[Progress in research of self-sampling for detection of genital chlamydia trachomatis and related factors in men who have sex with men].

Laboratory testing is a vital chain in the prevention and control of genital chlamydia trachomatis infection. The prevalence of genital chlamydia trachomatis infection is high, but the detection rate of the infection is low in men who have sex with men (MSM) in China. Self-sampling for genital chlamydia trachomatis detection by MSM is a new option to address this problem, which would play a significant role in expanding genital chlamydia trachomatis infection screening in this population. This paper summarizes the progress in research of self-sampling for the detection of genital chlamydia trachomatis and the related factors in MSM both at home and abroad to provide reference for the promotion of self-sampling for the detection of genital chlamydia trachomatis in this population.

[Epidemiological characteristics of incident cases and risk factors of hepatitis C infection in Beijing City from 2004 to 2021].

Objective: To analyze the epidemiological characteristics and related factors of hepatitis C in Beijing City from 2004 to 2021. Methods: Descriptive epidemiological method and Joinpoint regression were used to analyze the trend and other epidemiological characteristics of hepatitis C in Beijing City from 2004 to 2021 in National Notifiable Disease Reporting System. According to a 1∶1 matched case-control study design, logistic regression was used to investigate the risk factors of hepatitis C infection in 2021. Results: From 2004 to 2021, the reported incidence of hepatitis C in Beijing City ranged from 2.37/100 000 to 10.46/100 000. The reported cases were mainly aged 30-60 years, and most of them were chronic. The reported incidence of hepatitis C showed an initial increase from 2004 to 2006 (APC=45.37%, 95%CI:-1.56%-114.69%), and declined after 2006 (APC=-9.21%, 95%CI:-10.70%-7.70%). Logistic analysis showed that history of surgery (OR=1.84, 95%CI: 1.08-3.14) and previous blood transfusion (OR=34.22, 95%CI: 8.05-145.41) were risk factors for hepatitis C infection. Conclusion: The reported incidence of hepatitis C in Beijing City increases first and decreases later. It currently remains at a low level. The risk factors of infection are surgery and blood transfusion history. Safe blood supply and preventing iatrogenic transmission should be focused on the prevention of hepatitis C transmission.

[Epidemiological characteristics and serum antibody detection of a COVID-19 aggregated outbreak in vaccinated population].

An epidemiological investigation was conducted on a cluster epidemic of COVID-19 in the vaccinated population in Beijing in 2022, and serum samples were collected from 21 infected cases and 61 close contacts (including 20 cases with positive nucleic acid in the isolation observation period). The results of antibody detection showed that the IgM antibody of two infected persons was positive, and the IgG antibody positive rates of patients who were converted, not converted to positive and infected persons were 36.84% (7/19), 63.41% (26/41) and 71.43% (15/21), respectively. About 98.78% of patients had been vaccinated with the SARS-CoV-2 inactivated vaccine. The positive rate of IgG antibody in patients immunized with three doses of vaccine was 86.00% (43/50), which was higher than that in patients with one or two doses [16.12% (5/31)]. The antibody level of M (Q1, Q3) in patients immunized with three doses was 4.255 (2.303, 7.0375), which was higher than that in patients with one or two doses [0.500 (0.500, 0.500)] (all P values<0.001). The antibody level of patients who were vaccinated less than three months [7.335 (1.909, 7.858)] was higher than that of patients vaccinated more than three months after the last vaccination [2.125 (0.500, 4.418)] (P=0.007). The positive rate and level of IgG antibody in patients who were converted to positive after three doses were 77.78% (7/9) and 4.207 (2.216, 7.099), respectively, which were higher than those in patients who were converted after one or two doses [0 and 0.500 (0.500, 0.500)] (all P values<0.05).

[Analysis on infection sources and transmission chains of three outbreaks caused by 2019-nCoV Omicron variant in Beijing, China].

Objective: To investigate the infection sources and the transmission chains of three outbreaks caused by 2019-nCoV Omicron variant possibly spread through cross-border logistics in Beijing. Methods: Epidemiological investigation and big data were used to identify the exposure points of the cases. Close contacts were traced from the exposure points, and the cases' and environmental samples were collected for nucleic acid tests. Positive samples were analyzed by gene sequencing. Results: The Omicron variant causing 3 outbreaks in Beijing from January to April, 2022 belonged to BA.1, BA.1.1 and BA.2. The outbreaks lasted for 8, 12 and 8 days respectively, and 6, 42 and 32 cases infected with 2019-nCoV were reported respectively. International mail might be the infection source for 1 outbreak, and imported clothes might be the infection sources for another 2 outbreaks. The interval between the shipment start time of the imported goods and the infection time of the index case was 3-4 days. The mean incubation period (Q1, Q3) was 3 (2,4) days and the mean serial interval (Q1, Q3) was 3 (2,4)days. Conclusions: The 3 outbreaks highlighted the risk of infection by Omicron variant from international logistics-related imported goods at normal temperature. Omicron variant has stronger transmissibility, indicating that rapid epidemiological investigation and strict management are needed.

