Objective To investigate the effects of inclined axial compressive force and flexion moment on the anterior and posterior shear stiffness of the lumbosacral segment.Methods Six fresh-frozen human cadaveric L5-S1 segments were tested under intact and two progressively impaired structural conditions:intact,a 4-mm bilateral facet joint gap,and anterior discectomy with nucleus pulposus removal plus circumferential release of the inner annular fibers(disc injury).A 300 N axial compressive force was applied either vertically downward or with a 10° or 20° anterior inclination through the disc's shear center.Anterior(0 N to 250 N)and posterior(-50 N to 0 N)shear tests were conducted using a material testing machine.These tests were repeated under a 5 N-m flexion moment.The relative motion between L5 and Si was measured using a three-dimensional motion capture system.Results In the intact state,the inclination of the axial compressive force did not significantly alter anterior or posterior shear stiffness.However,the application of a flexion moment increased anterior shear stiffness by 49.3％.Progressive structural damage resulted in incremental increases in anteroposterior shear translation and corresponding reductions in stiffness.Notably,under combined loading with axial compression and flexion moment,anterior stiffness decreased from 939 N/mm(intact)to 224 N/mm(disc injury),while posterior stiffness decreased from 572 N/mm to 217 N/mm.Within the low-load range,no significant differences in shear stiffness were observed across any structural conditions,regardless of axial force inclination or combined with a flexion moment.Conclusions This study supports the clinical view that retro-inclination of the pelvis serves as a compensatory mechanism to enhance segmental shear stability.However,this compensatory capacity gradually diminishes and ultimately fails as spinal degeneration progresses.

Objective:To analyze the changes in the phylogenetic and antigenic characteristics of the hemagglutinin (HA) gene of influenza virus A(H3N2) [A(H3N2)] during the 2022-2024 influenza seasons in Beijing.Methods:The data of influenza-like cases and A(H3N2) strains from 17 network laboratories and their corresponding sentinel hospitals were collected during the 2022-2024 influenza seasons. The HA genes were amplified and sequenced after extracting nucleic acids of the chosen virus strains. BioEdit, the nucleotide and amino acid sequence identity were conducted, and the maximum likelihood method in MEGA 5.0 software was used to construct the phylogenetic tree of HA genes. Web Logo displayed the amino acid mutation, and the N-glycosylation sites of HA online were analyzed using the NetNGlyc1.0 Server online. The Datamonkey platform was utilized to analyze the positive selection pressure sites of the HA protein.Results:The 2022-2024 influenza season includes 2022-2023 and 2023-2024. During the influenza seasons of 2022-2024, the positive rates of A(H3N2) nucleic acid were 10.35% (2 127/20 543) and 10.47% (4 386/41 876), respectively. In the 2022-2023 influenza season, there were two peaks in the A(H3N2). The comparison of HA genes between all A(H3N2) strains studied with the 2022-2024 vaccine strain (A/Darwin/9/2021) revealed that all of the strains studied have the two amino acid mutations involving 186 and 225 receptor binding sites. There were 31 amino acid substitutions in the 2022-2023 influenza season, of which 18 variant sites involved antigenic determinants. There were 35 amino acid mutations during the 2023-2024 influenza season, of which 14 were related to antigenic determinants. There were changes in the genetic evolutionary subclades of A(H3N2) strains in two influenza seasons: from 2022 to 2023, three evolutionary subclades were co-prevalent together, with the 3C.2a1b.2a.2a.3a.1 accounting for 76.67% (23/30), the 3C.2a1b.2a.1a accounting for 20.00% (6/30), the 3C.2a1b.2a.2a.1 accounting for 3.33% (1/30); from 2023 to 2024, two subclades were prevalent, with 3C.2a1b.2a.2a.3a.1 accounting for 95.12% (39/41) and 3C.2a1b.2a.2a.1 accounting for 4.88% (2/41). The glycosylation site changes of the HA protein of A(H3N2) have been enhanced from 2023 to 2024. The 145 amino acid position of the HA protein of the A(H3N2) was the positive selection site for stress selection site analysis.Conclusions:The evolutionary subclades of the HA gene of A(H3N2) in Beijing showed changes from 2022 to 2024, and the glycosylation site polymorphism of the HA protein of A(H3N2) significantly increased from 2023 to 2024. Continuous monitoring of HA mutations in the A(H3N2) is crucial, providing a basis for developing influenza prevention and control strategies, as well as new strategic support for screening influenza vaccine components, vaccine design, and discovery of drug targets.

