AIM:To investigate the effects of high-altitude hypoxic exposure on retinal injury and the associated changes in oxidative stress-related indicators in rats. METHODS: Twenty-four healthy male Sprague-Dawley(SD)rats were randomly divided into a plain group and a high-altitude group, with 12 rats(24 eyes)in each group. Rats in the plain group were housed under normoxic conditions in an SPF-grade animal facility, whereas rats in the high-altitude group were placed in a special environmental chamber simulating an altitude of 6 000 m for 7 d. Optical coherence tomography(OCT)was used to assess retinal layer architecture and quantify retinal thickness. Hematoxylin-eosin(HE)staining was performed to observe retinal histopathological changes. Immunofluorescence(IF)was used to detect the expression of hypoxia-inducible factor-1α(HIF-1α)in retinal tissue. Transmission electron microscopy(TEM)was applied to examine the ultrastructure of retinal ganglion cells(RGCs). Enzyme-linked immunosorbent assay(ELISA)was used to measure the levels of malondialdehyde(MDA), total superoxide dismutase(T-SOD), and reduced glutathione(GSH)in retinal tissue. In addition, intracellular reactive oxygen species(ROS)levels in retinal tissue were assessed using the 2',7'-dichlorodihydrofluorescein diacetate(DCFH-DA)fluorescent probe. RESULTS: OCT examination revealed disorganized retinal architecture in the high-altitude group, with increased inner and middle ring thickness and decreased outer ring thickness compared with the plain group(all P<0.05). HE staining showed varying degrees of retinal layer damage, blurred layer boundaries, loosely arranged RGCs, and partial cellular necrosis in the high-altitude group. IF analysis demonstrated significantly increased HIF-1α expression in the inner nuclear layer of the high-altitude group(P<0.01). TEM revealed mitochondrial swelling, disrupted cristae, and reduced matrix electron density in RGCs of the high-altitude group. ELISA and fluorescence probe assays showed significantly elevated MDA levels and ROS fluorescence intensity, accompanied by decreased T-SOD and GSH levels in the retinal tissue of the high-altitude group(all P<0.05). CONCLUSION: Exposure to a high-altitude hypoxic environment induces marked morphological and ultrastructural damage in the rat retina and significantly enhances oxidative stress, suggesting that oxidative stress may play a critical role in retinal injury induced by high-altitude hypoxia.

ObjectivePancreatic ductal adenocarcinoma (PDAC) exhibits a limited response to current treatments due to its dense fibrotic stroma and highly immunosuppressive tumor microenvironment. In recent years, advancements in cellular immunotherapy, particularly chimeric antigen receptor macrophage (CAR-M) therapy, have offered new hope for pancreatic cancer treatment. Although CAR-M therapy demonstrates dual potential in directly killing tumor cells and remodeling the immune microenvironment, it still faces challenges such as complex in vitro preparation processes and low in vivo targeting and delivery efficiency. Therefore, developing strategies for efficient and targeted in vivo delivery of CAR genes has become crucial for overcoming current therapeutic limitations. This study aims to develop an orally administrable nano-gene delivery system for the targeted delivery of CAR genes to pancreatic tumor sites. MethodsCore nano-gene particles (PNP/pCAR) were constructed by loading plasmid DNA encoding CAR (pCAR) with cationic polypeptides (PNP). Subsequently, PNP/pCAR was surface-modified with β-glucan to prepare the targeted nanoparticles (βGlus-PNP/pCAR). The loading efficiency of PNP for pCAR was quantitatively assessed by gel retardation assay. The particle size, Zeta potential, morphology, and storage stability of PNP/pCAR were characterized using a Malvern particle size analyzer and transmission electron microscopy. At the cellular level, RAW 264.7 macrophages were selected. The cytotoxicity of PNP/pCAR was evaluated using the CCK-8 assay. The cellular uptake efficiency and lysosomal escape ability of the nanoparticles were assessed via flow cytometry and confocal microscopy. Transfection efficiency was quantitatively evaluated by detecting the expression