[A follow-up study on the pain changes trend and effects in patients diagnosed with herpes zoster in Beijing City].

Objective: To understand the changes in pain and its effects in patients with the diagnosis of herpes zoster. Methods: A total of 3 487 patients diagnosed with herpes zoster (HZ) for the first time at the outpatient department of Miyun District Hospital from January 1, 2017, to December 31, 2019, were included in the study. The information of patients was registered and issued with a record card. Patients were required to record the time of pain and rash by themselves. Telephone follow-up was conducted at 21, 90, 180 and 365 days after the onset of rashes, including hospitalization, location of rash and pain, and the time of start and end. The impact of pain on life was evaluated by the Zoster Brief Pain Inventory (ZBPI). Results: The age of 2 999 HZ patients included in the analysis were (53±16) years old, including 1 377 (45.91%) males and 1 903 (63.45%) patients aged 50 years and older. After 21 days of rash, mild, moderate and severe pain accounted for 20.87% (626 cases), 37.98% (1 139 cases) and 33.81% (1 014 cases), respectively. Only 5.07% (152 cases) had no pain or discomfort, and 2.27% (68 cases) had no pain but discomfort. Most of the pain sites were consistent with the rash sites. The chest and back and waist and abdomen were the most common, accounting for 35.58% (1 067 cases) and 29.18% (875 cases), respectively, followed by the limbs and face and neck, accounting for 16.74% (502 cases) and 16.40% (492 cases), respectively. The M (Q1, Q3) of pain days in the HZ patients was 14 (8, 20) days, and the incidence of post-herpetic neuralgia (PHN) was 6.63% (171/2 580) (excluding 419 patients who refused to visit or lost to visit on 90 days after the onset of rash). The pain score of HZ patients within 21 days after the rash was (5.19±2.73) points, and the pain score of PHN patients was (7.61±2.13) points, which was significantly higher than that of non-PHN patients [(5.04±2.69) points] (P<0.001). Daily activities, emotions, walking ability, work, social interaction, sleep and recreation were affected for 21 days after the rash in HZ patients, ranging from 60.79% to 83.83%, with sleep being the most affected (83.83%). The impact scores of pain and life dimensions in PHN patients ranged from 4.59 to 7.61 points on the ZBPI scale, which were higher than those in non-PHN patients (2.49-5.04) (t values ranged from 8.86 to 11.67, all P values <0.001). Conclusion: The proportion of pain in HZ patients after the diagnosis is high, and the pain is more obvious in patients with PHN and HZ patients aged 50 and older, which has a greater impact on their daily lives.

[Study of transmissibility of 2019-nCoV Omicron variant in Beijing].

Objective: To evaluate the transmissibility of 2019-nCoV Omicron variant under the current prevention and control strategy in Beijing, and provide evidence for the prevention and control of COVID-19. Methods: The information of 78 Omicron variant infection cases involved in clear transmission chains in Beijing during 7-25 March, 2022 were collected, the incubation period and serial interval of the disease were fitted by using Gamma and Weibull distribution. Markov Chain Monte Carlo approach was used to estimate the time-varying reproduction number (Rt). Results: The median of the incubation period (Q1, Q3) of Omicron variant infection was 4.0 (3.0, 6.0) days, and the serial interval was 3.0 (2.0, 5.0) days. The median of the serial interval (Q1, Q3) was 2.0 (1.0, 4.0) days in unvaccinated cases and 4.0 (2.0, 6.0) days in vaccinated cases (Z=-2.12, P=0.034), and 2.0 (1.5, 3.0) days in children and 4.0 (2.0, 6.0) days in adults, respectively (Z=-2.02,P=0.044), the differences were significant. The mean of Rt was estimated to be 4.98 (95%CI: 2.22-9.04) for Omicron variant in this epidemic. Conclusion: Omicron variant has stronger transmissibility compared with Delta variant. It is necessary to strengthen the routine prevention and control COVID-19, promote the vaccination and pay close attention to susceptible population, such as children.

[Analysis of HIV transmission hotspots and characteristics of cross-regional transmission in Guangxi Zhuang Autonomous Region based on molecular network].

