Objective To investigate the incidence of dental fluorosis and pit caries in school-age children from binhai new area of Tianjin, and to discuss the relationship between dental fluorosis and pit caries, providing the guidance for the prevention and treatment of them. Methods Referring to WHO’s“Oral Health Surveys Basic Methods”(Fourth Edition) and protocols of the third national oral epidemiology investigation, 3 778 children aged 7 to 9 year-old with similar levels of education were investigated for their dental fluorosis and fissure caries using the cross sectional survey method. Results The data showed that the incidence of dental fluorosis was less than 10%in the samples, and the community fluorosis index (CFI) was 0.075. The caries prevalence rate and mean decayed missing filled tooth (DMFT) of first permanent molars were 15.57%and 0.46 in male students, and those were 17.41%and 0.58 in female students. There were no significant differences in the caries prevalence rate and DMFT of first molar between male and female children (χ2=2.345, P>0.05). There were statistically significant differences in the caries rate and DMFT between different age groups (χ2=172.576, P<0.05), and both increased with age. Conclusion After years of defluoridation project in Tianjin, the detection rate and index of dental fluorosis in children have showed a downward trend. The caries prevalence rate may be related to the eruption rate of the first permanent molar.

BACKGROUND:Absorbable suture with good biocompatibility and mechanical strength has been extensively used in the clinic. OBJECTIVE: To explorein vitro degradation of different absorbable sutures, to analyze the clinical superiority of absorbable sutures and the influential factors for itsin vitro degradation. METHODS: After retrieval of related literatures concerning degradation and application of absorbable suture material, we retrospectively analyzed relevant articles addressing influential factors for performance and degradation of absorbable suture materials, and comparison of clinical absorbable and nonabsorbable sutures, thereby providing theoretical evidence for clinical application. RESULTS AND CONCLUSION: Absorbable sutures can be completely degraded and absorbed by the body, with no adverse reaction and no scars after wound healing. Absorbable sutures overcome the shortcomings of nonabsorbable sutures that cannot break down in the body. The absorption of its degradation products in vivo has two pathways: one is the phagocytosis of giant cels and phagocytes in the body, and the other is that the degradation products enter the body fluids and blood. For example, lactic acid is absorbed and excretedvia the systemic circulation. There is a very complicated physiological environment in the human body, and various factors can affect material properties. In addition, the different kinds of materials have different degradation mannersin vivo. Therefore, it is necessary to design, synthesize and process biodegradable polymer materialswith special properties within a certain range to meet the clinical needs.

Objective To study the effect of carbonated drinks on primary and permanent teeth replacement in Chil-dren. Method Dog tooth enamel samples were soaked in coca-cola, sprite and pure soda, and the calcium, phosphorus lev-el were analysed. Dental papilla stem cells were separated and cultured in the conditioned medium by adding three drinks. PCR and western blot were used to detect mRNA and protein levels of activator of nuclear factor-k B receptor ligand (RANKL), osteoprotegerin (OPG) and vitamin D receptor (VDR) , then the possible role of each gene and interactions rela-tionship were analyzed. Results Compared with saline, coca-cola and sprite showed their significantly decalcification and dephosphorization role, while plain soda water showed calcium and phosphorus protective effect. These three drinks had no effect on mRNA and protein levels of RANKL gene (P>0.05). Coca-cola and sprite can reduce OPG mRNA and protein lev-els, and at the same time increase transcription and expression of the VDR gene. Plain soda water has no effect on the OPG gene manifestation, but can significantly reduce the transcription and translation level of the VDR gene. Conclusion Car-bonated drinks may affect the dental health of the children's primary and permanent teeth replacement by regulating bone re-lated gene expression and vitamin D receptor family.

