BACKGROUND:Periprosthetic joint infection is the most common cause of early failure after total knee replacement.The current methods of preventing periprosthetic joint infection by improving the surface of the prosthesis have limitations to varying degrees.OBJECTIVE:To construct a coating material that can stably improve the surface of the implant,prevent the initial floating bacterial infection of periprosthetic infection,and regulate the bone transfer function around the implant.METHODS:(1)Material preparation:YGF polypeptide(which promotes bone formation),LL-37 polypeptide(with antibacterial properties)and YGF+LL-37 composite peptide were prepared by Fmoc solid phase peptide synthesis technology.The titanium-based materials were immersed in the three polypeptide solutions for 2 hours to obtain YGF coating,LL-37 coating and composite peptide coating coated titanium sheets.(2)In vitro experiment:Uncoated titanium sheets and coated titanium sheets were co-cultured with Escherichia coli(or Staphylococcus aureus)and the colonies were counted by plate method.MC3T3 cells were inoculated on the surface of uncoated titanium sheet and coated titanium sheet,respectively.Alizarin red staining was used to observe the calcium salt deposition on the surface of the material.Western blot assay was used to detect the protein expression of RUNX2,osteocalcin,osteopontin,and bone morphogenetic protein 2.(3)Animal experiment:24 SD rats were randomly divided into three groups:the blank group(n=8)was implanted with uncoated titanium nails in the femoral medullary canal;the control group(n=8)was implanted with uncoated titanium nails in the femoral medullary canal+intra-articular injection of Staphylococcus aureus suspension;the experimental group(n=8)was implanted with composite peptide coated titanium nails in the femoral medullary canal+intra-articular injection of Staphylococcus aureus suspension.After 5 weeks of implantation,micro-CT examination,hematoxylin-eosin staining and immunohistochemical staining of femur specimens were performed.RESULTS AND CONCLUSION:(1)In vitro experiment:Compared with uncoated titanium sheet and YGF coated titanium sheet,LL-37 coated and composite peptide coated titanium sheet could significantly inhibit the growth and reproduction of Escherichia coli and Staphylococcus aureus.Compared with uncoated titanium sheets and LL-37-coated titanium sheets,YGF-coated and composite peptide-coated titanium sheets could promote calcium salt deposition in osteoblasts and increase the protein expression of RUNX2,osteocalcin,osteopontin and bone morphogenetic protein 2.(2)Animal experiment:Micro-CT test showed that the control group had less bone mass than the blank group and the experimental group.Hematoxylin-eosin staining showed that there was a large amount of fibrous tissue around the nail channel in the control group,only a small amount of tissue fibrosis around the nail channel in the blank group,and only a small amount of tissue fibrosis around the nail channel in the experimental group.Immunohistochemical staining showed that the protein expression of interleukin 1β and tumor necrosis factor α in the control group was higher than that in the blank group and the experimental group,and the expression of osteocalcin,RUNX2 and osteopontin in the experimental group was higher than that in the blank group and the control group.(3)The results show that the titanium-based material coated with YGF+LL-37 composite peptide coating has good antibacterial ability and can promote bone transfer around the implant.

