During the 13th Five-Year Plan period, remarkable progress has been made in prevention and control of endemic diseases in China through implementation of the national plan for prevention and control of endemic diseases and the special three-year action plan for prevention and control of endemic diseases. This paper reviewed the achievements made in prevention and control of endemic diseases in China during the 13th Five-Year Plan period, discussed the current problems we are facing on prevention and control of endemic diseases. The key tasks of prevention and control of endemic diseases during the 14th Five-Year Plan period are indicated in order to carry out scientific and accurate prevention and control of endemic diseases.

The standardization of endemic diseases in China has made steady progress during the "13th Five-Year Plan" period. This article mainly summarized the current endemic diseases standard system, analyzed the major problems existed in the current endemic diseases standard, and introduced the key tasks of the "14th Five-Year Plan" of the endemic diseases standard in China. During the "14th Five-Year Plan" period, the work of endemic diseases standardization will be carried out in a targeted manner in accordance with the requirements of the "Planning of Health Standardization during the ′14th Five-Year Plan′ Period" of the National Health Commission, to establish an endemic diseases standard system suitable for China's economic and social development, to help eradicate poverty and consolidate and implement the rural revitalization strategy, promote the full realization of the goal of eliminating endemic diseases in the "Healthy China Action (2019-2030)".

Drinking brick-tea type of endemic fluorosis is a kind of chronic fluorosis caused by excessive intake of fluoride into the body from long-term and high consumption of brick-tea, milk tea, butter tea, or other tea drinks with high fluoride content. It mainly distributes in seven western provinces of China, including Tibet Autonomous Region, Qinghai Province, Sichuan Province, Xinjiang Uygur Autonomous Region, Inner Mongolia Autonomous Region, Gansu Province, and Ningxia Hui Autonomous Region. In order to govern the production and sale of brick-tea and control the epidemic of drinking brick-tea type of endemic fluorosis, the former Ministry of Health of China issued the national standard "Fluoride Content of Brick-tea" (GB 19965-2005) in 2005, which stipulated that the total amount of water-soluble inorganic fluorine in brick-tea should not exceed 300 mg/kg. In the past 20 years, the prevalence of drinking brick-tea type of endemic fluorosis in China became clear gradually, and the habit of drinking brick-tea of residents in the epidemic fluorosis area also changed to some extent. In this paper, the dose-effect relationship between fluoride intake from brick-tea and skeletal fluorosis is reviewed, the brick-tea consumption of residents in the endemic fluorosis areas is analyzed, and the safety risk of brick-tea fluoride exposure is evaluated. It is suggested that the fluoride limit of brick-tea, ≤300 mg/kg, is still suitable for the prevention and control of drinking brick-tea type of endemic fluorosis in China at the present stage.

Objective:To analyze the epidemic characteristics of Cornona virus disease 2019 (COVID-19) in Wangkui County, Heilongjiang Province, and to provide a reference for optimizing epidemic prevention and control strategies.Methods:The epidemic characteristics of COVID-19 in Wangkui County, Heilongjiang Province in January 2021 were analyzed by applying the national infectious disease report system and information management system of Heilongjiang Provincial Center for Disease Control and Prevention, the public health emergency report management information system, the epidemiological investigation report of the Heilongjiang Provincial Center for Disease Control and Prevention and Suihua Municipal Certer for Disease Control and Prevention, and the epidemic information publicly released by the Health Commission of Heilongjiang Province.Results:From January 9 to February 5, 2021, 804 cases infected with Cornona virus were reported in Wangkui County, with an infection rate of 280.29/100 000. The epidemic affected 20 districts and counties in 6 cities, including Suihua, Harbin, Mudanjiang, Qiqihar, Yichun and Daqing. The sex ratio of male to female was 1.08 ∶ 1.00 (418 ∶ 386), the age ranged from 3 months to 93 years old, and the median age was 50 years old. The proportion of confirmed cases and asymptomatic infection was 1.23 ∶ 1.00 (444 ∶ 360), there were significant differences in gender, age and occupation between them ( P < 0.05). There were 314 places where the aggregation epidemic occurred, with family aggregation as the main way (300 households, 95.54%). The places with the highert average number of cases were banquets (25.75 cases/place) and grocery stores/chess and card rooms (16.00 cases/place). Conclusions:In January 2021, the epidemic of COVID-19 in Wangkui County is a typical outbreak in rural areas of North China. The main reasons for the rapid spread of the epidemic are a large number of gathering activities, frequent contact of personnel in confined spaces and other factors.

