Searching an auxinic herbicide to use as positive control in toxicity assays.

Due to rising concerns for environmental and human health, many toxic compounds, such as auxin-based herbicides, have been tested in relation their toxicity effect. Especially cyto- and phytotoxic assays have been performed on a number monocot and eudicot plant species. In these approaches the toxicity level of the auxin is compared to a positive control - usually a commercial compound with known effects and chemical similarity to the target compound. However, many target compounds still lack an indication of an adequate positive control. Here, we evaluate the phytotoxic and cytotoxic effect of the auxins 2,4-dichlorophenoxyacetic acid, dicamba, and picloram in order test their potential use as positive controls. All tested auxinic herbicides showed clastogenic and aneugenic effect mechanisms. The results indicate 2,4-dichlorophenoxyacetic acid as the most phyto- and cytotoxic in the discontinuous method in Lactuca sativa L. and Allium cepa L., and also in the continuous method in A. cepa. Thus, we suggest 2,4-dichlorophenoxyacetic acid as a positive control for future mutagenesis studies involving new auxins. For studies with L. sativa in continuous method, we recommend the auxin picloram as positive control as this one was the only one which allowed the development of roots.

Hippocampal subregion volume changes associated with antipsychotic treatment in first-episode psychosis.

BACKGROUND: Hippocampal dysfunction is considered central to many neurobiological models of schizophrenia, yet there are few longitudinal in vivo neuroimaging studies that have investigated the relationship between antipsychotic treatment and morphologic changes within specific hippocampal subregions among patients with psychosis. METHOD: A total of 29 patients experiencing a first episode of psychosis with little or no prior antipsychotic exposure received structural neuroimaging examinations at illness onset and then following 12 weeks of treatment with either risperidone or aripiprazole in a double-blind randomized clinical trial. In addition, 29 healthy volunteers received structural neuroimaging examinations at baseline and 12-week time points. We manually delineated six hippocampal subregions [i.e. anterior cornu ammonis (CA) 1-3, posterior CA1-3, subiculum, dentate gyrus/CA4, entorhinal cortex, and fimbria] from 3T magnetic resonance images using an established method with high inter- and intra-rater reliability. RESULTS: Following antipsychotic treatment patients demonstrated significant reductions in dentate gyrus/CA4 volume and increases in subiculum volume. Healthy volunteers demonstrated non-significant volumetric changes in these subregions across the two time points. We observed a significant quadratic (i.e. inverted U) association between changes in dentate gyrus/CA4 volume and cumulative antipsychotic dosage between the scans. CONCLUSIONS: This study provides the first evidence to our knowledge regarding longitudinal in vivo volumetric changes within specific hippocampal subregions in patients with psychosis following antipsychotic treatment. The finding of a non-linear relationship between changes in dentate gyrus/CA4 subregion volume and antipsychotic exposure may provide new avenues into understanding dosing strategies for therapeutic interventions relevant to neurobiological models of hippocampal dysfunction in psychosis.

Karyotype characterization and nuclear DNA content measurement in Bromeliaceae: state of the art and future perspectives.

In Bromeliaceae, cytogenetic and flow cytometry analyses have been performed to clarify systematic and evolutionary aspects. Karyotyping approaches have shown the relatively high chromosome number, similar morphology and small size of the chromosomes. These facts have prevented a correct chromosome counting and characterization. Authors have established a basic chromosome number of x = 25 for Bromeliaceae. Recently, one karyomorphological analysis revealed that x = 25 is no longer the basic chromosome number, whose genome may have a polyploid origin. Besides cytogenetic characterization, the 2C DNA content of bromeliads has been measured. Nuclear DNA content has varied from 2C = 0.60 to 2C = 3.34 picograms. Thus, in relation to most angiosperms, the 2C DNA content of Bromeliaceae species as well as their chromosome size can be considered relatively small. In spite of some advances, cytogenetic and flow cytometry data are extremely scarce in this group. In this context, this review reports the state of the art in karyotype characterization and nuclear DNA content measurement in Bromeliaceae, emphasizing the main problems and suggesting prospective solutions and ideas for future research.

Stable hydrogen and oxygen isotopes reveal aperiodic non-river evaporative solute enrichment in the solute cycling of rivers in arid watersheds.

