Objective To study 18F-deoxyglueose positron emission tomography computed tomo graphy(18 FDG PET-CT) in the diagnosis of cervical lymph node(LN) metastasis from rabbit nasopharyngeal VX2 carcinoma.Methods Nasopharyngeal VX2 carcinoma model using 30 rabbits was established. 18 FDG PET-CT,MRI and pathological diagnosis were performed and compared.ResultsFifty-three cervi cal LNs were picked up from resected specimens of 30 rabbits with nasopharyngeal VX2 carcinoma.There were 42 pathologically confirmed positive LNs.Positivity rate was significantly correlated with the volume and the shortest diameter of the LNs (r = 9.18,P =0.007 ; r = 2.77,P = 0.008).The diagnostic sensitivity of PET-CT was 96% (24/25) and 29% (5/17) for LNs with volume >0.5 cm3 and ≤0.5 cm3 ,83% (25/30) and 33% (4/12) for LNs with the shortest diameter ≥0.5 cm and < 0.5 cm,respectively.The diagnostic sensitivity,specificity and accuracy of PET-CT was 69% (29/42) ,100% (11/11) and 95% (40/42) ,com paring with 60% (25/42) ,91% (10/11) and 83% (35/42) of MRl,respectively.The volume measured by PET-CT images was not significantly different from the pathologically measured volume (t =-1.23,P = 0.233) ,while the volume measured by MRI was significantly different from the pathologically measured vol ume (t =-3.99,P = 0.001).Conclusions The sensitivity,specificity and accuracy of PET-CT are better than those of MRl,especially for the cervical lymph nodes with volume >0.5 cm3 or the shortest diameter ≤ 0.5 cm.PET-CT also can be used to detect the smaller metastatic lymph nodes,though the false negative rate is higher.

Objective To evaluate the diagnostic efficacies of contrast-enhanced ultrasound(CEUS) combined with BRAF V600E mutation detection in ultrasound-guided fine-needle aspiration cytology of thyroid nodules with atypia of undetermined significance . Methods A total of 129 thyroid nodules underwent the examinations of CEUS and BRAF V600E mutation were analyzed retrospectively . With surgical pathology as the gold standard ,ROC curve was used to investigate the diagnostic values of CEUS , BRAF V600E and the combination of the two methods . Results The sensitivity ,specificity and accuracy of CEUS and BRAF V600E gene detection for thyroid nodules with atypia of undetermined significance diagnosed by ultrasound-guided fine-needle aspiration biopsy were 86 .7％ ,83 .3％ ,85 .3％ and 72 .0％ , 100％ ,83 .7％ ,respectively . The sensitivity and accuracy of CEUS were higher than those of BRAF V 600E gene detection ( all P < 0 .001 ) ,however its specificity was lower than BRAF V 600E with statistically significance( P < 0 .001) ,those of the combined test of CEUS and BRAF V600E mutation analysis were 94 .7％ ,83 .3％ ,89 .9％ ,respectively . The combination of two methods had the highest diagnostic efficacy , with statistically difference ( P <0 .001) ,and the area under the ROC curve ( AUC) was higher than that for each test(0 .951 vs 0 .860 vs 0 .901) . Conclusions The combined test of CEUS and BRAF V600E mutation has a higher diagnostic efficacy for cytologically indeterminate thyroid nodules compared with CEUS or BRAF V600E mutation alone .

Objective: To investigate the incidence of malnutrition in children and adolescents aged between 8 and 16 years in Zhongshan, Guangdong Province and to explore the impact of lower body mass index in early childhood on malnutrition in children and adolescents. Methods: A retrospective cohort of 2 188 students with complete data on weight and height from grade one in primary school to grade one in high school in Zhongshan were included in this analysis. Normal weight individuals with BMI lower than the 50th percentiles (P50) were defined as lower BMI, according to "Report on the Physical Fitness and Health Surveillance of Chinese School Students" in 2005. Screening Standard for Malnutrition of School-age Children and Adolescents in 2014 (WS/T 456—2014) was used to define malnutrition. Prevalence and incidence of malnutrition was calculated, and chi-square test was used to compare the difference of the incidence of malnutrition between children with BMI Results: The prevalence of malnutrition was 15.08% for children in grade one of primary school, which reached highest of 16.32% in grade two of primary school and decreased to 7.27% in grade one in high school. The annual incidence of malnutrition among students with normal weight decreased from 8.37% in grade two in primary school to 1.22% in grade one in high school. Boys with lower BMI in grade one in primary school had the incidence of malnutrition with 12.47% in grade two in primary school, while those with BMI ≥P50 had the incidence of 0.63%. Girls with lower BMI had higher incidence of malnutrition than those with BMI ≥P50. Conclusion Incident malnutrition between grade one in primary school and grade one in high school is more likely to occur in early childhood. Lower BMI in early childhood significantly increases the risk of malnutrition in children and adolescents. Malnutrition prevention should be implemented from early childhood, especially for those with lower BMI.

