On the evaporation dynamics of trinitrotoluene microparticles on the glass surface

The results of measuring the time dependence of the concentration of trinitrotoluene (TNT) vapor over its solid microconcentrations on the glass surface with a low TNT concentration on the surface of 100 ng/cm2 are presented. Such microconcentrations of traces are typical for the conditions of anti-terrorist control of objects for the presence of TNT. The measurements were made using a portable multicapillary gas chromatograph (GC) EKHO-V-IDTS (Russia) with TNT vapor concentration. The threshold for determining the concentration of TNT vapor by the EKHO-V-IDTS gas chromatograph corresponds to the modern level and is equal to 10-14 g/cm3. Vapor sampling is performed by a vortex sampling device (VSD), which is used in the anti-terrorist control of objects. It is shown that the initial surface concentration of TNT traces of 100 ng/cm2 on the glass surface decreases to 12 ng/cm2 in a time of 2.6 h due to evaporation into an open half-space under laboratory conditions. The vapor concentration over the residual TNT concentration of 12 ng/cm2 corresponds to the GC sensitivity threshold for TNT vapor concentration equal to 10-14 g/cm3

Highly Pathogenic Avian Flu A(H5N1): State of Affairs in 2009–2012 and Forecast of Its Pandemic Potential

Avian flu is an infectious viral disease in birds that still retains its positions in some parts of Asia and Africa. This review contains summarization and analysis of facts regarding the current situation on highly pathogenic avian flu A-type subtype H5N1 among people and animals for the period of the past four years. Excess incidence rate in 2009 in Egypt, as well as cluster cases of the disease in humans, closely related in time and space, virus mutations as it spreads all over the world and diversification of the host specter, testify of the fact that this agent possesses significant pandemic potential and requires continuous close attention to provide for the well-timed detection of the occurring epidemiological, clinical and virological changes

Interferons lambda – therapeutic application

Interferons are a group of protein molecules with a broad spectrum of effects on the human body. Interferon lambda (type III interferon) was discovered comparatively recently about 20 years ago and its action is still poorly understood. However, the study of its properties and mechanisms of action is of great interest, since it not only has similarity with type I interferons, but has a number of distinctive features that create prerequisites for expanding its clinical use. Particularly, interferon lambda is not produced by all cells of the body, and therefore has a more targeted effect and lower systemic side effects than type I interferons. This review considers the biological activity of exogenous interferon lambda: the mechanisms of its antiviral, antitumor, antifungal and immunomodulatory activity. The possibility of its use in clinical practice for the treatment of such diseases as Sjogren’s syndrome, atopic asthma, autoimmune arthritis, various tumors, as well as against a various of RNA- and DNA-containing viruses that attack the anatomical barrier surface of the respiratory tract, gastrointestinal tract, blood-brain barrier and liver is discussed. This review also considers pegylated recombinant interferon lambda. Recent clinical studies have demonstrated a higher safety profile of pegylated interferon lambda compared with pegylated interferon alpha

Investigation of Cytotoxic Effects of Recombinant Human Interferon Lambda-1 and Its Pegylated Form on Human Conjunctival Epithelial Cells

Currently, there are no efficacious, all-purpose antiviral medicines for the treatment of ocular surface infections caused by viruses. At the same time, type III interferons demonstrate high potency for histological barriers, such as the conjunctiva. Modification of protein molecules in native products can significantly improve their pharmacodynamic properties. Thus, it seems reasonable to develop antiviral medicines based on interferon lambda (IFN-λ1) and its pegylated form (PEG IFN-λ1).The aim of the study was to evaluate the in vitro cytotoxic effect of recombinant human IFN-λ1 and its pegylated form on Chang conjunctiva clone 1-5c-4 human conjunctival cells.Materials and methods: PEG IFN-λ1 was obtained by the electron beam immobilisation method. A normal human conjunctival cell line Chang conjunctiva clone 1-5c-4 was used for cell cultivation. The MTT test was used to assess the cytotoxic effect. Cell proliferative activity was studied by measuring microelectrode impedance. Ultrastructural changes were assessed by electron microscopy. Statistical processing was performed using the Statistica 10.0 software package.Results: IFN-λ1 (37 μg/mL) and PEG IFN-λ1 (42 μg/mL) had no significant cytotoxic effect on the human conjunctiva cell culture and the cell proliferative activity. The analysis of ultrastructural changes demonstrated that IFN-λ1 activated metabolic processes in the cells, and PEG IFN-λ1 promoted differentiation and keratinisation of epithelial cells and led to modification of the cell membrane. A ten-fold increase in IFN-λ1 and PEG IFN-λ1 concentration (to 370 μg/mL and 420 μg/mL, respectively) reduced the cell viability by 15–20% as compared to the intact control.Conclusions: the study results demonstrated that IFN-λ1 and PEG IFN-λ1 could be used as active pharmaceutical ingredients in the development of medicines for the treatment of conjunctival viral infections

Determination of the time-dependent change in the vapor concentration of 2,4,6-trinitrotoluene during the sublimation of its traces from the glass surface

