AIM:This study aims to investigate the mechanisms underlying skeletal muscle mitochondrial damage associated with decline in exercise function during high-altitude de-adaptation,using a mouse model.METHODS:Twen-ty-four healthy male C57BL/6J mice were randomly assigned to two groups:a high-altitude de-adaptation group and a plain control group.The model group was exposed to a low-pressure,low-oxygen chamber simulating an altitude of 7 000 meters for two weeks,followed by eight days of rearing in a plain environment.The control group was maintained in a plain envi-ronment for the same duration.Grip strength and pole-climbing tests were conducted on the 1st,3rd,and 5th days post-re-turn to assess muscle strength and motor coordination.Treadmill exercises were performed on the 4th and 8th days to eval-uate exercise endurance.After the treadmill exercise on the 8th day,serum,liver,and skeletal muscle tissues were col-lected.Levels of lactic acid(LA),glucose(GLU),creatine kinase(CK),lactate dehydrogenase(LDH),alanine trans-aminase(ALT),and aspartate aminotransferase(AST)in serum,as well as glycogen levels in the liver and muscle,were analyzed.Additionally,the expression of proteins related to mitochondrial biogenesis,fission,fusion,and oxidative phos-phorylation in muscle tissues was assessed using Western blot.RESULTS:(1)The model group exhibited significant re-ductions in grip strength,increased pole-climbing T-turn and total times,and decreased total time and distance in the ex-haustion running test.(2)Serum levels of LA,CK,LDH,ALT,and AST were elevated,while GLU levels decreased,and glycogen levels in both the liver and muscle were reduced in the model group following the treadmill exercise.(3)Ab-normal indicators in the model group did not return to normal by the end of the de-adaptation period.(4)Western blot analysis revealed decreased expression of mitochondrial oxidative phosphorylation proteins(ATP6V1A and Mt-CO2)and mitochondrial biogenesis proteins(PGC-1α and FGF21),increased levels of mitochondrial fusion proteins(OPA1 and MFN1),and no significant changes in fission protein expression(FIS1 and DRP1)in muscle tissue from the model group.CONCLUSION:Exercise capacity in mice during the high-altitude de-adaptation period significantly declined,particu-larly in terms of muscle strength,motor coordination,and endurance.This decline is closely associated with abnormal pro-tein expression related to skeletal muscle mitochondrial energy metabolism and production.

Objective:To investigate whether changes in CT pulmonary angiography (CTPA) parameters before and after balloon pulmonary angioplasty (BPA) are correlated with treatment effects in patients with chronic thromboembolic pulmonary hypertension (CTEPH).Methods:A retrospective study was conducted, including patients with CTEPH who underwent BPA treatment at Beijing Anzhen Hospital from November 2021 to Febbruary 2024. Clinical data and CTPA parameters were analyzed before the initial BPA session and at least 6 months after the final BPA session. Clinical data included WHO functional class, 6-minute walk distance (6MWD), and plasma N-terminal pro-brain natriuretic peptide (NT-proBNP) levels. The CTPA parameters included the widest diameter of the pulmonary artery diameter (dPA), ascending aorta diameter (dAA), the widest transverse diameter of the right atrium (dRA), the widest short-axis diameter of the right ventricle (dRV), the widest short-axis diameter of the left ventricle (dLV), and the diameter of right ventricular free wall thickness(dRVW). Multiple linear regression was applied to identify variables associated with the decrease in mean pulmonary artery pressure (mPAP) among the CTPA parameters.Results:All CTEPH patients underwent a total of 115 BPA treatments. Postoperatively, the WHO functional class of the patients improved compared to preoperative levels ( χ2=5.01, P<0.001), 6MWD improved ( t=4.50, P<0.001), and NT-proBNP levels decreased ( Z=4.47, P<0.001). Hemodynamic parameters, including mPAP, pulmonary vascular resistance, cardiac output, and cardiac index, were significantly improved postoperatively (all P<0.001). CTPA-related parameters, including dPA, dRA, dRV, dRVW, dPA/dAA, dRV/dLV, and dRA/dPA, significantly decreased compared to preoperative values (all P<0.001). Multiple linear regression analysis showed that the decrease in dPA ( β=0.314, P=0.037) and dRA ( β=0.334, P=0.046) were significantly correlated with the improvement in mPAP. Conclusions:Exercise tolerance, hemodynamics, and CTPA parameters in patients with CTEPH significantly improved after BPA treatment. The decrease in dPA and dRA were significantly correlated with the improvement in mPAP, suggesting that CTPA is a potentially novel, objective, effective, and noninvasive method for evaluating the therapeutic efficacy of BPA.

