984 resultados para SODIUM-PUMP ACTIVITY


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We investigated the effects of treatments with the enzymes pepsin and trypsin on the in vitro immunological reactivity of the major globulins found in the seeds of sweet lupin, chickpea, and lentil. Polyclonal major globulin-specific antiserum was obtained by immunization of rabbits with a solution of the 11 S globulin of each legume. The globulins were hydrolyzed with pepsin and trypsin for 1, 5, 15, and 30 min. The native globulins and their hydrolysates were analyzed by sodium dodecyl sulfate-polyacrylamide gel electrophoresis and immunoblotting to identify the polypeptide bands with antigenic activity, and the hypoantigenicity of the hydrolysates was analyzed by enzyme-linked immunosorbent assay. Our results show that enzymatic treatment of the major storage protein (11 S globulin) of sweet lupin, chickpea, and lentil with pepsin or trypsin lead to the formation of large amounts of short peptides and free amino acids that do not allow antibody binding, resulting in a weakened immunoreactivity.

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Fencamfamine (FCF) is an indirect dopamine agent with effects similar to amphetamine and cocaine. In the present study, we investigate changes in Na,K-ATPase, cyclic AMP-dependent protein kinase (PKA) and nitric oxide synthase (NOS) activity and cyclic GMP levels in the nucleus accumbens (NAc) and striatum (ST) of animals acutely or repeatedly treated with FCF (3.5 mg/kg). Na,K-ATPase had a similar activity in control and repeatedly treated animals, but was reduced in the NAc of the acute group. This enzyme was reduced in the ST in acute and repeatedly treated animals, compared to the control group. Expression of the alpha(1,2,3)-Na,K-ATPase isoforms in the NAc and the ST was not altered in all groups studied. Acute FCF induced a significant increase in PKA activity in both the ST and the NAc. Repeatedly treated animals showed a higher increase in PKA activity in the NAc, but not in the ST, when compared to the acute group. There was also an increase in both NOS activity and cyclic GMP levels only in the NAc of FCF repeatedly treated animals compared to the acute and control groups. We suggest that chronic FCF treatment is linked to a modification in Na,K-ATPase activity through the PKA and NO-cyclic GMP pathway. (C) 2003 Elsevier Ltd. All rights reserved.

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A microbiological assay applying the cylinder-plate method is described for determination of the activity of cefoxitin sodium in injectables. Using a strain of Staphylococcus epidermidis ATCC 12226 as the test organism, cefoxitin sodium was measured in concentrations ranging from 50.0 to 200.0 mu g/mL. The validation showed that the method was linear (r = 0.9998), precise (RSD 0.81%), and accurate. It was concluded that the microbiological assay is satisfactory for quantitation of cefoxitin sodium in injectables.

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The purpose of this study was to investigate and compare the efficacy of various disinfectants on planktonic cells and biofilm cells of Listeria monocytogenes, Staphylococcus aureus and Escherichia coli. Numbers of viable biofilm cells decreased after treatment with all tested disinfectants (iodine, biguanide, quaternary ammonium compounds, peracetic acid and sodium hypochlorite). Sodium hypochlorite was the most effective disinfectant against biofilm cells, while biguanide was the least effective. Scanning electron microscopy observations revealed that cells adhered on stainless steel surface after treatment with the disinfectants. No viable planktonic cells were observed after treatment with the same disinfectants. Based on our findings, we concluded that biofilm cells might be more resistant to disinfectants than plancktonic cells.

