BACKGROUND:Studies have shown that metformin has anti-inflammatory,anti-tumor,anti-aging and vasoprotective effects,and can inhibit the progression of osteoarthritis,but its specific mechanism of action remains unclear. OBJECTIVE:To investigate the mechanism of metformin on cartilage protection in a rat model of osteoarthritis. METHODS:Forty male Sprague-Dawley rats were randomly divided into four groups(n=10 per group):blank,control,sham-operated,and metformin groups.The blank group did not undergo any surgery.In the sham-operated group,the joint cavity was exposed.In the model group and the metformin group,the modified Hulth method was used to establish the osteoarthritis model.At 1 day after modeling,the rats in the metformin group were given 200 mg/kg/d metformin by gavage,and the model,blank,and sham-operated groups were given normal saline by gavage.Administration in each group was given for 4 weeks consecutively.Hematoxylin-eosin staining,toluidine blue staining,and safranin O-fast green staining were used to observe the morphological structure of rat knee joints.Immunohistochemical staining and western blot were used to detect the protein expression of SOX9,type Ⅱ collagen,a disintegrin and metalloproteinase with thrombospondin motifs 5(ADAMTS5),Beclin1,P62,phosphatidylinositol 3-kinase(PI3K),p-PI3K,protein kinase B(AKT),p-AKT,mammalian target of rapamycin(Mtor),and p-Mtor in rat cartilage tissue. RESULTS AND CONCLUSION:The results of hematoxylin-eosin,toluidine blue and safranin O-fast green staining showed smooth cartilage surface of the knee joints and normal histomorphology in the blank group and the sham-operated group,while in the model group,there was irregular cartilage surface of the knee joint and cartilage damage,with a decrease in the number of chondrocytes and the content of proteoglycans in the cartilage matrix.In the metformin group,there was a significant improvement in the damage to the structure of the cartilage in the knee joints of the rats,and the cartilage surface tended to be smooth,with an increase in the number of chondrocytes and the content of proteoglycans in the cartilage matrix.Immunohistochemistry staining and western blot results showed that compared with the control and sham-operated groups,the expression of SOX9,type Ⅱ collagen,and Beclin1 proteins in the cartilage tissue of rats in the model group was significantly decreased(P<0.05).Conversely,the expression of ADAMTS5,P62,as well as p-PI3K,p-AKT,and p-Mtor proteins was significantly increased(P<0.05).Furthermore,compared with the model group,the expression of SOX9,type Ⅱ collagen,and Beclin1 proteins in the cartilage tissue of rats in the metformin group was significantly increased(P<0.05),while the expression of ADAMTS5,P62,as well as p-PI3K,p-AKT,and p-Mtor proteins was significantly decreased(P<0.05).To conclude,Metformin can improve the autophagy activity of chondrocytes and reduce the degradation of cartilage matrix in osteoarthritis rats by inhibiting the activation of PI3K/AKT/Mtor signaling pathway,thus exerting a protective effect on articular cartilage.

Objective: To construct a scientific and perfect evaluation index system of infectious disease prevention and control ability in colleges and universities, so as to provide reference tools for colleges and universities to effectively respond to infectious disease. Methods: The initial framework of the evaluation index system of infectious disease prevention and control ability in colleges and universities was constructed by using literature analysis method. Experts familiar with infectious disease prevention and control or school health work were selected to conduct two rounds( n =16，18) of Delphi expert consultation for determining the evaluation index system. Analytical hierarchy process was used to calculate the index weights and combined weights. About 198 prevention and control personnel were conveniently selected from 3 universities in Inner Mongolia Autonomous Region to comprehensively evaluate the evaluation indicators by using fuzzy comprehensive evaluation method. Results: After two rounds of Delphi consultation questionnaire, the effective recovery rates were 80.0% and 90.0%, the expert authority levels were 0.89 and 0.86, the expert harmony coefficients for Kendall W were 0.166 and 0.310, and the variation coefficient of each index was <0.25. Finally, the evaluation index system of infectious disease prevention and control ability of colleges and universities included 4 first level indicators, 14 second level indicators and 75 third level indicators. The weights of prevention and monitoring and early warning, organizational system guarantee, emergency management, rehabilitation and summary were 0.176, 0.476, 0.268 and 0.080, respectively. The top 3 weights of the secondary indexes were 0.623 for infectious disease surveillance and early warning, 0.595 for loss assessment and 0.370 for emergency response. The score of fuzzy comprehensive evaluation of the index system of infectious disease prevention and control ability in colleges and universities was 79.148, suggesting a high level. Conclusion The established evaluation index system of infectious disease prevention and control ability in colleges and universities is scientific and reasonable, which is conducive to provide tool reference for the evaluation of infectious disease prevention and control ability in colleges and universities.

