ObjectiveThe exacerbating trend of global population aging poses profound socioeconomic and public health challenges, making the comprehensive elucidation of biological aging mechanisms and the discovery of effective anti-aging interventions an urgent priority in the life sciences. Based on our previous serum metabolomics findings that dimethylglycine, an intermediate metabolite of amino acid metabolism naturally present in the human body, was significantly enriched in the serum of longevity families, this study aimed to systematically investigate the anti-aging effects of dimethylglycine both in living organisms and in controlled laboratory environments, and to preliminarily elucidate its underlying molecular mechanisms. While existing literature indicates that dimethylglycine possesses antioxidant and immunomodulatory properties, its direct anti-aging efficacy and the specific molecular pathways through which it operates remain largely unexplored. MethodsTo comprehensively evaluate the anti-aging properties of dimethylglycine, we utilized replicative senescent human embryonic lung fibroblasts, specifically the WI-38 cell line, as an experimental model in a controlled laboratory environment. Cell viability and safety were thoroughly assessed using Cell Counting Kit-8 and lactate dehydrogenase release assays across various concentrations of dimethylglycine. The impact of dimethylglycine on cellular senescence phenotypes, oxidative stress, and proliferative capacity was evaluated via senescence-associated beta-galactosidase staining, reactive oxygen species fluorescence detection, and 5-ethynyl-2'-deoxyuridine incorporation assays. Furthermore, the molecular alterations of senescence-associated secretory phenotype factors and core senescence signaling pathways were quantified using quantitative reverse transcription polymerase chain reaction for the messenger RNA levels of interleukin-6, interleukin-8, p21, and matrix metalloproteinase-1, and enzyme-linked immunosorbent assay for the measurement of p16 and p21 protein expression levels. For the living organism model, the wild-type nematode Caenorhabditis elegans was used to evaluate systemic physiological effects. We conducted a comprehensive lifespan analysis at 20°C, heat stress resistance survival assays at 35℃, senescence-associated beta-galactosidase staining, lipofuscin accumulation tracking, intracellular reactive oxygen species measurement, and Oil Red O staining to ascertain systemic lipid accumulation. Additionally, network pharmacology bioinformatics tools, including PharmMapper and STRING databases, and Kyoto Encyclopedia of Genes and Genomes pathway enrichment analysis were utilized to predict target pathways, alongside highly detailed molecular docking simulations utilizing SwissDock and Protein-Ligand Interaction Profiler to examine interactions with the cytochrome P450 family 2 subfamily C member 9 protein. ResultsThe experimental outcomes robustly demonstrate the potent anti-aging capabilities of dimethylglycine. At the cellular level, toxicity analyses firmly confirmed that dimethylglycine is highly safe; continuous treatment with 50 mol/L and 70 mol/L of dimethylglycine for 5 d did not induce any cellular membrane damage or cytotoxicity, but rather actively promoted cellular proliferation. Utilizing the optimal standardized concentration of 50 mol/L, dimethylglycine treatment significantly ameliorated senescent phenotypic markers in human embryonic lung fibroblasts, which was evidenced by a drastic and highly significant reduction in the senescence-associated beta-galactosidase positive cell percentage (P<0.000 1) and intracellular reactive oxygen species levels (P<0.000 1), alongside a marked increase in the 5-ethynyl-2'-deoxyuridine-positive proliferation rate (P=0.003 5). On a molecular expression scale, dimethylglycine significantly downregulated the messenger RNA expression of multiple core senescence-associated secretory phenotype inflammatory factors, including interleukin-6, interleukin-8, p21, and matrix metalloproteinase-1. Concurrently, it effectively suppressed the protein expression of critical cell cycle arrest markers, diminishing p16 protein levels by 57.3% (P=0.000 4) and p21 protein levels by 27.2% (P=0.000 7). In the nematode Caenorhabditis elegans animal model, dimethylglycine significantly extended the mean lifespan from 20.402 d to an impressive 23.066 d (P<0.000 1) and notably enhanced overall survival rates under severe heat stress environmental conditions (P=0.017). Furthermore, systemic dimethylglycine intervention significantly mitigated age-related physiological decline by decreasing bodily lipofuscin accumulation (P<0.000 1), significantly reducing senescence-associated beta-galactosidase activity, lowering systemic reactive oxygen species fluorescence (P=0.008), and effectively alleviating overall fat accumulation (P<0.000 1). Mechanistically, extensive network pharmacology and Kyoto Encyclopedia of Genes and Genomes analyses strongly revealed that the potential targets of dimethylglycine are significantly enriched in fundamental drug metabolism and oxidative stress response pathways. Precision molecular docking simulations conclusively demonstrated that dimethylglycine forms highly stable structural interactions with the cytochrome P450 family 2 subfamily C member 9 protein, specifically highlighting the definitive formation of 5 stable hydrogen bonds involving serine 365, leucine 366, and serine 429 residues, as well as two critical salt bridge formations with arginine 97 and histidine 368 residues. It is additionally predicted to interact favorably with glutathione S-transferase family proteins. ConclusionDimethylglycine exhibits a profoundly significant and multifaceted anti-aging activity at both the cellular and entire living animal levels. By powerfully alleviating oxidative stress, heavily suppressing the core p16 and p21-dependent cellular senescence signaling pathways, and substantially mitigating the detrimental senescence-associated secretory phenotype, dimethylglycine effectively delays fundamental cellular senescence processes and drastically extends whole-organism lifespan. The biological mechanisms driving these robust protective effects are highly likely closely associated with its direct stable interactions with crucial metabolic and detoxifying enzyme systems, such as cytochrome P450 family 2 subfamily C member 9 and glutathione S-transferase family proteins, thereby systemically improving metabolic dysregulation and restoring critical redox homeostasis. This comprehensive study provides highly solid experimental evidence supporting dimethylglycine as a highly potent and safe potential anti-aging intervention agent, while simultaneously offering a clear molecular mechanistic explanation for the previously documented high abundance of dimethylglycine observed within exceptionally long-lived human populations.

