Anti-inflammatory effects of a triterpenoid isolated from Wilbrandia ebracteata Cogn

Wilbrandia ebracteata (WE), a Brazilian medicinal plant used in folk medicine for the treatment of rheumatic diseases, displays anti-inflammatory properties and constitutes a rich source of cucurbitacins and cucurbitacin-related compounds. The current study investigated the potential anti-inflammatory properties of Dihydrocucurbitacin B (DHCB), a cucurbitacin-derived compound isolated from roots of WE, in some in vivo and in vitro experimental models. Intraperitoneal treatment of mice with DHCB reduced both carrageenan-induced paw edema (0.3, 1 and 3 mg/kg caused inhibitions of 26, 44 and 56 % at 2 h after stimulation, respectively) and pleurisy (10 mg/kg inhibited leukocyte numbers and LTB(4) levels in the pleural fluid by 51 and 75% at 6 h after cavity challenge, respectively). In vitro, DHCB (up to 10 microg/mL) failed to modify LTB(4) production by human neutrophils or PGE(2) production by COS-7 cells transfected with COX-1, but PGE(2) production by COX-2 transfected COS-7 cells was markedly inhibited (by 72%). The levels of COX-1 or COX-2 proteins in IL-1alpha-stimulated NIH3T3 cells were unaffected by DHCB. The results corroborate the potential anti-inflammatory properties ascribed to W. ebracteata Cogn. in folk medicine and suggest that they might be attributed, at least in part, to the capacity of one of this plants main constituents, DHCB, to inhibit COX-2 activity (but not its expression) during inflammation.     

Co-Utilization of Canola Oil and Glucose on the Production of a Surfactant by <Emphasis Type="Italic">Candida lipolytica</Emphasis>

Candida lipolytica synthesized a surfactant in a cultivation medium supplemented with canola oil and glucose as carbon sources. Measurements of biosurfactant production and surface tension indicated that the biosurfactant was produced at 48 h of fermentation. The surface-active species is constituted by the protein–lipid–polysaccharide complex in nature. The cell-free broth was particularly influenced by the addition of salt, the pH and temperature depending on the emulsified substrate (hexadecane or a vegetable oil). After comparison between ethyl acetate and mixtures of chloroform and methanol as solvent systems for surfactant recovery, it was found that ethyl acetate was able to extract crude surfactant material with high product recovery (8.0 g/L). The isolated biosurfactant decreased the surface tension to values of 30 mN/m at the critical micelle concentration. Emulsification properties of the biosurfactant produced were compared to those of commercial emulsifiers and other microbial surfactants.     

Evaluating the Accuracy of Molecular Diagnostic Testing for Canine Visceral Leishmaniasis Using Latent Class Analysis

Host tissues affected by Leishmania infantum have differing degrees of parasitism. Previously, the use of different biological tissues to detect L. infantum DNA in dogs has provided variable results. The present study was conducted to evaluate the accuracy of molecular diagnostic testing (qPCR) in dogs from an endemic area for canine visceral leishmaniasis (CVL) by determining which tissue type provided the highest rate of parasite DNA detection. Fifty-one symptomatic dogs were tested for CVL using serological, parasitological and molecular methods. Latent class analysis (LCA) was performed for accuracy evaluation of these methods. qPCR detected parasite DNA in 100% of these animals from at least one of the following tissues: splenic and bone marrow aspirates, lymph node and skin fragments, blood and conjunctival swabs. Using latent variable as gold standard, the qPCR achieved a sensitivity of 95.8% (CI 90.4–100) in splenic aspirate; 79.2% (CI 68–90.3) in lymph nodes; 77.3% (CI 64.5–90.1) in skin; 75% (CI 63.1–86.9) in blood; 50% (CI 30–70) in bone marrow; 37.5% (CI 24.2–50.8) in left-eye; and 29.2% (CI 16.7–41.6) in right-eye conjunctival swabs. The accuracy of qPCR using splenic aspirates was further evaluated in a random larger sample (n = 800), collected from dogs during a prevalence study. The specificity achieved by qPCR was 76.7% (CI 73.7–79.6) for splenic aspirates obtained from the greater sample. The sensitivity accomplished by this technique was 95% (CI 93.5–96.5) that was higher than those obtained for the other diagnostic tests and was similar to that observed in the smaller sampling study. This confirms that the splenic aspirate is the most effective type of tissue for detecting L. infantum infection. Additionally, we demonstrated that LCA could be used to generate a suitable gold standard for comparative CVL testing.     

TESTING MITOCHONDRIAL CAPTURE AND DEEP COALESCENCE IN AMAZONIAN CICHLID FISHES (CICHLIDAE: CICHLA)

Hybridization and introgression have important consequences in evolution, such as increasing the genetic diversity and adaptive potential of a species. One of their most conspicuous footprints is discordance among gene trees or between genes and phenotypes. However, most studies that report introgression fail to disprove the null hypothesis that genetic incongruence may result from stochastic sorting of ancestral allelic polymorphisms. In the case of ancient introgression, these two processes may be especially difficult to distinguish topologically, but they make different predictions about the patterns of coalescence among loci. Here we apply three methods, molecular dating, multispecies coalescent models, and gene tree simulation under coalescence, to compare these two hypotheses that explain the polyphyletic mtDNA of the butterfly peacock bass, Cichla orinocensis. In comparison with a species tree based on 20 unlinked nuclear loci, we determined that mtDNA divergences were too recent to be explained by ancestral polymorphism. Similarly, coalescent species tree branches were significantly shorter when putative introgressed mtDNA was incorporated, and simulations showed the mtDNA topology to be unlikely under lineage sorting only. We conclude that introgression approximately 1.5 million years ago resulted in capture by C. orinocensis of an mtDNA lineage ancestral to the modern subspecies C. oc. monoculus.     

Azteca barbifex Forel (Hymenoptera: Formicidae): potential pest of citrus crops in eastern Amazon

Damage caused by the ant Azteca barbifex (Forel) was identified in orange trees (Citrus sinensis), in Capit?o Po?o County, Guamá microregion, Pará State. The damage caused by the scraping of stems and branches lead to reduction in yield with subsequent death of the plant. These characteristics indicate A. barbifex as a potential pest of citrus crops in the eastern region of Amazon.     

Gastrin-Releasing Peptide Receptor Knockdown Induces Senescence in Glioblastoma Cells

Glioblastoma multiforme (GBM) is the most aggressive type of brain tumor, characterized by excessive cell proliferation, resistance to apoptosis, and invasiveness. Due to resistance to currently available treatment options, the prognosis for patients with GBM is very dismal. The activation of gastrin-releasing peptide receptors (GRPR) stimulates GBM cell proliferation, whereas GRPR antagonists induce antiproliferative effects in in vitro and in vivo experimental models of GBM. However, the role of GRPR in regulating other aspects of GBM cell function related to tumor progression remains poorly understood, and previous studies have not used RNA interference techniques as tools to examine GRPR function in GBM. Here, we found that stable GRPR knockdown by a lentiviral vector using a short hairpin interfering RNA sequence in human A172 GBM cells resulted in increased cell size and altered cell cycle dynamics consistent with cell senescence. These changes were accompanied by increases in the content of p53, p21, and p16, activation of epidermal growth factor receptors (EGFR), and a reduction in p38 content. These results increase our understanding of GRPR regulation of GBM cells and further support that GRPR may be a relevant therapeutic target in GBM.