[Preliminary analysis of neuroprotective effects of capillary fascia preservation recurrent laryngeal nerve anatomical method in right level â ¥ dissection].

Objective: To investigate the application and effect of capillary fascia preservation between the recurrent laryngeal nerve (RLN) and common carotid artery (fascia preservation method) in nerve protection when dissecting right level Ⅵ lymph nodes for patients with papillary thyroid carcinoma. Methods: A retrospective cohort study enrolling 195 patients with papillary thyroid carcinoma undergoing right level Ⅵ lymph node dissection in Beijing Tongren Hospital from March 2021 to August 2022 was carried out. The RLN was dissected by fascia preservation method in study group and by routine method in control group. The intraoperative electrical signal amplitude of the RLN, the number of dissected lymph nodes, and the postoperative complications were recorded and analyzed. Results: A total of 195 patients (study group: 94 cases, control group: 101 cases) were collected. There were 71 males and 124 females, with the median age of 32 (39, 51) years. In the study group, the total number of right level Ⅵ lymph nodes was significantly larger than the number of right Ⅵa level lymph nodes [8 (6, 11) vs 6 (4, 8), P<0.001]. There were no significant differences between the two groups in the number of level Ⅵa or level Ⅵb lymph nodes [Ⅵa: 6 (4, 8) vs 5 (3, 7), P=0.373; Ⅵb: 3 (1, 4) vs 2 (1, 4), P=0.337] and metastasis rate [Ⅵa: 51.1% (48/94) vs 52.5% (53/101), P=0.844; Ⅵb: 12.8% (12/94) vs 15.8% (16/101), P=0.541]. The ratio of electromyography (EMG) amplitude R2 in lower level Ⅵ and entry into larynx (grouped as>90%, 50%~90%,<50%) in the study group was significantly higher than that in the control group (P<0.001). No significant differences were detected between the two groups in temporary RLN paralysis [1.1% (1/94) vs 2.0% (2/101), P=1.000]. Conclusions: Fascia preservation method can decrease the stimulus and traction to RLN and preserve the capillary network serving RLN. It can thoroughly dissect lymph nodes and decrease the injury of RLN.

[Clinical characteristics and prognosis in papillary thyroid carcinoma patients with recurrent laryngeal nerve invasion].

Objective: To investigate the clinical characteristics and risk factors of postoperative recurrence in papillary thyroid carcinoma (PTC) patients with recurrent laryngeal nerve (RLN) invasion. Methods: The data of PTC patients with recurrent laryngeal nerve invasion treated in Beijing Tongren Hospital, Capital Medical University from January 2006 to December 2019 were retrospectively analyzed. The acoustic parameters were compared between different subgroups. Kaplan-Meier method was used to calculate the overall survival (OS) and the recurrence-free rate (RFS), and univariate and multivariate Cox regression analyses were performed to determine the risk factors for postoperative recurrence. Results: A total of 150 PTC patients were enrolled in the final analysis, including 102 females and 48 males, with an average age of (53.5±13.7) years, and 62 patients (41.3%) aged over 55 years. There were 88 cases with stage Ⅰ, and 62 cases with stage Ⅲ. Fifty-five patients presented with preoperative vocal cord paralysis. There were 75 cases appearing adhesion between tumor or lymph node and recurrent laryngeal nerve while 75 cases presented with direct invasion. The comparisons of acoustic parameters showed that patients with RLN invasion had higher jitter compared with patients without RLN invasion [2.3% (1.4%, 3.2%) vs 1.8% (0.8%, 2.6%), P<0.001]. Moreover, patients with preoperative vocal cord paralysis (VCP) had higher jitter[3.1% (2.2%, 4.6%) vs 2.0% (1.1%, 2.8%), P<0.001] and shimmer [7.1% (4.9%, 9.9%) vs 5.5% (4.2%, 7.3%), P<0.001] and shorter maximum phonation time (MPT) [8.0 (6.0, 10.0) s vs 12.0 (10.0, 15.3) s, P<0.001] compared with patients without preoperative VCP. However, there was no statistical difference in acoustic parameters between cases with RLN adhesion and RLN invasion (all P>0.05). Postoperative follow-up time ranged between 12-196 months, with an average of (65.0±35.9) months. Sixteen patients (10.7%) had recurrence or metastasis, and 8 cases (5.3%) died of recurrence or metastasis. The 5-year OS rate was 95.1%, and the 10-year OS rate was 92.8%. The 5-year RFS rate was 88.9%, and the 10-year RFS rate was 86.2%. Univariate Cox analysis showed that age of onset ≥ 55 years, preoperative recurrent laryngeal nerve palsy, laryngeal, trachea or esophageal invasion were the risk factors for postoperative recurrence of PTC with RLN invasion (all P<0.05). Multivariate Cox analysis showed that age of onset ≥ 55 years (OR=1.060, 95%CI: 1.011-1.110, P=0.015) was an independent risk factor. Conclusions: Age of onset ≥ 55 years is an independent risk factor for postoperative recurrence in PTC patients with RLN invasion. Preoperative acoustic parameters may provide reference for evaluation of RLN function.

