Objective:To study the effects of chronic fluoride exposure on spatial learning and memory and the expression of phosphatidylinositol 3-kinase (PI3K), protein kinase B (Akt), and mammalian target of rapamycin (mTOR) in hippocampus of second offspring (F2 generation) rats.Methods:Sixteen clean-grade healthy SD pregnant rats were randomly divided into four groups according to their body mass [(200 ± 50) g] using a random number table method: the control group [0 mg/L sodium fluoride (NaF)], and the low, medium, and high fluoride groups (60, 120, 240 mg/L NaF), with four rats in each group. Fluoride exposure was carried out from the 0th day of pregnancy to the 21st day of birth (PND21) of first offspring (F1 generation) rats through free drinking water. The F1 generation rats continued to be exposed to fluoride at the same dose and method as the female rats in the same group until the 90th day of birth (PND90). Six rats (male to female ratio 2∶1) were selected from each group and housed together. Female F1 were continuously exposed with the same method until PND21 of the F2 generation rats. Eight F2 generation rats (4 males and 4 females, with a male to female ratio of 1∶1 in the same litter) were randomly selected from each group and exposed to NaF with corresponding concentrations from PND22 to PND90. Before the execution of F2 generation rats, Morris water maze experiment was used to examine spatial learning and memory ability. After execution, real-time fluorescence quantitative PCR (qRT-PCR) and Western blotting were used to detect the mRNA and protein expression levels of PI3K, Akt, and mTOR in the hippocampus, respectively.Results:Compared with the control group days 2 - 4 [(46.72 ± 4.24), (24.87 ± 3.15), (14.10 ± 2.52) s], the escape latency of F2 generation rats was prolonged in the medium and high fluoride groups on the second day [(53.96 ± 3.45), (54.48 ± 6.20) s] and on the fourth day [(19.47 ± 2.51), (25.02 ± 3.86) s], and in the low, medium and high fluoride groups on the third day [(32.37 ± 4.56), (37.32 ± 4.65), (41.79 ± 7.08) s, P < 0.05]. Compared with the control group, the first arrival time of F2 generation rats in the high fluoride group was prolonged, while the number of crossing platforms in both the medium and high fluoride groups decreased ( P < 0.05). Except for mTOR mRNA in the low fluoride group, the mRNA and protein expression levels of PI3K, Akt, mTOR in the hippocampus of rats in all other exposure groups were lower than those in the control group ( P < 0.05). The results of correlation analysis showed that NaF concentration was positively correlated with the escape latency and the first arrival time of F2 generation rats on days 1 - 4 ( r = 0.44, 0.57, 0.79, 0.80, 0.58, P < 0.05), and negatively correlated with the mRNA and protein expression levels of PI3K, Akt, mTOR in the hippocampus of F2 generation rats, as well as the number of crossing platforms ( r = - 0.71, - 0.67, - 0.73, - 0.61, - 0.58, - 0.71, - 0.82, P < 0.05). Conclusion:Chronic fluoride exposure can lead to spatial learning and memory impairment in F2 generation rats, and its mechanism of action may be related to the inhibition of the PI3K/Akt/mTOR signaling pathway in the hippocampus.
Objective:To analyze the monitoring results of skeletal fluorosis in coal-burning type endemic fluorosis areas in Guizhou Province, and evaluate the effectiveness of comprehensive treatment of coal-burning type endemic fluorosis in the affected areas.Methods:In 2009, 2014, and 2019, monitoring of skeletal fluorosis was carried out in six counties (cities, districts) of Renhuai City, Qixingguan District, Dafang County, Qianxi City, Puding County, and Pu'an County in Guizhou Province. Age stratification was conducted in each county (city, district) for permanent residents aged 25 and above, and survey subjects were selected for X-ray examination of skeletal fluorosis.Results:The detection rates of skeletal fluorosis in 2009, 2014, and 2019 were 51.48% (798/1 550), 34.88% (308/883), and 6.51% (60/922), respectively, showing a decreasing trend year by year (χ 2trend = 505.83, P < 0.001), decreased by 44.97 percentage points from 2009 to 2019. The age distribution of patients with skeletal fluorosis was mainly in the age group of 55 years and older, with annual proportions of 53.88% (430/798), 56.49% (174/308), and 78.33% (47/60), all higher than 50%. In 2009, 2014, and 2019, 483, 222 and 21 cases of mild skeletal fluorosis were detected, and 315, 86, and 39 cases of moderate to severe skeletal fluorosis were detected. There was a statistically significant difference in disease grading among different years(χ 2 = 32.63, P < 0.001). Among them, there were statistically significant differences in the grading of skeletal fluorosis in Qixingguan District, Qianxi City, Puding County, and Pu'an County(χ 2 = 14.56, 12.24, 35.01, 23.35, P < 0.05). Conclusions:The detection rate of skeletal fluorosis in Guizhou Province decreases year by year, and the prevention and control effect is significant. Patients with skeletal fluorosis are mainly in the age group of 55 years and older, and the proportion of patients with moderate to severe skeletal fluorosis is increasing. We should continue to monitor and manage the treatment of current patients with skeletal fluorosis.