Objective: To analyze HIV transmission hotspots and characteristics of cross-regional transmission in Guangxi Zhuang autonomous region (Guangxi) based on the molecular network analysis, and provide evidence for optimization of precise AIDS prevention and control strategies. Methods: A total of 5 996 HIV pol sequences sampled from Guangxi between 1997 and 2020 were analyzed together with 165 534 published HIV pol sequences sampled from other regions. HIV-TRACE was used to construct molecular network in a pairwise genetic distance threshold of 0.5%. Results: The proportion of HIV sequences entering the molecular network of HIV transmission hotspots in Guangxi was 31.5% (1 886/5 996). In the molecular network of HIV cross-regional transmission, the links within Guangxi accounted for 51.6% (2 613/5 062), the links between Guangxi and other provinces in China accounted for 48.0% (2 430/5 062), and the links between Guangxi and other countries accounted for 0.4% (19/5 062). The main regions which had cross-regional linked with Guangxi were Guangdong (49.5%, 1 212/2 449), Beijing (17.5%, 430/2 449), Shanghai (6.9%, 168/2 449), Sichuan (5.7%, 140/2 449), Yunnan (4.2%, 102/2 449), Shaanxi (3.8%, 93/2 449), Zhejiang (2.8%, 69/2 449), Hainan (2.0%, 49/2 449), Anhui (1.5%, 37/2 449), Jiangsu (1.3%, 33/2 449), and other regions (each one <1.0%), respectively. The risk factors of entering the molecular network of HIV transmission hotspots in Guangxi included being aged ≥50 years (compared with being aged 25-49 years, aOR=1.68,95%CI:1.46-1.95), males (compared with females, aOR=1.21,95%CI:1.05-1.40), being single (compared with being married, aOR=1.18,95%CI:1.00-1.39), having education level of high school or above (compared with having education level of junior high school or below, aOR=1.21,95%CI:1.04-1.42), acquired HIV through homosexual intercourse (compared with acquired with HIV through heterosexual intercourse, aOR=1.77, 95%CI:1.48-2.12). The risk factors of cross-regional transmission included males (compared with females, aOR=1.74,95%CI:1.13-2.75), having education level of high school or above (compared with having education level of junior high school or below, aOR=1.96,95%CI:1.43-2.69), being freelancer/unemployed/retired (compared with being farmers, aOR=1.50,95%CI:1.07-2.11), acquired HIV through homosexual intercourse (compared with acquired with HIV through heterosexual intercourse, aOR=3.28,95%CI:2.30-4.72). Conclusion: There are HIV transmission hotspots in Guangxi. Guangxi and other provinces in China form a complex cross-regional transmission network. Future studies should carry out social network surveys in high-risk populations inferred from the molecular network analysis for the timely identification of hidden transmission chains and reduction of the second-generation transmission of HIV.

Presence and clinical significance of acellular mucin pools in resected rectal cancer with pathological complete response after pre-operative chemoradiotherapy.

For patients with locally advanced rectal cancer (LARC), a pathological complete response (pCR) after pre-operative chemoradiotherapy (CRT) does not necessarily indicate a cure. Acellular mucin pools are often seen in patients with pCR. However, the clinical significance of acellular mucin pools in this group of patients remains unknown. This was a retrospective analysis of 225 LARC patients who achieved pCR following CRT and total mesorectal resection from 2011 to 2018. The outcomes of 5-year disease-free survival (DFS), 5-year overall survival (OS) and 5-year distant metastasis-free survival (DMFS) were compared in patients with versus without acellular mucin pools. Among 225 pCR patients, acellular mucin pools could be identified in 56 (24.9%) patients, and recurrence occurred in 30 (13.3%) patients at 5 years. Distant recurrence was seen in 13 (23.2%) patients with acellular mucin pools and in 17 (10.1%) patients without acellular mucin pools. Patients with acellular mucin pools versus those without had poorer DFS (76.8 versus 89.9%, P = 0.010) and OS (87.5 versus 97.0%, P = 0.004) at 5 years. The presence of acellular mucin pools was the independent parameter that remained significant for DFS [hazard ratio (HR) = 3.904; 95% confidence interval (CI) = 1.342-11.356; P = 0.047] and OS (HR = 3.850; 95% CI = 1.214-12.213; P = 0.022) on multivariate analysis. A total of 17 patients demonstrated acellular mucin pools in primary tumour and lymph nodes. Subgroup analysis demonstrated that pCR patients with acellular mucin pools in primary tumour and lymph nodes were more likely to develop distant metastasis compared to pCR patients with acellular mucin pools only in primary tumour (47.1 versus 12.8%, P = 0.005). In summary, acellular mucin pools in LARC patients with pCR after CRT might represent a sign of invasive tumour biology and significantly shorten the prognosis of patients, especially in patients with acellular mucin pools in lymph nodes.

