ObjectiveTo investigate the mechanism by which adrenoceptor alpha 2A (Adra2a) regulates lipopolysaccharide (LPS)-induced inflammation in primary hepatocytes from lipopolysaccharide-binding protein (LBP) knockout mice (Lbp^-/-). MethodsPrimary hepatocytes from C57BL/6J and Lbp^-/- mice were isolated using a two-step perfusion method. An in vitro inflammatory model was established by LPS stimulation, and an in vivo inflammatory mouse model was established by intraperitoneal injection of LPS. The in vitro experiments were grouped as follows: Control group, LPS group, BRL+LPS group, OE-NC+LPS group, and OE-Adra2a+LPS group. The Control group served as the blank control. The LPS group involved stimulating primary hepatocytes with LPS. The BRL+LPS group involved pretreating primary hepatocytes with BRL-44408 maleate followed by LPS stimulation. The OE-NC+LPS group involved transfecting primary hepatocytes with an empty vector followed by LPS stimulation. The OE-Adra2a+LPS group involved transfecting primary hepatocytes with a lentivirus overexpressing Adra2a, followed by LPS stimulation. The in vivo experimental groups were divided into Control', LPS', BRL+LPS', OE-NC+LPS', and OE-Adra2a+LPS' groups. The Control' group served as the blank control. The LPS' group received intraperitoneal injection of LPS. The BRL+LPS' group received intraperitoneal injection of BRL-44408 maleate for pretreatment, followed by LPS injection. The OE-NC+LPS' group received intraperitoneal injection of empty vector for pretreatment, followed by LPS injection. The OE-Adra2a+LPS' group received intraperitoneal injection of a lentivirus overexpressing Adra2a for pretreatment, followed by LPS injection. Cell viability after Adra2a inhibition and overexpression was assessed via the Cell Counting Kit-8 (CCK-8) assay. RT-qPCR measured changes in gene expression levels of tumor necrosis factor-α (TNF-α), interleukin-6 (IL-6), and interleukin-1β (IL-1β) after Adra2a inhibition and overexpression. Western blotting was performed to detect Adra2a protein expression and phosphorylation levels of extracellular signal-regulated kinase 1/2 (ERK1/2), p38 mitogen-activated protein kinase, and c-Jun N-terminal kinase (JNK) following LPS stimulation. ResultsIn vitro experiments revealed that LPS stimulation significantly decreased Adra2a protein expression in primary hepatocytes from C57BL/6J mice compared to the Control group (P<0.05), whereas it increased in primary hepatocytes from Lbp^-/- mice (P<0.001). Compared to the LPS group, the BRL+LPS group exhibited significantly increased cell viability (P<0.01), reduced TNF-α, IL-6, and IL-1β gene transcription levels (P<0.01, P<0.001, P<0.001), and decreased phosphorylation levels of MAPK signaling pathway-related proteins ERK1/2, p38, and JNK (P<0.01, P<0.001, P<0.001). Compared with the OE-NC+LPS group, the OE-Adra2a+LPS group showed significantly decreased cell viability (P<0.001), increased gene transcription levels of TNF-α, IL-6, and IL-1β genes (P<0.001, P<0.01, P<0.001), and elevated phosphorylation levels of MAPK signaling pathway-related proteins ERK1/2, p38, and JNK (P<0.001, P<0.01, P<0.001). In vivo experiments showed that, compared with the LPS' group, the BRL+LPS' group exhibited significantly reduced phosphorylation levels of MAPK signaling pathway-related proteins ERK1/2, p38, and JNK (P<0.001, P<0.01, P<0.01). In the OE-Adra2a+LPS' group, the phosphorylation levels of ERK1/2, p38, and JNK were significantly elevated compared to the OE-NC+LPS' group (P<0.01, P<0.001, P<0.01). ConclusionLPS stimulation can cause a significant increase in Adra2a protein expression in primary hepatocytes of Lbp^-/- mice. Adra2a protein can regulate the level of LPS-induced inflammation in primary hepatocytes of Lbp^-/- mice through the MAPK signaling pathway.

