Objective To investigate the role of the O-6-methylguanine-DNA methyltransferase (MGMT) gene-3′ untranslated region (UTR) microRNA-associated single nucleotide polymorphism (miRSNP) (rs7896488 G>A) in affecting miR-4297-targeted modulation of MGMT in senescence of lung cells with polymorphic genotypes induced by fractionated low dose ionizing radiation (LDIR). Methods i) MiRSNPs were predicted and screened using bioinformatics, and DNA from two types of lung cells, A549 cells and human bronchial epithelioid cells (HBE cells), was extracted for target gene sequencing. After co-transfection of pGL3c-MGMT-3′UTR-rs7896488 G>A reporter gene recombinant plasmid, pRL-TK Vector with micrON mimic NC #22 or micrON hsa-miR-4297 mimic (set up as the mimic NC group and the miR-4297 mimic group) in these two types of lung cells, dual luciferase reporter gene assay was performed. The relative expression of MGMT mRNA was detected by real-time fluorescence quantitative polymerase chain reaction, and the relative expression of MGMT protein was detected by Western blotting. ii) These two types of lung cells were randomly divided into the control group and irradiation group, which received either 0 or 100 mGy X-rays irradiation seven times. After irradiation, the cells were transfected with either micrON mimic NC #22 or micrON hsa-miR-4297 mimic, resulting in mimic NC + control group, miR-4297 mimic + control group, mimic NC + irradiation group, and miR-4297 mimic + irradiation group. Cells were collected for senescence-associated-β-galactosidase (SA-β-Gal) staining, and the relative expression of matrix metalloproteinase-9 (MMP-9) and chemokine (C-X-C motif) ligand-1 (CXCL-1) proteins was detected via Western blotting. Results i) The rs7896488 G>A was the miRSNP located in the conserved binding region targeted by miR-4297 in the MGMT gene 3′UTR. A549 cells were the rs7896488 GG wild-type homozygous genotype, while HBE cells were the rs7896488 GA heterozygous mutant genotype. In the miR-4297 mimic group, A549 and HBE cells carrying the rs7896488 G allele showed significantly lower dual-luciferase activity compared with that in the mimic NC group (both P<0.01). However, there was no significant difference in dual-luciferase activity between the two groups in both A549 and HBE cells carrying the rs7896488 A allele (both P>0.05). The relative expression levels of MGMT mRNA and MGMT protein of A549 cells in the miR-4297 mimic group were lower than those in the mimic NC group (both P<0.05). However, there was no significant difference in MGMT mRNA and MGMT protein of HBE cells between these two groups (both P>0.05). ii) The relative activity of SA-β-Gal and the relative expression of MMP-9 and CXCL-1 proteins of A549 cells in the miR-4297 mimic+irradiation group were higher than those in the mimic NC + control group, the miR-4297 mimic + control group, and the mimic NC + irradiation group (all P<0.05). The relative activity of SA-β-Gal and the relative expression of MMP-9 and CXCL-1 proteins of HBE cells in the miR-4297 mimic + irradiation group were higher than those in the mimic NC + control group and the miR-4297 mimic + control group (all P<0.05), while there was no significant difference compared with those in the mimic NC + irradiation group (all P>0.05). Conclusion MGMT-3′UTR-miRSNP rs7896488 G>A plays a role in LDIR-induced senescence of lung cells with different polymorphic genotypes by affecting miR-4297-targeted regulation of MGMT.

Objective To understand the situation of dental cone beam computed tomography (CBCT) quality control testing phantoms in radiation health technical service institutions in Guangdong province, analyze the differences among different phantoms, and provide a reference for dental CBCT quality control testing. Methods The testing phantoms of 49 radiation health technical service institutions were used as the research objects. The designated CBCT equipment was used for scanning and imaging. The Z-score method was used to evaluate the high-contrast resolution, low-contrast resolution, and distance measurement deviation of each phantom. Results The satisfaction rates of various items for the phantoms in 49 institutions ranged from 85.7% to 100%. The distance measurement deviations of four institutions were “suspicious”, and the high-contrast resolution of four institutions and the distance measurement deviation of one institution were “unsatisfactory”. Conclusion The overall performance of dental CBCT quality control testing phantoms in radiological health technical service institutions in Guangdong province is satisfactory. However, there are still some phantoms with poor results in items such as distance measurement deviation and high-contrast resolution. The structural design, material selection, and manufacturing process of the phantom may all affect the results of quality control testing. Therefore, appropriate phantoms, optimized exposure conditions, and suitable reconstruction algorithms should be used in CBCT quality control testing to ensure accurate and reliable measurements.

