Microminiaturization of Multichannel Multifrequency Radiographs.

Due to the COVID-19 epidemic, the challenge of introducing methods for investigating patients reducing or eliminating the probability of infection of medical staff is currently relevant. This article provides an analytical review of new technological approaches to organizing the work of medical personnel in carrying out auscultation of patients with COVID-19. The development and approval of such technologies is shown to have started around the world. The ubiquitous and large-scale introduction of these methods into medical practice therefore seems expedient.

Features of the immunological profile of blood and urine in patients with post-infectious glomerulonephritis.

The timely diagnosis and treatment of post-infectious glomerulonephritis (PIGN) is currently limited by the erased and low-symptom nature of the disease, which leads to the search for informative biological markers of the disease, which can be used as immunological indicators of blood and urine. The study was carried out in order to establish the characteristic changes in the immunological parameters of blood and urine in patients with PIGN. The study included 60 patients with PIGN from among the patients, hospitalized in the nephrology department of the Republican Clinical Hospital of Health Care Ministry of the Chuvash Republic in 2015-2018. In addition to the generally accepted research methods, the patients underwent: 1) the determination of indicators of innate and acquired immune response in the blood (CD3+ -, CD3+ CD4+-, CD3+CD8+-, CD4+CD25+-, CD95+-, CD20+-, CD14+CD282+-, CD14+CD284+- cells; levels of IgG, IgA, IgM, circulating immune complexes, C3, C4) and urine (levels of IgG, IgA, IgM, C3, C4); 2) the determination of the levels of cytokines - IL-1ß, Ra-IL-1ß, IL-2, IL-4, IL-8, IL-10, IL-17A in blood serum and urine. The data obtained were compared with those of the group of healthy individuals. The changes in blood immunological parameters, identified in the group of patients with PIGN, indicate the activation of innate immunity (the increase in the number of CD14+TLR2+- cells) and the humoral component of adaptive immunity (the increase in the number of B-lymphocytes, hyperimmunoglobulinemia - the increase in IgM and IgA levels) against the background of the decrease in the number of T (CD3+) - lymphocytes and regulatory (CD4+CD25high) - cells, hypocomplementemia (decreased levels of C3, C4). The increase in the content of C3, IgG and IgA was found in the urine. The cytokine profile of blood in patients with PIGN was characterized by the increase in the levels of pro- and anti-inflammatory cytokines IL-1ß, Ra-IL-1ß, IL-2, IL-8, IL-10, IL-17A, with the exception of IL-4, which remained on the levels of healthy individuals. The cytokine profile of urine in patients was characterized by the increase in the levels of pro-inflammatory cytokines IL-1ß, IL-2, IL-8, IL-17A and anti-inflammatory cytokine - IL-10, with no changes in the content of Ra-IL-1ß and IL-4. The revealed features of the immunological profile of blood and urine in patients with PIGN reflect the immunopathogenetic mechanisms of this disease.

PCR assays for detection of human astroviruses: In silico evaluation and design, and in vitro application to samples collected from patients in the Netherlands.

BACKGROUND: Human astroviruses (HAstV) comprise three phylogenetically compact and non-adjacent groups of species including classical HAstV (HAstV-C) and the novel ones (HAstV-VA/HMO and HAstV-MLB). Of these, HAstV-C is known to be responsible for gastroenteritis while the novel HAstV are associated with cases of neurological disorders. Accurate detection of all known variants by (real-time) PCR is challenging because of the high intra- and intergroup genetic divergence of HAstV. OBJECTIVES: To evaluate published HAstV PCR assays in silico, design de novo real-time PCR assays that can detect and discriminate three groups of HAstV, and apply those to patient samples to analyse the prevalence of HAstV in stool and cerebrospinal fluid (CSF) specimens. STUDY DESIGN: In silico evaluation of published PCR assays and design of real-time PCR assays for detection of different subsets of HAstV was conducted within a common computational framework that used all astrovirus full genome sequences from GenBank. The newly designed real-time PCR assays were evaluated in vitro and applied to faecal samples (collected in January-May 2016) and cerebrospinal fluid specimens (2010-2016) from patients in the Netherlands. RESULTS: Quantitative in silico evaluation of published PCRs is provided. The newly designed real-time PCR assays can reliably assign all available HAstV genome sequences to one of the three phylogenetic groups in silico, and differentiate among HAstV-specific controls in vitro. A total of 556 samples were tested using these PCR assays. Fourteen fecal samples (2.5%) tested positive for HAstV, 3 of which could be identified as the novel HAstV-MLB variants. No novel HAstV were found in CSF specimens. CONCLUSION: Newly designed real-time PCR assays with improved detection of all known HAstV allowed the first-time identification of novel astroviruses from stool samples in the Netherlands.

