Chemoprotective activity of the isoflavones, genistein and daidzein on mutagenicity induced by direct and indirect mutagens in cultured HTC cells

Isoflavones are phenolic compounds widely distributed in plants and found in a high percentage in soybeans. They have important biological properties and are regarded as potential chemopreventive agents. The aim of this study was to verify the preventive effect of two soy isoflavones (genistein and daidzein) by a micronucleus assay, analysis of GST activity, and real-time RT-PCR analysis of GSTa2 gene expression. Mutagens of direct (doxorubicin) and indirect (2-aminoanthracene) DNA damage were used. Hepatoma cells (HTC) were treated with genistein or daidzein for 26 h at noncytotoxic concentrations; 10 μM when alone, and 0.1, 1.0 and 10 μM when combined with genotoxic agents. The micronucleus test demonstrated that both isoflavones alone had no genotoxic effect. Genistein showed antimutagenic effects at 10 μM with both direct and indirect DNA damage agents. On phase II enzyme regulation, the current study indicated an increase in total cytoplasmic GST activity in response to genistein and daidzein at 10 μM supplementation. However, the mRNA levels of GSTa2 isozymes were not differentially modulated by genistein or daidzein. The results point to an in vitro antimutagenic activity of genistein against direct and indirect DNA damage-induced mutagenicity.     

A Four-Year Follow-Up Study of the Sleep-Wake Cycle of an Infant

The sleep-wake behavior of a boy was investigated from 5 weeks up to four years of age. The protocol consisted of recording waking and sleep states by direct observation by his mother and eventually by the housemaid. Data were divided in 7-day segments and these segments were then divided in 10-minute binary information about asleep or awake. Fast Fourier Transform (FFT) was applied to obtain the frequency spectrum for each 7-day epoch, and the results were submitted to statistical test for the identification of significant component frequencies. Data were also divided in 21-day epochs and 30-minute windows in order to detect infradian periodicities. Overall rhythmicity increased during the four years with the circadian component as the major contribution after the fifth week of life. The semicircadian and the 8-hour components had maximum contributions during the second and third years, and the 6-, 5- and 4-hour components during the first year. After the beginning of his attendance to school, the boy showed a decrease of the semicircadian component, explained by the absence of an afternoon nap and an increase of the circadian component. Infradian periodicities were not found during the whole four years.     

Building a Coherent Time Series with Behavioral Data from Staggered Chambers

Sampling of population with the design of staggered chambers is quite convenient, since it allows data collection from distinct time points at the same clock hour. In this short communication using an ethological approach we report results obtained with behavioral data collected from eight staggered chambers. The eight LD cycles (12:12; L = 350 lux; D = 1 lux, red light) were set with a lag of 3 h, thus completing 24 h. Male Wistar rats 6-month old were individually observed for five minutes in random order within each session along ten consecutive days. Behavioral circadian rhythms of general activity were detected both in the 10-day long time series and in each one of the days, with a statistical significance of 95%. Our results show close similarities with results of individual days, thus pointing to the convenience of such a design.     

The role of the Robertsonian rearrangements in the origin of the XX/XY1Y2 sex chromosome system and in the chromosomal differentiation in Harttia species (Siluriformes, Loricariidae)

Harttia is a genus of the subfamily Loricariinae that posses a broad chromosomal variation. In addition to interspecific karyotype diversity within this group, a multiple sex chromosome system, XX/XY₁Y₂, has been described for Harttia carvalhoi. Thus, this study aimed to determine the role of chromosomal rearrangements in karyotype differentiation in Harttia by classical and molecular cytogenetic procedures. The results show that Robertsonian rearrangements have a prominent role in the chromosomal diversification of the species analysed, which initially leads to hypothesize a diploid number reduction in Harttia torrenticola and H. carvalhoi. The metacentric chromosome 1, shared between H. torrenticola and H. carvalhoi, could have originated from centric fusions from the ancestral karyotype. A centric fission event associated with the first metacentric pair allowed for the origination of a multiple sex chromosome system XX/XY₁Y₂, specific to H. carvalhoi. This study highlights the relevance of Robertsonian rearrangements in karyotypic differentiation of the species studied and demonstrates that the occurrence of a centric fission, as opposed to a previously hypothesised chromosome fusion, is directly implicated in the origin of the sex chromosome system of H. carvalhoi.     

Three new species of Anacanthorus Mizelle & Price, 1965 (Monogenea: Dactylogyridae) from Markiana nigripinnis Perugia (Actinopterygii: Characidae) in Pantanal wetlands,Brazil

Systematic Parasitology - Three monogenean species, Anacanthorus luquei n. sp., A. scholzi n. sp. and A. cohenae n. sp. are described from the gills of the tetra fish Markiana nigripinnis (Perugia)...     

Identification of Zinc Absorption Biomarkers in Muscle Tissue of Nile Tilapia Fed with Organic and Inorganic Sources of Zinc Using Metallomics Analysis

Biological Trace Element Research - The development of metallomics techniques has allowed for metallomics analysis of biological systems, enabling a better understanding of the response mechanisms...     

Morphological phylogeny of the Tegulinae (Mollusca: Vetigastropoda) reinforces a Turbinidae position

A cladistic analysis of the Tegulinae (Turbinidae) is presented using 132 morphological characters and 41 taxa. Tegulinae is recovered and is sister to Prisogaster niger (Prisogasterinae) within the family Turbinidae. This scenario, with Tegulinae as a subfamily within Turbinidae, corroborates with the most molecular analyses. Tegulinae comprises >40 extant species, belonging to eight genera. Morphological studies have not resolved the placement of Tegulinae within Trochoidea sufficiently, and the systematic positions of the genera have never been investigated as a primary objective. The present morphology-based analysis of genus-level relationships within Tegulinae provides a robust, phylogenetic diagnosis of each group, rooted on a firm hypothesis of evolutionary relationships. An additional search was performed to include the tegulines Omphalius nigerrimus and Carolesia blakei terminals using unweighted and implied weighting. Our morphological data provide a solid foundation for ensuing systematic research on Tegulinae, as well as Trochoidea, and evidence facilitating the diagnosis of generic and suprageneric groups.     

Antimicrobial activity and antibiotic synergy of a biphosphinic ruthenium complex against clinically relevant bacteria

Abstract

The aim of this study was to investigate the antibacterial activity, antibiotic-associated synergy, and anti-biofilm activity of the ruthenium complex, cis-[RuCl₂ (dppb) (bqdi)]²⁺ (RuNN). RuNN exhibited antimicrobial activity against Gram-positive bacteria with minimum inhibitory concentration (MIC) values ranging from 15.6 to 62.5?µg ml^?1 and minimum bactericidal concentration (MBC) values ranging from 62.5 to 125?µg ml^?1. A synergistic effect against Staphylococcus spp. was observed when RuNN was combined with ampicillin, and the range of associated fractional inhibitory concentration index (FICI) values was 0.187 to 0.312. A time-kill curve indicated the bactericidal activity of RuNN in the first 1–5?h. In general, RuNN inhibited biofilm formation and disrupted mature biofilms. Furthermore, RuNN altered the cellular morphology of S. aureus biofilms. Further, RuNN did not cause hemolysis of erythrocytes. The results of this study provide evidence that RuNN is a novel therapeutic candidate to treat bacterial infections caused by Staphylococcus biofilms.     

Morphophysiological and Biochemical Responses of Lippia grata Schauer (Verbenaceae) to Water Deficit

Journal of Plant Growth Regulation - In the present study, we investigated the morphophysiological and biochemical responses of the species Lippia grata Schauer to water deficit. Plants from...