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 establish the method for content determination of three lignans of Dendrobium Fimbriatum Hook..Methods The lignans in Dendrobium tasselii were identified by high-performance liquid chromatography/multi-stage mass spectrometry(HPLC-ESI/MSn)coupled with ultraviolet absorption spectrometry(UV)coupled with retention time localization of high-performance liquid chromatography(HPLC).The separation was carried out on a Kromasil 100-5 C18 column(4.6 mm×250 mm,5 μm)using a gradient elution of acetonitrile-0.1%formic acid solution as the mobile phase,the volume flow rate was 0.8 mL·min-1 and the column temperature was 35℃,and the mass spectrometry was performed using an ESI ion source with the data collected in the negative ion mode.The HPLC content was determined on the same column as that of MS analysis,with the mobile phase methanol + acetonitrile(V/V=1∶1)-0.01 mol/L ammonium acetate solution,gradient elution,flow rate of 0.8 mL·min-1,column temperature of 40℃,and detection wavelength of 215 nm.Results Syringaresinol di-O-glucoside and(-)-Syringaresinol 4-O-β-D-glucopyranoside and DL-Syringaresinol were identified from Dendrobium fimbriatum Hook.,and the results of content determination showed that the linear ranges of above three components were respectively 0.1701-3.4020,0.1020-2.0400,0.0403-0.8060 μg(r≥0.9995),the average recoveries were in the range of 97.71%-101.67%,and the relative standard deviations(RSDs)were all less than 3.0%.The contents of Syringaresinol di-O-glucoside and(-)-Syringaresinol 4-O-β-D-glucopyranoside and DL-Syringaresinol in the 10 batches of samples were 0.7779-1.3852,0.0734-0.1966,0.0295-0.1882 mg·g-1.Conclusion This research method can provide a reference basis for the quality evaluation method of Dendrobium fimbriatum Hook..

A novel pair of Z/E isomeric compounds with unprecedented carbon skeleton were isolated from an aqueous extract of Aspongopus chinensis Dallas by macroporous resin, silica gel, and semi-preparative high performance liquid chromatography (HPLC). Their structures were identified by nuclear magnetic resonance (NMR), Infrared spectroscopy (IR), Mass spectroscopy (MS) and other spectroscopic methods as (Z)-3-(but-1″-en-1″-yl)-1-(2ʹ-hydroxyethyl)-4-propylpyridin-1-ium, namely aspongopyridine A, and (E)-3-(but-1″-en-1″-yl)-1-(2ʹ-hydroxyethyl)-4-propylpyridin-1-ium, namely aspongopyridine B, respectively. Besides, the anti-inflammatory, anti-tumor, acetylcholinesterase inhibition and butyrylcholinesterase inhibition activities of the compounds 1 and 2 were evaluated. The results showed that compounds 1 and 2 have no anti-inflammatory, anti-tumor, and butyrylcholinesterase inhibition activities instead of weak acetylcholinesterase inhibition activity.

Objective:To study the early predictors of refractory septic shock (RSS) in neonates.Methods:From July 2020 to December 2021, clinical data of neonates with septic shock admitted to the Neonatal Department of our hospital were retrospectively reviewed. According to the maximum septic shock score (SSS) during clinical course, the neonates were assigned into RSS group and non-RSS group. Perinatal data, laboratory results and hemodynamic parameters at diagnosis were compared between the two groups. Multiple logistic regression analysis was used to identify independent risk factors of RSS and septic shock-related death. Receiver operating characteristic (ROC) curve was constructed to evaluate the early predictors of poor prognosis.Results:A total of 130 neonates were enrolled, including 54 in RSS group and 76 in non-RSS group. Compared with the non-RSS group, the RSS group had significantly lower pH, base excess (BE), stroke volume index (SVI), cardiac output (CO) and cardiac index (CI).Meanwhile, the RSS group had significantly higher mean arterial pressure (MAP) to CI ratio (MAP/CI) and SSS [including bedside SSS (bSSS), computed SSS (cSSS) and modified version of cSSS (mcSSS)] (all P<0.05). Multiple logistic regression analysis showed that increased MAP/CI was an independent predictor of RSS. The cut-off value of MAP/CI was 11.6 [sensitivity 62%, specificity 87%, positive predictive value (PPV) 79% and negative predictive value (NPV) 77%], with an area under the curve (AUC) of 0.734. Increased mcSSS was an independent predictor of septic shock-related death. The cut-off value of mcSSS was 5.8 (sensitivity 83%, specificity 72%, PPV 21% and NPV 97%), with an AUC of 0.845. Conclusions:Increased MAP/CI (≥11.6) and mcSSS (≥5.8) may be early predictors of RSS and septic shock-related death in neonates.

