Ecological indicators based on trophic spectrum as a tool to assess ecosystems fishing impacts

Trophic indicators were used to compare two Malian freshwater reservoirs whose main differences are based on their different fishing pressures. Data were collected from a scientific survey of small-scale fishery landings conducted in 2002/2003. The trophic levels of fish species caught by artisanal fisheries are estimated from observations of scientific fishing or from the metabase Fishbase. Important differences exist in the trophic structure of both reservoirs. In Selingue (with high fishing pressure), very few top predators are found in the catches while the low trophic level fishes increase in total catches. In Manantali (with low fishing pressure), the top predators contribute twice as much to catches compared to Selingue. Hence, the mean trophic level of catches in Selingue (2.80) is lower than in Manantali (2.97). When comparing these results with those of study made in 1994/1995, it clearly appears that the effects of the fishing pressure in Selingue are obvious through a decrease of 0.12 in the mean trophic level while in Manantali this mean level has increased by 0.33 due to a recent strategic targeting of top predators. Trophic spectra seem to be relevant tools to characterize exploited fish communities from multi-specific and multi-gear small-scale fisheries catch data.     

Environmental stresses inhibit splicing in the aquatic fungus Blastocladiella emersonii

Background  

Exposure of cells to environmental stress conditions can lead to the interruption of several intracellular processes, in particular those performed by macromolecular complexes such as the spliceosome.     

Maize based diets and possible neurobehavioural after-effects among some populations in the world

Maize is a cereal particularly lacking in tryptophan, which is the precursor of serotonin, an important neurotransmitter. Altough complementary foods may eliminate tryptophan deficiency, serotonin deficiency may often continue to exist because of competition made by other Large Neutral Amino Acids (LNAA) against tryptophan for neuron access, since they use the same carrier to cross the blood-brain barrier. Thus serotonin synthesis depends on two variables: the amount of tryptophan and the trp/LNAA ratio (R). “R” is lowest for common maize, low for beans and, as a rule, for most vegetable foods, higher for meat. So, when maize is the preponderant food in the meal, the “R” value lowers and so in parallel serotonin synthesis does. Serotonin deficiency involves several behavioural consequences, such as the tendency towards aggressive behaviour or the religious fanaticism. Among native american populations, these consequences appear, as a rule, positively correlated with maize alimentary dependence (Aztecs appear as those who greatly suffered from serotonin deficiency). In the world these are thinkable for some african populations (i.e. Zulu) or european (i.e. Balkan peoples).     

Influence of the denticity of ligand systems on the in vitro and in vivo behavior of (99m)Tc(I)-tricarbonyl complexes: a hint for the future functionalization of biomolecules

Functionalization of biologically relevant molecules for the labeling with the novel fac-[(99m)Tc(OH(2))(3)(CO)(3)](+) precursor has gained considerable attention recently. Therefore, we tested seven different tridentate (histidine L(1)(), iminodiacetic acid L(2)(), N-2-picolylamineacetic acid L(3)(), N, N-2-picolylaminediacetic acid L(4)()) and bidentate (histamine L(5)(), 2-picolinic acid L(6)(), 2,4-dipicolinic acid L(7)()) ligand systems, with the potential to be bifunctionalized and attached to a biomolecule. The ligands allowed mild radiolabeling conditions with fac-[(99m)Tc(OH(2))(3)(CO)(3)](+) (30 min, 75 degrees C). The ligand concentrations necessary to obtain yields of >95% of the corresponding organometallic complexes 1-7 ranged from 10(-)(6) to 10(-)(4) M. Complexes of the general formula "fac-[(99m)TcL(CO)(3)]" (L = tridentate ligand) and "fac-[(99m)Tc(OH(2))L'(CO)(3)]" (L' = bidentate ligand), respectively, were produced. Challenge studies with cysteine and histidine revealed significant displacement of the ligands in complexes 5-7 but only little exchange with complexes 1-4 after 24 h at 37 degrees C in PBS buffer. However, no decomposition to (99m)TcO(4)(-) was observed under these conditions. All complexes showed a hydrophilic character (log P(o/w) values ranging from -2.12 to 0.32). Time-dependent FPLC analyses of compounds 1-7 incubated in human plasma at 37 degrees C showed again no decomposition to (99m)TcO(4)(-) after 24 h at 37 degrees C. However, the complexes with bidentate ligands (5-7) became almost completely protein bound after 60 min, whereas the complexes with tridentate coordinated ligands (1-4) showed no reaction with serum proteins. The compounds were tested for their in vivo stability and the biodistribution characteristics in BALB/c mice. The complexes with tridentate coordinated ligand systems (1-4) revealed generally a good and fast clearance from all organs and tissues. On the other hand, the complexes with only bidentate coordinated ligands (5-7) showed a significantly higher retention of activity in the liver, the kidneys, and the blood pool. Detailed radiometric analyses of murine plasma samples, 30 min p.i. of complex fac-[(99m)TcL(1)(CO)(3)], 1, revealed almost no reaction of the radioactive complex with the plasma proteins. By contrast, in plasma samples of mice, which were injected with complex fac-[(99m)Tc(OH(2))L(5)(CO)(3)](+), 5, the entire radioactivity coeluded with the proteins. On the basis of these in vitro and in vivo experiments, it appears that functionalization of biomolecules with tridentate-chelating ligand systems is preferable for the labeling with fac-[(99m)Tc(OH(2))(3)(CO)(3)](+), since this will presumably result in radioactive bioconjugates with better pharmacokinetic profiles.     

Immunological functions of leptin and adiponectin

Recent years have seen several advances in our understanding of the functions of adipose tissue regarding not only the energy storage, but also the regulation of complex metabolic and endocrine functions. In this context, leptin and adiponectin, the two most abundant adipocyte products, represent one of the best example of adipocytokines involved in the control of energy expenditure, lipid and carbohydrate metabolism as well as in the regulation of immune responses. Leptin and adiponectin secretion is counter-regulated in vivo, in relation to degree of adiposity, since plasma leptin concentrations are significantly elevated in obese subjects in proportion to body mass index while adiponectin secretion decreases in relation to the amount of adipose tissue. In this review we focus on the main biological activities of leptin and adiponectin on the lipid and carbohydrate metabolism and on their contribute in regulation of innate and adaptive immune responses.     

Molecular study of genes involved in virulence regulatory pathways in Bacillus anthracis vaccine strain "Carbosap"

This study investigated the genetic bases of attenuation in the Bacillus anthracis vaccine strain "Carbosap" used in Italy against anthrax in cattle and sheep. Twelve genes involved in virulence regulatory pathways underwent sequence analysis in comparison with a B. anthracis virulent strain.     

Curcumin derivatives as new ligands of Aβ peptides

Curcumin derivatives with high chemical stability, improved solubility and carrying a functionalized appendage for the linkage to other entities, have been synthesized in a straightforward manner. All compounds retained Curcumin ability to bind Aβ peptide oligomers without inducing their aggregation. Moreover all Curcumin derivatives were able to stain very efficiently Aβ deposits.