The development of organ transplantation has brought new hope to many patients with organ failure and their families， but it has also raised numerous ethical issues. How to balance the rights and interests between organ donors and recipients， as well as ensure the fairness and transparency of the transplantation process has become an urgent problem to be solved. Based on the latest Regulations on Organ Donation and Transplantation and the Working Rules of the Ethics Committee for Human Organ Transplantation， the current difficulties and challenges in organ transplantation ethics were deeply analyzed. Taking the ethical review practice of Shenzhen Third People’s Hospital as an example， this paper explored issues such as full informed consent of both donors and recipients， risk assessment of marginal donors， and the review of relationships between donors and recipients. It also explored and constructed a set of complete ethical review models for organ transplantation through refined management. This model improved the efficiency and quality of ethical review as well as enriched the related knowledge system. It is expected that the implementation of this model can provide a reference for promoting effective ethical review nationwide， advancing the improvement and development of ethical review work in organ transplantation. Meanwhile， more medical ethics experts and practitioners are called upon to focus on and engage in the research and practice of ethical review in organ transplantation， jointly promoting progress in this field.

Neutralizing antibodies have been designed to specifically target and bind to the receptor binding domain (RBD) of spike (S) protein to block severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) virus from attaching to angiotensin converting enzyme 2 (ACE2). This study reports a distinctive nanobody, designated as VHH21, that directly catalyzes the S-trimer into an irreversible transition state through postfusion conformational changes. Derived from camels immunized with multiple antigens, a set of nanobodies with high affinity for the S1 protein displays abilities to neutralize pseudovirion infections with a broad resistance to variants of concern of SARS-CoV-2, including SARS-CoV and BatRaTG13. Importantly, a super-resolution screening and analysis platform based on visual fluorescence probes was designed and applied to monitor single proteins and protein subunits. A spontaneously occurring dimeric form of VHH21 was obtained to rapidly destroy the S-trimer. Structural analysis via cryogenic electron microscopy revealed that VHH21 targets specific conserved epitopes on the S protein, distinct from the ACE2 binding site on the RBD, which destabilizes the fusion process. This research highlights the potential of VHH21 as an abzyme-like nanobody (nanoabzyme) possessing broad-spectrum binding capabilities and highly effective anti-viral properties and offers a promising strategy for combating coronavirus outbreaks.
Single-Domain Antibodies/immunology* ; Spike Glycoprotein, Coronavirus/metabolism* ; SARS-CoV-2/immunology* ; Animals ; Humans ; Antibodies, Neutralizing/immunology* ; Camelus ; COVID-19/immunology* ; Antibodies, Viral/immunology* ; Angiotensin-Converting Enzyme 2

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.

