Morphological and growth alterations on early development stages of Iridaea cordata (Rhodophyta) under different intensities of UVB radiation

This study describes the effects of different intensities of UVB radiation on growth and morphology of early development stages of Iridaea cordata in germlings, young gametophytes originated in the laboratory and young fronds collected in the Magellan Strait, Chile. The experiments were carried out during four weeks in controlled conditions of temperature and photoperiod and the results were compared with a control treatment (without UVB). All UVB irradiation treatments caused bleaching and decrease in growth rates of germlings. Additionally, initial upright fronds were not observed in any of the UVB treatments, where as those cultivated in UVB absence developed erect ones in the second week of culture. The young gametophytes exhibited morphological alteration (small number and size of basal ramifications, curling of tips, bleaching and necrosis) and decrease in growth when exposed to UVB radiation. Young fronds collected from the field showed mainly morphological alterations (curling of frond). Morphological alterations in young gametophytes and young fronds of I. cordata could be interpreted as a defense against UVB by reducing the area exposed to radiation. However, high level of UVB radiation can produce irreparable damage, such as necrosis, observed in young gametophytes originated in the laboratory. Finally, the UVB effects on early developmental stages of I. cordata depend on the UVB irradiance and time of exposition.

Effects of Molybdenum, Nickel, and Nitrogen Sources on the Mineral Nutrition and Growth of Rice Plants

Upland rice plants, cultivar `IAC 202,` were grown in nutrient solution until full tillering. Treatments consisted of ammonium nitrate (AN) or urea (UR) as nitrogen (N) source plus molybdenum (Mo) and/or nickel (Ni): AN + Mo + Ni, AN + Mo - Ni, AN - Mo + Ni, UR + Mo + Ni, UR + Mo - Ni, and UR - Mo + Ni. The experiment was carried out to better understand the effect of these treatments on dry-matter yield, chlorophyll, net photosynthesis rate, nitrate (NO3 --N), total N, in vitro activities of urease and nitrate reductase (NR), and Mo and Ni concentrations. In UR-grown plants, Mo and Ni addition increased yield of dry matter. Regardless of the N source, chlorophyll concentration and net photosynthesis rate were reduced when Mo or Ni were omitted, although not always significantly. The omission of either Mo or Ni led to a decrease in urease activity, independent of N source. Nitrate reductase activity increased in nutrient solutions without Mo, although NO3 --N increased. There was not a consistent variation in total N concentration. Molybdenum and Ni concentration in roots and shoots were influenced by their supply in the nutrient solution. Molybdenum concentration was not influenced by N sources, whereas Ni content in both root and shoots was greater in ammonium nitrate-grown plants. In conclusion, it can be hypothesized that there is a relationship between Mo and Ni acting on photosynthesis, although is an indirect one. This is the first evidence for a beneficial effect of Mo and Ni interaction on plant growth.

Seasonality and growth rings in lianas of Bignoniaceae

Lianas are one of the most important components of tropical forest, and yet one of the most poorly known organisms. Therefore, our paper addresses questions on the environmental and developmental aspects that influence the growth of lianas of Bignoniaceae, tribe Bignonieae. In order to better understand their growth, we studied the stem anatomy, seasonality of formation and differentiation of secondary tissues, and the influence of the cambial variant in xylem development on a selected species: Tynanthus cognatus. Afterwards, we compared the results found in T. cognatus with 31 other species of Bignonieae to identify general patterns of growth in lianas of this tribe. We found that cambial activity starts toward the end of the rainy season and onset of the dry season, in contrast to what is known for tropical trees and shrubs. Moreover, their pattern of xylem formation and differentiation is strongly influenced by the presence of massive wedges of phloem produced by a variant cambium. Thus, the variant cambium is the first to commence its activity and only subsequently does cambial activity progress towards the center of the regular region, leading to the formation of confluent growth rings. In summary, we conclude that: the cambium responds to environmental changes; the xylem growth rings are annual and produced in a brief period of about 2 months, something that may explain why lianas possess narrow stems; and furthermore, phloem wedges greatly influence cambial activity.

Life history, morphological variability and growth rates of the life phases of Gracilaria tenuistipitata (Rhodophyta: Gracilariales) in vitro

Gracilaria tenuistipitata, a species of commercial interest, is becoming a model organism for studies on red algal physiology and molecular biology as it can be grown easily in vitro under a broad range of conditions. Most of the experiments carried out around the world have been based on a tetrasporophytic clone isolated in our laboratory from a specimen collected in China. Here we describe the life history of this species, give anatomic details of the reproductive structures, illustrate the morphological variability of tetraspore progeny and compare the growth rate of gametophytic and sporophytic thalli. Tetrasporophytic branches showed higher growth rates than gametophytic branches.

