ObjectiveThis study aimed to elucidate the mechanistic role of Staphylococcus aureus in the pathogenesis of atopic dermatitis (AD), a chronic inflammatory skin disorder characterized by pruritus and barrier dysfunction. A key focus was screening traditional Chinese medicine (TCM) active components with dual antibacterial and antipruritic efficacy, followed by systematic evaluation of their in vitro antibacterial activity. Additionally, a novel drug delivery system was constructed to enable localized efficient drug delivery, inhibiting S. aureus proliferation and alleviating its induced pruritus, thereby providing new strategies for targeted AD therapy. MethodsMale C57BL/6J mice aged 6-8 weeks (body weight 18-22 g) were used to establish an AD model via repeated oxazolone sensitization. On day 14, microbial samples were collected from the lesional area (1 cm²) using sterile cotton swabs, followed by vortex mixing, serial dilution, and plating on 5% sheep blood agar plates (incubated at 37°C for 24 h). Single colonies with complete transparent β-hemolytic zones were isolated and identified as vancomycin-intermediate S. aureus (VISA) via 16S rRNA sequencing. An S. aureus mono-infection animal model was then established by applying gauze saturated with bacterial suspension (McFarland turbidity 0.1) to the nape and back skin of mice. The pruritic phenotype and inflammatory cell infiltration induced by S. aureus were evaluated using comprehensive approaches including behavioral assays (e.g., scratching frequency recording), hematoxylin-eosin (HE) staining, and toluidine blue staining. The in vitro antibacterial efficacy of the TCM monomer pseudolaric acid B (PAB) and double network hydrogel (DN) was separately assessed by disk diffusion assay, while the minimum inhibitory concentration (MIC) of PAB was determined via broth dilution method. Further validation of the pharmacodynamic characteristics of the composite system (PAB@DN, composed of PAB and DN) was conducted through behavioral assays, HE staining, and dermatitis scoring, with its drug release profile evaluated by mass spectrometry analysis. Based on scratching behavioral analysis and dermatitis scoring, the optimal ratio and concentration of PAB@DN were optimized. ResultsThe S. aureus load in AD lesional tissues was significantly higher than in normal skin ((5.3±0.33)×10⁶ CFU vs. (3.6±0.26)×10⁷ CFU, P<0.001). In the S. aureus mono-infection group, mice exhibited a 6.7-fold increase in scratching frequency compared to the control group. HE staining revealed marked epidermal thickening ((10.4±2.39) μm vs. (85.6±1.95) μm, P<0.000 1), and toluidine blue staining showed a 23-fold increase in mast cell degranulation. Pseudolaric acid B exhibited a significant concentration-dependent inhibitory effect onS. aureus growth, with its in vitro antibacterial effect being 57% that of the antibiotic cefepime (inhibition zone diameter: PAB (1.885±0.036) cm vs. cefepime (3.636±0.005) cm, P<0.000 1) and a minimum inhibitory concentration (MIC) of 1 g/L. The carrier double network hydrogel (DN) itself lacked direct antibacterial activity (no significant difference in inhibition zone diameter compared to the control) but effectively ameliorated the dry symptoms of AD-like lesions. The PAB@DN composite system demonstrated a synergistic effect compared to individual components, resulting in a 50% reduction in scratching behavior, an 86% decrease in dermatitis score, and a 60% reduction in epidermal thickening. It also reduced the S. aureus load in mouse skin by approximately 34%, with the optimal effective formulation being PAB at 1 g/L loaded onto DN. ConclusionS. aureus colonization plays a critical driving role in the onset and progression of AD. Using an S. aureus infection model, this study confirmed that the pseudolaric acidB-hydrogel composite delivery system (PAB@DN) can effectively alleviate S. aureus-induced pruritus and skin damage, providing experimental evidence for microbiota-targeted therapy of AD.