Objective:To analyze the changes in the phylogenetic and antigenic characteristics of the hemagglutinin (HA) gene of influenza virus A(H3N2) [A(H3N2)] during the 2022-2024 influenza seasons in Beijing.Methods:The data of influenza-like cases and A(H3N2) strains from 17 network laboratories and their corresponding sentinel hospitals were collected during the 2022-2024 influenza seasons. The HA genes were amplified and sequenced after extracting nucleic acids of the chosen virus strains. BioEdit, the nucleotide and amino acid sequence identity were conducted, and the maximum likelihood method in MEGA 5.0 software was used to construct the phylogenetic tree of HA genes. Web Logo displayed the amino acid mutation, and the N-glycosylation sites of HA online were analyzed using the NetNGlyc1.0 Server online. The Datamonkey platform was utilized to analyze the positive selection pressure sites of the HA protein.Results:The 2022-2024 influenza season includes 2022-2023 and 2023-2024. During the influenza seasons of 2022-2024, the positive rates of A(H3N2) nucleic acid were 10.35% (2 127/20 543) and 10.47% (4 386/41 876), respectively. In the 2022-2023 influenza season, there were two peaks in the A(H3N2). The comparison of HA genes between all A(H3N2) strains studied with the 2022-2024 vaccine strain (A/Darwin/9/2021) revealed that all of the strains studied have the two amino acid mutations involving 186 and 225 receptor binding sites. There were 31 amino acid substitutions in the 2022-2023 influenza season, of which 18 variant sites involved antigenic determinants. There were 35 amino acid mutations during the 2023-2024 influenza season, of which 14 were related to antigenic determinants. There were changes in the genetic evolutionary subclades of A(H3N2) strains in two influenza seasons: from 2022 to 2023, three evolutionary subclades were co-prevalent together, with the 3C.2a1b.2a.2a.3a.1 accounting for 76.67% (23/30), the 3C.2a1b.2a.1a accounting for 20.00% (6/30), the 3C.2a1b.2a.2a.1 accounting for 3.33% (1/30); from 2023 to 2024, two subclades were prevalent, with 3C.2a1b.2a.2a.3a.1 accounting for 95.12% (39/41) and 3C.2a1b.2a.2a.1 accounting for 4.88% (2/41). The glycosylation site changes of the HA protein of A(H3N2) have been enhanced from 2023 to 2024. The 145 amino acid position of the HA protein of the A(H3N2) was the positive selection site for stress selection site analysis.Conclusions:The evolutionary subclades of the HA gene of A(H3N2) in Beijing showed changes from 2022 to 2024, and the glycosylation site polymorphism of the HA protein of A(H3N2) significantly increased from 2023 to 2024. Continuous monitoring of HA mutations in the A(H3N2) is crucial, providing a basis for developing influenza prevention and control strategies, as well as new strategic support for screening influenza vaccine components, vaccine design, and discovery of drug targets.