Sequencing of the complete genome of an araphid pennate diatom Synedra acus subsp. radians from Lake Baikal.

High-throughput method of sequencing was applied to determine the complete nucleotide sequence of an araphid pennate diatom Synedra acus subsp. radians from Lake Baikal (East Siberia). The assembled genome has a total length of 98 Mbp, the mean coverage is 33x. Structure-functional annotation of the genome was performed.

Transcriptomic response to differentiation induction.

BACKGROUND: Microarrays used for gene expression studies yield large amounts of data. The processing of such data typically leads to lists of differentially-regulated genes. A common terminal data analysis step is to map pathways of potentially interrelated genes. METHODS: We applied a transcriptomics analysis tool to elucidate the underlying pathways of leukocyte maturation at the genomic level in an established cellular model of leukemia by examining time-course data in two subclones of U-937 cells. Leukemias such as Acute Promyelocytic Leukemia (APL) are characterized by a block in the hematopoietic stem cell maturation program at a point when expansion of clones which should be destined to mature into terminally-differentiated effector cells get locked into endless proliferation with few cells reaching maturation. Treatment with retinoic acid, depending on the precise genomic abnormality, often releases the responsible promyelocytes from this blockade but clinically can yield adverse sequellae in terms of potentially lethal side effects, referred to as retinoic acid syndrome. RESULTS: Briefly, the list of genes for temporal patterns of expression was pasted into the ABCC GRID Promoter TFSite Comparison Page website tool and the outputs for each pattern were examined for possible coordinated regulation by shared regelems (regulatory elements). We found it informative to use this novel web tool for identifying, on a genomic scale, genes regulated by drug treatment. CONCLUSION: Improvement is needed in understanding the nature of the mutations responsible for controlling the maturation process and how these genes regulate downstream effects if there is to be better targeting of chemical interventions. Expanded implementation of the techniques and results reported here may better direct future efforts to improve treatment for diseases not restricted to APL.

Estimation of cyclodextrin affinity to steroids.

A nonlinear spectrometric method for determination of the stability constant (Ks) for cyclodextrin complex with steroid was developed. The method is based on calculation of the parameters of competitive cyclodextrin complexation by simultaneous fitting of two types of curves. Those of the first type are the dependencies of absorbance of methyl orange solution on the cyclodextrin concentration, the second type being the absorption curves of displacement of the dye, by steroid, from the cyclodextrin complex. With the method proposed, Ks values were calculated with standard deviation less than 10%. This method is validated by determination of Ks values using the phase-solubility technique. For neutral steroid molecules, the effect of pH on Ks was found to be insignificant. Ks values for the cyclodextrin-dye complex were determined for randomly methylated beta-cyclodextrin, 2-hydroxypropyl-beta-cyclodextrin, carboxymethyl-beta-cyclodextrin and sulfobutylether-beta-cyclodextrin. More hydrophobic steroids were characterised by higher Ks values. Anionic beta-cyclodextrins showed high affinity for the steroids studied. Simple equipment and sufficient computing allowed recommendation of the method for express estimation of cyclodextrin's affinity for hydrophobic substrates.

Identification of dynamically distinct subpopulations of T lymphocytes that are differentially affected by HIV.