Objective To explore the effects of combined exposure to bisphenol A (BPA) and high-fat diet on liver lipid metabolism and hepatocyte senescence in mice, and to elucidate the potential mechanisms of the onset and development of non-alcoholic fatty liver disease (NAFLD). Methods Specific pathogen free C57BL/6J mice were randomly divided into six groups, with 10 mice with equal numbers of each sex in each group. The mice in the control group and the simple BPA group were fed with regular diet, while others four groups of mice were fed with high-fat diet. At the same time, the mice in the simple BPA group were intragastric administered with BPA at a dose of 50 μg/kg body weight, while the mice in the low-, medium- and high-dose BPA+high-fat groups were intragastric administered with BPA at doses of 5, 50 and 500 μg/kg body weight respectively. The mice in the control group and the high-fat group were intragastric administered with the same volume of corn oil once per day for 90 consecutive days. Liver tissues were subjected to hematoxylin-eosin (HE) and Oil Red O staining. Liver coefficients and lipid-stained area ratios were calculated. Serum level of total cholesterol, triglycerides, high-density lipoprotein, low-density lipoprotein, and the activities of alanine aminotransferase (ALT) and aspartate aminotransferase (AST) were determined using an automatic biochemical analyzer. The hepatic tumor necrosis factor-α (TNF-α), interleukin (IL)-6, and IL-10 levels were quantified by enzyme-linked immunosorbent assay. The relative expression of cholesterol regulatory element binding protein 1 (SREBP1), CCAAT enhancer binding protein α, P16, and phosphorylated histone H2AX (γ-H2AX) in liver tissues was detected using Western blotting. The interaction effect of the combined exposure to BPA and high-fat diet was observed based on the result of mice in the control group, the simple high-fat group, the simple BPA group, and the medium-dose BPA group+high-fat group (the combined exposure group) using a 2×2 factorial design. The results of mice in the simple high-fat group and the low-, medium-, and high-dose BPA+high-fat groups were used to observe the effect of BPA exposure dose under high-fat diet conditions. Results i) The interactive effect of combined exposure to BPA and high fat. The HE and Oil Red O staining results indicated that the combined exposure to BPA and high-fat diet successfully established NAFLD in mice. The interactive effect of combined exposure to BPA and high-fat diet on serum ALT activity and the relative expression of P16 in the liver tissue of female mice, as well as the serum ALT and AST activities and the relative expression of SREBP1 in the liver tissue of male mice was significant (all P<0.05). Specifically, the serum ALT activity of male mice in the combined exposure group was higher than that in the simple high-fat group (P<0.05), while the ALT activity in the serum of female mice in the combined exposure group was lower than that in the simple BPA group (P<0.05). The relative expression of SREBP1 protein in the liver tissue of male mice in the combined exposure group was higher than that in the control group, the simple high-fat group, and the simple BPA group (all P<0.05). For the other indicators, there were no significant differences in the interactive effect of combined exposure to BPA and high-fat diet (all P>0.05). ii) Dose effects of BPA exposure. The HE and Oil Red O staining result showed that the degree of vacuolar steatosis in the liver of female and male mice of medium- and high-dose BPA + high-fat groups was aggravated, and the range of inflammatory cell infiltration was expanded when compared with same-sex mice in the simple high-fat group. The serum ALT activity and the fat stained area ratio, as well as the relative expression of P16 in liver tissue of female mice in high-dose BPA + high-fat group increased (all P<0.05), while the level of IL-10 in liver tissue decreased (P<0.05), compared with the female mice in simple high-fat group. The serum ALT activity, the TNF-α level in liver tissue, and the relative expression of SREBP1, P16 and γ-H2AX proteins in liver tissue of male mice in high-dose BPA + high-fat group increased (all P<0.05), while the IL-6 level in liver tissue decreased (P<0.05), compared with the male mice in simple high-fat group. For the female or male mice in the low- and medium-dose BPA + high-fat groups, only some of the above indicators showed significant changes (all P<0.05). Conclusion The combined exposure to BPA and high-fat diet has a synergistic effect on the onset and development of NAFLD. The mechanism may be related to inducing cellular senescence and modulation of lipid synthesis pathways, thereby affecting liver steatosis. The exposure dose of BPA may affect the synergistic effect.

Objective: To investigate the spatial clustering characteristics of varicella public health emergency events in Nanjing City from 2017 to 2022, so as to provide the evidence for the development of varicella prevention and control strategies. Methods: Data of varicella public health emergency events in Nanjing City from 2017 to 2022 were collected through Emergency Public Health Management Information System of Chinese Disease Prevention and Control Information System. The software ArcGIS 10.2 was employed for trend-surface analysis, spatial autocorrelation analysis and hotspot analysis to understand the spatial clustering characteristics of varicella public health emergency events. Results: A total of 84 varicella public health emergency events were reported in Nanjing City from 2017 to 2022, with an average attack rate of 2.53% (2 558 cases). Ⅳ-level events were predominant, accounting for 90.48% (76 events). The trend-surface analysis showed lower incidence of varicella public health emergency events in the west of Nanjing City and higher in the east, and lower in the north and higher in the south. The global spatial autocorrelation analysis showed that there was a positive spatial correlation in varicella public health emergency events in 2017 and 2019, indicating spatial clustering (P<0.05). The hot spots were Jiangning District, Gaochun District, Yuhuatai District and Jianye District. Conclusion The incidence of varicella public health emergency events in Nanjing City from 2017 to 2022 has spatial aggregation, with a concentration in suburban areas such as Jiangning District and Gaochun District.

