Glioblastomas are the most aggressive brain tumors. Glioblastoma stem cells (GSCs) are thought to be responsible for the recurrence, chemoresistance, and poor prognosis of glioblastoma. Fatty acid binding protein 7 (FABP7), which is a cellular chaperone for a variety of omega-3 fatty acids, is a known marker for neural stem cells. In this study, using a newly developed anti-FABP7 antibody and patient-derived GSC lines, we evaluated the expression of FABP7 in GSCs. Using immunocytochemistry, Western blotting, and qPCR analyses, FABP7 was found to be highly enriched in GSCs and its localization was found in cytosol and nuclei. FABP7 expression was significantly downregulated in differentiated GSCs induced by the addition of serum. In the glioma surgical specimens, FABP7 was highly expressed in the majority of glioblastoma. Double immunostaining for FABP7 and Sox2 showed that FABP7 + Sox2 + tumor cells were significantly increased in glioblastoma (grade IV) compared with diffuse astrocytoma (grade II) and anaplastic astrocytoma (grade III). Our data introduces FABP7 as a marker for GSCs and further highlights its possible significance for glioma diagnosis and treatment.

The blood-brain-barrier (BBB) is formed by different cell types, of which brain microvascular endothelial cells are major structural constituents. The goal of this study was to examine the effects of cooling on the permeability of the BBB with reference to tight junction formation of brain microendothelial cells. The sensorimotor cortex above the dura mater in adult male Wistar rats was focally cooled to a temperature of 5 °C for 1 h, then immunostaining for immunoglobulin G (IgG) was performed to evaluate the permeability of the BBB. Permeability produced by cooling was also evaluated in cultured murine brain endothelial cells (bEnd3) based on measurement of trans-epithelial electric resistance (TEER). Immunocytochemistry and Western blotting of proteins associated with tight junctions in bEnd3 were performed to determine protein distribution before and after cooling. After focal cooling of the rat brain cortex, diffuse immunostaining for IgG was observed primarily around the small vasculature and in the extracellular spaces of parenchyma of the cortex. In cultured bEnd3, TEER significantly decreased during cooling (15 °C) and recovered to normal levels after rewarming to 37 °C. Immunocytochemistry and Western blotting showed that claudin-5, a critical regulatory protein for tight junctions, was translocated from the membrane to the cytoplasm after cooling in cultured bEnd3 cells. These results suggest that focal brain cooling may open the BBB transiently through an effect on tight junctions of brain microendothelial cells, and that therapeutically this approach may allow control of BBB function and drug delivery through the BBB.

In this study, all CBA patients exhibited right-to-left shunt. CBA might be caused by paradoxical embolization of a bacterial mass via PFO. Thus, more patients with CBA need to undergo TEE to detect PFO.

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Biomaterials to treat cancers hold therapeutic potential; however, their translation to bedside treatment requires further study. The carmustine (1,3-bis (2-chloroethyl)-1-nitrosourea; BCNU) wafer, a biodegradable polymer, currently is the only drug that is able to be placed at the surgical site to treat malignant tumors. However, how this wafer affects the surrounding tumor microenvironment is not well understood to date. We retrospectively reviewed all patients with glioblastoma treated with and without BCNU wafers who underwent repeat resection at tumor recurrence. We investigated radiological imaging; the interval between the two surgeries; and immunohistochemistry of CD3, CD4, CD8, CD20, CD68, FOXP3, and PD1. We implanted BCNU wafers in 41 newly diagnosed glioblastoma patients after approval of the wafer in Japan. Of them, 14 underwent surgery at recurrence and tissue was obtained from around the wafers. The interval between the first and second surgeries ranged from 63 to 421 days. The wafer could be observed on magnetic resonance imaging at up to 226 days, whereas intraoperatively the biodegraded material of the wafer could be found at up to 421 days after the initial surgery. Immunohistochemical analysis demonstrated that CD8+ and CD68+ cells were significantly increased, but FOXP3+ cells did not increase, after wafer implantation compared to tissue from cases without wafer implantation. MRI data and immune cells, as well as interval between surgeries and immune cells, demonstrated positive correlation. These results helped us to understand the bioactivity of bioengineered materials and to establish a new approach for immunotherapy.