Neutralizing antibodies have been designed to specifically target and bind to the receptor binding domain (RBD) of spike (S) protein to block severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) virus from attaching to angiotensin converting enzyme 2 (ACE2). This study reports a distinctive nanobody, designated as VHH21, that directly catalyzes the S-trimer into an irreversible transition state through postfusion conformational changes. Derived from camels immunized with multiple antigens, a set of nanobodies with high affinity for the S1 protein displays abilities to neutralize pseudovirion infections with a broad resistance to variants of concern of SARS-CoV-2, including SARS-CoV and BatRaTG13. Importantly, a super-resolution screening and analysis platform based on visual fluorescence probes was designed and applied to monitor single proteins and protein subunits. A spontaneously occurring dimeric form of VHH21 was obtained to rapidly destroy the S-trimer. Structural analysis via cryogenic electron microscopy revealed that VHH21 targets specific conserved epitopes on the S protein, distinct from the ACE2 binding site on the RBD, which destabilizes the fusion process. This research highlights the potential of VHH21 as an abzyme-like nanobody (nanoabzyme) possessing broad-spectrum binding capabilities and highly effective anti-viral properties and offers a promising strategy for combating coronavirus outbreaks.
Single-Domain Antibodies/immunology* ; Spike Glycoprotein, Coronavirus/metabolism* ; SARS-CoV-2/immunology* ; Animals ; Humans ; Antibodies, Neutralizing/immunology* ; Camelus ; COVID-19/immunology* ; Antibodies, Viral/immunology* ; Angiotensin-Converting Enzyme 2

Objective : To investigate the role of AdipoRon, an adiponectin receptor agonist, in treatment of carbon tetrachloride(CCl4) induced liver fibrosis mice model and the mechanisms. Methods : Forty mice were randomly divided into control group, model group, L-AdipoRon group and H-AdipoRon group, with 10 mice in each group. Hepatic fibrosis was induced by intraperitoneal injection of CCl4solution. The mice in L-and H-AdipoRon groups were given 100 mg/kg and 200 mg/kg AdipoRon by gavage, respectively. The activities of serum aspartate aminotransferase(AST) and alanine aminotransferase(ALT) were detected by biochemical method. Liver histopathological changes and fibrosis were detected by HE staining, Masson staining and Sirius scarlet stain. The protein expression levels of Collagen I, α-smooth muscle actin(α-SMA), matrix metalloproteinase 1(MMP-1) and matrix metalloproteinase inhibitor 1(TIMP-1) in mice liver were detected by Western blot. Lipid deposition in liver were detected by oil red O staining. The percentage(%) of CD68+ iNOS+ positive M1-type macrophages in the liver were detected by immunofluorescence. The expression levels of fatty acid synthetase(Fasn), stearoyl-CoA desaturase 1(Scd1), fatty acid transporter(Cd36), peroxissome proliferator activated receptor-α(Pparα) and carnitine palmitoyl transferase 1α(Cpt1α) in mice liver tissues, as well as M1 macrophage-related genes interleukin-6(IL-6) and tumor necrosis factor-α(TNF-α) and M2 macrophage-related genes arginase 1(Arg1), Chil3 chitinase-like 3(Ym-1) were detected by RT-qPCR assay. Results : Compared with model group, in low-dose AdipoRon group and high-dose AdipoRon group, serum ALT and AST activities significantly decreased(P<0.05); liver tissues structure were damaged, liver cells degeneration and inflammatory cells infiltration were improved; collagen fiber deposition was also significantly reduced; the relative expression levels of Collagen I, α-SMA and TIMP-1 proteins were significantly down-regulated(P<0.05), while the relative expression levels of MMP-1 protein were significantly up-regulated(P<0.05); the lipid droplets deposition in livers were significantly reduced. The relative Fasn, Scd1 and Cd36 mRNA expression levels in liver tissues were significantly down-regulated(P<0.05), and the relative Pparα and Cpt1α mRNA expression levels were significantly up-regulated(P<0.05); the percentage(%) of CD68+ iNOS+ positive M1-type macrophages significantly decreased(P<0.05); the relative IL-6 and TNF-α mRNA expression levels significantly decreased(P<0.05), the relative Arg1 and Ym-1 mRNA expression levels were significantly up-regulated(P<0.05). In addition, the improvement effects of high-dose AdipoRon group were better than those of low-dose AdipoRon group(P<0.05). Conclusion AdipoRon can improve the disorder of lipid metabolisms, inhibit the M1 type macrophages polarization, and improve the liver fibrosis in CCl4-induced liver fibrosis mice model.

