ObjectiveTo explore the mechanism by which Yizhi Qingxin prescription improves mitochondrial dysfunction in Alzheimer's disease （AD） through regulating mitochondrial Ca²⁺ homeostasis and kinetic balance based on the protein kinase A （PKA）/calcineurin （CaN） signaling pathway. MethodsSixty three-month-old amyloid precursor protein （APP）/presenilin 1 （PS1） double transgenic mice were randomly divided into a model group， a donepezil group（0.65 mg·kg^-1）， a low-dose Yizhi Qingxin prescription group （YQF-L，2.6 g·kg^-1）， a medium-dose Yizhi Qingxin prescription group （YQF-M，5.2 g·kg^-1）， and a high-dose Yizhi Qingxin prescription group （YQF-H，10.4 g·kg^-1）， with 12 mice in each group. Twelve C57BL/6J mice with the same genetic background served as a normal group. Each treatment group received gavage administration daily， with the model and normal groups receiving equal volume of physiological saline. Intervention continued for 12 consecutive weeks. The learning and memory abilities of the mice were assessed using the novel object recognition （NOR） and Morris water maze （MWM） tests. Hematoxylin-eosin （HE）/Nissl staining was used to observe histopathological changes in the hippocampus. Transmission electron microscopy （TEM） was used to observe mitochondrial ultrastructure. Fluo-4 acetoxymethyl ester （Fluo-4 AM） Ca²⁺ probe was used to measure intracellular Ca²⁺ concentration in brain tissue. Western blot was used to determine the protein expression of PKA， CaN， sodium/calcium/lithium exchanger （NCLX）， mitochondrial calcium uniporter （MCU）， calmodulin （CaM）， dynamin-related protein 1 （Drp1）， and phosphorylated dynamin-related protein 1 （serine 637 site） ［p-Drp1（S637）］ in the hippocampus. Real-time quantitative polymerase chain reaction （Real-time PCR） was used to measure the expression of PKA， CaN， CaM， NCLX， MCU， and Drp1 mRNAs. ResultsCompared with those in the normal group， the recognition index （RI） of the model group decreased （P0.01）， and the number of crossings through the original platform area， the duration of stay in the target quadrant， and the distance were reduced （P0.01）. The protein expression of PKA， NCLX， and p-DRP1 （ser637） significantly decreased （P0.05）， and the mRNA expression of PKA and NCLX significantly decreased （P0.05）. The escape latency （EL） was prolonged （P0.05）， and the intracellular Ca²⁺ level significantly increased （P0.01）. The protein expression of CaN， CaM， MCU， and Drp1， as well as the mRNA expression of CaN， MCU， and Drp1， significantly increased （P0.05）. After intervention with Donepezil and Yizhi Qingxin prescription， compared with that in the model group， the RI of the treatment group significantly increased （P0.05）， and the number of crossings through the platform and the duration of stay in the target quadrant significantly increased （P0.05）. The protein expression of PKA， NCLX， and p-Drp1 （ser637） and the mRNA expression of PKA and NCLX significantly increased （P0.05）. On the 4th and 5th days， the EL was shortened （P0.05）， and the intracellular Ca²⁺ level decreased （P0.05）. The protein expression of CaN， CaM， MCU， and Drp1 and the mRNA expression of CaN， MCU， and Drp1 significantly decreased （P0.05）. ConclusionYizhi Qingxin prescription regulates the PKA/CaN pathway， upregulates the expression of PKA， NCLX， and p-Drp1 （ser637） proteins， reduces the expression of CaN， CaM， MCU， and Drp1 proteins， and regulates Ca²⁺ homeostasis and mitochondrial dynamic balance， thereby enhancing the spatial learning and memory abilities of AD mice.

