Cannibalism in non-native brown trout Salmo trutta and rainbow trout Oncorhynchus mykiss stream-dwelling populations.

Introduced and allopatric populations of brown trout Salmo trutta and rainbow trout Oncorhynchus mykiss were sampled in Slovenia for stable isotope analysis to assess dietary niche shifts through ontogeny and estimate the propensity for cannibalism. Both S. trutta and O. mykiss are cannibals, with higher average relative contribution of conspecific assimilated energy for S. trutta (27·9%) compared with O. mykiss (7·7%). The smallest cannibal was 166 mm in the S. trutta population and 247 mm in the O. mykiss population.

Temporal changes in allele frequencies in a small marble trout Salmo marmoratus population threatened by extreme flood events.

The effect of extreme floods on the genetic composition of marble trout Salmo marmoratus living in Lipovscek, a tributary of the Soca River in Slovenia, which has been affected by multiple destructive flood events for centuries was investigated. By monitoring genetic variability during the period 2004-2011, apparent signatures of genetic erosion including a decline in observed and expected heterozygosities and allelic richness were observed. Contemporary effective population size was estimated between 11 and 55 individuals, which is congruent with census data. The data suggest asymmetric gene flow between the two sections of the river. The existence of substantial downstream migration (15-19%) was confirmed by paternity analysis. A small (1-3%) upstream migration was also suggested, which was confirmed by tagging data. Overall, low genetic diversity has not prevented the survival of the Lipovscek population, which might be a common feature of salmonid freshwater populations.

Eco-evolutionary dynamics induced by massive mortality events.

An eco-genetic model tuned on a population of marble trout Salmo marmoratus subject to periodic flood events was used to explore how the evolution of growth rates interacting with density-dependent processes can modify size at age and population structure and in turn influence the resilience of populations. Fish with greater growth potential were assumed to have higher mortality rates. The results of simulations were compared between two scenarios, one in which populations may evolve growth rates and the other one in which the distribution of growth rates within a population is kept fixed. Evolving populations had a greater proportion of age 1 year individuals in the population, greater median length at age 3 years (the typical age at sexual maturity for S. marmoratus) and lower population sizes. The slightly smaller population sizes did not affect realized extinction risk. Resilience, defined as the number of years necessary to rebound from flood-induced population collapse, was on average from 2 to 3 years in both scenarios, with no significant difference between them. Moderate heritability of growth, relaxation of density-dependent processes at low densities and rapid recovery to a safe population size combine to limit the capacity to evolve faster recovery after flood-induced population collapses via changing growth rates.

Empirical standard mass equation for Salmo marmoratus.

Total length (L(T)) (range 24-1000 mm; mean ±S.E. = 170.21 ± 0.36 mm) and mass (W) (range 0.10-9590 g; mean ±S.E. = 76.03 ± 0.87 g) of 36,460 specimens of marble trout Salmo marmoratus were used to compute a standard mass (W(s)) equation for this species by means of the empirical percentile (EmP) method. The EmP W(s) equation calculated was: log(10) W(s) = -5.208 + 3.202 log(10) L(T) - 0.046 (log(10) L(T))(2) (L(T) range 90-570 mm) and it is valid throughout the species' area of distribution across Europe.

Aqueous extract of Arbutus unedo inhibits STAT1 activation in human breast cancer cell line MDA-MB-231 and human fibroblasts through SHP2 activation.

Arbutus unedo L. has been for a long time employed in traditional and popular medicine as an astringent, diuretic, urinary anti-septic, and more recently, in the therapy of hypertension and diabetes. Signal transducer and activator of transcription 1 (STAT1) is a fascinating and complex protein with multiple yet contrasting transcriptional functions. Although activation of this nuclear factor is finely regulated in order to control the entire inflammatory process, its hyper-activation or time-spatially erroneous activation may lead to exacerbation of inflammation. The modulation of this nuclear factor, therefore, has recently been considered as a new strategy in the treatment of inflammatory diseases. In this study, we present data showing that the aqueous extract of Arbutus unedo's leaves exerts inhibitory action on interferon-gamma (IFN-gamma) elicited activation of STAT1, both in human breast cancer cell line MDA-MB-231 and in human fibroblasts. This down-regulation of STAT1 is shown to result from a reduced tyrosine phosphorylation of STAT1 protein. Evidence is also presented indicating that the inhibitory effect of this extract may be mediated through enhancement of tyrosine phosphorylation of SHP2 tyrosine phosphatase. The modulation of this nuclear factor turns out into the regulation of the expression of a number of genes involved in the inflammatory response such as inducible nitric oxide synthase (iNOS) and intercellular adhesion molecule-1 (ICAM-1). Taken together, our results suggest that the employment of the Arbutus unedo aqueous extract is promising, at least, as an auxiliary anti-inflammatory treatment of diseases in which STAT1 plays a critical role.

IgE-mediated allergy to corn: a 50 kDa protein, belonging to the Reduced Soluble Proteins, is a major allergen.

BACKGROUND: Although corn is often cited as an allergenic food, very few studies have been devoted to the identification of corn allergens and corn allergy has been rarely confirmed by double-blind, placebo-controlled food challenge (DBPCFC). Recently, Pastorello et al. (1) identified some salt-soluble IgE-binding proteins of corn flour as potential allergens. One of these, corresponding to corn Lipid Transfer Protein (LTP), appeared to be the major one. The aim of this study was to verify the clinical significance of the skin prick test (SPT) and CAP-FEIA CAP-System IgE fluozoenzyme immunosorbent assay (Pharmacia Diagnostic, Uppsala, Sweden) positivities to corn and to identify the presence of IgE-binding proteins in the corn flour salt-insoluble protein fractions (comprising up to 96% of the total protein) using sera of patients with DBPCFC-documented food allergy to corn. In addition the effect of cooking and proteolytic digestion on the corn allergens was investigated. METHODS: Sixteen subjects with SPT and CAP-FEIA positivities to corn flour were examined. Only six of them complained of suffering from urticaria and/or other symptoms after ingestion of corn-based foods. The patients were food challenged with cooked corn flour (polenta). IgE-binding proteins were detected by immunoblotting. The digestibility of the IgE-binding proteins was examined during a pepsin attack followed by a pancreatin digestion performed on a cooked corn flour sample. RESULTS: Oral challenge was positive only for six patients with symptoms after ingestion of corn. A 50 kDa protein, belonging to the corn Reduced Soluble Protein (RSP) fraction was recognized by the serum IgE of all the DBPCFC-positive subjects and resulted to be resistant to both heating and peptic/pancreatic digestion. SPT with the purified RSP fraction gave positive results for all of the DBPCFC-positive patients examined. CONCLUSIONS: SPT and CAP-FEIA positivities to corn flour had no clinical significance for most of the patients and food allergy to corn has to be proved by DBPCFC. A salt-unextractable protein of 50 kDa, belonging to the RSP fraction, represents a potential allergen in food hypersensitivity to corn because of its stability to cooking and digestion.