Non-hemagglutinating flaviviruses: molecular mechanisms for the emergence of new strains via adaptation to European ticks

Tick-borne encephalitis virus (TBEV) causes human epidemics across Eurasia. Clinical manifestations range from inapparent infections and fevers to fatal encephalitis but the factors that determine disease severity are currently undefined. TBEV is characteristically a hemagglutinating (HA) virus; the ability to agglutinate erythrocytes tentatively reflects virion receptor/fusion activity. However, for the past few years many atypical HA-deficient strains have been isolated from patients and also from the natural European host tick, Ixodes persulcatus. By analysing the sequences of HA-deficient strains we have identified 3 unique amino acid substitutions (D67G, E122G or D277A) in the envelope protein, each of which increases the net charge and hydrophobicity of the virion surface. Therefore, we genetically engineered virus mutants each containing one of these 3 substitutions; they all exhibited HA-deficiency. Unexpectedly, each genetically modified non-HA virus demonstrated increased TBEV reproduction in feeding Ixodes ricinus, not the recognised tick host for these strains. Moreover, virus transmission efficiency between infected and uninfected ticks co-feeding on mice was also intensified by each substitution. Retrospectively, the mutation D67G was identified in viruses isolated from patients with encephalitis. We propose that the emergence of atypical Siberian HA-deficient TBEV strains in Europe is linked to their molecular adaptation to local ticks. This process appears to be driven by the selection of single mutations that change the virion surface thus enhancing receptor/fusion function essential for TBEV entry into the unfamiliar tick species. As the consequence of this adaptive mutagenesis, some of these mutations also appear to enhance the ability of TBEV to cross the human blood-brain barrier, a likely explanation for fatal encephalitis. Future research will reveal if these emerging Siberian TBEV strains continue to disperse westwards across Europe by adaptation to the indigenous tick species and if they are associated with severe forms of TBE

THE ROLE OF THE STRUCTURAL PROTEINS IN THE NON-VIRAEMIC TRANSMISSION OF TICK-BORNE ENCEPHALITIS VIRUS

There are 3 subtypes of tick-borne encephalitis virus (TBEV) distinguished, at present time: European (EU), Siberian (SIB) and Far Eastern (FE). The former one is associated with Ixodes ricinus tick, whereas the latter two - with I. persulcatus. The circulation of TBEV in nature is mediated by the non-viraemic transmission, between infected and. uninfected ticks co-feeding on the same hosts and. it was shown that transmission rate of «Hypr» strain (EU subtype) is much higher than rate of «Vasilchenko» strain (SIB subtype) - 60 and 5 % respectively. To reveal the viral determinants of transmission efficacy, we constructed the series of recombinant viruses with gradually exchanged genes coding structural (str) and. non-structural (ns) viral proteins. The recombinant virus Hypr[str]Vs[ns] achieved the rate of non-viraemic transmission of 70 %. The introduction of separate structural genes of Hypr into Vs infectious clone has enhanced the transmission efficacy as well, though not to such extent as entire structural region but up to 33 % only. Thus, it was shown that efficacy of non-viraemic transmission of TBEV depends from properties of viral structural proteins mainly

ПРОБЛЕМЫ ДИАГНОСТИКИ ТУБЕРКУЛЕЗА У ПАЦИЕНТОВ С РАЗНОЙ КОМОРБИДНОСТЬЮ

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Towards an alternative testing strategy for nanomaterials used in nanomedicine: lessons from NanoTEST.

In spite of recent advances in describing the health outcomes of exposure to nanoparticles (NPs), it still remains unclear how exactly NPs interact with their cellular targets. Size, surface, mass, geometry, and composition may all play a beneficial role as well as causing toxicity. Concerns of scientists, politicians and the public about potential health hazards associated with NPs need to be answered. With the variety of exposure routes available, there is potential for NPs to reach every organ in the body but we know little about the impact this might have. The main objective of the FP7 NanoTEST project ( www.nanotest-fp7.eu ) was a better understanding of mechanisms of interactions of NPs employed in nanomedicine with cells, tissues and organs and to address critical issues relating to toxicity testing especially with respect to alternatives to tests on animals. Here we describe an approach towards alternative testing strategies for hazard and risk assessment of nanomaterials, highlighting the adaptation of standard methods demanded by the special physicochemical features of nanomaterials and bioavailability studies. The work has assessed a broad range of toxicity tests, cell models and NP types and concentrations taking into account the inherent impact of NP properties and the effects of changes in experimental conditions using well-characterized NPs. The results of the studies have been used to generate recommendations for a suitable and robust testing strategy which can be applied to new medical NPs as they are developed

DNA damage in circulating leukocytes measured with the comet assay may predict the risk of death