Objective To investigate the effects of inclined axial compressive force and flexion moment on the anterior and posterior shear stiffness of the lumbosacral segment.Methods Six fresh-frozen human cadaveric L5-S1 segments were tested under intact and two progressively impaired structural conditions:intact,a 4-mm bilateral facet joint gap,and anterior discectomy with nucleus pulposus removal plus circumferential release of the inner annular fibers(disc injury).A 300 N axial compressive force was applied either vertically downward or with a 10° or 20° anterior inclination through the disc's shear center.Anterior(0 N to 250 N)and posterior(-50 N to 0 N)shear tests were conducted using a material testing machine.These tests were repeated under a 5 N-m flexion moment.The relative motion between L5 and Si was measured using a three-dimensional motion capture system.Results In the intact state,the inclination of the axial compressive force did not significantly alter anterior or posterior shear stiffness.However,the application of a flexion moment increased anterior shear stiffness by 49.3％.Progressive structural damage resulted in incremental increases in anteroposterior shear translation and corresponding reductions in stiffness.Notably,under combined loading with axial compression and flexion moment,anterior stiffness decreased from 939 N/mm(intact)to 224 N/mm(disc injury),while posterior stiffness decreased from 572 N/mm to 217 N/mm.Within the low-load range,no significant differences in shear stiffness were observed across any structural conditions,regardless of axial force inclination or combined with a flexion moment.Conclusions This study supports the clinical view that retro-inclination of the pelvis serves as a compensatory mechanism to enhance segmental shear stability.However,this compensatory capacity gradually diminishes and ultimately fails as spinal degeneration progresses.

BACKGROUND:Osteoporosis is a disease in which bone density and structure are destroyed and fractures are caused by increased bone fragility,leading to high clinical disability and mortality rates. OBJECTIVE:To review the research progress in the role of bone immunity in physiological and pathological processes related to bone metabolism,providing ideas for the research and clinical application of bone immunity in bone diseases. METHODS:The first author searched PubMed and CNKI databases in November 2022 for relevant literature using the keywords of"osteoimmunology,immuno-skeletal interface,bone metabolism,skeletal metabolism,lymphocyte,immune factor"in English and Chinese,respectively.The time range of retrieval was mainly from January 2010 to November 2022,and a small number of classical long-term literatures were included.After reading the topic and abstract for preliminary screening and excluding repetitive studies,low-quality journals and unrelated literature,81 documents were finally included for review. RESULTS AND CONCLUSION:Osteoimmunology refers to that bone and immune cells share the same microenvironment and interact with each other to jointly perform the"bone immune system,"which includes all cells in the bone marrow.Immuno-skeletal interface has protective effects on bone under physiological conditions,but it may lead to bone destruction under pathological conditions.Osteoprotegerin is mainly derived from B cells and can inhibit osteoclast metabolism.However,when the body is in an inflammatory state,T cells and B cells work together to promote bone resorption.In addition,interleukin-1,interleukin-6 and tumor necrosis factor-α regulate the expression of receptor activator of nuclear factor-κB ligand in vivo and affect bone metabolism.In most clinical diseases(such as rheumatoid arthritis,estrogen deficiency,HIV infection,and hyperparathyroidism),the immuno-skeletal interface interacts with the bone immune system,resulting in the regulation of bone metabolism.In terms of clinical prospect,the interaction between bone immunity and bone metabolism should be studied in order to propose new strategies for therapeutic intervention to reduce the risk of fracture.

Purpose: This study aims to explore whether neoadjuvant chemotherapy with immunotherapy (NACI) leads to different tumor shrinkage patterns, based on magnetic resonance imaging (MRI), compared to neoadjuvant chemotherapy (NAC) alone in patients with triple-negative breast cancer (TNBC). Additionally, the study investigates the relationship between tumor shrinkage patterns and treatment efficacy was investigated. Methods: This retrospective study included patients with TNBC patients receiving NAC or NACI from January 2019 until July 2021 at our center. Pre- and post-treatment MRI results were obtained for each patient, and tumor shrinkage patterns were classified into three categories as follows: 1) concentric shrinkage (CS); 2) diffuse decrease; and 3) no change.Tumor shrinkage patterns were compared between the NAC and NACI groups, and the relevance of the patterns to treatment efficacy was assessed. Results: Of the 99 patients, 65 received NAC and 34 received NACI. The CS pattern was observed in 53% and 20% of patients in the NAC and NACI groups, respectively. Diffuse decrease pattern was observed in 36% and 68% of patients in the NAC and NACI groups. The association between the treatment regimens (NAC and NACI) and tumor shrinkage patterns was statistically significant (p = 0.004). The postoperative pathological complete response (pCR) rate was 45% and 82% in the NAC and NACI groups (p < 0.001), respectively. In the NACI group, 17% of patients with the CS pattern and 56% of those with the diffuse decrease pattern achieved pCR (p = 0.903). All tumor shrinkage patterns were associated with achieved a high pCR rate in the NACI group. Conclusion Our study demonstrates that the diffuse decrease pattern of tumor shrinkage is more common following NACI than that following NAC. Furthermore, our findings suggest that all tumor shrinkage patterns are associated with a high pCR rate in patients with TNBC treated with NACI.