We examined the effects of human immunodeficiency virus infection on the turnover of CD4 and CD8 T lymphocytes in 17 HIV-infected patients by 30 min in vivo pulse labeling with bromodeoxyuridine (BrdU). The percentage of labeled CD4 and CD8 T lymphocytes was initially higher in lymph nodes than in blood. Labeled cells equilibrated between the two compartments within 24 h. Based on mathematical modeling of the dynamics of BrdU-labeled cells in the blood, we identified rapidly and slowly proliferating subpopulations of CD4 and CD8 T lymphocytes. The percentage, but not the decay rate, of labeled CD4 or CD8 cells in the rapidly proliferating pool correlated significantly with plasma HIV RNA levels for both CD4 (r = 0.77, P < 0.001) and CD8 (r = 0.81, P < 0.001) T cells. In six patients there was a geometric mean decrease of greater than 2 logs in HIV levels within 2 to 6 mo after the initiation of highly active antiretroviral therapy; this was associated with a significant decrease in the percentage (but not the decay rate) of labeled cells in the rapidly proliferating pool for both CD4 (P = 0.03) and CD8 (P < 0.001) T lymphocytes. Neither plasma viral levels nor therapy had an effect on the decay rate constants or the percentage of labeled cells in the slowly proliferating pool. Monocyte production was inversely related to viral load (r = -0.56, P = 0.003) and increased with therapy (P = 0.01). These findings demonstrate that HIV does not impair CD4 T cell production but does increase CD4 and CD8 lymphocyte proliferation and death by inducing entry into a rapidly proliferating subpopulation of cells.

Correlation between reduction in plasma HIV-1 RNA concentration 1 week after start of antiretroviral treatment and longer-term efficacy.

BACKGROUND: Early assessment of antiretroviral drug efficacy is important for prevention of the emergence of drug-resistant virus and unnecessary exposure to ineffective drug regimens. Current US guidelines for changing therapy are based on measurements of plasma HIV-1 RNA concentrations 4 or 8 weeks after the start of treatment with cut-off points of 0.75 or 1.00 log, respectively. We investigated the possibility of assessing drug efficacy from measurements of plasma HIV-1 concentrations made during the first week on therapy. METHODS: The kinetics of virus decay in plasma during the first 12 weeks of treatment was analysed for 124 HIV-1-infected patients being treated for the first time with a protease inhibitor. Patients with a continuous decline of HIV-1 concentrations and in whom HIV-1 was either undetectable or declined by more than 1.5 log at 12 weeks were defined as good responders; the rest were poor responders. FINDINGS: The individual virus decay rate constants (k) at day 6 correlated significantly (r>0.66, p<0.0001) with changes in HIV-1 concentrations at 4, 8, and 12 weeks, and correctly predicted 84% of the responses with a cut-off value of k=0.21 per day (in log scale). Reduction in plasma HIV-1 of less than 0.72 log by day 6 after initiation of therapy predicted poor long-term responses in more than 99% of patients. INTERPRETATION: These results suggest that changes in HIV-1 concentration at day 6 after treatment initiation are major correlates of longer-term virological responses. They offer a very early measure of individual long-term responses, suggesting that treatment could be optimised after only a few days of therapy.

Hydrolysis of tripolyphosphate by purified exopolyphosphatase from Saccharomyces cerevisiae cytosol: kinetic model.

The kinetics of hydrolysis of tripolyphosphate by purified exopolyphosphatase from Saccharomyces cerevisiae cytosol has been studied in the presence of Mg2+. Two kinetic models suggesting the formation of complexes of tripolyphosphate and the enzyme with Mg2+ are compared. Both models suggest that only enzyme--substrate complexes containing Mg2+ and tripolyphosphate simultaneously are able to hydrolyze the tripolyphosphate. The first model suggests that the enzyme is able to bind to Mg2+ independently from substrate binding. The second model does not consider this possibility, but suggests that both complexes containing tripolyphosphate and Mg2+ in proportion 1:1 and 1:2 can serve as the reaction substrates. The description of the experimental data by both models is essentially the same. The complex containing tripolyphosphate and Mg2+ in proportion 1:1 is optimal for the enzyme activity, the complex containing tripolyphosphate and Mg2+ in proportion 1:2 being hydrolyzed at a lower rate.

