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.

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 effect of sleep on physical performance and the correlation between sleep quality and physical performance in the elderly.Methods:In this prospective multicenter case-control study, 472 elderly people aged 60-80 years were recruited from three regions in China, Beijing, Tianjin, and Hainan Province.Basic information of study participants was collected through face-to-face interviews, and physical performance of study participants was assessed by the time up and go(TUG)test on site, with 106 cases(22.5%)in the normal physical performance group and 366 cases(77.5%)in the abnormal group.The Pittsburgh Sleep Quality Index(PSQI)and the Epworth Sleepiness Scale(ESS)were applied to assess sleep quality of study subjects.Correlation analysis was performed to examine factors affecting subjects' physical performance.Results:Age, history of alcohol consumption, BMI, past medical history, the ESS score, daytime sleepiness, and some components of PSQI, such as sleep quality, sleep efficiency, sleep disturbances, use of sleeping drugs and daytime dysfunction, were influencing factors of the TUG score.Two components of PSQI, sleep duration and habitual sleep efficiency, and the ESS score were positively correlated with physical performance.Logistic regression analysis showed that risk factors for decreased physical performance in the elderly included increased age( OR=1.125, 95% CI: 1.083-1.168, P<0.01), history of alcohol consumption( OR=0.482, 95% CI: 0.384-0.605, P<0.001), abnormally high body mass index( OR=1.663, 95% CI: 1.340-2.063, P<0.01), hyperlipemia( OR=0.156, 95% CI: 0.077-0.318, P<0.01), digestive system diseases( OR=0.154, 95% CI: 0.044-0.532, P<0.01), use of sleeping drugs( OR=0.415, 95% CI: 0.202-0.854, P<0.05), daytime sleepiness( OR=4.234, 95% CI: 2.800-6.403, P<0.01), a high habitual sleep efficiency score of PSQI( OR=1.425, 95% CI: 1.214-1.672, P<0.01)and a high sleep disturbances score in PSQI( OR=3.356, 95% CI: 2.337-4.819, P<0.01). Conclusions:The incidence of physical performance decline is high in the elderly.There is a correlation between physical performance and sleep quality.

Objective:To explore the utility of applying low frequency transcranial magnetic stimulation (rTMS) in the acute stage of ischemic stroke in terms of improving upper limb motor function.Methods:Eighty ischemic stroke survivors in the acute stage were randomly divided into a control group and an experimental group, with 40 in each. In addition to routine rehabilitation, the experimental group was given low frequency rTMS, while the control group was provided with sham rTMS. Before and after 4-weeks of treatment, upper limb motor function was evaluated using the Fugl-Meyer rating scale (FMA), Wolf motor function tests (WMFTs), the modified Barthel index (MBI) and in terms of motor evoked potential (MEP) latency and amplitude.Results:There were no significant differences between the two groups before the treatment. Afterward, however, the average FMA, WMFT, MBI scores had improved significantly more in the experimental group, on average, as had the average MEP amplitude.Conclusion:Low frequency rTMS in the acute phase of ischemic stroke can improve upper limb motor function and ability in the activities of daily living.

Objective: Bariatric surgery effectively treats non-alcoholic fatty liver disease (NAFLD). The glutamate-serine-glycine (GSG) index has emerged as a non-invasive diagnostic marker for NAFLD, but its ability to monitor treatment response remains unclear. This study investigates the GSG index's ability to monitor NAFLD's response to bariatric surgery. Methodology: Ten NAFLD participants were studied at baseline and 6 months post-bariatric surgery. Blood samples were collected for serum biomarkers and metabolomic profiling. Hepatic steatosis [proton density fat fraction (PDFF)] and fibroinflammation (cT1) were quantified with multiparametric magnetic resonance imaging (mpMRI), and hepatic stiffness with magnetic resonance elastography (MRE). Amino acids and acylcarnitines were measured with mass spectrometry. Statistical analyses included paired Student’s t-test, Wilcoxon-signed rank test, and Pearson’s correlation. Results: Eight participants provided complete data. At baseline, all had hepatic steatosis (BMI 39.3 ± 5.6 kg/m2, PDFF ≥ 5%). Post-surgery reductions in PDFF (from 12.4 ± 6.7% to 6.2 ± 2.8%, p = 0.013) and cT1 (from 823.3 ± 85.4ms to 757.5 ± 41.6ms, p = 0.039) were significant, along with the GSG index (from 0.272 ± 0.03 to 0.157 ± 0.05, p = 0.001). Conclusion The GSG index can potentially be developed as a marker for monitoring the response of patients with NAFLD to bariatric surgery.
Non-alcoholic Fatty Liver Disease ; Amino Acids ; Metabolomics

