To investigate the risk factors for acute kidney injury (AKI) following the use of amphotericin B deoxycholate and to develop a predictive model to guide clinical monitoring and intervention.

OBJECTIVE To investigate the effect and mechanism of modified Lichong decoction （MLCD） on the apoptosis of transplanted tumor cells in nude mice. METHODS Human gastric cancer AGS cells were cultured， and a nude mice transplanted tumor model was established. The nude mice were divided into the model group and MLCD low-， medium- and high-dose groups （150， 300， 600 mg/kg）. They were given distilled water or the corresponding drug solution by gavage once daily for four consecutive weeks. The size of transplanted tumors in nude mice was measured every six days， and the tumor volume was calculated. After the medication， the nude mice were sacrificed， and the transplanted tumor tissues were isolated. The contents of lactate dehydrogenase （LDH） and reactive oxygen species （ROS） in the transplanted tumor tissues were detected， and the changes in mitochondrial membrane potential were assessed. The pathological morphological changes were observed. The enzymatic activities of caspase-3， caspase-8， and caspase-9， as well as protein expressions of Fas and FasL and mRNA expressions of caspase-3， caspase-8， caspase-9， Fas and FasL in the transplanted tumor tissues， were detected. RESULTS Compared with the model group， the volume of transplanted tumors in nude mice from all MLCD dose groups was reduced to varying degrees. The contents of LDH and ROS， as well as the enzymatic activities of caspase-3， caspase-8 and caspase-9， were significantly increased/enhanced. The mitochondrial membrane potential was significantly decreased. The protein expressions of Fas and FasL， and the mRNA expressions of caspase-3， caspase-8， caspase-9， Fas and FasL were significantly up-regulated. Most of these differences were statistically significant （ P ＜0.05 or P ＜0.01）. Pathological results showed that with increasing doses of MLCD， the cellular density in the transplanted tumor tissues gradually decreased， and typical morphological features of apoptosis， such as loosening and increasing fragmentation， became more prominent. CONCLUSIONS MLCD can induce apoptosis in transplanted tumor cells of nude mice， and its mechanism may be related to the activation of the Fas/FasL pathway and the caspase apoptotic pathway.

ObjectiveTo investigate the intervention mechanism of the traditional Chinese medicine Number 2 Feibi recipe （N2FBR） in idiopathic pulmonary fibrosis （IPF）， focusing on its effects on endoplasmic reticulum （ER） stress， apoptosis， stemness maintenance， and regenerative capacity of alveolar type Ⅱ epithelial cells （AT2 cells）， and to validate the modern translational pathway of the theory of "deficiency of Zong Qi leading to pulmonary atelectasis and atrophy". MethodsA mouse model of pulmonary fibrosis was induced by bleomycin （BLM）. Mice were randomly divided into blank control， model， low-， and high-dose N2FBR intervention groups （9.1， 18.2 g·kg^-1）， and prednisolone intervention group （6.5 mg·kg^-1）. Pulmonary histopathological changes and collagen deposition were evaluated using hematoxylin-eosin （HE） and Masson's trichrome staining. Hydroxyproline （HYP） content was measured by the alkaline hydrolysis method. Lung coefficient and pulmonary function parameters were evaluated. The mRNA expression levels of fibrosis-related factors， including collagen type Ⅰ alpha 1 chain （ColIa1）， alpha-smooth muscle actin （α-SMA）， and tissue inhibitor of metalloproteinase 1 （Timp1）， were detected by real-time polymerase chain reaction （Real-time PCR）. Cell apoptosis was assessed using the terminal deoxynucleotidyl transferase dUTP nick-end labeling （TUNEL） assay. Apoptosis of AT2 cells was further evaluated by double immunofluorescence staining for surfactant protein C （SPC） and cysteine-aspartic protease-3 （Caspase-3）. Endoplasmic reticulum （ER） stress in AT2 cells was examined by double staining for SPC and protein kinase R-like endoplasmic reticulum kinase （PERK）. Ultrastructural changes of ER and lamellar bodies in AT2 cells were observed by transmission electron microscopy （TEM）. The expression levels of key proteins involved in ER stress and apoptosis pathways， including PERK， activating transcription factor 4 （ATF4）， and Caspase-3， were detected by Western blot. Double immunofluorescence staining of SPC and Ki-67 antigen （Ki-67） was performed to evaluate the proliferative capacity of AT2 cells. Lineage tracing technology （labeling AT2 cells with GFP） combined with Krt8 labeling was used to evaluate