Microgel-based carriers enhance skeletal stem cell reprogramming towards immunomodulatory phenotype in osteoarthritic therapy.

Skeletal stem cells (SSC) have gained attentions as candidates for the treatment of osteoarthritis due to their osteochondrogenic capacity. However, the immunomodulatory properties of SSC, especially under delivery operations, have been largely ignored. In the study, we found that Pdpn+ and Grem1+ SSC subpopulations owned immunoregulatory potential, and the single-cell RNA sequencing (scRNA-seq) data suggested that the mechanical activation of microgel carriers on SSC induced the generation of Pdpn+Grem1+Ptgs2+ SSC subpopulation, which was potent at suppressing macrophage inflammation. The microgel carriers promoted the YAP nuclear translocation, and the activated YAP protein was necessary for the increased expression of Ptgs2 and PGE2 in microgels-delivered SSC, which further suppressed the expression of TNF-ɑ, IL-1ß and promoted the expression of IL-10 in macrophages. SSC delivered with microgels yielded better preventive effects on articular lesions and macrophage activation in osteoarthritic rats than SSC without microgels. Chemically blocking the YAP and Ptgs2 in microgels-delivered SSC partially abolished the enhanced protection on articular tissues and suppression on osteoarthritic macrophages. Moreover, microgel carriers significantly prolonged SSC retention time in vivo without increasing SSC implanting into osteoarthritic joints. Together, our study demonstrated that microgel carriers enhanced SSC reprogramming towards immunomodulatory phenotype to regulate macrophage phenotype transformation for effectively osteoarthritic therapy by promoting YAP protein translocation into nucleus. The study not only complement and perfect the immunological mechanisms of SSC-based therapy at the single-cell level, but also provide new insight for microgel carriers in stem cell-based therapy.

Evolution of prevalent H9N2 subtype of avian influenza virus during 2019 to 2022 for the development of a control strategy in China.

The H9N2 subtype of avian influenza virus (H9N2 AIV) has caused significant losses in chicken flocks throughout China. At present, consensus has been reached that field isolates of H9N2 underwent antigenic drift to evolve into distinct groups with significant antigenic divergence from the commercially available vaccines in China. This project continues to monitor the evolution characteristics of H9N2 hemagglutinin (HA) genes in China over the past 3 yr. The results showed that the current circling H9N2 viruses were diversified into h9.4.2.5 subclade, which was genetically distant from commonly used commercial vaccine strains. Compared with vaccine strains or 2014 strains, more than 42.1% of the variable antigenic sites in recent 3 yr' strains have shown significant changes and these stacked changes have caused significant differences in antigenicity. We constructed a recombinant vaccine strain rCQY-GHHA, which uses A/Chicken/China/SichuanCQY/2014 as the framework and A/Chicken/China/SichuanGH/2020 strain, which meets the recent viral antigenic characteristics, as the HA gene donor. The recombinant strain was prepared as an oil-adjuvant inactivated vaccine following an industrial process. The results of the immune protection experiment showed that the rCQY-GHHA vaccine was better than the commercial vaccine strain SS in reducing the morbidity, pathological lesion, virus shedding, and viral load. These results provide a reference for the control of H9N2 AIV in China.

Motion Decoupling Network for Intra-Operative Motion Estimation Under Occlusion.

In recent intelligent-robot-assisted surgery studies, an urgent issue is how to detect the motion of instruments and soft tissue accurately from intra-operative images. Although optical flow technology from computer vision is a powerful solution to the motion-tracking problem, it has difficulty obtaining the pixel-wise optical flow ground truth of real surgery videos for supervised learning. Thus, unsupervised learning methods are critical. However, current unsupervised methods face the challenge of heavy occlusion in the surgical scene. This paper proposes a novel unsupervised learning framework to estimate the motion from surgical images under occlusion. The framework consists of a Motion Decoupling Network to estimate the tissue and the instrument motion with different constraints. Notably, the network integrates a segmentation subnet that estimates the segmentation map of instruments in an unsupervised manner to obtain the occlusion region and improve the dual motion estimation. Additionally, a hybrid self-supervised strategy with occlusion completion is introduced to recover realistic vision clues. Extensive experiments on two surgical datasets show that the proposed method achieves accurate motion estimation for intra-operative scenes and outperforms other unsupervised methods, with a margin of 15% in accuracy. The average estimation error for tissue is less than 2.2 pixels on average for both surgical datasets.