Neurocritical care involves complex pathophysiological mechanisms, and its incidence is higher, injuries are more severe, and treatment is more challenging in high-altitude environments. This consensus, based on the latest domestic and international evidence-based medical data, establishes a standardized, goal-oriented framework for neurocritical care management applicable in high-altitude regions and nationwide. The consensus was developed following international standards for evidence quality assessment and underwent two rounds of Delphi expert consultation, resulting in 32 recommendation statements covering three parts: management systems, monitoring and assessment, and core strategies. Key updates include: advocating for the establishment of independent neurocritical care units and implementing precise tiered diagnosis and treatment based on the "Five Differences in Critical Care" concept; constructing a "trinity" multimodal brain monitoring system centered on cerebral blood flow, cerebral oxygenation, and brain function, emphasizing routine bedside transcranial Doppler ultrasound, cerebral oximetry, and continuous electroencephalography monitoring; shifting management strategies from mild hypothermia therapy to targeted temperature management, and defining the "446" target management pathway for the supercritical stage; emphasizing the assessment of static and dynamic cerebrovascular autoregulation functions through multimodal methods to achieve individualized optimal mean arterial pressure management; elevating cerebrospinal fluid management goals to the level of "glymphatic system" function maintenance; implementing a multidisciplinary collaborative, whole-process management model focusing on patients' long-term neurological functional outcomes; de-escalation criteria include multidimensional indicators such as recovery of brain structure, restoration of cerebrovascular autoregulation, improvement in cerebrospinal fluid dynamics, and reduction in biomarker levels; and integrating cutting-edge technologies like artificial intelligence into post-critical care management and rehabilitation planning. This consensus systematically integrates the entire process of neurocritical care management, reflecting the modern connotation of goal-oriented, dynamic, and multimodal integration in neurocritical care medicine. It aims to adapt to new trends such as deepening understanding of pathophysiological mechanisms, the integration of medicine and engineering, and the empowerment of artificial intelligence, thereby further advancing the discipline of critical care medicine.

Objective: To investigate the distribution characteristics of ABO and Rh blood group antigen phenotypes among blood donors in the Yantai, Shandong. Methods: Blood samples from 310 180 voluntary blood donors in Yantai collected from January 2019 to December 2023 were tested for ABO and Rh blood group antigens using standard serological methods. RhD-negative samples were further typed for C, c, E, and e antigens. Population genetic analysis of blood groups was performed: allele frequencies were inferred from ABO phenotypes, and Rh allele/haplotype frequencies were estimated based on the proportion of RhD-negative donors and CcEe antigen typing, followed by Hardy-Weinberg equilibrium testing. Results: The phenotypic distribution frequency of ABO blood groups was B(32.72%)>O(28.93%)>A(27.65%)>AB(10.70%). The inferred allele frequencies were r(53.74%)>q(24.78%)>p(21.48%), consistent with Hardy-Weinberg equilibrium (P>0.05). A total of 1 872 Rh-negative donors (0.603%) were identified. The most common Rh phenotypes were ccdee (59.56%) and Ccdee (30.18%). The distribution of Rh antigen phenotypes deviated significantly from Hardy-Weinberg equilibrium (χ =37.15, P<0.001), with the cde haplotype showing the highest frequency. There was no statistically significant difference in ABO blood group distribution between RhD-positive and RhD-negative donors (P>0.05). Conclusion: The ABO blood group distribution among voluntary blood donors in Yantai is generally stable and consistent with population genetic equilibrium, whereas the Rh antigen phenotype distribution deviates from equilibrium, indicating potential underlying genetic structural differences.

Objective To introduce the causes of accidents and the diagnosis and treatment of two patients with radiation-induced skin injury admitted to our hospital in 2023, and to provide a reference for the clinical treatment of subsequent radiation-induced skin injury. Methods The clinical treatment process of two patients with acute skin injury caused by external radiation exposure were summarized and analyzed. Results The exposure history of the two patients was reconstructed, the flaw detection scenario was simulated, the biological dose and hand skin exposure dose were estimated, and the infrared thermal imaging device was used for dynamic monitoring. A comprehensive analysis was conducted based on clinical manifestations and other data. The diagnosis of “Xie” was excessive exposure combined with acute radiation-induced skin injury on both hands (Grade IV for the right hand palm, index finger, and middle finger and Grade II for the left hand little finger). The diagnosis of “Hao” was acute radiation-induced skin injury on both hands (Grade I). The two patients received different clinical treatment measures: “Xie” was treated with both local and systemic therapies, while “Hao” was mainly treated with systemic therapy. Conclusion After systematic and effective treatment, the radiation-induced skin injuries healed in both patients.

