ABSTRACT
Type 1 diabetes mellitus (T1DM) represents one of the most frequent chronic illnesses affecting children. The early diagnosis of this disease is crucial, as it plays a key role in preventing the development of a life-threatening acute complication: diabetic ketoacidosis. The etiopathogenetic role of viral infections has long been suggested and emerging data are pointing towards a complex bidirectional relationship between diabetes and COVID-19. The aim of this study is to assess the impact of the COVID-19 pandemic on the incidence and severity of new T1DM cases in children in Romania. We analyzed the differences between a group of 312 patients diagnosed with T1DM in the period 2003-2019 and a group of 147 children diagnosed during the pandemic. The data were investigated using statistical analysis of a series of relevant variables. The total number of newly diagnosed T1DM increased by 30.08% in the period March 2020-February 2021 compared to the previous years. The patients in the pandemic group had a higher mean age at the onset of T1DM, were less frequently living in an urban area, and presented a higher mean value of HbA1c. Diabetic ketoacidosis at the onset of T1DM was 67.40% more frequent, and a higher percentage of these patients presented with a severe form. The duration of T1DM symptoms did not differ significantly between the two groups. A number of 8 patients associated SARS-CoV-2 infection at the time of T1DM diagnosis.
ABSTRACT
Human leukemia Jurkat T cells were analyzed for apoptosis and cell cycle by flow cytometry, using the Annexin V/propidium iodide (PI) standard assay, and a simple PI staining in Triton X-100/digitonin-enriched PI/RNase buffer, respectively. Cells treated with doxorubicin or menadione displayed a very strong correlation between the apoptotic cell fraction measured by the Annexin V/PI assay, and the weight of a secondary cell population that emerged on the forward scatter (FS)/PI plot, as well as on the side scatter (SS)/PI and FL1/PI plots generated from parallel cell cycle recordings. In both cases, the Pearson correlation coefficients were >0.99. In cell cycle determinations, PI fluorescence was detected on FL3 (620/30 nm), and control samples exhibited the expected linear dependence of FL3 on FL1 (525/40 nm) signals. However, increasing doses of doxorubicin or menadione generated a growing subpopulation of cells displaying a definite right-shift on the FS/FL3, SS/FL3 and FL1/FL3 plots, as well as decreased PI fluorescence, indicative of ongoing fragmentation and loss of nuclear DNA. By gating on these events, the resulting fraction of presumably sub-cycling cells (i.e. cells with cleaved DNA, counting sub-G0/G1, sub-S and sub-G2/M cells altogether) was closely similar to the apoptotic rate assessed by Annexin V/PI labeling. Taken together, these findings suggest a possible way to recognize the entire population of cells undergoing apoptotic DNA cleavage and simultaneously determine the cell cycle distribution of non-apoptotic cells in PI-labeled cell samples with various degrees of DNA fragmentation, using a simple and reproducible multiparametric analysis of flow cytometric recordings.