Objective:To study the effects of water fluoride and tea fluoride on the occurrence of dental fluorosis in children, and to provide a basis for scientific prevention and control of the disease.Methods:From April to September 2020, Baolongshan Town with qualified water fluoride but no habit of drinking brick tea, Xingyao Town with qualified water fluoride and habit of drinking brick tea, Baokang Town with exceeded water fluoride but no habit of drinking brick tea, and Wuliyasitai Town with exceeded water fluoride and habit of drinking brick tea were selected as survey sites in Inner Mongolia Autonomous Region based on historical monitoring data. In all Gacha (villages) of 4 towns, a survey was carried out on residents' drinking water, brick tea drinking habits and children's dental fluorosis detection, and the water fluoride, tea fluoride exceeding standard rates, daily per capita intake of brick tea fluoride and the detection rate of children's dental fluorosis were calculated. At the same time, multivariate logistic regression was used to analyze the influencing factors affecting the occurrence of dental fluorosis in children.Results:In 2020, a total of 165 water samples were collected in 4 towns of Inner Mongolia Autonomous Region, and the total water fluoride exceeding standard rate was 38.18% (63/165). A total of 320 tea samples were collected, the tea fluoride exceeding standard rates in Xingyao Town and Wuliyasitai Town were 96.38% (213/221) and 89.90% (89/99), respectively; the daily per capita intake of brick tea fluoride was 5.67 and 7.35 mg, respectively. A total of 1 652 children were examined for dental fluorosis, and 639 cases were detected, the detection rate was 38.68%. The detection rates of dental fluorosis in boys and girls were 37.18% (322/866) and 40.33% (317/786), respectively, with no significant difference between sexes (χ 2 = 1.72, P = 0.104); the detection rates of dental fluorosis in children aged 8 - 12 years were 43.93% (105/239), 40.50% (147/363), 46.57% (163/350), 30.56% (88/288) and 33.01% (136/412), respectively, with statistical significant difference among ages (χ 2 = 26.07, P < 0.001); the detection rates of dental fluorosis in children in Baolongshan, Baokang, Xingyao and Wuliyasitai towns were 0.68% (2/293), 14.09% (31/220), 24.79% (89/359) and 66.28% (517/780), respectively, with statistical significant differences among regions (χ 2 = 213.05, P < 0.001). Multivariate logistic regression analysis showed that when the fluoride content in water was 1.2 - < 2.0, 2.0 - < 2.5, and ≥2.5 mg/L, the risk of dental fluorosis in children was 3.93, 6.60, and 9.02 times of water fluoride content < 1.2 mg/L; when the daily per capita intakes of brick tea fluoride was 3.6 - 7.0 and > 7.0 mg, the risk of dental fluorosis in children was 2.94 and 3.90 times of daily per capita intakes of brick tea fluoride ≤3.5 mg; the risk of dental fluorosis in children aged 10 years was 1.81 times of children aged 8 years; the risk of dental fluorosis in children in Xingyao, Baokang, and Wuliyasitai towns was 22.35, 40.93, and 151.58 times of Baolongshan Town, respectively. Conclusions:The prevalence of dental fluorosis in children still exists in Inner Mongolia Autonomous Region, and the detection rate of dental fluorosis is high. High water fluoride and high tea fluoride are the main risk factors for dental fluorosis in children.
