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.

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.

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..

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 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.

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.

Background::Although overnight fasting is recommended prior to endoscopic retrograde cholangiopancreatography (ERCP), the benefits and safety of high-carbohydrate fluid diet (CFD) intake 2 h before ERCP remain unclear. This study aimed to analyze whether high-CFD intake 2 h before ERCP can be safe and accelerate patients’ recovery.Methods::This prospective, multicenter, randomized controlled trial involved 15 tertiary ERCP centers. A total of 1330 patients were randomized into CFD group ( n = 665) and fasting group ( n = 665). The CFD group received 400 mL of maltodextrin orally 2 h before ERCP, while the control group abstained from food/water overnight (>6 h) before ERCP. All ERCP procedures were performed using deep sedation with intravenous propofol. The investigators were blinded but not the patients. The primary outcomes included postoperative fatigue and abdominal pain score, and the secondary outcomes included complications and changes in metabolic indicators. The outcomes were analyzed according to a modified intention-to-treat principle. Results::The post-ERCP fatigue scores were significantly lower at 4 h (4.1 ± 2.6 vs. 4.8 ± 2.8, t = 4.23, P <0.001) and 20 h (2.4 ± 2.1 vs. 3.4 ± 2.4, t= 7.94, P <0.001) in the CFD group, with least-squares mean differences of 0.48 (95% confidence interval [CI]: 0.26–0.71, P <0.001) and 0.76 (95% CI: 0.57–0.95, P <0.001), respectively. The 4-h pain scores (2.1 ± 1.7 vs. 2.2 ± 1.7, t = 2.60, P = 0.009, with a least-squares mean difference of 0.21 [95% CI: 0.05–0.37]) and positive urine ketone levels (7.7% [39/509] vs. 15.4% [82/533], χ2 = 15.13, P <0.001) were lower in the CFD group. The CFD group had significantly less cholangitis (2.1% [13/634] vs. 4.0% [26/658], χ2 = 3.99, P = 0.046) but not pancreatitis (5.5% [35/634] vs. 6.5% [43/658], χ2 = 0.59, P = 0.444). Subgroup analysis revealed that CFD reduced the incidence of complications in patients with native papilla (odds ratio [OR]: 0.61, 95% CI: 0.39–0.95, P = 0.028) in the multivariable models. Conclusion::Ingesting 400 mL of CFD 2 h before ERCP is safe, with a reduction in post-ERCP fatigue, abdominal pain, and cholangitis during recovery.Trail Registration::ClinicalTrials.gov, No. NCT03075280.

Objective To investigate the difference of CT features of gastrointestinal stromal tumors(GIST),neurogenic tumors,and leiomyomas in stomach.Methods A retrospective analysis was performed on clinical and CT features from 312 cases of GIST,21 cases of neurogenic tumors,and 35 cases of leiomyomas in stomach.Results GIST were most commonly found in the body of stomach and exhibited large tumor sizes and late onset.CT showed GIST predominantly showed intraluminal and mixed growth pattern with irregular or round shapes and uneven density,and cystic degeneration and calcification were frequently observed.The CT values of GIST in the arterial phase and the degree of arterial enhancement were higher,with light to moderate arterial phase enhancement and moderate to marked venous phase enhancement.Gastric leiomyomas had smaller tumor sizes and presented mainly in the cardia,gastric fundus,and lesser curvature of gastric body.CT showed the intraluminal growth pattern,primarily in round shapes with uniform density,lower incidence of cystic degeneration and calcification,both the arterial and venous phase CT values and the extent of enhancement in these phases were lower,showed no or slight enhancement during the arterial phase and light to moderate enhancement during the venous phase.Gastric neurogenic tumors were predominantly located in the gastric body and antrum.CT showed the tumors demonstrated extraluminal and mixed growth patterns,most with oval-shaped appearace,uniform density and the venous phase CT values and the degree of enhancement were higher,with light to moderate arterial enhancement and moderate to marked venous enhancement.Conclusion GIST,neurogenic tumors,and leiomyomas in stomach can be differentiated based on their distinct CT features.Accurate recognition of these features aids in the differential diagnosis of these kinds of tumors.