Objective:In this study, we aimed to compare the short-term safety of two digestive tract reconstruction techniques, laparoscopic total abdominal overlap anastomosis and laparoscopic-assisted end-to-side anastomosis, following radical resection of Siewert Type II adenocarcinoma of the esophagogastric junction.Methods:In this retrospective cohort study, we analyzed relevant clinical data of 139 patients who had undergone radical surgery for Siewert Type II esophagogastric junction adenocarcinoma. These included 89 patients treated at the First Affiliated Hospital of Air Force Medical University from November 2021 to July 2023, 36 patients treated at the First Affiliated Hospital of Xi'an Jiaotong University from December 2020 to June 2021, and 14 patients treated at the Yuncheng Central Hospital in Shanxi Province from September 2021 to November 2022. The group consisted of 107 men (77.0%) and 32 women (23.0%) of mean age 62.5±9.3 years. Forty-eight patients underwent laparoscopic total abdominal overlap anastomosis (overlap group), and 91 laparoscopic-assisted end-to-side anastomosis (end-to-side group). Clinical data, surgical information, pathological findings, postoperative recovery, and related complications were compared between the two groups.Results:There were no significant differences in general clinical data between the overlap and end-to-side anastomosis groups (all P>0.05), indicating comparability. There was no significant difference in operation time (267.2±60.1 minutes vs. 262.8±70.6 minutes, t=0.370, P=0.712). However, the intraoperative blood loss in the overlap group (100 [50, 100] mL) was significantly lower compared to the end-to-side group (100[50, 175] mL, Z=2.776, P=0.005). Compared to the end-to-side group, longer distances between the tumor and distal resection margin proximal(1.7±1.0 cm vs. 1.3±0.9 cm, t=2.487, P=0.014) and the tumor and distal resection margin (9.5±2.9 cm vs. 7.9±3.5 cm, t=2.667, P=0.009) were achieved in the overlap group. Compared with the end-to-side group, the overlap group achieved significantly earlier postoperative ambulation (1.0 [1.0, 2.0] days vs. 2.0 [1.0, 3.0] days, Z=3.117, P=0.002), earlier time to first drink (4.7±2.6 days vs. 6.2±3.0 days, t=2.851, P=0.005), and earlier time to first meal (6.0±2.7 days vs. 7.1±3.0 days, t=2.170, P=0.032). However, the hospitalization costs were higher in the overlap group (113, 105.5±37, 766.3) yuan vs. (97, 250.2±27, 746.9) yuan; this difference is significant ( t=2.818, P=0.006). There were no significant differences between the two groups in postoperative hospital stay, total number of lymph nodes cleared, or time to first postoperative flatus (all P>0.05). The incidence of surgery-related complications was 22.9%(11/48) in the overlap group and 19.8% (18/91) in the end-to-side group; this difference is not significant (χ2=0.187, P=0.831). Further comparison of complications using the Clavien-Dindo classification also showed no significant differences ( Z=0.406, P=0.685). Conclusions:Both laparoscopic total abdominal overlap anastomosis and laparoscopic-assisted end-to-side anastomosis are feasible for radical surgery for Siewert Type II esophagogastric junction adenocarcinoma. Laparoscopic total abdominal overlap anastomosis achieves longer proximal and distal resection margins and better postoperative recovery; however, end-to-side anastomosis is more cost-effective.

