Metabolic features and oxidative stress have been extensively studied in cancer cells. However, comparative studies between cancer cell populations that coexist in human neoplastic tissue are not frequently available. The aim of the present study was to characterize markers of oxidative status and mitochondrial function in center vs. periphery of human fresh glioma samples; therefore, antioxidant systems, oxidative stress and mitochondrial parameters were assessed in gross total resections of gliomas. Mitochondrial protein and mitochondrial DNA content, enzymatic activities of mitochondrial oxidative and phosphorylative system, antioxidant mechanisms, mitochondrial H₂O₂ production, oxygen consumption and cellular oxidative damage were measured in human gliomas. Concentric regions of human glioma tissue showed similar mitochondrial structural markers; conversely, the functionality of their isolated mitochondria was significantly different. In this way, the tumor periphery exhibited higher respiratory rate and fewer antioxidant systems than tumor center. Our results have expanded previous investigations, which report the presence of cell populations with different oxidative susceptibility in human brain tumor samples. This is, to our knowledge, the first study to investigate metabolic differences in concentric regions of gross total resections of glioma. Interestingly, the cancer cell population that exhibits an increased antioxidant capacity within the tumor mass might be responsible for tumor resistance to chemotherapy and radiotherapy.

Amebic encephalitis is an uncommon central nervous system infection, usually caused by Acanthamoeba spp., which generally occurs in immunocompromised individuals. The infection might start from a minor, slowly progressive, skin ulceration that can be present for weeks to months before neurologic changes occur. We present a 40-year-old male with multiple visceral allografts, on immunosuppression, 9 months after transplantation. He had an active skin rash previously diagnosed as graft-versus-host disease by biopsy. The condition of the patient declined rapidly.

A 77-year-old woman presented with a 3-month history of a painless, progressively enlarging mass on the right side of the forehead. She reported no associated constitutional or neurological symptoms. Local examination revealed a 5 cm, domeshaped, tender mass. CT and MRI showed a well circumscribed, 11 × 10 × 7.5 cm osteolytic lesion in the right front-parietal region, which infi ltrates the overlying skin and the frontal lobe.Treatment included radical excision of the lesion and skin reconstruction with a microvascular free fl ap. Histopathological examination confi rmed the diagnosis of plasmacytoma with Lambda light chain restriction of the frontal bone. Th e patient had an uneventful recovery from the procedure and was subsequently referred to a haematologist to detect a possible multiple myeloma. On laboratory examination, there was anaemia and low albumin levels. Creatinin levels did not show renal dysfunction. A monoclonal IgG Lambda component was detected in serum protein electrophoresis.A bone scan was performed that revealed multiple osteolytic lesions in the cranial vault, ribs and both humerus, confi rming the diagnosis of a multiple myeloma. Th e patient was treated with radiotherapy (40 Gy on the frontal lesion) and chemotherapy (melphalan and prednisone), but died of disease 18 months after the diagnosis.