This study tested the hypothesis that 1,25-dihydroxyvitamin D(3) [1,25(OH)(2)D(3)] plays a role in human umbilical vein endothelial cells (HUVEC) cultures. HUVEC were incubated with 10 or 100 nM 1,25(OH)(2)D(3) for 24 h, in the absence or presence of 40 ng/ml tumor necrosis factor-alpha (TNF-alpha) or 2 ng/ml interleukin-1alpha (IL-1alpha). 1,25(OH)(2)D(3) did not affect HUVEC viability and proliferation, while TNF-alpha, alone or in combination with the hormone, significantly inhibited HUVEC viability. [(3)H]thymidine incorporation in HUVEC treated with TNF-alpha or IL-1alpha significantly decreased, in the absence or in the presence of the hormone, while the levels of vitamin D receptor markedly increased in the presence of 1,25(OH)(2)D(3) alone or associated with TNF-alpha or IL-1alpha, in comparison to the control. The noteworthy increase in protein levels of intercellular adhesion molecule-1 (ICAM-1) and vascular cell adhesion molecule-1 (VCAM-1) induced by TNF-alpha was significantly decreased after incubation of the cells with 1,25(OH)(2)D(3), this effect not being seen on E-selectin expression. Neither apoptosis nor nuclear translocation of NF-kappaB, induced in HUVEC by TNF-alpha was influenced by 1,25(OH)(2)D(3) treatment.

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Abstract:The effects of AISI 316L austenitic stainless steel, tested in untreated state or subjected to glow-discharge nitriding (at 10 or 20 hPa) and nitriding ϩ post-oxidizing treatments, on human umbilical vein endothelial cells (HUVEC) and on peripheral blood mononuclear cells (PBMC) were evaluated. All the treated samples showed a better corrosion resistance in PBS and higher surface hardness in comparison with the untreated alloy. In HUVEC put in contact for 72 h with the sample types, proliferation and apoptosis decreased and increased, respectively, in the presence of the nitrided ϩ post-oxidized samples, while only slight differences in cytokine (TNF-␣, IL-6, and TGF-␤1) release were registered. Intercellular adhesion molecule-1 (ICAM-1) increased in HUVEC incubated with all the treated samples, while vascular cell adhesion molecule-1 (VCAM-1) and E-selectin increased in the presence of all the sample types. PBMC incubated for 48 h with the samples showed a decrease in proliferation and an increase in apoptosis in the presence of the untreated samples and the nitrided ϩ post-oxidized ones. All the sample types induced a remarkable increase in TNF-␣ and IL-6 release in PBMC culture medium, while only the untreated sample and the nitrided at 10 hPa induced an increase in ICAM-1 expression. In HUVEC cocultured with PBMC, previously put in contact with the treated AISI 316L samples, increased levels of ICAM-1 were detected. In HUVEC coincubated with the culture medium of PBMC, previously put in contact with the samples under study, a noteworthy increase in ICAM-1, VCAM-1, and E-selectin levels was always registered, with the exception of VCAM-1, which was not affected by the untreated sample. In conclusion, even if the treated samples do not show a marked increase in biocompatibility in comparison with the untreated alloy, their higher corrosion resistance may suggest a better performance as the contact with physiological environment becomes longer.

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The Ti-6Al-4V titanium alloy is widely employed as an implant material. The effects of Ti-6Al-4V samples, tested in both an untreated state and one in which the samples were subjected to a glow-discharge treatment performed with the use of air, on human peripheral blood mononuclear cells (PBMC) were studied. Apoptosis, undetectable after 24-h contact of PBMC with the two sample types, is induced after 48 h by treated samples, and, after 48 h, but in the presence of 1.5 microg/mL PHA, by both sample types. The expression of intercellular adhesion molecule-1 (ICAM-1) always increases, in comparison with control, in PBMC put in contact with the two sample types. In the same way, a remarkable increase in tumor necrosis-alpha (TNF-alpha) release in the culture medium is registered, when PBMC are put in contact with the two sample types for 24 and 48 h. Human umbilical-vein endothelial cells (HUVEC) cocultured for 48 h with PBMC, previously incubated with the two sample types for 24 h, show an increase in ICAM-1 and vascular cell adhesion molecule-1 (VCAM-1) protein expression in comparison with control (HUVEC cocultured with control PBMC), indicating that inflammatory phenomena might occur. Taken together, these results suggest that, although plasma-treated titanium alloy shows a better biocompatibility in comparison with the untreated one, attention must be paid to the careful control of the first signs of inflammation.

The effect of nedocromil sodium on the plasma membrane fluidity of polymorphonuclear leukocytes (PMNs) was investigated by measuring steady-state fluorescence anisotropy of 1-[4-trimethylammonium-phenyl]-6-phenyl- 1,3,5-hexatriene (TMA-DPH) incorporated in the membrane. Our results show that nedocromil sodium 300 μM significantly decreased membrane fluidity of PMNs. The decrease in membrane fluidity of PMNs induced by fMLP was abolished in the presence of nedocromil sodium. These data suggest that nedocromil sodium interferes with the plasma membranes of PMNs and modulates their activities.