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.

Bacterial biofilms gave rise to persistent infections and multi-organ failure, thereby posing a serious threat to human health. Biofilms were formed by cross-linking of hydrophobic extracellular polymeric substances (EPS), such as proteins, polysaccharides, and eDNA, which were synthesized by bacteria themselves after adhesion and colonization on biological surfaces. They had the characteristics of dense structure, high adhesiveness and low drug permeability, and had been found in many human organs or tissues, such as the brain, heart, liver, spleen, lungs, kidneys, gastrointestinal tract, and skeleton. By releasing pro-inflammatory bacterial metabolites including endotoxins, exotoxins and interleukin, biofilms stimulated the body’s immune system to secrete inflammatory factors. These factors triggered local inflammation and chronic infections. Those were the key reason for the failure of traditional clinical drug therapy for infectious diseases.In order to cope with the increasingly severe drug-resistant infections, it was urgent to develop new therapeutic strategies for bacterial-biofilm eradication and anti-bacterial infections. Based on the nanoscale structure and biocompatible activity, nanobiomaterials had the advantages of specific targeting, intelligent delivery, high drug loading and low toxicity, which could realize efficient intervention and precise treatment of drug-resistant bacterial biofilms. This paper highlighted multiple strategies of biofilms eradication based on nanobiomaterials. For example, nanobiomaterials combined with EPS degrading enzymes could be used for targeted hydrolysis of bacterial biofilms, and effectively increased the drug enrichment within biofilms. By loading quorum sensing inhibitors, nanotechnology was also an effective strategy for eradicating bacterial biofilms and recovering the infectious symptoms. Nanobiomaterials could intervene the bacterial metabolism and break the bacterial survival homeostasis by blocking the uptake of nutrients. Moreover, energy-driven micro-nano robotics had shown excellent performance in active delivery and biofilm eradication. Micro-nano robots could penetrate physiological barriers by exogenous or endogenous driving modes such as by biological or chemical methods, ultrasound, and magnetic field, and deliver drugs to the infection sites accurately. Achieving this using conventional drugs was difficult. Overall, the paper described the biological properties and drug-resistant molecular mechanisms of bacterial biofilms, and highlighted therapeutic strategies from different perspectives by nanobiomaterials, such as dispersing bacterial mature biofilms, blocking quorum sensing, inhibiting bacterial metabolism, and energy driving penetration. In addition, we presented the key challenges still faced by nanobiomaterials in combating bacterial biofilm infections. Firstly, the dense structure of EPS caused biofilms spatial heterogeneity and metabolic heterogeneity, which created exacting requirements for the design, construction and preparation process of nanobiomaterials. Secondly, biofilm disruption carried the risk of spread and infection the pathogenic bacteria, which might lead to other infections. Finally, we emphasized the role of nanobiomaterials in the development trends and translational prospects in biofilm treatment.

ObjectiveDirect continuous monitoring of arterial blood pressure is invasive and continuous monitoring cannot be achieved by traditional cuffed indirect blood pressure measurement methods. Previously, continuous non-invasive arterial blood pressure monitoring was achieved by using photoplethysmography (PPG), but it is discrete values of systolic and diastolic blood pressures rather than continuous values constructing arterial blood pressure waves. This study aimed to reconstruct arterial blood pressure wave signal based on CNN-LSTM using PPG to achieve continuous non-invasive arterial blood pressure monitoring. MethodsA CNN-LSTM hybrid neural network model was constructed, and the PPG and arterial blood pressure wave synchronized recorded signal data from the Medical Information Mart for Intensive Care (MIMIC) were used. The PPG signals were input to this model after noise reduction, normalization, and sliding window segmentation. The corresponding arterial blood pressure waves were reconstructed from PPG by using the CNN-LSTM hybrid model. ResultsWhen using the CNN-LSTM neural network with a window length of 312, the error between the reconstructed arterial blood pressure values and the actual arterial blood pressure values was minimal: the values of mean absolute error (MAE) and root mean square error (RMSE) were 2.79 mmHg and 4.24 mmHg, respectively, and the cosine similarity is the optimal. The reconstructed arterial blood pressure values were highly correlated with the actual arterial blood pressure values, which met the Association for the Advancement of Medical Instrumentation (AAMI) standards. ConclusionCNN-LSTM hybrid neural network can reconstruct arterial blood pressure wave signal using PPG to achieve continuous non-invasive arterial blood pressure monitoring.

