[Highly pathogenic avian influenza: a new pandemic threat and possibilities to resist it].

The review presents modern data on outbreaks of avian influenza subtype H5N1 and the incidence of the infection in animals, birds, and humans. The authors adduce data on the resistance of influenza A virus to physical and chemical factors. Factors making avian influenza A virus potentially capable of causing human pandemia are considered. The review also deals with public health possibilities in the event of influenza pandemia, and measures directed towards lowering its negative social and economic consequences.

[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.

[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.

[Modification of mouse resistance to A/Aichi/2/68 influenza virus by a glucocorticoid immunosuppressant kenalog]. / Izmenenie ustoichivosti myshei k virusu grippa A/AIChI/2/68 pod vliianiem gliukokortikoidnogo immunodepressanta kenaloga.

Changes in the virulence of influenza virus A/Aichi/2/68 LD50 were studied in albino mice with immunosuppression induced by long-acting glucocorticoid kenalog (Kn). In high doses (5 and 10 micrograms/g) Kn induced a decrease in the adrenal, thymic, and splenic weight, which is typical of steroid immunosuppression. The susceptibility of mice preinjected with Kn to the virus increased more than ten-fold, judging by a decrease in LD50. The detected shifts may be due to disorders in lung tissue resistance and reactivity of alveolar macrophages and neutrophils observed previously in induced glucocorticism.