Objective To study the functional roles of 1,25(OH)2D3 in osteogenic differentiation of the dental papilla stem cells. Methods The dental papilla stem cells were isolated and cultured in medium supplemented with different con-centrations of 1,25(OH)2D3 (1, 10 and 100 nmol/L). MTT assay was used to detect the cell growth, and flow cytometry was used to detect the cell cycle. Western blot assay was used to detect protein expression levels of receptor activator of nuclear factor-κB ligand (RANKL), osteoprotegerin (OPG) and vitamin D receptor (VDR). After siRNA silencing VDR expression, protein levels of RANKL and OPG were detected. Results MTT and flow cytometry results showed that there were no sig-nificant differences in the cell proliferation between different concentrations of 1,25(OH)2D3 (1, 10 and 100 nmol/L) and con-trol groups (P>0.05). Western blot results showed that there were protein expressions of VDR, RANKL and OPG in control group. The protein expressions of VDR, RANKL and OPG were increased after adding 1,25(OH)2D3, in which the upward trend was the most significant in VDR. After VDR expression was silenced by siRNA, the protein expression levels of VDR, RANKL and OPG were decreased. Conclusion 1,25(OH) 2D3 affects the osteoblast differentiation process of the dental pa-pilla stem cells by adjusting the VDR expression.

OBJECTIVE Tostudytheeffectofmetforminonglucolipidmetabolicdisorderscaused byolanzapineorquetiapineinrats.METHODS Olanzapine1mg·kg-1·d-1wasgivenigorquetiapine 20 mg·kg -1·d -1 was given ig for 4 d,and the dose increased to 40 mg·kg -1·d -1 from the 5th day.Met-formin 100 mg·kg -1·d -1 was given ig from the 15th day.The treatment lasted 8 weeks.Body mass, fasting blood sugar (FBS)and postprandial 2 hours blood glucose (2hPBG)were measured at base-line,3 d,1 week,2 week,4 week,6 week and 8 week.At the end of the 8th week,serum cholesterol (TC),triglyceride (TG),low density lipoprotein (LDL-C),high density lipoprotein (HDL-C),fruc-tosamine(FA)andinsulin(IRS)weremeasured.RESULTS Therewasnosignificantstatisticaldiffer-ence between normal control group and metformin 1 00 mg·kg -1·d -1 group.At the end of the 6th week, compared with normal control group,the body mass and 2hPBG were significantly increased in olanzap-ine 1 mg·kg -1·d -1 group and quetiapine 40 mg·kg -1·d -1 group (P<0.05),respectively.At the end of the 8th week,body mass,2hPBG,INS,FA,TC,TG,LDL-C were significantly increased (P<0.05), and HDL-C decreased in olanzapine group and quetiapine group(P<0.05),respectively.FBS was increased only in olanzapine group(P<0.05).Compared with olanzapine group or quetiapine group, body mass,FBS,2hPBG,INS,FA,TC,TG,LDL-C were significantly decreased by metformin admin-istration(P<0.05).CONCLUSION Metformincaneffectivelypreventandtreatweightgainand glucolipid metabolic disorder caused by olanzapine or quetiapine.

