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 effects of Tongxie yaofang （TXYF） on the symptoms of rats with irritable bowel syndrome with diarrhea （IBS-D） by regulating colonic tryptophan hydroxylase 1 （TPH1）， serotonin transporter （SERT） and intestinal flora. METHODS Forty-two SD rats were randomly divided into control group （7 rats） and modeling group （35 rats）. In modeling group， rat model of IBS-D was established by intragastrical administration of 0.45 g/L senna leaf solution [10 mL/（kg·d）] combined with chronic unpredictable stimulation. Thirty-five successfully modeled rats were randomly divided into model group， pinaverium bromide group [15 mg/（kg·d）] and TXYF low-dose， medium-dose and high-dose groups [3.75、7.5、15 g/（kg·d）， calculated by crude drug]， with 7 rats in each group. Each administration group was orally administered the corresponding drug， once a day， for 10 consecutive days. The general condition and weight changes of each group of rats were compared before modeling， after modeling and before administration， after the last drug intervention； the diarrhea index and visceral sensitivity were detected， and pathological changes of colon tissue were observed after modeling and before administration， after the last drug intervention. The level and expression of 5-hydroxytryptamine （5-HT）， protein and mRNA expressions of TPH1 and SERT were determined in colon tissue. The diversity and structural changes of fecal intestinal flora of rats were analyzed. RESULTS There was no significant change in colon histopathology in each group. Compared with model group， the general condition of rats in each medication group improved. The daily body weight gain of rats was significantly increased， while diarrhea index， visceral sensitivity， the expressions of 5-HT and TPH1 in colon tissue were significantly decreased； SERT expression of colon tissue was significantly increased in TXYF medium-dose and high-dose groups （P＜0.05 or P＜0.01）. The diarrhea index， colon TPH1 protein expression and colon 5-HT protein positive rate in the TXYF low-dose group decreased while the mRNA expression of SERT increased significantly （P＜0.05）. There was a dose- dependent trend in the effect of TXYF. Compared with model group， Chao1 index and Shannon index of the rats in TXYF high- dose group were significantly decreased （P＜0.05 or P＜0.01）， the beneficial bacteria such as Firmicutes and Lactobacillus increased significantly， while the pathogenic bacteria such as Proteobacteria， Escherichia-Shigella and Rikenellaceae_RC9_gut_ group decreased significantly （P＜0.05 or P＜0.01）. CONCLUSIONS TXYF can decrease the level of 5-HT and improve intestinal flora disorder by inhibiting the expression of TPH1 and up-regulating the expression of SERT in colon tissue， thus promoting the symptoms of IBS-D rats.

As a rapidly developing frontier discipline, structural biology has penetrated into every field of life science research. The course of “Structural Biology” plays an important role in expanding the knowledge system of undergraduate students and promoting students’ scientific spirit and innovation. For the high-quality training of highly skilled talents, we aimed to promote the original innovation of students, the ability of thinking, and the ability of engineering practice. The trinity education concept, including shape of the value, passing on knowledge, and ability cultivation, was applied. During the reform, we explored a step-by-step course content and searched for factors involved in ideological and political education. Based on the problem-based learning (PBL) method, a hybrid teaching model was designed to cultivate the problem-thinking and problem-solving skills of students. Meanwhile, a number of evaluation systems for students and teachers were established, which may be generally adopted for the course of “Structural Biology”. The survey data suggested that the exploration has a good effect on teaching and training and is conducive to the cultivation of research-oriented, comprehensive, innovative talents under the background of “New Engineering”.

Pharmaceutical cocrystals are one of the effective strategies to improve the solubility and bioavailability of poorly water-soluble drugs. However, the phase transformation of cocrystals during dissolution can lead to the recrystallization of the parent drugs, and thus negating the solubility advantage of cocrystals. The introduction of suitable excipients into the cocrystal formulation may inhibit the phase transformation during dissolution, resulting in the enhanced dissolution and bioavailability of poorly soluble drugs. In addition, the complex gastrointestinal environment and absorption behavior of drugs can have significant impacts on the oral bioavailability of cocrystals. This review summarizes the recent studies of the dissolution and absorption of pharmaceutical cocrystals, and aims to provide guidance for the rational design of pharmaceutical cocrystal formulations.