Objective This study conducted molecular biological identification of the viruses carried by Culex pipiens pallens specimens collected in Shunyi District, Beijing in 2023, and observed the changes in the infection rate of the viruses carried by Cx. pipiens pallens at different collection times. Methods Cx. pipiens pallens were collected using carbon dioxide mosquito traps. The mosquito samples were ground in batches and analyzed by molecular biology technologies. The virus infection rate at different collection times was analyzed statistically. Results 17 strains of Culex pipiens pallens densovirus(CppDNV)were identified from Cx. pipiens pallens samples collected in Shunyi District, Beijing, in 2023. The nucleotide sequence analysis of the virus genome coding region showed that CppDNV was a single-stranded DNA virus with a total length of 3 335 nt, encoding 2 non-structural proteins(NS1, NS2)and 1 capsid protein(VP). The nucleotide(amino acid)sequence lengths of the three proteins were 2 376 nt(791 aa),1 092 nt(363 aa)and 1 071 nt(356 aa), respectively. Phylogenetic analysis showed that CppDNV was located in genus Brevihamaparvovirus. Statistical analysis showed no significant difference in infection rates across collection times(χ2=4.429, P=0.194). Conclusions CppDNV was identified in Cx. pipiens pallens in Beijing, and it was stably maintained in this natural population.

Objective To investigate the temporal changes in pathological damage and macrophage polarization in liver and spleen tissues of mice infected with Angiostrongylus cantonensis, and to preliminarily unravel the peripheral immune responses during the early stage of A. cantonensis infection. Methods Forty female BALB/c mice at ages of 6 to 8 weeks were randomly divided into four groups, including the control group and 7-, 14-, and 21-day infection groups, with 10 mice in each group. Each mouse in the infection groups was inoculated with 30 third-stage (L3) larvae of A. cantonensis by oral gavage, and five mice were randomly selected from each infection group on days 7, 14, and 21 post-infection, while mice in the control group were given the same volume of physiological saline and five mice were randomly selected from the control group on the day of oral gavage. Mouse liver and spleen tissues were sampled. The histopathological changes of mouse liver and spleen tissues were observed using hematoxylin and eosin (HE) staining, and the percentage of positive staining area and the co-localization positive rates of the macrophage surface antigens F4/80, CD86, and CD206 were quantified in mouse liver and spleen tissues using immunohistochemical and immunofluorescence staining. In addition, five mice were collected from each infection group on days 7, 14, and 21 post-infection, and five mice were collected from the control group on the day of oral gavage. Mouse liver and spleen tissues were sampled for detection of macrophage markers CD86 and CD206 and macrophage phenotyping using flow cytometry, and the expression of M1 macrophage markers, including inducible nitric oxide synthase (Nos2), tumor necrosis factor-α (TNF-α), interleukin-1β (IL-1β) and M2 markers, including arginase 1 (Arg1), mannose receptor C-type 1 (Mrc1) and chitinase-like protein 3 (Chil3) was quantified in mouse liver and spleen tissues using real-time quantitative PCR (RT-qPCR) assay. Results Proliferative lesions of the hepatocyte were observed in mouse liver tissues and the follicular structures of the mouse spleen white pulp were disrupted 21 days post-infection with A. cantonensis. Immunohistochemical staining showed that there were significant differences in the percentages of F4/80, CD86 and CD206 positive staining areas in the liver and spleen tissues among the four groups of mice (F = 242.40, 197.14, 183.19, 157.65, 242.35 and 146.24; all P values < 0.001), and the percentages of positive staining in the liver and spleen tissues of mice in the 14-day infection group [(4.45 ± 0.51)%, (3.74 ± 0.67)%, (8.32 ± 0.72)%, (16.56 ± 1.14)%, (11.62 ± 0.52)%, and (8.29 ± 0.72)%, respectively] and the 21-day infection group [(3.70 ± 0.11)%, (3.22 ± 0.43)%, (11.53 ± 1.03)%, (12.59 ± 1.05)%, (9.02 ± 0.83)%, and (11.67 ± 1.10)%, respectively] were higher than in the control group [(0.35 ± 0.16)%, (0.40 ± 0.02)%, (0.93 ± 0.05)%, (2.78 ± 0.26)%, (2.33 ± 0.20)%, and (1.85 ± 0.20)%, respectively] (all P values < 0.05). Immunofluorescence staining showed significant differences in the positive rates of F4/80 co-localization with CD86 and CD206 in mouse liver and spleen tissues among the four groups (F = 24.42, 25.28, 54.51 and 130.55; all P values < 0.001). Flow cytometry detected significant differences in the proportions of CD86⁺ and CD206⁺ macrophages in mouse liver and spleen tissues among the four groups (F = 67.98, 18.41, 29.77, 172.80; all P values < 0.001), and the proportions of CD206⁺ macrophages in the liver and spleen of the 21-day infection group were significantly higher than those in the control group [(9.25 ± 2.55)% vs (3.83 ± 0.72)%, and (4.22 ± 0.56)% vs (0.47 ± 0.18)%, respectively] (both P values < 0.05). In addition, RT-qPCR assay quantified significant differences in the relative mRNA expression of M1 macrophage markers (IL-1β, TNF-α and Nos2) and M2 macrophage markers (Arg1, Chil3 and Mrc1) in mouse liver and spleen tissues among the four groups (F = 41.30, 31.82, 199.33, 19.96, 62.01, 119.76, 23.67, 95.90, 72.27, 82.59, 123.41 and 29.75; all P values < 0.05). Conclusions A. cantonensis infection may cause progressive pathological damage in mouse liver and spleen tissues, accompanied by dynamic temporal changes in macrophage polarization. M1 macrophage polarization predominates at the early stage of A. cantonensis infection and shifts towards M2 polarization at the later stages, suggesting that M2 polarization may participate in immune regulation at late stages of A. cantonensis infection by suppressing excessive inflammatory responses and promoting tissue repair.

