Background/Aims: Obesity is associated with several gastrointestinal (GI) disorders and has been identified as a potential risk factor for various GI symptoms. Bowel frequency is an important indicator of bowel function. However, the causal link between obesity and gastrointestinal motility remains uncertain. This study aims to determine the causal effect of overall and central obesity on stool frequency. Methods: Four obesity-related anthropometric indicators–body mass index, body fat percentage, waist circumference (WC), and waist-tohip ratio (WHR)–were investigated. Individual-level baseline information from the UK Biobank was used to explore observational associations between obesity and stool frequency. Additionally, summary-level data from published genome-wide association studies were subjected to two-sample Mendelian randomization (MR) analyses to examine causal associations. Results: For all 4 indicators of obesity, higher levels of obesity were associated with more frequent bowel movements after adjusting for demographic characteristics, lifestyle, and dietary factors. After rigorous screening, 482 body mass index single nucleotide polymorphisms (SNPs), 7 body fat percentage SNPs, 48 WC SNPs, and 287 WHR SNPs were identified as instrument variables for MR analysis. The MR results were generally consistent with observational findings, proving that the associations observed in the overall obesity indicators were causal. For central obesity, the association between WHR and stool frequency remained consistent in both analysis phases, whereas WC showed a multidirectional association. Conclusions Obesity-related anthropometric indicators were causally associated with increased stool frequency in the overall and central obesity groups. Weight loss could be a potential approach to improve gastrointestinal regularity in individuals with obesity.

Background/Aims: Obesity is associated with several gastrointestinal (GI) disorders and has been identified as a potential risk factor for various GI symptoms. Bowel frequency is an important indicator of bowel function. However, the causal link between obesity and gastrointestinal motility remains uncertain. This study aims to determine the causal effect of overall and central obesity on stool frequency. Methods: Four obesity-related anthropometric indicators–body mass index, body fat percentage, waist circumference (WC), and waist-tohip ratio (WHR)–were investigated. Individual-level baseline information from the UK Biobank was used to explore observational associations between obesity and stool frequency. Additionally, summary-level data from published genome-wide association studies were subjected to two-sample Mendelian randomization (MR) analyses to examine causal associations. Results: For all 4 indicators of obesity, higher levels of obesity were associated with more frequent bowel movements after adjusting for demographic characteristics, lifestyle, and dietary factors. After rigorous screening, 482 body mass index single nucleotide polymorphisms (SNPs), 7 body fat percentage SNPs, 48 WC SNPs, and 287 WHR SNPs were identified as instrument variables for MR analysis. The MR results were generally consistent with observational findings, proving that the associations observed in the overall obesity indicators were causal. For central obesity, the association between WHR and stool frequency remained consistent in both analysis phases, whereas WC showed a multidirectional association. Conclusions Obesity-related anthropometric indicators were causally associated with increased stool frequency in the overall and central obesity groups. Weight loss could be a potential approach to improve gastrointestinal regularity in individuals with obesity.

Background/Aims: Obesity is associated with several gastrointestinal (GI) disorders and has been identified as a potential risk factor for various GI symptoms. Bowel frequency is an important indicator of bowel function. However, the causal link between obesity and gastrointestinal motility remains uncertain. This study aims to determine the causal effect of overall and central obesity on stool frequency. Methods: Four obesity-related anthropometric indicators–body mass index, body fat percentage, waist circumference (WC), and waist-tohip ratio (WHR)–were investigated. Individual-level baseline information from the UK Biobank was used to explore observational associations between obesity and stool frequency. Additionally, summary-level data from published genome-wide association studies were subjected to two-sample Mendelian randomization (MR) analyses to examine causal associations. Results: For all 4 indicators of obesity, higher levels of obesity were associated with more frequent bowel movements after adjusting for demographic characteristics, lifestyle, and dietary factors. After rigorous screening, 482 body mass index single nucleotide polymorphisms (SNPs), 7 body fat percentage SNPs, 48 WC SNPs, and 287 WHR SNPs were identified as instrument variables for MR analysis. The MR results were generally consistent with observational findings, proving that the associations observed in the overall obesity indicators were causal. For central obesity, the association between WHR and stool frequency remained consistent in both analysis phases, whereas WC showed a multidirectional association. Conclusions Obesity-related anthropometric indicators were causally associated with increased stool frequency in the overall and central obesity groups. Weight loss could be a potential approach to improve gastrointestinal regularity in individuals with obesity.

