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 analyze the nucleic acid load of human parvovirus B19 in major commercially available blood products in China, including human albumin, human intravenous immunoglobulin, human rabies immunoglobulin and various coagulation factor products, aiming to provide evidence for improving blood product manufacturing processes and quality control of source plasma. Methods: A total of 98 batches of coagulation factor products were tested for human parvovirus B19 nucleic acid using real-time fluorescent quantitative PCR, including 42 batches of human prothrombin complex, 35 batches of human coagulation factor Ⅷ, and 21 batches of human fibrinogen. Additionally, 6 batches of human albumin, 6 batches of human intravenous immunoglobulin, and 38 batches of human rabies immunoglobulin were tested for human parvovirus B19 nucleic acid. Results: Human parvovirus B19 nucleic acid were undetectable in human albumin, human intravenous immunoglobulin and human rabies immunoglobulin. Among the 98 batches of coagulation factor products tested for human parvovirus B19 nucleic acid, B19 nucleic acid reactivity rate was 69.0% (29/42) for human prothrombin complex batches, but nucleic acid concentration were all significantly lower than 10 IU/mL. The reactivity rate of B19 nucleic acid in 35 batches of human coagulation factor Ⅷ was 48.6% (17/35), with nucleic acid concentration all below 10 IU/mL. The reactivity rate of B19 nucleic acid in 21 batches of human fibrinogen was 61.9% (13/21), with nucleic acid concentration all below 10 IU/mL. Conclusion: No human parvovirus B19 has been detected in human albumin, human intravenous immunoglobulin, or human rabies immunoglobulin. Human parvovirus B19 nucleic acid may exist in commercially available coagulation factor products, highlighting the need for enhanced screening of human parvovirus B19 nucleic acid in these products. It is also recommended that B19 viral nucleic acid testing be conducted on source plasma, particularly for coagulation factor products.

Objective: To analyze the nucleic acid load of human parvovirus B19 in major commercially available blood products in China, including human albumin, human intravenous immunoglobulin, human rabies immunoglobulin and various coagulation factor products, aiming to provide evidence for improving blood product manufacturing processes and quality control of source plasma. Methods: A total of 98 batches of coagulation factor products were tested for human parvovirus B19 nucleic acid using real-time fluorescent quantitative PCR, including 42 batches of human prothrombin complex, 35 batches of human coagulation factor Ⅷ, and 21 batches of human fibrinogen. Additionally, 6 batches of human albumin, 6 batches of human intravenous immunoglobulin, and 38 batches of human rabies immunoglobulin were tested for human parvovirus B19 nucleic acid. Results: Human parvovirus B19 nucleic acid were undetectable in human albumin, human intravenous immunoglobulin and human rabies immunoglobulin. Among the 98 batches of coagulation factor products tested for human parvovirus B19 nucleic acid, B19 nucleic acid reactivity rate was 69.0% (29/42) for human prothrombin complex batches, but nucleic acid concentration were all significantly lower than 10 IU/mL. The reactivity rate of B19 nucleic acid in 35 batches of human coagulation factor Ⅷ was 48.6% (17/35), with nucleic acid concentration all below 10 IU/mL. The reactivity rate of B19 nucleic acid in 21 batches of human fibrinogen was 61.9% (13/21), with nucleic acid concentration all below 10 IU/mL. Conclusion: No human parvovirus B19 has been detected in human albumin, human intravenous immunoglobulin, or human rabies immunoglobulin. Human parvovirus B19 nucleic acid may exist in commercially available coagulation factor products, highlighting the need for enhanced screening of human parvovirus B19 nucleic acid in these products. It is also recommended that B19 viral nucleic acid testing be conducted on source plasma, particularly for coagulation factor products.

Objective To investigate the expression of PLCD3 mRNA in the synovium of osteoarthritis(OA)and its relationship with immune cell infiltration.Methods Based on the differentially expressed genes of OA found in the previous study,the expression of phospholipase Cδ3(PLCD3)mRNA was detected by col-lecting synovial samples from OA group and control group.CIBERSORT algorithm was used to analyze the infiltration pattern of immune cells in OA group and control group,and the correlation between PLCD3 and infiltrating immune cells was further analyzed.Results Compared with the control group,the relative expres-sion level of PLCD3 mRNA was significantly increased in synovial samples of OA group(P<0.05).The pro-portions of B cells naive,NK cells activated,M2 macrophages and mast cells activated in synovial tissues of OA group were relatively high(P<0.05).PLCD3 was positively correlated with the proportion of these four immune cells(P<0.05).Conclusion PLCD3 may be a key biomarker for the diagnosis of OA,which may be involved in the pathogenesis of OA by interacting with infiltrating immune cells.

