Objective:To investigate the prevalence of adult skeletal fluorosis caused by drinking tea-type endemic fluorosis in Yushu Tibetan Autonomous Prefecture (hereinafter referred to as Yushu Prefecture), Qinghai Province, and provide scientific basis for prevention and control of the disease.Methods:In August 2021, one village was selected as a survey site in six counties (cities) in Yushu Prefecture, including Nangqian, Chindu, Yushu, Zadoi, Qumarlêb, and Zhiduo. Drinking water samples and 10 brick tea samples were collected from each village to determine the fluoride content in water and brick tea; at least 100 permanent residents aged ≥ 25, who had a habit of drinking brick tea and had lived in the local area for more than 5 years, were selected for X-ray imaging to examine the prevalence of adult skeletal fluorosis.Results:A total of 75 samples of residential drinking water were collected, with a fluoride content of (0.21 ± 0.05) mg/L, ranging from 0.11 to 0.34 mg/L; 60 samples of brick tea, with a fluoride content of (626.70 ± 157.27) mg/kg, ranging from 324.00 to 2 102.00 mg/kg. A total of 1 136 adults were examined, and 318 cases of skeletal fluorosis were diagnosed, with a detection rate of 27.99%. Among them, the detection rates of mild, moderate, and severe skeletal fluorosis were 20.95% (238/1 136), 6.07% (69/1 136), and 0.97% (11/1 136), respectively, with mild symptoms being the main. The detection rates of skeletal fluorosis in males and females were 29.09% (121/416) and 27.36% (197/720), respectively, with no statistically significant difference between the gender (χ 2 = 0.39, P = 0.533). Comparison of the skeletal fluorosis in different gender, the differences were statistically significant (χ 2 = 22.31, P < 0.001). The detection rates of skeletal fluorosis in the age groups of 25 - 35, 36 - 45, 46 - 55, 56 - 65, 66 - 75, and ≥76 years old were 6.86% (7/102), 22.37% (51/228), 24.02% (92/383), 37.44% (73/195), 43.48% (70/161), and 37.31% (25/67), respectively. The differences between the groups were statistically significant (χ 2 = 59.84, P < 0.001). Moreover, there was a statistically significant difference in the composition of skeletal fluorosis among different age groups ( H = 37.66, P < 0.001). The Spearman correlation analysis results showed that the severity of adult skeletal fluorosis was positively correlated with age ( r = 0.34, P < 0.001). Conclusions:There is a certain degree of prevalence of adult skeletal fluorosis in Yushu Prefecture. And as age increases, the condition of skeletal fluorosis becomes more severe.

ObjectiveTo explore the relationship between the intestinal flora and the impairment of liver and kidney in HIV-infected men who have heterosexual sex with healthy women. MethodsFecal samples from 41 HIV-infected heterosexual men who have sex with women （PMSW） and 43 age- and BMI-matched healthy heterosexual men who have sex with women （NMSW） were collected and subjected to 16S rDNA sequencing. The blood levels of AST， ALT， TBIL， UREA， Cr， UA， β2-MG and other liver and kidney function indicators were measured. Bioinformatics methods were used to analyze the characteristics of the intestinal flora of the patients in these two groups， to compare the differential bacteria strains， and to analyze their correlation with liver and kidney function indicators. ResultsIn comparison with NMSW， the alpha diversity of intestinal flora was decreased in PMSW， and the beta diversity analysis showed significant differences in flora characteristics between the two groups （P<0.05）. The abundance of Clostridium， Phylum thick-walled， Trichosporon， and Clostridium tumefaciens decreased but Fusobacteriota increased （LDA score >4）. The comparison of liver and kidney function indexes revealed that AST， β2-MG levels were higher in PMSW than in NMSW， while TBIL was lower in PMSW than in NMSW. The number of patients with abnormal β2-MG was much higher in PMSW than in NMSW， and the difference was statistically significant （P<0.001）. It was also found that AST was negatively correlated with Clostridium （P<0.05）； TBIL was negatively correlated with Clostridium and positively correlated with Phylum thick-walled and Trichosporon （P<0.05）. β2-MG was negatively correlated with Phylum thick-walled， Clostridium， Trichosporon and Rumenococcus （P<0.05） and positively correlated with Clostridium （P<0.05）. ConclusionIn PMSW group， the alpha diversity of the flora is decreased. AST and β2-MG levels are increased， and TBIL level is decreased. These changes were significantly correlated with different strains of bacteria in the intestinal flora.

