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.

A growing body of research points out that gut microbiota plays a key role in tumor immunotherapy. By optimizing the composition of intestinal microbiota, it is possible to effectively improve immunotherapy resistance and enhance its therapeutic effect. This article comprehensively analyzes the mechanism of intestinal microbiota influencing tumor immunotherapy resistance, expounds the current strategies for targeted regulation of intestinal microbiota, such as traditional Chinese medicine and plant components, fecal microbiota transplantation, probiotics, prebiotics and dietary therapy, and explores the potential mechanisms of these strategies to improve patients' resistance to tumor immunotherapy. At the same time, the article also briefly discusses the prospects and challenges of targeting intestinal microbiota to improve tumor immunotherapy resistance, which provides a reference for related research to help the strategy research of reversing tumor immunotherapy resistance.

Objective To analyze the nonlinear relationship between hypothermic machine perfusion (HMP) parameters and delayed graft function (DGF) and optimize the construction of a predictive model for DGF. Methods The data of 923 recipients who underwent kidney transplantation from deceased donors were retrospectively analyzed. According to the occurrence of DGF, the recipients were divided into DGF group (n=823) and non-DGF group (n=100). Donor data, HMP parameters and recipient data were analyzed for both groups. The nonlinear relationship between HMP parameters and the occurrence of DGF was explored based on restricted cubic splines (RCS). Over-sampling, under-sampling and balanced sampling were used to address the imbalance in the proportion of DGF to construct logistic regression predictive models. The area under the curve (AUC) of each model was compared in the validation set, and a nomogram model was constructed. Results Donor BMI, cold ischemia time of the donor kidney, and HMP parameters (initial and final pressures, resistance, and perfusion time) were significantly different between the DGF and non-DGF groups (all P<0.05). The RCS analysis revealed a threshold-like nonlinear relationship between HMP parameters and the risk of DGF. Among the models constructed using different sampling methods, the balanced sampling model had the highest AUC. Using this model, a nomogram was constructed to stratify recipients based on risk scores. Recipients in the high-risk group had higher serum creatinine levels at 1, 6, and 12 months after kidney transplantation compared to those in the low-risk group (all P<0.05). Conclusions There is a nonlinear relationship between HMP parameters and the risk of DGF, and the threshold is helpful for organ quality assessment and monitoring of graft function after transplantation. The predictive model for DGF constructed on the base of balanced sampling algorithms helps perioperative decision-making and postoperative graft function monitoring of kidney transplantation.

This study investigated the epidemiological and genotypic characteristics of group A rotavirus(RVA)in children under 5 years of age with diarrhea at a viral diarrhea surveillance sentinel hospital in Guangdong Province from 2021 to 2022,to provide a basis for RVA prevention and control.A total of 1 858 fecal samples from children under 5 years of age with diarrhea in 2021-2022 were collected.Rotavirus antigen was detected with ELISA,and positive samples were further sequenced and categorized.Among the 1 858 samples,156 were RVA positive.The positivity rates in boys and girls were 8.76％and 7.87％,respectively.Significant differences were observed in the detection rates of RVA infection among age groups.The rate of RVA infection increased gradually from December to April of the following year.In 2021,the main endemic strains of RVA in the Guangdong region were of the G9P[8]subtype,and the rare G8P[8]subtype increased in China.In 2022,the G8P[8]subtype surpassed the G9P[8]subtype for the first time.In cases of diarrhea in infants younger than 5 years in Guangdong Province from 2021 to 2022,the RVA genotypes were diverse,the G9P[8]genotype significantly decreased,and the G8P[8]subtype became a dominant genotype.Continuous RVA genotype monitoring remains necessary to assess the risk of RVA-related disea-ses.

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]

Glyceryl phenylbutyrate(GPB)serves as a long-term management medication for Ornithine transcarbamylase deficiency(OTCD),effectively controlling hyperammonemia,but there is a lack of experience in using this medicine in China.This article retrospectively analyzes the case of a child diagnosed with OTCD at Shanghai Children's Medical Center,Shanghai Jiao Tong University School of Medicine,including a review of related literature.After diagnosis,the patient was treated with GPB,followed by efficacy follow-up and pharmacological monitoring.The 6-year and 6-month-old male patient exhibited poor speech development,disobedience,temper tantrums,and aggressive behavior.Blood ammonia levels peaked at 327 μmol/L;urine organic acid analysis indicated elevated uracil levels;cranial MRI showed extensive abnormal signals in both cerebral hemispheres.Genetic testing revealed de novo mutation in the OTC gene(c.241T＞C,p.S81P).Blood ammonia levels were approximately 43,80,and 56 μmol/L at 1,2,and 3 months after starting GPB treatment,respectively.During treatment,blood ammonia was well-controlled without drug-related adverse effects.The patient showed improvement in developmental delays,obedience,temperament,and absence of aggressive behavior.

