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.

Ferroptosis has received great attention as an iron-dependent programmed cell death for efficient cancer therapy. However, with the accumulation of iron in tumor cells, the antioxidant system is activated by reducing glutathione (GSH) with glutathione peroxidase 4 (GPX4), which critically limits the ferroptosis therapeutic effect. Herein, an iron and GPX4 silencing siRNA (siGPX4) co-encapsulated ferritin nanocage (HFn@Fe/siGPX4) was developed to enhance ferroptosis by disruption of redox homeostasis and inhibition of antioxidant enzyme synergistically. The siGPX4 were loaded into the nanocages by pre-incubated with iron, which could significantly improve the loading efficiency of the gene drugs when compared with the reported gene drug loading strategy by ferritin nanocages. And more iron was overloaded into the ferritin through the diffusion method. When HFn@Fe/siGPX4 was taken up by human breast cancer cell MCF-7 in a TfR1-mediated pathway, the excess iron ions in the drug delivery system could for one thing induce ferroptosis by the production of reactive oxygen species (ROS), for another promote siGPX4 escaping from the lysosome to exert gene silencing effect more effectively. Both the in vitro and in vivo results demonstrated that HFn@Fe/siGPX4 could significantly inhibit tumor growth by synergistical ferroptosis. Thus, the developed HFn@Fe/siGPX4 afforded a combined ferroptosis strategy for ferroptosis-based antitumor as well as a novel and efficient gene drug delivery system.

Mechanical pain is one of the most common causes of clinical pain, but there remains a lack of effective treatment for debilitating mechanical and chronic forms of neuropathic pain. Recently, neurotoxin GsMTx4, a selective mechanosensitive (MS) channel inhibitor, has been found to be effective, while the underlying mechanism remains elusive. Here, with multiple rodent pain models, we demonstrated that a GsMTx4-based 17-residue peptide, which we call P10581, was able to reduce mechanical hyperalgesia and neuropathic pain. The analgesic effects of P10581 can be as strong as morphine but is not toxic in animal models. The anti-hyperalgesic effect of the peptide was resistant to naloxone (an μ-opioid receptor antagonist) and showed no side effects of morphine, including tolerance, motor impairment, and conditioned place preference. Pharmacological inhibition of TRPV4 by P10581 in a heterogeneous expression system, combined with the use of Trpv4 knockout mice indicates that TRPV4 channels may act as the potential target for the analgesic effect of P10581. Our study identified a potential drug for curing mechanical pain and exposed its mechanism.

The polymerase 1 and transcript release factor (PTRF)-cytoplasmic phospholipase A2 (cPLA2) phospholipid remodeling pathway facilitates tumor proliferation in glioma. Nevertheless, blockade of this pathway leads to the excessive activation of oncogenic receptors on the plasma membrane and subsequent drug resistance. Here, CD26/dipeptidyl peptidase 4 (DPP4) was identified through screening of CRISPR/Cas9 libraries. Suppressing PTRF-cPLA2 signaling resulted in the activation of the epidermal growth factor receptor (EGFR) pathway through phosphatidylcholine and lysophosphatidylcholine remodeling, which ultimately increased DPP4 transcription. In turn, DPP4 interacted with EGFR and prevented its ubiquitination. Linagliptin, a DPP4 inhibitor, facilitated the degradation of EGFR by blocking its interaction with DPP4. When combined with the cPLA2 inhibitor AACOCF3, it exhibited synergistic effects and led to a decrease in energy metabolism in glioblastoma cells. Subsequent in vivo investigations provided further evidence of a synergistic impact of linagliptin by augmenting the sensitivity of AACOCF3 and strengthening the efficacy of temozolomide. DPP4 serves as a novel target and establishes a constructive feedback loop with EGFR. Linagliptin is a potent inhibitor that promotes EGFR degradation by blocking the DPP4-EGFR interaction. This study presents innovative approaches for treating glioma by combining linagliptin with AACOCF3 and temozolomide.

