ObjectiveThis study leverages structural data from antigen-antibody complexes of the influenza A virus neuraminidase (NA) protein to investigate the spatial recognition relationship between the antigenic epitopes and antibody paratopes. MethodsStructural data on NA protein antigen-antibody complexes were comprehensively collected from the SAbDab database, and processed to obtain the amino acid sequences and spatial distribution information on antigenic epitopes and corresponding antibody paratopes. Statistical analysis was conducted on the antibody sequences, frequency of use of genes, amino acid preferences, and the lengths of complementarity determining regions (CDR). Epitope hotspots for antibody binding were analyzed, and the spatial structural similarity of antibody paratopes was calculated and subjected to clustering, which allowed for a comprehensively exploration of the spatial recognition relationship between antigenic epitopes and antibodies. The specificity of antibodies targeting different antigenic epitope clusters was further validated through bio-layer interferometry (BLI) experiments. ResultsThe collected data revealed that the antigen-antibody complex structure data of influenza A virus NA protein in SAbDab database were mainly from H3N2, H7N9 and H1N1 subtypes. The hotspot regions of antigen epitopes were primarily located around the catalytic active site. The antibodies used for structural analysis were primarily derived from human and murine sources. Among murine antibodies, the most frequently used V-J gene combination was IGHV1-12*01/IGHJ2*01, while for human antibodies, the most common combination was IGHV1-69*01/IGHJ6*01. There were significant differences in the lengths and usage preferences of heavy chain CDR amino acids between antibodies that bind within the catalytic active site and those that bind to regions outside the catalytic active site. The results revealed that structurally similar antibodies could recognize the same epitopes, indicating a specific spatial recognition between antibody and antigen epitopes. Structural overlap in the binding regions was observed for antibodies with similar paratope structures, and the competitive binding of these antibodies to the epitope was confirmed through BLI experiments. ConclusionThe antigen epitopes of NA protein mainly ditributed around the catalytic active site and its surrounding loops. Spatial complementarity and electrostatic interactions play crucial roles in the recognition and binding of antibodies to antigenic epitopes in the catalytic region. There existed a spatial recognition relationship between antigens and antibodies that was independent of the uniqueness of antibody sequences, which means that antibodies with different sequences could potentially form similar local spatial structures and recognize the same epitopes.

Objective:To evaluate the effect of sleep deprivation on the expression of sirtuin 6 (SIRT6) in the cerebellum of immature mice.Methods:Fifty SPF healthy male C57BL/6 mice, aged 4 weeks, weighing 14-16 g, were divided into 2 groups ( n=25 each) using a random number table method: control group (Con group) and sleep deprivation group (SD group). The chronic sleep deprivation model was prepared by using the multi-platform water environment method, with 20 h of sleep deprivation per day for 10 consecutive days. After sleep deprivation, a balance beam experiment was performed to test the balance and coordination ability of mice. The mice were sacrificed after anesthesia and cerebellar lobular IV-VI (4-6 cb) tissues were taken for microscopic examination of the ultrastructure (with a transmission electron microscope) and for determination of the dendritic spine density of cerebellar 4-6cb Purkinje neurons (by Golgi staining), co-expression of SIRT6 and Calbindin D-28k (CbD-28k) and expression of glucose transporter Glut3 of cerebellar 4-6cb (by immunofluorescence staining). Results:Compared with group Con, the duration of passage through the balance beam was significantly prolonged, and the number of posterior foot slips was increased, the synaptic gap of cerebellar 4-6cb neurons was increased, the thickness of postsynaptic density was increased, the density of dendritic spines of Purkinje cells and the number of positive cells co-expressing SIRT6 and CbD-28k were decreased, and the expression of Glut3 was down-regulated in group SD ( P<0.05). Conclusions:The mechanism by which sleep deprivation decreases the abilities of balance and coordination is related to down-regulating SIRT6 expression in cerebellar Purkinje cells and decreasing neuronal glucose metabolism, thus damaging the synaptic plasticity of cerebellum in immature mice.

