Risk factors for the occurrence of infection in patients with oral squamous cell carcinoma after restorative reconstruction and its impact on recurrence and quality of life: a retrospective cohort study.

Background: Worldwide, there are approximately 300,000 new cases of oral squamous cell carcinoma (OSCC) and 100,000 deaths each year. The complexity of oral and maxillofacial structures leads to a high risk of surgical infection such as radical tumor resection and free flap reconstruction. Previous studies have shown that diabetes mellitus, previous radiotherapy, oral-neck communication, etc. are risk factors for postoperative infection, but the influence of time on prognosis has not been clarified in detail. This study supplements this aspect and provided a reference for improving the quality of life of patients. Methods: We retrospectively analyzed a total of 168 patients who developed OSCC from July 2014 to September 2019. According to the inclusion and exclusion criteria of this study, the general data questionnaire designed by ourselves was used to sort out the general characteristics and clinical data of the subjects. The t test, Chi-square test and binary logistic regression were used for statistical analysis. Surgical site infections (SSI) are defined as infections associated with surgical procedures. The quality of life was evaluated by the 36-Item Short Form Survey (SF-36) score. A 3-year follow-up was conducted by telephone, Email and outpatient review. Results: Among the 168 patients, the total number of postoperative infections was 22 (13.1%). Binary logistic regression analysis showed that body mass index (BMI) (OR =0.029, P=0.039), American Society of Anesthesiologists (ASA) classification (OR =21.443, P=0.042), preoperative radiotherapy (OR =19.993, P=0.022), Jaw resection status (OR =29.665, P=0.021), Perioperative transfusion (OR =29.148, P=0.020), preoperative white blood cell count (OR =1.763, P=0.017), albumin level (OR =0.853, P=0.033) were independent influencing factors between the two groups (P<0.05). Except for the social functioning and role-emotional dimensions, all dimensions of SF-36 in patients with infection were significantly lower than those without infection. Conclusions: The incidence of postoperative infection after restorative and reconstructive surgery for OSCC deserves the attention of clinicians. For high-risk infected persons, relevant anti-infection measures should be taken early against the infectious source, and the possibility of nosocomial infection should be attached great importance in clinical work. After discharge, patients should also actively do follow-up, education and other related work to reduce the incidence of postoperative infection.

MiR-503-5p functions as an oncogene in oral squamous cell carcinoma by targeting Smad7.

BACKGROND: Oral squamous cell carcinoma (OSCC) is a common oral malignancy. Previous studies indicated that the level of miR-503-5p was upregulated in OSCC tissues. However, the mechanism by which miR-503-5p regulates the proliferation and invasion of OSCC cells remains unclear. Therefore, this study aimed to investigate the role of miR-503-5p during the progression of OSCC. METHODS: The level of miR-503-5p in Tca8113 cells was detected using RT-qPCR assay. In addition, CCK-8, transwell assays and flow cytometry assays were conducted to detect cell viability, migration, invasion and apoptosis, respectively. Meanwhile, the dual luciferase reporter assay was applied to explore the interaction between miR-503-5p and Smad7 in Tca8113 cells. RESULTS: Overexpression of miR-503-5p significantly promoted the proliferation, migration and invasion of Tca8113 cells, while downregulation of miR-503-5p markedly inhibited proliferation, migration and invasion of cells. In addition, knockdown of miR-503-5p obviously induced the apoptosis of Tca8113 cells via increasing the levels of Bax and cleaved caspase 3, and decreased the expression of Bcl-2. Moreover, SMAD family member 7 (Smad7) was identified as a direct binding target of miR-503-5p in Tca8113 cells. Overexpression of miR-503-5p significantly downregulated the levels of Smad7 and E-cadherin, but upregulated the levels of N-cadherin and MMP-9 in Tca8113 cells. CONCLUSION: These results indicated that miR-503-5p might act as an oncogene in OSCC cells by targeting Smad7. Therefore, miR-503-5p might act as a novel and potential therapeutic target for the treatment of OSCC.

[Corrosion resistance and wear resistance of Ni-Cr alloy after coating titanium nitride (TiN) in oral containing fluorine environment].

PURPOSE: The aim of this study was to evaluate the corrosion resistance and wear resistance of Ni-Cr alloy after coating titanium nitride (TiN) in oral containing fluorine environment. METHODS: Physical vapor deposition was established to coat titanium nitride (TiN) on the surface of dental cast Ni-Cr alloy to form TiN/Ni-Cr compound. Both Ni-Cr alloy and TiN/Ni-Cr compound were exposed to 37 degrees centigrade, artificial saliva containing 0.24% NaF. The polarization curves of the specimens were measured by PARSTAT 2273 electrochemical station to investigate its corrosion resistance. Vicker's hardness was measured by HXD-1000TMC/LCD micro-hardness tester to investigate its wear resistance. Statistical analysis was performed by SAS 8.2 software package for Student's t methods. RESULTS: The corrosion potential of Ni-Cr alloy was -362.407 mV, the corrosion current density was 1.568µAcm(-2),the blunt-breaking potential was 426 mV bofor TiN coating. The corrosion potential of TiN/Ni-Cr compound was -268.638 mV, the corrosion current density was 0.114µAcm(-2),the blunt-breaking potential was 1142 mV after TiN coating. Polarization curves showed TiN/Ni-Cr compound improved the corrosion potential and blunt-breaking potential, decreased the corrosion current density. The Vicker's hardness of Ni-Cr alloy was 519.75±27.27 before TiN coating, the Vicker's hardness of TiN/Ni-Cr compound was 803.24±24.64, the D-value between them was 283.49±39.34. The difference of Vicker's harnesses between Ni-Cr alloy and TiN/Ni-Cr compound had significant (P<0.01). CONCLUSION: The results demonstrate that the TiN coating can improve the corrosion resistant to F-and the surface hardness of Ni-Cr alloy. Supported by Research Fund of Science and Technology Commission of Shanghai Municipality (Grant No.08DZ2271100), Shanghai Leading Academic Discipline Project (Grant No.S30206 ) and Research Fund of Health Bureau of Shanghai Municipality (Grant No.2009074).