Nicotinic acetylcholine receptors (nAChRs) belong to ligand-gated ion channel receptors, of which α7 nAChR subtype is widely distributed in the cerebral cortex, thalamus, hippocampus, and also identified in microglia, macrophages, bone marrow cells, etc. Previous studies revealed that α7 nAChR is closely related to the function of the cholinergic anti-inflammatory pathway, and is a vital target for drug development of Alzheimer's disease and schizophrenia. The establishment of a stable α7 nAChR in vitro drug screening system is crucial for the efficient screening of novel drugs targeting this target. Recombinant expression of different subtypes of nAChRs on Xenopus laevis oocyte membranes and current detected by two-electrode voltage clamp (TEVC) is an advanced and complex model for novel drug screening. Molecular chaperones can assist the assembly of some nAChR subunits to form functional receptors, providing a stable expression model for the screening of compounds targeting this receptor. In this study, a molecular chaperone gene of α7 nAChR, transmembrane protein 35A (Tmem35a), was isolated and cloned from rats. We constructed the recombinant expression vector and obtained the cRNA of Tmem35a by in vitro transcription technique. Two cRNAs (Tmem35a and α7) were mixed and injected into X. laevis oocytes for expression. Then, the effects of this molecular chaperone on the current expression and pharmacological properties of α7 nAChR were evaluated by the TEVC. The results revealed that TMEM35A, also known as novel acetylcholine receptor chaperone (NACHO) could effectively increase the expression of α7 nAChR protein on oocyte membranes, and the amount of α7 nAChR protein was increased about 1-fold. The peak current induced by agonist acetylcholine (ACh) was increased about 10-fold. After injection of Tmem35a cRNA, the median effect concentration (EC₅₀) value of α7 nAChR to agonist ACh is 228.5 μmol·L^-1, which shows almost no difference from native α7 nAChR (EC₅₀: 223.3 μmol·L^-1), indicating the preservation of the normal properties of α7 nAChR. The results of this investigation indicate that the molecular chaperone NACHO effectively assists the heterologous expression of α7 nAChR in X. laevis oocytes, which provides a model for screening the potency of lead compounds targeting α7 nAChR. All animal experiments in this study were reviewed and approved by the Ethics Committee of Guangxi University (approval number: GXU-2023-0249).

N-type voltage-gated calcium (Ca²⁺) channels (N-type VGCC, Ca_V2.2) mediate Ca²⁺ influx in response to action potential at the presynaptic terminal, and play an important role in synaptogenesis, neurotransmitter release and nociceptive signal transduction. It is a new target for the development of drugs for the treatment of neuralgia (chronic pain) and other major diseases. Due to the difficulty of calcium channel expression in vitro and the detection of channel current, there is a great lack of new drug screening models. In this study, we established and optimized the electrophysiological drug screening model using Xenopus laevis oocytes for the recombinant expression of Ca_V2.2 in vitro (this study were reviewed and approved by the Ethics Committee of Guangxi University, approval number: GXU-2023-0249). Firstly, the linear plasmids encoding cDNA of major subunit α1B and auxiliary subunits α2δ1 and β3 of rat Ca_V2.2 were used as templates for in vitro transcription to generate their related mRNA (cRNA), after which three kinds of cRNA were injected into Xenopus laevis oocytes at the mass ratio of 2∶1∶1 for expression. The two-electrode voltage clamp (TEVC) technique was used to detect the inward current produced by Ca_V2.2. At the same time, the expression conditions of Ca_V2.2 were optimized, and its gating function was characterized from the aspects of channel activation and inactivation. The results showed that 3-5 days after cRNA microinjection, stable Ca_V2.2-mediated barium ion (Ba²⁺) currents were successfully detected. The interference of endogenous potassium channels and Ca²⁺-activated chloride channels can be eliminated by tetraethylammonium hydroxide (TEAOH) and 1,2-bis(2-aminophenoxy)ethane-N,N,N',N'-tetraacetic acid tetrakis (BAPTA-AM) treatment. The maximum potential for Ca_V2.2 activation is 0 mV, and the current reverses to be outward when the membrane potential is greater than +50 mV. By fitting the steady-state activation and inactivation curves, the half-maximal activation potential and half-maximal inactivation potential of Ca_V2.2 are identified as -15.9 and -60.2 mV. In this study, a stable Ca_V2.2 expression system was established based on Xenopus laevis oocytes. The in vitro expression system can provide a new way for the screening of Ca_V2.2 active compounds or lead drugs.

