Publications by authors named "V D Semenova"

131 Publications

Changes in SARS CoV-2 Seroprevalence Over Time in Ten Sites in the United States, March - August, 2020.

Clin Infect Dis 2021 Feb 26. Epub 2021 Feb 26.

U.S. Centers for Disease Control and Prevention COVID-19 Response Team, Atlanta, Georgia, United States.

Background: Monitoring of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) antibody prevalence can complement case reporting to inform more accurate estimates of SARS-CoV-2 infection burden, but few studies have undertaken repeated sampling over time on a broad geographic scale.

Methods: We performed serologic testing on a convenience sample of residual sera obtained from persons of all ages, at ten sites in the United States from March 23 through August 14, 2020, from routine clinical testing at commercial laboratories. We age-sex-standardized our seroprevalence rates using census population projections and adjusted for laboratory assay performance. Confidence intervals were generated with a two-stage bootstrap. We used Bayesian modeling to test whether seroprevalence changes over time were statistically significant.

Results: Seroprevalence remained below 10% at all sites except New York and Florida, where it reached 23.2% and 13.3%, respectively. Statistically significant increases in seroprevalence followed peaks in reported cases in New York, South Florida, Utah, Missouri and Louisiana. In the absence of such peaks, some significant decreases were observed over time in New York, Missouri, Utah, and Western Washington. The estimated cumulative number of infections with detectable antibody response continued to exceed reported cases in all sites.

Conclusions: Estimated seroprevalence was low in most sites, indicating that most people in the U.S. have not been infected with SARS-CoV-2 as of July 2020. The majority of infections are likely not reported. Decreases in seroprevalence may be related to changes in healthcare-seeking behavior, or evidence of waning of detectable anti-SARS CoV-2 antibody levels at the population level. Thus, seroprevalence estimates may underestimate the cumulative incidence of infection.
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http://dx.doi.org/10.1093/cid/ciab185DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC7989518PMC
February 2021

Brain oscillations evoked by sound motion.

Brain Res 2021 Feb 29;1752:147232. Epub 2020 Dec 29.

Pavlov Institute of Physiology, Russian Academy of Sciences, Makarova emb. 6, 199034 Saint Petersburg, Russia. Electronic address:

The present study investigates the event-related oscillations underlying the motion-onset response (MOR) evoked by sounds moving at different velocities. EEG was recorded for stationary sounds and for three patterns of sound motion produced by changes in interaural time differences. We explored the effect of motion velocity on the MOR potential, and also on the event-related spectral perturbation (ERSP) and inter-trial phase coherence (ITC) calculated from the time-frequency decomposition of EEG signals. The phase coherence of slow oscillations increased with an increase in motion velocity similarly to the magnitude of cN1 and cP2 components of the MOR response. The delta-to-alpha inter-trial spectral power remained at the same level up to, but not including, the highest velocity, suggesting that gradual spatial changes within the sound did not induce non-coherent activity. Conversely, the abrupt sound displacement induced theta-alpha oscillations which had low phase consistency. The findings suggest that the MOR potential could be mainly generated by the phase resetting of slow oscillations, and the degree of phase coherence may be considered as a neurophysiological indicator of sound motion processing.
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http://dx.doi.org/10.1016/j.brainres.2020.147232DOI Listing
February 2021

Comparison of Estimated SARS-CoV-2 Seroprevalence through Commercial Laboratory Residual Sera Testing and a Community Survey.

Clin Infect Dis 2020 Dec 10. Epub 2020 Dec 10.

CDC COVID-19 Response, Centers for Disease Control and Prevention, Atlanta, GA.

We compared severe acute respiratory syndrome-related coronavirus-2 seroprevalence estimated from commercial laboratory residual sera and a community household survey in metropolitan Atlanta during April-May 2020 and found these two estimates to be similar (4.94% versus 3.18%). Compared with more representative surveys, commercial sera can provide an approximate measure of seroprevalence.
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http://dx.doi.org/10.1093/cid/ciaa1804DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC7799302PMC
December 2020

Serologic testing of U.S. blood donations to identify SARS-CoV-2-reactive antibodies: December 2019-January 2020.

Clin Infect Dis 2020 Nov 30. Epub 2020 Nov 30.

American Red Cross, Scientific Affairs, Gaithersburg, MD, USA.

Background: SARS-CoV-2, the virus that causes COVID-19 disease, was first identified in Wuhan, China in December 2019, with subsequent worldwide spread. The first U.S. cases were identified in January 2020.

Methods: To determine if SARS-CoV-2 reactive antibodies were present in sera prior to the first identified case in the U.S. on January 19, 2020, residual archived samples from 7,389 routine blood donations collected by the American Red Cross from December 13, 2019 to January 17, 2020, from donors resident in nine states (California, Connecticut, Iowa, Massachusetts, Michigan, Oregon, Rhode Island, Washington, and Wisconsin) were tested at CDC for anti-SARS-CoV-2 antibodies. Specimens reactive by pan-immunoglobulin (pan Ig) enzyme linked immunosorbent assay (ELISA) against the full spike protein were tested by IgG and IgM ELISAs, microneutralization test, Ortho total Ig S1 ELISA, and receptor binding domain / Ace2 blocking activity assay.

Results: Of the 7,389 samples, 106 were reactive by pan Ig. Of these 106 specimens, 90 were available for further testing. Eighty four of 90 had neutralizing activity, 1 had S1 binding activity, and 1 had receptor binding domain / Ace2 blocking activity >50%, suggesting the presence of anti-SARS-CoV-2-reactive antibodies. Donations with reactivity occurred in all nine states.

Conclusions: These findings suggest that SARS-CoV-2 may have been introduced into the United States prior to January 19, 2020.
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http://dx.doi.org/10.1093/cid/ciaa1785DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC7799215PMC
November 2020

Decline in SARS-CoV-2 Antibodies After Mild Infection Among Frontline Health Care Personnel in a Multistate Hospital Network - 12 States, April-August 2020.

