Eggshell appearance does not signal maternal corticosterone exposure in Japanese quail:an experimental study with brown-spotted eggs

Reproduction is a critical period for birds as they have to cope with many stressful events. One consequence of an acute exposure to stress is the release of corticosterone, the avian stress hormone. Prolonged stress can have negative impacts on the immune system, resulting in, for example, increased oxidative stress. Through maternal effects, females are known to modulate their investment in eggs content according to their own physiological condition. Less is known about maternal investment in eggshells, especially in pigments. The two main eggshell pigments may possess opposite antioxidant properties: protoporphyrin (brown) is a pro-oxidant, whereas biliverdin (blue-green) is an antioxidant. In Japanese quail, we know that the deposition of both pigments is related to female body condition. Thus, a chronic stress response may be reflected in eggshell coloration. Using female Japanese quails that lay brown-spotted eggs, we explored whether physiological exposure to corticosterone induces a change in female basal stress and antioxidant factors, and eggshell pigment concentration, spectrophotometric reflectance, and maculation coverage. We supplemented adult females over a 2 week period with either peanut oil (control) or corticosterone (treatment). We collected pre- and post-supplementation eggs and analysed the effect of corticosterone treatment on female physiology and eggshell appearance parameters. Except for corticosterone-fed birds which laid eggs with brighter spots, supplementation had no significant effect on female physiology or eggshell pigment concentration, reflectance and maculation. The change in eggshell spot brightness was not detected by a photoreceptor noise-limited color opponent model of avian visual perception. Our data confirms that eggshell reflectance in spotted eggs varies over the laying sequence, and spot reflectance may be a key factor that is affected by females CORT exposure, even if the changes are not detected by an avian visual model

Mono-\u3cem\u3eN\u3c/em\u3e-acyl-2,6-diaminopimelic Acid Derivatives: Analysis by Electromigration and Spectroscopic Methods and Examination of Enzyme Inhibitory Activity

Thirteen mono-N-acyl derivatives of 2,6-diaminopimelic acid (DAP)—new potential inhibitors of the dapE-encoded N-succinyl-l,l-diaminopimelic acid desuccinylase (DapE; EC 3.5.1.18)—were analyzed and characterized by infrared (IR) and nuclear magnetic resonance (NMR) spectroscopies and two capillary electromigration methods: capillary zone electrophoresis (CZE) and micellar electrokinetic chromatography (MEKC). Structural features of DAP derivatives were characterized by IR and NMR spectroscopies, whereas CZE and MEKC were applied to evaluate their purity and to investigate their electromigration properties. Effective electrophoretic mobilities of these compounds were determined by CZE in acidic and alkaline background electrolytes (BGEs) and by MEKC in acidic and alkaline BGEs containing a pseudostationary phase of anionic detergent sodium dodecyl sulfate (SDS) or cationic detergent cetyltrimethylammonium bromide (CTAB). The best separation of DAP derivatives, including diastereomers of some of them, was achieved by MEKC in an acidic BGE (500 mM acetic acid [pH 2.54] and 60 mM SDS). All DAP derivatives were examined for their ability to inhibit catalytic activity of DapE from Haemophilus influenzae (HiDapE) and ArgE from Escherichia coli (EcArgE). None of these DAP derivatives worked as an effective inhibitor of HiDapE, but one derivative—N-fumaryl, Me-ester-DAP—was found to be a moderate inhibitor of EcArgE, thereby providing a promising lead structure for further studies on ArgE inhibitors

Eggshell pigment composition covaries with phylogeny but not with life history or with nesting ecology traits of British passerines

No single hypothesis is likely to explain the diversity in eggshell coloration and patterning across birds, suggesting that eggshell appearance is most likely to have evolved to fulfill many nonexclusive functions. By controlling for nonindependent phylogenetic associations between related species, we describe this diversity using museum eggshells of 71 British breeding passerine species to examine how eggshell pigment composition and concentrations vary with phylogeny and with life-history and nesting ecology traits. Across species, concentrations of biliverdin and protoporphyrin, the two main pigments found in eggshells, were strongly and positively correlated, and both pigments strongly covaried with phylogenetic relatedness. Controlling for phylogeny, cavity-nesting species laid eggs with lower protoporphyrin concentrations in the shell, while higher biliverdin concentrations were associated with thicker eggshells for species of all nest types. Overall, these relationships between eggshell pigment concentrations and the biology of passerines are similar to those previously found in nonpasserine eggs, and imply that phylogenetic dependence must be considered across the class in further explanations of the functional significance of avian eggshell coloration