ObjectiveTo evaluate the therapeutic effect of Huazhuo SanJie Chubi presciption （HSCD） on chronic gouty arthritis （CGA） rats with low-grade inflammation and to explore the underlying mechanism with a focus on macrophage polarization. MethodsThe 41 male 6-week-old SD rats were randomly allocated， using the random number table， to a normal group （n=8） and a model group （n =33）. CGA with low-grade inflammation was induced in the model group by daily gavage of potassium oxonate （250 mg·kg^-1·d^-1） and hypoxanthine （300 mg·kg^-1·d^-1）， combined with intra-articular injection of a monosodium urate （MSU） crystal suspension （50 μL， 25 g·L^-¹） into the left ankle twice weekly. After 4 weeks of modeling， 3 rats were randomly selected from each group for model validation. The remaining successfully modeled rats were randomly divided into a model group， an HSCD group （10.35 g·kg^-1·d^-1， gavage once daily）， an M1 polarization agonist group （L-methionine sulfoximine， 300 mg·kg^-1， subcutaneous injection every other day）， an M1 polarization agonist + HSCD group， an M2 polarization inhibitor group （PD0325901， 10 mg·kg^-1·d^-1， gavage once daily）， and M2 polarization inhibitor + HSCD group. The corresponding drug or drug combination was administered according to group assignment， whereas rats in the normal and model groups received 0.5% carboxymethyl cellulose sodium （CMC-Na） vehicle （10.35 g·kg^-1·d^-1， gavage once daily）. All interventions were continued for four weeks. During the intervention period， except for the normal group， potassium oxonate （250 mg·kg⁻¹） and hypoxanthine （300 mg·kg^-1） were co-administered by gavage every other day to maintain the model. At the end of treatment， serum uric acid （SUA）， ankle joint diameter and joint swelling index were measured. The levels of high-sensitivity C-reactive protein （hs-CRP）， interleukin-1β （IL-1β）， interleukin-6 （IL-6）， tumor necrosis factor-α （TNF-α）， chemokine C-C motif ligand 2 （CCL2）， S100 calcium-binding protein A8/A9 （S100A8/A9）， interleukin-10 （IL-10） and arginase-1 （Arg-1） in serum and joint fluid were determined by enzyme-linked immunosorbent assay （ELISA）. High-frequency ultrasound was used to assess MSU deposition in the ankle joint. Hematoxylin-eosin （HE） staining was performed to evaluate synovial histopathological changes. Quantitative Real-time PCR and immunofluorescence were used to detect the mRNA and protein expression of the M1 macrophage polarization markers inducible nitric oxide synthase （iNOS） and the M2 macrophage polarization marker scavenger receptor cysteine-rich type 1 protein M130 （CD163） in synovial tissue. ResultsCompared with the normal group， the model group showed significantly elevated SUA level and joint swelling index， and increased levels of pro-inflammatory cytokines， CCL2， and S100A8/A9 in both serum and joint fluid （P<0.05）， accompanied by MSU deposition and synovial inflammation in the ankle joint. The mRNA and protein expression levels of macrophage polarization M1/M2 markers iNOS and CD163 in synovial tissues were also significantly up-regulated （P<0.05）. Compared with model group， rats in HSCD group had significantly lower SUA levels， attenuated joint swelling， reduced serum levels of pro-inflammatory cytokines， and decreased levels of CCL2 and S100A8/A9 in both serum and joint fluid， accompanied with alleviated MSU deposition and synovial inflammation （P<0.05）. HSCD markedly downregulated the mRNA and protein expression of M1 marker iNOS （P<0.05）， whereas it had no significant effect on the expression of M2 marker CD163. Compared with the M1 polarization agonist group， the M1 polarization agonist + HSCD group showed significantly reduced joint swelling， lower serum levels of pro-inflammatory cytokines， and decreased levels of CCL2 and S100A8/A9 in joint fluid （P<0.05）. In addition， synovial inflammatory cell infiltration and angiogenesis were attenuated， and iNOS mRNA and protein expression levels were significantly reduced （P<0.05）. Compared with the M2 polarization inhibitor group， the M2 polarization inhibitor + HSCD group exhibited reduced joint swelling， decreased levels of CCL2 and S100A8/A9 in joint fluid and ameliorated synovial inflammation （P<0.05）， whereas the levels of anti-inflammatory mediators （IL-10， Arg-1） and CD163 mRNA and protein expression were not significantly increased. ConclusionHSCD alleviates low-grade inflammation in CGA rats， at least in part， by inhibiting macrophage polarization toward the M1 phenotype.

