Objective:To quantitatively evaluate the effects of left bundle branch block（LBBB）on left ventricular structure，function and myocardial perfusion using left ventricular pressure-strain loop and single photon emission computed tomography（SPECT），and to investigate the relationship between myocardial work，myocardial perfusion and pathological changes of left ventricular remodeling in left bundle branch block induced cardiomyopathy（LBBB-CM）.Methods:Fourteen male beagle dogs were selected，and the main trunk of the left bundle branch was ablated to create an LBBB dog model. Electrocardiogram（ECG），transesophageal echocardiography and arterial blood pressure data of LBBB dogs were collected before and 12 months after the ablation of left bundle branch trunk. Global and segmental myocardial work parameters were obtained by left ventricular pressure-strain loop. The differences of above parameters between baseline and 12 months after the ablation of left bundle branch were compared. SPECT was performed in LBBB dogs 12 months after the creation of LBBB. The hearts were harvested for anatomy observation and histopathological analysis in LBBB dogs and another 7 male beagle dogs（normal control group）matched by age and weight. The correlation between myocardial perfusion（percentage of regional tracer uptake）and myocardial work parameters，myocardial fibrosis in LBBB dogs were analyzed.Results:Compared with baseline，the left ventricular end-diastolic volume of 12 months after the ablation increased［（20.78 ± 5.32）ml vs（26.71 ± 7.94）ml， P = 0.003］，left ventricular ejection fraction decreased［（59.17 ± 5.67）% vs（47.69 ± 5.45）%， P<0.001］；left ventricular global/segmental longitudinal strain，global/segmental constructive work and global/segmental work efficiency decreased（all P<0.05），left ventricular global/segmental wasted work increased（all P<0.001）. Heterogenous perfusion defect was observed in LBBB dogs by SPECT，compared with lateral wall segments，the percentage of regional tracer uptake of septum was decreased（all P<0.05）. Gross anatomical and myocardial pathological changes were manifested as cardiomegaly，flaky or focal grayish thickening of endocardium，cardiomyocyte degeneration and fibrosis. Compared with normal control group，the collagen fiber volume fraction（CVF）in all segmental endocardium and partial segmental myocardium of LBBB dogs were significantly increased（all P<0.05）. Percentage of regional tracer uptake was positively correlated with segmental myocardial work（SMW）and segmental myocardial efficiency（SWE）（ r s = 0.49，0.31；both P<0.001），and negatively correlated with CVF and segmental wasted work（SWW）（ r s = -0.51，-0.49；both P<0.001）. Conclusions:Isolated LBBB is not benign，which can result in left ventricular remodeling，decreased cardiac constructive function，abnormal myocardial perfusion，endocardial fibrosis and myocardial fibrosis.The parameters of myocardial work assecsed by echocardiograpgy and myocardial perfusion，as non-invasive examination，can to some extent reflect the degree of left ventricular remodeling in LBBB-CM.

Objective:To investigate the biomechanical correlation between ankle instability and osteochondral lesions of the talus (OLT) under loading conditionsMethods:A healthy 29-year-old male volunteer was selected for the study. A 64-slice spiral CT scan of the right lower limb was performed to construct a detailed finite element model of the ankle joint, including ligaments and cartilage. Three injury models were created: models of distal tibiofibular syndesmosis injury, lateral collateral ligament injury, and a combined injury of the distal tibiofibular syndesmosis and lateral collateral ligament. Differences in stress distribution on the tibiotalar joint surface, talus stress, and talus displacement were analyzed through anterior drawer test, inversion stress test, and external rotation stress test.Results:In the anterior drawer test, as the forward traction force increased (40, 60, 80, 100, 120, 140, and 150 N), all the injury models showed a progressive increase in tibiotalar joint surface stress, talus stress, and talus displacement. The combined injury model showed the highest tibiotalar joint surface stress (32.6 MPa), while the lateral collateral ligament injury model demonstrated the highest talus stress (56.5 MPa). Talus displacement increased significantly with traction, reaching the maximum (4.88 mm) in the combined injury model under 150 N. In the inversion stress test, stress on the tibiotalar joint surface in the lateral collateral ligament injury model was concentrated on the posterior-lateral and posterior-medial regions, whereas in the combined injury model, stress on the tibiotalar joint surface was predominantly concentrated in the posterior-medial region. Talus stress was localized to the talus neck and body in all the models, with the combined injury model showing the largest talus displacement (8.46 mm). In the external rotation stress test, stress on the tibiotalar joint surface was mainly distributed in the posterior-medial, posterior-lateral, and anterior-lateral regions in all the models. Talus stress was concentrated at the talus neck and body. The combined injury model exhibited the greatest talus displacement (12.50 mm).Conclusion:Ankle instability, particularly from combined injuries of the distal tibiofibular syndesmosis and lateral collateral ligament, significantly increases the stress concentration and talus displacement under loading conditions, thus elevating the risk of OLT.