Objective:To evaluate the effect of propofol on parvalbumin (PV) neurons in the medical prefrontal cortex(mPFC)of rats with social behavior disorders induced by chronic sleep deprivation.Methods:Forty-two SPF male Sprague-Dawley rats, aged 8 weeks, weighing 200-250 g, were divided into 3 groups ( n=14 each) using a random number table method: control group (group Con), chronic sleep deprivation plus natural sleep group (group CSD+ NS), and chronic sleep deprivation plus propofol group (group CSD+ Pro). Sleep deprivation model was established by the modified multiple platform method, the rats were placed in the sleep-deprivation tank for 20 h a day (14: 00-10: 00), and allowed to sleep naturally for 4 h (10: 00-14: 00) a day for 28 consecutive days. Propofol 40 mg/kg was intraperitoneally injected for 28 consecutive days after sleep deprivation in CSD+ Pro group. While the equal volume of 10% fat emulsion was given in Con and CSD+ NS groups. After the end of sleep deprivation, a three-box social experiment was used to detect the social behavior of rats, and the number of the PV positive cells and density of the perineuronal network (PNN) in the mPFC area were measured by immunofluorescence. Results:Compared with group Con, the pertentage of rapid eye movement sleep and sniffing time preference coefficients for the strange rat 1 in the first stage and for the strange rat 2 in the second stage were significantly decreased, and the number of the PV positive cells and density of PNN in the mPFC area were decreased in group CSD+ NS ( P<0.05). Compared with group CSD+ NS, the sniffing time preference coefficients for the strange rat 1 in the first stage and for the strange rat 2 in the second stage were significantly increased, the number of the PV positive cells and density of PNN in the mPFC area were increased( P<0.05), and no significant change was found in the percentage of the rapid eye movement sleep in group CSD+ Pro. Conclusions:Propofol probably increases the number and function of PV neurons in the mPFC and ameliorates sleep deprivation-induced social behavior disorders in sleep-deprived rats.

OBJECTIVE To evaluate the ameliorative effect of Juanbi Tongluo Oral Liquid on sciatic neuronal apoptosis in Type 2 diabetic model mice.METHODS The Type 2 diabetes mouse model was established by feeding with high-fat and high-sugar diet combined with intraperitoneal injection of streptozotocin(STZ).The mice were treated with metformin(200 mg·kg-1·d-1),low dose(3.9 g·kg-1·d-1)and high dose(7.8 g·kg-1·d-1)Juanbi Tongluo Oral Liquid for 35 days.The latency of response to thermal stimu-lation was detected by hot plate,and the values of blood glucose insulin and glycosylated hemoglobin were determined.Biochemical kits were used to detect the expression of serum total cholesterol(T-CHO),triglyceride(TG),high density lipoprotein cholesterol(HDL-C),low density lipoprotein cholesterol(LDL-C),superoxide dismutase(SOD),catalase(CAT),glutathione peroxidase(GSH-Px)and oxidation product malondialdehyde(MDA).The expression of tumor cytokine α(TNF-α),interleukin(IL)-1β,IL-6 and IL-10 in serum of mice were detected by ELISA method;the injury of sciatic nerve of model mice was detected by HE staining;the apoptosis of sciatic nerve was detected by TUNEL method;and the expression of neurofilament protein NF-L,apoptosis(cleaved Caspase-3,Caspase-3)and oxidative stress(Nrf2,HO-1)signal pathway proteins in sciatic nerve of model mice were detected by Western blot method.RESULTS High-dose Juanbi Tongluo Oral Liquid shortened the latent period of heat pain response in model mice(P<0.01);downregulated fasting blood glucose and glycated hemoglobin(P<0.01),and upregulated fasting plasma insulin in model mice(P<0.01);downregulated serum T-CHO,TG,and LDL-C levels(P<0.01),upregulated HDL-C levels(P<0.01);downregulated serum pro-inflammatory factors TNF-α,IL-1β and IL-6 levels(P<0.05),upregulated the anti-inflammatory cyto-kine IL-10 level(P<0.01);inhibited sciatic nerve structural damage and apoptosis(P<0.05);downregulated the ratio of cleaved Caspase-3 to Caspase-3 in the apoptosis pathway(P<0.01);upregulated the expression of neurofilament proteins NF-L and NF-H in sciatic nerve tissue(P<0.05,P<0.01);and upregulated the expression of antioxidant stress proteins Nrf2 and HO-1(P<0.01).CONCLUSION Juanbi Tongluo Oral Liquid can improve sciatic neuronal apoptosis of Type 2 diabetic mice,which may be related to its effect on improving oxidative stress and inflammatory stress.