Objective To analyze the changing trend of disease burden attributable to renal insufficiency in cardiovascular disease (CVD) among the elderly in China from 1990 to 2019, and to forecast the disability-adjusted life years (DALY) in the next 10 years, so as to provide a reference basis for accurate prevention and control of CVD attributable to renal insufficiency in China. Methods Data were obtained from the Global Health Data Exchange (GHDx) database to describe the current status of CVD prevalence attributable to renal insufficiency. The joinpoint model was used to estimate the annual percentage change and average annual percentage change to assess the temporal trend of CVD attributable to renal insufficiency in China. An autoregressive moving average model was created by R4.0.2 software to predict the disease burden of CVD attributable to renal insufficiency in China. Results Compared with 1990, CVD mortality and DALY rates attributed to renal insufficiency increased in the male elderly population and decreased in women. Mortality and DALY rates attributed to ischemic heart disease, ischemic stroke, and peripheral arterial disease attributed to renal insufficiency showed an increasing trend, and mortality and DALY rates for cerebral hemorrhage decreased. There was an overall increasing trend in the attribution of CVD due to renal insufficiency. Conclusion The burden of diseases attributable to renal insufficiency in Chinese elderly with CVD is relatively high, and the impact on each disease is different, which requires the attention of relevant authorities.

Objective:To explore the expressions of serum N-terminal osteocalcin (N-MID) and cytokeratin (CK) 5/6 in primary lung cancer patients with bone metastasis and their clinical significances.Methods:The clinical data of 96 patients with primary lung cancer admitted to Chengdu Second People's Hospital between February 2019 to February 2022 were retrospectively analyzed. All patients were divided into the bone metastasis group (38 cases) and the non-bone metastasis group (58 cases) according to whether bone metastasis occurred, and 45 healthy people who underwent physical examination during the same period were treated as the healthy control group. The expression levels of serum N-MID and CK5/6 in the bone metastasis group, the non-bone metastasis group and the healthy control group were compared. Logistic regression was used to analyze the factors affecting bone metastasis in patients with primary lung cancer; receiver operating characteristic (ROC) curve analysis was used to analyze the value of the expression levels of serum N-MID and CK5/6 in predicting bone metastasis in patients with primary lung cancer.Results:The composition ratio of patients with pathological stage Ⅲ-Ⅳ, serum bone-derived alkaline phosphatase and N-MID expression levels in the bone metastasis group were higher than those in the non-bone metastasis group (all P < 0.05). The expression level of serum N-MID in the bone metastasis group and non-bone metastasis group was higher than that in the healthy control group [(26.0±5.3) ng/ml, (15.3±3.1) ng/ml vs. (9.9±1.7) ng/ml, F = 224.27, P < 0.001], and there were statistically significant differences in the serum N-MID expression level of the pairwise comparison among the three groups (all P < 0.05). The expression level of serum CK5/6 in the bone metastasis group and the non-bone metastasis group was lower than that in the healthy control group [(3.6±0.7) ng/ml, (7.3±1.4) ng/ml vs. (10.6±2.4) ng/ml, F = 178.11, P < 0.001], and there were statistically significant differences in the serum CK5/6 expression level of the pairwise comparison among the three groups (all P < 0.05). Multivariate analysis showed that CK5/6, N-MID and bone-derived alkaline phosphatase were independent affecting factors for bone metastasis in patients with primary lung cancer ( OR = 4.088, 3.615, 2.892, all P < 0.05). ROC curve analysis showed that the optimal cut-off values of serum N-MID and CK5/6 expression levels for predicting bone metastasis in patients with primary lung cancer were 18.59 ng/ml and 4.71 ng/ml; the corresponding the area under the curve (AUC) was 0.881 and 0.862, respectively; and the specificity and AUC of the combination of serum N-MID and CK5/6 in predicting the bone metastasis in patients with primary lung cancer was 98.28% and 0.937 (95% CI 0.869-0.977), respectively; the AUC predicted by the combination of both was higher than that by serum N-MID or CK5/6 single (all P < 0.001). Conclusions:The expression levels of serum N-MID and CK5/6 in primary lung cancer patients with bone metastasis are abnormally changed. Clinical detection of serum N-MID and CK5/6 expression levels may be used as sensitive indicators for predicting the bone metastasis in patients with primary lung cancer.