The liver has diverse functions such as metabolism， detoxification， and immune defense， and the maintenance of hepatic microenvironment homeostasis is crucial for overall bodily health. The hepatic microenvironment consists of the components such as parenchymal cells， non-parenchymal cells， and non-cellular components. Chronic inflammatory responses induced by various etiological factors may promote the formation and progression of liver fibrosis. During the dynamic progression of liver fibrosis， from the early to advanced stages， various components within the hepatic microenvironment undergo a series of changes， which can promote the malignant progression of liver fibrosis. An in-depth exploration of the mechanisms underlying such changes in each component of the liver fibrosis microenvironment is of great significance for understanding the pathogenesis of liver fibrosis and discovering potential treatment strategies.

Objective: To examine the association of joint effect of overweight and obesity with dyslipidemia on left ventricular hypertrophy (LVH) in children, so as to provide scientific evidence for the prevention of early cardiovascular damage in children. Methods: Data were obtained from the second followup crosssectional survey of Huantai Childhood Cardiovascular Health Cohort study in 2021, comprising 1 047 children aged 10-15 years with complete information. Based on overweight and obesity status and dyslipidemia status, all participants were divided into four groups:normal weight with normal lipid levels, normal weight with dyslipidemia, overweight and obesity with normal lipid levels, and overweight and obesity with dyslipidemia. Left ventricular mass index (LVMI) levels and prevalence of LVH across four groups were compared. Multivariate Logistic regression model was used to examine the association of joint effect of overweight and obesity with dyslipidemia on LVH in children. Results: There were significant differences in LVMI levels [(28.66±7.10, 29.63±4.71,31.49±5.86,32.65±4.80)g/m2.7] and prevalence of LVH (4.28%, 12.50%, 22.74%, 31.30%) across four groups (F/χ2=50.76, 90.92, P<0.05). After adjustment for confounding variables such as gender,age,screen time,sleep duration,fruit and vegetable intake,carbonated beverage consumption,physical activity and elevated blood pressure, compared to children with both normal weight and normal lipid levels, the risk of LVH in children with dyslipidemia alone increased (OR=3.27, 95%CI=1.57-6.82，P<0.05). Children with overweight and obesity alone also had a significantly increased risk of LVH (OR=6.33, 95%CI=3.76-10.66), and the highest risk was observed in those with both overweight and obesity with dyslipidemia (OR=9.66, 95%CI=5.35-17.43) (P<0.05). Conclusions The joint effect of overweight and obesity with dyslipidemia is positively correlated with LVH in children. To prevent LVH in children, both overweight and obesity with dyslipidemia should be paid attention to.

This paper summarizes Professor YAN Huimin's clinical experience in the staged treatment of pediatric IgA vasculitis. It is believed that the pathogenesis in the acute stage is characterized by fire and heat entering the blood and damaging the collaterals， and the treatment should focus on clearing heat and stopping bleeding， using the self-formulated Qingzi Liangxue Formulation （青紫凉血方）. In the remission stage， the pathogenesis is qi rebellion leading to blood extravasation. The treatment principle is to regulate qi and stabilize blood， using the self-formulated Heqi Ningxue Formulation （和气宁血方）. During the protracted stage， the pathogenesis is latent pathogenic factors due to yin deficiency， and the treatment should aim to nourish the collaterals and strengthen the root， with the self-formulated Yangluo Guben Formulation （养络固本方）. Meanwhile， the method of promoting blood stasis resolution is consistently applied throughout the entire treatment process.

