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 investigate the accuracy of the mandibular curve of Spee and mandibular curve of Wilson curve, mandibular posterior crown inclination, maxillary and mandibular arch width, and mandibular incisor labial inclination changes in the invisible orthodontic treatment of extracted and non-extracted patients to provide a basis for the study of the therapeutic efficacy of the invisible aligner. Methods: This study was approved by the Unit Medical Ethics Committee. Adult bony Class I patients treated with invisible aligners between 2016 and 2023 were selected and categorized into 32 cases in a group with four first premolar extractions and 33 cases in a non-extraction group. The initial scanning model (T1), the orthodontic plan design model (T2), and the scanning model after alignment and leveling (T3) were collected, and the scanning data at different time points were exported to STL format files. They were then analyzed and measured using GOM Inspect 2019 software; the clinical effect (T1-T3) was defined as AC, and the expected result (T1-T2) was defined as CC. To explore the mandibular curve of Spee, the leveling accuracy of the mandibular Wilson curve (AC/CC×100%), the change in mandibular posterior crown inclination, the change in maxillary and mandibular arch width and the change in mandibular incisor labial inclination. The results were tallied using R4.3.2 software. Results: The leveling accuracy of the mandibular curve of Spee was 3.2% and 10.1% in the extraction and non-extraction groups, respectively; the leveling accuracy of the mandibular first molar in the extraction and non-extraction groups was 9.5% and 4.2%, respectively, and the leveling accuracy of the mandibular second premolar was 32.8% and 25%, respectively. The leveling accuracy of the mandibular curve of Wilson was 126% in the extraction group compared to 704% in the non-extraction group. The maximum values of AC for crown inclination of the mandibular posterior teeth were all found in the first molar and the minimum values in the second premolar (P< 0.05); CC was the greatest in the second premolar and the least in the first molar in the extraction group (P< 0.05), and in the second molar and the least in the second premolar in the non-extraction group (P< 0.05). There was no significant difference in the change of maxillary and mandibular arch widths in the extraction group (P> 0.05); the AC of the arch widths at the maxillary first molar and at the mandibular second premolar and first molar in the non-extraction group was significantly greater than the CC (P< 0.05). The AC of the mandibular second premolar crown inclination was significantly greater in the non-extraction group than in the extraction group (P < 0.05), showing a more pronounced buccal inclination of the crowns; in contrast, there was no significant difference between the mandibular molar crown inclination AC and CC in the two groups (P > 0.05). The CC of mandibular curve of Spee in the extraction group was significantly greater than that in the non-extraction group (P < 0.05), whereas there was no significant difference in AC between the two groups (P > 0.05). In addition, the AC of the labial inclination of the mandibular incisors in the extraction group and the non-extraction group was smaller than the CC, but both were positive, indicating an increase in the degree of labial inclination of the mandibular incisors. Conclusion The invisible aligner mandibular curve of Spee leveling was poorly expressed, and there was a tendency for overexpression of the mandibular curve of Wilson leveling. Increased labial inclination of the mandibular incisors was observed in patients. The extraction group was accurately predicted in arch width control, there was overexpansion in the non-extraction group.