[Effects of parity on nutrition and health status of Chinese women of childbearing age].

Objective: To analyze effects of parity on women's nutrition and health status. Methods: This study was based on the data bank of "Chinese Nutrition and Health Surveillance of Children and Adolescents Aged 0-17 years old and Lactating Mothers from 2016 to 2017". Using a multi-stage stratified random sampling method, 17 771 women at 0 to 24 months postpartum from 31 provinces in Mainland China were included in this study. Questionnaires were used to collect data on women's general demographic characteristics, parity, mode of delivery, pre-pregnancy weight, pre-delivery weight, diseases before and during pregnancy, postpartum hemorrhage. Current body height, body weight, waist circumference, and blood pressure were measured. Blood hemoglobin, blood glucose and blood lipids were detected. Pre-pregnancy BMI, gestational weight gain, postpartum weight retention, postpartum BMI, the rates of anemia, hypertension, diabetes, and dyslipidemia were calculated. Survey sample weights were calculated according to the sampling design and number of children under 2 years old from the sixth population census data of China. Effects of parity on the observational indicators after adjusting for confounding factors were analyzed by multivariate linear regression and multivariate logistic regression. Results: The age of 17 771 women was (29.5±5.0) years old, 12.2% (2 172) were over 35 but less than 40 years old, and 3.2% (563) were over 40 years old; the women with one parity, two parities, and three parities accounted for 47.3% (8 413), 48.5% (8 620) and 4.2% (738), respectively; urban women accounted for 49.9% (8 875), and rural women accounted for 50.1% (8 896). The results from multivariate linear regression showed that the pre-pregnancy BMI of women with two and three parities was 0.55 kg/m2 and 0.76 kg/m2 higher than women with one parity, respectively; the results of multivariate logistic regression showed that the OR(95%CI) of pre-pregnancy anemia was 1.45(1.04-2.02) for women with three parities compared with women with one parity, and the OR(95%CI) of anemia during pregnancy for women with two parities was 1.20(1.06-1.35) compared with women with one parity. Conclusion: Parity is associated with pre-pregnancy BMI and risk of anemia before and during pregnancy in women of reproductive age.

[A real-world study of the efficacy and safety of sofosbuvir and velpatasvir in the treatment of HCV-infected patients in a county in northern China].

Objective: To evaluate the real-world efficacy and safety of sofosbuvir and velpatasvir (SOF/VEL) tablets in the treatment of Chinese patients with chronic HCV infection. Methods: An open-label, single-center, prospective clinical study was conducted in a county in northern China. A total of 299 cases were enrolled. Of these, 161 cases with chronic hepatitis C and 73 cases with compensated cirrhosis received SOF/VEL for 12 weeks. 65 cases with decompensated cirrhosis received SOF/VEL combined with ribavirin for 12 weeks (22 cases) or SOF/VEL for 24 weeks (43 cases). Virological indicators, liver and renal function indexes, and liver stiffness measurement were detected at baseline, the fourth week of treatment, the end of treatment, and the 12-weeks of follow-up. Adverse reactions and laboratory abnormalities were observed during the course of treatment . The primary endpoint was undetectable rate of HCV RNA (SVR12) at 12 weeks of follow-up with the use of modified intention-to-treat (mITT) approach. Measurement data between two groups were compared using t-test. One Way ANOVA was used for comparison between multiple groups. Enumeration data were analyzed by chi-square test or Fisher's exact test. Results: 291 cases had completed treatment. HCV RNA was undetectable after 12 weeks of follow-up, and the SVR12 rate was 97.3% (95% confidence interval: 95.4%-99.3%). Among them, 97.4% of genotype 1b, 96.4% of genotype 2a, and 100% of those with undetected genotype achieved SVR12. The SVR12 rates in patients with chronic hepatitis C, compensated and decompensated liver cirrhosis were 98.1%, 98.6% and 93.8%, respectively. An improvement in alanine aminotransferase, aspartate aminotransferase and other liver biochemical indicators accompanied with virological clearance and reduced liver stiffness measurement was observed in patients with compensated cirrhosis, with statistically significant difference. There was no significant abnormality in renal function before and after treatment. The most common adverse reactions were fatigue, headache, epigastric discomfort and mild diarrhea. The overall adverse reactions were mild. One patient died of decompensated liver cirrhosis combined with massive upper gastrointestinal bleeding, which was unrelated to antiviral treatment. Four patients discontinued treatment prematurely due to adverse events. Relapse was occurred in four cases, and drug-resistance related mutations were detected in three cases. Conclusion: Sofosbuvir and velpatasvir tablets in Chinese HCV-infected patients with different genotypes, different clinical stages or previously treated with pegylated interferon combined with ribavirin resulted in higher SVR12, indicating that the treatment safety profile is good.