intermediate differentiation states， and morphological transformation of AT2 cells into alveolar type Ⅰ epithelial cells （AT1） was observed. ResultsBLM-induced mice exhibited significant structural disruption of lung tissue， increased collagen deposition， elevated lung coefficient， decreased pulmonary function， and upregulation of fibrosis-related factors （P<0.01）. High-dose N2FBR treatment significantly ameliorated lung tissue damage and dysfunction， significantly reduced HYP content （P<0.01）， and significantly downregulated ColIa1， α-SMA， and Timp1 expression （P<0.01）. Apoptosis analysis showed increased TUNEL-positive and Caspase-3-positive AT2 cells in the model group， which was significantly reduced by high-dose N2FBR treatment. TEM revealed swollen ER structures in AT2 cells of the model group， which tended to return to normal following treatment. PERK protein staining analysis showed evident ER stress in AT2 cells of the model group， which were markedly alleviated in the treatment group. The expression levels of ER stress-related proteins PERK and ATF4， as well as the apoptosis-related protein Caspase-3， were elevated in the model group and significantly reduced after treatment. TEM also revealed disrupted lamellar body structures in the model group， which tended to recover in the treatment group. Regarding the proliferative capacity of AT2 cells， the proportion of Ki-67⁺SPC⁺ AT2 cells significantly increased in the treatment group （P<0.01）. Lineage tracing showed that the proportion of keratin 8-positive green fluorescent protein-positive （Krt8⁺GFP⁺） cells increased in the model group， indicating differentiation arrest. This proportion was significantly reduced in the treatment group， and the morphology of GFP⁺ cells exhibited a flattened， extended shape， suggesting restored differentiation toward AT1 cells. ConclusionN2FBR alleviates ER stress in AT2 cells， reduces AT2 cell apoptosis， restores lamellar body structure and function， enhances proliferation activity， and alleviates differentiation arrest to promote differentiation into AT1 cells， thereby repairing the alveolar epithelium and effectively blocking the progression of pulmonary fibrosis. Its traditional Chinese medicine mechanism of "replenishing Zong Qi， harmonizing Qi and blood， and unblocking pulmonary meridians" closely aligns with the modern regulatory pathway of AT2 stem cells， providing a novel theoretical basis and experimental evidence for the intervention of IPF with traditional Chinese medicine.

ObjectiveThis paper aims to explore the in vitro anti-psoriasis activity and potential mechanism of Kangfuxin liquid （KFX liquid）， providing experimental evidence for the anti-psoriasis effect of KFX liquid. MethodsFirstly， the uninduced human immortalized keratinocyte cells （HaCaT cells） were divided into seven groups， namely the control group and KFX liquid groups with different doses （5， 10， 20， 40， 80， 160 g·L^-1）. After being treated with different concentrations of KFX liquid， the effect of KFX liquid on the normal cell proliferation was detected by using the cell counting kit-8 （CCK-8） method. Secondly， the uninduced HaCaT cells were divided into six groups， namely the control group and recombinant human interleukin-7A （rh-IL-7A） groups with different doses （5， 10， 50， 100， 120 g·L^-1）. After being treated with different concentrations of recombinant human interleukin-17A （rh IL-17A） liquid， the effect of rh IL-17A on cell proliferation was detected. The optimal induction concentration was screened. Then， normal HaCaT cells were divided into a control group and KFX liquid groups with different doses （5， 10， 20， 40， 80， 160 g·L^-1）. Except for the control group， the other groups established psoriasis cell models with the optimal induction concentration of rh IL-17A. After being treated with different concentrations of KFX liquid， the effects of KFX liquid on the psoriasis-like HaCaT cell proliferation were investigated. Finally， the uninduced HaCaT cells were divided into six groups， namely the control group， rh IL-17A group， methotrexate （MTX） group， and KFX liquid groups with different doses （20， 40， 80 g·L^-1）. Except for the control group， the other groups used the optimal induction concentration of rh IL-17A to establish psoriasis cell models. After being treated with different drugs， the cell migration levels were detected through scratch assays， and real-time quantitative polymerase chain reaction （Real-time PCR） was used to detect the relative mRNA expression levels of Ki-67 antigen （Ki67）， S100 calcium-binding protein A7 （S100A7）， S100 calcium-binding protein A8 （S100A8）， and S100 calcium-binding protein A9 （S100A9）， thereby comprehensively evaluating the in vitro anti-psoriasis activity of KFX liquid. By detecting the relative mRNA expression levels of interleukin-1β （IL-1β）， interleukin-6 （IL-6）， and chemokine-20 （CXCL-20） inflammatory-related factors in psoriasis-like HaCaT cells and the protein expression levels of Janus kinase 3 （JAK3）， phosphorylated Janus kinase 3 （p-JAK3）， signal transducer and activator of transcription 3 （STAT3）， and phosphorylated signal transducer and activator of transcription 3 （p-STAT3）， the mechanism was explored. ResultsCompared with that of control group， when treated with 80 g·L^-1 KFX liquid for 72 h （P<0.05） and at different times with 160 g·L^-1 KFX liquid， the HaCaT cell proliferation activity was significantly affected （P<0.01）， while the other concentrations of KFX liquid had no significant differences in cell morphology and cell proliferation activity at different times， indicating that the KFX liquid is relatively safe for HaCaT cells and has no obvious toxic side effects. Compared with that of control group， when treated with different concentrations of rh IL-17A for 24 h， the HaCaT cell proliferation activity was significantly enhanced， and the cell activity was the strongest when the concentration was 100 μg·L^-1 （P<0.05）， with a density close to 100% and intact cell morphology， indicating that 100 μg·L^-1 is the optimal concentration for inducing HaCaT cell proliferation. The results of the KFX liquid treatment on rh IL-17A-induced psoriasis-like cells show that the KFX liquid not only effectively inhibits the rh IL-17A-induced psoriasis-like HaCaT cell proliferation activity （P<0.01）， but also significantly reduces the migration ability of rh IL-17A-induced psoriasis-like HaCaT cells （P<0.01）， and the relative mRNA expression levels of Ki67， S100A7， S100A8， and S100A9 （P<0.01）. Moreover， the KFX liquid can significantly reduce the relative mRNA expression levels of IL-1β， IL-6， and CXCL-20 in rh IL-17A-induced psoriasis-like cells （P<0.01）， and significantly inhibit the phosphorylation levels of JAK3 and STAT3 proteins （P<0.05， P<0.01）. ConclusionThe KFX liquid has no obvious toxicity to uninduced HaCaT cells. It can inhibit rh IL-17A-induced psoriasis-like HaCaT cell proliferation， reduce the cell migration ability， and has good in vitro anti-psoriasis activity. Its action mechanism may be related to downregulating the expression levels of inflammation-related cytokines in the JAK3/STAT3 signaling pathway and inhibiting the phosphorylation levels of JAK3 and STAT3 proteins.

Objective To determine the molecular mechanism of Yuchang granule (YCG) against ulcerative colitis （UC） by network pharmacology-based approach combined with molecular docking. Methods TCMSP and HIT database were utilized to search the active components and potential targets of YCG. The effective targets of UC were obtained by GeneCards, CTD, and DisGeNET databases. Venn Diagram was exploited to receive common targets of YCG and UC. Network maps of the TCM of YCG-active component-common targets were constructed by the Cytoscape software to gain key active components. Protein-protein interaction （PPI） of common targets was constructed by the STRING database obtaining core common targets. The mechanism and therapeutic effects of YCG on UC were explored via gene ontology （GO） and the biological pathway （KEGG） enrichment analyses. Molecular docking technology was carried out to verify the combination of core active components with key common targets. Results 98 active components and 237 potential targets were sieved from YCG, and 1061 effective targets were screened from UC. 94 common targets of YCG and UC were regarded as potential therapeutic targets. Bioinformatics analysis revealed that quercetin, luteolin, β-quebrachol, stigmasterol, and kaempferol may be the potential candidate agents. Tumor necrosis factor （TNF）, serine/threonine-protein kinase （AKT1）, tumor protein p53 （TP53）, interleukin-6 （IL-6） and IL-1β could become potential therapeutic targets. KEGG showed pathways in cancer, AGE-RAGE signaling pathway in diabetic complications, TNF signaling pathway, and IL-17 signaling pathway might play an important role in YCG against UC. Molecular docking results showed that quercetin combined well with TNF, AKT1, and TP53. And stigmasterol did well with AKT1. Conclusion This study comprehensively illustrated the potential candidate agents, potential therapeutic targets, and pathways of YCG against UC. It also illustrated that YCG could act on multiple targets through multi-pathway treating UC.

