50 resultados para 1528
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Isatin (1H-indole-2,3-dione) is a chemical found in various medicinal plant species and responsible for a broad spectrum of pharmacological and biological properties that may be beneficial to human health, as an anticonvulsant, antibacterial, antifungal, antiviral, and anticancer agent. The aim of the present study was to determine in vitro the cytotoxic, mutagenic, and apoptotic effects of isatin on CHO-K1 and HeLa cells using the MTT viability assay (3-[4,5-dimethylthiazol-2-yl]-2,5-diphenyl tetrazolium bromide), micronucleus (MN) test, apoptosis index, and nuclear division index (NDI). The 5 isatin concentrations evaluated in the mutagenicity and apoptosis tests were 0.5, 1, 5, 10, and 50 μM, selected through a preliminary MTT assay. Positive (doxorubicin, DXR) and negative (phosphate buffered saline, PBS) control groups were also included in the analysis. Isatin did not exert a mutagenic effect on CHO-K1 after 3 and 24 h of treatment or on HeLa cells after 24 h. However, 10 and 50 μM concentrations inhibited cell proliferation and promoted apoptosis in both CHO-K1 and HeLa cells. Data indicate that the cytotoxic, apoptotic, and antiproliferative effects of isatin were concentration independent and cell line independent. The authors thank Profa Dra Eiko Nakagawa Itano for the use the spectrophotometer and the Conselho Nacional para o Desenvolvimento Científico e Tecnológico for master's scholarships to P. M. Cândido-Bacani and grants to T. R. Calvo, W. Vilegas, E. A. Varanda and I. M. S. Cólus. The Conselho Nacional para o Desenvolvimento Científico e Tecnológico provided funding for this study. © 2013 Taylor & Francis Group, LLC.
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STUDY DESIGN. Observational cohort study. OBJECTIVE. To investigate spinal coordination during preferred and fast speed walking in pain-free subjects with and without a history of recurrent low back pain (LBP). SUMMARY OF BACKGROUND DATA. Dynamic motion of the spine during walking is compromised in the presence of back pain (LBP), but its analysis often presents some challenges. The coexistence of significant symptoms may change gait because of pain or adaptation of the musculoskeletal structures or both. A history of LBP without the overlay of a current symptomatic episode allows a better model in which to explore the impact on spinal coordination during walking. METHODS. Spinal and lower limb segmental motions were tracked using electromagnetic sensors. Analyses were conducted to explore the synchrony and spatial coordination of the segments and to compare the control and subjects with LBP. RESULTS. We found no apparent differences between the groups for either overall amplitude of motion or most indicators of coordination in the lumbar region; however, there were significant postural differences in the mid-stance phase and other indicators of less phase locking in controls compared with subjects with LBP. The lower thoracic spinal segment was more affected by the history of back pain than the lumbar segment. CONCLUSION. Although small, there were indicators that alterations in spinal movement and coordination in subjects with recurrent LBP were due to adaptive changes rather than the presence of pain. © 2013, Lippincott Williams & Wilkins.
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Antimicrobial peptides (AMPs) are a promising solution to face the antibiotic-resistant problem because they display little or no resistance effects. Dimeric analogues of select AMPs have shown pharmacotechnical advantages, making these molecules promising candidates for the development of novel antibiotic agents. Here, we evaluate the effects of dimerization on the structure and biological activity of the AMP aurein 1.2 (AU). AU and the C- and N-terminal dimers, (AU)2K and E(AU)2, respectively, were synthesized by solid-phase peptide synthesis. Circular dichroism spectra indicated that E(AU)2 has a coiled coil structure in water while (AU)2K has an α-helix structure. In contrast, AU displayed typical spectra for disordered structures. In LPC micelles, all peptides acquired a high amount of α-helix structure. Hemolytic and vesicle permeabilization assays showed that AU has a concentration dependence activity, while this effect was less pronounced for dimeric versions, suggesting that dimerization may change the mechanism of action of AU. Notably, the antimicrobial activity against bacteria and yeast decreased with dimerization. However, dimeric peptides promoted the aggregation of C. albicans. The ability to aggregate yeast cells makes dimeric versions of AU attractive candidates to inhibit the adhesion of C. albicans to biological targets and medical devices, preventing disease caused by this fungus. © 2013 Springer-Verlag Wien.
