New monodisperse magnetic polymer microspheres biofunctionalized for enzyme catalysis and bioaffinity separations

Magnetic macroporous PGMA and PHEMA microspheres containing carboxyl groups are synthesized by multi-step swelling and polymerization followed by precipitation of iron oxide inside the pores. The microspheres are characterized by SEM, IR spectroscopy, AAS, and zeta-potential measurements. Their functional groups enable bioactive ligands of various sizes and chemical structures to couple covalently. The applicability of these monodisperse magnetic microspheres in biospecific catalysis and bioaffinity separation is confirmed by coupling with the enzyme trypsin and huIgG. Trypsin-modified magnetic PGMA-COOH and PHEMA-COOH microspheres are investigated in terms of their enzyme activity, operational and storage stability. The presence of IgG molecules on microspheres is confirmed.     

Protein kinase A activity at the endoplasmic reticulum surface is responsible for augmentation of human ether-a-go-go-related gene product (HERG)

Human ether-a-go-go-related gene product (HERG) is a cardiac potassium channel commonly implicated in the pathogenesis of the long QT syndrome, type 2 (LQT2). LQT2 mutations typically have incomplete penetrance and affect individuals at various stages of their lives; this may mirror variations in intracellular signaling and HERG regulation. Previous work showed that sustained protein kinase A (PKA) activity augments HERG protein abundance by a mechanism that includes enhanced protein translation. To investigate the subcellular site of this regulation, we generated site-specific probes to the cytoplasmic surface of the endoplasmic reticulum (ER), the presumed locale of channel synthesis. Real-time FRET-based indicators demonstrated both cAMP and PKA activity at the ER. A PKA inhibitor targeted to the ER surface (termed p4PKIg) completely abolished PKA-mediated augmentation of HERG in HEK293 cells as well as rat neonatal cardiomyocytes. Immunofluorescence co-localization, targeted FRET-based PKA biosensors, phospho-specific antibodies, and in vivo phosphorylation experiments confirmed that p4PKIg is preferentially active at the ER surface rather than the plasma membrane. Rerouting this inhibitor to the outer mitochondrial membrane diminishes its ability to block cAMP-dependent HERG induction. Our results support a model where PKA-dependent regulation of HERG synthesis occurs at the ER surface. Furthermore, reagents generated for this study provide novel experimental tools to probe compartmentalized cAMP/PKA signaling within cells.     

Comparison of Chemical Composition in Tuber aestivum Vittad. of Different Geographical Origin

Truffles are prized and nutrition‐rich edible hypogeous fungi. The aim of this study was a comprehensive investigation of chemical composition of Burgundy truffle (Tuber aestivum Vittad .). We tried to answer the question: what is the impact of the environment on the truffle quality. To know the nutritional value of Burgundy truffle we compared lipids, proteins, saccharides, polyphenolics, flavonoids, total sterols, ergosterol, volatile flavour and aroma compounds content in fruit bodies of the fungus collected in three different geographical regions, i.e., Poland, Slovakia, and Italy. A comparison of the above mentioned compounds is especially interesting due to environmental and climatic differences among the studied geographical regions. Results revealed that fruit bodies of T. aestivum from Poland and Slovakia possessed nearly similar content of proteins, total sterols, and saccharides. The fruiting bodies from Italy contained significantly larger amounts of most of the investigated compounds. In turn, Polish specimens had higher content of lipids and polyphenolics than Slovak and Italian ones. We have found higher similarity of volatile compounds composition between Polish and Italian specimens than those of Polish and Slovak origin.     

Oenothein B's contribution to the anti-inflammatory and antioxidant activity of Epilobium sp

Willow herb tea or preparation are available and relatively popular in the European market, and claimed to be effective inter alia because of their anti-inflammatory activity. The present study is therefore aimed at comparing the anti-inflammatory and antioxidant activity of extracts of the three most popular Epilobium species (E. angustifolium, E. hirsutum and E. parviflorum) and at juxtaposing this activity against the dominating compounds from the following extracts: oenothein B (OeB), quercetin-3-O-glucuronide and myricetin-3-O-rhamnoside. The phytochemical analysis of the extracts has shown that OeB quantities vary between 20% and 35%, while flavonoids content does not exceed 2%. All extracts have inhibited the activity of hyaluronidase and lipoxygenase with IC₅₀ around 5 μg/ml and 25 μg/ml. The inhibition of hyaluronidase is related with the presence of OeB, a strong inhibitor of this enzyme (IC₅₀ 1.1 μM). Additionally, the extracts inhibited myeloperoxidase (MPO) release from stimulated neutrophils. OeB inhibited MPO release similarly to the anti-inflammatory drug indomethacin with IC₅₀ 7.7 μM and 15.4 μM, respectively. Tested extracts significantly reduced the production of reactive oxygen species (ROS) from f-MLP and PMA induced neutrophils with IC₅₀ 5 μg/ml and 25 μg/ml, respectively. The flavonoids content seems to exert little influence on extracts’ activity, contrary to OeB, whose high concentration explains the activity of extract obtained from Epilobium. Tested currently marketed Epilobium preparations are often wrongly assigned, but we should stress that the level of OeB in all tested herbs was high and always exceeded 2% in raw material.     

