Objective To investigate the role and related mechanisms of exosomes derived from mesenchymal stem cells (MSCs) in radiation-induced lung injury (RILI). Methods Human umbilical cord-derived MSCs were isolated and cultured for the extraction and identification of exosomes. Eighteen male SD rats were randomly divided into Control group, RILI group and RILI + exosomes group (EXO group), with 6 rats in each group. Except for Control group, the other groups received a single X-ray dose of 30 Gy to the right lung. Immediately after irradiation, the EXO group was administered 2 × 10⁹ exosomes/kg via tail vein injection. Control group and RILI group were given the same volume of normal saline. Eight weeks post-irradiation, the rats were sacrificed, lung tissue and peripheral venous blood were collected. HE and Masson staining were employed to observe the pathological and fibrotic changes of lung tissue. The levels of serum inflammatory factors IL-6, IFN-γ, TNF-α, and IL-10 were detected by ELISA. RT-qPCR was used to assess the mRNA levels of IL-1β, IL-6, Cdh1, and Col1a1 in lung tissue. The expression levels of Vimentin and TGF-β1 in lung tissue were measured by immunohistochemical staining. The expression levels of AMPK, p-AMPK, and TGF-β1 in lung tissue were detected by Western blot. Results MSC-derived exosomes were successfully extracted and identified. Compared with RILI group, EXO group showed significantly reduced pathological changes of lung inflammation and collagen deposition. The levels of serum inflammatory factors IL-6, INF-γ, and TNF-α were significantly decreased (P < 0.05), and the level of anti-inflammatory factor IL-10 was significantly increased (P < 0.05). The mRNA levels of IL-1β, IL-6, and Col1a1 in lung tissue were significantly decreased (P < 0.05 or P < 0.01), and the mRNA level of Cdh1 was significantly increased (P < 0.05 or P < 0.01). The levels of Vimentin and TGF-β1 in lung tissue were significantly reduced, while p-AMPK level was significantly up-regulated (P < 0.05). Conclusion Exosomes derived from MSCs may alleviate RILI by inhibiting inflammatory responses and regulating epithelial-mesenchymal transition mediated by AMPK/TGF-β1 signaling pathway.

With the rapid development of sequencing technologies, the detection of alternative polyadenylation (APA) in mammals has become more precise. APA precisely regulates gene expression by altering the length and position of the poly(A) tail, and is involved in various biological processes such as disease occurrence and embryonic development. The research on APA in mammals mainly focuses on the following aspects:(1) identifying APA based on transcriptome data and elucidating their characteristics; (2) investigating the relationship between APA and gene expression regulation to reveal its important role in life regulation;(3) exploring the intrinsic connections between APA and disease occurrence, embryonic development, differentiation, and other life processes to provide new perspectives and methods for disease diagnosis and treatment, as well as uncovering embryonic development regulatory mechanisms. In this review, the classification, mechanisms and functions of APA were elaborated in detail and the methods for APA identifying and APA data resources based on various transcriptome data were systematically summarized. Moreover, we epitomized and provided an outlook on research on APA, emphasizing the role of sequencing technologies in driving studies on APA in mammals. In the future, with the further development of sequencing technology, the regulatory mechanisms of APA in mammals will become clearer.

