Wuhan is not only the first city to experience COVID-19 but is also among the first to emerge from the pandemic and currently has only 5 confirmed cases. The existence of asymptomatic carriers poses a threat for disease resurgence and also for virus transmission through transplantation. There are 2 types of asymptomatic carrier: the first is a recessive infection, with persistent but asymptomatic viral detection over 14 days or more, but with a relatively low-infectivity risk in the general community and unknown infection transmission risk from organ donation. The second group of asymptomatic cases are in the early stages of the incubation of the disease and become symptomatic over time but are contagious in the asymptomatic phase. To identify all asymptomatic carriers, Wuhan has carried out SARS-CoV-2 nucleic acid tests (NAT) for all city dwellers since May 14. As of May 24, 6 574 093 NAT tests have been completed, with a total of 227 new asymptomatic carriers and 1 new confirmed case.1 The asymptomatic infection rate in Wuhan has dropped from 0.5 per 1000 people2 to 0.03 per 1000 people. The outbreak of COVID-19 greatly slowed and then stopped organ donation and transplantation in Wuhan, but the decrease in the number of infections has allowed hospitals in Wuhan to carefully resume deceased donor organ donation and transplantation. Hyo-Lim Hong et al3 and Stephen Lagana et al4 have reported 2 cases of donor-derived transmission of COVID-19; therefore, a strategy is needed to prevent donor-derived transmission from all potential asymptomatic carriers. Because of the superficial understanding of COVID-19 and presence of asymptomatic infection in Wuhan, we instituted a protocol to prevent organ donor transmission of COVID-19. Before transplantation, both deceased donors and potential recipients undergo SARS-CoV-2 NAT and antibody tests as well as CT scans, which are repeated twice, to avoid the known false negative rates of single tests in COVID-19 patients and detect patients in the early stages of developing symptomatic disease. Donors and recipients must test negative twice to be eligible for transplant. To minimize transmission caused by asymptomatic carriers, potential deceased donors are quarantined in intensive care for >7 days while being tested. Suspected or confirmed COVID-19 patients would be eliminated from the donation process. From April 8, when Wuhan was reopened, to May 25, 43 cases of organ donation after brain death and 125 cases of organ transplant have been completed in Wuhan hospitals. There have been no cases of COVID-19 detected among organ transplant donors and recipients. This protocol may serve as a complex but necessary learning model for others.
Various treatments for hypertrophic scars (HS) are applied after wound re-epithelialization. However, the lack of early intervention within the wound bed leads to poor HS treatment outcomes. In this study, quaternized chitin (QC) derivatives with different degrees of deacetylation (7.4% and 78.9%) are synthesized and their effects on HS formation are evaluated in a rabbit ear scar model. Early application of QC alleviates scar hypertrophy without delayed wound healing. Fibroblast count, collagen content, and α-smooth muscle actin expression are decreased, while matrix metalloproteinase-1 is upregulated on day 35 in the QC treatment group. QC suppresses inflammatory cell infiltration and IL-6 expression. A subsequent reduction in transforming growth factor β1 expression is also observed. The inhibitory effect of QC on HS formation is eliminated through the administration of exogenous IL-6. Taken together, early application of QC inhibits HS formation by downregulating IL-6 expression, and QC with a low degree of deacetylation tends to be more effective. Considering its potential for accelerating wound healing, inhibiting HS formation, and its antibacterial activity, QC may be used as an effective dressing in clinical wound management.
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