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.

Diterpenoid ferruginol is a key intermediate in biosynthesis of active ingredients such as tanshinone and carnosic acid.However, the traditional process of obtaining ferruginol from plants is often cumbersome and inefficient. In recent years, the increasingly developing gene editing technology has been gradually applied to the heterologous production of natural products, but the production of ferruginol in microbe is still very low, which has become an obstacle to the efficient biosynthesis of downstream chemicals, such as tanshinone. In this study, miltiradiene was produced by integrating the shortened diterpene synthase fusion protein,and the key genes in the MVA pathway were overexpressed to improve the yield of miltiradiene. Under the shake flask fermentation condition, the yield of miltiradiene reached about(113. 12±17. 4)mg·L~(-1). Subsequently, this study integrated the ferruginol synthase Sm CYP76AH1 and Sm CPR1 to reconstruct the ferruginol pathway and thereby realized the heterologous synthesis of ferruginol in Saccharomyces cerevisiae. The study selected the best ferruginol synthase(Il CYP76AH46) from different plants and optimized the expression of pathway genes through redox partner engineering to increase the yield of ferruginol. By increasing the copy number of diterpene synthase, CYP450, and CPR, the yield of ferruginol reached(370. 39± 21. 65) mg·L~(-1) in the shake flask, which was increased by 21. 57-fold compared with that when the initial ferruginol strain JMLT05 was used. Finally, 1 083. 51 mg·L~(-1) ferruginol was obtained by fed-batch fermentation, which is the highest yield of ferruginol from biosynthesis so far. This study provides not only research ideas for other metabolic engineering but also a platform for the construction of cell factories for downstream products.
Saccharomyces cerevisiae/genetics* ; Diterpenes/metabolism* ; Metabolic Engineering ; Fermentation ; Abietanes

Mutations in myosin heavy chain 7(MYH7)and myosin binding protein C3(MYBPC3)genes encoding thick filaments are the main cause of hypertrophic cardiomyopathy(HCM),while a small part of HCM is caused by mutations of troponin C1,slow skeletal and cardiac type(TNNC1),troponin T2,cardiac type(TNNT2),troponin I3,cardiac type(TNNI3),actin alpha cardiac muscle 1(ACTC1),and tropomyosin 1(TPM1)genes encoding thin filaments.In this review,we mainly introduce the detailed mechanism and research status of HCM caused by mutations of the gene encoding cardiomyocyte sarcomere in the past few years,in order to provide reference for further study of the pathogenesis and treatment of HCM.

Objective To investigate the improvement effect and mechanism of marmesin on cognitive impairment in Alzheimer's disease(AD)mice.Methods Fifty mice were randomly divided into five groups:blank group,model group,low-and high-dose marmesin groups and donepezil(positive drug)group,with 10 mice in each group.After 21 days of continuous administration,except for the blank group,the mice in other groups were given intraperitoneal injection of scopolamine to establish the AD model.Network pharmacology was used to construct the protein-protein interaction(PPI)network of common targets of marmesin in the treatment of AD,and gene ontology(GO)and Kyoto Encyclopedia of Genes and Genomes(KEGG)enrichment analysis were performed to provide further research direction.The cognitive function of AD model mice was evaluated by Morris water maze,open field test and new object recognition test.Nissl staining was used to observe the damage of hippocampal neurons.The levels of acetylcholine(Ach),acetylcholine transferase(ChAT),acetylcholinesterase(AChE),reactive oxygen species(ROS),malondialdehyde(MDA)and catalase(CAT)in hippocampus of mice were detected by kit.The protein expression levels of interleukin 6(IL-6),interleukin 1β(IL-1 β),tumor necrosis factor α(TNF-α),nuclear factor E2-related factor 2(NRF2),silent information regulator homologous protein 3(SIRT3),Kelch-like ECH-associated protein 1(KEAP1),quinone oxidoreductase 1(NQO1)and heme oxygenase 1(HO-1)in hippocampus were detected by Western Blot.Results Compared with the model group,the latency of Morris water maze test was significantly shortened in the high-dose marmesin group,the time of entering the target area in the open field new object test and the movement distance in the central area of the open field were prolonged,the number of neurons in the hippocampal CA1 and CA3 regions was significantly increased,the levels of ChAT and Ach in the hippocampus were significantly increased,AChE level was significantly decreased,CAT level was significantly increased,ROS and MDA levels were significantly decreased,TNF-α expression level was decreased,SIRT3 and HO-1 expression levels were increased,and KE AP1 protein expression level was decreased,the differences being statistically significant(P＜0.05 or P＜0.01 or P＜0.001).Conclusion Marmesin can effectively improve the learning and memory impairment of AD mice,and its mechanism may be related to the activation of NRF2/SIRT3 signaling pathway,thereby alleviating oxidative stress level and neuroinflammation,and repairing cholinergic neuron function.