Objective To evaluate the bioequivalence of a single oral dose of ritonavir in fasted and fed conditions in healthy Chinese adult subjects with the test and reference formulations.Methods A single-center,open-label,randomized,single-dose,two-periods,two-sequence crossover design was used,and 64 subjects were enrolled in both the fasted and fed groups.The subjects received 100 mg of the test preparation or reference preparation orally per cycle,and the drug concentration of ritonavir in plasma was detected using the high performance liquid chromatography-tandem mass spectrometry(HPLC-MS/MS)method.Pharmacokinetic parameters were estimated by a non-compartment model,and SAS 9.4 software was used for statistical analysis.Results Arithmetic mean values of the main pharmacokinetic parameters of the subject formulation of ritonavir tablets and the reference formulation in the fasting group:Cmax were(791.90±400.20)and(809.60±449.14)ng·mL-1;AUC0_t were(6 072.61±2 631.98)and(6 296.30±3 388.95)ng·h·mL-1;AUC0-∞ were(6 129.59±2 655.57)and(6 347.26±3 434.12)ng·h·mL-1,respectively.Arithmetic mean values of the main pharmacokinetic parameters of the subject formulation of ritonavir tablets and the reference formulation in the fed group:Cmax were(512.37±233.60)and(521.74±223.87)ng·mL-1;AUC0_t were(4 203.43±2 221.33)and(4 200.13±1 993.50)ng·h·mL-1;AUC0_∞ were(4 259.21±2 266.88)and(4 259.63±2 044.12)ng·h·mL-1.The 90％confidence intervals for the geometric mean ratios of Cmax,AUC0_t and AUC0_∞ of the prototype drug ritonavir in plasma after oral administration of 100 mg of the test and reference formulations of ritonavir tablets under fasting and fed conditions fell within the 80.00％to 125.00％equivalence interval.Conclusion The test and reference formulations of ritonavir tablets were bioequivalent under fasting and postprandial conditions.

Objective To evaluate the bioequivalence and safety of ezetimibe tablets in healthy Chinese subjects.Methods The study was designed as a single-center,randomized,open-label,two-period,two-way crossover,single-dose trail.Subjects who met the enrollment criteria were randomized into fasting administration group and postprandial administration group and received a single oral dose of 10 mg of the subject presparation of ezetimibe tablets or the reference presparation per cycle.The blood concentrations of ezetimibe and ezetimibe-glucuronide conjugate were measured by high-performance liquid chromatography-tandem mass spectrometry(HPLC-MS/MS),and the bioequivalence of the 2 preparations was evaluated using the WinNonlin 7.0 software.Pharmacokinetic parameters were calculated to evaluate the bioequivalence of the 2 preparations.The occurrence of all adverse events was also recorded to evaluate the safety.Results The main pharmacokinetic parameters of total ezetimibe in the plasma of the test and the reference after a single fasted administration:Cmax were(118.79±35.30)and(180.79±51.78)nmol·mL-1;tmax were 1.40 and 1.04 h;t1/2 were(15.33±5.57)and(17.38±7.24)h;AUC0-t were(1 523.90±371.21)and(1 690.99±553.40)nmol·mL-1·h;AUC0-∞ were(1 608.70±441.28),(1 807.15±630.00)nmol·mL-1·h.The main pharmacokinetic parameters of total ezetimibe in plasma of test and reference after a single meal:Cmax were(269.18±82.94)and(273.93±87.78)nmol·mL-1;Tmax were 1.15 and 1.08 h;t1/2 were(22.53±16.33)and(16.02±5.84)h;AUC0_twere(1 463.37±366.03),(1 263.96±271.01)nmol·mL-1·h;AUC0-∞ were(1 639.01±466.53),(1 349.97±281.39)nmol·mL-1·h.The main pharmacokinetic parameters Cmax,AUC0-tand AUC0-∞ of the two preparations were analyzed by variance analysis after logarithmic transformation.In the fasting administration group,the 90％CI of the log-transformed geometric mean ratios were within the bioequivalent range for the remaining parameters in the fasting dosing group,except for the Cmax of ezetimibe and total ezetimibe,which were below the lower bioequivalent range.The Cmax of ezetimibe,ezetimibe-glucuronide,and total ezetimibe in the postprandial dosing group was within the equivalence range,and the 90％CI of the remaining parameters were not within the equivalence range for bioequivalence.Conclusion This test can not determine whether the test preparation and the reference preparation of ezetimibe tablets have bioequivalence,and further clinical trials are needed to verify it.

