Effect of moisture on the field dependence of mobility for gas-phase ions of organophosphorus compounds at atmospheric pressure with field asymmetric ion mobility spectrometry

The electric field dependence of the mobilities of gas-phase protonated monomers [(MH+(H2O)n] and proton-bound dimers [M2H+(H2O)n] of organophosphorus compounds was determined at E/N values between 0 and 140 Td at ambient pressure in air with moisture between 0.1 and 15 000 ppm. Field dependence was described as alpha (E/N) and was obtained from the measurements of compensation voltage versus field amplitude in a planar high-field asymmetric waveform ion mobility spectrometer. The alpha function for protonated monomers to 140 Td was constant from 0.1 to 10 ppm moisture in air with onset of effect at approximately 50 ppm. The value of alpha increased 2-fold from 100 to 1000 ppm at all E/N values. At moisture values between 1000 and 10 000 ppm, a 2-fold or more increase in alpha (E/N) was observed. In a model proposed here, field dependence for mobility through changes in collision cross sections is governed by the degree of solvation of the protonated molecule by neutral molecules. The process of ion declustering at high E/N values was consistent with the kinetics of ion-neutral collisional periods, and the duty cycle of the waveform applied to the drift tube. Water was the principal neutral above 50 ppm moisture in air, and nitrogen was proposed as the principal neutral below 50 ppm.

APPLICATION OF A COMPREHENSIVE APPROACH FOR EVALUATION OF TREATMENT EFFECTIVENESS OF MYCOPLASMA INFECTION IN CHILDREN WITH BRONCHIAL ASTHMA

Aim - improvement of efficiency assessment methods of therapy of mycoplasma infection in children with bronchial asthma. The effectiveness of treatment of mycoplasma infection in the period of exacerbation of bronchial asthma in 250 children, aged 1 to 7 years, was evaluated. The children were on basic therapy and received treatment with azithromycin: three courses at a dose of 10 mg/kg of weight for 3 days with an interval of 4 days 5-7 days. Microbiological (culturing), immunological (DIF, AHAA), and genetic (PCR) methods were used to identify mycoplasma markers. The main focus was on identifying two species - M. pneumoniae and M. hominis, most commonly found in mycoplasma respiratory infections, including bronchial asthma. In 250 children with bronchial asthma, antigens of Mycoplasma pneumoniae, Mycoplasma hominis, Ureaplasma urealyticum, Mycoplasma arthritidis and Mycoplasma fermentrans were detected in 62,8%, 42,8%, 46,8 %, 31,6%, 45,6% of cases, respectively. A detailed study of the presence of M. pneumoniae and M. hominis antigens in the blood of 83 children with bronchial asthma showed that before treatment, the detection rate of M. pneumoniae and M. hominis antigens was 67.5% and 50.6%, respectively, in the CIC - 65.1% and 61.5%, DNA in the blood serum - 4.8% and 16.9%, and in the CIC - 27.7% and 32.5%, respectively. From 7 CIC samples containing M. hominis DNA and 2 CIC samples containing M. pneumoniae DNA, atypical cultures of "mini-colonies" of M. hominis and M. pneumoniae were isolated, the specificity of which was confirmed not only by DIF and PCR, but also by the ability to grow on a solid medium for mycoplasmas. After treatment by azithromycin, the number of positive tests on antigens and DNA in free state and in structure of CIC significantly decreased. The identification of specific markers of mycoplasma cells in the comprehensive diagnostics of mycoplasma infection in children with exacerbation of asthma, increases the effectiveness of therapy control for mycoplasma infection and improves the prognosis of bronchial asthma in patients.

Structure and properties of polysaccharides from tetrasporophytes of Mazzaella parksii