We investigated the spatial and temporal variations of the stable isotope composition of hydrogen (δD) and oxygen (δ18O) and the total dissolved ions (TDI) concentrations in the Okavango River in the middle Kalahari Desert. We aimed to elucidate the role of evaporation in controlling river solute enrichment from samples collected at a one- to two-month frequency from nine stations along a ∼460 km river transect for one year. We found that the δD and δ18O composition and the TDI concentrations increased downriver. Seasonal increases in the δD and δ18O composition and TDI concentrations during the hot, rainy season were subdued or decreased during the cool, dry season from pulse flooding. The δD and δ18O values of the samples plot along the Okavango Delta Evaporation Line consistent with evaporation. The effect of evaporation during river transit was related to the mean δD (δD = 0.07*River distance (km) - 37.9; R2 = 0.98) and mean d-excess (d-excess = -0.04*River distance (km) + 9.9; R2 = 0.94). The effect of evaporation on the river solute behavior is characterized by the mean d-excess and TDI concentrations (d-excess = -0.29*TDI (mg/L) + 15.0; R2 = 0.97). Some samples from this study and those compiled from published studies plot at greater than one sigma standard deviation above and below the mean TDI concentration vs. mean d-excess regression model line. We use these marked deviations from the mean TDI concentration vs. the mean d-excess regression model to suggest that additional solutes from river-floodplain-wetland-island interaction driven by pulse flooding are delivered into the river. While our findings support an evaporation-dominated solute enrichment during river transit at the seasonal scale, we conclude that intermittent hydrology (pulse flooding) plays an important role in the sub-seasonal spatiotemporal behavior of solutes in rivers in arid watersheds, which must be considered in solute cycling models.

A long and stressful day: Photoperiod shapes aluminium tolerance in plants.

Aluminium (Al), a limiting factor for crop productivity in acidic soils (pH ≤ 5.5), imposes drastic constraints for food safety in developing countries. The major mechanisms that allow plants to cope with Al involve manipulations of organic acids metabolism and DNA-checkpoints. When assumed individually both approaches have been insufficient to overcome Al toxicity. On analysing the centre of origin of most cultivated plants, we hypothesised that day-length seems to be a pivotal agent modulating Al tolerance across distinct plant species. We observed that with increasing distance from the Equator, Al tolerance decreases, suggesting a relationship with the photoperiod. We verified that long-day (LD) species are generally more Al-sensitive than short-day (SD) species, whereas genetic conversion of tomato for SD growth habit boosts Al tolerance. Reduced Al tolerance correlates with DNA-checkpoint activation under LD. Furthermore, DNA-checkpoint-related genes are under positive selection in Arabidopsis accessions from regions with shorter days, suggesting that photoperiod act as a selective barrier for Al tolerance. A diel regulation and genetic diversity affect Al tolerance, suggesting that day-length orchestrates Al tolerance. Altogether, photoperiodic control of Al tolerance might contribute to solving the historical obstacle that imposes barriers for developing countries to reach a sustainable agriculture.

New Insights Into the Evolution of C4 Photosynthesis Offered by the Tarenaya Cluster of Cleomaceae.

Cleomaceae is closely related to Brassicaceae and includes C3, C3-C4, and C4 species. Thus, this family represents an interesting system for studying the evolution of the carbon concentrating mechanism. However, inadequate genetic information on Cleomaceae limits their research applications. Here, we characterized 22 Cleomaceae accessions [3 genera (Cleoserrata, Gynandropsis, and Tarenaya) and 11 species] in terms of genome size; molecular phylogeny; as well as anatomical, biochemical, and photosynthetic traits. We clustered the species into seven groups based on genome size. Interestingly, despite clear differences in genome size (2C, ranging from 0.55 to 1.3 pg) in Tarenaya spp., this variation was not consistent with phylogenetic grouping based on the internal transcribed spacer (ITS) marker, suggesting the occurrence of multiple polyploidy events within this genus. Moreover, only G. gynandra, which possesses a large nuclear genome, exhibited the C4 metabolism. Among the C3-like species, we observed intra- and interspecific variation in nuclear genome size as well as in biochemical, physiological, and anatomical traits. Furthermore, the C3-like species had increased venation density and bundle sheath cell size, compared to C4 species, which likely predisposed the former lineages to C4 photosynthesis. Accordingly, our findings demonstrate the potential of Cleomaceae, mainly members of Tarenaya, in offering novel insights into the evolution of C4 photosynthesis.

The pH Signaling Transcription Factor PAC-3 Regulates Metabolic and Developmental Processes in Pathogenic Fungi.

