Neoadjuvant chemotherapyeoadjuvant chemoradiotherapy (NAC/NACRT) can be performed in patients with pancreatic cancer to improve survival. We aimed to clarify the clinical outcomes of biliary drainage with a metal stent (MS) or a plastic stent (PS) during NAC/NACRT. Between October 2013 and April 2016, 96 patients with pancreatic cancer were registered for NAC/NACRT. Of these, 29 patients who underwent biliary drainage with MS or PS before NAC/NACRT and a subsequent pancreatoduodenectomy were retrospectively analyzed with regard to patient characteristics, preoperative recurrent biliary obstruction rate, NAC/NACRT delay or discontinuation rate, and operative characteristics. The median age of the patients was 67 years. NAC and NACRT were performed in 14 and 15 patients, respectively, and MS and PS were used in 17 and 12 patients, respectively. Recurrent biliary obstruction occurred in 6% and 83% of the patients in the MS and PS groups, respectively (p<0.001). NAC/NACRT delay was observed in 35% and 50% of the patients in the MS and PS groups, respectively (p=0.680). NAC/NACRT discontinuation was observed in 12% and 17% of the patients in the MS and PS groups, respectively (p=1.000). The operative time in the MS group tended to be longer than that in the PS group (625 minutes vs 497 minutes, p=0.051), and the operative blood loss volumes and postoperative adverse event rates were not different between the two groups. MS was better than PS from the viewpoint of preventing recurrent biliary obstruction, although MS was similar to PS with regards to perioperative outcomes.

The severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), a new zoonotic agent that emerged in December 2019, causes coronavirus disease 2019 (COVID-19). This infection can be spread by asymptomatic, presymptomatic, and symptomatic carriers. SARS-CoV-2 spreads primarily via respiratory droplets during close person-to-person contact in a closed space, especially a building. This article summarizes the environmental factors involved in SARS-CoV-2 transmission, including a strategy to prevent SARS-CoV-2 transmission in a building environment. SARS-CoV-2 can persist on surfaces of fomites for at least 3 days depending on the conditions. If SARS-CoV-2 is aerosolized intentionally, it is stable for at least several hours. SARS-CoV-2 is inactivated rapidly on surfaces with sunlight. Close-contact aerosol transmission through smaller aerosolized particles is likely to be combined with respiratory droplets and contact transmission in a confined, crowded, and poorly ventilated indoor environment, as suggested by some cluster cases. Although evidence of the effect of aerosol transmission is limited and uncertainty remains, adequate preventive measures to control indoor environmental quality are required, based on a precautionary approach, because COVID-19 has caused serious global damages to public health, community, and the social economy. The expert panel for COVID-19 in Japan has focused on the "3 Cs," namely, "closed spaces with poor ventilation," "crowded spaces with many people," and "close contact." In addition, the Ministry of Health, Labour and Welfare of Japan has been recommending adequate ventilation in all closed spaces in accordance with the existing standards of the Law for Maintenance of Sanitation in Buildings as one of the initial political actions to prevent the spread of COVID-19. However, specific standards for indoor environmental quality control have not been recommended and many scientific uncertainties remain regarding the infection dynamics and mode of SARS-CoV-2 transmission in closed indoor spaces. Further research and evaluation are required regarding the effect and role of indoor environmental quality control, especially ventilation.
Aerosols ; Air Pollution, Indoor/prevention & control* ; Betacoronavirus/physiology* ; COVID-19 ; Coronavirus Infections/transmission* ; Crowding ; Environment, Controlled ; Humans ; Pandemics/prevention & control* ; Pneumonia, Viral/transmission* ; SARS-CoV-2 ; Ventilation