Objective To understand the pathogen detection of hospitalized patients before antimicrobial therapy in a hospital through implementation of comprehensive intervention measures,and provide reference basis for the de-velopment of targeted measures.Methods Hospitalized patients who received therapeutic antimicrobial agents in this hospital were selected as the research subjects.Patients who were hospitalized from January to May 2022 were selected as the pre-intervention group,comprehensive intervention measures were taken from June to October 2022,and those who were hospitalized from November 2022 to March 2023 were selected as the post-intervention group.The pathogen detection rate before antimicrobial therapy,sterile specimen detection rate,antimicrobial use rate,de-tection rate of key multidrug-resistant organisms of patients before and after the intervention were analyzed.Results Compared to before intervention,the proportion of pathogen detection rate before antimicrobial therapy(62.09％vs 74.04％),detection rate of healthcare-associated infection diagnosis-related pathogens(62.82％vs 92.73％),and sterile specimen detection rate(35.17％vs 41.06％)of hospitalized patients after intervention all increased signifi-cantly,with statistically significant differences(all P＜0.05).After intervention,pathogen detection rate before the combination use of key antimicrobial agents was not statistically different from before intervention(93.33％vs 90.48％,P＞0.05),while antimicrobial use rate was lower than before intervention(39.93％vs 44.95％,P＜0.05).There was no statistically significant difference in the detection rate of key multidrug-resistant organisms be-fore and after intervention(all P＞0.05).Conclusion Adopting scientific and rational intervention measures can improve the pathogen detection rate,provide a reference basis for the rational use of antimicrobial agents.There was no significant improvement in the pathogen detection rate before the combination use of key antimicrobial agents and the detection rate of key multidrug-resistant organisms,indicating that relevant measures still need to be further optimized.

Objective To investigate the protective effect and mechanism of hyperoside(HYP)on paraquat(PQ)-induced acute lung injury in rats.Methods Rats were randomly divided into the control group,the PQ group,the low-dose hyperoside group(HYP-L group),the middle-dose hyperoside group(HYP-M group)and the high-dose hyperoside group(HYP-H group),with 12 rats in each group.After 7 days of corresponding treatment,the levels of interleukin(IL)-1β,IL-6 and macrophage inflammatory protein-2(MIP-2)in bronchoalveolar lavage fluid(BALF)of rats in each group,as well as the levels of malondialdehyde(MDA)and superoxide dismutase(SOD)in lung tissue were detected.The degree of lung injury and fibrosis of rats were evaluated by hematoxylin-eosin(HE)staining and Masson's trichrome staining.The expression levels of E-cadherin,α-smooth muscle actin(α-SMA),Vimentin,and protein expression levels of nuclear factor erythroid 2-related factor 2(Nrf2),nuclear factor-κB(NF-κB)p65,p-NF-κB p65,transforming growth factor-β1(TGF-β1),Smad3 and p-Smad3 in lung tissue were detected by Western blot.Results Compared with the control group,the levels of IL-1β,IL-6 and MIP-2 in BALF of rats in the PQ group increased(P<0.05),the level of SOD in the lung tissue decreased,while the level of MDA increased(P<0.05),and the lung tissue showed obvious damage and fibrosis(P<0.05).Compared with the PQ group,the levels of IL-1β,IL-6 and MIP-2 in BALF of rats in the HYP-L group,the HYP-M group and the HYP-H group decreased(P<0.05),the levels of SOD in the lung tissue increased(P<0.05),while the levels of MDA decreased(P<0.05),and the lung tissue damages were alleviated,and the fibrosis score decreased(P<0.05).Compared with the control group,the expression level of E-cadherin in the lung tissue of rats in the PQ group decreased(P<0.05),the expression levels of α-SMA and Vimentin increased(P<0.05),the protein expression level of Nrf2 decreased(P<0.05),the protein expression level of TGF-β1 and the phosphorylation levels of NF-κB p65 and Smad3 proteins increased(P<0.05).Compared with the PQ group,the expression levels of E-cadherin in the lung tissues of rats in the HYP-L group,the HYP-M group and the HYP-H group increased(P<0.05),the expression levels of α-SMA and Vimentin decreased(P<0.05),the protein expression levels of Nrf2 increased(P<0.05),the protein expression level of TGF-β1 and the phosphorylation levels of NF-κB p65 and Smad3 proteins decreased(P<0.05).Conclusion Hyperoside effectively alleviates paraquat-induced acute lung injury in rats,and it may reduce lung oxidative stress,inflammation and fibrosis by regulating Nrf2,NF-κB and TGF-β1/Smad2/3 signal pathways.

