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.

BACKGROUND:Molecular mechanisms targeting the miRNA/mRNA axis to regulate osteoarthritis disease process have been studied.We identified the mRNA:phospholipase C delta 3(PLCD3)and its target miRNA(miR-34a-5p)with clinical predictive value through previous bioinformatics studies,while experiments to verify their specific roles and mechanisms in regulating osteoarthritis are still lacking. OBJECTIVE:To investigate the regulatory role and mechanism of miR-34a-5p/PLCD3 axis on osteoarthritis progression. METHODS:The synovium of 15 patients with knee osteoarthritis was selected as the osteoarthritis group,and the synovium of 15 young patients with internal fixation of patellar fracture caused by trauma during the same period was selected as the control group.The expression of PLCD3 and miR-34a-5p in the synovium was detected by real-time PCR.Human fibroblast like synovial cells-osteoarthritis(HFLS-OA)cells were treated by cell transfection and divided into miR-34a-5p mimic group,pCDH-PLCD3 group,miR-34a-5p mimic+pCDH-PLCD3 group,miR-34a-5p inhibitor group,si-PLCD3 group,and miR-34a-5p inhibitor+si-PLCD3 group.The relationship between PLCD3 and miR-34a-5p expression was detected by real-time PCR.The effects of HFLS-OA cell viability and cell migration in each group were detected by CCK-8 assay and cell scratch test.Western blot assay was used to detect the expression level of apoptosis marker protein.The expression of inflammatory factors was detected by ELISA. RESULTS AND CONCLUSION:(1)PLCD3 was a direct target of miR-34a-5p,and the expression levels of PLCD3 and miR-34a-5p were negatively correlated.(2)Upregulation of PLCD3 promoted proliferation of HFLS-OA cells and inhibited cell migration.The up-regulation of miR-34a-5p significantly inhibited the activity of HFLS-OA cells and enhanced cell migration.Overexpression of miR-34a-5p significantly increased the levels of Casp3 and Casp9 proteins in HFLS-OA cells,while overexpression of PLCD3 showed the opposite trend.(3)PLCD3 overexpression significantly increased the expression of interleukin 6 and tumor necrosis factor alpha in HFLS-OA cells,while miR-34a-5p mimics showed protective activity.(4)The miR-34a-5p/PLCD3 axis may affect the progression of osteoarthritis by regulating the inflammatory process or apoptosis of synovial cells.

Objective To investigate the expression of PLCD3 mRNA in the synovium of osteoarthritis(OA)and its relationship with immune cell infiltration.Methods Based on the differentially expressed genes of OA found in the previous study,the expression of phospholipase Cδ3(PLCD3)mRNA was detected by col-lecting synovial samples from OA group and control group.CIBERSORT algorithm was used to analyze the infiltration pattern of immune cells in OA group and control group,and the correlation between PLCD3 and infiltrating immune cells was further analyzed.Results Compared with the control group,the relative expres-sion level of PLCD3 mRNA was significantly increased in synovial samples of OA group(P<0.05).The pro-portions of B cells naive,NK cells activated,M2 macrophages and mast cells activated in synovial tissues of OA group were relatively high(P<0.05).PLCD3 was positively correlated with the proportion of these four immune cells(P<0.05).Conclusion PLCD3 may be a key biomarker for the diagnosis of OA,which may be involved in the pathogenesis of OA by interacting with infiltrating immune cells.

