ABSTRACT
Objective To study the effect of surface physical properties of different materials for the artificial joint pros -thesis interface on Mycobacterium tuberculosis adhesion .Methods The surface polishing coating , titanium coating and hydroxyapatite coating were chosen as the experimental materials to analyze the surface topography and measure the surface roughness, contact angle and surface energy .The M.tuberculosis strains were used by in vitro cultivation method and ob-served by scanning electron microscopy (SEM) to study the morphology of M.tuberculosis and the material surface adhe-sion.The influence of surface physical properties of the interface of the artificial joint prostheses on the proliferation and ad -hesion of bacteria was evaluatd .Results The titanium coating and hydroxyapatite coating materials were hydrophobic , while the surface polishing coating was hydrophilic .The contact angle and surface energy were significantly different ( P0.05)in the OD value of bacterial solution .The titanium coating had the largest amount of interface adhesion for M.tuberculosis, fol-lowed by the hydroxyapatite coating and the polishing coating .The difference between various materials was statistically sig-nificant (P<0.05).Conclusion The adhesion of M.tuberculosis in the surface of artificial joint prosthesis materials is closely related to the surface physical properties .A adhesiveness improves with surface roughness .
ABSTRACT
Objective To discuss the significance of the detection of interferon-γin the diagnosis of active joint tuberculosis. Methods 5 kinds of specific proteins of mycobacterium tuberculosis were used as stimulating protein, the chemiluminescence enzyme immunoassay was used to test the content of interferon-γ. The interferon-γof 35 cases of patients with active joint tuberculosis and 35 cases of healthy people were detected. The difference of the sensitivity, specificity, positive predictive value, negative predictive value, positive likelihood ra-tio and negative likelihood ratio of 5 kinds of proteins to the diagnostic of active joint tuberculosis were compared. Results CFP10/ESAT6 fusion protein, Rv2041c protein, Rv0057/1352 fusion proteins, Rv1419 protein and Rv1656 protein were used as stimulating protein, the sensitivities of active joint tuberculosis by the whole blood interferon-γassay were 77.1%, 68.6%, 71.4%, 74.3%and 65.7%. The specifici-ties were 65.7%, 54.3%, 57.1%, 60.0%and 62.9%. The positive predictive values were 62.9%, 60%, 62.5%, 65%and 63.9%. The negative predictive values were 74.2%, 63.3%, 66.7%, 70%and 64.7%. The positive likelihood ratios were 2.25, 1.5, 1.67, 1.86 and 1.77. The nega-tive likelihood ratios were 0.348, 0.579, 0.5, 0.429 and 0.545. Conclusion The detection of interferon-γhas certain significance to joint tu-berculosis. But it is not as an index of diagnosing joint tuberculosis.