@article{mahajan_alexander_seabolt_catrambone_mcclung_odle_pfeiler_loboa_stahl_2011, title={Dietary Calcium Restriction Affects Mesenchymal Stem Cell Activity and Bone Development in Neonatal Pigs}, volume={141}, ISSN={["1541-6100"]}, url={http://www.scopus.com/inward/record.url?eid=2-s2.0-79951993863&partnerID=MN8TOARS}, DOI={10.3945/jn.110.131193}, abstractNote={The effects of dietary calcium (Ca) deficiency on skeletal integrity are well characterized in growing and mature mammals; however, less is known about Ca nutrition during the neonatal period. In this study, we examined the effects of neonatal Ca nutrition on bone integrity, endocrine hormones, and mesenchymal stem cell (MSC) activity. Neonatal pigs (24 ± 6 h of age) received either a Ca-adequate (1.2 g/100 g) or an ~40% Ca-deficient diet for 18 d. Ca deficiency reduced (P < 0.05) bone flexural strength and bone mineral density without major differences in plasma indicators of Ca status. There were no meaningful differences in plasma Ca, phosphate (PO(4)), parathyroid hormone, or 1,25-dihydroxycholecalciferol due to Ca nutrition throughout the study. Calcium deficiency also reduced (P < 0.05) the in vivo proliferation of MSC by ~50%. In vitro studies utilizing homologous sera demonstrated that MSC activity was affected (P < 0.05) by both the Ca status of the pig and the sera as well as by their interaction. The results indicate that neonatal Ca nutrition is crucial for bone integrity and suggest that early-life Ca restriction may have long-term effects on bone integrity via programming of MSC.}, number={3}, journal={JOURNAL OF NUTRITION}, author={Mahajan, Avanika and Alexander, Lindsey S. and Seabolt, Brynn S. and Catrambone, Daniel E. and McClung, James P. and Odle, Jack and Pfeiler, T. Wayne and Loboa, Elizabeth G. and Stahl, Chad H.}, year={2011}, month={Mar}, pages={373–379} }
 @article{sumanasinghe_pfeiler_monteiro-riviere_loboa_2009, title={Expression of Proinflammatory Cytokines by Human Mesenchymal Stem Cells in Response to Cyclic Tensile Strain}, volume={219}, ISSN={["1097-4652"]}, url={http://gateway.webofknowledge.com/gateway/Gateway.cgi?GWVersion=2&SrcAuth=ORCID&SrcApp=OrcidOrg&DestLinkType=FullRecord&DestApp=WOS_CPL&KeyUT=WOS:000263572000009&KeyUID=WOS:000263572000009}, DOI={10.1002/jcp.21653}, abstractNote={Abstract}, number={1}, journal={JOURNAL OF CELLULAR PHYSIOLOGY}, author={Sumanasinghe, Ruwan D. and Pfeiler, T. Wayne and Monteiro-Riviere, Nancy A. and Loboa, Elizabeth G.}, year={2009}, month={Apr}, pages={77–83} }
 @article{pfeiler_sumanasinghe_loboa_2008, title={Finite element modeling of 3D human mesenchymal stem cell-seeded collagen matrices exposed to tensile strain}, volume={41}, ISSN={["1873-2380"]}, DOI={10.1016/j.jbiomech.2008.04.007}, abstractNote={The use of human mesenchymal stem cells (hMSCs) in tissue engineering is attractive due to their ability to extensively self-replicate and differentiate into a multitude of cell lineages. It has been experimentally established that hMSCs are influenced by chemical and mechanical signals. However, the combined chemical and mechanical in vitro culture conditions that lead to functional tissue require greater understanding. In this study, finite element models were created to evaluate the local loading conditions on bone marrow-derived hMSCs seeded in three-dimensional collagen matrices exposed to cyclic tensile strain. Mechanical property and geometry data used in the models were obtained experimentally from a previous study in our laboratory and from mechanical testing. Eight finite element models were created to simulate three-dimensional hMSC-seeded collagen matrices exposed to different levels of cyclic tensile strain (10% and 12%), culture media (complete growth and osteogenic differentiating), and durations of culture (7 and 14 days). Through finite element analysis, it was determined that globally applied uniaxial tensile strains of 10% and 12% resulted in local strains up to 18.3% and 21.8%, respectively. Model results were also compared to experimental studies in an attempt to explain observed differences between hMSC response to 10% and 12% cyclic tensile strain.}, number={10}, journal={JOURNAL OF BIOMECHANICS}, author={Pfeiler, T. Wayne and Sumanasinghe, Ruwan D. and Loboa, Elizabeth G.}, year={2008}, month={Jul}, pages={2289–2296} }