ObjectiveThis paper aims to observe the effect of Huazhuo Sanjie Chubi prescription （HSCD） on the gouty bone erosion model rats and investigate its action mechanism. MethodsThirty-six two-month-old male SD rats were randomly divided into the blank group with nine rats and the modeling group with 27 rats. The rats in the modeling group were administered hypoxanthine solution at 300 mg·kg^-1·d^-1 and potassium oxonate solution at 250 mg·kg^-1·d^-1， combined with intra-articular injection of 200 μL monosodium urate （MSU） crystal suspension at 25 g·L^-1 into the right ankle joint （joint injection once every three days）， so as to induce the gouty bone erosion model. After four weeks of modeling， three rats were selected from these two groups to validate the model. The modeled 24 rats were randomly divided into the model group， HSCD group （10.35 g·kg^-1·d^-1）， allopurinol group （20 mg·kg^-1·d^-1）， and inhibitor group （LY294002， 10 mg·kg^-1·d^-1）， with six rats per group. Except for the blank group， rats in all other groups continued to receive hypoxanthine solution at 300 mg·kg^-1 and potassium oxonate solution at 250 mg·kg^-1 via gavage concurrently with administration to maintain modeling intervention. The rats in the HSCD group and allopurinol group received administration by gavage at the above doses. The rats in the inhibitor group received an intraperitoneal injection at the above dose. The rats in the blank group and model group received saline （10.35 g·kg^-1·d^-1） by gavage for four consecutive weeks. After administration， ankle joint swelling of the rats in all groups was observed， and the diameters were measured. Bone volume fraction （BV/TV） and bone surface area to bone volume （BS/BV） were observed and quantitatively analyzed by Micro-CT. Histopathological changes in the ankle joint were observed by hematoxylin-eosin （HE） staining and safranin O-fast green staining. The uric acid in the rats' serum was determined by enzyme colorimetry. The levels of inflammatory factors， including tumor necrosis factor-α （TNF-α）， interleukin （IL）-1β， and IL-6 were measured by enzyme-linked immunosorbent assay （ELISA）. The protein expressions of receptor activator of nuclear factor-κB ligand （RANKL） and phosphorylated （p）-phosphatidylinositol-3-kinase （PI3K） in ankle joint tissues of rats were detected by immunofluorescence staining. The mRNA levels of the proteins related to the bone erosion， including RANKL， tartrate-resistant acid phosphatase （TRAP）， cathepsin K （CTSK）， and matrix metalloproteinase-9 （MMP-9） in the ankle joint tissues of rats were determined by real-time fluorescence quantitative polymerase chain reaction （Real-time PCR）. The expressions of the proteins related to the bone erosion， including RANKL， CTSK， TRAP， MMP-9， and the proteins related to the PI3K/protein kinase B （Akt） signaling pathway， including PI3K， Akt， mammalian target of rapamycin （mTOR）， p-PI3K， phosphorylated protein kinase B （p-Akt）， and phosphorylated mammalian target of rapamycin （p-mTOR）， were detected by Western blot. ResultsCompared with the blank group， the modeling group showed marked ankle swelling and increased diameter. Micro-CT