Cellular internalization and morphological analysis after intravenous injection of a highly hydrophilic octahedral rhenium cluster complex - a new promising X-ray contrast agent

The octahedral cluster compound Na₂ H₈ [{Re₆ Se₈ }(P(C₂ H₄ CONH₂ )(C₂ H₄ COO)₂ )₆ ] has been shown to be highly radio dense, thus becoming a promising X-ray contrast agent. It was also shown that this compound had low cytotoxic effect in vitro, low acute toxicity in vivo and was eliminated rapidly from the body through the urinary tract. The present contribution describes a more detailed cellular internalization assay and morphological analysis after intravenous injection of this hexarhenium cluster compound at different doses. The median lethal dose (LD₅₀ ) of intravenously administrated compound was calculated (4.67 ± 0.69 g/kg). Results of the study clearly indicated that the cluster complex H_n [{Re₆ Se₈ }(P(C₂ H₄ CONH₂ )(C₂ H₄ COO)₂ )₆ ]^n-10 was not internalized into cells in vitro and induced only moderate morphological alterations of kidneys at high doses without any changes in morphology of liver, spleen, duodenum, or heart of mice. Copyright © 2016 John Wiley & Sons, Ltd.

Experimental infection and pathology of clade 2.2 H5N1 virus in gulls

During 2006, H5N1 HPAI caused an epizootic in wild birds, resulting in a die-off of Laridae in the Novosibirsk region at Chany Lake. In the present study, we infected common gulls (Larus canus) with a high dose of the H5N1 HPAI virus isolated from a common gull to determine if severe disease could be induced over the 28 day experimental period. Moderate clinical signs including diarrhea, conjunctivitis, respiratory distress and neurological signs were observed in virus-inoculated birds, and 50% died. The most common microscopic lesions observed were necrosis of the pancreas, mild encephalitis, mild myocarditis, liver parenchymal hemorrhages, lymphocytic hepatitis, parabronchi lumen hemorrhages and interstitial pneumonia. High viral titers were shed from the oropharyngeal route and virus was still detected in one bird at 25 days after infection. In the cloaca, the virus was detected sporadically in lower titers. The virus was transmitted to direct contact gulls. Thus, infected gulls can pose a significant risk of H5N1 HPAIV transmission to other wild migratory waterfowl and pose a risk to more susceptible poultry species. These findings have important implications regarding the mode of transmission and potential risks of H5N1 HPAI spread by gulls.

Biological characteristics of influenza A(H1N1)pdm09 virus circulating in West Siberia during pandemic and post-pandemic periods

We studied biological characteristics of influenza A(H1N1)pdm09 virus circulating in Siberia during the 2009 pandemic and the post-pandemic period of 2011. BALB/c mice were chosen as the experimental model. Virus titers in the lungs were evaluated on days 1, 3, 6 and blood serum titers on day 15 after infection with different strains. Blood sera of convalescents after influenza of 2010-2011 epidemic season were analyzed. Influenza A(H1N1)pdm09 virus strains isolated during the post-pandemic period of 2011 were characterized by low epidemic activity and virulence in comparison with the strains isolated during 2009 pandemic period, which indicates completion of the pandemic cycle.

[Biological properties of velogenic strains of the Newcastle disease virus isolated in the Northern Caucasian region]

The results of the biological property investigation of two Newcastle virus strains isolated in Northern Caucasian region--NDV/Adigeya/duck/8/2008 and NDV/Adigeya/duck/15/2008--were presented. The phylogenetic analysis revealed that these strains belonged to genotype 7 of clade 2. Using molecular-biological analysis of established nucleotide sequences including proteolytic site of fusion peptide it was demonstrated that the strains were velogenic. This conclusion was proved by testing the pathogenicity on the model of intracerebral infected chickens (ICPI--IntraCerebral Pathogenic Index--was found to be 2). Pathomorphological study of dead chickens made it possible to classify strains as neurotropic with low level of visceral tropism.

Effects of sodium diclofenac on the concentration function in animals with different neurohypophyseal status

The characteristics of the osmotic concentration system under conditions of sodium diclofenac treatment were studied in Wistar rats with normally functioning vasopressin gene and homozygotic Brattleboro rats completely lacking endogenous vasopressin. Blockade of prostaglandin synthesis in rats with different neurohypophyseal status stimulated urinary osmolality to a different degree. Different contribution of sodium cations and urea to osmotic concentration was revealed.

