Thermally cross-linked oligo(poly(ethylene glycol) fumarate) hydrogels support osteogenic differentiation of encapsulated marrow stromal cells in vitro

A novel polymer, oligo(poly(ethylene glycol) fumarate) (OPF), cross-linked with a thermal radical initiation system has recently been developed in our laboratory as an injectable, biodegradable cell carrier for regeneration of orthopaedic tissues. The cross-linking, swelling, and degradative properties of hydrogels prepared from OPF with poly(ethylene glycol) of two different chain lengths were assessed. The two OPF types had similar gelation onset times ( approximately 3.6 min) but, when cross-linked for 8 min at 37 degrees C, exhibited significantly different swelling characteristics (fold swelling: 17.5 +/- 0.2 vs 13.4 +/- 0.4). Rat marrow stromal cells (MSCs) were then directly combined with the hydrogel precursors and encapsulated in a model OPF formulation at approximately 14 million cells/mL, cultured in vitro in the presence of osteogenic supplements (dexamethasone), and monitored over 28 days via histology. MSC differentiation in these samples (6 mm diameter x 0.5 mm thick before swelling), as determined by Von Kossa staining for calcified matrix, was apparent by day 21. At day 28, mineralized matrix could be seen throughout the samples, many microns away from the cells. These experiments strongly support the usefulness of thermally cross-linked OPF hydrogels as injectable cell carriers for bone regeneration.     

Recovery of phenolic antioxidants from wine industry by-products

The recovery process of the phenolic compounds contained in the wine industry by-products and their antioxidant activity were examined in this work. To this purpose, a combined process of liquid and supercritical solvent extraction was employed. At first the effect of various process parameters of the liquid solvent extraction--the type of solvent and the pretreatment of the raw material (composition (skins, seeds, stems) and crushing)--on the antioxidant activity of the extract was examined. It was shown that an extract of a higher antioxidant activity was obtained by using ethyl acetate as solvent and raw material free of stems. These extracts were further treated with supercritical carbon dioxide (SC CO(2)) at various extraction pressures, which resulted in their significant enrichment in phenolic compounds and the improvement of their antioxidant and organoleptic properties, especially at pressures higher than 100 bar. The antioxidant activity of the products was determined by using the Rancimat method, as well as a simple and not time-consuming free radical method. It was proved that both the ethyl acetate extracts and those treated with SC CO(2) had antioxidant activity comparable to that of antioxidants commonly used in industry, that is butylhydroxytoluene (BHT), a synthetic antioxidant, and Rosemary extract, a widely known natural one.     

Using an individual-based model for assessment of sea turtle population viability

Marine turtle species have a complex life history characterized by interannual variability in reproductive performance and a long life span. These ecological features in combination with the animals highly migratory nature create numerous difficulties when trying to assess population dynamics. This study attempts to couple existing information on species demographics and behavioral strategies with simple energetic rules in a theoretical framework. We study sea turtle population dynamics using an individual-based model that incorporates known behavioral-ecological characteristics of the species. Methodology used to design the model was based on the superindividual approach (Scheffer et al. Ecol Model 80:161–170, 1995). We constructed our simulation experiment on a virtual sea turtle population, which was parameterized by using recent literature reviews with emphasis on reproductive parameters of the Mediterranean loggerhead sea turtle population. Switching rules describing critical processes of reproductive performances were established as theoretical functions of efficiency of energy transfer. In order to explore the significance of variable reproductive patterns upon population dynamics and persistence, a series of simulations was performed. The model was also run under fluctuated demographic variables to perform a sensitivity analysis of critical parameters and life-history stages. Based on the specific model parameterization, simulation results show that population persistence was most sensitive to fecundity and to survival at the pelagic juvenile stage. Additionally a surprising finding is the relatively high importance of egg survival in terms of both hatching and hatchling success. We conclude that enhancing the population with new individuals by increasing survival in the early life stages could compensate for additional losses in other age classes. The need for further research regarding biological and behavioral features as well as basic demographic insights into the endangered loggerhead sea turtle is also highlighted.     