[The IL-6/STAT3 signaling pathway mediated by radiotherapy regulates the expression of PD-L1 in esophageal cancer cells].

Objective: To explore the possible mechanism of radiotherapy regulating the expression of PD-L1 in esophageal carcinoma. Methods: Three esophageal cancer cell lines (Eca109, Kyse150, TE1) were irradiated with different doses of X-rays, and 6 Gy+ AG490 group was set. The mRNA expression of PD-L1 was detected by real-time quantitative polymerase chain reaction (RT-qPCR). The protein expressions of PD-L1, STAT3, p-STAT3 were detected by western blotting and the protein level of IL-6 was detected by ELISA. Results: The mRNA expressions of PD-L1 in Eca109, Kyse150 and TE1 were 2.86±0.30, 960.01±21.27 and 106.78±6.67, higher than 1.07±0.15 in normal esophageal cell line HET-1A (P<0.01). The protein expressions of PD-L1 in Eca109, Kyse150 and TE1 were 0.091±0.036, 1.533±0.079 and 0.914±0.035, higher than 0.063±0.01 in normal esophageal cell line HET-1A (P<0.01). After 48 hours of 6 Gy irradiation, the protein expression levels of PD-L1 in Eca109, Kyse150 and TE1 were 0.135±0.007, 1.66±0.06 and 1.32±0.06, higher than 0.09±0.01, 1.21±0.05 and 0.93±0.03 of the 0 Gy group (P<0.01), while the protein expression levels of p-STAT3 in Eca109, Kyse150 and TE1 were 1.44±0.26, 0.75±0.04 and 1.92±0.17, higher than 0.18±0.05, 0.48±0.02 and 0.36±0.06 of the 0 Gy group (P<0.01). IL-6 protein expression increased significantly after different doses of irradiation (P<0.01). After the IL-6/STAT3 signaling pathway was blocked by the specific inhibitor AG490, the expressions of PD-L1 of Eca109, Kyse150 and TE1 in the 6 Gy+ AG490 groups were 0.11±0.03, 1.07±0.08 and 0.96±0.11, without significant differences of 0.09±0.01, 0.96±0.05 and 0.85±0.09 of the 0 Gy group (P>0.05), while the protein expressions of p-STAT3 were 0.76±0.11, 0.59±0.06 and 0.96±0.12, without significant differences of 0.67±0.08, 0.54±0.06 and 0.84±0.11 of the 0 Gy group (P>0.05). Conclusion: Radiotherapy may regulate the expression of PD-L1 in esophageal cancer cells through IL-6 / STAT3 signaling pathway.

[An investigation on serum antibody level of varicella-zoster virus in healthy population in Beijing].

Objective: To assess the level and trend of varicella-zoster virus (VZV) antibody among healthy population in Beijing in 2017, after the five-year implementation of the two doses varicella vaccination strategy in 2012, and to provide evidence for scientific evaluation of immunization strategy. Methods: A total of 2 144 subjects in ten age groups from 8 districts of Beijing city were recruited in this study using cross-sectional survey based on multi-stage cluster random sampling method. Serum samples were collected and VZV antibody was detected by ELISA. The influencing factors of antibody concentration and positive rate were analyzed and compared with the study in 2012. The antibody concentration and antibody positive rate were analyzed by nonparametric test and χ² test respectively. Results: The ratio of subjects with registered residence in Beijing city to other provinces was 1∶1. The ratio of male to female was 1∶1.08. The median concentration of VZV antibody was 341.4 (78.6, 1 497.8) mIU/ml, and the total antibody positive rate was 71.1% (1 524/2 144). There were significant differences in antibody positive rate (χ²=736.39, P<0.01) and antibody concentration (χ²=740.34, P<0.01) among different age groups. The antibody positive rate generally increased with age (χ²trend=7.32, Ptrend<0.01). Among 862 children under 14 years old, the antibody positive rate of two doses vaccination 72.8% (182/250) was significantly higher than that of one dose vaccination 51.9% (154/297) (χ²=25.14, P<0.01). There was significant difference between 1-4 years old group (χ²=11.71, P<0.01) and 10-14 years old group (χ²=5.95, P=0.02), but not in 5-9 years old group (χ²=3.00, P=0.07). Compared with the study in 2012, the antibody positive rate increased in 5-9 years old group (χ²=14.35, P<0.01) and decreased in 1-4 years old group (χ²=11.51, P=0.01) in 2017. Conclusion: The recommended varicella booster vaccination has significantly improved the VZV antibody level of children in Beijing city. In the future, it is necessary to explore a more optimized two doses varicella vaccination schedule for children in combination with epidemiological evidence.

