Physiological and metabolic properties of a digestion-resistant maltodextrin, classified as type 3 retrograded resistant starch

There is a growing interest in highly fermentable dietary fibers having the potential to reduce risks of disease through the production of short-chain fatty acids (SCFA). Recently a digestion-resistant retrograded maltodextrin (RRM), classified as type 3 resistant starch was developed. Systematic work to determine its molecular and physiological properties was carried out to determine (1) the fraction resistant to digestion in vitro and in vivo, (2) its postconsumption effect on blood glucose in healthy volunteers, and (3) its in vitro fermentation pattern, at different ages, by use of pooled fresh human fecal inoculum. RESULTS: The digestion resistant fraction obtained in vivo from ileostomy patients (59.4%) is similar to that obtained by the AOAC method for measuring retrograded resistant starch (59.7%). The relative glycemic response after consumption of 50 g of RRM was 58.5% compared to glucose set as 100%. When exposed to colonic microbiota, in vitro obtained indigestible fractions behave similarly to those obtained in vivo in ileostomy patients. Fermentation of RRM and production of butyric acid is negligible during the first months of life but develops subsequently during weaning. In adults, RRM fermentation results in a high yield of SCFA, with butyrate representing 21-31 mol % of total SCFA. The high yield of SCFA during colonic fermentation, observed from weaning age on, as well as the potential to help reduce glycemic load may be of benefit to a number of health-related functions in the host. Further study on clear clinical end points is warranted.     

Anaerobic co‐digestion of perennials: Methane potential and digestate nitrogen fertilizer value

Co‐digestion of crop biomass improves the traditional manure‐based biogas yield due to an increased content of easily degradable carbon compounds. In this study, the methane potential of three perennials (grass, legumes, and grass+legume) was determined using various amounts together with animal manure. The nitrogen (N) mineralization dynamics in soil and the N‐fertilizer value of the derived digestates were subsequently tested in both a soil incubation study and a pot experiment with spring barley. Digestion of all tested perennials together with a manure‐based inoculum increased the cumulative methane yield four to five times compared to digestion of the inoculum alone, with the highest increases observed with pure grass. However, the methane potential decreased along with increasing grass biomass concentration. In the plant pot experiment, all tested digestates increased barley shoot biomass by 40–170%, to an extent statistically comparable to mineral N fertilizer. However, the application of the digestate originating from fermentation with pure grass resulted in lower plant growth and a more fluctuating soil mineral N content throughout the incubation study compared to the other digestates. Considering the high dry matter and methane yield ha^?1, the possibility to substitute mineral N fertilizer inputs by leguminous biological N₂ fixation capacity, and the digestate fertilizer value, the integration of grass–legume mixtures or sole legumes into anaerobic digestion systems as co‐substrate for manure seems to be promising. This could furthermore contribute to the diversification of cropping systems for bioenergy production.     

At-sea distribution of waved albatrosses and the Galápagos Marine Reserve

Albatross populations worldwide are threatened by incidental takes in longline fishery operations. The recent establishment of the Galápagos Marine Reserve (GMR) is relevant to the longline bycatch issue, as it prohibits industrial longlining in the vicinity of the major nesting site of waved albatrosses (Phoebastria irrorata). However, the legality of the fishing protections is being challenged, highlighting a need for data on use of the GMR by albatrosses. We used satellite tracking over a total of four breeding seasons to determine the distribution of waved albatrosses inside and outside the GMR, and thereby assess the degree of protection that GMR provisions offer to this species. During the incubation period, breeding adults made commuting trips from the nesting island (Isla Española) to the Peruvian upwelling zone, traveling north, east, and south after leaving the nest. During the brooding period, the distribution contracted markedly, and most satellite fixes were within the GMR. During the rearing period, breeders performed both long trips outside the GMR and short trips within. The southeastern portion of the GMR is used throughout the incubation, brooding, and early rearing periods by breeding waved albatrosses. Indirect information from non-breeding adults indicates that they are likely to use the waters of the GMR extensively.     

Extensive gene traffic on the mammalian X chromosome

Mammalian sex chromosomes have undergone profound changes since evolving from ancestral autosomes. By examining retroposed genes in the human and mouse genomes, we demonstrate that, during evolution, the mammalian X chromosome has generated and recruited a disproportionately high number of functional retroposed genes, whereas the autosomes experienced lower gene turnover. Most autosomal copies originating from X-linked genes exhibited testis-biased expression. Such export is incompatible with mutational bias and is likely driven by natural selection to attain male germline function. However, the excess recruitment is consistent with a combination of both natural selection and mutational bias.     