Objective:In this study, we aimed to compare the short-term safety of two digestive tract reconstruction techniques, laparoscopic total abdominal overlap anastomosis and laparoscopic-assisted end-to-side anastomosis, following radical resection of Siewert Type II adenocarcinoma of the esophagogastric junction.Methods:In this retrospective cohort study, we analyzed relevant clinical data of 139 patients who had undergone radical surgery for Siewert Type II esophagogastric junction adenocarcinoma. These included 89 patients treated at the First Affiliated Hospital of Air Force Medical University from November 2021 to July 2023, 36 patients treated at the First Affiliated Hospital of Xi'an Jiaotong University from December 2020 to June 2021, and 14 patients treated at the Yuncheng Central Hospital in Shanxi Province from September 2021 to November 2022. The group consisted of 107 men (77.0%) and 32 women (23.0%) of mean age 62.5±9.3 years. Forty-eight patients underwent laparoscopic total abdominal overlap anastomosis (overlap group), and 91 laparoscopic-assisted end-to-side anastomosis (end-to-side group). Clinical data, surgical information, pathological findings, postoperative recovery, and related complications were compared between the two groups.Results:There were no significant differences in general clinical data between the overlap and end-to-side anastomosis groups (all P>0.05), indicating comparability. There was no significant difference in operation time (267.2±60.1 minutes vs. 262.8±70.6 minutes, t=0.370, P=0.712). However, the intraoperative blood loss in the overlap group (100 [50, 100] mL) was significantly lower compared to the end-to-side group (100[50, 175] mL, Z=2.776, P=0.005). Compared to the end-to-side group, longer distances between the tumor and distal resection margin proximal(1.7±1.0 cm vs. 1.3±0.9 cm, t=2.487, P=0.014) and the tumor and distal resection margin (9.5±2.9 cm vs. 7.9±3.5 cm, t=2.667, P=0.009) were achieved in the overlap group. Compared with the end-to-side group, the overlap group achieved significantly earlier postoperative ambulation (1.0 [1.0, 2.0] days vs. 2.0 [1.0, 3.0] days, Z=3.117, P=0.002), earlier time to first drink (4.7±2.6 days vs. 6.2±3.0 days, t=2.851, P=0.005), and earlier time to first meal (6.0±2.7 days vs. 7.1±3.0 days, t=2.170, P=0.032). However, the hospitalization costs were higher in the overlap group (113, 105.5±37, 766.3) yuan vs. (97, 250.2±27, 746.9) yuan; this difference is significant ( t=2.818, P=0.006). There were no significant differences between the two groups in postoperative hospital stay, total number of lymph nodes cleared, or time to first postoperative flatus (all P>0.05). The incidence of surgery-related complications was 22.9%(11/48) in the overlap group and 19.8% (18/91) in the end-to-side group; this difference is not significant (χ2=0.187, P=0.831). Further comparison of complications using the Clavien-Dindo classification also showed no significant differences ( Z=0.406, P=0.685). Conclusions:Both laparoscopic total abdominal overlap anastomosis and laparoscopic-assisted end-to-side anastomosis are feasible for radical surgery for Siewert Type II esophagogastric junction adenocarcinoma. Laparoscopic total abdominal overlap anastomosis achieves longer proximal and distal resection margins and better postoperative recovery; however, end-to-side anastomosis is more cost-effective.