Social defeat stimulates local glucocorticoid regeneration in lymphoid organs

Stress is an important risk factors for human diseases. It activates the hypothalamic–pituitary–adrenal (HPA) axis and increases plasma glucocorticoids, which are powerful regulators of immune system. The response of the target cells to glucocorticoids depends not only on the plasma concentrations of cortisol and corticosterone but also on their local metabolism. This metabolism is catalyzed by 11β-hydroxysteroid dehydrogenases type 1 and 2, which interconvert glucocorticoid hormones cortisol and corticosterone and their 11-oxo metabolites cortisone and 11-dehydrocorticosterone. The goal of this study was to determine whether stress modulates glucocorticoid metabolism within lymphoid organs – the structures where immune cells undergo development and activation. Using the resident-intruder paradigm, we studied the effect of social stress on glucocorticoid metabolism in primary and secondary lymphoid organs of Fisher 344 (F344) and Lewis (LEW) rats, which exhibit marked differences in their HPA axis response to social stressors and inflammation. We show that repeated social defeat increased the regeneration of corticosterone from 11-dehydrocorticosterone in the thymus, spleen and mesenteric lymphatic nodes (MLN). Compared with the F344 strain, LEW rats showed higher corticosterone regeneration in splenocytes of unstressed rats and in thymic and MLN mobile cells after stress but corticosterone regeneration in the stroma of all lymphoid organs was similar in both strains. Inactivation of corticosterone to 11-dehydrocorticosterone was found only in the stroma of lymphoid organs but not in mobile lymphoid cells and was not upregulated by stress. Together, our findings demonstrate the tissue- and strain-dependent regeneration of glucocorticoids following social stress

Spojení CE-MS pro anaýzu peptidů a bílkovin

The review is focused on the latest developments in the analysis of proteins and peptides by capillary electrophoresis techniques coupled to mass spectrometry. First, the methodology and instrumentation are overviewed. In this section, recent progress in capillary electrophoresis with mass spectrometry interfaces and capillary electrophoresis with matrix-assisted laser desorption/ionization is mentioned, as well as separation tasks. The second part is devoted to applications-mainly bottom-up and top-down proteomics. It is obvious that capillary electrophoresis with mass spectrometry methods are well suited for peptide and protein analysis (proteomic research) and it is described how these techniques are complementary and not competitive with the often used liquid chromatography with mass spectrometry methods.Toto review je zaměřeno na nejnovější vývoj v analýze bílkovin a peptidů kapilární elektroforézou spojenou s hmotnostní spektrometrií. Nejprve je uveden přehled metodologie a instrumentace. V této části je zmíněn pokrok v oblastech kapilární elektroforéza s hmotnostní spektrometrií a kapilární elektroforéza s desorpcí / ionizací laserem za účasti matrice, stejně tak jako v oblasti separace uvedených látek. Druhá část je věnována aplikacím - především „bottom-up“ a „top-down“ proteomice. Je zřejmé, že kapilární elektroforéza s metodami hmotnostní spektrometrie je vhodná pro analýzu peptidů a bílkovin (proteomický výzkum) a je popsáno, jak jsou tyto techniky komplementární a nekompetitivní s často využívanou kapalinovou chromatografií s metodami hmotnostní spektrometrie

Chromatografické a elektromigrační metody v analýze fyziologicky významných látek

Práce shrnuje výsledky studia organických sloučenin s fyziologickými účinky s ohledem na jejich analýzu chromatografickými a elektromigračními metodami.Dokončená práce s úspěšnou obhajobo

Úloha separačních postupů v analýze fyziologicky významných komponent

Práce je věnována moderním analytickým metodám, které analyzují fyziologicky látky, s kterými přijde organismus do kontaktu a které s organismem nějakým způsobem interagují.Katedra analytické chemieDokončená práce s úspěšnou obhajobo

