Objective:To analyze the sensitivity and specificity of SARS-CoV-2 nucleic acid testing in 20 348 close contacts of COVID-19 cases in different prevention and control stages in Guangzhou and to provide scientific evidence for optimizing epidemic response strategies.Methods:A total of 20 348 close contacts of COVID-19 cases in Guangzhou were traced between February 21 and September 22,2020. All the close contacts were tested for the nucleic acid of SARS-CoV-2. The sensitivity and specificity of nucleic acid testing and diagnosis in the different prevention and control stages were compared.Results:In 20 348 close contacts, 12 462 were males (61.24%), the median ( P 25, P 75) of age of them was 31.0 years (23.0,43.0), the median number ( P 25, P 75) of nucleic acid testing for them was 2.0 (1.0,3.0), and the median ( P 25, P 75) of their quarantine days was 12.0 (8.0,13.0) days, respectively. A total of 256 COVID-19 cases were confirmed in the close contacts after seven nucleic acid tests. In the 1 st, 2 nd, 3 rd and 7 th nucleic acid testing, the sensitivity and specificity were 69.14% and 99.99% (177 cases confirmed), 89.84% and 99.99% (230 cases confirmed), 97.27% and 99.99% (249 cases confirmed), and 100.00% and 99.98%, respectively. In the three stages of COVID-19 prevention and control in China: domestic case stage, imported case stage, and imported case associated local epidemic stage, the sensitivity of the 1 st nucleic acid testing was 70.68%, 68.00% and 67.35%, and the specificity was 99.98%, 100.00% and 100.00%, respectively. Conclusions:The sensitivity of nucleic acid testing in the close contacts at the different stages were consistent with slight decrease, which might be related to the increased proportion of asymptomatic infections in the late stage of epidemic prevention and control with COVID-19 in Guangzhou. It is suggested to give three nucleic acid tests to improve the sensitivity and reduce false negative risk.

Objective:To describe the cancer incidences and mortalities in Henan cancer registries in 2013.Methods:Registration data were evaluated according to the criteria of quality control of cancer registry,and the qualified data were analyzed based on areas(urban/rural), gender,age and cancer sites.The age-standardized rates were applied according to Segi's population and the fifth Chinese population census in 2000.Results:The total coverage of population from 19 qualified cancer registries data was 16,225,815(15.13%),Among which,8,370, 772(51.59%)were males and 7,855,043(48.41%)were females;and 2,819,817(17.38%)live in urban areas and 13,405,998(82.62%) live in rural areas.The crude incidence rate in Henan was 250.34/105(males:264.35/105,females:235.42/105),whereas the age-standardized incidence rates by Chinese standard population and by world standard population were 208.66/105and 207.25/105,respectively.The cumulative incidence rate(0-74 years old)was 24.31%.The cancer mortality in Henan was 161.05/105(males:185.50/105,females:134.98/105),whereas the age-standardized mortality by Chinese standard population and by world standard population were 131.18/105and 131.52/105,respectively.The cumulative mortality rate(0-74 years old)was 15.05%.Cancer incidence and mortality rates were increasing by age, reaching the peak values at 80 age group and 85 plus age group,respectively.Lung cancer,gastric cancer,esophageal cancer,liver cancer and colorectal cancer were the most common cancers ranked by the incidence rate,and the most common cause of cancer death was lung cancer,followed by gastric cancer,esophageal cancer,liver cancer and colorectal cancer.Incidence rate and mortality rate of breast cancer ranked the first and the fifth among the females,respectively.Conclusion:Cancer incidence and mortality rates were higher in the rural areas and in males than in the urban areas and in females.Lung cancer,digestive system cancers,and female breast cancer are the major cancer types that require attention for the prevention and control in Henan.

