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 design and establish a new method for flow cytometry-based detection of commonly observed highly expressed antigens on red blood cells, and to further evaluate the differences and distribution characteristics of antigen expression levels between ABO blood type homozygotes and heterozygotes in healthy individuals. Methods: Residual blood samples after donor blood type identification by Shanghai Blood Center in April 2024 were collected. Among them, samples of 19 homozygous and 19 heterozygous individuals of type A and type B were selected. Then the expression level of ABO antigen on red blood cells were detected using the new method established in this study and the traditional aldehyde fixed red blood cell method. Both methods were tested independently three times and the results were compared. Results: The mean values of the three detection results of the new method was (×10 /RBC): AA homozygous 3.3±0.5, AO heterozygous 2.8±0.3, BB homozygous 3.6±0.3, BO heterozygous 3.1±2.8. The mean values of the three detection results of the aldehyde fixation method were AA homozygous 5.9±0.9, AO heterozygous 5.0±1.4, BB homozygous 3.8±0.6, and BO heterozygous 3.3±0.4. The average antigen distribution of each genotype followed a normal distribution. Comparing the average antigen expression levels of homozygotes and heterozygotes, both methods showed that A/B homozygotes had higher antigen levels than heterozygotes, with AA being 1.17 to 1.18 times that of AO and BB being 1.15 to 1.16 times that of BO. Comparing the inter batch differences in the three test results of two methods, the new method showed no significant difference in the three test results for four genotypes (P>0.05). The aldehyde fixation method showed significant differences in the test results for all three genotypes (P<0.01) except for BB homozygotes (P>0.05). The reliability and reproducibility of the new method were better than those of the traditional aldehyde fixation method. Conclusion: The antigen expression level of ABO homozygotes is higher than that of heterozygotes, and the difference in antigen level between type A homozygotes and heterozygotes is slightly higher than that of type B. The new method is superior to traditional aldolization fixation methods.

In this experiment, self-assembled nanoparticles(SANs) were prepared by the pH-driven method, and Her-HCP SAN was constructed by using herpetrione(Her) and Herpetospermum caudigerum polysaccharides(HCPs). The average particle size and polydispersity index(PDI) were used as evaluation indexes for process optimization, and the quality of the final formulation was evaluated in terms of particle size, PDI, Zeta potential, and microstructure. The proposed Her-HCP SAN showed a spheroid structure and uniform morphology, with an average particle size of(244.58±16.84) nm, a PDI of 0.147 1±0.014 8, and a Zeta potential of(-38.52±2.11) mV. Her-HCP SAN significantly increased the saturation solubility of Her by 2.69 times, with a cumulative release of 90.18% within eight hours. The results of in vivo unidirectional intestinal perfusion reveal that Her active pharmaceutical ingredient(API) is most effectively absorbed in the jejunum, where both K_a and P_(app) are significantly higher compared to the ileum(P<0.001). However, the addition of HCP leads to a significant reduction in the P_(app) of Her in the jejunum(P<0.05). Furthermore, the formation of the Her-HCP SAN results in a notably lower P_(app) in the jejunum compared to Her API alone(P<0.001), while both K_a and P_(app) in the ileum are significantly increased(P<0.001, P<0.05). The absorption of Her-HCP SAN at different concentrations in the ileum shows no significant differences, and the pH has no significant effect on the absorption of Her-HCP SAN in the ileum. The addition of the transporter protein inhibitors(indomethacin and rifampicin) significantly increases the absorption parameters K_a and P_(app) of Her-HCP SAN in the ileum(P<0.05,P<0.01), whereas the addition of verapamil has no significant effect on the intestinal absorption parameters of Her-HCP SAN, suggesting that Her may be a substrate for multidrug resistance-associated protein 2 and breast cancer resistance proteins but not a substrate of P-glycoprotein.
Nanoparticles/metabolism* ; Polysaccharides/pharmacokinetics* ; Intestinal Absorption/drug effects* ; Animals ; Rats ; Particle Size ; Drugs, Chinese Herbal/pharmacokinetics* ; Male ; Rats, Sprague-Dawley ; Drug Carriers/chemistry* ; Drug Compounding ; Cucurbitaceae/chemistry*