OBJECTIVE: To investigate the feasibility and prognostic implications of assessing volume status during early fluid resuscitation in septic patients based on estimated plasma volume status (ePVS). METHODS: A prospective study was conducted. Patients with sepsis admitted to intensive care unit (ICU) of the First Affiliated Hospital of Kunming Medical University from March to December in 2023 were enrolled. The general information and laboratory indicators at ICU admission were recorded, and ePVS, sequential organ failure assessment (SOFA) score, acute physiology and chronic health status evaluation II (APACHE II) score were calculated. The vital signs, arterial blood gas analysis and volume status related indicators before liquid resuscitation (T0h) and 3 hours (T3h) and 6 hours (T6h) of fluid resuscitation were recorded. The diameter and variability of the inferior vena cava (IVC) were measured by ultrasound, and ePVS, percentage change value of estimated plasma volume status (ΔePVS%), difference in central venous-to-arterial partial pressure of carbon dioxide (Pcv-aCO₂), and lactate clearance rate (LCR) were calculated. Patients were divided into sepsis group and septic shock group based on the diagnosis at ICU admission, and septic patients were subdivided into survival group and death group based on their 28-day survival status. The differences in clinical data between the groups were compared. The correlation between ePVS or ΔePVS% and volume status related indicators during early liquid resuscitation was analyzed by Spearman rank sum correlation test. The predictive value of each variable for 28-day survival in patients with sepsis was analyzed by receiver operator characteristic curve (ROC curve), and 28-day death risk factors were analyzed by Logistic regression method. RESULTS: Fifty-four septic patients were enrolled in the final analysis, including 17 with sepsis and 37 with septic shock; 34 survived at 28 days and 20 died, with a 28-day survival rate of 63.0%. Compared with the sepsis group, the septic shock group had a lower venous ePVS at ICU admission [dL/g: 4.96 (3.67, 7.15) vs. 7.55 (4.36, 10.07), P < 0.05]. Compared with the death group, the survival group had higher T6h arterial and venous ΔePVS%, and albumin [Alb; T6h arterial ΔePVS% (%): 11.57% (-1.82%, 31.35%) vs. 0.48% (-5.67%, 6.02%), T6h venous ΔePVS%: 9.62% (3.59%, 25.75%) vs. 1.52% (-9.65%, 7.72%), Alb (g/L): 27.57±4.15 vs. 23.77±6.97, all P < 0.05], lower SOFA score, APACHE II score, AST, T0h Lac, and T3h and T6h norepinephrine dosage [SOFA score: 9.00 (8.00, 10.00) vs. 11.50 (9.25, 14.50), APACHE II score: 18.00 (14.75, 21.25) vs. 25.50 (21.00, 30.00), AST (U/L): 34.09 (23.20, 56.64) vs. 79.24 (25.34, 196.59), T0h Lac (mmol/L): 1.75 (1.40, 2.93) vs. 3.25 (2.33, 5.30), norepinephrine dosage (mg): 0.98 (< 0.01, 3.10) vs. 4.60 (1.05, 8.55) at T3h, 1.82 (0.38, 5.30) vs. 8.20 (2.80, 17.73) at T6h, all P < 0.05]. While there were no significantly differences in other basic data and ePVS at all of the time points before and after resuscitation between the two groups. Correlation analysis showed that T6h venous ePVS was significantly positively correlated with T6h IVC variability in septic patients (r = 0.360, P < 0.05), T0h arterial ePVS was significantly negatively correlated with T3h and T6h liquid intake volume (r₁ = -0.367, r₂ = -0.280, both P < 0.05), and venous ePVS at ICU admission was significantly positively correlated with NT-proBNP at ICU admission (r = 0.409, P < 0.05). T6h venous ΔePVS% was significantly positively correlated with T3h liquid intake volume and T6h LCR (r₁ = 0.286, r₂ = 0.286, both P < 0.05), and significantly negatively correlated with T6h urine volume and T6h change value of Pcv-aCO₂ (ΔPcv-aCO₂; r₁ = -0.321, r₂ = -0.371, both P < 0.05). ROC curve analysis showed that the area under the ROC curve (AUC) of T6h venous ΔePVS% for predicting 28-day survival in septic patients was 0.726 [95% confidence interval (95%CI) was 0.578-0.875, P = 0.006], with a sensitivity of 82.4%, a specificity of 60.0%, and an optimal cut-off value of 3.09%. Binary multifactorial Logistic regression analysis showed that an increase in T6h venous ΔePVS% was a protective factor for 28-day death in patients with sepsis on early fluid resuscitation [odds ratio (OR) = 0.900, 95%CI was 0.834-0.972, P = 0.007]. CONCLUSIONS ePVS may have potential for assessing the volume status of septic patients during early fluid resuscitation. The ΔePVS% during early fluid resuscitation may help to identify septic patients with a poor prognosis.
Humans ; Prognosis ; Fluid Therapy ; Sepsis/physiopathology* ; Prospective Studies ; Plasma Volume ; Intensive Care Units ; Resuscitation ; Male ; Female ; Middle Aged ; Shock, Septic/therapy*