Epipolythiodiketopiperazines from the Marine Derived Fungus Dichotomomyces cejpii with NF-κB Inhibitory Potential

The Ascomycota Dichotomomyces cejpii was isolated from the marine sponge Callyspongia cf. C. flammea. A new gliotoxin derivative, 6-acetylmonodethiogliotoxin (1) was obtained from fungal extracts. Compounds 2 and 3, methylthio-gliotoxin derivatives were formerly only known as semi-synthetic compounds and are here described as natural products. Additionally the polyketide heveadride (4) was isolated. Compounds 1, 2 and 4 dose-dependently down-regulated TNFα-induced NF-κB activity in human chronic myeloid leukemia cells with IC_50s of 38.5 ± 1.2 µM, 65.7 ± 2.0 µM and 82.7 ± 11.3 µM, respectively. The molecular mechanism was studied with the most potent compound 1 and results indicate downstream inhibitory effects targeting binding of NF-κB to DNA. Compound 1 thus demonstrates potential of epimonothiodiketopiperazine-derived compounds for the development of NF-κB inhibitors.     

Molecular genetic approaches to increasing mineral availability and vitamin content of cereals

The present paper summarizes the current state of knowledge on molecular genetic approaches to increasing iron and zinc availability and vitamin content in cereals. We have also attempted to integrate the scientific issues into the wider context of human nutrition. In the cereal grain, iron and zinc are preferentially stored together with phytate in membrane-enclosed globoids in the protein storage vacuole (PSV) found in the aleurone and the embryo scutellum. The PSV is accordingly central for understanding mineral deposition during grain filling and mobilization of minerals during germination. Recent studies in Arabidopsis have led to the first identification of iron and zinc transporters of the PSV and further illustrate some of the dynamics associated with mineral and phytate transport and deposition into the vacuole. This provides new opportunities for modulating iron and zinc deposition in the cereal grain. Current strategies towards increasing the iron content of the endosperm are largely based on the expression of legume ferritin genes in an endosperm-specific manner. However, it is apparent that this approach, at least in rice, only allows a two- to three-fold increase in the iron content of the grain due to exhaustion of the iron stores in leaves. Further increases thus have to rely on additional uptake and transport of iron from the root. Phytate is generally considered to be the single most important anti-nutritional factor for iron and zinc availability. In the current paper we summarize attempts to increase phytase activity in the grain by transformation and evaluate the potential of this approach as well as the reduction of phytate biosynthesis for improving the bioavailability of iron and zinc. Vitamins constitute the second important group of micronutrients in grain and we discuss current efforts to increase the amounts of provitamin A, vitamin C and vitamin E.     

Modelling carbon dynamics in mixed grass–red clover swards

Growth and carbon dynamics in mixed grass–red clover leys were simulated using a growth model for pure stands based on radiation use, allocation within plant and loss of biomass. The model and its parameter values were taken from previous applications of the model to pure swards of grass and red clover grown in the same experiment at the same sites and years.     

Validating an empiric sulfadiazine–trimethoprim dosage regimen for treatment of Escherichia coli and Staphylococcus delphini infections in mink (Neovison vison)

Antimicrobial agents are used extensively off‐label in mink, as almost no agents are registered for this animal species. Pharmacokinetic (PK) and pharmacodynamic (PD) data are required to determine antimicrobial dosages specifically targeting mink bacterial pathogens. The aims of this study were to assess, in a PKPD framework, the empirical dosage regimen for a combination of trimethoprim (TMP) and sulfadiazine (SDZ) in mink, and secondarily to produce data for future setting of clinical breakpoints. TMP and SDZ PK parameters were obtained experimentally in 22 minks following IV or oral administration of TMP/SDZ (30 mg/kg, i.e. 5 mg/kg TMP and 25 mg/kg SDZ). fAUC/MIC with a target value of 24 hr was selected as the PKPD index predictive of TMP/SDZ efficacy. Using a modeling approach, PKPD cutoffs for TMP and SDZ were determined as 0.062 and 16 mg/L, respectively. By incorporating an anticipated potentiation effect of SDZ on TMP against Escherichia coli and Staphylococcus delphini, the PKPD cutoff of TMP was revised to 0.312 mg/L, which is above the tentative epidemiological cutoffs (TECOFF) for these species. The current empirical TMP/SDZ dosage regimen (30 mg/kg, PO, once daily) therefore appears adequate for treatment of wild‐type E. coli and S. delphini infections in mink.