Aim To study the neuroprotective effects of Herba siegesbeckiae extract on cerebral ischemia/ reperfusion rats and its mechanism. Methods Sixty SD rats were randomly divided into model group, low, middle and high dose groups of Herba siegesbeckiae, and Sham operation group, and the drug was given continuously for seven days. The degree of neurologic impairment was evaluated by mNSS, and the infarct volume was measured by MRI. The number of Nissl-posi- tive cells was detected by Nissl staining, and the apop- tosis was accessed by Tunel staining. Furthermore, the expression of Bax, Bcl-2 and NeuN was observed by Western blot, and the expression of NeuN was detected by immunofluorescence staining. The expression of IL- 1β, TNF-α and IL-6 mRNA was performed by RT- qPCR. Results The mNSS score and the volume of ischemic cerebral infarction in the model group were significantly increased, and Herba siegesbeckiae extract treatment significantly decreased the mNSS score and infarct volume (P<0.05, P<0.01). Herba siegesbeckiae extract could increase the number of Nissl-pos- itive cells and the expression of NeuN (P<0.01), and reduce the number of Tunel-positive cells (P<0.01). Western blot showed that Herba siegesbeckiae extract inhibited the expression of Bax, increased Bcl-2 and NeuN in ischemic brain tissue (P<0.01). RT-qPCR showed that Herba siegesbeckiae extract inhibited the expression of IL-1 β, TNF-α and IL-6 mRNA in the is-chemic brain tissue (P<0.01). Conclusions Herba siegesbeckiae extract can reduce the cerebral infarction volume, improve the neurological function damage, inhibit the apoptosis of nerve cells and the expression of inflammatory factors and promote the expression of NeuN, there by exerting protective effects on MCAO rats.

Objective To investigate the efficacy of the therapy of soothing liver and strengthening spleen(shortened as Shugan Jianpi therapy)in the treatment of active thyroid-associated ophthalmopathy(TAO)complicated with dry eye,and to provide a reference basis for clinical treatment.Methods A total of 108 patients with active TAO complicated with dry eye of liver depression and qi stagnation type were randomly divided into observation group and control group,54 patients in each group.Both groups were given conventional treatment for intervention of Graves'disease,and additionally the control group was given hormone shock therapy by intravenous injection of Methylprednisolone Sodium Succinate,and the observation group was treated with Chinese medicine prescription for soothing liver and strengthening spleen orally and intravenous injection of Methylprednisolone Sodium Succinate.The treatment period lasted for 12 weeks,and then the patients were followed up till to the 6th month.The changes of clinical activity score(CAS),proptosis,ocular surface disease index(OSDI),corneal fluorescein staining(FL),Schirmer I test(SIT)and tear film break-up time(BUT)in the two groups were observed before and after the treatment.After treatment,the clinical efficacy of the two groups was evaluated.Results(1)After 6 months of treatment,the total effective rate in the observation group was 94.44%(51/54)and that in the control group was 74.07%(40/54),and the intergroup comparison(tested by chi-square test)showed that the efficacy of the observation group was significantly superior to that of the control group(P＜0.05).(2)After treatment,the CAS,OSDI score and proptosis of the patients in the two groups were all lower than those before treatment(P＜0.01),and the reduction in the observation group was significantly superior to that in the control group(P＜0.01).(3)After treatment,the indicators of tear secretion function such as SIT,FL score and BUT of patients in the two groups were improved compared with those before treatment(P＜0.01),and the improvement in the observation group was significantly superior to that in the control group,the differences being all statistically significant(P＜0.01).Conclusion Shugan Jianpi therapy exerts certain clinical efficacy in treating patients with active TAO complicated with dry eye of liver depression and qi stagnation type,which can effectively relieve the proptosis,prolong the tear film break-up time,promote the secretion of tears and the repair of corneal epithelium,improve the visual function,and enhance the quality of life of the patients.

BACKGROUND:Animal models of diabetic encephalopathy that have been studied mainly include streptozotocin-induced model,high-sugar and high-fat diet-induced model and spontaneous animal model.Establishing a simple,easy,short-cycle,safe and effective model of diabetic encephalopathy can help to explore the subsequent pathogenesis and screen therapeutic drugs. OBJECTIVE:To further explore and evaluate the method of building diabetic encephalopathy rat models. METHODS:Twenty Sprague-Dawley rats were randomly divided into control(n=10)and model(n=10)groups.Rats in the model group were given a single injection of 45 mg/kg streptozotocin in the left lower abdominal cavity,and those in the control group were given the same amount of citrate buffer.During the experiment,the body mass,feed intake,water intake and blood glucose were measured.After 8 weeks,the glucose tolerance and oxidative stress levels were measured,and the pathological changes of brain tissue and the expression of apoptotic proteins were compared between groups. RESULTS AND CONCLUSION:Compared with the control group,the food intake,water intake,encephalization quotient,blood glucose and area under the blood glucose curve were significantly increased in the model group,while the body mass decreased significantly(P<0.01).Histopathological examination of the brain showed that compared with the control group,the number of surviving nerve cells was significantly reduced in the model group(P<0.01),with more significant pathological damage of nerve cells.Compared with the control group,the activities of serum superoxide dismutase,catalase and glutathione in the model group were significantly decreased(P<0.01),and the content of oxidative malondialdehyde was significantly increased(P<0.05).The expression levels of apoptosis-related proteins Bax and Caspase-3 in brain tissue increased in the model group compared with the control group,while the expression of Bcl-2 decreased(P<0.01).In conclusion,an 8-week injection of 45 mg/kg streptozotocin can cause obvious pathological damage to the brain tissue of diabetic rats,to successfully establish the rat model of diabetic encephalopathy.