Objective:To study the clinical characteristics of patients with brucella bloodstream infection in different age groups, and provide a basis for clinicians to take targeted diagnosis and treatment measures. Methods:Demographic data and general condition (age, sex, occupation, location, onset season, source of infection, clinical stage), clinical characteristics (main clinical symptoms and complications), and laboratory test results (routine and pathogenic tests) of adult patients with brucella bloodstream infection admitted to the Affiliated Hospital of Chengde Medical College from January 2015 to January 2020 were collected. According to the age stratification standards recommended by the World Health Organization, the patients were divided into a young group (18 - 44 years old), a middle-aged group (45 - 59 years old), and an elderly group (≥60 years old), and various indicators among different age groups were compared and analyzed. Results:A total of 75 patients were included, including 15 cases (20.00%) in the young group, 37 cases (49.33%) in the middle-aged group, and 23 cases (30.67%) in the elderly group. Among them, 61 cases (81.33%) were males and 14 cases (18.67%) were females, with statistically significant differences in gender ratios among different age groups (χ 2 = 7.28, P = 0.021). The majority of patients were farmers (64 cases, 85.33%), and 92.00% (69/75) of the patients came from rural areas. The main sources of infection were infected cattle and sheep, and contaminated food (39 cases, 52.00%). The main season of onset was spring and summer (45 cases, 60.00%). The clinical staging was mainly in the acute phase (66 cases, 88.00%). In terms of clinical symptoms, the young group of patients had no symptoms of low back pain, while the incidence rates of low back pain in the middle-aged and elderly groups were 35.14% (13/37) and 30.43% (7/23), respectively. There was a statistically significant difference between the three groups (χ 2 = 6.98, P = 0.031). In terms of complications, there were no cases of concurrent spondylitis in the young group of patients. The incidence rates of spondylitis in the middle-aged and elderly groups were 32.43% (12/37) and 34.78% (8/23), respectively. There was a statistically significant difference among the three groups (χ 2 = 6.86, P = 0.032). In terms of routine laboratory examinations, there were statistically significant differences in the proportion of blood lymphocytes and albumin levels among patients of different age groups ( F = 3.41, 3.27, P = 0.038, 0.044). In terms of pathogenic examination, there was a statistically significant difference in the median alarm time for positive blood culture among patients of different age groups ( H = 9.54, P = 0.008), with the middle-aged group having the longest (66.24 h) and the elderly group having the shortest (58.80 h). Conclusions:The clinical characteristics of patients with brucella bloodstream infection vary among different age groups, middle-aged and elderly patients are prone to low back pain symptoms, accompanied by spondylitis. Clinicians should pay attention to the patient's own characteristics and provide targeted diagnosis and treatment.
Fluorine is widely present in nature, and long-term excessive intake of fluoride by the body can cause damages to bone tissues such as teeth and bones, as well as non bone tissues and organs such as nervous, cardiovascular, digestive and immune systems. Fluoride can cause apoptosis and autophagy of spleen lymphocytes, ultimately leading to damage to the structure and function of spleen. This article reviews the research progress of signaling pathways related to fluoride induced spleen immune function damage, in order to provide a theoretical basis for molecular mechanism study.
Objective:To analyze the iodine nutrition status of key populations in water source high iodine areas in Jiangsu Province, providing a reference for scientific prevention and control of water source high iodine hazards.Methods:From May to June 2020, monitoring sites were determined by administrative villages in six high iodine counties (cities, districts) in Jiangsu Province, and drinking water samples were collected from residents to detect the iodine content in the water; 40 non boarding children aged 8 - 10 from one primary school in each village (half male and half female, with an age balance) and 20 pregnant women were selected. Salt samples were taken from children and pregnant women's homes, and urine samples were randomly taken once to detect salt and urine iodine contents. Thyroid volume of children was examined.Results:A total of 36 administrative villages were monitored, with a median of 45.3 μg/L for water iodine, ranging from 8.5 - 372.1 μg/L. A total of 1 422 salt samples were collected, of which 26 were iodized salt, accounting for 1.83%; and 1 396 non iodized salt, with the coverage rate of non iodized salt was 98.17%. A total of 1 365 urine samples were collected from children, with a median urine iodine of 405.6 μg/L. There were statistically significant differences in urine iodine levels among children in different regions, drinking water iodine contents, and age groups ( H = 128.39, 67.81, 39.94, P < 0.001). A total of 57 urine samples were collected from pregnant women, with a median urine iodine of 282.0 μg/L. There were statistically significant differences in urine iodine levels among pregnant women in different regions and drinking water iodine contents groups ( H = 17.54, 18.39, P < 0.001). A total of 1 365 children's thyroid volumes were examined, and 44 cases of thyroid enlargement were detected, with a goiter rate of 3.22%. There were no statistically significant differences in the incidence of thyroid enlargement among children in different regions, drinking water iodine contents, salt types, gender, and age groups ( P > 0.05). Conclusions:The iodine nutrition of children in water source high iodine areas in Jiangsu Province is at an iodine excess level, while the iodine nutrition of pregnant women is at an over optimal level. In areas with high iodine content in water sources, the iodine content in drinking water has a significant impact on the iodine intake of the local population. There is currently no correlation between the iodine content in drinking water, salt type, gender, and age factors and thyroid enlargement in children.
