[Lessons learnt from COVID-19: technology for organizing a forced self-isolation regime].

The lessons of COVID-19 have confirmed the effectiveness of measures aimed at strict self-isolation and quarantine. In the People's Republic of China, where any violation of the regime requirements was qualified as a criminal offense, the virus was neutralized when the pandemic was only gaining momentum in Europe and America. However, without proper organization of a restrictive regime, self-isolation can lead to negative consequences in terms of deterioration of health and standard of living. The pandemic has undoubtedly significantly complicated our lives, has taken millions of lives, caused disability, deterioration of material status, rupture of marital ties. One of the reasons for this development of events was the unsatisfactory organization of leisure during self-isolation. The inability to calmly wait out, endure COVID-associated adversities in most countries caused mass popular unrest, gave rise to panic moods. Only those who managed to curb the negative consequences and direct them in the right direction managed to come out of the pandemic with dignity. The authors have developed an organizational technology of the forced self-isolation regime based on the complex of measures and proposed this technology for introduction to daily life of the population during the period of restrictive regimes. The authors are sure that it is especially important to organize leisure and create the most comfortable conditions of the isolated living for the elderly, who are the most sensitive to changes in life stereotypes. The authors propose a set of measures to efficiently organize leisure during self-isolation with physical therapy, cognitive training, as well as measures to fit the body and develop psychological relief, making it possible to reverse the threat of the pandemic in higher health potential and better family relations.

Dataset on safety and protective efficacy studies of COVID-19 vaccine candidates based on structurally modified plant virus in female hamsters.

This data article is related to the previous research, which addressed the development of a COVID-19 recombinant vaccine candidate. Here, we present the additional data in support of the safety and protective efficacy evaluation of two COVID-19 vaccine candidates based on the coronaviruses' S protein fragments and a structurally modified plant virus - spherical particles. The effectiveness of the experimental vaccines was studied against the SARS-CoV-2 virus in an in vivo infection model in female Syrian hamsters. The body weight of vaccinated laboratory animals was monitored. The histological assessment data of the infected with the SARS-CoV-2 virus hamsters' lungs are provided.

Plant Viruses: New Opportunities under the Pandemic.

During the pandemic, an urgent task has become to develop new vaccine platforms that will help fight the infection caused by SARS-CoV-2 and quickly respond to newly emerging pathogens. Plant viruses can make a significant contribution to the solution of this problem. Phytoviruses, having the properties of any viral particles (self-assembly, immunogenicity, nanosize), are safe for humans since plants and mammals have no common infectious agents. As a result of thermal rearrangement of the tobacco mosaic virus, spherical particles of a protein nature have been obtained, which have unique immunostimulation and adsorption properties and can play the role of a universal adjuvant platform to create vaccines. Based on these particles, a scheme for obtaining vaccine preparations is proposed. This technology resembles a toy construction set for children. The basis is spherical particles, on the surface of which there are toy blocks-antigens. The "blocks" can be removed, added, or replaced, and this does not take much time and resources. Based on spherical particles, a polyvalent vaccine candidate against COVID-19 has been created as an adjuvant platform.

A Recombinant Rotavirus Antigen Based on the Coat Protein of Alternanthera Mosaic Virus.

Thanks to their strong immunostimulating properties and safety for humans, plant viruses represent an appropriate basis for the design of novel vaccines. The coat protein of Alternanthera mosaic virus can form virus-like particles that are stable under physiological conditions and have adjuvant properties. This work presents a recombinant human rotavirus A antigen based on the epitope of rotavirus structural protein VP6, using Alternanthera mosaic virus coat protein as a carrier. An expression vector containing the gene of Alternanthera mosaic virus (MU strain) coat protein fused to the epitope of rotavirus protein VP6 was designed. Immunoblot analysis showed that the chimeric protein was effectively recognized by commercial polyclonal antibodies to rotavirus and therefore is a suitable candidate for development of a vaccine prototype. Interaction of the chimeric recombinant protein with the native coat protein of Alternanthera mosaic virus and its RNA resulted in the formation of ribonucleoprotein complexes that were recognized by anti-rotavirus antibodies.

[A Recombinant Rotavirus Antigen Based on the Coat Protein of Alternanthera Mosaic Virus].