Objective:To investigate the short-term efficacy of left-sided three-port total laparoscopic distal gastrectomy (TPTLDG).Methods:The prospective randomized controlled study was conducted. The 68 patients undergoing laparoscopic distal gastrectomy in the First Affiliated Hospital of Air Force Medical University from March 2022 to March 2023 were collected. All patients were randomly assigned to the TPTLDG group with a double number, and to the five-port laparoscopic distal gastrectomy (FPLDG) group with a single number, respectively. Observation indicators: (1) grouping situations of the enrolled patients; (2) comparison of perioperative condition; (3) comparison of complications during postoperative 30 days; (4) comparison of pathological examination. Measure-ment data with normal distribution were represented as Mean± SD, and comparison between groups was conducted using the independent sample t test. Measurement data with skewed distribution were represented as M( Q1, Q3), and comparison between groups was conducted using the Mann-Whitney U test. Count data were described as absolute numbers, and comparison between groups was conducted using the chi-square test or continuous correction chi-square test. Comparison of ordinal data was analyzed using the non‐parameter rank sum test. Results:(1) Grouping situations of the enrolled patients. A total of 59 patients of gastric cancer were selected for eligibility. There were 40 males and 19 females, aged 59.00(52.00, 67.00)years. The gender (male, female), age, body mass index (BMI), Caprini score (≤2, ≥3), nutritional risk screening 2002 (<3, ≥3), Eastern Coopera-tive Oncology Group performance status (0, 1), preoperative hypersensitive C-reactive protein, preoperative IL-6, preoperative white blood cell count, preoperative albumin were 19, 11, 59.00(51.25,65.25)years, 21.92(20.93,22.73)kg/m 2, 7, 23, 24, 6, 18, 12, 0.78(0.78,1.46)mg/L, 3.07(1.50,10.56)μg/L, 6.07(4.94,7.19)×10 9/L, 44.30(40.83, 46.15) g/L in the 30 patients of TPTLDG group, versus 21, 8, 57.00(51.00, 67.00)years, 21.90(20.95, 23.35)kg/m 2, 11, 18, 24, 5, 17, 12, 1.13(0.78,11.40)mg/L, 5.56(1.88,15.12)μg/L, 5.54(4.71,6.70)×10 9/L, 43.55(40.25,44.88)g/L in the 29 patients of FPLDG group, showing no significant difference in the above indicators between the two groups ( χ2=0.557, Z=-0.444, -0.805, χ2=1.482, 0.074, 0.012, Z=-1.259, -1.262, -0.819, -1.199, P>0.05), confounding bias ensured comparability between the two groups. (2) Comparison of perioperative condition. The length of incision, time to removing drainage tube, IL-6 at postoperative day 3, cost of hospital stay were 6.65(6.48,6.93)cm, 3.00(0,3.00)days, 29.18 (13.67, 43.53)μg/L, 84 164.15(73 084.72, 96 782.14)yuan in the TPTLDG group, versus 8.00(7.50,8.35)cm, 3.00(3.00,4.00)days, 47.56(21.31,85.79)μg/L, 92 120.43(87 069.33, 113 089.74)yuan in the FPLDG group, showing significant differences in the above indicators between the two groups ( Z=-11.065, -2.141, -2.940, -2.220, P<0.05). (3) Comparison of complications during postoperative 30 days. The incidence rate of complications during postoperative 30 days was 30.00%(9/30) and 24.14%(7/29) in the TPTLDG group and FPLDG group, respectively, showing no significant difference between the two groups ( χ2=0.256, P>0.05). (4) Comparison of pathological examination. Cases with pathological N staging as 0 stage, 1 stage, 2 stage, 3 stage were 22, 2, 4, 2 in the TPTLDG group, versus 13, 7, 4, 5 in the FPLDG group, showing a significant difference between the two groups ( Z=-2.021, P<0.05). Conclusion:TPTLDG is safe and feasible for gastric cancer, with a good short-term efficacy.