ObjectiveTo explore the mechanism by which Buyang Huanwutang regulates the glutathione peroxidase 4 （GPX4）-acyl-CoA synthetase long-chain family member 4 （ACSL4） axis to inhibit ferroptosis and promote neurological functional recovery after spinal cord injury （SCI）. MethodsNinety rats were randomly divided into five groups： sham operation group， model group， low-dose Buyang Huanwutang group （12.5 g·kg^-1）， high-dose Buyang Huanwutang group （25 g·kg^-1）， and Buyang Huanwutang + inhibitor group （25 g·kg^-1 + 5 g·kg^-1 RSL3）. The SCI model was established by using the allen method. Tissue was collected on the 7th and 28th days after operation. Motor function was assessed by using the Basso-Beattie-Bresnahan （BBB） scale. Hematoxylin-eosin （HE）， Nissl， and Luxol fast blue （LFB） staining were performed to observe spinal cord histopathology. Transmission electron microscopy was used to examine mitochondrial ultrastructure. Immunofluorescence staining was used to detect the number of NeuN-positive cells and the fluorescence intensity of myelin basic protein （MBP）， GPX4， and ACSL4. Real-time fluorescent quantitative polymerase chain reaction （Real-time PCR） was used to analyze the mRNA expression of GPX4 and ACSL4. Enzyme linked immunosorbent assay （ELISA） was performed to measure the levels of reactive oxygen species （ROS）， malondialdehyde （MDA）， glutathione （GSH）， and superoxide dismutase （SOD）. Colorimetric assays were used to determine the iron content in spinal cord tissue. ResultsCompared to the sham operation group， the model group exhibited significantly reduced BBB scores （P<0.01）， severe pathological damage in spinal cord tissue， and marked mitochondrial ultrastructural disruption. In addition， the model group showed a decrease in the number of NeuN-positive cells （P<0.01）， reduced fluorescence intensity of MBP and GPX4 （P<0.01）， lower levels of GSH and SOD （P<0.01）， and downregulated mRNA expression of GPX4 （P<0.01）. Moreover， compared to the sham operation group， the model group had elevated levels of ROS， MDA， and tissue iron content （P<0.01）， along with increased fluorescence intensity and mRNA expression of ACSL4 （P<0.01）. Compared with the model group and Buyang Huanwutang + inhibitor group， the Buyang Huanwutang group showed significantly improved BBB scores （P<0.05， P<0.01） and exhibited less severe spinal cord tissue damage， reduced edema and inflammatory cell infiltration， increased neuronal survival， and more intact myelin structures. Additionally， mitochondrial ultrastructure was significantly improved in the Buyang Huanwutang group. Compared to the model group and Buyang Huanwutang + inhibitor group， the Buyang Huanwutang group significantly increased the number of NeuN-positive cells and the fluorescence intensity of MBP （P<0.05， P<0.01）. Furthermore， Buyang Huanwutang significantly increased the fluorescence intensity and mRNA expression of GPX4 （P<0.01） and decreased the fluorescence intensity and mRNA expression of ACSL4 （P<0.01） compared to the model group and Buyang Huanwutang + inhibitor group. Finally， the Buyang Huanwutang group significantly decreased ROS， MDA， and tissue iron content （P<0.01） and significantly increased GSH and SOD levels （P<0.01） compared to the model group and Buyang Huanwutang + inhibitor group. ConclusionBuyang Huanwutang inhibits ferroptosis through the GPX4/ACSL4 axis， reduces secondary neuronal and myelin injury and oxidative stress， and ultimately promotes the recovery of neurological function.

Objective: To explore the clinical characteristics of transfusion-associated graft-versus-host disease (TA-GVHD) in Chinese population, and to provide reference for effective prevention. Methods: Chinese and English medical databases were searched, and literature was screened based on inclusion and exclusion criteria. Data on patient information, clinical manifestations, outcomes and related risk factors from the selected studies were summarized and systematically analyzed. Results: A total of 17 studies were included in this study, involving 55 non-duplicated patients [14 males (14/55, 25.45%) and 41 females (41/55, 74.55%)], with a mean age of 51.72±18.34 years, (range: 2 months to 82 years). Among these cases, 2 had congenital immune deficiency (2/55, 3.64%), 16 had malignant hematological diseases (16/55, 29.09%), 4 had a history of surgery or trauma (4/55, 7.27%), 2 received non-surgical treatment (2/55, 3.64%), 31 were critically ill patients (31/55, 56.36%). Whole blood was transfused in 3 cases (3/55, 5.45%), erythrocyte in 9 (9/55, 16.36%), plasma in 2 (2/55, 3.64%), platelets in 7(7/55, 12.73%), human fibrinogen in 1 (1/55, 1.82%), and granulocytes in 2 (2/55, 3.64%). Two or more types of blood components were transfused in 16 cases (16/55, 29.09%). The main clinical signs and symptoms included fever (23/55, 41.82%), rash (22/55, 40.00%), diarrhea (14/55, 25.45%), abnormal liver function (18/55, 32.73%), bone marrow suppression and pancytopenia (22/55, 40.00%). The survival rate of 55 patients was 43.64% (24/55), and the mortality was 56.36% (31/55). Logistic regression analysis suggested that gender, misdiagnosis or missed diagnosis were major risk factors for mortality in TA-GVHD patients. Conclusion: The lack of specific indications for TA-GVHD often causes clinical misdiagnosis and missed diagnosis, and current treatments have limited efficacy. Therefore, it is of great significance to standardize clinical diagnosis criteria and improve prevention techniques to reduce the risk and mortality rate of TA-GVHD.

