Genotoxicity testing of Ambelania occidentalis (Apocynaceae) leaf extract in vivo

Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)

Lateral hypothalamus lesions influences water and salt intake, and sodium and urine excretion, and arterial blood pressure induced by L-NAME and FK 409 injections into median preoptic nucleus in conscious rats

Male Holtzman rats weighting 200-250 g were anesthetized with zoletil 50 mg/Kg (tiletamine chloridrate 125,0 mg and zolazepan chloridrate 125,0 mg) into quadriceps muscle and submitted an electrolytic lesion of the lateral hypothalamus (LH) and a stainless steel cannula was implanted into their median preoptic nucleus (MnPO). We investigated the effects of the injection into the (MnPO) of FK 409 (20 mug/0.5 mul), a nitric oxide (NO) donor, and N-W-nitro-L-arginine methyl ester (L-NAME) 40 mug/0.5 mul, a nitric oxide synthase inhibitor (NOSI), on the water and sodium appetite and the natriuretic, diuretic and cardiovascular effects induced by injection of L-NAME and FK 409 injected into MnPO in rats with LH lesions. Controls were injected with a similar volume of 0.15 M NaCl. L-NAME injected into MnPO produced an increase in water and sodium intake and in sodium and urine excretion and increase de mean arterial pressure (MAP). FK 409 injected into MnPO did not produce any change in the hydro electrolytic and cardiovascular parameters in LH-sham and lesioned rats. FK 409 injected before L-NAME attenuated its effects. These data show that electrolytic lesion of the LH reduces fluid and sodium intake as well as sodium and urine excretion, and the pressor effect induced by L-NAME. LH involvement with NO of the MnPO excitatory and inhibitory mechanisms related to water and sodium intake, sodium excretion and cardiovascular control is suggested. (C) 2004 Elsevier B.V. All rights reserved.

Lipopolysaccharide reduces sodium intake and sodium excretion in dehydrated rats

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Uso de hidrogel na sobrevivência de mudas de Eucalyptus urograndis produzidas com diferentes substratos e manejos hídricos

This study aimed to evaluate the use of hydrogel in the survival of cuttings of Eucalyptus urograndis produced with different types of substrate and water management. The experiment was carried out using cuttings of the same clone, produced up to 50 days after the cutting, in two different nurseries ("C" and "E"). Then, all the cuttings were allocated to the same nursery for 80 days, where they received irrigation at different frequencies. After this period, the cuttings were transplanted into polyethylene pots, in clay soil, with and without hydrogel. The results obtained were subjected to the variance technique for totally randomized experiments. Data analysis revealed that the plants with hydrogel displayed delayed symptoms of water deficit. Regardless of the cutting's origin ("C" or "E"), the hydrogel influenced survival, guaranteeing 37 days without additional irrigation. The nursery water management only influenced the plants from nursery "E", and the plants adapted to the lack of water (water management with one daily irrigation) took more time to present symptoms of water deficit.

Expression of renin-angiotensin system signalling compounds in maternal protein-restricted rats: effect on renal sodium excretion and blood pressure

Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)

Population structure, feeding and reproductive aspects of Serrapinnus heterodon (Characidae, Cheirodontinae) in a Mogi Guaçu reservoir (SP), upper Paraná River basin

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)

Cytotoxicity and genotoxicity of pulp capping materials in two cell lines

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)

Linking the hydrodynamic and kinetic description of a dissipative relativistic conformal theory

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Custo de bombas centrífugas funcionando como turbinas em microcentrais hidrelétricas

A implantação de microcentrais hidrelétricas é uma das alternativas para suprir com energia comunidades pequenas e isoladas, situadas normalmente na área rural. O aproveitamento de potenciais hidráulicos de pequeno porte é uma alternativa cada vez mais viável devido não só à falta de recursos financeiros para os grandes empreendimentos, mas também pelo imenso potencial de geração em centrais de pequeno porte, que pouco tem sido aproveitado. O objetivo deste trabalho foi de apresentar uma metodologia simples de engenharia para estimar o custo das Bombas Funcionando como Turbinas (BFTs) utilizadas em microcentrais hidrelétricas, que possam ser usadas em estudos preliminares de novos aproveitamentos hidrelétricos, sem uma investigação detalhada dos lugares onde se pretende implantar. Os custos foram obtidos consultando-se diretamente os fabricantes de equipamentos e o mercado da praça de Ponta Grossa - PR. Os resultados mostraram que, para as microcentrais hidrelétricas, sempre que os custos constituírem o aspecto dominante, e para potências até 50 kW, a opção por Bombas Funcionando como Turbinas (BFTs) deve ser considerada em lugar das turbinas hidráulicas.