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

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Os autores padronizaram métodos para a avaliação da atividade da glicose-6-fosfato desidrogenase e glutationa redutase. O princípio geral do primeiro método baseou-se na formação de metahemoglobina pelo nitrito de sódio, seguido da estimulação da via das pentoses pelo azul de metileno. Foram estudados 46 indivíduos adultos, sendo 23 do sexo masculino e 23 do feminino, não deficientes em glicose-6-fosfato desidrogenase (G6PD), com idades variando entre 20 e 30 anos. Os resultados revelaram que a redução da metahemoglobina pelo azul de metileno para sangue total, foram de 154.50 e 139.90 mg/min (p<0.05) respectivamente para o sexo masculino e feminino. Para hemácias lavadas os valores foram de 221.10 e 207.85 mg/min (n.s.) respectivamente. Estas observações permitiram concluir que ao se empregar hemácias lavadas e 0.7 g% de concentração de nitrito de sódio, por um lado não houve diferença entre os sexos e por outro, abreviou o tempo de leitura da quantidade residual de metahemoglobina para 90 minutos. A avaliação da atividade da glutationa redutase foi feita baseado no fato de que a cistamina (agente tiol) liga-se aos grupos SH da hemoglobina formando complexos. Estes complexos são revertidos pela ação da glutationa redutase, ocorrendo conjuntamente nesta reação a redução da metahemoglobina. Foram estudados 32 indivíduos adultos, sendo 16 do sexo masculino e 16 do feminino, não deficientes em G6PD, com idades variando entre 20 e 30 anos. Os resultados revelaram valores de redução da metahemoglobina pela cistamina de 81.27 e 91.13 mg/min (p<0.01) respectivamente para o sexo masculino e feminino. Estas observações permitiram concluir que o emprego de hemácias lavadas e 0.1 molar de concentração de cistamina torna possível a leitura da quantidade residual de metahemoglobina aos 180 minutos de incubação. A atividade da glutationa redutase avaliada por meio da redução da metahemoglobina pela cistamina, foi estudada em 14 indivíduos do sexo feminino antes e após o tratamento com 10 mg por dia de riboflavina durante 8 dias. Os resultados foram de 73.69 e 94.26 mg/min (p<0.01) antes e após o tratamento. Estas observações permitiram concluir que a oferta de riboflavina, mesmo para indivíduos normais, aumenta a atividade da glutationa redutase. Foram ainda avaliados 3 indivíduos da raça negra e deficientes em G6PD, sendo 2 do sexo masculino e 1 do feminino. Houve ativação parcial da G6PD e glutationa redutase, sendo estas alterações mais intensas nos indivíduos do sexo masculino. Considerando-se a raça e as características laboratoriais observadas, foi possível sugerir que a deficiência em G6PD verificada é do tipo Africano, bem como, permitiu considerar os indivíduos do sexo feminino coin o sendo heterozigoto para esta deficiência. Por fim, a análise dos resultados em seu conjunto permitiu concluir que os métodos propostos se mostraram eficientes para avaliar a atividade da G6PD e glutationa redutase. Esta última é dependente da via das pentoses, geradora de NADPH e da riboflavina, vitamina precursora de FAD.

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Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)

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Adult rats deprived of water for 24-30 h were allowed to rehydrate by ingesting only water for 1-2 h. Rats were then given access to both water and 1.8% NaCl. This procedure induced a sodium appetite defined by the operational criteria of a significant increase in 1.8% NaCl intake (3.8 +/- 0.8 ml/2 h; n = 6). Expression of Fos (as assessed by immunohistochemistry) was increased in the organum vasculosum of the lamina terminalis (OVLT), median preoptic nucleus (MnPO), subfornical organ (SFO), and supraoptic nucleus (SON) after water deprivation. After rehydration with water but before consumption of 1.8% NaCl, Fos expression in the SON disappeared and was partially reduced in the OVLT and MnPO. However, Fos expression did not change in the SFO. Water deprivation also 1) increased plasma renin activity (PRA), osmolality, and plasma Na+; 2) decreased blood volume; and 3) reduced total body Na+; but 4) did not alter arterial blood pressure. Rehydration with water alone caused only plasma osmolality and plasma Na+ concentration to revert to euhydrated levels. The changes in Fos expression and PRA are consistent with a proposed role for ANG II in the control of the sodium appetite produced by water deprivation followed by rehydration with only water.

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

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

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A water deprived animal that ingests only water efficiently corrects its intracellular dehydration, but remains hypovolemic, in negative sodium balance, and with high plasma renin activity and angiotensin II. Therefore, it is not surprising that it also ingests sodium. However, separation between thirst and sodium appetite is necessary to use water deprivation as a method to understand the mechanisms subserving sodium appetite. For this purpose, we may use the water deprivation-partial repletion protocol, or WD-PR. This protocol allows performing a sodium appetite test after the rat has quenched its thirst; thus, the sodium intake during this test cannot be confounded with a response to thirst. This is confirmed by hedonic shift and selective ingestion of sodium solutions in the sodium appetite test that follows a WD-PR. The separation between thirst and sodium appetite induced by water deprivation permits the identification of brain states associated with sodium intake in the appetite test. One of these states relates to the activation of angiotensin II All receptors. Other states relate to cell activity in key areas, e.g. subfornical organ and central amygdala, as revealed by immediate early gene c-Fos immunoreactivity or focal lesions. Angiotensin II apparently sensitizes the brain of the water deprived rat to produce an enhanced sodium intake, as that expressed by spontaneously hypertensive and by young normotensive rat. The enhancement in sodium intake produced by history of water deprivation is perhaps a clue to understand the putative salt addiction in humans.The paper represents an invited review by a symposium, award winner or keynote speaker at the Society for the Study of Ingestive Behavior [SSIB] Annual Meeting in Portland, July 2009. (C) 2010 Published by Elsevier B.V.

