Компетенции фтизиатров и врачей первичного звена здравоохранения при оказании противотуберкулезной помощи населению

.

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

ПРОБЛЕМЫ ДИАГНОСТИКИ ТУБЕРКУЛЕЗА У ПАЦИЕНТОВ С РАЗНОЙ КОМОРБИДНОСТЬЮ

.

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

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

Effect of Double Endotamponade with Perfluorocarbon Liquid and Silicone Oil: Experimental Study in vivo

Purpose. To examine how the retina is affected by double tamponade of the vitreous cavity with the combination of perfluorocarbon liquid (PFCL) and silicone oil (SO) in order to assess the prospect of such double tamponade employment in clinical practice, particularly in cases of retinal detachment.Material and methods. We examined retinal response on combination of perfluorodecalin (PFD) «Dk-line» (Bausch &amp; Lomb) and silicone oil «Oxane 1300» (Bausch &amp; Lomb) during long term vitreous cavity tamponade. The study included 90 chinchilla rabbits (90 eyes). Rabbits were randomized into three groups: I (test group) - vitreous cavities of right eyes were filled with PFD+SO; II (control) - the same but with SO only; III (control) - the same but with PFD only. Rabbits of each group were euthanized after 1, 2, or 3 months. We performed clinical examination and morphological examination of the rabbit retinas.Results. At 1 month, retina in all groups did not differ from the normal morphology. At 2 months in all groups we detected retinal edema. At 3 months in all groups retina has thinned. According to clinical findings and morphological study we found no difference between eyes filled with PFD+SO combination and eyes filled with SO.Conclusion. No signs of pathological response were found in the retinal morphology after 1 month of PFD+SO combination stay in vitreous cavity, thus representing the absence of any risk of double tamponade during 1 month. During a longer-term tamponade of the vitreous cavity this combination is safe to the same extent as SO is

Investigation of effectiveness of application of “Pear powder” food additive for bakery pressed yeast activation

The article presents the results of the study of the effect of "Pear powder" food additive on baking pressed yeast activation. It is established that the use of the studied food additive in the process of activating baking pressed yeast has a positive effect on their lifting power. It is revealed that the introduction of the studied "Pear powder" food additive in the amount of 1.5% to the mass of flour at the stage of activation of baking pressed yeast reduces the duration of the activation process by 1 hour

EVALUATION OF SAFETY OF DOUBLE TAMPONADE OF VITREOUS CAVITY IN SURGICAL TREATMENT OF RETINAL DETACHMENT

Purpose. To assess the safety of retinal detachment surgery employing double endotamponade with PFCL and silicone oil for 30 days. Material and methods. Inclusion criteria: retinal detachment with retinal breaks located in both upper and lower retina and/or with residual severe proliferative vitreoretinopathy. In the study group (26 eyes) the surgery was finished with double tamponade with PFCL and silicone oil. In the control group (20 eyes) the surgery was finished with silicone oil tamponade. Tamponade agents were removed 1 month later. Examinations included optical coherence tomography (OCT) and microperimetry along with standard eye examination. Results. Retinal reattachment by means of one surgical procedure was achieved in 81% in the study group and in 65% in the control group. There was no significant difference in BCVA between the two groups. OCT data analysis showed no significant differences between the groups in the thickness of outer and inner nuclear layers. Microperimetry detected no significant differences in light sensitivity between the groups. Conclusion. Double endotamponade with PFCL and silicone oil seems to be a safe method for the treatment of complicated retinal detachments