Objective:To explore the pathological type and clinical symptoms of heterotopic gastric mucosa in upper esophagus (HGM).Methods:From December 2018 to August 2019, at the First Affiliated Hospital of Xinjiang Medical University, the patients with HGM, reflux esophagitis (RE), Barrett esophagus (BE) and chronic non-atrophic gastritis (CNAG), who underwent gastroscopy were selected. The pathological type of HGM including acid secretion, mucinous and mixed type. The differences in the symptoms among HGM, RE, BE, and CNAG, as well as the differences in the clinical symptoms of different pathological types of HGM were analyzed. Chi-square test and analysis of variance were used for statistical analysis.Results:There were 82, 104, 76, and 178 cases of HGM, RE, BE, and CNAG, respectively. The acid secretion, mucinous and mixed types of HGM were 22, 20 and 40 cases, respectively. The incidence rates of pharyngeal reflux symptoms foreign body sensation in the throat, swallowing discomfort, hoarseness, and cough of HGM patients were higher than those of RE patients (63.4%, 52/82 vs. 14.4%, 15/104; 58.5%, 48/82 vs. 14.4%, 15/104; 50.0%, 41/82 vs. 6.7%, 7/104; 43.9%, 36/82 vs. 12.5%, 13/104), while the incidence rates of gastroesophageal reflux symptoms acid reflux, heartburn and belching were lower than those of RE patients (34.1%, 28/82 vs. 61.5%, 64/104; 14.6%, 12/82 vs. 72.1%, 75/104; 34.1%, 28/82 vs. 67.3%, 70/104), and the differences were statistically significant ( χ2= 47.80, 39.80, 44.80, 23.30, 13.80, 60.90 and 20.20, all P<0.01). The incidence rates of pharyngeal reflux symptoms foreign body sensation in the throat, swallowing discomfort, hoarseness, and cough of HGM patients were higher than those of BE patients (63.4%, 52/82 vs. 22.4%, 17/76; 58.5%, 48/82 vs. 19.7%, 15/76; 50.0%, 41/82 vs. 9.2%, 7/76; 43.9%, 36/82 vs. 6.6%, 5/76), and the incidence rates of reflux symptoms acid reflux, heartburn, belching, and post-sternal burning sensation were lower than those of BE patients (34.1%, 28/82 vs. 61.8%, 47/76; 14.6%, 12/82 vs. 55.3%, 42/76; 34.1%, 28/82 vs. 65.8%, 50/76; 20.7%, 17/82 vs. 42.1%, 32/76), and the differences were statistically significant ( χ2=27.00, 24.80, 31.00, 28.60, 12.10, 28.90, 15.80 and 8.40, all P<0.01). The incidence rates of pharyngeal reflux symptoms foreign body sensation in the throat, swallowing discomfort, hoarseness and cough, gastroesophageal reflux symptoms acid reflux, heartburn, belching and post-sternal burning, and non-reflux symptoms digestion, bloating and abdominal pain of HGM patients were higher than those of CNAG patients (63.4%, 52/82 vs. 5.1%, 9/178; 58.5%, 48/82 vs. 3.9%, 7/178; 50.0%, 41/82 vs. 3.9%, 7/178; 43.9%, 36/82 vs. 4.5%, 8/178; 34.1%, 28/82 vs. 12.4%, 22/178; 14.6%, 12/82 vs. 2.8%, 5/178; 34.1%, 28/82 vs. 3.9%, 7/178; 20.7%, 17/82 vs. 11.2%, 20/178; 30.5%, 25/82 vs. 15.2%, 27/178; 32.9%, 27/82 vs. 14.6%, 26/178; 15.9%, 13/82 vs. 9.6%, 17/178), and the differences were statistically significant ( χ2=106.50, 100.40, 79.10, 62.00, 17.20, 4.10, 74.00, 12.80, 8.20, 11.60 and 2.20, all P<0.01). The incidence rates of pharyngeal reflux symptoms foreign body sensation, swallowing discomfort, and hoarseness of patients with acid secretion type of HGM were higher than those of mucinous type (72.7%, 16/22 vs. 35.0%, 7/20; 72.7%, 16/22 vs. 15.0%, 3/20; 50.0%, 11/22 vs. 20.0%, 4/20), and the differences were statistically significant ( χ2=6.00, 14.10 and 4.10, all P<0.01). The incidence rates of pharyngeal reflux symptoms foreign body sensation in the throat, swallowing discomfort, hoarseness, and cough of mixed type were higher than those of mucinous type (72.5%, 29/40 vs. 35.0%, 7/20; 72.5%, 29/40 vs. 15.0%, 3/20; 65.0%, 26/40 vs. 20.0%, 4/20; 62.5%, 25/40 vs. 15.0%, 3/20), and the differences were statistically significant ( χ2=7.80, 17.70, 10.80 and 12.10, all P<0.01). Conclusions:The pathological classification of HGM patients with clinical symptoms of pharyngeal reflux may be acid secretion type or mixed type, which can be treated with acid suppression drugs or argon plasma coagulation under gastroendoscopy.