[Evaluation of Ebola virus reproduction in adult ICR white mice]

The investigators studied the ability of adult ICR mice (a laboratory model that was most approximated to the wildtype populations of mice) to maintain Ebola virus (EV) reproduction in the organism. The adult ICR mice inoculated with EV during 23 passages were shown to maintain viral reproduction in the liver. The elevated levels of platelets and the early generation of fibrin and fibrinogen degradation products suggested there were hemostatic changes that did not, however, progress to severe coagulopathy. The animals were in appearance apparently, other than adynamia observed on days 5-7. Thus, the susceptibility of the adult ICR mice to EV is characterized by their ability to maintain virus reproduction in the liver without evident signs of the infection. This pattern of susceptibility in the mice shows a possible role of this rodent species in the transmissive cycle of EV.

Involvement of interstitial structures of the kidney into hydrosmotic effect of vasopressin (morphofunctional study)

Administration of desmopressin for 4 days to homozygous Brattleboro rats lacking endogenous vasopressin induced an increase in osmotic concentration and was accompanied by typical changes in the morphofunctional state of interstitial cells of the renal papilla. These changes increase the permeability of extracellular matrix, which attested to the involvement of interstitial cells into hydrosmotic reaction to vasopressin.

Structural and functional changes in epitheliocytes of collecting tubes in renal papilla of Brattleboro rats treated with vasopressin

The functional response of the kidney to desmopressin and morphological changes in epitheliocytes of collecting tubes were studied on homozygotic Brattleboro rats. Redistribution of beta-glucuronidase fractions and increase in the number of osmiophilic granules reflecting increased production of vasopressin-dependent proteins and hyaluronate hydrolase exocytosis were typical structural correlates of the effect of vasopressin.

[Exocrinocytes of the gastric mucosa epithelium of Siberian chipmunk under different seasonal conditions]

The objective of this study was to analyze the morpho-functional remodeling of the epitheliocytes of stomach fundic glands in Siberian chipmunk under different seasonal conditions. The methods of light and electron microscopy were used. It was shown that during summer period, the structure of gastric fundic mucosa of Siberian chipmunk was similar to that one in other mammals. In contrast, in winter, during the periods of hypothermia, the cells of the fundic glands in the gastric corpus demonstrated the changes indicative of the suppression of their secretory activity. During the spontaneous arousals, all the elements of the gastric glands were activated, while the animals consumed the stored food. The present results were compared with the materials obtained earlier in the study of ground squirrels which also have a period of winter hibernation. Gastric cell remodeling in chipmunks during hypothermia was comparable in its trend with the changes taking place in ground squirrels, however, these changes were more pronounced in the latter. Food digestion in the stomach of chipmunk took place not only during the periods of normothermia, but also in the course of slow decline of the body temperature, when animals fell into a state of torpidity, and it recommenced at the early stages of animal rewarming during frequent episodes of its spontaneous arousal. Differences in the changes found in chipmunks and ground squirrels are associated with ecological peculiarities of these species and in the characteristics of the adaptation during the winter period.

Serotonin-producing cells in duodenum of Siberian chipmunk under various seasonal conditions

We studied species-specific characteristics of enterochromaffin cells in the duodenum in Siberian chipmunk in various physiological states. Predominance of synthetic or secretory phase in enterochromaffin cell activity depends on body temperature, metabolism, and feeding behavior.

[The morphometric characteristics of the serotonin-producing cells of the intestines in the red-cheeked suslik during its spontaneous arousal]

Duodenal serotonin-producing cells of the hibernating rodent (Citellus erythrogenys Brandt) were studied at its spontaneous arousal. Morphometric analysis of EC cells revealed alterations in endoplasmic reticulum and Golgi complex changes of numeral density and ratio of different types of ribosomes, retardation of granule content resorption at the spontaneous arousal of the animal. It is concluded that synthetic processes in EC-cells are rapidly activating, which probably restores the serotonin reserves, necessary for the normal course of hibernation.

[Serotonin-producing cells during normo- and hypothermia]

Ultrastructure of the serotonin-producing (EC) duodenum cells of a hibernant in euthermia (in summer and winter) and hypothermia has been studied. It has been found that EC cells of an active summer and spontaneously arousal animals belong to active population. This cells have protein-synthetic activity. The winter cells are characterized by the deficiency of the synthetic processes and the secretory granules disintegration. The results support the hypothesis that ES cells are an important element in the regulation of the hibernation.