Glutathione peroxidase and glutathione S-transferase in blood and liver from a hypoxia-tolerant fish under oxygen deprivation.

Liver enzyme activities can be employed as biomarkers, but liver can only be obtained with death of the specimen. On the other hand, blood withdrawal is a non-lethal procedure. Accordingly, the hypothesis of this study is to verify if glutathione peroxidase (GPX) and glutathione S-transferase (GST) activities in blood parallel those in the liver of the hypoxia-tolerant fish, Piaractus mesopotamicus (pacu), submitted to hypoxia conditions. GPX was assayed with H2O2 in cytosols from both liver and erythrocytes and exhibited no significant variation, either in erythrocytes or in liver, when comparing pacus under normoxia with those under hypoxia (42 h). GST activity with chloro-dinitrobenzene (CDNB), an artificial substrate suitable for almost all GST isoenzymes, was compared to activity with 4-hydroxy-nonenal (4-HNE), a physiological endogenous substrate. GST activity with CDNB did not change in liver or in erythrocyte cytosols in pacus under hypoxia compared to those under normoxia. On the other hand, a significant decrease in erythrocyte activity with 4-HNE was observed after 42 h of hypoxia in both erythrocytes and liver, which may be a response to increased lipid oxidation in erythrocytes. Erythrocyte GST activity was 3-fold higher with 4-HNE than with CDNB, indicating that 4-HNE is a more appropriate substrate to determine GST activity in pacu erythrocytes.

Extensive central ossifying fibroma of the maxilla: a case report with description of an alternative surgical technique.

Central ossifying fibroma (COF) is a fibrous-osseous lesion containing fibrous tissue and varying amounts of calcified tissue. Although the lesion is preferentially located in the jaws, it may be found elsewhere. It usually affects patients during their third and fourth decades of life, with a female predilection. The mandibular premolar-molar area is the most common site. Radiographically, COF may present a radiolucent, radiopaque or a mixed appearance. This article reports a case of an extensive COF in the maxilla of a 62-year-old patient. Intraoral examination revealed a swelling with undefined limits in the right side of the upper alveolar ridge, extending towards the palate. The lesion had invaded the maxillary sinus, nasal cavity and orbit. An incision including mucosa, periosteum, and a thin layer of the bone, was performed. The lesion was excised using a flap, and interrupted suture was utilized. The bone which was preserved in the flap was used as graft so that faster and more effective bone formation could occur. The patient has been followed-up for 5 years with no clinical or radiographic signs of recurrence. This article demonstrates that COF has a considerable growth potential. In addition, the surgical technique here in described shows very good cosmetic and functional results, especially when managing very large lesions.