BACKGROUND:Exosomes derived from mesenchymal stem cells play pivotal roles in cell communication and epigenetic regulation due to their low immunogenicity and targeted delivery effects,and have been clinically applied in the treatment of various diseases.OBJECTIVE:To review the isolation,purification,identification methods,and application progress of mesenchymal stem cell-derived exosomes,and to facilitate the development of large-scale preparation techniques and clinical translation of mesenchymal stem cell-derived exosomes.METHODS:The Chinese search terms"exosome,mesenchymal stem cells,isolation,purification,characterization,clinical application"and the English search terms"exosome,extracellular vesicles,mesenchymal stem cells,isolation,characterization,application"were used to search the literature published before September 2024 in CNKI,PubMed,and Web of Science databases.Articles with poor relevance to the topic,outdated,or duplicated content were excluded,and finally,109 articles were included for review.RESULTS AND CONCLUSION:(1)This paper reviews recent methods for isolating and purifying exosomes,comparing the characteristics of ultracentrifugation,ultrafiltration,size-exclusion chromatography,polymer precipitation,immunoaffinity,microfluidic methods,and other novel approaches based on their underlying principles.(2)Methods for identifying exosomes can be categorized into physical and biochemical analyses,characterizing exosomes based on their shape,size,and characteristic proteins.(3)Mesenchymal stem cell-derived exosomes have broad applications in multiple fields such as medical aesthetics,wound repair,and cancer treatment,due to their immune-regulatory properties and ability to cross biological barriers.(4)The clinical translation of exosomes faces challenges due to their complex structure,lack of universal isolation techniques,and poor stability,making it difficult to achieve in a short period of time.

BACKGROUND:Exosomes derived from mesenchymal stem cells play pivotal roles in cell communication and epigenetic regulation due to their low immunogenicity and targeted delivery effects,and have been clinically applied in the treatment of various diseases.OBJECTIVE:To review the isolation,purification,identification methods,and application progress of mesenchymal stem cell-derived exosomes,and to facilitate the development of large-scale preparation techniques and clinical translation of mesenchymal stem cell-derived exosomes.METHODS:The Chinese search terms"exosome,mesenchymal stem cells,isolation,purification,characterization,clinical application"and the English search terms"exosome,extracellular vesicles,mesenchymal stem cells,isolation,characterization,application"were used to search the literature published before September 2024 in CNKI,PubMed,and Web of Science databases.Articles with poor relevance to the topic,outdated,or duplicated content were excluded,and finally,109 articles were included for review.RESULTS AND CONCLUSION:(1)This paper reviews recent methods for isolating and purifying exosomes,comparing the characteristics of ultracentrifugation,ultrafiltration,size-exclusion chromatography,polymer precipitation,immunoaffinity,microfluidic methods,and other novel approaches based on their underlying principles.(2)Methods for identifying exosomes can be categorized into physical and biochemical analyses,characterizing exosomes based on their shape,size,and characteristic proteins.(3)Mesenchymal stem cell-derived exosomes have broad applications in multiple fields such as medical aesthetics,wound repair,and cancer treatment,due to their immune-regulatory properties and ability to cross biological barriers.(4)The clinical translation of exosomes faces challenges due to their complex structure,lack of universal isolation techniques,and poor stability,making it difficult to achieve in a short period of time.

Skeletal muscle atrophy refers to a pathological condition characterized by muscle fiber atrophy as well as decreased muscle mass and muscle strength induced by various predisposing factors. It falls under the category of “flaccidity syndrome” in traditional Chinese medicine， and its pathogenesis is mainly associated with disturbed protein homeostasis， mitochondrial dysfunction and oxidative stress injury. Active ingredients of traditional Chinese medicine exerts synergistic regulatory effects via multiple pathways， thus possessing unique advantages in the clinical prevention and treatment of skeletal muscle atrophy. This paper reviews the mechanisms by which active ingredients of traditional Chinese medicine alleviate skeletal muscle atrophy. Existing studies have demonstrated that such active ingredients can ameliorate skeletal muscle atrophy through multiple approaches： regulating protein metabolic balance （geniposide， matrine， schisandrin A， etc.） and oxidative stress （astragaloside Ⅳ， Gastrodia elata polysaccharide， Angelica sinensis polysaccharide， etc.）， improving mitochondrial function （parthenolide， berberine， curcumin， etc.）， facilitating myogenesis and myogenic differentiation （cucurbitacin Ⅱb， saikosaponin A， saikosaponin D， etc.）， suppressing inflammatory response （ursolic acid， triptolide， emodin， etc.）， ameliorating insulin resistance （akebiasaponin D， etc.）. In the future， active ingredients of traditional Chinese medicine are expected to achieve breakthroughs in clinical treatment for skeletal muscle atrophy， providing novel ideas and strategies for the prevention and treatment of degenerative disorders.