ObjectiveThe malaria parasites remodel the host erythrocyte structure by exporting parasite proteins that interact with the membrane skeleton proteins of red blood cells (RBCs), facilitating their intracellular survival and pathogenicity. Skeleton-binding protein 1 (SBP1) is a conserved exported protein across Plasmodium species. In Plasmodium falciparum, SBP1 has been reported to interact with erythrocyte membrane skeleton proteins 4.1R and spectrin, while its contribution to erythrocyte remodeling and parasite virulence in Plasmodium berghei (Pb) remains unclear. This study aims to determine whether PbSBP1 associates with the host cytoskeletal protein 4.1R and to investigate its role in the remodeling of host RBCs and the pathogenicity of Plasmodium berghei. MethodsIn Plasmodium berghei, the relationship between PbSBP1 and the erythrocyte cytoskeletal protein 4.1R was examined using co-immunoprecipitation. A Pbsbp1 gene knockout mutant of Plasmodium berghei (Pbsbp1∆) was generated based on the principle of double crossover homologous recombination. The deformability of erythrocytes infected with Pbsbp1∆ parasites was assessed using microfluidic methods. Microchannels with an array of cylindrical pillars were used to detect modifications in infected RBC deformability. The infected RBCs were squashed between the rows and recovered between the columns and the transit velocity (μm/s) of infected RBCs travelling through the microchannel was recorded. The component of the erythrocyte membrane skeleton junctional complex, tropomodulin (TMOD), was fluorescently labeled, and the cytoskeletal network of infected erythrocytes was imaged using super-resolution stochastic optical reconstruction microscopy (STORM) to analyze ultrastructural changes in the cytoskeleton of wild-type (WT) and Pbsbp1∆-infected erythrocytes. Actin-based junctional complexes were displayed as individual clusters by the labeled TMOD in the STORM images, and the cluster densities and distances between adjacent clusters of infected RBCs were calculated. Additionally, rodent malaria models (BALB/c mice) and experimental cerebral malaria models (C57BL/6 mice) were employed to monitor the growth of Pbsbp1∆ and WT parasites during the intraerythrocytic stage and their capacity to induce cerebral malaria in mice. ResultsPbSBP1 may participate in the remodeling of infected erythrocytes through direct or indirect interaction with the erythrocyte cytoskeletal protein 4.1R. Microfluidic assays revealed that the deformability of erythrocytes infected with Pbsbp1∆ parasites was significantly enhanced compared to those infected with WT parasites. STORM imaging further demonstrated that the ultrastructure of the erythrocyte cytoskeleton in Pbsbp1∆-infected cells was altered relative to that in WT-infected erythrocytes. The distances between nearest neighbors of clusters had a tendency to increase while the cluster densities were decreased in Pbsbp1∆-infected RBCs compared to WT-infected RBCs. Subsequent phenotypic analysis indicated that the growth rate of Pbsbp1∆ parasites during the intraerythrocytic stage was significantly slower than that of WT parasites, and their ability to induce cerebral malaria in mice was also attenuated. These findings suggest that PbSBP1 is involved in the remodeling of the erythrocyte membrane skeleton, likely through its direct or indirect interaction with protein 4.1R, thereby regulating the deformability of infected erythrocytes and influencing the pathogenicity of the blood-stage parasites. ConclusionThis study establishes a role for PbSBP1 in host erythrocyte remodeling and parasite virulence, providing new research strategies for the prevention and treatment of malaria.

Objective To investigate the synergistic therapeutic effects of HER2 antibody-drug conjugate(HER2-ADC)combined with anti-PD-1 antibody(anti-PD-1)on HER2-expressing bladder cancer and elucidate its regulatory mechanisms on the tumor immune microenvironment.Methods Orthotopic tumor models were established in 40 female C57BL/6 mice(6～8 weeks old,body mass 18～22 g)using MB49 bladder cancer cells overexpressing human HER2.When tumors reached 100 mm3,the mice were randomized into(n=10)control(intraperitoneal injection of 1.0 mL PBS),anti-PD-1(200 μg per mouse every 3 d),HER2-ADC(2.5 mg/kg once weekly),and combination groups(same regimens as above monotherapy).Tumor volume and body mass were measured every 3 d during 28-day treatment.Tumor growth kinetics and survival rates were analyzed.Post-treatment survival was monitored until natural death to determine median survival time(n=5).At day 28,blood and tumor samples(n=5)were collected to detect myeloid-derived suppressor cells(MDSCs;CD11b?Gr1?)and regulatory T cells(Tregs;CD4?CD25?FOXP3?)with flow cytometry,tumor-infiltrating CD3?T,CD8?T,and FOXP3?T cells with immunohistochemical assasy,and liver/kidney functions[alanine aminotransferase(ALT),aspartate aminotransferase(AST),blood urea nitrogen(BUN),creatinine(CRE)]and tissue damage indicators[lactate dehydrogenase isoenzyme(LDH-L)].Results In 28 d after treatment,the combination group obtained significantly smallest tumor volume than the control group and the 2 monotherapy groups(all P<0.01).The longest median survival was observed in the combination group(65 d,P<0.01),followed by the HER2-ADC group(55 d),anti-PD-1 group(53 d)and control group(41 d).After 28 d of treatment,the combination group exhibited obviously the smallest peripheral proportions of MDSCs/Tregs,most tumor-infiltrating CD3?T/CD8?T cells,and less FOXP3?T cells when compared with the 2 monotherapy groups and control group(all P<0.05).While,the 2 monotherapy groups had smaller MDSCs/Tregs proportions than the control group(P<0.05).No significant differences were observed among the 4 groups in serum ALT,AST,BUN,CRE,or LDH-L levels,and all of them were within normal ranges.Conclusion HER2-ADC combined with anti-PD-1 suppresses the growth of orthotopic bladder tumor,probably through their synergic effects on down-regulating MDSCs/Treg and enhancing CD8?T cell infiltration.