In recent years, mesenchymal stem cell-derived exosomes (MSC-EXO) have garnered increasing attention in the field of stomatology and have become an established research area in biomedical research. This article reviews the engineering of exosomes derived from mesenchymal stem cells and their application in the field of stomatology, in order to provide new ideas for the development of stomatology. Exosomes are nanoscale membrane vesicles secreted by cells and contain a variety of proteins, RNAs, lipids, and other biomolecules. They are transported through the circulatory system and can interact with other cells to regulate their biological behavior and participate in a variety of physiological and pathological processes. In the treatment of oral diseases, exosomes have shown great potential due to their natural biological activity and versatility. However, studies have found that relying solely on the function of natural exosomes may not fully meet the complex clinical requirements. Therefore, the concept of engineered exosomes has emerged. Engineered exosomes can be modified by bioengineering technology to enhance their targeting, allowing them to reach the lesion site more accurately. At the same time, engineered exosomes can also be surface modified or loaded internally to carry specific therapeutic molecules, such as drugs, gene editing tools or signaling molecules to improve the therapeutic effect. In addition, this engineered treatment can also confer greater stability to exosomes, making them better able to resist clearance by the immune system when circulating in the body, extending their half-life, and improving the effectiveness of treatment. Although engineered exosomes have attracted extensive attention in the fields of stomatology and other fields, their application is still mainly in the stage of basic research. To promote the clinical application of engineered exosomes, it is necessary to provide more sufficient evidence of biocompatibility and clarify their therapeutic effect and mechanism.

Objective To investigate the reproductive and developmental effects of Clothianidin in rats. Methods Clothianidin was administrated by diet to both parental and first filial (F 1) generations of rats at the dosages of 0, 30.51, 110.84 and 304.26 mg/(kg·d) in females, and 0, 26.45, 92.69 and 279.42 mg/(kg·d) in males. Clothianidin was administered through diet to male and female rats for 8 weeks before mating. Clothianidin was administered to female rats in the parental and F1 generations during mating, gestation and lactation periods. During the test, toxicity performance was observed, reproduction index was calculated, and pathological examination was carried out. Results The body weights of rats in the parent and F1 generations in the high-dose group were lower than those in the control group during pre-mating exposure and at various time points during pregnancy and lactation (P<0.05). The pregnancy rates of parental and F1 generations in the high-dose group were lower than those of the control group (48.57% vs 71.43%, 45.71% vs 80.00%, P＜0. 05). Sperm concentration and sperm motility of the parental generation were lower than those of the control group [(42.55±12.87) vs (53.84±7.65) ×106/ml, (58.94±10.59) vs (65.59±6.03), （P＜0.05）]. Sperm concentration and sperm motility of the F1 generation were lower than those of the control group [(41.64±12.42) vs (53.09±9.48), (55.13±9.19) vs (64.53±6.31), (P＜0.05). Conclusion Exposure to clothianidin has reproductive toxicity to Wistar rats, and the no-observed adverse effect level (NOAEL) in the two-generation reproductive toxicity test is 92.69 mg/kg·BW for males and 110.84 mg/kg·BW for females in Wistar rats.

Objective:To analyze the results of the practice test and formal test of the annual professional proficiency test for residents in 2022, to investigate related influencing factors and the effectiveness of the practice test, and to propose the measures for improving the results of the annual professional proficiency test.Methods:The scores of the annual professional proficiency test were analyzed for 202 residents who participated in the test in 2022, and the data on sex, education background, type of personnel, whether they passed the medical licensing examination, and practice test scores were analyzed to investigate related influencing factors. SPSS 23.0 and GraphPad Prism 8 were used for the chi-square test, the t-test, the one-way of variance, and the Fisher's exact test. A multiple linear regression analysis was used to identify influencing factors, and a Pearson correlation analysis was also performed. Results:The scores of the annual professional proficiency test for 202 residents were normally distributed with the highest number of the residents with a score of 90-99 points and the lowest number of the residents with a score of <70 points. The residents who passed the medical licensing examination had a significantly higher score of the annual professional proficiency test than those who failed the examination ( t=2.87, P=0.005), and the residents who passed the three practice tests had a significantly higher score of the annual professional proficiency test than those who failed the practice tests ( P<0.05). The score of the second practice test, the score of the third practice test, and the passing of medical licensing examination were independent influencing factors for the score of annual professional proficiency test ( R2=0.236, R2=0.201, F=6.60, P<0.05). The correlation analysis showed that the scores of the three practice tests were positively correlated with the final score ( r=0.189, 0.373, and 0.311, P<0.05). Conclusions:Improving the passing rate of medical licensing examination and strengthening pre-examination practice tests can help to improve the score of annual professional proficiency test. At the same time, it is necessary to improve the quality of training through the measures such as strengthening the homogenization management of different types of students, improving the attention and enthusiasm of all levels, and accelerating the construction of question banks.