Decreased expression of p38 MAPK mediates protective effects of hydrogen sulfide on hepatic fibrosis.

AIM: To investigate the in vitro and in vivo effects of hydrogen sulfide (H2S) on activated hepatic stellate cells (HSCs) and carbon tetrachloride (CCl4)-induced hepatic fibrosis rats. To explore the in vitro and in vivo expression of Phospho-p38, Phospho-Akt and NF-kB in HSCs treated with H2S. MATERIALS AND METHODS: HSC-T6 cells were incubated and activated with 500 µg/L ferric nitrilotriacetate (Fe-NTA), and then were incubated with NaHS, an H2S-releasing molecule for 6, 12, 24 and 48 h. MTT assay was performed to detect cell viability. Propidium iodide (PI) staining was used to determine cell cycle by flow cytometry. Apoptosis was detected with Annexin-V FITC (fluorescein isothiocyanate) and PI (propidium iodide) double staining. Western blotting was performed to detect protein expressions of Phospho-p38, Phospho-Akt and NF-kB. Hepatic fibrosis model was established by intraperitoneal injection of CCl4 in male Wistar rats, and rats were randomly divided into three groups, including healthy control, rats treated with CCl4 + saline, and rats treated with CCl4 + NaHS. Immunohistochemistry analysis was performed to measure protein expression of Phospho-p38 and Phospho-Akt in rat hepatic samples. RESULTS: NaHS inhibited the proliferation of Fe-NTA (nitrilotriacetic acid)-induced HSC-T6 cells in a dose-dependent way at 6, 12, 24 and 48 h. NaHS (500 µmol/L) induced G1 phase cell cycle arrest and promoted survival in Fe-NTA-induced HSC-T6 cells. NaHS decreased Phospho-p38 and increased Phospho-Akt expressions in Fe-NTA-induced HSC-T6 cells and CCl4-induced liver fibrosis rats. CONCLUSIONS: Exogenous H2S inhibits activated HSC-T6 cells and induces cell cycle arrest and apoptosis. Decreased Phospho-p38 and increased Phospho-Akt expressions may mediate the anti-fibrosis effect by exogenous H2S.

[A new classification of maxillary defect and simultaneous accurate reconstruction].

Objective: To select the preferred flaps for the reconstruction of different maxillary defects and to propose a new classification of maxillary defects. Methods: A total of 219 patients (136 males and 83 females) underwent the simultaneous reconstruction of maxillary defects in the Beijing Tongren Hospital, Capital Medical University, between January 2005 and December 2018 were reviewed. Age ranged from 16 to 78 years. Based on the proposed new classification of the maxillary defects, 22 patients with class Ⅰ defects (inferior maxillectomy), 44 patients with class Ⅱ defects (supperior maxillectomy), 132 patients with class Ⅲ defects (total maxillectomy) and 21 patients with class Ⅳ defects (extensive maxillectomy) were enrolled. Survival rate, functional and aesthetic outcomes of flaps were evaluated. Survival analysis was performed in 169 patients with malignant tumor, Kaplan-Meier method was used to calculate the survival rate, and Log-rank method was used to compare the difference of survival rate in each group. Results: A total of 234 repairs for maxillary defects were performed in 219 patients. Fibula flaps were used in 4/13 of class Ⅰ defects; temporal muscle flaps (11/24, 45.8%) and anterolateral thigh flaps (6/24, 25.0%) used in class Ⅱ defects; temporal muscle flaps (71/128, 55.5%), anterolateral thigh flaps (6/24, 25.0%) and fibula flaps (12/128, 9.4%) used in class Ⅲ defects; and anterolateral thigh flaps (8/20, 40.0%) and rectus abdominis flaps (8/20, 40.0%) used in class Ⅳ defects. The success rate of local pedicled flaps was 95.6% (109/114) and that of free flaps was 95.8% (115/120). Thrombosis(10/234,4.3%) was a main reason for repair failure. Among the followed-up 88 patients, swallowing and speech functions recovered, 82 (93.2%) of them were satisfied with appearance, and 75 (85.2%) were satisfied with visual field. The 3-year and 5-year overall survival rates were 66.5% and 63.6%, and the 3-year and 5-year disease-free survival rates were 57.1% and 46.2%, respectively, in the 169 patients with malignant tumors. Conclusion: A new classification of maxillary defects is proposed, on which suitable flaps are selected to offer patients good functional and aesthetic outcomes and high quality of life.

