Characteristics of Transfer RNA-Derived Fragments Expressed during Human Renal Cell Development: The Role of Dicer in tRF Biogenesis

tRNA-derived fragments participate in the regulation of many processes, such as gene silencing, splicing and translation in many organisms, ranging from bacteria to humans. We were interested to know how tRF abundance changes during the different stages of renal cell development. The research model used here consisted of the following human renal cells: hESCs, HEK-293T, HK-2 and A-489 kidney tumor cells, which, together, mimic the different stages of kidney development. The characteristics of the most abundant tRFs, tRFGly(CCC), tRFVal(AAC) and tRFArg(CCU), were presented. It was found that these parental tRNAs present in cells are the source of many tRFs, thus increasing the pool of potential regulatory RNAs. Indeed, a bioinformatic analysis showed the possibility that tRFGly(CCC) and tRRFVal(AAC) could regulate the activity of a range of kidney proteins. Moreover, the distribution of tRFs and the efficiency of their expression is similar in adult and embryonic stem cells. During the formation of tRFs, HK-2 cells resemble A-498 cancer cells more than other cells. Additionally, we postulate the involvement of Dicer nuclease in the formation of tRF-5b in all the analyzed tRNAs. To confirm this, 293T NoDice cells, which in the absence of Dicer activity do not generate tRF-5b, were used.     

Underestimated Properties of Nanosized Amorphous Titanium Dioxide

Titanium dioxide is one of the best described photosensitive materials used in photocatalysis, solar cells, self-cleaning coatings, and sunscreens. The scientific and industrial attention has been focused on the highly photoactive crystalline phase of titanium dioxide (TiO₂). It is commonly accepted that the smaller TiO₂ particles, the higher photoactivity they present. Therefore, titanium dioxide nanoparticles are massively produced and widely used in everyday products. The amorphous phase of titanium dioxide has been treated with neglect, as the lack of its photocatalytic properties is assumed in advance. In this work, the complex experimental proof of the UV-protective properties of the nano-sized amorphous TiO₂ phase is reported. Amorphous n-TiO₂ is characterized by photocatalytic inactivity and, as a consequence, low cytotoxicity to fibroblast cells. When exposed to UV radiation, cells with amorphous TiO₂ better survive under stress conditions. Thus, we postulate that amorphous n-TiO₂ will be more beneficial and completely safe for cosmetic applications. Moreover, the results from in situ FTIR studies let us correlate the low toxicity of amorphous samples with low ability to form hydroperoxo surface species.     

Effect of menadione (vitamin K3) addition on lipid oxidation and tocopherols content in plant oils

The effect of added menadione (vitamin K3) on stored corn and wheat germ oil on the dissolution and dimerization of natural tocopherols and autoxidation of triacylglycerols was investigated. Samples of corn and wheat germ oils pure and with added menadione were stored at +20 degrees C in brown and transparent glass bottles. During storage their peroxide value, changes of the content of fatty acids and dissolution of tocopherols were measured. Destruction of individual tocopherols in tested oils with menadione stored in both dark and transparent glass bottles was greater than in the oil samples without menadione. However, the degradation of individual tocopherols was different in each oil. Addition of menadione to the both oils resulted in accelerated the process of autoxidation of these oils. The corn oil stored in transparent bottles was oxidized faster than the one stored in brown bottles. The pro-oxidant activity of menadione was additionally activated by light. In contrast, in the case of germ oil, the process of autoxidation was very fast regardless of sort of container. Addition of menadione to the plant oils influenced the dissolution of natural tocopherols but did not influence the dimerization of tocopherols. As from the experiment, the addition of menadione to the oils decreased their nutritive value.     

Effect of artichoke extract (Cynara scolymus L.) on palmitic-1-14C acid oxidation in rats

Studies on the effect of the artichoke extract (AE) on oxidation of palmitic-1-14C acid administered intravenously to rats at a dose 25 and 50 mg/kg bw demonstrated marked enhancement of both 14CO2 expiration rate and 14CO2 recovery in the expired air. The extract suppressed accumulation of palmitic-1-14C acid in serum lipids and epididymal fat pad tissue as well. The effects of the extract on 14CO2 expiration rate, 14CO2 recovery, as well as accumulation of palmitic-1-14C acid were dose dependent. Total14CO2 recovery in expired air during 60 min was elevated by 17.3% (p < 0.05) and 52.1% (p < 0.001) in rats administered the extract at a dose of 25 and 50 mg/kg, respectively. The rats supplemented with the AE at a dose of 25 and 50 mg/kg bw were characterized by 10.0% (not significant) and 19% (p < 0.05) decrease in( 14)C radioactivity of serum lipids as well as reduction of epididymal fat tissue 14C radioactivity by 8.7 and 17.5% (p < 0.05), respectively, in comparison with the control rats. Thus, the results demonstrate that the AE possess stimulatory properties with respect to oxidation of palmitic acid administered to rats, and provide new information on the mechanism of antilipemic activity of the extract associated with activation of lipid oxidation in the organism.     

