ObjectiveTo evaluate the effects of drinking chlorinated water on the intestinal flora of rats and mice and to explore differences in the intestinal microecological responses of model animals to chlorine stimulation in chlorinated drinking water systems. MethodsSix 8-week-old male SD rats and six 8-week-old male C57BL/6J mice were acclimated for 5 days. Subsequently, the drinking water for both rats and mice was changed from pure water to water containing free chlorine at a concentration of 25.4–32.4 nmol/L. The intervention lasted for 8 weeks, during which all animals were fed the same diet. Fecal samples were collected before the intervention (week 0, as the control group) and on the last day of week 3 and week 8 (as the chlorinated water group), and microbial composition was analyzed by 16S rRNA sequencing, including α diversity (Chao1 and Shannon indices), β diversity [principal component analysis (PCA)], and linear discriminant analysis effect size (LEfSe) analysis. ResultsAfter 3 weeks of intervention, α diversity of the intestinal flora in both rats and mice in the chlorinated water group was significantly lower than that in the control group (P < 0.01). After 8 weeks of intervention, no significant difference in α diversity was observed between rats in the chlorinated water group and those in the control group, whereas α diversity in mice remained significantly lower than that in the control group (P < 0.01). β diversity analysis showed significant alterations in microbial structure in the chlorinated water group. LEfSe analysis indicated that, compared with the control group, the abundances of Bacteroides and Ruminococcus were significantly reduced in the chlorinated water group, and microbial disturbance was more pronounced in mice [linear discriminant analysis (LDA) > 4.0], with a greater decrease in microbial diversity and a larger number of differentially abundant genera. ConclusionConsumption of chlorinated water can alter the diversity and structure of the intestinal flora in both rats and mice, with mice being more sensitive to this exposure. These findings suggest that the potential effects of chlorine on gut microecology should be considered in drinking water management and model selection for animal experiments.

ObjectiveThis study aims to investigate the regulatory effects of microcapsules with different matrix stiffness on the survival, proliferation, adhesion, and osteogenic differentiation of mesenchymal stem cells (MSCs), to further explore the relationship between matrix stiffness and MSCs osteogenic behavior, and to evaluate the in vivo histological responses and osteogenic-related protein expression of the microcapsules using an animal subcutaneous implantation model. MethodsIn this study, three-dimensional carbon nanofiber (CNF)/sodium alginate (SA) microcapsules with different matrix stiffness were constructed. By adjusting the CNF content, three groups of microcapsules with stiffness values of 27.05, 35.90, and 52.40 kPa were prepared, and their physicochemical properties, including morphology, mechanical properties, particle size, chemical structure, and degradation properties, were characterized. The effects of these microcapsules with different stiffness on the survival, adhesion, and osteogenic differentiation of MSCs were evaluated. Live/dead staining was used to observe cell survival and distribution in the microcapsules, while alkaline phosphatase (ALP) activity and the expression of osteopontin (OPN) and osteocalcin (OCN) were examined to assess osteogenic differentiation. Immunofluorescence staining was further performed to observe the expression of Yes-associated protein (YAP) and integrin β1 under different stiffness conditions. In addition, a rat subcutaneous implantation model was used to evaluate the in vivo tissue compatibility of the microcapsules. Histological staining and immunohistochemical analysis were carried out to examine local tissue responses and the expression of osteogenic-related proteins. ResultsThe results showed that all three groups of microcapsules exhibited regular and uniform morphology and similar particle size, and all groups showed good degradability. Except for the differences in mechanical properties, no obvious differences were found in the other physicochemical properties among the three groups. Live/dead staining indicated that all groups of microcapsules had good cytocompatibility. MSCs in the low-stiffness group were mostly round, whereas cells in the medium- and high-stiffness groups showed more obvious spreading. Higher matrix stiffness was more favorable for MSC adhesion, growth, and survival. ALP staining and quantitative analysis showed that ALP activity increased significantly with increasing matrix stiffness. The expression of the osteogenic-related proteins OPN and OCN also increased with increasing stiffness, and the high-stiffness group showed the strongest positive signals. Immunofluorescence results further indicated that YAP and integrin β1 fluorescence signals tended to increase in MSCs with increasing matrix stiffness, suggesting that matrix stiffness may influence MSC osteogenic differentiation through stiffness-related cell adhesion and mechanotransduction. In vivo experiments showed that all three groups of microcapsules exhibited good histocompatibility after subcutaneous implantation, although different degrees of degradation and local tissue response were observed. Immunohistochemical analysis showed that the expression levels of OPN and OCN increased with increasing matrix stiffness, and the high-stiffness group exhibited higher expression of these osteogenic-related proteins. ConclusionCNF endows SA microcapsules with tunable matrix stiffness. While maintaining good biocompatibility, the high-stiffness microenvironment can effectively promote the adhesion and osteogenic differentiation of MSCs, accompanied by increased ALP activity and enhanced OPN and OCN expression. The increased YAP and integrin β1 fluorescence signals in the high-stiffness group further indicate that matrix stiffness is closely related to cellular mechanical responses. These findings provide a three-dimensional cell carrier with potential application value for MSC delivery and bone tissue regeneration based on mechanical microenvironment regulation.

