@article{ashwell_gonda_gray_maltecca_audrey t. o'nan_cassady_mente_2013, title={Changes in chondrocyte gene expression following in vitro impaction of porcine articular cartilage in an impact injury model}, volume={31}, ISSN={["1554-527X"]}, url={http://www.scopus.com/inward/record.url?eid=2-s2.0-84872761673&partnerID=MN8TOARS}, DOI={10.1002/jor.22239}, abstractNote={AbstractOur objective was to monitor chondrocyte gene expression at 0, 3, 7, and 14 days following in vitro impaction to the articular surface of porcine patellae. Patellar facets were either axially impacted with a cylindrical impactor (25 mm/s loading rate) to a load level of 2,000 N or not impacted to serve as controls. After being placed in organ culture for 0, 3, 7, or 14 days, total RNA was isolated from full thickness cartilage slices and gene expression measured for 17 genes by quantitative real‐time RT‐PCR. Targeted genes included those encoding proteins involved with biological stress, inflammation, or anabolism and catabolism of cartilage extracellular matrix. Some gene expression changes were detected on the day of impaction, but most significant changes occurred at 14 days in culture. At 14 days in culture, 10 of the 17 genes were differentially expressed with col1a1 most significantly up‐regulated in the impacted samples, suggesting impacted chondrocytes may have reverted to a fibroblast‐like phenotype. © 2012 Orthopaedic Research Society. Published by Wiley Periodicals, Inc. J Orthop Res 31: 385–391, 2013}, number={3}, journal={JOURNAL OF ORTHOPAEDIC RESEARCH}, author={Ashwell, Melissa S. and Gonda, Michael G. and Gray, Kent and Maltecca, Christian and Audrey T. O'Nan and Cassady, Joseph P. and Mente, Peter L.}, year={2013}, month={Mar}, pages={385–391} }
 @article{ashwell_o'nan_gonda_mente_2008, title={Gene expression profiling of chondrocytes from a porcine impact injury model}, volume={16}, ISSN={["1522-9653"]}, DOI={10.1016/j.joca.2007.12.012}, abstractNote={ObjectiveTo identify differentially expressed genes between axially impacted and control articular cartilage taken from porcine patellae maintained in organ culture for 14 days.MethodsPorcine patellae were impacted perpendicular to the articular surface to create an impact injury. Intact patellae (control and impacted) were maintained in culture for 14 days. Total RNA was then extracted from the articular cartilage beneath the impaction and used to prepare two Serial Analysis of Gene Expression (SAGE) libraries. Approximately 42,500 SAGE long tags were sequenced from the libraries. The expression of select genes was confirmed by quantitative real-time PCR analysis.ResultsThirty-nine SAGE tags were significantly differentially expressed in the impacted and control libraries, representing 30 different annotated pig genes. These genes represented gene products associated with matrix molecules, iron and phosphate transport, protein biosynthesis, skeletal development, cell proliferation, lipid metabolism and the inflammatory response. Twenty-three of the 30 genes were down-regulated in the impacted library and five were up-regulated in the impacted library. Quantitative real-time PCR follow-up of four genes supported the results found with SAGE.ConclusionWe have identified 30 putative genes differentially expressed in a porcine impact injury model and validated these findings for four of these genes using real-time PCR. Results using this impact injury model have contributed further evidence that damaged chondrocytes may de-differentiate into fibroblast-like cells and proliferate in an attempt to repair themselves. Additional work is underway to study these genes in further detail at earlier time points to provide a more complete story about the fate of chondrocytes in articular cartilage following an injury.}, number={8}, journal={OSTEOARTHRITIS AND CARTILAGE}, author={Ashwell, M. S. and O'Nan, A. T. and Gonda, M. G. and Mente, P. L.}, year={2008}, month={Aug}, pages={936–946} }
 @article{gonda_kirkpatrick_shook_collins_2007, title={Identification of a QTL on BTA20 affecting susceptibility to Mycobacterium avium ssp paratuberculosis infection in US Holsteins}, volume={38}, ISSN={["0268-9146"]}, DOI={10.1111/j.1365-2052.2007.01627.x}, abstractNote={SummaryThe objective of this study was to identify QTL affecting susceptibility toMycobacterium paratuberculosisinfection in US Holsteins. Twelve paternal half‐sib families were selected for the study based on large numbers of daughters in production and limited relationships among sires. Serum and faecal samples from 4350 daughters of these 12 sires were obtained for disease testing. Case definition for an infected cow was an ELISA sample‐to‐positive ratio ≥0.25, a positive faecal culture or both. Three families were selected for genotyping based on a high apparent prevalence (6.8–10.4% infected cows), high faecal culture prevalence (46.2–52.9% positive faecal cultures) and large numbers of daughters tested for disease (264–585). DNA pooling was used to genotype cows, with an average of 159 microsatellites within each sire family. Infected cows (the positive pool) were matched with two of their non‐infected herdmates in the same lactation (the negative pool) to control for herd and age effects. Eight chromosomal regions putatively linked with susceptibility toM. paratuberculosisinfection were identified using aZ‐test (P < 0.01). Significant results were more rigorously tested by individually genotyping cows with three to five informative microsatellites within 15 cM of the significant markers identified with the DNA pools. Probability of infection based on both diagnostic tests was estimated for each individual and used as the dependent variable for interval mapping. Based on this analysis, evidence for the presence of a QTL segregating within families on BTA20 was found (chromosome‐wideP‐value = 0.0319).}, number={4}, journal={ANIMAL GENETICS}, author={Gonda, M. G. and Kirkpatrick, B. W. and Shook, G. E. and Collins, M. T.}, year={2007}, month={Aug}, pages={389–396} }