Objective To analyze the disease burden of multidrug-resistant tuberculosis (MDR-TB) in China and regions with different income levels in the world from 1990 to 2019. Methods Using the Global Burden of Disease Study 2019 (GBD2019) results, the changes of the disease burden of MDR-TB in China and regions with different income levels in the world were described and analyzed using the Joinpoint Regression Program 4.8.0.1 software. Results From 1990 to 2019, the age standardized incidence, mortality and DALY rates in China and other areas with different income levels in the world basically showed a trend of first rising and then decreasing at the turning point of the late 20th century and early 21st century, except for low-income areas where the age standardized incidence rate showed an overall upward trend. In 2019, the incidence rate, mortality and DALY rate of MDR-TB in China were 9 times, 6.67 times and 6.89 times higher than those in high-income areas, respectively. The incidence rate in China was 6 times lower than that in low and middle-income areas, while the mortality and DALY rate in China were 26 times and 32.53 times lower than those in low-income areas, respectively. The age standardized incidence, mortality rate and DALY rate of MDR-TB in men were higher than those in women. Risk factors for the burden of MDR-TB disease included alcohol consumption, smoking, and high fasting blood glucose. Conclusion From 1990 to 2019, there are significant regional and gender differences in the disease burden of multidrug-resistant tuberculosis in China and regions with different income levels in the world. Multidrug-resistant tuberculosis is still a major challenge for tuberculosis control in the world. It is necessary to develop more effective control strategies and health care systems to deal with multidrug-resistant tuberculosis.

Objective:To understand the epidemic situation of Redondoviridae in Beijing and analyze its epidemiologic characteristics.Methods:Pharyngeal swab samples of healthy people and patients with acute respiratory infection in Beijing, including influenza like cases and severe acute respiratory infection (SARI) cases in hospitals were collected. Real time PCR was used to detect the nucleic acid of Redondoviridae. The positive samples were amplified and sequenced to analyze their species. The age and sex distribution of patients and species distribution of Redondoviridae were obtained through statistical analysis. Multiplex PCR was used to detect other common respiratory pathogens in the positive samples of Redondoviridae in influenza like cases and SARI cases, and the pathogenicity of Redondoviridae was analyzed.Results:The positive rates of Redondoviridae in healthy people and acute respiratory infection cases were 20.48% (189/923) and 11.23% (43/390), respectively, with a statistically significant difference ( P<0.05). The positive rate of male was higher than that of female in the healthy population, and the positive rate of the elderly group was higher than that of the adult group and the underage group, with a statistically significant difference ( P<0.05). The positive rate of male patients with acute respiratory tract infection was higher than that of female patients, but there was no significant difference. The proportion of Vientovirus in the positive samples of Redondoviridae was higher than that of Brisavirus, and the difference was statistically significant ( P<0.05). Among the throat swabs of respiratory tract infection cases, 43 were positive for Redondoviridae, of whom 24 were not detected for other pathogens. Conclusions:Redondoviridae widely exists in healthy people of all age groups in Beijing, and is also found in acute respiratory infection cases. The positive rate of Redondoviridae is different in different ages and genders. Both Vientovirus and Brisavirus were detected, and the proportion of Vientovirus was significantly higher than Brisavirus.