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 significance of total vitamin D (tVD), total procollagen type I amino-terminal propeptide (tPINP) and β-CrossLaps (β-CTx) in the staging and prognosis of patients with multiple myeloma (MM). METHODS: A total of 54 patients with newly diagnosed MM admitted to the Second Affiliated Hospital of Fujian Medical University from 2020 to 2022 were selected as the observation group (MM group), and 50 healthy persons who underwent physical examinations in our hospital were selected as the control group. The expression levels of tVD, tPINP and β-CTx in the two groups were detected by chemiluminescence method. The differences in the expression levels of tVD, tPINP and β-CTx among MM patients at different ISS stages were analyzed. The expression levels of tVD, tPINP and β-CTx in MM patients with different levels of hemoglobin (Hb), serum calcium (Ca), creatinine (Crea), albumin (ALB), β₂-microglobulin (β₂-MG) and lactate dehydrogenase (LDH) were compared. The correlations between the expression levels of tVD, tPINP, β-CTx and the aforementioned clinical parameters were analyzed, respectively. The relationship between the expression levels of tVD, tPINP, β-CTx and the progression-free survival (PFS) of MM patients was analyzed. RESULTS: The expression level of tVD in the MM group was significantly lower than that in the control group (21.73±14.45 ng/ml vs 30.78±9.94 ng/ml, P =0.022). The expression level of β-CTx in the MM group was significantly higher than that in the control group (1.43±0.99 ng/ml vs 0.53±0.29 ng/ml, P =0.013). The tVD level in MM patients with ISS stage I-II was significantly higher than that of MM patients with ISS stage III (29.50±14.59 ng/ml vs 12.62±7.73 ng/ml, P =0.028), indicating that the higher the ISS stage, the lower the tVD level. The tPINP and β-CTx levels in MM patients with high Ca levels (>2.65 mmol/L) were significantly higher than those in patients with low Ca levels (≤2.65 mmol/L) (P =0.016, P =0.021). The tVD level of MM patients was positively correlated with the ALB level (r =0.570), tPINP was positively correlated with Ca and β₂-MG levels (r =0.791,r =0.673), and β-CTx was positively correlated with tPINP level (r =0.616). The PFS of the low tVD expression group was significantly lower than that of the high tVD expression group (P =0.041). CONCLUSION The expression level of tVD is decreased in MM patients, which can be used as an indicator to evaluate the disease stage and prognosis of the patients. The β-CTx expression level is increased in MM patients. tPINP and β-CTx may be correlated with clinical symptoms such as osteolytic lesions and renal function changes in MM patients.
Humans ; Multiple Myeloma/pathology* ; Procollagen/blood* ; Vitamin D/blood* ; Prognosis ; Peptide Fragments/blood* ; Collagen Type I/blood* ; Female ; Male ; Middle Aged ; Aged ; Neoplasm Staging

Early-life stress (ES) leads to cognitive dysfunction in female adolescents, but the underlying neural mechanisms remain elusive. Recent evidence suggests that the cell adhesion molecules NECTIN1 and NECTIN3 play a role in cognition and ES-related cognitive deficits in male rodents. In this study, we aimed to investigate whether and how nectins contribute to ES-induced cognitive dysfunction in female adolescents. Applying the well-established limited bedding and nesting material paradigm, we found that ES impairs recognition memory, suppresses prefrontal NECTIN1 and hippocampal NECTIN3 expression, and upregulates corticotropin-releasing hormone (Crh) and its receptor 1 (Crhr1) mRNA levels in the hippocampus of adolescent female mice. Genetic experiments revealed that the reduction of dorsal CA1 (dCA1) NECTIN3 mediates ES-induced object recognition memory deficits, as knocking down dCA1 NECTIN3 impaired animals' performance in the novel object recognition task, while overexpression of dCA1 NECTIN3 successfully reversed the ES-induced deficits. Notably, prefrontal NECTIN1 knockdown did not result in significant cognitive impairments. Furthermore, acute systemic administration of antalarmin, a CRHR1 antagonist, upregulated hippocampal NECTIN3 levels and rescued object and spatial memory deficits in stressed mice. Our findings underscore the critical role of dCA1 NECTIN3 in mediating ES-induced object recognition memory deficits in adolescent female mice, highlighting it as a potential therapeutic target for stress-related psychiatric disorders in women.