Fast instruments and tissues segmentation of micro-neurosurgical scene using high correlative non-local network.

Surgical scene segmentation provides critical information for guidance in micro-neurosurgery. Segmentation of instruments and critical tissues contributes further to robot assisted surgery and surgical evaluation. However, due to the lack of relevant scene segmentation dataset, scale variation and local similarity, micro-neurosurgical segmentation faces many challenges. To address these issues, a high correlative non-local network (HCNNet), is proposed to aggregate multi-scale feature by optimized non-local mechanism. HCNNet adopts two-branch design to generate features of different scale efficiently, while the two branches share common weights in shallow layers. Several short-term dense concatenate (STDC) modules are combined as the backbone to capture both semantic and spatial information. Besides, a high correlative non-local module (HCNM) is designed to guide the upsampling process of the high-level feature by modeling global context generated from the low-level feature. It filters out confused pixels of different classes in the non-local correlation map. Meanwhile, a large segmentation dataset named NeuroSeg is constructed, which contains 15 types of instruments and 3 types of tissues that appear in meningioma resection surgery. The proposed HCNNet achieves the state-of-the-art performance on NeuroSeg, it reaches an inference speed of 54.85 FPS with the highest accuracy of 59.62% mIoU, 74.7% Dice, 70.55% mAcc and 87.12% aAcc.

Mutation of D201G near the receptor binding site significantly drives antigenic drift of circulating H9N2 subtype avian influenza virus.

The H9N2 subtype of avian influenza virus (H9N2 AIV) has caused significant losses in chicken flocks throughout China. Our previous research has shown that field isolates of H9N2 underwent antigenic drift to evolve into distinct groups with significant antigenic divergence from the commercially available vaccines. The present study sought to identify which single mutations that have naturally appeared in isolates from the past 5 years have driven antigenic drift. Six high-frequency mutation sites in/near the receptor binding site region were screened by comparing amino acid alignments of the H9N2 AIVs isolated from China between 2014 and 2019. Two substitutions (A168N and D201G) were demonstrated to have a significant impact on the antigenicity but did not change the growth kinetics of the virus. It is worth noting that the D201G substitution not only significantly changed the antigenicity but also caused immune escape against the parental virus. In conclusion, A168N and D201G substitution are newly discovered determinants that can significantly change the antigenicity of H9N2 AIV, which should be tracked during outbreaks.

Incorporating Personality Traits to Assess the Risk Level of Aberrant Driving Behaviors for Truck Drivers.

Economic globalization and the internet economy have resulted in a dramatic increase in freight transportation. Traffic crashes involving trucks usually result in severe losses and casualties. The fatality and injury rates for heavy truck accidents have been 10 times higher than for sedans in Taiwan in recent years. Thus, understanding driving behavior and risk are important for freight carriers. Since personality traits may result in different driving behaviors, the main objective of this study is to apply artificial neural network (ANN) models to predict the frequency of aberrant driving behavior and the risk level of each driver according to drivers' personality traits. In this case study, relevant information on truck drivers' personality traits and their tendency to engage in aberrant driving behavior are collected by using respectively a questionnaire and a fleet surveillance system from a truck company. A relative risk level evaluation mechanism is developed considering the frequency and distribution of aberrant driving behavior. The Jenks natural breaks optimization method and the elbow method are adopted to optimally classify 40 truck drivers into 4 aberrant driving behavior levels and 5 driving risk levels. It was found that 5% of drivers were at the highest aberrant driving behavior level, and 7.5% of drivers were at the highest driving risk level. Based on the results, the proposed models show good and stable predictive performance, especially for the class of drivers with excessive rotation speed, hard acceleration, excessive rotation speed, hard deceleration, and driving risk. With the proposed models, the predictive class for aberrant driving behavior and driving risk can be determined by plugging in a driver's personality traits before or after employment. Based on the prediction results, the manager of a transportation company could plan the training program for each driver to reduce the aberrant driving behavior occurrence.