[Interventional effect of metformin on pulmonary inflammation and pulmonary fibrosis in silicotic rats].

Objective: To investigate the interventional effect of metformin on pulmonary inflammation and pulmonary fibrosis in silicotic rats. Methods: In April 2019, 48 Wistar male rats of SPF grade were randomly divided into negative control group, metformin control group, silicon dioxide (SiO2) model group, low, medium and high dose metformin intervention group according to the random number table method, 8 rats in each group. The SiO2 model group and the low, medium and high dose metformin intervention groups were given 1 ml 50 mg/ml of SiO2 by intratracheal instillation, the negative control group and the metformin control group were given 1 ml normal saline by intratracheal instillation. 24 hours later, the low, medium and high dose metformin intervention groups and the metformin control group were treated with 100, 200, 400 and 400 mg/kg metformin daily, the control and SiO2 model groups received normal saline daily. Then the rats were sacrificed at the 28th day after SiO2 exposure. The changes of rat body weight and pathological examination of rat lung tissue were observed, and the lung organ coefficient, the content of hydroxyproline (HYP) , the expression levels of inflammatory factors transforming growth factor beta1 (TGF-ß1) , tumor necrosis factor-alpha (TNF-α) , interleukin-1beta (IL-1ß) and the protein expression of E-cadherin (E-Cad) , Vimentin, α-SMA were detected. Results: Compared with the negative control group, SiO2 model group had a significant decrease in the body weight of rats (P<0.05) , lung organ coefficient, alveolitis and fibrosis scores, HYP content and the levels of TGF-ß1, TNF-α, IL-1ß were all significantly increased (P<0.05) . Compared with the SiO2 model group, the weights of the rats in the medium and high dose intervention group of metformin increased significantly (P<0.05) . And after intervention with different doses of metformin, the lung organ coefficient, alveolitis and fibrosis scores, HYP content and the levels of TGF-ß1, TNF-α and IL-1ß were significantly decreased (P<0.05) . Immunohistochemistry and Western blotting results showed that compared with the negative control group, the expression of E-Cad of the SiO2 model group was decreased, and the expression levels of Vimentin and α-SMA were significantly increased (P<0.05) . After metformin intervention, the expression of E-Cad was significantly increased, the expression levels of Vimentin and α-SMA were significantly decreased (P<0.05) . Conclusion: Metformin can reduce lung tissue inflammation and fibrosis in rats exposed to SiO2 dust, which may be related to reducing the expression of inflammatory factors in lung tissue and inhibiting the EMT process.

[Association between dietary vitamin A intake and gestational diabetes mellitus in the first trimester].

Objective: To investigate the relationship between dietary vitamin A intake and its sources in the first trimester and gestational diabetes mellitus (GDM). Methods: A prospective study was conducted to select women at 6-14 weeks of gestation in an obstetric clinic of a maternal and child health care medical institution in Chengdu in 2017. The types and quantities of food during the first trimester were collected by 3-day 24-hour dietary recalls. Dietary vitamin A intake was calculated based on the Chinese Food Composition Table (2018), and it was divided into animal and plant vitamin A intakes according to its food sources. An oral glucose tolerance test was performed at 24-28 weeks of gestation to diagnose GDM according to the Chinese guidelines for diagnosis and treatment of gestational diabetes mellitus (2014). According to the estimated average requirement (EAR) and recommended nutrient intake (RNI), dietary vitamin A intake was divided into low-level group (RNI). Animal and plant vitamin A intakes were divided into four groups (Q1-Q4) according to the quartile method, respectively. The association between dietary vitamin A intake, its different sources of vitamin A intake and GDM in the first trimester was analyzed by log-binomial regression models. Results: A total of 1 298 valid samples were finally included. The average dietary vitamin A intake, animal and plant vitamin A intakes in the first trimester were 341.1 (227.8-501.0) µgRAE/d, 139.3 (69.6-195.3) µgRAE/d and 184.2 (99.4-301.1) µgRAE/d, respectively. After adjusting for confounding factors, log-binomial regression analysis showed that the risk of GDM in high-level group of dietary vitamin A intake was lower than that in low-level group [RR (95%CI):0.53 (0.36-0.80)]. Pregnant women in the highest quartile of animal vitamin A intake had a lower risk of GDM than those in the lowest quartile [RR (95%CI):0.66 (0.47-0.95)]. No relationship between plant vitamin A intake and GDM was found. Conclusion: Dietary vitamin A intake in the first trimester is associated with the occurrence of GDM, and higher intake than RNI may reduce the risk of GDM. Higher vitamin A intake from animal-derived food is associated with decreased risk of GDM.