Objective:To explore the arsenic trioxide (As 2O 3)-induced apoptosis of human neuroblastoma cells (SH-SY5Y cells) and the protection mechanisms of folic acid (FA) and vitamin B 12 (VB 12). Methods:SH-SY5Y cells were cultured in vitro and divided into six groups by group design: control group (normal cultured), arsenic exposed group (10.00 μmol/L As 2O 3), FA intervention group (0.30 mmol/L FA + 10.00 μmol/L As 2O 3), VB 12 intervention group (0.06 mmol/L VB 12 + 10.00 μmol/L As 2O 3), combined intervention group (0.30 mmol/L FA + 0.06 mmol/L VB 12 + 10.00 μmol/L As 2O 3) and reagent control group (0.30 mmol/L FA + 0.06 mmol/L VB 12). Cells in each group were cultured for 24 h ( n = 3). Flow cytometry was used to determine the apoptosis rate of cells in each group. Transmission electron microscopy was used to observe the ultrastructural changes of the cells. The expression levels of mRNA and protein of apoptosis-related indicator B-cell lymphoma-2 (Bcl-2) and Bcl-2 associated X (Bax) were detected by fluorescence quantitative PCR and Western blotting. The activity of cysteinyl aspartate specific proteinase (Caspase) 3 was detected by luminescent assay. The above indicators were statistically analyzed. Results:There was statistically significant difference in the apoptosis rate among different groups ( F = 213.036, P < 0.05). The apoptosis rate in arsenic exposed group [(44.43 ± 3.54)%] was higher than that in control, FA intervention, VB 12 intervention, and combined intervention groups [(1.80 ± 0.06)%, (14.37 ± 0.13)%, (19.10 ± 1.56)%, (17.11 ± 2.34)%, P < 0.05]. Under transmission electron microscope, the apoptotic bodies, mitochondria swelling and degeneration, chromatin agglutination were observed in SH-SY5Y cells exposed to arsenic. The morphological and organelle changes of SH-SY5Y cells were significantly improved after respective and combined intervention of FA and VB 12. The expression levels of Bcl-2, Bax mRNA and protein were significantly different among different groups ( F = 5.178, 7.169, 6.142, 9.194, P < 0.05). The expression level of Bcl-2 protein in arsenic exposed group was lower than that in control group ( P < 0.05), and the expression levels of Bax mRNA and protein were higher than those in control group ( P < 0.05). The expression levels of Bcl-2 mRNA and protein in FA intervention group and combined intervention group were higher than those in arsenic exposed group ( P < 0.05), and Bcl-2 mRNA expression level in VB 12 intervention group was higher than that in arsenic exposed group ( P < 0.05). The expression levels of Bax mRNA and protein in FA intervention, VB 12 intervention and combined intervention groups were lower than those in arsenic exposed group ( P < 0.05). There were statistically significant differences in Caspase 3 activity among different groups ( F = 84.604, P < 0.05). Caspase 3 activity in arsenic exposed group was significantly higher than those in control, FA intervention, VB 12 intervention, and combined intervention groups ( P < 0.05). Conclusions:Arsenic exposure can lead to apoptosis and ultrastructural changes of SH-SY5Y cells. FA and VB 12 may effectively inhibit apoptosis through regulating Bcl-2/Bax pathway and decrease Caspase 3 activity, thus playing a protective role on nerve cells.

Funding of research projects within the category of Endemiology (H2401) funded by National Natural Science Foundation of China (NSFC) from 2010-2019 was summarized in this paper. Granted projects were categorized and analyzed based on the funding type, support institute and disease classification. The characteristics and trends of granted projects supported by NSFC were analyzed and summarized in order to provide reference for researchers to apply for projects in the future.

Radiotherapy is one of the most commonly used and effective method to treat malignant tumors in clinical practice. However, there are still some limitations including high radiotherapy doses, harmful side effects on normal tissues, and radiation resistance of tumor cells. Therefore, seeking safe and effective radiotherapy sensitizers to improve radiation sensitivity of tumor cells has been focused for a long time. Histone deacetylase inhibitors (HDACIs), as a kind of epigenetic modifiers, can regulate the sensitivity of tumor cells to ionizing radiation and ultraviolet radiation in addition to the inherent anticancer characteristics. This article reviewed the molecular mechanisms of HDACIs in enhancing radiation sensitivity and by selectively killing tumor cells.

According to the general goal of long term development of basic science from 2021 to 2035 and the "14th Five-Year Plan" in China, starting from the reasearch characteristics and the basic situation of endemiology, this study discusses the strategic position, development law, development trend, development status and layout, development goals and realization ways of endemiology, combined with the strategic needs of the discipline, the important interdisciplinary research areas of endemiology are put forward. The purpose of this study is to promote the rapid development of basic research on endemic diseases, to provide reference for the scientific and technological layout and policy formulation of the endemiology, to provide reference for the "14th Five-Year Plan" in China, and to provide guarantee for the people in the sick area to seek health.

Objective:To explore the serum different metabolites in population of dietary intervention with high iodine.Methods:Thirty-eight healthy volunteers were recruited in Harbin Medical University, all women, aged > 20 years. Dietary intervention was carried out by eating iodine-rich food (kelp) for 11 consecutive days. The effect of intervention was evaluated through urinary iodine test. Peripheral blood was collected, the metabolic alterations associated with high iodine intake before and after intervention were investigated using ultra-performance liquid chromatography coupled with quadrupole time-of-flight tandem mass spectrometry (UPLC-Q-TOF MSMS). Multivariate statistical analysis was used to screen potential biomarkers. And disturbed metabolic pathway analysis was performed.Results:The medians urinary iodine before and after intervention were 129.48 and 795.94 μg/L, respectively. A total of 20 serum biomarkers were screened and their chemical structures were identified. Glycerol phospholipid metabolic pathway, tryptophan metabolic pathway and pentose and glucuronate interconversions pathway were closely related with high iodine intake (impact value > 0.1).Conclusions:After the intervention of high iodine diet, there are obvious differential metabolites in peripheral blood, which may be used as biomarkers for evaluation of population iodine nutrition. High iodine intake has an impact on metabolic pathway of glycerol phospholipid in human body.

Based on the general goal of the medium and long term development of basic science from 2021 to 2035 and the "14th Five-Year Plan" in China, combined with the national strategic needs, this paper discusses the five priority development areas of endemiology according to the development trends and characteristics of endemiology in the next 5 - 15 years. The five areas are study on the pathogenesis and prevention measures of endemic fluorosis; study on risk assessment, pathogenic mechanism and control strategy of environmental arsenic exposure; research on the basis and application transformation of the pathogenesis of iodine nutrition-related diseases; molecular mechanism and targeted intervention of cartilage injury in Kashin-Beck disease; precise prevention and treatment, preservation of biological samples and etiology study of Keshan disease. Combined with the scientific significance and national strategic needs of various field, the authors analyze its main study directions and core scientific issues.