MMWR Morb Mortal Wkly Rep 2020 Nov 27;69(47):1762-1766. Epub 2020 Nov 27.

Most persons infected with SARS-CoV-2, the virus that causes coronavirus disease 2019 (COVID-19), develop virus-specific antibodies within several weeks, but antibody titers might decline over time. Understanding the timeline of antibody decline is important for interpreting SARS-CoV-2 serology results. Serum specimens were collected from a convenience sample of frontline health care personnel at 13 hospitals and tested for antibodies to SARS-CoV-2 during April 3-June 19, 2020, and again approximately 60 days later to assess this timeline. The percentage of participants who experienced seroreversion, defined as an antibody signal-to-threshold ratio >1.0 at baseline and <1.0 at the follow-up visit, was assessed. Overall, 194 (6.0%) of 3,248 participants had detectable antibodies to SARS-CoV-2 at baseline (1). Upon repeat testing approximately 60 days later (range = 50-91 days), 146 (93.6%) of 156 participants experienced a decline in antibody response indicated by a lower signal-to-threshold ratio at the follow-up visit, compared with the baseline visit, and 44 (28.2%) experienced seroreversion. Participants with higher initial antibody responses were more likely to have antibodies detected at the follow-up test than were those who had a lower initial antibody response. Whether decay in these antibodies increases risk for reinfection and disease remains unanswered. However, these results suggest that serology testing at a single time point is likely to underestimate the number of persons with previous SARS-CoV-2 infection, and a negative serologic test result might not reliably exclude prior infection.
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http://dx.doi.org/10.15585/mmwr.mm6947a2DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC7727600PMC
November 2020

Experimental Modeling of Leprosy in BALB/c, BALB/c Nude, CBA, and C57BL/6ТNF Mice.

Bull Exp Biol Med 2020 Oct 24;169(6):836-839. Epub 2020 Oct 24.

State Research Center of Dermatovenereology and Cosmetology, Ministry of Health of the Russian Federation, Moscow, Russia.

Leprosy was modeled in an experiment on BALB/c, BALB/cNude, CBA, and C57BL/6ТNF mice using three Mycobacterium leprae strains obtained from patients with a diagnosis of A30 according to ICD-10 from different regions of the Russian Federation. Proliferation of M. leprae of the used strains showed a temporal-quantitative dependence on the used mouse line. CBA and BALB/cNude mice were optimal for strain R and BALB/c and BALB/cNude lines were optimal for strain I. BALB/cNude mice infected with strain I had low lifespan. M. leprae strain M showed low proliferation activity in BALB/cNude and C57BL/6ТNF mice.
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http://dx.doi.org/10.1007/s10517-020-04991-7DOI Listing
October 2020

Seroprevalence of SARS-CoV-2 Among Frontline Health Care Personnel in a Multistate Hospital Network - 13 Academic Medical Centers, April-June 2020.

MMWR Morb Mortal Wkly Rep 2020 Sep 4;69(35):1221-1226. Epub 2020 Sep 4.

Health care personnel (HCP) caring for patients with coronavirus disease 2019 (COVID-19) might be at high risk for contracting SARS-CoV-2, the virus that causes COVID-19. Understanding the prevalence of and factors associated with SARS-CoV-2 infection among frontline HCP who care for COVID-19 patients are important for protecting both HCP and their patients. During April 3-June 19, 2020, serum specimens were collected from a convenience sample of frontline HCP who worked with COVID-19 patients at 13 geographically diverse academic medical centers in the United States, and specimens were tested for antibodies to SARS-CoV-2. Participants were asked about potential symptoms of COVID-19 experienced since February 1, 2020, previous testing for acute SARS-CoV-2 infection, and their use of personal protective equipment (PPE) in the past week. Among 3,248 participants, 194 (6.0%) had positive test results for SARS-CoV-2 antibodies. Seroprevalence by hospital ranged from 0.8% to 31.2% (median = 3.6%). Among the 194 seropositive participants, 56 (29%) reported no symptoms since February 1, 2020, 86 (44%) did not believe that they previously had COVID-19, and 133 (69%) did not report a previous COVID-19 diagnosis. Seroprevalence was lower among personnel who reported always wearing a face covering (defined in this study as a surgical mask, N95 respirator, or powered air purifying respirator [PAPR]) while caring for patients (5.6%), compared with that among those who did not (9.0%) (p = 0.012). Consistent with persons in the general population with SARS-CoV-2 infection, many frontline HCP with SARS-CoV-2 infection might be asymptomatic or minimally symptomatic during infection, and infection might be unrecognized. Enhanced screening, including frequent testing of frontline HCP, and universal use of face coverings in hospitals are two strategies that could reduce SARS-CoV-2 transmission.
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http://dx.doi.org/10.15585/mmwr.mm6935e2DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC7470460PMC
September 2020

Seroprevalence of Antibodies to SARS-CoV-2 in 10 Sites in the United States, March 23-May 12, 2020.

JAMA Intern Med 2020 Jul 21. Epub 2020 Jul 21.

CDC COVID-19 Response Team, Centers for Disease Control and Prevention, Atlanta, Georgia.

Importance: Reported cases of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection likely underestimate the prevalence of infection in affected communities. Large-scale seroprevalence studies provide better estimates of the proportion of the population previously infected.

Objective: To estimate prevalence of SARS-CoV-2 antibodies in convenience samples from several geographic sites in the US.

