Objective A new type of double-tube standard source load model provides better simulation of the human thyroid than does a traditional single-tube standard source load model. The radioactive counts of these two models were compared, as were their impacts on thyroid iodine-131 (13lI) uptake rates. Methods A double-tube standard source load model was used to analyze its impact on the rates of 131I uptake by the subjects' thyroid glands, and to compare the results with those obtained using a single-tube standard source load model. Radioactive counts in different positions were measured by thyroid function instruments, and compared. Results The 131I uptake rates by the subjects' thyroid glands at 2, 4, and 24 hours obtained using a double-tube standard source load model were lower than those obtained using a single-tube standard source load model; the differences were statistically significant (P ＜ 0. 05). Radioactive counts obtained using the double-tube standard source load model in different positions were higher than those obtained with the single-tube standard source load model; the differences were statistically significant (P ＜ 0. 05). Radioactive counts decreased with increased displacement when models were placed at 10, 12, 14, 16, and 18 cm in the horizontal direction, and at 0, 1, 2, and 3 cm in the vertical direction. Conclusion The l31I uptake rates by the subjects' thyroid glands observed using a double-tube standard source load model were lower than those observed using a single-tube standard source load model.

Objective:To investigate the effect of butyrate produced by bacterial metabolism on immune features of murine bone marrow-derived dendritic cells(BMDCs) and its potential mechanisms.Methods: BMDCs were prepared from bone marrow cells of C57BL/6 mice by being cultured with GM-CSF and IL-4.The expression of CD80,CD86,B7-DC and MHCⅡ on BMDCs and its pri-ming ability on the proliferation of OVA257-264 antigen specific CD8+T cell were analyzed by using Flow cytometry.The mRNA levels of IL-6 and IL-12 in BMDCs were detected by real-time fluorescence quantitative PCR(q-PCR).Simultaneously,Griess reaction and Western blot was used for analyzing the levels of NO2-in BMDCs culture supernatant and the ERK phosphortylation in BMDCs respectivly.Results:Butyrate could decrease the levels of CD80,CD86,MHCⅡand B7-DC,and downregulate the capability of BMDCs in priming the proliferation of CD8+T cells.Furthermore,the secretions of IL-6,IL-12,NO2-and the phosphorylation of ERK were sup-pressed.Conclusion:Butyrate down-regulats the immune functions of BMDCs via inhibition of ERK phosphorylation in TLR 4 signaling pathway.