Objective To investigate the effects of fractionated low-dose ionizing radiation (LDIR) on the ferroptosis in human bronchial epithelial (HBE) cells as well as the associated differentially expressed genes (DEGs), biological processes, and signaling pathways. Methods HBE cells were exposed to different single doses of X-ray irradiation (0, 25, 50, 75, and 100 mGy) for 24, 48, and 72 h, respectively. The change in cell viability was detected by MTT assay. Cells were irradiated with 0, 25, 50, and 100 mGy X-rays 5 times, with 48 h between each irradiation and a dose rate of 50 mGy/min. Cells were harvested 24 h after irradiation for the measurement of the expression of ferroptosis-related genes SLC7A11 and GPX4 at the mRNA and protein levels, cellular iron content, and the expression of FTH1 and FTL mRNAs. High-throughput sequencing was used to screen for the DEGs in each dose group, followed by Gene Ontology-Biological Process (GO-BP) analysis, Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway analysis, and Gene Set Enrichment Analysis (GSEA). Results Compared with the control group, single-dose LDIR significantly increased cell proliferation at 75 mGy after 24 h (P < 0.05), at 50, 75, and 100 mGy after 48 h (P < 0.05), and at 75 and 100 mGy after 72 h (P < 0.05). Compared with the control group, at the end of the fifth fractionated LDIR, SLC7A11 and GPX4 mRNAs decreased at all doses (P < 0.05), SLC7A11 protein decreased at all doses, GPX4 protein decreased at 25 and 100 mGy, iron content increased at all doses, and FTH1 and FTL mRNAs decreased at all doses (P< 0.05). Sequencing analysis identified 248, 30, and 291 DEGs and 10, 2, and 9 ferroptosis-associated genes at the three doses compared to the control. Gene Ontology-Biological Process analysis showed that DEGs were mainly enriched in biological processes such as response to lipids, cell death, and response to unfolded proteins. Kyoto Encyclopedia of Genes and Genomes analysis showed that DEGs were mainly enriched in the JAK-STAT signaling pathway, lipids and atherosclerosis, ferroptosis, protein processing in the endoplasmic reticulum, and FoxO signaling pathway. Gene set enrichment analysis showed that DEGs were mainly enriched in ferroptosis, fatty acid degradation, and glutathione metabolism. Conclusion Fractionated low-dose radiation induced ferroptosis in HBE cells, and DEGs were predominantly enriched in biological processes and signaling pathways related to inflammation, ferroptosis, and endoplasmic reticulum stress.

Objective To explore the differentially expressed mRNAs and related biological processes and pathways in fractional low-dose ionizing radiation (LDIR)-induced senescence of normal human bronchial epithelial (HBE) cells by high-throughput mRNA sequencing and bioinformatics techniques. Methods Senescence-associated β-galactosidase staining and senescence-associated secretion phenotype gene mRNA and protein expression levels were measured at 24 and 48 h after irradiating HBE cells 7 times at doses of 0, 50, 100, and 200 mGy, respectively. The differentially expressed genes were screened by high-throughput sequencing for Gene Ontology (GO) and Kyoto Encyclopedia of Genes and Genomes (KEGG) analyses. Results The senescence-positive area of fractional low-dose irradiated HBE cells increased in a dose-dependent manner (P < 0.05). The mRNA levels and protein expression of transforming growth factor-β1(TGF-β1) and matrix metalloproteinase-9(MMP-9) genes were increased in the 100 mGy × 7 and 200 mGy × 7 groups at 24 and 48 h after the end of irradiation compared with the control group. High-throughput sequencing showed that there were 882, 475, and 1205 differentially expressed mRNAs in each dose group compared with the control group. GO analysis showed that the differentially expressed mRNAs in each dose group were mainly enriched in biological processes such as cell cycle regulation, regulation of nitrogen compound metabolic process, regulation of cell division and response to stimulus. KEGG analysis showed that the differentially expressed mRNAs were mainly enriched in the pathways of cell cycle, cell senescence, and ferroptosis. Conclusion Fractional LDIR induced senescence in HBE cells, and differentially expressed mRNA-associated biological processes and pathways in senescent cells are related to cell cycle and cell senescence.