The recombinant human thyroid-stimulating hormone (rhTSH) can be used for differentiated thyroid cancer (DTC) preparation before ¹³¹I therapy, and follow-up. Since its approval by the American Food and Drug Administration (FDA) in 1998, rhTSH has been clinically used in European countries, the United States, and other countries for nearly 30 years. In April 2024, China’s first independently developed rhTSH agent was approved. Based on clinical experience and evidence from domestic and international studies, an expert consensus on the application of rhTSH has been developed following thorough consultations among experts. The consensus offers evidence-based recommendations to guide the appropriate use of rhTSH in clinical practice.

AIM:This study explores whether curcumin(Cur)promotes mitophagy to attenuate nonalcoholic steatohepatitis(NASH)in mice,as well as the possible molecular mechanisms involved.METHODS:A high-fat and high-cholesterol diet was used to replicate the NASH mouse model.Thirty-two male C57BL/6J mice were randomly divided into normal control(NC)group,high-fat and high-cholesterol model(M)group,M+low-dose Cur(Cur-L)group,and M+high-dose Cur(Cur-H)group,with 8 mice in each group.The weight of 8 mice in each group was recorded weekly.After feeding for 18 weeks,the serum and liver of mice were collected.Serum levels of total cholesterol(TC),triglyceride(TG),low-density lipoprotein(LDL-C),alanine aminotransferase(ALT),aspartate aminotransferase(AST),and tumor necrosis factors-α(TNF-α)were measured.Liver index was calculated,and steatosis,inflammation,and fibrosis of the liver were observed by HE and Masson staining.Western blot analysis was performed to detect the protein expression of mi-tophagy-related protein,TNF-α and α-SMA in the liver.(2)HepG2 cells were treated with oleic acid and cholesterol to replicate the hepatocyte injury model,which was divided into NC group,Cur group,M group,and M+Cur group.Small interfering RNA for PTEN-induced kinase 1(PINK1)knockdown was used to explore the relationship between PINK1-me-diated mitophagy and NASH.Compound C(CC)was used to inhibit AMP-activated protein kinase(AMPK)to explore the effect of the AMPK/silent information regulator 1(Sirt1)pathway on mitophagy.The lipid droplets of HepG2 cells were ob-served by oil red O staining,and the levels of TC,TG,LDL-C,ALT,and AST in cell suspension were detected.RE-SULTS:(1)Compared with M group,treatment with Cur significantly reduced the body weight,liver coefficient,and se-rum levels of TC,TG,LDL-C,ALT,AST,and TNF-α in NASH mice,while the steatosis and fibrosis in the liver were improved(P<0.05).(2)Different concentrations of Cur could increase or decrease the expression of mitophagy-related proteins in HepG2 cells in a concentration gradient.Compared with the M group,Cur reduced lipid droplets and de-creased TC,TG,LDL-C,ALT,and AST levels(P<0.05).(3)Compared with the NC group,the expression levels of mi-tophagy-related proteins in the liver of mice in the M group decreased,and the expression levels of TNF-α and α-SMA pro-teins increased.Different concentrations of Cur intervention promoted the increase of mitophagy-related proteins and the decrease of TNF-α and α-SMA proteins(P<0.05).(4)After Cur intervention,the expression levels of mitophagy-related proteins increased and the expression levels of in TNF-α and α-SMA levels decreased in HepG2 cells induced by oleic acid and cholesterol(P<0.05).(5)Compared with M group,oleic-acidand cholesterol-induced mitophagy function in HepG2 cells was decreased after PINK1 knockdown(P<0.05).After CC inhibited AMPK,Cur increased the expression of p-AMPK(P<0.01),Sirt1(P<0.01),peroxisome proliferator-activated receptor γ coactivator-1α(P>0.05),PINK1(P<0.01)and parkin(P<0.01)proteins to some extent.CONCLUSION:Treatment with Cur attenuates liver injury in NASH mice and reduces lipid accumulation in HepG2 cells induced by oleic acid and cholesterol,and the mechanism may be related to promotion of mitophagy,which may involve the AMPK/Sirt1 signaling pathway.

