Yasuhiko Hayashi

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A 55-year-old man was admitted to our hospital complaining of left hemiparesis. Magnetic resonance imaging (MRI) showed a smooth ring-like enhanced cystic tumor in the right parietal lobe. He underwent gross total resection of the tumor under neuronavigation and 5-aminolevulinic acid (5-ALA) fluorescence guiding method. Histopathological examination of the(More)
Although there are many reports on the clinical use of the MIB-1 labeling index (LI), which is a measure of proliferative activity in astrocytomas; its significance varies between studies. There are no known molecules that are directly linked to the MIB-1 LI in astrocytomas. We evaluated the clinical value of the MIB-1 LI in our human glioblastoma cases and(More)
OBJECTIVES Hemangiopericytomas (HPCs) are rare neoplasms with relatively high rates of recurrence and extracranial metastasis. Though the differential diagnoses from angiomatous meningiomas and from solitary fibrous tumors (SFTs) are both important, the latter diagnosis is somewhat more important in light of the benign prognosis of SFTs and the difficulties(More)
High-grade (World Health Organization grades II and III) meningiomas grow aggressively and recur frequently, resulting in a poor prognosis. Assessment of tumor malignancy before treatment initiation is important. We attempted to determine predictive factors for high-grade meningioma on magnetic resonance (MR) imaging before surgery. We reviewed 65(More)
OBJECT Fluorescence-guided surgery using 5-aminolevulinic acid (5-ALA) has been broadly recognized as a beneficial tool for the resection of glioblastoma multiforme (GBM). Fluorescence in the ventricular walls, which were apparently free of macroscopic tumor or MR imaging enhancement indicative of CSF dissemination, was detected during surgery for GBM. To(More)
BACKGROUND Pituitary apoplexy during pregnancy is so rare that only 15 cases (12 pituitary adenomas, 2 lymphocytic neurohypophysitis, and 1 normal pituitary gland) have been published to date. Here, we report the case of a pregnant woman presenting with pituitary apoplexy from a nonfunctioning pituitary adenoma and provide a possible mechanism and(More)
A number of diarylmethanofullerene derivatives were synthesized. The cyclopropane ring of the derivatives has two aryl groups substituted with electron-withdrawing and -donating groups, the latter with long alkyl chains to improve solubility in organic solvents, an important property in processing cells. First reduction potentials of most derivatives were(More)
A 5-year-old male presented with scrotal migration of the catheter from a ventriculoperitoneal shunt manifesting as left scrotal swelling 4 months after implantation. Surgical obliteration of the patent peritoneal processus vaginalis that forms a corridor from the peritoneum to the scrotum was performed to avoid shunt malfunction. Review of the 26 reported(More)
Zinc oxide (ZnO) nanoparticles are widely used in various products, and the safety evaluation of this manufactured material is important. The present study investigated the inflammatory and fibrotic effects of pulmonary exposure to ZnO nanoparticles in a mouse model of pulmonary fibrosis. Pulmonary fibrosis was induced by constant subcutaneous infusion of(More)
Schwannomas of the orbit are very rare benign neoplasms. Intraorbital cystic schwannomas originating from the frontal nerve are even rarer, with only 1 case reported to date. This is most likely due to the fact that, in most cases, the origin of the orbital schwannoma cannot be identified intraoperatively. The nerve origin is usually speculated from(More)