New 2-(1-adamantylcarbonyl)pyridine and 1-acetyladamantane thiosemicarbazones-thiocarbonohydrazones: cell growth inhibitory, antiviral and antimicrobial activity evaluation

The new thiosemicarbazones and thiocarbonohydrazones derived from 2-(1-adamantylcarbonyl)pyridine and 1-acetyladamantane were synthesized and evaluated for their inhibitory effect on tumor cell proliferation and their antiviral and antimicrobial activity. Thiosemicarbazone inhibited tumor cell proliferation (GI50's range: 2.4-100 microM and mean GI50 43.9 microM against various human leukemic cell lines) while thiosemicarbazone and thiocarbonohydrazone 5d exhibited significant inhibition of tumor cell proliferation (GI50's range 2.3-23.6 microM and mean GI50 7.2 microM for and GI50's range 2.4-32.4 microM and mean GI50 12.8microM for ). These GI50 values are comparable to that of 2-acetylpyridine thiosemicarbazone an important lead in TSC's family. The compounds did not afford specific activity against any of the viruses tested when examined at non-toxic concentrations. A weak activity was found for thiocarbonohydrazones against Gram-(+) bacteria (MIC(50) 117.3 and 133 microM, respectively). Using a combination of molecular mechanics calculations and NOE spectroscopy it was shown that the parent compounds and have opposite configuration around C=N bond. Whether this difference in structure can be correlated with the biological activity will be investigated in future studies.     

A simple and rapid method for the differentiation of C-13 manoyl oxide epimers in biologically important samples using GC-MS analysis supported with NMR spectroscopy and computational chemistry results

There is confusion in the literature related to the characterization of biologically important C13 manoyl oxide epimers by using their mass spectrometric data. Furthermore a method for calculating the epimeric purity has not been established. In this work mixtures of manoyl oxide C13 epimers and pure ent-13-epi-manoyl oxide have been isolated from plant extracts. The GC–MS analysis allows the characterization of each stereoisomer in a sample of natural origin: the ratio of intensities of peaks m/z 275 : 257 is lower in ent-13-epi-manoyl oxide than in manoyl oxide. NMR spectroscopy is used to give experimental evidence and simple calculations were performed to support the MS data. On the basis of these results the characterization of the two stereoisomers and the calculation of their ratio in plant extracts and essential oils can be done in a routine basis. The biological activity evaluation of mixtures with different epimeric composition of manoyl oxide showed that the ratio of the two epimers is important for their antibacterial activity. Ent-13-epi-manoyl oxide seems to be more active than its epimeric congener against Gram-positive bacteria.     

Modulation of Myelopoiesis Progenitors Is an Integral Component of Trained Immunity

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Are Mediterranean marine threatened species at high risk by climate change?

Rapid anthropogenic climate change is driving threatened biodiversity one step closer to extinction. Effects on native biodiversity are determined by an interplay between species' exposure to climate change and their specific ecological and life-history characteristics that render them even more susceptible. Impacts on biodiversity have already been reported, however, a systematic risk evaluation of threatened marine populations is lacking. Here, we employ a trait-based approach to assess the risk of 90 threatened marine Mediterranean species to climate change, combining species' exposure to increased sea temperature and intrinsic vulnerability. One-quarter of the threatened marine biodiversity of the Mediterranean Sea is predicted to be under elevated levels of climate risk, with various traits identified as key vulnerability traits. High-risk taxa including sea turtles, marine mammals, Anthozoa and Chondrichthyes are highlighted. Climate risk, vulnerability and exposure hotspots are distributed along the Western Mediterranean, Alboran, Aegean, and Adriatic Seas. At each Mediterranean marine ecoregion, 21%–31% of their threatened species have high climate risk. All Mediterranean marine protected areas host threatened species with high risk to climate change, with 90% having a minimum of 4 up to 19 species of high climate risk, making the objective of a climate-smart conservation strategy a crucial task for immediate planning and action. Our findings aspire to offer new insights for systematic, spatially strategic planning and prioritization of vulnerable marine life in the face of accelerating climate change.     

Functional conservation of a glucose-repressible amylase gene promoter from Drosophila virilis in Drosophila melanogaster

Summary Previous studies have demonstrated that the expression of the -amylase gene is repressed by dietary glucose in Drosophila melanogaster. Here, we show that the -amylase gene of a distantly related species, D. virilis, is also subject to glucose repression. Moreover, the cloned amylase gene of D. virilis is shown to be glucose repressible when it is transiently expressed in D. melanogaster larvae. This cross-species, functional conservation is mediated by a 330-bp promoter region of the D. virilis amylase gene. These results indicate that the promoter elements required for glucose repression are conserved between distantly related Drosophila species. A sequence comparison between the amylase genes of D. virilis and D. melanogaster shows that the promoter sequences diverge to a much greater degree than the coding sequences. The amylase promoters of the two species do, however, share small clusters of sequence similarity, suggesting that these conserved cis-acting elements are sufficient to control the glucose-regulated expression of the amylase gene in the genus Drosophila.Offprint requests to: D.A. Hickey