In recent years,the market share of food and medicine homology substances has continued to grow,and various types of contamination issues have become the focus of attention both inside and outside the industry.The contamination not only affects the original medicinal quality,but also leads to the accumulation of toxic substances in the human body,causing acute and chronic severe hazards such as vomiting,poisoning and cancer.Therefore,the development of biosensors that can conveniently,accurately and sensitively detect various pollutants in food and medicine homology substances has become a research hotspot.Aptasensors based on metal-organic frameworks(MOFs)with advantages such as strong specificity,rapid response and simple operation,have been widely used in detection of various pollutants.This review focused on the research progress of aptasensors based on MOFs for detection of food and medicine homology contamination in the past few years,and provided a detailed comparison and analysis for detection of chemical pollutants(such as pesticide residues,heavy metal residues,mycotoxins,etc.)and microbial contamination in food and medicine homology substances.Besides,the development trend and possible challenges of MOFs aptasensors in detection of food and medicine homology substances in the future were discussed,which was anticipated to provide a reference for the development of new MOFs aptasensors.

6-Thioguanine(6-TG)is an antineoplastic agent used in treatment of acute leukemia.However,significant interindividual variability in dosing regimens and frequent clinical manifestations of hepatotoxicity and myelosuppression as adverse effects have affected its therapeutic efficacy.Consequently,the development of rapid analytical methods for 6-TG in clinical samples,enabling continuous therapeutic drug monitoring of plasma concentrations,holds substantial significance in optimizing dosage regimens,mitigating adverse reactions,and investigating drug metabolism mechanisms.In this study,multi-tipped gold nanostars(AuNSs)were prepared.With bis-(p-sulfonylphenyl)phenylphosphine molecule as the protecting agent and internal standard molecule,the AuNSs were assembled onto a highly sensitive surface-enhanced Raman(SERS)substrate for developing a ratio-based SERS quantitative analysis method for 6-TG in serum.The AuNSs containing multiple tips and gaps exhibited strong local surface plasmon resonance effect and SERS activity,ensuring the sensitivity of the analytical method.Furthermore,the introduction of internal standard molecules could improve the reproducibility,which guaranteed this method suitable for rapid analysis of drug molecules in complex samples.Quantitative analysis of 6-TG was achieved with linear detetion range of 1.0×10?4-1.0 mmol/L.In the spiked recovery experiments of serum,the RSD was less than 5.32%,and the recoveries were 94%-104%,which proved that this method could be used for rapid quantitative determination of 6-TG in serum.This method provided a powerful tool for studying drug pharmacokinetics,which could promote the optimization of the usage methods of anti-cancer drugs,and it was expected to further enhance the clinical efficacy and safety of 6-TG,enabling it to achieve the best therapeutic effect.

