Age-related sarcopenia is a progressive, systemic skeletal muscle disorder associated with aging. It is primarily characterized by a significant decline in muscle mass, strength, and physical function, rather than being an inevitable consequence of normal aging. Despite ongoing research, there is still no globally unified consensus among physicians regarding the diagnostic criteria and clinical indicators of this condition. Nonetheless, regardless of the diagnostic standards applied, the prevalence of age-related sarcopenia remains alarmingly high. With the global population aging at an accelerating rate, its incidence is expected to rise further, posing a significant public health challenge. Age-related sarcopenia not only markedly increases the risk of physical disability but also profoundly affects patients’ quality of life, independence, and overall survival. As such, the development of effective prevention and treatment strategies to mitigate its dual burden on both societal and individual health has become an urgent and critical priority. Skeletal muscle regeneration, a vital physiological process for maintaining muscle health, is significantly impaired in age-related sarcopenia and is considered one of its primary underlying causes. Skeletal muscle satellite cells (MSCs), also known as muscle stem cells, play a pivotal role in generating new muscle fibers and maintaining muscle mass and function. A decline in both the number and functionality of MSCs is closely linked to the onset and progression of sarcopenia. This dysfunction is driven by alterations in intrinsic MSC mechanisms—such as Notch, Wnt/β‑Catenin, and mTOR signaling pathways—as well as changes in transcription factors and epigenetic modifications. Additionally, the MSC microenvironment, including both the direct niche formed by skeletal muscle fibers and their secreted cytokines, and the indirect niche composed of extracellular matrix proteins and various cell types, undergoes age-related changes. Mitochondrial dysfunction and chronic inflammation further contribute to MSC impairment, ultimately leading to the development of sarcopenia. Currently, there are no approved pharmacological treatments for age-related sarcopenia. Nutritional intervention and exercise remain the cornerstone of therapeutic strategies. Adequate protein intake, coupled with sufficient energy provision, is fundamental to both the prevention and treatment of this condition. Adjuvant therapies, such as dietary supplements and caloric restriction, offer additional therapeutic potential. Exercise promotes muscle regeneration and ameliorates sarcopenia by acting on MSCs through various mechanisms, including mechanical stress, myokine secretion, distant cytokine signaling, immune modulation, and epigenetic regulation. When combined with a structured exercise regimen, adequate protein intake has been shown to be particularly effective in preventing age-related sarcopenia. However, traditional interventions may be inadequate for patients with limited mobility, poor overall health, or advanced sarcopenia. Emerging therapeutic strategies—such as miRNA mimics or inhibitors, gut microbiota transplantation, and stem cell therapy—present promising new directions for MSC-based interventions. This review comprehensively examines recent advances in MSC-mediated muscle regeneration in age-related sarcopenia and systematically discusses therapeutic strategies targeting MSC regulation to enhance muscle mass and strength. The goal is to provide a theoretical foundation and identify future research directions for the prevention and treatment of this increasingly prevalent condition.

Objective:To understand the major cognition, major choice motivation and the relationship between the two of medical students, and provide references and suggestions for the selection of talents in various majors of medical schools and the effective development of enrollment work.Methods:This study selected undergraduates of Batch 2019 from Peking University Health Science Center as the survey objects, conducted a questionnaire survey on their major cognition, major choice motivation and influencing factors, and used principal component analysis and Spearman rank correlation analysis.Results:The study found that the major cognition scores of 640 undergraduates of Batch 2019 from Peking University Health Science Center were clinical medicine (3.24±0.89) > stomatology (2.89±1.00) > basic medicine (2.66±1.02) > pharmacy (2.54±0.97) > preventive medicine (2.29±0.93) > nursing medicine (2.21±0.99) > medical laboratory (1.98±0.95) > medical English (1.95±0.93). Six major motivation factors for professional choice were school and professional strength, professional learning and job prospects, own factors, Peking University sentiments and the influence of others, medical factors, school policies, and the contribution rates were 34.60%, 12.97%, 7.42%, 6.00%, 5.59% and 5.37%, respectively. Major cognition scores and major choice motivation factors were positively correlated with each other to some extent.Conclusions:At present, students' major cognition level of medical majors still has a large room for improvement, and the motivational factors of major choice are more complicated, among which "the school and professional strength" and "the prospects of study and work" are important factors. Medical schools should focus on strengthening major publicity, improving students' major cognition, attracting aspiring students to apply for medical majors from many aspects, and improving the training quality of medical professionals.