[Clinical comparative study of free posterior tibial artery perforator flap and radial forearm free flap for head and neck reconstruction].

Objective: To compare the clinical application results of the FPTF (free posterior tibial artery perforator flap) and RFFF (radial forearm free flap) for reconstruction of head and neck defects. Methods: A retrospective analysis of 27 cases treated with FPTF (19 males and 8 females, aged 14-69 years) and 24 cases with RFFF (11 males and 13 females, aged 22-69 years) for head and neck defect reconstruction at Beijing Tongren Hospital of Capital Medical University from January 2015 to December 2020 was conducted. Flap size, vascular pedicle length, matching degree of recipient area blood vessels, preparation time, total operation time, hospital stay, recipient area complications, donor area complications and scale-based patient satisfaction were compared between two groups of patients with FTPF and RFFF. SPSS 26.0 statistical software was used for statistical analysis. Results: There was no statistically significant difference between the two groups of patients in tumor T staging (P=0.38), primary sites (P=0.05) and mean flap areas ((53.67±29.84) cm2 vs. (41.13±11.08) cm2, t=-1.472, P=0.14). However the mean vascular pedicle length of FPTF was more than that of RFFF ((11.15±2.48)cm vs. (8.50±1.69)cm, t=-4.071, P<0.01). The donor sites of 4 patients in FPTF group could be sutured directly, while all the 24 patients in RFFF group received skin grafts from the donor sites. There was no statistically significant difference in the recipient area arteries between two groups of flaps (P=0.10), with more commonly using of the facial artery (RFFF: FPTF=21∶27), but there was significant difference in the recipient area veins (P<0.01), with more commonly using of the external jugular vein in RFFF (14/24) than FPTF (4/32) and the posterior facial vein in FPTF (27/32) than RFFF (9/24). There were 10 recipient complications and 3 donor complications in RFFF group; no recipient complication and 3 donor complications occurred in FPTF group. With patient's subjective evaluation of the donor site at 12 months after surgery, FPTF was better than RFFF (χ²=22.241, P<0.01). Conclusions: FPTF is an alternative to RFFF in head and neck reconstruction and has unique advantages in aesthetics and clinical application.

[Retrospective study of thyroid invasion and central lymph node metastasis in 124 patients with hypopharyngeal carcinoma].

