Experimental Testing of an Approach to Establishing Combined Toxicity of Ternary Nanoparticle Mixtures

Our studies of exposure to binary mixtures of nanoparticles (TiO₂ + SiO₂; TiO₂ + Al₂O₃ and SiO₂ + Al₂O₃) based on mathematical modelling show that their combined subchronic toxicity can either be of an additive type or deviate from it depending on the outcome, dose ratio, and levels of effect. To characterize the type of toxicity of ternary mixtures of nanoparticles, we successfully tested a previously developed approach for assessing the combined toxicity of metal ions. In this approach, the effects are classified by a null, positive, or negative change in the toxicity of binary nanoparticle mixtures when modeled against the toxicity of the third agent added.     

Purification of tall oil fatty acids by removing of stilbenes

European Journal of Wood and Wood Products - The composition of tall oil fatty acids includes rosin acids and unsaponifiable substances as impurities. The latter include stilbenes. The total...     

Genetic Deletion of Trace-Amine Associated Receptor 9 (TAAR9) in Rats Leads to Decreased Blood Cholesterol Levels

In the last two decades, interest has grown significantly in the investigation of the role of trace amines and their receptors in mammalian physiology and pathology. Trace amine-associated receptor 9 (TAAR9) is one of the least studied members of this receptor family with unidentified endogenous ligands and an unknown role in the central nervous system and periphery. In this study, we generated two new TAAR9 knockout (TAAR9-KO) rat strains by CRISPR-Cas9 technology as in vivo models to evaluate the role of TAAR9 in mammalian physiology. In these mutant rats, we performed a comparative analysis of a number of hematological and biochemical parameters in the blood. Particularly, we carried out a complete blood count, erythrocyte osmotic fragility test, and screening of a panel of basic biochemical parameters. No significant alterations in any of the hematological and most biochemical parameters were found between mutant and WT rats. However, biochemical studies revealed a significant decrease in total and low-density lipoprotein cholesterol levels in the blood of both strains of TAAR9-KO rats. Such role of TAAR9 in cholesterol regulation not only brings a new understanding of mechanisms and biological pathways of lipid exchange but also provides a new potential drug target for disorders involving cholesterol-related pathology, such as atherosclerosis.     

Genetic diversity of the human pathogen Vibrio vulnificus: a new phylogroup

The biotype 3 group of the human pathogen Vibrio vulnificus emerged in Israel probably as a result of genome hybridization of two bacterial populations. We performed a genomic and phylogenetic study of V. vulnificus strains isolated from the environmental niche from which this group emerged — fish aquaculture in Israel. The genetic relationships and evolutionary aspects of 188 environmental and clinical isolates of the bacterium were studied by genomic typing. Genetic relations were determined based on variation at 12 variable number tandem repeat (VNTR, also termed SSR) loci. Analysis revealed a new cluster, in addition to the main groups of biotype 1& 2 and biotype 3. Similar grouping results were obtained with three different statistical approaches. Isolates forming this new cluster presented unclear biochemical profile nevertheless were not identified as biotype 1 or biotype 3. Further examination of representative strains by multilocus sequence typing (MLST) of 10 housekeeping genes and 5 conserved hypothetical genes supported the identification of this as yet undiscovered phylogroup (phenotypically diverse), termed clade A herein. This new clonal subgroup includes environmental as well as clinical isolates. The results highlight the fish aquaculture environment, and possibly man-made ecological niches as a whole, as a source for the emergence of new pathogenic strains.     

Development of xMAP Assay for Detection of Six Protein Toxins

xMAP technology was used for simultaneous identification of six protein toxins (staphylococcal enterotoxins A and B, cholera toxin, ricin, botulinum toxin A, and heat labile toxin of E. coli). Monoclonal antibody-conjugated xMAP microspheres and biotinilated monoclonal antibodies were used to detect the toxins in a sandwich immunoassay format. The detection limits were found to be 0.01 ng/mL for staphylococcal enterotoxin A, cholera toxin, botulinum toxin A, and ricin in model buffer (PBS-BSA) and 0.1 ng/mL for staphylococcal enterotoxin B and LT. In a complex matrix, such as cow milk, the limits of detection for staphylococcal enterotoxins A and B, cholera toxin, botulinum toxin A, and ricin increased 2- to 5-fold, while for LT the detection limit increased 30-fold in comparison with the same analysis in PBS-BSA. In the both PBS-BSA and milk samples, the xMAP test system was 3-200 times (depending on the toxin) more sensitive than ELISA systems with the same pairs of monoclonal antibodies used. The time required for a simultaneous analysis of six toxins using the xMAP system did not exceed the time required for ELISA to analyze one toxin. In the future, the assay may be used in clinical diagnostics and for food and environmental monitoring.