Objective To compare the application value of three image post-processing techniques volume rendering(VR),multiplanar reformation(MPR)and curved planar reformation(CPR)in the identifi-cation of rib fracture malunion.Methods The types and numbers of rib fracture malunion in 75 pa-tients were recorded,and the sensitivity,specificity,accuracy and Youden index of VR,MPR and CPR in the diagnosis of rib fracture malunion were compared.Receiver operator characteristic(ROC)curve was drawn and area under the curve(AUC)was calculated,and the detection rates of three image post-processing techniques for different types of rib fracture malunion were compared.Results A total of 243 rib fractures were malunion in 75 patients.The diagnostic sensitivity of VR,MPR and CPR for rib fracture malunion was 52.67%,79.84%and 91.36%,the specificity was 99.58%,97.89%and 99.15%,the accuracy was 83.66%,91.76%and 96.51%,the Youden index was 0.52,0.78 and 0.91,the AUC was 0.761,0.889 and 0.953,respectively.Compared with VR,there were statistically signifi-cant differences in the number of broken rib end misalignment over 1/3,broken rib end overlap,bro-ken rib end angulation and intercostal bridge detected in MPR(P<0.05).Compared with VR,there was a statistically significant difference in the number of different types of rib fracture malunion de-tected by CPR(P<0.05).Compared with MPR,there were statistically significant differences in the number of broken rib end misalignment over 1/3,broken rib end separation and intercostal bridge de-tected in CPR(P<0.05).Conclusion The three image post-processing techniques are of great signifi-cance for the identification of rib fracture malunion.Especially CPR is highly effective in the diagno-sis of rib fracture malunion,and can be used as the main post-processing technique for forensic clini-cal identification of rib fracture malunion.

Objective:To screen interleukin(IL)-1β secretion-related membrane transporters by macrophage experiment in vitro and conventional knockout mice.Methods:THP-1 cell line was differentiated to obtain human THP-1-derived macrophages,and the primary macrophages were obtained from human peripheral blood.FVB wild-type mice with the same sex and age were used as the controls of MRP1 knockout mice.The macrophages in abdominal cavity and bone marrow of mice were cultivated.The cells were treated with ABCC1/MRP1,ABCG2/BCRP,ABCB1/P-gp,OATP1B1,and MATE transporter inhibitors,then stimulated by lipopolysaccharide and adenosine triphosphate.The secretion level of IL-iβ was detected by ELISA,Western blot,and immunofluorescence.Results:After inhibiting ABCC1/MRP1 transporter,the secretion of IL-1β decreased significantly,while inhibition of the other 4 transporters had no effect.In animal experiment,the level of IL-1 β secreted by macrophages in bone marrow of MRP1 knockout mice was significantly lower than control group(P＜0.05).Conclusion:ABCC1/MRP1 transporter is a newly discovered IL-1β secretion pathway,which is expected to become a new target for solving clinical problems such as cytokine release syndrome.