Objective As primary Sj?gren's syndrome(pSS)primarily affects the salivary glands,saliva can serve as an indicator of the glands'pathophysiology and the disease's status.This study aims to illustrate the salivary proteomic profiles of pSS patients and identify potential candidate biomarkers for diagnosis. Methods The discovery set contained 49 samples(24 from pSS and 25 from age-and gender-matched healthy controls[HCs])and the validation set included 25 samples(12 from pSS and 13 from HCs).Totally 36 pSS patients and 38 HCs were centrally randomized into the discovery set or to the validation set at a 2:1 ratio.Unstimulated whole saliva samples from pSS patients and HCs were analyzed using a data-independent acquisition(DIA)strategy on a 2D LC-HRMS/MS platform to reveal differential proteins.The crucial proteins were verified using DIA analysis and annotated using gene ontology(GO)and International Pharmaceutical Abstracts(IPA)analysis.A prediction model for SS was established using random forests. Results A total of 1,963 proteins were discovered,and 136 proteins exhibited differential representation in pSS patients.The bioinformatic research indicated that these proteins were primarily linked to immunological functions,metabolism,and inflammation.A panel of 19 protein biomarkers was identified by ranking order based on P-value and random forest algorichm,and was validated as the predictive biomarkers exhibiting good performance with area under the curve(AUC)of 0.817 for discovery set and 0.882 for validation set. Conclusions The candidate protein panel discovered may aid in pSS diagnosis.Salivary proteomic analysis is a promising non-invasive method for prognostic evaluation and early and precise treatments for pSS patients.DIA offers the best time efficiency and data dependability and may be a suitable option for future research on the salivary proteome.

ObjectiveDetection and quantification of RNA synthesis in cells is a widely used technique for monitoring cell viability, health, and metabolic rate.After exposure to environmental stimuli, both the internal reference gene and target gene would be degraded. As a result, it is imperative to consider the accurate capture of nascent RNA and the detection of transcriptional levels of RNA following environmental stimulation. This study aims to create a Click Chemistry method that utilizes its property to capture nascent RNA from total RNA that was stimulated by the environment. MethodsThe new RNA was labeled with 5-ethyluridine (5-EU) instead of uracil, and the azido-biotin medium ligand was connected to the magnetic sphere using a combination of “Click Chemistry” and magnetic bead screening. Then the new RNA was captured and the transcription rate of 16S rRNA was detected by fluorescence molecular beacon (M.B.) and quantitative reverse transcription PCR (qRT-PCR). ResultsThe bacterial nascent RNA captured by “Click Chemistry” screening can be used as a reverse transcription template to form cDNA. Combined with the fluorescent molecular beacon M.B.1, the synthesis rate of rRNA at 37℃ is 1.2 times higher than that at 15℃. The 16S rRNA gene and cspI gene can be detected by fluorescent quantitative PCR,it was found that the measured relative gene expression changes were significantly enhanced at 25℃ and 16℃ when analyzed with nascent RNA rather than total RNA, enabling accurate detection of RNA transcription rates. ConclusionCompared to other article reported experimental methods that utilize screening magnetic columns, the technical scheme employed in this study is more suitable for bacteria, and the operation steps are simple and easy to implement, making it an effective RNA capture method for researchers.