Приведены результаты измерения во времени концентрации пара 2,4,6-тринитротолуола (ТНТ) над его следовыми количествами, названными тонкими пленками, на поверхности стекла с концентрацией 100 нг/см2 на квадратном участке со стороной 1 см. Следовые количества ТНТ на стекле образовывали путём нанесения раствора ТНТ в ацетонитриле, разбавленного химически чистым ацетоном с последующим испарением растворителей. Для измерения концентрации пара ТНТ использовали портативный поликапиллярный газовый хроматограф ЭХО-В-ИДПС с предварительным концентрированием пара ТНТ. Отбор проб пара ТНТ над объектом осуществляли и дистанционным вихревым пробоотборником. Пробу пара отбирали с дистанции 2 см от поверхности стекла. Концентрирование в режиме полного улавливания паров ТНТ осуществляли на сетках из проволоки диаметром 0,05 мм из нержавеющей стали. Концентрацию паров определяли по амплитуде хроматографического пика. Установлено, что концентрация пара ТНТ над исследуемой поверхностью площадью 1 см2 уменьшается с 10-13 до 10-14 г/см3 за время 2.6 ± 0.3 часа. Концентрация пара ТНТ 10-14 г/см3 соответствует пороговой концентрации пара ТНТ для современных обнаружителей. Из предположения пропорциональности концентрации пара количеству массы ТНТ на поверхности для рассматриваемых следовых количеств ТНТ оценили, что исходная поверхностная концентрация тринитротолуола 100 нг/см2 на поверхности стекла за счёт сублимации в открытое полупространство уменьшается до 12 нг/см2 за 2.6 ± 0.3 часа. Показано, что вихревой отбор проб пара ТНТ интенсифицирует сублимацию ТНТ с поверхности стекла.The results of the measurements of 2,4,6-trinitrotoluene (TNT) vapor concentration over its trace amounts, called thin films, on the glass surface with a concentration of 100 ng/cm2 in a square area with a side of 1 cm over time are presented. The trace amounts of TNT on the glass were formed by applying a solution of TNT in the acetonitrile diluted with the chemically pure acetone, followed by the evaporation of the solvents. In order to measure the TNT vapor concentration, an EKHO-V-IDTS portable multibacillary gas-chromatograph with preliminary TNT vapor concentration was used. A sampling of the TNT vapor above the object was carried out with a remote vortex sampler. The vapor sample was taken from a distance of 2 cm from the glass surface. The concentration in the mode of the complete capture of TNT vapors was carried out to the stainless-steel wire mesh. The vapor concentration was determined from the chromatographic peak amplitude. It was found that the concentration of vapor over the examined surface with an area of 1 cm2 decreases from 10-13 to 10-14 g/cm3 within 2.6 ± 0.3 hours. TNT vapor concentration value of 10-14 g/cm3 corresponds to the threshold concentration of TNT vapor for the modern detectors. Based on the assumption that the vapor concentration is proportional to the amount of the TNT mass on the surface for the considered trace amounts of TNT, it was estimated that the initial surface concentration of trinitrotoluene of 100 ng/cm2 on the glass surface decreases to 12 ng/cm2 within 2.6 ± 0.3 hours due to sublimation into an open half-space. It was shown that the use of vortex sampling of vapor intensifies the sublimation of TNT from the glass surface.Работа выполнена при финансовой поддержке Комплексной программы фундаментальных исследований СО РАН (проекты № 0385-2018-0014, №0331-2019-0029, № 0331-2018-0009). Авторы благодарят Засыпкину Ирину Ивановну за помощь при оформлении статьи.Current work was financially supported by the Comprehensive Program for the Fundamental Research of the Siberian Branch of the Russian Academy of Sciences (projects No. 0385-2018-0014, No. 0331-2019-0029, No. 0331-2018-0009). The authors are grateful to Irina Ivanovna Zasypkina for her help in preparing the manuscript

INTERFERONS AND EYE DISEASES

The review contains an analysis of the medical use of interferons – a group of signaling protein molecules that have antiviral, antitumor, and immunomodulatory activity – in ophthalmic practice. Interferons have a wide spectrum of action, including antiviral, immunomodulatory, antitumor and other types of activity. This provides a great potential for interferon use in ophthalmology, both in combination and as a first-line therapy for conjunctival papillomatosis, squamous cell neoplasia, conjunctival melanoma, keratitis caused by the herpes simplex virus, uveitis, geographical choriopathy, cystic and diabetic macular edemas, etc. There are considered mechanism of action, dosing regimens, side effects of using interferons and such their solutions as use of newly discovered interferon lambda and interferon pegylation. In contrast to the ubiquitous expression of the IFN-α receptor, IFN-λ receptor is determined mainly in the epithelial cells of the mucous membranes and skin keratinocytes, which provides a more targeted effect of the drugs. Modifying the properties of biologically active substances by combining them with low molecular weight carriers, for example, polyethylene glycol molecules (PEG), leads to a decrease in the therapeutic dose of the drug and an increase in the selectivity of its action due to changes in pharmacokinetic and pharmacodynamic parameters

Investigation of the antiviral activity of the recombinant human interferon lambda 1 in human conjunctiva cell culture

The aim of the study was to determine the efficacy of recombinant human interferon lambda 1 (IFN-λ1) against human adenovirus serotype 5 in a culture of human conjunctival cells Chang conjunctiva clone 1-5c-4. Material and methods. The study design consisted of three experimental schemes, reflecting a prophylactic and two options for a therapeutic and prophylactic treatment regimen (with the constant presence of the virus in the culture medium and with its removal after adsorption). The antiviral activity of IFN-λ1 was determined by the number of viable cells after exposure to the virus (MTT test). Results and discussion. It has been established that IFN-λ1 has antiviral activity against human adenovirus in vitro under a prophylactic and therapeutic-prophylactic scheme of administration at an infection dose of 1 and 10 TCID50 (50% tissue culture infectious dose), but not at an infection dose of 100 TCID50. The antiviral effect of the use of IFN-λ1 in a therapeutic and prophylactic regimen at an infection dose of 1 TCID50 was comparable to that of IFN-α. At the same time, both interferons did not have a toxic effect on the cell culture even at a concentration of 84 and 58 mg/ml, respectively. The antiviral activity and the absence of cytotoxic action provide the basis for further study of the possibility of development of based on IFN-λ1 drug for eye conjunctiva viral diseases treatment