Computer-assisted sacral tumor resection. A case report

Resection of sacral tumors is one of the most difficult operations in orthopaedic oncology because complex imaging modalities is that intraoperative identification can increase the accuracy of surgical resection. We report a case of sacral chondrosarcoma in which computer-assisted surgery provided intraoperative real-time imaging, thereby allowing us to achieve adequate surgical margins while preserving the sacral nerve roots. Additionally, the tumor resection was carried out through a posterior approach only. The patient was informed that data concerning the case would be submitted for publication, and he consented. anatomy and important internal organs in the pelvic area make it difficult to achieve wide surgical margins1. Wide resection of sacral tumors may lead to serious functional impairments due to injury to important internal organs and/or the lumbosacral nerve roots or through the disruption of loadbearing through the sacroiliac joint. Recent advances in diagnostic modalities facilitate better surgical planning and can help in the performance of surgeries as planned. Computer-assisted surgery has been used in orthopaedic operations such as cruciate ligament reconstruction, hip and knee arthroplasty, and pedicle screw placement. The main advantage of computer-assisted navigation over othe

Spatially resolved penetration depth measurements and vortex manipulation in the ferromagnetic superconductor ErNi2B2C

We present a local probe study of the magnetic superconductor, ErNi$_2$B$_2$C, using magnetic force microscopy at sub-Kelvin temperatures. ErNi$_2$B$_2$C is an ideal system to explore the effects of concomitant superconductivity and ferromagnetism. At 500 mK, far below the transition to a weakly ferromagnetic state, we directly observe a structured magnetic background on the micrometer scale. We determine spatially resolved absolute values of the magnetic penetration depth $\lambda$ and study its temperature dependence as the system undergoes magnetic phase transitions from paramagnetic to antiferromagnetic, and to weak ferromagnetic, all within the superconducting regime. In addition, we estimate the absolute pinning force of Abrikosov vortices, which shows a position- and temperature dependence as well, and discuss the possibility of the purported spontaneous vortex formation

EMMPRIN expression is associated with metastatic progression in osteosarcoma

Background Extracellular matrix metalloproteinase inducer (EMMPRIN), a cell-surface glycoprotein, is overexpressed in several cancer types. EMMPRIN induces a metastatic phenotype by triggering the production of matrix metalloproteinase proteins (MMPs) such as MMP1 and MMP2, and vascular endothelial growth factor (VEGF) in cancer cells and the surrounding stromal cells. The purpose of this study was to investigate the expression and role of EMMPRIN in osteosarcoma. Methods The level of EMMPRIN expression was evaluated using reverse transcriptase polymerase chain reaction (RT-PCR) in 6 tumor-derived osteosarcoma cell lines and compared with that in normal osteoblasts. To study the prognostic significance of EMMPRIN expression, immunohistochemistry was carried out in prechemotherapy biopsies of 54 patients. siRNA knockdown of EMMPRIN in SaOS-2 cells was conducted to explore the role of EMMPRIN. To study the role of EMMPRIN in tumor-stromal interaction in MMP production and invasion, co-culture of SaOS-2 cells with osteoblasts and fibroblasts was performed. Osteosarcoma 143B cells were injected into the tail vein of BALB/c mice and lung metastasis was analyzed. Results EMMRIN mRNA expression was significantly higher in 5 of 6 (83%) tumor-derived cells than in MG63 cells. 90% of specimens (50/54) stained positive for EMMPRIN by immunohistochemistry, and higher expression of EMMPRIN was associated with shorter metastasis-free survival (p = 0.023). Co-culture of SaOS-2 with osteoblasts resulted in increased production of pro-MMP2 and VEGF expression, which was inhibited by EMMPRIN-targeting siRNA. siRNA knockdown of EMMPRIN resulted in decreased invasion. EMMPRIN shRNA-transfected 143B cells showed decreased lung metastasis in vivo. Conclusions Our data suggest that EMMPRIN acts as a mediator of osteosarcoma metastasis by regulating MMP and VEGF production in cancer cells as well as stromal cells. EMMPRIN could serve as a therapeutic target in osteosarcoma.The authors declare that they have nothing to disclose. This study was supported by National Research Foundation of Korea Grant funded by the Korean Government (Grant no. 2009–0136) and Doosan Yonkang Foundation (Grant no. 30–2014-0120). The funding body had no role in the design of the study and collection, analysis, and interpretation of data and in writing this manuscript