Effect of copper sulfate on experimental atherosclerosis

Serum copper concentration increases significantly (p<0.01) in rats with experimental atherosclerosis compared to a control group. The serum zinc, the zinc, and copper concentration in abdominal aorta and in liver decreases significantly (p<0.05) compared to the control group. Administration of copper sulfate for 100 d in these animals induces a significant increase of serum copper (p<0.01), decrease of serum cholesterol (p<0.05) and increase of liver copper concentration as compared with the group fed only a high cholesterol diet. In the aorta of these animals the copper concentration increases and edema and lipid infiltration are considerably less than in the group of animals fed only a high lipid diet.     

Estimates of forest floor litter frog communities: A comparison of two methods

Estimates of forest leaf litter frog density, mass, richness and diversity given by the widely used 8 m × 8 m large plot method (LPM) were compared with estimates obtained by a newly proposed method (small 2 m × 1 m plots with leaf removal; SPLR). The study site was an undisturbed area of the Atlantic Rainforest of Ilha Grande, an island located in the south of Rio de Janeiro State, Brazil. Twenty‐four LPM (totalling 1536 m² of forest floor) and 90 SPLR (totalling 180 m² of forest floor) were performed. The estimates obtained by the two methods differed markedly, indicating that even using a much smaller sampling area (11.7% of that of LPM), SPLR gave frog density estimates six times higher, and frog mass estimates approximately 2.5 times higher than estimates provided by LPM. The species richness and diversity obtained by the two methods were similar, despite the fact that the total area sampled with SPLR was much smaller. These data suggest that LPM may underestimate the abundance and biomass of leaf litter frogs in a given area.     

Optical method for monitoring of photodynamic inactivation of bacteria

Photodynamic inactivation is a new promising approach to treat bacterial infections. Usually, the evaluation of the efficacy of this method is done through time-consuming and labor-intensive microbiological test methods. This paper describes the development and implementation of an optical method to evaluate the photodynamic inactivation of bacteria based on non-invasive diffuse reflectance measurements. Five Staphylococcus aureus cultures and 15 mice have been used in this study. A skin lesion was created on the back of all animals, and it was contaminated with S. aureus (5.16 ± 0.013 log CFU/ml). Toluidine Blue O (c = 8.67 × 10 ^− 3 M) has been used as a photosensitiser agent. The bacterial cultures and animals were exposed to laser radiation (λ = 635 nm, P = 15 mW, DE = 8.654 J/cm²) for 20 min. The photodynamic inactivation of bacteria was monitored by acquiring the wounds’ reflection spectra at different time points and by microbiological exams on the bioptical material. The good correlation between the diffuse reflectance and colony-forming units demonstrates the value of this optical method based on diffuse reflectance measurements as a rapid technique to monitor photodynamic bacterial inactivation.     

Exploitation of mitochondrial nad6 as a complementary marker for studying population variability in Lepidoptera

The applicability of mitochondrial nad6 sequences to studies of DNA and population variability in Lepidoptera was tested in four species of economically important moths and one of wild butterflies. The genetic information so obtained was compared to that of cox1 sequences for two species of Lepidoptera. nad6 primers appropriately amplified all the tested DNA targets, the generated data proving to be as informative and suitable in recovering population structures as that of cox1. The proposal is that, to obtain more robust results, this mitochondrial region can be complementarily used with other molecular sequences in studies of low level phylogeny and population genetics in Lepidoptera.     

Unraveling the plant diversity of the Amazonian canga through DNA barcoding

The canga of the Serra dos Carajás, in Eastern Amazon, is home to a unique open plant community, harboring several endemic and rare species. Although a complete flora survey has been recently published, scarce to no genetic information is available for most plant species of the ironstone outcrops of the Serra dos Carajás. In this scenario, DNA barcoding appears as a fast and effective approach to assess the genetic diversity of the Serra dos Carajás flora, considering the growing need for robust biodiversity conservation planning in such an area with industrial mining activities. Thus, after testing eight different DNA barcode markers (matK, rbcL, rpoB, rpoC1, atpF‐atpH, psbK‐psbI, trnH‐psbA, and ITS2), we chose rbcL and ITS2 as the most suitable markers for a broad application in the regional flora. Here we describe DNA barcodes for 1,130 specimens of 538 species, 323 genera, and 115 families of vascular plants from a highly diverse flora in the Amazon basin, with a total of 344 species being barcoded for the first time. In addition, we assessed the potential of using DNA metabarcoding of bulk samples for surveying plant diversity in the canga. Upon achieving the first comprehensive DNA barcoding effort directed to a complete flora in the Brazilian Amazon, we discuss the relevance of our results to guide future conservation measures in the Serra dos Carajás.     

The heat shock protein HSP70 promotes mouse NK cell activity against tumors that express inducible NKG2D ligands

The stress-inducible heat shock protein (HSP) 70 is known to function as an endogenous danger signal that can increase the immunogenicity of tumors and induce CTL responses. We show in this study that HSP70 also activates mouse NK cells that recognize stress-inducible NKG2D ligands on tumor cells. Tumor size and the rate of metastases derived from HSP70-overexpressing human melanoma cells were found to be reduced in T and B cell-deficient SCID mice, but not in SCID/beige mice that lack additionally functional NK cells. In the SCID mice with HSP70-overexpressing tumors, NK cells were activated so that they killed ex vivo tumor cells that expressed NKG2D ligands. In the tumors, the MHC class I chain-related (MIC) A and B molecules were found to be expressed. Interestingly, a counter selection was observed against the expression of MICA/B in HSP70-overexpressing tumors compared with control tumors in SCID, but not in SCID/beige mice, suggesting a functional relevance of MICA/B expression. The melanoma cells were found to release exosomes. HSP70-positive exosomes from the HSP70-overexpressing cells, in contrast to HSP70-negative exosomes from the control cells, were able to activate mouse NK cells in vitro to kill YAC-1 cells, which express NKG2D ligands constitutively, or the human melanoma cells, in which MICA/B expression was induced. Thus, HSP70 and inducible NKG2D ligands synergistically promote the activation of mouse NK cells resulting in a reduced tumor growth and suppression of metastatic disease.     

Malnutrition enhances cardiovascular responses to chemoreflex activation in awake rats

Several studies in the literature suggest that low-protein intake is associated with increases in sympathetic efferent activity and cardiovascular disease. Among the possible mechanisms, changes in the neurotransmission of cardiovascular reflexes have been implicated. Therefore, the present study comprised the evaluation of chemoreflex responsiveness in rats subjected to a low-protein diet during the 35 days after weaning. As a result, we observed that malnourished rats presented higher levels of baseline mean arterial pressure and heart rate and exhibited a mild increase in the pressor response to chemoreflex activation. They also exhibited a massive bradycardic response to chemoreflex activation. Interestingly, bilateral ligature of the carotid body arteries further increased baseline mean arterial pressure and heart rate in malnourished animals. The data suggest severe autonomic imbalance and/or change in the central interplay between neural and cardiovascular mechanisms.