Matrix metalloproteinases, TIMPs and growth factors regulating ameloblastoma behaviour

Aims: Ameloblastoma is an odontogenic neoplasm with local invasiveness and recurrence. We have previously suggested that growth factors and matrix metalloproteinases (MMPs) influence ameloblastoma invasiveness(1). The aim was to study expression of MMPs, tissue inhibitor of metalloproteinases (TIMPs) and growth factors in ameloblastoma. Methods and results: Thirteen cases of solid/multicystic ameloblastoma were examined. As a control, calcifying cystic odontogenic tumour (CCOT), a non-invasive odontogenic neoplasm with ameloblastomatous epithelium was also studied. Immunohistochemistry detected MMPs, TIMPs and growth factors in ameloblastoma and CCOT. The labelling index (LI) of MMP-9 and TIMP-2 was significantly higher in ameloblastoma compared with CCOT. The LI of epidermal growth factor (EGF), transforming growth factor (TGF)-alpha and epidermal growth factor receptor (EGFR) was also increased in ameloblastoma. This neoplasm showed greater expression of MMPs, TIMPs and growth factors compared with CCOT. We then analysed these molecules in ameloblastoma cells and stroma. Ameloblastoma cells exhibited increased LI of MMP-1, -2 and EGFR. We found a positive correlation between EGF and TIMP-1, and between TGF-alpha and TIMP-2. It is known that signals generated by growth factors are transduced by the ERK pathway. Ameloblastoma stroma exhibited the phosphorylated (activated) form of ERK. Conclusions: These results suggest an interplay involving growth factors MMPs and TIMPs that may contribute to ameloblastoma behaviour. Signals generated by this molecular network would be transduced by ERK 1/2 pathway.

Economic viability of doses and split-applications of nitrogen fertilization in corn crop in a eutrophic Red Latosol

Nitrogen is the nutrient that is most absorbed by the corn crop, with the most complex management, and has the highest share on the cost of corn production. The objective of this work was to evaluate the economic viability of different rates and split-applications of nitrogen fertilization, as such as urea, in the corn crop in a eutrophic Red Latosol (Oxisol). The study was carried out in the Experimental Station of the Regional Pole of the Sao Paulo Northwest Agribusiness Development (APTA), in Votuporanga, State of Sao Paulo, Brazil. The experimental design was randomized complete blocks with nine treatments and four replications, consisting of five N rates: 0, 55, 95, 135 and 175 kg ha(-1), 15 kg ha-l applied in the seeding and the remainder in top dressing: 40 and 80 kg ha(-1) N at forty days after seeding (DAS), or 1/2 + 1/2 at 20 and 40 DAS; 120 kg ha-1 N split in 1/2 + 1/2 or 1/3 + 1/3 + 1/3 at 20, 40 or 60 DAS; 160 kg ha(-1) N split in 1/4 + 3/8 + 3/8 or 114 + 1/4 + 1/4 + 1/4 at 20, 40, 60 and 80 DAS. The application of 135 kg ha-l of N split in three times provided the best benefit/cost ratio. The non-application of N provided the lowest economic return, proving to be unviable.

Dignified death: Concept development involving nurses and doctors in Pediatric Intensive Care Units

The aim of this study was to develop the concept of the dignified death of children in Brazilian pediatric intensive care units (PICUs). The Hybrid Model for Concept Development was used to develop a conceptual structure of dignified death in PICUs in an attempt to define the concept. The fieldwork study was carried out by means of in-depth interviews with nine nurses and seven physicians working in PICUs. Not unexpectedly, the concept of dignified death was found to be a complex phenomenon involving aspects related to decisions made by the multidisciplinary team as well as those related to care of the child and the family. Knowledge of the concept`s dimensions can promote reflection on the part of healthcare professionals regarding the values and beliefs underlying their conduct in end-of-life situations. Our hope is that this study may contribute to theoretic and methodological development in the area of end-of-life care.

Fluoxetine induces preventive and complex effects against colon cancer development in epithelial and stromal areas in rats

