Objective To develop an ion-pairing reversed-phase high performance liquid chromatography(IP-RP-HPLC)method for the determination of L-methionine sulphoximine(MSX) residues in recombinant protein therapeutics, and to verify and preliminarily apply it, so as to provide a reference for the quality control of related products.Methods A chromatographic analysis method was screened and the mobile phase conditions such as ion-pairing reagent, pH and salt concentration were optimized to develop an IP-RP-HPLC method for the determination of MSX residues in recombinant protein therapeutics. The method was verified for specificity, system applicability, linearity, limit of detection(LOD) and limit of quantitation(LOQ), precision, accuracy and solution stability, by which the residual MSX contents in multiple batches of in-process sample and bulk of recombinant protein therapeutics were determined.Results The chromatographic conditions were determined as follows: using Hypersil GOLDTMC18 column(4. 6 mm × 250 mm, 5 μm) at column temperature of 25 ℃; 50 mmol/L sodium dihydrogen phosphate(containing 5 mmol/L sodium 1-octane sulfonate, pH 2. 0)-acetonitrile(volume fraction of 85 ∶ 15) as mobile phase for isocratic elution at a flow rate of 0. 6 mL/min; detection wavelength of 200 nm; injection volume of 50 μL. The method exhibited good specificity and system applicability. The control substance showed good linearity in the concentration range of 10-100 μg/mL, with a correlation coefficient(R) of 0. 999 95. The LOD and LOQ were 5 and 0. 5 μg/mL, respectively. MSX was not detected in either recombinant protein A or B, and the relative standard deviations(RSDs) of the measured concentrations of six parallel spiked samples were 1. 3% and 1. 1%, respectively, with the recovery rates ranged from 94% to 103%. For recombinant protein A spiked test sample placed at 10 ℃, the RSD of the measured concentrations at 0 h and 12 h were 2. 1%. MSX was not detected in the in-process samples and bulk of recombinant protein A test samples and three batches of recombinant protein B samples.Conclusion The developed IP-RP-HPLC method has the characteristics of simple operation and high sensitivity, and can be used for the quality control of MSX residues in recombinant protein therapeutics.

Objective To investigate the predictive value of the combined tumor burden score (TBS) and platelet-albumin-bilirubin (PALBI) score model for postoperative tumor recurrence in liver transplant recipients with hepatocellular carcinoma (HCC). Methods The general information of 158 recipients diagnosed with HCC and underwent liver transplantation at the 900th Hospital of the Joint Logistics Support Force of the Chinese People's Liberation Army from 2008 to 2021 was collected. Lasso regression analysis combined with multivariate Cox regression analysis were used to identify independent risk factors for postoperative tumor recurrence after liver transplantation with HCC. A nomogram prediction model was constructed based on variables selected by Lasso regression analysis, and the predictive performance of the model was verified by calibration curve and clinical decision curve. The optimal cut-off values for postoperative tumor recurrence in liver transplant recipients with HCC were determined by receiver operating characteristic (ROC) curve, and Kaplan-Meier analysis was used to compare survival differences among different groups. Results Among the 158 liver transplant recipients with HCC, 82 experienced tumor recurrence, with a recurrence rate of 51.9% and a median tumor-free survival time of 10 (4, 25) months. Results of Lasso regression analysis and multivariate Cox regression analysis showed that alpha-fetoprotein (AFP) ≥400 ng/mL, TBS and PALBI score were all independent risk factors for postoperative tumor recurrence in liver transplant recipients with HCC (all P<0.05). The combined high TBS-high PALBI score showed the highest predictive value (hazard ratio 6.909, 95% confidence interval 3.067-15.563, P<0.001). A nomogram prediction model was constructed based on six variables selected by Lasso regression analysis. Calibration curve showed good consistency between the model's predicted results and the ideal curve. Decision curve analysis indicated that the nomogram prediction model provided the highest clinical benefit for predicting 1-year tumor-free survival after liver transplantation with HCC. Time-dependent ROC curves at 1, 3 and 5 years after surgery showed that TBS-PALBI model had good predictive performance, with no significant difference in area under the curve (AUC) compared with TBS-PALBI-AFP model. The optimal cut-off values for predicting postoperative tumor recurrence were determined by ROC curve, with a PALBI score cut-off of −2.334 and a TBS cut-off of 5.305. Recipients were divided into a low TBS-low PALBI score group (n=47) and a low/high TBS-low/high PALBI score group (at least one score was high) (n=111). Kaplan-Meier survival analysis showed that the low TBS-low PALBI score group had a higher tumor-free survival rate than the low/high TBS-low/high PALBI score group, with a significant difference (P<0.05). Conclusions TBS-PALBI model provides a novel, simple and effective tool for assessing the prognosis of liver transplant recipients with HCC. The nomogram model constructed based on this has significant advantages in predictive performance and may serve as a reference for guiding individualized treatment plans and improving clinical outcomes.