Objective: To evaluate the feasibility of dynamic contrast-enhanced MRI (DCE-MRI) in differentiating tumor deposits (TDs) from metastatic lymph nodes (MLNs) in rectal cancer. Materials and Methods: A retrospective analysis was conducted on 70 patients with rectal cancer, including 168 lesions (70 TDs and 98 MLNs confirmed by histopathology), who underwent pretreatment MRI and subsequent surgery between March 2019 and December 2022. The morphological characteristics of TDs and MLNs, along with quantitative parameters derived from DCE-MRI (K trans , kep, and v e) and DWI (ADCmin, ADCmax, and ADCmean), were analyzed and compared between the two groups.Multivariable binary logistic regression and receiver operating characteristic (ROC) curve analyses were performed to assess the diagnostic performance of significant individual quantitative parameters and combined parameters in distinguishing TDs from MLNs. Results: All morphological features, including size, shape, border, and signal intensity, as well as all DCE-MRI parameters showed significant differences between TDs and MLNs (all P < 0.05). However, ADC values did not demonstrate significant differences (all P > 0.05). Among the single quantitative parameters, v e had the highest diagnostic accuracy, with an area under the ROC curve (AUC) of 0.772 for distinguishing TDs from MLNs. A multivariable logistic regression model incorporating short axis, border, v e, and ADC mean improved diagnostic performance, achieving an AUC of 0.833 (P = 0.027). Conclusion The combination of morphological features, DCE-MRI parameters, and ADC values can effectively aid in the preoperative differentiation of TDs from MLNs in rectal cancer.

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.