Evaluation of the use of fibrin and microcrystalline chitosan membranes as carriers for transforming growth factor beta‐1

The aim of this study was to describe the mechanical features of homogeneous and layered chitosan (Ch) and fibrin–chitosan (Fb–Ch) membranes as well the kinetics of transforming growth factor beta‐1 (TGF‐β1) release from five types of polymer carriers. Composites in the form of a film containing physiologically clotted fibrin (Fb) and microcrystalline chitosan (MCCh) were prepared and then crosslinked with calcium chloride. The films were characterized by Infrared (IR) spectroscopy, mechanical tests (film thickness, maximal tensile force, breaking strength, and elongation at break), and SEM images. The results reveal that Ch film demonstrates higher efficiency in binding TGF‐β1 and, at the same time, is less effective in its release—1.25% of the total amount between 6 h and 14 days. However, the Fb membrane binds TGF‐β1 not as strongly, which leads to more effective release of the compound—25% after 6 h and 28.98% of the total amount after 14 days. The factor TGF‐β1 is released in vitro from Fb–Ch membranes with different kinetics. The most efficient release of TGF‐β1 was observed in the case of the layered Fb–Ch (M4 L) membrane (after 14 days it reached a maximal value of 14.08% of the total amount). The release was lower with increasing Ch concentrations in the film, suggesting a high affinity of TGF‐β1 with the Fb–Ch component. The Fb–Ch membrane with incorporated TGF‐β1 may prove to be a very useful scaffold in the tissue regeneration process. This study demonstrates that Fb and MCCh gels could be used as carrier matrices for the controlled release of bioactive TGF‐β1. It was found that the degree of TGF‐β1 release from the membrane is influenced by the physiochemical and mechanical characteristics of the films and by its affinity to growth factor TGF‐β1. © 2012 Wiley Periodicals, Inc. J. Appl. Polym. Sci., 2013     

Detection of Penicillium expansum by polymerase chain reaction

Penicillium expansum is a major causative agent of postharvest decay in a variety of fruits, including apples, peaches, nectarines, and cherries. It causes significant economic losses to the fruit industry and is also of potential public health significance, since it produces patulin, a mycotoxin known to cause harmful effects in animals. Rapid and specific detection of P. expansum is important for ensuring microbiological quality and safety of fruits and fruit juices. The traditional methods for identification of P. expansum are time-consuming and labor-intensive. In this study, we report a polymerase chain reaction utilizing primers based on the polygalacturonase gene of P. expansum. The PCR amplified a 404-bp DNA product from all the P. expansum isolates tested, but not in other common foodborne Penicillium species and Escherichia coli. Experiments to determine the sensitivity of the PCR indicated that it can detect the DNA equivalent from as low as 25 spores of P. expansum. The PCR could potentially be used as a rapid tool for screening fruits for the presence of P. expansum.     

Evaluation of bioactive compounds content and antioxidant properties of soil‐growing and wood‐growing edible mushrooms

The aim of the study was to estimate the content of the macroelements (Ca, K, Mg, Na), ergosterol, ascorbic acid, and the profile of phenolic compounds in seventeen wild growing edible mushrooms from Poland. Mean content of Ca, K, Mg, Na in wood‐growing mushrooms was 315, 12,402, 597, and 130 mg/kg DM. Soil‐growing species contained 246, 15,586, 531, and 114 mg/kg DM, respectively. The highest total phenolic and flavonoid contents were confirmed for Leccinum scabrum (9.24 and 0.77 mg/g DM). The highest content of ascorbic acid was indicated in Calvatia gigantea (108.11 mg/kg DM). The richest in phenolic compounds were Lepista gilva and L. scabrum. The soil‐growing mushrooms possessed a better scavenging activity in comparison to wood‐growing varieties, with L. scabrum as the species with the greatest antioxidant properties. EC₅₀ value was correlated with total phenolic and flavonoid contents. The content of ergosterol reached 0.540 mg/g DM for Laetiporus sulphureus.

Practical applications

Consumers appreciate wild edible mushrooms mainly because of the taste and aroma. This research on both popular and rare edible wild growing mushrooms shows that they are a good source of bioactive compounds including macroelements, phenolics, and ergosterol. This knowledge influences consumers' awareness by enabling them to better match the products of the daily diet, which in consequence can improve well‐being and health quality. The results are also valuable for other applications of mushrooms, for example, as extracts or other forms of supplements.     