The zinc finger transcription factor PAC-3/RIM101/PacC has a defined role in the secretion of enzymes and proteins in response to ambient pH, and also contributes to the virulence of species. Herein we evaluated the role of PAC-3 in the regulation of Neurospora crassa genes, in a model that examined the plant-fungi interactions. N. crassa is a model fungal species capable of exhibiting dynamic responses to its environment by employing endophytic or phytopathogenic behavior according to a given circumstance. Since plant growth and productivity are highly affected by pH and phosphorus (P) acquisition, we sought to verify the impact that induction of a Δpac-3 mutation would have under limited and sufficient Pi availability, while ensuring that the targeted physiological adjustments mimicked ambient pH and nutritional conditions required for efficient fungal growth and development. Our results suggest direct regulatory functions for PAC-3 in cell wall biosynthesis, homeostasis, oxidation-reduction processes, hydrolase activity, transmembrane transport, and modulation of genes associated with fungal virulence. Pi-dependent modulation was observed mainly in genes encoding for transporter proteins or related to cell wall development, thereby advancing the current understanding regarding colonization and adaptation processes in response to challenging environments. We have also provided comprehensive evidence that suggests a role for PAC-3 as a global regulator in plant pathogenic fungi, thus presenting results that have the potential to be applied to various types of microbes, with diverse survival mechanisms.

mus-52 disruption and metabolic regulation in Neurospora crassa: Transcriptional responses to extracellular phosphate availability.

Advances in the understanding of molecular systems depend on specific tools like the disruption of genes to produce strains with the desired characteristics. The disruption of any mutagen sensitive (mus) genes in the model fungus Neurospora crassa, i.e. mus-51, mus-52, or mus-53, orthologous to the human genes KU70, KU80, and LIG4, respectively, provides efficient tools for gene targeting. Accordingly, we used RNA-sequencing and reverse transcription-quantitative polymerase chain reaction amplification techniques to evaluate the effects of mus-52 deletion in N. crassa gene transcriptional modulation, and thus, infer its influence regarding metabolic response to extracellular availability of inorganic phosphate (Pi). Notably, the absence of MUS-52 affected the transcription of a vast number of genes, highlighting the expression of those coding for transcription factors, kinases, circadian clocks, oxi-reduction balance, and membrane- and nucleolus-related proteins. These findings may provide insights toward the KU molecular mechanisms, which have been related to telomere maintenance, apoptosis, DNA replication, and gene transcription regulation, as well as associated human conditions including immune system disorders, cancer, and aging.

Localizing the lexicon for reading aloud:replication of a PET study using fMRI.

Functional magnetic resonance imaging (fMRI) was used to investigate the neural basis of written word recognition in two normal subjects. With a 1.5T scanner and temporal surface coil, T2 gradient echo images were obtained while subjects read words aloud. As a control condition, subjects visualized false font strings and said the word "range' each time such a string appeared. These two conditions were presented in an oscillatory pattern, alternating 30 s of each condition for a total of 4 min. Comparison of the two conditions using cross-correlation demonstrated strong activation in both subjects in the left posterior superior temporal gyrus, near the site predicted for the visual input lexicon by Déjerine and recently demonstrated by positron emission tomography.

Physicochemical properties of sildenafil citrate (Viagra) and sildenafil base.

Sildenafil citrate (Viagra) [I] and sildenafil base [II] are easily and unequivocally characterized by a set of physicochemical methods that include X-ray diffractometry, infrared spectroscopy, and thermal analysis. Monoclinic lattice constants: [I]: a = 26.98 A; b = 11.95 A; c = 16.68 A; beta = 106.97 degrees. [II]: a = 8.66 A; b = 34.27 A; c = 8.93 A; beta = 96.63 degrees. Both compounds decompose at 189.4 degrees C [I] and 251.9 degrees C [II]. Densities and refractive indices are given.

Performance of phalangeal quantitative ultrasound parameters in the evaluation of reduced bone mineral density assessed by DX in patients with 21 hydroxylase deficiency.

The purpose of this study was to verify the performance of quantitative ultrasound (QUS) parameters of proximal phalanges in the evaluation of reduced bone mineral density (BMD) in patients with congenital adrenal hyperplasia due to 21-hydroxylase deficiency (21 OHD). Seventy patients with 21 OHD (41 females and 29 males), aged between 6-27 y were assessed. The QUS measurements, amplitude-dependent speed of sound (AD-SoS), bone transmission time (BTT), and ultrasound bone profile index (UBPI) were obtained using the BMD Sonic device (IGEA, Carpi, Italy) on the last four proximal phalanges in the non-dominant hand. BMD was determined by dual energy X-ray (DXA) across the total body and lumbar spine (LS). Total body and LS BMD were positively correlated to UBPI, BTT and AD-SoS (correlation coefficients ranged from 0.59-0.72, p < 0.001). In contrast, when comparing patients with normal and low (Z-score < -2) BMD, no differences were found in the QUS parameters. Furthermore, UBPI, BTT and AD-SoS measurements were not effective for diagnosing patients with reduced BMD by receiver operator characteristic curve parameters. Although the AD-SoS, BTT and UBPI showed significant correlations with the data obtained by DXA, they were not effective for diagnosing reduced bone mass in patients with 21 OHD.

