Search

We report the case of a 70‐year‐old woman with metastatic brain tumors who underwent surgical removal of the tumor and radiation necrosis. The patient had a history of colon cancer and had undergone surgical removal of a left occipital tumor. Histopathological evaluation revealed a metastatic brain tumor. The tumor recurred six months after surgical removal, followed by whole‐brain radiotherapy, and the patient underwent stereotactic radiosurgery. Six months later, the perifocal edema had increased, and the patient became symptomatic. The diagnosis was radiation necrosis and corticosteroids were initially effective. However, radiation necrosis became uncontrollable, and the patient underwent removal of necrotic tissue two years after stereotactic radiosurgery. Pathological findings predominantly showed necrotic tissue with some tumor cells. Since the vascular endothelial growth factor (VEGF) and hypoxia‐inducible factor‐1α (HIF‐1α) were expressed around the necrotic tissue, the main cause of the edema was determined as radiation necrosis. Differences in the expression levels and distribution of HIF‐1α and VEGF were observed between treatment‐naïve and recurrent tumor tissue and radiation necrosis. This difference suggests the possibility of different mechanisms for edema formation due to the tumor itself and radiation necrosis. Although distinguishing radiation necrosis from recurrent tumors using MRI remains challenging, the pathophysiological mechanism of perifocal edema might be crucial for differentiating radiation necrosis from recurrent tumors. [ABSTRACT FROM AUTHOR]

On the basis of new concept using a solid disperse phase we have developed an efficient catalytic solid-phase-system for epoxidations of alkenes using urea–hydrogen peroxide (urea–H2O2) complex and cetylpyridinium dodecatungstate ((CetylPy)10[H2W12O42]) catalyst on fluorapatite (FAp). The recovered solid catalyst phase was reused to keep the catalytic activity after several times. In the conceptual idea it is a key point that in situ solid-phase-activation of the catalyst with urea–H2O2 proceeds to form microcrystals of the active species dispersed on the solid phase. The dispersion of the catalyst on FAp in the case of tungstic acid (H2WO4) was suggested by EPMA analysis. We proposed the peroxo type of species keeping the parent polyoxometalate framework as novel active species from FT-IR spectroscopic studies. FAp phase plays important roles of dispersing the active species on its surface to have high catalytic activity and of stabilizing the active species to lead to high reusability. [Copyright &y& Elsevier]

Objective: We report an unusual case of tentorial dural arteriovenous fistula(DAVF)with bithalamic lesions and bilateral intracranial hemorrhage., Case Presentation: A 73-year-old man presented with lethargy and progressive cognitive decline. Imaging demonstrated bithalamic edematous lesions and bilateral basal ganglia hemorrhage in the right putamen and left internal capsule. Angiography revealed tentorial DAVF fed by both the internal and external carotid arteries. A shunted pouch was present in the superior petrosal sinus, and retrograde reflux drainage was see in the deep venous system, including the basal vein, vein of Galen, and internal cerebral veins with congestion. Initially, transarterial embolization was palliatively performed, and subsequently, a microsurgery achieved obliteration of the tentorial DAVF. Postoperatively, the bilateral thalamic changes disappeared, although sequela of the intracranial hemorrhage persisted., Conclusion: Deep venous congestion due to tentorial DAVF induced unusual bithalamic lesions and bilateral basal ganglia hemorrhage. Tentorial DAVF was treated with combined endovascular and surgical operations. Tentorial AVF is an aggressive vascular disease, and prompt diagnosis and treatment are necessary.

Endoscopic third ventriculostomy(ETV)is the first-line treatment for fourth ventricle outlet obstruction(FVOO)-associated hydrocephalus. However, because FVOO is difficult to diagnose in the acute stage, ventriculoperitoneal shunt(VPS)is also used. Herein, we report two cases of shunted FVOO resulting in overdrainage or slit ventricle syndrome(SVS)that were treated successfully with the shunt-clamp system. In addition, we discuss the efficacy of the shunt-clamp system for FVOO-associated hydrocephalus. CASE 1:A 79-year-old man complained of severe postural headaches. One year earlier, he underwent VPS for secondary hydrocephalus associated with hemorrhagic cerebellar infarction. CT revealed that the ventricle had become slit-like. Although the shunt valve adjusted the maximum pressure, his complaint and the ventricle shape did not improve. After the on-off valve was inserted in the shunt system and clamped, his symptoms were resolved and the ventricle size was normalized. CASE 2:A 21-year-old man who complained of drowsiness, diplopia, and severe intermittent retroocular pain was admitted to our hospital. One year earlier, he underwent VPS with the shunt-clamp system for a secondary hydrocephalus after surgery for medulloblastoma. CT on admission revealed ventricle dilatation;however, the shape of the ventricle became slit-like 3 days after admission. We made a diagnosis of SVS and planned ETV. Owing to the difficulty in approaching the lateral ventricle, the shunt system was clamped 8 hours before the operation. After confirming ventricle dilatation, ETV was successfully performed. After the operation, the symptoms were resolved, and magnetic resonance imaging confirmed that the ventricle size was normalized.