Thanks to their strong immunostimulating properties and safety for humans, plant viruses represent an appropriate basis for the design of novel vaccines. The coat protein of Alternanthera mosaic virus can form virus-like particles that are stable under physiological conditions and have adjuvant properties. This work presents a recombinant human rotavirus A antigen based on the epitope of rotavirus structural protein VP6, using Alternanthera mosaic virus coat protein as a carrier. An expression vector containing the gene of Alternanthera mosaic virus (MU strain) coat protein fused to the epitope of rotavirus protein VP6 was designed. Immunoblot analysis showed that the chimeric protein was effectively recognized by commercial polyclonal antibodies to rotavirus and therefore is a suitable candidate for development of a vaccine prototype. Interaction of the chimeric recombinant protein with the native coat protein of Alternanthera mosaic virus and its RNA resulted in the formation of ribonucleoprotein complexes that were recognized by anti-rotavirus antibodies.

Surface Charge Mapping on Virions and Virus-Like Particles of Helical Plant Viruses.

Currently, the assembly of helical plant viruses is poorly understood. The viral assembly and infection may be affected by the charge distribution on the virion surface. However, only the total virion charge (isoelectric point) has been determined for most plant viruses. Here, we report on the first application of positively charged magnetic nanoparticles for mapping the surface charge distribution of helical plant viruses. The charge was demonstrated to be unevenly distributed on the surface of viruses belonging to different taxonomic groups, with the negative charge being predominantly located at one end of the virions. This charge distribution is mainly controlled by viral RNA.

Data in support of toxicity studies of structurally modified plant virus to safety assessment.

This data article is related to the research article entitled "Assessment of structurally modified plant virus as a novel adjuvant in toxicity studies" (Nikitin et al., 2018), devoted to the safety study of structurally modified plant virus - spherical particles (SPs). SPs are generated by thermally denatured tobacco mosaic virus (TMV) coat protein and act as effective adjuvant for development of new vaccine candidates. This article reports the additional results on the toxicity studies of TMV SPs. The weight coefficients of laboratory animals internal organs complements the data of the subchronic toxicity studies. Also plaque-forming cell assay, delayed-type hypersensitivity test and peritoneal macrophage assay as a part of immunotoxicity studies of TMV SPs are presented.

Spherical particles derived from TMV virions enhance the protective properties of the rabies vaccine.

In this study the ability of spherical particles (SPs) obtained from the tobacco mosaic virus (TMV) virions to enhance the immunogenic potential of the vaccine was evaluated. TMV SPs were shown to increase the protective properties of the widely used effective Russian adjuvant-free rabies vaccine, composed of killed rabies virions. The results of the NIH potency test showed enhancement of protectivity, that is comparable with the effect of the incomplete Freund׳s adjuvant on the same vaccine.

Assessment of structurally modified plant virus as a novel adjuvant in toxicity studies.

Spherical particles (SPs) generated by thermally denatured tobacco mosaic virus (TMV) coat protein can act as an adjuvant, as they are able to enhance the magnitude and longevity of immune responses to different antigens. Here, the toxicity of TMV SPs was assessed prior to it being offered as a universal safe adjuvant for the development of vaccine candidates. The evaluation included nonclinical studies of a local tolerance following the single administration of TMV SPs, and of the local and systemic effects following repeated administrations of TMV SPs. These were conducted in mice, rats and rabbits. General health status, haematology and blood chemistry parameters were monitored on a regular basis. Also, reproductive and development toxicity were studied. No significant signs of toxicity were detected following single or repeated administrations of the adjuvant (TMV SPs). The absence of toxicological effects following the injection of TMV SPs is promising for the further development of recombinant vaccine candidates with TMV SPs as an adjuvant.

Translational Cross-Activation of the Encapsidated RNA of Potexviruses.

We had shown the genomic RNA of potexviruses potato virus X and the alternanthera mosaic virus to be inaccessible in vitro to ribosomes while in intact virion form, but the RNAs can be translationally activated following the binding of movement protein 1 (MP1) to virus particles. Here, we present the results of the follow-up study targeting two more potexvirus species - the Narcissus mosaic virus and the Potato aucuba mosaic virus. We found encapsidated potexviral RNA to share common translational features in vitro and the MP1 to be potent over homological virions of its "own" species and over heterological virions of other species, as well exhibiting selective specificity. Reciprocal cross-activation is observed among viral species phylogenetically either close or distant. There is direct evidence that MP1 binding to the end of the virion is necessary, but not sufficient, for translational activation of encapsidated RNA.