Animals ; Female ; Mice ; CA1 Region, Hippocampal/metabolism* ; Cell Adhesion Molecules/metabolism* ; CRF Receptor, Type 1/metabolism* ; Memory Disorders/etiology* ; Mice, Inbred C57BL ; Nectins/genetics* ; Receptors, Corticotropin-Releasing Hormone/antagonists & inhibitors* ; Recognition, Psychology/physiology* ; Stress, Psychological/complications*

OBJECTIVE: To develop and validate a nomogram model for predicting 30-day mortality among elderly patients with sepsis-associated liver dysfunction (SALD), to identify high-risk patients and improve prognosis. METHODS: A retrospective cohort study was conducted using data extracted from the Medical Information Mart for Intensive Care-IV (MIMIC-IV) database for elderly patients with SALD who were first admitted to the intensive care unit (ICU) of Beth Israel Deaconess Medical Center between 2008 and 2019, including basic characteristics, severity scores, underlying diseases, infection foci, 24-hour vital signs, initial laboratory indicators, 24-hour complications, and prognosis related indicators. Patients were randomly assigned to training group and validation group in a ratio of 7 : 3. The training group used the LASSO regression analysis, as well as multivariate Logistic regression analysis to screen for independent risk factors for 30-day mortality. A nomogram prediction model was constructed, and receiver operator characteristic curve (ROC curve), calibration curves, and decision curve analysis (DCA) were used to evaluate the model, and validate the model using the validation cohort. RESULTS: A total of 630 elderly patients with SLAD were included in the study, including 441 in the training group and 189 in the validation group. Oxford acute severity of illness score (OASIS) for training group [odds ratio (OR) = 1.060, 95% confidence interval (95%CI) was 1.034-1.086], 24-hour pulse oxygen saturation (SpO₂; OR = 0.876, 95%CI was 0.797-0.962), initial mean corpuscular volume (MCV; OR = 1.043, 95%CI was 1.009-1.077), initial red blood cell distribution width (RDW; OR = 1.237, 95%CI was 1.123-1.362), initial blood glucose (OR = 1.008, 95%CI was 1.004-1.013), and initial aspartate aminotransferase (AST; OR = 1.000, 95%CI was 1.000-1.001) were independent risk factors for 30-day mortality in patients (all P < 0.05). Based on the above variables, a nomogram model was constructed, and the ROC curve showed that the area under the curve (AUC) of the model in the training group was 0.757 (95%CI was 0.712-0.803), with a sensitivity of 65.05% and a specificity of 74.90%; the AUC of the model in the validation group was 0.712 (95%CI was 0.631-0.792), with a sensitivity of 58.67% and a specificity of 81.58%. The calibration curves of the training and validation groups show that both the fitted curves were close to the standard curves. The Hosmer-Lemeshow test: the training group (χ ² = 6.729, P = 0.566), the validation group (χ ² = 13.889, P = 0.085), indicating that the model can fit the observed data well. The DCA curve shows that when the threshold probability of the training group was 16% to 94% and the threshold probability of the validation group was 27% to 99%, the net benefit of the model was good. CONCLUSIONS OASIS, 24-hour SpO₂, initial MCV, initial RDW, initial blood glucose and initial AST are independent risk factors for 30-day mortality in elderly patients with SALD. The nomogram based on these six variables demonstrates good predictive performance.
