Ursodeoxycholic acid (UDCA) is a naturally occurring, low-toxicity, and hydrophilic bile acid (BA) in the human body that is converted by intestinal flora using primary BA. Solute carrier family 7 member 11 (SLC7A11) functions to uptake extracellular cystine in exchange for glutamate, and is highly expressed in a variety of human cancers. Retroperitoneal liposarcoma (RLPS) refers to liposarcoma originating from the retroperitoneal area. Lipidomics analysis revealed that UDCA was one of the most significantly downregulated metabolites in sera of RLPS patients compared with healthy subjects. The augmentation of UDCA concentration (≥25 μg/mL) demonstrated a suppressive effect on the proliferation of liposarcoma cells. [¹⁵N₂]-cystine and [¹³C₅]-glutamine isotope tracing revealed that UDCA impairs cystine uptake and glutathione (GSH) synthesis. Mechanistically, UDCA binds to the cystine transporter SLC7A11 to inhibit cystine uptake and impair GSH de novo synthesis, leading to reactive oxygen species (ROS) accumulation and mitochondrial oxidative damage. Furthermore, UDCA can promote the anti-cancer effects of ferroptosis inducers (Erastin, RSL3), the murine double minute 2 (MDM2) inhibitors (Nutlin 3a, RG7112), cyclin dependent kinase 4 (CDK4) inhibitor (Abemaciclib), and glutaminase inhibitor (CB839). Together, UDCA functions as a cystine exchange factor that binds to SLC7A11 for antitumor activity, and SLC7A11 is not only a new transporter for BA but also a clinically applicable target for UDCA. More importantly, in combination with other antitumor chemotherapy or physiotherapy treatments, UDCA may provide effective and promising treatment strategies for RLPS or other types of tumors in a ROS-dependent manner.

BACKGROUND: Simple nanotube surface modification of titanium implant has been shown to promote adhesion, proliferation and differentiation of osteoblasts. Collagen coating can promote osteoblast adhesion and osseointegration in vivo. OBJECTⅠVE: To observe the effects of type collagen combined titanium dioxide nanotube composite coating modified titanium surface on osteoblast adhesion in vitro and osseointegration in vivo. METHODS: The titanium dioxide nanotube was fabricated on the pure titanium surface, then type Ⅰ collagen was combined with the nanotube structure to form composite coating. Scanning electron microscope observation was used to characterize the surface topography of the pure titanium, titanium dioxide nanotube and type Ⅰ collagen combined titanium dioxide nanotube surfaces. Contact angle test was employed to evaluate the hydrophilicity of different samples. MC3 T3-E1 murine preosteoblasts were seeded on the three kinds of materials for 4 hours. Cell adhesion morphology was examined by scanning electron microscope. Adherent cell counting was detected under inverted fluorescence microscope. Expression of actin cytoskeleton and vinculin was observed under laser scanning confocal microscope. The gene expression of vinculin and osteoprotegerin mRNA was detected by real-time quantitative PCR. The three kinds of samples were implanted into the tibia of Sprague-Dawley rats (provided by Laboratory Animal Center, Ⅰnstitute of Radiation Medicine, Chinese Academy of Medical Sciences) , and tibia samples were removed after 4 weeks of implantation for biological push-out test and histological observation. RESULTS AND CONCLUSⅠON: (1) Scanning electron microscope: There was mechanical scratch on the pure titanium surface. There was controllable, and uniform vertical arrangement of nanotubular structures with a diameter of approximately 70 nm on the titanium dioxide nanotube surface, and collagen adhered surrounding the nanotubular structures on the type Ⅰ collagen combined titanium dioxide nanotube substrate, and partial tubule orifices were closed. (2) The hydrophicility of type Ⅰ collagen combined titanium dioxide nanotube was significantly larger than those of the other two materials (P < 0.05) . (3) Compared with the pure titanium and titanium dioxide nanotube surfaces, the type Ⅰ collagen combined titanium dioxide nanotube substrate displayed increased adherent cell number, much well-organized cytoskeleton, enhanced immunofluorescence intensity of vinculin protein staining, and increased expression levels of vinculin and osteoprotegerin mRNA levels (all P < 0.05) . (4) Ⅰn vivo test revealed that the maximum push-out force in the type Ⅰ collagen combined titanium dioxide nanotube group was significantly higher than that in the pure titanium and titanium dioxide nanotube groups (P < 0.05) . Hematoxylin-eosin staining results showed that there were few bones, but many fibrous connective tissue surrounding the implant in the pure titanium group; there were more newly-born bones, and less fibrous connective tissue surrounding the implant in the titanium dioxide nanotube group; there were dense newly-born bones, and few thin fibrous connective tissue surrounding the implant in the type Ⅰ collagen combined titanium dioxide nanotube group. (5) These results indicate that type Ⅰ collagen combined titanium dioxide nanotube surface can facilitate osteoblast cell adhesion and promote osseointegration in vivo.

Objective To explore the effect of the rehabilitation self-efficacy of patient with total knee arthroplasty on the first time of ambulation after operation.Methods Totally 110 patients undergoing total knee arthroplasty were recruited,they were investigated with self-designed general information and disease situation questionnaire and recorded the first time of ambulation.The self-efficacy was measured by the Self-Efficacy for Rehabilitation outcome scale(SER).Results The earliest time of ambulation was 7.5 hours after surgery.The latest time of ambulation was 54.0 hours after surgery.The median time of the first ambulation was 46.0 h.The mean score of self-efficacy for rehabilitation therapy exercises was (28.58 ± 9.18) points,and the mean score of self-efficacy in overcoming barriers was (43.07 ± 11.04) points,and the mean score of SER was (71.65 ± 18.47) points.The total score of self-efficacy for rehabilitation therapy exercises,self-efficacy in overcoming barriers,and the score of SER were negatively correlated with the first time of ambulation (r=-0.442,-0.299,-0.399,P＜ 0.01).The self-efficacy of rehabilitation was one of the influencing factors of patient's first time of ambulation(P ＜ 0.05),which explained 9.7％ of total variance of early ambulation of patients with total knee arthroplasty.Conclusions The self-efficacy of rehabilitation after total knee arthroplasty was significantly correlated with the first time of ambulation,and the higher self-efficacy of rehabilitation,the earlier the first time of ambulation.The self-efficacy of rehabilitation was one of the important factors that affect the first time of the patient's ambulation after total knee arthroplasty.