ObjectiveTo explore the mechanism by which Yizhi Qingxin prescription improves mitochondrial dysfunction in Alzheimer's disease （AD） through regulating mitochondrial Ca²⁺ homeostasis and kinetic balance based on the protein kinase A （PKA）/calcineurin （CaN） signaling pathway. MethodsSixty three-month-old amyloid precursor protein （APP）/presenilin 1 （PS1） double transgenic mice were randomly divided into a model group， a donepezil group（0.65 mg·kg^-1）， a low-dose Yizhi Qingxin prescription group （YQF-L，2.6 g·kg^-1）， a medium-dose Yizhi Qingxin prescription group （YQF-M，5.2 g·kg^-1）， and a high-dose Yizhi Qingxin prescription group （YQF-H，10.4 g·kg^-1）， with 12 mice in each group. Twelve C57BL/6J mice with the same genetic background served as a normal group. Each treatment group received gavage administration daily， with the model and normal groups receiving equal volume of physiological saline. Intervention continued for 12 consecutive weeks. The learning and memory abilities of the mice were assessed using the novel object recognition （NOR） and Morris water maze （MWM） tests. Hematoxylin-eosin （HE）/Nissl staining was used to observe histopathological changes in the hippocampus. Transmission electron microscopy （TEM） was used to observe mitochondrial ultrastructure. Fluo-4 acetoxymethyl ester （Fluo-4 AM） Ca²⁺ probe was used to measure intracellular Ca²⁺ concentration in brain tissue. Western blot was used to determine the protein expression of PKA， CaN， sodium/calcium/lithium exchanger （NCLX）， mitochondrial calcium uniporter （MCU）， calmodulin （CaM）， dynamin-related protein 1 （Drp1）， and phosphorylated dynamin-related protein 1 （serine 637 site） ［p-Drp1（S637）］ in the hippocampus. Real-time quantitative polymerase chain reaction （Real-time PCR） was used to measure the expression of PKA， CaN， CaM， NCLX， MCU， and Drp1 mRNAs. ResultsCompared with those in the normal group， the recognition index （RI） of the model group decreased （P0.01）， and the number of crossings through the original platform area， the duration of stay in the target quadrant， and the distance were reduced （P0.01）. The protein expression of PKA， NCLX， and p-DRP1 （ser637） significantly decreased （P0.05）， and the mRNA expression of PKA and NCLX significantly decreased （P0.05）. The escape latency （EL） was prolonged （P0.05）， and the intracellular Ca²⁺ level significantly increased （P0.01）. The protein expression of CaN， CaM， MCU， and Drp1， as well as the mRNA expression of CaN， MCU， and Drp1， significantly increased （P0.05）. After intervention with Donepezil and Yizhi Qingxin prescription， compared with that in the model group， the RI of the treatment group significantly increased （P0.05）， and the number of crossings through the platform and the duration of stay in the target quadrant significantly increased （P0.05）. The protein expression of PKA， NCLX， and p-Drp1 （ser637） and the mRNA expression of PKA and NCLX significantly increased （P0.05）. On the 4th and 5th days， the EL was shortened （P0.05）， and the intracellular Ca²⁺ level decreased （P0.05）. The protein expression of CaN， CaM， MCU， and Drp1 and the mRNA expression of CaN， MCU， and Drp1 significantly decreased （P0.05）. ConclusionYizhi Qingxin prescription regulates the PKA/CaN pathway， upregulates the expression of PKA， NCLX， and p-Drp1 （ser637） proteins， reduces the expression of CaN， CaM， MCU， and Drp1 proteins， and regulates Ca²⁺ homeostasis and mitochondrial dynamic balance， thereby enhancing the spatial learning and memory abilities of AD mice.

