Essential language sites and the arcuate fasciculus（AF） have been extensively researched. However, the relationship between them remains insufficiently studied,especially in healthy people. Navigated transcranial magnetic stimulation（n TMS） is increasingly used in language mapping. While enjoying the advantage of non-invasiveness, it is also capable of inducing a virtual lesion in the brain. Thus, it offers the possibility of using the virtuallesion method to study the healthy brain. This study combined n TMS and diffusion tensor imaging（DTI）tractography to investigate the relationship between essential language sites and the AF in 30 healthy right-handedvolunteers. A total of 143 essential language sites were identified using n TMS, and a total of 175 AF terminations were identified using DTI tractography. Sixty-six sites had a direct correlation with the AF, accounting for 46% of the total essential language sites. Forty-seven AF terminations harbored essential language sites, accounting for 27% of the total AF terminations. Upon data rendering to the cortical parcellation system, a region-related heterogeneity of the correlation rate was found. This study provides the first data on the relationship between essential language sites and the AF in healthy adults.
Background Recent studies have suggested that cancer stem cells are one of the major causes for tumor recurrence due to their resistance to radiotherapy and chemotherapy. Although the highly invasive nature of glioblastoma （GBM） cells is also implicated in the failure of current therapies, it is not clear how glioma stem cells （GSCs） are involved in invasiveness. Racl activity is necessary for inducing reorganization of actin cytoskeleton and cell movement. In this study, we aimed to investigate the distribution characteristics of CD133＋ cells and Racl＋ cells in GBM as well as Racl activity in CD133＋ GBM cells, and analyze the migration and invasion potential of these cells. Methods A series of 21 patients with GBM were admitted consecutively and received tumor resection in Tianjin Medical University General Hospital during the first half of the year 2011. Tissue specimens were collected both from the peripheral and the central parts for each tumor under magnetic resonance imaging （MRI） navigation guidance. Immunohistochemical staining was used to detect the CD133＋ cells and Racl＋ cells distribution in GBM specimens. Double-labeling immunofluorescence was further used to analyze CD133 and Racl co-expression and the relationship between CD133＋ cells distribution and Racl expression. Serum-free medium culture and magnetic sorting were used to isolate CD133＋ cells from U87 cell line. Racl activation assay was conducted to assess the activation of Racl in CD133＋ and CD133- U87 cells. The migration and invasive ability of CD133＋ and CD133- U87 cells were determined by cell migration and invasion assays in vitro. Student＇s t-test and one-way analysis of variance （ANOVA） test were used to determine statistical significance in this study. Results In the central parts of GBMs, CD133＋ cells were found to cluster around necrosis and occasionally cluster around the vessels under the microscope by immunohistological staining. In the peripheral parts of the tumors, CD133＋ cells were line
ZHANG Bin SUN Jian YU Sheng-ping CHEN Cong LIU Bin LIU Zhi-feng REN Bing-cheng MING Hao-lang YANG Xue-jun