BACKGROUND:O-arm navigation integrates CT image quality and the flexible mobility of the C-arm. Surgery for severe spinal deformity is very difficult, with high incidence of nerve injury, so it is a chalenging surgery for spinal surgery. The role of O-arm in the correction of spinal deformity is particularly important. OBJECTIVE:To explore the effect and safety of pedicle screw placement in severe spinal deformity under the guidance of O-arm navigation system. METHODS:Clinical data of 25 patients with severe spinal deformity with the aid of O-arm navigation were retrospectively analyzed. We observed pedicle screw insertion, operation time, intraoperative blood loss, correction of scoliosis and correction of kyphosis, and assessed the safety of screw insertion. RESULTS AND CONCLUSION:(1) Totaly 326 pedicle screws were implanted in 25 patients. According to NEO classification, 280 pedicle screws (92%) belonged to grade 0 (no perforation of pedicle cortex). Grade 1: perforation of pedicle cortex, < 2 mm, including 44 screws (8%); grade 2: perforation of pedicle cortex, > 2 mm, < 4 mm, including 0 screw (0%); grade 3: perforation of pedicle cortex, > 4 mm, including 0 screw (0%). (2) Operation time was (272.3±17.3) minutes. Intraoperative blood loss was (1 710.0±229.1) mL. (3) Cobb angle of scoliosis was changed from (70.5±6.0)° preoperatively to (22.8±4.8)° postoperatively. Cobb angle of kyphosis was changed from (72.0±5.2)° preoperatively to (28.1±5.7)° postoperatively. Significant differences were detected (P< 0.05). (4) These findings verify that with the guide of the O-arm navigation system, the accuracy of screw insertion is high. The risk of intraoperative nerve injury was reduced. The scoliosis and kyphosis deformity were improved effectively.

Objective To observe the illness change trend of drinking water type endemic arsenic poisoning in Qinghai Province, comprehensively evaluate the effect of prevention and control measures, in order to provide a scientific basis for timely adjustment of the prevention and control measures. Methods From 2010 to 2013, according to the Drinking Water Type Endemic Arsenic Poisoning Monitoring Programs, 3 villages in 2 counties within Qinghai Province were randomly selected as monitoring sites. The arsenic content in drinking water of residents was measured, water improvement projects in all monitoring villages were investigated; at the same time an investigation of arsenic disease in resident population was conducted, and urinary arsenic content was monitored. Arsenic in drinking water and urine was determined by hydride generation atomic fluorescence spectrometry, and arsenic poisoning was diagnosed using Endemic Arsenic Poisoning Diagnostic Criteria (WS/T 211-2001). Results Of the three water improvement projects, two were water arsenic exceeded the standard, and one was intermittently operated. From 2010 to 2013, the arsenic poisoning detec tion rate in Baoning Village was 27.30% (193/707), 31.90%(245/768), 29.35%(221/753) and 28.22%(219/776); in Kecai Village was 32.62%(107/328), 34.83%(124/356), 31.26%(131/419) and 29.35%(118/402);and in Manimotai Village was 56.58%(43/76), 52.81%(47/89), 45.10%(46/102) and 34.69% (34/98), there was no significant difference statistically of the arsenic poisoning detection rates in the three monitored villages in the 4 years (χ2 =3.09, 0.04, 0.92, all P>0.05). From 2010 to 2013, women arsenic poisoning detection rate was 36.45%(203/557), 40.59%(246/606), 36.12%(225/623) and 34.77%(218/627), respectively;men was 25.27%(140/554), 28.01%(170/607), 26.57%(173/651) and 23.57%(153/649), respectively;women arsenic poisoning detection rates were higher than those of men (χ2 = 16.25, 21.32, 13.49, 19.38, all P < 0.05). Arsenic poisoning detection rate of people younger than 60 years old had a tendency to increase with age. In 2012 and 2013, 105 and 93 urine samples were tested, respectively; urinary arsenic geometric mean was 0.113 and 0.149 mg/L. Conclusions Water improvement projects and water quality are not optimistic, and prevalence of arsenic poisoning is still at a higher level. A sound long-term monitoring program should be established as soon as possible, the management and maintenance of water improvement projects should be strengthened, and the monitoring and prevention work should not be neglected.