Effective removal of cardiac interference noise is essential to improve the accuracy of thoracic impedance respiration measurements.A cascaded LMS adaptive filter which can effectively remove the cardiac interference noise is proposed according to the characteristics of the real thoracic impedance respiration signal.The comparisons with several commonly used denoising algorithms reveal that the proposed algorithm can better remove cardiac interference while retaining the respiratory component of the original thoracic impedance respiration signal.The feasibility and accuracy of the proposed algorithm are further verified using real respiratory data with cardiac interference,and the experimental data show that the proposed method has a signal-to-noise ratio of(23.568±3.037)dB,a mean square error of 0.002±0.001,and a mean absolute error of 0.033±0.011,which fully confirms its effectiveness and stability.

Objective:To compare the impact of different treatment strategies on the survival outcomes in rectal cancer patients with poor response to neoadjuvant therapy, and to explore the survival-related influencing factors.Methods:A retrospective cohort study was conducted. Between January 2018 and November 2022, the clinical, pathological, and follow-up data of 106 rectal cancer patients who received neoadjuvant therapy and were evaluated as grade 4 or 5 based on the Magnetic Resonance Tumor Regression Grade (mrTRG) from the rectal cancer database at Peking Union Medical College Hospital were retrospectively collected. Based on the post-neoadjuvant therapy assessment, patients were classified into three groups: the chemotherapy-radiotherapy group (23 patients), the consolidation therapy group (18 patients), and the standard treatment group (65 patients). General condition, pathological findings, selection of neoadjuvant therapy, comorbidities, as well as 3-year expected DMFS and OS were observed in the three groups.Results:All 106 patients were followed up, with a median follow-up time of 28 (21, 38) months. The overall 3-year DMFS rate was 60%, and the 3-year OS rate was 74%. The 3-year DMFS in the standard treatment and consolidation therapy groups were 74% and 72%, respectively; the 3-year OS were 84%, 81%, respectively. The Log-rank test showed that there was no significant difference in the 3-year expected DMFS and OS between the standard treatment group and the consolidation therapy group (both P>0.05), but both groups had better survival outcomes than the chemotherapy-radiotherapy group (10% and 39%, respectively; all P<0.001). Multivariate Cox regression analysis indicated that the chemotherapy-radiotherapy only regimen was an independent risk factor for DMFS (HR=12.425, 95% CI: 4.436–34.594, P<0.001), and the independent risk factors for OS were chemotherapy-radiotherapy only regimen (HR=8.991, 95%CI:2.220–36.403, P=0.002) and age≥65 years (HR=3.495, 95%CI: 1.017–12.009, P=0.047). Stratified analysis showed that chemotherapy-radiotherapy only regimen was the independent risk factors for DMFS and OS in patients with extramural vascular invasion (EMVI) positive ( n=66) and mesorectal fascial invasion (MRF) positive (n=56) (all P<0.05). Whether consolidation therapy was added to the standard neoadjuvant treatment regimen was not an independent factor affecting 3-year expected DMFS or OS in rectal cancer patients with poor response to neoadjuvant therapy. Further comparisons between the standard neoadjuvant treatment and consolidation therapy groups showed no statistically significant differences in spincter-preservation rate or postoperative complication rates (both P>0.05). However, the consolidation therapy group had a longer interval between the end of radiotherapy and surgery [80.1 (50.8, 109.4) days vs. 61.8 (48.8, 74.8) days, P<0.001], and a higher incidence of chemotherapy-related adverse effects ([10/18] vs. 26.2% [17/65], P=0.018). Conclusion:In rectal cancer patients with poor response to neoadjuvant therapy and clear adverse prognostic features before surgery (locally advanced stage, MRF positive or EMVI positive), the addition of short- or long-course chemotherapy-based systemic therapy does not provide short- or long-term survival benefits. Moreover, an extended chemotherapy duration increases the incidence of chemotherapy-related adverse effects.

