196 resultados para renal biological activity


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Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)

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Many people who live in the cerrado regions use plant species for therapeutic purposes. However, due to intensive extraction of some species, native botanical populations are at risk of disappearing or suffering a dramatic decrease, such as, for instance, individuals of the Lychnophora genus. This has 24 species distributed into the categories vulnerable, endangered, critically endangered, and possibly extinct. These individuals are known in folk medicine as “arnica” and their leaves and flowers are commonly used as anti-inflammatory, analgesic, and healing agents. The chemical profile of the genus is characterized by the presence of sesquiterpene lactones, sesquiterpenes, diterpenes, triterpenes, flavonoids, steroids, polyacetylenes, and caryophyllene derivatives which also have lignans with analgesic activity. Studies with Lychnophora species show significant results with regard to their biological activities against Leishmania amazonensis, Staphylococcus aureus, and Tripanosoma cruzi. Therefore, this study aimed to perform a survey of the morphology, chemical composition, and biological activity, as well as the use and current conservation status of the Lychnophora genus in Brazil.

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Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)

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Sea anemones contain a variety of biologically active substances. Bunodosoma caissarum is a sea anemone from the Cnidaria phylum, found only in Brazilian coastal waters. The aim of the present work was to study the biological effects of PLA(2) isolated from the sea anemone B. caissarum on the isolated perfused kidney, the arteriolar mesenteric bed and on insulin secretion. Specimens of B. caissarum were collected from the Sao Vicente Channel on the southern coast of the State of São Paulo, Brazil. Reverse phase HPLC analysis of the crude extract of B. caissarum detected three PLA(2) proteins (named BcPLA(2)1, BCPLA(2)2 and BcPLA(2)3) found to be active in B. caissarum extracts. MALDI-TOF mass spectrometry of BcPLA(2)1 showed one main peak at 14.7 kDa. The N-terminal amino acid sequence of BcPLA(2)1 showed high amino acid sequence identity with PLA(2) group III protein isolated from the Mexican lizard (PA23 HELSU, HELSU, PA22 HELSU) and with the honey bee Apis mellifera (PLA(2) and 1POC_A). In addition, BcPLA(2)1 also showed significant overall homology to bee PLA(2). The enzymatic activity induced by native BCPLA(2)1 (20 mu g/well) was reduced by chemical treatment with p-bromophenacyl bromide (p-BPB) and with morin. BcPLA(2)1 strongly induced insulin secretion in presence of high glucose concentration. In isolated kidney, the PLA(2) from B. caissarum increased the perfusion pressure, renal vascular resistance, urinary flow, glomerular filtration rate, and sodium, potassium and chloride levels of excretion. BcPLA(2)1, however, did not increase the perfusion pressure on the mesenteric vascular bed. In conclusion, PLA(2), a group III phospholipase isolated from the sea anemone B. caissarum, exerted effects on renal function and induced insulin secretion in conditions of high glucose concentration. (C) 2009 Elsevier Ltd. All rights reserved.

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

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A duplicated nitrotienyl derivative was obtained as a by-product from the synthesis of a proposed molecular hybrid of a nitrotienyl derivative and isoniazid with an expected dual antimycobacteria mechanism. The structure was shown to be the 5,5'-dinitro-2(2,3-diaza-4-(2'-tienyl)buta-1,3-dienyl)tiophene by X-ray crystallography. The minimal inhibitory concentration (MIC) determination of this compound proved to be promising against Mycobacterium pathogenic strains such as M. avium and M. kansasei, although it had a high level of mutagenicity, as observed in mutagenic activity tests. (c) 2006 Elsevier Masson SAS. All rights reserved.

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Crotoxin B (CB or Cdt PLA(2)) is a basic Asp49-PLA(2) found in the venom of Crotalus durissus terrificus and it is one of the subunits that constitute the crotoxin (Cro). This heterodimeric toxin, main component of the C. d. terrificus venom, is completed by an acidic, nontoxic, and nonenzymatic component (crotoxin A, CA or crotapotin), and it is related to important envenomation effects such as neurological disorders, myotoxicity, and renal failure. Although Cro has been crystallized since 1938, no crystal structure of this toxin or its subunits is currently available. In this work, the authors present the crystal structure of novel tetrameric complex formed by two dimers of crotoxin B isoforms (CB1 and CB2). The results suggest that these assemblies are stable in solution and show that Ser1 and Glu92 of CB1 and CB2, respectively, play an important role in the oligomerization. The tetrameric and dimeric conformations resulting from the association of the isoforms may increase the neurotoxicity of the toxin CB by the creation of new binding sites, which could improve the affinity of the molecular complexes to the presynaptic membrane.