of the reporter gene GFP using flow cytometry. At the in vivo level, an orthotopic pancreatic cancer mouse model was established. Cy7-labeled βGlus-PNP/pCAR nanoparticles were administered orally, and the fluorescence distribution in mice was dynamically monitored at 1, 2, 4, 8, and 16 h post-administration using a small animal in vivo imaging system. Forty-eight hours after oral gavage, the mice were euthanized, and pancreatic tumor tissues were collected for further analysis of intratumoral fluorescence signals using the imaging system. Additionally, βGlus-PNP/pCAR-GFP nanoparticles loaded with the reporter gene (GFP) were administered orally. Forty-eight hours post-administration, pancreatic tumor tissues were harvested to prepare frozen sections, and GFP expression was observed and analyzed under a fluorescence microscope. ResultsThe PNP carrier exhibited a high loading capacity for pCAR. The successfully prepared PNP/pCAR nanoparticles were regular spheres with a hydrodynamic diameter of approximately (120±10) nm and a Zeta potential of about +(6±1) mV. They maintained good structural stability after incubation in PBS buffer for 7 d. Cell experiments demonstrated that PNP/pCAR exhibited no significant cytotoxicity in RAW 264.7 cells while being efficiently internalized and effectively escaping lysosomal degradation. The transfection positive rate of PNP/pCAR-GFP in RAW 264.7 cells reached (25±3)%, surpassing that of Lipofectamine 2000-loaded pCAR-GFP (Lipo/pCAR-GFP), which was (20±1)%.In vivo experiments revealed that, compared to unmodified PNP/pCAR, βGlus-PNP/pCAR exhibited strongerin situ pancreatic tumor targeting ability after oral administration. Furthermore, oral administration of βGlus-PNP/pCAR-GFP resulted in significant GFP protein expression detectable within pancreatic tumor tissues. ConclusionThis study successfully constructed and validated an orally administrable, pancreatic cancer-targeting polypeptide-based nano-gene delivery system. It provides an important technological foundation in delivery systems and experimental basis for the subsequent development of in situ CAR-M-based therapeutic strategies for pancreatic cancer.

ObjectivePancreatic ductal adenocarcinoma (PDAC) exhibits a limited response to current treatments due to its dense fibrotic stroma and highly immunosuppressive tumor microenvironment. In recent years, advancements in cellular immunotherapy, particularly chimeric antigen receptor macrophage (CAR-M) therapy, have offered new hope for pancreatic cancer treatment. Although CAR-M therapy demonstrates dual potential in directly killing tumor cells and remodeling the immune microenvironment, it still faces challenges such as complex in vitro preparation processes and low in vivo targeting and delivery efficiency. Therefore, developing strategies for efficient and targeted in vivo delivery of CAR genes has become crucial for overcoming current therapeutic limitations. This study aims to develop an orally administrable nano-gene delivery system for the targeted delivery of CAR genes to pancreatic tumor sites. MethodsCore nano-gene particles (PNP/pCAR) were constructed by loading plasmid DNA encoding CAR (pCAR) with cationic polypeptides (PNP). Subsequently, PNP/pCAR was surface-modified with β-glucan to prepare the targeted nanoparticles (βGlus-PNP/pCAR). The loading efficiency of PNP for pCAR was quantitatively assessed by gel retardation assay. The particle size, Zeta potential, morphology, and storage stability of PNP/pCAR were characterized using a Malvern particle size analyzer and transmission electron microscopy. At the cellular level, RAW 264.7 macrophages were selected. The cytotoxicity of PNP/pCAR was evaluated using the CCK-8 assay. The cellular uptake efficiency and lysosomal escape ability of the nanoparticles were assessed via flow cytometry and confocal microscopy. Transfection efficiency was quantitatively evaluated by detecting the expression of the reporter gene GFP using flow cytometry. At the in vivo level, an orthotopic pancreatic cancer mouse model was established. Cy7-labeled βGlus-PNP/pCAR nanoparticles were administered orally, and the fluorescence distribution in mice was dynamically monitored at 1, 2, 4, 8, and 16 h