Brain metastasis frequently occurs in cancer patients and is associated with a poor prognosis. We previously reported that S100B was highly expressed in PC14/B, a specific brain metastatic lung adenocarcinoma cell line, which suggests that it is associated with brain metastasis of lung cancer. However, the role of S100B in brain metastasis remains to be elucidated. In this study, using PC14/B cell line, we found that siRNA mediated depletion of S100B in PC14/B cells led to notable differences in cell proliferation, apoptosis, cell cycle progression, colony formation ability, cell migratory and invasive activity compared with the mock-transfected cells. Therefore, our data suggest that S100B promotes the brain metastasis of lung adenocarcinoma by promoting cell proliferation, preventing apoptosis and increasing cell migration and invasion.
BackgroundAlthough bone defect is one of the most common orthopaedic diseases, treatment remains a challenge and an issue of debate. Guided bone regeneration (GBR) is primarily accompanied by barrier membranes; however, optional membranes show some inherent flaws in clinical application. The purpose of this study was to observe the healing velocity and quality of repairing canine radius segmental defect using transferred autologous periosteum combined with fascia lata, which can provide better biological safety than other materials.Materials and methodsTwenty adult male beagles weighing 11.45 ± 1.29 kg were used as animal models. The animals were randomly allocated into three groups, a blank control group, a fascia lata control group and a combined fascia lata and periosteum group. Standardised artificial bony defects were prepared at the radius and treated with autologous periosteum combined with fascia lata under stable external fixation. The newly formed bone-growth curve was made according to ultrasound (US) detection, and histopathologic and scanning electronic microscope (SEM) evaluations were also performed.ResultsBone union was seen in most individuals from the autologous periosteum combined with fascia lata group, within an average of 14.2 weeks. Histopathologic and SEM examinations both showed the different osteogenesis state between groups. Necropsy confirmed US findings with regard to distance of bone defects and location.ConclusionThese findings suggest that autologous periosteum combined with fascia lata is as effective as a GBR membrane, even in long tubular bone defects. With reliable biological safety, the autologous periosteum combined with fascia lata is expected to achieve increasing application in orthopaedic trauma patients.Level of evidenceNot applicable, animal study.
Background In orthopedic application, stress-shielding effects of implant materials cause bone loss, which often induces porosis, delayed bone healing, and other complications. We aimed to compare the stress-shielding effects of locked compression plate (LCP) and limited-contact dynamic compression plate (LC-DCP) in dogs with plate-fixed femurs. Methods Bilateral intact femurs of 24 adult dogs were fixed by adult forearm 9-hole titanium plates using minimally invasive plate osteosynthesis (MIPPO) technology, with LCP on the left and LC-DCP on the right femurs. Dogs were sacrificed at 6 weeks, 12 weeks, and 24 weeks after surgery, and bone specimens were used to evaluate the efficacies of different fixing methods on bones through X-ray, dual-energy X-ray absorptiometry (DEXA), histology, MicroCT, and biomechanics analyses. Results X-ray results showed significant callus formation and periosteal reaction in the LC-DCP group. Bone cell morphology, degree of osteoporosis, and bone mineral density (BMD) changes of the LCP group were significantly better than that of the LC-DCP group. MicroCT results showed that the LCP group had significantly reduced degree of cortical bone osteoporosis than the LC-DCP group. Tissue mineral density (TMD) in the LCP group was higher than that in the LC-DCP group at different time points (6 weeks, 12 weeks, and 24 weeks). Biomechanics analyses demonstrated that the compressive strength and flexural strength of bones fixed by LCP were better than that by LC-DCP. Conclusions Stress-shielding effects of LCP are significantly weaker than that of LC-DCP, which is beneficial to new bone formation and fracture healing, and LCP can be widely used in clinic for fracture fixation.
Background This study investigated the cardioprotective effect of isosorbide dinitrate (ISDN) postconditioning against rat myocardial ischemia/reperfusion injury in vivo and provided a theoretical basis for clinical application. Material/Methods We randomly divided 32 Wistar rats into 4 groups: sham group, I/R (ischemia/reperfusion) group, I-PostC group (with 3 cycles of 30 s reperfusion and 30 s reocclusion applied at the onset of reperfusion), and P-PostC group (nitrate postconditioning: isosorbide dinitrate (5mg/kg) was given 1 min before reperfusion). The left anterior descending artery (LAD) was occluded for 40 min, followed by a 180-min reperfusion. Relevant indicators were tested. The LAD was occluded again, then we determined the myocardial infarct size. Paraffinized sections were prepared and TUNEL detection was performed. Results There were no significant differences in ischemic sizes between different groups. Compared with the I/R group, the levels of cTnI and myocardial infarct size in the I-PostC group and P-PostC group were significantly decreased (p<0.05). However, there were no significant difference between the I-PostC group and P-PostC group. Compared with the sham-operated group, the levels of cTnI and MDA in the I/R group, I-PostC group, and P-PostC group were significantly increased (p<0.05) and the levels of SOD were significantly decreased (p<0.05). Compared with the I/R group, I-PostC and P-PostC decreased the level of MDA and increased the level of SOD (both P <0.05). Conclusions ISDN postconditioning induces a similar cardioprotective effect as I-PostC. The potential mechanisms of cardioprotection of ISDN postconditioning might be via improvement of myocardial antioxidant capacity and reduced generation of reactive oxygen species.
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