Taxonomic characters of the staminal tube and epicalyx in Brazilian Pavonia (Malvaceae)

This study was based on the analysis of staminal tube and epicalyx morphology of species ofPavonia (Malvaceae) from northeastern and southeastern Brazil. The importance of characters in the infrageneric taxonomy is discussed. In general, the variability in staminal tube and epicalyx characters are useful mainly in separating closely related species and a few sections; these characters, however, cannot be used to separate subgenera.     

Comparison of normalisation methods for surface-enhanced laser desorption and ionisation (SELDI) time-of-flight (TOF) mass spectrometry data

Background  

Mass spectrometry for biological data analysis is an active field of research, providing an efficient way of high-throughput proteome screening. A popular variant of mass spectrometry is SELDI, which is often used to measure sample populations with the goal of developing (clinical) classifiers. Unfortunately, not only is the data resulting from such measurements quite noisy, variance between replicate measurements of the same sample can be high as well. Normalisation of spectra can greatly reduce the effect of this technical variance and further improve the quality and interpretability of the data. However, it is unclear which normalisation method yields the most informative result.     

Insulin resistance is improved in high‐fat fed mice by photobiomodulation therapy at 630 nm

Photobiomodulation therapy (PBMT) in the infrared spectrum exerts positive effects on glucose metabolism, but the use of PBMT at the red spectrum has not been assessed. Male Swiss albino mice were divided into low‐fat control and high‐fat diet (HFD) for 12 weeks and were treated with red (630 nm) PBMT or no treatment (Sham) during weeks 9 to 12. PBMT was delivered at 31.19 J/cm², 60 J total dose per day for 20 days. In HFD‐fed mice, PBMT improved glucose tolerance, insulin resistance and fasting hyperinsulinemia. PBMT also reduced adiposity and inflammatory infiltrate in adipose tissue. Phosphorylation of Akt in epididymal adipose tissue and rectus femoralis muscle was improved by PBMT. In epididymal fat PBMT reversed the reduced phosphorylation of AS160 and the reduced Glut4 content. In addition, PBMT reversed the alterations caused by HFD in rectus femoralis muscle on proteins involved in mitochondrial dynamics and β‐oxidation. In conclusion, PBMT at red spectrum improved insulin resistance and glucose metabolism in HFD‐fed mice.      

The urea transporter DUR3 is differentially regulated by abiotic and biotic stresses in coffee plants

The high costs of N fertilizers in the coffee production emphasizes the need to optimize fertilization practices and improve nitrogen use efficiency. Urea is widespread in nature, characterizing itself as a significant source of nitrogen for the growth and development of several organisms. Thus, the characterization of genes involved in urea transport in coffee plants is an important research topic for the sustainable production of this valuable cash crop. In the current study, we evaluated the expression of the DUR3 gene under abiotic and biotic stresses in coffee plants. Here, we show that the expression of a high-affinity urea transporter gene (CaDUR3) was up-regulated by N starvation in leaves and roots of two out of three C. arabica cultivars examined. Moreover, the CaDUR3 gene was differentially expressed in coffee plants under different abiotic and biotic stresses. In plants of cv. IAPAR59, CaDUR3 showed an increased expression in leaves after exposure to water deficit and heat stress, while it was downregulated in plants under salinity. Upon infection with H. vastatrix (coffee rust), the CaDUR3 was markedly up-regulated at the beginning of the infection process in the disease susceptible Catuaí Vermelho 99 in comparison with the resistant cultivar. These results indicate that besides urea acquisition and N-remobilization, CaDUR3 gene may be closely involved in the response to various stresses.     

Nitrogen and phosphorus concentration of different structures of the aquatic macrophytes Eichhornia azurea Kunth and Scirpus cubensis Poepp & Kunth in relation to water level variation in Lagoa Infernão (São Paulo, Brazil)

We evaluated the nitrogen and phosphorus concentration of floating meadows of Eichhornia azurea and Scirpus cubensis in Lagoa do Infernao (State of Sao Paulo, Brazil). The chemical composition of these plants and of the water (littoral and limnetic zones) was determined during the period March 1987 to march 1988. During high water, the water becomes enriched by soluble nutrients and particulates washed from the flooded areas adjacent to the lake, especially from areas situated between the river and Lagoa do Infernão. The soluble allochthonous material is rapidly assimilated and stocked in the plant tissues, which results in an increase in its concentration. Besides this, it was established that the aquatic macrophytes studied utilize the nutrients dissolved in the water of the floating meadow itself, these nutrients being derived principally from their own decomposition.Since these are floating stands, the sediment does not function as a direct source of nutrients, and since concentrations in the water are low, the nutrients excreted by the aquatic macrophytes during growth and liberated during decomposition do not remain available in the water, but are rapidly absorbed by the young plants.This closed nutrient system makes possible the maintenance of the high biomass of the stands during the entire hydrological cycle.     