This article summarized Professor GUAN Guo-Hua's clinical experience in treating central serous chorioretinopathy(CSC)in Lingnan area.Based on the theory of"macula due to the spleen dysfunction",and by taking the geographical and climatic characteristics of Lingnan area as well as the body constitutional features of Lingnan residents into account,Professor GUAN Guo-Hua proposed that spleen deficiency leading to damp encumbrance was the fundamental pathogenesis of CSC in Lingnan area,and liver and kidney were gradually affected in the middle and late stages of CSC,which finally resulted into blood stasis and water retention.For the treatment of initial attack of CSC,the focus was on treating the spleen,and Erchen Decoction was adopted as the basic prescription for modified application to strengthen the spleen and drain dampness;for the treatment of CSC in the middle and late stages,the emphasis was on simultaneous treatment of the liver,spleen and kidney as well as blood and water,and Zhujing Pills and Wuling Powder were adopted as the basic prescriptions for nourishing the liver and kidney and for strengthening the spleen,activating blood and promoting urination.The treatment of the spleen is advocated throughout the whole treatment process,and the medication of drugs should be modified based on syndrome differentiation and according to the specific conditions,thus to achieve significant results.

Sonogenetics is an emerging synthetic biology technique that uses sound waves to activate mechanosensitive ion channel proteins on the cell surface to regulate cell behavior and function.Due to the widespread presence of mechanically sensitive ion channel systems in cells and the advantages of non-invasion,strong penetrability,high safety and high accuracy of sonogenetics technology,it has great development potential in basic biomedical research and clinical applications,especially in neuronal regulation,tumor mechanism research,sonodynamic therapy and hearing impairment.This review discusses the basic principles of sonogenetics,the development status of sonogenetics and its application in the prevention and treatment of noise-induced hearing loss,summarizes and analyzes the current challenges and future development direction,thus providing a reference for further research and development of sonogenetics in the field of military medicine.

Platycodonis Radix is the dry root of Platycodon grandiflorum of Campanulaceae, which has a variety of pharmacological effects and is a commonly used bulk Chinese medicine. In this study, the chloroplast genome sequences of six P. grandiflorum from different producing areas has been sequenced with Illumina HiSeq X Ten platform. The specific DNA barcodes were screened, and the germplasm resources and genetic diversity were analyzed according to the specific barcodes. The total length of the chloroplast genome of 6 P. grandiflorum samples was 172 260-172 275 bp, and all chloroplast genomes showed a typical circular tetrad structure and encoded 141 genes. The comparative genomics analysis and results of amplification efficiency demonstrated that trnG-UCC and ndhG_ndhF were the potential specific DNA barcodes for identification the germplasm resources of P. grandiflorum. A total of 305 P. grandiflorum samples were collected from 15 production areas in 9 provinces, for which the fragments of trnG-UCC and ndhG_ndhF were amplificated and the sequences were analyzed. The results showed that trnG-UCC and ndhG_ndhF have 5 and 11 mutation sites, respectively, and 5 and 7 haplotypes were identified, respectively. The combined analysis of the two sequences formed 13 haplotypes (named Hap1-Hap13), and Hap4 is the main genotype, followed by Hap1. The unique haplotypes possessed by the three producing areas can be used as DNA molecular tags in this area to distinguish from the germplasm resources of P. grandiflorum from other areas. The haplotype diversity, nucleotide diversity and genetic distance were 0.94, 4.79×10^-3 and 0.000 0-0.020 3, respectively, suggesting that the genetic diversity was abundant and intraspecific kinship was relatively close. This study laid a foundation for the identification of P. grandiflorum, the protection and utilization of germplasm resources, and molecular breeding.

Objective To determine the related substances in the pharmaceutical excipient triacetin by gas chromatography(GC).Methods Rtx-1701 and DB-1701 chromatographic column(30 m×0.25 mm,0.25 μm)was used,with nitrogen as the carrier gas,the flow rate was 1.5 mL/min,the inlet temperature was 200℃,the hydrogen flame ionization detector was used,the temperature of the measuring instrument was 250℃,and the program heating was used.Results Under this chromatographic condition,each substance could be effectively separated,and showed good linearity at 2-40 μg/mL(r>0.99).The recovery rates of acetic acid,glycerol,1-monoglyceryl acetate,1,2-diglyceryl acetate and 1,3-diglyceryl acetate were 100.7%(RSD=3.12%),95.1%(RSD=3.66%),99.43%(RSD=4.62%),103.66%(RSD=5.88%)and 103.15%(RSD=4.17%)(n=6),respectively.Conclusion This method has high accuracy and good reproducibility,which can be used for the determination of related substances in the triacetin,and provides a reference for the quality standard of triacetin.