"MS/MS spectrum to structure"plays a critical role in the confirmative identification of complicated matrices and is currently regarded as an extremely challenging endeavor.MS/MS information provides vital clues to structural identification.In this study,a strategy was proposed to facilitate unambiguous identification through matching MS3 with MS2 spectra.Initially,MS3 spectra of the featured ions(c-and y-type ions)generated by the decomposition of ester functional group in esters and the MS2 spectrum of the structural unit([M-H]-)were all captured on the Qtrap-MS platform equipped with two tandem-in-space collision cells,including the second quadrupole cell(q2)and linear ion trap(LIT)chambers(actually the third quadrupole unit).Subsequently,the MS/MS spectrum matching between MS3 spectra of the ester compound and MS2 spectra of the structural unit(s)were achieved.As a result,the findings corresponding to MS3 and MS2 spectra matching were summarized.Finally,based on HR-MS/MS information of total salvianolic acid derivatives(TSA),36 kinds of compounds were preliminarily identified through matching with literature information and database retrieval.The applicability of MS3 and MS2 spectra matching strategy was further justified by the confirmative identification of phenolic acid compounds(Rosmarinic acid and salvianolic acid B)in TSA.Above all,MS3 and MS2 spectra matching strategy was quite meaningful towards advancing"MS/MS spectrum to structure"analysis through recognizing and identifying featured fragment ions,and also provided inspiration and new insights for the structural characterization.

A precursor ion selection (PIS) based ultra high performance liquid chromatography-quadrupole time of flight mass spectrometry (UHPLC-Q-TOF-MS) analytical method was used to screen the chemical components in Jiawei Dingzhi pills (JWDZP) comprehensively and rapidly. To compile the components of the compound medicine, a total of 1 921 components were found utilizing online databases and literature. After verifying the sources, unifying the component names, merging the multi-flavor attributed components, and removing the weak polar molecules, 450 components were successfully retained. The Acquity UPLC HSS T3 column (100 mm × 2.1 mm, 1.8 μm) was used, with a 0.1% formic acid water (A)-acetonitrile (B) as the mobile phase. The flow rate was 0.35 mL·min^-1, the column temperature was 35 ℃, and an electrospray ion source was used. Data was collected with the PIS strategy in both positive and negative ion modes. Compounds were screened through matching accurate molecular weight of the database, and identified according to MS/MS data (characteristic fragment ions and neutral loss), with comparison of reference. Some compounds were confirmed using standard products. A total of 176 compounds were screened out in the extract of JWDZP, among which 26 compounds were confirmed by standard products. These compounds include 96 components from the sovereign drug, and 34 coefflux components with low ion intensity. The PIS-UHPLC-Q-TOF-MS/MS method established in this study can quickly and comprehensively screen the chemical components of JWDZP, which enhanced the screening rate of components with co-elution compounds of low ion intensities and provided a basis for the study of the material foundation of JWDZP.

Objective To investigate the mechanism underlying the neuroprotective effect of linarin(LIN)against microglia activation-mediated inflammation and neuronal apoptosis following spinal cord injury(SCI).Methods Fifty C57BL/6J mice(8-10 weeks old)were randomized to receive sham operation,SCI and linarin treatment at 12.5,25,and 50 mg/kg following SCI(n=10).Locomotor function recovery of the SCI mice was assessed using the Basso Mouse Scale,inclined plane test,and footprint analysis,and spinal cord tissue damage and myelination were evaluated using HE and LFB staining.Nissl staining,immunofluorescence assay and Western blotting were used to observe surviving anterior horn motor neurons in injured spinal cord tissue.In cultured BV2 cells,the effects of linarin against lipopolysaccharide(LPS)-induced microglia activation,inflammatory factor release and signaling pathway changes were assessed with immunofluorescence staining,Western blotting,RT-qPCR,and ELISA.In a BV2 and HT22 cell co-culture system,Western blotting was performed to examine the effect of linarin against HT22 cell apoptosis mediated by LPS-induced microglia activation.Results Linarin treatment significantly improved locomotor function(P<0.05),reduced spinal cord damage area,increased spinal cord myelination,and increased the number of motor neurons in the anterior horn of the SCI mice(P<0.05).In both SCI mice and cultured BV2 cells,linarin effectively inhibited glial cell activation and suppressed the release of iNOS,COX-2,TNF-α,IL-6,and IL-1β,resulting also in reduced neuronal apoptosis in SCI mice(P<0.05).Western blotting suggested that linarin-induced microglial activation inhibition was mediated by inhibition of the TLR4/NF-κB signaling pathway.In the cell co-culture experiments,linarin treatment significantly decreased inflammation-mediated apoptosis of HT22 cells(P<0.05).Conclusion The neuroprotective effect of linarin is medicated by inhibition of microglia activation via suppressing the TLR4/NF-κB signaling pathway,which mitigates neural inflammation and reduce neuronal apoptosis to enhance motor function of the SCI mice.