ObjectiveTo investigate the intervention mechanism of the traditional Chinese medicine Number 2 Feibi recipe （N2FBR） in idiopathic pulmonary fibrosis （IPF）， focusing on its effects on endoplasmic reticulum （ER） stress， apoptosis， stemness maintenance， and regenerative capacity of alveolar type Ⅱ epithelial cells （AT2 cells）， and to validate the modern translational pathway of the theory of "deficiency of Zong Qi leading to pulmonary atelectasis and atrophy". MethodsA mouse model of pulmonary fibrosis was induced by bleomycin （BLM）. Mice were randomly divided into blank control， model， low-， and high-dose N2FBR intervention groups （9.1， 18.2 g·kg^-1）， and prednisolone intervention group （6.5 mg·kg^-1）. Pulmonary histopathological changes and collagen deposition were evaluated using hematoxylin-eosin （HE） and Masson's trichrome staining. Hydroxyproline （HYP） content was measured by the alkaline hydrolysis method. Lung coefficient and pulmonary function parameters were evaluated. The mRNA expression levels of fibrosis-related factors， including collagen type Ⅰ alpha 1 chain （ColIa1）， alpha-smooth muscle actin （α-SMA）， and tissue inhibitor of metalloproteinase 1 （Timp1）， were detected by real-time polymerase chain reaction （Real-time PCR）. Cell apoptosis was assessed using the terminal deoxynucleotidyl transferase dUTP nick-end labeling （TUNEL） assay. Apoptosis of AT2 cells was further evaluated by double immunofluorescence staining for surfactant protein C （SPC） and cysteine-aspartic protease-3 （Caspase-3）. Endoplasmic reticulum （ER） stress in AT2 cells was examined by double staining for SPC and protein kinase R-like endoplasmic reticulum kinase （PERK）. Ultrastructural changes of ER and lamellar bodies in AT2 cells were observed by transmission electron microscopy （TEM）. The expression levels of key proteins involved in ER stress and apoptosis pathways， including PERK， activating transcription factor 4 （ATF4）， and Caspase-3， were detected by Western blot. Double immunofluorescence staining of SPC and Ki-67 antigen （Ki-67） was performed to evaluate the proliferative capacity of AT2 cells. Lineage tracing technology （labeling AT2 cells with GFP） combined with Krt8 labeling was used to evaluate intermediate differentiation states， and morphological transformation of AT2 cells into alveolar type Ⅰ epithelial cells （AT1） was observed. ResultsBLM-induced mice exhibited significant structural disruption of lung tissue， increased collagen deposition， elevated lung coefficient， decreased pulmonary function， and upregulation of fibrosis-related factors （P<0.01）. High-dose N2FBR treatment significantly ameliorated lung tissue damage and dysfunction， significantly reduced HYP content （P<0.01）， and significantly downregulated ColIa1， α-SMA， and Timp1 expression （P<0.01）. Apoptosis analysis showed increased TUNEL-positive and Caspase-3-positive AT2 cells in the model group， which was significantly reduced by high-dose N2FBR treatment. TEM revealed swollen ER structures in AT2 cells of the model group， which tended to return to normal following treatment. PERK protein staining analysis showed evident ER stress in AT2 cells of the model group， which were markedly alleviated in the treatment group. The expression levels of ER stress-related proteins PERK and ATF4， as well as the apoptosis-related protein Caspase-3， were elevated in the model group and significantly reduced after treatment. TEM also revealed disrupted lamellar body structures in the model group， which tended to recover in the treatment group. Regarding the proliferative capacity of AT2 cells， the proportion of Ki-67⁺SPC⁺ AT2 cells significantly increased in the treatment group （P<0.01）. Lineage tracing showed that the proportion of keratin 8-positive green fluorescent protein-positive （Krt8⁺GFP⁺） cells increased in the model group， indicating differentiation arrest. This proportion was significantly reduced in the treatment group， and the morphology of GFP⁺ cells exhibited a flattened， extended shape， suggesting restored differentiation toward AT1 cells. ConclusionN2FBR alleviates ER stress in AT2 cells， reduces AT2 cell apoptosis， restores lamellar body structure and function， enhances proliferation activity， and alleviates differentiation arrest to promote differentiation into AT1 cells， thereby repairing the alveolar epithelium and effectively blocking the progression of pulmonary fibrosis. Its traditional Chinese medicine mechanism of "replenishing Zong Qi， harmonizing Qi and blood， and unblocking pulmonary meridians" closely aligns with the modern regulatory pathway of AT2 stem cells， providing a novel theoretical basis and experimental evidence for the intervention of IPF with traditional Chinese medicine.