BACKGROUND:After the internal fixation of cannulated screws in femoral neck fractures,because the affected limb is often unable to bear weight in the short term and the implants with high stiffness have a stress shielding effect on the fracture end,it is easy to cause osteoporosis of the affected limb and changes in the biomechanical distribution of the proximal femur,the incidence of osteonecrosis of the femoral head is high after surgery.At present,few studies have been conducted on the biomechanical effects of osteoporosis at the proximal end of the femur occurring after femoral neck fracture surgery on femoral neck fracture treated with cannulated screws. OBJECTIVE:Using finite element analysis,to investigate the biomechanical effects of osteoporosis occurring after femoral neck fracture surgery on femoral neck fracture treated with cannulated screws and explore the role of biomechanical factors in osteonecrosis of the femoral head. METHODS:Based on the obtained CT scan data of the femur in a patient with a femoral neck fracture,a proximal femoral model for internal fixation for femoral neck fracture was established by Mimics 19.0,3-Matic,UG 11.0,Hypermesh 14.0,and Abaqus software.One finite element model of the proximal femur without osteoporosis and three finite element models of the proximal femur with osteoporosis were analyzed using Abaqus software.The stress,contact pressure,displacement peak and cloud map under different components of the four models were measured and analyzed,and the internal stress changes and distribution of the femoral head were compared and analyzed. RESULTS AND CONCLUSION:The stresses and contact pressures of the femoral head and lower anterior cannulated screws varied more with the degree of osteoporosis.The peak displacement of the four models increased slowly with the degree of osteoporosis.By one-way analysis of variance,there was no significant effect of the degree of osteoporosis on the peak stress,contact pressure,and displacement of the different components.The internal stress distribution of the femoral head changed with the degree of osteoporosis.Changes in the biomechanical environment of the proximal femur have an important impact on osteonecrosis of the femoral head.

Objective:To investigate the efficacy of tibiofibular-based reconstruction technique with single femoral tunnel for Fanelli type C posterolateral complex (PLC) injury.Methods:A retrospective case series study was conducted to analyze the clinical data of 16 patients with Fanelli type C PLC injury admitted to Tianjin Hospital from July 2016 to July 2019, including 10 males and 6 females, aged 20-61 years [(36.5±13.9)years]. PLC reconstruction was performed by tibiofibular-based technique with single femoral tunnel using gracilis tendon and semi-tendinosus autografts. If the posterior and anterior cruciate ligaments (PCL/ACL) rupture were combined, arthroscopic single bundle reconstruction was performed simultaneously. If the posteromedial corner (PMC) injury was combined, PMC repair or reconstruction surgery was performed simultaneously. Operation time and intraoperative blood loss were recorded. When the bone needle and tunnel for PLC were drilled during the operation, the interference of the femoral tunnel through the cruciate ligament was observed under the arthroscope. Before and at 6 and 12 months after operation, the varus stability of the knee joint was evaluated with the difference of lateral joint space width of both knees and the International Knee Documentation Committee (IKDC) objective classification of varus stability of the knee joint; the external rotation stability was evaluated with the difference of external rotation angle of both knees and the IKDC objective classification of external rotation stability of the knee joint. Before, at 6 and 12 months after operation and at the last follow-up, IKDC 2000 subjective score and Lysholm score were compared. The occurrence of complications was observed.Results:All the patients were followed up for 12-36 months [24(15, 33)months]. The operation time was 100-220 minutes [175.0(111.3, 200.0)minutes], with intraoperative blood loss of 30-150 ml [(84.3±36.5)ml]. Intraoperative arthroscopy showed no interference of perforation between PLC and cruciate ligament femoral tunnel. The differences of lateral joint space width of both knees at 6 and 12 months after operation were 0.5(0.2, 1.4)mm and 0.6(0.2, 1.5)mm respectively, which were both significantly improved compared with 12.1(10.8, 12.6)mm before operation ( P<0.05), while there was no significant difference at 6 and 12 months after operation ( P>0.05). The IKDC objective classification of varus stability of the knee joint was grade A in 13 patients, grade B in two and grade C in one at 6 or 12 months after operation, and showed statistical difference from grade D in all the patients before operation ( P<0.01). At 6 and 12 months after operation, the difference of external rotation angle of both knees was -2.0(-3.2, 1.3)° and -1.4(-3.0, 1.7)° respectively, which were significantly improved compared with 16.8(13.9, 18.4)° before operation ( P<0.05), while there was no significant difference at 6 and 12 months after operation ( P>0.05). IKDC objective classification of external rotation stability of the knee joint was grade A in 14 patients, grade B in one and grade C in one at 6 or 12 months after operation, and showed statistical difference from grade C in 14 patients and grade D in 2 before operation ( P<0.01). At 6 and 12 months after operation and at the last follow-up, the IKDC 2000 subjective scores [(76.3±4.7)points, (80.3±4.4)points, (79.9±3.8)points respectively] and the Lysholm scores [(76.1±3.9)points, (81.1±4.3)points, (82.8±3.2)points respectively] were significantly improved compared with those before operation [(48.6±3.7)points and (52.6±2.4)points] ( P<0.05). The IKDC 2000 subjective scores and Lysholm scores were significantly improved at 12 months after operation and at the last follow-up than those at 6 months after operation ( P<0.05). There were no significant differences in the IKDC 2000 subjective scores and Lysholm scores at 12 months after operation and at the last follow-up ( P>0.05). There were no complications such as wound infection, vascular and nerve injury, joint stiffness or ectopic ossification. Conclusion:For Fanelli type C PLC injury, tibiofibular-based reconstruction technique with single femoral tunnel reduces the interference between the lateral femoral tunnels, significantly improves the varus and external rotation stability and the function of the knee joint, and has few complications and satisfactory short-term clinical efficacy.