Objective To observe the effects of melatonin on autophagy in cortical neurons of neonatal rats with hypoxic-ischemic brain damage(HIBD)and to explore its mechanisms via the PI3K/AKT signaling pathway,aiming to provide a basis for the clinical application of melatonin.Methods Seven-day-old Sprague-Dawley neonatal rats were randomly divided into a sham operation group,an HIBD group,and a melatonin group(n=9 each).The neonatal rat HIBD model was established using the classic Rice-Vannucci method.Neuronal morphology in the neonatal rat cerebral cortex was observed with hematoxylin-eosin staining and Nissl staining.Autophagy-related protein levels of microtubule-associated protein 1 light chain 3(LC3)and Beclin-1 were detected by immunofluorescence staining and Western blot analysis.Phosphorylated phosphoinositide 3-kinase(p-PI3K)and phosphorylated protein kinase B(p-AKT)protein expression levels were measured by immunohistochemistry and Western blot.The correlation between autophagy and the PI3K pathway in the melatonin group and the HIBD group was analyzed using Pearson correlation analysis.Results Twenty-four hours post-modeling,neurons in the sham operation group displayed normal size and orderly arrangement.In contrast,neurons in the HIBD group showed swelling and disorderly arrangement,while those in the melatonin group had relatively normal morphology and more orderly arrangement.Nissl bodies were normal in the sham operation group but distorted in the HIBD group;however,they remained relatively intact in the melatonin group.The average fluorescence intensity of LC3 and Beclin-1 was higher in the HIBD group compared to the sham operation group,but was reduced in the melatonin group compared to the HIBD group(P<0.05).The number of p-PI3K+and p-AKT+cells decreased in the HIBD group compared to the sham operation group but increased in the melatonin group compared to the HIBD group(P<0.05).LC3 and Beclin-1 protein expression levels were higher,and p-PI3K and p-AKT levels were lower in the HIBD group compared to the sham operation group(P<0.05);however,in the melatonin group,LC3 and Beclin-1 levels decreased,and p-PI3K and p-AKT increased compared to the HIBD group(P<0.05).The correlation analysis results showed that the difference of the mean fluorescence intensity of LC3 and Beclin-1 protein in the injured cerebral cortex between the melatonin and HIBD groups was negatively correlated with the difference of the number of p-PI3K+and p-AKT+cells between the two groups(P<0.05).Conclusions Melatonin can inhibit excessive autophagy in cortical neurons of neonatal rats with HIBD,thereby alleviating HIBD.This mechanism is associated with the PI3K/AKT pathway.

Objective To study the diagnosis,treatment,and complications of hypophosphatemic rickets(HR)in children,explore effectiveness evaluation indicators for the disease,and understand the pattern in height growth among these patients.Methods A retrospective analysis of the initial clinical data and five-year follow-up data of 85 children with HR treated at Children's Hospital of Nanjing Medical University from January 2008 to December 2022.Results Among the 85 children with HR,there were 46 males(54%)and 39 females(46%).The age at initial diagnosis ranged from 6 months to 13 years and 9 months,with a median age of 2.75 years.The average height standard deviation score was-2.0±1.1.At initial diagnosis,children exhibited reduced blood phosphate levels and elevated alkaline phosphatase(ALP),with 99%(84/85)presenting with lower limb deformities.The positive rate for PHEX gene mutations was 93%(55/59).One year post-treatment,there was a significant reduction in ALP levels and the gap between the lower limbs(P<0.05).The fastest height growth occurred in the first year after treatment,at 8.23 cm/year,with a peak height velocity(PHV)phase lasting about two years during puberty.The height increased by 9-20 cm in male children during the PHV stage and 10-15 cm in female children.Major complications included nephrocalcinosis and hyperparathyroidism.The incidence rate of nephrocalcinosis in the first year after treatment was 55%(22/40),which increased with the duration of the disease(P<0.001);an increased urinary phosphate/creatinine ratio was positively associated with a higher risk of nephrocalcinosis(OR=1.740,P<0.001).The incidence of hyperparathyroidism in the first year after treatment was 64%(27/42).Conclusions For children presenting with lower limb deformities,short stature,and slow growth,early testing for blood levels of phosphate,calcium,and ALP,along with imaging examinations of the lower limbs,can aid in the early diagnosis of HR.Genetic testing may be utilized for definitive confirmation when necessary.ALP combined with improvements in skeletal deformities and annual height growth can serve as indicators of therapeutic effectiveness for HR.Compared to normal children,children with HR demonstrate a lower height increase during the PHV phase,necessitating close follow-up and timely adjustment of treatment plans