Design, Setting, And Participants: This cross-sectional study performed serologic testing on a convenience sample of residual sera obtained from persons of all ages. The serum was collected from March 23 through May 12, 2020, for routine clinical testing by 2 commercial laboratory companies. Sites of collection were San Francisco Bay area, California; Connecticut; south Florida; Louisiana; Minneapolis-St Paul-St Cloud metro area, Minnesota; Missouri; New York City metro area, New York; Philadelphia metro area, Pennsylvania; Utah; and western Washington State.

Exposures: Infection with SARS-CoV-2.

Main Outcomes And Measures: The presence of antibodies to SARS-CoV-2 spike protein was estimated using an enzyme-linked immunosorbent assay, and estimates were standardized to the site populations by age and sex. Estimates were adjusted for test performance characteristics (96.0% sensitivity and 99.3% specificity). The number of infections in each site was estimated by extrapolating seroprevalence to site populations; estimated infections were compared with the number of reported coronavirus disease 2019 (COVID-19) cases as of last specimen collection date.

Results: Serum samples were tested from 16 025 persons, 8853 (55.2%) of whom were women; 1205 (7.5%) were 18 years or younger and 5845 (36.2%) were 65 years or older. Most specimens from each site had no evidence of antibodies to SARS-CoV-2. Adjusted estimates of the proportion of persons seroreactive to the SARS-CoV-2 spike protein antibodies ranged from 1.0% in the San Francisco Bay area (collected April 23-27) to 6.9% of persons in New York City (collected March 23-April 1). The estimated number of infections ranged from 6 to 24 times the number of reported cases; for 7 sites (Connecticut, Florida, Louisiana, Missouri, New York City metro area, Utah, and western Washington State), an estimated greater than 10 times more SARS-CoV-2 infections occurred than the number of reported cases.

Conclusions And Relevance: During March to early May 2020, most persons in 10 diverse geographic sites in the US had not been infected with SARS-CoV-2 virus. The estimated number of infections, however, was much greater than the number of reported cases in all sites. The findings may reflect the number of persons who had mild or no illness or who did not seek medical care or undergo testing but who still may have contributed to ongoing virus transmission in the population.
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http://dx.doi.org/10.1001/jamainternmed.2020.4130DOI Listing
July 2020

F MRI of human lungs at 0.5 Tesla using octafluorocyclobutane.

Magn Reson Med 2020 10 10;84(4):2117-2123. Epub 2020 Apr 10.

Faculty of Physics, Lomonosov Moscow State University, Moscow, Russia.

Purpose: The aim of this study was to demonstrate the feasibility of fluorine-19 ( F) MRI of the human lungs using octafluorocyclobutane (OFCB, C F ). This gas has 8 magnetically equivalent fluorine nuclei and relatively long T and T (˜50 ms), which render it suitable as an MRI contrast agent. Previous experiments in small laboratory animals showed that OFCB could be successfully used as an alternative to the gases often used for F MRI (sulfur hexafluoride and perfluoropropane).

Methods: One male volunteer participated in this study. Immediately before an MRI scan, the volunteer inhaled the gas mixture-80% OFCB with 20% oxygen-and held his breath. Experiments were performed on a 0.5T whole-body MR scanner with a customized transmit-receive coil tuned at F frequency. Fast spin echo in 2D and 3D modes was used for image acquisition. 2D images were obtained with in-plane resolution of 10 × 10 mm without slice selection. 3D images were obtained with the voxel size of 10 × 10 × 30 mm . Breath-hold duration was 20 s for 2D and 40 s for 3D imaging, respectively.

Results: Anatomically consistent F MR images of the human lungs were obtained with SNR around 50 in 2D mode and 20 in 3D mode. 3D volumetric images of the lungs were reconstructed and provided physiologically reasonable volume estimates.

Conclusion: The application of OFCB enables informative F lung imaging even at low magnetic field strengths. The OFCB gas shows promise as an inhalable contrast agent for fluorine lung MRI and has a potential for clinical translation.
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http://dx.doi.org/10.1002/mrm.28270DOI Listing
October 2020

Lateralization of brain responses to auditory motion: A study using single-trial analysis.

Neurosci Res 2021 Jan 27;162:31-44. Epub 2020 Jan 27.

Pavlov Institute of Physiology, Russian Academy of Sciences 199034, Makarova emb., 6, St. Petersburg, Russia. Electronic address:

The present study investigates hemispheric asymmetry of the ERPs and low-frequency oscillatory responses evoked in both hemispheres of the brain by the sound stimuli with delayed onset of motion. EEG was recorded for three patterns of sound motion produced by changes in interaural time differences. Event-related spectral perturbation (ERSP) and inter-trial phase coherence (ITC) were computed from the time-frequency decomposition of EEG signals. The participants either read books of their choice (passive listening) or indicated the sound trajectories perceived using a graphic tablet (active listening). Our goal was to find out whether the lateralization of the motion-onset response (MOR) and oscillatory responses to sound motion were more consistent with the right-hemispheric dominance, contralateral or neglect model of interhemispheric asymmetry. Apparent dominance of the right hemisphere was found only in the ERSP responses. Stronger contralaterality of the left hemisphere corresponding to the "neglect model" of asymmetry was shown by the MOR components and by the phase coherence of the delta-alpha oscillations. Velocity and attention did not change consistently the interhemispheric asymmetry of both the MOR and the oscillatory responses. Our findings demonstrate how the lateralization pattern shown by the MOR potential was interrelated with that of the motion-related single-trial measures.
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http://dx.doi.org/10.1016/j.neures.2020.01.007DOI Listing
January 2021

Performance of InBios ZIKV Detect™ 2.0 IgM Capture ELISA in two reference laboratories compared to the original ZIKV Detect™ IgM Capture ELISA.

J Virol Methods 2019 09 7;271:113671. Epub 2019 Jun 7.

Microbial Pathogenesis and Immune Response Laboratory, Division of Bacterial Diseases, Centers for Disease Control and Prevention, Atlanta, GA, United States.