Preimplantation polygenic testing， as a frontier technology in assisted reproduction， provides a new way to prevent genetic diseases and reduce birth defects. However， it may also trigger a series of ethical issues. Combined with the research progress of preimplantation polygenic testing， this paper explored the ethical issues that may be caused by this technology， including the risks and uncertain benefits for future offspring and the challenges of informed consent， the dilemmas of autonomous decision-making and genetic responsibility of prospective parents， as well as social risks such as the distortion of the view of life and health inequities. Given the technical safety issues and ethical challenges posed by preimplantation polygenic testing， it was proposed to revise the regulations related to preimplantation genetic testing， as well as improve the ethical review of preimplantation polygenic testing， genetic counseling services， and public education on genetic science and genetic ethics. These ethical countermeasures aim to prevent and mitigate risks and ensure that technology truly benefits human society.

Based on his extensive clinical experience and the team's mechanistic research, Professor XU Nenggui has proposed the academic concept that "the governor vessel governs the brain and treats cerebral viscus diseases", and established a novel acupuncture approach for encephalopathy treatment centered on the integrated theory of "governor vessel-brain-mind", and developed a staged acupuncture protocol of "governor vessel regulating spirit" for ischemic stroke. This article introduces the academic features of this method in treating post-stroke dysphagia from four aspects: theoretical framework, treatment principles and point selection, mechanistic research, and clinical case studies. In clinical application, the method emphasizes syndrome differentiation based on meridians, harmonization between the conception and governor vessels; precise acupoint selection to treat both form and spirit; stage-specific differentiation with targeted needling. Furthermore, Professor XU integrates basic research with clinical practice, focusing on the neurobiological mechanisms underlying the efficacy of acupuncture in treating post-stroke dysphagia.
Acupuncture Therapy/methods* ; Humans ; Deglutition Disorders/psychology* ; Stroke/complications* ; Meridians ; Acupuncture Points

Two novel diketopiperazines (1 and 5), along with ten known compounds (2-4, 6-12) demonstrating significant skin inflammation inhibition, were isolated from a marine-derived fungus identified as Aspergillus sp. FAZW0001. The structural elucidation and configurational reassessments of compounds 1-5 were established through comprehensive spectral analyses, with their absolute configurations determined via single crystal X-ray diffraction using Cu Kα radiation, Marfey's method, and comparison between experimental and calculated electronic circular dichroism (ECD) spectra. Compounds 1, 2, and 8 exhibited significant anti-inflammatory activities in Propionibacterium acnes (P. acnes)-induced human monocyte cell lines. Compound 8 demonstrated the ability to down-regulate interleukin-1β (IL-1β) expression by inhibiting Toll-like receptor 2 (TLR2) expression and modulating the activation of myeloid differentiation factor 88 (MyD88), mitogen-activated protein kinase (MAPK), and nuclear factor κB (NF-κB) signaling pathways, thus reducing the cellular inflammatory response induced by P. acnes. Additionally, compound 8 showed the capacity to suppress mitochondrial reactive oxygen species (ROS) production and nucleotide-binding oligomerization domain-like receptor protein 3 (NLRP3) inflammasome activation, thereby reducing IL-1β maturation and secretion. A three-dimensional quantitative structure-activity relationships (3D-QSAR) model was applied to compounds 5-12 to analyze their anti-inflammatory structure-activity relationships.
Humans ; Aspergillus/chemistry* ; Diketopiperazines/isolation & purification* ; Anti-Inflammatory Agents/isolation & purification* ; Interleukin-1beta/genetics* ; Toll-Like Receptor 2/immunology* ; Propionibacterium acnes/drug effects* ; NF-kappa B/genetics* ; Molecular Structure ; Myeloid Differentiation Factor 88/immunology* ; Monocytes/immunology* ; NLR Family, Pyrin Domain-Containing 3 Protein/genetics* ; Cell Line