Integrating Ground-based Observations and Radar Data Into Gridding Sub-daily Precipitation

A new and general approach is proposed for interpolating 6-h precipitation series over large spatial areas. The outputs are useful for distributed hydrological modelling and studies of flooding. We apply our approach to large-scale data, measured between 2014 and 2016 at 159 weather stations network of Meteo Romania, using weather radar information and local topography as ancillary data. Novelty of our approach is in systematic development of a statistical model underlying the interpolation. Seven methods have been tested for the interpolation of the 6-h precipitation measurements: four regression methods (linear regression via ordinary least squares (OLS), with and without logarithmic transformation, and two models of generalized additive model (GAM) class, with logarithmic and identity links), and three regression-kriging models (one uses semivariogram fitted separately every 6-h, based on the residuals of the GAM with identity links models, and other two with pooled semivariograms, based on the OLS and GAM with identity links models). The prediction accuracy of the spatial interpolation methods was evaluated on a part of the dataset not used in the model-fitting stage. Due to the good results in interpolating sub-daily precipitation, normal general additive model with identity link followed with kriging of residuals with kriging parameters estimated from pooled semivariograms was applied to construct the final 6-h precipitation maps (PRK-NGAM). The final results of this work are the 6-h precipitation gridded datasets available in high spatial resolution (1000 m?×?1000 m), together with their estimated accuracy.

     

Ultralow fouling and functionalizable surface chemistry based on a zwitterionic polymer enabling sensitive and specific protein detection in undiluted blood plasma

A crucial step in the development of implanted medical devices, in vivo diagnostics, and microarrays is the effective prevention of nonspecific protein adsorption from real-world complex media such as blood plasma or serum. In this work, a zwitterionic poly(carboxybetaine acrylamide) (polyCBAA) biomimetic material was employed to create a unique biorecognition coating with an ultralow fouling background, enabling the sensitive and specific detection of proteins in blood plasma. Conditions for surface activation, protein immobilization, and surface deactivation of the carboxylate groups in the polyCBAA coating were determined. An antibody-functionalized polyCBAA surface platform was used to detect a target protein in blood plasma using a sensitive surface plasmon resonance (SPR) sensor. A selective protein was directly detected from 100% human blood plasma with extraordinary specificity and sensitivity. The total nonspecific protein adsorption on the functionalized polyCBAA surface was very low (<3 ng/cm (2) for undiluted blood plasma). Because of the significant reduction of nonspecific protein adsorption, it was possible to monitor the kinetics of antigen-antibody interactions in undiluted blood plasma. The functionalization effectiveness and detection characteristics using a cancer protein marker candidate of polyCBAA were compared with those of the conventional nonfouling oligo(ethylene glycol)-based surface chemistry.     

<Emphasis Type="Italic">In vivo</Emphasis> evaluation of riboflavin receptor targeted fluorescent USPIO in mice with prostate cancer xenografts

Riboflavin (Rf) receptors bind and translocate Rf and its phosphorylated forms (e.g. flavin mononucleotide, FMN) into cells where they mediate various cellular metabolic pathways. Previously, we showed that FMN-coated ultrasmall superparamagnetic iron oxide (FLUSPIO) nanoparticles are suitable for labeling metabolically active cancer and endothelial cells in vitro. In this study, we focused on the in vivo application of FLUSPIO using prostate cancer xenografts. Size, charge, and chemical composition of FLUSPIO were evaluated. We explored the in vitro specificity of FLUSPIO for its cellular receptors using magnetic resonance imaging (MRI) and Prussian blue staining. Competitive binding experiments were performed in vivo by injecting free FMN in excess. Bio-distribution of FLUSPIO was determined by estimating iron content in organs and tumors using a colorimetric assay. AFM analysis and zeta potential measurements revealed a particulate morphology approximately 20–40 nm in size and a negative zeta potential (–24.23 ± 0.15 mV) in water. X-ray photoelectron spectroscopy and time-of-flight secondary ion mass spectrometry data confirmed FMN present on the USPIO nanoparticle surface. FLUSPIO uptake in prostate cancer cells and human umbilical vein endothelial cells was significantly higher than that of control USPIO, while addition of excess of free FMN reduced accumulation. Similarly, in vivo MRI and histology showed specific FLUSPIO uptake by prostate cancer cells, tumor endothelial cells, and tumor-associated macrophages. Besides prominent tumor accumulation, FLUSPIO accumulated in the liver, spleen, lung, and skin. Hence, our data strengthen our hypothesis that targeting riboflavin receptors is an efficient approach to accumulate nanomedicines in tumors opening perspectives for the development of diagnostic and therapeutic systems.