Fluorine is an essential element widespread in nature. Appropriate concentration of fluorine is beneficial to prevent dental caries and promote the development of bones and teeth. But long-term excessive intake of fluorine can lead to fluorosis, causing dental fluorosis and skeletal fluorosis. In addition, fluorosis can also damage the structure and function of myocardium, thereby affecting human health. However, the underlying mechanism has not been thoroughly elucidated, so it is of great significance to explore its related mechanism for prevention and treatment of fluorosis. Apoptosis, Ca 2+ channel, oxidative stress, and imbalance of related cytokines all play important roles in myocardium injury caused by fluorosis. This article mainly reviews the effects of fluorosis on myocardium and its related molecular mechanisms, and proposes prospects for future research directions.
Objective:To investigate the status of iodine deficiency disorders in children and pregnant women in Ganzhou City, Jiangxi Province, and to provide a basis for scientific iodine supplementation and adjustment of prevention and control strategies.Methods:According to the requirements of the National Iodine Deficiency Disorders Surveillance Program (2016 Edition), iodine deficiency disorders surveillance was carried out in 18 counties (cities, districts) under the jurisdiction of Ganzhou City from 2018 to 2022. Edible salt and urine samples taken from children aged 8 to 10 and pregnant women were collected to detect salt and urine iodine levels. At the same time, B-ultrasound method was adopted to measure children's thyroid volume, and the goiter rate was calculated.Results:From 2018 to 2022, a total of 27 075 edible salt samples were collected from key populations (children aged 8 - 10 and pregnant women), with a median salt iodine of 25.00 mg/kg and a qualified iodized salt consumption rate of 96.24% (26 057/27 075). The difference in the qualified iodized salt consumption rate among key populations in different years was statistically significant (χ 2 = 29.09, P < 0.001). A total of 18 061 urine samples were collected from children, with a median urine iodine of 192.10 μg/L, there was a statistically significant difference in the urine iodine level of children between different years ( H = 82.59, P < 0.001). A total of 9 014 urine samples were collected from pregnant women, with a median urine iodine of 177.20 μg/L, there was a statistically significant difference in urine iodine level of pregnant women between different years ( H = 78.78, P < 0.001). A total of 8 621 children's thyroid glands were examined, including 34 cases of goiter, with a goiter rate of 0.39%, and the goiter rate showed a decreasing trend year by year (χ 2trend = 11.09, P < 0.001). Conclusions:From 2018 to 2022, the iodine nutrition of children and pregnant women in Ganzhou City is at an appropriate level, the consumption rate of qualified iodized salt (> 90%) and the children's goiter rate (< 5%) met the national iodine deficiency disorders elimination standards. Ganzhou City continues to maintain the status of eliminating iodine deficiency disorders.
Objective:To investigate the epidemic situation of drinking water-borne endemic fluorosis in Henan Province, evaluate the effectiveness of prevention and control measures, and provide a basis for formulating further prevention and control policies.Methods:From April to November 2021, a census of all diseased villages registered in 112 drinking water-borne endemic fluorosis counties (cities, districts, hereinafter referred to as counties) of 17 provincial-level cities and 9 provincial-level counties (cities) in Henan Province was conducted to collect the basic information of diseased counties and villages. The content of fluoride in drinking water and the prevalence of dental fluorosis in children aged 8 - 12 years old were measured on a village by village basis.Results:By the end of 2021, drinking water-borne endemic fluorosis was prevalent in 112 diseased counties in Henan Province, involving 17 450 diseased villages. Among them, 17 433 villages had implemented measures to reduce fluoride and improve water quality, with a water improvement rate of 99.90% (17 433/17 450). There were 14 920 villages with qualified water, and the qualified rate of water fluoride was 85.50% (14 920/17 450). There were a total of 4 232 water improvement projects in all diseased villages, with a normal operation rate of 97.09% (4 109/4 232) and a qualified rate of 93.03% (3 937/4 232) for water fluoride in the projects. The total detection rate of dental fluorosis in children in the province was 9.64% (39 391/408 584), with moderate to severe dental fluorosis accounted for 8.08% (3 182/39 391), the dental fluorosis index was 0.18. The prevalence of fluorosis was negative.Conclusions:In 2021, the prevalence of drinking water-borne endemic fluorosis is widespread in Henan Province, and measures to reduce fluoride and improve water quality in diseased villages have been basically implemented. However, the fluoride content of water in some villages still does not meet the standard, and some water improvement projects cannot operate normally throughout the year. In the future, it is necessary to address the above issues one by one and consolidate the achievements in prevention and control of drinking water-borne endemic fluorosis.