Objective To explore mechanism of piracetam for the treatment of spinal cord injury in rats through mitogen-activated protein kinase(MAPK)pathway.Methods Fifty-four healthy 6-week-old SD female rats with body weight of 80 to 100 g were divided into sham operation group,spinal cord injury group and piracetam group by random number table method,with 18 rats in each group.Spinal cord injury model was established in spinal cord injury group and piracetam group using percussion apparatus,while sham operation group did not damage spinal cord.Piracetam group was injected with pirac-etam injection through tail vein according to 5 ml·kg-1 standard,once a day for 3 days;the other two groups were injected with normal saline at the same dose,the same frequency and the same duration.The rats were sacrificed at 1,3,and 7 days after surgery,and changes of Basso,Beattie and Bresnahan(BBB)locomotor rating scale was observed and compared.Enzyme-linked immunosorbent assay(ELISA)was used to detect spinal cord inflammatory factors,such as interleukin-6(IL-6),in-terleukin-10(IL-10),interleukin-1β(interleukin-1β),necrosis factor-α(IL-1β)and tumor necrosis factor-α(TNF-α);HE staining was used to observe morphological changes of rats with spinal cord injury,and immunohistochemistry was used to observe expression level of aquaporin 4(AQP4).The activation of MAPK signaling pathway in spinal cord of rats after spinal cord injury was observed by western blotting(WB).Results BBB scores of sham operation group on 1,3 and 7 day were 21 points.In spinal cord injury group,the scores were(1±1),(4±1)and(7±2);piracetam group was(1±1),(5±1),(9±2),re-spectively;the difference between spinal cord injury group and sham operation group was statistically significant(P＜0.05).HE staining showed that no abnormality was found in sham operation group.In spinal cord injury group,bleeding and degeneration of spinal cord tissue appeared at 1 day after operation;flaky necrotic areas were appeared in spinal cord at 3 days after surgery,and spinal cord tissue began to slowly repair at 7 days after surgery.In piracetam group,the bleeding area was less than that of spinal cord injury group at 1 day after surgery;at 3 days after operation,the necrotic area was reduced and the range of nuclear disappearance was reduced;and the spinal cord began to recover slowly at 7 days after surgery.AQP4 staining of spinal cord of rats in sham operation group was weak at 1,3 and 7 days after modeling,AQP4 staining was deepened and area increased in spinal cord injury group,AQP4 staining of piracetam group was lighter than that of spinal cord injury group,and the positive cells were slightly increased and the staining was slightly darker than that of sham operation group.At 1,3 and 7 days,the level of IL-6,IL-10,IL-1β and TNF-α in spinal cord injury group were higher than those in sham operation group and piracetam group(P＜0.05).Compared with spinal cord injury group,the area of spinal cord bleeding and necrosis were de-creased by HE staining in piracetam group,and AQP4 staining was decreased by immunohistochemistry.WB results showed that P-ERK,P-JNK and P-P38 levels in spinal cord injury group at 3 days were higher than those in sham operation group and piracetam group(P＜0.05).Conclusion Piracetam not only showed significant effect in promoting motor function recovery after spinal cord injury,but also showed positive therapeutic potential in reducing lesion area,regulating AQP4 expression to reduce edema,and reducing inflammatory response by regulating MAPK signaling pathway.

Objective To investigate the effect of artemisinin(ART)on the malignant biological behavior of colorectal cancer(CRC)cells stimulated by glucose and its mechanism.Methods The concentration gradients of 0,5,10,20,40 and 60 μmol/L of ART were used to treat the human colorectal cancer cell line SW480,and then the cell viability was detected by CCK-8.Cell apoptosis was detected by flow cytometry.Transwell was used to detect the cell migration and invasion.Western blot was used to detect the apoptosis,epithelial-mesenchymal transition(EMT)and Janus kinase 2(JAK2)/signal transducer and activator of transcription 3(STAT3)related proteins expression.Results Compared with the 0 μmol/L of ART,the viability of SW480 cells decreased under 5,10,20,40,60 μmol/L of ART treatment(P<0.05),and IC50 was 36.91 μmol/L.Therefore,the cells treated with 10,20 and 40 μmol/L of ART were as the low-dose,medium-dose and high-dose ART groups,the cells treated with 0 μmol/L of ART were as the control group,and the cells treated with 40 μmol/L of ART and 10 μmol/L of Coumermycin A1 were as the Coumermycin A1 group.Compared with the control group,the cell scratch wound healing rate,invasion ability,and expression levels of Bcl-2,N-cadherin,Vimentin,p-JAK2,and p-STAT3 in the low-dose ART group,the medium-dose ART group,and the high-dose ART group decreased obviously(P<0.05),while the apoptosis rate,and expression levels of Bax,Caspase-3 and E-cadherin increased(P<0.05).Compared with the high-dose ART group,the cell scratch wound healing rate,invasion ability,and expression levels of Bcl-2,N-cadherin,Vimentin,p-JAK2,and p-STAT3 in the Coumermycin A1 group increased obviously(P<0.05),while the apoptosis rate,and expression levels of Bax,Caspase-3 and E-cadherin decreased(P<0.05).Conclusion ART may inhibit the viability,migration,invasion and EMT of glucose-stimulated CRC cells and promote apoptosis by inhibiting the JAK2/STAT3 signaling pathway.