post-administration using a small animal in vivo imaging system. Forty-eight hours after oral gavage, the mice were euthanized, and pancreatic tumor tissues were collected for further analysis of intratumoral fluorescence signals using the imaging system. Additionally, βGlus-PNP/pCAR-GFP nanoparticles loaded with the reporter gene (GFP) were administered orally. Forty-eight hours post-administration, pancreatic tumor tissues were harvested to prepare frozen sections, and GFP expression was observed and analyzed under a fluorescence microscope. ResultsThe PNP carrier exhibited a high loading capacity for pCAR. The successfully prepared PNP/pCAR nanoparticles were regular spheres with a hydrodynamic diameter of approximately (120±10) nm and a Zeta potential of about +(6±1) mV. They maintained good structural stability after incubation in PBS buffer for 7 d. Cell experiments demonstrated that PNP/pCAR exhibited no significant cytotoxicity in RAW 264.7 cells while being efficiently internalized and effectively escaping lysosomal degradation. The transfection positive rate of PNP/pCAR-GFP in RAW 264.7 cells reached (25±3)%, surpassing that of Lipofectamine 2000-loaded pCAR-GFP (Lipo/pCAR-GFP), which was (20±1)%.In vivo experiments revealed that, compared to unmodified PNP/pCAR, βGlus-PNP/pCAR exhibited strongerin situ pancreatic tumor targeting ability after oral administration. Furthermore, oral administration of βGlus-PNP/pCAR-GFP resulted in significant GFP protein expression detectable within pancreatic tumor tissues. ConclusionThis study successfully constructed and validated an orally administrable, pancreatic cancer-targeting polypeptide-based nano-gene delivery system. It provides an important technological foundation in delivery systems and experimental basis for the subsequent development of in situ CAR-M-based therapeutic strategies for pancreatic cancer.

ObjectiveTo investigate the mechanism by which Bushao Tiaozhi capsules （BSTZ） ameliorate hyperlipidemia based on untargeted metabolomics and targeted bile acid quantification. MethodsA rat model of hyperlipidemia was established with a high-fat diet. The rats were randomized into five groups： normal control， model， atorvastatin calcium （1.8 mg·kg^-1）， and low-dose （2.88 g·kg^-1） and high-dose （5.76 g·kg^-1） BSTZ groups. All treatments were administered for four consecutive weeks. Serum levels of total cholesterol （TC）， triglycerides （TG）， low-density lipoprotein cholesterol （LDL-C）， and high-density lipoprotein cholesterol （HDL-C） were measured by biochemical assays. Hepatic histopathological changes were evaluated via hematoxylin-eosin （HE） staining， and lipid droplet deposition was assessed by oil red O staining. Integrated untargeted metabolomics and targeted bile acid quantification were employed to investigate BSTZ-induced alterations in hepatic metabolic profile and bile acid profile. Additionally， correlation analyses were conducted between differential bile acids and lipid parameters to identify key bile acids. ResultsCompared with the normal control group， the model group exhibited elevated serum TC， TG， and LDL-C levels （P<0.01） and a reduced HDL-C level （P<0.01）， along with marked hepatic steatosis and extensive lipid droplet deposition. Compared with the model group， all BSTZ treatment groups showed decreased TC， TG， and LDL-C levels （P<0.01） and increased HDL-C levels （P<0.01）， accompanied by notably alleviated hepatic steatosis and lipid deposition. Untargeted metabolomics and targeted bile acid quantification revealed that BSTZ significantly remodeled the hepatic bile acid profile， characterized by elevated levels of secondary bile acids （DCA， HDCA， TDCA， and TLCA） and reduced levels of primary bile acids （CDCA and TCDCA）. Correlation analyses further demonstrated strong associations between differential bile acids and lipid parameters： elevated secondary bile acids were negatively correlated with serum TC， TG， and LDL-C levels， whereas primary bile acids were positively correlated with these parameters. ConclusionBSTZ can ameliorate dyslipidemia and hepatic lipid accumulation in hyperlipidemic rats by regulating hepatic bile acid homeostasis， which provides metabolic clues for subsequent mechanism validation.