Objective Viral encephalitis is an infectious disease severely affecting human health.It is caused by a wide variety of viral pathogens,including herpes viruses,flaviviruses,enteroviruses,and other viruses.The laboratory diagnosis of viral encephalitis is a worldwide challenge.Recently,high-throughput sequencing technology has provided new tools for diagnosing central nervous system infections.Thus,In this study,we established a multipathogen detection platform for viral encephalitis based on amplicon sequencing. Methods We designed nine pairs of specific polymerase chain reaction(PCR)primers for the 12 viruses by reviewing the relevant literature.The detection ability of the primers was verified by software simulation and the detection of known positive samples.Amplicon sequencing was used to validate the samples,and consistency was compared with Sanger sequencing. Results The results showed that the target sequences of various pathogens were obtained at a coverage depth level greater than 20×,and the sequence lengths were consistent with the sizes of the predicted amplicons.The sequences were verified using the National Center for Biotechnology Information BLAST,and all results were consistent with the results of Sanger sequencing. Conclusion Amplicon-based high-throughput sequencing technology is feasible as a supplementary method for the pathogenic detection of viral encephalitis.It is also a useful tool for the high-volume screening of clinical samples.

Background/Aims: Despite the high efficacy of direct-acting antivirals (DAAs), approximately 1–3% of hepatitis C virus (HCV) patients fail to achieve a sustained virological response. We conducted a nationwide study to investigate risk factors associated with DAA treatment failure. Machine-learning algorithms have been applied to discriminate subjects who may fail to respond to DAA therapy. Methods: We analyzed the Taiwan HCV Registry Program database to explore predictors of DAA failure in HCV patients. Fifty-five host and virological features were assessed using multivariate logistic regression, decision tree, random forest, eXtreme Gradient Boosting (XGBoost), and artificial neural network. The primary outcome was undetectable HCV RNA at 12 weeks after the end of treatment. Results: The training (n=23,955) and validation (n=10,346) datasets had similar baseline demographics, with an overall DAA failure rate of 1.6% (n=538). Multivariate logistic regression analysis revealed that liver cirrhosis, hepatocellular carcinoma, poor DAA adherence, and higher hemoglobin A1c were significantly associated with virological failure. XGBoost outperformed the other algorithms and logistic regression models, with an area under the receiver operating characteristic curve of 1.000 in the training dataset and 0.803 in the validation dataset. The top five predictors of treatment failure were HCV RNA, body mass index, α-fetoprotein, platelets, and FIB-4 index. The accuracy, sensitivity, specificity, positive predictive value, and negative predictive value of the XGBoost model (cutoff value=0.5) were 99.5%, 69.7%, 99.9%, 97.4%, and 99.5%, respectively, for the entire dataset. Conclusions Machine learning algorithms effectively provide risk stratification for DAA failure and additional information on the factors associated with DAA failure.

OBJECTIVE: To evaluate the effectiveness and safety of Chinese medicine (CM) in the treatment of coronavirus disease 2019 (COVID-19) in China. METHODS: A multi-center retrospective cohort study was carried out, with cumulative CM treatment period of ⩾3 days during hospitalization as exposure. Data came from consecutive inpatients from December 19, 2019 to May 16, 2020 in 4 medical centers in Wuhan, China. After data extraction, verification and cleaning, confounding factors were adjusted by inverse probability of treatment weighting (IPTW), and the Cox proportional hazards regression model was used for statistical analysis. RESULTS: A total of 2,272 COVID-19 patients were included. There were 1,684 patients in the CM group and 588 patients in the control group. Compared with the control group, the hazard ratio (HR) for the deterioration rate in the CM group was 0.52 [95% confidence interval (CI): 0.41 to 0.64, P<0.001]. The results were consistent across patients of varying severity at admission, and the robustness of the results were confirmed by 3 sensitivity analyses. In addition, the HR for all-cause mortality in the CM group was 0.29 (95% CI: 0.19 to 0.44, P<0.001). Regarding of safety, the proportion of patients with abnormal liver function or renal function in the CM group was smaller. CONCLUSION This real-world study indicates that the combination of a full-course CM therapy on the basic conventional treatment, may safely reduce the deterioration rate and all-cause mortality of COVID-19 patients. This result can provide the new evidence to support the current treatment of COVID-19. Additional prospective clinical trial is needed to evaluate the efficacy and safety of specific CM interventions. (Registration No. ChiCTR2200062917).
Humans ; Retrospective Studies ; Male ; Female ; Middle Aged ; COVID-19/epidemiology* ; COVID-19 Drug Treatment ; Aged ; Medicine, Chinese Traditional/methods* ; Drugs, Chinese Herbal/adverse effects* ; SARS-CoV-2 ; Treatment Outcome ; China/epidemiology* ; Adult