Antisense oligonucleotides are a type of gene therapy that targets mRNA and inhibits gene expression. They have been applied in the treatment of various diseases, but there are still problems with poor enzyme stability and high dosage in vivo, due to the shortage of appropriate delivery system. Insulin-like growth factor 1 receptor (IGF1R) is a cell surface receptor with tyrosine kinase activity. Its expression is abnormal in a variety of malignant tumors. It mediates the malignant proliferation, migration and invasion of tumor cells through a variety of ways. In this study, an antisense oligonucleotide (ASO, N04) targeting IGF1R mRNA was designed and chemically modified (PS, 2'-OMOE), then neutral cytidine lipid DNCA and cystine backbone cationic lipid CLD (Mix) were used to encapsulate ASOs. The particle size, polymer dispersity index and ζ potential of the formulations were 151 nm, 0.18 and -3.9 mV. The nanoparticles entered liver cancer cells (HepG-2, Huh-7), silenced target mRNA, arrested cell cycle in S phase, promoted apoptosis, and inhibited the proliferation efficiently. These results indicate that Mix/N04_MOE5 has great potential in tumor treatment, which provides a basis for further research on novel agents against hepatocellular carcinoma.

Traumatic supraorbital fissure syndrome (TSOFS) is a symptom complex caused by nerve entrapment in the supraorbital fissure after skull base trauma. If the compressed cranial nerve in the supraorbital fissure is not decompressed surgically, ptosis, diplopia and eye movement disorder may exist for a long time and seriously affect the patients′ quality of life. Since its overall incidence is not high, it is not familiarized with the majority of neurosurgeons and some TSOFS may be complicated with skull base vascular injury. If the supraorbital fissure surgery is performed without treatment of vascular injury, it may cause massive hemorrhage, and disability and even life-threatening in severe cases. At present, there is no consensus or guideline on the diagnosis and treatment of TSOFS that can be referred to both domestically and internationally. To improve the understanding of TSOFS among clinical physicians and establish standardized diagnosis and treatment plans, the Skull Base Trauma Group of the Neurorepair Professional Committee of the Chinese Medical Doctor Association, Neurotrauma Group of the Neurosurgery Branch of the Chinese Medical Association, Neurotrauma Group of the Traumatology Branch of the Chinese Medical Association, and Editorial Committee of Chinese Journal of Trauma organized relevant experts to formulate Chinese expert consensus on the diagnosis and treatment of traumatic supraorbital fissure syndrome ( version 2024) based on evidence of evidence-based medicine and clinical experience of diagnosis and treatment. This consensus puts forward 12 recommendations on the diagnosis, classification, treatment, efficacy evaluation and follow-up of TSOFS, aiming to provide references for neurosurgeons from hospitals of all levels to standardize the diagnosis and treatment of TSOFS.

Objective:To explore the rescue effect and application value of chest pain center construction in patients with acute myocardial infarction(AMI).Methods:A total of 144 AMI patients admitted our hospital from March 2020 to March 2021 were selected.According to the double-blind method,they were divided into traditional first-aid group(traditional first-aid procedure intervention,n=72)and chest pain center group(chest pain center con-struction intervention,n=72).Medical staff comprehensive first-aid ability[assessed by Mini-Clinical Evaluation Exercise(Mini-CEX)],first-aid efficiency,thrombolytic condition,mortality,incidence rates of 1-year rehos-pitalization and adverse cardiovascular events were compared between two groups.Results:Compared with tradi-tional first-aid group,there was significant rise in Mini-CEX score[(5.17±1.09)points vs.(7.41±1.27)points],and significant reductions in onset-to-first medical contact time[(12.40±1.93)min vs.(5.51±0.76)min],door-to-balloon time[(114.37±26.06)min vs.(67.05±8.34)min],first medical contact-to-reperfu-sion time[(104.63±3.30)min vs.(79.72±2.73)min],admission-to-thrombolysis time[(68.08±2.17)min vs.(52.84±1.58)min],time in bed[(65.27±2.02)h vs.(41.67±1.77)h],mortality(11.11％vs.2.78％),incidence rates of 1-year rehospitalization(15.28％vs.4.17％)and adverse cardiovascular events(18.06％vs.5.56％)in chest pain center group(P＜0.05 or＜0.01).Conclusion:Chest pain center construction can signifi-cantly improve the comprehensive quality of medical staff,complete the first-aid process,and further improve the efficiency of first-aid for AMI patients,which has a high value of clinical promotion.