Objective:To explore the value of a scoring system based on preoperative abdominal computed tomography (CT) for predicting the difficulty of laparoscopic cholecystectomy (LC).Methods:A retrospective analysis was conducted on 105 patients diagnosed with gallstones or cholecystitis who underwent LC at Beijing Jishuitan Hospital, Capital Medical University from January 2021 and February 2022. Based on surgical video reviews, patients were divided into the easy group ( n=58) and the difficult group ( n=47) according to the intraoperative Parkland Grading Scale (PGS), with PGS grades 1-2 assigned to the easy group, and PGS grades 3-5 assigned to the difficult group. The normally distributed measurement data were expressed as mean±standard deviation ( ± s), and compared using independent samples t-test; the non-normally distributed measurement data were expressed as median (interquartile range) [ M ( Q1, Q3)], and compared using the rank-sum test. The count data were expressed as the number of cases and percentage, and compared using the Chi-square test or Fisher exact probability method. Univariate analysis and cut-off value determination: for continuous CT variables, univariate Logistic regression and stepwise regression analyses (with surgical difficulty grouping as the dependent variable) were performed to identify the optimal combination of predictive variables and establish a scoring system. For each significantly associated continuous variable or important CT image feature from a clinical perspective, receiver operating characteristic (ROC) curve analysis was used to evaluate its predictive performance for difficult surgery. The area under the curve (AUC) was calculated, and the optimal cut-off value was determined using the Youden index to maximize the sum of sensitivity and specificity. The categorical CT image features were scored according to their original groups. The Kappa consistency test was used to assess the strength of agreement between the preoperative abdominal CT score (grouped by the optimal cut-off) and PGS grades (easy/difficult). Decision curve analysis (DCA) was employed to validate the predictive performance of the model. Results:Stepwise Logistic regression identified seven key imaging features as the optimal predictive variables for constructing the preoperative abdominal CT scoring system: maximum gallbladder cross-sectional diameter, maximum gallbladder cross-sectional width, gallbladder wall thickness, common bile duct diameter, pericholecystic fat stranding, periductal fat stranding, and impacted cystic duct stones. Each case was scored after assigning scores based on the optimal cut-off values. The total score of the preoperative abdominal CT scoring system was ≥3 points predicted difficult LC with an AUC of 0.745 (95% CI: 0.650-0.839), sensitivity of 66.0%, and specificity of 75.9%. DCA confirmed the model′s reliable predictive performance, and the preoperative abdominal CT scoring system showed good agreement with PGS grades ( Kappa value was 0.420, P<0.001). Conclusions:The preoperative abdominal CT scoring system based on pericholecystic imaging features can effectively predict the difficulty of LC with good discriminative ability. It provides a quantitative tool for preoperative assessment, surgical scheduling, and ambulatory surgery management.

Objective To explore the anatomical landmarks and segmentation method for the intraoperative identification of the cervical segment of the internal carotid artery by studying cadaveric dissections with an endoscopic transoral medial pterygomandibular fold approach and to investigate its clinical significance.Methods The head specimens of five fresh frozen cadavers were dissected in the anatomical laboratory of the Surgical Treatment Technology Innovation Unit of Nasal Skull Base Tumor in Eye&ENT Hospital of Fudan University.The parapharyngeal space was dissected layer by layer through the endoscopic transoral medial pterygomandibular fold approach,and the location marks of parapharyngeal internal carotid artery(ppICA)and adjacent structures of ppICA were anatomically studied.The anatomical landmarks associated with ppICA were observed and characterized,and the ppICA was segmented anatomically according to its adjacent structures.Then,the length of each ppICA segment was measured.Results Muscle structures were essential anatomical landmarks for an endoscopic transoral pterygoid medial approach that identifies mandibular folds.The first layer of muscles included the superior pharyngeal constrictor,tensor veli palatini,and medial pterygoid muscles.The second layer includes the stylopharyngeus,styloglossus,longus capitis,and levator veli palatini muscles.The stylopharyngeal and levator veli palatini muscles were close to the ppICA and were reliable landmarks for locating the ppICA.Furthermore,the ppICA was divided into three segments according to their positional relationship with the ppICA.The first segment of ppICA(P1 ICA)was located between the greater horn plane of the hyoid bone and the intersection plane between the upper margin of stylopharyngeal muscle and ppICA.The second segment of ppICA(P2 ICA)was between the plane where the upper edge of the stylopharyngeal muscle intersected with the ppICA and the plane where the projection of inferior edge of the levator veli palatini muscle intersected with the ppICA.The third segment of ppICA(P3 ICA)was between the intersection of the lower margin projection of the levator veli palatini muscle and ppICA and the external orifice of the carotid canal.The P2 ICA was within an anatomical region bounded by the levator veli palatini muscle,longus capitis muscle,and stylopharyngeus muscle.This region was termed"ICA window"in this paper measured under the cadaver head specimen,the lengths of P1 ICA,P2 ICA,and P3 ICA were(36.5±7.3)mm,(15.5±1.6)mm,(7.4±1.7)mm respectively.Conclusion The muscular structure refers to the relatively constant anatomical reference landmarks within the endoscopic transoral medial pterygomandibular fold.The stylopharyngeus and levator veli palatini muscles are reliable landmarks for precisely locating and segmenting the ppICA,thus having essential clinical implications.

