Effect of residual volume after surgery of the discoid lateral meniscus on tibiofemoral joint biomechanics: a finite element analysis.

BACKGROUND: The purpose of this study was to investigate the influence of different residual meniscus volume on the biomechanics of tibiofemoral joint after discoid lateral meniscus (DLM) surgery by finite element analysis. METHODS: A knee joint model was established based on CT and MRI imaging data. The DLM model was divided into five regions according to conventional meniscectomy, with volumes of 15%, 15%, 15%, 15%, 15%, and 40% for each region. Additionally, the DLM model was divided into anterior and posterior parts to obtain ten regions. The DLM was resected according to the design scheme, and together with the intact discoid meniscus, a total of 15 models were obtained. Finite element analysis was conducted to assess shear and pressure trends on the knee joint. RESULTS: The study observed significant changes in peak shear stress and compressive stress in the lateral meniscus and lateral femur cartilage. As the meniscus volume decreased, there was an increase in these stresses. Specifically, when the meniscus volume reduced to 40%, there was a sharp increase in shear stress (302%) and compressive stress (152%) on the meniscus, as well as shear stress (195%) and compressive stress (157%) on the lateral femur cartilage. Furthermore, the model grouping results showed that preserving a higher frontal volume in the meniscus model provided better biomechanical advantages. CONCLUSION: The use of finite element analysis has demonstrated that preserving more than 55% of the meniscus volume is necessary to prevent a significant increase in joint stress, which can potentially lead to joint degeneration. Additionally, it is crucial to preserve the front volume of the DLM in order to achieve improved knee biomechanical outcomes.

The Regulation of Exosome-Mediated miR-132-3p/miR-132-3p-UUU on Radiation-Induced Esophageal Injury.

Radiation-induced esophageal injury (RIEI) is a major dose-limiting complication of radiotherapy, mainly acute esophagitis. However, understanding of radiation injury and repair mechanisms in esophageal epithelial cells remains limited. MiR-132-3p and its uridylated isoform (miR-132-3p-UUU) are upregulated in radiation esophageal injury, yet their role in radiation-induced esophageal injury progression remains unexplored. We expressed miR-132-3p and its uridine form in irradiated human esophageal epithelial cells (HEEC) and secreted exosomes was examined by real-time polymerase chain reaction (RT-PCR). Cell proliferation, migration, apoptosis and colony formation were used to determine biological effects. Cell cycle assays and dual luciferase reporter assays were used to assess the relationship between miR-132-3p and its uridylated isoforms and MEF2A. The addition of miR-132-3p mimics or overexpression of miR-132-3p significantly inhibited the proliferation and migration of esophageal epithelial cells (HEEC cells as well as primary cells) and increased radiation damage. This was reversed by its uridylated isoform by reducing binding to MEF2A and regulating the cell cycle. Furthermore, miR-132-3p and its triuridylated isomer also regulate apoptosis after irradiation through pathways other than reactive oxygen species (ROS). In conclusion, our data reveal that radiation-induced miR-132-3p uridylation and exosome-mediated intercellular communication and tri-uridylated isoforms are protective against radiation-induced esophageal injury. Furthermore, miR-132-3p offers new opportunities as a promising biomarker widely present in human body fluids for the prediction of radiation esophagitis as a biomarker.

The hyaluronic acid gel promotes the formation of osteoblasts mineralized nodules and fracture callus by regulating the expression of Runx2 and osteocalcin.

