[Antitumor properties of a liposomal form of a differentiation factor HLDF fragment in cultured cells].

Cytotoxic properties of a liposomal form of the HLDF6 hexapeptide, representing an HL-60 cell differentiation factor fragment, have been studied on a murine primary lymphosarcoma cell culture. It is established that the liposomal HLDF6 peptide is capable of inhibiting proliferation and enhancing death of the cells of both LS and RLS lymphosarcoma strains distinguished by their sensitivity to cytostatic agents. The effect of the preparation is determined by its antiproliferative and apoptogenic actions on the cells. Free HLDF6 peptide showed a lower cytotoxic activity with respect to the tumor cells as compared to the liposomal preparation.

[Comparison of in vitro and in vivo methods of evaluation of the efficacy of influenza virus hemagglutinin inhibitors].

One of the problem in the selection of the most effective antiviral preparations with a broad spectrum of antiviral protective activity, is the "continuity" of assays of different level of complexity so, that the most effective antiviral therapeutic, selected by in vitro assays would be the most effective in vivo. Comparative study of the efficacy of the influenza virus inhibitor in the assays of inhibition of virus binding with fetuin, inhibition of infectious focus forming units in MDCK cells, inhibition of virus yield in infected MDCK cells, and inhibition of influenza virus infectivity in mice infected by viral aerosol are presented. The value of 50% inhibiting concentration IC50 for the pare "influenza virus strain A/NIB/23/89-MA-inhibitor tetra-Aca6-6'SLN" corresponded to 6-10 microM and was invariant for three different tests--in vitro assay of inhibition of virus binding with fetuin, inhibition of yield in infected MDCK cell culture, and inhibition of virus infectivity in mice, but not for the assay of inhibition of infectious focus forming units in cell culture.

A prototype prophylactic anti-influenza preparation in aerosol form on the basis of Abies sibirica polyprenols.

This research investigates a promising antiviral compound based on polyprenols from Siberian silver fir (Abies sibirica). The physico-chemical characteristics of a preparation developed in aerosol form and an estimation of its protective efficacy against aerosol challenge of laboratory animals are presented. It is shown that (1) by using a simple ultrasonic disperser one can obtain aerosol of three formulations studied with about 70% of its mass accumulated in the size range below 1.8 microm; (2) 40-100% of aerosol particles contain preparation for different formulations; (3) after delivering under specified schedules, the preparations as developed can protect up to 100% of mice against 5 LD(50) of influenza A/Aichi/2/68 (H3N2) virus aerosol infection. Animals inhaled twice the preparation doses (which were 100 times lower than injection ones of the same efficacy) and did not exceed 10 microg/mouse. It was shown that the mode of action of this immunomodulating preparation was nonspecific stimulation of immune cells' various activities.

[An intensification of antiviral and interferon effects of ridostin (an interferon inducer) by cationic liposomes in vitro and in intranasal administration]. / Usilenie kationnymi liposomami protivovirusnogo i interferonogennogo deistviia induktora interferona ridostina in vitro i pri intranazal'nom primenenii.

Combined application of ridostine with catonic liposomes was shown to essentially enhance the interferon-inducing and antiviral activity of the former in experiments with cell cultures L-929, which is apparently related with an improved efficiency of intracellular delivery of dsRNA. A comparative study demonstrated that ridostine, when combined with liposomes, is needed by 10(3)-10(4) times less as when it is used alone. A pretreatment of the cellular monolayer by cationic liposomes contributes also to enhancing the activity of ridostine, which can be explained by an enhanced permeability of cells for dsRNA holding on-for as long as 30 minutes after the removal of liposomes from the liquid culture. A separate successive administration of, first, liposomes and, then, of ridostine in BALB/c mice (20 mg/kg) leads to a more intensified induction of interferon in the upper respiratory tract tissues as compared with the administration of ridostine alone.

[The simple method of direct estimation of infectious process in mice and rats aerogenically infected with influenza virus]. / Prostoi metod priamoi otsenki infektsionnogo protsessa u myshei i krys, aerogenno zarazhennykh virusom grippa.

Multiplication of influenza virus in laboratory animals (mice and rats) after aerogenic inoculation was recorded directly (by the agent accumulation in the lungs and trachea) and indirectly (by interferon concentration in the lungs of mice). Thermal inactivation of influenza virus in chick embryo allantoic fluid was observed (by 4.5-6 Ig within 48 h at 37 degrees C). The authors claim that influenza (strain A/Aichi/2/68) infection in the respiratory tract of mice and rats can be experimentally validated by inoculation of chick embryos with 10 and 20% mouse or rat lung homogenate (undiluted or diluted 10-fold) or with 1 and 5% mouse and rat trachea homogenate, respectively, 48 h after aerogenic inoculation of animals, and the virus AID50 be thus determined.

[Mechanisms of mice resistance to influenza virus A/AICHI/2/68 after preventive injection with polyprenols ]. / Mekhanizmy rezistentnosti myshei k virusu grippa A/AIChI/2/68 pri profilakticheskom vvedenii poliprenolov.

