The combined action of microwave radiation and hydrogen peroxide on the viability and ultrastructure of Pseudomonas aeruginosa cells

The comparative study of the action of microwave radiation and hydrogen peroxide, as well as their combined action, on the viability and ultrastructure of P. aeruginosa cells has been made. The combined use of microwave radiation and hydrogen peroxide has been shown to decrease the viability of P. aeruginosa 1.5-2 times in comparison with the isolated action of each factor. The electron microscopic study of the ultrastructure of cells have shown the deterioration of the surface structures, nuclear and ribosomal apparatus of the cells under the isolated action of each of the above-mentioned factors or under their combined action. The morphological picture of these changes has proved to be different. The maximum changes in the ultrastructure of P. aeruginosa cells have been registered after the combined action of these bactericidal factors.     

The Physical Aspects of the Primary Interaction of Therapeutic Ultrasound with Biological Tissue

Biophysics - The biophysical aspects of the effects of ultrasound on biological tissues are considered. A mathematical model that describes the effects of the primary interaction of mechanical...     

Body Size,Growth and Life Span: Implications for the Polewards Range Shift of Octopus tetricus in South-Eastern Australia

Understanding the response of any species to climate change can be challenging. However, in short-lived species the faster turnover of generations may facilitate the examination of responses associated with longer-term environmental change. Octopus tetricus, a commercially important species, has undergone a recent polewards range shift in the coastal waters of south-eastern Australia, thought to be associated with the southerly extension of the warm East Australian Current. At the cooler temperatures of a polewards distribution limit, growth of a species could be slower, potentially leading to a bigger body size and resulting in a slower population turnover, affecting population viability at the extreme of the distribution. Growth rates, body size, and life span of O. tetricus were examined at the leading edge of a polewards range shift in Tasmanian waters (40°S and 147°E) throughout 2011. Octopus tetricus had a relatively small body size and short lifespan of approximately 11 months that, despite cooler temperatures, would allow a high rate of population turnover and may facilitate the population increase necessary for successful establishment in the new extended area of the range. Temperature, food availability and gender appear to influence growth rate. Individuals that hatched during cooler and more productive conditions, but grew during warming conditions, exhibited faster growth rates and reached smaller body sizes than individuals that hatched into warmer waters but grew during cooling conditions. This study suggests that fast growth, small body size and associated rapid population turnover may facilitate the range shift of O. tetricus into Tasmanian waters.     

Exploring the dark genome: implications for precision medicine

Mammalian Genome - The increase in the number of both patients and healthcare practitioners who grew up using the Internet and computers (so-called “digital natives”) is likely to...     

Characteristics of immunomodulating effect of histamine in inbred strain mice]

The activity of 5'-nucleotidase of peritoneal exudate in subcutaneous injection of histamine in a dose of 1.0-100 microliters was studied in mice of different lines (CBA, C57, B1/6, Balb/c, NFS/n, NFR/n). There were interline differences in the influence of histamine on this metabolic index.     

Characterization of the neutral aminopeptidase activity associated to the mouse thymocyte-activating molecule

We previously characterized a dimeric, Mr = 115,000, developmentally regulated mouse T cell-activating molecule (THAM). We show in this report that the THAM-specific mAb H194-112 exhibits strong reactivity with several nonlymphoid tissues including polarized enterocytes from small intestine, kidney cortical tubuli, and liver bile ductuli, as well as kidney glomeruli and lung alveoloar pneumocytes. Both the tissue distribution and the structural features of THAM made it likely that this molecule belongs to the ectoenzyme family. This was confirmed by the following experimental evidence: 1) the H194-112+ molecules from enterocyte brush borders (BB) or M14.T thymoma cells were recognized by several antisera specific for intestinal aminopeptidase N (AP-N); 2) mAb H194-112 was found to immunodeplete the AP-N activity from both thymic or enterocyte BB detergent extracts; 3) the hydrophilic, Mr = 115,000 form obtained by papain treatment of thymoma or enterocyte BB could be immunopurified on H194-112 column and exhibited, after hypotonic elution, strong enzymatic activity on the AP-N substrates (i.e., leucyl or alanyl beta-derivatives); 4) mAb H194-112 was found to inhibit the AP-N activity when assayed on alanyl but not leucyl beta-naphthylamide substrate; and 5) preincubation of AP-N with mAb H194-112 prevented the inhibiting effects of bestatin and D,L-methionyl hydroxamate on AP-N activity. These data add a new member to the list of functional ectoenzymatic markers of lymphoid cells (i.e., CD10, CD13, CD26, CD55, and CD73). In view of the known immunomodulating properties of bestatin, one may speculate that the T cell-activating effects of mAb H194-112 is related to an impairment of a surface enzymatic function regulating lymphoid cell activation.     

Enzymic activity of salivary amylase when bound to the surface of oral streptococci

The enzymatic activity of salivary amylase bound to the surface of several species of oral streptococci was determined by the production of acid from starch and by the degradation of maltotetraose to glucose in a coupled, spectrophotometric assay. Most strains able to bind amylase exhibited functional enzyme on their surface and produced acid from the products of amylolytic degradation. These strains were unable to utilise starch in the absence of salivary amylase. Two strains failed to produce acid from starch, despite the presence of functional salivary amylase, because they could not utilise maltose. Strains that could not bind salivary amylase failed to produce acid from starch. In no case was all the bound salivary amylase active, and two strains of Streptococcus mitis which bound amylase did not exhibit any enzyme activity on their cell surface. The ability to bind amylase may confer a survival advantage on oral bacteria which inhabit hosts that consume diets containing starch.