Objective To prepare monoclonal antibodies against bovine CD4 and identify their basic biological characteristics. Methods Recombinant bovine CD4 (rHis-BoCD4 and rGST-BoCD4) was successfully expressed and purified by constructing a prokaryotic plasmid of bovine CD4 gene. The bovine CD4 monoclonal antibody was produced using hybridoma technology. The subtype and potency of the monoclonal antibody were identified and analyzed by ELISA, while specificity was analyzed through indirect immunofluorescence assay (IFA) and Western-blot. Results Four hybridoma cell lines, namely, 1H4, 6A10, 3F9 and 4G10, stably secreting monoclonal antibodies against BoCD4 were successfully obtained. The subclasses of the monoclonal antibodies subclass 6A10 was IgG2b and the rest of the monoclonal antibodies were of IgM type. Western-blot results showed that the four anti-bovine CD4 mAb strains were able to specifically bind to the bovine CD4 protein expressed in vitro. Indirect immunofluorescence assay showed that four monoclonal antibodies were able to specifically recognize the natural bovine CD4 protein. Flow cytometry assay showed that 3F9 was best to recognize bovine natural CD4 molecules. Conclusion Four monoclonal antibody strains with high specificity to natural bovine CD4 protein were successfully prepared, which lays the foundation for the subsequent studies on the function of bovine CD4 and diagnosis and treatment of bovine T-lymphocyte diseases.
Animals ; Antibodies, Monoclonal/isolation & purification* ; Cattle ; CD4 Antigens/genetics* ; Hybridomas/immunology* ; Antibody Specificity/immunology* ; Mice ; Mice, Inbred BALB C ; Enzyme-Linked Immunosorbent Assay ; Fluorescent Antibody Technique, Indirect

Objective To assess the diagnostic efficacy of extracellular volume fraction(fECV)based on multi-slice spiral CT in evaluating lymph node metastasis of pancreatic ductal adenocarcinoma.Methods A total of 74 patients diagnosed as pancreatic ductal adenocarcinoma from March 2018 to March 2023 in the First Hospital of Jiaxing were retrospectively collected.All patients underwent enhanced multi-slice spiral CT examination.Hematocrit was collected before examination.CT values at the plain phase,portal phase,the equilibrium phase of the lesion and CT values of abdominal aorta at the same level were respectively measured after examination,and fECV was calculated.Using postoperative pathological results as the"gold standard",the efficacy of fECV in diagnosing lymph node metastases of pancreatic ductal adenocarcinoma was evaluated by receiver operating characteristic curve.Results There were 33 cases with lymph node metastasis in positive group and 41 cases in negative group.There was no statistically significant difference in fECV at the portal phase between lymph node metastasis positive group and negative group(t=0.80,P＞0.05).There was statistically significant difference in fECV at the equilibrium phase between positive and negative lymph node metastasis group(t=2.84,P＜0.001).The area under the curve of lymph node metastasis in portal phase and equilibrium phase were 0.517 and 0.870,respectively.Conclusion The fECV based on multi-slice spiral CT equilibrium phase can evaluate lymph node metastasis of pancreatic ductal adenocarcinoma.

Objective To retrospectively analyze the ultra-fast track anesthesia(UFTA)methods and perioperative anesthesia management experiences of transcatheter mitral valve edge-to-edge repair(TEER)in the treatment of functional mitral regurgitant.Methods In this retrospective study,patients underwent the TEER procedure and received UFTA in Fuwai Yunnan Hospital,from May 2022 to September 2022 for heart failure combined with moderate to severe or severe functional mitral regurgitant were included.Baseline,preoperative complications,cardial function and anesthesia classification,amino-terminal probrain natriuretic peptide(NT-proBNP),ultrasound examination results,surgery time,extubation time,intraoperative anesthetic and vasoactive drug,complications related to TEER and UFTA,perioperative,and postoperative 30-day and one-year follow-up data were collected.All perioperative clinical data were recorded and analyzed.Results A total of 30 patients were enrolled,11 patients(36.7％)were female,mean age was(63.6±6.1)years,NYHA classification IV 14 patients(46.7％),left ventricular ejection fraction(LVEF)(36.0±8.1)％,the end-diastolic volume of the left ventricle(66.0±8.2)mm,mitral regurgitation 4+14 patients(56.7％),3+17 patients(43.3％),NT-proBNP(1 934.1±1 973.5)pg/ml,1 patient(3.3％)used high-dose vasoactive drugs during surgery.All patients did not experience nausea,vomiting,delirium,respiratory depression,perioperative transesophageal echocardiography-related gastrointestinal bleeding,pericardial effusion,cerebrovascular accidents,emergency surgery or secondary intervention,or other serious adverse events within 24 hours after surgery.No 30-day all-cause death occurred;the mean postoperative hospital stay was(7.4±2.8)days.All patients completed one-year follow-up,LVEF(37.6±11.1)％,the end-diastolic volume of the left ventricle(63.2±8.6)mm,mitral regurgitation 2+7 patients(23.3％),1+23 patients(76.7％),NT-proBNP(1 949.2±2 576.6)pg/ml.Conclusions Ultra-fast track anesthesia can be safely applied to TEER in treating functional mitral regurgitant patients.