revealed an uneven articular surface and honeycomb-like bone erosion in the ankle joint. Quantitative analysis showed decreased BV/TV and increased BS/BV （P<0.05）. HE staining revealed a narrowed joint space， rough and discontinuous cartilage surfaces， reduced and unevenly distributed chondrocytes， partial hypertrophy， and blurred tidemarks， confirming successful model establishment. After four weeks of intervention， compared with those in the blank group， the rats in the model group exhibited severe ankle swelling and increased diameters （P<0.05）. Micro‑CT showed that the ankle joint surface was irregular， and bone erosion exhibited a honeycomb‑like morphology. The microstructural parameters of the bone revealed a decreased BV/TV and an increased BS/BV （P<0.05）. Histopathological examination revealed a narrowed joint space and severe articular cartilage destruction. The levels of uric acid in the serum and inflammatory factors （IL-1β， IL-6， and TNF-α） were increased （P<0.05）. The mRNA and protein levels of the proteins related to bone erosion in joint tissue， including RANKL， CTSK， TRAP， and MMP-9， were upregulated （P<0.05）. The ratios of p-PI3K/PI3K， p-Akt/Akt， and p-mTOR/mTOR in the proteins related to the PI3K/Akt signaling pathway were increased （P<0.05）. RANKL and p-PI3K protein fluorescence intensities were elevated （P<0.05）. Compared with those in the model group， the above indicators in all other administration groups showed varying degrees of improvement. The HSCD group and inhibitor groups exhibited more significant effects in reducing ankle swelling， improving bone erosion， bone microstructure （significant decrease in BV/TV and increase in BS/BV）， and the pathology of cartilage erosion， lowering inflammatory factor levels， downregulating the proteins related to the bone erosion， and suppressing activation of the PI3K/Akt/mTOR pathway （P<0.05）. The uric acid levels in rats' serum were reduced in both HSCD and allopurinol groups （P<0.05）. Compared with those in the HSCD group， the rats in the allopurinol group had larger ankle diameters （P<0.05）， more severe bone erosion and bone microstructure damage （P<0.05）， worse improvement of the pathology of cartilage erosion， higher levels of IL-6 and TNF-α （P<0.05）， elevated expressions of the proteins related to the bone erosion， higher expression ratio of proteins related to the PI3K/Akt signaling pathway （P<0.05）， and higher fluorescence intensities of RANKL and p-PI3K proteins （P<0.05）. The inhibitor group achieved comparable results to the HSCD group in improvements of bone microstructure and the reduction of IL-1β and IL-6， stronger suppression of TNF-α and PI3K/Akt/mTOR signaling pathway activation （P<0.05）， but weaker effects on cartilage repair and serum uric acid reduction （P<0.05）. ConclusionHSCD effectively reduces uric acid levels in serum， suppresses inflammatory factor secretion， and downregulates the expressions of proteins related to bone erosion， including RANKL， CTSK， TRAP， and MMP-9 in the joint tissues. Its action mechanism of improving gouty bone erosion may be associated with inhibition of the PI3K/Akt signaling pathway.