Objective To analyze the latent classes of social alienation in colorectal cancer patients and further explore the influencing factors and cumulative effects of risk factors across different classes,thereby providing a reference for individualized interventions.Methods Convenience sampling was used to select colorectal cancer patients hospitalized in the gastrointestinal surgery and oncology departments of 3 tertiary-level hospitals in Shandong Province from January to June 2023 as the study subjects.A questionnaire survey was conducted using the General Information Questionnaire,Social Avoidance Scale,Social Anxiety Scale,UCLA Loneliness Scale,Sense of Coherence Scale,Family Cohesion Scale,and Social Support Rating Scale.Data analysis was performed using latent profile analysis and multivariate logistic regression analysis.Results A total of 292 questionnaires were distributed,with 270 valid responses collected,yielding a response rate of 92.47％.The results of the latent profile analysis indicated that social alienation among colorectal cancer patients could be categorized into 3 latent groups:the"low alienation group"(42.59％),the"high alienation-high social avoidance group"(14.08％),and the"moderate alienation-high social anxiety group"(43.33％).Results of logistic regression analysis revealed that employment status,stoma status,metastasis,sense of coherence,family cohesion,and social support were influencing factors across different categories.Moreover,a cumulative effect of sense of coherence,family cohesion,and social support on distinct categories was observed(P＜0.05).Conclusion Social alienation among colorectal cancer patients exhibits group heterogeneity.Healthcare professionals should identify the characteristic differences among patients,prioritise those with multiple risk factors,and develop targeted intervention measures to help them better integrate into society.

Objective To examine the changing prevalence and antimicrobial resistance profiles of Burkholderia cepacia in 52 hospitals across China from 2015 to 2021.Methods A total of 9 261 strains of B.cepacia were collected from 52 hospitals between January 1,2015 and December 31,2021.Antimicrobial susceptibility of the strains was tested using Kirby-Bauer method or automated antimicrobial susceptibility testing systems according to a unified protocol.The results were interpreted according to the breakpoints released in the Clinical & Laboratory Standards Institute(CLSI)guidelines(2023 edition).Results A total of 9 261 strains of B.cepacia were isolated from all age groups,especially elderly patients.The proportion was 11.1％(1 032 strains)in children,significantly lower than the proportion in adults.About half(46.5％,4 310/9 261)of the strains were isolated from patients at least 60 years old and 42.3％(3 919/9 261)of the strains were isolated from young adults.Most isolates(71.1％)were isolated from sputum and respiratory secretions,followed by urine(10.7％)and blood samples(8.1％).B.cepacia isolates were highly susceptible to the five antimicrobial agents recommended in the CLSI M100 document(33rd edition,2023).B.cepacia isolates showed relatively higher resistance rates to meropenem and levofloxacin.However,the resistance rates to ceftazidime,trimethoprim-sulfamethoxazole,and minocycline remained below 8.1％.The percentage of B.cepacia strains resistant to levofloxacin was the highest compared to other antibiotics in any of the three age groups(from 12.4％in the patients＜18 years old to 20.6％in the patients aged 60 years or older).Conclusions B.cepacia is one of the clinically important non-fermenting gram-negative bacteria.Accurate and timely reporting of antimicrobial susceptibility test results and ongoing antimicrobial resistance surveillance are helpful for rational prescription of antimicrobial agents and proper prevention and control of nosocomial infections.