Objective:To learn about the detection quality and external quality control assessment of fluoride and arsenic in laboratories at all levels in Qinghai Province.Methods:The Z-score method was used to analyze and evaluate the evaluation results of 1 provincial, 8 municipal and 43 county level laboratories of disease prevention and control institutions participating in the external quality control assessment of water fluoride and brick tea fluoride in Qinghai Province in 2021, as well as 1 provincial, 1 municipal and 2 county level laboratories of disease prevention and control institutions participating in the external quality control assessment of water arsenic and urine arsenic. The feedback rate and qualification rate of external quality control of each assessment laboratory were calculated.Results:In 2021, the feedback rate of external quality control of water fluoride, brick tea fluoride, water arsenic and urine arsenic in provincial and municipal level laboratories of Qinghai Province were 100.00%; except that the qualified rate of water fluoride was 7/9, the qualified rate of external quality control of other projects was 100.00%. The feedback rate of external quality control of water fluoride, brick tea fluoride, water arsenic and urine arsenic in county level laboratories was 100.00%; except that the qualified rate of water fluoride was 86.05% (37/43), the qualified rate of external quality control of other projects was 100.00%. In the specific assessment results of the laboratory, the assessment results of water fluoride sample FS20210101 from 1 provincial, 1 municipal and 2 county level laboratories, and FS20210102 from 1 county level laboratory were suspicious; the assessment results of water fluoride sample FS20210101 from 3 county level laboratories were not satisfactory; the assessment results of fluoride and arsenic sample in other laboratories were satisfactory.Conclusions:The qualified rate of external quality control of fluoride and arsenic in laboratories at all levels in Qinghai Province is relatively high, but some county level laboratories are still dissatisfied with the assessment results of water fluoride. Therefore, it is necessary to strengthen the detection level of water fluoride in laboratories.

Objective:To observe the changes of serum C-terminal peptide of type Ⅰ collagen (CTX-1) and N-terminal lengthening peptide of type Ⅰ collagen (P1NP) in adult patients with skeletal fluorosis in the tea-drinking-borne endemic fluorosis area in Qinghai Province, and to find sensitive indicators for diagnosis of skeletal fluorosis.Methods:From April to August 2019, a case-control study was carried out in tea-drinking-borne endemic fluorosis area in Zhiduo County, Yushu Tibetan Autonomous Prefecture, and Gangcha County, Haibei Tibetan Autonomous Prefecture of Qinghai Province. According to the Diagnostic Standard for Endemic Skeletal Fluorosis (WS/T 192-2008), the clinical diagnosis and X-ray examination of skeletal fluorosis were carried out for permanent residents ≥25 years old and living for more than 10 years in the area, combined with face-to-face inquiry and investigation of past disease history, lifestyle and clinical manifestations. The patients with skeletal fluorosis and healthy people were selected as skeletal fluorosis group and control group, respectively. Randomized urine samples and fasting venous blood from the two groups were collected. The content of fluoride in urine was determined by ion selective electrode method, and the contents of CTX-1 and P1NP in serum were determined by enzyme-linked immunosorbent assay (ELISA).Results:A total of 127 people in the disease area were investigated, including 63 cases in skeletal fluorosis group and 64 cases in control group. There was no statistically significant difference in age and sex ratio between the two groups ( t = 0.42, χ 2 = 0.07, P > 0.05). The X-ray examination results showed that the patients with skeletal fluorosis were mainly mild, accounting for 71.43% (45/63); X-ray changes were mainly ossification of interosseous membrane and tendon. The urinary fluoride in control group and skeletal fluorosis group was 1.62 (1.12, 1.95) and 3.22 (2.38, 4.89) mg/L, respectively, with statistically significant difference between the two groups ( Z = 7.07, P < 0.001). The difference of serum CTX-1 and P1NP contents between the two groups was statistically significant ( Z = 2.00, 4.89, P < 0.05). Conclusions:The levels of serum CTX-1 and P1NP in patients with skeletal fluorosis are higher than those in healthy people. Serum CTX-1 and P1NP may be used as sensitive indicators for diagnosis of skeletal fluorosis.