A case of secondary pulmonary infection in a patient with acute exacerbation of chronic obstructive pulmonary disease was admitted.The patient was initially giren piperacillin-tazobactam combined with levofloxacin for anti-infective treatment before the pathogen was identified.lafer,the HRZE anti-tuberculosis regimen was added,but the patient continued to experience high fever,yellow purulent sputum,and dyspnea.Subsequent,bronchoalveolar lavage fluid pathogen metagenomic sequencing revealed Nocardia terpenica.Clinical pharmacists,based on the patient's condition changes and in accordance with relevant guidelines and literature,suggested using various antimicrobial agents,including compound sulfamethoxazole tablets,linezolid glucose injection,amikacin injection combined with imipenem-cilastatin,to manage the patient's intolerance to sulfonamides and the bone marrow suppression induced by linezolid and to provide medication suggestions.The clinician adopted all the suggestions.Through the collaborative efforts of physicians and clinical pharmacists,the patient's condition improved,allowing for discharge with medication.Post-discharge,medication education and follow-up were conducted,leading to successful recovery.In this case,the clinical pharmacist reviewed domestic and international literature on Nocardia terpenica and the characteristics of antimicrobial drugs,and utilized their expertise to assist clinicians in treating rare infection cases,realizing their professional value.

Objective To evaluate the clinical utility of the f-wave to QRS complex amplitude ratio(f/R ratio)in intracardiac electrogram(IC-ECG)-guided positioning of peripherally inserted central catheter(PICC)tips in patients with atrial fibrillation(AF),providing evidence to enhance clinical practice.Methods This study employed a conve-nience sampling method to enroll eligible AF patients admitted to a tertiary hospital in Suzhou from July 2023 to July 2024.During PICC placement,IC-ECG was utilized to monitor f-wave and QRS complex amplitude variations.Following successful catheterization,the f/R ratio was measured,and chest X-ray was performed to confirm the catheter tip position.The accuracy of PICC tip positioning across different f/R ratio ranges was analyzed,and the incidence of arrhythmias was recorded.A receiver operating characteristic curve was constructed to assess the diag-nostic performance of the f/R ratio in PICC tip localization.Results A total of 68 AF patients were included,with f/R ratios ranging from 20.63％to 91.24％.PICC tip positioning accuracy varied significantly across different f/R ratio ranges(P=0.006).The area under the ROC curve(AUC)for f/R ratio in PICC tip positioning was 0.784(P=0.009),with a maximum Youden index of 0.567,an optimal diagnostic threshold of 40.00％,a sensitivity of 81.7％,a speci-ficity of 75.0％,a positive predictive value of 96.1％,and a negative predictive value of 35.3％.No arrhythmias other than AF occurred during the procedure.Conclusion The f/R ratio provides reliable and safe guidance for PICC tip positioning in AF patients.An f/R ratio ≥40％is associated with higher accuracy in identifying the optimal catheter tip position.

Myocardial fibrosis is a serious cause of heart failure and even sudden cardiac death. However, the mechanisms underlying myocardial ischemia-induced cardiac fibrosis remain unclear. Here, we identified that the expression of sterile alpha and TIR motif containing 1 (SARM1), was increased significantly in the ischemic cardiomyopathy patients, dilated cardiomyopathy patients (GSE116250) and fibrotic heart tissues of mice. Additionally, inhibition or knockdown of SARM1 can improve myocardial fibrosis and cardiac function of myocardial infarction (MI) mice. Moreover, SARM1 fibroblasts-specific knock-in mice had increased deposition of extracellular matrix and impaired cardiac function. Mechanically, elevated expression of SARM1 promotes the deposition of extracellular matrix by directly modulating P4HA1. Notably, by using the Click-iT reaction, we identified that the increased expression of ZDHHC17 promotes the palmitoylation levels of SARM1, thereby accelerating the fibrosis process. Based on the fibrosis-promoting effect of SARM1, we screened several drugs with anti-myocardial fibrosis activity. In conclusion, we have unveiled that palmitoylated SARM1 targeting P4HA1 promotes collagen deposition and myocardial fibrosis. Inhibition of SARM1 is a potential strategy for the treatment of myocardial fibrosis. The sites where SARM1 interacts with P4HA1 and the palmitoylation modification sites of SARM1 may be the active targets for anti-fibrosis drugs.