[Objective] To establish a real-time fluorescence quantitative PCR nucleic acid detection method of human parvovirus B19 and validate the method systematically. [Methods] Specific primers and probes for the highly conserved regions of the three genotypes of B19 virus were designed, and B19 quantitative amplification standard curves were established. The accuracy, precision (repeatability and intermediate precision), linear range, quantification limit, detection limit, specificity, anti cross contamination, genotyping and anti-interference ability of this method were verified. [Results] When the quantitative reference range for B19 virus was 2.0×10¹ to 1.0×10⁸ IU/mL, a double logarithmic regression analysis was performed between the measured values and the theoretical values, and the regression equation R²≥0.98 showed good linear correlation. The quantification limit was 20 IU/mL, with a detection rate of 100%. The detection limit was 10 IU/mL, and the detection rate is 95.23%. Three genotypes of B19 virus samples can be effectively detected. The plasma of seven non B19 pathogens, including hepatitis A virus, hepatitis B virus, hepatitis C virus, human immuno-deficiency virus, human cytomegalovirus, hepatitis E virus and Treponema pallidum, was non reactive and has good species specificity. Simultaneously, in the presence of seven other concurrent pathogens, positive samples with a weak positive concentration of E3 IU/mL could be stably detected, and the B19 nucleic acid testing method was not interfered with. When the hemoglobin concentration was 431 mg/dL, triglycerides (1 269 turbidity) and unconjugated bilirubin concentration was 20 mg/dL, this method was non reactive for all three common plasma interfering substances. In the presence of three common plasma interfering substances, positive samples with a weak positive concentration of E3 IU/mL could be stably detected, and the B19 nucleic acid testing method was not interfered with. The deviation between the detection values of standard substances at two concentration levels of S1 (E5 IU/mL) and S2 (E4 IU/mL) and the target values were≤±0.5 log value. The CV values of positive sample 1 (concentration level E5 IU/mL) and positive sample 2 (concentration level E4 IU/mL) for daily precision confirmation and continuous 5-day intra-day precision confirmation were both≤5%. [Conclusion] This method has strong specificity, high sensitivity, wide linear range, stability, reliability and high accuracy, and can be used for the detection of human parvovirus B19 nucleic acid in plasma.

Objective:To study the stability and morphological changes of the convexity sulci in normal fetuses between 20 and 32 weeks, and to explore the simplified grade for evaluating the convexity sulci development and analyzing its clinical significance.Methods:This study was a cross-sectional analysis. A total of 551 cases of normal singleton pregnancies between 20 and 32 weeks of gestation were retrospectively collected, who underwent routine ultrasound examinations at Shenzhen Maternity and Child Healthcare Hospital from September 2019 to June 2022. The display of the far-field convexity sulci on the transcalvarial axial plane was observed as 0 for not displayed and 1 for displayed.Further, based on the morphology and number of convexity sulci, they were classified into five grades: no sulcus displayed (grade 0), one sulcus (grade 1), two sulci (grade 2), three sulci (grade 3), and four or more sulci (grade 4). The gestational age at examination and pregnancy outcomes were recorded. The distribution characteristics of gestational weeks for each grade of the convexity sulci were analyzed, and the gestational week distribution of the left and right convexity sulci was compared to analyze bilateral symmetry. The Weighted Kappa coefficient was used to analyze inter-observer and intra-observer consistency, and curve regression analysis was employed to establish a model for predicting grade based on gestational weeks.Results:Before 25 weeks of gestation, the convexity of the fetal cranial vertex was completely smooth.The central sulcus consistently appeared after 26 weeks, while the superior frontal sulcus, intraparietal sulcus, postcentral sulcus, and precentral sulcus consistently appeared between 28 and 31 weeks. Among these, the superior frontal sulcus had a lower display rate before 29 weeks. By 32 weeks, all convexity sulci of the cranial vertex should be visible. Three hundred and eleven fetuses were graded for the left, and 240 fetuses were graded for the right. The developmental grade of the convexity sulci increased from Grade 0 to Grade 4 as the gestational age progressed. Grade 0 appeared between 20-26 weeks, grade 1 between 25-28 weeks, grade 2 between 26-28 weeks, grade 3 between 27-30 weeks, and grade 4 between 27-32 weeks. The distribution of grade did not differ significantly between the left and right sides of grade 0, 1, 3 and 4 (all P>0.05), while there was a significant difference in the distribution of gestational age between the convexity sulci of grade 2 ( P<0.05). The Weighted Kappa coefficients for intra-observer and inter-observer consistency were 0.94 and 0.86, respectively, indicating strong consistency. Conclusions:The simplified grade for assessing the development of convexity sulci in normal fetuses on the transcalvarial axial plane via prenatal ultrasound can provide a preliminary evaluation of the maturation of convexity sulci in fetuses between 20 and 32 weeks of gestation.