Histone Acetylation Dynamics during In Vivo and In Vitro Oocyte Aging in Common Carp Cyprinus carpio

Aging is the most critical factor that influences the quality of post-ovulatory oocytes. Age-related molecular pathways remain poorly understood in fish oocytes. In this study, we examined the effect of oocyte aging on specific histone acetylation in common carp Cyprinus carpio. The capacity to progress to the larval stage in oocytes that were aged for 28 h in vivo and in vitro was evaluated. Global histone modifications and specific histone acetylation (H3K9ac, H3K14ac, H4K5ac, H4K8ac, H4K12ac, and H4K16ac) were investigated during oocyte aging. Furthermore, the activity of histone acetyltransferase (HAT) was assessed in fresh and aged oocytes. Global histone modifications did not exhibit significant alterations during 8 h of oocyte aging. Among the selected modifications, H4K12ac increased significantly at 28 h post-stripping (HPS). Although not significantly different, HAT activity exhibited an upward trend during oocyte aging. Results of our current study indicate that aging of common carp oocytes for 12 h results in complete loss of egg viability rates without any consequence in global and specific histone modifications. However, aging oocytes for 28 h led to increased H4K12ac. Thus, histone acetylation modification as a crucial epigenetic mediator may be associated with age-related defects, particularly in oocytes of a more advanced age.     

Metabolic Response in Endothelial Cells to Catecholamine Stimulation Associated with Increased Vascular Permeability

Disruption to endothelial cell homeostasis results in an extensive variety of human pathologies that are particularly relevant to major trauma. Circulating catecholamines, such as adrenaline and noradrenaline, activate endothelial adrenergic receptors triggering a potent response in endothelial function. The regulation of the endothelial cell metabolism is distinct and profoundly important to endothelium homeostasis. However, a precise catalogue of the metabolic alterations caused by sustained high catecholamine levels that results in endothelial dysfunction is still underexplored. Here, we uncover a set of up to 46 metabolites that exhibit a dose–response relationship to adrenaline-noradrenaline equimolar treatment. The identified metabolites align with the glutathione-ascorbate cycle and the nitric oxide biosynthesis pathway. Certain key metabolites, such as arginine and reduced glutathione, displayed a differential response to treatment in early (4 h) compared to late (24 h) stages of sustained stimulation, indicative of homeostatic metabolic feedback loops. Furthermore, we quantified an increase in the glucose consumption and aerobic respiration in endothelial cells upon catecholamine stimulation. Our results indicate that oxidative stress and nitric oxide metabolic pathways are downstream consequences of endothelial cell stimulation with sustained high levels of catecholamines. A precise understanding of the metabolic response in endothelial cells to pathological levels of catecholamines will facilitate the identification of more efficient clinical interventions in trauma patients.     

Light sensitivity of colourants used in alcoholic beverages

Quantum yields for photobleaching in ethanol solutions of Hexacol Red 2G Supra (E 128), Hexacol Sunset Yellow FCF Supra (E 110), caramel colour (E 150) and Liquid Red Colour (E 128) based on carminic acid, have been determined at 25° C in continuous photolysis experiments using monochromatic light at each of three wavelengths 334 nm, 366 nm and 436 nm, in order to obtain an objektive measure of the sensitivity to ultraviolet and visible light of colourants used in alcoholic beverages. For photobleaching of carminic acid from Liquid Red Colour in fruit wine [pH 3.1, with 15% (v/v) ethanol] quantum yield was determined as 2.1·10^–2 mol·einstein^–1 for 334 nm irradiation, 1.3·10^–3 mol·einstein^–1 for 366 nm irradiation and 5.6·10^–5 mol·einstein^–1 for 436 nm irradiation, respectively. For Hexacol Sunset Yellow FCF Supra in fruit wine, the quantum yield for 334 nm irradiation was determined as 5.9·10^–4 mol·einstein^–1 and for 366 nm irradiation as 2.4·10^–4 mol·einstein^–1. Hexacol Red 2G Supra in fruit wine had a quantum yield of 3.7·10^–5 mol·einstein^–1 for 366 nm irradiation. For Hexacol Red 2G Supra and Hexacol Sunset Yellow FCF Supra for 436 nm irradiation and for Hexacol Red 2G Supra for 334 nm irradiation the quantum yields were less than 10^–6 mol·einstein^–1. The following order was determined for light sensitivity in fruit wine (366 nm light): Liquid Red Colour > Hexacol Sunset Yellow FCF Supra > Hexacol Red 2G Supra. The caramel colour in aquavit [pH 7.1, with 42% (v/v) ethanol] was moderately sensitive to light with a quantum yield almost independent of irradiation wavelength. Relative quantum yields were determined as 1.6 for 334 nm irradiation, 1.0 for 366 nm and 1.0 for 436 nm irradiation. The latter value corresponded to 2.6 g caramel per einstein absorbed.

