Homo- or heterodimeric compounds that affect dimeric protein function through interaction between monomeric moieties and protein subunits can serve as valuable sources of potent and selective drug candidates. Here, we screened an in-house dimeric natural product collection, and panepocyclinol A (PecA) emerged as a selective and potent STAT3 inhibitor with profound anti-tumor efficacy. Through cross-linking C712/C718 residues in separate STAT3 monomers with two distinct Michael receptors, PecA inhibits STAT3 DNA binding affinity and transcription activity. Molecular dynamics simulation reveals the key conformation changes of STAT3 dimers upon the di-covalent binding with PecA that abolishes its DNA interactions. Furthermore, PecA exhibits high efficacy against anaplastic large T cell lymphoma in vitro and in vivo, especially those with constitutively activated STAT3 or STAT3^Y640F. In summary, our study describes a distinct and effective di-covalent modification for the dimeric compound PecA to disrupt STAT3 function.

Ursodeoxycholic acid (UDCA) is a naturally occurring, low-toxicity, and hydrophilic bile acid (BA) in the human body that is converted by intestinal flora using primary BA. Solute carrier family 7 member 11 (SLC7A11) functions to uptake extracellular cystine in exchange for glutamate, and is highly expressed in a variety of human cancers. Retroperitoneal liposarcoma (RLPS) refers to liposarcoma originating from the retroperitoneal area. Lipidomics analysis revealed that UDCA was one of the most significantly downregulated metabolites in sera of RLPS patients compared with healthy subjects. The augmentation of UDCA concentration (≥25 μg/mL) demonstrated a suppressive effect on the proliferation of liposarcoma cells. [¹⁵N₂]-cystine and [¹³C₅]-glutamine isotope tracing revealed that UDCA impairs cystine uptake and glutathione (GSH) synthesis. Mechanistically, UDCA binds to the cystine transporter SLC7A11 to inhibit cystine uptake and impair GSH de novo synthesis, leading to reactive oxygen species (ROS) accumulation and mitochondrial oxidative damage. Furthermore, UDCA can promote the anti-cancer effects of ferroptosis inducers (Erastin, RSL3), the murine double minute 2 (MDM2) inhibitors (Nutlin 3a, RG7112), cyclin dependent kinase 4 (CDK4) inhibitor (Abemaciclib), and glutaminase inhibitor (CB839). Together, UDCA functions as a cystine exchange factor that binds to SLC7A11 for antitumor activity, and SLC7A11 is not only a new transporter for BA but also a clinically applicable target for UDCA. More importantly, in combination with other antitumor chemotherapy or physiotherapy treatments, UDCA may provide effective and promising treatment strategies for RLPS or other types of tumors in a ROS-dependent manner.

The incomplete degradation of tumour cells by macrophages (Mϕ) is a contributing factor to tumour progression and metastasis, and the degradation function of Mϕ is mediated through phagosomes and lysosomes. In our preliminary experiments, we found that overactivation of NADPH oxidase 2 (NOX2) reduced the ability of Mϕ to degrade engulfed tumour cells. Above this, we screened out liquiritin from Glycyrrhiza uralensis Fisch, which can significantly inhibit NOX2 activity and inhibit tumours, to elucidate that suppressing NOX2 can enhance the ability of Mϕ to degrade tumour cells. We found that the tumour environment could activate the NOX2 activity in Mϕ phagosomes, causing Mϕ to produce excessive reactive oxygen species (ROS), thus prohibiting the formation of phagolysosomes before degradation. Conversely, inhibiting NOX2 in Mϕ by liquiritin can reduce ROS and promote phagosome-lysosome fusion, therefore improving the enzymatic degradation of tumour cells after phagocytosis, and subsequently promote T cell activity by presenting antigens. We further confirmed that liquiritin down-regulated the expression of the NOX2 specific membrane component protein gp91 phox, blocking its binding to the NOX2 cytoplasmic component proteins p67 phox and p47 phox, thereby inhibiting the activity of NOX2. This study elucidates the specific mechanism by which Mϕ cannot degrade tumour cells after phagocytosis, and indicates that liquiritin can promote the ability of Mϕ to degrade tumour cells by suppressing NOX2.

Volume electron microscopy (vEM) imaging technology was rapidly developed in recent years. It has been the advanced technology to solve high-resolution three-dimensional structures of biological samples. Much wonderful work has revealed the fine structure and interactions of intracellular organelles, the ultrastructure of tissues, and even the three-dimensional structure of entire small biological organisms. With the continuous improvement of resolution, scale and throughput, vEM is becoming more and more widely used in medicine, life sciences, clinical diagnostics and other fields. As a result, this technology has been rated by Nature as one of the seven most noteworthy frontier technologies to watch in 2023. However, the development and application of vEM-related technologies started late in China and need to be further promoted. We write this review to introduce all related vEM technologies, covering the development history of vEM, technology classification, sample preparation, data collection, image processing, etc., which is convenient for people in various fields to understand, learn, apply and further develop this technology.

