Lateral skull base surgery for posterior oral cavity cancer.

The aim of this study was to better understand posterior oral cavity cancer (POCC) and its surgical treatment. This was a retrospective study of 76 patients who were diagnosed with POCC and underwent surgical treatment. Twenty-eight patients were treated with anatomical unit resection surgery (AURS) and 48 patients with conventional surgery. After initial treatment with curative intent, the patients were followed-up regularly with clinical examinations and imaging; the median duration of follow-up was 30.9 months (range 2-67 months). The 3-year overall survival was 64.3% in the experimental AURS group and 39.6% in the conventional surgery control group (hazard ratio 0.49, 95% confidence interval 0.26-0.93; P=0.031). The 3-year disease-free survival was 64.3% in the experimental group and 37.5% in the control group (hazard ratio 0.53, 95% confidence interval 0.27-1.02; P=0.114). In conclusion, AURS is an effective surgical treatment for POCC that can considerably improve patient survival rates.

[Clinical application of thoracodorsal artery perforator flaps in the repair of head and neck defects].

Objective: To analyse the clinical application of thoracodorsal artery perforator flaps (TDAPF) in the repair of head and neck defects. Methods: A retrospective review was conducted on 38 patients with oral and maxillofacial head and neck malignant tumors who underwent radical resection of oral and oropharyngeal carcinoma and TDAPF repair in the Department of Oral and Maxillofacial Head and Neck Oncology of the Ninth People's Hospital Affiliated to Shanghai Jiao Tong University School of Medicine from June 2017 to November 2018. Among them, 32 were males and 6 were females, aged 30-74 years. Flap size, vessel pedicle length, diameter and number of perforators, and flap fat thickness were recorded and counted. Elasti Meter and Skin Fibro Meter were applied to measure the skin elasticity and hardness in the donor areas of 4 kinds of skin flaps before the flap preparation. SPSS 19.0 statistical software was used for statistical analysis of the data. Results: All the flaps survived (100%). The mean elasticity of TDAPF [(41.2±12.9) N/m] was significantly lower than that of anterolateral thigh [(77.6±23.3) N/m, χ²=88.89, P<0.05], anterolateral thigh [(62.6±17.7) N/m, χ²=59.99, P<0.05] and or forearm flap [(51.7±8.6) N/m, χ²=37.82, P<0.05]. The hardness of TDAPF [(0.037±0.016) N] was also significantly lower than that of anterolateral femoral [(0.088±0.019) N, F=93.27, P<0.05], anteromedial femoral [(0.059±0.020) N, F=25.71, P<0.05] or forearm flap [(0.062±0.016) N, F=29.11, P<0.05]. Follow-up period ranged from 2 to 14 months. The 38 patients treated with TDAPF had a good recovery of the functions in the recipient areas, and the scars of the donor areas were not obvious after surgery, without serious complications. Conclusion: TDAPF is suitable for reconstruction of head and neck defect, with ductile texture and good recovery of the morphology and function of head and neck.

[Free anterolateral thigh flap with superficial temporal vessels as recipient vessels for reconstruction of defect after maxillectomy in malignant tumor].

Objective: To study the effects of superficial temporal artery and vein as recipient vessels for the free anterolateral thigh flap on the appearance and functions after maxillectomy. Methods: Clinical data of 21 patients with malignant maxillary tumors in Department of Oral and Maxillofacial Surgery, the Second Xiangya Hospital of Central South University from January 2014 to November 2019, who were treated by free anterolateral thigh flap with temporal superficial vessels as the recipient vessels were analyzed retrospectively. There were 18 males and 3 females, with the age ranging from 29 to 73 years old, including 19 cases of squamous carcinoma, 1 case of adenoid cystic carcinoma and 1 case of osteosarcoma. Of those 7 patients underwent primary surgery, 14 patients received resurgery, and 6 patients had a history of postoperative radiotherapy and chemotherapy. Among 14 patients with resurgery, 13 had recurrent ipsilateral second site tumor and 1 had recurrent tumor, and all of them received the maxillectomy and reconstructive surgery with the free anterolateral thigh flap. Patients were evaluated with water swallow test and speech intelligibility score in 1, 3 and 6 months after operation. The data were statistically analyzed with SPSS 22.0 statistical software. Water swallow test results before and after operation were compared using the Wilcoxon rank sum test. The mean speech intelligibility scores before and after operation were compared by the paired t test. Results: Patients were followed up for 10-60 months. All free flaps survived after operation. No diplopia occurred. Breathing, swallowing and speaking functions were normal. No movement disorders caused by the donor of thigh flap. Water swallow test showed no phenomenon of water flowing into the nasal cavity or oral and nasal leakage with level Ⅰ for 4 cases, level Ⅱ for 13 cases, level Ⅲ for 3 cases and level Ⅳ for 1 case. The mean speech intelligibility scores before surgery and 1, 3 and 6 months after surgery were 4.31±0.13, 1.46±0.21, 2.15±0.45 and 2.87±0.76 respectively. There was statistically significant difference in the mean speech intelligibility scores between 1 and 6 months after surgery (F=78.456, P<0.05). Conclusion: It is safe and reliable to use the superficial temporal vessels as recipient vessels for free anterolateral thigh flap in the reconstruction of defect after maxillectomy in malignant tumors, with good outcomes of functions and a satisfactory restoration of outward appearance.

Physiological dissection revealed that both uptake and assimilation are the major components regulating different growth responses of two tobacco cultivars to nitrogen nutrition.

K326 and HD represent major tobacco cultivars in China, which required large N fertiliser input but at different application rates. To understand primary components affecting tobacco N use physiology, we adopted these two varieties as valuable genetic material to assess their growth response to N nutrition. We established a hydroponic culture system to grow plants supplied with different N regimes. Plant biomass, N, ammonium, nitrate, arginine, GS and NR activity, N transfer and use efficiency as well as root uptake were examined. Our data revealed the preference of K326 and HD to utilise nitrate or ammonium nitrate but not ammonium alone, with 2 mm N supply probably sufficient and economical to achieve good biomass production at the vegetative stage. Moreover, both varieties were very sensitive to ammonium, perhaps due to lack of or abnormal signalling related to nitrate and/or arginine rather than impairment of N acquisition and initial assimilation; this was supported by measurements of the plant content of N, ammonium and activities of GS and NR. Notably, short-term 15 N root influx studies identified differential uptake kinetics of K326 and HD, with distinct affinities and transport rates for ammonium and nitrate. The data suggest that the growth adaptation of K326 or HD to higher or lower N may be ascribed to different competences for effective N uptake/translocation and assimilation. Thus, our work provides valuable information to prompt deeper investigation of the molecular basis controlling plant N use efficiency.