[HYPOTHERMIA INFLUENCES ON OXYGEN TENSION IN THE BRAIN PARENCHYMA IN PATIENTS WITH ANEURYSMAL SUBARACHNOID HEMORRHAGE].

Aneurysmal subarachnoid hemorrhage is a serious medical and social problem. The main physiological mechanisms that determine secondary brain damage in this patients are intracranial hypertension, cerebral vasospasm, dysfunction of autoregulation mechanisms, violation of liquorodynamics and delayed cerebral ischemia. The multimodal neuromonitoring for prevention and timely correction ofsecondary brain injury factors has become routine practice in neuroICU. Measurement of oxygen tension in the brain parenchyma is one of neuromonitoring options. During the years of intensive use of this method in clinical practice the reasons for reducing the oxygen tension in the brain parenchyma were revealed, as well as developed and clinically validated algorithms for correction of such conditions. However, there are clinical situations that are difficult to interpret and even more difficult to make the right tactical and therapeutic solutions. We present the clinical observation of the patient with aneurysmal subarachnoid hemorrhage, who had dramatically reduced brain intraparenchymal oxygen pressure although prolonged hypothermia were used. Despite this, the outcome was favorable. The analysis allowed to assume that the reason for this decrease in oxygen tension in the brain parenchyma could be hypothermia itself

PO-56 - Subsequent clot properties depend on the storage time of platelet concentrates.

INTRODUCTION: Despite platelets properties varies during storage, transfused platelets are included in blood clot in the same way as well as native. We assume that after transfusion the prevalence of platelets with changed activity lead to worse quality of blood clot in vivo. AIM: The aim was the in vitro study of platelet-dependent clot properties that are formed from some stored platelet concentrates (PCs). MATERIALS AND METHODS: Twenty-six PCs in autologous plasma and 24 PCs in platelet additive solution SSP+ (MacoPharma, France) (70vol.%) were analized by thromboelastography with and without platelets activation, and by standard aggregometry. The testing were carried out at the day of proceeding, after 24 hours, and at 3rd and 5th days of storage. We used Trima Accel (Terumo BCT, USA) for the proceeding of platelets apheresis. RESULTS: We found that clot demonstrated gradual reduction of elasticity and deformability starting from second day to fifth day in stored PCs suspended in autologous plasma. From the third storage day platelets lost their meaning for clot properties. The platelets apheresis with next re-suspending in SSP+ solution leads to the depression for platelets aggregability. Actived platelets had no impact to clot properties during full storage time. Total decline of clot quality including low elasticity and impaired deformability were found starting from 3rd storage day compared to the day of proceeding. CONCLUSIONS: We assume that such properties of clot as both elasticity and deformability are forming in PCs at the day of proceeding. Further clot changes observed in PCs does not depend directly from platelets aggregability because clot forming are under other influences. The last are determined mainly by the coagulation what was no included in this study. Also obtained results confirms the 5th-days storage as a benefit independent from PCs proceeding method.

Physical-chemical properties and the reactivity of pyridoxine and pyrrolidone carboxylate and their protolytic forms.

Preparation Methadoxine is equimolar salt, which cationic component (pyridoxine) is 3-oxypyridine derivative, possessing B6-vitamine like activity, while anionic component is the cyclic lactame of glutamic acid. Since biopharmaceutical and pharmacological properties of this drug depend on biochemical transformation its components, of the aim of this work was to determine the structure of possible ionized pyridoxine and pyrrolidone carboxylate forms and their reaction ability in biochemical processes. Physical-chemical properties of compounds (pKa, logP, logD, proton donor/acceptor quantity, solubility (g/l)) were calculated with ACD/pKaDB program or obtained from Pub-Med physical/chemical properties database. UV spectra of compounds were obtained after dissolution in different pH solutions (1.0, 4.5 and 6.8). It was found that at different pH values one can observe changes of the absorption spectra due to the presence of prevailing amount of the protonated form. An analysis of both pKa, logP and logD indicators and reactive functional groups of Methadoxine components has revealed that they can be protonated in different regions of gastro-intestinal tract, that influences their solubility in hydrophilic and lypophilic media. Pharmacological properties of pyridoxine and pyrrolidone carboxylate themselves are performed after their preliminary biotransformation to active metabolites. Only ionic interaction between Methadoxine components in the substance composition can appear, that provides its pharmaceutical stability and ensures its activity only in the organism conditions.