OBJECTIVE To explore the effect of the comprehensive unit-based safety program(CUSP)collaborative action strategy on reducing the incidence of catheter-associated urinary tract infection(CAUTI)in elderly patients.METHODS From Jun.to Nov.2024,the Seventh Medical Center of the PLA General Hospital implemented the CUSP collaborative action strategy for intervention.Comparisons were made between pre-intervention(from Dec.2023 to May 2024)and post-intervention(from Jun.to Nov.2024)regarding nurses' know ledge-attitude-practice(KAP)scores on CAUTI prevention,implementation rates of key nursing measures for elderly CAUTI prevention and CAUTI incidence rates among elderly patients.RESULTS The pre-intervention KAP score of nurses from geriatric de-partment on CAUTI prevention was(83.44±6.67),significantly lower than the post-intervention score(108.19±16.27)(P＜0.001).The implementation rates of 10 key nursing measures for elderly CAUTI prevention improved(P＜0.05).The incidence rate of CAUTI was 2.88‰(16/5 546)among 5 546 catheter days before the intervention,and the incidence rate of CAUTI was 0.73‰(4/5 496)among 5 496 catheter days after the intervention(P=0.008).CONCLUSIONS The CUSP collaborative action strategy effectively enhances the KAP levels of nurses from geriatric department on CAUTI prevention,improves the implementation rates of key nursing measures,and reduces CAUTI incidence rates among elderly patients.

