Synthesis and biological activity of a potent optically pure autoinducer-2 quorum sensing agonist.

Quorum sensing (QS) regulates population-dependent bacterial behaviours, such as toxin production, biofilm formation and virulence. Autoinducer-2 (AI-2) is to date the only signalling molecule known to foster inter-species bacterial communication across distantly related bacterial species. In this work, the synthesis of pure enantiomers of C4-propoxy-HPD and C4-ethoxy-HPD, known AI-2 analogues, has been developed.

Quantum dot and superparamagnetic nanoparticle interaction with pathogenic fungi: internalization and toxicity profile.

For several years now, nanoscaled materials have been implemented in biotechnological applications related to animal (in particular human) cells and related pathologies. However, the use of nanomaterials in plant biology is far less widespread, although their application in this field could lead to the future development of plant biotechnology applications. For any practical use, it is crucial to elucidate the relationship between the nanomaterials and the target cells.

CdSe/ZnS quantum dots trigger DNA repair and antioxidant enzyme systems in Medicago sativa cells in suspension culture.

Background: Nanoparticles appear to be promising devices for application in the agriculture and food industries, but information regarding the response of plants to contact with nano-devices is scarce. Toxic effects may be imposed depending on the type and concentration of nanoparticle as well as time of exposure. A number of mechanisms may underlie the ability of nanoparticles to cause genotoxicity, besides the activation of ROS scavenging mechanisms.

Evaluation of cytotoxicity of 3-mercaptopropionic acid-modified quantum dots on Medicago sativa cells and tissues.

Like most of the new technologies designed to interact with biological systems, the applications of -nanomaterials needs a proper assessment for their potential impacts. It is only through addressing the issues raised by toxicological studies that nanotechnology will be able to acquire its full potential. Here, we describe the detailed protocols to study the responses of plant cells to their exposure to nanoparticles, including viability, oxidative stress detection, and reactive oxygen species enzymatic detoxification, as well as particle uptake.

Synthesis and functionalization of CdSe/ZnS QDs using the successive ion layer adsorption reaction and mercaptopropionic acid phase transfer methods.

Detailed protocols for the preparation of CdSe nanocrystals coated with a multishell structure of ZnS and their surface modification based on the successive ion layer adsorption and reaction method are described. The first phase of the synthesis produces a hydrophobic surface consisting of a TOPO/HDA ligand mixture. This is followed by a surface modification of the quantum dots (QDs) with 3-mercaptopropionic acid by the phase transfer method.

The impact of CdSe/ZnS Quantum Dots in cells of Medicago sativa in suspension culture.

Background: Nanotechnology has the potential to provide agriculture with new tools that may be used in the rapid detection and molecular treatment of diseases and enhancement of plant ability to absorb nutrients, among others. Data on nanoparticle toxicity in plants is largely heterogeneous with a diversity of physicochemical parameters reported, which difficult generalizations. Here a cell biology approach was used to evaluate the impact of Quantum Dots (QDs) nanocrystals on plant cells, including their effect on cell growth, cell viability, oxidative stress and ROS accumulation, besides their cytomobility.

Losartan attenuates the antimigratory effect of diclofenac in spontaneously hypertensive rats.

Many patients with hypertension, particularly elderly patients, take nonsteroidal antiinflammatory drugs (NSAIDs) and antihypertensive agents. However, few studies describe the effect of the association of antihypertensive agents with NSAIDs on inflammatory response in hypertension. To investigate this, spontaneously hypertensive rats (SHRs) were treated with either diclofenac alone or diclofenac combined with losartan (an AT1 angiotensin II antagonist).

Enalapril interferes with the effect of diclofenac on leucocyte-endothelium interaction in hypertensive rats.

Nonsteroidal anti-inflammatory drugs are known to attenuate the effects of some antihypertensive agents. However, the effect these drugs have on leukocyte migration when combined with antihypertensive agents has not been studied. To investigate this effect, we treated spontaneously hypertensive rats with saline, diclofenac, enalapril, or diclofenac combined with enalapril and observed leukocyte-endothelium interaction.