 @article{yan_gurumurth_wright_pfeiler_loboa_everett_2007, title={Genetic background influences fluoride's effects on osteoclastogenesis}, volume={41}, ISSN={["8756-3282"]}, DOI={10.1016/j.bone.2007.07.018}, abstractNote={Excessive fluoride (F) can lead to abnormal bone biology. Numerous studies have focused on the anabolic action of F yet little is known regarding any action on osteoclastogenesis. Little is known regarding the influence of an individual's genetic background on the responses of bone cells to F. Four-week old C57BL/6J (B6) and C3H/HeJ (C3H) female mice were treated with NaF in the drinking water (0 ppm, 50 ppm and 100 ppm F ion) for 3 weeks. Bone marrow cells were harvested for osteoclastogenesis and hematopoietic colony-forming cell assays. Sera were analyzed for biochemical and bone markers. Femurs, tibiae, and lumbar vertebrae were subjected to microCT analysis. Tibiae and femurs were subjected to histology and biomechanical testing, respectively. The results demonstrated new actions of F on osteoclastogenesis and hematopoietic cell differentiation. Strain-specific responses were observed. The anabolic action of F was favored in B6 mice exhibiting dose-dependent increases in serum ALP activity (p < 0.001); in proximal tibia trabecular and vertebral BMD (tibia at 50&100 ppm, p = 0.001; vertebrae at 50 and 100 ppm, p = 0.023&0.019, respectively); and decrease in intact PTH and sRANKL (p = 0.045 and p < 0.001, respectively). F treatment in B6 mice also resulted in increased numbers of CFU-GEMM colonies (p = 0.025). Strain-specific accumulations in bone [F] were observed. For C3H mice, dose-dependent increases were observed in osteoclast potential (p < 0.001), in situ trabecular osteoclast number (p = 0.007), hematopoietic colony forming units (CFU-GEMM: p < 0.001, CFU-GM: p = 0.006, CFU-M: p < 0.001), and serum markers for osteoclastogenesis (intact PTH: p = 0.004, RANKL: p = 0.022, TRAP5b: p < 0.001). A concordant decrease in serum OPG (p = 0.005) was also observed. Fluoride treatment had no significant effects on bone morphology, BMD, and serum PYD cross-links in C3H suggesting a lack of significant bone resorption. Mechanical properties were also unaltered in C3H. In conclusion, short term F treatment at physiological levels has strain-specific effects in mice. The expected anabolic effects were observed in B6 and novel actions hallmarked by enhanced osteoclastogenesis shifts in hematopoietic cell differentiation in the C3H strain.}, number={6}, journal={BONE}, author={Yan, Dong and Gurumurth, Aruna and Wright, Maggie and Pfeiler, T. Wayne and Loboa, Elizabeth G. and Everett, Eric T.}, year={2007}, month={Dec}, pages={1036–1044} }
 @article{pfeiler_lalush_loboa_2007, title={Semiautomated finite element mesh generation methods for a long bone}, volume={85}, ISSN={["1872-7565"]}, DOI={10.1016/j.cmpb.2006.10.009}, abstractNote={The objective of this work was to develop and test a semi-automated finite element mesh generation method using computed tomography (CT) image data of a canine radius. The present study employs a direct conversion from CT Hounsfield units to elastic moduli. Our method attempts to minimize user interaction and eliminate the need for mesh smoothing to produce a model suitable for finite element analysis. Validation of the computational model was conducted by loading the CT-imaged canine radius in four-point bending and using strain gages to record resultant strains that were then compared to strains calculated with the computational model. Geometry-based and uniform modulus voxel-based models were also constructed from the same imaging data set and compared. The nonuniform voxel-based model most accurately predicted the axial strain response of the sample bone (R(2)=0.9764).}, number={3}, journal={COMPUTER METHODS AND PROGRAMS IN BIOMEDICINE}, author={Pfeiler, T. W. and Lalush, D. S. and Loboa, E. G.}, year={2007}, month={Mar}, pages={196–202} }