Objective To investigate the distribution and antimicrobial resistance profiles of clinically isolated Haemophilus influenzae and Moraxella catarrhalis in hospitals across China from 2015 to 2021,and provide evidence for rational use of antimicrobial agents.Methods Data of H.influenzae and M.catarrhalis strains isolated from 2015 to 2021 in CHINET program were collected for analysis,and antimicrobial susceptibility testing was performed by disc diffusion method or automated systems according to the uniform protocol of CHINET.The results were interpreted according to the CLSI breakpoints in 2022.Beta-lactamases was detected by using nitrocefin disk.Results From 2015 to 2021,a total of 43 642 strains of Haemophilus species were isolated,accounting for 2.91％of the total clinical isolates and 4.07％of Gram-negative bacteria in CHINET program.Among the 40 437 strains of H.influenzae,66.89％were isolated from children and 33.11％were isolated from adults.More than 90％of the H.influenzae strains were isolated from respiratory tract specimens.The prevalence of β-lactamase was 53.79％in H.influenzae strains.The H.influenzae strains isolated from children showed higher resistance rate than the strains isolated from adults.Overall,779 strains of H.influenzae did not produce β-lactamase but were resistant to ampicillin(BLNAR).Beta-lactamase-producing strains showed significantly higher resistance rates to these antimicrobial agents than the β-lactamase-nonproducing strains.Of the 16 191 M.catarrhalis strains,80.06％were isolated from children and 19.94％isolated from adults.M.catarrhalis strains were mostly susceptible to both amoxicillin-clavulanic acid and cefuroxime,evidenced by resistance rate lower than 2.0％.Conclusions The emergence of antibiotic-resistant H.influenzae due to β-lactamase production poses a challenge for clinical anti-infective treatment.Therefore,it is very important to implement antibiotic resistance surveillance for H.influenzae and guide rational antibiotic use.All local clinical microbiology laboratories should actively improve antibiotic susceptibility testing and strengthen antibiotic resistance surveillance for H.influenzae.

Body weight abnormalities, including overweight, obesity, and underweight, have become a dual public health challenge in Chinese adults: overweight and obesity lead to a variety of chronic complications, while underweight increases the risks of malnutrition, sarcopenia, and organ dysfunction. To systematically address these issues, multidisciplinary experts in endocrinology, sports science, nutrition, and psychiatry from various regions have held multiple weight management seminars. Based on the latest epidemiological data and clinical evidence, they expanded the guideline to include assessment and intervention strategies for underweight, in addition to the core content of obesity management. This guideline outlines the etiological mechanisms, evaluation methods, and multidimensional management strategies for overweight and obesity, covering key areas such as diagnosis and assessment, medical nutrition therapy, exercise prescription, pharmacological intervention, and psychological support. It is intended to provide a scientific and standardized approach to weight management across the adult population, aiming to curb the rising prevalence of obesity, mitigate complications associated with abnormal body weight, and improve nutritional status and overall quality of life.