BACKGROUND:Periprosthetic joint infection is the most common cause of early failure after total knee replacement.The current methods of preventing periprosthetic joint infection by improving the surface of the prosthesis have limitations to varying degrees.OBJECTIVE:To construct a coating material that can stably improve the surface of the implant,prevent the initial floating bacterial infection of periprosthetic infection,and regulate the bone transfer function around the implant.METHODS:(1)Material preparation:YGF polypeptide(which promotes bone formation),LL-37 polypeptide(with antibacterial properties)and YGF+LL-37 composite peptide were prepared by Fmoc solid phase peptide synthesis technology.The titanium-based materials were immersed in the three polypeptide solutions for 2 hours to obtain YGF coating,LL-37 coating and composite peptide coating coated titanium sheets.(2)In vitro experiment:Uncoated titanium sheets and coated titanium sheets were co-cultured with Escherichia coli(or Staphylococcus aureus)and the colonies were counted by plate method.MC3T3 cells were inoculated on the surface of uncoated titanium sheet and coated titanium sheet,respectively.Alizarin red staining was used to observe the calcium salt deposition on the surface of the material.Western blot assay was used to detect the protein expression of RUNX2,osteocalcin,osteopontin,and bone morphogenetic protein 2.(3)Animal experiment:24 SD rats were randomly divided into three groups:the blank group(n=8)was implanted with uncoated titanium nails in the femoral medullary canal;the control group(n=8)was implanted with uncoated titanium nails in the femoral medullary canal+intra-articular injection of Staphylococcus aureus suspension;the experimental group(n=8)was implanted with composite peptide coated titanium nails in the femoral medullary canal+intra-articular injection of Staphylococcus aureus suspension.After 5 weeks of implantation,micro-CT examination,hematoxylin-eosin staining and immunohistochemical staining of femur specimens were performed.RESULTS AND CONCLUSION:(1)In vitro experiment:Compared with uncoated titanium sheet and YGF coated titanium sheet,LL-37 coated and composite peptide coated titanium sheet could significantly inhibit the growth and reproduction of Escherichia coli and Staphylococcus aureus.Compared with uncoated titanium sheets and LL-37-coated titanium sheets,YGF-coated and composite peptide-coated titanium sheets could promote calcium salt deposition in osteoblasts and increase the protein expression of RUNX2,osteocalcin,osteopontin and bone morphogenetic protein 2.(2)Animal experiment:Micro-CT test showed that the control group had less bone mass than the blank group and the experimental group.Hematoxylin-eosin staining showed that there was a large amount of fibrous tissue around the nail channel in the control group,only a small amount of tissue fibrosis around the nail channel in the blank group,and only a small amount of tissue fibrosis around the nail channel in the experimental group.Immunohistochemical staining showed that the protein expression of interleukin 1β and tumor necrosis factor α in the control group was higher than that in the blank group and the experimental group,and the expression of osteocalcin,RUNX2 and osteopontin in the experimental group was higher than that in the blank group and the control group.(3)The results show that the titanium-based material coated with YGF+LL-37 composite peptide coating has good antibacterial ability and can promote bone transfer around the implant.

ObjectiveTo identify the pathogen species responsible for the wilt disease of Tetradium ruticarpum in Chongqing， investigate there biological characteristics， and screen effective fungicides， so as to provide a theoretical basis for disease control in production. MethodsThe pathogen was isolated via the tissue culture method. Pathogenicity was verified according to Koch's postulates. The pathogen was identified based on morphological characteristics and multi-gene phylogenetic analysis. The mycelial growth rate method was used for biological characterization of the pathogen and fungicide screening. ResultsThe pathogen colonies were nearly circular with irregular edges， white， short， velvety aerial hyphae， and pale purple undersides. Macroconidia were colorless， sickle-shaped， with 3-5 septa， while microconidia were transparent， elliptical， aseptate or with 1-2 septa. Multi-gene phylogenetic analysis showed that the pathogen clustered in the same clade as Fusarium fujikuroi with 100% support， which， combined with morphological characteristics， identified the pathogen causing wilt of T. ruticarpum in Chongqing as F. fujikuroi. The optimal conditions for the mycelial growth of F. fujikuroi were mung bean agar （MBA） with glucose as the carbon source， beef extract and yeast powder as nitrogen sources， 28 ℃， pH 7.0， and alternating light/dark conditions. The optimal conditions for sporulation were potato dextrose agar （PDA） with glucose as the carbon source， beef extract as the nitrogen source， 28 ℃， pH 7.0， and complete darkness. Among chemical fungicides， phenazine-1-carboxylic acid exhibited the strongest inhibitory effect on F. fujikuroi. Shenqinmycin and tetramycin were the most effective bio-fungicides. ConclusionThis study is the first to report F. fujikuroi as the causal agent of wilt disease in T. rutaecarpa. The chemical fungicide phenazine-1-carboxylic acid and the bio-fungicides shenqinmycin and tetramycin showed strong inhibitory effects against F. fujikuroi.