Objective To elucidate the application scope and delineate the criteria of dobutamine stress echocardiography (DSE) in assessing surgical risk associated with valvular heart diseases in patients presenting with reduced left ventricular ejection fraction (LVEF). Methods This retrospective analysis encompassed data from patients with reduced LVEF (LVEF<40%) who underwent DSE prior to valvular heart surgery at the Valvular Surgery Center of Beijing Anzhen Hospital between May 2016 and September 2024. Patients were stratified based on the terminal dose of dobutamine into two cohorts: a limited dose group [receiving a maximum dobutamine dose of <5 µg/(kg·min) due to concomitant conditions such as suspected atrial thrombus, aortic dilation, or previous myocardial infarction] and a non-limited dose group (where dosage was adjusted to either achieve the maximum positive standard or the maximal dose tolerable by the patient). Within the non-limited dose group, patients were further classified into positive and negative response groups. The positive response post DSE was defined based on the following criteria: LVEF≥55% (the maximum positive standard), LVEF<55% but with a 5% improvement (the minimum positive standard) from resting situation, aortic maximum velocity (AVmax)≥400 cm/s, or mean pressure gradient (meanPG)≥40 mm Hg, latter two applicable only to patients with aortic stenosis. Clinical indicators were compared in the three groups. Results A total of 99 patients were enrolled, aged 35 to 87 years, with an average age of (61.7±10.1) years. The number of males was significantly higher than that of females (3:1). There were 61 (61.6%) patients undergoing aortic valve surgery, 25 (25.3%) undergoing mitral valve surgery, and 13 (13.1%) undergoing combined aortic and mitral valve surgery. Nineteen (19.2%) patients experienced adverse symptoms such as palpitations, head and face numbness, dizziness, chest tightness post DSE. Additionally, new-onset or aggravated ventricular premature ventricular contractions were in 40 (40.4%) patients. All above symptoms and signs resolved minutes after cessation of the test. No severe adverse events necessitating oxygen therapy or emergency intervention occurred. Among the 93 patients in the non-limited dose group, 86 were classified in the positive response group and 7 in the negative response group. The left ventricular end diastolic diameter, left ventricular end systolic diameter, and LVEF in the positive group all showed significant improvement compared to preoperative values, and were also significantly better than those in the negative group (P<0.05). All 7 patients with negative DSE results underwent interventional surgery, which was significantly different from the positive group (36 patients, 41.9%). In the limited dose group (n=6), 4 patients with a positive result or a positive trend on DSE underwent median sternotomy, 2 received interventional treatment due to a negative response. No significant differences in mortality were observed among the groups (P>0.05). Conclusion Dobutamine stress echocardiography significantly contributes to risk stratification in surgical interventions for patients with valvular heart disease complicated by reduced LVEF. It aids in determining optimal timing and methods for surgery. With comprehensive patient evaluation and controlled dobutamine dosing, the application of DSE can be safely expanded.

Objective To observe the alterations of protein expression of nicotinamide adenine di-nucleotide phosphatase oxidase 4-silent mating type information regulation 2 homolog 1(NOX4-SIRT1)signaling pathway in ApoE-/-mice and C57BL/6J mice induced by high-fat diet.Methods Twenty ApoE-/-mice and 40 C57BL/6J mice,aged of 10 weeks and half male and half female,were randomly divided into a NC group and a HFD group,with 10 mice in each group(ApoE-/-+NC and ApoE-/-+HFD groups,and C57+NC and C57+HFD groups).After 1 week of adaptive feed-ing period,each group was fed with their corresponding diet for subsequent 12 weeks,and then blood samples were collected from the anesthetized orbits and aortic arch tissues were harvested.HE staining and Masson staining were performed to examine the pathological morphology of the aortic arch tissues.The serum levels of TG,TC,HDL-C and LDL-C were measured using an auto-matic biochemical analyzer.The content of ox-LDLC was detected with ELISA,and the contents of ROS,GSH,GPX and NAD+were measured by colorimetry.The expression of SIRT1,p53,p21 and NOX4 was detected by Western blotting.Results Compared with the C57+NC group,the ApoE-/-+NC group showed significant lipid deposition,increased collagen fibers,elevated levels of TC,TG,HDLC,LDL-C,ox-LDL-C and ROS and increased p21 expression level,and obviously decreased contents of GSH,GPX and NAD+(P＜0.05,P＜0.01).Compared with the ApoE-/-+NC group,the ApoE-/-+HFD group showed larger plaque areas,lessened elastic fibers,more col-lagen fibers,increased levels of TC,HDL-C,LDL-C,ox-LDL-C and ROS,and p21 expression level(P＜0.01),and declined expression of GSH,GPX,NAD+and NOX4[6.4±0.8 μmol/L vs 9.6±0.8 μmol/L,242.0±39.0 U/ml vs 362.7±11.1 U/ml,0.61±0.15 nmol/L vs 1.07±0.20 nmol/L,0.26±0.01 vs 0.32±0.03;P＜0.05,P＜0.01[.Conclusion High-fat diet may accelerate vascular aging by elevating lipid and oxidative stress levels,decreasing NAD+and NOX4 expression,ele-vating p21 expression,and thereby activating the NOX4-SIRT1 pathway.