AIM: To explore the role and mechanism of silent mating type information regulator 2 homolog 3 (SIRT3) in attenuation of intestinal ischemia-reperfusion (I/R) injury by dexmedetomidine in mice. METHODS: Twenty-four healthy male C57BL mice were divided into 4 groups randomly (n=6): sham operation group (Sham group), intestinal ischemia-reperfusion group (I/R group), dexmedetomidine group (Dex group), SIRT3 inhibitor 3-TYP group (3-TYP group). Superior mesenteric artery was clamped for 45 min followed by reperfusion for 2 h to establish intestinal I/R model in I/R group, Dex group, and 3-TYP group. Sham group received sole sham operation. 1 h prior to onset of ischemia, 3-TYP was injected into mice in 3-TYP group intraperitoneally (5 mg/kg, diluted to 0.3 mL), and 0.3 mL normal saline into mice in Dex group intraperitoneally. 30 min prior to onset of ischemia, dexmedetomidine was injected into mice in 3-TYP group and Dex group intraperitoneally (25 μg/kg, diluted to 0.3 mL). 1 h and 30 min prior to onset of ischemia, 0.3 mL normal saline was injected into mice in Sham group and I/R group intraperitoneally, respectively. 2 h of after reperfusion, the mice were sacrificed under anesthesia. Intestinal tissues were took and observed for pathological changes under light microscope after HE staining, and the injury was assessed via the Chiu's score method, and activities of SIRT3 and superoxide dismutase 2 (SOD2) were detected via spectrophotometry, and malondialdehyde (MDA) via spectrophotometry. RESULTS: The pathological injury was exacerbated, and the Chiu's score, the MDA level elevated remarkably, while the activity level of SIRT3 and SOD2 declined remarkably in I/R group, Dex group and 3-TYP group compared to Sham group (P<0.05). The pathological injury was alleviated, and the Chiu's score declined remarkably in Dex group and 3-TYP group compared to I/R group (P<0.05); and the MDA level declined remarkably, while activity level of SIRT3 and SOD2 elevated remarkably in Dex group compared to I/R group (P<0.05); and there was no significant difference both in the activity level of SIRT3 and SOD2 and in the MDA level between 3-TYP group and I/R group. The pathological injury was exacerbated, and the Chiu's score, the MDA level elevated remarkably, while the activity level of SIRT3 and SOD2 declined remarkably in 3-TYP group compared to Dex group (P<0.05). CONCLUSION: SIRT3 and its downstream SOD2 are involved in mediating the effect of attenuation of intestinal ischemia-reperfusion injury through inhibiting oxidative stress response by dexmedetomidine.

Objective:To analyze the external quality control assessment results of fluoride in brick tea in the provincial, city (prefecture) and county (city, district)-level endemic fluorosis laboratories in Qinghai Province, and to evaluate the testing capabilities of laboratories at all levels.Methods:The Z-score method was used to analyze and evaluate the results of provincial, city (prefecture) and county (city, district)-level laboratories that participated in the external quality control assessment of fluoride in brick tea in Qinghai Province from 2014 to 2020, and│Z│≤2 was qualified; 2 <│Z│ < 3 was basic qualified; │Z│≥3 was unqualified.Results:From the feedback, the feedback rate of external quality control of fluoride in brick tea in provincial and city (prefecture)-level laboratories in Qinghai Province from 2014 to 2020 was 100.00%; the feedback rate of county (city, district)-level laboratories from 2014 to 2018 was 100.00%, and there were no feedback units in 2019 and 2020. From the assessment of qualification, the qualification rate of provincial, city (prefecture)-level laboratories was 100.00% in all other years except one unit failed in 2017; the qualification rate of county (city, district)-level laboratories was 100.00% in 2014, 2015, 2016 and 2019, and there were 6 unqualified units in other years.Conclusions:From 2014 to 2020, some endemic fluorosis laboratories in Qinghai Province still fail to pass the external quality control assessment of fluoride in brick tea. In the future, it will be the focus of work to strengthen personnel training and improve the detection ability.

Objective:To evaluate the water fluoride detection ability of county (city, district) level (referred to as the county-level) laboratories in Qinghai Province.Methods:During the "13th Five-Year Plan" period (2016 - 2020), 4, 4, 4, 43, 43 county-level laboratories in Qinghai Province were organized to participate in the national water fluoride external quality control assessment, and the assessment results were evaluated by Z-ratio scoring method.Results:The response rate of county-level laboratories was 86.05% (37/43) in 2019, and 100.00% in other years. The qualified rate of county-level laboratories was 100.00% from 2016 to 2018; in 2019 and 2020, the assessment was fully covered, and the qualified rate was 81.40% (35/43) and 95.35% (41/43), respectively. Compared with 2019, the response rate and qualified rate in 2020 increased significantly, and the differences were statistically significant (χ 2 = 6.450, 4.074, P < 0.05). In the past 5 years, two assessment samples│Z│ < 1 in each laboratory were the most common, but with two assessment samples 2≤│Z│ < 3 in some qualified laboratories. Conclusion:The consistency of water fluoride determination in Qinghai Province is not very ideal, and the detection ability of county-level laboratories still needs to be strengthened.