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Objectives. The objectives of this study were to evaluate pH, available chlorine content, and antibacterial activity of endodontic irrigants and their combinations.Study design. The pH and chlorine content of sodium hypochlorite (NaOCl) were analyzed pure and in combination with 10% citric acid (CA) and apple vinegar (AV). The antibacterial effect of the following solutions was measured by direct contact test against Enterococcus faecalis: 2.5% NaOCl, 2.5% NaOCl + 10% CA (7:3), 2.5% NaOCl + AV (5:5), 10% CA, and AV. Sterile saline was used as control. The colony-forming units were determined by serial decimal dilutions.Results. The combination of 2.5% NaOCl with CA or AV lowered the pH and the chlorine content. NaOCl, alone or in combination was able to eliminate E. faecalis in 30 seconds, and CA, after 10 minutes. AV promoted reduction (32.2%) after 10 minutes.Conclusions. NaOCl with acidic solutions lowered the pH and the chlorine content, but did not alter its antibacterial effect. (Oral Surg Oral Med Oral Pathol Oral Radiol Endod 2011; 112:132-135)

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Ocimum gratissimum L. (Lamiaceae) and other species of the same genus are used as medicines to treat central nervous system (CNS) diseases, commonly encountered in warm regions of the world. The chemical composition of Ocimum gratissimum essential oil varies according to their chemotypes: timol, eugenol or geraniol. In this study, the essential oil type eugenol was extracted by hydrodistillation in each of the four seasons of the year. Activity upon CNS was evaluated in the open-field and rota-rod tests; sleeping time induced by sodium pentobarbital (PBS, 40 mg/kg, intraperitoneally, i.p.) and anticonvulsant activity against seizures induced by both pentylenetetrazole (PTZ; 85 mg/kg, s.c.) and maximal electroshock (MES, 50 mA, 0.11 s) were determined. Essential oils obtained in each season were effective in increasing the sleeping duration and a preparation obtained in Spring was able to protect animals against tonic seizures induced by electroshock. In each season, eugenol and 1,8-cineole were the most abundant compounds, and in Spring the essential oil presented the greatest relative percentage of sesquiterpenes, suggesting that these compounds could explain the differences observed in the biological activity in essential oils obtained in different seasons of the year. (c) 2005 Elsevier B.V.. All rights reserved.

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Results from our laboratory revealed propolis activity on Giardia trophozoites proliferation. Since therapeutic agents can inhibit the activity of proteases related to relevant biologic and physiologic processes of parasites, this study was undertaken to characterise the proteolytic activity of excretory/secretory products (ESP) of trophozoites treated with propolis. ESP was obtained from culture supernatants of trophozoites exposed to 250 and 500 mu g mL(-1) of propolis. ESP were tested in sodium dodecyl sulfate-polyacrylamide gel electrophoresis for the protein profiles and the protease activity was assayed in gelatin-containing gels. Synthetic inhibitors were used to characterise the protease classes. Treated and non-treated ESP showed a similar protein and hydrolysis pattern. A simple pattern of protein composed by five evident bands of approximately 167, 132, 79, 61 and 51 kDa was found, and the zymograms comprised hydrolysis zones distributed from > 170 to 23 kDa. No inhibition was seen on protease activity of propolis-treated trophozoites, whose hydrolysis pattern was similar to control. One may conclude that both ESP degraded gelatin and the activity was predominantly due to cysteine proteases. Although propolis had no effect on the proteolytic activity, further studies could identify the active constituents responsible for propolis antigiardial activity and their mechanisms of action.

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Ultrastructural and cytochemical characteristics of mononuclear phagocyte cells in turtles are not well described in the literature, especially in Phrynops hilarii. Thus, the aim of this study was to evaluate these characteristics in the mononuclear phagocyte cells and their phagocytic activity in vitro using the turtle P. hilarii as an experimental animal model. The six turtles used in the study were observed in two seasons, spring and summer. Results showed that mononuclear phagocytes incubated only in diluted solution or with colloidal charcoal have cytoplasm phagolysosomes. The cells incubated with colloidal charcoal and further exposed to the cytochemical reaction for acid P-glycerophosphatase, showed cytoplasm phagolysosomes filled by charcoal particles being digested and some positively stained lysosomes. Acid P-glycerophosphatase positive reaction was present in lysosomes and inside the phagolysosomes, while acid cytidine 5-monophosphatase staining occurred in lysosome surroundings. A positive reaction for trimetaphosphatase was also found inside phagolysosomes. In conclusion, the presence of lysosomal enzymes like trimetaphosphatase and cytidine-5'-sodium monophosphate, in the circulating blood of P. hilarii indicate that mononuclear phagocytes participate in the phagocytic process by gathering many phagocytic cells and forming multinucleated giant cells, which probably have a role in the blood clearance process. (C) 2008 Elsevier Ltd. All rights reserved.