The structure and anti-SARS-CoV-2 activity of sulfated polysaccharides (Mzpt) obtained in high yield (60 %) from tetrasporophytes of Mazzaella parksii were studied. Stepwise fractionation with KCl showed that Mzpt consisted of eight (MzptF1-MzptF8) carrageenans fractions, differing in structure and molecular weight. The yield of non-gelling MzptF8 was 58.1 % of the original Mzpt. According to IR and NMR spectroscopies, gelling MzptF1 and MzptF2 were mainly kappa/iota/nu-carrageenans. MzptF7 included mainly lambda-carrageenan and in smaller quantities kappa-, iota-, mu- and nu-carrageenans. MzptF8 had a complex composition and included gamma-carrageenan, unsulfated carrageenan, probably, delta-carrageenan and also structural elements of xi-, psi- and omicron-carrageenans. According to atomic force microscopy data, MzptF8 involved several polymer chains associated with each other in a disordered structure, in contrast to MzptF2, which formed three-dimensional networks. Unlike ribavirin and remdesivir, Mzpt was not cytotoxic to Vero E6 cells at concentrations >2000 μg mL-1. Mzpt was shown to inhibit SARS-CoV-2 replication in a dose-dependent manner in CPE inhibition and RT-PCR assays. IC50 was 92.0 μg mL-1, SI - 22. At concentration 250 μg mL-1, Mzpt caused the highest reduction in viral RNA levels with an inhibition coefficient of 31.1 % and exhibited significant inhibition of the early stages of virus-cell interaction.

Right heart function in patients with viral pneumonia of varying severity caused by SARS-n-COV-2

Funding Acknowledgements

Type of funding sources: None.

Purpose

the purpose of this study was to estimate condition of right heart in patients with COVID-19 and viral pneumonia.

Material and methods

 87 patients were included (age 53 ± 13, 58% male) with established diagnosis of COVID-19 via PСR and viral pneumonia on CT scans. Patient’s clinical condition was assessed by SHOCS-COVID and NEWS scales. Transthoracic echocardiography was performed on 12 ± 4.6 day from the first symptoms of disease. Levels of high-sense Troponin I and NT-proBNP were measured in blood samples.

Results

Patients were divided into 3 groups according to pattern of viral pneumonia severity on CT scans. Group I with CT 1 grade (involvement of the pulmonary parenchyma 0-25%) - 11(12.6%) patients; mid age- 48.9 ± 17 years; NEWS score – 1.4 ± 0.9; SHOCS-COVID score – 7.5 ± 3.7.

Group II with CT 2 grade (involvement of the pulmonary parenchyma 25-50%). 48 (55.2%) patients; mid age- 51.6 ± 13.1 years; NEWS score - 2 ± 1; SHOCS-COVID score - 9 ± 2.1.

Group III with CT 3 grade (involvement of the pulmonary parenchyma 50%-75%). 28 (32.2%) patients; mid age- 57.1 ± 10.3 years; NEWS score – 3.2 ± 1.5; SHOCS-COVID score – 12.4 ± 2. 

Groups didn’t differ in age (p-value >0.05). Highest NEWS and SHOCS-COVID scores were observed in group III (p < 0.0001 and p = 0.01, accordingly). All patients had preserved LV ejection fraction (62 ± 4.2%). Range of right heart echocardiography parameters was higher in patients with more severe grade of viral pneumonia:

- pulmonary artery systolic pressure in group I – 26,3 ± 4 mmHg, in II ­– 28.7 ± 4 mmHg, in III – 29.1 ± 13.2 mmHg (pI-III= 0.002), r = 0.4, p < 0.0001;

- myocardial systolic velocity (s’) of free tricuspid annulus site by TDI in group I–11 ± 0.5 cm/s, in II–13 ± 2 cm/s, in III –14 ± 2 cm/s (pI-III= 0.02), r = 0.4. p < 0.0001;

- GLS of right ventricle (RV) in group I -18.6 ± 3%, in II – 21.6 ± 3.9%, in III – 21 ± 3.9% (pI-III = 0.038), r = 0.4, p = 0.005;

- RV mid diameter in apical position in group I– 27 ± 2.8 mm, in II – 31 ± 5.1 mm, in III – 29 ± 4.2 mm (pI-III = 0.03), r = 0.3, p = 0.002.

TAPSE and right heart areas didn’t differ between groups (p > 0.05). Levels of high-sense Troponin I were under 0.2 ng/ml in all groups (p > 0.05). NT-proBNP level were elevated only in group III – 172 [97,7;330] ng/l (pI-III = 0,03) and correlated with SHOCS-COVID scores (r = 0.4, p = 0.04), CT grade (r = 0.3, p = 0.01) and RV Tei index from pulse-wave Doppler (r = 0.3, p = 0.02).

Conclusion

perhaps, RV hyperfunction is compensatory reaction in response to increased afterload of right heart in patients with severe viral pneumonia caused by SARS-n-COV-2. Increased level of NT-proBNP indirectly confirms presence of myocardial stress in patients with severe viral pneumonia caused by SARS-n-COV-2.