THE ISOLATION OF INFLUENZA A VIRUS FROM PLUMAGE OF WATERFOWL DURING AUTUMN MIGRATION

Aim. In the present work we investigated the circulation of AIV in wild bird populations and studied the sorption of the influenza virus in the feathers of wild waterfowl nesting on reservoirs during the autumn mass migration. Material and methods. Sampling was carried out on the territory of the Novosibirsk region on Lake Chany during the period from August to September 2014-2016. Biological samples were collected from 188 wild waterfowl of various species. AIV isolation from cloacal swabs and swabs collected from feathers was carried out in the developing chick embryo system (RCC) as previously recommended. The isolated viruses were tested by HA/HI with specific sera, PCR analysis was carried out with subtyping primers. The genomes of the isolated viruses were sequenced for phylogenetic analysis. Results and discussion. As a result of monitoring, cloacal and feather swabs were collected from 188 individuals belonging to 13 species of the Anseriformes and Charadriiformes, whose representatives are the main natural reservoir of AIV. Fifteen new AI viruses were isolated from the collected samples. Four of them were isolated from plumage samples and the rate was more than 2 times lower, compared with virus isolation from cloacal swabs. Main conclusions. Thus, it can be assumed that avian influenza virus transmission by plumage during migration is not sufficiently taken into account. The key role in AIV ecology may play the virus spreading by its adsorption on bird feathers

Amylase-Sensitive Polymeric Nanoparticles Based on Dextran Sulfate and Doxorubicin with Anticoagulant Activity

This study looked into the synthesis and study of Dextrane Sulfate−Doxorubicin Nanoparticles (DS−Dox NP) that are sensitive to amylase and show anticoagulant properties. The particles were obtained by the method of solvent replacement. They had a size of 305 ± 58 nm, with a mass ratio of DS:Dox = 3.3:1. On heating to 37 °C, the release of Dox from the particles was equal to 24.2% of the drug contained. In the presence of amylase, this ratio had increased to 42.1%. The study of the biological activity of the particles included an assessment of the cytotoxicity and the effect on hemostasis and antitumor activity. In a study of cytotoxicity on the L929 cell culture, it was found that the synthesized particles had less toxicity, compared to free doxorubicin. However, in the presence of amylase, their cytotoxicity was higher than the traditional forms of the drug. In a study of the effect of DS−Dox NP on hemostasis, it was found that the particles had a heparin-like anticoagulant effect. Antitumor activity was studied on the model of ascitic Zaidel hepatoma in rats. The frequency of complete cure in animals treated with the DS−Dox nanoparticles was higher, compared to animals receiving the traditional form of the drug

Rough-legged buzzards, arctic foxes and red foxes in a tundra ecosystem without rodents

Small rodents with multi-annual population cycles strongly influence the dynamics of food webs, and in particular predator-prey interactions, across most of the tundra biome. Rodents are however absent from some arctic islands, and studies on performance of arctic predators under such circumstances may be very instructive since rodent cycles have been predicted to collapse in a warming Arctic. Here we document for the first time how three normally rodent-dependent predator species—rough-legged buzzard, arctic fox and red fox – perform in a low-arctic ecosystem with no rodents. During six years (in 2006-2008 and 2011-2013) we studied diet and breeding performance of these predators in the rodent-free Kolguev Island in Arctic Russia. The rough-legged buzzards, previously known to be a small rodent specialist, have only during the last two decades become established on Kolguev Island. The buzzards successfully breed on the island at stable low density, but with high productivity based on goslings and willow ptarmigan as their main prey – altogether representing a novel ecological situation for this species. Breeding density of arctic fox varied from year to year, but with stable productivity based on mainly geese as prey. The density dynamic of the arctic fox appeared to be correlated with the date of spring arrival of the geese. Red foxes breed regularly on the island but in very low numbers that appear to have been unchanged over a long period – a situation that resemble what has been recently documented from Arctic America. Our study suggests that the three predators found breeding on Kolguev Island possess capacities for shifting to changing circumstances in low-arctic ecosystem as long as other small - medium sized terrestrial herbivores are present in good numbers