147 resultados para BIOLOGICAL SOURCES

em Scielo Saúde Pública - SP


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We review here the chemistry of reactive oxygen and nitrogen species, their biological sources and targets; particularly, biomolecules implicated in the redox balance of the human blood, and appraise the analytical methods available for their detection and quantification. Those biomolecules are represented by the enzymatic antioxidant defense machinery, whereas coadjutant reducing protection is provided by several low molecular weight molecules. Biomolecules can be injured by RONS yielding a large repertoire of oxidized products, some of which can be taken as biomarkers of oxidative damage. Their reliable determination is of utmost interest for their potentiality in diagnosis, prevention and treatment of maladies.

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The sylvatic triatomine Rhodnius pallescens is considered to be the most important and widespread vector of Trypanosoma cruzi and Trypanosoma rangeli in Panama. However, its behavior and biological characteristics have only been partially investigated. Thus, to achieve sustainable and efficient control over Chagas disease in Panama, a better understanding of the ecology and biology of R. pallescens is essential. In this study we evaluated R. pallescens host feeding sources using a dot-blot assay, and the trypanosome infection index by PCR analysis in a Chagas disease endemic area of central Panama. It was found that in peridomestic palm trees, 20.3% of the examined bugs had fed on opossums (Didelphis marsupialis). However, we observed an increased anthropophagy (25.4%) for those bugs collected inside houses. Considering the domestic and peridomestic habitats as a whole, the proportion of collected R. pallescens infected with trypanosomes was 87.4%. In the two habitats the predominant infection was with T. cruzi (80-90%). Between 47-51% of the analyzed triatomines were infected with T. rangeli. Mixed infections (40-51%) were also detected. These findings provide a better basis for the implementation of a rational control and surveillance program for Chagas disease in regions where R. pallescens is endemic.

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Biological parameters of five Trypanosoma cruzi strains from different sources were determined in order to know the laboratory behaviour of natural populations. The parameters evaluated were growth kinetics of epimastigotes, differentiation into metacyclic forms, infectivity in mammalian cells grown in vitro and parasite susceptibility to nifurtimox, benznidazole and gentian violet. Differences in transformation to metacyclic, in the percentage of infected cells as well as in the number of amastigotes per cell were observed among the strains. Regarding to pharmacological assays, Y strain was the most sensitive to the three assayed compounds. These data demonstrate the heterogeneity of natural populations of T. cruzi, the only responsible of infection in humans.

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Biological aspects of Leucothyreus ambrosius Blanchard (Coleoptera, Melolonthidae, Rutelinae). Coleopterans of the family Melolonthidae comprise a large group of species that feed on different food sources, including plant roots, stems, and leaves, in addition to plant materials at different decomposition stages. Several species are found in the genus Leucothyreus, occurring in different regions of Brazil, including the various biomes in the country. Information on the biology of species of the genus Leucothyreus is scarce, therefore, we conducted studies on the biological aspects of Leucothyreus ambrosius Blanchard, 1850. The period of adult occurrence was determined with a light trap installed between a cropped and pasture area in the municipality of Aquidauana, Mato Grosso do Sul State, Brazil. Adults collected in the field were used to form insect pairs and the studies were initiated in the entomology laboratory as the adults began ovipositing. Adults were observed flying in the field from October to December. Eggs were obtained as pairs were formed and a colony was established, the embryonic period lasting 14.6 days on average. The larval period in the 1st instar lasted 21.6 days, in the 2nd instar 19.6 days, and in the 3rd instar, 85.6 days. The head capsule width was 1.48 mm in the 1st instar, 2.44 mm in the 2nd, and 3.83 mm in 3rd larval instar. The pupal stage had an average duration of 35.5 days. The egg to adult period lasted 173.3 days. Morphometric information for the larval and adult stages is presented in this study.