ZIKV Detect™ 2.0 IgM Capture ELISA (InBios International, Seattle, WA) recently replaced the ZIKV Detect™ IgM Capture ELISA and a number of significant changes have been made to the original version. This study compares data generated from the ZIKV Detect™ 2.0 IgM Capture ELISA, to data generated using the original version of the kit. The same sample sets were used in this comparison, and reference test results for these samples were used to assess sensitivity, specificity, accuracy and concordance of results across two laboratories. Average sensitivity increased from 90.4% to 92.5% with the updated kit where the increase was not statistically different, and specificity increased from 79.5% to 97.4%, a statistically-significant difference. Accuracy of the ZIKV Detect™ 2.0 IgM Capture ELISA was 89% compared to 63.9% for the original version of the kit, and agreement across the laboratories increased from 79.5% to 97.4%. With secondary dengue virus infections, specificity increased from 9.3% to 82.6% with the updated kit, primarily due to the change in interpretation criteria that no longer includes "Possible Zika positive."
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http://dx.doi.org/10.1016/j.jviromet.2019.05.011DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC7176032PMC
September 2019

Data on the productivity of plant cover of the main types of soils of the North-Western precaspian in connection with the dynamics of ecological factors.

Data Brief 2019 Jun 15;24:103713. Epub 2019 Mar 15.

Federal State Budgetary Scientific Institution Kisriev Dagestan Research Institute of Agriculture, Akushinskogo Avenue, Makhachkala, The Republic of Dagestan, 367014, Russia.

The data of the researches describes the were to establish the species composition of pasture cenoses and the productivity potential of light-chestnut and meadow-chestnut soils under different climatic conditions and in different periods of the year in the Terek-Kuma lowland of the North-Western Precaspian. Two peaks of productivity of phytocoenosis have been observed: the first is - ephemeral synusia in the middle of May- early June; second - motley grass and saltworts in the second half of September. The data on receipt of photosynthetically active radiation (PAR) on the soil surface and the coefficient of its use over the years and periods of the year depending on the hydrothermal conditions and dynamics of harmful salts in the soil are given. On light-chestnut soil formed cereals-wormwood, grass-cereals, wormwood-ephemeral in combination with wormwood-saltworts association, and meadow-chestnut soil - ephemera-wormwood. The phytocenosis on light-chestnut soil is inherent in the maximum species diversity - 35 species. On meadow-chestnut soil there are only 25 species. The items of the changes in the species composition of phytocenoses depending on the environmental factors are considered. The data in this article support and augment information presented in the research articles [1], [2], [3], [4], [5], [6], [7].
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http://dx.doi.org/10.1016/j.dib.2019.103713DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC6441725PMC
June 2019

Spatio-temporal and spatiospectral metrology of terahertz broadband uniformly topologically charged vortex beams.

Appl Opt 2019 Feb;58(5):A90-A100

A comprehensive characterization of the diffraction properties of terahertz (THz) pulsed broadband vortex beams consisting of several electromagnetic field oscillations requires state-of-the-art techniques for studying the evolution of a wavefront as it propagates. For this purpose, we have applied the capabilities offered by THz pulse time domain holography. Accurate metrological study of pulsed single-period THz field propagation allowed us to reveal the spatio-temporal and spatiospectral couplings in broadband uniformly topologically charged vortex beams. Here, we reveal dynamics of such beam propagation in a free space as well as in the experiment with edge diffraction with 50% blocking of the beam focal waist. In this study, we compare the dynamics of freely propagating and edge-diffracted THz vortex. Despite the fact that in the amplitude representation one can observe the emergence of strong asymmetry, analysis of the spectral trajectory of the singular point at some distance from the obstacle and the visualization of phase distribution for individual spectral components testify to the conservation of transverse energy circulation. Similar to the edge diffraction of monochromatic optical vortices, it can be interpreted as self-reconstruction of vortex properties. The given term has not previously been used for the case of pulsed broadband THz beams, to the best of our knowledge.
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http://dx.doi.org/10.1364/AO.58.000A90DOI Listing
February 2019

[The refinement of leprosy PCR diagnostics by the amplification of specie-specific repeated fragment of the Mycobacterium leprae genome.]

Klin Lab Diagn 2018;63(8):511-516

FGBU "State Scientific Center of Dermatovenereology and Cosmetology" Ministry of Health of Russia, 107076, Moscow, Russia.

Certain level of new registered cases of leprosy in a number of endemic countries in the world, as well as growing rate of transboundary migratory flows, raise the issue of effective diagnosis of this disease in countries with sporadic incidence of leprosy, including the Russian Federation. The purpose of the study was to develop a highly sensitive PCR test for detecting the genetic material of Mycobacterium leprae and to compare the test robustness and sensitivity with the commercially available Leprosy Genesig Standard Kit (Primerdesign Ltd., UK). The proposed approach uses real time PCR of non-coding repeating element RLEP, unique for the M. leprae genome, using TaqMan probe. The high test specificity was shown using the reference DNA samples of pathogenic and conditionally pathogenic mycobacterium, as well and its comparison with single-copy genes of M. leprae (rrs, fbp, MntH) PCR detection. The use of a commercially available test system based on the single-copy rpoB gene detection provided 59.4% sensitivity to the detection of M. leprae in the clinical material, while the application of the developed approach increased this index to 96.8%. The developed PCR diagnostics test of leprosy is submitted for state clinical approval process, whereupon the practical use of the test diagnostics allows solving a wide range of tasks to identify and confirm new cases of leprosy, and monitoring both the effectiveness of leprosy treatment, and epidemiological (including transboundary) the spread of the disease.
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http://dx.doi.org/10.18821/0869-2084-2018-63-8-511-516DOI Listing
July 2019

Lateral root initiation and formation within the parental root meristem of Cucurbita pepo: is auxin a key player?

