High glucose increases B1-kinin receptor expression and signaling in endothelial cells

The loss of endothelial function is the initiating factor in the development of diabetic vascular disease. Kinins control endothelial function by the activation of two receptors: the B2 which is constitutively expressed, and the B1 which is highly induced in pathological conditions. In the present study, we observed that the levels of B1-receptor mRNA and protein are induced in endothelial cells incubated in high glucose. An increase in B1-receptor was also observed in the endothelial layer of aortas, from 4-week diabetic rats. When cells were grown in high glucose, the B1 agonist des-Arg9-BK increased nitrite levels, whereas in normal glucose nitrite levels were unchanged. Nitrite increase was blocked by L-NAME and 1400W indicating the participation of the inducible Nitric Oxide Synthase (iNOS). iNOS protein levels were also increased in high glucose. These results demonstrate the participation of the B1 receptor in the signaling pathways mediated by kinins in high glucose.     

Effects of macromolecular crowding on the inhibition of virus assembly and virus-cell receptor recognition

Biological fluids contain a very high total concentration of macromolecules that leads to volume exclusion by one molecule to another. Theory and experiment have shown that this condition, termed macromolecular crowding, can have significant effects on molecular recognition. However, the influence of molecular crowding on recognition events involving virus particles, and their inhibition by antiviral compounds, is virtually unexplored. Among these processes, capsid self-assembly during viral morphogenesis and capsid-cell receptor recognition during virus entry into cells are receiving increasing attention as targets for the development of new antiviral drugs. In this study, we have analyzed the effect of macromolecular crowding on the inhibition of these two processes by peptides. Macromolecular crowding led to a significant reduction in the inhibitory activity of: 1), a capsid-binding peptide and a small capsid protein domain that interfere with assembly of the human immunodeficiency virus capsid, and 2), a RGD-containing peptide able to block the interaction between foot-and-mouth disease virus and receptor molecules on the host cell membrane (in this case, the effect was dependent on the conditions used). The results, discussed in the light of macromolecular crowding theory, are relevant for a quantitative understanding of molecular recognition processes during virus infection and its inhibition.     

Body size as an important factor determining trophic niche partitioning in three syntopic rhinolophid bat species

We investigated a community of syntopically occurring horseshoe bats (Rhinolophus hipposideros, R. euryale, R. ferrumequinum) in southern Slovakia. The faecal pellets of these bat species were collected in the field and later analysed under a dissecting microscope. The three species studied are known to be very similar as far as their ecology, echolocation and preferred habitats are concerned, but they diverge significantly in their body sizes. In this study, all three species fed predominantly on moths [59–80 percentage frequency (%f); 87–95 percentage volume (%vol)], but their diet compositions differed in the size of individuals consumed. The smallest bat species (R. hipposideros) fed only on the smallest moths (%f = 59; %vol = 87), the medium-sized species (R. euryale) mainly on medium-sized moths (%f = 60; %vol = 74) and the largest one (R. ferrumequinum) especially on the largest moths (%f = 54; %vol = 89). Despite similar preferred habitat and the main prey category, the rates of trophic niche overlap were surprisingly low. The trophic niche percentage overlap was 7–31% (computed from %f data) and 1–20% (computed from %vol data), respectively and suggests an extraordinary importance of mere divergences of bats in their body sizes for trophic niche partitioning and stable species coexistence.     

Evaluating mortality rates and causalities in a critically endangered felid across its whole distribution range

The conservation of endangered species requires accurate data, and knowledge of cause-specific mortality rates is one of the most important issues. In recent years, conservation programs for the critically endangered Iberian lynx Lynx pardinus have been developed on the basis of mortality data derived 30 years ago from the small Doñana population. Thus, there is an urgent need for an update of mortality rates and causes in both populations (Sierra Morena and Doñana). Here we use radio-tracking information from the whole range of the Iberian lynx to quantify mortality rates and identify their causes. Between 2006 and 2011, we radio-tagged 78 Iberian lynxes from its two remaining populations (39 from Sierra Morena and 39 from Doñana). Mortality events were evaluated to identify causes, and cause-specific annual mortality rates (AMR) were obtained using the nonparametric cumulative incidence function estimator. Overall, AMR was estimated at 0.16?±?0.05 (0.19?±?0.09 in Sierra Morena and 0.12?±?0.07 in Doñana). Disease was the main cause of mortality both for the whole population and the Doñana population. Poaching was the main cause of mortality in Sierra Morena. Our results suggest that the best strategy for conserving this species is to focus action on decreasing the fatal effect of disease and poaching. Given the possible existence of an underlying inbreeding-mediated immunosuppression, genetic management aimed at increasing the genetic diversity of this population is also recommended.     

