RESUMO
Background: Histone deacetylases (HDACs) regulate gene expression by changing histone deacetylation status. Neurotoxicity is one of the major side effects of cisplatin, which reacts with deoxyribonucleic acid (DNA) and has excellent antitumor effects. Suberoylanilide hydroxamic acid (SAHA) is an HDAC inhibitor with neuroprotective effects against cisplatin-induced neurotoxicity. Purpose: We investigated how cisplatin with and without SAHA pretreatment affects HDAC expression/activity in the brain by using 6-([18F]fluoroacetamido)-1-hexanoicanilide ([18F]FAHA) as a positron emission tomography (PET) imaging agent for HDAC IIa. Materials and Methods: [18F]FAHA and [18F]fluoro-2-deoxy-2-D-glucose ([18F]FDG) PET studies were done in 24 mice on 2 consecutive days and again 1 week later. The mice were divided into three groups according to drug administration between the first and second imaging sessions (Group A: cisplatin 2 mg/kg, twice; Group B: cisplatin 4 mg/kg, twice; Group C: cisplatin 4 mg/kg, twice, and SAHA 300 mg/kg pretreatment, 4 times). Results: The Ki value of [18F]FAHA was increased and the percentage of injected dose/tissue g (% ID/g) of [18F]FDG was decreased in the brains of animals in Groups A and B. The Ki value of [18F]FAHA and % ID/g of [18F]FDG were not significantly different in Group C. Conclusions: [18F]FAHA PET clearly showed increased HDAC activity suggestive of cisplatin neurotoxicity in vivo, which was blocked by SAHA pretreatment.
Assuntos
Cisplatino/efeitos adversos , Histona Desacetilases/metabolismo , Síndromes Neurotóxicas/diagnóstico por imagem , Tomografia por Emissão de Pósitrons/métodos , Compostos Radiofarmacêuticos/química , Animais , Antineoplásicos/efeitos adversos , Encéfalo/metabolismo , Radioisótopos de Flúor , Fluordesoxiglucose F18/metabolismo , Fluordesoxiglucose F18/farmacocinética , Histona Desacetilases/análise , Camundongos , Síndromes Neurotóxicas/etiologia , Compostos Radiofarmacêuticos/farmacocinética , Vorinostat/farmacologia , Vorinostat/uso terapêuticoRESUMO
PURPOSE: To evaluate the CAD system for screening mammograms. MATERIALS AND METHODS: Mammograms of patients with asymptomatic breast cancerwere examined retrospectively. A total of 260 screening mammograms from 65 patients (bilateral cranio-caudal and medio-lateral-oblique views from each) were tested by using the CAD system (ImageChecker M1000 system, R2 Technology, Los Altos, CA, USA). Results: With 0.58 microcalcifications marks/film and 0.20 mass marks/film set as the false positive rate, 100% of microcalcifications cases and 79% of mass cases were detected correctly. Conclusion: The CAD system has the potential to become a second reader. Further developments are expected to improve the accuracy of detection of mass lesions
