AND Logic Gates Based on Small Molecules with Chemical Inputs and Luminescence Output

AND logic gate behaviour can be recognized in chemical-responsive luminescence phenomena concerning small molecules. Though initial developments concerned separate and distinguishable chemical species as inputs, consideration of other types of input sets allows substantial expansion of the sub-field. Dissection of these molecular devices into modules, where possible, enables analysis of their logic behaviour according to supramolecular photochemical mechanisms.

IONIC COMPOSITION OF THE LIVER FLUKE FASCIOLA-HEPATICA FROM DIFFERENT MAMMALIAN HOSTS AND COMPARISON WITH HOST BILE

A qualitative analysis of the cationic profile of bovine and ovine biles and of bovine, ovine and rat liver flukes has been carried out by DC are emission spectrography. A quantitative assessment of the concentrations of Na+, K+, Ca2+ and Mg2+ ions in bovine, ovine and rat flukes has been determined by atomic absorption spectrophotometry. The levels of these ions in bovine and ovine bile samples have also been assessed and compared with those of Hedon-Heig saline. The ionic composition of the two biles is similar and the concentration of each ion is greater than that in Hedon-Heig saline. Despite the similarity in biles, ion levels in bovine flukes are generally higher than those in ovine flukes. Ion levels in rat flukes are different again but show closer similarity to those in bovine, not ovine, flukes. The results are discussed in relation to the proposed operation of the osmoregulatory system in the fluke.

Burkholderia cenocepacia disrupts host cell actin cytoskeleton by inactivating Rac and Cdc42

Burkholderia cenocepacia, a member of the Burkholderia cepacia complex, is an opportunistic pathogen that causes devastating infections in patients with cystic fibrosis. The ability of B. cenocepacia to survive within host cells could contribute significantly to its virulence in immunocompromised patients. In this study, we explored the mechanisms that enable B. cenocepacia to survive inside macrophages. We found that B. cenocepacia disrupts the actin cytoskeleton of infected macrophages, drastically altering their morphology. Submembranous actin undergoes depolymerization, leading to cell retraction. The bacteria perturb actin architecture by inactivating Rho family GTPases, particularly Rac1 and Cdc42. GTPase inactivation follows internalization of viable B. cenocepacia and compromises phagocyte function: macropinocytosis and phagocytosis are markedly inhibited, likely impairing the microbicidal and antigen-presenting capability of infected macrophages. The type VI secretion system is essential for the bacteria to elicit these changes. This is the first report demonstrating inactivation of Rho family GTPases by a member of the B. cepacia complex.

Diverse pathogenicity of Burkholderia cepacia complex strains in the Caenorhabditis elegans host model

A fast screening method was developed to assess the pathogenicity of a diverse collection of environmental and clinical Burkholderia cepacia complex isolates in the nematode Caenorhabditis elegans. The method was validated by comparison with the standard slow-killing assay. We observed that the pathogenicity of B. cepacia complex isolates in C. elegans was strain-dependent but species-independent. The wide range of observed pathogenic phenotypes agrees with the high degree of phenotypic variation among species of the B. cepacia complex and suggests that the taxonomic classification of a given strain within the complex cannot predict pathogenicity.