This study was aimed at understanding the serotypes,virulence,drug resistance,and genetics of the pathogenic genes from 29 strains of foodborne Listeria monocytogenes in Guizhou Province in 2022.The minimum inhibitory concentration(MIC)values against eight antibiotics were determined with the microbroth dilution method,and whole genome sequencing was performed on 29 L.monocytogenes strains isolated from food microbiology and foodborne disease surveillance efforts in the province in 2022.The genome sequences were assembled,and bioinformatics analyses were conducted to examine genealogy,serogroups,sequence analysis(ST type),clonal groups(CC type),resistance genes,and virulence genes.A total of 29 strains of L.monocytogenes had resistance to zero to eight antibiotics,and carried six resistance genes.All strains of L.monocytogenes carried fosX,mprF,Lin,and norB.The 29 strains of L.monocytogenes belonged to 2 lineages(Ⅰ and Ⅱ):17 strains belonged to lineage Ⅱ,which was the dominant strain,and 12 strains belonged to lineage Ⅰ.The strains were classified into 13 ST types,among which ST8 was dominant,accounting for 31.03％(9/29 strains),and was followed by ST619 and ST121,accounting for three strains each.The strains were di-vided into four serogroups,with 15 strains in serogroups 1/2a and 3a;11 strains in serogroups 1/2b,3b,and 7;2 strains in serogroups 1/2c and 3c;and 1 strain in serogroups 4b,4d,and 4e.The strains were divided into 12 CC types,and one unsub-divided CC type,ST2348,among which CC8 was dominant,accounting for 27.59％(nine strains).A total of 25 virulence genes were found,which belonged to three virulence islands(LIPI-1,LIPI-2,and LIPI-3)and 23 CL types,including one or two strains each,and three CL types including two strains each.Foodborne L.monocytogenes in Guizhou Province has a low level of drug resistance,carries a high number of virulence genes,and shows genetic diversity in serogroups and molecular phe-notypes.These findings should strengthen the continuous surveillance efforts for Listeria monocytogenes.

Effectively assessing oxygen delivery and demand is one of the key targets for fluid resuscitation in sepsis. Clinical signs and symptoms, blood lactic acid levels, and mixed venous oxygen saturation (S O 2) or central venous oxygen saturation (ScvO 2) all have their limitations. In recent years, these limitations have been overcome through the use of derived indicators from carbon dioxide (CO 2) such as mixed veno-arterial carbon dioxide partial pressure difference (P -aCO 2, PCO 2 gap, or ΔPCO 2), the ratio of mixed veno-arterial carbon dioxide partial pressure difference to arterial-mixed venous oxygen content difference (P -aCO 2/Ca- O 2). P -aCO 2, PCO 2 gap or ΔPCO 2 is not a purely anaerobic metabolism indicator as it is influenced by oxygen consumption. However, it reliably indicates whether blood flow is sufficient to carry CO 2 from peripheral tissues to the lungs for clearance, thus reflecting the adequacy of cardiac output and metabolism. The P -aCO 2/Ca- O 2 may serve as a marker of hypoxia. S O 2 and ScvO 2 represent venous oxygen saturation, reflecting tissue oxygen utilization. When oxygen delivery decreases but tissues still require more oxygen, oxygen extraction rate usually increases to meet tissue demands, resulting in decreased S O 2 and ScvO 2. But in some cases, even if the oxygen delivery rate and tissue utilization rate of oxygen are reduced, it may still lead to a decrease in S O 2 and ScvO 2. Sepsis is a classic example where tissue oxygen utilization decreases due to factors such as microcirculatory dysfunction, even when oxygen delivery is sufficient, leading to decrease in S O 2 and ScvO 2. Additionally, the solubility of CO 2 in plasma is approximately 20 times that of oxygen. Therefore, during sepsis or septic shock, derived variables of CO 2 may serve as sensitive markers for monitoring tissue perfusion and microcirculatory hemodynamics. Its main advantage over blood lactic acid is its ability to rapidly change and provide real-time monitoring of tissue hypoxia. This review aims to demonstrate the principles of CO 2-derived variables in sepsis, assess the available techniques for evaluating CO 2-derived variables during the sepsis process, and discuss their clinical relevance.

