Fungal infection of the feet in soccer players and non-athlete individuals

This study was conducted to evaluate the occurrence of mycoses affecting the feet of soccer players and to compare this results with those in non-athlete individuals of the same age and sex. Initial evaluation consisted of a dermatological examination of the foot in 22 Chinese athletes, 83 Brazilian athletes and 24 Brazilian non-athletes. Scales of plantar skin, interdigital and subungual areas of the foot were collected for mycological examination (direct and culture). Nail clippings were obtained for histopathologic analysis. Tinea pedis was diagnosed more frequently among the non-athlete individuals. None of the Chinese athletes had tinea pedis alone. However, in this group onychomycosis was frequently higher when compared to the other groups. The fungal microbiota comprised Trichophyton rubrum (40%), Trichophyton mentagrophytes (36.4%) and Candida spp (20%). Candida spp was isolated only from Brazilian athletes. Results obtained with KOH wet mounts agreed with the results obtained in culture and with histopathologic examinations (50.5% vs 40.9%). The frequency of tinea pedis among soccer players was lower than the other groups in this study, possibly due to health education and professional feet care.     

Base flipping in nucleotide excision repair

UvrB, the ultimate damage-binding protein in bacterial nucleotide excision repair is capable of binding a vast array of structurally unrelated lesions. A beta-hairpin structure in the protein plays an important role in damage-specific binding. In this paper we have monitored DNA conformational alterations in the UvrB-DNA complex, using the fluorescent adenine analogue 2-aminopurine. We show that binding of UvrB to a DNA fragment with cholesterol damage moves the base adjacent to the lesion at the 3' side into an extrahelical position. This extrahelical base is not accessible for acrylamide quenching, suggesting that it inserts into a pocket of the UvrB protein. Also the base opposite this flipped base is extruded from the DNA helix. The degree of solvent exposure of both residues varies with the type of cofactor (ADP/ATP) bound by UvrB. Fluorescence of the base adjacent to the damage is higher when UvrB is in the ADP-bound configuration, but concomitantly this UvrB-DNA complex is less stable. In the ATP-bound form the UvrB-DNA complex is very stable and in this configuration the base in the non-damaged strand is more exposed. Hairpin residue Tyr-95 is specifically involved in base flipping in the non-damaged strand. We present evidence that this conformational change in the non-damaged strand is important for 3' incision by UvrC.     

Intrapopulational genetic diversity of Araucaria angustifolia (Bertol.) Kuntze is different when assessed on the basis of chloroplast or nuclear markers

A natural population of Araucaria angustifolia (Bertol.) Kuntze was evaluated to quantify genetic diversity, using nucleotide sequences of chloroplast maturase K genes (matK) and six specific nuclear polymorphic microsatellite loci (nuSSR). Estimates of nucleotide diversity assessed from matK sequences were low (π = 0.001), but they indicated the potential of this gene for evaluating divergence among widespread populations. The matK sequence (1,565 bp) was used for analysis of phylogenetic relationships, enabling clustering of the South American species (A. angustifolia and A. araucana). For analysis of intraspecific genetic diversity, nuSSR were more informative than matK, resulting in a polymorphic loci percentage of 69, a number average of alleles per locus of 11.6, expected genetic diversity 0.741, and significant spatial genetic structure up to 25 m. Our data can help in the selection of genetic sources for conservation of this species, which is at risk of extinction.     

Radionuclides in plants growing on sludge and water from uranium mine water treatment

Chemical treatment of uranium mine acid drainage generates sludge containing high radioactivity levels with, for example, ²³⁸U and ²²⁶Ra concentrations at about 18 and 9 kBq kg⁻¹ dry weight, respectively. Spontaneous vegetation, such as grass (Polygonum sp.), reeds (Phragmites australis), and bullrush (Typha latifolia) growing in sludge dewatering ponds concentrated uranium and uranium daughter radionuclides. However, bullrush growing in natural wetlands by the stream receiving treated mine water discharges contained even higher radionuclide concentrations, e.g., 21 Bq kg⁻¹ dry weight of ²³⁸U, about four times higher than bullrush growing on sludge, probably because the uranium in water is more bioavailable to Typha than uranium in the chemical sludge. It is suggested that wetlands with plant species could be used as a secondary treatment to further reduce radioactivity in chemically treated uranium mine water and to improve water quality in streams receiving treated water discharges. Furthermore, it is concluded that vegetation both from sludge drying ponds and from streams receiving treated water discharges, due to the high radionuclide concentrations in the vegetation, is not suitable as cattle feeding.     