Objective: To investigate the characteristics of thyroid invasion and central lymph node metastasis of hypopharyngeal carcinoma, and the impact on survival rate and quality of life. Methods: A retrospective analysis of 124 cases (122 males and 2 females with age range from 36 to 78 years old) with laryngopharyngeal squamous cell carcinoma who were initially treated in the Department of Head and Neck Surgery, Beijing Tongren Hospital Affiliated to Capital Medical University from January 2014 to December 2017 was performed. The clinical data included tumor location, pathological T stage, pathological N stage, invasion of thyroid gland, central lymph node metastasis, surgical procedures and so on. Patients were grouped according to if presence of thyroid invasion and central lymph node metastasis. With follow-up, the survival was analyzed by Kaplan-Meier method, and tumor recurrence and metastasis were evaluated. Results: Of the patients, 12 patients had thyroid involvement and 5 patients had central lymph node metastasis. The incidence of thyroid involvement was 8.16% (8/98) in pyriform sinus, 1/18 in posterior pharyngeal wall and 3/8 in posterior cricoid wall, with statistically significant difference (χ2=15.076,P=0.008). The incidence of central lymph node metastasis was 1.02% (1/98) in pyriform sinus, 3/18 in posterior pharyngeal wall and 1/8 in posterior cricoid wall, also with statistically significant difference (χ2=11.205, P=0.008). There was no statistical correlation between thyroid invasion or central lymph node metastasis and gender, smoking or alcohol exposure history and tumor pathological differentiation (all P>0.05). The 3-year overall survival rate was 80.65% and the 3-year recurrence free rate was 85.48%. Totally 24 patients died in 3 years, including 4 cases in thyroid invasion group and 1 case in central lymph node metastasis group. Local recurrence occurred in 18 patients, including 4 cases in thyroid invasion group and 1 case in central lymph node metastasis group. There was no significant difference in survival between patients with and without thyroid invasion and central lymph node metastasis (all P>0.05). There were significantly difference in 3-year overall survival and relapse-free survival among the groups with different T stages, N stages, pathological stages and tumor pathological differentiation levels (all P<0.05). There were significantly differences in the levels of serum calcium and FT3 between the groups with or without thyroid invasion and central lymph node metastasis (all P<0.05). Conclusion: The incidences of thyroid invasion and central lymph node metastasis of hypopharyngeal carcinoma are rare, and the risk of occurrence is related to the primary site of tumor. Comprehensive evaluation, correct decision-making and accurate treatment could be helpful to cure radically the tumor, to prevent recurrence and to improve the quality of life of patients.

[Protection of nerve function during transoral endoscopic thyroidectomy by vestibular approach].

Objective: To explore the method of functional protection in transoral endoscopic thyroidectomy by vestibular approach. Methods: Retrospective analysis was performed on the case data of 66 patients who underwent transoral endoscopic thyroidectomy by vestibular approach in the Department of Otorhinolaryngology Head and Neck Surgery of Beijing Tongren Hospital from February 2018 to February 2020. There were 11 males and 55 females aged 22-64 years, including 19 patients with benign diseases and 47 patients with malignant diseases. Important neurological functions were protected by a combination of anatomical exposure and intraoperative nerve monitoring. The clinical data and the effect of neurofunctional protection were summarized. SPSS 25.0 software was used for statistical analysis. Results: All operations were successfully completed with none transferred to open surgery. Three weeks after surgery, the numbness and tingling symptoms in the lower jaw and lower lip were basically relieved. There was no permanent mental nerve palsy, no permanent recurrent laryngeal nerve palsy but 2 cases with temporary recurrent laryngeal nerve palsy, no external branch injury of superior laryngeal nerve. There were 3 cases of temporary parathyroid gland dysfunction, 1 case of neck infection, 2 cases of subcutaneous effusion, 1 case of neck skin injury, and 2 cases of postoperative eye conjunctivitis. Conclusion: In transoral endoscopic thyroidectomy by vestibular approach, anatomical exposure can decrease mental nerve injury, and anatomical exposure combined with intraoperative nerve monitoring can protect the functions of the external branches of the superior laryngeal nerve and the recurrent laryngeal nerve.

Silencing of long non-coding RNA LINC00958 inhibits head and neck squamous cell carcinoma progression and AKT/mTOR signaling pathway by targeting miR-106a-5p.