Objective To study the effects of intramedullary pressure on the fluid flow behavior in bones.Methods Multi-scale models of macro bone tissue and macro-meso osteon groups were established using the COMSOL Multiphysics software.Considering the interrelationship of different pore scales,such as the bone marrow cavity,Haversia canal,and bone lacunar-canaliculus,the pore pressure and flow rate of hollow bone tissues and bone tissues with intramedullary pressure were compared,and the effects of the amplitude and frequency of intramedullary pressure on the pressure and flow velocity of the liquid in the bone were analyzed.Results When intramedullary pressure was considered,the pore pressure in bone tissues with intramedullary pressure was 6.4 kPa higher than that in hollow bone tissues.The flow pressure increased significantly with an increase in the intramedullary pressure amplitude,but the flow velocity remained unchanged.The frequency of intramedullary pressure had little effect on pore pressure and flow velocity.Conclusions The multi-scale pore model established in this study can accurately analyze bone fluid flow behavior.These results are of great significance for an in-depth understanding of force conduction in the bone.

Objective:To investigate the application value of nectin-4 targeting radiotracer 68Ga-N188 in the diagnosis of pancreatic cancer. Methods:The prospective study was conducted. The clinicopathologic data of 16 patients diagnosed as pancreatic cancer on enhanced computed tomography (CT) who were admitted to the Peking University First Hospital from August to December 2022 were collected. There were 9 males and 7 females, aged (62±8)years. All patients underwent 18F-flurodeoxyglucose ( 18F-FDG) and 68Ga-N188 positron emission tomography (PET)/CT examination. Observation indicators: (1) distribution of 68Ga-N188 in different tissues and tumor primary lesion of patients; (2) expression of Nectin-4 and uptake of 68Ga-N188 in pancreatic cancer; (3) comparison of examination results between 68Ga-N188 and 18F-FDG PET/CT. Measurement data with normal distribution were represented as Mean± SD, and comparison between groups was conducted using the independent sample t test. Count data were described as absolute numbers or percentages. Results:(1) Distribution of 68Ga-N188 in different tissues and tumor primary lesion of patients. Results of PET/CT examination showed that in 1 hour after injection, the maximum standard uptake value (SUVmax) and mean standard uptake value (SUVmean) of 68Ga-N188 in fat, muscle, skin, and brain tissues of 16 patients were 0.40±0.16 and 0.25±0.09, 0.68±0.20 and 0.44±0.12, 0.39±0.14 and 0.28±0.11, 0.09±0.04 and 0.05±0.02, respectively. In the tissues of the esophagus, liver, spleen, and pancreas, the above indicators were 1.53±0.48 and 1.16±0.31, 1.49±0.45 and 0.91±0.30, 1.40±0.30 and 1.02±0.24, 1.24±0.31 and 0.96±0.25, respectively. In tumor primary lesion, the above indicators were 3.28±1.02 and 2.14±0.62, respectively, showing significant differences in SUVmax and SUVmean compared with pancreatic tissue ( t=8.03, 6.75, P<0.05). The tumor background ratio in tumor primary lesion based on SUVmax was 1.82±0.58. (2) Expression of Nectin-4 and uptake of 68Ga-N188 in pancreatic cancer. Results of immunohistochemical staining in 16 patients showed that there were 7 patients with high Nectin-4 expression and 9 patients with low Nectin-4 expression. Results of PET/CT examination showed that the SUVmax of 68Ga-N188 in tumor primary lesion of the 7 patients with high Nectin-4 expression and 9 patients with low Nectin-4 expression were 3.77±1.10 and 2.64±0.68, showing a significant difference between them ( t=2.64, P<0.05). The SUVmax of 18F-FDG in tumor primary lesion of the 7 patients with high Nectin-4 expression and 9 patients with low Nectin-4 expression were 6.73±3.24 and 6.43±3.45, showing no significant difference between them ( t=0.17, P>0.05). (3) Comparison of examination results between 68Ga-N188 and 18F-FDG PET/CT. Of the 16 patients, cases with positive results of tumor primary lesion on 68Ga-N188 and 18F-FDG PET/CT were 14 and 11, respectively, for the 14 pancreatic cancer patients diagnosed by postoperative histopathology. Among them, cases with positive results of tumor primary lesion on 68Ga-N188 and 18F-FDG PET/CT were 3 and 1 for the 3 pancreatic cancer patients receiving evaluation for chemotherapy. The SUVmax of 18F-FDG in tumor primary lesion of the 3 patients with chemotherapy and the 11 patients without chemotherapy were 2.80±0.69 and 6.97±2.11, showing a significant difference between them ( t=3.29, P<0.05). The SUVmax of 68Ga-N188 in tumor primary lesion of the 3 patients with chemotherapy and the 11 patients without chemotherapy were 3.38±1.12 and 2.93±0.50, showing no significant difference between them ( t=0.66, P>0.05). Cases with positive results of lymph node metastases in 68Ga-N188 and 18F-FDG PET/CT were 6 and 4, respectively, for the 6 pancreatic cancer patients diagnosed with lymph node metastases by postoperative histopathology, and the SUVmax of 68Ga-N188 and 18F-FDG in lymph node metastases were 2.25±1.12 and 4.02±1.27. Conclusion:68Ga-N188 PET/CT can be used for imaging diagnosis of tumor primary lesion and lymph node metastases of pancreatic cancer.

