Objective To investigate the role and related mechanisms of exosomes derived from mesenchymal stem cells (MSCs) in radiation-induced lung injury (RILI). Methods Human umbilical cord-derived MSCs were isolated and cultured for the extraction and identification of exosomes. Eighteen male SD rats were randomly divided into Control group, RILI group and RILI + exosomes group (EXO group), with 6 rats in each group. Except for Control group, the other groups received a single X-ray dose of 30 Gy to the right lung. Immediately after irradiation, the EXO group was administered 2 × 10⁹ exosomes/kg via tail vein injection. Control group and RILI group were given the same volume of normal saline. Eight weeks post-irradiation, the rats were sacrificed, lung tissue and peripheral venous blood were collected. HE and Masson staining were employed to observe the pathological and fibrotic changes of lung tissue. The levels of serum inflammatory factors IL-6, IFN-γ, TNF-α, and IL-10 were detected by ELISA. RT-qPCR was used to assess the mRNA levels of IL-1β, IL-6, Cdh1, and Col1a1 in lung tissue. The expression levels of Vimentin and TGF-β1 in lung tissue were measured by immunohistochemical staining. The expression levels of AMPK, p-AMPK, and TGF-β1 in lung tissue were detected by Western blot. Results MSC-derived exosomes were successfully extracted and identified. Compared with RILI group, EXO group showed significantly reduced pathological changes of lung inflammation and collagen deposition. The levels of serum inflammatory factors IL-6, INF-γ, and TNF-α were significantly decreased (P < 0.05), and the level of anti-inflammatory factor IL-10 was significantly increased (P < 0.05). The mRNA levels of IL-1β, IL-6, and Col1a1 in lung tissue were significantly decreased (P < 0.05 or P < 0.01), and the mRNA level of Cdh1 was significantly increased (P < 0.05 or P < 0.01). The levels of Vimentin and TGF-β1 in lung tissue were significantly reduced, while p-AMPK level was significantly up-regulated (P < 0.05). Conclusion Exosomes derived from MSCs may alleviate RILI by inhibiting inflammatory responses and regulating epithelial-mesenchymal transition mediated by AMPK/TGF-β1 signaling pathway.

Objective To establish a rat model of Alzheimer's disease (AD) expressing human triple mutant amyloid precursor protein (APP) in the hippocampus, and to provide a model for the study of disease mechanisms and drug development. Methods Twenty-four 12-week-old SPF-grade female SD rats were randomly divided into a blank control group, a virus control group and an experimental group, with eight rats in each group; among them, the experimental group received a stereotaxic injection of adeno-associated virus (AAV) carrying the human triple mutant APP and NanoLuc luciferase genes into the hippocampus. In vivo imaging was used to observe viral expression in the brains of rats in each group, the novel object recognition test was used to assess the recognition memory of the rats in each group, real-time fluorescent quantitative PCR was used to detect the expression level of the APP gene, HE staining was used to examine the brain histopathology, Nissl staining was used to assess the hippocampal lesions, and immunohistochemistry was used to detect the deposition of amyloid β-protein (Aβ). Results In vivo imaging showed that reporter fluorescence was detected in the brains of rats in both experimental and virus control groups. Fluorescence quantitative PCR showed that the expression level of the APP gene was significantly increased in the brains of rats in the experimental group (P<0.01). Novel object recognition test revealed that the recognition memory of rats in the experimental group was significantly reduced compared with that of the blank control group (P<0.01). Six months after recombinant AAV virus infection, HE staining and Nissl staining of brain tissues showed that the number of neurons and Nissl bodies in the CA1 region of the hippocampus in the experimental group was reduced and disorganized; immuno-histochemistry testing of the CA1 region of the hippocampus and the pyramidal cell layer of the experimental group revealed prominent brown deposits, indicating Aβ protein deposition. Conclusion The rat model successfully established by stereotaxic injection and AAV-mediated delivery of human triple mutant APP gene exhibits typical AD features, providing a valuable animal model for studying AD pathology and developing drug therapies targeting Aβ protein deposition.