This study aimed to investigate the effect of hyaluronic acid (HA) gel regulating the expression of Runx2 and osteocalcin (OCN) on osteoblast mineralization nodules and fracture callus formation. To achieve this aim, MC3T3-E1 cells were divided into two groups, the HA group and the control group, based on the intervention of HA gel. In addition, a fracture callus model was constructed to observe cell proliferation, cell mineralization, and fracture callus formation. Results showed that HA at different concentrations had no obvious outcome on the proliferation of MC3T3-E1 cells (P>0.05). The area of mineralized nodules in the HA intervention group (65.38±4.27) was higher than in the control (9.52±2.16, P<0.05). The expression levels of Runx2 and OCN in the HA intervention group were higher than control (P<0.05). The callus area in the HA group (110.05±4.16) and (143.16±8.84) was significantly higher as against control (72.51±6.32, 88.92±5.28) at 2 and 4 weeks after intervention (P<0.05). It was concluded that HA gel promotes the proliferation and differentiation of osteoblasts by regulation of Runx2 and OCN, and then promotes the formation of mineralized nodules of osteoblasts and fracture callus, thereby promoting fracture healing.

Mechanism of TNF- α inducing apoptosis and autophagy of chondrocytes by activating NF- κ B signal pathway.

This study aimed to explore the mechanism of apoptosis and autophagy of chondrocytes induced by tumor necrosis factor α (TNA-α) by activating the NF-κB signal pathway. For this purpose, 24 SD rats were selected for feeding. The knee cartilage was cut by ophthalmology and the chondrocytes were extracted. The chondrocytes were randomly divided into a control group (CG) and an observation group (OG). TNF-α of 50ng/mL was added before the beginning of the study, while the control group did not receive any treatment. The levels of IL-1, IL-6, IL-12, autophagy markers (Atg5, Atg7, LC3II/I), apoptosis-related indexes (Bax, Bcl-2), NF-κB signal pathway-related indexes (p-p65, p65, IκBα) protein expression, mRNA expression and apoptosis rate in chondrocytes were compared in each group. Results showed that the levels of IL-1, IL-6 and IL-12 in the OG were raised than those in the CG. The expression levels of autophagy markers Atg5, Atg7, LC3II/I and mRNA in the OG were reduced than those in the CG. The apoptosis rate and the expression of BaxmRNA and protein in the OG were higher than those in the CG, while the expression of Bcl-2mRNA and protein were lower than those in the CG. The p-p65, p65, IκBα protein and mRNA related to NF-κB signal pathway in the OG were raised than those in the CG. In conclusion, TNF-α can induce apoptosis and autophagy of chondrocytes by activating the NF-κB signal pathway.

The effect of psychological nursing on the short- and long-term negative emotions and quality of life of cervical cancer patients undergoing postoperative chemotherapy.

OBJECTIVE: The purpose of this study was to analyze the effect of psychological nursing intervention on the short- and long-term negative emotions and changes in the quality of life in patients with cervical cancer who underwent postoperative chemotherapy. METHODS: 141 patients with cervical cancer who received postoperative chemotherapy in our hospital were recruited as the study cohort. They were divided into the study group (80 cases) and the control group (61 cases) according to the different nursing methods each underwent. The patients in the control group underwent routine nursing, and the study group also underwent psychological nursing. The changes in the quality of life and the negative emotions of the patients in the two groups before and after the intervention were compared, and the correlation between the quality of life and the negative emotions were explored. RESULTS: The patients' Quality of Life Questionnaire (EROTC-QLQ-C30) and Self-rating Anxiety Scale (SAS) scores in the two groups before the intervention were not significantly different (P > 0.05). A re-evaluation at the end of the 90 day-intervention showed that the EROTC-QLQ-C30 scores in the study group were significantly higher than they were in the control group (P < 0.05). A dynamic evaluation showed that the proportion of patients with mild anxiety in the study group was higher than it was in the control group at 30, 60, and 90 days of intervention (P < 0.05). A Spearman correlation analysis showed that the SAS scale and EROTC-QLQ-C30 scores were negatively correlated (r=-0.4438, P < 0.05). CONCLUSION: The implementation of psychological intervention can help alleviate the short- and long-term negative emotions of cervical cancer patients who underwent postoperative chemotherapy, and it is feasible and conducive to the patients' quality of life. We recommend carrying out the clinical promotion and application of this psychological intervention.