RESUMEN
Naringin (NRG) is a flavonoid with recognized cardioprotective effects. Then, it was investigated the cardioprotective mechanisms of NRG against ischemia-reperfusion (I/R) injury. The rats were pretreated for 7 days (v.o.) with NRG (25 mg/kg) or n-acetylcysteine (NAC, 100 mg/kg) and their isolated hearts were subjected to global ischemia (30 min) and reperfusion (60 min). Furthermore, isolated hearts were perfused with 5 µM NRG in the presence of 10 µM glibenclamide (GLI) and subjected to I/R protocol. In healthy ventricular cardiomyocyte, it was evaluated the acute effect of 5 µM NRG on the GLI sensitive current. The results showed that NRG pretreatment restored the cardiac function and electrocardiogram (ECG) alterations induced by I/R injury, decreasing arrhythmia scores and the occurrence of severe arrhythmias. Lactate dehydrogenase and infarct area were decreased while superoxide dismutase (SOD), catalase and citrate synthase activities increased. Expression of SOD CuZn and SOD Mn not was altered. NRG treatment decreased reactive oxygen species (ROS) generation and lipid peroxidation without alter sulfhydryl groups and protein carbonylation. Also, NRG (5 µM) increased the glibenclamide sensitive current in isolated cardiomyocytes. In isolated heart, the cardioprotection of NRG was significantly reduced by GLI. Furthermore, NRG promoted downregulation of Bax expression and Bax/Bcl-2. Histopathological analysis showed that NRG decreased cell edema, cardiomyocytes and nucleus diameter. Thus, NRG has a cardioprotective effect against cardiac I/R injury which is mediated by its antioxidant and antiapoptotic actions and KATP channels activation.
RESUMEN
Hyalinizing clear cell carcinoma (HCCC) is a rare malignant neoplasm that commonly arises in the palate, whose occurrence in other intraoral sites is extremely uncommon. We present a case of a 74 years old afro-descendant female presenting an asymptomatic swelling in the lingual region of teeth 32, 33 and 34, with four months of Evolution, promoting an area of bone resorption with imprecise margins. Incisional biopsy revealed proliferative nests of clear cells within a hyalinized fibrous connective tissue. Tumor cells showed immunohistochemical positivity for AE1/AE3, CK7, p63 and ki67 (30%), but negativity for CK14, CK19 and α-SMA. The final diagnosis was HCCC. The tumor was subjected to surgical resection and no recurrence was observed after 16 months. CCCH is a low-grade malignant tumor that must be differentiated from other malignant clear cell tumors, including epithelial-myoepithelial carcinoma, myoepithelial carcinoma, mucin-depleted mucoepidermoid carcinoma and metastatic renal clear cell carcinoma. Immunohistochemistry is a useful tool to achieve the correct diagnosis and provide the proper therapy for the tumor.