Structural Properties of Potexvirus Coat Proteins Detected by Optical Methods.

It has been shown by X-ray analysis that cores of coat proteins (CPs) from three potexviruses, flexible helical RNA-containing plant viruses, have similar α-helical structure. However, this similarity cannot explain structural lability of potexvirus virions, which is believed to determine their biological activity. Here, we used circular dichroism (CD) spectroscopy in the far UV region to compare optical properties of CPs from three potexviruses with the same morphology and similar structure. CPs from Alternanthera mosaic virus (AltMV), potato aucuba mosaic virus (PAMV), and potato virus X (PVX) have been studied in a free state and in virions. The CD spectrum of AltMV virions was similar to the previously obtained CD spectrum of papaya mosaic virus (PapMV) virions, but differed significantly from the CD spectrum of PAMV virions. The CD spectrum of PAMV virions resembled in its basic characteristics the CD spectrum of PVX virions characterized by molar ellipticity that is abnormally low for α-helical proteins. Homology modeling of the CP structures in AltMV, PAMV, and PVX virions was based on the known high-resolution structures of CPs from papaya mosaic virus and bamboo mosaic virus and confirmed that the structures of the CP cores in all three viruses were nearly identical. Comparison of amino acid sequences of different potexvirus CPs and prediction of unstructured regions in these proteins revealed a possible correlation between specific features in the virion CD spectra and the presence of disordered N-terminal segments in the CPs.

Functional characteristics and clinical effectiveness of platelet concentrates treated with riboflavin and ultraviolet light in plasma and in platelet additive solution.

BACKGROUND AND OBJECTIVES: Pathogen reduction technologies may affect platelet quality during storage. We studied functional characteristics and clinical effectiveness of platelet concentrates (PCs) treated with Mirasol in plasma and in platelet-additive solution SSP+. MATERIALS AND METHODS: Mirasol-treated, gamma-irradiated and untreated apheresis PCs were examined on days 0, 1, 3 and 5 of storage. Phosphatidylserine, P-selectin and active glycoprotein IIb/IIIa were analysed using flow cytometry before and after platelet stimulation. Platelet count increments, the numbers of inefficient transfusions and post-transfusion reactions were analysed to estimate clinical effectiveness. RESULTS: A significant increase in all platelet activation markers occurred during storage in all PC groups. Activation markers in Mirasol-treated samples were already significantly higher compared with the control ones on the day of harvesting, and continued to grow during the storage. Mirasol treatment increased the number of platelets with a mitochondrial membrane potential loss. On the 3rd day of storage, 50% of Mirasol-treated platelets did not respond to activation; on the 5th day, none did. This agreed well with a decrease (approximately twofold) in the effectiveness of Mirasol-treated PC transfusions. Transfusions of PCs stored in SSP+ were accompanied by fewer inefficient transfusions and post-transfusion reactions than of PCs stored in plasma. CONCLUSION: Treatment with Mirasol decreased platelet function, particularly profoundly on the 5th day of storage, and led to a decrease in the effectiveness of transfusions. SSP+ did not affect laboratory parameters significantly compared with plasma, but decreased the percentage of transfusion complications.

Double Subgenomic Promoter Control for a Target Gene Superexpression by a Plant Viral Vector.

Several new deconstructed vectors based on a potexvirus genome sequence for efficient expression of heterologous proteins in plants were designed. The first obtained vector (AltMV-single), based on the Alternanthera mosaic virus (AltMV) strain MU genome, bears a typical architecture for deconstructed plant viral vectors, i.e. a triple gene block was deleted from the viral genome and the model gene of interest was placed under control of the first viral subgenomic promoter. To enhance the efficiency of expression, maintained by the AltMV-single, another vector (AltMV-double) was designed. In AltMV-double, the gene of interest was controlled by two viral subgenomic promoters located sequentially without a gap upstream of the target gene. It was found that AltMV-double provided a significantly higher level of accumulation of the target protein in plants than AltMV-single. Moreover, our data clearly show the requirement of the presence and functioning of both the subgenomic promoters for demonstrated high level of target protein expression by AltMV-double. Taken together, our results describe an additional possible way to enhance the efficiency of transient protein expression maintained in plants by a plant viral vector.