Objective To explore the effect of targeted inhibition of miR-628-5p by long non-coding RNA(lncRNA)KCNQ1 overlapping transcript 1(KCNQ1OT1)on high glucose(HG)-induced retinal pigment epithelial cell injury.Meth-ods The real-time fluorescence quantitative polymerase chain reaction(RT-qPCR)was performed to detect KCNQ1OT1 expression in serum and aqueous humor of patients with diabetic retinopathy(DR),type 2 diabetes mellitus(T2DM)and uveitis.Human retinal pigment epithelial cells(ARPE-19)were treated with different concentrations of glucose,and their KCNQ1OT1 expression was detected to determine the optimal glucose concentration.ARPE-19 cells were divided into the control(CON)group,HG group,HG+si-NC group,HG+si-KCNQ1OT1 group,HG+miR-NC group,HG+miR-628-5p group,HG+si-KCNQ1OT1+anti-miR-NC group,and HG+si-KCNQ1OT1+anti-miR-628-5p group.The expression levels of KCNQ1OT1 and miR-628-5p in cells were measured by RT-qPCR.The cell apoptosis was detected by flow cytometry.The malondialdehyde(MDA)level and superoxide dismutase(SOD)activity were detected by enzyme-linked immunosorbent assay.The expression level of cleaved Caspase-3 protein was measured by Western blot.The targeting relationship between KCNQ1OT1 and miR-628-5p was detected by dual-luciferase reporter assay.Results The expression levels of KCNQ1OT1 in serum and aqueous humor of DR patients were higher than those of T2DM patients and uveitis patients,and those of uve-itis patients were the lowest(all P＜0.05).Compared with the 0 mmol·L-1 glucose group,the expression levels of KC-NQ1OT1 in ARPE-19 cells in the 5 mmol·L-1 glucose group,15 mmol·L-1 glucose group,and 30 mmol·L-1 glucose group significantly increased,and those in the 30 mmol·L-1 glucose group were the highest(all P＜0.05);thus,30 mmol·L-1 glucose was selected for subsequent experiments.Compared with the CON group,the KCNQ1OT1 expres-sion,apoptosis rate,cleaved Caspase-3 protein expression,and MDA level in the HG group significantly increased,while the SOD activity and miR-628-5p significantly decreased(all P＜0.05).Compared with the HG+si-NC group,the KC-NQ1OT1 expression,apoptosis rate,cleaved Caspase-3 protein expression,and MDA level in the HG+si-KCNQ1OTl group significantly decreased,while the SOD activity significantly increased(all P＜0.05).Compared with the HG+miR-NC group,miR-628-5p and SOD activity in the HG+miR-628-5p group significantly increased,while the apoptosis rate,cleaved Caspase-3 protein expression,and MDA level significantly decreased(all P＜0.05).Compared with the HG+si-KCNQ1OT1+anti-miR-NC group,miR-628-5p and SOD activity in the HG+si-KCNQ1OT1+anti-miR-628-5p group significantly decreased,while the apoptosis rate,cleaved Caspase-3 protein expression,and MDA level significantly increased(all P＜0.05).Conclusion lncRNA KCNQ1OT1 can reduce the HG-induced apoptosis and oxidative damage of ARPE-19 cells by targeted inhibition of miR-628-5p.

Objective To compare the efficacy and safety of leflunomide (LEF) combined with medium/low dose corticosteroids and full dose of corticosteroids in the treatment of IgA nephropathy. Method Primary IgAN patients diagnosed by renal biopsy with 18?65 years old and eGFR≥30 ml·min?1·(1.73 m2)?1 and proteinuria>0.5 g/24 h were enrolled in a prospective controlled clinical study. They were randomly divided into leflunomide combined with medium/low dose corticosteroids (LEF group) and corticosteroids alone (steroid group). The primary outcomes were (1) end stage renal disease or dialysis (2) 50% increase in serum creatinine above the baseline. Secondary outcome was the remission of proteinuria. Results Ninety patients completed the follow?up. The 24?hour proteinuria at baseline were 2.00(1.10, 2.88) g and 1.87(1.13 ,3.08) g in LEF group and steroid group respectively. Compared with baseline, it was significantly decreased in both groups at 6 months [0.30(0.11, 0.93) g, 0.30(0.14, 1.33) g] and 12 months [0.30(0.09, 0.82) g, 0.32(0.14, 0.66) g], (P<0.05). Estimated glomerular filtration rate (eGFR) at baseline, 6 months and 12 months were (80.39 ± 28.56), (87.12±28.70) and (88.20±30.26) ml·min-1·(1.73 m2)-1. It was decreased in steroid group (P<0.05), while no significant difference was detected in LEF group[baseline (87.63 ± 27.35), 6 months (86.91 ± 32.45), 12 months (90.06 ± 30.00) ml·min-1·(1.73 m2)-1, P>0.05]. At 6 and 12 months, there was no significant difference in terms of 24?hour proteinuria, serum creatinine and eGFR (CKD?EPI) between groups (P>0.05). There was no statistically significant difference in adverse events between groups during the treatment (9/40 cases in LEF group and 11/50 cases in steroid group, P>0.05). The average follow?up was 79 months, and there was no difference in the renal prognosis between the two groups. Multivariate Cox regression analysis revealed that serum creatinine at baseline and renal interstitial inflammatory cell infiltration predicted the risk of the progress of IgA nephropathy. Conclusion Leflunomide plus medium/low dose corticosteroids has a similar effect as full dose of corticosteroids in IgA nephropathy and does not increase the risk for adverse events during the treatment.