Cardiac fibrosis is characterized by an elevated amount of extracellular matrix (ECM) within the heart. However, the persistence of cardiac fibrosis ultimately diminishes contractility and precipitates cardiac dysfunction. Circular RNAs (circRNAs) are emerging as important regulators of cardiac fibrosis. Here, we elucidate the functional role of a specific circular RNA CELF1 in cardiac fibrosis and delineate a novel feedback loop mechanism. Functionally, circ-CELF1 was involved in enhancing fibrosis-related markers' expression and promoting the proliferation of cardiac fibroblasts (CFs), thereby exacerbating cardiac fibrosis. Mechanistically, circ-CELF1 reduced the ubiquitination-degradation rate of BRPF3, leading to an elevation of BRPF3 protein levels. Additionally, BRPF3 acted as a modular scaffold for the recruitment of histone acetyltransferase KAT7 to facilitate the induction of H3K14 acetylation within the promoters of the Celf1 gene. Thus, the transcription of Celf1 was dramatically activated, thereby inhibiting the subsequent response of their downstream target gene Smad7 expression to promote cardiac fibrosis. Moreover, Celf1 further promoted Celf1 pre-mRNA transcription and back-splicing, thereby establishing a feedback loop for circ-CELF1 production. Consequently, a novel feedback loop involving CELF1/circ-CELF1/BRPF3/KAT7 was established, suggesting that circ-CELF1 may serve as a potential novel therapeutic target for cardiac fibrosis.

A case of secondary pulmonary infection in a patient with acute exacerbation of chronic obstructive pulmonary disease was admitted.The patient was initially giren piperacillin-tazobactam combined with levofloxacin for anti-infective treatment before the pathogen was identified.lafer,the HRZE anti-tuberculosis regimen was added,but the patient continued to experience high fever,yellow purulent sputum,and dyspnea.Subsequent,bronchoalveolar lavage fluid pathogen metagenomic sequencing revealed Nocardia terpenica.Clinical pharmacists,based on the patient's condition changes and in accordance with relevant guidelines and literature,suggested using various antimicrobial agents,including compound sulfamethoxazole tablets,linezolid glucose injection,amikacin injection combined with imipenem-cilastatin,to manage the patient's intolerance to sulfonamides and the bone marrow suppression induced by linezolid and to provide medication suggestions.The clinician adopted all the suggestions.Through the collaborative efforts of physicians and clinical pharmacists,the patient's condition improved,allowing for discharge with medication.Post-discharge,medication education and follow-up were conducted,leading to successful recovery.In this case,the clinical pharmacist reviewed domestic and international literature on Nocardia terpenica and the characteristics of antimicrobial drugs,and utilized their expertise to assist clinicians in treating rare infection cases,realizing their professional value.

Objective To evaluate the clinical utility of the f-wave to QRS complex amplitude ratio(f/R ratio)in intracardiac electrogram(IC-ECG)-guided positioning of peripherally inserted central catheter(PICC)tips in patients with atrial fibrillation(AF),providing evidence to enhance clinical practice.Methods This study employed a conve-nience sampling method to enroll eligible AF patients admitted to a tertiary hospital in Suzhou from July 2023 to July 2024.During PICC placement,IC-ECG was utilized to monitor f-wave and QRS complex amplitude variations.Following successful catheterization,the f/R ratio was measured,and chest X-ray was performed to confirm the catheter tip position.The accuracy of PICC tip positioning across different f/R ratio ranges was analyzed,and the incidence of arrhythmias was recorded.A receiver operating characteristic curve was constructed to assess the diag-nostic performance of the f/R ratio in PICC tip localization.Results A total of 68 AF patients were included,with f/R ratios ranging from 20.63％to 91.24％.PICC tip positioning accuracy varied significantly across different f/R ratio ranges(P=0.006).The area under the ROC curve(AUC)for f/R ratio in PICC tip positioning was 0.784(P=0.009),with a maximum Youden index of 0.567,an optimal diagnostic threshold of 40.00％,a sensitivity of 81.7％,a speci-ficity of 75.0％,a positive predictive value of 96.1％,and a negative predictive value of 35.3％.No arrhythmias other than AF occurred during the procedure.Conclusion The f/R ratio provides reliable and safe guidance for PICC tip positioning in AF patients.An f/R ratio ≥40％is associated with higher accuracy in identifying the optimal catheter tip position.