Objective To monitor the susceptibility of clinical isolates to antimicrobial agents in tertiary hospitals in major regions of China in 2022.Methods Clinical isolates from 58 hospitals in China were tested for antimicrobial susceptibility using a unified protocol based on disc diffusion method or automated testing systems.Results were interpreted using the 2022 Clinical &Laboratory Standards Institute(CLSI)breakpoints.Results A total of 318 013 clinical isolates were collected from January 1,2022 to December 31,2022,of which 29.5％were gram-positive and 70.5％were gram-negative.The prevalence of methicillin-resistant strains in Staphylococcus aureus,Staphylococcus epidermidis and other coagulase-negative Staphylococcus species(excluding Staphylococcus pseudintermedius and Staphylococcus schleiferi)was 28.3％,76.7％and 77.9％,respectively.Overall,94.0％of MRSA strains were susceptible to trimethoprim-sulfamethoxazole and 90.8％of MRSE strains were susceptible to rifampicin.No vancomycin-resistant strains were found.Enterococcus faecalis showed significantly lower resistance rates to most antimicrobial agents tested than Enterococcus faecium.A few vancomycin-resistant strains were identified in both E.faecalis and E.faecium.The prevalence of penicillin-susceptible Streptococcus pneumoniae was 94.2％in the isolates from children and 95.7％in the isolates from adults.The resistance rate to carbapenems was lower than 13.1％in most Enterobacterales species except for Klebsiella,21.7％-23.1％of which were resistant to carbapenems.Most Enterobacterales isolates were highly susceptible to tigecycline,colistin and polymyxin B,with resistance rates ranging from 0.1％to 13.3％.The prevalence of meropenem-resistant strains decreased from 23.5％in 2019 to 18.0％in 2022 in Pseudomonas aeruginosa,and decreased from 79.0％in 2019 to 72.5％in 2022 in Acinetobacter baumannii.Conclusions The resistance of clinical isolates to the commonly used antimicrobial agents is still increasing in tertiary hospitals.However,the prevalence of important carbapenem-resistant organisms such as carbapenem-resistant K.pneumoniae,P.aeruginosa,and A.baumannii showed a downward trend in recent years.This finding suggests that the strategy of combining antimicrobial resistance surveillance with multidisciplinary concerted action works well in curbing the spread of resistant bacteria.

This study was to determine the expression of the cell cycle inhibitor p21 in alveolar macrophages (AMs) and the role of p21 in activation of AMs in bleomycin (BLM) injury-induced lung fibrosis. The expression of CD206 in AMs was measured by immunofluorescence staining. Reverse transcription-polymerase chain reaction (RT-PCR) assay was used to detect the expression of macrophage activation markers. The coculture assay for macrophage and fibroblast was employed to explore the effect of macrophage on fibroblast activation. Immunofluorescence staining and western blotting assay were adopted to detect the expression of p21 in fibrotic tissues. AMs were treated with p21 knockdown or overexpression virus, RT-PCR and the co-culture system were used to explore the effect of p21 expression on macrophage activation. The Experimental Animal Welfare Ethics Committee of the Institute of Materia Medica, Chinese Academy of Medical Sciences and Peking Union Medical College approved all of the protocols for this research. Our results showed that the expression of CD206 and macrophage activation markers was increased in AMs from fibrotic mice, indicating that AMs from fibrotic mice were associated with a profibrotic phenotype. Moreover, the expression of p21 was upregulated in AMs after BLM treatment. Depletion of p21 suppressed macrophage activation, while overexpression of p21 promoted the profibrotic phenotype of AMs from healthy mice. In summary, BLM injury causes the progressive accumulation of p21 in AMs, which induces the production of a number of profibrotic factors promoting the development of pulmonary fibrosis.

