Research progress of the effects of mtDNA deletion on the biological behavior of tumor cells

The writer summarizes the biological behavior of Mitochondrial DNA deleted cells (ρ0 cells) of multiple tumor cells to investigate the effects of mitochondrial DNA (mtDNA) deletion on tumor. Apoptosis, growth and invasion ability of tumor cells can be affected by mtDNA deletion. It can also induce the multidrugresistance phenotype of tumor cells. MtDNA deletion mainly affects the tumor in two aspects: energy metabolism and intracellular signal transduction. This study may lead to the development of anti-cancer drugs targeting mtDNA.

Volatile profile analysis and quality prediction of Longjing tea(Camellia sinensis) by HS-SPME/GC-MS

This study aimed to analyze the volatile chemical profile of Longjing tea, and further develop a prediction model for aroma quality of Longjing tea based on potent odorants. A total of 21 Longjing samples were analyzed by headspace solid phase microextraction (HS-SPME) coupled with gas chromatography-mass spectrometry (GC-MS).Pearson's linear correlation analysis and partial least square (PLS) regression were applied to investigate the relationship between sensory aroma scores and the volatile compounds. Results showed that 60 volatile compound scould be commonly detected in this famous green tea. Terpenes and esters were two major groups characterized,representing 33.89% and 15.53% of the total peak area respectively. Ten compounds were determined to contribute significantly to the perceived aroma quality of Longjing tea, especially linalool (0.701), nonanal (0.738), (Z)-3-hexenyl hexanoate (-0.785), and β-ionone (-0.763). On the basis of these 10 compounds, a model (correlation coefficient of89.4% and cross-validated correlation coefficient of 80.4%) was constructed to predict the aroma quality of Longjingtea. Summarily, this study has provided a novel option for quality prediction of green tea based on HS-SPME/GC-MStechnique.

Computer Navigation-aided Resection of Sacral Chordomas

Background： Resection of sacral chordomas is challenging. The anatomy is complex, and there are often no bony landmarks to guide the resection. Achieving adequate surgical margins is, therefore, difficult, and the recurrence rate is high. Use of computer navigation may allow optimal preoperative planning and improve precision in tumor resection. The purpose of this study was to evaluate the safety and feasibility of computer navigation-aided resection of sacral chordomas. Methods： Between 2007 and 2013, a total of 26 patients with sacral chordoma underwent computer navigation-aided surgery were included and followed for a minimum of 18 months. There were 21 primary cases and 5 recurrent cases, with a mean age of 55.8 years old （range： 35 84 years old）. Tumors were located above the level of the $3 neural foramen in 23 patients and below the level of the $3 neural foramen in 3 patients. Three-dimensional images were reconstructed with a computed tomography-based navigation system combined with the magnetic resonance images using the navigation software. Tumors were resected via a posterior approach assisted by the computer navigation. Mean follow-up was 38.6 months （range： 18-84 months）. Results： Mean operative time was 307 min. Mean intraoperative blood loss was 3065 ml. For computer navigation, the mean registration deviation during surgery was 1.7 ram. There were 18 wide resections, 4 marginal resections, and 4 intralesional resections. All patients were alive at the final follow-up, with 2 （7.7%） exhibiting tumor recurrence. The other 24 patients were tumor-free. The mean Musculoskeletal Tumor Society Score was 27.3 （range： 19-30）. Conclusions： Computer-assisted navigation can be safely applied to the resection of the sacral chordomas, allowing execution of preoperative plans, and achieving good oncological outcomes. Nevertheless, this needs to be accomplished by surgeons with adequate experience and skill.

Is There a Reliable Method to Predict the Limb Length Discrepancy after Chemotherapy and Limb Salvage Surgery in Children with Osteosarcoma？

Background： For a child with osteosarcoma, prediction of the limb length discrepancy at maturity is important when planning for limb salvage surgery. The purpose of this study was to provide a reliable prediction method. Methods： A retrospective review of Chinese children receiving chemotherapy for osteosarcoma before skeletal maturity was conducted. Standing full-length radiographs of the lower extremity were used for length measurements. Length-for-age curves were constructed using the LMS method. The lower limb multiplier for a specific age and gender was calculated using the formula M =Lm/L, where M was the gender- and age-specific multiplier, Lm was the bone length at maturity, and L was the age-specific bone length. Prematurity and postmaturity radiographs were used to assess the accuracy of the prediction methods. Results： A total of 513 radiographs of 131 boys and 314 radiographs of 86 girls were used to calculate the coefficients of the multiplier. The multipliers of 8-, 9-, 10-, 11-, 12-, 13-, 14-, 15-, 16-, 17-, and 18-year-old boys after chemotherapy for osteosarcoma were 1.394, 1.306, 1.231, 1.170, 1.119, 1.071, 1.032, 1.010, 1.004, 1.001, and 1.000, respectively; while for girls at the same ages, the multipliers were 1.311, 1.221, 1.146, 1.092, 1.049, 1.021, 1.006, 1.001, 1.000, 1.000, and 1.000, respectively. Prematurity and postmaturity femoral and tibial lengths of 21 patients were used to assess the prediction accuracy. The mean prediction error was 0 cm, 0.8 cm, and 1.6 cm fbr the multiplier method using our coefficients, Paley＇s coefficients, and Anderson＇s method, respectively. Conclusions： Our coefficients for the multiplier method are reliable in predicting lower limb length growth of Chinese children with osteosarcoma.

Magnetic Resonance Imaging for the Assessment of Long Bone Tumors

Background： Wide resection margins of osseous tumors are associated with a low incidence of local recurrence, making accurate measurement of the intraosseous extent of primary malignant long bone tumors is crucial. We compared the intraosseous tumor extent assessed by magnetic resonance imaging （MRI） with the gross specimen to evaluate the accuracy of MRI. Methods： A total of 255 patients with primary malignant tumors in the long bones were included. Using MRI, we defined the length of tumor as the distance from the articular surface to the boundary between abnormal and normal marrow signal. The extent of the abnormal intraosseous signal was measured on unenhanced T1-weighted （T1WI） magnetic resonance images after chemotherapy. All gross surgical specimens were sectioned, and tumor extent was measured. Wilcoxon signed-rank test was used to test the differences between MRI and gross specimen findings. Spearman＇s correlation analysis was used to test the correlation between groups. Results： Median tumor length by gross specimen （112 mm; range, 45–300 mm） was longer than that by MRI （108 mm; range, 45–304 mm;Z = -6.916, P 〈 0.001）. Of 255 images, tumor length was accurately represented on 27 T1WI magnetic resonance images, overestimated on 79 images, and underestimated on 149 images. The median difference between imaging and gross specimen measurements was 2.0 mm （range： 1.0–15.0 mm） for the 79 cases where tumor length was overestimated, and 5.0 mm （range： 1.0–18.0 mm） for the 149 cases where tumor length was underestimated. The Spearman correlation demonstrated a high correlation of tumor length on gross specimen with the tumor length on MRI （R = 0.99, P 〈 0.01）. Conclusions： We conclude that preoperative MRI could be a useful method in determining intramedullary malignant bone tumor boundaries and may serve as an accepted assessment method of long bone tumors before limb-sparing surgery.

Biomechanical Properties of Synthetic Mesh Reconstructed Glenohumeral Joint Capsule

Synthetic mesh is often used in soft tissue reconstruction after artificial prosthesis replacement for patients with proximal humeral bone tumors.We carried out biomechanical and histological tests on two amputated extremities to test the stability of the joint and the biocompatibility of the synthetic meshes.