Chinese materia medica and its compound formulas have the characteristics of multi-component,multi-target,and multi pathway effects,and have unique advantages in preventing and treating complex diseases.Network pharmacology explains disease patterns and drug mechanisms from the perspective of complex biological networks,and explores the pharmacological substance basis and target of Chinese medicine.This article summarized the application of network pharmacology from the aspects of biological basis of TCM syndrome,the substance basis and pharmacological mechanism of TCM,compatibility theory of TCM compound formulas,etc.,with the purpose to provide a reference for the research and application of network pharmacology in TCM.

Objective To investigate the role and underlying mechanisms of miR-34a/SIRT1 in intensive care unit acquired weakness(ICU-AW).Methods(1)C2C12 mouse skeletal muscle cells were induced to differentiate into myotubes,and were divided into two groups:model group[ICU-AW group,treated with lipopolysaccharides(LPS)for 12 hours]and normal control group(treated with the same amount of sterile water for 12 hours).Western blotting was used to detect the protein expression level of Muscle ring finger 1(MuRF-1),atrophy gene 1(Atrogin-1)and Sirtuin-1(SIRT1).RT-qPCR was used to assess the mRNA expression level of microRNA-34a(miR-34a),MuRF-1,Atrogin-1 and SIRT1,and light microscope was used to observe the growth and differentiation of C2C12 skeletal muscle cells in each group.(2)ICU-AW cells were further subdivided into control group(treated with siRNA transfection agent intervention),Scra siRNA group(treated with transfection agent and non-specific siRNA),miR-34a siRNA group(treated with transfection agent and specific siRNA intervention),vehicle group(treated with agonist solvent dimethyl sulfoxide)and SRT1720 group(treated with SIRT1 agonist SRT1720).Western blotting was used to detect the protein expression level of SIRT1,Atrogin-1 and MuRF-1 in each group.RT-qPCR was used to detect the miR-34a and the mRNA expression level of SIRT1,Atrogin-1 and MuRF-1 in each group.(3)In addition,another group of ICU-AW cells were divided into control group(treated with siRNA transfection),miR-34a siRNA group(treated with transfection agent and specific siRNA intervention),miR-34a siRNA+vehicle group(treated with transfection agent,specific siRNA and Dimethyl sulfoxide intervention)and miR-34a siRNA+EX-527 group(treated with transfection agent,specific siRNA and SIRT1 inhibitor EX-527).Western blotting was used to detect the protein expression level of Atrogin-1 and MuRF-1.RT-qPCR was used to assess the mRNA expression level of Atrogin-1 and MuRF-1.Results Myotube differentiation was observed on the 4th day.Compared with control group,myotube atrophy was obvious in ICU-AW group.RT-qPCR and Western blotting results revealed that,compared with normal control group,in ICU-AW group,the mRNA and protein expression levels of Atrogin-1 and MuRF-1 significantly increased(P＜0.05),and the expression level of miR-34a significantly increased(P＜0.05),while the mRNA and protein expression levels of SIRT1 significantly decreased(P＜0.05).RT-qPCR results showed that,compared with control group(treated with siRNA transfection agent intervention)and Scra siRNA group,the expression of miR-34a and mRNA expression of Atrogin-1 and MuRF-1 in miR-34a siRNA group significantly decreased(P＜0.05),while the mRNA expression of SIRT1 significantly increased(P＜0.05),meanwhile the protein expression of Atrogin-1 and MuRF-1 decreased significantly(P＜0.01),and the protein expression of SIRT1 significantly increased(P＜0.05).RT-qPCR results also showed that,compared with vehicle group,the mRNA expression of Atrogin-1 and MuRF-1 in SRT1720 group decreased significantly(P＜0.05),while SIRT1 increased significantly(P＜0.05).Western blotting results demonstrated that,compared with control group and Scra siRNA group,the protein expression of Atrogin-1 and MuRF-1 in miR-34a siRNA group decreased significantly(P＜0.05),while SIRT1 increased significantly(P＜0.05).RT-qPCR and Western blotting results indicated that,compared with miR-34a siRNA+vehicle group,the mRNA and protein expression of Atrogin-1 and MuRF-1 in miR-34a siRNA+EX-527 group increased significantly(P＜0.05).Conclusion Overactivation of miR-34a in ICU-AW contributes to skeletal muscle atrophy by inhibiting the expression of SIRT1,which may play an important role in the pathogenesis of ICU-AW.