[Survey on source of infection of the first local outbreak caused by SARS-CoV-2 Alpha variant in China].

Objective: To investigate the epidemiological characteristics and the chain of infection of a local outbreak, which was the first outbreak caused by severe acute respiratory syndrome corona virus 2 Alpha variant in China and occurred in Daxing district, Beijing. Methods: Epidemiological investigation and big data technology were used to verify the exposure points of the cases. Close contacts were traced from the exposure points, and their human and environmental samples were collected for nucleic acid tests. Serum samples were collected from key persons for antibody detection. Results: A total of 33 corona virus disease 2019(COVID-19) cases were reported in the local outbreak, from January 17, 2021 to January 29, 2021 in Daxing district, Beijing, and there was epidemiological association in 32 cases. Except for one case who was infected in the workplace, other cases were all infected in the community and family. All cases involved 14 families, of which 6 families were all infected. The attack rate of all family members was 69%(33/48), and the secondary attack rate was 56%(19/34). There was no obvious source of infection found after the investigation of entry-exit personnel and goods. Conclusion: The first outbreak caused by severe acute respiratory syndrome corona virus 2 Alpha variant in China is found and handled in time, and thus the scope of influence is limited, but the family clustering characteristics are more obvious than previous outbreaks.

[Effects of radical radiotherapy combined with different regimens of chemotherapy on radiation intestinal injury in patients with non-metastatic anal squamous cell carcinoma].

Objective: To investigate the effects of radical radiotherapy combined with different chemotherapy regimens (fluorouracil-based versus docetaxel plus cisplatin) on the incidence of radiation intestinal injury and the prognosis in patients with non-metastatic anal squamous cell carcinoma. Methods: A retrospective cohort study was conducted to recruit non-metastatic anal squamous cell carcinoma patients who underwent chemoradiotherapy in the Sixth Affiliated Hospital of Sun Yat-sen University and Nanfang Hospital from July 2013 to January 2021. Inclusion criteria: (1) newly diagnosed anal and perianal squamous cell carcinoma; (2) completed radical radiotherapy combined with concurrent chemotherapy; (3) tumor could be evaluated before radiotherapy. Exclusion criteria: (1) no imaging evaluation before treatment, or the tumor stage could not be determined; (2) patients undergoing local or radical resection before radiotherapy; (3) distant metastasis occurred before or during treatment; (4) recurrent anal squamous cell carcinoma. A total of 55 patients (48 from the Sixth Affiliated Hospital of Sun Yat-sen University and 7 from Nanfang Hospital) were given fluorouracil (the 5-FU group, n=34) or docetaxel combined with the cisplatin (the TP group, n=21). The evaluation of radiation intestinal injury, hematological toxicity and 3-year disease-free survival (DFS) rate were compared between the two groups. The effects of chemotherapy regimen and other clinicopathological factors on the incidence and severity of acute and chronic radiation intestinal injury were analyzed. The assessment of radiation intestinal injury was based on the American Cancer Radiotherapy Cooperation Group (RTOG) criteria. Results: During radiotherapy and within 3 months after radiotherapy, a total of 45 patients developed acute radiation intestinal injury, including 18 cases of grade 1 (32.7%), 22 cases of grade 2 (40.0%) and 5 cases of grade 3 (9.1%). No patient developed chronic radiation intestinal injury. Among the 34 patients in the 5-FU group, 21 had grade 2-3 radiation intestinal injury (21/34, 61.8%), which was significantly higher than that in the TP group (6/21, 28.6%) (χ(2)=5.723, P=0.017). Multivariate analysis showed that 5-FU chemotherapy regimen was an independent risk factor for radiation intestinal injury (HR=4.038, 95% CI: 1.250-13.045, P=0.020). With a median follow-up period of 26 (5-94) months, the 3-year DFS rate of patients in TP group and 5-FU group was 66.8% and 77.9%, respectively, whose difference was not significant (P=0.478). Univariate analysis showed that the DFS rate was associated with sex, age, tumor location, T stage, N stage, and induction chemotherapy (all P<0.05), while the DFS rate was not associated with chemotherapy regimen or radiation intestinal injury (both P>0.05). Multivariate analysis revealed that age ≥ 50 years old was an independent risk factor affecting the prognosis of patients (HR=8.301, 95% CI: 1.130-60.996, P=0.038). Conclusions: For patients with non-metastatic anal squamous cell carcinoma, radical radiotherapy combined with TP chemotherapy regimen can significantly reduce the incidence of radiation intestinal injury as compared to 5-FU regimen. However, due to the short follow-up time, the effect of different chemotherapy regimens on the prognosis is not yet clear.