To perform the phylogenetic characterization of an isolated porcine rotavirus(PoRV)and investigate its pathogenicity in suckling mice and piglets.A G4P[23]genotype PoRV strain JSJR2023 was successfully isolated from the diarrheic piglet feces through propagation in MA104 cells.The viral proliferation kinetics were analyzed using TCID50 assays,followed by complete genome sequencing through Sanger sequencing platforms.Comprehensive genotyping and phylogenetic reconstruction were conducted using MEGA7.0 with maximum likelihood algorithms.Pathogenicity was assessed in the following animal models:5-day-old C57BL/6 mice and 3-day-old piglets.Multidimensional evaluation included clinical monitoring(diarrhea scoring,growth parameters),virological detection,and histopathological analysis of intestinal tissues.The virus strain JSJR2023 could replicate efficiently in MA104 cells,achieving peak titers of 107.5 TCID50/mL.Whole genome genotype analysis showed that the strain belonged to G4-P[23]-I5-R1-C1-M1-A8-N1-T1-E1-H1.Phylogenetic analysis indicated that the VP3 and NSP4 genes of JSJR2023 strain were most closedrelated to human species rotaviruses,suggesting genetic reassortment between human and porcine RV strains.The animal experiments in suckling mice showed that the JSJR2023 strain infection caused diarrhea symptoms,intestinal edema and congestion,and shedding of intestinal villus epithelial cells.The pathogenicity experiments in piglets showed that compared with the control group,the challenged group of pig-lets had severe diarrhea symptoms,accompanied by reduced appetite and listlessness.Post-mortem examination revealed that the intes-tines were significantly thinner,congested,and filled with yellow watery contents.The challenged piglets showed typical pathological changes such as thinning of the intestinal wall and shortening and shedding of intestinal villi.In conclusion,this study successfully iso-lated a human-porcine recombinant G4P[23]PoRV strain and established the infection models in suckling mice and piglets,providing important tools for investigating the pathogenic mechanism of PoRV,evaluating vaccines and developing antiviral drug.

AIM:This study aims to investigate the mechanisms underlying skeletal muscle mitochondrial damage associated with decline in exercise function during high-altitude de-adaptation,using a mouse model.METHODS:Twen-ty-four healthy male C57BL/6J mice were randomly assigned to two groups:a high-altitude de-adaptation group and a plain control group.The model group was exposed to a low-pressure,low-oxygen chamber simulating an altitude of 7 000 meters for two weeks,followed by eight days of rearing in a plain environment.The control group was maintained in a plain envi-ronment for the same duration.Grip strength and pole-climbing tests were conducted on the 1st,3rd,and 5th days post-re-turn to assess muscle strength and motor coordination.Treadmill exercises were performed on the 4th and 8th days to eval-uate exercise endurance.After the treadmill exercise on the 8th day,serum,liver,and skeletal muscle tissues were col-lected.Levels of lactic acid(LA),glucose(GLU),creatine kinase(CK),lactate dehydrogenase(LDH),alanine trans-aminase(ALT),and aspartate aminotransferase(AST)in serum,as well as glycogen levels in the liver and muscle,were analyzed.Additionally,the expression of proteins related to mitochondrial biogenesis,fission,fusion,and oxidative phos-phorylation in muscle tissues was assessed using Western blot.RESULTS:(1)The model group exhibited significant re-ductions in grip strength,increased pole-climbing T-turn and total times,and decreased total time and distance in the ex-haustion running test.(2)Serum levels of LA,CK,LDH,ALT,and AST were elevated,while GLU levels decreased,and glycogen levels in both the liver and muscle were reduced in the model group following the treadmill exercise.(3)Ab-normal indicators in the model group did not return to normal by the end of the de-adaptation period.(4)Western blot analysis revealed decreased expression of mitochondrial oxidative phosphorylation proteins(ATP6V1A and Mt-CO2)and mitochondrial biogenesis proteins(PGC-1α and FGF21),increased levels of mitochondrial fusion proteins(OPA1 and MFN1),and no significant changes in fission protein expression(FIS1 and DRP1)in muscle tissue from the model group.CONCLUSION:Exercise capacity in mice during the high-altitude de-adaptation period significantly declined,particu-larly in terms of muscle strength,motor coordination,and endurance.This decline is closely associated with abnormal pro-tein expression related to skeletal muscle mitochondrial energy metabolism and production.