Eighteen compounds were isolated from the methanol extract of the fruits of Litsea cubeba by silica gel, ODS, Sephadex LH-20 column chromatography, semi-preparative RP-HPLC, chiral HPLC and recrystallization. Their structures were elucidated by spectroscopic analyses and by comparison with reported spectroscopic data and physicochemical properties, and the absolute configurations of the enantiomers were established by experimental and calculated electronic circular dichroism spectra. These compounds were identified as (+)-(R)-4-hydroxypiperitenone (1a), (-)-(S)-4-hydroxypiperitenone (1b), (3S,4S,6R)-3,6-dihydroxy-1-menthene (2), (4S,5R)-4-hydroxy-5-isopropyl-2-methylcyclohex-2-en-1-one (3), (R)-6-hydroxy-3-(2-hydroxypropan-2-yl)-6-methylcyclohex-2-enone (4), (4S,6R)-4-hydroxy-6-isopropyl-3-methylcyclohex-2-enone (5), (1R,3S,4R)-3-hydroxy isopulegol (6), subamone (7), (6S)-3,7-dimethyl-7-hydroxy-2(Z)-octen-6-olide (8), (6S)-6,7-dihydroxy-3,7-dimethyloct-2(Z)-enoate (9), holostylactone (10), sesamin (11), dimethylmatairesinol (12), p-hydroxybenzoylcarbinol (13), syringaldehyde (14), p-hydroxybenzaldehyde (15), 4-hydroxy-3-methoxybenzaldehyde (16), 5,4ʹ-dihydroxy-7-methoxyflavone (17). Among them, compounds 1a and 1b were a pair of new monoterpenoid enantiomers, 8 and 9 were new natural products, 2-7, 10, 11 and 17 were isolated from Litsea genus for the first time. The in vitro anti-inflammatory effects of compounds 1-17 were evaluated using lipopolysaccharide-stimulated RAW264.7 cells, the results showed that compound 14 exhibited significant anti-inflammatory activity with NO inhibitory rate of 66.27% at a concentration of 40 μmol·L^-1.

Objective To develop a self-care scale for patients with lymphedema after breast cancer surgery and verify its reliability and validity.Methods Based on the model of knowledge,belief and practice,a questionnaire item pool was constructed after literature reviews and qualitative interviews.A questionnaire-based scale was drafted based on the established item pool by carrying out two rounds of consultation with 15 clinical nursing specialists,nursing administrators and nursing educators from 8 provinces or cities in China.Reliability and validity of the scale were tested using convenience sampling,involving 444 patients with breast cancer surgery related lymphedema from 7 general hospitals in Hubei and Henan provinces,China,between May and July 2023.Results The response rates for the two rounds of expert consultation were 93.75%and 93.33%,respectively.The authority coefficients of the two rounds were 0.86 and 0.89,respectively,and the coordination coefficients for the 2 rounds were 0.130 and 0.379,respectively.In the first round,the average importance rating was from 4.33 to 4.93 with the coefficient of variation from 0.05 to 0.19,and the full score ratio from 53.33%to 93.33%.In the second round,the average importance rating ranged from 2.86 to 4.93 with the coefficient of variation from 0.05 to 0.36,and the full score ratios from 7.14%to 92.86%.A total of 421 patients completed the survey.The overall Cronbach's α coefficient of the scale was 0.943,the overall split-half reliability was 0.824,the scale-level content validity index(S-CVI)was 0.912,and the item-level content validity index(I-CVI)of the total scale ranged from 0.857 to 1.000.The KMO value of exploratory factor analysis was 0.919,the Bartrett spherical test value was 4671.724(P<0.001),and the cumulative variance contribution rate was 64.155%.Confirmatory factor analysis showed a good model fit.After the reliability and validity tests,the scale was finalised and determined to consist of three dimensions with 33 items:knowledge(9 items),attitude(6 items)and behaviour(18 items).Conclusion The self-care scale for the patients with lymphedema after breast cancer surgery has demonstrated good reliability and validity,and makes it an effective assessment tool for the patients with lymphedema after breast cancer surgery.

