ABSTRACT
(1) BackgroundThis study aims to investigate the clinical characteristics and risk prediction of severe or critical events of COVID-19 in the elderly patients in China. (2) MethodsThe clinical data of COVID-19 in the elderly patients admitted to the Shanghai Public Health Clinical Center during the period of January 20, 2020 to March 16, 2020 were collected. A retrospective cohort study design was conducted to screen out independent factors through Cox univariable regression analysis and multivariable regression analysis, and the efficacy of risk prediction of severe or critical illness was examined through the receiver operating characteristic (ROC) curve. (3) ResultsA total of 110 elderly patients with COVID-19 were enrolled. 52 (47.3%) were males and 21 (19.1%) had severe or critical illness. Multivariable regression analysis showed that CD4 cells and D-dimer were independent risk factors. D-dimer, CD4 cells, and D-dimer/CD cells ratios with cut off values of 0.65 (mg/L), 268 (cell/ul) and 431 were in the prediction of severe or critical illness of the elderly COVID-19. The AUC value of D-dimer, CD4 cells, CD4 cells/D-dimer ratio, the tandem group and the parallel group were 0.703, 0.804, 0.794, 0.812 and 0.694, respectively. (4) ConclusionsD-dimer, CD4 cells and their combination have risk assessment value in predicting severe or critical illness of COVID-19 in the elderly.
ABSTRACT
BACKGROUND: Currently, mesenchymal stem cells have been widely explored and applied in scientific research field, and many studies suggest that the underlying mechanism of mesenchymal stem cells mainly relies on its exosomes. OBJECTIVE: To isolate and identify human adipose-derived stem cells and its exosomes, and to identify their biological characteristics. METHODS: Human adipose tissue was digested with collagenase l, and adipose-derived stem cells were isolated and purified. Immunophenotype, osteogenic and adipogenic abilities of adipose-derived stem cells were identified. Exosomes were isolated by using ultrafiltration method. Morphology of exosomes was observed by Nanosight and electron microscope. Expression of proteins in exosomes was detected by antibody array method. RESULTS AND CONCLUSION: Adipose-derived stem cells exhibited long spindle-like or fibroblast-like appearance, expressed CD73, CD44, CD90, CD105 and had the potential to differentiate into many tissues, including bone and adipose tissues. The exosomes had the similar size, with the diameter of 30-150 nm. They possessed many proteins including FLOT1, ICAM, ALIX, CD81, CD63, ANXA5, TSG101, and so on. Findings from the present study indicate the successful isolation of exosomes from human adipose-derived stem cells.