Aim To study the difference in hepatotox-icity of psoralen on normal rats and Yin-deficiency rats from the perspective of lipid metabolism,so as to help explain the mechanism of psoralen cautiously used in patients with Yin deficiency recorded in ancient books.Methods SD rats were randomly divided into the nor-mal control group(carboxymethyl cellulose-Na,CMC-Na),normal administration group(CMC-Na+psor-alen),Yin-deficiency control group(CMC-Na+thy-roxine)and Yin-deficiency administration group(CMC-Na+thyroxine+psoralen).The model of Yin-deficiency was established by thyroxine(1 mg·kg-1)for ten days,and then psoralen(200 mg·kg-1)was given for three days.The serum indexes related to liver injury were detected by automatic biochemical analy-zer,the morphological changes of liver tissue were ob-served using HE and oil red O staining,and the relative transcription levels of lipid metabolism related enzymes and mRNA of transporter and endoplasmic reticulum stress related factors were detected using Real-time PCR.Results After intragastric administration of psoralen for three days,compared with the normal group,the levels of serum alanine aminotransferase(ALT),aspartate transaminase(AST),total bile acid(TBA)and triglyeride(TG)in Yin deficiency group increased more significantly,while TC,ALB and TP de-creased more significantly,and liver HE and oil red O staining showed more obvious lipid degeneration.TG synthesis factors adrenocortical carcinoma(ACC),fatty acid synthase(FASN)and sterolregulatory element binding protein-1(SREBP-1)were down-regulated more significantly,TG transport factors mili-total pro-tein(MTP)and lipoprotein pipase(LPL)were down-regulated more evidently,fatty acid β-oxidation related factors carnitine palmitoyltransferase 1A(CPT1A),carnitine/organic cation transporter 2(OCTN2)and peroxisome proliferators-activated receptors-alpha(PPARα)were down-regulated more apparently,TC transporter adenosine triphosphate binding cassette transporter G8(ABCG8)and bile acid receptor farne-soid X receptor(FXR)were down-regulated more ob-viously,and endoplasmic reticulum stress factor activa-ting transcription factor 4(ATF4)was up-regulated more significantly.Conclusions Psoralen can cause more severe hepatotoxicity in Yin deficiency rats than that in normal administration group,and its mechanism may be related to the disorder of hepatic lipid metabo-lism,aggravation of hepatic cholestasis and steatosis,and activation of endoplasmic reticulum stress re-sponse.

Aim To explore the therapeutic effects of resveratrol(Res)on hepatic inflammation and oxida-tive stress in rheumatoid arthritis(RA),and to eluci-date the relationship of the regulatory mechanism of the Nrf2/Keap1 signaling pathway in it.Methods A mouse model of arthritis was induced using chicken type Ⅱ collagen in combination with complete Freund's adjuvant,and Res was administered by tube feeding for treatment.Serum liver function indices and levels of hepatic inflammation and oxidative stress were detected in mice.An in vitro cellular model of hepatic inflam-mation and oxidative stress was established by treating mouse primary hepatocytes(MPHs)with TNF-α(5μg·L-1),cell proliferation inhibition was detected by CCK-8,and inflammation and oxidative stress-relat-ed indices were detected by protein blotting.The in-trinsic mechanisms by which Res attenuated hepatic in-flammation and oxidative stress in rheumatoid arthritis were explored by treating MPHs with Nrf2 inhibitor and Keap1 overexpression plasmid.Results Res signifi-cantly reduced the levels of inflammation and oxidative stress in hepatic tissues of collagen-induced arthritis mice as well as TNF-α-treated MPHs,and activated the Nrf2/Keap1 signaling pathway.Inflammation and oxidative stress levels in MPHs were exacerbated by the use of Nrf2 inhibitors and Keap1 overexpression,which promoted apoptosis.Conclusion Res attenuates he-patic inflammation and oxidative stress in rheumatoid arthritis via the Nrf2/Keap1 pathway.

Objective To study the relationship between the mandibular bone arch and the dental arch in patients with skeletal Class Ⅱ malocclusion and compare it with the Class Imalocclusion by establishing a 3D digital model.Methods A total of 25 cases with skeletal Class Ⅱ malocclusion and 25 cases with skeletal Class Ⅰ normal occlusion were selected.The mandibular model was scanned and a three-dimensional digital model was set up.After the determination of the WALA ridge and the FA point,the reference plane and coordinate system was established.Four degree polynomial curve fitting was performed with WALA ridge and FA point coordinates to re-present the corresponding basal and dental arch curves.The width difference between the basal arch curve and the dental arch curve was measured and calculated at 3 mm,10 mm,and 18 mm away from the horizontal axis of the coordinate.The differences of basal bone and dental arch width between skeletal Class Ⅱ and skeletal Class Ⅰ malocclusion was compared.Results The width differences be-tween the arch and the dental arch in the anterior,middle and posterior mandibular segments of skeletal Class Ⅱ patients were-1.58 mm,1.80 mm and 3.80 mm,respectively.The width differences between the arch and the dental arch in the anterior,middle and pos-terior mandibular segments of skeletal Class Ⅰ patients were 2.08 mm,2.92 mm and 4.24 mm,respectively.There was a significant difference between skeletal Class Ⅱ and skeletal Class Ⅰ in the anterior and middle segments(P＜0.05),but no significant difference in the posterior segment(P＞0.05).Conclusion In skeletal Class Ⅰ patients,the width of the basal bone is larger than that of the dental arch,and the dental arch was located medial to the basal bone.In skeletal Class Ⅱ patients,the width of the anterior arch is larger than the width of the basal bone,that is,the dental arch is located outside the basal bone.The width difference of the basal arch in skeletal Class Ⅱ is smaller than that in skeletal Class Ⅰ.

