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Your search keyword '"Holdsworth, David W."' showing total 734 results
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734 results on '"Holdsworth, David W."'

231. Functional Neoangiogenesis Imaging of Genetically Engineered Mouse Prostate Cancer Using Three-Dimensional Power Doppler Ultrasound

Author

Xuan, Jim W., primary, Bygrave, Michael, additional, Jiang, Hongyi, additional, Valiyeva, Fatma, additional, Dunmore-Buyze, Joy, additional, Holdsworth, David W., additional, Izawa, Jonathan I., additional, Bauman, Glenn, additional, Moussa, Madeleine, additional, Winter, Scott F., additional, Greenberg, Norman M., additional, Chin, Joseph L., additional, Drangova, Maria, additional, Fenster, Aaron, additional, and Lacefield, James C., additional

Published
2007
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235. Repeated Exposure to High-Frequency Low-Amplitude Vibration Induces Degeneration of Murine Intervertebral Discs and Knee Joints.

Author

McCann, Matthew R., Patel, Priya, Pest, Michael A., Ratneswaran, Anusha, Lalli, Gurkeet, Beaucage, Kim L., Backler, Garth B., Kamphuis, Meg P., Esmail, Ziana, Lee, Jimin, Barbalinardo, Michael, Mort, John S., Holdsworth, David W., Beier, Frank, Dixon, S. Jeffrey, and Séguin, Cheryle A.

Subjects
TREATMENT of musculoskeletal system diseases, VIBRATION therapy, ACADEMIC medical centers, ANIMAL experimentation, BIOLOGICAL models, GENE expression, IMMUNOHISTOCHEMISTRY, MICE, POLYMERASE chain reaction, RESEARCH funding, T-test (Statistics), VIBRATION (Mechanics), REVERSE transcriptase polymerase chain reaction
Abstract

Objective High-frequency, low-amplitude whole-body vibration (WBV) is being used to treat a range of musculoskeletal disorders; however, there is surprisingly limited knowledge regarding its effect(s) on joint tissues. This study was undertaken to examine the effects of repeated exposure to WBV on bone and joint tissues in an in vivo mouse model. Methods Ten-week-old male mice were exposed to vertical sinusoidal vibration under conditions that mimic those used clinically in humans (30 minutes per day, 5 days per week, at 45 Hz with peak acceleration at 0.3 g). Following WBV, skeletal tissues were examined by micro-computed tomography, histologic analysis, and immunohistochemistry, and gene expression was quantified using real-time polymerase chain reaction. Results Following 4 weeks of WBV, intervertebral discs showed histologic hallmarks of degeneration in the annulus fibrosus, disruption of collagen organization, and increased cell death. Greater Mmp3 expression in the intervertebral disc, accompanied by enhanced collagen and aggrecan degradation, was found in mice exposed to WBV as compared to controls. Examination of the knee joints after 4 weeks of WBV revealed meniscal tears and focal damage to the articular cartilage, changes resembling osteoarthritis. Moreover, mice exposed to WBV also demonstrated greater Mmp13 gene expression and enhanced matrix metalloproteinase-mediated collagen and aggrecan degradation in articular cartilage as compared to controls. No changes in trabecular bone microarchitecture or density were detected in the proximal tibia. Conclusion Our experiments reveal significant negative effects of WBV on joint tissues in a mouse model. These findings suggest the need for future studies of the effects of WBV on joint health in humans. [ABSTRACT FROM AUTHOR]

Published
2015
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236. Metrology test object for dimensional verification in additive manufacturing of metals for biomedical applications.

Author

Teeter, Matthew G., Kopacz, Alexander J., Nikolov, Hristo N., and Holdsworth, David W.

Subjects
METROLOGY, BIOMATERIALS, COMPUTED tomography
Abstract

Additive manufacturing continues to increase in popularity and is being used in applications such as biomaterial ingrowth that requires sub-millimeter dimensional accuracy. The purpose of this study was to design a metrology test object for determining the capabilities of additive manufacturing systems to produce common objects, with a focus on those relevant to medical applications. The test object was designed with a variety of features of varying dimensions, including holes, cylinders, rectangles, gaps, and lattices. The object was built using selective laser melting, and the produced dimensions were compared to the target dimensions. Location of the test objects on the build plate did not affect dimensions. Features with dimensions less than 0.300 mm did not build or were overbuilt to a minimum of 0.300 mm. The mean difference between target and measured dimensions was less than 0.100 mm in all cases. The test object is applicable to multiple systems and materials, tests the effect of location on the build, uses a minimum of material, and can be measured with a variety of efficient metrology tools (including measuring microscopes and micro-CT). Investigators can use this test object to determine the limits of systems and adjust build parameters to achieve maximum accuracy. [ABSTRACT FROM AUTHOR]

Published
2015
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239. Adventitial Microvessel Formation After Coronary Stenting and the Effects of SU11218, a Tyrosine Kinase Inhibitor

Author

Cheema, Asim N., primary, Hong, Tony, additional, Nili, Nafiseh, additional, Segev, Amit, additional, Moffat, John G., additional, Lipson, Kenneth E., additional, Howlett, Anthony R., additional, Holdsworth, David W., additional, Cole, Michael J., additional, Qiang, Beiping, additional, Kolodgie, Frank, additional, Virmani, Renu, additional, Stewart, Duncan J., additional, and Strauss, Bradley H., additional

Published
2006
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