Objective The loss of NF2 gene in cutaneous schwannomas of neurofibromatosis type 2 patients was investigated in order to explore the tumorigenesis and characteristics of NF2 tumor suppressor gene, and to provide evidence for presymptomatic gene diagnosis for NF2 patients. Methods DNA was extracted from whole blood and frozen tumor tissue, respectively. Genotyping was performed using 6 microsatellite markers flanking or within the NF2 gene: CRYB2－ D22S193－ NF2CA1－ NF2CA3－ D22S268－ D22S430, which is tightly linked to the NF2 gene and analyzed on an ABI Genetic Analyzer 310 after PCR amplification. Results A total of 18,14,0,13,16,12 samples showed loss of heterozygosity at microsatellite markers CRYB2， D22S193， NF2CA1， NF2CA3， D22S268， D22S430 in 43 samples of cutaneous schwannomas, respectively. Conclusions The method for detection of NF2 allelic loss was established. Frequent allelic loss reconfirms that NF2 gene is a tumor suppressor gene. The observation that tumors with or without allelic loss of the NF2 gene exist in the same patient indicates that these tumors are originated from different clones in which genetic alterations occurred independently.

Objective To investigate the value of introvoxel incoherent motion(IVIM)using 3.0 T MRI to evaluate response to concurrent chemoradiotherapy(CCRT)in patients with advanced uterine cervix cancer. Methods From July 2015 to December 2016,63 patients with advanced(≥ⅡB)cervical cancer diagnosed by clinical and imaging study, who had completed CCRT plan in Henan Cancer Hospital, were prospectively enrolled.Pelvic MRI protocol including T1WI,T2WI,IVIM and dynamic contrasted enhanced scans were performed in each patient before CCRT and 3 weeks after starting therapy(total dose of 30 Gy), and at the end of therapy (total dose of 90 Gy, 8 weeks after therapy). The mean values of ADC, true molecular diffusion coefficient(D),pseudodiffusion coefficient(D*)and perfusion fraction(f)in each tumor at pre-therapy, in the middle of therapy and post-therapy were measured and recorded as ADC-pre, D-pre, D*-pre,f-pre;ADC-mid,D-mid,D*-mid,f-mid and ADC-post,D-post,D*-post,f-post,respectively;the change rates of these parameters during and after therapy (recorded as ΔADC-mid, ΔD-mid, ΔD*-mid, Δf-mid;ΔADC-post, ΔD-post, ΔD*-post, Δf-post) were also calculated. Patients were classified into response group and non-response group,according to response evaluation criteria in solid tumors after CCRT.MRI imaging study was performed in each patient within 1 month after CCRT to follow up,and tumor regression rate was calculated.The Mann-Whitney U test was used to compare differences of parameters and their change rates between response group and non-response group. Spearman correlation analysis was performed to assess relationships between parameters, parameter change rates and tumor regression rate. Logistic regression model was applied to find potential ADC values for predicting therapeutic response. ROC was used to analyze efficacy of ADC values for evaluating therapeutic response in advanced uterine cervix cancer after CCRT. Results The mean value of tumor maximum diameter before and after therapy was (47.5 ± 12.9) and(12.8 ± 10.0)mm,tumor regression rate was(66.7 ± 33.6)%.Forty-eight patients were in the response group and 15 in the non-response group.The mean value of ADC-pre,D-pre,D*-pre and f-pre was 0.74(0.43, 1.14)×10-3,0.58(0.33,0.91)×10-3,12.12(2.30,21.4)×10-3mm2/s,9.65%(4.45%,13.89%),respectively.Tumor regression rate had positive correlation with ADC-pre and D-pre (r=0.773,0.840;P<0.05). Responders had increased ADC-pre, D-pre values than non-responders, which had statistically significant difference (P<0.05). Responders had increased ADC-mid, D-mid and f-mid values than non-responders, which had statistically significant difference (P<0.05), tumor regression rate had positive correlation with ADC-mid, D-mid and f-mid (r=0.808,0.834,0.563;P<0.05). Responders had increased ADC-post, D-post and f-post values than non-responders,which had statistically significant difference(P<0.05),tumor regression rate had positive correlation with ADC-post and D-post (r=0.799, 0.829;P<0.05).Tumor regression rate had positive correlation with ΔADC-mid,ΔD-mid,Δf-mid(r=0.526,0.573,0.454;P<0.05)and with ΔADC-post,ΔD-post, Δf-post (r=0.541, 0.555, 0.388;P<0.05). Responders had increased ΔADC-mid, ΔD-mid, Δf-mid and ΔADC-post, ΔD-post, Δf-post, which had statistically significant difference (P<0.05). Logistic regression analysis revealed only ADC-pre and D-post could be independent factors to predict therapeutic response in advanced uterine cervix cancer after CCRT,values of B,Wald,odds ratio and P was 22.488,8.431,1.429, 0.004 and 16.542,8.517,1.779,0.004.ROC analysis showed the area under the curve(AUC)of ADC-pre, D-pre,ΔADC-mid,ΔD-mid,Δf-mid,ΔADC-post,ΔD-post and Δf-post for predicting therapeutic response in advanced uterine cervix cancer after CCRT were 0.890,0.926,0.942,0.851,0.803,0.929,0.951 and 0.906, respectively. Conclusion The IVIM parameters before and during CCRT process and their changes are valuable for predicting and evaluating therapeutic response in advanced uterine cervix cancer after CCRT, with high clinical practice value.