Objective To investigate the attributable risk(AR)of Acinetobacter baumannii(AB)infection in criti-cally ill patients.Methods A multicenter retrospective cohort study was conducted among adult patients in inten-sive care unit(ICU).Patients with AB isolated from sterile body fluid and confirmed with AB infection in each cen-ter were selected as the infected group.According to the matching criteria that patients should be from the same pe-riod,in the same ICU,as well as with similar APACHE Ⅱ score(±5 points)and primary diagnosis,patients who did not infect with AB were selected as the non-infected group in a 1:2 ratio.The AR was calculated.Results The in-hospital mortality of patients with AB infection in sterile body fluid was 33.3％,and that of non-infected group was 23.1％,with no statistically significant difference between the two groups(P=0.069).The AR was 10.2％(95％CI:-2.3％-22.8％).There is no statistically significant difference in mortality between non-infected pa-tients and infected patients from whose blood,cerebrospinal fluid and other specimen sources AB were isolated(P＞0.05).After infected with AB,critically ill patients with the major diagnosis of pulmonary infection had the high-est AR.There was no statistically significant difference in mortality between patients in the infected and non-infec-ted groups(P＞0.05),or between other diagnostic classifications.Conclusion The prognosis of AB infection in critically ill patients is highly overestimated,but active healthcare-associated infection control for AB in the ICU should still be carried out.

Objective To analyze the atrioventricular synchronization rate after implantation of Micra AV leadless pacemaker,and the impact of postoperative programming optimization on atrioventricular synchronization rate.Methods A prospective cohort study was conducted to select patients with complete atrioventricular block who underwent Micra AV leadless pacemaker implantation at Beijing Anzhen Hospital from August 2022 to June 2023.Programming optimization were performed at 1 week,1 month,and 3 months postoperatively,and atrioventricular synchronization rate,electrical parameters,and echocardiography were recorded.Results A total of 68 patients with complete atrioventricular block implanted with Micra AV were selected,with an average age of(68.2±9.7)years,including 47 males(69.1％).All patients were successfully implanted with Micra AV,and there were no serious postoperative complications;The average threshold,sense,and impedance parameters were stable during 1 week,1 month,and 3 months after the procedure;There was no significant difference in the EF value of postoperative echocardiography(P=0.162);The average atrioventricular synchronization rates at 1 week,1 month,and 3 months postoperatively were(75.2％vs.83.8％vs.91.6％,P=0.001).Conclusions As an mechanical atrial sensing,Micra AV requires personalized adjustment of relevant parameters;Postoperative follow-up programming optimization plays an important role in the atrioventricular synchronization and comfort level in patients with complete atrioventricular block after implantation of Micra AV leadless pacemaker.

