Objective To explore the value of MRI-R2 * and to compare clinical effect of two iron chelators(deferasirox and deferoxamine) in iron-overloaded patients.Methods By completely randomized balanced design,24 iron-overloaded patients were randomly divided into 2 groups,which consisted of 12 patients treated with deferasirox and 12 patients treated with deferoxamine.The planned deferasirox dose was 40 mg· kg-1 · d-1,and the deferoxamine dose was no less than 50 mg · kg-1 · d-1 All patients underwent quantitative MRI at the time points of the primary screening,6 months and 12 months.Pair Wilcoxon rank sum test was used to compare the differences of liver R2 * values of the 2 groups at various time points respectively.Wilcoxon rank sum test was used to compare the differences of change rate of liver R2 * values between the two groups at the time point of 6 months,12 months,respectively.Results Deferasirox group's liver R2 * values of primary screening,6 months and 12 months were 1081,889 and 712 Hz,while deferoxamine group's liver R2 * values were 1042,838 and 488 Hz.There was no statistically significant difference between liver R2 * values of two groups at primary screening (Z =-0.029,P ＞ 0.05).The change rate of liver R2 * of deferasirox group at 12 month was-32％,while it was-58％ for the deferoxamine group,and there was statistically significant difference between the two groups (Z =-3.060,P ＜0.01).The change rate of serum ferritin of deferasirox group at 12 month was-15％,while it was -55％ for the deferoxamine group,and there was statistically significant difference between the two groups (Z =-2.945,P ＜ 0.01).Conclusion By using MRI-R2*,it suggest that both deferasirox and deferoxamine can effectively remove liver iron and deferoxamine is superior to deferasirox.

Objective:To analyze the influence of different number of blood pressure measurement on the detection of elevated blood pressure in Tibetan adolescents and provide scientific reference for standardizing the number of blood pressure measurement and accurately diagnosing elevated blood pressure in adolescents.Methods:Data were from the project "survey of the risk factors for elevated blood pressure among Tibetan adolescents" conducted from August to September 2018 in Shigatse in Tibet. A total of 2 822 Tibetan adolescents aged 12-17 years, including 1 275 boys (45.2%), were recruited by a convenient, stratified cluster sampling method. Each participant underwent three consecutive blood pressure measurements. Elevated blood pressure was defined according to the Health Industry Criterion of China: WS/T 610-2018 "Reference of screening for elevated blood pressure among children and adolescents aged 7-18 years" . Analysis of variance and χ2 test were used to analyze the effect of different blood pressure measurement on blood pressure levels and detection of elevated blood pressure, respectively. Results:SBP and DBP decreased substantially across three consecutive blood pressure measurements[SBP: (112.7±9.7), (110.7±9.7) and (110.2±9.5) mmHg (1 mmHg=0.133 kPa); DBP: (62.7±8.2), (61.1±8.5) and (60.6±8.5) mmHg; P value for trend<0.001]. The detection rates of elevated blood pressure based on three blood pressure measurements were 12.8%, 8.7% and 7.9%, respectively ( P value for trend <0.001). Of note, the difference in the detection of elevated blood pressure based on the second blood pressure measurement or based on the average value of the second and third blood pressure measurements showed no significance (8.7% and 7.2%, P=0.039). Conclusions:Blood pressure levels and the detection of elevated blood pressure in adolescents decreased substantially across three consecutive blood pressure measurements. The second blood pressure measurement might be sufficient for screening elevated blood pressure in adolescents.