Synthesis and evaluation of NHC derivatives and 4'-fluorouridine prodrugs.

ß-D-N4-Hydroxycytidine (NHC) derivatives with structural modifications at the C4', O4' or C6 position and 4'-fluorouridine prodrugs were synthesized and evaluated for their antiviral activities against respiratory syncytial virus (RSV) or influenza virus (IFV) in vitro. The NHC derivatives were found inactive, but 4'-fluorouridine and its prodrugs had potent anti-RSV and anti-IFV activities. 4'-Fluorouridine was proved to be a nucleoside with poor stability, but the tri-ester prodrugs exhibited enhanced stability, especially tri-isobutyrate ester 1a. This prodrug also showed excellent oral pharmacokinetic properties in rats, with potential to be an oral antiviral candidate.

[Expression and clinical significance of serum squamous cell carcinoma antigen（SCCAg） in sinonasal inverted papilloma].

Objective:To compare the expression levels of SCCAg in inverted papilloma of the nasal sinuses and other sinuses and sinus masses. To investigate the correlation between the expression of SCCAg in sinonasal inverted papilloma and outcome. Methods:Sixty-eight patients with unilateral nasal and sinus masses admitted to the Otorhinolaryngology Center of the Affiliated Hospital of Guangdong Medical University from September 2020 to February 2023 were randomly selected, including 31 patients with inverted papilloma （experimental group） and 37 patients with unilateral nasal and sinus masses excluding inverted papilloma （control group）. The application of automatic chemiluminescence immunoassay to test the serum SCCAg of the experimental group before surgery and 1 week after surgery, and the control group to measure the serum SCCAg before surgery. Clinical data were also collected. Results:There was no significant difference between the experimental group and the control group in gender and preoperative peripheral blood inflammatory indicators. However, there was significant difference in age and preoperative serum SCCAg level（P<0.001）. The serum SCCAg levels of the experimental group before and 1 week after surgery were significantly different（P<0.001）. The positive predictive value, negative predictive value, sensitivity and specificity of serum SCCAg in the diagnosis of varus papilloma were 92.6%, 85.4%, 77.4%, 94.6% and 0.72, respectively. The effect of serum SCCAg in the diagnosis of varus papilloma was analyzed by drawing the subject's working characteristic curve, and the area under the curve was 0.968（P<0.001）. When serum SCCAg greater than 2.7 ng/mL, the sensitivity and specificity were 67.7% and 94.6%, respectively. There was statistical significance in serum SCCAg levels between patients with and without recurrence（P<0.05）. Conclusion:The level of SCCAg in unilateral nasal and sinuses tumors, excluding squamous cell carcinoma, was significantly increased in inverted papilloma. The detection of serum SCCAg can be used as a simple and cost-effective auxiliary diagnostic tool for patients with nasal inverted papilloma before operation. Significant differences in preoperative and postoperative levels can be used for preliminary evaluation of surgical efficacy. Monitoring the serum SCCAg level in patients with inverted papilloma after surgery can predict recurrence and provide a simple and feasible method for postoperative follow-up.

[Application experience of prelacrimal recess combined with septotomy in resection of recurrent inverted papilloma].

Objective:To investigate the effectiveness of nasal endoscopic anterior lacrimal recess approach combined with temporary fenestration of the nasal septum in resecting recurrent nasal inverted papilloma. Methods:Patients with recurrent nasal inverted papilloma who underwent reoperation in our hospital during the past 2 years were included . The nasal septum may hinder full access to and effective treatment of the lesions at the anterior and medial wall of the maxillary sinus by endoscope, aspirator and surgical instrument in the narrow aperture of the prelacrimal recess, although these lesions could be observed by 70° nasal endoscope. Results:The nasal septum is temporarily opened on the basis of the prelacrimal recess approach, and the nasal endoscope and instrument was introduced through trans-septal window, so as to provide a better view of the operative field and the angular range of the instrument's movement. Conclusion:The recurrent nasal inverted papilloma could be successfully managed by re-endoscopic anterior lacrimal recess approach combined with temporary fenestration of the nasal septum, and no recurrence was observed during the 2-year follow-up. This surgical approach is recommended for the inverted papilla which originates from the anterior medial wall of the maxillary sinus, as the tumor can be removed completely using this surgical approach.

[Clinical application of nasal mucosa flap in the repair of nasopharyngeal skull base bone exposure after radiotherapy for nasopharyngeal carcinoma].

Objective:To observe the effect of nasal mucosa flap in the repair of nasopharyngeal skull base bone exposure after radiotherapy for nasopharyngeal carcinoma, and to provide a basis for the repair with nasal mucosa flap in skull base bone exposure after radiotherapy. Methods:The clinical data of 8 patients who underwent nasal endoscopic surgery were analyzed retrospectively. The survival of mucosal flap, the mucosal epithelialization of bone defect or exposed site, the improvement of main clinical symptoms and complications were followed up after operation. Results:Severe mucosal flap necrosis and bone exposure occurred in 1 case after operation, in the other 7 cases, the mucosal flap survived and the mucosal epithelium of nasopharynx recovered well. After operation, most of the patients' clinical symptoms such as headache and nasal odor were improved compared with those before operation. Conclusion:Nasal mucosal flap is a safe and minimally invasive autogenous material with good biocompatibility. It has a good application prospect in repairing bone defect or exposure of nasopharyngeal skull base after radiotherapy and is worth popularizing in clinic.