Cycle ergometer and inspiratory muscle training offer modest benefit compared with cycle ergometer alone: a comprehensive assessment in stable COPD patients.

BACKGROUND: Cycle ergometer training (CET) has been shown to improve exercise performance of the quadriceps muscles in patients with COPD, and inspiratory muscle training (IMT) may improve the pressure-generating capacity of the inspiratory muscles. However, the effects of combined CET and IMT remain unclear and there is a lack of comprehensive assessment. MATERIALS AND METHODS: Eighty-one patients with COPD were randomly allocated to three groups: 28 received 8 weeks of CET + IMT (combined training group), 27 received 8 weeks of CET alone (CET group), and 26 only received 8 weeks of free walking (control group). Comprehensive assessment including respiratory muscle strength, exercise capacity, pulmonary function, dyspnea, quality of life, emotional status, nutritional status, and body mass index, airflow obstruction, and exercise capacity index were measured before and after the pulmonary rehabilitation program. RESULTS: Respiratory muscle strength, exercise capacity, inspiratory capacity, dyspnea, quality of life, depression and anxiety, and nutritional status were all improved in the combined training and CET groups when compared with that in the control group (P<0.05) after pulmonary rehabilitation program. Inspiratory muscle strength increased significantly in the combined training group when compared with that in the CET group (ΔPImax [maximal inspiratory pressure] 5.20±0.89 cmH2O vs 1.32±0.91 cmH2O; P<0.05). However, there were no significant differences in the other indices between the two groups (P>0.05). Patients with weakened respiratory muscles in the combined training group derived no greater benefit than those without respiratory muscle weakness (P>0.05). There were no significant differences in these indices between the patients with malnutrition and normal nutrition after pulmonary rehabilitation program (P>0.05). CONCLUSION: Combined training is more effective than CET alone for increasing inspiratory muscle strength. IMT may not be useful when combined with CET in patients with weakened inspiratory muscles. Nutritional status had slight impact on the effects of pulmonary rehabilitation. A comprehensive assessment approach can be more objective to evaluate the effects of combined CET and IMT.

[Inspiratory muscle training followed by non-invasive positive pressure ventilation in patients with severe chronic obstructive pulmonary disease: a randomized controlled trial].

OBJECTIVE: To investigate the effects of inspiratory muscle training followed by non-invasive positive pressure ventilation in patients with severe chronic obstructive pulmonary disease (COPD). METHODS: This investigator-initiated randomized, controlled trial recruited 88 patients with stable GOLD stage IV COPD, who were randomized into 4 equal groups to continue oxygen therapy (control group) or to receive inspiratory muscle training followed by non-invasive positive pressure ventilation (IMT-NPPV group), inspiratory muscle training only (IMT group), or noninvasive positive pressure ventilation only (NPPV group) for at least 8 weeks. The outcomes of the patients were assessed including the quality of life (SRI scores), maximum inspiratory pressure (MIP), maximum expiratory pressure (MEP), dyspnea (MRC scores), 6-min walking distance (6MWD) and lung function. RESULTS: s Compared to baseline values, SRI scores, 6MWT and MRC scores increased significantly after 8 weeks in IMT-NPPV, IMT and NPPV groups, and the improvements were significantly greater in IMT-NPPV group than in IMT and NPPV groups (P<0.05 for all). In IMT-NPPV and IMT groups, MIP and MEP increased significantly after the training (P<0.05), and the improvement was more prominent in IMT-NPPV group (P<0.05). No significant changes were found in pulmonary functions in the groups after 8 weeks of treatment (P>0.05). CONCLUSION: Inspiratory muscle training followed by non-invasive positive pressure ventilation, compared with inspiratory muscle training or non-invasive positive pressure ventilation alone, can better enhance the quality of life, strengthen the respiratory muscles, improve exercise tolerance and relieve the dyspnea in patients with COPD.