OBJECTIVE: The long non-coding RNA LINC00958 acts as an oncogenic regulator in many human tumors. In this study, we aimed to investigate the role and potential molecular biological mechanisms of LINC00958 in head and neck squamous cell carcinoma (HNSCC). MATERIALS AND METHODS: Aberrantly expressed LINC00958 was screened out of TCGA database. The quantitative Real Time-Polymerase Chain Reaction (qRT-PCR) was used to determine LINC00958 and miR-106a-5p expression. Cellular biological behaviors were investigated using CCK-8, colony formation, wound healing and transwell assays. Xenograft mouse models were established to determine the role of LINC00958 in HNSCC growth in vivo. The interaction between LINC00958 and miR-106a-5p was validated by Dual-Luciferase reporter gene assay. Additionally, the underlying pathways affected by LINC00958 were measured by Western blot. RESULTS: LINC00958 expression was upregulated in HNSCC tissues and cells. High LINC00958 level was correlated with the poor prognosis of HNSCC patients. Functional assays showed that the knockdown of LINC00958 inhibited HNSCC malignant phenotypes in vitro and in vivo. Mechanistically, miR-106a-5p was a potential target of LINC00958, and its expression was negatively regulated by LINC00958 in HNSCC. LINC00958 could activate AKT/mTOR signaling pathway, which was mediated by miR-106a-5p. CONCLUSIONS: Taken together, our results suggest that LINC00958 acts as an oncogenic role in HNSCC and activates AKT/mTOR signaling pathway by sponging miR-106a-5p. LINC00958 may serve as a potential target for HNSCC diagnosis and treatment.

[Application of submental artery perforator flap in reconstruction surgery in pharyngeal carcinoma].

Objective: To evaluate clinical applications and efficacy of submental artery perforator flap in reconstruction surgery after removal of pharyngeal carcinoma. Methods: A total of 27 patients in the Department of Otorhinolaryngology Head and Neck Surgery, Beijing Tongren Hospital, Capital Medical University were included, 23 males and 4 females with age from 40 to 70 years old, and 17 patients were hypopharyngeal carcinoma (HPC) and 10 patients were oropharyngeal carcinoma (OPC). All patients underwent tumor resection followed by simultaneously reconstruction surgery using submental artery perforator flap between January 2015 and December 2019. Of 5 patients with palatine tonsil cancer, 4 underwent the combined approach of neck and oral resection and 1 with madibulotomy. All 5 patients with tongue base cancer received transhyoid partial glossotomy with or without partial laryngectomy. Sixteen patients with pyriform sinus carcinoma received partial laryngo-pharyngectomy with preservation of laryngeal functions. One patient with posterior hypopharyngeal wall carcinoma had partial pharyngectomy. Prognosis and laryngeal functions were analyzed after reconstruction surgery with submental artery perforator flap in patients with pharyngeal carcinoma. Results: The 27 patients were followed up for 6-66 months, with a median of 13 months, of them 24 patients were alive without recurrence or metastasis, 1 patient died of recurrence, 1 patient died of esophageal carcinoma and 1 patient was alive with the recurrence of tongue base carcinoma. Postoperative complications included flap failure for 1 case, pharyngeal fistula for 1 case, subcutaneous hydrops for 2 cases and lymphatic fistula for 1 case. Total 2 and 3 year survival rates were 92.9% and 88.9%, respectively. Total decanulation rate was 92.6%; decanulation rate and intubation time were 16/17 and 3.5 months in HPC patients; and decanulation rate and intubation time were 9/10 and 2 months in OPC patients. Total oral feeding rate was 92.6% and nasogastric feeding time was 3.5 weeks in HPC patients and 3 weeks in OPC patients. Conclusion: The submental artery perforator flap is an excellent choice for reconstruction surgery after removal of oropharyngeal and hypopharyngeal carcinoma, with good outcomes of laryngeal functions.

[Application of computer-assisted design and three-dimensional printing technique in reconstruction of maxillary defects with individual free fibular flap].

Objective: To evaluate the application of computer-assisted design and three-dimensional printing technique in reconstruction of maxillary defects with individual free fibular flap. Methods: A total of 13 patients, 7 males and 6 females with age from 12 to 55 years old, underwent the reconstruction of maxillary defects after subtotal or total maxillectomy for benign or malignant tumors between January 2016 and December 2018 were reviewed. Ther were 4 cases of subtotal maxillectomy and 9 cases of total maxillectomy. Before operation, osteotomy line was planned on three-dimensional images. A three-dimensional individual resin fibula model based on mirror images of the healthy side maxilla was obtained to fabricate an anatomically adapted osteomyocutaneous fibula free flap using computer-assisted design and forming. Oral, nasal, and eye functions and facial appearance were evaluated. Results: The 13 cases were followed up for 5-40 months, all flaps were alive except one due to flap failure and all cases were tumor free confirmed by CT or MRI. Ten patients could eat normal food without nasal food return, and 3 cases had palatal fistula. Eleven cases showed good speaking functional results. All cases had normal eye positions, no cases with diplopia and loss of vision. With evaluation by VAS, an average score of 8 was obtained, and most of patients were satisfied with their postoperative facial appearances. Conclusion: Reconstruction of maxillary defects by free fibular flap designed by three-dimensional printing and computer-assisted technique not only restored oral, nasal and eye functions, but also showed satisfactory facial appearance.

