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.

ObjectiveTo investigate the mechanism through which miR‑21 improves chronic renal fibrosis in mice via targeted modulation of the phosphatase and tensin homolog （PTEN）/protein kinase B （AKT）/mammalian target of rapamycin （mTOR） pathway. MethodsThirty‑two chronic kidney disease model mice were randomly divided into four groups （n=8 each group）： model group， miR‑21 overexpression group， miR‑21 inhibition group， and miR‑21 inhibition + MK‑2206 group. Eight healthy mice were included as the control group. The miR‑21 overexpression， miR‑21 inhibition， and miR‑21 inhibition + MK‑2206 groups received tail‑vein injections of lentivirus （50 μL， 1×10⁸ TU per mouse） once weekly for three weeks. The control and model groups were injected with an equal volume of empty vector （LV‑NC）. The miR‑21 inhibition + MK‑2206 group additionally received gavage of the AKT/mTOR pathway inhibitor MK‑2206 （480 mg/kg） once weekly for three weeks. The expressions of miR‑21， 24 h urinary protein， serum creatinine （Scr）， blood urea nitrogen （BUN）， and renal tissue levels of collagen Ⅰ， collagen Ⅲ， α‑smooth muscle actin （α‑SMA）， and PTEN protein， as well as p‑AKT/AKT and p‑mTOR/mTOR ratios， were compared among groups. HE staining was used to observe pathological changes in renal tissue， and Masson staining was used to observe the degree of renal fibrosis. A dual‑luciferase assay was performed to verify the targeting relationship between miR‑21 and PTEN. ResultsCompared with the model group， miR‑21 expression in renal tissue increased in the miR‑21 overexpression group （P<0.05） and decreased in the miR‑21 inhibition group （P<0.05）. Compared with the model group， the miR‑21 overexpression group showed increased 24 h urinary protein， Scr， BUN， and renal tissue expression of collagen Ⅰ， collagen Ⅲ， and α‑SMA （all P<0.05）， while these indicators decreased in the miR‑21 inhibition group （P<0.05）. Compared with the miR‑21 inhibition group， the miR‑21 inhibition + MK‑2206 group exhibited lower 24‑h urinary protein， Scr， BUN， and renal tissue expression of Collagen Ⅰ， Collagen Ⅲ， and α‑SMA （all P<0.05）. Compared with the model group， the miR‑21 overexpression group showed decreased PTEN protein expression （P<0.05） and increased p‑AKT/AKT and p‑mTOR/mTOR ratios （P<0.05）， while the miR‑21 inhibition group showed increased PTEN expression （P<0.05） and decreased p‑AKT/AKT and p‑mTOR/mTOR ratios （P<0.05）. Compared with the miR‑21 inhibition group， the miR‑21 inhibition + MK‑2206 group had lower p‑AKT/AKT and p‑mTOR/mTOR ratios （P<0.05）， with no significant difference in PTEN protein expression. HE and Masson staining showed normal kidney structure and almost no fibrosis in the control group. The model group exhibited glomerular enlargement， capillary loop adhesion， and focal fibrosis. The miR-21 overexpression group showed severe destruction of glomerular structure， accompanied by extensive fibrosis and renal tubular atrophy. The pathological changes and degree of fibrosis were alleviated in the miR-21 inhibition group. The miR-21 inhibition + MK-2206 group showed only mild pathological changes and mild fibrosis， with the interstitium being largely normal. Compared with PTEN-WT + NC mimics 1， the relative luciferase activity in the PTEN-WT + miR-21 mimics group decreased （P<0.001）. There was no statistically significant difference in relative luciferase activity between PTEN-WT + NC mimics group and PTEN-MUT + miR-21 mimics group. ConclusionmiR‑21 may improve renal function indicators and alleviate renal fibrosis in chronic kidney disease mice via targeted modulation of PTEN and subsequently inhibiting the AKT/mTOR 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.

