Silver-Containing Humic Substance-Based Nanocomposites—Agents for Healing of Potatoes from the Ring Rot

The influence of silver-containing humic substance (HS)-based nanocomposites (NCs) obtained from mud, shale, and coals of three kinds of deposits in Mongolia on the viability and ability to biofilm formation of a phytopathogenic gram-positive bacterium Clavibacter michiganensis subsp. sepedonicus (Cms), as well as peroxidase activity and potato plant growth in vitro, has been investigated. The maximum reduction of the viability of bacterial cells was found in the case of incubation with HS-mu/Ag NC and HS-coal/Ag NC. It was found that HSs, including HS-mu and HS-sl, and NCs synthesized on the base of these HSs, HS-mud/Ag NC and HS-sl/Ag NC reduce more than twofold the activity of peroxidase in potato tissues. It was also found that HS-co and HS-coal/Ag NC stimulate the potato peroxidase activity, as well as biofilm formation of Cms bacterium. No negative effect of the studied NCs on the growth of potato has been revealed. Moreover, NC HS-mud/Ag based on mud had a stimulating effect on leaf formation in plants.     

Toxoplasma gondii seroprevalence in goats,cats and humans in Russia

Toxoplasmosis, a most common zoonosis, is caused by the protozoan parasite Toxoplasma gondii. However, there is little epidemiological information on T. gondii infections in humans and livestock animals in Russia. Therefore, in this study, the seroprevalence of T. gondii in goats in Russia was investigated. A total of 216 goats from 32 farms were investigated and 95 of them were seropositive for T. gondii. The difference in seroprevalence between the examined regions was not statistically significant. We next collected serum samples from 99 cats and 181 humans in Kazan city, the state capital of the Republic of Tatarstan, Russia, and examined their T. gondii seroprevalences. Thirty-nine of the 99 cat samples and 56 of the 181 human samples showed seropositivity. Logistical regression analysis revealed that the cat breeding history of the human subjects, but not their sex or age is a significant risk factor for T. gondii seropositivity. These findings suggest that the natural environment in Russia may be widely polluted with T. gondii oocysts shed by cats, and ingestion of these oocysts provides a major route for human infection with this parasite.     

Loss of periostin occurs in aging adipose tissue of mice and its genetic ablation impairs adipose tissue lipid metabolism

Remodeling of the extracellular matrix is a key component of the metabolic adaptations of adipose tissue in response to dietary and physiological challenges. Disruption of its integrity is a well‐known aspect of adipose tissue dysfunction, for instance, during aging and obesity. Adipocyte regeneration from a tissue‐resident pool of mesenchymal stem cells is part of normal tissue homeostasis. Among the pathophysiological consequences of adipogenic stem cell aging, characteristic changes in the secretory phenotype, which includes matrix‐modifying proteins, have been described. Here, we show that the expression of the matricellular protein periostin, a component of the extracellular matrix produced and secreted by adipose tissue‐resident interstitial cells, is markedly decreased in aged brown and white adipose tissue depots. Using a mouse model, we demonstrate that the adaptation of adipose tissue to adrenergic stimulation and high‐fat diet feeding is impaired in animals with systemic ablation of the gene encoding for periostin. Our data suggest that loss of periostin attenuates lipid metabolism in adipose tissue, thus recapitulating one aspect of age‐related metabolic dysfunction. In human white adipose tissue, periostin expression showed an unexpected positive correlation with age of study participants. This correlation, however, was no longer evident after adjusting for BMI or plasma lipid and liver function biomarkers. These findings taken together suggest that age‐related alterations of the adipose tissue extracellular matrix may contribute to the development of metabolic disease by negatively affecting nutrient homeostasis.     