Humans ; Sepsis/complications* ; Retrospective Studies ; Nomograms ; Aged ; Prognosis ; Risk Factors ; Liver Diseases/mortality* ; Intensive Care Units ; ROC Curve ; Male ; Female ; Logistic Models

Objective:To investigate the feasibility and safety of intracardiac echocardiography(ICE)combined with total three-dimensional(T3D)technique in zero-fluoroscopy individualized transseptal puncture.Methods:A total of 112 patients with atrial fibrillation who underwent radiofrequency ablation in Yongchuan Hospital Affiliated to Chongqing Medical University from April 2021 to March 2024 were enrolled,and according to the method for transseptal puncture,they were randomly divided into ICE+T3D group with 56 patients and ICE group with 56 patients.The two groups were analyzed in terms of baseline data,time to atrial reconstruc-tion,time to coronary sinus electrode placement,frequency of ICE probe adjustment during transseptal puncture,duration of transsep-tal puncture,pretreatment time before ablation,incidence rate of complications,and the duration and dosage of X-ray exposure.Results:There were no significant differences in baseline data between the two groups.Compared with the ICE group,the ICE+T3D group had a significantly lower frequency of ICE probe adjustment during transseptal puncture(1.70±0.63 vs.5.34±1.71,P<0.001)and the duration of transseptal puncture(3.66±1.09 min vs.4.90±1.92 min,P<0.001).Compared with the ICE group,the ICE+T3D group had significantly longer time to atrial reconstruction(22.44±3.13 min vs.12.34±2.12 min,P<0.001)and pretreatment time be-fore ablation(49.41±3.52 min vs.37.65±4.04 min,P<0.001).In the ICE+T3D group,43(76.8%)patients achieved zero radiation during pretreatment before ablation,and 13 patients received X-ray due to the difficulty in catheter placement;compared with the ICE group,the ICE+T3D group had a significantly shorter duration of X-ray exposure(1.68±0.72 min vs.3.14±1.95 min,P=0.010)and a significantly lower dosage of X-ray exposure(6.28±2.78 mGy vs.23.85±21.32 mGy,P=0.004).During the stage of transseptal punc-ture,all patients in the ICE+T3D group achieved zero radiation,while 45 patients(80.4%)in the ICE patients received X-ray.In terms of complications,there were no life-threatening complications such as cardiac tamponade,perforation of the aorta by mistake,and embolization in either group,while there was one case(1.8%)of vascular complications in each group.Conclusions:ICE combined with T3D after integration and improvement is a safe and reliable procedure for zero-fluoroscopy individualized transseptal puncture.

Objective To investigate the types and mechanisms of microglial cell death induced by interaction between palmitic acid(PA)and lipopolysaccharide(LPS).Methods BV-2 microglial cells were divided into three groups for apoptosis research,BSA group,PA treatment group,and staurosporine(STA)group.They were further divided into four groups for necrosis research,BSA group,BSA+inhibitor group,PA group,and PA+inhibitor group.Western blotting was conducted to assess the expression levels of key proteins involved in apoptosis and necrosis pathways.The effect of PA on microglial cells was validated through feeding a high-fat diet to Institute of Cancer Research(ICR)mice.Results Apoptotic microglia were observed in both BSA group and PA group,PA significantly induced the activation of caspase-3,caspase-7,and poly ADP-ribose polymerase(PARP).However,compared to the BSA group,the level of activated Caspase-7 in the STA group did not change significantly.Inhibition of ferroptosis,necroptosis,or autophagy did not protect against PA-induced cell damage,while the Caspase-11 inhibitor,wedelolactone(WE),significantly improved PA induced cell damage.This study also found that PA could promote LPS entry into microglial cells and induce pyroptosis.This phenomenon and the protective effect of WE were further confirmed in a high-fat diet mouse model through immunofluorescent staining and Western blotting.Conclusion PA induces apoptosis and pyroptosis in microglial cells,while simultaneously promoting LPS entry into microglial cells and inducing pyroptosis.