Ann Bot 2018 11;122(5):873-888

Laboratory of Cellular and Molecular Mechanisms of Plant Development, Komarov Botanical Institute, Russian Academy of Sciences, Saint-Petersburg, Russia.

Background And Aims: In some plant families, including Cucurbitaceae, initiation and development of lateral roots (LRs) occur in the parental root apical meristem. The objective of this study was to identify the general mechanisms underlying LR initiation (LRI). Therefore, the first cellular events leading to LRI as well as the role of auxin in this process were studied in the Cucurbita pepo root apical meristem.

Methods: Transgenic hairy roots harbouring the auxin-responsive promoter DR5 fused to different reporter genes were used for visualizing of cellular auxin response maxima (ARMs) via confocal laser scanning microscopy and 3-D imaging. The effects of exogenous auxin and auxin transport inhibitors on root branching were analysed.

Key Results: The earliest LRI event involved a group of symmetric anticlinal divisions in pericycle cell files at a distance of 250-350 µm from the initial cells. The visualization of the ARMs enabled the precise detection of cells involved in determining the site of LR primordium formation. A local ARM appeared in sister cells of the pericycle and endodermis files before the first division. Cortical cells contributed to LR development after the anticlinal divisions in the pericycle via the formation of an ARM. Exogenous auxins did not increase the total number of LRs and did not affect the LRI index. Although exogenous auxin transport inhibitors acted in different ways, they all reduced the number of LRs formed.

Conclusions: Literature data, as well as results obtained in this study, suggest that the formation of a local ARM before the first anticlinal formative divisions is the common mechanism underlying LRI in flowering plants. We propose that the mechanisms of the regulation of root branching are independent of the position of the LRI site relative to the parental root tip.
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http://dx.doi.org/10.1093/aob/mcy052DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC6215038PMC
November 2018

Mismatch negativity and psychophysical detection of rising and falling intensity sounds.

Biol Psychol 2018 03 5;133:99-111. Epub 2018 Feb 5.

I.P. Pavlov Institute of Physiology, Russian Academy of Sciences, Saint-Petersburg, Russia.

Human subjects demonstrate a perceptual priority for rising level sounds compared with falling level sounds. The aim of the present study was to investigate whether or not the perceptual preference for rising intensity can be found in the preattentive processing indexed by mismatch negativity (MMN). Reversed oddball stimulation was used to produce MMNs and to test the behavioral discrimination of rising, falling and constant level sounds. Three types of stimuli served as standards or deviants in different blocks: constant level sounds and two kinds of rising/falling sounds with gradual or stepwise change of intensity. The MMN amplitudes were calculated by subtracting ERPs to identical stimuli presented as standard in one block and deviant in another block. Both rising and falling level deviants elicited MMNs which peaked after 250 ms and did not overlap with N1 waves. MMN was elicited by level changes even when the deviants were not discriminated behaviorally. Most importantly, we found dissociation between earlier and later stages of auditory processing: the MMN responses to the level changes were mostly affected by the direction of deviance (increment or decrement) in the sequence, whereas behavioral performance depended on the direction of the level change within the stimuli (rising or falling).
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http://dx.doi.org/10.1016/j.biopsycho.2018.01.018DOI Listing
March 2018

On terahertz pulsed broadband Gauss-Bessel beam free-space propagation.

Sci Rep 2018 01 23;8(1):1390. Epub 2018 Jan 23.

ITMO University, International Institute "Photonics and Optoinformatics", Kadetskaya line 3, 199034, Russia.

Terahertz pulse time-domain holography is the ultimate technique allowing the evaluating a propagation of pulse broadband terahertz wavefronts and analyze their spatial, temporal and spectral evolution. We have numerically analyzed pulsed broadband terahertz Gauss-Bessel beam's both spatio-temporal and spatio-spectral evolution in the non-paraxial approach. We have characterized two-dimensional spatio-temporal beam behavior and demonstrated all stages of pulse reshaping during the propagation, including X-shape pulse forming. The reshaping is also illustrated by the energy transfer dynamics, where the pulse energy flows from leading edge to trailing edge. This behavior illustrates strong spatio-temporal coupling effect when spatio-temporal distribution of Bessel beam's wavefront depends on propagation distance. The spatio-temporal and spatio-spectral profiles for different spectral components clearly illustrate the model where the Bessel beam's wavefront at the exit from the axicon can be divided into radial segments for which the wave vectors intersect. Phase velocity via propagation distance is estimated and compared with existing experimantal results. Results of the phase velocity calculation depend strongly on distance increment value, thus demonstrating superluminal or subluminal behavior.
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http://dx.doi.org/10.1038/s41598-018-19830-zDOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC5780439PMC
January 2018

Image-guided resection of glioblastoma in eloquent brain areas facilitated by laser surface thermal therapy: clinical outcomes and long-term results.

Neurosurg Rev 2018 Oct 22;41(4):1045-1052. Epub 2018 Jan 22.

National Cancer Registry of Ukraine, National Cancer Institute, Kiev, Ukraine.