Antagonistic interactions among T cell subsets of old mice revealed by limiting dilution analysis.

When CD4 spleen cells from old (but not young) mice are tested for Con A-induced proliferation in limiting dilution assays, the dose response curve shows a nonlinear relationship. We interpret these observations using a two-cell model, in which proliferation of one cell type (LPC1) can be blocked by a second cell type (LPC2), which can itself generate detectable proliferation only at high multiplicities. The two-cell model accounts for several observations: 1) the variation in curve shape as a function of incubation time; 2) the skewed distribution of wells scored as "negative" in cultures of old splenocytes; and 3) the initially antagonistic effects of old splenocytes titrated into cultures containing fixed numbers of young responders. To provide a further test of the two-cell model, ionomycin-resistant (CaR) and ionomycin-sensitive (CaS) cells were separated using a Percoll/ionomycin gradient. The CaR preparation, shown previously to consist largely of memory T cells, showed the dose curve predicted for the LPC2 cell type, whereas the CaS (naive) cells showed the single-hit kinetics postulated for LPC1 cells. Furthermore, mixtures of CaR and CaS cells from young mice reproduced the zigzag dose curve characteristically produced by unseparated cells from old mice. These data suggest that the spleens of both young and old mice contain two kinds of Con A-responsive CD4 cell: one that proliferates vigorously, and a second, calcium ionophore-resistant type that proliferates less well, that can interfere with proliferation of the first cell type, and whose frequency increases with age.

Mathematical modeling of T-cell proliferation.

A mathematical model of the T-lymphocyte proliferation process (in vivo and in vitro) is presented. This model takes into account cell-cycle progression and the regulation by lymphokines (lymphocyte activating factor interleukin 1 and T-cell growth factor interleukin 2). Using data on the generalized picture of the short-term course of viral hepatitis B, the parameter estimation procedure is carried out. The possibility of immunocorrection (by means of injection of a pharmacologic dose of IL-2) during the immune response to viral hepatitis B with T-lymphocyte deficiency is shown.

Quantitative analysis of interleukin-2-induced proliferation in the presence of inhibitors using a mathematical model.

The proliferative response of CTLL-2 cells to human recombinant interleukin-2 (IL-2) can be modeled mathematically using enzyme kinetic equations. This approach has been used to analyze dose-response curves (IL-2 concentration vs. level of proliferation) measured by MTT and [3H]TdR assays. The values of functional dissociation constants, equivalent to IL-2 concentrations giving 50% of the maximal response, depended on the cell concentration and increased from 4 to 60 pM for the [3H]TdR assay and from 40 to 140 pM for the MTT assay when the cell concentration was increased from 2 x 10(3) to 4 x 10(4) cells/well. The types of inhibition and dissociation constants for various inhibitors of IL-2-dependent proliferation such as mAbs against IL-2 receptor (7D4 and AMT13) and normal mouse serum (NMS) were also analyzed. Both mAbs exhibited competitive mechanisms of inhibition whereas NMS inhibited IL-2-driven proliferation in a mixed manner. Two gel-filtration fractions of NMS with inhibitory activity manifested different types of inhibition: purely competitive type of inhibition in the case of a 10-15 kDa fraction and a mixed type of inhibition for a 100-150 kDa fraction. The proposed model can also be used for quantitative analysis of the influence of various factors (pH, temperature, cultivation condition) on the level of proliferation.

[Relationship of the pKMR plasmids detected in Shigella circulating in the Krasnodar Territory to incompatibility groups]. / Otnoshenie pKMR-plazmid, vyiavlennykh u shigell, tsirkuliruiushchikh v Krasnodarskom krae, k gruppam nesovmestimosti.