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.

Objective:To explore the relationship between the prognostic nutritional index(PNI)and the prevalence of coronary heart disease(CHD)in adults.Methods:A cross-sectional analysis was conducted based on the 2017-2020 National Health and Nutrition Examination Survey(NHANES)database.A total of 12,141 adult participants were initially included and divided into CHD group and control group according to the disease status questionnaire.PNI was calculated using serum albumin level and lymphocyte count.Multivariable logistic regression was applied to explore the association between PNI and the prevalence of CHD in adults.Subgroup analysis was conducted to assess whether this association remained consistent across different populations.A restricted cubic spline model was con-structed to clarify the dose-response relationship between PNI and CHD prevalence in adults.Results:Among the 3,894 adult participants,200(5.14％)had CHD.The PNI level in CHD patients was significantly lower than that of the control group[(49.20±8.59)vs.(51.57±4.80),P＜0.001].Multivariable logistic regression analysis showed that,after adjustment for sex,age,race,marital status,body mass index(BMI),hypertension,diabetes and family history of cardiovascular disease,an increase in PNI was still independently associated with a lower prev-alence of CHD(odds ratio[OR]=0.92,95％CI 0.89～0.94,P＜0.001).The dose-response relationship indica-ted a negative linear correlation between PNI and CHD prevalence(P＜0.001).Subgroup analysis showed that the association between PNI and CHD differed significantly across BMI,hypertension and diabetes subgroups(P for in-teraction＜0.05 or＜0.01).Conclusion:Increasing PNI was significantly associated with a lower prevalence of CHD in adults,and this association was more pronounced in specific high-risk populations,such as those with obe-sity,hypertension,and diabetes.Our findings suggest that maintaining good nutritional status is of great significance in reducing the risk of CHD.

Objective To summarize the clinical features,treatment and prognosis of patients with primary central nervous system lymphoma(PCNSL)with clonal bone marrow B cells,and to explore the influence on clinical diagnosis and treatment.Methods PCNSL patients with clonal bone marrow B cells diagnosed by flow cytometry between Jan 2020 and Jul 2023 at Huashan Hospital of Fudan University were enrolled.The auxiliary examination data of these patients were collected,including complete blood count,routine biochemistry,bone marrow aspiration and biopsy,contrast-enhanced brain MRI,and whole-body PET-CT.Kaplan-Meier was used to draw the survival curve,and relevant literature was reviewed.Results A total of 223 newly diagnosed PCNSL patients were included,187 of whom completed bone marrow puncture and biopsy evaluation.We found clonal bone marrow B cells in 16 of 187 cases(8.56%)by flow cytometry.2 patients showed B lymphoma involving the bone marrow.All patients received a high-dose methotrexate based chemotherapy.The median progression free survival(PFS)of 16 patients with clonal bone marrow B cells was 11.1 months,and the median PFS of 171 patients with normal bone marrow was 12.6 months.There was no significant difference in the PFS between the two groups.Conclusion PCNSL with clonal bone marrow B cells had no specific clinical features,but bone marrow flow cytometry showed clonal B cells.High-dose methotrexate treatment regimen is effective.There was no significant difference in PFS for PCNSL patients with clonal B cells and normal findings in bone marrow.Clonal B cells in bone marrow may be caused by monoclonal B-cell lymphocytosis(MBL),lymphoma involves the bone marrow and the presence of common precursor cells.Bone marrow examination should be performed in the initial evaluation of suspected PCNSL.