Aim To compare the observation results of atomic force microscopy(AFM)and scanning electron microscopy(SEM),and to summarize the main problems and solutions of AFM in observing biological macromolecules,using the observa-tion subjects of protein samples purified by our research group.Methods The protein samples were diluted to 15 nmol·L-1 with PBS,fixed on glass slides,silicon wafers,and mica sheets,dried,and made into solid-phase observation samples.SEM sam-ples were plated with platinum before observation.The surface structures of proteins were observed using AFM and SEM,sample heights were calculated,and differences in results were com-pared.Results Protein samples with positive charges tended to shift to the right during observation due to the repulsion of the AFM probe;mica sheets could effectively eliminate the positive charge of proteins to avoid sample movement;PBS provided a stable environment for protein samples,but the crystallization of PBS salts interfered with probe operation and imaging clarity;SEM samples needed to be plated with platinum before observa-tion and could not achieve the precision of AFM.Conclusions Both AFM and SEM can directly observe protein structures in vitro,with AFM providing higher precision results;when protein sample stability permits,ultrapure water is preferred as the sol-vent carrier,and volatile liquids such as ethanol can also serve as solvent carriers.The application of AFM offers a new approach for pharmacological studies on interactions between biological macromolecules.

Background: Psoralea corylifolia L. (Buguzhi, BGZ), known for its efficacy in supporting pregnancy and preventing miscarriage, has been used in China for over 1000 years. Recently, BGZ has been identified as a potential cause of drug-induced liver injury. However, its safety during pregnancy remains unclear, which significantly hinders its routine clinical application. Objective: To investigate the effects of BGZ administration during pregnancy on the liver of mouse mothers and their weaned 21-day-old offspring. Methods: Mice were orally administered BGZ at doses of 2.5 and 10 g/kg during pregnancy, with BGZ withdrawal during the lactation period. Liver histopathology (hematoxylin-eosin staining), biochemical analysis, and evaluation of liver bile acid metabolism were performed after the lactation period. Results: BGZ administration at doses of 2.5 and 10 g/kg during pregnancy, followed by withdrawal during the lactation period, caused mild liver damage in both mothers and their 21-day-old offspring. Serum total bile acid (TBA) levels were elevated compared with those in the control group. Additionally, changes were observed in the levels and proportions of various bile acids (BAs) in the liver, suggesting mild effects on BA metabolism. Conclusion: BGZ administration during pregnancy caused mild liver damage and increased serum TBA levels in both mouse mothers and their 21-day-old offspring. This phenomenon may be associated with imbalanced BA metabolism in the liver. Based on the present study and the limited toxicological research on BGZ, pregnant women should avoid prolonged use of BGZ. If BGZ is administered during pregnancy, serum TBA levels should be monitored, and if elevated, BGZ should be discontinued.

Background: Aristolochic acid II (AAII), a major nephrotoxic and carcinogenic component of aristolochic acids (AAs), has been less studied compared with its well-characterized analog, aristolochic acid I (AAI). Although AAs are known to induce carcinogenesis via DNA adduct formation, the toxicity mechanisms, environmental prevalence, and long-term health impacts of AAII remain poorly understood. Objective: This study aimed to systematically evaluate AAII’s acute and chronic toxicity, carcinogenic mechanisms, and environmental exposure patterns using integrated murine models and phytochemical analyses to clarify its toxicological profile and associated health risks. Methods: C57BL/6J mice were used in the following experiments: (1) determination of AAII content in 3 commonly used Aristolochia medicinal materials via liquid chromatography-mass spectrometry/mass spectrometry; (2) acute toxicity testing with single doses of 10, 20, or 40 mg/kg; and (3) chronic exposure with 1 or 10 mg/kg administered every other day for 24 weeks, followed by 21 to 40 weeks of postexposure monitoring. Histopathological examination, whole-exome sequencing, biochemical assays, and micronucleus tests were performed to assess multi-organ damage, tumorigenesis, genomic mutation signatures, and direct clastogenicity. Phytochemical analyses were used to evaluate environmental distribution. Results: (1) A single 40 mg/kg dose of AAII induced dose-dependent renal tubular degeneration without hepatotoxicity; (2) the 10 mg/kg group showed significant mortality (20%), tumor incidence (33.3%, primarily forestomach and bladder transitional cell carcinomas), persistent renal interstitial fibrosis, and subclinical hepatic injury. Chronic exposure to 1 mg/kg still induced 13.3% mortality and 15.5% tumor incidence over a 64-week period; (3) whole-exome sequencing revealed a predominance of C>T mutations and pathway enrichment in chemical carcinogenesis and cytochrome P450-mediated metabolism, indicating reactive metabolite-driven mechanisms distinct from classical AA-DNA adducts; and (4) no histopathological changes were observed in nontarget organs (brain, heart, and testes), and micronucleus assays confirmed the absence of direct clastogenicity. Conclusion: This study highlights the delayed carcinogenic risks of low-dose chronic AAII exposure and emphasizes the need to update regulatory frameworks to ensure the safe use of aristolochiaceae-containing herbal products.