Fluoxetine (FIX) is a drug commonly used as antidepressant. However, its effects on tumorigenesis remain controversial. Aiming to evaluate the effects of FIX treatment on early malignant changes, we analyzed serotonin (5-HT) metabolism and recognition, aberrant crypt foci (ACF), proliferative process, microvessels, vascular endothelial growth factor (VEGF), and cyclooxygenase-2 (COX-2) expression in colon tissue. Male Wistar rats received a daily FLX-gavage (30 mg kg(-1)) and, a single dose of 1.2 dimethylhydrazine (DMH; i.p., 125 mg kg(-1)). After 6 weeks of FIX-treatment, our results revealed that FIX and nor-fluoxetine (N-FIX) are present in colon tissue, which was related to significant increase in serotonin (5-HT) levels (P < 0.05) possibly through a blockade in SERT mRNA (serotonin reuptake transporter; P < 0.05) resulting in lower 5-hydroxyindoleacetic acid (5-HIAA) levels (P < 0.01) and, 5-HT2C receptor mRNA expressions. FIX-treatment decreased dysplastic ACF development (P < 0.01) and proliferative process (P < 0.001) in epithelia. We observed a significant decrease in the development of malignant microvessels (P < 0.05), VEGF (P < 0.001), and COX-2 expression (P < 0.01). These findings suggest that FIX may have oncostatic effects on carcinogenic colon tissue, probably due to its modulatory activity on 5-HT metabolism and/or its ability to reduce colonic malignant events. (C) 2011 Elsevier Ireland Ltd. All rights reserved.

Coordinated regulation of follicle development by germ and somatic cells

The continuum of folliculogenesis begins in the fetal ovary with the differentiation of the oogonia and their isolation within the primordial follicles. Primordial follicle activation is an enigmatic process, whereby some follicles enter the growing pool to become primary follicles, thereby embarking on an irreversible progression towards ovulation or atresia. This process is under the coordinated regulation of factors from the oocyte itself, as well as from the somatic cells of the ovary, in particular the theca and granulosa cells, which are structural components of the follicle. These two influences provide the principal stimuli for the growth of the follicle to the late preantral or early antral stage of development. The endocrine effects of the gonadotrophins FSH and LH are essential to the continued progression of the follicle and most atresia can be attributed to the failure to receive or process the gonadotrophin signals. The peri-ovulatory state has received intensive investigation recently, demonstrating a coordinated role for gonadotrophins, steroids, epidermal growth factor family proteins and prostaglandins. Thus, a complex programme of coordinated interaction of governing elements from both germ and somatic cell sources is required for successful follicle development.

Development of impedimetric and optical calcium biosensor by using modified gold electrode with porcine S100A12 protein

We describe the development of a label free method to analyze the interactions between Ca(2+) and the porcine S100A12 protein immobilized on polyvinyl butyral (PVB). The modified gold electrodes were characterized using cyclic voltammetry (CV), electrochemical impedance spectroscopy (EIS), scanning electron microscopy (SEM) and surface plasmon resonance (SPR) techniques. SEM analyses of PVB and PVB-S100A12 showed a heterogeneous distribution of PVB spherules on gold surface. EIS and CV measurements have shown that redox probe reactions on the modified gold electrodes were partially blocked due the adsorption of PVB-S100A12, and confirm the existence of a positive response of the immobilized S100Al2 to the presence of calcium ions. The biosensor exhibited a wide linear response to Ca(2+) concentrations ranging from 12.5 to 200 mM. The PVB-S100A12 seems to be bound to the gold electrode surface by physical adsorption: we observed an increase of 1184.32 m degrees in the SPR angle after the adsorption of the protein on the PVB surface (in an indication that 9.84 ng of S100A12 are adsorbed per mm(2) of the Au-PVB electrode), followed by a further increase of 581.66 m degrees after attachment of the Ca(2+) ions. In addition, no SPR response is obtained for non-specific ions. These studies might be useful as a platform for the design of new reusable and sensitive biosensing devices that could find use in the clinical applications. (C) 2010 Elsevier B.V. All rights reserved.

Cation size effects-modified phase and PTCR development in Er3+ and Ca2+ co-doped BaTiO3 ceramics during sintering

Development of the positive temperature coefficient of resistivity (PTCR) in Er3+ and Ca2+ co-doped ferroelectric BaTiO3 was studied in this work, with Er3+ being used to act as a donor doping. Irrespective of all the materials showing high densities after sintering at 1200 to 1300 ºC, these revealed insulator at the lowest sintering temperature, changing to semiconducting and PTCR-type materials only when the sintering temperature was further increased. Observations from X-ray diffraction help correlating this effect with phase development in this formulated (Ba,Ca,Er)TiO3 system, considering the formation of initially two separated major (Ba,Ca)TiO3- and minor (Ca,Er)TiO3-based compounds, as a consequence of cation size-induced stress energy effects. Thus, appearance and enhancement here of the semiconducting and PTCR responses towards higher sintering temperatures particularly involve the incorporation of Er3+ into the major phase, rendering finally possible the generation and "percolative-like" migration of electrons throughout the whole material.