The comet assay or single cell gel electrophoresis, is the most common method used to measure strand breaks and a variety of other DNA lesions in human populations. To estimate the risk of overall mortality, mortality by cause, and cancer incidence associated to DNA damage, a cohort of 2,403 healthy individuals (25,978 person-years) screened in 16 laboratories using the comet assay between 1996 and 2016 was followed-up. Kaplan-Meier analysis indicated a worse overall survival in the medium and high tertile of DNA damage (p < 0.001). The effect of DNA damage on survival was modelled according to Cox proportional hazard regression model. The adjusted hazard ratio (HR) was 1.42 (1.06-1.90) for overall mortality, and 1.94 (1.04-3.59) for diseases of the circulatory system in subjects with the highest tertile of DNA damage. The findings of this study provide epidemiological evidence encouraging the implementation of the comet assay in preventive strategies for non-communicable diseases

Biological response of an in vitro human 3D lung cell model exposed to brake wear debris varies based on brake pad formulation

Wear particles from automotive friction brake pads of various sizes, morphology, and chemical composition are significant contributors towards particulate matter. Knowledge concerning the potential adverse effects following inhalation exposure to brake wear debris is limited. Our aim was, therefore, to generate brake wear particles released from commercial low-metallic and non-asbestos organic automotive brake pads used in mid-size passenger cars by a full-scale brake dynamometer with an environmental chamber simulating urban driving and to deduce their potential hazard in vitro. The collected fractions were analysed using scanning electron microscopy via energy-dispersive X-ray spectroscopy (SEM-EDS) and Raman microspectroscopy. The biological impact of the samples was investigated using a human 3D multicellular model consisting of human epithelial cells (A549) and human primary immune cells (macrophages and dendritic cells) mimicking the human epithelial tissue barrier. The viability, morphology, oxidative stress, and (pro-)inflammatory response of the cells were assessed following 24 h exposure to similar to 12, similar to 24, and similar to 48 A mu g/cm(2) of non-airborne samples and to similar to 3.7 A mu g/cm(2) of different brake wear size fractions (2-4, 1-2, and 0.25-1 A mu m) applying a pseudo-air-liquid interface approach. Brake wear debris with low-metallic formula does not induce any adverse biological effects to the in vitro lung multicellular model. Brake wear particles from non-asbestos organic formulated pads, however, induced increased (pro-)inflammatory mediator release from the same in vitro system. The latter finding can be attributed to the different particle compositions, specifically the presence of anatase.Web of Science9272351233

Investigation of consumer properties of sweet buns enriched with herbal food additives

Consumer characteristics of a bakery product have been assessed. It’s been established that the developed "Topitam" sweet bun has a higher rating and nutritional value according to organoleptic, physicochemical indicators and safety indicators than the product developed according to the traditional recipe

Удосконалення математичної моделі захищеної інформаційно- телекомунікаційної системи з використанням теорії чутливості

Offered approach to the design protected informatively - telecommunication system on the basis of theory of sensitiveness. The research of the existing approaches to the mathematical modeling of complex technical systems. Which showed some of their disadvantages associated with limitations and assumptions are not compatible with the real process of their functioning. A mathematical model is improved by protected informatively - telecommunication system, different from known the account of existent features of ill-intentioned external influences and corresponding changes of internal descriptions of the system. Equalizations and functions of sensitiveness, allowing to take into account possible changes protected informatively, are specified - telecommunication system in the conditions of affecting her ill-intentioned attacks. Developed higher-order sensitivity equation that can improve the accuracy of the description of the change process parameters secure information technology system under the conditions of independent malicious actions. Bibl. 11Предложен подход к моделированию защищенной информационно телекоммуникационной системы на основе теории чувствительности. Проведены исследования существующих подходов к математическому моделированию сложных технических систем. Усовершенствована математическая модель защищенной информационно -телекоммуникационной системы, отличающаяся от известных учетом существующих особенностей злоумышленных внешних воздействий и соответствующих изменений внутренних характеристик системы. Разработаны уравнения чувствительности высших порядков, которые позволяют улучшить точность описания процесса изменений параметров защищенной информационно-телекоммуникационной системы в условиях независимых злоумышленных воздействий. Библ. 10.Запропонований підхід щодо моделювання захищеної інформаційно-телекомунікаційної системи на основі теорії чутливості. Проведено дослідження існуючих підходів до математичного моделювання складних технічних систем. Які показали ряд їх недоліків, пов'язаних з обмеженнями та припущеннями не сумісними з реальним процесом їх функціонування. Вдосконалена математична модель захищеною інформаційно - телекомунікаційної системи, що відрізняється від відомих врахуванням існуючих особливостей зловмисних зовнішніх дій і відповідних змін внутрішніх характеристик системи. Розроблено рівняння чутливості вищих порядків, які дозволяють поліпшити точність опису процесу змін параметрів захищеної інформаційно-телекомунікаційної системи в умовах незалежних злочинних впливів. Бібл. 1