The 5'-proximal region of Potato virus X RNA involves the potential cap-dependent "conformational element" for encapsidation.

Filamentous helical Potato virus X (PVX) can be regarded as one of the well-studied viruses. Nevertheless, some aspects of the PVX assembly remained obscure. Previously, we have shown that the presence of a cap structure at the 5' end of PVX RNA is indispensable for assembly of viral ribonucleoprotein (vRNP) particles varying in length. Here, most significantly, removal of the cap structure from previously capped PVX RNA did not affect the efficiency of decapped RNA molecules to be assembled into vRNP. This result provided evidence that the cap structure by itself does not act as a signal for initiation of vRNP assembly. These observations allowed to presume that the capping triggers some spatial changes in the 5'-proximal site of PVX RNA creating a "conformational encapsidation signal for vRNP assembly", which is capable of triggering vRNP assembly in the absence of cap structure. Apparently, during capping the 5'-proximal segment of PVX RNA acquires a unique conformation which is stable to be retained even after cap removal.

Normal level of sepsis-associated phenylcarboxylic acids in human serum.

Previous studies showed that large amounts of phenylcarboxylic acids (PhCAs) are accumulated in a septic patient's blood due to increased endogenous and microbial phenylalanine and tyrosine biotransformation. Frequently, biochemical aromatic amino acid transformation into PhCAs is considered functionally insignificant for people without monogenetic hereditary diseases. The blood of healthy people contains the same PhCAs that are typical for septic patients as shown in this paper. The overall serum PhCAs level was 6 µM on average as measured by gas chromatography with flame ionization detection. This level is a stable biochemical parameter indicating the normal metabolism of aromatic amino acids. The concentrations of PhCAs in the metabolic profile of healthy people are distributed as follows: phenylacetic ≈ p-hydroxyphenyllactic > p-hydroxyphenylacetic > phenyllactic ≈ phenylpropionic > benzoic. We conclude that maintaining of stable PhCAs level in the serum is provided as the result of integration of human endogenous metabolic pathways and microbiota.

[Association of factors of vascular tone regulation with the development of hemorrhagic transformation in patients with ischemic stroke].

Concentrations of plasma vascular tone regulation markers that are indicators of endothelium dysfunction in the acute phase of ischemic stroke and their effect on the development of hemorrhagic transformation (HT) of the lesion focus have been studied. Concentrations of renin, endothelin 1-21, neuron-specific enolase, NT-proCNP, soluble adhesion molecules (sICAM) were measured in 67 patients on days 1, 3-4. Significantly higher concentrations of renin, endothelin 1-21, neuron-specific enolase were found in patients with HT in the first day compared to patients without HT. The level of NT-proCNP was lower in patients with HT; the increase in the severity of hemorrhagic component led to the elevation of neuron-specific enolase and sICAM concentrations. In conclusion, both markers of blood-brain barrier damage and regulating factors of vascular tone may play a predictive role in the development of HT in ischemic stroke.

Characteristics of Artificial Virus-like Particles Assembled in vitro from Potato Virus X Coat Protein and Foreign Viral RNAs.

Potato virus X (PVX) and some other potexviruses can be reconstitutedin vitrofrom viral coat protein (CP) and RNA. PVX CP is capable of forming viral ribonucleoprotein complexes (vRNP) not only with homologous, but also with foreign RNAs. This paper presents the structure and properties of vRNP assembledin vitroupon incubation of PVX CP and RNAs of various plant and animal viruses belonging to different taxonomic groups. We have shown that the morphology and translational properties of vRNPs containing foreign (heterologous) RNA are identical to those of homological vRNP (PVX RNA - PVX CP). Our data suggest that the assembly of the "mixed" vRNPin vitrocould be started at the 5'-proximal region of the RNA, producing a helical structure of vRNPs with foreign nucleic acids. The formation of heterologous vRNPin vitrowith PVX CP appears not to require a specific 5' end RNA nucleotide sequence, and the PVX CP seems to be able to pack foreign genetic material of various sizes and compositions into artificial virus-like particles.