Objective To determine the reference intervals for thyroid function tests during the second half of pregnancy (20-40 gestational weeks),and to assess the relationship between thyroid peroxidase antibody (TPOAb) levels and the incidence of gestational thyroid diseases.Methods Levels of thyroid stimulating hormone (TSH),free thyroxine (FT4),TPOAb and urinary iodine excretion were determined in 4 729 pregnant women,who received prenatal health care at First Affiliated Hospital of Nanjing Medical University from July 2011 to August 2013.Among these women,2 568 were selected using the recommendations of the American National Academy of Clinical Biochemistry,and were divided into five groups according to their gestational age:≥ 20 to ＜24 weeks (682 cases),≥ 24 to ＜28 weeks (1 322 cases),≥ 28 to ＜32 weeks (178 cases),≥ 32 to ＜36 weeks (185 cases) and ≥ 36 to ≤ 40 weeks (201 cases).Reference intervals of thyroid function tests in the second half of pregnancy were calculated.The reference values of thyroid functions in different gestational weeks were compared,and the reference intervals of thyroid functions in the second half of pregnancy were determined.The effects of maternal age and positive TPOAb on gestational thyroid diseases were analyzed.A non-parametric test,analysis of variance or Chi-square test was used for statistical analysis.Results (1) Reference intervals for maternal thyroid function in the second half of pregnancy in our hospital were established [TSH:0.65-5.27 mU/L and FT4:8.74-14.84 pmol/L].(2) The percentage of thyroid diseases was higher using the non-pregnancy reference intervals (TSH:0.27-4.20 mU/L and FT4:12.00-22.00 pmol/L) than using the pregnancy reference intervals [64.0％ (3 025/4 729) vs 16.1％ (763/4 729),x2=47.465,P ＜ 0.01],which manifested as a higher rate of clinical hypothyroidism and simple hypothyroxinemia [5.4％ (255/4 729) vs 0.4％ (20/4 729),x2=14.321;54.1％ (2 560/4 729) vs 9.1％ (429/4 729),x2=47.108;both P＜0.01] and a lower rate of subclinical and clinical hyperthyroidism [1.2％ (58/4 729) vs 3.3％ (155/4 729),x2=6.650;0.3％ (13/4 729) vs 0.6％ (27/4 729),x2=2.062;both P＜0.05].(3) The incidence of clinical hypothyroidism and simple hypothyroxinemia in pregnant women aged ＞30 years was higher than in those aged ≤ 30 years [0.7％ (10/1 377) vs 0.3％ (10/3 352),x2=4.257;11.7％ (161/1 377) vs 8.0％ (268/3 352),x2=16.102;both P＜0.05].The incidence of clinical hypothyroidism and clinical hyperthyroidism in TPOAb positive women was higher than that in TPOAb negative women [2.7％ (9/335) vs 0.3％ (11/4 394),x2=44.009;3.9％ (13/335) vs 1.2％ (52/4 394),x2=16.784;both P＜0.01].Conclusions The established pregnancy-specific reference ranges of thyroid function tests can reduce the missed diagnosis and misdiagnosis of gestational thyroid diseases.Maternal age ＞30 years and positive TPOAb may increase the risk ofgestational thyroid diseases.

Objective To assess the value of clinical applications of whole-body diffusion-weighted imaging (WB-DWI) in diagnosing patients with malignant tumors compared with positron emission tomography (PET). Methods A total of 22 patients with highly suspected malignant tumors underwent WB-DWI after PET. The differences between the two imaging methods were compared in displaying lesions, and the correlation between ADC and SUV value was analyzed. Results More lesions were showed with WB-DWI than PET. There was no significant difference between the two methods in detecting the lesions of lung, mediastinal septum or abdomen (P>0.05), but more lesions in skeleton were showed with WB-DWI (P<0.05). No significant correlation between ADC and SUV value was found. Conclusion Compared with PET, WB-DWI can detect more tumor lesions. The sensitivity of WB-DWI in detecting metastatic tumors of bone is higher than that of PET.

Objective: To discuss the main causes and risk factors of disability and death among current Chinese adolescents. Methods: Subnational data of China from Global Burden of Disease Study 2015 (GBD 2015) was used to rank the causes and risk factors leading to death and disability adjusted life years (DALY) in Chinese adolescents aged between 10 and 19 years old, and thereby to analyze the main cauese and risk factors of death and DALY among Chinese adolescents in different genders. Results: In 2015, among Chinese adolescents aged 10-19 years old, the total DALY was 13 million 490 thousand years, and the total number of deaths was 63 258 cases. The top 3 causes of DALY were skin and subcutaneous diseases, iron-deficiency anemia and road injuries, resulting in DALY (constituent ratio) of 1 411 (10.5%), 1 094 (8.1%) and 1 029 (7.6%) thousand years respectively. The top 3 causes of death were road injuries, drowning and leukemia, causing 13 881 (21.9%), 9 895 (15.6%) and 4 620 (7.3%) deaths (constituent ratio) respectively. The top 3 risk factors of DALY were iron deficiency, alcohol use and drug use, causing 1 094 (8.1%), 487 (3.6%) and 220 thousand years (1.6%) DALY (constituent ratio) respectively. The top 3 risk factors of death were alcohol use, occupational injuries and drug use, causing 5 957 (9.4%), 1 523 (2.4%) and 810 (1.3%) deaths respectively. Conclusion Unintentional injury was the top cause of DALY and death in Chinese adolescents, followed by skin and subcutaneous diseases and iron-deficiency anemia. Iron deficiency and alcohol use were the top two risk factors of DALY and death.