Objective:To combine ultrasound and clinical characteristics for predicting the treatment time of strontium 90( 90Sr) radioisotope applicator therapy for pathological scars when the therapeutic effect meets the clinical effective criteria. Methods:From September 2022 to October 2023, 48 patients (90 lesions) with pathological scars who underwent 90Sr radioisotope applicator therapy at the Department of Nuclear Medicine, Nanfang Hospital, Southern Medical University were prospectively collected. The clinically effective criteria of 90Sr radioisotope applicator therapy for pathological scars were defined as a reduction of the superficial height of the scar higher than 50%. All lesions were divided into short period treatment group (2 months, 38 lesions) and long period treatment group (>2 months, 52 lesions) according to the duration of treatment when the therapeutic effect met the clinical criteria. Univariate comparative analyses of ultrasound and clinical characteristics between the two groups were performed. The statistically significant variates were used to build a multivariate logistic regression model for analyzing the independent predictors of the treatment time of 90Sr radioisotope applicator therapy for pathological scars. Results:Family history, blood flow signal, disease duration, age, and scar Young′s modulus were independent predictors of the effective treatment time of 90Sr radioisotope applicator therapy for pathological scars (all P<0.05). By using the selected variables, a predictive model was developed, area under the ROC curve (AUC) were 0.886 (95% CI=0.817-0.955, P<0.001), and the calibration curve showed that the model was well calibrated(χ 2=5.668, P=0.684). Conclusions:The multivariate logistic regression model with family history, blood flow signal, disease duration, age, and scar Young′s modulus could be used to predict the treatment time of 90Sr radioisotope applicator therapy for pathologic scars, which can help to guide the design of treatment plan, reduce unnecessary radiation damage, and improve patient compliance.

This experiment aims to investigate the effects of a dietary supplement of herbal tea resi-due on white feather broilers in the prospectives of growth performance,serum indexes and intesti-nal immune indexes.A total of 280 1-day-old white feather broilers with similar body mass and good health were randomly divided into 4 groups with 5 replicates per group and 14 birds per repli-cate.Group Ⅰ(control group)was fed a basal diet.Groups Ⅱ,Ⅲ and Ⅳ were fed a diet supple-mented with 2％,4％and 6％herbal tea residue powder,respectively.The feeding lasted for 49 days,and was divided into 2 phases from 1 to 21 days of age and 22 to 49 days of age.Blood,tissue and mucosa of the duodenum and jejunum were collected on 21 d and 49 d.Total cholesterol(T-CHO),triglyceride(TG),high density lipoprotein cholesterol(HDL-C),low density lipoprotein cholesterol(LDL-C)and the activities of aspartate aminotransferase(AST)and alanine amin-otransferase(ALT)in the serum were examined.The villus height and crypt depth of the jejunum were observed and measured by morphology.The mRNA expression levels of intestinal interleukin-1β(IL-1β),interleukin-2(IL-2),interleukin-4(IL-4),interleukin-10(IL-10)and tumor necrosis factor-α(TNF-α)were determined by qPCR.The results showed that compared with group Ⅰ,the mass of group Ⅲ on 21 d and 49 d significantly increased(P＜0.05).The average daily feed intake of 22-49 d and 1-49 d significantly increased(P＜0.05).The average daily mass gain of 1-21 d,22-49 d and 1-49 d significantly increased(P＜0.05).In the serum of 21 d,compared with group Ⅰ,T-CHO in group Ⅱ significantly decreased(P＜0.05).TG in groups Ⅱ,m and Ⅳ significantly de-creased(P＜0.05).LDL-C and AST activity in group Ⅳ significantly decreased(P＜0.05).In the serum of 49 d,T-CHO in group Ⅲ,LDL-C in group Ⅳ,HDL-C of groups Ⅲ and Ⅳ significantly increased(P＜0.05),and the ALT activity of these two groups decreased(P＜0.05).AST activity in group Ⅱ significantly decreased(P＜0.05).In the duodenum of 21 d,compared with group Ⅰ,the expressions of TNF-α in group Ⅱ was significantly decreased(P＜0.05).In the duodenum of 49 d,the expression of IL-10 in group Ⅱ was significantly increased(P＜0.05),and the expression of IL-2 in groups Ⅲ and Ⅳ was significantly decreased(P＜0.05).In the jejunum of 49 d,the ex-pression of IL-10 in group Ⅱ was increased(P＜0.05),and the expression of IL-2 in groups Ⅲand Ⅳ was significantly decreased(P＜0.05).In conclusion,dietary herbal tea residue can regulate circulating lipid level and enhance intestinal immunity of white feather broilers without affecting their normal growth performance.This experiment also suggested that the a 2％-4％supplementa-tion of herbal tea residues to white feather broilers was of good effect.