Objective To establish a reversed-phase HPLC method for determining three stereoisomers in baloxavir marboxil and provide a basis for the quality specification of baloxavir marboxil.Methods The chromatographic column was CHIRALPAK IC-3(4.6 mm × 150 mm,3 μm),The mobile phase was acetonitrile-0.1％formic acid aqueous solution-isopropanol(35:50:15).The column temperature was 40 ℃.The flow rate was 0.5 mL·min-1.The injection volume was 10 μL.The detection wavelength was 259 nm.Result The isomer peaks were completely separated from the principal component peak.The detection limits for stereoisomers 1,2 and 3 were 0.024 7,0.038 7,0.038 1 μg·mL-1 respectively.The quantitation limits for stereoisomers 1,2 and 3 were 0.049 4,0.077 3,0.076 1 μg·mL-1 respectively.There were good linear relationships between the concentrations and peak area within the ranges of the study,and the linearity concentration ranges of stereoisomers 1,2 and 3 were 0.049 5-0.989 0 μg·mL-1,0.051 6-1.031 0 μg·mL-1,0.050 8-1.015 0 μg·mL-1 respectively.The linear correlation coefficients were 0.999 4.The recovery was 92.28％-103.90％.The sample solution was stable in 48 h at room temperature.Conclusion The method is accurate and reliable for determining stereoisomers in baloxavir marboxil,and provide a guideline of quality standards of baloxavir marboxil and safety evalution.

Objective To construct a nursing follow-up checklist for patients undergoing autologous hematopoietic stem cell transplantation,providing a basis for postoperative follow-up care.Methods Using evidence-based methods,the literature from major guide websites and databases using Chinese and English search terms was retrieved,and their quality was evaluated.The relevant items were extracted,and a first draft was formed.15 experts were selected in relevant fields from 14 tertiary hospitals in 13 provinces,cities,and autonomous regions across the country for Delphi inquiry.The nursing follow-up checklist was revised again based on expert opinions and clinical practice.The nursing follow-up checklist was initially applied and then revised again to form the final draft.Results 15 experts include 12 undergraduate and 3 master's degree holders.The positivity coefficients of the 2 rounds of inquiry were 100％;the authority coefficients of the experts were 0.815;the Kendall coefficients were 0.119 and 0.144,respectively;the differences were statistically significant(P＜0.001).The final nursing follow-up checklist was formed,which includes 6 primary indicators,including physiological status,psychological status,social and family support,living conditions,disease knowledge,and laboratory tests.19 patients(95％)found the follow-up content to be comprehensive.The follow-up nurses's satisfaction rate exceeded 85％.There were 27 secondary indicators and 61 tertiary indicators,with coefficients of variation of all indicators less than 0.25.Conclusion The nursing follow-up checklist is scientific,reliable,and practical,which can provide a basis for clinical nursing staff to follow up and comprehensively manage patients after autologous hematopoietic stem cell transplantation.

Aim To explore the possible regulatory effect of leptin on acyl-CoA synthetase long chain fami-ly member ACSL5 and their effect on migration and in-vasion of breast cancer cell,and to explore the underly-ing mechanism.Methods The expression of leptin receptor was detected by immunofluorescence assay.The migration and invasion ability of MCF-7 cells were detected by wound healing assay and Transwell assay respectively.The downstream target gene of leptin was analyzed by PCR microarray data.The expression of ACSL5 in breast cancer and its correlation with the staging and prognosis of breast cancer patients were as-sessed uing bioinformatics methods.The expression of ACSL5 in MCF-7 cells treated with different concentra-tions of leptin was detected using real time fluorescence quantitative polymerase chain reaction(RT-qPCR).Overexpressing ACSL5 was constructed by lentiviral transfection;the expressions of EMT related proteins,AMPK-α and p-AMPK-α were detected by Western blot.Results Leptin promoted breast cancer cell mi-gration and invasion and EMT.ACSL5 was significant-ly low expressed in breast cancer and related to progno-sis.Leptin downregulated the expression of ACSL5 through OBR.Leptin activated AMPK pathway to downregulate ACSL5 and promote migration,invasion and EMT of breast cancer cells.Conclusions Leptin may promote the migration,invasion and EMT of breast cancer by downregulating ACSL5 through activating AMPK pathway.