Anti-Bacterial Agents ; Titanium

AIM:To investigate the mechanism of curcumin inhibiting the choroidal neovascularization(CNV)of brown Norway(BN)rats.METHODS: CNV model of 36 BN rats was established through laser photocoagulation induction, and they were divided into 6 groups with 6 rats in each group. Normal group was fed normally with no intervention, while 532nm laser photocoagulation was used to establish a experimental CNV model in BN rats. Rats after modeling were respectively intervened for 14d and divided into model group, ranibizumab group, curcumin low [100mg/(kg·d)], medium [200mg/(kg·d)], and high [400mg/(kg·d)] dose group. The model group was given intragastric administration of saline for 14d, ranibizumab(10mg/mL, 0.2mL/dose)was injected at 2d after photocoagulation with 5μL once for rats in ranibizumab group, and different concentrations of curcumin were intragastrically administrated to the rats in low, medium and high groups for 14d. Fundus photography, fundus fluorescein angiography(FFA)and indocyanine green angiography(ICGA)examination were performed at 14d after photocoagulation. Ocular histopathological specimens of rats with CNV were made, and the central thickness of CNV were observed by HE staining. Ocular histopathological specimens were made, and the expressions of AKT/p-AKT/HIF-1α/VEGF signaling pathway-related proteins were observed by immunohistochemistry. The mRNA relative expressions of AKT/HIF-1α/VEGF factor in CNV tissues were detected by RT-qPCR, and the protein expressions of AKT/p-AKT/HIF-1α/VEGF factor in CNV tissues were detected by Western-blot.RESULTS: CNV generation rates in the model group, the ranibizumab group, and the low, medium and high-dose curcumin groups were 78.18%, 73.21%, 77.19%, 75.86%, 74.55%, respectively, which were higher than 70%. The average absorbance were 182.12±6.59, 119.22±8.03, 166.45±8.33, 164.34±5.69, 149.22±6.45, respectively; the ranibizumab group was significantly lower than the model group(P<0.05); the low-dose, medium-dose and high-dose groups were significantly higher than the ranibizumab group(P<0.05), and the curcumin high-dose group was significantly lower than the model group(P<0.05). HE staining showed that the retinal tissue structure of BN rats in normal group was clear and neatly arranged. The central thickness of CNV in the ranibizumab group was significantly reduced at 14d after photocoagulation compared with the model group(P<0.05); While the curcumin high-dose group was significantly reduced compared with the model group(P<0.05), but increased when compared with ranibizumab group(P<0.05). Immunohistochemistry results showed that AKT, p-AKT, HIF-1α, and VEGF factors were negatively expressed in the retinal tissue structure of BN rats in the normal group, and no brown-yellow reactants were found. The expression of AKT, p-AKT, HIF-1α, and VEGF factors in the model group were higher than that in the normal group at 14d after photocoagulation(P<0.05); the ranibizumab group was lower than the model group(P<0.05). While the expression of the curcumin high-dose group was significantly decreased compared with the model group(P<0.05), but significantly increased when compared with ranibizumab group(P<0.05). The mRNA results showed that the relative expression levels of AKT, HIF-1α and VEGF mRNA in the model group at 14d after photocoagulation were higher than those of the normal group(P<0.05); the ranibizumab group was lower than the model group(P<0.05). While curcumin high-dose group was significantly decreased compared with the model group(P<0.05), but significantly increased when compared with ranibizumab group(P<0.05). Western-blot results showed that there was no significant difference in the relative expression of AKT protein among each experimental groups at 14d after photocoagulation. The relative expression of p-AKT protein in the model group was significantly higher than that in the normal group(P<0.05); the ranibizumab group was significantly lower than the model group(P<0.05); the curcumin high-dose group was significantly lower than the model group(P<0.05). The relative expression levels of HIF-1α protein were significantly higher in the model group than in the normal group(P<0.05), and the ranibizumab group was lower than in the model group(P<0.05). The relative expression levels of HIF-1α protein was lower in the curcumin high-dose group than in the model group(P<0.05)but higher than ranibizumab group(P<0.05). The relative expression level of VEGF protein was significantly lower in the curcumin medium/high-dose group than in the model group(P<0.05).CONCLUSION: Curcumin at 400mg/(kg·d)has an inhibitory effect on CNV in BN rats. The mechanism may be closely related to inhibiting the activation of AKT/p-AKT/HIF-1α/VEGF signaling pathways.