Background::Genetic variants of dopaminergic transcription factor-encoding genes are suggested to be Parkinson’s disease (PD) risk factors; however, no comprehensive analyses of these genes in patients with PD have been undertaken. Therefore, we aimed to genetically analyze 16 dopaminergic transcription factor genes in Chinese patients with PD.Methods::Whole-exome sequencing (WES) was performed using a Chinese cohort comprising 1917 unrelated patients with familial or sporadic early-onset PD and 1652 controls. Additionally, whole-genome sequencing (WGS) was performed using another Chinese cohort comprising 1962 unrelated patients with sporadic late-onset PD and 1279 controls.Results::We detected 308 rare and 208 rare protein-altering variants in the WES and WGS cohorts, respectively. Gene-based association analyses of rare variants suggested that MSX1 is enriched in sporadic late-onset PD. However, the significance did not pass the Bonferroni correction. Meanwhile, 72 and 1730 common variants were found in the WES and WGS cohorts, respectively. Unfortunately, single-variant logistic association analyses did not identify significant associations between common variants and PD. Conclusions::Variants of 16 typical dopaminergic transcription factors might not be major genetic risk factors for PD in Chinese patients. However, we highlight the complexity of PD and the need for extensive research elucidating its etiology.

Aim To investigate the effect of recombi-nant glycoprotein hormone β5/α2(rCGH)on lipolysis in 3T3-L1 adipocytes,and explore the underlying mechanism.Methods 3T3-L1 preadipocytes were cultured and induced to differentiate into mature adipo-cytes,then treated with different concentrations of rCGH for 24 h in vitro.Cell viability of 3T3-L1 adipo-cytes was evaluated by CCK-8 assay,the levels of in-tracellular triglyceride(TG)and glycerol in the culture supernatant were measured by enzymatic method,and the changes of lipid droplets were observed by oil red O staining.The expression levels of HSL and ATGL lipo-lytic proteins in adipocytes were detected by Western blot.To carry out the intervention experiment with dif-ferent concentrations of rCGH with or without the PKA inhibitor,H89,on the mature 3T3-L1 adipocytes,the cultured cells were divided into the control group,H89 pre treatment group,1 μmol·L-1 rCGH group,and(1 μmol·L-1 rCGH+H89)combined intervention group.The contents of intracellular TG and free glycer-ol were measured by enzymatic method,and the ex-pression of CREB and lipolysis-related proteins was de-tected using Western blot.Results Different concen-trations of rCGH(0.25,0.5,1,and 2 μmol·L-1)had no significant effect on the cell viability of adipo-cytes(P＞0.05).Compared with the control group,the treatment with rCGH significantly decreased the size of lipid droplets and intracellular TG content,while significantly elevated glycerol concentration in cell supernatant.rCGH treatment also stimulated the protein expression of p-HSL,ATGL,and p-PKA.In addition,the addition of a PKA inhibitor,H89,atten-uated the effects of rCGH on free glycerol level,intra-cellular TG content,and the expression of p-HSL,p-PLIN1,and p-CREB.Conclusions rCGH enhances the lipolysis of 3T3-L1 adipocytes by up-regulating the activities of HSL,ATGL and PKA,promoting glycerol release,inhibiting TG synthesis and lipid accumula-tion,and its mechanism of action is related to the acti-vation of cAMP/PKA/CREB signaling pathway.