Preventive effect in influenza can be attained by intramuscular injections of fir (Abies) polyprenols. One of 5 tested polyprenol preparations (No. 1), injected 2 days before aerogenic infection with influenza virus, reliably protected mice from disease. Mice pretreated with polyprenol preparations or Hanks' solution did not differ by accumulation of interferon in the lungs One day after aerogenic infection. Three days after injection of polyprenol preparation No. 1 the weights of the spleen and thymus significantly decreased. One day after injection cell count in the bronchoalveolar tract of mice was almost 2-fold higher than in the control at the expense of lymphocytes and macrophages. After 3 days the relative and absolute counts of macrophages decreased and those of lymphocytes decreased significantly. Three days after injection macrophages were 2-fold more active in absorption of zymosan granules. Preparation No. 1 affected the production of superoxide anion radicals, whose production by all macrophages in the bronchoalveolar tract of mice was significantly higher on day 1 postinjection than on day 3 and higher than on days 1 and 3 after injection of preparation No. 2.

[Prophylactic efficacy of aerosol preparations based on Abies siberica polyprenols in experimental influenza infection]. / Profilakticheskaia éffektivnost' aérozolei preparatov na osnove poliprenolov pikhty sibirskoi pri éksperimental'noi grippoznoi infektsii.

Preliminary investigations showed high preventive activity of two of three aerosol preparations of Abies sibirica polyprenols with nonionic surface active substances towards influenza infection. At least 2 aerosol administrations are needed to attain a high protective effect, the second dose depending on the first. Relationship between animal reaction to influenza virus infection changed in a nonmonotonous mode, depending on the drug dose injected during the first treatment: as the dose increased, the death rate first decreased and reached the minimum and then increased again. Such a reaction to aerosol treatment can be explained by the hypothesis of hyperstimulation followed by exhaustion of the host defense systems after high doses of the preparation.

[Mechanisms of action of aerosol preparations based on Abies siberica polyprenols in experimental influenza infection]. / Mekhanizmy deistviia aérozolei preparatov na osnove poliprenolov pikhty sibirskoi pri éksperimental'noi grippoznoi infektsii.

Humoral and cellular mechanisms of Abies sibirica polyprenol effects on nonspecific resistance of mice to influenza A/Aichi/2/68 virus were investigated. Two aerosol doses of polyprenols had a high protective effect in mice challenged with influenza virus. Aerosol polyprenol preparations in the studied doses induced no interferon or tumor necrosis factor production in the lungs. Lung macrophage counts and capacity to produce superoxide anion radicals increased in survivors after influenza in comparison with intact animals. Double aerosol administration of polyprenols prior to influenza infection promoted an increase in the thymus weight, bronchoalveolar tract cell counts (predominantly at the expense of lymphocytes), and of superoxide-producing potential of macrophages, which, in turn, can contribute to improvement of the defense potential of the organism towards influenza virus.

Effect of intramuscularly injected polyprenols on influenza virus infection in mice.

This study demonstrates the possibility of achieving a prophylactic effect by intramuscular injection of Abies sibirica polyprenols for the control of influenza virus infection in mice. One of the five polyprenol preparations tested, preparation N1, which had the lowest hydrophilic-lipophilic balance (8.6), produced a significant protective effect when injected in a dose of 2000 microg/mouse 2 days before aerosol infection of mice with influenza virus. A moderate protective effect was also observed using a second preparation, designated N2. One day after aerosol infection, animals pre-treated with 2000 microg doses of the polyprenol preparations or Hanks' solution showed no difference in the level of interferon accumulation in the lungs. Three days after injection of preparation N2 and N1, a significant decrease in spleen and thymus weights was, observed in the mice. One day after injection of these preparations, the number of lymphocytes in the bronchoalveolar tract of the mice exceeded almost twice that seen in mice treated with placebo. After 3 days, relative and absolute numbers of macrophages decreased, whereas those of lymphocytes increased significantly. Three days after the administration of preparations N1 and N2, macrophages became approximately twice as active in absorbing zymozan granules. Preparation N1 affected the system of superoxide radical anion production to a greater extent than preparation N2. The production of radical anions by the macrophages of the bronchoalveolar tract in the mice, 1 day after intramuscular injection of preparation N1, was significantly higher than that seen on day 3 and that induced by preparation N2 1 and 3 days after injection. These data indicate that emulsions of polyprenols that have relatively low hydrophilic-lipophilic balance, inhibit influenza virus infection in mice through a modulation of the host immune response.

[Sensitivity of white mice to influenza virus (A/Aichi/2/68) in aerogenic infection]. / Chuvstvitel;nost' belykh myshei k virusu grippa (A/Aichi/2/68) pri aérogennom zarazhenii.

Polydispersed aerosols from allantoic fluid of chick embryos induced with influenza virus with different median weight aerodynamic diameters of corpuscles (0.5, 0.8, 1.1, 2.2, and 6.0 mu are effectively deposited in respiratory organs of mice weighing 18-19 g. The sensitivity of mice of different weight to aerogenic infection with influenza virus (strain A/Aichi/2/68) was virtually the same. The efficacies of aerogenic 50% infective and lethal doses (1.8-2.5 lg) for mice of the same weight were different. The sensitivity of mice to aerogenic infection and of developing chicken embryos to the virus (ID50 = EID50) is the same. Mice weighing 10-19 g can be infected via airways with adapted influenza virus in studies of therapeutic and prophylactic effects of drugs.