Objective: To investigate the incidence and survival of esophageal cancer with different histological types and to understand the incidence trend and burden of esophageal cancer in Linzhou during 2003-2012. Methods: All incidence records of esophageal cancer and population reported were collected from Linzhou Cancer Registry during 2003-2012. Incidence rate was calculated using gender and histological types. Age standardized incidence rate was calculated according to world Segi's population and Chinese census data in 2000. Age standardized incidence rate by world population between 2003 and 2012 was analyzed with JoinPoint regression model and estimated annual percentage change (EAPC) was calculated. 5-year survival rate was calculated with Kaplan-Meier model. Results: There were 8 229 esophageal cancer cases in Linzhou during 2003-2012. The average annual incidence rate was 80.08/100 000 (8 229/10 276 481). Among all esophageal cancer cases, 7 019 (85.3%) were diagnosed as esophageal squamous cell carcinoma (ESCC). In Linzhou, the age standardized incidence rate by Chinese standard population and by world standard population was 80.92/100 000 and 81.85/100 000 in 2003, 67.97/100 000 and 68.63/100 000 in 2012. JoinPoint regression model showed that EAPC was-12.9% (95%CI:-16.4%--9.1%) for other and unspecified histological type between 2003 and 2012. The EAPC was-5.5% (95%CI:-9.2%--1.6%) for esophageal cancer between 2007 and 2012,-5.4% (95%CI:-7.0%--3.9%) for esophageal cancer in female between 2006 and 2012,-4.9% (95%CI:-9.5%--0.1%) for ESCC between 2007 and 2012. The 5-year prevalence of esophageal cancer was 215.49 per 100 000 (2 337/1 084 493), and 5 489 died within 5 years after incidence. 5-year survival rate of esophageal cancer was 34.6% (95%CI: 33.5%-35.6%). Conclusion Esophageal cancer had a decreasing trend in Linzhou. The survival rate was increasing. But, esophageal cancer was still a major burden in Linzhou. The major histological type was ESCC. ESCC had a similar decreasing trend with esophageal cancer.

Aim To discuss the impact of important ac-tive ingredient of garlic diallyl sulfide———DATS on platelet activating factor (PAF ) mediated melanoma metastasis and its mechanisms.Methods ①MTT was used to test the effect of different concentrations of DATS on B16F10 and A375 melanoma cell growth number;②Scratch test and transwell were employed to test the effect of different concentrations of DATS on B16F10 and A375 melanoma cell migration;③ West-ern blot was used to test the effect of DATS on expres-sion of MMP-2,ERK,p38 induced by PFA;④Intrave-nous injection of tumor metastasis model was used to check the inhibition of DATS in PAF-mediated melano-ma metastasis.Results B16F10 cells relative growth rate fell to 73.21% and 48.78%,respectively,when DATS concentration reached 50 and 100 μmol·L-1 . DATS inhibited the levels of PAF-induced migration of melanoma cells B16F10 and vertical migration signifi-cantly,and inhibited B16F10 cells migration induced by PAF through inhibiting the expression of MMP-2, paxillin protein,FAK and other proteins.Conclusion DATS can significantly inhibit PAF-induced tumor metastasis, which is related to the inactivation of MAPKs.

BACKGROUND:Stem cel transplantation is a promising strategy for treatment of ischemic heart diseases, which has obtained great achievements in recent years. OBJECTIVE: To analyze the clinical trends of stem cel therapy for ischemic heart diseases reported from 2001 to 2015 in Medline, CNKI, Wanfang, ClinicalTrials.gov and Chinese Clinical Trial Register. METHODS:The relevant articles addressing stem cel therapy for ischemic heart diseases were retrieved using the keywords of “stem cel transplantation” and “ischemic heart disease” in Chinese and English in Medline, CNKI, Wanfang, ClinicalTrials.gov and Chinese Clinical Trial Register folowed by statistical analysis. The retrieval time was from 2001 to 2015, including 2001-2005, 2006-2010 and 2011-2015. RESULTS AND CONCLUSION: In Medline database, there were 219 clinical studies about stem cel therapy for ischemic heart disease published from 2001 to 2015, and the number of retrieved articles was most from 2006 to 2010, and decreased from 2011 to 2015. In CNKI and Wanfang databases, the number of relevant articles which had a similar trend with that in the Medline database decreased remarkably after 2011. In ClinicalTrials.gov, there were 63 clinical trials about stem cel therapy for ischemic heart disease, most of which were registered from 2006 to 2015 and came from Europe and North America. In Chinese Clinical Trial Register, there was no clinical trial about stem cel therapy for ischemic heart disease, which may result from the strict management in China.

In this article, the authors expounded the necessary and problems of animal experiment post-ap-proval monitoring ( PAM) , which included who should do PAM, how to do PAM, and what the PAM can do. The authors also exposed the following suggestion: formulating the detailed rules, regulations and SOP, strengthening the training of PAM team member and animal experiment personnel, and monitoring the whole process of animal protocol review using the software.