Matrix effects in PIXE analysis of aerosols and ashes

A comparison of instrumental neutron activation analysis (INAA) and proton-induced X-ray emission (PIXE) results for sizefractionated atmospheric aerosols (“coarse” and “fine” fractions with an equivalent aerodynamic diameter of 2–10 Μm and < 2 Μm, respectively, or the PM10 fraction) showed that PIXE yielded significantly lower results for the PM10 and coarse fractions, especially for elements with a low Z resulting from a particle size effect. Somewhat lower PIXE results were also obtained for the fine fraction of atmospheric aerosols. A correction is also needed for irregularly shaped deposits of combustion aerosols collected by a cascade impactor in 11 size fractions ranging from 0.016 to 14.3 Μm, as well as for thick samples of fly and bottom ashes. An equivalent layer thickness (ELT) model is proposed to correct the matrix effects in PIXE. The approaches for the calculation of ELT using a comparison of PIXE and INAA results or by comparing PIXE results obtained using two different incident proton beam energies (1.31 and 2.35 MeV) are described. The correction for the ash pellets and irregular deposits are also discussed.     

Endozoochorous seed dispersal by free-ranging herbivores in an abandoned landscape

Seed dispersal is a crucial process for the dynamics and maintenance of plant populations. Free-ranging animals are effective dispersal vectors because they can move between similar habitats and transport seeds into favourable environments. Dung samples from two species of common free-ranging mammals—deer and wild boar—were used to study endozoochorous dispersal of seeds in a military training area in western Bohemia. The area was abandoned after WWII, and the military training area was established in 1953. The vegetation consists of shrublands and dry grasslands. Data on the local species pool of grassland herbs and forbs were collected to compare the characteristics of dispersed versus non-dispersed plants. Deer and wild boar dispersed 84 plant species; however, species composition of seedlings emerging from dung samples showed significant differences between dispersal vectors and notable change across the growing season. 80% of all seedlings extracted from the dung samples belonged to stinging nettle, Urtica dioica. From trait analyses, seeds of endozoochorous plants had a higher longevity index in the soil seed bank than non-endozoochorous plants and more often possessed a mucilaginous surface. Our results show that deer and boar are successful, though not substitutable dispersers.     

Codiversification of gastrointestinal microbiota and phylogeny in passerines is not explained by ecological divergence

Vertebrate gut microbiota (GM) is comprised of a taxonomically diverse consortium of symbiotic and commensal microorganisms that have a pronounced effect on host physiology, immune system function and health status. Despite much research on interactions between hosts and their GM, the factors affecting inter‐ and intraspecific GM variation in wild populations are still poorly known. We analysed data on faecal microbiota composition in 51 passerine species (319 individuals) using Illumina MiSeq sequencing of bacterial 16S rRNA (V3–V4 variable region). Despite pronounced interindividual variation, GM composition exhibited significant differences at the interspecific level, accounting for approximately 20%–30% of total GM variation. We also observed a significant correlation between GM composition divergence and host's phylogenetic divergence, with strength of correlation higher than that of GM vs. ecological or life history traits and geographic variation. The effect of host's phylogeny on GM composition was significant, even after statistical control for these confounding factors. Hence, our data do not support codiversification of GM and passerine phylogeny solely as a by‐product of their ecological divergence. Furthermore, our findings do not support that GM vs. host's phylogeny codiversification is driven primarily through trans‐generational GM transfer as the GM vs. phylogeny correlation does not increase with higher sequence similarity used when delimiting operational taxonomic units. Instead, we hypothesize that the GM vs. phylogeny correlation may arise as a consequence of interspecific divergence of genes that directly or indirectly modulate composition of GM.