Z. Hao

University of Wisconsin, Madison, Madison, MS, United States

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Publications (2)2.63 Total impact

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    ABSTRACT: Biocompatibilities of uncoated and diamond like carbon (DLC) coated Ti–20%Hf alloy have been investigated by means of 3T3 mouse fibroblast cell viability quantification using flow cytometry. For comparison, similar tests were performed for pure Ti, Hf, and V as well as a commercial orthopaedic alloy, Ti–6Al–4V. Under the test conditions used, the biocompatibilities of uncoated and DLC coated Ti–20%Hf alloy, pure Hf, and Ti–6Al–4V alloy were comparable to that of pure Ti, a metal known for its superior biocompatibility, while pure V clearly exhibited the lowest biocompatibility of all the materials that were evaluated. The addition of Hf to Ti resulted in significant solid solution strengthening and at 20%Hf concentration the hardness of this alloy was comparable to that of the Ti–6Al–4V alloy. Ti–Hf alloys and wear resistant, low friction DLC coatings may either be used in conjunction with or may independently hold promise for orthopaedic implants and possibly other biomedical applications.
    Materials Science and Technology 04/2008; 24(5):575-578. · 0.75 Impact Factor
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    ABSTRACT: Dysregulation of immune responses within joints plays an important role in development of inflammatory arthritis. We determined expression of a panel of immune response and matrix turnover genes in synovial fluid collected from a group of dogs with stifle oligoarthritis and associated degenerative cranial cruciate ligament (CCL) rupture (n=27). We also studied synovial fluid gene expression in dogs affected with other forms of degenerative arthritis (n=9) and in the stifle joint of healthy dogs with intact CCL (n=14). After collection, synovial cells were pelleted and RNA was isolated. Relative expression of cathepsin K, cathepsin S, tartrate-resistant acid phosphatase (TRAP), matrix metalloproteinase-9 (MMP-9), invariant chain (li), toll-like receptor-2 (TLR-2), and TLR-9 was determined using real-time quantitative RT-PCR. Data were normalized to peripheral blood mononuclear cells (PBMC) as an internal control. Relative expression of cathepsin K, MMP-9, TRAP, and li was increased in the stifle synovial fluid of dogs with oligoarthritis, when compared with the stifles of healthy dogs (P<0.05). In contrast, relative expression of all of the genes-of-interest in synovial fluid from joints affected with other forms of arthritis was not significantly different from the stifles of healthy dogs. TRAP expression was also significantly increased in the stifle joints of dogs with oligoarthritis, when compared to joint expression of TRAP in dogs with other forms of degenerative arthritis (P<0.05). In the dogs with stifle oligoarthritis, expression of both matrix turnover and immune response genes was increased in stifle synovial fluid, when compared with the internal PBMC control, whereas in healthy dogs and dogs with other forms of arthritis, only expression of matrix turnover genes was increased in synovial fluid, when compared with the internal PBMC control (P<0.05). Taken together, these findings suggest that antigen-specific immune responses within the stifle joint may be involved in the pathogenesis of persistent synovitis and associated joint degradation in dogs with oligoarthritis and degenerative CCL rupture.
    Veterinary Immunology and Immunopathology 11/2007; 119(3-4):214-21. · 1.88 Impact Factor