953 resultados para Algorithms to Activity of the Crew


Relevância:

100.00% 100.00%

Publicador:

Resumo:

Isoflavones are phenolic compounds widely distributed in plants and found in a high percentage in soybeans. They have important biological properties and are regarded as potential chemopreventive agents. The aim of this study was to verify the preventive effect of two soy isoflavones (genistein and daidzein) by a micronucleus assay, analysis of GST activity, and real-time RT-PCR analysis of GSTa2 gene expression. Mutagens of direct (doxorubicin) and indirect (2-aminoanthracene) DNA damage were used. Hepatoma cells (HTC) were treated with genistein or daidzein for 26 h at noncytotoxic concentrations; 10 μM when alone, and 0.1, 1.0 and 10 μM when combined with genotoxic agents. The micronucleus test demonstrated that both isoflavones alone had no genotoxic effect. Genistein showed antimutagenic effects at 10 μM with both direct and indirect DNA damage agents. On phase II enzyme regulation, the current study indicated an increase in total cytoplasmic GST activity in response to genistein and daidzein at 10 μM supplementation. However, the mRNA levels of GSTa2 isozymes were not differentially modulated by genistein or daidzein. The results point to an in vitro antimutagenic activity of genistein against direct and indirect DNA damage-induced mutagenicity. © 2012 Springer Science+Business Media B.V.

Relevância:

100.00% 100.00%

Publicador:

Resumo:

The peptide LYS-[TRP6]-Hy-A1 (Lys-a1) is a synthetic derivative of the peptide Hy-A1, initially isolated from the frog species Hypsiboas albopunctatus. According to previous research, it is a molecule with broad antimicrobial activity. The objective of this study was to evaluate the antimicrobial activity of the synthetic peptide Lys-a1 (KIFGAIWPLALGALKNLIK- NH2) on the planktonic and biofilm growth of oral bacteria. The methods used to evaluate antimicrobial activity include the following: determination of the minimum inhibitory concentration (MIC) and minimum bactericidal concentration (MBC) in microtiter plates for growth in suspension and quantification of biomass by crystal violet staining and counting of colony forming units for biofilm growth. The microorganisms Streptococcus oralis, Streptococcus sanguinis, Streptococcus parasanguinis, Streptococcus salivarius, Streptococcus mutans and Streptococcus sobrinus were grown in Brain Heart Infusion broth at 37 °C under atmospheric pressure with 10% CO2. The peptide was solubilized in 0.1% acetic acid (v/v) at various concentrations (500-1.9 μg mL-1). Chlorhexidine gluconate 0.12% was used as the positive control, and BHI culture medium was used as the negative control. The tested peptide demonstrated a remarkable antimicrobial effect, inhibiting the planktonic and biofilm growth of all strains tested, even at low concentrations. Thus, the peptide Lys-a1 is an important source for potential antimicrobial agents, especially for the control and prevention of microbial biofilms, which is one of the most important factors in cariogenic processes. © 2012 Elsevier Inc.

Relevância:

100.00% 100.00%

Publicador:

Resumo:

As cisteína-proteases estão entre os alvos mais promissores para o desenvolvimento de novos agentes terapêuticos, visto que participam de eventos fundamentais do ciclo de vida de muitos microorganismos, inclusive Giardia. Como a atividade das proteases pode ser controlada por inibidores específicos, essas substâncias têm sido avaliadas quanto ao potencial antiparasitário. Diante disso, o presente estudo teve por objetivo avaliar o efeito in vitro do inibidor de cisteína-proteases E-64 sobre o crescimento, a aderência e a viabilidade de trofozoítos de cepa de Giardia isolada em Botucatu. Nos ensaios de crescimento e aderência, o número de trofozoítos foi estimado microscopicamente em hemocitômetro, enquanto que a viabilidade celular foi avaliada pelo método do MTT. No presente estudo, embora o metronidazol tenha se apresentado bastante efetivo, o E-64 mostrou ser capaz de inibir o crescimento, a aderência e a viabilidade em taxas superiores a 50%, especialmente nos cultivos expostos à concentração de 100 µM. A despeito de preliminares, esses resultados demonstram que o inibidor E-64 pode interferir em processos primordiais para a sobrevivência do parasita, além do que, abrem novas perspectivas para investigações futuras a fim de se avaliar o real potencial giardicida dos inibidores de proteases.