Influence of programmed physical activity on body composition among adolescent students.

OBJECTIVE: To verify the influence of programmed physical activity on body composition among adolescent students during 1 school year. METHODS: The sample included 383 students (age range: 10 to 15 years) separated into two groups: 186 cases (96 male and 90 female) and 197 controls (108 male and 89 female). This was an intervention study with pre- and post-test assessments in which interventions consisted of programmed physical activity; the control group had conventional school physical education. Body composition was assessed by anthropometric measurements, body mass index (BMI), body fat percentage and fat and lean body mass. RESULTS: In the case group, subscapular skinfold thickness, BMI, body fat percentage and fat body mass remained stable; there were significant reductions in tricipital skinfold thickness and in abdominal perimeter among girls and significant increases in arm, waist and calf perimeters and in lean body mass. In the control group, there were significant increases in BMI, tricipital skinfold thickness, abdominal perimeter and fat body mass among girls. At post-test, overweight and obesity significantly decreased among case group subjects, but not among controls. CONCLUSION: Programmed physical activity resulted in improvement or maintenance of body composition parameters and in reduction of overweight and obesity in the intervention group.

Comparative study of the cephalic index of the population from the regions of the north and south of Brazil / Estudio comparativo de índice cefálico de la población de las regiones norte y sur de Brasil

Since the beginning of the century in various countries, investigations to determine the anthropometric characteristics of a population were carried out. The issue of miscegenation in Brazil is of great importance in this study to define a population representative data on the cranial anthropometry. The large size of Brazil, with 8.514.876 km2 leads to an investigation between the two extreme regions of the country: North and South, because of the ethnic composition of their colonizers. This study aims to investigate, compare and rank possible differences in cephalic index of the populations from these regions of Brazil. Therefore, an anthropometric study was performed at the School of Aeronautics Expert (single training center for graduates of Brazilian Air Force), measurements were performed in 110 male students, divided by regions, and also the parents of these students who came from the same region of Brazil. The average width of the head shown in the Northern region is 15.80 +/- 0.69 and 15.75 +/- 0.53 in the Southern region, with significant difference (P <0.05). The average length of the head lodged in the Northern region is 19.54 +/- 0.61 and 19.94 and in the South +/- 0.67, significant difference (P <0.05). With respect to the cephalic index the average in the North is 80.93 +/- 3.84 and in the South 79.06 +/- 3.60, significant difference (P <0.05). In the Northern region, for the classification, mesocephalic is predominant, but with a tendency to brachycephalic and hyperbrachycephalic, dolichocephalic type was rare in the South and the opposite occurs with respect to the rare type, the classification is to mesocephalic predominantly the second type is also brachycephalic, dolichocephalic but it is the third most common, often presented as the brachycephalic type.

Desde el comienzo del siglo en varios países, se llevaron a cabo investigaciones para determinar las características antropométricas de la población. El tema del mestizaje en Brasil es de gran importancia en este estudio para definir una base de datos representativa de la población en la antropometría craneal. El gran tamaño de Brasil, con 8.514.876 km2 nos lleva a realizar una investigación en individuos pertenecientes a las dos regiones extremas del país: Norte y Sur, debido a la composición étnica de sus colonizadores. Este estudio tiene como objetivo investigar, comparar y clasificar las posibles diferencias en el índice cefálico de las poblaciones de estas regiones de Brasil. Por anterior, se llevó a cabo un estudio antropométrico en la Escuela de Aeronáutica de expertos (centro de entrenamiento único para los graduados de la Fuerza Aérea de Brasil). Las mediciones se realizaron en 110 estudiantes de sexo masculino, divididos por regiones, y también en los padres de estos estudiantes que vinieron de la misma región de Brasil. El ancho medio de la cabeza en los individuos de la región Norte fue 15,80 +/- 0,69 cm y 15,75 +/- 0.53 cm en la Región Sur, con diferencias significativas (P <0,05). La longitud media de la cabeza en los individuos de la Región Norte fue 19,54 +/- 0,61cm y 19,94 +/- 0,67 cm en los individuos del Sur, diferencia significativa (P <0,05). Con respecto al índice cefálico en el Norte fue 80,93 +/- 3,84 y emn el Sur 79,06 +/- 3,60, diferencia significativa (P <0,05). En la región Norte, la mesocefalia es predominante, pero con tendencia a la braquicefalia y hiperbraquicefalia. El tipo mesocefálico predominaba en los individuos del Sur pero con distribución más hacia la braquicefalia que hacia la dolicocefalia.