Efficiency of neural respiratory drive for the assessment of bronchodilator responsiveness in patients with chronic obstructive pulmonary disease: an exploratory study.

BACKGROUND: Conventional lung function parameters, such as forced vital capacity (FVC), forced expiratory volume in 1 second (FEV1) and inspiratory capacity (IC) are often used to assess the therapeutic outcomes of bronchodilators, but they lack sensitivity. A novel indicator, namely efficiency of neural respiratory drive (NRD), may objectively evaluate the physiological changes in patients with chronic obstructive pulmonary disease (COPD). We investigated whether this indicator could be used to more accurately assess the responsiveness to inhaled bronchodilators. METHODS: Thirty-six subjects with moderate-to-severe COPD were randomized into group A (n=18) and group B (n=18). Participants in group A inhaled 400 µg placebo, 400 µg salbutamol and 80 µg ipratropium in sequence whereas those in group B had the salbutamol and ipratropium reversed. At different time points after administration of placebo or bronchodilators, evaluated indices included FEV1, FVC, IC, root mean square (RMS) of diaphragm electromyogram (EMGdi), and efficiency of NRD [herein defined as the ratio of minute ventilation (VE) to RMS, or VE/RMS]. RESULTS: FEV1, FVC, IC, RMS, and VE/RMS significantly improved after inhaled bronchodilators and VE/RMS had the largest improvement among five indices. The detection efficiency of VE/RMS was greater than FEV1, FVC, IC (all P<0.05), but not different from RMS. The accuracy and sensitivity of VE/RMS were significantly higher than FEV1, FVC, IC, and RMS (all P<0.05). CONCLUSIONS: Efficiency of NRD may be a sensitive tool to evaluate the efficacy of inhaled bronchodilators in COPD.

[Effects of inhaled short-acting bronchodilators on diaphragm function and neural respiratory drive during maximal isocapnic ventilation in patients with chronic obstructive pulmonary disease].

OBJECTIVE: To investigate the effects of inhaled short-acting bronchodilators on diaphragm function and neural respiratory drive in patients with chronic obstructive pulmonary disease (COPD) during maximal isocapnic ventilation (MIV). METHODS: Forty-seven patient with moderate to severe COPD were randomized into 4 groups: placebo group (n=12), salbutamol group (n=13), ipratropium group (n=10), and combined group (salbutamol and ipratropium, n=12). Each subject received an initial MIV for 3 min at baseline and inhaled placebo (400 µg), salbutamol (400 µg), ipratropium (80 µg), or both salbutamol and ipratropium, followed 30 min later by another 3 min of MIV. The parameters of diaphragm function and neural respiratory drive were monitored continuously and calculated during MIV. RESULTS: During the initial MIV, all the patients experienced a linear increase in root mean square (RMS) of diaphragm electromyogram with a gradual decrease in transdiaphragmatic pressure (Pdi), minute ventilation (VE), and VE/RMS, and these parameters all improved significantly after inhalation of the bronchodilators. Compared with the placebo group at the same time point, the 3 bronchodilator-treated groups showed significantly decreased RMS and Borg score and increased Pdi, VE and VE/RMS; VE/RMS was the highest in the combined treatment group (P<0.05). The Delta Borg was significantly correlated with Delta Pdi, Delta VE, Delta RMS, and Delta VE/RMS (P<0.05). CONCLUSIONS: In COPD patients, inhaled short-acting bronchodilators can alleviate diaphragm fatigue during MIV, increase lung ventilation, reduce neural respiratory drive, and improve neuro-ventilatory coupling to relieve dyspnoea, and the combination of ß-2 agonists and anti-muscarinic antagonists produces a stronger efficacy.