Objective:To investigate the epidemiological situation of drinking water-type endemic fluorosis in Gansu Province, and scientifically evaluate the effectiveness of water improvement and fluoride reduction projects in preventing and controlling the disease.Methods:The drinking water-type endemic fluorosis areas in Gansu Province were divided into five regions according to different ecological types: the Longzhong Loess Plateau Hilly Area in central Gansu, the Longdong Loess Plateau Gully Area in eastern Gansu, the Longnan Qinling Zhongshan Canyon Area in southern Gansu, the Gobi area of the Hexi Desert, and the Alpine Grassland Meadow Area in southern Gansu. In 2021, a survey was conducted on the basic situation, running situation of the water improvement and fluoride reduction projects, fluoride content in drinking water(fluorine ion-selective electrode), and the prevalence of dental fluorosis (Dean) among children aged 8 to 12 in all drinking water-type endemic fluorosis villages in the five regions. The pertinent assessments were executed in accordance with national guidelines such as the "Standards for Drinking Water Quality" (GB 5749-2006) and "Diagnosis of Dental Fluorosis" (WS/T 208-2011).Results:A total of 2 000 villages in drinking water-type endemic fluorosis areas were monitored, among which 1 999 villages had implemented water improvement and fluoride reduction projects, with a coverage rate of 99.95% (1 999/2 000). All water improvement and fluoride reduction projects were operating normally, with no intermittent operation or scrapping. A total of 34 616 children aged 8 to 12 were investigated for dental fluorosis. The detection rate of dental fluorosis was 4.18% (1 448/34 616), and the dental fluorosis index was 0.09. There was a statistically significant difference in the detection rate of dental fluorosis among children of different ages (χ 2 = 69.77, P < 0.001). The difference in the detection rate of dental fluorosis among children of different ecological types of areas was statistically significant (χ 2 = 775.11, P < 0.001). The dental fluorosis index of children aged 8 - 12 was significantly correlated with the historical water fluoride level ( r = 0.29, P = 0.042). The water improvement time in the Gobi area of the Hexi Desert was significantly correlated with the detection rate of dental fluorosis in local children ( r = - 0.48, P = 0.023). Conclusions:In 2021, the prevention and control of drinking water-type endemic fluorosis in all villages in Gansu Province has reached the national control standards. However, due to the different ecological characteristics and changes in water source distribution in different ecological types of areas, it is still necessary to further strengthen the monitoring of the condition of drinking water-type endemic fluorosis in all the affected villages and consolidate the existing prevention and control achievements.
Objective:To investigate the oral health knowledge awareness, attitude and behavior of children in endemic fluorosis areas of Guizhou Province, and evaluate the effectiveness of health education, so as to provide a scientific basis for improving oral health.Methods:In September 2020, 6 counties (cities and districts) were selected as survey sites from the historical fluorosis medium and severe areas in Guizhou Province. One township/village primary school was selected from each survey site to carry out health education activities for one school year. A questionnaire survey was conducted among students from grades 1 to 6 to analyze the changes in children's oral health knowledge, attitude, and behavior before and after health education and their influencing factors.Results:Before and after health education, the awareness rate of children's oral health knowledge increased from 79.22% (7 744/9 775) to 94.38% (9 169/9 715), the recognition rate of children's importance of oral health increased from 89.26% (3 490/3 910) to 95.88% (3 726/3 886), and the formation rate of children's oral health behavior increased from 62.59% (6 118/9 775) to 80.38% (7 809/9 715), with an increase of 15.16, 6.62 and 17.79 percentage points, respectively, the differences were statistically significant (χ 2 = 975.62, 15.17, 756.29, P < 0.001). The analysis of influencing factors showed that whether to stay, gender, and ethnic characteristics could significantly affect the overall score ( t = - 3.94, - 3.86, - 3.62, P < 0.001). Conclusion:The implementation of oral health education in endemic fluorosis areas in Guizhou Province has significantly improved the health knowledge, attitude and behavior of oral health among children in endemic fluorosis areas.
Dental caries is one of the common chronic diseases in children. Fluoride plays a key role in the prevention and treatment of dental caries, but it also carries certain health risks. There are many sources of fluoride in daily life, and appropriate intake is beneficial to the human body. Excessive intake can easily cause dental fluorosis, gastrointestinal adverse reactions, and even fluorosis. This article focuses on the mechanism and health risks of fluoride in preventing and treating dental caries in this progress, aiming to provide theoretical support for the rational use of dental fluoride preparation and the formulation of fluoride content standard in water.