Objective:To evaluate the clinical application of three dimensional artificial intelligence(3D-AI) localization technology in chest CT scan.Methods:A total of 100 patients who underwent chest CT for COVID-19 screening in Nanjing University Medical School Affiliated Drum Tower Hospital were collected from September 2020 to October 2020 were analyzed retrospectively. The patients were divided into manual positioning group ( n=50) and 3D-AI automatic positioning group ( n=50) with block randomization method. All patients were scanned with the same CT scanning protocol. The off-center distance, CT dose index (CTDI), dose length product (DLP) and CT examination time were measured and recorded. Quantitative image evaluation of mediastinal window images and qualitative image evaluation of chest window images were assessed by two radiologists. The off-center distance, CTDI, DLP, CT examination time and objective indexes of image quality of two groups were compared by independent sample t test. The quantitative image quality scores were compared with χ 2 test. Results:Compared with manual positioning group, the overall off-center distance of 3D-AI automatic positioning group was reduced by 42.86% [(15.4±9.7) vs. (8.8±7.2)mm, t=3.65, P<0.01], CTDI was reduced by 10.67%[(7.5±2.5) vs. (6.7±2.6)mGy, t=0.59, P=0.04], DLP was reduced by 13.33%[(270±95) vs. (234±86)mGy·cm, t=1.98, P=0.02], the average examination time was reduced by 29.91% [(214±26) vs. (150±14)s, t=15.79, P<0.01]. There were no significant differences in the background noise, signal to noise ratio of descending aorta and erecting spinal muscle, and subjective score between two groups ( P>0.05). Conclusion:The 3D-AI automatic positioning technology can greatly improve the accuracy of patient positioning and reduce the radiation dose for chest CT imaging, and improve work efficiency with qualified chest CT image quality.

Objective:To understand the situation of drinking water-borne endemic fluorosis (short for drinking water fluorosis) in Huangzhong, Ping'an and Ledu districts of Qinghai Province and operation status of water improvement projects, and to evaluate the effect of control measures.Methods:In historical drinking water fluorosis villages of Huangzhong, Ping'an and Ledu districts of Qinghai Province in 2018, the status of water improvement, the operation of water improvement projects and the content of water fluoride were investigated; the dental fluorosis of 8-12 years old children in all investigated villages was checked; 3 villages from 3 districts were selected, X-ray examination for skeletal fluorosis and urinary fluoride detection of adults over 25 years old of age were performed.Results:Eight-two historical drinking water fluorosis villages in 3 districts were investigated and all the villages had water improvement projects, in addition, the water improvement projects were operating normally, and the water fluoride content ranged from 0.10 to 0.37 mg/L, which were in line with the drinking water fluoride content standard (< 1.2 mg/L). Totally 2 503 children aged 8-12 years old were examined, the detection rate of dental fluorosis was 6.03% (151/2 503), the index of dental fluorosis was 0.13, the epidemic intensity was negative; the detection rates of dental fluorosis in 3 districts were 6.24% (129/2 068), 4.05% (7/173), 5.73% (15/262), respectively, reaching the control standard (< 30%), and the detection rate of dental fluorosis in 81 villages was less than 30%; 198 adults over 25 years old were examined, the detection rate of skeletal fluorosis was 5.05% (10/198), the geometric mean of urinary fluoride was 0.81 mg/L, and skeletal fluorosis cases were mainly in the age group over 40 years old, all of them were mild cases.Conclusions:The fluoride content in drinking water and the detection rate of children's dental fluorosis are all up to the control standard, and the condition of skeletal fluorosis is significantly reduced after the implementation of water improvement measures in Huangzhong, Ping'an and Ledu districts. It can be seen that the prevention and control of drinking water fluorosis in Huangzhong, Ping'an and Ledu districts have achieved good results, but later management and condition monitoring of water improvement projects should be strengthened to prevent the disease from rebounding.

The CRISPR system is able to accomplish precise base editing in genomic DNA, but relies on the cellular homology-directed recombination repair pathway and is therefore extremely inefficient. Base editing is a new genome editing technique developed based on the CRISPR/Cas9 system. Two base editors (cytosine base editor and adenine base editor) were developed by fusing catalytically disabled nucleases with different necleobase deaminases. These two base editors are able to perform C>T (G>A) or A>G (T>C) transition without generating DNA double-stranded breaks. The base editing technique has been widely used in gene therapy, animal models construction, precision animal breeding and gene function analysis, providing a powerful tool for basic and applied research. This review summarized the development process, technical advantages, current applications, challenges and perspectives for base editing technique, aiming to help the readers better understand and use the base editing technique.
Adenine ; Animals ; CRISPR-Cas Systems/genetics* ; Cytosine ; DNA Breaks, Double-Stranded ; Gene Editing