With the development of point-of-care testing(POCT)technology,the demand for pre-hospital applications has gradually increased.Blood glucose,troponin,blood gas analysis and other projects have been gradually carried out in pre-hospital.The development of the above projects has played an important role in the timely diagnosis of critical diseases such as pre-hospital stroke,chest pain,and out-of-hospital cardiac arrest.However,due to the shortcomings of trained professionals and standardized equipment in pre-hospital systems,it is challenging to carry out quality control work such as POCT in-house quality control,comparison,ability verification,etc.,and POCT pre-hospital quality management has shortcomings.In order to improve the quality of POCT and eliminate potential safety hazards,the"expert consensus on POCT pre-hospital quality management standards"was formulated after consultation between pre-hospital and in-hospital experts.The consensus focuses on the establishment of POCT pre-hospital quality management system,management organization,quality control plan formulation and implementation path,personnel access,equipment access,digital intelligence integration and other issues,which can be used by pre-hospital medical emergency institutions at all levels to carry out POCT quality management.

Addressing the challenge of traditional physical/semi physical simulation methods being difficult to achieve full process and full element simulation of extravehicular activities,virtual reality technology is utilized to break through the limitations of physical environments and establish a virtual reality simulation system for extravehicular activities.Based on the application characteristics of space station extravehicular activity engineering,with the goal of improving system practicality and usability,integrating the visual immersion of virtual images,the ontology of real operation,and the consistency of virtual and real space perception,a three-dimensional scene simulation,multi-mode joystick interaction paradigm,continuous operation actions simulation of extravehicular operations,and interactive operation virtual/real space consistency method that were proposed and designed for the realistic visual perception and extravehicular operation.The system has been successfully applied to astronaut training,program validation,joint exercise,and flight control support for sixteen extravehicular activities from SZ-12 to SZ-18.The results showed that the complete reproduction of the static/dynamic realistic comprehensive scene was achieved on the ground for the human-machine operation in the entire process of extravehicular activity,and the system is an essential and important means of ground simulation for extravehicular activity.

Objective:To analyze the application effects of case-based learning (CBL) + Seminar teaching method based on Toulmin model in the education and teaching of clinical medicine innovation class.Methods:A total of 60 students from the clinical medicine innovation class at The Second Affiliated Hospital of Guangzhou Medical University from September 2021 to September 2023 were selected as research objects. These students were divided into control group ( n=30) and research group ( n=30) according to different teaching programs. The traditional teaching method was adopted in the control group, and the CBL + Seminar teaching method based on Toulmin model was adopted in the research group. The two groups were compared in terms of clinical knowledge, clinical skill, and clinical case analysis scores; changes in clinical thinking ability after teaching; and satisfaction with the teaching process. SPSS 22.0 was used for t-test and chi-square test. Results:The research group significantly outperformed the control group in clinical knowledge [(89.59±3.46) points vs. (83.23±3.02) points], clinical skill [(88.87±3.23) points vs. (83.62±3.13) points], and clinical case analysis [(89.73±3.51) points vs. (82.62±3.19) points] ( t=7.58, 6.39, 8.21, P<0.001). The clinical thinking ability after teaching was significantly higher in the research group compared to the control group [(258.49±13.36) points vs. (242.56±13.02) points] ( t=4.67, P<0.001). The overall satisfaction rate of teaching was significantly higher in the research group compared to the control group (100.00% vs. 80.00%, χ2=4.63, P=0.031). Conclusions:The CBL + Seminar teaching method based on Toulmin model can effectively improve student learning performance and clinical thinking ability, demonstrating a promising application value in the education and teaching of clinical medicine innovation class.

