Clinical diagnostic utility of contrast-enhanced three-dimensional fluid-attenuated inversion recovery for selection of brain biopsy sites in neurosarcoidosis: A case report.

Neurosarcoidosis is difficult to diagnose, because definite diagnosis requires detailed histology of the central nervous system. Three-dimensional contrast-enhanced fluid-attenuated inversion recovery (CE-FLAIR) is more useful for detecting leptomeningeal lesions compared with 3D CE-T1 weighted imaging. However, the clinical diagnostic utility of 3D CE-FLAIR for neurosarcoidosis is unclear. We describe a case of a 46-year-old Japanese woman who was admitted to our department due to chronic headache with fever and diplopia. Using 3D CE-FLAIR, we performed brain biopsy from right cerebellar lesion. The histological examination revealed typical non-caseating granulomas, indicating neurosarcoidosis. Our findings suggest that 3D CE-FLAIR may detect leptomeningeal lesions that are candidates for biopsy in chronic meningitis undetermined etiology.

Inhibitory effects of trichostatin A on adrenocorticotropic hormone production and proliferation of corticotroph tumor AtT-20 cells.

Cushing's disease is primarily caused by adrenocorticotropic hormone (ACTH)-producing pituitary adenomas. Pituitary tumor-transforming gene 1 (PTTG1) expression, a hallmark of pituitary tumors, stimulates pituitary cell proliferation. Histone deacetylases (HDACs) play an important role in regulating gene transcription and HDAC inhibitors induce cellular differentiation and suppress tumor cell proliferation. HDAC inhibitors also repress PTTG1 mRNA levels. Trichostatin A (TSA) is a potent cell-permeable HDAC inhibitor that blocks cell cycle progression. In the present study, we determined the effect of TSA on ACTH production and cellular proliferation in mouse AtT-20 corticotroph tumor cells. TSA decreased proopiomelanocortin (POMC) mRNA levels in AtT-20 cells and reduced ACTH levels in the culture medium of these cells. The TSA-induced decreases in POMC mRNA levels were not modulated when TSA and dexamethasone were simultaneously administered. Drug treatment also decreased AtT-20 cell proliferation, induced apoptosis, and increased the percentage of cells in G0/G1 phase using flow cytometry. TSA decreased PTTG1 mRNA levels. Furthermore, PTTG1 knockdown inhibited cellular proliferation. Its knockdown also inhibited POMC mRNA and ACTH levels. TSA inhibits ACTH production and corticotroph tumor cell proliferation. TSA may inhibit cellular proliferation, and ACTH synthesis and secretion by decreasing PTTG1 expression.