BACKGROUND:Tyrosine kinase inhibitors,as well as other types of small-molecule cancer drugs,can cause severe cardiotoxicity. OBJECTIVE:To perform a heart safety re-evaluation by observing the effects of antitumor drugs on isolated heart electrocardiograph,cardiac action potential and associated ion channels and cytotoxicity. METHODS:Extracorporeal cardiac perfusion was given to the isolated rabbit heart using Langendorff perfusion:Sunitinib(0.3,3,10 μmol/L),Crizotinib(0.3,1,3 μmol/L),and Doxorubicin(1,30 μmol/L)were perfused sequentially for 120 minutes to record electrocardiograph and left ventricular pressure.A blank control group was set for comparison.Manual patch clamp was used to record the effects of Crizotinib,Sunitinib,Doxorubicin on hERG,Cav1.2,Nav1.5 channel currents and action potential in human induced pluripotent stem cell derived cardiomyocytes.Adenosine triphosphate level in human induced pluripotent stem cell derived cardiomyocytes was detected by CellTiter-Glo luminescent cell viability assay. RESULTS AND CONCLUSION:Isolated rabbit heart using Langendorff perfusion:Compared with the blank ontrol group,Sunitinib and Crizotinib at≥3 μmol/L decreased heart rate(P<0.01)and prolonged QT/QTc interval(P<0.01),and reduced left ventricular pressure to different extents.Manual patch clamp recording:Compared with the blank control group,Sunitinib and Crizotinib at 3 μmol/L inhibited the activities of hERG,Nav1.5 and Cav1.2 channels and significantly prolonged the duration of action potential(P<0.01).According to the analysis of the test article,the difference between the labeled concentration and the measured concentration of the recovered solution was not significant.Cell viability assays:Compared with the blank control group,adenosine triphosphate content in human induced pluripotent stem cell derived cardiomyocytes significantly decreased after treatment with Sunitinib(IC50=4.64 μmol/L),Doxorubicin(IC50=4.21 μmol/L)and Crizotinib(IC50=2.87 μmol/L),indicating that cell viability significantly decreased(P<0.01).To conclude,this study successfully established an early cardiac safety evaluation method for antitumor drugs,which provides good support and help for the subsequent development of antitumor drugs.

Objective: To evaluate the preventive effect of implementing the free influenza vaccination policy on school absence among primary and secondary school students, so as to provide a reference for formulating and adjusting vaccination strategies. Methods: Among primary and secondary school students aged 6 to 18 in Longgang District, Shenzhen, they were divided into a vaccinated group (265 996 students) and an unvaccinated group (122 513 students) according to their influenza vaccination history during November 2023. Propensity score matching was used to conduct a 1∶1 match between the two groups to balance covariates. The number of absences per month was set as the dependent variable to construct a difference in differences model, and Poisson regression was employed to analyze the overall and multi time point effects. Results: Vaccination against influenza was associated with low rate of absenteeism among primary and secondary school students, with an overall preventive effect of 26.52% (95% CI = 23.47% -29.45%). The preventive effects in November (the month of vaccination) and December 2023, January and March 2024 were 42.12%, 40.12%, 30.33% and 20.91%, respectively. The preventive effect of the influenza vaccine on absenteeism among primary school students (26.39%) was not significantly different from that among secondary school students ( 27.97% ) ( P >0.05). The regression coefficient for class vaccination rates ranged from 0.998 to 0.999 ( P <0.01), indicating that for every 10% increase in influenza vaccination rates, absenteeism could be reduced by 1.5% to 2.2%. Conclusion Implementing free influenza vaccination for primary and secondary school students might help to reduce the risk of absenteeism, yielding significant socioeconomic benefits.