High dietary salt decreases antioxidant defenses in the liver of fructose-fed insulin-resistant rats

In this study we investigated the hypothesis that a high-salt diet to hyperinsulinemic rats might impair antioxidant defense owing to its involvement in the activation of sodium reabsorption to lead to higher oxidative stress. Rats were fed a standard (CON), a high-salt (HS), or a high-fructose (HF) diet for 10 weeks after which, 50% of the animals belonging to the HF group were switched to a regimen of high-fructose and high-salt diet (HFS) for 10 more weeks, while the other groups were fed with their respective diets. Animals were then euthanized and their blood and liver were examined. Fasting plasma glucose was found to be significantly higher (approximately 50%) in fructose-fed rats than in the control and HS rats, whereas fat liver also differed in these animals, producing steatosis. Feeding fructose-fed rats with the high-salt diet triggered hyperinsulinemia and lowered insulin sensitivity, which led to increased levels of serum sodium compared to the HS group. This resulted in membrane perturbation, which in the presence of steatosis potentially enhanced hepatic lipid peroxidation, thereby decreasing the level of antioxidant defenses, as shown by GSH/GSSG ratio (HFS rats, 7.098±2.1 versus CON rats, 13.2±6.1) and superoxide dismutase (HFS rats, 2.1±0.05 versus CON rats, 2.3±0.1%), and catalase (HFS rats, 526.6±88.6 versus CON rats, 745.8±228.7 U/mg ptn) activities. Our results indicate that consumption of a salt-rich diet by insulin-resistant rats may lead to regulation of sodium reabsorption, worsening hepatic lipid peroxidation associated with impaired antioxidant defenses.     

Differences in uptake of labelled serotonin, dopamine and noradrenaline by the CNS and other tissues in Anodontacygnea L., depending on the activity of the animal

Among monoamines injected intracardially during activity, 3H-serotonin was taken up by the kidney, while 3H-dopamine and 3H-noradrenaline by the ganglia in the highest amount. The uptake of the labelled monoamines in the corresponding tissue was significantly lower during rest.     

Soil chemical properties affect the concentration of elements (N,P, K,Ca, Mg,As, Cd,Cr, Cu,Fe, Mn,Ni, Pb,and Zn) and their distribution between organs of Rumex obtusifolius

Background and aims

The ionome (elemental composition) of grassland species has rarely been studied at the level of individual organs and little is known about effects of soil chemical properties on the ionome. Using the model oxalate plant Rumex obtusifolius, we asked how its biomass production and the distribution of elements between its organs is affected by soil chemical properties.

Methods

We established a pot experiment with R. obtusifolius planted in acidic non-contaminated control and in slightly acidic and alkaline soils anthropogenically contaminated by the risk elements As, Cd, Pb, and Zn. Both contaminated soils were untreated and treated by lime and superphosphate. We determined biomass production and the concentrations of elements in its organs.

Results

Biomass production was negatively related to the mobility of micro- and risk elements. Restricted transport of micro- and risk elements from belowground organs into leaves was recorded in untreated contaminated soils. In both lime-treated soils and in superphosphate-treated alkaline soil, elevated transport of micro- and risk elements from belowground organs into leaves was recorded in comparison to untreated contaminated soils. The lowest concentrations of micro- and risk elements were recorded in stems and seeds, followed by belowground organs and leaves.

Conclusions

R. obtusifolius is an As-, Cd-, Pb-, and Zn-excluder and is sensitive to high availability of micro- and risk elements in the soil. Soil chemical properties affect the distribution of essential elements within the plant greatly.     

A comparative study of molecular and morphological methods of describing relationships between perennial ryegrass (Lolium perenne L.) varieties

A sample set of registered perennial ryegrass varieties was used to compare how morphological characterisation and AFLP^® (AFLP^® is a registered trademark of Keygene N.V.) and STS molecular markers described variety relationships. All the varieties were confirmed as morphologically distinct, and both the STS and AFLP markers exposed sufficient genetic diversity to differentiate these registered ryegrass varieties. Distances obtained by each of the approaches were compared, with special attention given to the coincidences and divergences between the methods. When correlations between morphological, AFLP and STS distances were calculated and the corresponding scatter-plots constructed, the variety relationships appeared to be rather inconsistent across the methods, especially between morphology and the molecular markers. However, some consistencies were found for closely related material. An implication could be that these molecular-marker techniques, while not yet suited to certain operations in the traditional registration of new varieties, could be suitable methods for investigating disputable distinctness situations or possible EDV (EDV= essentially derived variety. An EDV is a variety being clearly distinct from, but conforming in the expression of the essential characteristics of, an ’initial variety’ (IV) from which it is found to have been predominantly derived) relationships, subject to establishing standardised protocols and statistical techniques. Some suggestions for such a protocol, including a statistical test for distinctness, are given.     

Association od the DdeI growth hormone gene polymorphism with some performance traits in Polish Large White and Czech Large White x Polish Large White pigs

The genotypes of growth hormone gene polymorphisms (GH-DdeI, GH-MspI, GH-HaeII, GH-ApaI, GH-CfoI) were determined in 78 pigs [Czech Large White sires (CLWsire line) x Polish Large White (PLW) sows, Polish Large White sires x Polish Large White sows], by the PCR-RFLP method. Preliminary studies found only GH DdeI polymorphism to be associated with performance traits. The associations of this polymorphism with growth and carcass traits were investigated. The linear model included the effects of candidate genes, genetic groups, sex and linear covariables of age at slaughter and body weight at weaning. The DdeI polymorphism of the GH gene showed associations with carcass length (P 相似文献