Objective To investigate the role of programmed necrosis pathway in testicular tissue damage in rats with erectile dysfunction(ED)and the mechanism of sildenafil intervention.Methods An ED rat model was established by high-fat chow feeding,and the rats were randomly divided into model group,experimental group,interleukin 18 group,and experimental+interleukin 18 group;10 rats were randomly selected as the normal control group.The experimental group was gavaged with 20 mg·kg-1sildenafil;the interleukin 18 group was injected intraperitoneally with 0.2 μg·kg-1interleukin 18 recombinant protein;the experimental+interleukin 18 group was gavaged with an equal amount of sildenafil,and the experimental+interleukin 18 group was injected intraperitoneally with an equal amount of interleukin 18 recombinant protein;the normal control and model groups were given with an equal amount of 0.9％NaCl by gavage and intraperitoneally injected with an equal amount of saline;and the experimental group was injected with an equal amount of 0.9％NaCl.Interleukin 18 group was gavaged with an equal amount of 0.9％NaCl,and the five groups of rats were administered once a day at regular intervals for 14 consecutive days.Reverse transcription polymerase chain reaction(RT-qPCR)and Western blotting were used to detect the expression of receptor-interacting protein kinase 1(RIP1),receptor-interacting protein kinase 3(RIP3),mixed-spectrum kinase structural domain-like protein(MLKL),and calcium-calmodulin-dependent protein kinase Ⅱ(CaMKⅡ)in rat testis tissues.Results The relative expression levels of RIP1 protein in the normal control group,model group,experimental group,interleukin 18 group and experimental+interleukin 18 group were 0.58±0.05,0.99±0.09,0.71±0.05,1.23±0.07 and 0.81±0.07;the relative expression levels of RIP3 protein were 0.61±0.05,1.05±0.10,0.77±0.04,1.19±0.07 and 0.84±0.08,respectively;the relative expression levels of MLKL protein were 0.63±0.05,1.13±0.08,0.79±0.05,1.30±0.02 and 1.00±0.04,respectively;the relative expression levels of CaMK Ⅱ protein were 0.54±0.04,1.12±0.07,0.77±0.05,1.36±0.04 and 1.00±0.07;the differences of the above indexes were statistically significant when the model group was compared with the normal control group,the experimental group was compared with the model group,the interleukin 18 group was compared with the model group,and the experimental+interleukin 18 group was compared with the interleukin 18 group(all P＜0.05).Conclusion The RIP1/RIP3-mediated necroptosis pathway plays multiple regulatory roles in testicular injury in ED rats,and sildenafil may improve testicular function in rats by inhibiting the above necroptosis signaling pathway.

The expression level of NOD-like receptors(NLRP3)inflammasome is significantly elevated in breast cancer tissues,and a high level of NLRP3 inflammasomes is closely associated with breast cancer metastasis.Activation of NLRP3 inflammasome can induce the release of inflammatory factors into the tumor microenvironment(TME).These inflammatory factors,by signaling to cancer cells,reshape the TME to promote tumor growth and invasion,ultimately facilitating the process of epithelial-mesenchymal transition.This equips cancer cells with the ability to establish distant metastases and increase the formation of metastatic lesions.This review addresses the current research status and prospects of NLRP3 inflammasomes in the breast cancer TME and their role in breast cancer metastasis.The goal is to provide new insights for the study of breast cancer metastasis mechanisms and treatment strategies.

ObjectiveBody fluid stains left at crime scenes are frequently trace amounts, while the identification of body fluids through real time fluorogenic quantitative technique often necessitates the repeated detection within the limited sample, as multiple miRNA markers are the basis for the identification. Based on the goal of both the throughput and efficiency improvement of miRNA analysis in trace samples, a duplex real time fluorogenic quantitative PCR assay system was designed to accurately quantify two miRNAs simultaneously, and the system should be further verified by actual sample for the body fluid identification. MethodsThe duplex real time fluorogenic quantitative PCR system of miR-451a to miR-21-5p was established with specially designed primers and probes, and the concentrations of the primers and probes were both optimized. The specificity, sensitivity and reproducibility of the system were validated, while its capability for body fluid identification was assessed using the miR-451a to miR-21-5p ratio. ResultsThe optimized assay system exhibited excellent specificity and repeatability, with coefficients of variation consistently below 8% for both intra- and inter-batch variability. The amplification efficiency of miR-451a and miR-21-5p reached 71.77% and 74.81%, respectively, with high and relatively consistent results. By utilizing this duplex real time fluorogenic quantitative PCR assay system, a total of 58 body fluid samples were analyzed, exhibiting a discrimination rate of 100% between blood and non-blood samples, as well as between peripheral blood and menstrual blood samples. Moreover, the results, obtained from single real time fluorogenic quantitative PCR assay system and duplex real time fluorogenic quantitative PCR assay system, showed no statistically significant difference with randomly selected blood samples (n=20). Compared to previous single real time fluorogenic quantitative PCR assay system, the sensitivity of duplex real time fluorogenic quantitative PCR assay system exhibited remarkable improvement. A minimum input of only 0.1 ng total RNA was sufficient for accurate detection of peripheral blood and menstrual blood samples, while saliva, semen, and vaginal secretion required only 1 ng total RNA for precise identification purposes. Additionally, the duplex real time fluorogenic quantitative PCR assay system successfully differentiated between different types of body fluids in simulated samples under natural outdoor conditions. ConclusionThe duplex real time fluorogenic quantitative PCR assay system effectively reduced both the time and material costs by half compared to the single system, especially suitable for the examination of body fluid stains left at crime scenes, solving the contradiction between the trace amount and the multiple sample volumes demand of repeated real time fluorogenic quantitative PCR. The duplex real time fluorogenic quantitative PCR assay successfully distinguished blood and other body fluid, as well as peripheral blood and menstrual blood samples, which maintains an equivalent capability for body fluid identification with half sample, time and reagent consumption. This system provides an efficient tool for identifying suspicious body fluids, as well as a foundation for more multiplexed real time fluorogenic quantitative PCR assay system research.