Objective To investigate the function of tripartite motif protein 22 (TRIM22) and the interaction with eukaryotic translation initiation factor-4E (eIF4E) in the differentiation of NB4 cells, one kind of acute promyelocytic leukemia cells, which elucidates the mechanism of TRIM22 targeting to regulate eIF4E.Methods The model of NB4 cells inducing differentiation was established in vitro.The expression changes of gene and protein of TRIM22 and eIF4E were detected by using quantitative real-time polymerase chain reaction (qRT-PCR) and Western blotting.In addition, the effect on cell function and protein expression level of eIF4E after adopting electroporation technology to depress or over-express TRIM22 was detected by CCK-8 and flow cytometry.Finally, the interaction of TRIM22 and eIF4E was verified by using co-immunoprecipitation (CO-IP).Results The mRNA relative expression level of TRIM22 was gradually increasing from 1.01±0.15 to 30.98±2.79 (F=280.700, P=0.000), and the protein relative expression level was gradually increasing from 0.22±0.03 to 0.51±0.05 (F=51.430, P=0.000) after the all-trans-retinoic acid (ATRA) induction for NB4 cell.However, the mRNA relative expression level of eIF4E was gradually decreasing from 1.01±0.09 to 0.47±0.06 (F=20.520, P=0.000), with the same trend, the protein relative expression level was gradually decreasing from 0.97±0.02 to 0.64±0.09 (F=14.700, P=0.001).The expression level of PE-CD11b in the TRIM22 over-expression group with ATRA detected by flow cytometry [(78.80±2.00)%] was higher than that in the transfection group of empty vetor with ATRA [(58.70±2.70)%] (t=9.535, P=0.000) and the cotransfection group with ATRA [(61.60±3.80)%] (t=8.187, P=0.000).Meanwhile, the protein level of eIF4E changed reversely after over-expressing the gene level of TRIM22 (t=4.985, P=0.007).The CO-IP experiment was used to verify the interaction of TRIM22 and eIF4E.ConclusionTRIM22 is able to promote the cell differentiation during the process of NB4 cells differentiation.Furthermore, eIF4E is a target of TRIM22 for binding with, which plays an important role in depressing the expression of eIF4E.

Objective: An innovative technique was established to rapidly construct various cell lines that could be induced to express multiple influenza A virus (IAV) proteins. Method: The HA protein genes of multiple IAVs were cloned into the Cumate-induced expression system which was positioned between two PiggyBac transposon sites. These HA plasmids were transfected into the HEK293A cell line with the PiggyBac transposase plasmids. The transfected cells were screened with puromycin, and after that the corresponding virus proteins were induced with Cumate. Results: The results of flow cytometry and Western blotting showed that the virus proteins were expressed in most of the cells in corresponding lines after the induction of Cumate. Conclusion Cell lines which were inducible to express IVA HA protein can be efficiently constructed by using the PiggyBac transposon system.

Objective To analyze the blind area monitoring and independent image acquisition function of gastroscopic elves ( a real-time gastroscopic monitoring system) in gastroscopy. Methods A total of 38522 gastroscopic images from the database of Digestive Endoscopy Center of Renmin Hospital of Wuhan University were collected to train and validate the gastroscopic elves. Using computer to generate random numbers, 91 gastroscopic videos were selected to assess the position recognition accuracy of the gastroscopic elves, and 45 gastroscopic videos and matching gastroscopic images collected by endoscopists were selected to compare the coverage number and rate of gastroscopy sites between gastroscopic elves and endoscopists image acquisition. Two endoscopists entered the study to perform gastroscopies with or without gastroscopic elves. Forty-five gastroscopies respectively performed by the endoscopist A before and after usage of gastroscopic elves were collected, and 42 gastroscopies divided into 20 and 22 performed by the endoscopist B without use of gastroscopic elves in the same period were also collected. The coverage rate of gastroscopy sites was compared between the two endoscopists. Results The total position recognition accuracy of gastroscopic elves was 85. 125％ ( 1156/1358) . The coverage rate of gastroscopic sites for the endoscopist A was (76. 790±8. 848)％ and (87. 325±7. 065)％, respectively, before and after using gastroscopic elves, and the coverage rate in the same period for the endoscopist B was (75. 926 ±11. 565)％ and (75. 253 ± 14. 662)％, respectively. The coverage rate before using gastroscopic elves had no statistical difference between the two endoscopists (t=0. 324, P=0. 747). The coverage rate for the endoscopist A after using gastroscopic elves was higher than that before using gastroscopic elves ( t=6. 222, P=0. 001) , and that of the endoscopist B in the same period ( t'=3. 588, P=0. 002) . The coverage number and rate of gastroscopy sites for gastroscopic elves and endoscopists image acquisition were 20. 956 ± 3. 406 and ( 77. 613 ± 12. 613)％, and 15. 467 ± 2. 296 and ( 57. 284 ± 8. 503)％, respectively, with statistical differences ( t=11. 523, P=0. 000; t=11. 523, P=0. 000). Conclusion Gastroscopic elves can improve the coverage number and rate of gastroscopy sites, and is worthy of promotion in clinics.