Objective West Nile virus(WNV)is one of the most common mosquito-borne zoonotic viruses worldwide,with unique transmission dynamics and varied hosts.Lots of ecological and host factors have been reported to influence the host adaptation and transmission of WNVs,however,general genomic features of WNVs are less focused,except for some exact host-specific genotypes at molecular level.Artificial intelligence that analyzes genome composition characteristics currently shows significant advantages in identifying and predicting viral host adaptability.This research aimed to establish a convolutional neural network(CNN)model to predict the host adaptability of WNVs based on general genomic features.Methods Presently available WNV gene sequences were embedded for their genomic features with an embedding approach of dinucleotide composition representation(DCR).And DCR-based distribution difference of WNV samples among various hosts was performed with unsupervised learning methods.Then a classification model was built with a convolutional neural network(CNN)framework based on genomic DCR to evaluate the adaptation of the WNVs from birds,mammals and mosquitos.Additionally,host-specific amino acids in WNV proteins were inferred via Bayes method.Results DCR features could effectively distinguish host-specific WNVs.The trained CNN model predicted accurately mammalian susceptible WNVs from avian susceptible WNVs,however,much less accurately for mosquito/mammalian WNVs.Such predicted host adaptation was interpreted as host specified significance of biased amino acid distribution on the bayes-inferred sites in WNV proteins,implying a possible high significance of these sites for WNV adaptive phenotypes.Conclusions Genomic compositional features of WNVs are host-specific,and such genomic bias facilitates predicting the adaptation of WNVs to avian or mammalian hosts via deep learning methods.DCR-based decomposition is helpful to recognize the high risk of infecting mammals of WNVs.The present study provides a general knowledge of genomic features contributing to host adaptation to WNVs.

Objective:To develop a bacterial endotoxin detection method suitable for mRNA vaccines based on lipid nanoparticle（LNP）delivery system.Methods:The gel clot limit test outlined in the third section of the Chinese Pharmacopoeia（2020 edition）was utilized. Taking the human herpesvirus type 2 mRNA vaccine as the detection object，the optimal conditions for bacterial endotoxin detection were established by evaluating sample dilution factors，diluents，and other interfering elements. The results were validated using the recombinant C factor method. Finally，the applicability of the established method was validated through testing the respiratory syncytial virus mRNA vaccine and the shingles mRNA vaccine.Results:Increasing the sample dilution factor to 480 times with a magnesium-containing buffer and using 0.06 EU/ml tachypleus amebocyte lysate effectively mitigated the interference caused by LNP on the test results of the human herpesvirus type 2 mRNA vaccine，the respiratory syncytial virus mRNA vaccine，and the shingles mRNA vaccine. The results from recombinant C factor method and the gel clot limit method were consistent.Conclusion:A bacterial endotoxin gel clot limit detection method tailored for human herpesvirus type 2 mRNA vaccine，respiratory syncytial virus mRNA vaccine，and shingles mRNA vaccine is successfully developed based on existing protocols in the Chinese Pharmacopoeia（2020 edition）. This study offers insights for the detection of bacterial endotoxin in LNP-based biological products.