Tumor necrosis factor receptor-associated protein 1 (TRAP1),as one of the main members of the heat shock protein 90 family, resists oxidative stress-induced apoptosis as well as predominantly maintains the integrity of mitochondria and cellu-lar homeostasis. Abnormal expression of TRAP1 was herein closely related to the onset and progression of a wide variety of tumors. As a key regulatory factor mediating energy metabolism within tumor cells, TRAP1 may be able to kill them by interfer-ing with such metabolism. More importantly, the abnormal ex-pression of TRAP1 played a less important role in normal cells, allowing TRAP1 to be a particularly attractive target as it can be used in tumor treatment or interference. The relationship be-tween abnormal expression of TRAP1 protein and tumor onset was reviewed. Besides, the mechanism by which disordered TRAP1 protein expression induced tumor formation was postula-ted, which may provide references for future research and clini-cal treatment.

OBJECTIVETo investigate the association between obesity and the risk of lung cancer and evaluate a dose-response relationship between body mass index (BMI) and incidence risk of lung cancer in the Chinese population.

METHODSA systematic literature search for BMI and incidence risk of lung cancer in the Chinese population, as well as through the reference lists of retrieved articles. The literature databases including Chinese National Knowledge Infrastructure, Wanfang, PubMed, Embase and Google Scholar. Time range was from the founding of each database to September 2014 and a total of 93 research papers were collected. Meta-analysis was conducted to calculate pooled odds ratio and corresponding 95% CI. Generalized least-squares regression methods were used to make a dose-response meta-analysis between BMI and incidence risk of lung cancer.

RESULTSSeven studies were included in the meta-analysis, with a number of 2 351 lung cancer cases. Results showed that obesity was inversely associated with lung cancer incidence (OR = 0.68, 95% CI: 0.59-0.79) (heterogeneity test: I² = 0, P = 0.594). The association did not change with stratification by study design, sex, smoking status, BMI measurement method and study population. A linear dose-response association between BMI and risk of lung cancer was visually significant, and lung cancer risk would be reduced 21% for per 5 kg/m² BMI increase (OR = 0.79, 95% CI: 0.71-0.89) (heterogeneity test: q = 22.43, P = 0.002).

CONCLUSIONThe results of this meta-analysis indicated that higher BMI was a protective factor against lung cancer, but smoking may play a stronger role as a confounding factor for the most important role with lung cancer incidence.

Asian Continental Ancestry Group ; Body Mass Index ; China ; Humans ; Incidence ; Lung Neoplasms ; Obesity ; Odds Ratio ; Protective Factors ; Risk ; Smoking

Tumor metastasis is one of the most important biologi-cal characteristics of malignant tumor, and it is also the main factor resulting in poor prognosis and leading to failure of treat-ment. In recent years, studies have shown that the extracellular matrix ( ECM) of tumor microenvironment plays a critical role in tumor metastasis. Tumor ECM fibrogenesis could form the cross-linked network structure, which not only provides nutrition and support to tumor, also it is necessary to tumor growth and inva-sion. These research results indicate that blocking ECM fibro-genesis may exert an inhibitory effect on tumor metastasis. Therefore, targeting ECM fibrogenesis has become a particularly attractive strategy as it can be used in the treatment of metasta-sis-related diseases. The ECM fibrogenesis in tumor is reviewed in this paper as well as the treatment strategies on tumor metas-tasis by targeting ECM fibrogenesis, which may provide refer-ences for follow-up research and clinical treatment.

Objective To investigate the association between obesity and the risk of lung cancer and evaluate a dose-response relationship between body mass index (BMI) and incidence risk of lung cancer in the Chinese population. Methods A systematic literature search for BMI and incidence risk of lung cancer in the Chinese population, as well as through the reference lists of retrieved articles. The literature databases including Chinese National Knowledge Infrastructure, Wanfang, PubMed, Embase and Google Scholar. Time range was from the founding of each database to September 2014 and a total of 93 research papers were collected. Meta-analysis was conducted to calculate pooled odds ratio and corresponding 95%CI. Generalized least-squares regression methods were used to make a dose-response meta-analysis between BMI and incidence risk of lung cancer. Results Seven studies were included in the meta-analysis, with a number of 2 351 lung cancer cases. Results showed that obesity was inversely associated with lung cancer incidence (OR=0.68, 95%CI:0.59-0.79) (heterogeneity test:I2=0,P=0.594). The association did not change with stratification by study design, sex, smoking status, BMI measurement method and study population. A linear dose-response association between BMI and risk of lung cancer was visually significant, and lung cancer risk would be reduced 21% for per 5 kg/m2 BMI increase (OR=0.79, 95% CI: 0.71- 0.89) (heterogeneity test:q=22.43,P=0.002). Conclusion The results of this meta-analysis indicated that higher BMI was a protective factor against lung cancer, but smoking may play a stronger role as a confounding factor for the most important role with lung cancer incidence.