ObjectiveTo evaluate the validity of four screening questionnaires on chronic obstructive pulmonary disease (COPD) among community residents in Shanghai, and to provide a scientific basis for selecting suitable screening questionnaires and plans for the community use. MethodsA multi-stage random sampling method was used to select community residents aged ≥40 for COPD questionnaire screening and spirometry. The screening questionnaires included the COPD Population Screener Questionnaire (COPD-PS), the COPD Screening Questionnaire (COPD-SQ), the COPD Diagnosis Questionnaire (CDQ), and the Lung Function Questionnaire (LFQ). The diagnostic gold standard for COPD was defined as a ratio of post-bronchodilator forced expiratory volume in one second to forced vital capacity (FEV1/FVC) less than 0.7. The receiver operating characteristic (ROC) curve was used to assess the validity of each questionnaire, and DeLong’s test was used to compare the area under the curve (AUC) of different questionnaires. ResultsAmong the 1 122 residents screened, 99 (8.8%) were diagnosed with COPD based on the gold standard criteria. The AUC values for the four questionnaires ranged from 0.643 to 0.682, with no statistically significant differences in screening accuracy among them (P>0.05). The sensitivity, specificity, positive predictive value (PPV), and negative predictive value (NPV) for each questionnaire at recommended cut-off points were as follows: COPD-PS (sensitivity: 33.3%, specificity: 84.9%, PPV: 17.6%, NPV: 92.9%), COPD-SQ (34.3%, 85.8%, 19.0%, 93.1%), CDQ (73.7%, 42.4%, 11.0%, 94.4%), and LFQ (48.5%, 74.8%, 15.7%, 93.8%). Optimal cut-off values for this population differed from the recommended values. When selecting the optimal cut-off value, the sensitivity of COPD-PS (58.6%), COPD-SQ (55.6%), and LFQ (64.7%) increased, while the specificity of CDQ (75.9%) increased. The AUC of sequential lung function testing for all four screening questionnaires increased to 0.7 or above. The optimal cut-off values for the four questionnaires in this population differed from the recommended values. When applying the optimal cut-off values, the sensitivity of three questionnaires increased: COPD-PS (58.6%), COPD-SQ (55.6%), and LFQ (64.7%), while the specificity of CDQ rose to 75.9%. The AUC of each questionnaire increased to above 0.7 when followed by sequential lung function testing. ConclusionThe COPD-PS, COPD-SQ, CDQ, and LFQ have limited value for COPD screening among Shanghai community residents, indicating that further refinement of these tools is needed.

Objective:A microsurgical simulation training device based on real clinical scenes was designed and its effectiveness was tested.Methods:From January 1, 2020 to January 1, 2023, postgraduate students in the Plastic and Reconstructive Surgery Department of the First Medical Center of PLA General Hospital and the Plastic Surgery Hospital of Chinese Academy of Medical Sciences were enrolled in this prospective study. The simulation training device consists of four parts: (1)Blood perfusion system, which is used to simulate living animal blood vessels.(2)The inner baffling rod system, which is used to simulate the operation in deep cavity.(3) The exterior baffling rod system, which is used to simulate the operation in difficult positions.(4) A pulsating platform system is used to simulate microsurgery under the influence of respiratory movement. Preliminary verification of the effect of the simulated training device was as follows: Surgeons with no experience in microsurgery were completely randomized assigned to the control group (traditional microsurgery training group) and the experimental group (training group using the simulated training device). After 4 weeks of microsurgical training, the trainees were assigned to perform two surgical skill assessments, the first using a live animal model for end-to-end anastomosis of rat tail arteries, and the second assessment using end-to-end anastomosis of free latissimus dorsi flap arteries in a real case. The performance of the two groups was compared by using operation time and microsurgical GRS score scale including four items of dexterity, visuospatial ability, operative flow and judgment. Chi-squared test was used to analyze gender between the two groups. GRS scores between the two groups were compared by the Mann-Whitney U test. Participants’ ageand operation time between the two groups was compared by independent t-test. P<0.05 was considered statistically significant. Results:A total of 18 trainees were enrolled, including 10 in the control group, 6 males and 4 females, with an average age of (27.80±1.87) years. There were 8 subjects in the experimental group, 4 males and 4 females, with an average age of (28.10±1.56) years old. There were no significant differences in age, gender and other baseline characteristics between the two groups ( P>0.05). There was no significant difference in GRS score and operation time between the control group and the experimental group ( P> 0.05) in the first assessment. However, in the second assessment of real cases, the GRS score of the experimental group was significantly higher than that of the control group(14.25 vs. 5.70), and the operation duration of the experimental group was also shorter than that of the control group, and the difference was statistically significant[(100.37±24.65 ) min vs. (105.60±22.84) min] ( P<0.05). Conclusion:Compared with traditional microsurgery training methods, using microsurgery training devices based on clinical real scenes can effectively shorten the learning curve and enable trainees to master complex micromanipulation skills more quickly.