The prevention and research of military training injuries(MTI)are crucial for reducing non-battle casualties,ensuring combat readiness,and enhancing the effectiveness of military training.In-depth analyses of the prevention and treatment strategies of MTI and related research can provide concrete guidance for scientific training practices.As a critical component of national defense,the Chinese Navy has experienced rapid development in recent years,and the prevention and research of MTI in naval forces have become a key focus.In recent years,rehabilitation medicine has been increasingly recognized for its importance in areas such as physical capability enhancement and injury prevention.The comprehensive adoption of rehabilitation concepts and the early implementation of rehabilitation measures have been widely accepted.It has important guiding significance for further strengthening the application of rehabilitation in preventing and treating injuries in naval training.This article discusses how to further strengthen the rehabilitation strategies for the prevention and research of MTI in the Navy,so as to provide insights and prospects for this field.

AIM:To investigate the effect of silent information regulator 1(SIRT1)on the degree of aging and apoptosis in a mouse cardiomyocyte aging model through the regulation of Wnt/β-catenin pathway.METHODS:An in vi-tro aging model was established by inducing HL-1 cells with 40 μmol/L D-galactose(D-Gal).The HL-1 cells were trans-fected with a lentivirus overexpressing SIRT1,and the transfection efficiency was verified by Western blot.Western blot was used to detect the protein expression levels of SIRT1,P53,P21,cleaved caspase-3,B-cell lymphoma-2(Bcl-2),Bcl-2-associated X protein(Bax),β-catenin,Wnt3a and c-Myc.Senescence-associated β-galactosidase(SA-β-Gal)staining was used to detect cellular senescence level.MTT colorimetric assay was used to detect the cell viability,and flow cytometry was used to detect the apoptosis.RESULTS:Treatment of HL-1 mouse cardiomyocytes with D-Gal led to in-creases in the expression levels of aging-related proteins P53 and P21,as well as an increase in SIRT1 protein level.Addi-tionally,the SA-β-Gal staining showed a significant increase in the positive area(P＜0.05).The expression levels of apop-tosis-related proteins cleaved caspase-3 and Bax were elevated,while the level of the anti-apoptotic protein Bcl-2 was re-duced(P＜0.05).There was a marked decrease in cell viability(P＜0.05),and flow cytometry analysis demonstrated a significant increase in cell apoptosis rate(P＜0.05),which was positively correlated with the duration of D-Gal treatment.Overexpression of SIRT1 notably reduced both aging and apoptosis levels after 48 h of D-Gal treatment(P＜0.05).After D-Gal treatment,the expression levels of β-catenin,c-Myc and Wnt3a proteins were up-regulated.However,these levels were reduced when SIRT1 was overexpressed.Moreover,the addition of LiCl,a Wnt/β-catenin pathway agonist,resulted in increased expression levels of β-catenin,c-Myc and Wnt3a proteins compared with the group with SIRT1 overexpres-sion and D-Gal treatment(P＜0.05).CONCLUSION:SIRT1 inhibits cardiomyocyte apoptosis and alleviates cardiomyo-cyte aging through the Wnt/β-catenin pathway.