The increased interest in the application of lasers in neuro-oncology prompted us to present our experience of using the laser technologies in the treatment of cerebral gliomas. The aim of the study was to evaluate the clinical efficacy of image-guided laser surface thermal therapy (LSTT) and its influence on survival of patients with glioblastoma (GBM).Data of 91 patients (49 males, 42 females, mean age 51.4 years, range 23-70 years) with supratentorial GBMs located in close vicinity to or within the eloquent brain areas were retrospectively analyzed.All patients were divided into two groups: LSTT group (n = 28) and control group (n = 63). There were no significant differences by gender, age, Karnofsky Performance Scale (KPS) score, and tumor location between groups. Total removal in the LSTT group was performed in 67.9%, in the control group-31.7% (p < 0.01); on the contrary, subtotal removal prevailed in the control group-52.4%; in the LSTT group, it was 32.1%. In postoperative period, there was no significant difference in KPS score between the groups (p = 0.89). A higher degree of resection provided an increase in survival rates (p < 0.01). The median overall survival was 15.5 ± 10.5 months, in the LSTT group 18.4 ± 11.7 and in the control group 14.3 ± 9.1 (p = 0.03). The application of image-guided LSTT in patients with GBMs of eloquent brain areas allowed the high rate of complete resection and improved overall survival without the negative effect on the functional status after surgery.
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http://dx.doi.org/10.1007/s10143-018-0948-yDOI Listing
October 2018

SHORT DURATION IMMOBILIZATION OF ATLANTIC WALRUS ( ODOBENUS ROSMARUS ROSMARUS) WITH ETORPHINE, AND REVERSAL WITH NALTREXONE.

J Zoo Wildl Med 2017 12;48(4):972-978

Forty adult, male Atlantic walruses ( Odobenus rosmarus rosmarus) were successfully immobilized for the attachment of global positioning system loggers on their tusks and collection of various biological samples. A standard dose of 7.8 mg etorphine was used for each animal, regardless of body size. All animals were reversed with an iv or im injection of 250 mg naltrexone, immediately after tag attachment. Twenty-seven of the animals were intubated and ventilated with 100% oxygen during the recovery period. The induction time was, on average, 4 min 51 sec ± 1 min 46 sec. Several animals had venous pH, and Pco levels that indicated severe acidosis and hypercarbia. All animals recovered within an average of 5 min 16 sec ± 2 min 47 sec after reversal. The total time from darting to recovery was 15 min 23 sec ± 3 min 33 sec. The use of naltrexone is recommended for reversal of etorphine immobilization in adult, male walruses, and the use of positive-pressure ventilation with oxygen is highly encouraged.
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http://dx.doi.org/10.1638/2016-0232R.1DOI Listing
December 2017

Phase Diagram of the Sn-As-Ge System.

Acta Chim Slov 2018 sept;65(3):662-669

The paper presents the phase diagram of the Sn-As-Ge system. The diagram of polythermal Sn-GeAs section was constructed using the results of X-ray powder diffraction analysis and differential thermal analysis. We found that in a concentration interval with arsenic content of less than 50 mol%, four-phase peritectic equilibria L + SnAs ∆ GeAs + Sn4As3 (834 ∆) and L + GeAs ∆ Ge + Sn4As3 (821 ∆) are present. When the temperature is close to the melting point of pure tin, non-variant equilibrium with tin, germanium and Sn4As3 is implemented as well. The study of Sn0.39As0.61-Ge0.28As0.72, SnAs-Ge0.4As0.6 and SnAs-GeAs2 sections and elaboration of the type of the SnAs-GeAs phase diagram demonstrated that polythermal sections SnAs-GeAs and SnAs-GeAs2 can perform phase subsolidus demarcation of the phase diagram of the Sn-As-Ge system. There are also invariant peritectic equilibria L + GeAs2 ∆ GeAs + SnAs (840 ∆) and L + As ∆ SnAs + GeAs2 (843 ∆) in the system.
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February 2021

TGF-β1 expression by glioma C6 cells in vitro.

Exp Oncol 2017 Dec;39(4):258-263

SI "Romodanov Neurosurgery Institute, National Academy of Medical Sciences of Ukraine", Kyiv 04050, Ukraine.

The aim of the work was to study the impact of fetal rat brain cell supernatant (FRBCS) on the expression of transforming growth factor β1 (TGF-β1) and p53 in C6 cells of rat glioma in vitro.

Materials And Methods: FRBCS was obtained from suspensions of fetal rat brain cells on the 14 (E14) day of gestation. C6 glioma cells were cultured for 48 h in the presence of FRBCS or FRBCS + anti-TGF-β1 monoclonal antibody. Immunocytochemical staining for TGF-β1 and p53 was performed.

Results: The proportion of TGF-β1-immunopositive tumor cells in C6 glioma cultures was statistically significantly higher than in the control cell cultures of normal fetal rat brain. FRBCS reduced the proportion of TGF-β1-immunopositive tumor cells and increased the proportion of p53-immunopositive cells in C6 glioma cultures. In cells cultured with FRBCS + anti-TGF-β1 monoclonal antibody, the above effects of FRBCS were abrogated.

Conclusion: The obtained results suggest that TGF-β1 seems to be responsible for decrease in TGF-β1 expression and increase in p53 expression in C6 glioma cells treated with FRBCS.
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December 2017

[[Durable persistence of a biocompatible foreign body in a vertebral channel in open penetrating trauma of a spinal cord: clinico-experimental and pathomorphological peculiarities].]

Klin Khir 2016 Aug(8):64-69

Simulation model of open penetrating wound of a spinal cord (SC) with its durable com- pression by biocompatible foreign body, was tasted. Experimental animals - mature male rats (inbred line, descendent from a Wistar breed); the trauma simulation model - a left- sided transsection of the SC half on the Txi level; experimental groups: the main (a SC trau- ma + homotopic implantation of microporous hydrogel fragment - foreign body [n=10]), groups of comparison (the SC trauma [n=16]; the SC trauma + homotopic implantation of chemically identical analogue of hydrogel - NeuroGelTM [n=20]). A SC compression by a foreign body worsens the regeneration process course essentially: during first 2 mo the function index of a hind ipsilateral extremity in experimental animals of the main group was the lowest in the experiment - (1.30 ? 0.94) points in accordance to BBB scale, during 3 - 4 mo - the function index had enhanced trustworthy - up to (2.35 ? 0.95) points in accor- dance to BBB scale, what is connected with lowering of a local pressure on a SC tissue due to change of the foreign body form and volume. In 24 weeks the function index of hind ipsi- lateral extremity had constituted (8.45 ? 0.92) points - while application of NeuroGeTM and (2.35 ? 0.95) points - of the foreign body; the tissue processes in the implants localization zone had differed essentially. The tasted simulation model reproduces satisfactory a mechanical component of the foreign body impact on a SC tissue. The SC compression reduction, even in a late follow-up period, had improved the conditions and results of recenerative process essentially.
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August 2016

Self-assembly of Deinococcus radiodurans supports nanocell scenario of life origin.