Objective To identify clinical risk factors for early major adverse cardiovascular events (MACEs) following surgical correction of supravalvar aortic stenosis (SVAS). Methods Patients who underwent SVAS surgical correction between 2002 and 2019 in Beijing and Yunnan Fuwai Cardiovascular Hospitals were included. The patients were divided into a MACEs group and a non-MACEs group based on whether MACEs concurring during postoperative hospitalization or within 30 days following surgical correction for SVAS. Their preoperative, intraoperative, and postoperative clinical data were collected for multivariate logistic regression. Results This study included 302 patients. There were 199 males and 103 females, with a median age of 63.0 (29.2, 131.2) months. The incidence of early postoperative MACEs was 7.0% (21/302). The multivariate logistic regression model identified independent risk factors for early postoperative MACEs, including ICU duration (OR=1.01, 95%CI 1.00-1.01, P=0.032), intraoperative cardiopulmonary bypass (CPB) time (OR=1.02, 95%CI 1.01-1.04, P=0.014), aortic annulus diameter (OR=0.65, 95%CI 0.43-0.97, P=0.035), aortic sinus inner diameter (OR=0.75, 95%CI 0.57-0.98, P=0.037), and diameter of the stenosis (OR=0.56, 95%CI 0.35-0.90, P=0.016). Conclusion The independent risk factors for early postoperative MACEs include ICU duration, intraoperative CPB time, aortic annulus diameter, aortic sinus inner diameter, and diameter of the stenosis. Early identification of high-risk populations for MACEs is beneficial for the development of clinical treatment strategies.

BACKGROUND:There are many treatment methods for knee osteoarthritis,among which electroacupuncture,as an important non-drug treatment,is effective in the treatment of knee osteoarthritis,but its exact mechanism is not clear. OBJECTIVE:Effect of electroacupuncture on the expression of p53 and P21 in articular cartilage and subchondral bone of aged rats with knee osteoarthritis. METHODS:Eight 6-month-old male Sprague-Dawley rats were included in the young group and sixteen 24-month-old male Sprague-Dawley rats were randomly divided into old group(n=8)and electroacupuncture group(n=8).The rats in the electroacupuncture group received electroacupuncture stimulation once a day,5 days a week,for 8 continuous weeks,and the other two groups did not do any treatment.Eight weeks later,the level of type Ⅱ collagen C-terminal peptide in peripheral blood was detected by ELISA,the morphology of left knee cartilage and subchondral bone was observed by safranin O-fast green staining,the degree of knee cartilage degeneration was evaluated by modified Mankin's score,the microstructure of left knee cartilage and subchondral bone was detected by micro-CT,and the expression levels of matrix metalloproteinase 13,P53,P21 Mrna and protein were detected by RT-PCR and western blot respectively. RESULTS AND CONCLUSION:Compared with the young group,the level of C-terminal peptide of type Ⅱ collagen in the peripheral blood was increased in the old group(P<0.05).The micro-CT results showed that the bone volume fraction,bone mineral density and the number of bone trabeculae were decreased in the old group compared with the young group(P<0.05),while the trabecular separation increased(P<0.05).Safranin O-fast green staining showed that in the old group,the surface layer of cartilage was uneven with fissures,the morphology of chondrocytes was irregular and stained unevenly,the boundary between the cartilage and subchondral bone was blurred,and the matrix loss was serious.The Mankin's score was higher in the old group than the young group(P<0.05).The expression of matrix metalloproteinase 13,P53,P21 at Mrna and protein levels increased in the old group compared with the young group(P<0.05).Compared with the old group,electroacupuncture decreased the level of C-terminal peptide of type Ⅱ collagen(P<0.05),increased the bone volume fraction,bone mineral density and the number of bone trabeculae(P<0.05),and decreased the trabecular separation(P<0.05).Safranin O-fast green staining showed that in the electroacupuncture group,the surface of cartilage was smooth and red staining was uniform,and the cell morphology and structure were between the young group and the old group.Following electroacupuncture treatment,the Mankin's score(P<0.05),matrix metalloproteinase 13 and P21 Mrna expression(P<0.05),and matrix metalloproteinase 13 and P53 protein expression decreased(P<0.05),while there was a decreasing trend of P53 Mrna and P21 protein expression,but with no statistical significance(P>0.05).To conclude,electroacupuncture may delay articular cartilage degeneration and subchondral osteoporosis in aged rats by inhibiting the expression of P53 and P21,so as to protect joints and delay joint aging.