Objective:To evaluate the impact of artificial intelligence (AI) system on the diagnosis rate of precancerous state of gastric cancer.Methods:A single center self-controlled study was conducted under the premise that such factors were controlled as mainframe and model of the endoscope, operating doctor, season and climate, and pathology was taken as the gold standard. The diagnosis rate of precancerous state of gastric cancer, including atrophic gastritis (AG) and intestinal metaplasia (IM) in traditional gastroscopy (from September 1, 2019 to November 30, 2019) and AI assisted endoscopy (from September 1, 2020 to November 15, 2020) in the Eighth Hospital of Wuhan was statistically analyzed and compared, and the subgroup analysis was conducted according to the seniority of doctors.Results:Compared with traditional gastroscopy, AI system could significantly improve the diagnosis rate of AG [13.3% (38/286) VS 7.4% (24/323), χ2=5.689, P=0.017] and IM [33.9% (97/286) VS 26.0% (84/323), χ2=4.544, P=0.033]. For the junior doctors (less than 5 years of endoscopic experience), AI system had a more significant effect on the diagnosis rate of AG [11.9% (22/185) VS 5.8% (11/189), χ2=4.284, P=0.038] and IM [30.3% (56/185) VS 20.6% (39/189), χ2=4.580, P=0.032]. For the senior doctors (more than 10 years of endoscopic experience), although the diagnosis rate of AG and IM increased slightly, the difference was not statistically significant. Conclusion:AI system shows the potential to improve the diagnosis rate of precancerous state of gastric cancer, especially for junior endoscopists, and to reduce missed diagnosis of early gastric cancer.

Objective:To compare the cost-effectiveness before and after using an artificial intelligence gastroscopy-assisted system for early gastric cancer screening.Methods:The gastroscopy cases before (non-AI group) and after (AI group) the use of artificial intelligence gastroscopy-assisted system were retrospectively collected in Renmin Hospital of Wuhan University from January 1, 2017 to February 28, 2022. The proportion of early gastric cancer among all gastric cancer was analyzed. Costs were estimated based on the standards of Renmin Hospital of Wuhan University and the 2021 edition of Wuhan Disease Diagnosis-related Group Payment Standards. Cost-effectiveness analysis was conducted per 100 thousand cases with and without the system. And the incremental cost-effectiveness ratio was calculated.Results:For the non-AI group, the proportion of early gastric cancer among all gastric cancer was 28.81% (70/243). The cost of gastroscopy screening per 100 thousand was 54 598.0 thousand yuan, early gastric treatment cost was 221.8 thousand yuan, and a total cost was 54 819.8 thousand yuan. The direct effectiveness was 894.2 thousand yuan, the indirect effectiveness was 1 828.2 thousand yuan and the total effectiveness was 2 722.4 thousand yuan per 100 thousand cases. For the AI group, the early gastric cancer diagnositic rate was 36.56%(366/1 001), where gastroscopy cost was 53 440.0 thousand yuan, early gastric treatment cost 315.8 thousand yuan, the total cost 53 755.8 thousand yuan. The direct effectiveness was 1 273.5 thousand yuan, indirect effectiveness 2 603.1 thousand yuan and the total effectiveness 3 876.6 thousand yuan per 100 thousand cases. The use of the system reduced the cost of early gastric cancer screening by 1 064.0 thousand yuan, and increased the benefit by 1 154.2 thousand yuan per 100 thousand cases. The incremental cost-effectiveness ratio was -0.92.Conclusion:The use of artificial intelligence gastroscopy-assisted system for gastric early cancer screening can reduce medical costs as well as improve the efficiency of screening, and it is recommended for gastroscopy screening .