Relevância:

100.00% 100.00%

Publicador:

Resumo:

Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)

Relevância:

100.00% 100.00%

Publicador:

Resumo:

Given the spread of antibiotic resistance in bacterial pathogens, antimicrobial peptides that can also modulate the immune response may be a novel approach for effectively controlling periodontal infections. In the present study, we used a three-dimensional (3D) co-culture model of gingival epithelial cells and fibroblasts stimulated with Aggregatibacter actinomycetemcomitans lipopolysaccharide (LPS) to investigate the anti-inflammatory properties of human beta-defensin-3 (hBD-3) and cathelicidin (LL-37) and to determine whether these antimicrobial peptides can act in synergy. The 3D co-culture model composed of gingival fibroblasts embedded in a collagen matrix overlaid with gingival epithelial cells had a synergistic effect with respect to the secretion of IL-6 and IL-8 in response to LPS stimulation compared to fibroblasts and epithelial cells alone. The 3D co-culture model was stimulated with non-cytotoxic concentrations of hBD-3 (10 and 20 mu M) and LL-37 (0.1 and 0.2 mu M) individually and in combination in the presence of A. actinomycetemcomitans LPS. A multiplex ELISA assay was used to quantify the secretion of 41 different cytokines. hBD-3 and LL-37 acted in synergy to reduce the secretion of GRO-alpha, G-CSF, IP-10, IL-6, and MCP-1, but only had an additive effect on reducing the secretion of IL-8 in response to A. actinomycetemcomitans LPS stimulation. The present study showed that hBD-3 acted in synergy with LL-37 to reduce the secretion of cytokines by an LPS-stimulated 3D model of gingival mucosa. This combination of antimicrobial peptides thus shows promising potential as an adjunctive therapy for treating inflammatory periodontitis.

Relevância:

100.00% 100.00%

Publicador:

Resumo:

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

Relevância:

100.00% 100.00%

Publicador:

Resumo:

1. 1. Some parameters (glycolysis, respiration, levels of glycolytic enzymes) of the lymphoid cells from the Sticker's lymphosarcoma were established in order to better define the biochemical behavior of the venereal tumor of the dog. 2. 2. For comparative purposes lymphocytes from peripheral blood of normal tumor-bearing dogs were also studied. 3. 3. Lactic acid produced by the tumor cells during aerobic glycolysis is liberated in the reaction medium. 4. 4. Oxygen uptake is enhanced in the presence of succinate, but not with pyruvate, α-ketoglutarate, or malate as substrates. 5. 5. Higher levels of some of the enzymes from the glycolytic pathways as well as differences on the physicochemical and kinetic properties of the glycolytic regulatory enzymes are found in Sticker's tumor cells, when compared with the lymphocytes from peripheral blood of normal and tumor-bearing dogs. 6. 6. A fructose-bisphosphate positively modulated pyruvatekinase is found in the tumor cells. © 1987.

Relevância:

100.00% 100.00%

Publicador:

Resumo:

Anacardium humile St. Hil. is being used in traditional medicine to treat ulcer. The present work evaluated the mechanisms of action involved in the anti-ulcer properties of the aqueous fraction from leaves of A. humile (AHQ). Gastroprotection of A. humile was evaluated in ethanol and piroxicam models. Mechanisms of action such as mucus production, nitric oxide (NO), sulfhydryl compounds (SH) and the anti-secretory action were evaluated. The acetic acid-induced gastric ulcer model was used to evaluate the A. humile healing properties. Results obtained in the ethanol model showed that AHQ provided significant gastroprotection at all the tested doses (50, 100, and 200 mg/kg). Thereby, the following protocols were performed using the dose capable of producing the most effective gastroprotection, which was the AHQ 200 mg/kg (P < 0.001). Moreover, AHQ (200 mg/kg) protected the mucosa from piroxicam-induced damage. Mucus, NO, and SH did not participate on this gastroprotection. AHQ interfere in H+ secretion in gastric mucosa, thus exerting an anti-secretory activity. Our results suggest that the gastroprotection and cicatrisation process executed by AHQ occurred due to its anti-secretory activity. This study reinforces its traditional medicinal use. Considering that the current therapies are based on the use of anti-secretory agents, the A. humile arises as a promising alternative antiulcer therapy.

Relevância:

100.00% 100.00%

Publicador:

Resumo:

Trypanosoma rangeli is the trypanosomatid that colonizes the salivary gland of its insect vector, with a profound impact on the feeding capacity of the insect. In this study we investigated the role of the phosphotyrosine (P-Tyr) ecto-phosphatase activity of T. rangeli in its interaction with Rhodnius prolixus salivary glands. Long but not short epimastigotes adhered to the gland cells and the strength of interaction correlated with the enzyme activity levels in different strains. Differential interference contrast microscopy demonstrated that clusters of parasites are formed in most cases, suggesting cooperative interaction in the adhesion process. The tightness of the correlation was evidenced by modulating the P-Tyr ecto-phosphatase activity with various concentrations of inhibitors. Sodium orthovanadate, ammonium molybdate and zinc chloride decreased the interaction between T. rangeli and R. prolixus salivary glands in parallel. Levamisole, an inhibitor of alkaline phosphatases, affected neither process. EDTA strongly inhibited adhesion and P-Tyr ecto-phosphatase activity to the same extent, an effect that was no longer seen if the parasites were pre-incubated with the chelator and then washed. When the P-Tyr ecto-phosphatase of living T. ranged epimastigotes was irreversibly inactivated with sodium orthovanadate and the parasite cells were then injected into the insect thorax, colonization of the salivary glands was greatly depressed for several days after blood feeding. Addition of P-Tyr ecto-phosphatase substrates such as p-nitrophenyl phosphate (pNPP) and P-Tyr inhibited the adhesion of T. rangeli to salivary glands, but P-Ser, P-Thr and beta-glycerophosphate were completely ineffective. Immunoassays using anti-P-Tyr-residues revealed a large number of P-Tyr-proteins in extracts of R. prolixus salivary glands, which could be potentially targeted by T. rangeli during adhesion. These results indicate that dephosphorylation of structural P-Tyr residues on the gland cell surfaces, mediated by a P-Tyr ecto-phosphatase of the parasite, is a key event in the interaction between T. rangeli and R. prolixus salivary glands. (C) 2012 Australian Society for Parasitology Inc. Published by Elsevier Ltd. All rights reserved.

Relevância:

100.00% 100.00%

Publicador:

Resumo:

The potato tuberworm Phthorimaea operculella (Zeller) is an important agricultural pest that causes significant economic losses to potato growers worldwide. The addition of an effective method of biological control for the potato tuberworm is greatly needed, and is currently unavailable in Brazil. The granulosis virus (Baculoviridae) is a promising biological control agent to protect post-harvest potatoes and in storage from the potato tuberworm. However, the control measure must be economically feasible. Liquid suspensions of a granulosis virus applied alone or in mixture with two commercial neem oil-based products (DalNeem (TM) and NeemAzal (TM)), and a dry powder formulation of viral granules were evaluated for control of potato tuberworm larvae by treating potato tubers under laboratory conditions. High larval mortality (86.7%) was achieved when DalNeem and virus were applied together at 4 mg of azadirachtin/L and 10(4) occlusion bodies (OBs)/mL, respectively. This combination resulted in a parts per thousand yen50% efficacy in relation to their counterparts alone. Conversely, NeemAzal did not enhance virus effectiveness against larvae of the potato tuberworm. The talc-based virus formulation was used for dusting seed tubers at different concentrations and resulted in 100% larval mortality at 5 x 10(8) OBs/g. Formulated and unformulated virus provided 50% mortality at 166 OBs/g and at 5.0 x 10(5) OBs/mL, respectively. As a result, talc-based virus formulation had a better control efficiency on potato tuberworm than the aqueous virus suspension. The granulosis virus combined with DalNeem at low rates or formulated with talc powder is a viable option to control the potato tuberworm under storage conditions.

Relevância:

100.00% 100.00%

Publicador:

Resumo:

Mutations in the coding region of telomerase complex genes can result in accelerated telomere attrition and human disease. Manifestations of telomere disease include the bone marrow failure syndromes dyskeratosis congenita and aplastic anemia, acute myeloid leukemia, liver cirrhosis, and pulmonary fibrosis. Here, we describe a mutation in the CCAAT box (GCAAT) of the TERC gene promoter in a family in which multiple members had typical features of telomeropathy. The genetic alteration in this critical regulatory sequence resulted in reduced reporter gene activity and absent binding of transcription factor NF-Y, likely responsible for reduced TERC levels, decreased telomerase activity, and short telomeres. This is the first description of a pathogenic mutation in the highly con-served CCAAT box and the first instance of a mutation in the promoter region of TERC producing a telomeropathy. We propose that current mutation-screening strategies should include gene promoter regions for the diagnosis of telomere diseases. This clinical trial was registered at www.clinicaltrials.gov as #NCT00071045. (Blood. 2012;119(13):3060-3063)

Relevância:

100.00% 100.00%

Publicador:

Resumo:

The aim of this research was to evaluate economic costs of respiratory and circulatory diseases in the municipality of Cubatao, in the state of Sao Paulo, Brazil. Data on hospital admissions and on missed working days due to hospitalization (for age group 14 to 70 years old) from the database of Sistema Unico de Sa de (SUS - Brazilian National Health System) were used. Results: Based on these data, it was calculated that R$ 22.1 million were spent in the period 2000 to 2009 due to diseases of the respiratory and circulatory systems. Part of these expenses can be directly related to the emission of atmospheric pollutants in the city. In order to estimate the costs related to air pollution, data on Cubatao were compared to data from two other municipalities that are also located at the coast side (Guaruja and Peru be), but which have little industrial activity in comparison to Cubatao. It was verified that, in both, average per capita costs were lower when compared to Cubatao, but that this difference has been decreasing in recent years.