[Stabilization of influenza virus with antioxidants]. / Stabilizatsiia virusa grippa antioksidantami.

Antioxidant stabilizers can be selected by the effects of their components on biological activity of influenza viruses and their antioxidative effects on influenza virions and model membranes--liposomes.

[Dynamics of interferon induction in albino mice by interferon inducer ridostin administered by various routes]. / Izuchenie dinamiki interferonoobrazovaniia v organizme belykh myshei pri razlichnykh putiakh vvedeniia induktora interferona ridostina.

The time dependence of interferon production in blood, tissues of the respiratory tract, brain and olfactory tract of mice BALB/c was investigated after administration of the interferon inductor ridostin by various routes. Intraperitoneal injection of ridostin in a dose of 5 mg/kg induced intensive accumulation of interferon in the blood serum with the peak in 8 hours (2560 U/0.2 ml) while no interferon was detected in the tissues of the respiratory tract and brain of the animals. Intracerebral injection of ridostin in the same dose induced accumulation of interferon in both the tissues of the brain (maximum 160 U/0.2 ml in 24 hours) and the blood serum (maximum 1280 U/0.2 ml in 8 hours). After respiratory administration of ridostin interferon was detected only in the site of the administration in the tissues of the upper respiratory tract and lungs of the mice.

[Effect of components of virus-containing allantoic fluid on the stability of influenza virus during storage]. / Vliianie komponentov virussoderzhashchei allantoisnoi zhidkosti na ustoichivost' virusa grippa pri khranenii.

Effects of allantoic fluid fractions (isolated by sedimentation and gel chromatography) on inactivation of influenza virus and lipid peroxidation in viral envelopes and phospholipid liposomes indicate the presence of both components with prooxidant effects enhancing inactivation and of endogenous antioxidants stabilizing the viral activity. The hypothesized "lipid" mechanism of inactivation (suggesting activation of lipid peroxidation in viral envelopes followed by inactivation of viral nucleoprotein) permits a satisfactory interpretation of viral material inactivation.

[A thermodynamic analysis of oxidative inactivation of influenza virus and lipid peroxidation of viral envelope lipids]. / Termodinamicheskii analiz okislitel'noi inaktivatsii virusa grippa i perekisnogo okisleniia lipidov virusnykh obolochek.

The "activation energy" values for virus inactivation (22.2 kcal/mol) calculated using Arrenius formula and the levels of accumulation of the final product of lipid peroxidation, fluorescent pigment (21.2 kcal/mol), in virus envelopes were found to be in good correlation for purified influenza A/PR8/34 virus suspensions stored at temperatures from 6 to 37 degrees C. A "lipid" mechanism of inactivation of enveloped viruses is proposed, permitting, together with the "nucleic" and "protein" mechanisms, a satisfactory interpretation of the relationship between the stability of viral material and the medium composition, lipid composition of virus envelopes, and other factors.

[The efficacy of the therapeutic and prophylactic actions of immunomodulators in experimental infection due to the causative agent of Venezuelan equine encephalomyelitis]. / Effektivnost' lechebno-profilakticheskogo deistviia immunomoduliatorov pri éksperimental'noi infektsii, vyzvannoi vozbuditeliami venesuél'skogo éntsefalomielita loshadei.

The investigation of the prevention and treatment action of some immunomodulators (ridostin, reaferon and polyribonate) used alone and in combinations was conducted on laboratory animals infected aerogenically by Venezuelan equine encephalitis (VEE) virus. A lower death rate of the aerogenically infected mice (10-30 respiratory LD50) was observed after intramuscular injection of ridostin. The preventive affect of ridostin and ridostin + reaferon administered intranasally and intramuscularly was achieved in the aerogenically infected guinea pigs (10 respiratory LD50). The results of the study on the early virus reproduction in the animals were used for the choice of the treatment scheme. The immunomodulators had no effect when the treatment was started 1 day after the VEE virus infection.

[The effect of conditions of storage and composition of viral material on lipid peroxidation of the viral envelope and inactivation of the influenza virus]. / Vliianei uslovii khraneniia i sostava virusnogo materiala na perekis noe okislenie lipidov virusnoi obolochki i inaktivatsiiu virusa grippa.

Lipid peroxidation (LPO) develops in the virus envelopes in the course of storage of influenza virus suspensions. It is registered by fluorescent methods by the time course of intermediate products (short-chain dialdehydes) and final products of LPO (fluorescent pigment), this being characteristic of an autocatalytic process. The conformity of the basic regularities of LPO and virus inactivation in samples differing by the storage conditions, concentrations of virions and antioxidants (alpha-tocopherol acetate and phenosan) permits us to consider LPO as an important mechanism of enveloped virus inactivation during storage.