Masahiro Kagawa

Association between YKL-40 and adult primary astrocytoma.

The YKL‐40 coding chitinase 3‐like 1 gene is 1 of the most overexpressed genes in human glioblastomas. The objectives of this study were to explore YKL‐40 protein expression status and World Health Organization (WHO) pathologic grades of primary human astrocytoma and to investigate the role of YKL‐40 in the proliferation of both established and primary astrocytoma cells in vitro.

Treatment of vasogenic brain edema with arginine vasopressin receptor antagonist--an experimental study.

We determined the effect of a centrally administered V1 receptor antagonist of arginine vasopressin on the brain water content in an animal model of vasogenic brain edema. Using adult rats, a cold injury was induced in the left hemisphere of the brain by applying a frozen copper rod. 50 ng of V1 receptor antagonist was administered into the left lateral ventricle 10 minutes prior to and/or 1 hour after injury. Twenty four hours after the cold injury, the brain water and sodium contents and plasma osmolality were measured. The V1 receptor antagonist significantly suppressed the increase of the brain water and sodium contents in the cortical structure adjacent to the lesion without any changes in plasma osmolality. Our results demonstrate the effectiveness of a V1 receptor antagonist of vasopressin on vasogenic brain edema.

Indications and limitations of endoscopic endonasal orbitotomy for orbital lesion.

Background Endoscopic endonasal surgical techniques have developed tremendously in the last 20 years. Endoscopic techniques have been applied to the treatment of cranial base lesions, pituitary tumors, orbital lesions, pterygopalatine fossa lesions, infratemporal fossa lesions, posterior cranial fossa lesions, and clival lesions. In some reports, endoscopic endonasal transparanasal orbitotomies have been indicated for lesions localized to the medial and inferomedial parts of the orbit. The aim of this article was to present the technique of endoscopic endonasal orbitotomy (EEO) for orbital extraperiosteal and intraperiosteal lesions, as well as its indications and limitations. Methods We present cases of 4 patients who underwent EEO for typical extraperiosteal and intraperiosteal orbital lesions. We examined the indications and limitations in each case. Results All 4 orbital lesions were completely removed by EEO with no major complications. Conclusions The EEO procedure, which does not require a skin incision, is a minimally invasive surgery used for treating orbital retrobulbar lesions. It leads to excellent cosmetic results with little bleeding. In the future, we need to determine its operative indications, safety, and dangers. It is necessary for us to further improve this surgical technique to allow for the generalization of the procedure.

Treatment of Vasogenic Brain Edema by V1 Receptor Antagonist of Arginine Vasopressin

Centrally released arginine vasopressin (AVP) has been reported to increase the water permeability of brain capillaries under normal and pathological conditions. In present experiment, we divided cold-injured brain into cortical and deep structure, and studied the effect of central administration of V1 receptor antagonist (5 ng, 50 ng, and 500 ng per rat) on vasogenic brain edema. Cold injury induced significant increases in brain water and tissue sodium content of bilateral cortical structures, but no changes in bilateral deep structures. Intraventricular administration of Vi receptor antagonist (50 ng) significantly reduced this accumulation of water and sodium in cortical structures without any change in plasma osmolality. A large quantity of this antagonist (500 ng) showed no changes in brain water content of bilateral cortical structures. It is suggested that this antagonist has an optimal concentration of this antagonist for inhibiting vasogenic brain edema.