Background::Pulmonary arterial hypertension (PAH) is characterized by excessive proliferation of small pulmonary arterial vascular smooth muscle cells (PASMCs), endothelial dysfunction, and extracellular matrix remodeling. G protein-coupled receptor kinase 2 (GRK2) plays an important role in the maintenance of vascular tone and blood flow. However, the role of GRK2 in the pathogenesis of PAH is unknown.Methods::GRK2 levels were detected in lung tissues from healthy people and PAH patients. C57BL/6 mice, vascular smooth muscle cell-specific Grk2-knockout mice ( Grk2?SM22), and littermate controls ( Grk2flox/flox) were grouped into control and hypoxia mice ( n = 8). Pulmonary hypertension (PH) was induced by exposure to chronic hypoxia (10%) combined with injection of the SU5416 (cHx/SU). The expression levels of GRK2 and Yes-associated protein (YAP) in pulmonary arteries and PASMCs were detected by Western blotting and immunofluorescence staining. The mRNA expression levels of Grk2 and Yes-associated protein ( YAP) in PASMCs were quantified with real-time polymerase chain reaction (RT-PCR). Wound-healing assay, 3-(4,5)-dimethylthiahiazo (-z-y1)-3,5-di-phenytetrazoliumromide (MTT) assay, and 5-Ethynyl-2′-deoxyuridine (EdU) staining were performed to evaluate the proliferation and migration of PASMCs. Meanwhile, the interaction among proteins was detected by immunoprecipitation assays. Results::The expression levels of GRK2 were upregulated in the pulmonary arteries of patients with PAH and the lungs of PH mice. Moreover, cHx/SU-induced PH was attenuated in Grk2?SM22 mice compared with littermate controls. The amelioration of PH in Grk2?SM22 mice was accompanied by reduced pulmonary vascular remodeling. In vitro study further confirmed that GRK2 knock-down significantly altered hypoxia-induced PASMCs proliferation and migration, whereas this effect was severely intensified by overexpression of GRK2. We also identified that GRK2 promoted YAP expression and nuclear translocation in PASMCs, resulting in excessive PASMCs proliferation and migration. Furthermore, GRK2 is stabilized by inhibiting phosphorylating GRK2 on Tyr86 and subsequently activating ubiquitylation under hypoxic conditions. Conclusion::Our findings suggest that GRK2 plays a critical role in the pathogenesis of PAH, via regulating YAP expression and nuclear translocation. Therefore, GRK2 serves as a novel therapeutic target for PAH treatment.

Objective    To analyze the influencing factors for re-positive nucleic acid test in discharged corona-virus disease 2019 (COVID-19) patients in Chengdu, Sichuan Province, and to provide data support for the epidemics prevention and control. Methods    The clinical data of 660 discharged COVID-19 patients from January 23, 2020 to February 28, 2021 in our center were retrospectively analyzed. The patients were divided into two groups according to the reexamination of virus nucleic acid, including a negative group [549 patients, including 428 males and 121 females with a median age of 33.0 (28.0, 48.0) years] and a positive group [111 patients, including 76 males and 35 females with a median age of 39.0 (28.0, 51.0) years]. The clinical data of the two groups were compared. Results     The re-positive rate of the discharged patients was 16.82%. Univariate analysis showed that the re-positive rate of females was higher than that of males (χ2=4.608, P=0.032). The re-positive rate of confirmed patients was higher than that of asymptomatic infected patients (χ2=8.140, P=0.004). The re-positive rate of domestic patients was higher than that of imported patients (χ2=9.178, P=0.002). The counts of CD3+ (P=0.038), CD4+ (P=0.048) and CD8+ (P=0.040) T lymphocytes in the negative group were higher than those in the positive group. The binary logistic regression analysis showed that the clinical classification and CD8+ T lymphocyte count were independent risk factors affecting the recurrence of virility. Conclusion    The gender, origin, T lymphocyte subsets count and clinical type are the influencing factors for re-positive result, and clinical type and CD8+ T lymphocyte count are the independent influencing factors for re-positive result. Therefore, improving the immunity of infected patients, as well as early detection and timely treatment are effective means to reduce the re-positive occurrence.