ObjectiveThis paper aims to explore the in vitro anti-psoriasis activity and potential mechanism of Kangfuxin liquid （KFX liquid）， providing experimental evidence for the anti-psoriasis effect of KFX liquid. MethodsFirstly， the uninduced human immortalized keratinocyte cells （HaCaT cells） were divided into seven groups， namely the control group and KFX liquid groups with different doses （5， 10， 20， 40， 80， 160 g·L^-1）. After being treated with different concentrations of KFX liquid， the effect of KFX liquid on the normal cell proliferation was detected by using the cell counting kit-8 （CCK-8） method. Secondly， the uninduced HaCaT cells were divided into six groups， namely the control group and recombinant human interleukin-7A （rh-IL-7A） groups with different doses （5， 10， 50， 100， 120 g·L^-1）. After being treated with different concentrations of recombinant human interleukin-17A （rh IL-17A） liquid， the effect of rh IL-17A on cell proliferation was detected. The optimal induction concentration was screened. Then， normal HaCaT cells were divided into a control group and KFX liquid groups with different doses （5， 10， 20， 40， 80， 160 g·L^-1）. Except for the control group， the other groups established psoriasis cell models with the optimal induction concentration of rh IL-17A. After being treated with different concentrations of KFX liquid， the effects of KFX liquid on the psoriasis-like HaCaT cell proliferation were investigated. Finally， the uninduced HaCaT cells were divided into six groups， namely the control group， rh IL-17A group， methotrexate （MTX） group， and KFX liquid groups with different doses （20， 40， 80 g·L^-1）. Except for the control group， the other groups used the optimal induction concentration of rh IL-17A to establish psoriasis cell models. After being treated with different drugs， the cell migration levels were detected through scratch assays， and real-time quantitative polymerase chain reaction （Real-time PCR） was used to detect the relative mRNA expression levels of Ki-67 antigen （Ki67）， S100 calcium-binding protein A7 （S100A7）， S100 calcium-binding protein A8 （S100A8）， and S100 calcium-binding protein A9 （S100A9）， thereby comprehensively evaluating the in vitro anti-psoriasis activity of KFX liquid. By detecting the relative mRNA expression levels of interleukin-1β （IL-1β）， interleukin-6 （IL-6）， and chemokine-20 （CXCL-20） inflammatory-related factors in psoriasis-like HaCaT cells and the protein expression levels of Janus kinase 3 （JAK3）， phosphorylated Janus kinase 3 （p-JAK3）， signal transducer and activator of transcription 3 （STAT3）， and phosphorylated signal transducer and activator of transcription 3 （p-STAT3）， the mechanism was explored. ResultsCompared with that of control group， when treated with 80 g·L^-1 KFX liquid for 72 h （P<0.05） and at different times with 160 g·L^-1 KFX liquid， the HaCaT cell proliferation activity was significantly affected （P<0.01）， while the other concentrations of KFX liquid had no significant differences in cell morphology and cell proliferation activity at different times， indicating that the KFX liquid is relatively safe for HaCaT cells and has no obvious toxic side effects. Compared with that of control group， when treated with different concentrations of rh IL-17A for 24 h， the HaCaT cell proliferation activity was significantly enhanced， and the cell activity was the strongest when the concentration was 100 μg·L^-1 （P<0.05）， with a density close to 100% and intact cell morphology， indicating that 100 μg·L^-1 is the optimal concentration for inducing HaCaT