Objective To investigate the distribution and antimicrobial resistance profiles of clinically isolated Haemophilus influenzae and Moraxella catarrhalis in hospitals across China from 2015 to 2021,and provide evidence for rational use of antimicrobial agents.Methods Data of H.influenzae and M.catarrhalis strains isolated from 2015 to 2021 in CHINET program were collected for analysis,and antimicrobial susceptibility testing was performed by disc diffusion method or automated systems according to the uniform protocol of CHINET.The results were interpreted according to the CLSI breakpoints in 2022.Beta-lactamases was detected by using nitrocefin disk.Results From 2015 to 2021,a total of 43 642 strains of Haemophilus species were isolated,accounting for 2.91％of the total clinical isolates and 4.07％of Gram-negative bacteria in CHINET program.Among the 40 437 strains of H.influenzae,66.89％were isolated from children and 33.11％were isolated from adults.More than 90％of the H.influenzae strains were isolated from respiratory tract specimens.The prevalence of β-lactamase was 53.79％in H.influenzae strains.The H.influenzae strains isolated from children showed higher resistance rate than the strains isolated from adults.Overall,779 strains of H.influenzae did not produce β-lactamase but were resistant to ampicillin(BLNAR).Beta-lactamase-producing strains showed significantly higher resistance rates to these antimicrobial agents than the β-lactamase-nonproducing strains.Of the 16 191 M.catarrhalis strains,80.06％were isolated from children and 19.94％isolated from adults.M.catarrhalis strains were mostly susceptible to both amoxicillin-clavulanic acid and cefuroxime,evidenced by resistance rate lower than 2.0％.Conclusions The emergence of antibiotic-resistant H.influenzae due to β-lactamase production poses a challenge for clinical anti-infective treatment.Therefore,it is very important to implement antibiotic resistance surveillance for H.influenzae and guide rational antibiotic use.All local clinical microbiology laboratories should actively improve antibiotic susceptibility testing and strengthen antibiotic resistance surveillance for H.influenzae.

Objective:To investigate the predictive value of morphology,immunology,and cytogenetics for isocitrate dehydrogenase 1 and 2(IDH1/2)gene mutation in newly diagnosed acute myeloid leukemia(AML)patients.Methods:The clinical data of 186 newly diagnosed AML patients(except M3 subtype)in the First People's Hospital of Changzhou were retrospectively analyzed,and the variables associated with IDH1/2 mutation in patients were screened using LASSO regression to construct a multivariate logistic regression analysis model.The Bootstrap method was used for internal validation of the model and nomograms were used to visualize the model,and receiver operating characteristic(ROC)curve was used to evaluate the predictive performance of the model.Results:A total of 60 AML patients had IDH1/2 mutation at initial diagnosis.LASSO regression screened 9 predictive variables associated with IDH1/2 mutation,including CD7,CD56,CD11b,CD15,CD64,HLA-DR,platelet count ≥ 50 × 109/L,isolated+8 and normal karyotype.The nomogram and ROC curve were plotted based on the above 9 variables.The area under the ROC curve(AUC)of the training set and the validation set were 0.871 and 0.806,respectively.Internal validation showed that the nomogram had good predictive ability.Conclusion:The prediction model based on MIC typing constructed in this study has a good predictive ability for the presence of IDH1/2 mutations in newly diagnosed AML patients and has important clinical application value when the gene mutation detection results are unavailable.