HIV-1 tropism and CD4 T lymphocyte recovery in a prospective cohort of patients initiating HAART in Ribeirão Preto, Brazil

While human immunodeficiency virus (HIV)-1 chemokine co-receptors 5 tropism and the GWGR motif in the envelope third variable region (V3 loop) have been associated with a slower disease progression, their influence on antiretroviral response remains unclear. The impact of baseline V3 characteristics on treatment response was evaluated in a randomised, double blind, prospective cohort study with patients initiating highly active antiretroviral therapy with lopinavir or efavirenz plus azithothymidine/3TC (1:1) over 48 weeks. Similar virological and immunological responses were observed for both treatment regimens. The 43 individuals had a mean baseline CD4 T cell count of 119 cells/mm(3) [standard deviation (SD) = 99] and a mean viral load of 5.09 log(10) copies/mL (SD = 0.49). The GWGR motif was not associated with a CD4 T cell response, but predicted R5 tropism by the geno2pheno([clinical20%]) algorithm correlated with higher CD4 T cell levels at all monitoring points (p < 0.05). Moreover, higher false-positive rates (FPR) values from this analysis revealed a strong correlation with CD4 T cell recovery (p < 0.0001). Transmitted drug resistance mutations, documented in 3/41 (7.3%) cases, were unrelated to the assigned antiretroviral regimen and had no impact on patient outcomes. In conclusion, na?ve HIV-1 R5 infected patients exhibited higher CD4 T cell counts at baseline; this difference was sustained throughout therapy. The geno2pheno([clinical]) option FPR positively correlated with CD4 T cell gain and may be useful in predicting CD4 T cell recovery.     

Effect of grazing by isopods and amphipods on growth of Ulva spp. (Chlorophyta)

Eutrophication of shallow coastal waters often leads to blooms of macroalgae. Grazing by crustaceans, such as amphipods and isopods, can reduce macroalgal biomass accumulation. At the same time, growth of the macroalgae can be stimulated by epiphyte removal. The role of grazing by isopods and amphipods on Ulva spp. biomass development was investigated in the Veerse Meer, a brackish lagoon situated in the southwest Netherlands. Exclusion of grazing in the field did not stimulate Ulva spp. growth. In fact, growth rates were higher in exclosures that allowed grazers to enter. Edibility tests identified the amphipod Gammarus locusta, and the isopods Idotea chelipes and Sphaeroma hookeri as potential grazers on Ulva spp. However, when epiphytic diatoms were present on the Ulva spp. thalli, Gammarus and Sphaeroma grazed on ephiphytes and not on Ulva tissue. Only Idotea continued to graze on Ulva spp. A laboratory growth experiment revealed a positive effect of Gammarus presence on Ulva spp. growth, probably caused by preferential removal of epiphytic diatoms from the Ulva spp. thalli. The growth stimulation by epiphyte removing grazers such as Gammarus may explain the higher growth rates in the presence of grazers observed in the field. When determining the potential role of invertebrate grazers in controlling macroalgal biomass accumulation, it is important to include an assessment of the epiphyte abundance on the macroalgae, as preferential removal of epiphytes may stimulate growth and thus have the opposite effect.     

Study on the scavenging and anti-<Emphasis Type=Italic>Staphylococcus</Emphasis><Emphasis Type=Italic>aureus</Emphasis> activities of the extracts,fractions and subfractions of two <Emphasis Type=Italic>Volvariella volvacea</Emphasis> strains

Scavenging and anti-Staphylococcus aureus activities of extracts, fractions and subfractions from the in vitro mycelium of two strains of the edible mushroom Volvariella volvacea were determined. Chloroform subfractions of the ATCC62890 strain showed the highest inhibition percentage of the DPPH radical (over 80%) after 180 min. When chloroform and hexane subfractions of the R83 strain were combined they showed moderate (inhibition zone of 8.99 ± 0.78 mm) to high (inhibition zone of 13.06 ± 0.41 mm) activity against the Gram-positive bacteria Staphylococcus aureus, which are 74.4 and 51.2% of tetracycline (inhibition zone of 17.55 ± 0.11 mm). Partitioning suggested that the substances in the chloroform and hexane fractions of the R83 strain act synergistically to give the antimicrobial activity, while separating the substances of the ATCC62890 subfractions reduced their activity. In general, the R83 strain seems to be a source of antimicrobial substances, while the ATCC62890 strain appears to be an alternative source of antioxidants.     