Objective To investigate the distribution and antimicrobial resistance profiles of common pathogens isolated from cerebrospinal fluid(CSF)in CHINET program from 2015 to 2021.Methods The bacterial strains isolated from CSF were identified in accordance with clinical microbiology practice standards.Antimicrobial susceptibility test was conducted using Kirby-Bauer method and automated systems per the unified CHINET protocol.Results A total of 14 014 bacterial strains were isolated from CSF samples from 2015 to 2021,including the strains isolated from inpatients(95.3％)and from outpatient and emergency care patients(4.7％).Overall,19.6％of the isolates were from children and 80.4％were from adults.Gram-positive and Gram-negative bacteria accounted for 68.0％and 32.0％,respectively.Coagulase negative Staphylococcus accounted for 73.0％of the total Gram-positive bacterial isolates.The prevalence of MRSA was 38.2％in children and 45.6％in adults.The prevalence of MRCNS was 67.6％in adults and 69.5％in children.A small number of vancomycin-resistant Enterococcus faecium(2.2％)and linezolid-resistant Enterococcus faecalis(3.1％)were isolated from adult patients.The resistance rates of Escherichia coli and Klebsiella pneumoniae to ceftriaxone were 52.2％and 76.4％in children,70.5％and 63.5％in adults.The prevalence of carbapenem-resistant E.coli and K.pneumoniae(CRKP)was 1.3％and 47.7％in children,6.4％and 47.9％in adults.The prevalence of carbapenem-resistant Acinetobacter baumannii(CRAB)and Pseudomonas aeruginosa(CRPA)was 74.0％and 37.1％in children,81.7％and 39.9％in adults.Conclusions The data derived from antimicrobial resistance surveillance are crucial for clinicians to make evidence-based decisions regarding antibiotic therapy.Attention should be paid to the Gram-negative bacteria,especially CRKP and CRAB in central nervous system(CNS)infections.Ongoing antimicrobial resistance surveillance is helpful for optimizing antibiotic use in CNS infections.

Objective To investigate the antimicrobial resistance of clinical isolates from elderly patients(≥65 years)in major medical institutions across China.Methods Bacterial strains were isolated from elderly patients in 52 hospitals participating in the CHINET Antimicrobial Resistance Surveillance Program during the period from 2015 to 2021.Antimicrobial susceptibility test was carried out by disk diffusion method and automated systems according to the same CHINET protocol.The data were interpreted in accordance with the breakpoints recommended by the Clinical and Laboratory Standards Institute(CLSI)in 2021.Results A total of 514 715 nonduplicate clinical isolates were collected from elderly patients in 52 hospitals from January 1,2015 to December 31,2021.The number of isolates accounted for 34.3％of the total number of clinical isolates from all patients.Overall,21.8％of the 514 715 strains were gram-positive bacteria,and 78.2％were gram-negative bacteria.Majority(90.9％)of the strains were isolated from inpatients.About 42.9％of the strains were isolated from respiratory specimens,and 22.9％were isolated from urine.More than half(60.7％)of the strains were isolated from male patients,and 39.3％isolated from females.About 51.1％of the strains were isolated from patients aged 65-＜75 years.The prevalence of methicillin-resistant strains(MRSA)was 38.8％in 32 190 strains of Staphylococcus aureus.No vancomycin-or linezolid-resistant strains were found.The resistance rate of E.faecalis to most antibiotics was significantly lower than that of Enterococcus faecium,but a few vancomycin-resistant strains(0.2％,1.5％)and linezolid-resistant strains(3.4％,0.3％)were found in E.faecalis and E.faecium.The prevalence of penicillin-susceptible S.pneumoniae(PSSP),penicillin-intermediate S.pneumoniae(PISP),and penicillin-resistant S.pneumoniae(PRSP)was 94.3％,4.0％,and 1.7％in nonmeningitis S.pneumoniae isolates.The resistance rates of Klebsiella spp.(Klebsiella pneumoniae 93.2％)to imipenem and meropenem were 20.9％and 22.3％,respectively.Other Enterobacterales species were highly sensitive to carbapenem antibiotics.Only 1.7％-7.8％of other Enterobacterales strains were resistant to carbapenems.The resistance rates of Acinetobacter spp.(Acinetobacter baumannii 90.6％)to imipenem and meropenem were 68.4％and 70.6％respectively,while 28.5％and 24.3％of P.aeruginosa strains were resistant to imipenem and meropenem,respectively.Conclusions The number of clinical isolates from elderly patients is increasing year by year,especially in the 65-＜75 age group.Respiratory tract isolates were more prevalent in male elderly patients,and urinary tract isolates were more prevalent in female elderly patients.Klebsiella isolates were increasingly resistant to multiple antimicrobial agents,especially carbapenems.Antimicrobial resistance surveillance is helpful for accurate empirical antimicrobial therapy in elderly patients.