Defensive behaviors induced by innate fear or Pavlovian fear conditioning are crucial for animals to avoid threats and ensure survival. The zona incerta (ZI) has been demonstrated to play important roles in fear learning and fear memory, as well as modulating auditory-induced innate defensive behavior. However, whether the neuronal subtypes in the ZI and specific circuits can mediate the innate fear response is largely unknown. Here, we found that somatostatin (SST)-positive neurons in the rostral ZI of mice were activated by a visual innate fear stimulus. Optogenetic inhibition of SST-positive neurons in the rostral ZI resulted in reduced flight responses to an overhead looming stimulus. Optogenetic activation of SST-positive neurons in the rostral ZI induced fear-like defensive behavior including increased immobility and bradycardia. In addition, we demonstrated that manipulation of the GABAergic projections from SST-positive neurons in the rostral ZI to the downstream nucleus reuniens (Re) mediated fear-like defensive behavior. Retrograde trans-synaptic tracing also revealed looming stimulus-activated neurons in the superior colliculus (SC) that projected to the Re-projecting SST-positive neurons in the rostral ZI (SC-ZIr^SST-Re pathway). Together, our study elucidates the function of SST-positive neurons in the rostral ZI and the SC-ZIr^SST-Re tri-synaptic circuit in mediating the innate fear response.
Mice ; Animals ; Zona Incerta/metabolism* ; Neurons/metabolism* ; Fear/physiology* ; Somatostatin/metabolism*

Objectives: To investigated the safety and efficacy of treating patients with acute non-ST-segment elevation myocardial infarction (NSTEMI) and elevated levels of N-terminal pro-hormone B-type natriuretic peptide (NT-proBNP) with levosimendan within 24 hours of first medical contact (FMC). Methods: This multicenter, open-label, block-randomized controlled trial (NCT03189901) investigated the safety and efficacy of levosimendan as an early management strategy of acute heart failure (EMS-AHF) for patients with NSTEMI and high NT-proBNP levels. This study included 255 patients with NSTEMI and elevated NT-proBNP levels, including 142 males and 113 females with a median age of 65 (58-70) years, and were admitted in the emergency or outpatient departments at 14 medical centers in China between October 2017 and October 2021. The patients were randomly divided into a levosimendan group (n=129) and a control group (n=126). The primary outcome measure was NT-proBNP levels on day 3 of treatment and changes in the NT-proBNP levels from baseline on day 5 after randomization. The secondary outcome measures included the proportion of patients with more than 30% reduction in NT-proBNP levels from baseline, major adverse cardiovascular events (MACE) during hospitalization and at 6 months after hospitalization, safety during the treatment, and health economics indices. The measurement data parameters between groups were compared using the t-test or the non-parametric test. The count data parameters were compared between groups using the χ² test. Results: On day 3, the NT-proBNP levels in the levosimendan group were lower than the control group but were statistically insignificant [866 (455, 1 960) vs. 1 118 (459, 2 417) ng/L, Z=-1.25,P=0.21]. However, on day 5, changes in the NT-proBNP levels from baseline in the levosimendan group were significantly higher than the control group [67.6% (33.8%,82.5%)vs.54.8% (7.3%,77.9%), Z=-2.14, P=0.03]. There were no significant differences in the proportion of patients with more than 30% reduction in the NT-proBNP levels on day 5 between the levosimendan and the control groups [77.5% (100/129) vs. 69.0% (87/126), χ²=2.34, P=0.13]. Furthermore, incidences of MACE did not show any significant differences between the two groups during hospitalization [4.7% (6/129) vs. 7.1% (9/126), χ²=0.72, P=0.40] and at 6 months [14.7% (19/129) vs. 12.7% (16/126), χ²=0.22, P=0.64]. Four cardiac deaths were reported in the control group during hospitalization [0 (0/129) vs. 3.2% (4/126), P=0.06]. However, 6-month survival rates were comparable between the two groups (log-rank test, P=0.18). Moreover, adverse events or serious adverse events such as shock, ventricular fibrillation, and ventricular tachycardia were not reported in both the groups during levosimendan treatment (days 0-1). The total cost of hospitalization [34 591.00(15 527.46,59 324.80) vs. 37 144.65(16 066.90,63 919.00)yuan, Z=-0.26, P=0.80] and the total length of hospitalization [9 (8, 12) vs. 10 (7, 13) days, Z=0.72, P=0.72] were lower for patients in the levosimendan group compared to those in the control group, but did not show statistically significant differences. Conclusions: Early administration of levosimendan reduced NT-proBNP levels in NSTEMI patients with elevated NT-proBNP and did not increase the total cost and length of hospitalization, but did not significantly improve MACE during hospitalization or at 6 months.
Male ; Female ; Humans ; Aged ; Natriuretic Peptide, Brain ; Simendan/therapeutic use* ; Non-ST Elevated Myocardial Infarction ; Heart Failure/drug therapy* ; Peptide Fragments ; Arrhythmias, Cardiac ; Biomarkers ; Prognosis

