Pulsed electric fields-processed orange juice consumption increases plasma vitamin C and decreases F2-isoprostanes in healthy humans

Orange juice, a rich source of vitamin C, accounts for 60% of all fruit juices and juice-based drinks consumed in western Europe. Orange juice preservation is currently accomplished by traditional pasteurization. Pulsed electric fields (PEF) have been studied as a nonthermal food preservation method. Food technology needs in the area of processing are driven by nutrition. Therefore, the objectives of this study were to assess the bioavailability of vitamin C from pulsed electric fields-treated orange juice in comparison with freshly squeezed orange juice and its impact on 8-epiPGF(2alpha) concentrations (biomarker of lipid peroxidation) in a healthy human population. Six subjects consumed 500 mL/day of pulsed electric fields-treated orange juice and six subjects consumed 500 mL/day of freshly squeezed orange juice for 14 days, corresponding to an intake of about 185 mg/day of ascorbic acid. On the first day of the study, subjects drank the juice in one dose, and on days 2-14 they consumed 250 mL in the morning and 250 mL in the afternoon. Blood was collected every hour for 6 hours on the first day and again on days 7 and 14. In the dose-response study, the maximum increase in plasma vitamin C occurred 4 hours postdose. Vitamin C remained significantly higher on days 7 and 14 in both orange juice groups. Plasma 8-epiPGF(2alpha) concentrations was lower at the end of the study (P < 0.001) in both groups. Plasma levels of vitamin C and 8-epiPGF(2alpha) were inversely correlated. Pulsed electric fields-preservation of orange juice retains the vitamin C bioavailability and antioxidant properties of fresh juice with a longer shelf-life.     

Adult Stromal Cells Derived from Human Adipose Tissue Provoke Pancreatic Cancer Cell Death both In Vitro and In Vivo

Background

Normal tissue homeostasis is maintained by dynamic interactions between epithelial cells and their microenvironment. Disrupting this homeostasis can induce aberrant cell proliferation, adhesion, function and migration that might promote malignant behavior. Indeed, aberrant stromal-epithelial interactions contribute to pancreatic ductal adenocarcinoma (PDAC) spread and metastasis, and this raises the possibility that novel stroma-targeted therapies represent additional approaches for combating this malignant disease. The aim of the present study was to determine the effect of human stromal cells derived from adipose tissue (ADSC) on pancreatic tumor cell proliferation.

Principal Findings

Co-culturing pancreatic tumor cells with ADSC and ADSC-conditioned medium sampled from different donors inhibited cancer cell viability and proliferation. ADSC-mediated inhibitory effect was further extended to other epithelial cancer-derived cell lines (liver, colon, prostate). ADSC conditioned medium induced cancer cell necrosis following G1-phase arrest, without evidence of apoptosis. In vivo, a single intra-tumoral injection of ADSC in a model of pancreatic adenocarcinoma induced a strong and long-lasting inhibition of tumor growth.

Conclusion

These data indicate that ADSC strongly inhibit PDAC proliferation, both in vitro and in vivo and induce tumor cell death by altering cell cycle progression. Therefore, ADSC may constitute a potential cell-based therapeutic alternative for the treatment of PDAC for which no effective cure is available.     

Effect of streamlining taxa lists on diatom-based indices: implications for intercalibrating ecological status

Intercalibration of ecological status class boundaries between member states is a requirement of the European Union’s Water Framework Directive. Although a preliminary intercalibration of boundaries established for phytobenthos has been performed, a number of questions remain, including the extent to which variations in taxonomic concepts used in different member states influences the position of these boundaries. In this paper, the robustness of the diatom-based metrics used for intercalibration is assessed. Whilst use of genus-level identification led to a loss of ecological information, merging representatives of closely-related taxa has little effect on these metrics. Similarly, taxa that occur only rarely or never have high relative abundances in a dataset can also be ignored without the loss of ecological information. Similar results were obtained when modern taxonomic concepts were compared with concepts in use 80 years ago. Fine scale taxonomy may play a valuable role within member states; however, our results suggest that, at a continental scale, a simplified approach to diatom taxonomy should not affect intercalibration results.     