Objective:A microsurgical simulation training device based on real clinical scenes was designed and its effectiveness was tested.Methods:From January 1, 2020 to January 1, 2023, postgraduate students in the Plastic and Reconstructive Surgery Department of the First Medical Center of PLA General Hospital and the Plastic Surgery Hospital of Chinese Academy of Medical Sciences were enrolled in this prospective study. The simulation training device consists of four parts: (1)Blood perfusion system, which is used to simulate living animal blood vessels.(2)The inner baffling rod system, which is used to simulate the operation in deep cavity.(3) The exterior baffling rod system, which is used to simulate the operation in difficult positions.(4) A pulsating platform system is used to simulate microsurgery under the influence of respiratory movement. Preliminary verification of the effect of the simulated training device was as follows: Surgeons with no experience in microsurgery were completely randomized assigned to the control group (traditional microsurgery training group) and the experimental group (training group using the simulated training device). After 4 weeks of microsurgical training, the trainees were assigned to perform two surgical skill assessments, the first using a live animal model for end-to-end anastomosis of rat tail arteries, and the second assessment using end-to-end anastomosis of free latissimus dorsi flap arteries in a real case. The performance of the two groups was compared by using operation time and microsurgical GRS score scale including four items of dexterity, visuospatial ability, operative flow and judgment. Chi-squared test was used to analyze gender between the two groups. GRS scores between the two groups were compared by the Mann-Whitney U test. Participants’ ageand operation time between the two groups was compared by independent t-test. P<0.05 was considered statistically significant. Results:A total of 18 trainees were enrolled, including 10 in the control group, 6 males and 4 females, with an average age of (27.80±1.87) years. There were 8 subjects in the experimental group, 4 males and 4 females, with an average age of (28.10±1.56) years old. There were no significant differences in age, gender and other baseline characteristics between the two groups ( P>0.05). There was no significant difference in GRS score and operation time between the control group and the experimental group ( P> 0.05) in the first assessment. However, in the second assessment of real cases, the GRS score of the experimental group was significantly higher than that of the control group(14.25 vs. 5.70), and the operation duration of the experimental group was also shorter than that of the control group, and the difference was statistically significant[(100.37±24.65 ) min vs. (105.60±22.84) min] ( P<0.05). Conclusion:Compared with traditional microsurgery training methods, using microsurgery training devices based on clinical real scenes can effectively shorten the learning curve and enable trainees to master complex micromanipulation skills more quickly.

Patients with severe trauma require an extremely timely treatment and transfusion plays an irreplaceable role in the emergency treatment of such patients. An increasing number of evidence-based medicinal evidences and clinical practices suggest that patients with severe traumatic bleeding benefit from early transfusion of low-titer group O whole blood or hemostatic resuscitation with red blood cells, plasma and platelet of a balanced ratio. However, the current domestic mode of blood supply cannot fully meet the requirements of timely and effective blood transfusion for emergency treatment of patients with severe trauma in clinical practice. In order to solve the key problems in blood supply and blood transfusion strategies for emergency treatment of severe trauma, Branch of Clinical Transfusion Medicine of Chinese Medical Association, Group for Trauma Emergency Care and Multiple Injuries of Trauma Branch of Chinese Medical Association, Young Scholar Group of Disaster Medicine Branch of Chinese Medical Association organized domestic experts of blood transfusion medicine and trauma treatment to jointly formulate Chinese expert consensus on blood support mode and blood transfusion strategies for emergency treatment of severe trauma patients ( version 2024). Based on the evidence-based medical evidence and Delphi method of expert consultation and voting, 10 recommendations were put forward from two aspects of blood support mode and transfusion strategies, aiming to provide a reference for transfusion resuscitation in the emergency treatment of severe trauma and further improve the success rate of treatment of patients with severe trauma.