Objective To establish a rat model of Alzheimer's disease (AD) expressing human triple mutant amyloid precursor protein (APP) in the hippocampus, and to provide a model for the study of disease mechanisms and drug development. Methods Twenty-four 12-week-old SPF-grade female SD rats were randomly divided into a blank control group, a virus control group and an experimental group, with eight rats in each group; among them, the experimental group received a stereotaxic injection of adeno-associated virus (AAV) carrying the human triple mutant APP and NanoLuc luciferase genes into the hippocampus. In vivo imaging was used to observe viral expression in the brains of rats in each group, the novel object recognition test was used to assess the recognition memory of the rats in each group, real-time fluorescent quantitative PCR was used to detect the expression level of the APP gene, HE staining was used to examine the brain histopathology, Nissl staining was used to assess the hippocampal lesions, and immunohistochemistry was used to detect the deposition of amyloid β-protein (Aβ). Results In vivo imaging showed that reporter fluorescence was detected in the brains of rats in both experimental and virus control groups. Fluorescence quantitative PCR showed that the expression level of the APP gene was significantly increased in the brains of rats in the experimental group (P<0.01). Novel object recognition test revealed that the recognition memory of rats in the experimental group was significantly reduced compared with that of the blank control group (P<0.01). Six months after recombinant AAV virus infection, HE staining and Nissl staining of brain tissues showed that the number of neurons and Nissl bodies in the CA1 region of the hippocampus in the experimental group was reduced and disorganized; immuno-histochemistry testing of the CA1 region of the hippocampus and the pyramidal cell layer of the experimental group revealed prominent brown deposits, indicating Aβ protein deposition. Conclusion The rat model successfully established by stereotaxic injection and AAV-mediated delivery of human triple mutant APP gene exhibits typical AD features, providing a valuable animal model for studying AD pathology and developing drug therapies targeting Aβ protein deposition.

The view of youth moral cultivation clearly defines the scope of “morality” and puts forward the requirement of “cultivating morality” for the youth. This is a systematic concept aligned with the main theme of the times and is worth deeply exploring and integrating into the practice of medical ethics education for medical students. With the requirements for innovation and development in medical education， the cultivation of medical students has also been endowed with new connotations. Guided by the connotations of the view of youth moral cultivation and aligned with the objective requirements of medical students’ cultivation， this paper leveraged the core values of traditional Chinese medicine as its entry point. It also explored the realization paths of medical ethics education for medical students that reflect advantages， highlight characteristics， and maintain clear orientation through strengthening the medical ethics education of “dedicated study of medicine，” “honesty and prudence in words and deeds，” “benevolence in heart and skills，” and “doctor-patient trust and harmony，” aiming to cultivate guardians of people’s health with noble medical ethics and superb medical skills.

The present case report described a patient with paroxysmal atrial fibrillation who received pulsed-filed ablation guided by intracardiac echocardiography and 3-dimentional mapping system.All four pulmonary veins were isolated in the procedure,good clinical results and acute safety profile were achieved.The present case reveals the safety and feasibility of the technique for the treatment of paroxysmal atrial fibrillation.

Necrozoospermia is a special type of asthenospermia,in which mass sperm death is commonly seen,with an inci-dence rate of 0.2％-0.4％.Studies on necrospermia are rarely reported.Its etiology is complicated,and its diagnosis and treatment are very difficult.This article focuses on the main etiological factors,pathophysiological mechanism,diagnostic methods and treatment strategies of necrospermia,aiming to provide some reference for andrologists and reproduction physicians,as well as a theoretical guid-ance for intracytoplasmic sperm injection(ICSI)in the treatment of the patients with necrospermia.

AIM To study the secondary metabolites from the endophytic fungi Candida sp.of Berberis atrocarpa Schneid.METHODS The ethyl acetate fraction and petroleum ether fraction from the secondary metabolites of Candida sp.fermentation extract were separated and purified by silica gel,Sephadex LH-20 and preparative liquid chromatography,then the structures of obtained compounds were identified by physicochemical properties and spectral data.RESULTS Eighteen compounds were isolated and identified as 1-phenyl-1,2-ethanediol(1),4-hydroxyphenethyl alcohol(2),4-hydroxybenzoic acid(3),4-hydroxyphenylacetic acid(4),3-hydroxyphenylacetic acid(5),3-methylsulfinyl propionic acid(6),phenylacetic acid(7),(S)-N-nitroso-1-amino-p-hydroxy phenylethanol(8),2-phenylacetamide(9),p-hydroxybenzaldehyde(10),ethyl 2-(4-hydroxyphenyl)acetate(11),dibutyl phthalate(12),5,5'-dimethoxybiphenyl-2,2'-diol(13),3-indolealdehyde(14),N-acetyl-L-phenylalanine(15),9-hydroxy-10E,12Z-octadecadienoic acid(16),9-hydroxy-10E,12E-octadecadienoic acid(17),(6E)-5-methylene-6-tetradecenoic acid(18).CONCLUSION Compounds 1,3-8 and 10-18 are isolated from Candida sp for the first time.