Discoveries (Craiova) 2017 May 8;5(1):e72. Epub 2017 May 8.

Division of Physiological Chemistry I, Department of Medical Biochemistry and Biophysics, Karolinska Institutet, Stockholm, Sweden.

In many origin-of-life scenarios, first a kit of elements and simple compounds emerges, then a primitive membrane and then a nanocell with a minimal genome is self-assembled, which then proceeds to multiply by copying itself while mutating. Testing this scenario, we selected Deinococcus Radiodurans known for its exceptional self-repair properties as a model system, separated its bacterial lysis into DNA, RNA and protein fractions, while lipids were used for liposome formation. The fractions were sealed in glass tubes individually and in combinations and stored for three weeks. Upon seeding on Petri dishes, the fractions containing liposomes together with nucleic acid and/or proteins gave in total 19 colonies of Deinococcus radiodurans (confirmed by proteomics), while liposome-free fractions as well as liposome-only fractions gave no colonies. The self-assembly of viable cells from essentially dead mixtures validates the lyposome-based origin-of-life scenario.
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http://dx.doi.org/10.15190/d.2017.2DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC6941539PMC
May 2017

Validation of high throughput screening of human sera for detection of anti-PA IgG by Enzyme-Linked Immunosorbent Assay (ELISA) as an emergency response to an anthrax incident.

Biologicals 2017 Jan 1;45:61-68. Epub 2016 Nov 1.

Centers for Disease Control and Prevention (CDC), 1600 Clifton Rd., Atlanta, GA 30329, USA.

To improve surge testing capability for a response to a release of Bacillus anthracis, the CDC anti-Protective Antigen (PA) IgG Enzyme-Linked Immunosorbent Assay (ELISA) was re-designed into a high throughput screening format. The following assay performance parameters were evaluated: goodness of fit (measured as the mean reference standard r), accuracy (measured as percent error), precision (measured as coefficient of variance (CV)), lower limit of detection (LLOD), lower limit of quantification (LLOQ), dilutional linearity, diagnostic sensitivity (DSN) and diagnostic specificity (DSP). The paired sets of data for each sample were evaluated by Concordance Correlation Coefficient (CCC) analysis. The goodness of fit was 0.999; percent error between the expected and observed concentration for each sample ranged from -4.6% to 14.4%. The coefficient of variance ranged from 9.0% to 21.2%. The assay LLOQ was 2.6 μg/mL. The regression analysis results for dilutional linearity data were r = 0.952, slope = 1.02 and intercept = -0.03. CCC between assays was 0.974 for the median concentration of serum samples. The accuracy and precision components of CCC were 0.997 and 0.977, respectively. This high throughput screening assay is precise, accurate, sensitive and specific. Anti-PA IgG concentrations determined using two different assays proved high levels of agreement. The method will improve surge testing capability 18-fold from 4 to 72 sera per assay plate.
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http://dx.doi.org/10.1016/j.biologicals.2016.09.012DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC5737902PMC
January 2017

[Motion-Onset Responses During Active and Passive Listening to the Moving Sound Stimuli].

Zh Vyssh Nerv Deiat Im I P Pavlova 2016 09;66(5):565-578

This study investigated the energy-onset and motion-onset responses (N1, P2, cN 1 and cP2 components of the auditory evoked potential) elicited by moving sound stimuli in the passive and active listening conditions. In the passive conditions the subjects were distracted from auditory information; in active conditions they lo- calized the starting and final points of the stimulus trajectory. The sound movement to the left/right from the head midline was produced by linear-changes of the interaural time delay (ITD). The onset of motion was preceded by stationary sound located near the head midline. In the active conditions, the NI component was higher and the P2 component was higher and peaked later as compared to the passive listening. The early and later parts of the motion-onset response (cN 1 and cP2) also were larger in magnitude and peaked later during active listening. Both in active and passive conditions, cNI and cP2 amplitude exhibited increase and latency showed decrease when the stimulus velocity increased. Contralateral asymmetry was found only in the mo- tion-onset responses recorded from the left hemisphere.
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September 2016

BREADTH SPREADING OF VIRAL HEPATITIS MARKERS IN THE RISK GROUPS IN THE REPUBLIC OF SAKHA (YAKUTIA).

Wiad Lek 2015 ;68(4):476-9

Introduction: Republic of Sakha (Yakutia) is a hyperendemic region of Russian Federation for spreading of parenteral viral hepatitis B, C and D. In risk groups of these diseases are firstly medical personnel, who contacting with infection carriers including latent infections family and members of families of chronic viral hepatitis carriers.

Aim: To reveal the breadth of spreading of viral hepatitis markers in the risk groups.

Materials And Methods: The level of HBV- and HC- infection were determined in medical staff of large multi specialty hospital and family members of people with viral hepatitis B and C. Epidemiological, clinical, serological and molecular biology methods of viral hepatitis diagnostics were applied in this study.

Results: Results of this study showed that the staff at surgery and hematology departments and all nursing staff belong to the high-risk of HBV-infection groups. Therefore, they are a priority for active immunization. Attention is paid on the fact that infectivity of medical staff is not equally distributed in dependence on type of department and position of medical staff. Rate HBV-marker detecting in "family hearths" was dependent on degree of interrelationship with infection source. According received information, in families of patientwith chronic hepatitis B spreading of infection was higher (77.6%) then in families of patients with acute hepatitis B (39.7%). At primary examination of families an anti-HCV was detected in 9.3 ± 1.8% cases, i.e. the spreading of HCV was at low-activity.

