Higher procoagulatory potential but lower DIC score in COVID-19 ARDS patients compared to non-COVID-19 ARDS patients
Authors: Hoechter, D. J.; Becker-Pennrich, A.; Langrehr, J.; Bruegel, M.; Zwissler, B.; Schaefer, S.; Spannagl, M.; Hinske, L. C.; Zoller, M.
Background: COVID-19 is a novel viral disease. Severe courses may present as ARDS. Several publications report a high incidence of coagulation abnormalities in these patients. We aimed to compare coagulation and inflammation parameters in patients with ARDS due to SARS-CoV-2 infection versus patients with ARDS due to other causes. Methods: This retrospective study included intubated patients admitted with the diagnosis of ARDS to the ICU at Munich university hospital. 22 patients had confirmed SARS-CoV2-infection (COVID-19 group), 14 patients had bacterial or other viral pneumonia (control group). Demographic, clinical parameters and laboratory tests including coagulation parameters and thromboelastometry were analysed. Results: No differences were found in gender ratios, BMI, Horovitz quotients and haemoglobin values. The median SOFA score, serum lactate levels, renal function parameters (creatinine, urea) and all inflammation markers (IL-6, PCT, CRP) were lower in the COVID-19 group (all: p < 0.05). INR (p < 0.001) and antithrombin (p < 0.001) were higher in COVID-19 patients. D-dimer levels (p = 0.004) and consecutively the DIC score (p = 0.003) were lower in this group. In ExTEM (R), Time-to-Twenty (TT20) was shorter in the COVID-19 group (p = 0.047), these patients also had higher FibTEM (R) MCF (p = 0.005). Further, these patients presented with elevated antigen and activity levels of von-Willebrand-Factor (VWF). Conclusion: COVID-19 patients presented with higher coagulatory potential (shortened global clotting tests, increased viscoelastic and VWF parameters), while DIC scores were lower. An intensified anticoagulation regimen based on an individual risk assessment is advisable to avoid thromboembolic complications.
Novel electrochemical biosensing platform for microRNA detection based on G-quadruplex formation in nanochannels
SENSORS AND ACTUATORS B-CHEMICAL
Authors: Zhao, Fei; Zhang, Hongfang; Zheng, Jianbin
Ultrasensitive detection of microRNA is crucial important in the diagnosis of related diseases. By immobilizing the capture probes in nanochannels, we developed a label-free electrochemical biosensing platform based on guanine-quadruplex (G-quadruplex) formation in nanochannels. The designed capture probe contains both the microRNA-21 (MiR-21) recognition sequence and guanine-rich sequence. The presence of the target MiR-21 would trigger the enzymatic cleaving of the RNA/DNA heteroduplexes which led some of the guanine-rich sequences escape from the nanochannels and thus reduced the formation of the G-quadruplex/hemin complex. Therefore, the quantity of methylene blue fluxed through the nanochannels changed because of the variation of the steric hindrance. A optimized carbon nanofibers modified electrode was applied to monitor the quantity difference of methylene blue. In this way, the biosensing platform realized the label-free electrochemical detection of MiR-21 with a ultralow detection limit of 0.5 aM. Meanwhile, this biosensing platform was assessed for MiR-21 detection in serum samples. The biosensing platform can be readily extended to the assay of other scarcetumor-related genes.