Recent trends in maternal, newborn, and child health in Brazil: progress toward Millennium Development Goals 4 and 5

We analyzed Brazil's efforts in reducing child mortality, improving maternal and child health, and reducing socioeconomic and regional inequalities from 1990 through 2007. We compiled and reanalyzed data from several sources, including vital statistics and population-based surveys. We also explored the roles of broad socioeconomic and demographic changes and the introduction of health sector and other reform measures in explaining the improvements observed. Our findings provide compelling evidence that proactive measures to reduce health disparities accompanied by socioeconomic progress can result in measurable improvements in the health of children and mothers in a relatively short interval. Our analysis of Brazil's successes and remaining challenges to reach and surpass Millennium Development Goals 4 and 5 can provide important lessons for other low- and middle-income countries

Quantification of MgO surface excess on the SnO(2) nanoparticles and relationship with nanostability and growth

In this work, we experimentally showed that the spontaneous segregation of MgO as surface excess in MgO doped SnO(2) nanoparticles plays an important role in the system`s energetics and stability. Using Xray fluorescence in specially treated samples, we quantitatively determined the fraction of MgO forming surface excess when doping SnO(2) with several different concentrations and established a relationship between this amount and the surface energy of the nanoparticles using the Gibbs approach. We concluded that the amount of Mg ions on the surface was directly related to the nanoparticles total free energy, in a sense that the dopant will always spontaneously distribute itself to minimize it if enough diffusion is provided. Because we were dealing with nanosized particles, the effect of MgO on the surface was particularly important and has a direct effect on the equilibrium particle size (nanoparticle stability), such that the lower the surface energy is, the smaller the particle sizes are, evidencing and quantifying the thermodynamic basis of using additives to control SnO(2) nanoparticles stability. (C) 2010 Elsevier B.V. All rights reserved.

DOSES OF INDOLBUTYRIC ACID IN THE ROOTING AND GROWTH OF EUCALYPT CUTTINGS (Eucalyptus urophylla)

This work aimed to evaluate the effect of different concentrations of IBA (indolbutyric acid) in the rooting and growth of Eucalyptus urophylla cuttings. The experimental design used was the randomized blocks, in factorial with an arrangement of split plots, with three concentrations of IBA (2.000; 5.000 and 8.000 mg L(-1)), two ways of the application of plant gowth regulators (paste and powder), and three period of evaluations (30, 45 and 60 days). The experiment was carried out in the Farm Buriti de Prata, an entreprise property of Souza Cruz, in the city of Prata - MG in 2003. After the preparation of the cuttings, patterned in 10 cm of length and 0.8 cm of diameter, those were immersed in mixtures of IBA for 10 seconds, in the forms of dry powder and paste and than planted in plastic tubes contening Plantmax substrate with vermiculite. The cuttings were transported to greenhouse with controled humidity, where they remained for 60 days. The variables studied were: height of plant in the 30(th), 45(th) and 60(th) days after seeding; fresh mass of the aerial part and roots. The IBA applied in powder form as well as in paste form, resulted in an greater seedling growth. To the 60 days, the seedlings presented greater growth, being significantly superior to the heights measured in other times of evaluation. The application of 2.000 mg L(-1) and 5,000 mg L(-1) resulted in significant increases on weight of fresh mass of the aerial part and root system.

CpG-Induced Th1-Type Response in the Downmodulation of Early Development of Allergy and Inhibition of B7 Expression on T Cells of Newborn Mice

Several differences have been described between neonatal and adult immune responses. The predisposition in early life to Th2-type response or tolerance makes it a susceptible period for infections and allergic sensitization. The aim of this work was to evaluate the effects of CpG-containing oligodeoxynucleotides on neonatal and adult immunization with ovalbumin and Blomia tropicalis extract and compare the CpG effects on B and T cells of neonatal and adult mice. Mice that received CpG showed reduced immunoglobulin E (IgE) antibody production in both neonatal and adult periods, in parallel to increased IgG2a antibody levels. We observed that spleen cells of mice that received CpG in early life produced increased amounts of interferon-gamma upon anti-CD3 stimulation. Negative regulation of IgE response was more pronounced in adult than neonate mice; further, CpG decreased anaphylactic antiovalbumin IgG1 only in adults. Also, an upregulation of toll-like receptor 9 expression was detected in adult B cells, but not in neonatal, upon CpG stimuli. Neonatal B cells showed enhanced interleukin (IL)-10 expression and decreased IL-6 levels than adult B cells in response to CpG. When we analyzed in vitro activation of CD4+ T cells, an increased expression of B7 molecules on T cells in neonates was suppressed by CpG. Altogether, we verified qualitative and quantitative evidences regarding CpG effect on neonatal and adult allergens immunizations, which points to the importance of understanding neonatal immune system to establish immunomodulatory strategies for prevention of allergic diseases.