Conclusions: Results of our study on spreading of hepatitis B and C in Yakutia showed the high rate of appearance of HCV and HBV markers in the risk groups.
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March 2016

Humoral and Cell-Mediated Immune Responses to Alternate Booster Schedules of Anthrax Vaccine Adsorbed in Humans.

Clin Vaccine Immunol 2016 Apr 4;23(4):326-38. Epub 2016 Apr 4.

Centers for Disease Control and Prevention, Atlanta, Georgia, USA.

Protective antigen (PA)-specific antibody and cell-mediated immune (CMI) responses to annual and alternate booster schedules of anthrax vaccine adsorbed (AVA; BioThrax) were characterized in humans over 43 months. Study participants received 1 of 6 vaccination schedules: a 3-dose intramuscular (IM) priming series (0, 1, and 6 months) with a single booster at 42 months (4-IM); 3-dose IM priming with boosters at 18 and 42 months (5-IM); 3-dose IM priming with boosters at 12, 18, 30, and 42 months (7-IM); the 1970 licensed priming series of 6 doses (0, 0.5, 1, 6, 12, and 18 months) and two annual boosters (30 and 42 months) administered either subcutaneously (SQ) (8-SQ) or IM (8-IM); or saline placebo control at all eight time points. Antibody response profiles included serum anti-PA IgG levels, subclass distributions, avidity, and lethal toxin neutralization activity (TNA). CMI profiles included frequencies of gamma interferon (IFN-γ)- and interleukin 4 (IL-4)-secreting cells and memory B cells (MBCs), lymphocyte stimulation indices (SI), and induction of IFN-γ, IL-2, IL-4, IL-6, IL-1β, and tumor necrosis factor alpha (TNF-α) mRNA. All active schedules elicited high-avidity PA-specific IgG, TNA, MBCs, and T cell responses with a mixed Th1-Th2 profile and Th2 dominance. Anti-PA IgG and TNA were highly correlated (e.g., month 7,r(2)= 0.86,P< 0.0001, log10 transformed) and declined in the absence of boosters. Boosters administered IM generated the highest antibody responses. Increasing time intervals between boosters generated antibody responses that were faster than and superior to those obtained with the final month 42 vaccination. CMI responses to the 3-dose IM priming remained elevated up to 43 months. (This study has been registered at ClinicalTrials.gov under registration no. NCT00119067.).
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http://dx.doi.org/10.1128/CVI.00696-15DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC4820509PMC
April 2016

Maternal cadmium, iron and zinc levels, DNA methylation and birth weight.

BMC Pharmacol Toxicol 2015 Jul 15;16:20. Epub 2015 Jul 15.

Department of Biological Sciences, Center for Human Health and the Environment, North Carolina State University, Raleigh, NC, 27695, USA.

Background: Cadmium (Cd) is a ubiquitous and environmentally persistent toxic metal that has been implicated in neurotoxicity, carcinogenesis and obesity and essential metals including zinc (Zn) and iron (Fe) may alter these outcomes. However mechanisms underlying these relationships remain limited.

Methods: We examined whether maternal Cd levels during early pregnancy were associated with offspring DNA methylation at regulatory sequences of genomically imprinted genes and weight at birth, and whether Fe and Zn altered these associations. Cd, Fe and Zn were measured in maternal blood of 319 women ≤ 12 weeks gestation. Offspring umbilical cord blood leukocyte DNA methylation at regulatory differentially methylated regions (DMRs) of 8 imprinted genes was measured using bisulfite pyrosequencing. Regression models were used to examine the relationships among Cd, Fe, Zn, and DMR methylation and birth weight.

Results: Elevated maternal blood Cd levels were associated with lower birth weight (p = 0.03). Higher maternal blood Cd levels were also associated with lower offspring methylation at the PEG3 DMR in females (β = 0.55, se = 0.17, p = 0.05), and at the MEG3 DMR in males (β = 0.72, se = 0.3, p = 0.08), however the latter association was not statistically significant. Associations between Cd and PEG3 and PLAGL1 DNA methylation were stronger in infants born to women with low concentrations of Fe (p < 0.05).

Conclusions: Our data suggest the association between pre-natal Cd and offspring DNA methylation at regulatory sequences of imprinted genes may be sex- and gene-specific. Essential metals such as Zn may mitigate DNA methylation response to Cd exposure. Larger studies are required.
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http://dx.doi.org/10.1186/s40360-015-0020-2DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC4502530PMC
July 2015

Independent Living Oldest Old and Their Primary Health Provider: A Mixed Method Examination of the Influence of Patient Personality Characteristics.

J Appl Gerontol 2015 Oct 15;34(7):906-28. Epub 2013 Apr 15.

Walden University, Minneapolis, MN, USA.

This convergent mixed methods study examined 35 healthy, independent living individuals' (above 85 years) perceptions of their relationship with their primary health provider (PHP) and health practices. The relationship between PHP relationship perceptions and locus of control (LOC), resilience, and self-efficacy was explored through surveys and interviews. The majority indicated they visited their PHP just for preventative care; the number of PHP visits per year was significantly lower than reported for individuals above 85 by the CDC, possible reasons for this finding are provided. A positive relationship between LOC, resiliency, and self-efficacy for the oldest old was found. Few participants indicated their PHP had discussed normal changes with aging. This study has deepened understanding of the complexity inherent to the healthy oldest olds' relationship with their PHP. The findings suggest this relationship relates to the PHP's personal characteristics, the older adult patients' personality, and the influence of the accompanying patient escort.
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http://dx.doi.org/10.1177/0733464813482182DOI Listing
October 2015