Objective To establish a reversed-phase HPLC method for determining three stereoisomers in baloxavir marboxil and provide a basis for the quality specification of baloxavir marboxil.Methods The chromatographic column was CHIRALPAK IC-3(4.6 mm × 150 mm,3 μm),The mobile phase was acetonitrile-0.1％formic acid aqueous solution-isopropanol(35:50:15).The column temperature was 40 ℃.The flow rate was 0.5 mL·min-1.The injection volume was 10 μL.The detection wavelength was 259 nm.Result The isomer peaks were completely separated from the principal component peak.The detection limits for stereoisomers 1,2 and 3 were 0.024 7,0.038 7,0.038 1 μg·mL-1 respectively.The quantitation limits for stereoisomers 1,2 and 3 were 0.049 4,0.077 3,0.076 1 μg·mL-1 respectively.There were good linear relationships between the concentrations and peak area within the ranges of the study,and the linearity concentration ranges of stereoisomers 1,2 and 3 were 0.049 5-0.989 0 μg·mL-1,0.051 6-1.031 0 μg·mL-1,0.050 8-1.015 0 μg·mL-1 respectively.The linear correlation coefficients were 0.999 4.The recovery was 92.28％-103.90％.The sample solution was stable in 48 h at room temperature.Conclusion The method is accurate and reliable for determining stereoisomers in baloxavir marboxil,and provide a guideline of quality standards of baloxavir marboxil and safety evalution.

Aim To explore the possible regulatory effect of leptin on acyl-CoA synthetase long chain fami-ly member ACSL5 and their effect on migration and in-vasion of breast cancer cell,and to explore the underly-ing mechanism.Methods The expression of leptin receptor was detected by immunofluorescence assay.The migration and invasion ability of MCF-7 cells were detected by wound healing assay and Transwell assay respectively.The downstream target gene of leptin was analyzed by PCR microarray data.The expression of ACSL5 in breast cancer and its correlation with the staging and prognosis of breast cancer patients were as-sessed uing bioinformatics methods.The expression of ACSL5 in MCF-7 cells treated with different concentra-tions of leptin was detected using real time fluorescence quantitative polymerase chain reaction(RT-qPCR).Overexpressing ACSL5 was constructed by lentiviral transfection;the expressions of EMT related proteins,AMPK-α and p-AMPK-α were detected by Western blot.Results Leptin promoted breast cancer cell mi-gration and invasion and EMT.ACSL5 was significant-ly low expressed in breast cancer and related to progno-sis.Leptin downregulated the expression of ACSL5 through OBR.Leptin activated AMPK pathway to downregulate ACSL5 and promote migration,invasion and EMT of breast cancer cells.Conclusions Leptin may promote the migration,invasion and EMT of breast cancer by downregulating ACSL5 through activating AMPK pathway.

Objective To explore the effect of rituximab on cellular immunity and cytokines in children with new-onset steroid-sensitive nephrotic syndrome(SSNS).Methods Clinical data of 60 children with new-onset SSNS treated at Xuzhou Children's Hospital from December 2021 to March 2023 were retrospectively analyzed.Children were allocated according to rituximab use into a control group(no rituximab)and an observation group(rituximab).The relapse rate,T-lymphocyte subsets and cytokines before and after treatment,and the incidence of adverse reactions were compared between groups.Results The relapse rate was lower in the observation group than in the control group(27%vs 73%,P<0.05).After treatment,CD3+and CD4+T-lymphocyte counts,the CD4+/CD8+ratio,and serum interleukin-2 increased in the observation group and were higher than in the control group(P<0.05).Interleukin-6 and tumor necrosis factor-α levels decreased after treatment in the observation group and were lower than in the control group(P<0.05).After treatment,CD8+T-lymphocyte counts decreased,interferon-γ increased,and interleukin-10 decreased in both groups,with no significant differences between the two groups(P>0.05).The incidence of adverse reactions did not differ significantly between the two groups(P>0.05).Conclusions Rituximab can reduce the relapse rate in children with new-onset nephrotic syndrome and shows good safety.Its therapeutic effect is achieved by regulating the number and function of T cells and by modulating the anti-inflammatory effects of cytokines.