Objective: To investigate the correlation between magnetic resonance imaging-based vertebral bone quality (VBQ) score and screw loosening after dynamic pedicle screw fixation with polyetheretherketone (PEEK) rods, and evaluate its predictive value. Methods: A retrospective analysis was conducted on the patients who underwent dynamic pedicle screw fixation with PEEK rods from March 2017 to June 2022. Data on age, sex, body mass index, hypertension, diabetes, hyperlipidemia history, long-term smoking, alcohol consumption, VBQ score, L1–4 average Hounsfield unit (HU) value, surgical fixation length, and the lowest instrumented vertebra were collected. Logistic regression analysis was employed to assess the relationship between VBQ score and pedicle screw loosening (PSL). Results: A total of 24 patients experienced PSL after surgery (20.5%). PSL group and non-PSL group showed statistical differences in age, number of fixed segments, fixation to the sacrum, L1–4 average HU value, and VBQ score (p < 0.05). The VBQ score in the PSL group was higher than that in the non-PSL group (3.56 ± 0.45 vs. 2.77 ± 0.31, p < 0.001). In logistic regression analysis, VBQ score (odds ratio, 3.425; 95% confidence interval, 1.552–8.279) were identified as independent risk factors for screw loosening. The area under the receiver operating characteristic curve for VBQ score predicting PSL was 0.819 (p < 0.05), with the optimal threshold of 3.15 (sensitivity, 83.1%; specificity, 80.5%). Conclusion The VBQ score can independently predict postoperative screw loosening in patients undergoing lumbar dynamic pedicle screw fixation with PEEK rods, and its predictive value is comparable to HU value.

Objective: To investigate the correlation between magnetic resonance imaging-based vertebral bone quality (VBQ) score and screw loosening after dynamic pedicle screw fixation with polyetheretherketone (PEEK) rods, and evaluate its predictive value. Methods: A retrospective analysis was conducted on the patients who underwent dynamic pedicle screw fixation with PEEK rods from March 2017 to June 2022. Data on age, sex, body mass index, hypertension, diabetes, hyperlipidemia history, long-term smoking, alcohol consumption, VBQ score, L1–4 average Hounsfield unit (HU) value, surgical fixation length, and the lowest instrumented vertebra were collected. Logistic regression analysis was employed to assess the relationship between VBQ score and pedicle screw loosening (PSL). Results: A total of 24 patients experienced PSL after surgery (20.5%). PSL group and non-PSL group showed statistical differences in age, number of fixed segments, fixation to the sacrum, L1–4 average HU value, and VBQ score (p < 0.05). The VBQ score in the PSL group was higher than that in the non-PSL group (3.56 ± 0.45 vs. 2.77 ± 0.31, p < 0.001). In logistic regression analysis, VBQ score (odds ratio, 3.425; 95% confidence interval, 1.552–8.279) were identified as independent risk factors for screw loosening. The area under the receiver operating characteristic curve for VBQ score predicting PSL was 0.819 (p < 0.05), with the optimal threshold of 3.15 (sensitivity, 83.1%; specificity, 80.5%). Conclusion The VBQ score can independently predict postoperative screw loosening in patients undergoing lumbar dynamic pedicle screw fixation with PEEK rods, and its predictive value is comparable to HU value.