cell proliferation. The results of the KFX liquid treatment on rh IL-17A-induced psoriasis-like cells show that the KFX liquid not only effectively inhibits the rh IL-17A-induced psoriasis-like HaCaT cell proliferation activity （P<0.01）， but also significantly reduces the migration ability of rh IL-17A-induced psoriasis-like HaCaT cells （P<0.01）， and the relative mRNA expression levels of Ki67， S100A7， S100A8， and S100A9 （P<0.01）. Moreover， the KFX liquid can significantly reduce the relative mRNA expression levels of IL-1β， IL-6， and CXCL-20 in rh IL-17A-induced psoriasis-like cells （P<0.01）， and significantly inhibit the phosphorylation levels of JAK3 and STAT3 proteins （P<0.05， P<0.01）. ConclusionThe KFX liquid has no obvious toxicity to uninduced HaCaT cells. It can inhibit rh IL-17A-induced psoriasis-like HaCaT cell proliferation， reduce the cell migration ability， and has good in vitro anti-psoriasis activity. Its action mechanism may be related to downregulating the expression levels of inflammation-related cytokines in the JAK3/STAT3 signaling pathway and inhibiting the phosphorylation levels of JAK3 and STAT3 proteins.

OBJECTIVE To investigate the neuroprotective effect and mechanism of eleutheroside B （ELB） on Parkinson’s disease （PD） model mice by regulating the IκB kinase β （IKKβ）/nuclear factor-κB （NF-κB） signaling pathway. METHODS Fifty mice were randomly divided into normal control group， model group， positive control group （selegiline hydrochloride， 10 mg/kg）， and ELB low-dose and high-dose groups （80， 160 mg/kg）， with 10 mice in each group. Each group was given relevant medicine or normal saline intragastrically for 14 consecutive days. Starting from the 10th day of administration， the model group and all administration groups were intraperitoneally injected with 1-methyl-4-phenyl-1，2，3，6-tetrahydropyridine （MPTP） 30 mg/kg， for five consecutive days to establish the chronic PD model. After the last administration for 24 h， six mice were randomly selected from each group to test their behavioral abilities； detect the levels of interleukin-1β （IL-1β）， IL-10， tumor necrosis factor-α （TNF-α） in brain tissue and their mRNA expressions were measured， and positive expression of tyrosine hydroxylase （TH）， protein expressions of TH， α -synuclein （ α -syn）， ionized calcium-binding adaptor molecule 1 （Iba-1）， as well as phosphorylation levels of IKKβ and NF-κB p65 proteins in the brain tissue were detected. The ultrastructure of neurons in substantia nigra was observed. RESULTS Compared with the model group， rotarod endurance time and climbing score of each administration group （except for the ELB low-dose group） were increased significantly （ P ＜0.05）， while the levels and mRNA expressions of IL-1β， TNF-α， α -syn， and Iba-1， as well as phosphorylation levels of IKKβ and NF-κB p65 proteins in brain tissue were decreased significantly （except for TNF-α in the ELB low-dose group）. Conversely， the level and mRNA expression of IL-10 （except for the ELB low-dose group）， TH positive expression and protein expressions were significantly increased （ P ＜0.05）. Typical neurodegenerative pathological changes， such as neuronal karyopyknosis， mitochondrial swelling and vacuolization， and endoplasmic reticulum dilation， all showed varying degrees of improvement. CONCLUSIONS ELB may exert neuroprotective effects by inhibiting the activation of the IKKβ/NF-κB signaling pathway， alleviating inflammatory responses， reducing abnormal α -syn aggregation and neuronal loss， and further improving motor dysfunction in PD mice.