Objective: To investigate the influencing factors of smoking tendency of adolescents and to analyze the influence of e-cigarette on smoking tendency of teenagers and the possible interaction, to provide evidence for tobacco control measures. Methods: Stratified multistage cluster probability sampling method was used to select 6 178 students from junior middle school, high school and vocational high school students in Shanghai for questionnaire survey from September to October 2019. Students with smoking tendency were taken as case group, adolescents with same sex and similar age(within 1 year) were mathed in 1∶3 ratio. A total of 631 adolescents with smoking tendency and 1 870 non-smoking tendency were included in the study. Conditional Logistic regression was used to analyze the influencing factors and possible interactions. Results: After adjusting gender, age and other covariates, conditional Logistic analysis results showed that the smoking tendency of middle school students was associated with factors such as their friends smoking, trying cigarettes and trying e-cigarettes. The OR value and 95%CI were 3.26(2.47-4.29), 5.90(3.76-9.24), and 3.28(2.11-5.10), respectively. The interaction analysis results showed that the OR value and 95%CI of the multiplying interaction between friends smoking and trying e-cigarettes, trying smoking and trying e-cigarettes were 8.62(4.90-15.17) and 12.01(6.02-23.95), respectively. There was no additive interaction. Conclusion Tobacco control interventions, such as e-cigarette harm publicity and peer education, can help to change teenagers smoking tendency and further reduce their tobacco use rate.

ObjectiveTo understand the experience， knowledge and attitudes of e-cigarette users in Shanghai， and to provide evidence for the development of intervention programs for e-cigarette use. MethodsThe Respondent-Driven Sampling （RDS） method was used to recruit 40 e-cigarette users for qualitative interviews from November 2020 to February 2021. NVivo （11.0） software was used to code interview records， and the thematic pattern and relationship analysis were conducted. ResultsIn terms of the reasons and user experience of e-cigarette use， most respondents used e-cigarettes for the first time after recommendation of friends； The reasons for the current use of e-cigarettes focus on the subjective feelings generated by the use of e-cigarettes （easy to use， replacing traditional tobacco， and having many flavors）. Compared with traditional tobacco use， respondents said e-cigarettes tasted good and had no physical impact （they could be used all the time without making them uncomfortable）. In terms of the awareness of e-cigarette use related knowledge， the respondents' opinions on whether e-cigarettes caused health risks were mostly based on their own experience of using them， and they said it was difficult to identify real information online. As for whether they were interested in relevant knowledge， most respondents said they wanted to learn about the professional knowledge related to e-cigarettes. Regarding the attitude related to the use of e-cigarettes， most respondents believed that e-cigarettes are addictive， e-cigarettes are not a safe alternative to traditional tobacco， ande-cigarettes couldn't help them quit smoking. Three out of ten respondents said they supported including e-cigarettes in the Regulation on Smoking Control in Public. ConclusionThere are certain characteristics of e-cigarette users' feelings， related knowledge and attitude towards e-cigarette use that should be targeted to carry out publicity， education and intervention.