Background::To date, there is still a lack of standardized management strategies for gastric low-grade dysplasia (LGD), which is a direct neoplastic precancerous lesion and requires specifically superficial destruction. Radiofrequency ablation (RFA) is expected to be an effective method for gastric LGD, but post-RFA pain may affect patients’ satisfaction and compliance. The current study aimed to evaluate the value of a submucosal injection prior to RFA (SI-RFA) for postoperative pain and treatment outcomes.Methods::Between October 2014 and July 2021, gastric LGDs without risk factors (size >2 cm, unclear boundary, and abnormal microsurface and microvascularity) undergoing regular RFA and SI-RFA were retrospectively analyzed. Postoperative pain scores, wound healing, and clinical efficacy were compared. Propensity score matching, stratified analysis, and multivariable logistic regression were performed to control the confounding variables.Results::One hundred and ninety-seven gastric LGDs in 151 patients received regular RFA. Forty-nine gastric LGDs in 36 patients received SI-RFA. Thirty-six pairs of patients were selected for the assessment of postoperative pain by propensity score matching. Compared to regular RFA, SI-RFA significantly decreased the degree and duration of postoperative pain (OR, 0.32; 95% CI, 0.13-0.84; P = 0.020), improved wound healing rate (80.0% [36/45] vs. 58.9% [89/151], P = 0.012), increased the complete ablation rate (91.8% [45/49] vs. 86.3% [170/197], χ 2 = 1.094, P = 0.295), but correlated with higher rates of local recurrence and progression (25.6% [10/39] vs. 13.2% [18/136], χ 2 = 3.471, P = 0.062; 8.3% [3/36] vs. 0.9% [1/116], P = 0.042). The multivariable logistic regression model confirmed that submucosal injection was associated with local recurrence (OR, 2.93; 95% CI, 1.13-7.58; P = 0.027). Conclusions::Submucosal injections prior to RFA may reduce postoperative pain and scar formation while ensuring complete ablation of gastric LGD. However, local recurrence and progression should be considered seriously.

Objective To explore the effectiveness of a PBL-CBL teaching model oriented towards competency evaluation after the introduction of standardized patients in orthopedic clinical internship teaching.Methods Eighty-nine medical students undergoing orthopedic internships at our hospital from 2022 to 2023 were divided into an S-PC teaching group and a PC teaching group.Based on Milestones 2.0,a competency evaluation model for orthopedic interns was established,including six primary in-dicators:patient care,clinical knowledge and skills,interpersonal communication,and more.After the course,students were as-sessed according to the established model.Results The S-PC group showed statistically significant differences in scores for pa-tient care,clinical knowledge and skills,interpersonal communication,system-based practice,and practice-based learning com-pared to the PC group(P＜0.05),with all scores in the S-PC group being higher than those in the PC group.Conclusion In-troducing standardized patients into the PBL-CBL teaching model in clinical education significantly enhances the competency of orthopedic interns.

Objective This study uses whole-genome methylation capture sequencing technology to screen differential sites and regions of gene methylation in mouse liver and colon under simulated weightlessness conditions to reveal the specific impact of weightlessness on gene methylation.Methods Six 8-week-old male C57BL/6J mice were randomized into the tail suspension group and the control group,with 3 in each.The 3 mice in the tail suspension group recieved tail suspension for simulated weightlessness for 42 days.After the experiment,DNA was extracted from liver and colon tissue and analyzed using genome-wide methylation capture sequencing technology.Results DNA analysis of liver tissue showed that a total of 7 517 differentially methylated sites and 997 differentially methylated regions were found,involving 4 892 genes.DNA analysis of colon tissue revealed 70 340 differentially methylated sites and 12 004 differentially methylated regions,affecting 12 877 genes.GO and KEGG path analysis revealed that these differentially methylated genes were mainly involved in protein binding,cell adhesion,cell activation,and various metabolic pathways.Conclusion This study successfully identified differential methylation sites and regions in mouse liver and colon under simulated weightlessness conditions through high-throughput sequencing technology.These findings help to further understand the impact of long-term space residence on biological gene methylation.It provides new research ideas for the prevention and early treatment of space flight-related diseases.

