@article{ahlborn_delker_roop_geter_allen_deangelo_winnik_2009, title={Early alterations in protein and gene expression in rat kidney following bromate exposure}, volume={47}, ISSN={["1873-6351"]}, DOI={10.1016/j.fct.2009.02.003}, abstractNote={Bromate, a common disinfectant byproduct of drinking water ozonation, has been linked to human and animal renal toxicity, including renal cell carcinomas in multiple animal species. Here, we evaluate changes in protein and gene expression through two-dimensional difference gel electrophoresis (2D-DIGE) and Affymetrix arrays to identify potential modes of action involved in potassium bromate carcinogenicity. Male rats were exposed to potassium bromate in drinking water at concentrations of 0, 1, 20 and 400 ppm for two weeks. Differential expression of glycolytic proteins including enolase 1 (Eno1), triosephosphate isomerase 1 (Tpi1) and glyceraldehyde-3-phosphate dehydrogenase (Gapdh) suggests that bromate toxicity is associated with changes in energy consumption and utilization in renal cells involving up-regulation of glycolytic processes that may be the result of altered mitochondrial function. Several alterations in glycolysis and mitochondrial gene transcripts were also observed to be consistent with this mode of action. These studies provide insight into early events in renal cell physiology altered by bromate exposure.}, number={6}, journal={FOOD AND CHEMICAL TOXICOLOGY}, author={Ahlborn, Gene J. and Delker, Don A. and Roop, Barbara C. and Geter, David R. and Allen, James W. and DeAngelo, Anthony B. and Winnik, Witold M.}, year={2009}, month={Jun}, pages={1154–1160} }
 @article{ahlborn_nelson_grindstaff_waalkes_diwan_allen_kitchin_preston_hernandez-zavala_adair_et al._2009, title={Impact of life stage and duration of exposure on arsenic-induced proliferative lesions and neoplasia in C3H mice}, volume={262}, number={2}, journal={Toxicology (Amsterdam, Netherlands)}, author={Ahlborn, G. J. and Nelson, G. M. and Grindstaff, R. D. and Waalkes, M. P. and Diwan, B. A. and Allen, J. W. and Kitchin, K. T. and Preston, R. J. and Hernandez-Zavala, A. and Adair, B. and et al.}, year={2009}, pages={106–113} }
 @misc{ahlborn_nelson_ward_knapp_allen_ouyang_roop_chen_o'brien_kitchin_et al._2008, title={Dose response evaluation of gene expression profiles in the skin of K6/ODC mice exposed to sodium arsenite}, volume={227}, number={3}, journal={Toxicology and Applied Pharmacology}, author={Ahlborn, G. J. and Nelson, G. M. and Ward, W. O. and Knapp, G. and Allen, J. W. and Ouyang, M. and Roop, B. C. and Chen, Y. and O'Brien, T. and Kitchin, K. T. and et al.}, year={2008}, pages={400–416} }
 @article{ahlborn_clare_sheldon_kelly_2006, title={Identification of Eggshell Membrane Proteins and Purification of Ovotransferrin and β-NAGase from Hen Egg White}, volume={25}, ISSN={1572-3887 1573-4943}, url={http://dx.doi.org/10.1007/s10930-006-0010-8}, DOI={10.1007/s10930-006-0010-8}, abstractNote={Exposure of selected Gram-positive and Gram-negative bacterial pathogens to egg shell membranes (ESM) significantly reduced their thermal resistance and/or inactivated cells. Although the components responsible for this antibacterial activity have not been conclusively identified, several proteins associated with the ESM activity have been identified including beta-N-acetylglucosaminidase, lysozyme and ovotransferrin, with each displaying varying degrees of antibacterial activity. Numerous attempts to purify active fractions of beta-N-acetylglucosaminidase, lysozyme and ovotransferrin from the ESM proved somewhat limited; however, hen egg white (HEW) beta-N-acetylglucosaminidase was purified using a two-step chromatographic procedure, isoelectric focusing followed by cation exchange chromatography. Pure fractions of ovotransferrin were also obtained in the process. SDS-PAGE electrophoresis and Matrix-Assisted Laser Desorption Time-of-Flight Mass Spectrometry were then used to partially characterize the individual protein components. Purified protein fractions such as these will be required in order to fully elucidate the mechanism responsible for the antimicrobial properties associated with the ESM.}, number={1}, journal={The Protein Journal}, publisher={Springer Science and Business Media LLC}, author={Ahlborn, G. J. and Clare, D. A. and Sheldon, B. W. and Kelly, R. W.}, year={2006}, month={Jan}, pages={71–81} }