Objective:To investigate the significance of urinary 8-oxo-7, 8-dihydroguanosine(8-oxoGuo)in assessing the short-term prognosis of sepsis in frail elderly patients.Methods:We conducted a cross-sectional study involving 62 frail elderly patients diagnosed with sepsis who were admitted to the Emergency Intensive Care Unit(EICU)at Beijing Hospital between March 2021 and March 2022.Based on their 28-day prognosis, the patients were categorized into two groups: those who died and those who survived.Upon admission, we collected urine samples and clinical data from both groups.We employed isotope dilution high-performance liquid chromatography-mass spectrometry to measure the levels of the RNA oxidation marker 8-oxoGuo in the urine.Results:A total of 62 frail elderly patients[aged(85.1±6.3)years]diagnosed with sepsis were included in the study, comprising 36 patients in the 28-day mortality group and 26 patients in the survival group.Univariate analysis revealed that the survival group had significantly lower body temperature, blood calcitonin(PCT)levels, sequential organ failure assessment(SOFA)scores, and urinary 8-oxoGuo levels compared to the mortality group.Additionally, the survival group exhibited a higher mean arterial pressure(MAP)than the mortality group, with all differences reaching statistical significance(all P<0.05).Spearman correlation analysis indicated that urinary 8-oxoGuo levels were positively correlated with both PCT and SOFA scores in frail elderly sepsis patients( r=0.426, 0.768, both P<0.05).Furthermore, logistic regression analysis identified urinary 8-oxoGuo and SOFA as independent risk factors for 28-day mortality in this population( OR=1.936, 1.427; P=0.006, 0.002).The area under the receiver operating characteristic curve(AUC)for urinary 8-oxoGuo and SOFA in predicting the 28-day prognosis of frail elderly sepsis patients was 0.761 and 0.741, respectively, both demonstrating statistical significance(both P<0.001). Conclusions:Our findings suggest that urinary 8-oxoGuo possesses strong predictive value for the short-term prognosis of sepsis in this vulnerable population.

Objective:To investigate the current status and challenges of pediatric life support training in China and provide references for improving training quality.Methods:A cross-sectional study was conducted to collect data from pediatric life support training centers across the country，covering basic institutional information，training capacity and training faculty，training program funding，as well as existing challenges and issues.The domestic registry of training centers in 2023 was obtained through the American Heart Association's online platform.After contacting and verifying each center，an online questionnaire was distributed，and the aggregated data were statistically analyzed.Results:A total of 42 institutions participated in the survey，including 19 children's hospitals，14 general hospitals，6 maternal and child health hospitals，2 women and children’s hospitals，and 1 training institution.The distribution of training centers showed a concentration in coastal areas，with the top three provinces/municipalities being Guangdong（7/42，16.7%），Zhejiang（6/42，14.3%），and Shanghai（4/42，9.5%）.As of December 31 2023，the 42 institutions had an annual basic life support（BLS）training volume of 8 587 individuals，the median was 120 (100,200)，and an annual pediatric advanced life support（PALS）training volume of 2 448 individuals，the median was 30 (20,50).Among the 42 institutions，there were 598 BLS instructors and 306 PALS instructors.Among the surveyed institutions，24（24/42，57.1%）reported BLS instructor teams comprising fewer than 10 members，and 33（33/42，78.6%）reported PALS instructor teams comprising fewer than 10.Only 7 centers(7/42,16.7%）reported having dedicated funding support.The top three challenges were：training sessions occupying instructors’personal time（27/42，64.3%），low instructor compensation（16/42，38.1%），and issues with the data submission system（16/42，38.1%）.Conclusion:Pediatric life support training centers in China are primarily children’s hospitals，with a geographical concentration in coastal areas，which is also reflected in the distribution of training scale and instructor resources.Most centers have relatively small training scales and limited instructor capacity，with many instructors conducting training during their personal time.These issues may hinder the implementation and effectiveness of training programs.