Comparison of inducible versus constitutive expression of plectasin on yields and antimicrobial activities in Pichia pastoris.

BACKGROUND: Plectasin might serve as a substitute for traditional antibiotics, but its yields and antimicrobial activities warrant further investigation. OBJECTIVE: To identify the influence of inducible versus constitutive expression of plectasin on yields and antimicrobial activities. METHODS: Through SOE-PCR, a recombinant plectasin gene was generated and inserted into inducible (pPICZαA) and constitutive (pGAPZαA) vectors in order to create Pichia pastoris GS115 strains. After 120 h of fermentation, supernatants were purified by an AKTA purifier using nickel columns. Minimal inhibitory concentration (MIC) and inhibition zone assays were performed after Tricine-SDS-PAGE. RESULTS: After 120 h of fermentation, the yield of constitutive plectasin (370 µg/ml) was much lower than that from inducible vector (880 µg/ml) (P < 0.05). However, constitutive strain reached its plateau phase faster and keep more consistent yield (P < 0.05). The MICs of inducible plectasin against Methicillin-resistant Staphylococcus aureus (MRSA) 15471118, vancomycin-resistant Enterococcus feces (VREF), and penicillin-resistant Streptococcus pneumonia (PRSP) 31355 were 64, 32, and 64 µg/ml, respectively, while those of constitutive plectasin were 4, 4, and 16 µg/ml. No significant differences were observed in antimicrobial activities between inducible and constitutive plectasin for MRSA 15471118, VREF and PRSP 31355 (all P ï¼ž 0.05). However, constitutive plectasin had a larger inhibition zone than inducible plectasin with the same mass. CONCLUSIONS: Although P. pastoris GS115 (pGAPZαA-Plectasin-GS115) had lower expression than P. pastoris GS115 (pPICZαA-plectasin-GS115), it reached the plateau phase faster, had steadier yields and showed superiority in antimicrobial activities. Therefore, pGAPZαA might be more suitable for expression of plectasin in GS115 compared with pPICZαA.

Addition to inhaled corticosteroids of leukotriene receptor antagonists versus theophylline for symptomatic asthma: a meta-analysis.

BACKGROUND: Inhaled corticosteroids (ICSs) are widely used in combination with second controller medications in the management of asthma in adults and children. There lacks a systematic comparison between addition of leukotriene receptor antagonists (LTRAs) and theophylline to ICS. The purpose of this meta-analysis was to evaluate the difference of the efficacy and safety profile of adding either LTRAs or theophylline to ICS in adults and children with symptomatic asthma. METHODS: Randomised controlled trials (RCTs) published prior to November 2014 were acquired through systematically searching and selected based on the established inclusion criteria for publications. The data extracted from the included studies were further analyzed by a meta-analysis. RESULTS: We included eight RCTs, of which six recruited adults and two recruited children aged 5 to 14 years. The primary outcomes were changes in lung function from baseline, including forced expiratory volume in the first second (FEV1) and peak expiratory flow (PEF). Overall, addition of LTRAs led to significantly better morning PEF {mean difference (MD) 16.94 [95% confidence interval (CI): 11.49-22.39] L/min, P<0.01} and FEV1 [MD 0.09 (95% CI: 0.03-0.15) L, P=0.005] as compared to addition of theophylline. There were no differences between the two treatments in terms of evening PEF, adverse events, rescue medication use and asthma exacerbation. CONCLUSIONS: The combination of LTRA and ICS leads to modestly greater improvement in lung function than the combination of theophylline and ICS in the treatment of symptomatic asthma. Long-term trials are required to assess the efficacy and safety of these two therapies.