Objective:To investigate the biomechanical correlation between ankle instability and osteochondral lesions of the talus (OLT) under loading conditionsMethods:A healthy 29-year-old male volunteer was selected for the study. A 64-slice spiral CT scan of the right lower limb was performed to construct a detailed finite element model of the ankle joint, including ligaments and cartilage. Three injury models were created: models of distal tibiofibular syndesmosis injury, lateral collateral ligament injury, and a combined injury of the distal tibiofibular syndesmosis and lateral collateral ligament. Differences in stress distribution on the tibiotalar joint surface, talus stress, and talus displacement were analyzed through anterior drawer test, inversion stress test, and external rotation stress test.Results:In the anterior drawer test, as the forward traction force increased (40, 60, 80, 100, 120, 140, and 150 N), all the injury models showed a progressive increase in tibiotalar joint surface stress, talus stress, and talus displacement. The combined injury model showed the highest tibiotalar joint surface stress (32.6 MPa), while the lateral collateral ligament injury model demonstrated the highest talus stress (56.5 MPa). Talus displacement increased significantly with traction, reaching the maximum (4.88 mm) in the combined injury model under 150 N. In the inversion stress test, stress on the tibiotalar joint surface in the lateral collateral ligament injury model was concentrated on the posterior-lateral and posterior-medial regions, whereas in the combined injury model, stress on the tibiotalar joint surface was predominantly concentrated in the posterior-medial region. Talus stress was localized to the talus neck and body in all the models, with the combined injury model showing the largest talus displacement (8.46 mm). In the external rotation stress test, stress on the tibiotalar joint surface was mainly distributed in the posterior-medial, posterior-lateral, and anterior-lateral regions in all the models. Talus stress was concentrated at the talus neck and body. The combined injury model exhibited the greatest talus displacement (12.50 mm).Conclusion:Ankle instability, particularly from combined injuries of the distal tibiofibular syndesmosis and lateral collateral ligament, significantly increases the stress concentration and talus displacement under loading conditions, thus elevating the risk of OLT.

Body weight abnormalities, including overweight, obesity, and underweight, have become a dual public health challenge in Chinese adults: overweight and obesity lead to a variety of chronic complications, while underweight increases the risks of malnutrition, sarcopenia, and organ dysfunction. To systematically address these issues, multidisciplinary experts in endocrinology, sports science, nutrition, and psychiatry from various regions have held multiple weight management seminars. Based on the latest epidemiological data and clinical evidence, they expanded the guideline to include assessment and intervention strategies for underweight, in addition to the core content of obesity management. This guideline outlines the etiological mechanisms, evaluation methods, and multidimensional management strategies for overweight and obesity, covering key areas such as diagnosis and assessment, medical nutrition therapy, exercise prescription, pharmacological intervention, and psychological support. It is intended to provide a scientific and standardized approach to weight management across the adult population, aiming to curb the rising prevalence of obesity, mitigate complications associated with abnormal body weight, and improve nutritional status and overall quality of life.

Objective:To quantitatively evaluate the effects of left bundle branch block（LBBB）on left ventricular structure，function and myocardial perfusion using left ventricular pressure-strain loop and single photon emission computed tomography（SPECT），and to investigate the relationship between myocardial work，myocardial perfusion and pathological changes of left ventricular remodeling in left bundle branch block induced cardiomyopathy（LBBB-CM）.Methods:Fourteen male beagle dogs were selected，and the main trunk of the left bundle branch was ablated to create an LBBB dog model. Electrocardiogram（ECG），transesophageal echocardiography and arterial blood pressure data of LBBB dogs were collected before and 12 months after the ablation of left bundle branch trunk. Global and segmental myocardial work parameters were obtained by left ventricular pressure-strain loop. The differences of above parameters between baseline and 12 months after the ablation of left bundle branch were compared. SPECT was performed in LBBB dogs 12 months after the creation of LBBB. The hearts were harvested for anatomy observation and histopathological analysis in LBBB dogs and another 7 male beagle dogs（normal control group）matched by age and weight. The correlation between myocardial perfusion（percentage of regional tracer uptake）and myocardial work parameters，myocardial fibrosis in LBBB dogs were analyzed.Results:Compared with baseline，the left ventricular end-diastolic volume of 12 months after the ablation increased［（20.78 ± 5.32）ml vs（26.71 ± 7.94）ml， P = 0.003］，left ventricular ejection fraction decreased［（59.17 ± 5.67）% vs（47.69 ± 5.45）%， P<0.001］；left ventricular global/segmental longitudinal strain，global/segmental constructive work and global/segmental work efficiency decreased（all P<0.05），left ventricular global/segmental wasted work increased（all P<0.001）. Heterogenous perfusion defect was observed in LBBB dogs by SPECT，compared with lateral wall segments，the percentage of regional tracer uptake of septum was decreased（all P<0.05）. Gross anatomical and myocardial pathological changes were manifested as cardiomegaly，flaky or focal grayish thickening of endocardium，cardiomyocyte degeneration and fibrosis. Compared with normal control group，the collagen fiber volume fraction（CVF）in all segmental endocardium and partial segmental myocardium of LBBB dogs were significantly increased（all P<0.05）. Percentage of regional tracer uptake was positively correlated with segmental myocardial work（SMW）and segmental myocardial efficiency（SWE）（ r s = 0.49，0.31；both P<0.001），and negatively correlated with CVF and segmental wasted work（SWW）（ r s = -0.51，-0.49；both P<0.001）. Conclusions:Isolated LBBB is not benign，which can result in left ventricular remodeling，decreased cardiac constructive function，abnormal myocardial perfusion，endocardial fibrosis and myocardial fibrosis.The parameters of myocardial work assecsed by echocardiograpgy and myocardial perfusion，as non-invasive examination，can to some extent reflect the degree of left ventricular remodeling in LBBB-CM.