ObjectiveTo explore the mechanism by which Yizhi Qingxin prescription improves mitochondrial dysfunction in Alzheimer's disease （AD） through regulating mitochondrial Ca²⁺ homeostasis and kinetic balance based on the protein kinase A （PKA）/calcineurin （CaN） signaling pathway. MethodsSixty three-month-old amyloid precursor protein （APP）/presenilin 1 （PS1） double transgenic mice were randomly divided into a model group， a donepezil group（0.65 mg·kg^-1）， a low-dose Yizhi Qingxin prescription group （YQF-L，2.6 g·kg^-1）， a medium-dose Yizhi Qingxin prescription group （YQF-M，5.2 g·kg^-1）， and a high-dose Yizhi Qingxin prescription group （YQF-H，10.4 g·kg^-1）， with 12 mice in each group. Twelve C57BL/6J mice with the same genetic background served as a normal group. Each treatment group received gavage administration daily， with the model and normal groups receiving equal volume of physiological saline. Intervention continued for 12 consecutive weeks. The learning and memory abilities of the mice were assessed using the novel object recognition （NOR） and Morris water maze （MWM） tests. Hematoxylin-eosin （HE）/Nissl staining was used to observe histopathological changes in the hippocampus. Transmission electron microscopy （TEM） was used to observe mitochondrial ultrastructure. Fluo-4 acetoxymethyl ester （Fluo-4 AM） Ca²⁺ probe was used to measure intracellular Ca²⁺ concentration in brain tissue. Western blot was used to determine the protein expression of PKA， CaN， sodium/calcium/lithium exchanger （NCLX）， mitochondrial calcium uniporter （MCU）， calmodulin （CaM）， dynamin-related protein 1 （Drp1）， and phosphorylated dynamin-related protein 1 （serine 637 site） ［p-Drp1（S637）］ in the hippocampus. Real-time quantitative polymerase chain reaction （Real-time PCR） was used to measure the expression of PKA， CaN， CaM， NCLX， MCU， and Drp1 mRNAs. ResultsCompared with those in the normal group， the recognition index （RI） of the model group decreased （P0.01）， and the number of crossings through the original platform area， the duration of stay in the target quadrant， and the distance were reduced （P0.01）. The protein expression of PKA， NCLX， and p-DRP1 （ser637） significantly decreased （P0.05）， and the mRNA expression of PKA and NCLX significantly decreased （P0.05）. The escape latency （EL） was prolonged （P0.05）， and the intracellular Ca²⁺ level significantly increased （P0.01）. The protein expression of CaN， CaM， MCU， and Drp1， as well as the mRNA expression of CaN， MCU， and Drp1， significantly increased （P0.05）. After intervention with Donepezil and Yizhi Qingxin prescription， compared with that in the model group， the RI of the treatment group significantly increased （P0.05）， and the number of crossings through the platform and the duration of stay in the target quadrant significantly increased （P0.05）. The protein expression of PKA， NCLX， and p-Drp1 （ser637） and the mRNA expression of PKA and NCLX significantly increased （P0.05）. On the 4th and 5th days， the EL was shortened （P0.05）， and the intracellular Ca²⁺ level decreased （P0.05）. The protein expression of CaN， CaM， MCU， and Drp1 and the mRNA expression of CaN， MCU， and Drp1 significantly decreased （P0.05）. ConclusionYizhi Qingxin prescription regulates the PKA/CaN pathway， upregulates the expression of PKA， NCLX， and p-Drp1 （ser637） proteins， reduces the expression of CaN， CaM， MCU， and Drp1 proteins， and regulates Ca²⁺ homeostasis and mitochondrial dynamic balance， thereby enhancing the spatial learning and memory abilities of AD mice.

