Inflammatory Response to Cobalt-Chromium Alloys Fabricated With Different Techniques.

OBJECTIVES: To explore the in vitro cytokine expression of human peripheral blood mononuclear cells exposed to cobalt-chromium alloys, manufactured with different techniques, in comparison with commercially pure titanium grade 4 and titanium alloy grade 23. MATERIAL AND METHODS: Peripheral blood mononuclear cells (PBMC) were collected from 10 healthy blood donors and exposed to machine-ground coin-shaped: (a) cobalt-chromium (Co-Cr) specimens (n = 5) manufactured by four techniques, i.e. cast, milled, laser melted and presintered milled; (b) commercially pure titanium grade 4; and (c) titanium alloy grade 23. The cells were cultured for 4, 24 and 72 hours followed by investigations of pro- and anti-inflammatory cytokine release using Bio-Plex Pro™. RESULTS: In general, the PBMC produced significantly more cytokines when exposed to the cast and presintered milled Co-Cr materials compared to laser melted, milled Co-Cr and titanium materials. CONCLUSIONS: Within the limitation of the present study, it may be suggested that cast and presintered milled cobalt-chromium alloys provoke a stronger inflammatory response compared to milled and laser melted cobalt-chromium alloys and titanium materials.

Distinguishing vegan-, vegetarian-, and omnivorous diets by hair isotopic analysis.

BACKGROUND: Dietary risks contribute heavily to disability-adjusted life years (DALYs), being more important than hypertension, obesity, or smoking. To measure dietary exposure remains a challenge in nutrition research. AIMS: The aim of the present study was to test the hypothesis that isotope ratios of 15N and 13C in human hair could distinguish between subjects adhering to different habitual diets. METHODS: 20 male and 29 female subjects average 31 years old (range 19-53), with stable dietary habits volunteered. Diets were vegan, vegetarian and omnivorous. Hair samples were processed on an elemental analyser coupled to isotope-ratio mass spectrometry. RESULTS: δ15N differed between vegan, vegetarian and omnivorous diets, p < 0.05 for all. δ13C differed between vegan and omnivorous diets, p < 0.05, but neither of these diets were separated from the vegetarian diet. CONCLUSION: Elemental Analysis of δ13C and especially δ15N with isotope ratio mass spectrometry seems to be a promising, non-invasive and objective way to distinguish groups of subjects on different habitual diets, at least if n=>10.

Inflammatory cytokine release from human peripheral blood mononuclear cells exposed to polyetheretherketone and titanium-6 aluminum-4 vanadium in vitro.

Objective To investigate the cytokine expression profiles of blood cells exposed to polyetheretherketone and titanium-6 aluminum-4 vanadium materials in vitro. Materials and methods Coin-shaped samples composed of titanium-6 aluminum-4 vanadium, polyetheretherketone, and blasted polyetheretherketone were manufactured. The surfaces of the coins were characterized using optical interferometry, scanning electron microscopy, and contact angle measurements. Peripheral blood mononuclear cells collected from 10 blood donors were cultured for one, three, and six days in the presence or absence of the coins, and then assayed for cytokine production. Quantification of the peripheral blood mononuclear cells attached to the coins was performed using confocal microscopy after immunofluorescence staining. Results The machined titanium-6 aluminum-4 vanadium coins had a smoother surface topography compared to the machined polyetheretherketone and blasted polyetheretherketone. The highest mean contact angle was noted for the blasted polyetheretherketone, followed by the machined polyetheretherketone and titanium-6 aluminum-4 vanadium. The peripheral blood mononuclear cells produced significantly more proinflammatory cytokines when exposed to the polyetheretherketone surface compared to the titanium-6 aluminum-4 vanadium surface, while the blasted polyetheretherketone induced the highest level of proinflammatory cytokine release from the peripheral blood mononuclear cells. Significantly more cells attached to both polyetheretherketone surfaces, as compared to the titanium-6 aluminum-4 vanadium surface. Conclusion Polyetheretherketone induces a stronger inflammatory response from peripheral blood mononuclear cells than does titanium-6 aluminum-4 vanadium. Surface topography has an impact on cytokine release from peripheral blood mononuclear cells.