Effect of asiatic and ursolic acids on morphology, hydrophobicity, and adhesion of UPECs to uroepithelial cells

Adhesion of bacteria to epithelial tissue is an essential step in the progression of the urinary tract infections. Reduction of virulence factors responsible for microbial attachment may help to decrease or inhibit colonization of the host organism by pathogens. In the age of increasing bacterial antibiotic resistance, more and more attention is being paid to the use of plants and/or their bioactive components in the prevention and treatment of human infections. Asiatic acid (AA) and ursolic acid (UA), two plant secondary metabolites, were used as potential antibacterial agents. The current study aimed to determine the possible impact of AA and UA on morphology, hydrophobicity, and adhesion of clinical uropathogenic Escherichia coli strains (UPEC) to the uroepithelial cells. Our work describes for the first time the effects exerted by AA and UA on virulence factors of UPECs. The impact of both acids on the cell surface hydrophobicity of the investigated strains was very weak. The results clearly show the influence of AA and UA on the presence of P fimbriae and curli fibers, morphology of the UPECs cells and their adhesion to epithelium; however, some differences between activities of AA and UA were found.     

Different haplotypes for cystic fibrosis-linked DNA polymorphisms in Polish and Dutch populations

Summary We analyzed DNA from 34 Polish and 63 Dutch cystic fibrosis (CF) patients and their families using the polymorphic markers XV2c and KM19, which are in linkage disequilibrium with the CF mutation. Strong linkage disequilibrium was found in the Dutch population sample, but the haplotypes of the Polish chromosomes showed a significantly less extreme disequilibrium. Our data and previous studies indicate that the highest degree of homogeneity of the CF defect and hence the best possible use of the XV2c/KM19/CF linkage disequilibrium for CF carrier detection/exclusion is in populations of northern European origin.     

A new single nucleotide polymorphism in the rabbit (Oryctolagus cuniculus) myostatin (MSTN) gene is associated with carcass composition traits

This study aimed at the identification of genetic variations in the myostatin (MSTN) gene and testing their effects on carcass quality traits. We comparatively sequenced Giant Grey (GG) and New Zealand White (NZW) rabbits that were founders of a cross‐bred population. Alignment of our sequence data with the GenBank sequence of the rabbit MSTN gene (Ensembl Gene ID ENSOCUG00000012663) identified three single nucleotide polymorphisms (SNPs). The two novel SNPs (c.?125T>C, c.373+234G>A) and one known SNP (c.747+34C>T) were subsequently analysed for linkage with carcass composition traits in 363 F₂ animals of the cross GG × NZW. Significant linkage was found between c.373+234G>A and nine carcass composition traits (P < 0.05). No significant effects were found for c.?125T>C and c.747+34C>T. Because the linked SNP is located in intron 1 and no genetic variation was found in the coding region, further investigations are necessary to understand the functional effect of the c.373+234G>A variant on the variability of the traits.     

Revealing Sulfate-Reducing Microorganisms in Oilfield Waters (Flysch Carpathians,South-eastern Poland)

Sulphidogenous microorganism communities were isolated from selected oilfield waters in the Flysch Carpathians of south-eastern Poland. Organisms were incubated using the microcosms method with application of two media: minimal medium and modified Postgate C medium with yeast extract or trisodium citrate or monocyclic hydrocarbons from the BTEX group (benzene, toluene, ethylbenzene, and xylene) as the sole carbon source. Activity of sulphidogenic, autochthonous microorganism communities was noted only on the Postgate medium. Beside active sulphate reduction – max. 70%, ca. 74% biodegradation of organic compounds was also observed in the cultures. The highest content of sulphate-reducing bacteria (SRB) in the COD (ca. 83%) was noted in cultures, in which trisodium citrate and yeast extract were applied as the sole carbon source. Molecular analysis indicated not only the presence of SRB such as Desulfobacterium autothrophicum, Desulfovibrio desulfuricans, but also other microorganisms, e.g., Geobacter metallireducens. All these taxa are obligatory or facultative anaerobes, with metabolism linked mostly with elemental sulphur and/or its oxidized forms, as well as iron. Analysis of the mineral composition of the residues confirmed the presence of elemental sulphur, testifying for the active reduction of sulphates by incompletely oxidizing sulphate reducers assigned to the SRB group. Based on the obtained results, it is concluded that the physical and chemical properties of the oilfield waters are favorable for the growth and development of sulphidogenic microorganism assemblages and mineral-forming processes conducted by them.     