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Seeds with a high concentration of P or Mo can improve the growth and N accumulation of the common bean (Phaseolus vulgaris L.), but the effect of enriched seeds on biological N2 fixation has not been established yet. This study aimed to evaluate the effect of seeds enriched with P and Mo on growth and biological N2 fixation of the common bean by the 15N isotope dilution technique. An experiment was carried out in pots in a 2 x 3 x 2 x 2 factorial design in randomized blocks with four replications, comprising two levels of soil applied P (0 and 80 mg kg-1), three N sources (without N, inoculated with rhizobia, and mineral N), two seed P concentrations (low and high), and two seed Mo concentrations (low and high). Non-nodulating bean and sorghum were used as non-fixing crops. The substrate was 5.0 kg of a Red Latosol (Oxisol) previously enriched with 15N and mixed with 5.0 kg of sand. Plants were harvested 41 days after emergence. Seeds with high P concentration increased the growth and N in shoots, particularly in inoculated plants at lower applied P levels. Inoculated plants raised from high P seeds showed improved nodulation at both soil P levels. Higher soil P levels increased the percentage of N derived from the atmosphere (%Ndfa) in bean leaves. Inoculation with the selected strains increased the %Ndfa. High seed P increased the %Ndfa in inoculated plants at lower soil P levels. High seed Mo increased the %Ndfa at lower soil P levels in plants that did not receive inoculation or mineral N. It is concluded that high seed P concentration increases the growth, N accumulation and the contribution of the biological N2 fixation in the common bean, particularly in inoculated plants grown at lower soil P availability.

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The microalgae biomass production from swine wastewater is a possible solution for the environmental impact generated by wastewater discharge into water sources. The biomass can be added to fish feed, which can be used in the formulation of meat products. This work addresses the adaptation of the microalgae Spirulina platensis (Arthrospira platensis) in swine wastewater and the study of the best dilution of the wastewater for maximum biomass production and for removal of Chemical Oxygen Demand (COD), ammonia and phosphorous to the microalgae. The cultivation of Spirulina platensis, strain Paracas presented maximum cellular concentrations and maximum specific growth rates in the wastewater concentration of 5.0 and 8.5%. The highest COD removals occurred with 26.5 and 30.0% of wastewater in the medium. The maximum removal of total phosphorous (41.6%), was with 8.5% of wastewater, which is related to the microalgae growth. The results of Spirulina culture in the swine wastewater demonstrated the possibility of using these microalgae for the COD and phosphorous removal and for biomass production.

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There have been two key initiatives taken in the last two decades in Brazil to create a counter-hegemonic project for the country. One initiative resulted from Brazil's business community and high-level State bureaucracy and aimed at forming a regional economic and political bloc that would guarantee and enlarge a relative independence from the hegemonic powers. The other resulted from the emergence of the new unionist movement in São Paulo and from the formation of Partido dos Trabalhadores and aimed at promoting radical democratization and reducing social exclusion. Both initiatives have created policies and changes that have converged to enhance Brazil's counter-hegemonic position as a regional and emerging power.

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Due to the high energy requirement and demand for non-renewable resources for the production of chemical fertilizers, added also to the environmental impact caused by the use of such products, it is important to intensify research on bio-based agricultural inputs. The use of nitrogen-fixing endophytic and phosphate solubilizing bacteria can provide these nutrients to the plants from the air and poorly soluble phosphorus sources, such as phosphate rock. The objective of this study was to evaluate the nutrition and initial growth of maize (Zea mays L.) in response to the inoculation of nitrogen-fixing and rock phosphate solubilizing endophytic bacteria, in single or mixed formulation, applied with vermicompost. The treatments containing bacteria, both diazotrophic and phosphate solubilizing, when compared to controls, showed higher levels of leaf nitrogen and phosphorus in maize, as well as higher growth characteristics. The application of vermicompost showed synergistic effect when combined with endophytic bacteria. Thus, the innovation of the combination of the studied factors may contribute to the early development of maize.

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Phenolic compounds have been extensively studied in recent years. The presence of these compounds in various foods has been associated with sensory and health promoting properties. These products from the secondary metabolism of plants act as defense mechanisms against environmental stress and attack by other organisms. They are divided into different classes according to their chemical structures. The objective of this study was to describe the different classes of phenolic compounds, the main food sources and factors of variation, besides methods for the identification and quantification commonly used to analyze these compounds. Moreover, the role of phenolic compounds in scavenging oxidative stress and the techniques of in vitro antioxidant evaluation are discussed. In vivo studies to evaluate the biological effects of these compounds and their impact on chronic disease prevention are presented as well. Finally, it was discussed the role of these compounds on the sensory quality of foods.

