Antinociceptive and hypothermic evaluation of the leaf essential oil and isolated terpenoids from Eugenia uniflora L. (Brazilian Pitanga)

Eugenia uniflora L. (Myrtaceae), known as Brazilian cherry tree, is a fruity tree spread all over Brazil used in popular medicine to treat inflammations, rheumatic pain and fever, as hypoglycemic, diuretic and has been widely used in the cosmetics industry. The present study discusses the chemical composition, the antinociceptive and hypothermic profile of the essential oil of pitangueira leaves. The chemical composition was evaluated by GC-MS and the main constituent of the oil was characterized, after isolation, as a mixture of atractylone (1) and 3-furanoeudesmene (2). The essential oil, its pentane fraction and the isolated mixture of sesquiterpenes (1 and 2), given orally, significantly inhibited the acetic acid-induced abdominal constrictions, increased the latency time in hot plate test and showed a hypothermic effect. The results suggest that the responsible for the antinociceptive and hypothermic effect were the isolated furanosesquiterpenes. These findings provided additional pharmacological information and may contribute for the use of Brazilian cherry tree as a phytomedicine.     

The Tropical Biominer Project: mining old sources for new drugs

The Tropical Biominer Project is a recent initiative from the Federal University of Minas Gerais (UFMG) and the Oswaldo Cruz foundation, with the participation of the Biominas Foundation (Belo Horizonte, Minas Gerais, Brazil) and the start-up Homologix. The main objective of the project is to build a new resource for the chemogenomics research, on chemical compounds, with a strong emphasis on natural molecules. Adopted technologies include the search of information from structured, semi-structured, and non-structured documents (the last two from the web) and datamining tools in order to gather information from different sources. The database is the support for developing applications to find new potential treatments for parasitic infections by using virtual screening tools. We present here the midpoint of the project: the conception and implementation of the Tropical Biominer Database. This is a Federated Database designed to store data from different resources. Connected to the database, a web crawler is able to gather information from distinct, patented web sites and store them after automatic classification using datamining tools. Finally, we demonstrate the interest of the approach, by formulating new hypotheses on specific targets of a natural compound, violacein, using inferences from a Virtual Screening procedure.     

A three-step molecular protocol employing DNA obtained from dried blood spots for neonatal screening for 45,X Turner syndrome

Turner syndrome (TS) is one of the most common human chromosomal abnormalities; it is characterized by the presence of one normal X chromosome and the complete or partial loss of the second X chromosome. The early recognition of TS patients allows for adequate therapy for short stature and pubertal sex steroid substitution. We developed a cost-effective molecular diagnostic tool that can be used to identify 45,X TS patients from dried blood spots, for possible use in neonatal screening for TS. We used a three-step method for 45,X TS detection: i) DNA extraction from dried blood spot samples, ii) pre-PCR HpaII digestion (methylation-sensitive enzyme) and iii) GeneScan analysis of selected cases. DAX-1 gene amplification was used to recognize DNA integrity, and the androgen receptor gene (Xq11-12), which is both a highly polymorphic and methylated gene, was used to determine the number of X chromosome alleles. Using this three-step diagnostic procedure, we detected apparent TS in 1/304 (0.33%) samples; such individuals should be submitted to clinical examination and karyotype confirmation. The three-step 45,X TS neonatal screening protocol is a simple, reliable, fast (under 30 h) and cost-effective diagnostic tool, useful for the neonatal detection of TS.     

Carbon, nitrogen and phosphorus mineralization in two soils amended with distillery yeast

The concentrations and the seasonal changes of heavy metals and organic carbon in the sediments underlying a Zostera marina L. bed were measured monthly during one year, in two Mediterranean lagoons: Thau (France) and Venice (Italy). While at Thau sediments showed Cu (18.7+/-3.9 microg g-1) and Pb (13.8+/-3.8 microg g-1) average concentrations twofold higher than at Venice (Cu: 8.4+/-4.8 microg g-1; Pb: 6.1+/-0.70 microg g-1), the Italian site exhibited average concentrations of Fe (13383+/-955 microg g-1 versus 6098+/-1089 microg g-1 at Thau), Mn (339+/-12 microg g-1 versus 190+/-23 microg g-1 at Thau), Zn (61.6+/-12.7 microgg -1 versus 36.1+/-7.4 microg g-1 at Thau), Cr (47.3+/-7.3 microg g-1 versus 21.8+/-8.0 microg g-1 at Thau) and Ni (12.7+/-1.7 microg g-1 versus 8.9+/-3.1 microg g-1 at Thau) approximately 1.5-2 times as high as the French site. The organic carbon concentration was systematically higher at Thau (1.0+/-0.3) than at Venice (0.7+/-0.2). A significant seasonal fluctuation was found for Zn, Cu, Ni, Cr in both lagoons while no significant variations were recorded for Pb at Venice and for Cd at Thau. Some of those changes appeared to be significantly correlated with the biomass of Zostera at Thau and the concentration of organic carbon at Venice.     

Enzymatic degradation of nitriles by a Candida guilliermondii UFMG-Y65

Candida guilliermondii UFMG-Y65, isolated from a gold mine, was able to utilize different nitriles and the corresponding amides as sole source of nitrogen, at concentrations up to 2 M. Resting cells cultivated on YCB-acetonitrile medium showed nitrile hydrolyzing enzyme activities against acrylonitrile and benzonitrile. These enzymes were inducible and intracellular; the optimum pH was 7.0-8.0, and the optimum temperature 25 degrees C-30 degrees C. Liquid chromatographic analysis indicated that C. guilliermondii UFMG-Y65 metabolized 12 mM benzonitrile to 11 mM benzoic acid and 10 mM acrylonitrile to 7.9 mM acrylic acid. The results suggest that C. guilliermondii UFMG-Y65 may be useful for the bioproduction of amides and acids, and for the bioremediation of environments contaminated with nitriles.     

