Harmonization of serum 25-hydroxycalciferol assay results from high-performance liquid chromatography, enzyme immunoassay, radioimmunoassay, and immunochemiluminescence systems: A multicenter study.

BACKGROUND: Remarkable disagreement among different systems of 25-hydroxy vitamin D 25(OH)D assay makes decision making for both clinical and community interventions very difficult. This study aimed to harmonize the results obtained from different 25(OH)D assay systems. METHODS: A total of 275 serum samples were analyzed for 25(OH)D using DIAsource-enzyme immunoassay (EIA), DIAsource-radioimmunoassay (RIA), Roche-electrochemiluminescence (ECL), Diasorin-chemiluminescent immunoassay (CLIA), and high-performance liquid chromatography (HPLC), as the reference method. Serum intact parathyroid hormone (iPTH) was also measured in all samples. Between-system agreement and harmonization were evaluated using Bland-Altman analysis, receiver operating characteristic (ROC), and regression analysis. RESULTS: Mean serum 25(OH)D concentrations and frequency distribution of vitamin D status showed a significant difference among the studied systems (P<.001 for both). Serum 25(OH)D assay results from all systems correlated with those from HPLC. As compared with HPLC, ECL showed a positive bias (+3.8 nmol/L), whereas CLIA had a negative bias (-11.9 nmol/L). Both EIA and RIA showed a more or less similar positive bias (8.0 and 8.1 nmol/L, respectively). Using serum iPTH-based 25(OH)D cutoff points, only ECL results became comparable to and without significant difference with HPLC. However, when system-specific cutoffs were defined based on HPLC results using regression equations, mean 25(OH)D and frequency distribution of vitamin D status were more harmonized compared with the other methods. CONCLUSION: Our findings showed that with adjustment of circulating 25(OH)D based on HPLC, frequency distribution of vitamin D status, as judged by different methods, can be well harmonized with no statistically significant inter-system difference.

Cytotoxic Effects of the Ethanol Bane Skin Extract in Human Prostate Cancer Pc3 Cells.

BACKGROUND: It is extensively supposed that vegetarian diet could affect cancer progress and increase the influence of formal chemotherapy. OBJECTIVES: The present study was designed to determine the effect of the ethanol Bane skin extract against chemo resistant prostate cancer PC3 cells. MATERIALS AND METHODS: PC3 and L929 cells were cultivated and then incubated in the ethanol Bane skin extract with various concentrations of 0.78, 1.5, 3.13, 6.25, 12.5 mg/mL in 3 times 24, 48, 72 hours. Cytotoxic effect of the ethanol Bane skin extract on PC3 and L929 cells was examined by MTT assay after 24, 48, and 72 hours. Morphology of PC3 cells was evaluated by Gimsa staining. RESULTS: The ethanol Bane skin extract inhibited proliferation and caused cell death with IC50 values of 2.8 mg/mL on PC3 cells and the IC50 was 6.1 mg/mL on l929 cells. Morphological changes and apoptotic bodies were observed in PC3 cells faced with the ethanol Bane skin extract by staining with Gimsa. CONCLUSIONS: The ethanol Bane skin extract could repress the growth of PC3 cell line. This inhibitory effect of the Bane extract depended on the dose and the time on PC3. The result of this study shows that the ethanol Bane skin extract includes photochemical and inhibitory function against proliferation and inducer of apoptosis in human prostate cancer PC3 cells and also has less cytotoxic effect on l929 than PC3 cells. The ethanol Bane skin extract might be a good candidate for the new herbal anticancer drug.