Shigella strains showed that in 43.9 per cent of the strains this feature was controlled by conjugative R plasmids. On the whole these were the plasmids allotting the bacterial cell with resistance simultaneously to SmTcCm (37.1 per cent) and SmTc (17.1 per cent). The plasmids with other phenotypes were less frequent: SmApCm, 11.4 per cent, TcApCm, 8.6 per cent; SmTcApCm, 8.6 per cent; Tc, 8.6 per cent; Sm, 2.9 per cent; Cm, 2.9 per cent and TcCm, 2.9 per cent. The incompatibility groups of 19 plasmids were determined: Inc I zeta, 28.6 per cent; Inc zeta I and Inc B, 14.2 per cent; Inc FII, 8.6 per cent and Inc I alpha, 2.9 per cent.

[Characteristics of R plasmids expressed by dysenteric bacteria]. / Kharakteristika R-plazmid, vyiavlennykh u dizenteriinykh bakterii.

One hundred and eighty-six clinical strains of Enterobacteriaceae isolated in the Krasnodar region and Krasnodar in 1982 from patients with acute intestinal diseases were studied. 137 strains of Shigella were investigated in detail. It was shown that S. flexneri, S. sonnei, S. boydii and S. dysenteriae accounted for 77, 15, 5 and 2 per cent, respectively. 78.1 per cent of the wild Shigella strains were resistant to antibiotics and in 43.9 per cent of the strains this property was controlled by conjugative R plasmids. 11 variants of the antibiotic resistance spectra were revealed. However, strains of SmTcApCm, SmTc and SmTcAp phenotypes were the most frequent. Among the resistant strains 80.3 per cent were resistant to tetracycline, 75.7 per cent to streptomycin, 50.4 per cent to ampicillin, 31.7 per cent to chloramphenicol, 1.8 per cent to trimethoprim, and 0.9 per cent to kanamycin. The investigation showed that the strains isolated in one region usually had similar phenotypes of antibiotic resistance. The frequency of the plasmid transfer varied from 10(-1) to 10(-7). However, the majority of the plasmids were transferred at a frequency of 10(-4)-10(-5). Only one of the investigated plasmids had a capacity for transmitting fd phage sensitivity to the host cells. 33 plasmids belong to the fi+ type and the others belong to the fi- type. The majority of the plasmids have molecular weights of 46 to 50 mD.

[Physicochemical properties of the pKMR plasmids controlling antibiotic resistance and the capacity to produce colonization antigen]. / Izuchenie fiziko-khimicheskikh svoistv pKMR-plazmid, kontroli-ruiushchikh antibiotikorezistentnost' i sposobnost' produtsirovat' antigen kolonizatsii.

KMR plasmids controlling antibiotic resistance and the capacity for production of the colonization antigen were identified in wild strains of E. coli (026, 0126, 0124) and S. sonnei isolated from patients with acute intestinal diseases. The strains of E. coli 026 and E. coli 0126 carried p KMR207-1 plasmid determining resistance to chloramphenicol and tetracycline and the adhesive properties. The molecular weight of the plasmid is 98 mD. The strain of S. sonnei carried p KMR 208-1 plasmid responsible for resistance to streptomycin, chloramphenicol and tetracycline and the adhesive properties. The molecular weight of this plasmid is 98 mD. The resistance to streptomycin and tetracycline and the capacity for the synthesis of the colonization antigen in E. coli 0214 was controlled by p KMR209 plasmid with the molecular weight of 2.66 mD. The restriction analysis suggests that p KMR207a-1 and p KMR 207b-1 plasmids detected in E. coli of different serotypes were identical, since they could be broken with BamH1 endonuclease into equal numbers of fragments similar by their molecular weights. p KMR207-1 and p KMR208-1 plasmids differed in their sensitivity to BamH-1 endonuclease. However, they were broken into 6 fragments similar by their molecular weights. p KMR207-1 and p KMR208-1 plasmids are probably closely related but not identical.