BackgroundThe existing tools in China for assessing psychiatric nurses' knowledge， attitude and practice towards the use of protective restraint do not sufficiently consider the specialty in psychiatric practice， and the scale items are somewhat cumbersome to use， which together restrict their further promotion and application. Accordingly， there is an urgent need for developing a more scientific assessment tool. ObjectiveTo construct a scale for assessing psychiatric nurses' knowledge， attitude and practice towards the use of protective restraint and to verify its reliability and validity， so as to provide a generic tool for the assessment. MethodsBased on the theoretical framework of the knowledge-attitude-practice model， the preliminary scale was formed through systematic literature review， qualitative interview and Delphi method. From July to December 2021， a stratified sampling was utilized to select 729 psychiatric nurses from tertiary， secondary and primary （including unclassified medical institutions and grassroots hospitals） psychiatric hospitals in Guangdong Province. The formal scale was developed through item analysis， exploratory factor analysis and confirmatory factor analysis. The validity of the scale was evaluated by content validity and structure validity， and the reliability was verified by procedures including Cronbach's α coefficient， test-retest reliability， and split-half reliability. ResultsA total of 12 items of three dimensions （knowledge， attitude， practice） were included in the scale for assessing psychiatric nurses' knowledge， attitude and practice towards the use of protective restraint. The scale-level content validity index （S-CVI） was 0.941， and the item-level content validity index （I-CVI） ranged from 0.812 to 1.000. Exploratory factor analysis extracted three common factors， and the cumulative variance contribution rate was 62.948%. The confirmatory factor yielded adequate fit. Cronbach's α coefficient was found to be 0.887 for the scale， 0.819 for knowledge dimension， 0.842 for attitude dimension， and 0.831 for practice dimension. The split-half reliability and test-retest reliability for the scale were 0.712 and 0.922， respectively. ConclusionThe scale shows satisfactory reliability and validity， which can be used to assess psychiatric nurses' knowledge， attitude and practice towards the use of protective restraint. ［Funded by Guangdong Clinical Teaching Base Teaching Reform Research Project （number， 2021JD119）］

Objective To analyze the current situation of unplanned reoperation in cardiac surgery and to discuss the management measures of unplanned reoperation.Methods The information of patients undergoing cardiac surgery in a class A tertiary comprehensive hospital during 2018-2022 was collected to analyze the incidence of unplanned reoperation,major ca uses,disease types,surgica l moda lities and Complications.Results A tota l of 3902 patients underwent surgery,of whom 73(1.87%)underwent unplanned reoperation.The main cause of unplanned reoperation was bleeding(50%).The disease types with the highest unplanned reoperation composition ratio were coronary heart disease(38.4%),and the disease types with the highest incidence were dilated cardiomyopathy(11.1%).The average hospitalization cost,the average length of hospitalization,mortality rate and medical dispute rate of patients who had unplanned reoperation were significantly higher than those who did not have unplanned reoperation,the difference was statistically significant(P=0.001).Conclusion The hospital should strengthen the perioperative management of cardiac surgery,focus on supervising disease types and surgical modalities with high incidence of unplanned reoperation,and strictly implement the system of operation classification and the system of reporting unplanned reoperation to ensure the quality of patient surgery.

Objective To investigate the needs and feedback from clinical medical students on the diversified teaching mode adopted by the Department of Endocrinology in Peking Union Medical College Hospital.Methods Questionnaires were distributed to the medicine students who were in clinical rotation in Peking Union Medical Col-lege,and the teaching status and teaching effect was investigated.Results A total of 95 valid questionnaires were received.The attending physicians and the teaching resident physicians performed well in the daily teaching activi-ties.The medical students believed that outpatient training was necessary in addition to ward rotations.After the ro-tation in the endocrinology department,the self-evaluated score of mastery of endocrinology knowledge had been significantly improved,especially in those who rotated in outpatient clinic,suggesting that outpatient teaching was of great significance.In addition,the establishment of a self-learning platform including clinical cases and videos in endocrinology could be used as an important supplementary means for clinical teaching.Conclusions Outpatient training improves learning outcomes of medical students,so must be kept and further strengthened in the future.Building a database of typical clinical cases and teaching videos can improve the training quality.