Length-weight relationships of ornamental fish species from Amanã Lake,Amanã Reserve,Amazonas, Brazil

Length-weight relationships (LWRs) were estimated for 16 ornamental fish species from Amanã Lake and nine tributary streams, in Central Brazilian Amazonia. Sampling was carried out bimonthly for a year (2007–2008), using two sets of four gillnets (20 m × 2 m, 2,5; 3,5; 04; 4,5 cm stretch mesh size); trawls were performed with seine nets (35 m × 6 m, 3 mm stretch mesh size); native fish-traps (fyke-net like fish-traps woven from local lianas), and dip nets (0.5 m × 0.5 m stretch mesh size). Measurements were done for standard length (SL – 0.1 cm precision) and total weight (Wt – 0.01 g precision). This study provides information on the length–weight relationships for all sampled species and, in addition, provides new maximum standard lengths for six species.     

Effect of handling on ATP utilization of cerebral Na,K-ATPase in rats with trimethyltin-induced neurodegeneration

Molecular and Cellular Biochemistry - Previously it was shown that for reduction of anxiety and stress of experimental animals, preventive handling seems to be one of the most effective methods....     

Almost half of the RTX domain is dispensable for complement receptor 3 binding and cell-invasive activity of the Bordetella adenylate cyclase toxin

The whooping cough agent Bordetella pertussis secretes an adenylate cyclase toxin (CyaA) that through its large carboxy-proximal Repeat-in-ToXin (RTX) domain binds the complement receptor 3 (CR3). The RTX domain consists of five blocks (I–V) of characteristic glycine and aspartate-rich nonapeptides that fold into five Ca²⁺-loaded parallel β-rolls. Previous work indicated that the CR3-binding structure comprises the interface of β-rolls II and III. To test if further portions of the RTX domain contribute to CR3 binding, we generated a construct with the RTX block II/III interface (CyaA residues 1132–1294) linked directly to the C-terminal block V fragment bearing the folding scaffold (CyaA residues 1562–1681). Despite deletion of 267 internal residues of the RTX domain, the Ca²⁺-driven folding of the hybrid block III/V β-roll still supported formation of the CR3-binding structure at the interface of β-rolls II and III. Moreover, upon stabilization by N- and C-terminal flanking segments, the block III/V hybrid-comprising constructs competed with CyaA for CR3 binding and induced formation of CyaA toxin-neutralizing antibodies in mice. Finally, a truncated CyaAΔ_1295-1561 toxin bound and penetrated erythrocytes and CR3-expressing cells, showing that the deleted portions of RTX blocks III, IV, and V (residues 1295–1561) were dispensable for CR3 binding and for toxin translocation across the target cell membrane. This suggests that almost a half of the RTX domain of CyaA is not involved in target cell interaction and rather serves the purpose of toxin secretion.     

Evaluation of Antioxidant,Antibacterial and Enhancement of Antibiotic Action by Punica granatum Leaves Crude Extract and Enriched Fraction against Multidrug-Resistant Bacteria

The aim of this study was to evaluate the phytochemical composition, antioxidant, and antimicrobial potential of crude extract and fractions of Punica granatum leaves. The extract was produced by turbo extraction, after which hexanic, ethyl acetate, and aqueous fractions were obtained by partitioning. The chemical analyses were performed by thin layer chromatography and high-performance liquid chromatography, and the antioxidant activities were assayed by DPPH^. and ABTS^.+. Minimal inhibitory and bactericidal concentrations (MIC/MBC) were applied to twenty-two bacteria. Most strains susceptible to extract/fractions and resistant to antibiotics were selected, and ampicillin, azithromycin, ciprofloxacin, and gentamicin were associated with the ethyl acetate fraction (EAF) against multidrug-resistant strains in modulatory and checkboard models. The data from chromatographic analyses showed flavonoids and tannins in the extract, as well as the enrichment of EAF in phenols, mainly flavonoids. The flavonoids were connected to the electron transfer activity demonstrated in the DPPH^. and ABTS^.+ assays. Gram-positive strains are more susceptible to EAF. The subinhibitory concentrations of P. granatum enhanced the antimicrobial activity of the agents and reduced the EAF individual MIC, and the combination of EAF and antibiotics demonstrated a synergistic effect. These results present a promising approach for developing a therapy in which antioxidant extracts and fractions can be used in combination with antibiotics.     

Antimicrobial Peptides as Potential Therapeutic Agents: A Review

International Journal of Peptide Research and Therapeutics - The growth of pathogens across the globe is developing at a very fast rate, thus turning into a worldwide health problem. Since, current...