Objective: To investigate the correlation between magnetic resonance imaging-based vertebral bone quality (VBQ) score and screw loosening after dynamic pedicle screw fixation with polyetheretherketone (PEEK) rods, and evaluate its predictive value. Methods: A retrospective analysis was conducted on the patients who underwent dynamic pedicle screw fixation with PEEK rods from March 2017 to June 2022. Data on age, sex, body mass index, hypertension, diabetes, hyperlipidemia history, long-term smoking, alcohol consumption, VBQ score, L1–4 average Hounsfield unit (HU) value, surgical fixation length, and the lowest instrumented vertebra were collected. Logistic regression analysis was employed to assess the relationship between VBQ score and pedicle screw loosening (PSL). Results: A total of 24 patients experienced PSL after surgery (20.5%). PSL group and non-PSL group showed statistical differences in age, number of fixed segments, fixation to the sacrum, L1–4 average HU value, and VBQ score (p < 0.05). The VBQ score in the PSL group was higher than that in the non-PSL group (3.56 ± 0.45 vs. 2.77 ± 0.31, p < 0.001). In logistic regression analysis, VBQ score (odds ratio, 3.425; 95% confidence interval, 1.552–8.279) were identified as independent risk factors for screw loosening. The area under the receiver operating characteristic curve for VBQ score predicting PSL was 0.819 (p < 0.05), with the optimal threshold of 3.15 (sensitivity, 83.1%; specificity, 80.5%). Conclusion The VBQ score can independently predict postoperative screw loosening in patients undergoing lumbar dynamic pedicle screw fixation with PEEK rods, and its predictive value is comparable to HU value.

Background::Carotid intima-media thickness (IMT) and diameter, stiffness, and wave reflections, are independent and important clinical biomarkers and risk predictors for cardiovascular diseases. The purpose of the present study was to establish nationwide reference values of carotid properties for healthy Chinese adults and to explore potential clinical determinants.Methods::A total of 3053 healthy Han Chinese adults (1922 women) aged 18-79 years were enrolled at 28 collaborating tertiary centers throughout China between April 2021 and July 2022. The real-time tracking of common carotid artery walls was achieved by the radio frequency (RF) ultrasound system. The IMT, diameter, compliance coefficient, β stiffness, local pulse wave velocity (PWV), local systolic blood pressure, augmented pressure (AP), and augmentation index (AIx) were then automatically measured and reported. Data were stratified by age groups and sex. The relationships between age and carotid property parameters were analyzed by Jonckheere-Terpstra test and simple linear regressions. The major clinical determinants of carotid properties were identified by Pearson’s correlation, multiple linear regression, and analyses of covariance.Results::All the parameters of carotid properties demonstrated significantly age-related trajectories. Women showed thinner IMT, smaller carotid diameter, larger AP, and AIx than men. The β stiffness and PWV were significantly higher in men than women before forties, but the differences reversed after that. The increase rate of carotid IMT (5.5 μm/year in women and 5.8 μm/year in men) and diameter (0.03 mm/year in both men and women) were similar between men and women. For the stiffness and wave reflections, women showed significantly larger age-related variations than men as demonstrated by steeper regression slopes (all P for age by sex interaction <0.05). The blood pressures, body mass index (BMI), and triglyceride levels were identified as major clinical determinants of carotid properties with adjustment of age and sex. Conclusions::The age- and sex-specific reference values of carotid properties measured by RF ultrasound for healthy Chinese adults were established. The blood pressures, BMI, and triglyceride levels should be considered for clinical application of corresponding reference values.