Condition of the Right Heart in Patients With COVID-19­Associated Pneumonia: Follow-Up During Hospitalization.

Aim      Dynamic assessment of the right heart in patients with COVID-19-associated pneumonia of different severity during regression of the systemic inflammatory response (SIR).Material an methods    This single-center prospective study included 46 patients with the novel coronavirus infection COVID-19 and viral pneumonia according to chest multispiral computed tomography (CT). Laboratory and echocardiographic examinations of patients were performed.Results Based on the results of evaluation with the Clinical Condition Scale (CCS-COVID), patients were divided into two groups: group A, patients with a score from 6 to 9 and group B, patients with a score from 10 to 14. The study results of both groups were evaluated twice: on day 10±2.5 from the onset of symptoms (groups A10 and B10, respectively) and again on day 17±1.8 (groups A17 and B17, respectively). Patients of group B10 had more pronounced SIR (C-reactive protein, 111.38±52.5 mg / l) and a larger volume of ground-glass opacity (38.3±9.6 %). At the first stage, higher values of right ventricular global longitudinal strain (RV GLS) were detected in group B10 compared to group A10 (23.2±4.8 % vs. 19.9±3.5 %, р=0.048). During the regression of SIR intensity and the positive dynamics of CT, lower values of Е / А were observed in group B17 (1.0 [0.98; 1.2]) vs. group А17 (1.4 [1.18; 1.5, p=0.015), and е' / a' in group B17 (0.66 [0.58; 0.85]) vs. 0.95 [0.79; 1.12] in group B17 (p=0.010). Е / А and е' / a' ratios were correlated with total lactate dehydrogenase fraction (r= -0.452 and p=0.006; r= -0.334 and p=0.050, respectively).Conclusion      In patients with severe COVID-19-associated pneumonia during regression of SIR intensity, changes in the parameters that reflected RV diastolic dysfunction were observed.

Leader sequences of eukaryotic mRNA can be simultaneously bound to initiating 80S ribosome and 40S ribosomal subunit.

Binding of mRNA leader sequences to ribosomes was studied in conditions of a cell-free translation system based on wheat germ extract. Leader sequence of TMV mRNA (the so-called omega-RNA sequence) was able to bind simultaneously 80S ribosome and 40S ribosomal subunit. It was found that nucleotide substitutions in omega-RNA resulting in destabilization of RNA structure have no effect on the complex formation with both 80S ribosome and 40S ribosomal subunit. Leader sequence of globin mRNA is also able to form a similar joint complex. It is supposed that the ability of mRNA leader sequences to bind simultaneously 80S ribosome and 40S subunit is independent of leader nature and may reflect previously unknown eukaryotic mechanisms of translation initiation.