[Analysis for potential targeting genes of TPF regimen induction chemotherapy in hypopharyngeal squamous cell carcinoma].

Objective: To analyze the differentially expressed genes related to the chemosensitivity with the TPF regimen for hypopharyngeal squamous cell carcinoma and to measure potential functional targeting genes expressions. Methods: Twenty-nine patients with primary hypopharyngeal cancer who underwent induction chemotherapy with TPF from January 2013 to December 2017 in Beijing Tongren Hospital were enrolled for microarray analysis, including 28 males and 1 female, aged from 43 to 73 years old. Among them, 16 patients were sensitive to chemotherapy while 13 patients were non-sensitive. Illumina Human HT-12 Bead Chip was applied to analyze the gene expressions and online bioinformatics analysis was used to analyze the differentially expressed genes. Reverse transcription and quantitative real-time PCR (RT-qPCR) was used to measure the mRNA expression of potential functional genes of TPF induction chemotherapy in 43 samples, 29 from original patients and 14 from additional patients. Graphpad prism 7.0 software was used for statistical analysis. Results: A total of 1 381 significantly differentially expressed genes were screened out. By GO analysis, up-regulated genes included sequestering in extracellular matrix, chemokine receptor binding and potassium channel regulator activity; down-regulated genes included regulation of angiogenesis, calcium ion binding and natural killer cell activation involved in immune response. With KEGG database analysis, down-regulated pathways included ECM-receptor interaction and peroxisome and up-regulated pathways included Glutathione metabolism and PPAR signaling pathway. The expressions of CD44 and IL-6R were significantly different and appeared biologically significant. CD44 was significantly upregulated in insensitive tissues (0.54±0.06) compared with sensitive tissues (0.33±0.04)(P<0.01). IL-6R was significantly downregulated in insensitive tissues (0.44±0.03) compared with sensitive tissues. (0.68±0.03) (P<0.01). Conclusion: CD44 and IL-6R may be potentially functional genes of TPF induction chemotherapy in hypopharyngeal squamous cell carcinoma.

[A single-arm prospective study on induction chemotherapy and subsequent comprehensive therapy for advanced hypopharyngeal squamous cell carcinoma: report of 260 cases in a single center].

Objective: To study the significance of induction chemotherapy and subsequent comprehensive therapy for overall survival rate (OS) and larynx dysfunction-free survival rate (LDFS) in patients with advanced hypopharyngeal carcinoma. Methods: Patients who met the inclusion criteria with the diagnoses of advanced hypopharyngeal carcinoma between 2011 and 2017 received 2 or 3 cycles of TPF regimen induction chemotherapy. Patients who attained complete response (CR) received radical chemotherapy. Patients who attained partial response (PR) and the reduction of tumor volume was more than 70% were defined as large PR and received concurrent chemoradiotherapy. When the tumor volume reduction of PR patients was less than 70%, they were defined as small PR. (CR+large PR) group was defined as effective group. Patients who did not reach CR and large PR were defined as uneffective group and underwent radical surgery and received adjuvant radiotherapy as appropriate after the surgery. The end points of the study were OS, progression-free survival (PFS) and LDFS. Chi-square (χ(2)) test was used for correlation analysis. Survival analysis was performed by the Kaplan-Meier method with a Log-rank test. Cox proportional hazards model was used for univariate and multivariate survival analysis. Results: A total of 260 patients were enrolled in the study. The follow-up period ranged from 5 to 83 months, with an average of 24.7 months. The 3-year and 5-year OS rate was 46.0% and 32.6%, respectively. The 3-year and 5-year PFS rate was 41.0% and 26.6%, respectively. The 3-year and 5-year LDFS rate was 37.9% and 24.8%, respectively. Poor outcome of induction chemotherapy, advanced N stage, strong positive Ki-67 immunohistochemistry (all P<0.001) were negative prognostic factors. The advanced clinical stage was positively related to the poor outcome of induction chemotherapy (P=0.015). There was no significant difference in OS and PFS between the large PR group and the small PR group (all P>0.005). Conclusion: TPF regimen induction chemotherapy and subsequent comprehensive therapy for patients with advanced hypopharyngeal carcinoma may improve the quality of life of patients, with high OS rate and LDFS rate.