BACKGROUND:Current studies have confirmed that Ganoderma lucidum polysaccharides can promote nerve regeneration in neurodegeneration-related diseases.The occurrence of neurodegenerative diseases is closely related to mitochondrial dysfunction,but the role of Ganoderma lucidum polysaccharides on the regulation of apoptosis and mitochondrial function in neurodegenerative diseases is not yet clarified. OBJECTIVE:To explore the regulatory effects and mechanisms of Ganoderma lucidum polysaccharides on apoptosis and mitochondrial dysfunction in H2O2-induced SH-SY5Y cells. METHODS:SH-SY5Y cells were divided into three groups:control group,H2O2 group,and Ganoderma lucidum polysaccharides group.Cells in the control group were normally cultured.Cells in the H2O2 group were treated with 300 μmol/L H2O2 for 24 hours.In the Ganoderma lucidum polysaccharides group,the intervention with 300 μg/L Ganoderma lucidum polysaccharides was conducted first for 1-2 hours,followed by the addition of 300 μmol/L H2O2 for 24 hours.The mitochondrial membrane potential was detected by JC-1 kit.Apoptosis was detected by TUNEL staining kit.The activities of malondialdehyde and superoxide dismutase were detected by malondialdehyde test kit and superoxide dismutase test kit,respectively.The apoptosis and expression of mitochondrial dynamics-related proteins were detected by immunofluorescence staining and western blot assay. RESULTS AND CONCLUSION:(1)Compared with the control group,the mitochondrial membrane potential and superoxide dismutase activity were significantly reduced,as well as apoptotic rate and malondialdehyde levels were significantly increased in the H2O2 group(P<0.05).After treatment with Ganoderma lucidum polysaccharides,the membrane potential and superoxide dismutase activities were significantly increased,and apoptotic rate and malondialdehyde levels were significantly reduced compared with the H2O2 group(P<0.05).(2)The expression levels of pro-apoptotic proteins Bax and Caspase-3 were significantly increased,but the expression of anti-apoptotic protein Bcl-2 was significantly decreased in the H2O2 group compared with the control group(P<0.05).Compared with the H2O2 group,the levels of Bax and Caspase-3 were significantly decreased,but the expression of anti-apoptotic protein Bcl-2 was significantly increased in the Ganoderma lucidum polysaccharides group(P<0.05).(3)Compared with the control group,the expression of mitochondrial splitting proteins Fis1 and p-Drp1 was significantly increased,but the expression of mitochondrial fusion proteins OPA1,Mfn1,and Mfn2 was decreased in the H2O2 group(P<0.05).Compared with the H2O2 group,Fis1 and p-Drp1 expression was significantly reduced,but the expression levels of OPA1,Mfn1,and Mfn2 were significantly increased in the Ganoderma lucidum polysaccharides group(P<0.05).(4)The above results confirm that Ganoderma lucidum polysaccharides can attenuate H2O2-induced oxidative stress damage and apoptosis in SH-SY5Y cells by ameliorating mitochondrial dysfunction.

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 explore the microbiological and disease distribution characteristics of multidrug-resistant bacteria in patients hospitalized in a critical care rehabilitation ward, and to analyze the risk factors leading to multidrug-resistant bacterial infections.Methods:Microbiology screening data describing 679 patients admitted to a critical care rehabilitation ward were retrospectively analyzed to divide the subjects into a multidrug-resistant group (positive for multidrug-resistant bacterial infections, n=166) and a non-multidrug-resistant group (negative for multidrug-resistant bacterial infections, n=513). The risk factors were then analyzed using logistic regression. Results:Among 369 strains of multidrug-resistant bacteria observed, 329 were gram-negative bacteria (89.2%), mainly Pseudomonas aeruginosa, Klebsiella pneumoniae and Escherichia coli. They were distributed in sputum (56.9%) and mid-epidemic urine (28.2%) specimens. Patients whose primary disease was hemorrhagic or ischemic cerebrovascular disease accounted for 40.96% and 23.49% of the multidrug-resistant bacterial infections, respectively. Logistic regression analysis showed that albumin level, dependence on mechanical ventilation, central venous cannulation, or an indwelling urinary catheter or cystostomy tube were significant independent predictors of such infections.Conclusion:The multidrug-resistant bacterial infections of patients admitted to the critically ill rehabilitation unit are mainly caused by gram-negative bacteria. Their occurrence is closely related to low albumin levels and mechanical ventilation, as well as to bearing an indwelling central venous catheter, a urinary catheter or a cystostomy catheter.