[Relationship between respiratory viral load of cases of COVID-19 and secondary attack risk in close contacts].

Objective: To analyze the relationship between the cycle threshold (Ct) values of N gene of COVID-19 cases and the secondary attack risk in close contacts, and identify the relationship between respiratory viral load and infectivity in COVID-19 cases. Methods: The COVID-19 cases with records of Ct values of N gene within 0-7 days of onset were selected, and their close contacts were recruited as the subjects of study. We collected the information of close contacts, including name, gender, age, isolation mode, exposure mode and outcome (whether they were infected with SARS-CoV-2 or not) and other variables. Multivariate logistic regression models were used to identify the relationship between Ct values of N gene of COVID-19 cases and secondary attack risk in close contacts. Results: A total of 1 618 close contacts were recruited, in whom 77 were confirmed as symptomatic or asymptomatic COVID-19 patients with overall secondary attack rate of 4.8%. The multivariate logistic regression analysis indicated that eating together (OR=2.741, P=0.054), living together (OR=9.721, P<0.001), non-centralized isolation (OR=18.437, P<0.001) and COVID-19 case's values of N gene within 0-7 days of onset being <20 (OR=8.998, P=0.004) or 20-25 (OR=3.547, P=0.032) were significantly associated with higher likelihood of being infected with SARS-CoV-2 in close contacts. Conclusion: The results indicated that positive relationship exists between respiratory viral load and infectivity in COVID-19 cases, suggesting that Ct values of N gene can be used as an early warning indicator for the management of close contacts of COVID-19 cases.

[Construction of professional competency model of center for disease prevention and control].

Objective: Analyze and contruct the post competency model of professionals in centers for disease prevention and control in Beijing, so as to provide information for cultivation and construction of public health personnel, and the human Resource Management in relevant institutions. Methods: Cross-sectional research method was used, and based on literature research, functional analysis and referring to Hay Group Competency Dictionary and McClellan Competency Dictionary, the post competency dictionary was established after the unified discussion of the subject group. Hierarchical cluster sampling method was used to investigate an online survey on competency factors of professionals in centers for Disease prevention and Control in Beijing, and factor analysis was conducted on the survey data. Results: The competency model of professionals in centers for disease prevention and control in Beijing was composed of six factors, which are Public health practical operation skills and norms, public health emergency response thinking and deductive and inductive ability, professional quality and professional ethics, communication, coordination ability and team spirit, medicine humanities knowledge and health management and guidance. Conclusions: This competency model is basically in line with the job responsibilities of professionals in centers for disease prevention and control in Beijing. However, it can only reflect the post competence and ability of the middle and junior technical personnel for practice, so which should belongs to the category of basic competence.

[Preliminary audiological evaluation of the SoundBite bone conduction devices in adults with single-sided deafness].

Objective: The auditory deficits of single-sided deafness (SSD) can be treated with a novel intra-oral device, SoundBite, which delivers sound by applying vibratory signal to the teeth. The purpose of this study was to evaluate the efficacy and benefit of the bone conduction device for Chinese adults with SSD. Methods: Eighteen patients aged 19-66 yrs with acquired, permanent sensorineural SSD and no current treatment by any other devices for SSD, were recruited in a prospective controlled, nonrandomized, unblinded study. They were requested the continually daily wear of the new device over a 30-day free trial period. The intra-oral hearing device was placed around two maxillary teeth and was similar to a small partial denture or retainer. The audiological tests included pure tone air conduction thresholds, monosyllable word recognition score (WRS) in quiet and sentence reception thresholds in noise (via CMNmatrix test). The benefit was determined with the Abbreviated Profile of Hearing Aid Benefit (APHAB) and the Speech, Spatial and Qualities of Hearing Scale (SSQ) questionnaire. Results: The monosyllable WRS and the 50% threshold of signal-to-noise ratio (SNR50) were significantly better in all aided conditions. The head shadow effect, assessed by the SNR50 via CMNmatrix test improved an average of 2.6 dB after 30 days' wearing compared with unaided condition (P<0.001). The APHAB scores improved (P<0.05) for all subjects for the Global and Ease of Communication, Reverberation, Background Noise subscales. The SSQ scores improved (P<0.05) for all subjects for Speech, Spatial and Qualities of Hearing subscales. Conclusion: The SoundBite is a good alternative to the well-established implantable bone conduction devices in patients with SSD. An improvement in listening ability in noise and quiet as well as a decrease of the head shadow effect is validated as the expected.