OBJECTIVES: To study the changes in cell free-DNA (cf-DNA), a marker of neutrophil extracellular traps (NETs), in neonates with acute respiratory distress syndrome (ARDS), and to evaluate its relationship with the severity and early diagnosis of ARDS. METHODS: The neonates diagnosed with ARDS in the Affiliated Hospital of Jiangsu University from January 2021 to June 2022 were enrolled in the prospective study. The neonates were divided into mild, moderate, and severe ARDS groups based on the oxygen index (OI) (4≤OI<8, 8≤OI<16, and OI≥16, respectively). The control group was selected from jaundice neonates who were observed in the neonatal department of the hospital during the same period, and they had no pathological factors causing neonatal jaundice. Peripheral blood samples were collected on day 1, day 3, and day 7 after admission for the ARDS group, and on the day of admission for the control group. Serum cf-DNA levels were measured using a fluorescence enzyme-linked immunosorbent assay. Serum interleukin-6 (IL-6) and tumor necrosis factor-α (TNF-α) levels were measured using enzyme-linked immunosorbent assay. A Pearson correlation analysis was used to evaluate the correlation of serum cf-DNA levels with serum IL-6 and TNF-α levels. RESULTS: A total of 50 neonates were enrolled in the ARDS group, including 15 neonates with mild ARDS, 25 with moderate ARDS, and 10 with severe ARDS. Twenty-five neonates were enrolled in the control group. Compared with the control group, the serum levels of cf-DNA, IL-6, and TNF-α in all ARDS groups were significantly increased (P<0.05). Compared with the mild ARDS group, the serum levels of cf-DNA, IL-6, and TNF-α in the moderate and severe ARDS groups were significantly increased (P<0.05), and the increase was more significant in the severe ARDS group (P<0.05). The serum levels of cf-DNA, IL-6, and TNF-α in all ARDS groups were significantly increased on day 3 after admission and significantly decreased on day 7 after admission compared with those on day 1 after admission (P<0.05). The Pearson correlation analysis showed that there was a positive correlation between serum cf-DNA levels and IL-6 levels as well as TNF-α levels in 50 neonates with ARDS (P<0.05). CONCLUSIONS There is an excessive expression of NETs in neonates with ARDS, and dynamic monitoring of serum cf-DNA levels has certain clinical value in evaluating the severity and early diagnosis of ARDS in neonates.
Infant, Newborn ; Humans ; Extracellular Traps ; Prospective Studies ; Tumor Necrosis Factor-alpha ; Interleukin-6 ; Prognosis ; ROC Curve ; Respiratory Distress Syndrome ; DNA