Objective:To understand the epidemiological characteristics of imported COVID-19 cases in Guangzhou and provide scientific basis for the prevention and control of the disease.Methods:The data of imported COVID-19 in Guangzhou reported as of April 1, 2020 were collected from National Notifiable Disease Report System of China. The software Excel 2010 and SPSS 19.0 were applied for data cleaning and statistical analysis.Results:As of April 1, 2020, a total of 103 imported COVID-19 cases had been reported in Guangzhou, in which 92 were confirmed cases and 11 were asymptomatic infection cases. The number of the confirmed imported cases accounted for 11.4 % (92/806) in of the total in China at the same time. The male to female ratio of the cases was 1.58∶1 (63∶40). The median age of the cases was 31 years ( P 25- P 75:22-40 years), range of age was 11-63 years. The main occupational distributions of the cases were business services (41/103, 39.8 %) and students (36/103, 35.0 %). The imported cases whose destinations were 19 provinces and municipalities rather than Guangdong after entering the country accounted for 43.7 %. The main source countries of infections were the United Kingdom (27/103, 26.2 %), the Philippines (13/103, 12.6 %), the United States (13/103, 12.6 %) and Nigeria (7/103, 6.8 %). There were 34 inbound flights from which the imported COVID-19 cases were detected, in which 10 flights (10/34, 29.4 %) were found to carry more than 3 cases, with an average voyage time of (11.14±0.53) hours. A total of 29 imported cases(28.2 %) showed symptoms before entering the country, and 65 cases (63.1 %) had been isolated before the onset of the disease. The mean free activity time of the isolated cases after the onset was (6.76±0.79) days. The average number of the imported cases’ close contacts was 53. There were 13 clusters of COVID-19 caused by the imported cases, involving 36 cases (including 1 imported associated case). Conclusions:The sources of the imported COVID-19 cases in Guangzhou were widely distributed, and no cases had been found to be infected on the flights. In the early stage of the imported epidemic, there was high risk for the spread of the epidemic. Strengthened prevention and control of imported COVID-19 effectively reduced the of transmission risk of COVID-19 in communities.

Objective To investigate the impact of statistical uncertainty per control point(SUpCP)on dose calculation on volumetric modulated arc therapy(VMAT)for rectum cancer,and to analyze the accuracy and efficiency of calculation.Methods 19 patients with rectum cancer undergoing radiotherapy were selected.The initial VMAT plans were generated on Monaco TPS using SUpCP=3,then changed SUpCP in the dose calculation process as follow:10 SUpCPs(1～10)for each patient,and totally190 VMAT dose distributions were obtained.For plan evaluation,Dmax,Dmean,D95%,V50,homogeneity index(HI),conformity index(CI)of the planning target volume(PTV),dissymmetric variations of bladder,small intestine and femoral head,and time calculation(Time)were analyzed.Patient specific quality assurance(PSQA),dose deviation of isocenter(ΔDISO)and passing rate of three-dimensional dose distribution(γ33,γ32,γ22)between calculated and delivered radiation doses were measured.Results AsSUpC increased,Dmax and HI of PTV,Dmax of bladder were increased,but D95%and V50 of PTV,Time,γ32 and γ22 were decreased(P<0.05).Dmax and CI of PTV,Dmean of bladder,Dmax and Dmean of small intestine and femoral head,ΔDISO and γ33 showed no statistical significance(P>0.05).When ΔDISO<1%,gamma passing rate>90%for all VMAT plan.When SUpCP<6,Dmax of PTV<110%of the prescribed dose was obtained;while SUpCP>2,time for dose calculation was less than 5 min.Conclusion For VMAT plan of rectum cancer on Monaco TPS using XVMC algorithm,3%～5%of statistical uncertainty per control point for dose calculation,and 3%2 mm or 2%2 mm gamma criteria for three-dimensional dose verification is recommended.This study provides clinical application basis for precise dose calculation of VMAT plan of rectum cancer.