As an important model animal, fruit fly is characterized by outstanding genetic characteristics, relatively perfect nervous system, rapid reproduction, and low cost. Thus, it has been applied in the research on neuropsychiatric disorders in recent years, showing great potential in life science. The incidence of neuropsychiatric disorders has been on the rise, and the disorders have high disability rate and low case fatality rate. The global drug demand for such diseases is second only to cardiovascular and cerebrovascular diseases. At the moment, the demand of the drugs for the diseases have been rising, and it is an urgent task to develop related drugs. However, the research and development of the drugs are time-intensive and have a high failure rate. A suitable animal model can help shorten the time for drug screening and development, thereby reducing the cost and failure rate. This study reviews the application of fruit flies in several common neuropsychiatric disorders, which is expected to provide new ideas for the research and application of the model animals in traditional Chinese medicine.
Animals ; Medicine, Chinese Traditional ; Drugs, Chinese Herbal/therapeutic use* ; Models, Animal ; Cerebrovascular Disorders

OBJECTIVES: To investigate the risk factors for neonatal asphyxia in Hubei Enshi Tujia and Miao Autonomous Prefecture and establish a nomogram model for predicting the risk of neonatal asphyxia. METHODS: A retrospective study was conducted with 613 cases of neonatal asphyxia treated in 20 cooperative hospitals in Enshi Tujia and Miao Autonomous Prefecture from January to December 2019 as the asphyxia group, and 988 randomly selected non-asphyxia neonates born and admitted to the neonatology department of these hospitals during the same period as the control group. Univariate and multivariate analyses were used to identify risk factors for neonatal asphyxia. R software (4.2.2) was used to establish a nomogram model. Receiver operator characteristic curve, calibration curve, and decision curve analysis were used to assess the discrimination, calibration, and clinical usefulness of the model for predicting the risk of neonatal asphyxia, respectively. RESULTS: Multivariate logistic regression analysis showed that minority (Tujia), male sex, premature birth, congenital malformations, abnormal fetal position, intrauterine distress, maternal occupation as a farmer, education level below high school, fewer than 9 prenatal check-ups, threatened abortion, abnormal umbilical cord, abnormal amniotic fluid, placenta previa, abruptio placentae, emergency caesarean section, and assisted delivery were independent risk factors for neonatal asphyxia (P<0.05). The area under the curve of the model for predicting the risk of neonatal asphyxia based on these risk factors was 0.748 (95%CI: 0.723-0.772). The calibration curve indicated high accuracy of the model for predicting the risk of neonatal asphyxia. The decision curve analysis showed that the model could provide a higher net benefit for neonates at risk of asphyxia. CONCLUSIONS The risk factors for neonatal asphyxia in Hubei Enshi Tujia and Miao Autonomous Prefecture are multifactorial, and the nomogram model based on these factors has good value in predicting the risk of neonatal asphyxia, which can help clinicians identify neonates at high risk of asphyxia early, and reduce the incidence of neonatal asphyxia.
Infant, Newborn ; Humans ; Male ; Pregnancy ; Female ; Nomograms ; Retrospective Studies ; Cesarean Section ; Risk Factors ; Asphyxia Neonatorum/etiology*

Objective To observe the effect of calcified lymph nodes on video-assisted thoracoscopic surgery (VATS) lobectomy in the chronic obstructive pulmonary disease (COPD) patients with lung cancer. Methods A retrospective analysis was conducted on the COPD patients with lung cancer who underwent VATS lobectomy in the Department of Thoracic Surgery in the First Affiliated Hospital of Hebei North University from May 2014 to May 2018.The patients were assigned into a calcified lymph node group and a control group according to the presence or absence of calcified lymph nodes in CT,and the size,morphology,and calcification degree of the lymph nodes were recorded.The operation duration,intraoperative blood loss,chest tube retention time,hospitalization days,and overall complication rate were compared between the two groups. Results The 30 patients in the calcified lymph node group included 17 patients with one calcified lymph node and 13 patients with two or more calcified lymph nodes,and a total of 65 calcified lymph nodes were recorded.The calcified lymph nodes with the size ≤5 mm were the most common (53.8%),and complete calcification was the most common form (55.4%) in lymph node calcification.The mean operation duration had no significant difference between the calcified lymph node group and the control group (t=-1.357,P=0.180).The intraoperative blood loss (t=-2.646,P=0.010),chest tube retention time (t=-2.302,P=0.025),and hospitalization days (t=-2.274,P=0.027) in the calcified lymph node group were higher than those in the control group. Conclusion Calcified lymph nodes increase the difficulty and risk of VATS lobectomy in the COPD patients with lung cancer.The findings of this study are conducive to predicting the perioperative process of VATS lobectomy.
Humans ; Blood Loss, Surgical ; Retrospective Studies ; Lung Neoplasms/surgery* ; Pulmonary Disease, Chronic Obstructive ; Calcinosis ; Lymph Nodes