Objective:To explore the construction method of a resistant multiple myeloma(MM)patient-derived xenotransplantation(PDX)model.Methods:1.0 × 107 MM patient-derived mononuclear cells(MNCs),2.0 × 106 MM.1S cells and 2.0 × 106 NCI-H929 cells were respectively subcutaneously inoculated into NOD.CB17-Prkdcscid Il2rgtml/Bcgen(B-NDG)mice with a volume of 100 p1 per mouse to establish mouse model.The morphologic,phenotypic,proliferative and genetic characteristics of PDX tumor were studied by hematoxylin-eosin staining,immunohistochemical staining(IHC),cell cycle analysis,flow cytometry and fluorescence in situ hybridization(FISH).The sensitivity of PDX tumor to bortezomib and anlotinib monotherapy or in combination was investigated through cell proliferation,apoptosis and in vitro and in vivo experiments.The effects of anlotinib therapy on tumor blood vessel and cell apoptosis were analyzed by IHC,TUNEL staining and confocal fluorescence microscope.Results:MM PDX model was successfully established by subcutaneously inoculating primary MNCs.The morphologic features of tumor cells from MM PDX model were similar to those of mature plasma cells.MM PDX tumor cells positively expressed CD138 and CD38,which presented 1q21 amplification,deletion of Rb1 and IgH rearrangement,and had a lower proliferative activity than MM cell lines.In vitro,PDX,MM.1S and NCI-H929 cells were treated by bortezomib and anlotinib for 24 hours,respectively.Cell viability assay showed that the IC50 value of bortezomib were 5 716.486,1.025 and 2.775 nmol/L,and IC50 value of anlotinib were 5 5107.337,0.706 and 5.13 μmol/L,respectively.Anlotinib treatment increased the apoptosis of MM.1S cells(P＜0.01),but did not affect PDX tumor cells(P＞0.05).In vivo,there was no significant difference in PDX tumor growth between bortezomib monotherapy group and control group(P＞0.05),while both anlotinib monotherapy and anlotinib combined with bortezomib effectively inhibited PDX tumor growth(both P＜0.05).The vascular perfusion and vascular density of PDX tumor were decreased in anlotinib treatment group(both P＜0.01).The apoptotic cells in anlotinib treatment group were increased compared with those in control group(P＜0.05).Conclusion:Bortezomib-resistant MM PDX model can be successfully established by subcutaneous inoculation of MNCs from MM patients in B-NDG mice.This PDX model,which retains the basic biological characteristics of MM cells,can be used to study the novel therapies.