Open-tubular capillary electrochromatography with bare gold nanoparticles-based stationary phase applied to separation of trypsin digested proteins

Open-tubular capillary electrochromatography (OT-CEC) using bare gold nanoparticles-based stationary phase has been applied to separation of tryptic peptide fragments of native and glycated proteins, bovine serum albumin and human transferrin. OT-CEC with bare gold nanoparticles stationary phase was found to be a suitable technique for separation of complex peptide mixtures originating from enzymatic (tryptic) digestion of native and glycated bovine serum albumin and human transferrin, and for glycation studies of these proteins

Nové poznatky v oblasti chirálních separací bílkovin a peptidů

Like many biological compounds, proteins are found primarily in their homochiral form. However, homochirality is not guaranteed throughout life. Determining their chiral proteinogenic sequence is a complex analytical challenge. This is because certain D-amino acids contained in proteins play a role in human health and disease. This is the case, for example, with D-Asp in elastin, beta-amyloid and alpha-crystallin which, respectively, have an action on arteriosclerosis, Alzheimer's disease and cataracts. Sequence-dependent and sequence-independent are the two strategies for detecting the presence and position of D-amino acids in proteins. These methods rely on enzymatic digestion by a site-specific enzyme and acid hydrolysis in a deuterium or tritium environment to limit the natural racemization of amino acids. In this review, chromatographic and electrophoretic techniques, such as LC, SFC, GC and CE, will be recently developed (2018-2020) for the enantioseparation of amino acids and peptides. For future work, the discovery and development of new chiral stationary phases and derivatization reagents could increase the resolution of chiral separations.Jako mnoho biologických sloučenin se bílkoviny nacházejí primárně ve své homochirální formě. Homochiralita však není zaručena po celý život. Stanovení jejich chirální proteinogenní sekvence je složitý analytický problém. Některé D-aminokyseliny obsažené v bílkovinách totiž hrají významnou roli v lidském zdraví a nemocech. To je případ i D-Asp v elastinu, beta-amyloidu a alfa-krystalinu, které působí na arteriosklerózu, Alzheimerovu chorobu a šedý zákal. Sekvenčně závislá a sekvenčně nezávislá jsou dvě strategie pro detekci přítomnosti a polohy D-aminokyselin v bílkovinách. Tyto metody spoléhají na enzymatické štěpení místně specifickým enzymem a kyselou hydrolýzu v prostředí deuteria nebo tritia, aby se omezila přirozená racemizace aminokyselin. V tomto přehledu budou uvedeny nedávno vyvinuté (2018–2020) chromatografické a elektroforetické techniky, jako jsou LC, SFC, GC a CE, pro enantioseparaci aminokyselin a peptidů. Pro budoucí práci by objev a vývoj nových chirálních stacionárních fází a derivatizačních činidel mohl zvýšit rozlišení u chirálních separací

Application of Sol–Gels Modified with Natural Plants Extracts as Stationary Phases in Open-Tubular Capillary Electrochromatography

Ethanol extracts of three widely growing plants were added to silica sol–gel solutions, which were subsequently applied as wall surface modifiers in inner quartz capillaries. Modified capillaries were used for open-tubular capillary electrochromatographic separation of nucleotides and amino groups containing biological compounds (neurotransmitters, amino acids and oligopeptides). The experiments were performed at physiological pH 7.40, and eventual changes of effective mobilities were calculated. Specific compounds characteristic for each plant were tested as sol–gel additives as well, and thus-modified capillaries were used for the separations of the same analytes under identical conditions. The aim of this study was to find out possible interactions between physiological compounds and extracts of freely available plants anchorded in the sol-gel stationary phase in the flowing system. Even though the amount of the modifier in each capillary is very small, basic statistical evaluation showed some not negligible changes in effective mobility of tested analytes. These changes were bigger than ±5% for separations of nucleotides in capillaries with curcuma, Moringa or the mixture of synthetic additives as the sol-gel aditive, and for separations of amino compounds where these changes varying by additive, analyte by analyte