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ABSTRACT Pathogenic fungi cause skin darkening and peach quality depreciation in post harvest. Therefore, alternative techniques to chemical treatment are necessary in order to reduce risks to human health. The aim of this study was to evaluate the effect of the application of Trichoderma harzianum in association with different fungicides applied before harvest to 'Eldorado' peaches for brown rot control and other quality parameters during storage. The treatments consisted of five preharvest fungicide applications (control, captan, iprodione, iminoctadine and tebuconazole) associated with postharvest application of T. harzianum, after cold storage (with and without application), in three evaluation times (zero, two and four days at 20 °C), resulting in a 5x2x3 factorial design. The application of T. harzianum only brought benefits to the control of brown rot when combined with the fungicide captan, at zero day shelf life. After two days, there was a greater skin darkening in peaches treated with T. harzianum compared with peaches without the treatment, except for peaches treated with the fungicide iprodione and T. harzianum The application of T. harzianum during postharvest showed no benefits for the control of brown rot, however, the association with fungicides reduced the incidence of Rhizopus stolonifer during the shelf life.

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ABSTRACT New nitrogen fertilizers are available in the market actually, however, does not have results on the efficiency of the Cerrado conditions. With that objective of this study was to evaluate the effect of urea including stabilized and controlled release urea on yield of irrigated common beans (Phaseolus vulgaris L) in no-tillage system. The experiment was conducted in the winter crop, at Embrapa Arroz e Feijão, in Santo Antônio de Goiás, State of Goiás, Brazil. The experimental design was randomized blocks, with five replicates. Treatments consisted of five N sources (urea, urea + NBPT, urea + polymer, ammonium sulphate, and ammonium nitrate) and a control (without N) being applied 20 kg ha-1 of N at sowing and 80 kg ha-1 onf N in topdressing. We evaluated the chlorophyll content in leaves of common beans, the leaf N content and dry mass weight (MSPA) in the flowering of common beans, the number of pods per plant, number of grains per pod, mass of 100 grains, grain yield and final stand of the common beans. The sources of nitrogen fertilizer did not influence, leaf N content, the mass of MSPA and the relative chlorophyll index of common beans. The use of polymerized urea and urea with urease inhibitor, did not produce increases in the number of grains per pod, number of pods per plant, mass of 100 grains and common beans yield compared to traditional sources of N, urea, ammonium sulfate and ammonium nitrate.

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In the context of the design of working hours inequities in health associated with biological, psychological, social, and socioeconomic diversities can be observed. The paper first tries to set up a frame of reference for a discussion of this topic, relating to the Universal Declaration of Human Rights and some recent discussions on equity in health and then goes into some factors that produce inequities in health in the context of the design of working hours, dealing with sex or gender, age and job age, personality traits, marital status, social support, diversities in values, and socio-economic differences; the discussion deals with approaches on how to deal with these differences and inequities.

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OBJECTIVE To analyze the access and utilization profile of biological medications for psoriasis provided by the judicial system in Brazil.METHODSThis is a cross-sectional study. We interviewed a total of 203 patients with psoriasis who were on biological medications obtained by the judicial system of the State of Sao Paulo, from 2004 to 2010. Sociodemographics, medical, and political-administrative characteristics were complemented with data obtained from dispensation orders that included biological medications to treat psoriasis and the legal actions involved. The data was analyzed using an electronic data base and shown as simple variable frequencies. The prescriptions contained in the lawsuits were analyzed according to legal provisions.RESULTS A total of 190 lawsuits requesting several biological drugs (adalimumab, efalizumab, etanercept, and infliximab) were analyzed. Patients obtained these medications as a result of injunctions (59.5%) or without having ever demanded biological medication from any health institution (86.2%), i.e., public or private health services. They used the prerogative of free legal aid (72.6%), even though they were represented by private lawyers (91.1%) and treated in private facilities (69.5%). Most of the patients used a biological medication for more than 13 months (66.0%), and some patients were undergoing treatment with this medication when interviewed (44.9%). Approximately one third of the patients discontinued treatment due to worsening of their illness (26.6%), adverse drug reactions (20.5%), lack of efficacy, or because the doctor discontinued this medication (13.8%). None of the analyzed medical prescriptions matched the legal prescribing requirements. Clinical monitoring results showed that 70.3% of the patients had not undergone laboratory examinations (blood work, liver and kidney function tests) for treatment control purposes.CONCLUSIONS The plaintiffs resorted to legal action to get access to biological medications because they were either unaware or had difficulty in accessing them through institutional public health system procedures. Access by means of legal action facilitated long-term use of this type of medication through irregular prescriptions and led to a high rate of adverse drug reactions as well as inappropriate clinical monitoring.