Objective:To explore the risk factors affecting the survival and efficacy of patients with acute myeloid leukemia with myelodysplasia-related changes(AML-MRC)transformed from myelodysplastic syndrome(MDS).Methods:The clinical data of 60 patients with AML-MRC transformed from MDS who hospitalized in The Third Affiliated Hospital of Soochow University from January 2010 to December 2021 were retrospectively analyzed.The demographic data and laboratory parameters,cytogenetic karyotypes,target genes of AML detected by next generation sequence,risk stratification,treatment regimen,therapeutic efficacy and survival outcome were documented.Rank sum test and Chi-square test or Fisher exact test were used to compare the survival and efficacy.The effects of clinical parameters,risk stratification and treatment regimens on the survival and efficacy of the AML-MRC patients were analyzed by univariate and multivariate analysis.Results:The median overall survival(OS)of the AML-MRC patients was 4.5 months,the 1-year OS rate was 28.3％,and the complete remission(CR)rate after treatment was 33.3％.The univariate analysis showed that age≥60 years,leukocytosis,severe thrombocytopenia,poor-risk group and only accepted hypomethylating agents(HMAs)or supportive therapy were the risk factors affecting OS.COX multivariate analysis showed that thrombocytopenia(HR=4.46),HMAs therapy(compared to transplantation,HR=10.47),supportive therapy(compared to transplantation,HR=25.80)and poor-risk group(compared to medium-risk group,HR=13.86)were independent hazard factors for median OS of patients with AML-MRC.The univariate analysis showed that the risk factors affecting 1-year OS in patients with AML-MRC were age ≥ 60 years,thrombocytopenia,time of transformation from MDS to AML(TTA)≥3 months,fibrinogen-albumin ratio index(FARI)≥ 0.07,CONUT score≥5,poor-risk group and supportive therapy.Binary logistic regression analysis showed that the independent risk factors for 1-year OS in AML-MRC patients were age ≥ 60 years(HR=11.23),thrombocytopenia(HR=8.71),FARI ≥ 0.07(HR=5.19)and poor-risk group(HR=14.00).The risk factors affecting CR of AML-MRC patients in univariate analysis were age ≥ 60 years,thrombocytopenia,FARI ≥ 0.1,CONUT score ≥ 5,poor-risk group and supportive therapy,while binary logistic regression analysis showed that age ≥ 60 years(HR=7.35),CONUT score ≥ 5(HR=9.60),thrombocytopenia(HR=12.05)and poor-risk group(HR=32.5)were independent risk factors affecting CR of the patients.Conclusion:The OS of AML-MRC patients is poor,old age(≥ 60 years old),supportive therapy,HMA therapy,poor-risk,thrombocytopenia,FARI ≥ 0.07 and CONUT score ≥ 5 may be associated with poor prognosis.