OBJECTIVES: Since the outbreak of coronavirus disease 2019 (COVID-19), it has spread rapidly in China and many other countries. The rapid increase in the number of cases has caused widespread panic among people and has become the main public health problem in the world. Severe patients often have difficult breathing and/or hypoxemia after 1 week of onset. A few critically ill patients may not only rapidly develop into acute respiratory distress syndrome, but also may cause coagulopathy, as well as multiple organs failure (such as heart, liver and kidney) or even death. This article is to analyze the predictive role of clinical features in patients with COVID-19 for severe disease, so as to help doctor monitor the severity-related features, restrain the disease progress, and provide a reference for improvement of medical treatment. METHODS: The clinical data of 208 patients with COVID-19 who were isolated and treated in Changsha Public Health Treatment Center from January 17, 2020 to March 14, 2020 were collected. All patients were the mild and ordinary adult patients on admission, including 105 males and 103 females from 19 to 84 (median age 44) years old. According to the "Program for the diagnosis and treatment of novel coronavirus (COVID-19) infected pneumonia (Trial version 7)" issued by the General Office of National Health Committee and Office of State Administration of Traditional Chinese Medicine as the diagnostic and typing criteria. According to progression from mild to severe disease during hospitalization, the patients were divided into a mild group (=183) and a severe transformation group (=25). The clinical features such as age, underlying disease, blood routine, coagulation function, blood biochemistry, oxygenation index, and so on were analyzed. Among them, laboratory tests included white blood cell (WBC), lymphocytes (LYM), neutrophil (NEU), hemoglobin (Hb), platelet (PLT), prothrombin time (PT), plasma fibrinogen (Fib), activated partial prothrombin time (APTT), thrombin time (TT), -dimer, total bilirubin (TBIL), albumin (ALB), alanine aminotransferase (ALT), aspartate aminotransferase (AST), blood urea nitrogen (BUN), serum creatinine (Cr), creatine kinase (CK), creatine kinase isoenzyme-MB (CK-MB), lactate dehydrogenase (LDH), C-reactive protein (CRP), and oxygen partial pressure in arterial blood. Partial pressure of oxygen in arterial blood/fractional concentration of inspiratory oxygen (PaO/FiO) was calculated. The variables with statistical significance were analyzed by logistic regression analysis. RESULTS: Patients in the severe transformation group had more combined underlying diseases than those in the mild group (<0.05). From the perspective of disease distribution, patients in the severe transformation group had more combined hypertension (<0.05). In the severe transformation group, PT was significantly longer, the levels of Fib, ALT, AST, CK, LDH, and CRP were significantly higher than those in the mild group (<0.05 or <0.001), while LYM, ALB, and PaO/FiO were significantly lower than those in the mild group (<0.05 or <0.001). Logistic regression analysis was performed on clinical features with statistically significant differences. Combined with hypertension, LYM, PT, Fib, ALB, ALT, AST, CK, LDH, and CRP as independent variables, and having severe disease or not was the dependent variable. The results show that combined hypertension, decreased LYM, longer PT, and increased CK level were independent risk factors that affected the severity of COVID-19 (<0.05). CONCLUSIONS The patients with mild COVID-19 who are apt to develop severe diseases may be related to combined hypertension, decreased LYM, and longer PT, and increased CK level. For the mild patients with these clinical features, early intervention may effectively prevent the progression to severe diseases.
Adult ; Aged ; Aged, 80 and over ; Betacoronavirus ; China ; Coronavirus Infections ; diagnosis ; physiopathology ; Disease Progression ; Female ; Hospitalization ; Humans ; Male ; Middle Aged ; Pandemics ; Pneumonia, Viral ; diagnosis ; physiopathology ; Retrospective Studies ; Young Adult