ObjectiveTo determine the influence of COVID-19 prevention and control on the epidemic characteristics and dynamics of notifiable infectious diseases in the first quarters， Zhejiang Province， and to explore more effective countermeasures against infectious diseases. MethodsDescriptive epidemiology was conducted to determine the change in notifiable infectious diseases during the prevention and control of COVID-19 in Zhejiang Province by retrieving the data of notifiable infectious diseases from 2017 to 2022 in the Chinese information system for disease control and prevention. Cumulative reported new cases of notifiable infectious diseases in the first quarters of 2017‒2019 were compared with that of 2020‒2022. ResultsA total of 546 753 cases of notifiable infectious diseases were newly reported in the first quarters of 2017‒2019， with an average incidence of 321.92/10⁵. In contrast， a total of 509 908 cases of notifiable infectious diseases were newly reported in the first quarters of 2020‒2022， during which the COVID-19 epidemic occurred， with an average incidence of 270.39/10⁵. The incidence in 2020‒2022 significantly declined by 51.53/10⁵， compared with that in 2017‒2019 （χ²=8 072.06， P<0.001）. In the first quarters of 2020‒2022， the average incidence of zoonotic diseases and vector-borne diseases decreased by more than 50%. In addition， the incidence of respiratory， enteric， blood-borne， and sexually transmitted diseases declined to certain degree. ConclusionThe decline in the newly reported cases of non-COVID-19 notifiable infectious diseases in the first quarters of 2020‒2022 indicates that the countermeasures against COVID-19 epidemic， such as multi-disease co-prevention， multi-sectoral collaboration， societal mobilization and personal hygiene and protection， may also decrease the incidence of multiple infectious diseases. It suggests the countermeasures are effective， which would provide evidence for routine prevention and control of infectious diseases in future.

OBJECTIVES: To explore the cytotoxicity of four wild mushrooms involved in a case of Yunnan sudden unexplained death (YNSUD), to provide the experimental basis for prevention and treatment of YNSUD. METHODS: Four kinds of wild mushrooms that were eaten by family members in this YNSUD incident were collected and identified by expert identification and gene sequencing. Raw extracts from four wild mushrooms were extracted by ultrasonic extraction to intervene HEK293 cells, and the mushrooms with obvious cytotoxicity were screened by Cell Counting Kit-8 (CCK-8). The selected wild mushrooms were prepared into three kinds of extracts, which were raw, boiled, and boiled followed by enzymolysis. HEK293 cells were intervened with these three extracts at different concentrations. The cytotoxicity was detected by CCK-8 combined with lactate dehydrogenase (LDH) Assay Kit, and the morphological changes of HEK293 cells were observed under an inverted phase contrast microscope. RESULTS: Species identification indicated that the four wild mushrooms were Butyriboletus roseoflavus, Boletus edulis, Russula virescens and Amanita manginiana. Cytotoxicity was found only in Amanita manginiana. The raw extracts showed cytotoxicity at the mass concentration of 0.1 mg/mL, while the boiled extracts and the boiled followed by enzymolysis extracts showed obvious cytotoxicity at the mass concentration of 0.4 mg/mL and 0.7 mg/mL, respectively. In addition to the obvious decrease in the number of HEK293 cells, the number of synapses increased and the refraction of HEK293 cells was poor after the intervention of Amanita manginiana extracts. CONCLUSIONS The extracts of Amanita manginiana involved in this YNSUD case has obvious cytotoxicity, and some of its toxicity can be reduced by boiled and enzymolysis, but cannot be completely detoxicated. Therefore, the consumption of Amanita manginiana is potentially dangerous, and it may be one of the causes of the YNSUD.
Humans ; HEK293 Cells ; Sincalide ; China ; Amanita ; Death, Sudden