Objective:To construct a recombinant Efs-EmⅡ/3-Em14-3-3 vaccine against Echinococcus multilocularis (Em) using Enterococcus faecalis (Efs) as a vector, and investigate its antigenicity. Methods:The recombinant plasmid pGEX-EmⅡ/3-Em14-3-3 was transformed into Efs ATCC47077 strain using electroporation method, and the recombinant Efs-EmⅡ/3-Em14-3-3 vaccine was constructed. The plasmid was extracted for PCR amplification and identification. The recombinant Efs-EmⅡ/3-Em14-3-3 vaccine was expressed through isopropyl-β-D-thiogalactoside (IPTG) induction, and the recombinant protein was verified by sodium dodecyl sulfate polyacrylamide gel electrophoresis (SDS-PAGE) and Western blotting, and the proportion of expressed proteins in the total proteins of the bacteria was analyzed by thin layer scanning technology.Results:Using the plasmid extracted from recombinant Efs bacteria as a template, the EmⅡ/3-Em14-3-3 fusion gene with a size of about 2 554 bp could be amplified by PCR. The relative molecular mass ( Mr) of the expressed EmⅡ/3-Em14-3-3 fusion protein was approximately 119 × 10 3 by SDS-PAGE; after 5 h induction by IPTG, the expression level of target protein was high, accounting for about 9% of the total bacterial protein. Western blotting showed that the expressed protein could be recognized by mouse serum infected with alveolar hydatid cyst. Conclusion:The recombinant Efs-EmⅡ/3-Em14-3-3 vaccine is successfully constructed, and the expressed fusion protein shows specific antigenicity.
Objective:To assess the changes of selenium nutrition of school-age children in Kashin-Beck disease (KBD) areas of Linzhou County, Lhasa City and Xietongmen County, Shigatse City in Tibet Autonomous Region (referred to as Tibet), and provide a scientific basis for evaluating the effectiveness of prevention and control measures.Methods:According to the historical condition of KBD, a total of 344 children's hair samples were collected to determine the content of selenium in Kazi (KBD area) and Jiangxia townships (non-KBD area) of Linzhou County in 2013 and 2021, Renqinze (KBD area) and Tongmen townships (non-KBD area) of Xietongmen County in 2015 and 2021.Results:Compared to 2013/2015, in 2021, the hair selenium level of children in the four townships increased ( P < 0.001). The selenium nutritional level of more than 90% of the children reached medium or above (hair selenium > 0.25 μg/g) in 2021. The hair selenium levels of girls in the two KBD areas (Kazi and Renqinze townships) were lower than those of boys ( Z = - 2.83, - 2.83, P < 0.05). Conclusions:The selenium nutrition level of school-age children in KBD areas in Linzhou and Xietongmen counties has increased rapidly in recent years. However, the selenium nutrition level of girls is significantly lower than that of boys. It is necessary to strengthen prevention, controlling and monitoring, and to further improve the dietary structure of school-age children through the joint efforts of families and schools, to increase the proportion of exogenous high selenium food intake.
Objective:To investigate the iodine nutrition status of residents and its changing trend in Baoji City, Shaanxi Province during the 10 years implementation of a new salt iodine standard, evaluate the prevention and treatment effects, and provide a basis for implementing iodine supplementation measures scientifically.Methods:From 2013 to 2015, each county (district) in Baoji City, Shaanxi Province was divided into 5 districts based on east, west, south, north, and central regions. One town (street, referred to as the town) was selected from each district, and four administrative villages were selected from each town. Fifteen residents from each administrative village were selected to collect edible salt samples from their homes and test the iodine content of the salt. At the same time, one primary school was selected from each selected town, and 42 children (age and gender were balanced) aged 8 - 10 were selected from each primary school for thyroid palpation examination. From 2016 to 2022, each county (district) was divided into 5 districts based on east, west, south, north, and central regions. One town was selected from each district, and one primary school was selected from each town. Forty-two non boarding students aged 8 - 10 were selected from each primary school to undergo thyroid palpation examination, and edible salt samples were collected from their home to detect salt iodine content. At the same time, 4 administrative villages were selected from each town, and 10 households were selected from each administrative village to collect edible salt samples and test the salt iodine content; 21 pregnant women were selected from each of the 5 towns in each county (district) to collect edible salt samples and test the salt iodine content. From 2013 to 2022, synchronous collection of urine samples from children and pregnant women (early, middle, and late pregnancy were balanced) was