ObjectiveTo explore the mechanism by which Yizhi Qingxin prescription improves mitochondrial dysfunction in Alzheimer's disease （AD） through regulating mitochondrial Ca²⁺ homeostasis and kinetic balance based on the protein kinase A （PKA）/calcineurin （CaN） signaling pathway. MethodsSixty three-month-old amyloid precursor protein （APP）/presenilin 1 （PS1） double transgenic mice were randomly divided into a model group， a donepezil group（0.65 mg·kg^-1）， a low-dose Yizhi Qingxin prescription group （YQF-L，2.6 g·kg^-1）， a medium-dose Yizhi Qingxin prescription group （YQF-M，5.2 g·kg^-1）， and a high-dose Yizhi Qingxin prescription group （YQF-H，10.4 g·kg^-1）， with 12 mice in each group. Twelve C57BL/6J mice with the same genetic background served as a normal group. Each treatment group received gavage administration daily， with the model and normal groups receiving equal volume of physiological saline. Intervention continued for 12 consecutive weeks. The learning and memory abilities of the mice were assessed using the novel object recognition （NOR） and Morris water maze （MWM） tests. Hematoxylin-eosin （HE）/Nissl staining was used to observe histopathological changes in the hippocampus. Transmission electron microscopy （TEM） was used to observe mitochondrial ultrastructure. Fluo-4 acetoxymethyl ester （Fluo-4 AM） Ca²⁺ probe was used to measure intracellular Ca²⁺ concentration in brain tissue. Western blot was used to determine the protein expression of PKA， CaN， sodium/calcium/lithium exchanger （NCLX）， mitochondrial calcium uniporter （MCU）， calmodulin （CaM）， dynamin-related protein 1 （Drp1）， and phosphorylated dynamin-related protein 1 （serine 637 site） ［p-Drp1（S637）］ in the hippocampus. Real-time quantitative polymerase chain reaction （Real-time PCR） was used to measure the expression of PKA， CaN， CaM， NCLX， MCU， and Drp1 mRNAs. ResultsCompared with those in the normal group， the recognition index （RI） of the model group decreased （P0.01）， and the number of crossings through the original platform area， the duration of stay in the target quadrant， and the distance were reduced （P0.01）. The protein expression of PKA， NCLX， and p-DRP1 （ser637） significantly decreased （P0.05）， and the mRNA expression of PKA and NCLX significantly decreased （P0.05）. The escape latency （EL） was prolonged （P0.05）， and the intracellular Ca²⁺ level significantly increased （P0.01）. The protein expression of CaN， CaM， MCU， and Drp1， as well as the mRNA expression of CaN， MCU， and Drp1， significantly increased （P0.05）. After intervention with Donepezil and Yizhi Qingxin prescription， compared with that in the model group， the RI of the treatment group significantly increased （P0.05）， and the number of crossings through the platform and the duration of stay in the target quadrant significantly increased （P0.05）. The protein expression of PKA， NCLX， and p-Drp1 （ser637） and the mRNA expression of PKA and NCLX significantly increased （P0.05）. On the 4th and 5th days， the EL was shortened （P0.05）， and the intracellular Ca²⁺ level decreased （P0.05）. The protein expression of CaN， CaM， MCU， and Drp1 and the mRNA expression of CaN， MCU， and Drp1 significantly decreased （P0.05）. ConclusionYizhi Qingxin prescription regulates the PKA/CaN pathway， upregulates the expression of PKA， NCLX， and p-Drp1 （ser637） proteins， reduces the expression of CaN， CaM， MCU， and Drp1 proteins， and regulates Ca²⁺ homeostasis and mitochondrial dynamic balance， thereby enhancing the spatial learning and memory abilities of AD mice.