Objective To investigate the mechanism of an inhibitor of NADPH oxidases,diphenylene iodonium (DPI),in preventing radiation-induced lung injury.Methods Totally 48 adult SD male rats were randomly classified into 4 groups:control group (C),radiation group (R),radiation plus DPI group (R + D) and DPI group (D).The radiation induced pulmonary injury model was preformed by using 6 MV X-rays to deliver 8 Gy per day for 5 consecutive days with 40 Gy in total to the thorax of each animal.Rats in R + D group were subcutaneously administered with 0.02％ DPI (1 mg/kg) at 1 h prior to radiation while rats in D group received the same dose of DPI without radiation.DPI was given from 3 d before radiation to 30 d after the first radiation.Rats in C and D groups received the same dose of saline.Animals were sacrificed at 1 month and 6 months after radiation,respectively.The lungs were removed and processed for HE and Masson staining,hydroxyproline content measurement,and TGF-β1 immunohistochemical detection.Results At 1 month post-radiation,rats in R group showed typical alveolitis,the level of hydroxyproline was (0.69 ± 0.05) μg/mg,and the positive area of TGF-β1 expression was (39.97 ± 0.90) ％,while the level of hydroxyproline in R + D group was (0.55 ± 0.03) μg/mg and the positive area of TGF-β1 expression was(33.83 ± 1.55) ％,rats in R + D group showed less severe alveolitis compared with R group(t =5.32,5.93,P ＜0.05).At 6 months post-radiation,rats in R group showed typical lung fibrosis with hydroxyproline level of (1.04 ±-0.02) μg/mg and TGF-β1 expression of (37.80 ± 0.85) ％,whereas the hydroxyproline level in R + D group was (0.85 ± 0.02) μg/ mg,the TGF-β1 expression was(23.93 ± 1.16)％,rats in R + D group showed moderate lung fibrosis(t =15.77,16.68,P ＜ 0.05),rats in C and D group had no noticeable changes.Conclusions Diphenylene iodonium could prevent radiation-induced lung injury by reducing the level of hydroxyproline and the expression of TGF-β1.

Respiratory mucosal immune system is the body''s first line of defense against infection.Since the outbreak of novel coronavirus disease 2019 (COVID-19) in 2019,nasal mucosal immune vaccine, with its ability to induce cellular, humoral and mucosal triple immune responses, has become a research hotspot.This article focuses on novel coronavirus, with an understanding of its structure and pathogenesis, a brief introduction to the immune mechanism of nasal mucosa, a summary of the different types of nasal mucosal immune vaccines and their clinical research, aiming to provide some theoretical reference for the development of new vaccines, and exploration of the best methods and strategies to combat COVID-19.

Coronavirus disease 2019 (COVID-19) is an acute respiratory infectious disease caused by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection. It is highly contagious and can cause death in severe cases. As reported by the World Health Organization (WHO), as of 6:36 pm Central European Summer Time (CEST), 12 August 2022, there had been 585 950 285 confirmed cases of COVID-19, including 6 425 422 deaths (WHO, 2022).
Humans ; COVID-19 ; SARS-CoV-2 ; Mental Health ; Cohort Studies ; Quality of Life ; China/epidemiology* ; Health Personnel ; Hospitals ; Lung