Surface charge and hydrophobicity of wild and mutant Crithidia fasciculata.

Surface charge of wild-type Crithidia fasciculata and three drug-resistant mutants (TR3, TFRR1, and FUR11) was studied by direct zeta-potential determination and ultrastructural cytochemistry. Surface tension was also investigated by measurements of the advancing contact angle formed by the protozoa monolayers with drops of liquids of different polarities. The individual zeta potential varies markedly among the C. fasciculata cells. The wild and FUR11 mutant strains displayed lower negative surface charge (-12.5 and -9.5 mV, respectively) as compared with the TR3 (-14.8 mV) and TFRR1 (-14.7 mV) mutant strains. Binding of cationized ferritin (CF) was observed at the cell surface of wild and mutant strains of C. fasciculata. Neuraminidase treatment reduced the negative surface charge in the TFRR1 and TR3 mutants in about 37 and 29%, respectively, whereas no significant change was observed with the wild and FUR11 mutant strains. These findings suggest that sialic acid residues are the major anionogenic groups on the surface of C. fasciculata. The density of sialic acid residues per cell in wild and mutant strains of C. fasciculata falls in a range of 1.4 x 10(4) to 3.6 x 10(4). Marked differences of hydrophobicity were also observed. For example, the TFRR1, FUR11, and TR3 drug-resistant mutant strains showed higher contact angle values (55.4, 54.2, and 49.3, respectively) than the wild-type (35.6), as assessed by alpha-bromonaphtalene.     

The relation between mitogen activated protein kinase (MAPK) pathway and different genes expression in patients with beta Thalassemia

Backgroundβ-thalassemia is an inherited hemoglobinopathy resulting in quantitative changes in the β-globin chain. Understanding the molecular basis of that disorder requires studying the expression of genes controlling the pathways that affect the erythropoietic homeostasis especially the MAPK pathway. The MAPKs are a family of serine/threonine kinases that play an essential role in connecting cell-surface receptors to DNA in the nucleus of the cell.Aimto study the effect of expression of GNAI2, DUSP5 and ARRB1 genes on MAPK signaling pathway in pediatric patients with beta thalassemia.MethodsForty children with beta thalassemia major (TM), forty children with beta thalassemia intermedia (TI) and forty age and gender matched healthy controls were enrolled in this study. Detection of GNAI2, DUSP5 and ARRB1 mRNA expression was done by real time polymerase chain reaction (RT-PCR).Resultsrevealed increased expression of ARRB1 (Arrestin Beta 1) gene, and decreased expression of both GNAI2 (Guanine nucleotide-binding protein G (i) subunit alpha-2) and DUSP5 (Dual specificity protein phosphatase 5) genes in both patient groups than control groups respectively.ConclusionsChange in the rate of expression of ARRB1, GNAI2 and DUSP5 may have a role in the pathogenesis of abnormal hematopoiesis in cases of β thalassemia through affecting the MAPK pathway.     

Influence of water level variation on fertilization of an oxbow lake of Rio Mogi-Guaçu,state of São Paulo,Brazil

Variation in water level in Lagoa do Mato, an oxbow lake of the Rio Mogi-Guaçu, fertilized the water column with phosphorus, nitrogen and silicates during periods when the waters of the Rio Mogi-Guaçu overflowed to the lake. An increase in electrical conductivity and a reduction in transparency was also observed. After fertilization, the nutrients declined rapidly, remaining low until the next floods. Principal component analysis revealed three distinct periods relative to the concentration of nutrients,i.e. a fertilization period, an assimilation period, and a period of stocking in biomass. These results are discussed in relation to other oxbow lakes, in an attempt to identify ecological factors responsible for the fertilization of these ecosystems.