Characterization of an unidentified Sarcocystis falcatula-like parasite from the South American opossum, Didelphis albiventris from Brazil

An unidentified isolate of a Sarcocystis falcatula-like parasite was obtained from the lungs of budgerigars (Melopsittacus undulatus) fed sporocysts from a naturally-infected South American opossum, Didelphis albiventris from Brazil. Four captive budgerigars fed sporocysts from the opossum intestine died of acute sarcocystosis 8, 10, and 12 days after oral inoculation (DAI); one budgerigar was killed 12 DAI when it was lethargic. Schizonts and merozoites found in the lungs of the budgerigars reacted mildly with polyclonal S. falcatula antibody. The parasite was isolated in equine kidney cell cultures inoculated with lung tissue from a budgerigar that was killed 12 DAI. Two budgerigars inoculated subcutaneously with 100,000 culture-derived S. falcatula merozoites developed acute sarcocystosis and S. falcatula-like schizonts were found in their lungs 15 and 16 DAI. Four budgerigars kept as unfed controls in the same environment remained free of Sarcocystis infection. The parasite underwent schizogony in African green monkey kidney cells and bovine turbinate cells. Merozoites divided by endopolygeny, often leaving a residual body. Polymerase chain reaction studies using primers JNB33/JNB54 and Hinf I and Dra I digestion indicated that the isolate was not S. falcatula. Results of this study indicated that the South American opossum, D. albiventris, is a definitive host for yet another S. falcatula-like parasite.     

Improving Feedback Merging for Source-Adaptive Layered Multicast Schemes

Current source-adaptive layered multicast schemes exploit merging capabilities at special nodes in the network to combine feedback from the multicast group. The merging procedures reduce network load and avoid feedback implosion at the source. In this paper, we demonstrate how to increase the efficiency of a merger node. We show how to tune two mechanisms: feedback transmission, on the timer settings used by receivers, and temporal merging, on the timer settings used by intermediate nodes. Our approach is generic, relating purely to timer settings, and does not touch on content merging, or the decision regarding which packets to forward. We investigate the effects of temporal merging on packet suppression. We show that periodic feedback transmission coupled with a suitable timer setting at the merger node increases efficiency.     

Characterization of alpha-galactosidases from germinating soybean seed and their use for hydrolysis of oligosaccharides

Raffinose oligosaccharides (RO) are the major factors responsible for flatulence following ingestion of soybean derived products. Removal of RO from seeds or soymilk would then have a positive impact on the acceptance of soy-based foods. Enzymic hydrolysis of the RO is accomplished by alpha-galactosidase. While the content of RO decreases during seed germination, the activity of alpha-galactosidase increases substantially. Two alpha-galactosidases were isolated from germinating seeds by partition in an aqueous two-phase system followed by ion-exchange and affinity chromatography. One of the enzyme preparations (P1) showed a single protein with M(r) of 33 kDa, and the second (P2) had two proteins with M(r) of 31 and 33 kDa. Maximal activities against the synthetic substrate rho-nitrophenyl-alpha-D-galactopyranoside (rhoNPGal) were detected at pH 5.0-5.5 and 45-50 degrees C. Both enzymes were fairly stable at 40 degrees C, but lost most of their activities after 30 min at 50 degrees C. The K(m) values for hydrolysis of rhoNPGal by the P1 and P2 enzymes were 1.55 and 0.76 mM, respectively. The K(m) values determined for hydrolysis of raffinose and melibiose by the P2 enzyme were 5.53 and 5.34 mM, respectively and galactose was a competitive inhibitor (K(i)=0.65 mM). To different extents, both enzymes were sensitive to inhibition by galactose, melibiose, CuSO(4), and SDS. Sucrose and beta-mercaptoethanol showed discrete inhibitory effects on both enzymes.     

When nonshivering thermogenesis equals maximum metabolic rate: thermal acclimation and phenotypic plasticity of fossorial Spalacopus cyanus (Rodentia)

Many small mammals inhabiting fluctuating and cold environments display enhanced capacity for seasonal changes in nonshivering thermogenesis (NST) and thermoregulatory maximum metabolic rate (MMR). However, it is not known how this plasticity remains in a mammal that rarely experiences extreme thermal fluctuations. In order to answer this question, we determined body mass (m(b)), basal metabolic rate (BMR), NST, MMR, and minimum thermal conductance (C) on a Chilean fossorial caviomorph (Spalacopus cyanus) from a coastal population, acclimated to cold (15 degrees C) and warm (30 degrees C) conditions. NST was measured as the maximum response of metabolic rate (NST(max)) after injection of norepinephrine (NE) in thermoneutrality minus BMR. Maximum metabolic rate was assessed in animals exposed to enhanced heat-loss atmosphere (He-O2) connected with an open-flow respirometer. Body mass and metabolic variables increased significantly after cold acclimation with respect to warm acclimation but to a low extent (BMR, 26%; NST, 10%; and MMR, 12%). However, aerobic scope (MMR/BMR), calculated shivering thermogenesis (ST), and C did not change with acclimation regime. Our data suggest that physiological plasticity of S. cyanus is relatively low, which is in accordance with a fossorial mode of life. Although little is known about MMR and NST in fossorial mammals, S. cyanus has remarkably high NST; low MMR; and surprisingly, a nil capacity of ST when compared with other rodents.