ObjectiveTo investigate the mechanism of danshenol A （DA） pretreatment in alleviating myocardial ischemia-reperfusion injury （MIRI） by regulating cardiomyocyte ferroptosis by in vivo and in vitro experiments. MethodsA MIRI model was established in SD rats， and an in vitro oxygen-glucose deprivation/reoxygenation （OGD/R） model was constructed with H9C2 cells. Both models were treated with DA. H9C2 cells were allocated into blank， model （OGD/R）， DA， ferroptosis inducer （erastin）， and ferroptosis inhibitor （Fer-1） groups. Cell viability was assessed by the methyl thiazolyl tetrazolium （MTT） assay. Biochemical assays were performed to measure the superoxide dismutase （SOD）， malondialdehyde （MDA）， glutathione （GSH）， and ferrous ion （Fe²⁺） levels. Dihydroethidium （DHE） fluorescence assay was adopted to quantify the reactive oxygen species （ROS） level. Real-time PCR and Western blot were employed to quantify the mRNA and protein levels， respectively， of prostaglandin-endoperoxide synthase 2 （PTGS2）， glutathione peroxidase 4 （GPX4）， ferritin heavy chain 1 （FTH1）， and acyl-coA synthetase long-chain family 4 （ACSL4）. Sixty SPF-grade healthy male SD rats were randomly assigned to control， model （MIRI）， DA， erastin， and Fer-1 groups. Enzyme-linked immunosorbent assay （ELISA） was adopted to measure the serum levels of cardiac troponin I （cTnI）， lactate dehydrogenase （LDH）， and creatine kinase （CK）. Histopathological changes in the myocardial tissue were observed by hematoxylin-eosin （HE） staining. Cardiomyocyte apoptosis was detected by terminal deoxynucleotidyl transferase-mediated nick end labeling （TUNEL）. The effect of DA on cardiomyocyte ferroptosis were observed and analyzed by in vivo and in vitro experiments. ResultsIn vitro experiment： compared with the blank group， the OGD/R model group showed reduced cell viability， elevated levels of ROS， MDA， and Fe²⁺， up-regulated mRNA and protein levels of ACSL4， lowered levels of SOD and GSH， and down-regulated mRNA and protein levels of PTGS2， GPX4， and FTH1 （P<0.05，P<0.01）. The DA and Fer-1 groups exhibited consistent trends： cell viability， SOD and GSH levels， and the mRNA and protein levels of PTGS2， GPX4， and FTH1 were significantly restored， while the ROS， MDA， and Fe²⁺ levels， and the mRNA and protein levels of ACSL4 were reduced （P<0.05，P<0.01）. In vivo experiment： Compared with the control group， the MIRI model group showed elevated serum levels of cTnI， LDH， and CK， increased cardiomyocyte apoptosis rate， risen levels of ROS， MDA， and Fe²⁺， and up-regulated mRNA and protein levels of ACSL4. However， both DA and Fer-1 groups exhibited reductions in the indicators above （P<0.05）. Compared with the control group， the MIRI model group demonstrated reduced levels of SOD and GSH and down-regulated mRNA and protein levels of PTGS2， GPX4， and FTH1 （P<0.05）. In contrast， both DA and Fer-1 upregulated these indicators （P<0.05）， effectively reversing the trends in the model group. In addition， the MIRI model group showed swelling of cardiomyocytes， disarrangement of cardiac muscle fibers， and massive inflammatory cell infiltration， which were alleviated in the DA and Fer-1 groups. ConclusionDA alleviates MIRI by inhibiting ferroptosis and inflammation， demonstrating therapeutic potential in acute myocardial infarction.