Efeito da atividade física programada sobre a composição corporal em escolares adolescentes / Influence of programmed physical activity on body composition among adolescent students

OBJETIVO: Verificar o efeito da atividade física programada na escola sobre a composição corporal em escolares adolescentes durante 1 ano letivo. MÉTODOS: Amostra foi composta por 383 alunos, divididos em dois grupos: caso com 186 (96 meninos e 90 meninas) e controle com 197 (108 meninos e 89 meninas), com idade entre 10 e 15 anos. Trata-se de estudo de intervenção com pré e pós-teste, no qual o grupo caso foi submetido a atividade física programada e o grupo-controle a aulas convencionais de educação física escolar. A composição corporal foi avaliada por medidas antropométricas e cálculos de índice de massa corporal, percentual de gordura e massas gorda e magra. RESULTADOS: O grupo caso apresentou estabilidade na prega cutânea subescapular, índice de massa corporal, percentual de gordura e na massa gorda; redução significativa na prega cutânea triciptal, perímetro do abdome nas meninas e aumento significativo dos perímetros do braço, cintura e panturrilha e da massa magra. No grupo-controle houve aumento do índice de massa corporal, prega cutânea triciptal, perímetro do abdome e da massa gorda nas meninas. O grupo caso apresentou diminuição significativa na proporção de sobrepesos e obesos no pós em relação ao pré-teste, o mesmo não ocorrendo no grupo-controle. CONCLUSÃO: A atividade física programada resultou em melhoria e manutenção nas variáveis da composição corporal e redução da frequência de sobrepeso e obesidade no grupo que sofreu intervenção.

OBJECTIVE: To verify the influence of programmed physical activity on body composition among adolescent students during 1 school year. METHODS: The sample included 383 students (age range: 10 to 15years) separated into two groups: 186 cases (96 male and 90 female) and 197 controls (108 male and 89 female). This was an intervention study with pre- and post-test assessments in which interventions consisted of programmed physical activity; the control group had conventional school physical education. Body composition was assessed by anthropometric measurements, body mass index (BMI), body fat percentage and fat and lean body mass. RESULTS: In the case group, subscapular skinfold thickness, BMI, body fat percentage and fat body mass remained stable; there were significant reductions in tricipital skinfold thickness and in abdominal perimeter among girls and significant increases in arm, waist and calf perimeters and in lean body mass. In the control group, there were significant increases in BMI, tricipital skinfold thickness, abdominal perimeter and fat body mass among girls. At post-test, overweight and obesity significantly decreased among case group subjects, but not among controls. CONCLUSION: Programmed physical activity resulted in improvement or maintenance of body composition parameters and in reduction of overweight and obesity in the intervention group.

The soybean sucrose binding protein gene family: genomic organization, gene copy number and tissue-specific expression of the SBP2 promoter.

The sucrose binding protein (SBP) from soybean has been implicated as an important component of the sucrose uptake system. Two SBP genomic clones, gsS641.1 and gsS641.2, which correspond to allelic forms of the GmSBP2/S64 gene, have been isolated and characterized. As a member of the seed storage protein superfamily, it has been shown that the SBP gene structure is similar to vicilin genes with intron/exon boundaries at conserved positions. Fluores cence in situ hybridization (FISH) suggested that the soybean SBP gene family is represented by at least two non-allelic genes corresponding to the previously isolated GmSBP1 and GmSBP2/S64 cDNAs. These two cDNAs share extensive sequence similarity but are located at different loci in the soybean genome. To investigate transcriptional activation of the GmSBP2 gene, 2 kb 5'-flanking sequences of gsS641.1 and gsS641.2 were fused to the beta-glucuronidase (GUS) reporter gene and to the green fluorescent protein (GFP) reporter gene and inde pendently introduced into Nicotiana tabacum by Agrobacterium tumefaciens-mediated transformation. The SBP2 promoter directed expression of both GUS and GFP reporter genes with high specificity to the phloem of leaves, stems and roots. Thus, the overall pattern of SBP-GUS or SBP-GFP expression is consistent with the involvement of SBP in sucrose translocation-dependent physiological processes.