ObjectiveTo investigate the protective effect of the extract of Liuwei Dihuangwan （LW） on mitochondrial damage in the Alzheimer's disease （AD） model of Caenorhabditis elegans （C. elegans）. MethodC. elegans transfected with human β-amyloid protein （Aβ） _1-42 gene was used as an AD model. The rats were divided into blank group， model group， metformin group （50 mmol·L^-1）， and low， medium， and high dose （1.04， 2.08， 4.16 g·kg^-1） LW groups. Behavioral methods were used to observe the sensitivity of 5-hydroxytryptamine （5-HT） in nematodes. Western blot was used to detect the expression of Aβ in nematodes. Total ATP content in nematodes was detected by the adenine nucleoside triphosphate （ATP） kit， and mitochondrial membrane potential was detected by the JC-1 method. In addition， the mRNA expression of Aβ expression gene （Amy-1）， superoxide dismutase-1 （SOD-1）， mitochondrial transcription factor A homologous gene-5 （HMG-5）， mitochondrial power-associated protein 1 （DRP1）， and mitochondrial mitoprotein 1 （FIS1） was detected by real-time fluorescence quantitative polymerase chain reaction （RT-PCR）. ResultThe extract of LW could reduce the hypersensitivity of the AD model of nematodes to exogenous 5-HT （P<0.05） and delay the AD-like pathological characteristics of hypersensitivity to exogenous 5-HT caused by toxicity from overexpression of Aβ in neurons of the AD model of nematodes. Compared with the blank group， in the model group， the mRNA expression of Aβ protein and Amy-1 increased （P<0.01）， and the mRNA expression of SOD-1 and HMG-5 decreased （P<0.01）. The mRNA expression of DRP1 and FIS1 increased （P<0.01）， and the level of mitochondrial membrane potential decreased （P<0.05）. The content of ATP decreased （P<0.01）. Compared with the model group， in the positive medicine group and medium and high dose LW groups， the mRNA expression of Aβ protein and Amy-1 decreased （P<0.05，P<0.01）， and the mRNA expression of SOD-1 and HMG-5 increased （P<0.01）. The mRNA expression of DRP1 decreased （P<0.05，P<0.01）， and that of FIS1 decreased （P<0.01）. The level of mitochondrial membrane potential increased （P<0.01）， and the content of ATP increased （P<0.05，P<0.01）. ConclusionThe extract of LW may enhance the antioxidant ability of mitochondria， protect mitochondrial DNA， reduce the fragmentation of mitochondrial division， repair the damaged mitochondria， adjust the mitochondrial membrane potential， restore the level of neuronal ATP， and reduce the neuronal damage caused by Aβ deposition.

Objective To investigate the clinical characteristics and prognosis of pneumococcal meningitis(PM),and drug sensitivity of Streptococcus pneumoniae(SP)isolates in Chinese children.Methods A retrospective analysis was conducted on clinical information,laboratory data,and microbiological data of 160 hospitalized children under 15 years old with PM from January 2019 to December 2020 in 33 tertiary hospitals across the country.Results Among the 160 children with PM,there were 103 males and 57 females.The age ranged from 15 days to 15 years,with 109 cases(68.1% )aged 3 months to under 3 years.SP strains were isolated from 95 cases(59.4% )in cerebrospinal fluid cultures and from 57 cases(35.6% )in blood cultures.The positive rates of SP detection by cerebrospinal fluid metagenomic next-generation sequencing and cerebrospinal fluid SP antigen testing were 40% (35/87)and 27% (21/78),respectively.Fifty-five cases(34.4% )had one or more risk factors for purulent meningitis,113 cases(70.6% )had one or more extra-cranial infectious foci,and 18 cases(11.3% )had underlying diseases.The most common clinical symptoms were fever(147 cases,91.9% ),followed by lethargy(98 cases,61.3% )and vomiting(61 cases,38.1% ).Sixty-nine cases(43.1% )experienced intracranial complications during hospitalization,with subdural effusion and/or empyema being the most common complication[43 cases(26.9% )],followed by hydrocephalus in 24 cases(15.0% ),brain abscess in 23 cases(14.4% ),and cerebral hemorrhage in 8 cases(5.0% ).Subdural effusion and/or empyema and hydrocephalus mainly occurred in children under 1 year old,with rates of 91% (39/43)and 83% (20/24),respectively.SP strains exhibited complete sensitivity to vancomycin(100% ,75/75),linezolid(100% ,56/56),and meropenem(100% ,6/6).High sensitivity rates were also observed for levofloxacin(81% ,22/27),moxifloxacin(82% ,14/17),rifampicin(96% ,25/26),and chloramphenicol(91% ,21/23).However,low sensitivity rates were found for penicillin(16% ,11/68)and clindamycin(6% ,1/17),and SP strains were completely resistant to erythromycin(100% ,31/31).The rates of discharge with cure and improvement were 22.5% (36/160)and 66.2% (106/160),respectively,while 18 cases(11.3% )had adverse outcomes.Conclusions Pediatric PM is more common in children aged 3 months to under 3 years.Intracranial complications are more frequently observed in children under 1 year old.Fever is the most common clinical manifestation of PM,and subdural effusion/emphysema and hydrocephalus are the most frequent complications.Non-culture detection methods for cerebrospinal fluid can improve pathogen detection rates.Adverse outcomes can be noted in more than 10% of PM cases.SP strains are high sensitivity to vancomycin,linezolid,meropenem,levofloxacin,moxifloxacin,rifampicin,and chloramphenicol.[Chinese Journal of Contemporary Pediatrics,2024,26(2):131-138]