Objective:To investigate the effect of regional leptomeningeal collateral circulation (rLMC) score based on CT angiography (CTA) and onset-to-reperfusion time (OTR) on the outcome after endovascular treatment (EVT) in patients with anterior circulation acute large vessel occlusive stroke (ACA-LVOS).Methods:Patients with ACA-LVOS underwent EVT in the Department of Neurology, the Affiliated Hospital of Yangzhou University from July 2017 to July 2023 were included retrospectively. The rLMC score 0-10 was defined as poor collateral circulation, and 11-20 were defined as good collateral circulation. At 90 days after EVT, the modified Rankin Scale (mRS) was used to evaluate the outcome. A score of 0-2 was defined as a good outcome and 3-6 were defined as a poor outcome. Multivariate logistic regression analysis was used to determine the independent influencing factors of the outcome after EVT. Results:A total of 144 patients with ACA-LVOS underwent EVT were enrolled, including 78 males (54.2%), median aged 73 years. The median baseline National Institutes of Health Stroke Scale (NIHSS) score was 16, the median baseline Alberta Stroke Program Early CT Score (ASPECTS) was 9, and the median OTR was 330.5 minutes. Eighty patients (55.6%) had good collateral circulation, 63 (43.8%) had poor outcome, including 13 deaths. Univariate analysis showed that there were significant differences in hypertension, previous stroke history, smoking, triglycerides, baseline NIHSS score, baseline ASPECTS, OTR, and collateral circulation status between the good outcome group and the poor outcome group (all P<0.05). Multivariate logistic regression analysis showed that good collateral circulation (odds ratio [ OR] 0.223, 95% confidence interval [ CI] 0.077-0.643; P=0.005) was an independent predictor of good outcome. In the poor collateral circulation group, longer OTR was an independent predictor of poor outcome ( OR 1.020, 95% CI 1.008-1.032; P=0.001). In the good collateral circulation group, longer OTR was not an independent risk factor for poor outcome ( OR 1.005, 95% CI 1.000-1.010; P=0.062). Conclusion:rLMC score based on CTA and OTR are the independent predictors of the outcome after EVT in patients with ACA-LVOS.

Objective To analyze the distribution of carbapenem-resistant strains and the transmission mode of resistance genes in the bacteria strains from urinary system of the individuals outside hospitals,and further explore the impacts of the antibiotics with different antibacterial mechanisms on the conjugation transfer of resistant plasmids.Methods The imipenem-resistant strains from 991 non-re-petitive urine samples of healthy individuals were screened for determining the carbapenem-resistance genotypes.Using the multilocus sequence typing(MLST)method,the main carbapenem-resistant strains were classified to determine the phylogenetic relationship be-tween different sequence types(STs)and reveal the transmission mode of resistance genes in the individuals outside hospitals.The conjugation experiment was used to analyze the effects of different sub-inhibitory concentrations of ampicillin,ciprofloxacin,and genta-micin on the conjugation efficiency of resistant plasmids in the bacteria of donor and/or recipient at different times.Results A total of 18 non-repetitive carbapenem-resistant strains(1.82％,18/991)were detected in healthy individuals outside hospitals,among which Escherichia coli(E.coli)(44.44％,8/18)was the main strain with main genotype being blaKPC-2(7/8).MLST showed that the 7 strains of E.coli with blaKPC-2 genotype belonged to ST-10,ST-101,ST-131,ST-405,ST-410,ST-1193,and ST-2562,respectively.Homologous clustering analysis showed that the type of the 7 E.coli strains exhibited high diversity.The range of joint efficiency was(1.59±0.20)× 10-4 to(4.01±1.31)× 10-4.The highest conjugation efficiency was observed in the donor bacteria treated with 1/8 of MIC of antibiotics for 9 hours,and the conjugation efficiency most significantly increased compared to the group without antibiotic treat-ment.Three antibiotics with different mechanisms of action could all improve conjugation efficiency,among which ampicillin exhibited the most significant improvement.Conclusion In this study,the genotype of carbapenem-resistant Escherichia coli(CREC)was mainly blaKPC-2 with a main mode of horizontal transmission.Antibiotics with sub-inhibitory concentrations could promote the conjugation transfer of the resistant plasmid.There may be significant differences in the effects of antibiotics with different mechanisms of action and different antibiotic stress conditions on the conjugation efficiency.

Sarcopenia is an age-related degenerative disease.Type 2 diabetes mellitus(T2DM)is a senile disease.These two diseases often coexist.Early identification and intervention of T2DM combined with sarcopenia can improve the quality of life to a certain extent.This article reviews the research progress of T2DM combined with sarcopenia.