With the increasing maturity and progress of China's space technology,astronauts can stay longer in the space station and complete more complex space experiments and tasks.In the Microgravity(MG)environment of space,the digestive system of astronauts is inevitably affected,especially the liver and colon,and there are many physiological and pathological changes.MG can affect liver metabolic function,cell proliferation and differentiation,oxidative stress response and inflammatory factor levels.MG can disrupt the intestinal barrier of the colon,intestinal flora and microecology,intestinal immunity,and the gut-liver axis.However,the existing studies on the effects of MG on liver and colon are not completely clear,and there is a lack of reliable diagnostic indicators for the pathological changes of both.Therefore,in order to explore the damage mechanism of MG on liver and colon and ensure the digestive system health of astronauts,this paper reviews the research progress on the effects of MG on liver and colon.

Inflammatory bowel disease(IBD)is a kind of immune disease.Although immune cells and related immunological reactions play a crucial role in the pathogenesis,non-immune cells of IBD,including intestinal epithelial cells,stromal cells,and endothelial cells are also involved in this process.Recent studies have shown that gut non-immune cells play an important role in the maintenance of intestinal epithelial homeostasis,matrix remodeling,immune response and inflammation.The composition,gene expression characteristics and cell functions of gut non-immune cells,as well as their role in the occurrence and progression of IBD,have been paid much attention in the field of gut research.In particular,recently,single-cell RNA sequencing(scRNA-seq)technology has initially clarified the gene expression characteristics and cell functions of different subgroups of intestinal cells,and the correlation between these changes and the occurrence and progression of IBD.Therefore,this review summarizes the progress of intestinal non-immune cells in IBD.

Objective:To explore whether chronic fluorosis can cause liver fibrosis in rats by observing expression changes in type Ⅰcollagen (Col-Ⅰ), type Ⅲ collagen (Col-Ⅲ) and alpha smooth actin (α-SMA) in the liver tissue of chronic fluorosis rats.Methods:According to body weight (90 - 100 g), forty-eight SD rats were randomly divided into control group (drinking water fluoride ion concentration < 0.5 mg/L), low, medium and high concentration fluoride groups (drinking water fluoride ion concentration of 5.0, 50.0 and 100.0 mg/L), with 12 rats in each group (half male and half female), and fed for 6 months. Fluoride ion selective electrode method was used to detect bone fluoride and urinary fluoride levels; hematoxylin-eosin staining (HE staining) and Masson staining were used to observe the pathological and morphological changes and the collagen deposition of liver tissue; quantitative real-time polymerase chain reaction and immunohistochemical staining were used to observe Col-Ⅰ, Col-Ⅲ and α-SMA mRNA and protein expressions.Results:There was significant difference in bone fluoride and urine fluoride between the 4 groups [bone fluoride: (92.52 ± 5.64), (112.21 ± 11.86), (142.99 ± 7.87), (235.63 ± 11.55) mg/kg; urinary fluoride: (5.47 ± 0.88), (17.78 ± 1.48), (54.16 ± 5.96), (121.11 ± 6.32) mg/L, P < 0.001]. Under light microscope, with the increase of fluoride concentration, the degree of hepatic cell edema was aggravated, and the deposition of collagen fiber around the central vein and the portal area increased significantly. The mRNA expression level of Col-Ⅰ in low, medium and high concentration fluoride groups (1.20 ± 0.09, 1.80 ± 0.08, 1.58 ± 0.06) was significantly higher than that in control group (1.00 ± 0.00, P < 0.05); Col-Ⅲ and α-SMA mRNA expression levels in medium and high concentration fluoride groups (Col-Ⅲ: 1.15 ± 0.14, 1.64 ± 0.24; α-SMA: 1.69 ± 0.02, 2.34 ± 0.06) were significantly higher than those of low concentration fluoride group (Col-Ⅲ: 0.59 ± 0.17; α-SMA: 0.80 ± 0.13, P < 0.05). With the increase of fluoride concentration, the liver tissue Col-Ⅰ(0.00 ± 0.00, 0.03 ± 0.01, 0.08 ± 0.01, 0.13 ± 0.02), Col-Ⅲ (17 803.05 ± 3 221.16, 47 523.15 ± 3 490.10, 127 786.35 ± 13 008.86, 237 233.03 ± 47 614.63) and α-SMA (516.83 ± 181.18, 2 885.03 ± 864.92, 11 186.94 ± 2 394.08, 37 182.43 ± 12 390.59) protein levels were also increased significantly ( P < 0.05). Conclusion:Long-term excessive intake of fluorine may cause the production of collagen fibers around the central vein and the portal area of the liver in rats to increase, and then lead to the formation of liver fibrosis.