Objective: To explore the intervention effect of different intensity of classroom physical exercise on cardiorespiratory fitness and executive function of Tibetan first grade students at high altitude, so as to provide reference for improving the level of cardiorespiratory fitness and executive function of Tibetan adolescents. Methods: From September to December 2020, 184 Tibetan students from five first grade classes in a middle school in Lhasa, Tibet, were randomly assigned into a control group (81 students in two classes) and an intervention group (103 students in three classes). Both groups followed the same teaching programme, but the intervention group received 36 sessions of moderate to high intensity classroom physical activity, one session per day, Monday,Wednesday and Friday, for 12 weeks. Before and after the intervention, cardiorespiratory fitness and executive function were tested by 20m round trip running and Flanker s experimental paradigm, 2-back s experimental paradigm, and More odd shifting experimental paradigm for inhibitory control, refreshing memory, and switching flexibility, and the results were analysed by analysis of covariance (ANCOVA) to compare the results of the pre and post intervention periods. Results: The maximum oxygen uptake (VO 2max ) of Tibetan first grade students in the intervention group increased by 2.25 mL/(kg〖WW）〗·〖WW(〗min) compared with the control group after the intervention ( t =-3.89, P <0.01); the response time of the inhibitory function was reduced by 4.40 ms, that of the refreshing function by 196.06 ms, and that of the switching function by 92.72 ms in the intervention group compared with the control group ( t =2.98, 4.82 ,3.21, P <0.05). Conclusion The 12 week moderate to high intensity classroom physical activity intervention has different degrees of improvement effects on cardiorespiratory fitness and executive function in Tibetan adolescents.

ObjectiveAngle-closure glaucoma (ACG) is one of the major eye-blinding diseases. To diagnose ACG, it is crucial to examine the anterior chamber angle. Current diagnostic tools include slit lamp gonioscopy, water gonioscopy, ultrasound biomicroscopy (UBM), and anterior segment optical coherence tomography (AS-OCT). Slit lamp and water gonioscopy allow convenient observation of the anterior chamber angle, but pose risks of invasive operation and eye infections. UBM can accurately measure the structure of the anterior chamber angle. However, it is complex to operate and unsuitable for patients, who have undergone trauma or ocular surgery. Although AS-OCT provides detailed images, it is costly. The aim of this study is to explore a non-invasive, non-destructive optical reflection tomography (ORT) technique. This technique can achieve low-cost three-dimensional imaging and full-field anterior chamber angle measurement of the porcine eye. MethodsThe experiment involved assembling an optical reflection tomography system, which included a complementary metal oxide semiconductor (CMOS) camera, a telecentric system, a stepper motor, and a white light source, achieving a spatial resolution of approximately 8.5 μm. The process required positioning the porcine eye at the center of the field of the imaging system and rotating it around its central axis using a stepper motor. Reflection projection images were captured at each angle with an exposure time of 1.0 ms and an interval of 2°. The collected reflection-projection data were processed using a filtered reflection tomography algorithm, generating a series of two-dimensional slice data. These slices essentially represented cross-sectional views of the three-dimensional structural image, and were reconstructed into a complete three-dimensional structural image. Based on the reconstructed three-dimensional structural image of the porcine eye, the anterior chamber angles at different positions were measured, and a distribution map of these angles was drawn. Simultaneously, the ORT measurements were compared with the standard results obtained from optical coherence tomography (OCT) to assess the accuracy of ORT measurements. ResultsIn this study, we successfully obtained the reflection projection data of a porcine eye using ORT technology, reconstructed its three-dimensional structural image, and measured the anterior chamber angle, generating the corresponding distribution map. To better distinguish the different structural parts of porcine eye, the three-dimensional structural image was marked with blue, green, and yellow dashed lines from the outer to the inner layers. The area between the blue and green dashed lines corresponded to the sclera. The area between the green and yellow dashed lines corresponded to the iris. The area inside the yellow dashed line corresponded to the pupil. The three-dimensional structural image clearly revealed the key anatomical features of the porcine eye. It was able to measure the anterior chamber angle at different positions. Additionally, the anterior chamber angle measurements of the porcine eye using ORT were compared with the measurements obtained using a TEL320C1 type OCT system, showing an average deviation of 0.51° and a mean square error MSE of 0.317. ConclusionORT is a non-invasive, non-destructive, low-cost, and high-resolution imaging technique capable of achieving three-dimensional structural imaging and full-field anterior chamber angle measurement of a porcine eye. This technology offers a new perspective for the diagnosis of angle-closure glaucoma and is significant for the screening, diagnosis, and monitoring of eye diseases, potentially benefiting clinics and small hospitals in remote areas in the future.