[Simultaneous repairing defects of orbital floor and palate with the modified temporalis muscle flap after the maxillectomy].

Objective: To evaluate the outcome of one-stage reconstruction of maxillary and orbital defects with modified temporalis muscle flap (TMF) following the removal of malignant neoplasms. Methods: In this retrospective study, 15 patients underwent the reconstruction of defects of orbital floor and palate after maxillectomy for malignant tumor were included from June 2008 to June 2014. The modified temporalis muscle flap was used to repair the defects after surgery, and functional outcomes were analyzed. Results: All the patients were followed up for 12-81 months. Three cases of them received preoperative radiotherapy and 12 cases underwent postoperative radiotherapy. All flaps were survived. Epithelization of the tissues in oral and nasal cavity was completed in 4-6 weeks. Good functional reconstruction on swallowing and speaking functional results were achieved with maxillary and orbital reconstruction and no secondary deformity of external nose was observed. The eye positions in all cases were normal. Diplopia, diminution and loss of vision were not found. Conclusion: The modified TMF can be used for simultaneous reconstruction for the defects of orbital floor and palate after maxillectomy in patients whom free tissue flap can not be applied to, showing better cosmetic and functional results.

[Fabrication of tissue engineered skin equivalent].

OBJECTIVE: To fabricate artificial human skin with the tissue engineering methods. METHODS: The artificial epidermis and dermis were fabricated based on the successful achievements of culturing human keratinocytes(Kc) and fibroblasts (Fb) as well as fabrication of collagen lattice. It included: 1. Culture of epidermal keratinocytes and dermal fibroblasts: Kc isolated from adult foreskin by digestion of trypsin-dispase. Followed by comparison from aspects of proliferation, differentiation of the Kc, overgrowth of Fb and cost-benefits. 2. Fabrication of extracellular matrix sponge: collagen was extracted from skin by limited pepsin digestion, purified with primary and step salt fraction, and identified by SDS-PAGE. The matrix lattice was fabricated by freeze-dryer and cross-linked with glutaraldehyde, in which the collagen appeared white, fibrous, connected and formed pores with average dimension of 180 to 260 microns. 3. Fabrication artificial human skin: The artificial skin was fabricated by plating subcultured Kc and Fb separately into the lattice with certain cell density, cultured for one week or so under culture medium, then changed to air-liquid interface, and cultured for intervals. RESULTS: The artificial skin was composed of dermis and epidermis under light microscope. Epidermis of the skin consisted of Kc at various proliferation and differentiation stages, which proliferated and differentiated into basal cell layer, prickle cell layer, granular layer, and cornified layer. Conifilament not only increased in number, but also gathered into bundles. Keratohyalin granules at different development stages increased and became typical. The kinetic process of biochemistry of the skin was coincide with the changes on morphology. CONCLUSION: Tissue engineered skin equivalent has potential prospects in application of repairing skin defect with advantages of safe, effective and practical alternatives.

[Effect of concanavalin A on morphology and DNA synthesis of resting chondrocyte cultures].

Rabbit chondrocytes were isolated from resting cartilage of ribs of 4-week-old New Zealand rabbits. Chondrocytes were seeded at low density and grown to confluency in medium (DME) with 10% fetal bovine serum, 50 micrograms/ml ascorbic acid, and antibiotics, at 37 degrees C under 5% CO2 in air, and then serum concentration was reduced to 0.3%. At the low serum concentration, chondrocytes adopted fibroblastic morphology. Addition of concanavalin A to the culture medium induced a morphologic alteration of the fibroblastic cells to polygonal or spherical chondrocytes that were surrounded by refractile matrix. Wheat germ agglutinin and garden pea lectin induced similar cell shape changes without any increase in matrix synthesis. Concanavalin A decreased [3H]thymidine incorporation into DNA in a dose-dependent manner with an ED50 of 0.4-1 micrograms/ml in the presence of various concentrations of serum ranging from 0.3 to 20%. The concanavalin A inhibition of DNA synthesis was abolished by 10 mmol/L methyl-D-mannopyranoside. The inhibition of chondrocyte proliferation does not seem to be specific to concanavalin A. Wheat germ agglutinin, lentil lectin, phytohemagglutinin, Ulex europeaus agglutinin, and garden pea lectin also decreased, dose-dependently, [3H]thymidine incorporation into DNA in chondrocytes. Other lectins at 0.01-20 micrograms/ml had little effect on [3H] thymidine incorporation. Because the molecular structure of concanavalin A and its mode of actions have been extensively characterized, chondrocytes exposed to this lectin will be useful as a novel model in studying of the control of cellular differentiation.

