Objective To refine the loss of heterozygosity(LOH) on chromosome 20q11-13 and identify the new tumor suppressor gene(s) in colorectal tumorigenesis. Methods From 1998 to 1999, 83 patients with colorectal cancer had been admitted to Shanghai First People's Hospital. Tumor tissues and adjacent normal mucosal tissues were collected. Ten polymorphic microsatellite markers were analyzed on chromosome 20 and another 10 markers were applied on chromosome 20q11-13 in 83 cases of colorectal and normal DNA by PCR. PCR products were eletrophoresed on an ABI 377 DNA sequencer. Genesean 3.1 and Genotyper 2.1 software were used for LOH scanning and analysis. Results We observed a distinct region of frequent allelic deletions on chromosome, another 10 polymorphric microsatellite markers were applied to 20q11-13 and 2 minimal regions of frequent LOH were established, that is to say 20q11.2, 20q12. Tumor suppressor genes E2F1, PMP24 and MAFB were found in the regions of 20q11.2 and 20q12. Conclusion Through our detailed deletion mapping studies, we have found 2 critical and precise regions, which must contain one or more unknown tumor suppressor gene (s) on colorectal cancer.

ObjectiveTo investigate the epidemic characteristics and influencing factors of acute conjunctivitis caused by human adenovirus（HAdv）in Yantian District of Shenzhen City， Guangdong Province from 2014 to 2022， and to provide evidence for formulating effective prevention and control measures. MethodsDescriptive epidemiology was used to analyze the epidemiological characteristics of acute hemorrhagic conjunctivitis （AHC） cases reported from the Chinese disease prevention and control information system. Etiological characteristics of laboratory-confirmed cases were analyzed， and a case-control study method of test-negative design （TND） was conducted as well. According to the result of HAdv detection， analysis was used to identify the influencing factors of morbidity. ResultsA total of 1 005 AHC cases were reported in Yantian District， Shenzhen City from 2014 to 2022， with an average annual incidence rate of 49.49/10⁵. The incidence rate ranged from 4.67/10⁵ to 117.28/10⁵. The peak incidence occurred from July to October each year， with a male-to-female ratio of 1.42∶1. The median （P₂₅，P₇₅） age of onset was 29（12，40） years. A total of 716 eye swabs were collected for etiological detection from 2014 to 2022. HAdv positive detection rate was 36.45% （263/716）， Cox 24v positive detection rate was 0.28% （2/716）， while EV70 was not detected. The longest viral shedding time in eye swabs was 10 days， with a median of 2 days. The highest HAdv positive detection rate （47.47%） was observed when the sampling-to-onset interval was 4‒5 days， and the difference was statistically significant （P<0.05）， with a trend of first increasing and then decreasing. Multivariate logistic regressing analysis showed that aged 18‒ years， and average temperature higher than 24.90 ℃ 3 days before onset （P<0.05） were the risk factors for acute HAdv conjunctivitis. ConclusionAHC in Yantian District， Shenzhen City showed a low level of prevalence from 2014 to 2022， with HAdv being the predominant pathogen. The peak period of viral shedding occurred on the 4th to 5th day after symptom onset， suggesting the importance of adherence to strict home isolation for infected persons. Aged18‒ years and average temperature increased 3 days before onset are associated with an increased risk of adenoviral conjunctivitis. It is recommended to strengthen personal protection and keep doing a good job of AHC surveillance and early warning， so as to timely prevent the outbreaks of AHC.

Objective: To evaluate the efficacy of ultraviolet light in influenza B prevention and control in schools in Yantian District of Shenzhen in winter, and to provide a reference for preventing and controlling influenza B in schools. Methods: Multistage stratified cluster sampling was conducted. Ultraviolet irradiance was detected in 98 classes of 11 schools. The irradiance of different distances under each ultraviolet lamp were measured. Correlational analysis was conducted with influenza cases reported by Shenzhen Student Health Surveillance System. Results: A total of 473 ultraviolet lamps were detected, the qualified rate was 53.91%. The effective distance from the lamp corresponding power supply to efficient irradiance was (1.43±0.54)m. The total effective irradiance volume per unit time of each class was(13.65±32.66)m3. Totally 599 influenza cases in 74 classes were reported, with incidence rate of 13.76%. Fifty-eight classes reported influenza clustering, accounting for 59.18%. Average duration of the epidemic was(14.5±25.25)d. Spearman correlation analysis showed that the proportion of irradiance volume per unit time in classroom volume was negatively correlated with class influenza incidence(r=-0.32, P=0.00), but not significant with duration of influenza epidemic(P=0.78). Covariance analysis showed that the incidence of influenza and the duration of influenza epidemic in classes was not significantly correlated with the proportion of irradiance volume per class per unit time in classroom volume (P>0.05). Conclusion Ultraviolet light might not effectively reduce the incidence rate of influenza B and the duration of influenza epidemic in schools in Yantian District of Shenzhen over 2017-2018 winter.

Objective To compare epidemiology characteristics and control measures of dengue fever (DF) outbreaks in public places in Shenzhen and Hong Kong and integrate the advantages for better response to DF outbreaks. Methods Data of DF cases and mosquito vector surveillance in Shenzhen and Hong Kong were collected for descriptive epidemiological analysis and measures of mosquito control were compared. Results A total of 19DF cases were recorded in 13 d among six districts of Hong Kong, the male: female ratio was 1 ∶〗0.9. In Shenzhen, 20 cases were recorded in 33 d, the cases were distributed in three sub-districts, the Male: female ratio was 1 ∶〗0.82; Age difference between Shenzhen and Hong Kong was statistically significant (Z=-2.855, P=0.004). The time interval between date of onset and laboratory confirmation ranging from 5.5 to 8.5 d (median:7d) in Hong Kong, and ranged from 1.5 to 5.4 d (median:2 d) in Shenzhen, the difference was statistically significant (Z=-3.818, P<0.001). On the 4th day of the outbreak, Hong Kong declared 30 d closure for anti-mosquito operations with a range of 500 m, and monthly area ovitrap index (AOI) was used to monitor the territory-wide situation of Aedes albopictus. On the 2nd day of the outbreak, Shenzhen declared source closure for mosquito control with a range of 400 m and emergency vector surveillance was conducted, using Breteau Index (BI) and Human-baited double net trap(HDN) every 3 d. Conclusions The nature, scale, time and place of the two local DF outbreaks in Shenzhen and Hong Kong are similar. The prevention and control system is more sensitive and prompt, the ability of early detection is stronger, mosquito vector surveillance program is more comprehensive and the frequency is higher in Shenzhen. The epidemic information dissemination and risk communication with media is more active, mosquito management and control is more professional in Hong Kong.