[Effects of environmental enrichment on the repair and proliferation of neurons in neonatal rats with hypoxic-ischemic brain damage].

OBJECTIVE: To study the effects of environmental enrichment on neuron proliferation, learning and memory ability and motor ability in neonatal rats with hypoxic-ischemic brain damage (HIBD). METHODS: One hundred and eight 7-day-old Sprague-Dawley rats were randomly divided into three groups: sham operation (CON group), HIBD and intervention group. HIBD model was prepared according to the classic Rice-Vannucci method. Environmental enrichment was administered for the rats in the intervention group after HIBD inducement. Behavioral tests (Water maze test, Suspension test and Slope test) were performed and the number of neural cells in the left hippocampus was examined 7, 14 and 28 days after intervention. RESULTS: The pyramid cells in the hippocampus CA1 area in the HIBD group were significantly less than in the CON group at 7, 14 and 28 days (P<0.05). The number of pyramid cells in the hippocampus CA1 area in the intervention group was significantly higher than in the HIBD group (P<0.01) at 7, 14 and 28 days. The hidden platform escape latency period (EL) in the Water maze test was significantly more prolonged and the cross-platform number within 2 minutes was significantly less in the HIBD and the intervention groups than in the CON group at all observed time points (P<0.01). The EL was significantly shorter and the cross-platform number within 2 minutes was significantly higher in the intervention group than in the HIBD group at all observed time points (P<0.01). The maintain time and score in the Suspension test were significantly lower and the time in the Slope test was significantly more prolonged in the HIBD and intervention groups than in the CON group at 7, 14 and 28 days (P<0.01). An increased maintain time and score and a decreased time in the Slope test were found in the intervention group compared with the HIBD group at 14 and 28 days (P<0.01). CONCLUSIONS: Environmental enrichment can improve motor function, learning and memory ability, and promote the repair and proliferation of neurons in neonatal rats with HIBD.

Endolymphatic sac tumor: case report and review of the literature.

Endolymphatic sac tumor (ELST) is a rare neoplasm which can be encountered sporadically or in Von Hippel-Lindau (VHL) disease. Here we report a sporadic case of ELST in 31-year-old man. Neither the symptoms nor a family history of VHL disease were found in the patient. CT imaging demonstrated an expansile lytic lesion of the mastoid process of the left petrous bone. MR scanning revealed a 5.2 cm × 4.7 cm × 4.2 cm mass which showed hyperintensity on T1- and T2-weighted images. Histologic sections showed a papillary, cystic or glandular architecture. The papillary and glandular structures were lined by a single layer of flattened cuboidal-to-columnar cells. The stroma of the papillary fronds was richly vascularized and chronically inflamed. The tumor showed diffusely positive reactivity with cytokeratin (Pan), cytokeratin 19, cytokeratin 5/6, cytokeratin 7, EMA, vimentin, CD56, and NSE and also showed variable reactivity with glial fibrillary acidic protein (GFAP) and VEGF. The Ki-67 immunostain showed a proliferation index of < 1%. Because the mass was large, it was difficult to extirpate surgically. After surgery, the patient underwent gamma-knife radiosurgery for residual tumor. The findings indicate that ELST is a rare neoplasm with benign histopathological appearance and clinically destructive behavior. Because of the rarity of this tumor, it can easily be confused with other tumors such as paraganglioma, middle ear adenoma, adenocarcinoma, papillary carcinoma of thyroid or choroid plexus papilloma. Owing to its locally aggressive nature, it is difficult to extirpate surgically when it is large. VIRTUAL SLIDES: The virtual slide(s) for this article can be found here: http://www.diagnosticpathology.diagnomx.eu/vs/7973320646763012.