Objctive To investigate the protective effect of resveratrol on oxidative stress damage of follicular granulosa cells induced by hydrogen peroxide. Methods Granulosa cells were collected from the follicular fluid of in vitro fertilization(IVF) patients after oocyte retrieval and cultured. The cultured granulosa cells were divided into four groups: control group, injury model group, 10 μmol / L resveratrol group and 50 μmol / L resveratrol group. Cell viability was determined by CCK-8 assay, malondialdehyde(MDA) content by thiobarbituric(TBA) assay, superoxide dismutase(SOD) level by water soluble tetrazdium-1(WST-1) assay, apoptosis by AnnexinV-FITC / PI double-staining flow cytometry, Bcl-2 and Caspase-3 protein expression by Western blotting, and progesterone secretion by competitive ELISA. Resutls Compared with the control group, the cell viability, SOD level, Bcl-2 protein expression and progesterone secretion were significantly decreased in the injury model group, while MDA content, apoptosis rate and Caspase-3 apoptotic protein expression were significantly increased (P<0. 05) . Compared with the injury model group, the 10 μmol / L resveratrol group showed no statistically significant differences in various parameters; however, the cell viability, SOD level, progesterone secretion, and Bcl-2 and silent information regulator factor 2 related enzyme 1(SIRT1) protein expression were significantly increased, and the MDA content, apoptosis rate, and Caspase-3 apoptotic protein expression were significantly decreased in the 50 μmol / L resveratrol group (P < 0. 05) . Conclusion 50 μmol / L resveratrol can increase the activity of SIRT1, enhance the anti-oxidation and anti-apoptosis ability of granulosa cells and improve the function of granulosa cells.

AIM:To explore whether there is synergistic effect of recombinant human endostatin ( rh-Endo ) and paclitaxel (Pac) in the time window of vascular normalization and the role of magnetic resonance imaging (MRI) in early assessment of chemotherapy by observing the response of human triple -negative breast cancer ( TNBC) to Pac after vascular normalization in nude mice .METHODS:The human TNBC MDA-MB-231 cells were planted in the subcutaneous region of right lower abdomen of BALB/c-nu female nude mice .These nude mice were randomly divided into 4 groups (n=7).rh-Endo was given for 17 consecutive days in rh-Endo group and rh-Endo+Pac group.Pac was given on the 6th and 12th days in Pac group and rh-Endo+Pac group.The dosage of both drugs was 10 mg· kg-1· d-1(ip).On the day before the treatment and the 5th, 11th and 17th days after treatment, all the transplanted tumors were examined by MRI . All the mice were killed by cervical dislocation and their transplanted tumors were taken down for examinations after the last MRI on the 17th day.The changes of pathology, immunohistochemisty, microvessel density (MVD) and Ki67 expression were measured.RESULTS:On the 17th day, the volume of transplanted tumor in rh-Endo+Pac group was smaller than that in model group and rh-Endo group ( P<0.05 ) , and no difference between rh-Endo+Pac group and Pac group was found.On the 17th day, the tumor inhibitory rates in rh-Endo group, Pac group and rh-Endo+Pac group were 14.61%, 39.08%and 54.79%, respectively.The slow diffusion coefficient in Pac group was increased compared with model group , while it was decreased compared with rh-Endo+Pac group (P<0.05).No distant metastatic lesion in the tumor-bearing mice was observed .The necrotic rates in rh-Endo+Pac group and Pac group were higher than those in model group and rh-Endo group.The MVD in model group was higher than that in the other 3 groups.The MVD in rh-Endo+Pac group was decreased compared with Pac group and rh-Endo group .The Ki67 level in rh-Endo+Pac group was decreased compared with rh-Endo group , and no difference between rh-Endo+Pac group and Pac group was detected .CONCLUSION:In the time window of vascular normalization , the combination of Pac and rh-Endo has a significant antitumor effect on TNBC , but this study did not observe a significant synergistic effect of the 2 drugs.The change of slow diffusion coefficient can predict the therapeutic effect in advance .