The zinc-finger protein ZFR is critical for Staufen 2 isoform specific nucleocytoplasmic shuttling in neurons

In mammalian neurons, transport and translation of mRNA to individual potentiated synapses is believed to occur via a heterogeneous population of RNA granules. To identify components of Staufen2-containing granules, we used the yeast two-hybrid system. A mouse fetal cDNA library was screened with the N-terminal fragment of Staufen2 as bait. ZFR, a three zinc finger protein, was identified as an interacting protein. Confocal microscopy showed that ZFR, although mainly nuclear, was also found in the somatodendritic compartment of primary hippocampal neurons where it localized as granule-like structures. Co-localization with Staufen2 was observed in several granules. Biochemical analyses (immunoprecipitation, cell fractionation) further confirmed the ZFR/Staufen2 association. ZFR was shown to interact with at least the Staufen2(62) isoform, but not with Staufen1. ZFR also co-fractionated with ribosomes and Staufen2(59) and Staufen2(52) in a sucrose gradient. Interestingly, knockdown expression of ZFR through RNA interference in neurons relocated specifically the Staufen2(62), but not the Staufen2(59), isoform to the nucleus. Our results demonstrate that ZFR is a native component of Staufen2-containing granules and likely plays its role during early steps of RNA transport and localization. They also suggest that one of these roles may be linked to Staufen2(62)-containing RNA granule formation in the nucleus and/or to their nucleo-cytoplasmic shuttling.     

Molecular Basis of the Behavior of Hepatitis A Virus Exposed to High Hydrostatic Pressure

Food-borne hepatitis A outbreaks may be prevented by subjecting foods at risk of virus contamination to moderate treatments of high hydrostatic pressure (HHP). A pretreatment promoting hepatitis A virus (HAV) capsid-folding changes enhances the virucidal effect of HHP, indicating that its efficacy depends on capsid conformation. HAV populations enriched in immature capsids (125S provirions) are more resistant to HHP, suggesting that mature capsids (150S virions) are more susceptible to this treatment. In addition, the monoclonal antibody (MAb) K24F2 epitope contained in the immunodominant site is a key factor for the resistance to HHP. Changes in capsid folding inducing a loss of recognition by MAb K24F2 render more susceptible conformations independently of the origin of such changes. Accordingly, codon usage-associated folding changes and changes stimulated by pH-dependent breathings, provided they confer a loss of recognition by MAb K24F2, induce a higher susceptibility to HHP. In conclusion, the resistance of HAV to HHP treatments may be explained by a low proportion of 150S particles combined with a good accessibility of the epitope contained in the immunodominant site close to the 5-fold axis.     

Detection of flavonoids in microalgae from different evolutionary lineages

Flavonoids are important secondary plant metabolites believed to be present mainly in land plants. As phenolics were detected previously in microalgae using photometric assays, we wanted to investigate the nature of these phenolics and verify whether flavonoids are present. Therefore, in this study, we used state‐of‐the‐art ultra‐high performance liquid chromatography‐two‐dimensional mass spectrometry (UHPLC‐MS/MS) technology to investigate whether microalgae also contain flavonoids. For this, representative microalgal biomass samples from divergent evolutionary lineages (Cyanobacteria, Rhodophyta, Chlorophyta, Haptophyta, Ochrophyta) were screened for a set of carefully selected precursors, intermediates, and end products of the flavonoid biosynthesis pathways. Our data unequivocally showed that microalgae contain a wide range of flavonoids and thus must possess the enzyme pool required for their biosynthesis. Further, some of the microalgae displayed an intricate flavonoid pattern that is compatible with the established basic flavonoid pathway as observed in higher plants. This implies that the flavonoid biosynthesis pathway arose much earlier in evolution compared to what is generally accepted.     

The Microbial Diversity of Traditional Spontaneously Fermented Lambic Beer

Lambic sour beers are the products of a spontaneous fermentation that lasts for one to three years before bottling. The present study determined the microbiota involved in the fermentation of lambic beers by sampling two fermentation batches during two years in the most traditional lambic brewery of Belgium, using culture-dependent and culture-independent methods. From 14 samples per fermentation, over 2000 bacterial and yeast isolates were obtained and identified. Although minor variations in the microbiota between casks and batches and a considerable species diversity were found, a characteristic microbial succession was identified. This succession started with a dominance of Enterobacteriaceae in the first month, which were replaced at 2 months by Pediococcus damnosus and Saccharomyces spp., the latter being replaced by Dekkera bruxellensis at 6 months fermentation duration.