 @article{ahlborn_sheldon_2006, title={Identifying the components in eggshell membrane responsible for reducing the heat resistance of bacterial pathogens}, volume={69}, ISSN={["1944-9097"]}, DOI={10.4315/0362-028x-69.4.729}, abstractNote={The biological activity (D-value determination) of eggshell membrane (ESM) was examined to determine the membrane components and mechanisms responsible for antibacterial activity. Biological and enzymatic activities (i.e., beta-N-acetylglucosaminidase [beta-NAGase], lysozyme, and ovotransferrin) of ESM denatured with trypsin, lipases, or heat were compared with those of untreated ESM. Trypsin-treated ESM lost all biological activity (D-values at 54 degrees C were 5.12 and 5.38 min for immobilized and solubilized trypsin, respectively) but showed no significant loss of enzymatic activities. Treatments with porcine lipase and a lipase cocktail did not impact biological or enzymatic activities. Heat denaturation of ESM (at 80 and 100 degrees C for 15 min) resulted in significant decreases in biological activity (D-values of 3.99 and 4.43 min, respectively) and loss of beta-NAGase activity. Lysozyme and ovotransferrin activities remained but were significantly reduced. Purified ESM and hen egg white components (i.e., beta-NAGase, lysozyme, and ovotransferrin) were added to Salmonella Typhimurium suspensions (in 0.1% peptone water) at varying concentrations to evaluate their biological activity. D-values at 54 degrees C were 4.50 and 3.68 min for treatment with lysozyme or beta-NAGase alone, respectively, and 2.44 min for ovotransferrin but 1.47 min for a combination of all three components (similar to values for ESM). Exposure of Salmonella Typhimurium cells to a mixture of ovotransferrin, lysozyme, and beta-NAGase or ESM resulted in significant increases in extracellular concentrations of Ca2+, Mg2+, and K+. Transmission electron microscopic examination of Salmonella Typhimurium cells treated with a combination of ovotransferrin, lysozyme, and beta-NAGase revealed membrane disruption and cell lysis. The findings of this study demonstrate that ovotransferrin, lysozyme, and beta-NAGase are the primary components responsible for ESM antibacterial activity. The combination of these proteins and perhaps other ESM components interferes with interactions between bacterial lipopolysaccharides, sensitizing the outer bacterial membrane to the lethal affects of heat and possibly pressure and osmotic stressors.}, number={4}, journal={JOURNAL OF FOOD PROTECTION}, author={Ahlborn, G and Sheldon, BW}, year={2006}, month={Apr}, pages={729–738} }
 @article{ahlborn_sheldon_2005, title={Enzymatic and microbiological inhibitory activity in eggshell membranes as influenced by layer strains and age and storage variables}, volume={84}, ISSN={["1525-3171"]}, DOI={10.1093/ps/84.12.1935}, abstractNote={Eggshell membranes (ESM) have been shown to exhibit antibacterial activity. The purpose of this study was to evaluate the enzymatic and biological [decimal reduction times (D-values)] activities of ESM as a function of bird breed, age, and ESM stabilization treatments. Younger White Leghorn (WL) hens produced ESM with 28% higher lysozyme activity than Rhode Island Red (RIR) layers. In contrast, older WL layers produced ESM with 17% less lysozyme activity than ESM from RIR layers. Similarly, beta-N-acetylglucosaminidase (beta-NAGase) ESM activities differed by hen age within breeds with younger hens yielding 14 to 16% more enzyme activity. D54 degrees C-values of Salmonella Typhimurium cells preexposed to WL ESM did not differ as a function of bird age (33, 50, and 81 wk). The ESM Lysozyme and beta-NAGase activities varied somewhat over a 6-mo storage study after treatment with 1 of 5 stabilization methods [i.e., storage at 4 degrees C, -20 degrees C, or ambient air storage after freeze drying, air drying (23 degrees C), or forced-air drying (50 degrees C)]. Both air and forced-air drying yielded significant reductions in beta-NAGase and lysozyme ESM activity (ca 12 to 30%) after the initial 24 h and then remained fairly stable during the extended storage. Freeze-dried samples retained the most enzymatic activity (95%) throughout the 6-mo trial, whereas refrigerated ESM lost 20 and 18% of the beta-NAGase and lysozyme activities, respectively. Frozen ESM lost 22% of the beta-NAGase activity, whereas lysozyme was nearly unaffected after 6 mo. The ESM biological activities against S. Typhimurium were not adversely impacted by layer breed or age. No significant loss in biological activity of ESM was detected 24 h after processing or after 6 mo of storage for refrigerated, frozen, and freeze-dried membranes, whereas significant reductions were observed for air- and heat-dried ESM. These findings demonstrate that ESM enzyme and biological activities are relatively constant across layer breeds and over extended storage. Based on these and other findings, ESM may have potential commercial value as a processing adjuvant in food and pharmaceutical product applications.}, number={12}, journal={POULTRY SCIENCE}, author={Ahlborn, G and Sheldon, BW}, year={2005}, month={Dec}, pages={1935–1941} }