conducted to detect urine iodine content. Direct titration method was adopted for determination of salt iodine content, and arbitration method was adopted for Sichuan salt and other fortified edible salt (GB/T 13025.7-1999). Thyroid examination was performed according to the Diagnostic Criteria for Endemic Goiter (WS 276-2007). Urine iodine was detected by Arsenic Cerium Catalytic Spectrophotometric Method for Determination of Iodine in Urine (WS/T 107 - 2006).Results:From 2013 to 2022, a total of 37 609 household edible salt samples were collected. The coverage rate of iodized salt, the qualified rate of iodized salt and the consumption rate of qualified iodized salt for each year ranged from 98.00% to 100.00%, 94.16% to 99.55%, and 92.28% to 99.67%, respectively. The median range of salt iodine was 22.42 to 26.80 mg/kg. A total of 25 437 children aged 8 - 10 were examined, and the annual incidence of thyroid enlargement (goiter) ranged from 0.35% to 3.02%. A total of 33 270 urine samples were collected, including 21 698 from children and 11 572 from pregnant women. The median range of urine iodine for children in each year was 203.70 - 275.47 μg/L, median range of urine iodine in pregnant women was 167.65 - 218.57 μg/L. The median urine iodine in children showed a decreasing trend from 2013 to 2022 ( Z = 3.04, P = 0.002); the median urine iodine of pregnant women did not show a significant decrease ( Z = 1.61, P = 0.110). Conclusions:During the 10 years implementation of the new salt iodine standard in Shaanxi Province, all indicators of iodine deficiency disorders monitoring in Baoji City have met the standards and maintained the elimination status of iodine deficiency disorders. The urine iodine levels of children have shown a downward trend, while urine iodine levels of pregnant women do not show significant changes. It is recommended that Baoji City expand the scope of iodine nutrition monitoring for key populations, and effectively carry out iodine supplementation measures scientificlly guided by monitoring information, tailored to local conditions, and classified guidance.
Objective:To investigate the impact of excessive fluoride exposure on the expression profile of microRNA (miRNA) in mouse testes, and elucidate the reproductive toxicity mechanism of fluoride.Methods:A total of 24 8-week-old C57BL/6J male mice weighing (23 ± 1) g were randomly divided into a control group [0 mg/L sodium fluoride (NaF)] and a fluoride exposure group (50 mg/L NaF) using a random number table method, with 12 mice in each group. After 90 days of treatment, the mice were anesthetized and euthanized. Sperm samples were collected to assess their quantity, viability, and deformity rate. Additionally, testicular tissue was stained with hematoxylin-eosin (HE). RNA was extracted from testicular tissue, and high-throughput sequencing technology was employed to analyze the effect of fluoride on the expression profile of mouse testicular miRNA. Deferentially expressed miRNA was screened and its target genes were predicted, and functional annotation and pathway enrichment analysis were performed. Real-time fluorescence quantitative PCR (qRT-PCR) was used to verify the expression level of deferentially expressed miRNA.Results:Compared with the control group [number of sperm: (11.30 ± 2.52) × 10 6/ml; viability rate: (90.07 ± 4.34)%; deformity rate: (15.49 ± 3.25)%], the number of sperm of mice exposed to fluoride [(9.01 ± 2.25) × 10 6/ml] and the viability rate [(84.34 ± 4.21)%] decreased ( P = 0.041, 0.003), while deformity rate [(22.36 ± 6.51)%] increased ( P = 0.003). Furthermore, in the fluoride exposure group, the interstitial distance of testis increased, the number of sperm in the spermatogenic tubule decreased, and the cell arrangement was disordered. Through sequencing, 34 deferentially expressed miRNAs were identified in the testes of mice exposed to fluoride. According to qRT-PCR verification, compared with the control group, the expression levels of mmu-miR-29b-1-5p ( P < 0.001), mmu-miR-196a-5p ( P = 0.002), and mmu-miR-196b-5p ( P = 0.031) in the testes of mice exposed to fluoride were significantly increased, and the expression levels of mmu-let-7a-2-3p ( P < 0.001) and mmu-miR-466n-3p ( P = 0.018) were significantly decreased, consistent with the sequencing results. By KEGG enrichment of deferentially expressed miRNA target genes, it was found that fluoride exposure could change the axon guidance signal pathway, olfactory transduction pathway, neuroactive ligand-receptor interaction pathway, and lysosome signal pathway, etc., in mouse testes. Conclusions:Fluoride exposure may induce testicular injury by altering the expression profile of miRNA in the testes and by mediating the post-transcriptional regulatory signal pathway. Testicular miRNA may be a potential biomarker of fluoride reproductive toxicity, which may provide a new idea and perspective for exploring the mechanism of fluoride poisoning.