Due to the poor ionization efficiency and the weak mass spectrometry(MS)intensity of weakly polar substances,direct analysis using the traditional electrospray ionization mass spectrometry(ESI-MS)is a big challenge.In this study,a novel rapid on-site detection method of four prohibited sex hormones in cosmetics was proposed using online derivatization strategy coupled with a miniature mass spectrometer.The target substances in the samples were extracted by a custom-made polyaniline/multi-walled carbon nanotube solid-phase microextraction(SPME)probe.The stirring speed was 200 r/min,the extraction temperature was 40℃,and the extraction time was 2 min.A pulled dual-channel θ borosilicate glass capillary emitter was used as the nano-ESI ion source.The SPME probe was inserted into the channel containing methanol in theθborosilicate glass capillary.When the spray voltage was applied,the four sex hormones were desorbed and formed spray microdroplets,which then collided with the hydroxylamine microdroplets generated from the other channel.The microdroplets of reaction product entered into the miniature mass spectrometer for direct analysis.The limits of detection(LOD)and limits of quantification(LOQ)for the four sex hormones were 10-20 ng/mL and 20-50 ng/mL,respectively.The recoveries were from 84.6%to 107.8%with the relative standard deviations(RSD)from 4.1%to 11.6%.Compared to detection without derivatization,the MS signals of the four target substances were increased by 3 to 15 times.This method was simple,rapid,highly efficient and sensitive,and suitable for on-site rapid analysis of weakly polar sex hormones in cosmetics.

Objective:To investigate the rate-limiting steps of hand-assisted laparoscopic donor nephrectomy, analyze the relevant factors affecting surgical difficulty, and subsequently construct a mathematical model to predict the difficulty of the procedure preoperatively.Methods:A retrospective study was conducted on 100 kidney donors who underwent hand-assisted laparoscopic donor nephrectomy performed by the same surgeon at Beijing Friendship Hospital, Capital Medical University from January 2021 to January 2024. Preoperative demographic data, imaging findings, general condition, donor kidney size, and postoperative complications were collected and analyzed. The surgeon′s subjective rating (1-3 points) was used as a quantitative measure of surgical difficulty. ANOVA and Chi-square tests were employed to explore the differences in postoperative complications, recovery, operative time, and intraoperative blood loss among groups with varying levels of difficulty. The main procedure was divided into four steps (excluding abdominal closure): Trocar placement, renal hilar dissection, perinephric dissection, and kidney retrieval. The time for each step and the total operative time were recorded. Pearson correlation test was used to analyze the relationship between each step and the total operative time, and ANOVA test was used to assess the time differences between steps and to determine if the time for the same step varied across different difficulty subgroups, thereby identifying the rate-limiting step of hand-assisted laparoscopic donor nephrectomy. In terms of the risk factors influencing the difficulty of surgery, Pearson and Spearman correlation tests were used to investigate the relationship between preoperative donor data and surgical difficulty scores, and a predictive model was constructed using multiple linear regression. Finally, the model was internally and externally validated to confirm its accuracy and effectiveness.Results:As the surgical difficulty increased (groups 1, 2, and 3), the postoperative drainage tube duration was correspondingly prolonged [(5.92±1.48) d, (8.00±1.75) d, and (11.88±4.45) d, respectively, P<0.05], and the severity of postoperative complications also significantly increased (the incidence of Clavien-Dindo grade ≥2 was 5.66%, 31.82% and 64.00%, respectively, P<0.01). In the analysis of rate-limiting steps, the time taken for all steps, except for Trocar placement, showed significant differences among the difficulty subgroups ( P<0.001). However, the average time for renal hilar dissection was (19.82±5.65) min, which was significantly longer than the other steps ( P<0.001). Therefore, renal hilar dissection was identified as the rate-limiting step of hand-assisted laparoscopic donor nephrectomy. In terms of the influencing factors of surgical difficulty, donor obesity, kidney width, abdominal anteroposterior sagittal diameter, number of renal arteries, distance from renal artery bifurcation to the abdominal aorta, degree of renal artery calcification, and mayo adhesive probability (MAP) score were all correlated with the surgical difficulty score ( P<0.05). However, multiple linear regression analysis revealed that only the number of renal arteries and the MAP score were the independent risk factors for higher surgical difficulty of hand-assisted laparoscopic donor nephrectomy. The predictive equation was: surgical difficulty=0.649×number of renal arteries+ 0.770×MAP score. Both internal and external validation confirmed the model's good accuracy. Conclusions:This study established a reliable and objective predictive model for the difficulty of hand-assisted laparoscopic donor nephrectomy based on the number of renal arteries and the MAP score. Renal hilar dissection was identified as the rate-limiting step of the procedure. This provides a reference for selecting an appropriate surgeon based on the predicted surgical difficulty.