Objective To investigate the mechanism of fractionated low-dose ionizing radiation (LDIR) in the induction of EA.hy926 cell senescence. Methods EA.hy926 cells were irradiated with X-ray at 0, 50, 100, and 200 mGy × 4, respectively, and cultured for 24, 48, and 72 h. Several indicators were measured, including the levels of cellular senescence-associated β-galactosidase (SA-β-gal) staining, mRNA levels of senescence-associated cell cycle protein-dependent kinase inhibitor genes CDKN1A and CDKN2A, reactive oxygen species (ROS), total antioxidant capacity (T-AOC), and phosphorylated H2A histone family member X (γ-H2AX). Results After 4 fractionated LDIR, compared with the control group, the treatment groups showed increased nucleus area, blurred cell edge, and increased SA-β-gal positive area (P < 0.05) at 24, 48 and 72 h. After 4 fractionated LDIR, the mRNA level of CDKN1A increased in the 100 and 200 mGy × 4 groups at 24 and 48 h (P < 0.05), and CDKN2A mRNA level increased in the 100 and 200 mGy × 4 groups at 48 and 72 h (P < 0.05). The fluorescence intensity of ROS increased in treatment groups at 24, 48, and 72 h after 4 fractionated LDIR (P < 0.05). After 4 fractionated LDIR, the T-AOC level increased in the 100 and 200 mGy × 4 groups at 24 h (P < 0.05), and T-AOC level increased in all treatment groups at 48 and 72 h (P < 0.05). After 4 fractionated LDIR, γ-H2AX fluorescence intensity increased in all treatment groups at 24 h (P < 0.05), and the fluorescence intensity increased in the 100 and 200 mGy × 4 groups at 48 and 72 h (P < 0.05). Conclusion Fractionated LDIR can induce cellular senescence in EA.hy926 cells by impacting the cellular oxidation-antioxidation and oxidative damage levels, and the effects were relatively evident at 100 and 200 mGy.

Objective:To explore the interaction effect of diabetes and obesity on recurrence or anal fistula in patients with perianal abscess after simple incision and drainage.Methods:The clinical data of 163 patients with perianal abscess who underwent simple incision and drainage from Jun. 2021 to Jun. 2023 were analyzed retrospectively. The incidence of recurrence or anal fistula in 6 months after surgery was calculated. Multivariate Logistic regression model was used to analyze the influencing factors of postoperative recurrence or anal fistula. The multiplicative and additive models were used to analyze the interaction effect of diabetes and obesity on the risk of postoperative recurrence or anal fistula.Results:In 6 months after simple incision and drainage, the incidence of recurrence or anal fistula was 28.22% (46/163). Univariate analysis results showed that gender, obesity, and diabetes were related to recurrence of perianal abscess or incidence of anal fistula ( P<0.05). Multivariate Logistic regression analysis results showed that obesity ( OR=2.447, 95% CI: 1.320-4.538) and diabetes ( OR=2.162, 95% CI: 1.187-3.938) were independent risk factors for postoperative recurrence or anal fistula ( P<0.05). Interaction effect analysis found that after adjusting for confounding factors, diabetes and obesity had additive interaction effect on the risk of postoperative recurrence or anal fistula. The relative excess risk due to interaction (RERI), attribution percentage (AP), and interaction effect index (S) were 1.829 (95% CI: 0.605-3.007), 0.405 (95% CI: 0.143-0.597), and 2.098 (95% CI: 1.201-3.172), respectively. There was no multiplicative interaction effect between the two ( P>0.05) . Conclusions:Diabetes and obesity are independent risk factors for recurrence or anal fistula in patients with perianal abscess after simple incision and drainage. The two may have synergistic effect on the risk of postoperative recurrence or anal fistula.