AIM To investigate the effects of Shuyu Pills combined with evolimus on the epithelial mesenchymal transformation of triple negative breast cancer cells 4T1 and MDA-MB-231 induced by TGF-β1.METHODS The 4T1 and MDA-MB-231 cells were divided into the blank group and the induction group to induce the epithelial mesenchymal transformation with TGF-β1 cytokine treatment,followed by the assignment into the model group,the Shuyu Pills group,the everolimus group and the Shuyu Pills combined with everolimus group.CCK8 method,plate cloning method,cell scratch test and Transewll test were used to detect the proliferation,cloning formation,migration and invasion ability of the cells whose expressions of E-cadherin,N-cadherin,Vimentin,MMP9,MMP2 and pathway proteins PTEN,PI3K,Akt and mTOR were detected by Western blot.RESULTS Compared with the blank group,the induction group displayed a cell morphological change from epithelioid to stromal,decreased expression of E-cadherin protein(P＜0.01);and increased protein expressions of N-cadherin and Vimentin(P＜0.05).Compared with the model group,each group intervened with the medicine displayed decreased proliferation,clone formation,migration and invasion ability of both kinds of cells(P＜0.01);increased protein expressions of PTEN and E-cadherin(P＜0.05,P＜0.01);and decreased protein expressions of PI3K,Akt,mTOR,N-cadherin,Vimentin,MMP9 and MMP2(P＜0.05,P＜0.01);and more significantly in the Shuyu Pills combined with evolimus group(P＜0.05,P＜0.01).CONCLUSION With a more ideal effect than the single uses in inhibiting the TGF-β1-induced epithelial mesenchymal transformation of triple-negative breast cancer cells,the combination use of Shuyu Pills and everolimus may work through the regulation of PI3K/Akt/mTOR signaling pathway.

Heatstroke,especially in high-temperature and high-humidity environments,is a life-threatening acute heat-injury disease that seriously endangers human health.Timely and effective on-site treatment is crucial for patients'survival and prognosis.Early recognition,rapid assessment,and on-site cooling are the core of pre-hospital treatment of heatstroke.Currently,there is a lack of standardized application procedures for pre-hospital emergency care of heatstroke.Therefore,the"Expert Consensus on Pre-hospital Emergency Management of Heatstroke(2024 edition)"was initiated by the Expert Group on Heatstroke Prevention of the People's Liberation Army and developed in collaboration with experts from local pre-hospital emergency care,emergency departments,and intensive care units.This consensus focuses on heatstroke prevention,on-site and ambulance-based treatment,and early emergency room interventions,and puts forward 10 evidence-based recommendations,aiming to provide a reference for scientific and standardized pre-hospital emergency care of heatstroke.