The hazards of water-borne iodine excess is a relatively serious public health problem in China. The government has made great progress in prevention and controlling of the hazards of water-borne iodine excess through measures such as supplying non-iodized salt and implementing measures such as improving water quality to decrease iodine. However, there is a lack of corresponding evaluation criteria for measuring the implementation level and effectiveness of prevention and control measures, which urgently needs to be addressed. This article explores the technical indicators for establishing control standards for water source high iodine hazards in China through a review and analysis of relevant laws and regulations, normative documents, standards, and research progress in the field of high iodine prevention and control at home and abroad. It is recommended that administrative villages be used as units to evaluate the control status of water source high iodine hazards; after water improvement and iodine reduction, the iodine content of residents' drinking water should be ≤100 μg/L; meanwhile, the median urinary iodine for school-age children should be between 100 and < 300 μg/L, thyroid enlargement rate should be less than 5%.
Objective:To learn about the application of medical ethics review in scientific research and prevention of endemic diseases.Methods:The method of retrospective analysis was used, original articles on field epidemiological investigation and clinical medicines published by Chinese Journal of Epidemiology from 2017 to 2020 were collected. Examination of medical ethics in national, provincial and municipal fund programs and nonfund projects was carried out. Statistical analysis was performed using Cochran-Armitage trend test and Cochran-Mantel-Haenszel (CMH) test.Results:A total of 638 articles were collected from 2017 - 2020, with 36 excluded and 602 remaining. The proportion of papers published after medical ethics review over the past four years was 56.85% (83/146), 62.50% (105/168), 59.87% (94/157), and 60.31% (79/131), respectively. There was no statistically significant difference in trend testing ( Z = 0.41, P > 0.05). There was no statistically significant difference in the proportion of papers produced by academic works, on-site investigations, and clinical medicine programs among different years (χ 2 = 0.01, 1.31, 1.92, P > 0.05). The proportion of papers published that supported by various fund programs that had undergone medical ethics review over the past four years was 60.55% (66/109), 62.28%(71/114), 62.38% (63/101), and 60.22% (56/93), respectively. The trend test showed no statistically significant difference( Z = - 0.03, P > 0.05). There was no statistically significant difference in the proportion of papers published that supported by national level projects, provincial and ministerial level projects, and municipal level projects among different years (χ 2 = 0.06, 0.02, 0.19, P > 0.05). The difference in the trend test of the output papers of research projects approved by the higher-level ethics committee and marked with approval numbers over the past 4 years was statistically significant ( Z = 2.85, P < 0.01); the difference was statistically significant when compared across years (χ 2 = 8.13, P < 0.01); the proportion of papers increased from 8.22% (12/146) in 2017 to 18.08% (25/131) in 2020 (χ 2 = 7.04, P = 0.008). There was no statistically significant difference ( Z = - 0.53, P > 0.05) in the proportion of papers that expressed their consent in terms of informed consent over the past 4 years; There was no statistically significant difference in comparison between different years (χ 2 = 0.28, P > 0.05). Conclusions:Medical ethics review has been taken seriously by the majority of researchers and is widely used in endemic scientific research and prevention projects.
Objective:To establish an antimony cerium catalytic spectrophotometric method for determination of iodine in water (referred to as the new method).Methods:Using the fading reaction principle of iodine catalyzed kinetics of antimony cerium to determine the iodine content in water. Methodological evaluations were conducted on the linear relationship, quantitative detection limit, precision, and accuracy (determination of national water iodine first level standard substances GBW09113f, GBW09114f, and addition recovery experiments) of the new method within the range of 0 to 100 μg/L iodine mass concentration. And the method was compared with the determination results of water iodine by arsenic cerium catalytic spectrophotometry recommended by the national iodine reference laboratory (NRL).Results:Within the range of 0 - 100 μg/L iodine mass concentration, the curve correlation coefficient of the new method was greater, and | r| > 0.999 0, and the quantitative detection limit was 0.15 μg/L (the sampling volume was 1 ml), the relative standard deviation of the detection precision of water samples with low, medium and high iodine mass concentrations were less than 2%. The new method had determined the average values of national water iodine first level standard substances GBW09113f and GBW09114f were 8.32 and 54.54 μg/L, respectively, all within the standard value range. The recovery range of standard addition was 92.6% - 99.2%, and the total average recovery was 96.4%. Compared with the NRL recommended method, the difference was not statistically significant ( t = 0.99, P > 0.05). Conclusion:The new method does not require the use of highly toxic substance arsenic trioxide, has high reaction sensitivity and accuracy, and is suitable for the promotion and use of water iodine detection.