Objective:To investigate the changes in liver injury and oxidative-antioxidant level in mice exposed to X-rays at varying doses.Methods:Fifty-four 8-week-old male C57BL/6J mice were divided into three groups, namely the control, 2 Gy irradiation, and 4 Gy irradiation groups. Then, each of the groups was further divided by days post-irradiation (i.e., 1, 3, and 7 d), and so nine sub-groups ( n = 6). After irradiation was performed as planned, all the mice were dissected and weighed, and their liver indexes were calculated to determine any histopathological changes in the liver. The peripheral blood cell count and the levels of aspartate aminotransferase (AST), alanine aminotransferase (ALT), and alkaline phosphatase (ALP) were detected. Furthermore, spectrophotometry was also used to determine the superoxide dismutase (SOD) activity, the malondialdehyde (MDA) concentration, and the reduced glutathione (GSH) concentration in liver tissues. Results:Compared to the control group, mice undergoing irradiation exhibited a significant reduction in body weight ( F = 84.03, 27.11, 25.50, P < 0.001), but significantly increased liver indexes ( F = 28.40, 17.75, P <0.001) at 1, 3, and 7 d post-irradiation. Pathological observations of these mice revealed liver injury, which proved related to dose and time course. The counts of leukocytes, neutrophils, and lymphocytes in peripheral blood decreased significantly ( F = 8.42-22.91, P < 0.05), trending downward with an increase in the radiation dose. For mice in the 4 Gy irradiation group, their AST and ALT levels increased significantly at 1 d post-irradiation ( H = 7.24, 7.82, P < 0.05), and their ALP levels rose notably at 1 and 3 d post-irradiation ( F = 11.86, 9.75, P < 0.05). Furthermore, their MDA and SOD levels initially rose and then dropped but their GSH levels exhibited an opposite trend at 1, 3, and 7 d post-irradiation. There was a positive correlation between their MDA levels in the liver and the degree of damage to histopathological lesions at 1, 3, and 7 d post-irradiation ( r = 0.30, P < 0.001). Conclusions:A model for radiation-induced liver injury of mice was preliminarily established in this study. It can be concluded that X-rays at varying doses affect the severity of liver injury, pathological grade, peripheral blood cell count, liver function index, and liver oxidative and antioxidant levels of mice, presenting a certain relationship between dose and time course effects.

Objective To investigate the status of metabolically unhealthy status (MUS) and its influencing factors in male residents living around a uranium mine in Guangdong Province. Methods A total of 867 local male residents born and living around a uranium mine in Guangdong Province were selected as the study subjects using two-stage random sampling method. The residents were divided into 10 km- and 20 km- radius groups, according to their living distance <10 km or 10-20 km from the uranium mine. Blood pressure, fasting blood glucose, and blood lipid levels were tested among the study subjects. The influencing factors of MUS and its components were analyzed by multiple logistic regression. Results The detection rate of MUS was 42.2%. The detection rates of MUS component such as elevated diastolic blood pressure, elevated systolic blood pressure, elevated fasting blood glucose, elevated triglyceride and low high-density lipoprotein cholesterol (HDL-C) were 48.8%, 60.9%, 11.9%, 40.7% and 19.3%, respectively. The MUS detection rate in the 10 km group was lower than that in the 20 km group (38.5% vs 45.9%, P<0.05). The result of multivariate logistic regression analysis showed that subjects aged >50 years had a higher risk of MUS and elevated systolic blood pressure than those aged ≤ 50 years (all P<0.05). Drinkers had a higher risk of MUS, elevated systolic blood pressure, elevated diastolic blood pressure, elevated triglyceride, and low HDL-C than non-drinkers (all P<0.05). Those who ate fruit occasionally had a higher risk of MUS than those who ate fruit regularly (P<0.05). Overweight and obese individuals had a higher risk of MUS, elevated systolic blood pressure, elevated diastolic blood pressure, elevated triglyceride, and low HDL-C than those with normal body mass (all P<0.05). Individuals in the 20 km group had a higher risk of MUS and low HDL-C than the 10 km group (all P<0.05). Conclusion The risk factors of MUS detection among male residents living around the uranium mines are age > 50 years, drinking, occasional fruit intake, and being overweight or obese. Age > 50 years, drinking alcohol, overweight and obesity can affect the detection of MUS components in different degrees. Environmental radiation levels have not been identified as a risk factor for MUS in these study subjects.