The endoscopic transnasal approach in management of the sinonasal tumor invading the anterior skull base / 中华耳鼻咽喉头颈外科杂志

Objective: To evaluate the feasibility of the endoscopic transnasal approach (ETA) and to analyze the outcomes and factors of this surgical technique in the management of the tumor invading the anterior skull base. Methods: A retrospective analysis was performed on 42 patients (31 males and 11 females, with mean age of 49 years) with sinonasal tumor invading the anterior skull base, who underwent ETA from June 2015 to April 2019 in Eye, Ear, Nose and Throat Hospital of Fudan University. Pathologically, there were 15 cases of squamous carcinoma (14 patients with T4bN0M0 and 1 patient with T4bN1M0) and 27 of olfactory neuroblastomas with Kadish stage C. Anterior skull base reconstruction was performed using the vascular pedicled nasoseptal mucoperiosteal flap and fascia lata. Brain non-contrast-enhanced CT was performed on the first postoperative day to exclude massive pneumocephalus, relevant brain edema and subarachnoid hemorrhage. Sinonasal contrast-enhanced MR was performed to assess the extent of the tumor removal. Kaplan-Meier analysis was used to calculate the overall survival (OS) and Cox multivariate regression analysis was used to determine the prognostic factors. Results: The mean duration of the surgery was 452 minutes. Total resection was performed in 36 patients (85.7%), subtotal resection in 2 patients (4.8%) with orbital involvement, partial resection in one patient (2.4%) with injury of the internal carotid artery. One patient (2.4%) underwent the second resection because of the tumor residual, two patients (4.8%) with unsure tumor residual. Mean follow-up was 20 months, with 17 months of median follow-up. One-, two-and three-year overall survival was 86.5%, 76.9% and 64.5%, respectively. For squamous carcinoma, one-, two-and three-year overall survival was 86.2%, 86.2% and 57.4%, respectively. For olfactory neuroblastomas, One-, two-and three-year overall survival was 86.9%, 75.3% and 67.8%, respectively. Multivariate analysis showed that tumor residual (P=0.001) and recurrence (P<0.01) were independent prognostic factors for survival. Conclusions: The ETA is safe and feasible in selected patients with sinonasal tumor invading the anterior skull base. Tumor residual and recurrence are independent prognostic factors for survival.

Olfactory ensheathing cells promote the survival of newborn rat spiral ganglion cells in vitro / 生理学报

The objective of this study is to explore whether olfactory ensheathing cells (OECs) can promote the survival of newborn rat spiral ganglion cells (SGCs) and the underlying possible mechanisms. Co-culture of OECs from adult rats with SGCs from newborn rat cochlea was established and single culture of SGCs acted as control. OECs were obtained and purified based on their special rate of attachment which was different from the other harvested cell types during culture. OECs and SGCs were immunocytochemically characterized and confirmed by expression of low-affinity nerve growth factor receptor p75 or positive label of neuron-specific betaIII-tubulin. To investigate the mechanisms of the role of OECs in survival of SGCs, brain derived neurotrophic factor (BDNF) and anti-BDNF antibody (IgY) were added into the media of the co-cultures respectively, and the surviving SGCs were examined after treatment. Single layer of OECs (92% pure) was seen seven days after plating. Surviving SGCs, which extended their primary neurites, were found on the surface of the layer in the co-cultures. When OECs and SGCs were co-cultured, the number of surviving SGCs was significantly greater than that in the single culture (P<0.01). Nine days after culture, there was even no change in the number of surviving SGCs in the co-culture while the number reduced to almost zero in the single culture. In comparison with co-culture without treatment, addition of BDNF (500 pg/mL) into the media had no obvious promoting effect on the survival of SGCs. The number of surviving SGCs reduced significantly when anti-BDNF antibody was applied into the media of co-cultures (P<0.01). These results suggest that OECs can promote the survival of SGCs when they are co-cultured in vitro. BDNF released from OECs, as one of the survival factors, plays an important role in the survival of SGCs.

Apoptosis of olfactory receptor neurons induced by bulbectomy / 中华耳鼻咽喉头颈外科杂志

<p><b>OBJECTIVE</b>To study whether apoptosis plays a role in controlling the number of olfactory receptor neurons, so as to reveal the specialty and mystery of neurogenesis.</p><p><b>METHODS</b>Using terminal deoxynucleotidyl transferase-mediated dUTP-fluorescein nick end labeling (TUNEL) and transmission electron microscopy to detect apoptosis in olfactory mucosa of normal adult rats and damaged olfactory mucosa of 16, 32, 48 hours and 3, 7, 30 days after bulbectomy.</p><p><b>RESULTS</b>In normal olfactory epithelium, a subpopulation of immature neurons, as well as mature neurons, showed internucleosomal DNA-fragmentation. The number of TUNEL-labeled neurons increased dramatically 32 hours after removal of olfactory bulb. Then it declined quickly and remained at low level. Ultrastructural data of olfactory mucosa showed that the feature of apoptotic neurons was chromatin condensation and cell shrinkage. Besides, some dying cells were characterized by the formation of numerous autophagic vacuoles, and few had some of the features of necrosis but without obvious mitochondrial swelling.</p><p><b>CONCLUSIONS</b>Apoptosis might play a role in turnover of the olfactory epithelium and regeneration in adult rats. There might be other two types of neural death through different mechanism.</p>