To perform the phylogenetic characterization of an isolated porcine rotavirus(PoRV)and investigate its pathogenicity in suckling mice and piglets.A G4P[23]genotype PoRV strain JSJR2023 was successfully isolated from the diarrheic piglet feces through propagation in MA104 cells.The viral proliferation kinetics were analyzed using TCID50 assays,followed by complete genome sequencing through Sanger sequencing platforms.Comprehensive genotyping and phylogenetic reconstruction were conducted using MEGA7.0 with maximum likelihood algorithms.Pathogenicity was assessed in the following animal models:5-day-old C57BL/6 mice and 3-day-old piglets.Multidimensional evaluation included clinical monitoring(diarrhea scoring,growth parameters),virological detection,and histopathological analysis of intestinal tissues.The virus strain JSJR2023 could replicate efficiently in MA104 cells,achieving peak titers of 107.5 TCID50/mL.Whole genome genotype analysis showed that the strain belonged to G4-P[23]-I5-R1-C1-M1-A8-N1-T1-E1-H1.Phylogenetic analysis indicated that the VP3 and NSP4 genes of JSJR2023 strain were most closedrelated to human species rotaviruses,suggesting genetic reassortment between human and porcine RV strains.The animal experiments in suckling mice showed that the JSJR2023 strain infection caused diarrhea symptoms,intestinal edema and congestion,and shedding of intestinal villus epithelial cells.The pathogenicity experiments in piglets showed that compared with the control group,the challenged group of pig-lets had severe diarrhea symptoms,accompanied by reduced appetite and listlessness.Post-mortem examination revealed that the intes-tines were significantly thinner,congested,and filled with yellow watery contents.The challenged piglets showed typical pathological changes such as thinning of the intestinal wall and shortening and shedding of intestinal villi.In conclusion,this study successfully iso-lated a human-porcine recombinant G4P[23]PoRV strain and established the infection models in suckling mice and piglets,providing important tools for investigating the pathogenic mechanism of PoRV,evaluating vaccines and developing antiviral drug.

Effective removal of cardiac interference noise is essential to improve the accuracy of thoracic impedance respiration measurements.A cascaded LMS adaptive filter which can effectively remove the cardiac interference noise is proposed according to the characteristics of the real thoracic impedance respiration signal.The comparisons with several commonly used denoising algorithms reveal that the proposed algorithm can better remove cardiac interference while retaining the respiratory component of the original thoracic impedance respiration signal.The feasibility and accuracy of the proposed algorithm are further verified using real respiratory data with cardiac interference,and the experimental data show that the proposed method has a signal-to-noise ratio of(23.568±3.037)dB,a mean square error of 0.002±0.001,and a mean absolute error of 0.033±0.011,which fully confirms its effectiveness and stability.