PEGylated recombinant L-asparaginase from <Emphasis Type="Italic">Erwinia carotovora</Emphasis>: Production,properties, and potential applications

N-hydroxysuccinimide ester of monomethoxy polyethylene glycol hemisuccinate was synthesized. It acylated amino groups in a molecule of recombinant L-asparaginase from Erwinia carotovora. A method of L-asparaginase modification by the obtained activated polyethylene glycol derivative was developed. The best results were produced by modification of the enzyme with a 25-fold excess of reagent relative to the enzyme tetramer. The modified L-asparaginase was isolated from the reaction mixture by gel filtration on Sepharose CL-6B. The purified bioconjugate did not contain PEG unbound to the protein, demonstrated high catalytic activity, and exhibited antiproliferative action on cell cultures.     

Adult human retinal pigment epithelial cells - a potential source of cells for regeneration retina

Retinal pigment epithelium (RPE) arises from neuroectoderm and plays a key role in support of photoreceptor functions. Several degenerative eye diseases, such as macular degeneration or retinitis pigmentosa, are associated with impaired RPE function that may lead to photoreceptor loss and blindness. RPE cell culture derived from adult human eyes autopsy could be an important source for transplantation to cure such retinal degenerative diseases. RPE cells subsequent isolation and maintenance in culture are described. Besides the results of immunocytochemical analysis that characterizes dedifferentiated state of cultured adult human RPE cells are given. Our findings demonstrate that mature human RPE cells have the capacity to express neural markers in response to conditions that promote dedifferentiation.     

Effect of head-down tilt on respiratory responses and human inspiratory muscles activity

The effect of head-down tilt on respiration and diaphragmal and parasternal muscles activity was investigated in 11 healthy subjects. The short-time (30 min) head-down tilt posture (-30 degrees relatively horizont) increased the inspiratory time (P < 0.05), decreased breathing frequency (P < 0.05), inspiratory and expiratory flow rate (P < 0.05) and increased the airway resistance (P < 0.05) compared with values in vertical posture. There were no significant changes in tidal volume and minute ventilation. Constant values of tidal volume and minute ventilation during head-down tilt were provided by increasing in EMG activity of parasternal muscles more then twice. It was established that the contribution of chest wall inspiratory muscles increased while the diaphragm's contribution decreased during head-down spontaneous breathing. Maximal inspiratory effort (Muller's maneuver) during head-down tilt evoked the opposite EMG-activity pattern: the contribution of inspiratory thoracic muscles was decreased and diaphragm's EMG-activity was increased compared with vertical posture. These results suggest that coordinate modulations in inspiratory muscles activity allows to preserve the functional possibility of human inspiratory muscles during short-time head-down tilt.     

4'-C-modified nucleosides: synthesis and antiviral properties

The synthetic methods for 4'-C-modified nucleosides as well as structure activity relationship of obtained compounds towards hepatitis C virus are reviewed.     

Effect of head-down tilt on respiratory responses and human inspiratory muscle activity

The effect of a head-down tilt on the responses of the external respiration system and the functional capacity of the diaphragm and parasternal muscles were investigated in 11 healthy subjects. A 30-min head-down tilt posture (−30° relative to the horizontal) significantly increased the inspiratory time, decreased the respiration rate and the inspiratory and expiratory flow rates; and increased the airway resistance compared to these values in the vertical posture. There were no significant changes in tidal volume or minute ventilation. The electromyograms (EMGs) of the diaphragm and parasternal muscles showed that the constant values of tidal volume and minute ventilation during head-down tilt could be provided by an increase in the electric activity of the thoracic inspiratory muscles. It was established that the contribution of the thoracic inspiratory muscles increased, while the diaphragms’ contribution decreased, during patient, spontaneous breathing. The maximal inspiratory effort (Muller’s maneuver) during a head-down tilt evoked the opposite EMG-activity pattern: the contribution of inspiratory thoracic muscles was decreased and the diaphragm EMG activity was increased compared to the vertical posture. These results suggest that coordinated modulations in inspiratory muscle activity make it possible to preserve the functional reserve of human inspiratory muscles during a short-term head-down tilt.