Background and purpose:Postoperative sore throat (POST) is one of the common complaints of patients after radical thyroidectomy. Tracheal intubation is the main cause of POST. This study compared the effect of intubation with visual endoscopy and general laryngoscope on POST in patients undergoing radical thyroidectomy. Methods:One hundred patients (18-60 years, ASAⅠ-Ⅱ) undergoing elective radical thyroidectomy were randomized into two groups:patients in group A (n=50) were intubated with visual endoscope while patients in group B (n=50) were intubated with general laryngoscope. Endotracheal tube cuffs pressure was maintained at 20mmHg in all patients. Visual analogue scale (VAS) and Bruggrmann comfort scale (BCS) were recorded at the time points of 1, 6 and 24 h after extubation. Results:Compared with group B, the incidence of POST in group A was signifcantly reduced (42%vs 64%, P=0.027). The VAS of group A was lower than that of group B (3.05±1.56 vs 4.25±1.30, 3.05±1.56 vs 4.01±1.98, 2.72±1.77 vs 3.31±1.12) (P<0.05). The BCS of group A was higher than that of group B (0.99±0.46 vs 0.69±0.30, 1.95±0.47 vs 1.51±0.58, 2.82±0.87 vs 2.31±0.72) (P<0.05). Conclusion:Using visual endoscopic intubation can reduce the incidence of the POST in patients undergoing radical thyroidectomy.

Objective To assess the safety and efficacy of balloon dilation of pulmonary valve stenosis with 10 F domestic balloon catheter in children ≥ 10 kg. Methods From May 2009 to June 2014, eighty-three consecutive children with weight ≥ 10 kg and age of (4.5±2.8)(ranged from 1-12) years underwent percutaneous balloon pulmonary valvoloplasty(PBPV) with 10 F domestic balloon catheter. Indication for treatment, procedural details, catheterization data, complication rate, peak-to-peak systolic gradient across the valve and pulmonary insufficiency on echocardiography were respectively analyzed. Forty-four patients were followed up 6-44 months after procedure. Results All procedures were completed successfully. The peak-to-peak systolic gradient across the pulmonary valve decreased from (67.7±26.2) mmHg to (15.4±11.6) mmHg (P < 0.01) immediately after PBPV. Two patients developed reactive infundibular spasm after dilation. They were relieved at 6 months post PBPV. No patient had severe pulmonary insufficiency, tricuspid regurgitation or reintervetion. Conclusions PBPV with 10 F domestic balloon catheter in children with weight≥10 kg is a safe and effective method.

OBJECTIVETo explore the relationship between the polymorphisms of DNA repair gene (XRCC1 194, 280 and 399) and the chromosomal damage induced by benzene.

METHODSThe chromosomal damage of the peripheral lymphocytes in 459 workers occupationally exposed to benzene and 88 non-exposed controls were detected with cytokinesis-block micronucleus (CBMN) assay. PCR-RFLP technique was used to measure polymorphisms in XRCC1 194, 280 and 399.

RESULTSIt was found that the MN frequency (2.12‰ ± 1.88‰) of the exposed group was significantly higher than that (1.19‰ ± 1.68‰) of the control group (P < 0.05), in the exposed group, the MN frequency (3.00‰ ± 2.76‰) of older workers (> 35 years) was significantly higher than that (2.02‰ ± 1.71‰) of younger workers (≤ 35 years) (P < 0.05). The effect of genetic polymorphisms of XRCC1 on CBMN was not found. The haplotypes AAA/BAA, AAB/AAB, ABA/ABA, ABB/ABB could associated with the increased frequencies of total micronucleus (P < 0.05).

CONCLUSIONBenzene exposure could result in chromosome damage. Age of workers and diplotypes of XRCC1 could associated with chromosomal damage induced by benzene.

Adult ; Benzene ; adverse effects ; DNA Damage ; drug effects ; genetics ; DNA-Binding Proteins ; genetics ; Humans ; Micronuclei, Chromosome-Defective ; Micronucleus Tests ; Occupational Exposure ; Polymorphism, Single Nucleotide ; X-ray Repair Cross Complementing Protein 1 ; Young Adult