Objective:To examine the application of a novel pedagogical approach multidimensional supportive psychological intervention(MSPI)in the clinical practice teaching of andrological nursing care.Methods:Using the Hamilton Depression Scale(HAMD),we assessed the psychology of 100 nursing interns about to enter clinical practice in the Department of Andrology from De-cember 2021 to December 2022.We equally randomized the subjects into an experimental and a control group,the former receiving MSPI and the latter trained on the conventional teaching model without any psychological support intervention.Results:Compared with the baseline,the HAMD scores were significantly decreased in the experimental group after intervention(12.4±2.1 vs 8.9±2.4,P＜0.01),but increased in the controls(13.1±1.8 vs 14.7±1.9,P＜0.01);the skill scores dramatically increased in the experimental group(82.6±4.7 vs 91.2±2.4,P＜0.01),but decreased in the control group after intervention(81.0±3.5 vs 80.4±2.7,P=0.28).Conclusion:MSPI can significantly enhance the learning enthusiasm of nursing students in a short period,re-duce their psychological stress and improve teaching outcomes.This approach,combining psychology with teaching,can also strength-en the mental resilience of nursing students and better confront them with future professional challenges.

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]

Objective To investigate the differentiation of oligodendrocyte precursor cells after neural injury utilizing Sox10 cell lineage tracing in the cortical tissue.Methods C57BL/6 mice and Sox10-CreERT2/red fluorescent protein(RFP)model mice were used in the current study.The Sox10-CreERT2/RFP model mice generated by crossing Sox10-CreERT2 and Ai9 were 8-week-old F1 mice(n=16),which were randomly divided into control group(n=4)and 7 days(n=4),14 days(n=4),and 30 days feed groups(n=4).Tamoxifen(TAM)was used to induce the expression of RFP.The control group received tamoxifen dissolved in sunflower seed oil by gavage(40 mg/kg once daily for three consecutive days)and the brain tissues were obtained after 4 days.The feed group mice were fed with tamoxifen-containing feed to induce RFP expression,and the brain tissues were obtained after 7,14,and 30 days,respectively.Immunofluorescent staining was performed to detect the expressions of neuronal nuclei(NeuN),microtubule-associated protein 2(MAP2),phosphorylated histone 2AX(γ-H2AX),cluster of differentiation 13(CD 13),γ-aminobutyric acid(GABA),glial fibrillary acidic protein(GFAP),cluster of differentiation 11b(CD11b),vesicular glutamate transporter 2(VGLUT2),and adenomatous polyposis coli(APC,CC-1)in the brains of each group mice.The number of positive cells was counted,and the proportion was calculated.Eight-week-old male C57BL/6 mice were randomly divided into wild type(WT)group(n=4)and WT+TAM group(n=4).They were fed with regular feed and tamoxifen-containing feed for 30 days,respectively,and then brain tissues were obtained.Immunofluorescent double-labeling was used to detect the expressions of γ-H2AX positive neurons in the cortex of mice in both groups.Results In the control group,feed 7 days,14 days,and 30 days groups,the proportions of RFP+pericytes among all RFP+cells in the cortical tissue were(0.8±0.1)％,(2.7±0.1)％,(3.2±0.1)％,(4.0±0.1)％,respectively,and the proportion of mature oligodendrocytes(CC-1+RFP+)in the feed 7 days group was(51.2±0.7)％.The proportions of RFP-positive neurons in the cortex after 14 and 30 days of tamoxifen feed were(0.7±0.1)％and(1.5±0.1)％,respectively,while no conversion to RFP-positive neurons was observed in the gavage group and 7 days feed group.RFP cells in the cortex of the 7 days or 30 days feed group did not express GFAP or CD11b.Extensive γ-H2AX+NeuN+staining was observed in the WT group and WT+TAM group.Conclusion Long-term administration of tamoxifen can promote the differentiation of Sox10 cells into pericytes and neurons.Further investigation into the role of OPC in the neurovascular unit repair mechanism may contribute to a better understanding of the pathogenesis underlying AD.