Relevância:

100.00% 100.00%

Publicador:

Resumo:

Background: It had long been thought that a lateral meristem, the so-called primary thickening meristem (PTM) was responsible for stem thickening in monocotyledons. Recent work has shown that primary thickening in the stems of monocotyledons is due to the meristematic activity of both the endodermis and the pericycle. Aims: The aim of this work is to answer a set of questions about the developmental anatomy of monocotyledonous plants: (1) Do the stem apices of monocots have a special meristematic tissue, the PTM? (2) Are the primary tissues of the stem the same as those of the root? (3) Is there good evidence for the formation of both the cortex and the vascular tissue from a single meristem, the PTM, in the shoot and from two distinguishable meristems in the root? (4) If the PTM forms only the cortex, what kind of meristem forms the vascular tissue? Methods: Light microscopy was used to examine stem and root anatomy in 16 species from 10 monocotyledonous families. Results: It was observed that radially aligned cortical cells extend outwards from endodermal initial cells in the cortex of the roots and the stems in all the species. The radial gradation in size observed indicates that the cortical cells are derivatives of a meristematic endodermis. In addition, perfect continuity was observed between the endodermis of the root and that of the stem. Meristematic activity in the pericycle gives rise to cauline vascular bundles composed of metaxylem and metaphloem. Conclusion: No evidence was obtained for the existence in monocotyledons of a PTM. Monocotyledons appear to resemble other vascular plants in this respect.

Relevância:

100.00% 100.00%

Publicador:

Resumo:

Solanum lycocarpum (Solanaceae), a Brazilian medicinal plant known as "wolf fruit," contains about 1.5% of glycoalkaloids in its dried fruits, consisting mainly of solamargine and solasonine. The present work reports the obtainment of the alkaloidic extract of the S. lycocarpum fruit by acid-base extraction and the isolation of the major alkaloid heterosides by chromatographic means, as well as the evaluation of their in vitro schistosomicidal activities. The in vitro schistosomicidal activities of the alkaloidic extract of S. lycocarpum fruits and its isolated steroidal alkaloids were undertaken against adult worms of Schistosoma mansoni. The alkaloidic extract (20, 32, and 50 mu g mL(-1)), solasonine (50 mu M), solamargine (32 and 50 mu M), and equimolar mixture of glycoalkaloids (20, 32, and 50 mu M) lead to the separation of all couple worms and extensive disruption on their teguments, such as sloughing, as well as their deaths within 24 h of incubation. In addition, the alkaloidic extract (10 and 15 mu g mL(-1)), solasonine (50 mu M), solamargine (10, 15, and 20 mu M), and equimolar mixtures of glycoalkaloids (10 and 15 mu M) reduced the development of eggs produced by the adult worms. Solamargine, containing the sugar chain moiety chacotriose, was more active than the solasonine, which contains solatriose sugar chain moiety. A synergistic effect was also observed for a mixture of solamargine and solasonine. Therefore, the alkaloidic extract of S. lycocarpum, and its major components, solamargine and solasonine, showed promising schistosomicidal activity.

Relevância:

100.00% 100.00%

Publicador:

Resumo:

A hyaluronidase (CdtHya1) from Crotalus durissus terrificus snake venom (CdtV) was isolated and showed to exhibit a high activity on hyaluronan cleavage. However, surveys on this enzyme are still limited. This study aimed at its isolation, functional/structural characterization and the evaluation of its effect on the spreading of crotoxin and phospholipase A(2) (PLA(2)). The enzyme was purified through cation exchange, gel filtration and hydrophobic chromatography. After that, it was submitted to a reverse-phase fast protein liquid chromatography (RP-FPLC) and Edman degradation sequencing, which showed the first N-terminal 44 amino acid residues whose sequence evidenced identity with other snake venom hyaluronidases. CdtHya1 is a monomeric glycoprotein of 64.5 kDa estimated by SDS-PAGE under reducing conditions. It exhibited maximum activity in the presence of 0.2 M NaCl, at 37 degrees C, pH 5.5 and a specificity to hyaluronan higher than that to chondroitin-4-sulphate, chondroitin-6-sulphate or dermatan. Divalent cations (Ca2+ and Mg2+) and 1 M NaCl significantly reduced the enzyme activity. The specific activity of CdtHya1 was 5066 turbidity reducing units (TRU)/mg, against 145 TRU/mg for the soluble venom, representing a 34.9-fold purification. The pure enzyme increased the diffusion of crotoxin and PLA (2) through mice tissues. CdtHya1 (32 TRU/40 mu L) potentiated crotoxin action, as evidenced by mice death, and it decreased the oedema caused by subplantar injections of buffer, crotoxin or PLA(2), thus evidencing the relevance of hyaluronidase in the crotalic envenoming. This work yielded a highly active antiedematogenic hyaluronidase from CdtV, the first one isolated from rattlesnake venoms. (C) 2012 Elsevier Masson SAS. All rights reserved.