Refractory acute T-lymphoblastic leukemia (T-ALL), which is characterized by a low sensitivity to conventional induction therapy and poor prognosis, poses significant challenges during treatment. This study reported a case of refractory T-ALL patient with mutations in the JAK1, JAK3, and STAT5B genes from Nanjing University’s Gulou Hospital. Following an unsuccessful course of standard VDLP regimen chemotherapy, the treatment was modified to include ruxolitinib in combination with venetoclax and azacitidine. Subsequent to this therapy, the patient achieved bone marrow minimal residual disease (MRD) negativity. Notably, pleural effusion and mediastinal mass significantly improved the post-chest cavity infusion of dexamethasone combined with etoposide at the same stage. The patient also underwent allogeneic hematopoietic stem cell transplantation upon achieving bone marrow remission and was followed up until January 2024. Ruxolitinib combined with venetoclax and azacytidine has shown promising efficacy and safety in treating refractory T-ALL harboring the JAK1, JAK3, and STAT5B mutations, providing a novel therapeutic approach for such patients.

Objective To develop a biological safety protection third-level(BSL-3)laboratory based on folding-modular shelters to solve the problems of the existing laboratories in space and function expansion,large-scale deployment and low-cost transportation.Methods The BSL-3 laboratory was composed of a folding combined shelter module,a ventilation and purification module,a power supply and distribution module,a monitoring and communication module,a control system module and an equipment module.The folding combined shelter module used a leveling base frame as the foundation and a lightweight panel as the enclosure mechanism,and was divided into an auxiliary area and a protection protected area;the ventilation and purification module was made up of an air supply unit and an air exhaust unit,the air supply unit was integrated with a fresh-air air conditioner and the exhaust unit was equipped with a main fan,a standby fan and a bag in/bag out filter;the control system module adopted a supervision mode of decentralized control and centralized management,which executed communication with the data server as the center and Profinet protocol and MODBUS-TCP.Results The BSL-3 laboratory proved to meet the requirements of relevant standards in internal microenvironment,airflow direction,airtightness,working condition and disinfection effect.Conclusion The BSL-3 laboratory is compatible with large-scale transport and deployment and facilitates reliable and safe experiments for epidemic prevention and control and cross-regional support.[Chinese Medical Equipment Journal,2024,45(3):41-46]

Objective:To investigate the impact of serum vitamin A levels on all-cause mortality risk in diabetes patients.Methods:Diabetes patients aged 20 years and above who participated in the US National Health and Nutrition Examination Survey during 2003-2004 and 2005-2006 were enrolled as the study population,with death data up to 2019 as the endpoint.Cox proportional hazards regression models were employed to calculate the hazard ratios of all-cause mortality in diabetes patients with different serum vitamin A levels,both unadjusted and adjusted for confounders.Restricted cubic spline methods were used to analyze the dose-response relationship between serum vitamin A levels and all-cause mortality risk in diabetes patients.Results:A total of 484 diabetes patients were included,with a median follow-up period of 13.7 years,during which 211 deaths occurred.Cox proportional hazards analysis showed that compared to the lowest quartile of serum vitamin A,higher quartiles of serum vitamin A were not associated with all-cause mortality risk in diabetes patients without adjusting for confounders.However,after adjusting for confounders,higher quartiles of serum vitamin A significantly reduced the all-cause mortality risk.The dose-response analysis indicated a significantly increased risk of all-cause mortality in diabetes patients with lower serum vitamin A levels.As the vitamin A levels increased,the mortality risk gradually decreased.A significant reduction in all-cause mortality risk was observed when serum vitamin A levels were between 2.17 and 2.50 μmol/L.Beyond this range,there was a tendency for increased all-cause mortality risk with further increases in vitamin A levels.Conclusion:Lower serum vitamin A levels increase the all-cause mortality risk in diabetes patients,while moderate serum vitamin A levels help reduce the all-cause mortality risk in diabetes patients.