In the fight against COVID-19, under the guidance of medical professionalism, the majority of medical workers adhered to the scientific spirit of rigorous truth-seeking and innovation, and the humanitarian feelings of boundless love and dedication, and made outstanding contributions to prevention and control. However, the epidemic situation fluctuates repeatedly, the virus mutates frequently, and the risk of major public health emergencies has caused deep thinking on the cultivation of medical students’ professionalism. Medical students are the reserve force for the sustainable development of China’s medical and health undertakings. The times and society endow medical students with a more lofty and arduous historical mission, and also call for strengthening the cultivation of medical students’ professional spirit. Under the background of normalization of epidemic prevention and control, responding to the demands of the times, providing high-quality medical talents for the society, promoting building the doctor-patient desting community, and promoting the reality of the healthy China strategy, efforts to explore the path of cultivating medical students’ professionalism with "three combinations, two considerations and one emphasis".

Objective:To determine the status of nutritional literacy and its influencing factors among the peritoneal dialysis (PD) patients. Methods:The patients who underwent PD and long-term follow-up in the Department of Nephrology,General Hospital of Eastern Theater Command between January and October,2023 were enrolled in this study. The status of nutritional literacy in the patients was assessed through collecting and analyzing the data on the patients' general information,the current nutritional status,and laboratory-and dialysis-related indicators. Results:The average score of nutritional literacy in the enrolled patients were (24.49±3.35). Significant differences in nutritional literacy scoring were observed in the different patient subgroups according to the patients' educational background,dialysis time or times of receiving multidisciplinary diet guidance (all P values<0.05). The nutritional literacy levels of PD patients were negatively correlated to the concentrations of serum calcium and prealbumin,and left ventricular posterior wall thickness,and postively correlated to prealbumin level(P<0.05). Basing on multiple linear regression analysis,the times of receiving multidisciplinary diet guidance,educational background and serum prealbumin level were identified as independent influencing factors for the nutritional literacy levels in PD patients,respectively (all P values<0.05). Conclusions:The present study showed that the nutritional literacy of PD patients was in the middle level. In clinical practice,to enhance multidisciplinary diet guidance and management at the early stage of PD could contribute to improve the nutritional status of PD patients. In addition,to increase the patients' nutritional knowledge and health management ability might be also helpful for the nutritional levels of PD patients.

Objective To investigate the effects of exercise and complex environment on lipopolysaccharide(LPS)-induced dopaminergic neuron death in the substantia nigra of midbrain.Methods C57BL/6 mice were divided into control group,LPS group,LPS+swimming group and LPS+complex environment group,with 7 mice in each group.The mice in the LPS group were injected with LPS into the brain to establish an inflammatory model of Parkinson's disease and lived in cages for 2 weeks.Mice in LPS+swimming group were forced to swim for 15 minutes every day for 2 weeks after modeling.The mice in the LPS+complex environment group were placed in a complex environment for 2 weeks after modeling.The control group mice were not treated.After 14 days of modeling,behavioral experiments such as footprint,open field and rotating rod were performed on each group of mice to detect the autonomous exercise ability,exercise balance ability and depression level of mice.The expressions of tyrosine hydroxylase(TH)in substantia nigra was detected by immunohistochemical staining and Western blotting.The expressions of brain-derived neurotrophic factor(BDNF),Caspase-3,interleukin-1β(IL-1β),interleukin-6(IL-6)and tumor necrosis factor-α(TNF-α)in the substantia nigra of the midbrain were detected by Western blotting.The transcription levels of IL-1β,IL-6 and TNF-α in substantia nigra were detected by RT-PCR.Results Compared with the control group,the exercise ability and balance ability of mice in LPS group,LPS+swimming group and LPS+complex environment group decreased,the depression level increased(P＜0.001),the number of TH positive neurons and BDNF protein decreased significantly(P＜0.001),and the contents of Caspase-3,IL-1β,IL-6 and TNF-α increased significantly(P＜0.001).Compared with the LPS group,the exercise ability and balance ability of the mice in the LPS+swimming group and the LPS+complex environment group were restored,the depression level decreased significantly(P＜0.01),the survival number of TH positive neurons and the content of BDNF increased significantly(P＜0.01),Caspase-3,IL-1β,IL-6 and TNF-α reduced significantly(P＜0.01),and the phenomenon in the LPS+complex environment group was more significant.Conclusion Exercise and complex environment can inhibit LPS-induced central nervous system inflammation in mice,thereby reducing damage to midbrain substantia nigra neurons,and the inhibitory effect of LPS+complex environment group is more significant.

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]