ObjectiveTo investigate microbial contamination status and distribution characteristics in laboratory animal barrier facilities, so as to provide a scientific basis for environmental quality control in barrier facilities. MethodsIn accordance with the national standard "Laboratory Animals—Environment and Housing Facilities" and the "Standard Operating Procedures" of the barrier facility, bacterial monitoring was performed on samples of air-settling bacteria, materials, and personnel gloves in the single-corridor barrier facility of the Animal Core Facility, Center for Excellence in Molecular Cell Science, Chinese Academy of Sciences (CEMCS). The monitoring data from January 2020 to December 2024 were collected, organized and statistically analyzed, and partial samples were subjected to species identification using PCR and sequencing methods. ResultsA total of 7 898 samples were collected from 2020 to 2024, including 3 175 air-settling bacteria samples, 3 353 material samples, and 1 370 glove samples. The overall compliance rate was 95.7% (7 559/7 898), among which the compliance rate of air-settling bacteria was 97.1% (3 084/3 175), that of materials was 93.2% (3 125/3 353), and that of personnel gloves was 98.5% (1 350/1 370). Over the five years, the compliance rates of all three types of monitored samples were above 90%. There were statistically significant differences in the compliance rates of air-settling bacteria and material samples among different quarters (P<0.05). Further investigation was conducted on samples collected from January to March 2024, and 190 bacterial strains were obtained through isolation and culture, including 126 strains from air-settling bacteria, 52 strains from materials, and 12 strains from personnel gloves. The strains were identified by PCR amplification and sequencing, and the 190 bacterial strains belonged to 9 genera and 20 species. Gram-positive bacteria accounted for the majority, with Staphylococcus as the dominant genus, accounting for 77.9% (148/190). ConclusionMicroorganisms carried by air, materials, and personnel gloves in barrier facilities are mainly Gram-positive bacteria. Regular monitoring of air-settling bacteria, materials, and personnel gloves in barrier facilities enables timely detection and control of potential risks during husbandry management and facility operation, which is of great significance for maintaining the sound operation of the barrier facility system and ensuring the quality of animal experiments.

ObjectiveTo determine the optimal bedding depth of wood shavings and cage-changing interval for post-weaning (21-day-old) SPF C57BL/6J mice housed in open cages within a barrier environment. MethodsThree bedding groups with average depths of 3 cm, 4 cm, and 5 cm were established, forming six experimental groups (three groups each for female and male mice, with 60 mice per group and 20 mice per cage, totaling 18 cages). The mice were housed in accordance with the maximum housing density requirements specified in GB 14925—2023 Laboratory Animal—Environment and Housing Facilities. Indicators, including body weight, food intake, waste load, and bedding cleanliness, were continuously monitored in mice aged 21-54 days. ResultsAt the age of 21-54 days, the body weight of male mice in the 4 cm bedding group at 42 days was significantly higher than that in the 3 cm and 5 cm groups (P<0.01); at the age of 45-54 days, the waste load of male mice in the 4 cm group was significantly higher than that in the 3 cm group (P<0.05). There were no statistically significant differences in body weight, feed intake and waste load of female mice among each bedding height group (P>0.05). Gender comparison showed that the body weight, feed intake and waste load of male mice were significantly higher than those of female mice at multiple age groups (P<0.05). However, there was no statistically significant difference in cleanliness scores between female and male mice (P>0.05). The scores of mice in the 3 cm and 4 cm groups were close to 3 points from day 6 to day 12, and the scores of mice in the 5 cm group were close to 3 points on day 12. After 42 days of age, the cleanliness scores of each group increased rapidly, and the cage change cycle needed to be shortened to 4 days. Comprehensive recommendation: the cage change cycle for 3 cm and 4 cm bedding heights is 6 days, and it can be extended to 12 days at a height of 5 cm bedding, and shortened to 4 days after 42 days of age. ConclusionUnder the open-cage housing mode, a bedding depth of 4 cm combined with a 6-day cage-changing interval during the growth phase can maintain cage cleanliness through bedding adsorption while optimizing the use of bedding resources. This protocol successfully balances animal welfare assurance with facility operational efficiency and is suitable for the large-scale management of C57BL/6J mice and inbred strains with similar genetic backgrounds.