Objective To find out the distribution of drinking-tea-borne fluorosis in the six ethnics in Qinghai Province, and to provide basic data for prevention and control of the disease. Methods In 2010, according to the requirement of “The National Surveillance Program of Drinking-Tea-borne Fluorosis”, six ethnics accounted for 99.59% of total population in Qinghai Province were investigated in 28 counties having brick-tea drinking habit. Three townships and a town in each county, two administrative villages(residents’ committee) in each township and town were chosen and 50 adults in each administrative village and residents ’ committee were selected to check skeletal fluorosis, dental fluorosis, urine fluoride and daily drinking amount of tea water. Five to six samples of drinking tea water were determined. Dental fluorosis was examined by Deans method; the fluoride content of brick-tea and urine were determined by fluoride ion selective electrode; the skeletal fluorosis was diagnosed based on “Endemic Osteofluorosis Clinical Indexing Diagnosis Standard”( WS 192-2008 ) . Results A total of 10 335 adults were surveyed, the number of Tibetan, Han, Hui, Mongolian, Tu and Salar ethnics were 4 972, 3 063, 1 196, 634, 235 and 235, respectively. The daily drinking amounts of tea water in Mongolian, Tibetan, Hui, Tu, Han and Salar ethnics were 2.53, 2.19, 1.74, 1.63, 1.22 and 1.07 L, respectively. Daily fluoride intakes in Tibetan, Mongolian, Tu, Hui, Han and Salar ethnics were 3.99, 2.78,2.27, 2.16, 1.78 and 1.28 mg, respectively. The medians of urinary fluoride concentration of the Tibetan, Tu, Hui, Han, Mongolian and Salar ethnics were 1.46, 1.19, 1.12, 0.98, 0.93 and 0.81 mg/L, respectively. The prevalence rates of dental fluorosis of the Hui, Han, Tibetan, Tu, Mongolian and Salar ethnics were 34.53%(413/1 196), 27.07%(829/3 063), 21.60%(1 074/4 972), 20.00%(47/235), 17.98%(114/634) and 6.38%(15/235), respectively. The incidence rates of clinical skeletal fluorosis of the Tibetan, Mongolian, Han, Hui, Tu and Salar ethnics were 13.42%(667/4 972), 11.04%(70/634), 9.31%(285/3 063), 7.61%(91/1 196), 5.53%(13/235) and 4.26%(10/235), respectively. Conclusions The distribution and prevalent status of drinking-tea-borne fluorosis in the six ethnics of Qinghai Province are different. Tibetan and Mongolian ethnics are the key population concerning the prevention and control of the disease.

Objective To investigate the effect of sodium demethylcantharidate injection on adherence,invasion and metastasis and to investigate the related mechanism in human hepatocarcinoma cell line HepG2.Methods Adherence ability,migration and invasion of HepG2 cells inhibited by sodium demethylcantharidate injection were assessed by MTT and Transwell techniques.Expression levels of MMP-9 protein in HepG2 cells were determined by immunohistochemistry.Results The number of adhesion,migration and invasion of HepG2 cells were significantly lower in sodium demethylcantharidate injection group than those in the control group (P ＜ 0.05).HepG2 cells co-incubated with sodium demethylcantharidate injection in the concentration of 0.25 μg/ml for 30,60,90 and 120 min showed higher cell adhesion than the control group.The adhesion inhibition ratios were 48.11％,33.81％,28.97 ％ and 16.83 ％,respectively.The migration and invasion inhibition rates were 64.19 ％ and 58.19 ％.With concentration of sodium demethylcantharidate injection to increasing,expression levels of MMP-9 protein in HepG2 cells more and more lower than control group.Conclusion The adherence,migration and invasion abilities of HepG2 cells are markedly inhibited by sodium demethylcantharidate injection,the mechanisms is possible related to the expression levels of MMP-9 protein.