[Stimulation of maturing and terminal differentiation by concanavalin A in rabbit permanent chondrocyte cultures].

The effect of concanavalin A (Con A) on maturing and terminal differentiation in permanent chondrocyte cultures were examined. Chondrocytes isolated from permanent cartilage were seeded at low density and grown in MEM medium containing 10% fetal bovine serum, 50 micrograms/ml of ascorbic acid and antibiotics, at 37 degrees C under 50% CO2 in air. At 0.3% of low serum concentration, addition of Con A to the culture medium increased by 3- to 4-fold the incorporation of [35S] sulfate into large chondroitin sulfate proteoglycan that characteristically found in cartilage. Chemical analysis showed a 4-fold increase in the accumulation of macromolecular containing hexuronic acid in Con A-maintained cultures. The effect of Con A on [35S]sulfate incorporation into proteoglycan was greater than that of various growth factor or hormones. Brief exposure of the permanent chondrocytes to Con A (5 micrograms/ml) for 24 hours and subsequent incubation in its absence for 5-10 days resulted in 10- to 100-fold increase in alkaline phosphatase and binding of 1.25 (OH)2 vitamin D3 to cells. Treatment with Con A also resulted in 10- to 20-fold increase in calcium content and 45Ca incorporation into insoluble material. Methyl-D-mannopyranoside reversed the effect of Con A on [35S]sulfate incorporation into proteoglycan and alkaline phosphatase activity. Since other lectins, such as wheat germ agglutinin, lentil lectin, phytohemagglutinin, Ulex europeasu agglutinin and garden pea lectin had been tested to have little effect on [35S]sulfate incorporation into proteoglycans and induction of alkaline phosphatase activity, the Con A action on chondrocytes seems specific. These results indicate that Con A is a potent modulator of differentiation of chondrocytes, which induces the onset on a maturing and a terminal differentiation in chondrocytes, leading to extensive calcification of the extracellular matrix.

[Reorganization of growth-plate-like tissue by isolated chondrocytes in culture].

Growth-plate cartilage is organized into four cellular zones containing resting, proliferating, maturing, and hypertrophic cells. Rabbit chondrocytes were isolated from growth-plate costal cartilage of 4-week-old New Zealand rabbits, the cells (15 x 10(4)) were suspended in 1 ml of Iscove's modified Dulbecco's medium (IMDM) with 10% fetal bovine serum, 50 micrograms ascorbic acid, and 60 micrograms kanamycin (medium A), then transferred to a 15 ml of plastic centrifuge tube, and centrifuged at 1500 rpm for 5 min. The cell pellet was incubated at 37 degrees C under 5% CO2 in air. The cultures reorganized into growth plate-like tissue which could be seen 7-14 days after cell seeding. This growth-plate, histologically, was organized longitudinally into cellular columns and horizontally into four cellular zones containing resting, proliferating, maturing and hypertrophic cells. The hypertrophic cells in the upper were large in size and round or oval in shape, the proliferating and the mature chondrocytes in the lower were small in size and spherical or elongated in shape. These chondrocytes were surrounded by an extensive matrix. Biochemically, DNA content of cultures began to rise on the 2nd day after cell seeding and reached a plateau after 10 days later. The uronic acid content increased from day 4 and reached the maximum on day 15. In contrast in the early culture, alkaline phosphatase activity was extremely low, it began to rise on day 9 and was the highest on day 20. The sequential increase of DNA, uronic acid and alkaline phosphatase contents was analogous to the in vivo changes of growth-plate chondrocytes.