Objective:To observe the protein and mRNA expressions of microtubule-associated protein 1 light chain 3 (LC3)B, P62 and Beclin1 in the liver of rats with chronic fluorosis, and to explore the role of autophagy in pathogenesis of liver injury induced by fluorosis.Methods:Using a group design, 54 SD rats were divided into 9 groups according to their weight (100 - 120 g) using a random number table method, each group with 6 rats, half male and half female. They were control group (NC group), low fluoride group (LF group), high fluoride group (HF group), NC + rapamycin (RAP) group, LF + RAP group, HF + RAP group, NC + chloroquine (CQ) group, LF + CQ group, and HF + CQ group. The NC group drank tap water (fluoride concentration was 0.5 mg/L), LF group drank fluoride water (fluoride concentration was 5.0 mg/L), HF group drank fluoride water (fluoride concentration was 50.0 mg/L); NC + RAP group, LF + RAP group and HF + RAP group were fed with corresponding drinking water, respectively, for 3 months, and then RAP (1.5 mg/kg) was intraperitoneally administered for 10 d; NC + CQ group, LF + CQ group and HF + CQ group were fed with corresponding drinking water, respectively, for 3 months, and then CQ (60 mg/kg) was intraperitoneally administered for 10 d. Bone and 24-hour urine samples of rats in each group were collected to detect the contents of bone fluoride and urine fluoride; liver histomorphological changes were observed through hematoxylineosin staining; protein and mRNA expressions of LC3B, P62 and Beclin1 in liver were detected by immunohistochemistry and real-time fluorescence quantitative PCR, respectively.Results:Compared with the NC group [(0.03 ± 0.00) mg/kg, (0.34 ± 0.08) mg/L], the contents of bone fluoride [(3.86 ± 0.08) mg/kg] and urine fluoride [(1.11 ± 0.16) mg/L] in HF group were higher ( P < 0.05). In the NC group, the lobule structure of liver tissue was clear, the hepatic cords were arranged in order, and the cell structure was normal. There were different degrees of hepatocyte edema in LF and HF groups. After intraperitoneal injection of RAP, compared with the corresponding fluoride group, the morphology of hepatocytes did not change significantly. After intraperitoneal injection of CQ, compared with the corresponding fluoride group, the liver cells showed obvious edema, and the degree of edema aggravated with the increase of fluoride concentration. Compared with the NC group, the protein expressions of LC3B and Beclin1 in HF group were higher ( P < 0.05), and the protein expression of P62 was lower ( P < 0.05). After intraperitoneal injection of RAP, the protein expressions of LC3B and P62 in LF + RAP group was lower than that in LF group ( P < 0.05); Compared with HF group, the protein expressions of LC3B and Beclin1 in HF + RAP group were lower ( P < 0.05). After intraperitoneal injection of CQ, protein expression of P62 in LF + CQ group was higher than that in LF group ( P < 0.05); Compared with HF group, protein expression of P62 in HF + CQ group was higher ( P < 0.05). Conclusions:Early (3 month) fluoride intake could promote autophagy and induce edema of hepatocytes in rats, and RAP had similar effects. CQ may induce liver injury by inhibiting autophagy of hepatocytes.