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Plants have been used for thousands of years to flavor and conserve food, to treat health disorders and to prevent diseases including epidemics. The knowledge of their healing properties has been transmitted over the centuries within and among human communities. Active compounds produced during secondary vegetal metabolism are usually responsible for the biological properties of some plant species used throughout the globe for various purposes, including treatment of infectious diseases. Currently, data on the antimicrobial activity of numerous plants, so far considered empirical, have been scientifically confirmed, concomitantly with the increasing number of reports on pathogenic microorganisms resistant to antimicrobials. Products derived from plants may potentially control microbial growth in diverse situations and in the specific case of disease treatment, numerous studies have aimed to describe the chemical composition of these plant antimicrobials and the mechanisms involved in microbial growth inhibition, either separately or associated with conventional antimicrobials. Thus, in the present work, medicinal plants with emphasis on their antimicrobial properties are reviewed.

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The main method used for the control of gastrointestinal nematodes in sheep production is the application of chemotherapeutic agents, which often lead to the selection of parasites resistant to given active principles. Biological control can be considered a promising alternative, contributing to an increase in the efficacy of verminous control. We determined the in vitro activity and in situ survival of the predatory fungi Arthrobotrys musiformis and Arthrobotrys conoides during passage through the gastrointestinal tract of sheep after oral administration of conidia in microencapsulated form and as a liquid in natura. Initial in vitro tests showed that both fungi were efficient in the predation of trichostrongylid L3 larvae present in the faeces of sheep naturally infected with gastrointestinal nematodes. The fungi presented high nematophagous activity, which was 99.3% for A. conoides and 73.7% for A. musiformis. A. conoides did not survive passage through the gastrointestinal tract under the conditions of the present experiment. On the other hand, A. musiformis was reisolated after administration in either microencapsulated or liquid form, suggesting that this species is a promising alternative for the control of nematodes in sheep since it survives without any protection (in natura). © Springer 2005.

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Background: Chronic kidney disease (CKD) is one of the most serious public health problems. The increasing prevalence of CKD in developed and developing countries has led to a global epidemic. The hypothesis proposed is that patients undergoing dialysis would experience a marked negative influence on physiological variables of sleep and autonomic nervous system activity, compromising quality of life.Methods/Design: A prospective, consecutive, double blind, randomized controlled clinical trial is proposed to address the effect of dialysis on sleep, pulmonary function, respiratory mechanics, upper airway collapsibility, autonomic nervous activity, depression, anxiety, stress and quality of life in patients with CKD. The measurement protocol will include body weight (kg); height (cm); body mass index calculated as weight/height(2); circumferences (cm) of the neck, waist, and hip; heart and respiratory rates; blood pressures; Mallampati index; tonsil index; heart rate variability; maximum ventilatory pressures; negative expiratory pressure test, and polysomnography (sleep study), as well as the administration of specific questionnaires addressing sleep apnea, excessive daytime sleepiness, depression, anxiety, stress, and quality of life.Discussion: CKD is a major public health problem worldwide, and its incidence has increased in part by the increased life expectancy and increasing number of cases of diabetes mellitus and hypertension. Sleep disorders are common in patients with renal insufficiency. Our hypothesis is that the weather weight gain due to volume overload observed during interdialytic period will influence the degree of collapsibility of the upper airway due to narrowing and predispose to upper airway occlusion during sleep, and to investigate the negative influences of haemodialysis in the physiological variables of sleep, and autonomic nervous system, and respiratory mechanics and thereby compromise the quality of life of patients.

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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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Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)

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Nitric oxide (NO) is a free radical gas, inorganic, which has seven electrons of nitrogen and oxygen eight, possessing an unpaired electron. This radical is produced from L-arginine by a reaction mediated by the enzyme NO synthase. NO it is about a radical of who acts abundant on a variety of biological processes, particularly when produced by endothelial cells plays a significant role in cardiovascular control, as a modulator of peripheral vascular resistance and platelet aggregation. This free radical has also a neurotransmitter and mediator of the immune system. NO kidney function has been considered in many physiological functions such as: (a) regulation of hemodynamics and glomerular function tubuloglomerular, (b) participation in pressure natriuresis (c) maintaining medullar perfusion (d) inhibiting sodium reabsorption tubular, and (e) acting as a modulator of the activity of the sympathetic nervous system. Given these functions, the occurrence of its deficiency is associated with chronic kidney disease (CKD) in vasoconstriction and consequently glomerular hypertension, high blood pressure (HBP), proteinuria and progression of renal dysfunction. This work has the scope to describe the role of NO in renal physiology and pathophysiology of CKD.