AIM To compare total sugar,total protein,total phenol,total flavonoid,calycosin-7-O-β-D-glucoside,liquiritin,lobetyolin,quercetin,isoferulic acid,hesperidin,glycyrrhizic acid contents and their antioxidant activities,hypoglycemic activities of big honey pill,small honey pill,water pill,concentrated pill,granule,mixture and decoction of Buzhong Yiqi Recipe.METHODS Anthraquinone-sulfuric acid method,Coomassie brilliant blue method,Folin-phenol colorimetry method,sodium nitrite-aluminum nitrate method and HPLC were adopted in the content determination of total sugar,total protein,total phenol,total flavonoid and seven constituents,respectively,after which the scavenging capacities,reducing powers on DPPH·free radical,ABTS+free radical,hydroxyl free radical,and inhibition capacity on α-glucosidase activity were detected.Subsequently,correlation analysis was performed.RESULTS Total sugar,total protein,total phenol and total flavonoid contents demonstrated significant differences among different dosage forms(P＜0.05,P＜0.01).Calycosin-7-O-β-D-glucoside,glycyrrhizin,codonoside and quercetin displayed the highest contents in the decoction,while those of isoferulic acid,hesperidin and glycyrrhizin were observable in the mixture.The water pill exhibited the strongest antioxidant activity,while those of the concentrated pill and mixture were weak;the big honey pill exhibited the strongest hypoglycemic activity,while that of the decoction was the weakest.Total protein,total phenol,total flavonoid and liquiritin contents displayed significant positive correlations between antioxidant activity(P＜0.05,P＜0.01),while hesperidin content displayed significant negative correlation between the latter(P＜0.05);total protein,calycosin-7-O-β-D-glucoside,codonoside and quercetin contents displayed significant negative correlations between hypoglycemic activity(P＜0.05,P＜0.01).CONCLUSION Active constituent contents and their biological activities of Buzhong Yiqi Recipe with different dosage forms exist differences,total sugar,total protein,total flavonoids,calycosin-7-O-β-D-glucoside,licorice glycoside,hesperidin,codonoside and quercetin can be taken as quality control indices for this prescription.

Objective To investigate the distribution and antimicrobial resistance profiles of common pathogens isolated from cerebrospinal fluid(CSF)in CHINET program from 2015 to 2021.Methods The bacterial strains isolated from CSF were identified in accordance with clinical microbiology practice standards.Antimicrobial susceptibility test was conducted using Kirby-Bauer method and automated systems per the unified CHINET protocol.Results A total of 14 014 bacterial strains were isolated from CSF samples from 2015 to 2021,including the strains isolated from inpatients(95.3％)and from outpatient and emergency care patients(4.7％).Overall,19.6％of the isolates were from children and 80.4％were from adults.Gram-positive and Gram-negative bacteria accounted for 68.0％and 32.0％,respectively.Coagulase negative Staphylococcus accounted for 73.0％of the total Gram-positive bacterial isolates.The prevalence of MRSA was 38.2％in children and 45.6％in adults.The prevalence of MRCNS was 67.6％in adults and 69.5％in children.A small number of vancomycin-resistant Enterococcus faecium(2.2％)and linezolid-resistant Enterococcus faecalis(3.1％)were isolated from adult patients.The resistance rates of Escherichia coli and Klebsiella pneumoniae to ceftriaxone were 52.2％and 76.4％in children,70.5％and 63.5％in adults.The prevalence of carbapenem-resistant E.coli and K.pneumoniae(CRKP)was 1.3％and 47.7％in children,6.4％and 47.9％in adults.The prevalence of carbapenem-resistant Acinetobacter baumannii(CRAB)and Pseudomonas aeruginosa(CRPA)was 74.0％and 37.1％in children,81.7％and 39.9％in adults.Conclusions The data derived from antimicrobial resistance surveillance are crucial for clinicians to make evidence-based decisions regarding antibiotic therapy.Attention should be paid to the Gram-negative bacteria,especially CRKP and CRAB in central nervous system(CNS)infections.Ongoing antimicrobial resistance surveillance is helpful for optimizing antibiotic use in CNS infections.