@article{ashwell_freire_o’nan_benito_hash_mcculloch_lascelles_2019, title={Characterization of gene expression in naturally occurring feline degenerative joint disease-associated pain}, volume={243}, ISSN={1090-0233}, url={http://dx.doi.org/10.1016/j.tvjl.2018.11.008}, DOI={10.1016/j.tvjl.2018.11.008}, abstractNote={Degenerative joint disease (DJD) associated-pain is a clinically relevant and common condition affecting domesticated cats and other species including humans. Identification of the neurobiological signature of pain is well developed in rodent pain models, however such information is lacking from animals or humans with naturally occurring painful conditions. In this study, identification of housekeeping genes (HKG) for neuronal tissue and expression levels of genes considered associated with chronic pain in rodent models were explored in cats with naturally occurring osteoarthritic pain. Fourteen adult cats were evaluated — seven without clinical signs of osteoarthritic pain, and seven with hind limb radiographic DJD and pain. Expression of an investigator-selected set of pain signaling genes (including ASIC3, ATF3, COX2, CX3CL1, NAV1.7, NAV1.8, NAV1.9, NGF, NK1R, TNFα, TRKA) in lumbar spinal cord dorsal horn and lumbar dorsal root ganglia tissues from clinically healthy cats and cats with DJD were studied using quantitative RT-PCR (qPCR). HKG identified as the most stable across all tissue samples were many of the ribosomal protein genes, such as RPL30 and RPS19. qPCR results showed ATF3 and CX3CL1 up-regulated in DJD-affected dorsal root ganglia compared to clinically healthy controls. In spinal cord, CX3CL1 was up-regulated and NGF was down-regulated when DJD-affected samples were compared to healthy samples. Further work is needed to understand the neurobiology of pain in naturally occurring disease and what rodent models are predictive of these changes in more heterogeneous populations such as domestic cats.}, journal={The Veterinary Journal}, publisher={Elsevier BV}, author={Ashwell, M. and Freire, M. and O’Nan, A.T. and Benito, J. and Hash, J. and McCulloch, R.S. and Lascelles, B.D.X.}, year={2019}, month={Jan}, pages={42–47} }
 @article{mcculloch_mente_o’nan_ashwell_2018, title={Articular cartilage gene expression patterns in the tissue surrounding the impact site following applications of shear and axial loads}, volume={19}, ISSN={1471-2474}, url={http://dx.doi.org/10.1186/s12891-018-2374-2}, DOI={10.1186/s12891-018-2374-2}, abstractNote={Osteoarthritis is a degradative joint disease found in humans and commercial swine which can develop from a number of factors, including prior joint trauma. An impact injury model was developed to deliver in vitro loads to disease-free porcine patellae in a model of OA.Axial impactions (2000 N normal) and shear impactions (500 N normal with induced shear forces) were delivered to 48 randomly assigned patellae. The patellae were then cultured for 0, 3, 7, or 14 days following the impact. Specimens in the tissue surrounding the loading site were harvested and expression of 18 OA related genes was studied via quantitative PCR. The selected genes were previously identified from published work and fell into four categories: cartilage matrix, degradative enzymes, inflammatory response, and apoptosis.Type II collagen (Col2a1) showed significantly lower expression in shear vs. axial adjacent tissue at day 0 and 7 (fold changes of 0.40 & 0.19, respectively). In addition, higher expression of degradative enzymes and Fas, an apoptosis gene, was observed in the shear specimens.The results suggest that a more physiologically valid shear load may induce more damage to surrounding articular cartilage than a normal load alone.}, number={1}, journal={BMC Musculoskeletal Disorders}, publisher={Springer Nature}, author={McCulloch, R. S. and Mente, P. L. and O’Nan, A. T. and Ashwell, M. S.}, year={2018}, month={Dec} }
 @article{jin_mcculloch_mirka_2009, title={Biomechanical evaluation of postures assumed when harvesting from bush crops}, volume={39}, ISSN={["1872-8219"]}, DOI={10.1016/j.ergon.2008.07.005}, abstractNote={The objectives of this research were to explore the changes in the low back biomechanical responses during a harvesting task as a function of different harvesting techniques/postures and to explore the effects of an ergonomic intervention designed to reduce the low back stress during this work activity. Nine participants performed a series of simulated harvesting activities in a laboratory setting using four different harvesting techniques: full kneeling posture, squatting posture, stooping posture and kneeling on a knee support device (the intervention). As they performed these tasks the activity of muscles of the torso and thighs was captured using electromyography and trunk kinematics were captured using the lumbar motion monitor and a magnetic field-based motion tracking system. The results showed that (1) three postures – knee support, squatting, and stooping – required high flexion of low back (more than 60°) and (2) squatting and stooping postures showed significantly higher passive tissue moment compared with two kneeling postures. The results also indicate that the beneficial aspects of the knee support intervention appear to be outweighed by reduced productivity and the high degree of trunk flexion and that the current strategy used by these workers of alternating between the various harvesting postures may be the best strategy available. Understanding how changes in harvesting technique affect lumbar biomechanics can help ergonomists design effective interventions for the prevention of back injury in farm workers.}, number={2}, journal={INTERNATIONAL JOURNAL OF INDUSTRIAL ERGONOMICS}, author={Jin, Sangeun and McCulloch, Ryan and Mirka, Gary A.}, year={2009}, month={Mar}, pages={347–352} }