From Plinthic Acrisols to Plinthosols and Gleysols: iron and groundwater dynamics in the tertiary sediments of the upper Amazon basin

Topography has been reported to be the major factor ruling the spatial distribution of Acrisols, Plinthosols and Gleysols on the seasonally flooded, low elevation plateaux of the upper Amazon basin occupied by Tertiary (Ica & Solimoes) sediments. In this study, detailed morphological and mineralogical investigations conducted in a representative 25-ha site were combined with hydro-geochemical data to relate the vertical and lateral soil differentiations observed to the hydro-geological history of that part of the basin. As a result of the uplift of the Andes, several cuts in the extensive Tertiary marshlands have formed, at first, slightly incised plateaux of low elevation. There, weathering under hot and humid climates would have generated a reddish, freely drained and bioturbated topsoil layer and the vertical differentiation in subsoil sediments of a plinthite over an iron-depleted mottled clay. The second episode of soil differentiation is linked to the replacement of the forest by a savannah under the drier climates of the late Pleistocene, which favours surface runoff and the infill of the incisions by fine particles. This infill, combined with the return to the present humid climate, has then enabled the local groundwater to rise on the plateaux and to generate episaturation at the topsoil/subsoil transition close to the depressions. Nowadays, ferrous iron is released from the partly iron-depleted topsoil weathering front at high water levels during the rainy seasons. It moves from footslope to low-lying positions and from top to bottom in the soil profile according to the groundwater dynamics. The present general trend is thus to the lateral export of iron at high water levels due to subsurface and overland flows, its vertical transfer during the recession of the groundwater and accumulation in a nodular plinthite. In the latter, ferrous iron is adsorbed onto its softest iron masses where it feeds the neoformation of ferrihydrite that rapidly dehydrates into haematite.

Assessment and statistics of Brazilian hydroelectric power plants: Dam areas versus installed and firm power

The Brazilian relief, predominantly composed by small mountains and plateaus, contributed to formation of rivers with high amount of falls. With exception to North-eastern Brazil, the climate of this country are rainy, which contributes to maintain water flows high. These elements are essential to a high hydroelectric potential, contributing to the choice of hydroelectric power plants as the main technology of electricity generation in Brazil. Though this is a renewable source, whose utilized resource is free, dams must to be established which generates a high environmental and social impact. The objective of this study is to evaluate the impact caused by these dams through the use of environmental indexes. These indexes are ratio formed by installed power with dam area of a hydro power plant, and ratio formed by firm power with this dam area. In this study, the greatest media values were found in South, Southeast, and Northeast regions respectively, and the smallest media values were found in North and Mid-West regions, respectively. The greatest encountered media indexes were also found in dams established in the 1950s. In the last six decades, the smallest indexes were registered by darns established in the 1980s. These indexes could be utilized as important instruments for environmental impact assessments, and could enable a dam to be established that depletes an ecosystem as less as possible.

Efficacy of florfenicol and intravenous fluid therapy for treatment of experimental salmonellosis in newborn calves

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Application of propolis to dental sockets and skin wounds.

The purpose of this study was to examine histologically the effects of propolis topical application to dental sockets and skin wounds. After topical application of either a 10% hydro-alcoholic solution of propolis or 10% hydro-alcoholic solution alone, cutaneous wound healing and the socket wound after tooth extraction were examined. The rats were sacrificed at 3, 6, 9, 15 and 21 days after the operation. The specimens were subjected to routine laboratory studies after staining with hematoxylin and eosin. It was concluded that topical application of propolis hydro-alcoholic solution accelerated epithelial repair after tooth extraction but had no effect on socket wound healing.

Composição fitoquímica dos óleos essenciais de folhas de Lippia alba (Mill.)N.E.Br. em diferentes épocas de colheita e partes do ramo

This work aimed to determine the best harvest time for biomass production, yield and essential oil composition considering the seasonal variation (spring, summer, autumn and winter) on different plant parts (apical, medial and basal). Essential oils were extracted by hydro-distillation with a Clevenger apparatus for both fresh and dry mass obtained in field and lab conditions respectively. The extracted essential oils were analyzed by GS/MS (Shimadzu, QP-5000). The chemical components were identified by comparing their mass spectrum to the patterns filed in the MS computer memory (Wiley,139,Lib.), to the literature references, and by co-injection with authentic standards. Applying phyto-chemical tests on fresh and dry mass, the chemical component percentages of essential oils were calculated and identified as follows: citral (neral and geranial), myrcene, caryophylene and elemene.

Efeito do extrato aquoso de sete-sangrias [Cuphea mesostemon (Koehne) Lourt] sobre o fluxo de água, medido em bexiga urinária de sapo in vitro

The Cuphea mesostemon specie, known as sete-sangrias, is widely used as a diuretic substance in popular medicine. As the toad urinary bladder is an epithelium analogous to the distal nephron of mammals, it is used in order to study the transport water and electrolytes in many laboratories. This preparation permits excellent observation in water flow, from the urinary bladder lumen to the external side or the serosal one (water re-absorption), by means of gravimetrical measures. In the present work the hydrosmotic effect of aqueous extract (AE) of sete-sangrias leaf was studied. A 20% solution was added to the serosal side (S) of the bladder preparation, and the water flow was measured every 15 minutes after that. The results showed that 4mL of AE in the S side, increased the JH20 in a significant manner (p<0,05). This effect had a dose - response shape, with the volumes of 0,2mL, 0,4mL and 0,8mL of AE in the S bath. The hydro-osmotic effect of the anti-diuretic hormone (ADH) was studied as well and a significant stimulation (p<0,05) in the JH2O was observed with the magnitude of 150%. The AE effect was similar to the ADH one, and was not antagonized by this hormone. We concluded that Cuphea possesses an anti-diuretic activity similar to that presented by ADH, in toad urinary bladder, in vitro.