SARS-CoV-2 reactive memory T cell immunity in healthy individuals / 中国输血杂志

【Objective】 To understand the memory phenotype and function of SARS-CoV-2 reactive CD4+ T cells in healthy individuals. 【Methods】 In this study, SARS-CoV-2-derived peptides were used to stimulate PBMC from participants.SARS-CoV-2 reactive memory T cells were detected by intracellular staining and flow cytometry, and memory phenotype analysis was performed.CBA was used to detect cytokine secretion after SARS-CoV-2-derived peptides stimulation to evaluate the function of SARS-CoV-2 reactive memory T cells. 【Results】 We found that SARS-CoV-2 reactive CD4+ memory T cells could be detected in 40% (6/15) healthy donors.Phenotypic analysis of memory showed that these T cells were mainly composed of central memory T cells(82.2%), and other memory cells accounted for 17.8%.Compared with negative control, IL-10 was significantly decreased after stimulation of SARS-CoV-2-derived peptides (P<0.05), while the secretion of IFNγ, TNFα, IL-2 and IL-4 showed no significant difference. 【Conclusions】 SARS-CoV-2 reactive CD4+ memory T cells are present in healthy individuals from China.

Advances in applicaiton of platelets with cold storage at 4℃ and its storage lesion / 中国输血杂志

Platelet transfusion is one of the important therapeutic methods for clinical prevention of bleeding and hemostasis. At present, agitated storage at (22±2)℃used for platelets leads to risk of bacterial growth, which limits platelet shelf life and safety in transfusion. Cold storage at 4 ℃ can significantly promote the abovementioned drawbacks and present a better hemostatic effect. Platelets storage lesion(PSL) due to the cold storage, however, may lead to platelet activation following transfusion, thus reducing the effective survival rate in vivo. This paper reviews the research advances in PSL and the application of platelets stored at 4 ℃.

Evaluating the different control policies for COVID-19 between mainland China and European countries by a mathematical model in the confirmed cases

This study focuses on evaluating the different policies of controlling the outbreak of COVID-19 in mainland China and in some European countries. The study is based on mathematical model which is a modified susceptible-infected-recovered (SIR) model. The model takes death and recovery into consideration which in convenience is called the susceptible-infected-recovered-death (SIRD) model. The criterion for the recovered patients is assumed by COVID-19 nucleic acid testing negative. The mathematical model is constructed by retrospective study. Determination of the parameters in the model is based on the epidemic bulletin supplied by the Chinese Center for Disease Control and Prevention (CDC) and National Health Commission of the Peoples Republic of China (NHC) from Jan 16 2020 to Mar 5 2020. The data cover the date when the epidemic situation is reported and the data showed that the epidemic situation is almost under control in China. The mathematical model mainly simulates the active cases and the deaths during the outbreak of COVID-19. Then apply the mathematical model to simulate the epidemic situations in Italy and Spain, which are suffering the outbreak of COVID-19 in Europe. The determination of the parameters for the 2 European countries is based on the data supplied by Worldometers. By comparing the difference of the parameters based on the same mathematical model, it is possible to evaluate the different policies in different countries. It turns out that the relatively easing control policies might lead to rapid spread of the disease.