ObjectiveTo investigate the mechanism of danshenol A （DA） pretreatment in alleviating myocardial ischemia-reperfusion injury （MIRI） by regulating cardiomyocyte ferroptosis by in vivo and in vitro experiments. MethodsA MIRI model was established in SD rats， and an in vitro oxygen-glucose deprivation/reoxygenation （OGD/R） model was constructed with H9C2 cells. Both models were treated with DA. H9C2 cells were allocated into blank， model （OGD/R）， DA， ferroptosis inducer （erastin）， and ferroptosis inhibitor （Fer-1） groups. Cell viability was assessed by the methyl thiazolyl tetrazolium （MTT） assay. Biochemical assays were performed to measure the superoxide dismutase （SOD）， malondialdehyde （MDA）， glutathione （GSH）， and ferrous ion （Fe²⁺） levels. Dihydroethidium （DHE） fluorescence assay was adopted to quantify the reactive oxygen species （ROS） level. Real-time PCR and Western blot were employed to quantify the mRNA and protein levels， respectively， of prostaglandin-endoperoxide synthase 2 （PTGS2）， glutathione peroxidase 4 （GPX4）， ferritin heavy chain 1 （FTH1）， and acyl-coA synthetase long-chain family 4 （ACSL4）. Sixty SPF-grade healthy male SD rats were randomly assigned to control， model （MIRI）， DA， erastin， and Fer-1 groups. Enzyme-linked immunosorbent assay （ELISA） was adopted to measure the serum levels of cardiac troponin I （cTnI）， lactate dehydrogenase （LDH）， and creatine kinase （CK）. Histopathological changes in the myocardial tissue were observed by hematoxylin-eosin （HE） staining. Cardiomyocyte apoptosis was detected by terminal deoxynucleotidyl transferase-mediated nick end labeling （TUNEL）. The effect of DA on cardiomyocyte ferroptosis were observed and analyzed by in vivo and in vitro experiments. ResultsIn vitro experiment： compared with the blank group， the OGD/R model group showed reduced cell viability， elevated levels of ROS， MDA， and Fe²⁺， up-regulated mRNA and protein levels of ACSL4， lowered levels of SOD and GSH， and down-regulated mRNA and protein levels of PTGS2， GPX4， and FTH1 （P<0.05，P<0.01）. The DA and Fer-1 groups exhibited consistent trends： cell viability， SOD and GSH levels， and the mRNA and protein levels of PTGS2， GPX4， and FTH1 were significantly restored， while the ROS， MDA， and Fe²⁺ levels， and the mRNA and protein levels of ACSL4 were reduced （P<0.05，P<0.01）. In vivo experiment： Compared with the control group， the MIRI model group showed elevated serum levels of cTnI， LDH， and CK， increased cardiomyocyte apoptosis rate， risen levels of ROS， MDA， and Fe²⁺， and up-regulated mRNA and protein levels of ACSL4. However， both DA and Fer-1 groups exhibited reductions in the indicators above （P<0.05）. Compared with the control group， the MIRI model group demonstrated reduced levels of SOD and GSH and down-regulated mRNA and protein levels of PTGS2， GPX4， and FTH1 （P<0.05）. In contrast， both DA and Fer-1 upregulated these indicators （P<0.05）， effectively reversing the trends in the model group. In addition， the MIRI model group showed swelling of cardiomyocytes， disarrangement of cardiac muscle fibers， and massive inflammatory cell infiltration， which were alleviated in the DA and Fer-1 groups. ConclusionDA alleviates MIRI by inhibiting ferroptosis and inflammation， demonstrating therapeutic potential in acute myocardial infarction.

Iron metabolism is a critical factor in tumorigenesis and development. Although TP53 mutations are prevalent in glioblastoma (GBM), the mechanisms by which TP53 regulates iron metabolism remain elusive. We reveal an imbalance iron homeostasis in GBM via TCGA database analysis. TP53 mutations disrupted iron homeostasis in GBM, characterized by elevated total iron levels and reduced ferritin (FTH). The gain-of-function effect triggered by TP53 mutations upregulates itchy E3 ubiquitin-protein ligase (ITCH) protein expression in astrocytes, leading to FTH degradation and an increase in free iron levels. TP53-mut astrocytes were more tolerant to the high iron environment induced by exogenous ferric ammonium citrate (FAC), but the increase in intracellular free iron made them more sensitive to Erastin-induced ferroptosis. Interestingly, we found that Erastin combined with FAC treatment significantly increased ferroptosis. These findings provide new insights for drug development and therapeutic modalities for GBM patients with TP53 mutations from iron metabolism perspectives.
Ferroptosis/drug effects* ; Humans ; Iron/metabolism* ; Glioblastoma/metabolism* ; Tumor Suppressor Protein p53/metabolism* ; Homeostasis/physiology* ; Ferritins/metabolism* ; Brain Neoplasms/genetics* ; Mutation ; Astrocytes/drug effects* ; Cell Line, Tumor ; Piperazines/pharmacology* ; Quaternary Ammonium Compounds/pharmacology* ; Ferric Compounds