Nitroso-aldicarb induces sister-chromatid exchanges in human lymphocytes in vitro

Nitroso-aldicarb was tested for its ability to induce sister-chromatid exchanges (SCE) and cell-cycle delay in human peripheral blood lymphocytes in vitro. This derivative of aldicarb induced a dose-dependent increase in SCE values per cell. In addition, a slight decrease in the successive mitotic progression of cells in culture was observed.     

Tight control of the amount of yeast plasma membrane ATPase during changes in growth conditions and gene dosage

The activity of the plasma membrane ATPase in growing yeast is increased by low pH and by glucose, conditions which result in a higher demand for proton pumping. The amount of enzyme is not significatively modified under these conditions. The amount of ATPase is only slightly increased by introducing extra copies of its gene in autonomous plasmids. In addition, the expression of the ATPase gene in a multi-copy plasmid causes a reduction of the copy number of the plasmid and slows growth. Therefore, overexpression of the ATPase is detrimental for the cell, justifying a regulatory mechanism based on increasing the catalytic activity and not the amount of enzyme.     

Life history and production of the burrowing mayfly Ephoron virgo (Olivier, 1791) (Ephemeroptera: Polymitarcyidae) in the lower Ebro river: a comparison after 18 years

The life history of the burrowing mayfly Ephoron virgo (Olivier, 1791) (Ephemeroptera: Polymitarcyidae) was studied during spring and summer 2005 in the lower Ebro river (Catalonia) and compared to a previous study performed in 1987 (Ibáñez, Escosa, Muñoz and Prat 1991). The results showed an advancement of Ephoron virgo life cycle and an increase of production estimates. In 2005 larval development reached the maximum size one month earlier than in 1987, and adult emergence peak began three weeks earlier. Comparing adult sex ratios (F:M), there was a major presence of females in 2005 (1:4), while the opposite was observed in 1987 (2:1). Secondary production was higher in 2005 than in 1987, obtaining 950 mg dry weight/m²/year with the increment summation method and 1080 mg dry weight/m²/year using the removal summation method. Higher water temperatures were measured for the entire 2005 larval growth period, which were related to higher air temperatures. Therefore, that temperature increment was likely the main cause of changes observed in the Ephoron virgo life cycle.     

Seasonal Habitat Use of Agoutis (Dasyprocta azarae) is Driven by the Palm Attalea phalerata in Brazilian Pantanal

Resource availability can influence animal movement causing changes in home‐range size and arrangement between seasons. We investigated the influence of acuri palm (Attalea phalerata) on the occupancy of agouti Dasyprocta azare during both the dry and rainy seasons, as well as the abandonment probabilities in the transition between seasons in the Brazilian Pantanal. The agoutis occupied a high proportion of the forested areas in the rainy season (0.83), but the occupancy decreased in the dry season (0.39). In the rainy season, occupancy by agoutis was not correlated with acuri palm availability, while in the dry season, it was positively correlated with the palm's availability. The acuri palm availability also drove the agoutis' probability of site abandonment from the rainy to the dry season, with higher abandonment probability in sites with low acuri palm availability. These findings show that this large‐seeded palm can be an important resource for the agoutis' populations during the fruit‐scarcity period. The acuri palm seeds may be particularly important for agoutis using fragmented forests, given that the large‐seeded palms are able to persist even in small fragments, which is untrue for other important resource.     

Effects of (−)-epicatechin and derivatives on nitric oxide mediated induction of mitochondrial proteins

Impaired mitochondrial function represents an early manifestation of endothelial dysfunction and likely contributes to the development of cardiovascular diseases (CVD). The stimulation of mitochondrial function and/or biogenesis is seen as a means to improve the bioenergetic and metabolic status of cells and thus, reduce CVD. In this study we examined the capacity of the flavanol (?)-epicatechin and two novel derivatives to enhance mitochondrial function and protein levels in cultured bovine coronary artery endothelial cells. As nitric oxide production by endothelial cells is suspected in mediating mitochondria effects (including biogenesis), we also examined the dependence of responses on this molecule using an inhibitor of nitric oxide synthase. Results indicate that the flavanol (?)-epicatechin and derivatives are capable of stimulating mitochondrial function as assessed by citrate synthase activity as well as induction of structural (porin, mitofilin) and oxidative phosporylation protein levels (complex I and II). Effects were blocked by the use of the chemical inhibitor of the synthase thus, evidencing a role for nitric oxide in mediating these effects. The results observed indicate that the three agents are effective in enhancing mitochondria function and protein content. The effects noted for (?)-epicatechin may serve to explain the healthy effects on cardiometabolic risk ascribed to the consumption of cocoa products.     

Murine Cell Glycolipids Customization by Modular Expression of Glycosyltransferases

Functional analysis of glycolipids has been hampered by their complex nature and combinatorial expression in cells and tissues. We report an efficient and easy method to generate cells with specific glycolipids. In our proof of principle experiments we have demonstrated the customized expression of two relevant glycosphingolipids on murine fibroblasts, stage-specific embryonic antigen 3 (SSEA-3), a marker for stem cells, and Forssman glycolipid, a xenoantigen. Sets of genes encoding glycosyltansferases were transduced by viral infection followed by multi-color cell sorting based on coupled expression of fluorescent proteins.     

Effects of co-cropping Bidens pilosa (L.) and Tagetes minuta (L.) on bioaccumulation of Pb in Lactuca sativa (L.) growing in polluted agricultural soils

Polluted agricultural soils are a serious problem for food safety, with phytoremediation being the most favorable alternative from the environmental perspective. However, this methodology is generally time-consuming and requires the cessation of agriculture. Therefore, the purpose of this study was to evaluate two potential phytoextractor plants (the native species Bidens pilosa and Tagetes minuta) co-cropped with lettuce growing on agricultural lead-polluted soils. The concentrations of Pb, as well as of other metals, were investigated in the phytoextractors, crop species, and in soils, with the potential risk to the health of consumers being estimated. The soil parameters pH, EC, organic matter percentage and bioavailable lead showed a direct relationship with the accumulation of Pb in roots. In addition, the concentration of Pb in roots of native species was closely related to Fe (B. pilosa, r = 0.81; T. minuta r = 0.75), Cu (T. minuta, r = 0.93), Mn (B. pilosa, r = 0.89) and Zn (B. pilosa, r = 0.91; T. minuta, r = 0.91). Our results indicate that the interaction between rhizospheres increased the phytoextraction of lead, which was accompanied by an increase in the biomass of the phytoextractor species. However, the consumption of lettuce still revealed a toxicological risk from Pb in all treatments.     

Proximodistal Organization of the CA2 Hippocampal Area

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