Objective:To compare the impact of different treatment strategies on the survival outcomes in rectal cancer patients with poor response to neoadjuvant therapy, and to explore the survival-related influencing factors.Methods:A retrospective cohort study was conducted. Between January 2018 and November 2022, the clinical, pathological, and follow-up data of 106 rectal cancer patients who received neoadjuvant therapy and were evaluated as grade 4 or 5 based on the Magnetic Resonance Tumor Regression Grade (mrTRG) from the rectal cancer database at Peking Union Medical College Hospital were retrospectively collected. Based on the post-neoadjuvant therapy assessment, patients were classified into three groups: the chemotherapy-radiotherapy group (23 patients), the consolidation therapy group (18 patients), and the standard treatment group (65 patients). General condition, pathological findings, selection of neoadjuvant therapy, comorbidities, as well as 3-year expected DMFS and OS were observed in the three groups.Results:All 106 patients were followed up, with a median follow-up time of 28 (21, 38) months. The overall 3-year DMFS rate was 60%, and the 3-year OS rate was 74%. The 3-year DMFS in the standard treatment and consolidation therapy groups were 74% and 72%, respectively; the 3-year OS were 84%, 81%, respectively. The Log-rank test showed that there was no significant difference in the 3-year expected DMFS and OS between the standard treatment group and the consolidation therapy group (both P>0.05), but both groups had better survival outcomes than the chemotherapy-radiotherapy group (10% and 39%, respectively; all P<0.001). Multivariate Cox regression analysis indicated that the chemotherapy-radiotherapy only regimen was an independent risk factor for DMFS (HR=12.425, 95% CI: 4.436–34.594, P<0.001), and the independent risk factors for OS were chemotherapy-radiotherapy only regimen (HR=8.991, 95%CI:2.220–36.403, P=0.002) and age≥65 years (HR=3.495, 95%CI: 1.017–12.009, P=0.047). Stratified analysis showed that chemotherapy-radiotherapy only regimen was the independent risk factors for DMFS and OS in patients with extramural vascular invasion (EMVI) positive ( n=66) and mesorectal fascial invasion (MRF) positive (n=56) (all P<0.05). Whether consolidation therapy was added to the standard neoadjuvant treatment regimen was not an independent factor affecting 3-year expected DMFS or OS in rectal cancer patients with poor response to neoadjuvant therapy. Further comparisons between the standard neoadjuvant treatment and consolidation therapy groups showed no statistically significant differences in spincter-preservation rate or postoperative complication rates (both P>0.05). However, the consolidation therapy group had a longer interval between the end of radiotherapy and surgery [80.1 (50.8, 109.4) days vs. 61.8 (48.8, 74.8) days, P<0.001], and a higher incidence of chemotherapy-related adverse effects ([10/18] vs. 26.2% [17/65], P=0.018). Conclusion:In rectal cancer patients with poor response to neoadjuvant therapy and clear adverse prognostic features before surgery (locally advanced stage, MRF positive or EMVI positive), the addition of short- or long-course chemotherapy-based systemic therapy does not provide short- or long-term survival benefits. Moreover, an extended chemotherapy duration increases the incidence of chemotherapy-related adverse effects.

Objective:To investigate whether changes in CT pulmonary angiography (CTPA) parameters before and after balloon pulmonary angioplasty (BPA) are correlated with treatment effects in patients with chronic thromboembolic pulmonary hypertension (CTEPH).Methods:A retrospective study was conducted, including patients with CTEPH who underwent BPA treatment at Beijing Anzhen Hospital from November 2021 to Febbruary 2024. Clinical data and CTPA parameters were analyzed before the initial BPA session and at least 6 months after the final BPA session. Clinical data included WHO functional class, 6-minute walk distance (6MWD), and plasma N-terminal pro-brain natriuretic peptide (NT-proBNP) levels. The CTPA parameters included the widest diameter of the pulmonary artery diameter (dPA), ascending aorta diameter (dAA), the widest transverse diameter of the right atrium (dRA), the widest short-axis diameter of the right ventricle (dRV), the widest short-axis diameter of the left ventricle (dLV), and the diameter of right ventricular free wall thickness(dRVW). Multiple linear regression was applied to identify variables associated with the decrease in mean pulmonary artery pressure (mPAP) among the CTPA parameters.Results:All CTEPH patients underwent a total of 115 BPA treatments. Postoperatively, the WHO functional class of the patients improved compared to preoperative levels ( χ2=5.01, P<0.001), 6MWD improved ( t=4.50, P<0.001), and NT-proBNP levels decreased ( Z=4.47, P<0.001). Hemodynamic parameters, including mPAP, pulmonary vascular resistance, cardiac output, and cardiac index, were significantly improved postoperatively (all P<0.001). CTPA-related parameters, including dPA, dRA, dRV, dRVW, dPA/dAA, dRV/dLV, and dRA/dPA, significantly decreased compared to preoperative values (all P<0.001). Multiple linear regression analysis showed that the decrease in dPA ( β=0.314, P=0.037) and dRA ( β=0.334, P=0.046) were significantly correlated with the improvement in mPAP. Conclusions:Exercise tolerance, hemodynamics, and CTPA parameters in patients with CTEPH significantly improved after BPA treatment. The decrease in dPA and dRA were significantly correlated with the improvement in mPAP, suggesting that CTPA is a potentially novel, objective, effective, and noninvasive method for evaluating the therapeutic efficacy of BPA.