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Lichtempfindlichkeit von Farbstoffen in alkoholischen Getränken

Zusammenfassung Um einen objektiven Wert für die Empfindlichkeit von Farbstoffen in alkoholischen Getränken gegenüber ultraviolettem und sichtbarem Licht festlegen zu können, wurde die Quantenausbeute für Photobleichung in ethanolischen Lösungen von Hexacol Red 2G Supra (E 128), Hexacol Sunset Yellow FCF Supra (E110), Caramel Farbe (E 150) und Liquid Red Colour (E 128; auf Carminsäure basieren) bei 25 °C in kontinuierlichen Photolyse-Experimenten mit monochromatischem Licht mit den Wellenlängen 334 nm, 366 nm und 436 nm bestimmt. Die Quantenausbeute für Photobleichung von Carminsäure in Liquid Red Colour in Fruchtwein (pH 3,1 mit 15%, v/v, Ethanol) war 2,1·10^–2 Mol·Einstein^–1 bei 334 nm; 1,3·10^–3 Mol·Einstein^–1 bei 366 nm und 5,6·10^–5 Mol·Einstein^–1 bei 436 nm. Die Quantenausbeute für Hexacol Sunset Yellow FCF Supra in Fruchtwein war 5,9·10^–4 Mol·Einstein^–1 bei 334 nm und 2,4·10^–4 Mol·Einstein^–1 bei 366 nm. Die Quantenausbeute für Photobleichung für Hexacol Red 2G Supra war 3,7·10^–5 Mol·Einstein^–1 bei 366 nm Bestrahlung. Für Hexacol Red 2G Supra und Hexacol Sunset Yellow FCF Supra war die Quantenausbeute bei 436 nm Bestrahlung geringer als 10^–6 Mol·Einstein^–1, das gleiche gilt für Hexacol Red 2G Supra bei 334 nm Bestrahlung. Folgende Reihenfolge der Lichtempfindlichkeit in Fruchtwein wurde festgestellt (bei 366 nm): Liquid Red Colour > Hexacol Sunset Yellow FCF Supra > Hexacol Red 2G Supra. Caramel Farbe in Aquavit (pH 7,1, mit 42%, v/v, Ethanol) war mäßig lichtempfindlich; die Quantenausbeute war fast unabhängig von der Bestrahlungswellenlänge. Relative Quantenausbeuten von 1,6 bei 334 nm, 1,0 bei 366 nm und 1,0 bei 436 nm wurden bestimmt. Der letzte Wert entspricht 2,6 g Caramel per Einstein.

     

Tyrosine-derived polycarbonate membrane in treating mandibular bone defects. An experimental study.

This study was designed to evaluate the suitability of a novel bioabsorbable material in treating bone defects. A poly(desaminotyrosyl-tyrosine-ethyl ester carbonate) (PDTE carbonate) membrane (thickness 0.2-0.3 mm) was implanted into the mandibular angle of 20 New Zealand White rabbits to cover a through-and-through defect (12 x 6 mm). In group 1, the defects were left unfilled but covered with membrane and in group 2 the defects were filled with bioactive glass mesh and covered with membrane, too. Controls were left uncovered and unfilled. The animals were followed for 6, 12, 24 and 52 weeks, respectively. The material was evaluated by qualitative analysis of histological reactions and newly formed bone.We found that PDTE carbonate elicited a modest foreign body reaction in the tissues, which was uniform throughout the study. New bone formation was seen in all samples after six weeks. Group 1 had more new bone formation until 24 weeks and after this the difference settled. Based on findings of this study it was concluded that PDTE carbonate membranes have good biocompatibility and are sufficient to enhance bone growth without additional supportive matrix.     

Fragile‐to‐Strong Crossover in Supercooled Liquid Ag‐In‐Sb‐Te Studied by Ultrafast Calorimetry

Phase‐change random‐access memory relies on the reversible crystalline‐glassy phase change in chalcogenide thin films. In this application, the speed of crystallization is critical for device performance: there is a need to combine ultrafast crystallization for switching at high temperature with high resistance to crystallization for non‐volatile data retention near to room temperature. In phase‐change media such as nucleation‐dominated Ge₂Sb₂Te₅, these conflicting requirements are met through the highly “fragile” nature of the temperature dependence of the viscosity of the supercooled liquid. The present study explores, using ultrafast‐heating calorimetry, the equivalent temperature dependence for the growth‐dominated medium Ag‐In‐Sb‐Te. The crystallization shows (unexpectedly) Arrhenius temperature dependence over a wide intermediate temperature range. Here it is shown that this is evidence for a fragile‐to‐strong crossover on cooling the liquid. Such a crossover has many consequences for the interpretation and control of phase‐change kinetics in chalcogenide media, helping to understand the distinction between nucleation‐ and growth‐dominated crystallization, and offering a route to designing improved device performance.     

Water characteristics in cooked beef as influenced by ageing and high-pressure treatment-an NMR micro imaging study

The water characteristics in cooked pressure-heat treated (45?°C for 45 min prior to pressurisation at 150 MPa for 30 min) and non-pressurised, cooked (control) samples of beef Longissimus aged for 1, 3, 8 or 16 days were studied by nuclear magnetic resonance microscopy. A multi-echo sequence was used to obtain T2 images, and independent of ageing period, the T2 values were found to be lower in pressure-heat treated meat revealing alterations in water characteristics of pressure-treated, cooked meat compared with cooked meat. With increasing ageing duration, the T2 values in both pressure-treated, cooked and cooked meat decreased indicating that the water became more tightly trapped in the protein network. In addition, independent of length of ageing period the relationship between cooking loss in the cooked meat and transverse relaxation differed between non-pressurised and pressure-treated meat, which reveals that the mechanisms changing the water properties in beef during ageing are different from those occuring during pressure-heat treatment of meat.