualitative techniques for data collection involved open-ended questionnaires and interviews, and emergent category designation was employed for qualitative data analysis. International Baccalaureate students from Estado de México and Texas revealed complex, yet well-developed, perceptions of globalization that spoke of a system which privileges the powerful and leaves the developing world behind. Both U.S. and Mexican students were skeptical of the United Statesâ position as the dominant player in world politics, economics, and global culture, and students from both sides of the border lamented local culture loss in globalization

Demographic Characteristics and Habitat Associations of an Expanding Black Bear (Ursus Americanus) Population In Oklahoma

Recent black bear expansion into Oklahoma from Arkansas has led to management questions involving the growing bear population. Demographic characteristics of the peripheral portion of the black bear population were analyzed using live-trapping. Distribution, population estimation, and habitat preferences of the population were determined using hair sampling and genetic analysis. Black bears in the peripheral part of Oklahoma were equally composed of males and females (0.95M:1F) and had a relatively young age structure. Brown coloration occurred more in black bears captured in Oklahoma compared with Arkansas. The population size was estimated at 451 bears: 174 � 46 (95% confidence interval: 108 - 294) females and 277 � 71 (95% confidence interval: 174 - 461) males. Black bears in Oklahoma were associated positively with forest, streams, and development. Black bears were associated negatively with roads, highways, and areas farther away from Arkansas.Department of Natural Resource Ecology and Managemen

France and the Remilitarization of the Rhineland

Histor

Defective function of leukocytes from cattle persistently infected with bovine viral diarrhea virus, and the influence of recombinant cytokines

Cattle persistently infected with bovine viral diarrhea (BVD) virus have decreased neutrophil and lymphocyte functions. We reevaluated these functions and further characterized the inhibition of persistent BVD virus infection in neutrophils, using sensitive kinetic assays. In addition, the influence of in vitro incubation of neutrophils with recombinant bovine interferon gamma (~IloIFN gamma) and in vitro incubation of lymphocytes with recombinant bovine interleukin-2 was evaluated