EPR Oximetry Sensor—Developing a TAM Derivative for In Vivo Studies

Oxygenation is one of the most important physiological parameters of biological systems. Low oxygen concentration (hypoxia) is associated with various pathophysiological processes in different organs. Hypoxia is of special importance in tumor therapy, causing poor response to treatment. Triaryl methyl (TAM) derivative radicals are commonly used in electron paramagnetic resonance (EPR) as sensors for quantitative spatial tissue oxygen mapping. They are also known as magnetic resonance imaging (MRI) contrast agents and fluorescence imaging compounds. We report the properties of the TAM radical tris(2,3,5,6-tetrachloro-4-carboxy-phenyl)methyl, (PTMTC), a potential multimodal (EPR/fluorescence) marker. PTMTC was spectrally analyzed using EPR and characterized by estimation of its sensitivity to the oxygen in liquid environment suitable for intravenous injection (1?mM PBS, pH?=?7.4). Further, fluorescent emission of the radical was measured using the same solvent and its quantum yield was estimated. An in vitro cytotoxicity examination was conducted in two cancer cell lines, HT-29 (colorectal adenocarcinoma) and FaDu (squamous cell carcinoma) and followed by uptake studies. The stability of the radical in different solutions (PBS pH?=?7.4, cell media used for HT-29 and FaDu cells culturing and cytotoxicity procedure, full rat blood and blood plasma) was determined. Finally, a primary toxicity test of PTMTC was carried out in mice. Results of spectral studies confirmed the multimodal properties of PTMTC. PTMTC was demonstrated to be not absorbed by cancer cells and did not interfere with luciferin-luciferase based assays. Also in vitro and in vivo tests showed that it was non-toxic and can be freely administrated till doses of 250?mg/kg BW via both i.v. and i.p. injections. This work illustrated that PTMTC is a perfect candidate for multimodal (EPR/fluorescence) contrast agent in preclinical studies.     

The optimality of the standard genetic code assessed by an eight-objective evolutionary algorithm

Background

The standard genetic code (SGC) is a unique set of rules which assign amino acids to codons. Similar amino acids tend to have similar codons indicating that the code evolved to minimize the costs of amino acid replacements in proteins, caused by mutations or translational errors. However, if such optimization in fact occurred, many different properties of amino acids must have been taken into account during the code evolution. Therefore, this problem can be reformulated as a multi-objective optimization task, in which the selection constraints are represented by measures based on various amino acid properties.

Results

To study the optimality of the SGC we applied a multi-objective evolutionary algorithm and we used the representatives of eight clusters, which grouped over 500 indices describing various physicochemical properties of amino acids. Thanks to that we avoided an arbitrary choice of amino acid features as optimization criteria. As a consequence, we were able to conduct a more general study on the properties of the SGC than the ones presented so far in other papers on this topic. We considered two models of the genetic code, one preserving the characteristic codon blocks structure of the SGC and the other without this restriction. The results revealed that the SGC could be significantly improved in terms of error minimization, hereby it is not fully optimized. Its structure differs significantly from the structure of the codes optimized to minimize the costs of amino acid replacements. On the other hand, using newly defined quality measures that placed the SGC in the global space of theoretical genetic codes, we showed that the SGC is definitely closer to the codes that minimize the costs of amino acids replacements than those maximizing them.

Conclusions

The standard genetic code represents most likely only partially optimized systems, which emerged under the influence of many different factors. Our findings can be useful to researchers involved in modifying the genetic code of the living organisms and designing artificial ones.