Modeling the emergence of circadian rhythms in a clock neuron network

Circadian rhythms in pacemaker cells persist for weeks in constant darkness, while in other types of cells the molecular oscillations that underlie circadian rhythms damp rapidly under the same conditions. Although much progress has been made in understanding the biochemical and cellular basis of circadian rhythms, the mechanisms leading to damped or self-sustained oscillations remain largely unknown. There exist many mathematical models that reproduce the circadian rhythms in the case of a single cell of the Drosophila fly. However, not much is known about the mechanisms leading to coherent circadian oscillation in clock neuron networks. In this work we have implemented a model for a network of interacting clock neurons to describe the emergence (or damping) of circadian rhythms in Drosophila fly, in the absence of zeitgebers. Our model consists of an array of pacemakers that interact through the modulation of some parameters by a network feedback. The individual pacemakers are described by a well-known biochemical model for circadian oscillation, to which we have added degradation of PER protein by light and multiplicative noise. The network feedback is the PER protein level averaged over the whole network. In particular, we have investigated the effect of modulation of the parameters associated with (i) the control of net entrance of PER into the nucleus and (ii) the non-photic degradation of PER. Our results indicate that the modulation of PER entrance into the nucleus allows the synchronization of clock neurons, leading to coherent circadian oscillations under constant dark condition. On the other hand, the modulation of non-photic degradation cannot reset the phases of individual clocks subjected to intrinsic biochemical noise.     

Molecular phylogeny and evolution of the order Tribonematales (Heterokonta, Xanthophyceae) based on analysis of plastidial genes rbcL and psaA

Tribonematales is an order of filamentous algae in the class Xanthophyceae (Heterokonta). Few molecular studies, all with a limited taxon sampling, have previously investigated its evolutionary history and phylogenetic relationships. We sequenced the chloroplast-encoded rbcL and psaA genes of several tribonematalean species and of several coccoid and siphonous forms that previous studies revealed to be strictly related to Tribonematales. Multiple alignments included mostly new sequences obtained from 42 taxa. Phylogenetic reconstructions were performed using the maximum likelihood method. The rbcL and psaA data sets were analyzed independently and combined in a single multiple alignment. Neither rbcL nor psaA genes showed intraspecific sequence variation. The former proved to be a better diagnostic marker than the latter for characterization of species. We explored effects produced on phylogenetic outcomes by selected genes. Congruent results were obtained from analyses performed on single gene multiple alignments as well as on the combined data set. There is strong statistical support for trees that show several currently recognized taxonomic groups to be polyphyletic. The siphonous orders Botrydiales and Vaucheriales do not form a clade. Botrydiales and Tribonematales are polyphyletic as are the families Botrydiaceae, Centritractaceae and Tribonemataceae and the genera Xanthonema and Bumilleriopsis. We tentatively define new boundaries of the Tribonematales to include both coccoid and filamentous species having a bipartite cell wall and also the siphonous members of the genus Botrydium. Also, our results support morphological convergence at all taxonomic ranks in the evolution of the Xanthophyceae.     

Production of Extracellular Biopolymers and Identification of Intracellular Proteins and Rhizobium tropici

The objective of this study was to identify species of rhizobia (from the IPA 403 and IPA 49 isolates), to assess the physico-chemical characteristics of the biopolymers produced by these rhizobia and to determine the soluble intracellular proteins that are present in these rhizobia. The polysaccharides containing acetyl and pyruvic acid groups that were produced by different strains that had been cultivated in yeast extract mannitol (YEM) medium for 132, 144, and 168?h were evaluated for yield, viscosity, and concentration. Based on the analysis of their partial 16S rDNA sequences, both isolates were identified as Rhizobium tropici. The polymers produced in liquid YEM medium were recovered, dried and weighed to determine culture yield. Soluble intracellular proteins were identified through the techniques of 2D-PAGE and mass spectrometry for cultures that were cultivated for 168?h. The largest biopolymer yield and the highest viscosity and concentration of acetyl and pyruvic acids were obtained from the IPA 403 isolate after 168?h of culture. The proteins that were identified for the CIAT 899 isolate included elongation factor TU, a chaperone; GroE/GroEs and a putative glycosyltransferase, all of which catalyze the production of polysaccharides. For the IPA 403 strain, dinitrogenase and nitrogenase iron proteins were found. In the IPA 49 strain, glyceraldehyde-3-phosphate dehydrogenase was found along with two other proteins, the beta subunit of an electron-transferring flavoprotein and a dehydrogenase.