Traditional mass measurement methods are not applicable in microgravity environments,and the main challenge for in-orbit body mass measurement technology based on inertial principles is to address the random errors brought about by the weightless environment.These include additional torques due to shifts in the center of mass,nonlinear accelerations due to non-rigid human bodies,mechanical energy consumption due to organ vibrations,and random vibrations of the measurement device itself.To address the above difficulties,the project proposes a technical scheme based on the principle of linear acceleration,designs and constructs a ground-specific air-floating experimental and simulation platform,studies key data such as motion trajectory,acceleration change,and vibration frequency amplitude during the mass measurement process,and simulates the changes in the center of mass and random vibrations of the human body in a weightless environment.The project has designed an adjustable posture bracket to adapt to changes in the center of mass,enhance body restraint,and greatly reduce shaking;it has also developed an integrated four-bar linkage motion guidance mechanism,high-precision integrated photoelectric distance measurement,and modular motion constant force measurement device to ensure the accurate measurement of acceleration and constant force data.The product has undergone simulation calculations,ground human applicability tests,and in-orbit applicability verification in the space station.Ground test results show that the device achieves a body mass measurement accuracy better than 0.5%,and the dispersion is better than 0.38%;after flight mission verification and evaluation,the in-orbit body mass measurement dispersion is less than 0.4%,which is superior to the SLAMMD,a mass measurement device of the same principle on the International Space Station,and is at the forefront internationally,achieving accurate body mass measurement.

Objective To conduct a quantitative risk assessment of Listeria monocytogenes(LM)in prepackaged,non-vacuum sealed,short shelf-life,ready-to-eat meat products in Chengdu using the@Risk software.Methods Based on monitoring data of LM contamination in pre-packaged,non-vacuum sealed,refrigerated ready-to-eat meat products in Chengdu obtained from a previous study,a risk assessment model was established.The risk of LM infection caused by consuming cooked meat products in different groups of people was quantitatively assessed.In addition,the growth of LM in cooked meat products,from retail to consumption,was also taken into consideration in the assessment.Results In Chengdu,the numbers of potential cases of listeriosis caused by consumption of prepackaged,non-vacuum sealed,refrigerated ready-to-eat meat products were 0.01(95％confidence interval[CI]:0-1.71 × 10-2)per year per million in healthy individuals aged 5-＜65 years old,0.22(95％CI:0-2.67 × 10-1)in healthy individuals aged 65 and above,and 2.88(95％CI:3.85 × 10-8-4.35)in pregnant women.According to the results of the sensitivity analysis,the initial pollution level of LM in the retail stage was the most important factor affecting the prevalence(R=0.25),followed by retail temperature(R=0.08),retail time(R=0.07),and amount of consumption per meal(R=0.07).Conclusions For pre-packaged,non-vacuum sealed,cooked meat products,the most important measure to reduce the prevalence of listeriosis is to control the initial contamination level,which requires food processing plants to regularly clean and strictly disinfect the processing environment and equipment to minimize LM contamination at the source.Retail delicatessens should strictly maintain a storage temperature below 5.0℃ and strictly adhere to product shelf-life recommendations.As for consumers,they should consume these meat products as soon as possible after purchase or store them under refrigerated conditions and shorten the storage time.Pregnant women should thoroughly heat the meat products before eating to reduce the risk of listeriosis.

Objective To identify S-palmitoylation sites on angiotensin-converting enzyme 2(ACE2),the cellular receptor for severe acute respiratory syndrome corona virus(SARS-CoV)and SARS-CoV-2,and to investigate the functional relevance of these modifications in regulating ACE2 localization and activity.Methods An optimized multi-site mutagenesis strategy was performed by simultaneously substitution of all eight cysteine(Cys)residuesin ACE2 by serine to create a non-palmitoylatable mutant(8CS).Then individual cysteine residues were re-introduced one by one.Palmitoylation level of mutants was evaluated using a bioorthogonal click chemistry method to identify palmitoylation-competent residues.Immune-fluorescence staining and extra-cellular vesicle isolation assays were then used to evaluate the impact of specific palmitoylation sites on ACE2 sub-cellular localization.Results An efficient strategy for multi-site palmitoylation site mapping was optimized and successfully identified three critical palmitoylation sites on ACE2:Cys141,Cys344 and Cys498.Functional analyses showed that palmi-toylation of these sites significantly promotes the enrichment of ACE2 in extra-cellular vesicles.Conclusions S-palmitoylation at Cys141,Cys344 and Cys498 is essential for the trafficking of ACE2 to extra-cellular vesicles,which suggests a potential regulatory mechanism of its impact on viral receptor presentation and ACE2-associated signaling pathways.