Objective:To explore the application of endoscopic narrow-band imaging(NBI) in the early diagnosis of throat malignant tumors.Methods:From January 2014 to December 2019, 512 patients with suspected benign or malignant diseases of the throat in the First People's Hospital of Wenling were selected, and all patients were performed white light endoscopy and NBI endoscopy.The biopsies were taken for pathological examination.The histopathological results were seemed as gold standard for diagnosis.Results:NBI endoscopy was superior to white light endoscope in terms of microvascular morphology and lesion outline(χ 2=457.497, 293.209, all P<0.05). The diagnostic coincidence rate, sensitivity and negative coincidence rate of NBI endoscope for malignant tumors were higher than those of white light endoscope(χ 2=10.131, 6.197, 4.084, all P<0.05). The sensitivity of NBI endoscope type Ⅰ-Ⅱ in the diagnosis of benign lesions was 90.65%, and the specificity was 96.88%.The sensitivity and specificity of NBI endoscope type Ⅲ-Ⅳ in the diagnosis of mild-moderate dysplasia were 80.99% and 97.52%, respectively.The sensitivity and specificity of NBI endoscopy type Va in the diagnosis of severe atypical hyperplasia were 15.18% and 98.54%, respectively.The sensitivity and specificity of NBI endoscope Va-c in the diagnosis of invasive cancer were 93.24% and 96.93%, respectively. Conclusion:Compared with white light endoscope, NBI endoscope can more clearly show the outline of lesions and submucosal blood vessels, and can more accurately diagnose malignant tumors in the throat, especially can more recognized the pre-cancerous lesions and early malignant tumors.It has important clinical application value in early diagnosis of malignant tumor in the throat.

Objective To investigate the optimal centrifugation conditions for preparation of rat and mouse platelet rich plasma (PRP) by single centrifugation.Methods Arterial blood of rats and mice by femoral artery cannulation and cardiac puncture were obtained respectively, anticoagulation with 14％CPDA-1, while white blood cells in the blood were filtered out.Then the blood was divided into sterile EP tubes, while PRP was prepared by centrifugation in different conditions (the centrifugal force was 300×g-600×g, and the centrifugal time was 4-12min).The number of blood cells of the anticoagulant whole blood, the leukocyte-depleted blood sample and PRP were counted by hematology analyzer, and platelet recovery rates were compared between different methods.Results The platelet recovery rate was highest when the blood samples of rats and mice were centrifuged at 400×g and 300×g for 8min respectively.Conclusion It is a key to prepare PRP by single centrifugation that selecting the appropriate centrifugal force and time and reaching a critical state before the formation of the buffy coat.