AIM To investigate the variation rules of main secondary metabolites in Hedysari Radix before and after rubbing strip.METHODS UPLC-MS/MS was adopted in the content determination of formononetin,ononin,calycosin,calycosin-7-glucoside,medicarpin,genistein,luteolin,liquiritigenin,isoliquiritigenin,vanillic acid,ferulic acid,γ-aminobutyric acid,adenosine and betaine,after which cluster analysis,principal component analysis and orthogonal partial least squares discriminant analysis were used for chemical pattern recognition to explore differential components.RESULTS After rubbing strip,formononetin,calycosin,liquiritigenin and γ-aminobutynic acid demonstrated increased contents,along with decreased contents of ononin,calycosin-7-glucoside and vanillic acid.The samples with and without rubbing strip were clustered into two types,calycosin-7-glucoside,formononetin,γ-aminobutynic acid,vanillic acid,calycosin-7-glucoside and formononetin were differential components.CONCLUSION This experiment clarifies the differences of chemical constituents in Hedysari Radix before and after rubbing strip,which can provide a reference for the research on rubbing strip mechanism of other medicinal materials.

Objective To elucidate the effect of curcumol on hepatic stellate cell iron death and epithelial-mesenchymal transition(EMT),and to investigate the molecular mechanism of its anti-liver fibrosis effect.Methods A model of hepatic stellate cell activation was constructed using normal cultured hepatic stellate cells in vitro,and the cells were divided into blank group and experimental-L,-M,-H groups.The blank group was given DMEM complete culture solution for normal culture;the experimental-L,-M,-H groups were given DMEM complete culture solution containing 12.5,25.0 and 50.0 mg·L-1 curcumol for 48 h of intervention.The effects of curcumol on the proliferation of hepatic stellate cells was observed by CCK-8.The expression levels of glutathione peroxidase 4(GPX4)and solute carrier family 7 member 11(SLC7A11)were detected by Western blot.The expression levels of E-cadherin and N-cadherin were detected by immunofluorescence.Results The cell proliferation rates of the experimental-M,-H groups and blank group were(68.97±5.61)％,(61.91±4.40)％and(118.07±10.01)％;the relative expression levels of GPX4 were 0.37±0.04,0.28±0.03 and 0.58±0.05;the relative expression levels of SLC7A11 were 0.38±0.04,0.28±0.03 and 0.60±0.05;E-cadherin levels were 6.76±1.09,9.57±1.73 and 2.05±0.72;N-cadherin levels were 5.66±0.66,3.44±0.78 and 10.37±0.66.The differences of above indicators were statistically significant between the blank group and the experimental-M,-H groups(P＜0.05,P＜0.01).Conclusion Curcumol promotes iron death in hepatic stellate cells,thereby inhibiting hepatic stellate cell EMT,which may be its molecular mechanism to prevent and treat liver fibrosis.

Objective To study the bioequivalence of two glipizide tablets in healthy Chinese subjects.Methods Randomized,open,single-administration,two-period,self-cross-over trial design was used in the study.There were 28 Chinese healthy subjects in the fasted state and 28 in the fed state,complete repeat cross single dose oral glipizide tablets test preparation or reference preparation 5 mg.The plasma concentration of glipizide was determined by liquid chromatography/tandem mass spectrometry at different time points after administration.The non-compartmental model was used to calculate the pharmacokinetic parameters and evaluate the bioequivalence of the two formulations.Results The main pharmacokinetic parameters of glipizide in the fasted state were as follows:Cmax were(551.60±91.26)and(518.10±105.10)ng·mL-1;AUC0-t were(3 074.33±861.91)and(3 026.77±934.25)h·ng·mL-1;AUC0-∞ were(3 204.85±990.78)and(3 166.35±1 107.36)h ng·mL-1.The parameters of glipizide in the fed state were as follows:Cmax were(517.30±98.97)and(472.80±114.48)ng·mL-1;AUC0-t were(3 001.12±830.87)and(2 932.79±736.35)h·ng·mL-1;AUC0-∞ were(3 067.00±918.84)and(2 997.44±819.14)h·ng·mL-1.The 90％confidence interval of the Cmax,AUC0-t and AUC0-∞ of the test formulation and the reference formulation were from 80.00％to 125.00％.The incidence of adverse events in fasted group and fed group was no serious adverse events.Conclusion The two glipizide tablets were bioequivalent under fasted and fed conditions,and good security.