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Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)
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Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)
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Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)
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The aim of this study was to determine the no-observable-adverse-effect concentration (NOAEC) for trichlorfon, an antiparasitic agent used in aquaculture, in Piractus mesopotamicus (pacu) using acetylcholinesterase (AChE) activity as an end point. Fish were exposed 24 h/d for 15 d to different concentrations of trichlorfon in tanks of water for which a curve of dissipation was previously determined. Analysis of trichlorfon in water and fish plasma using gas chromatography with electron capture detection (GC-ECD) enabled measurement of limit of detection (LOD) and limit of quantification (LOQ), respectively, to be 3 and 10 ppb. Thirty-six hours after trichlorfon dilution in water, the concentration was below the LOD, and data showed that plasma concentrations did not exceed the LOQ. Apart from the 6.25 g/L, all concentrations of trichlorfon significantly inhibited plasma and brain AChE activity compared to controls. The AChE activity levels returned to control values in 7 d. These data may be useful to determine the concentration of trichlorfon that destroys parasites without producing adverse effects in fish.
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Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)
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Background: The high prevalence of dysphagia after stroke leads to increased mortality, and cerebral reperfusion therapy has been effective in reducing neurologic deficits. The aim of this study was to investigate the severity and evolution of dysphagia and the occurrence of pneumonia in patients submitted to cerebral reperfusion therapy. Methods: Seventy ischemic stroke patients were evaluated. Of these, 35 patients (group 1) were submitted to cerebral reperfusion therapy and 35 (group 2) did not receive thrombolytic treatment. The following were evaluated: severity of dysphagia by means of videofluoroscopy, evolution of oral intake rate by means of the Functional Oral Intake Scale, and the occurrence of pneumonia by international protocol. The relation between the severity of dysphagia and the occurrence of pneumonia with the treatment was evaluated through the chi-square test; the daily oral intake rate and its relation to the treatment were assessed by the Mann-Whitney test and considered significant if P is less than .05. Results: The moderate and severe degrees of dysphagia were more frequent (P = .013) among the patients who were not submitted to cerebral reperfusion therapy. The daily oral intake evolved independently of the treatment type, without statistical significance when compared between the groups, whereas pneumonia occurred more frequently in group 2 (28%) in relation to group 1 (11%) and was associated with the worst degrees of dysphagia (P = .045). Conclusions: We can conclude that there is improvement in the oral intake rate in both groups, with lower severity of dysphagia and occurrence of pneumonia in ischemic stroke patients submitted to cerebral reperfusion therapy. (C) 2014 by National Stroke Association
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Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)
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Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)
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Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)
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Throughout the world, biomonitoring has become the standard for assessing exposure of individuals to toxic elements as well as for responding to serious environmental public health problems. However, extensive biomonitoring surveys require rapid and simple analytical methods. Thus, a simple and high-throughput method is proposed for the determination of arsenic (As), cadmium (Cd), copper (Cu), manganese (Mn), nickel (Ni), lead (Pb), and selenium (Se) in blood samples by using inductively coupled plasma–mass spectrometry (ICPMS). Prior to analysis, 200 ml of blood samples was mixed with 500 ml of 10% v/v tetramethylammonium hydroxide (TMAH) solution, incubated for 10 min, and subsequently diluted to 10 ml with a solution containing 0.05% w/v ethylenediamine tetraacetic acid (EDTA) + 0.005% v/v Triton X-100. After that, samples were directly analyzed by ICP-MS (ELAN DRC II). Rhodium was selected as an internal standard with matrix-matching calibration. Method detection limits were 0.08, 0.04, 0.5, 0.09, 0.12, 0.04, and 0.1 mg//L for As, Cd, Cu, Mn, Ni, Pb, and Se, respectively. Validation data are provided based on the analysis of blood samples from the trace elements inter-\comparison program operated by the Institut National de Santé Publique du Quebec, Canada. Additional validation was provided by the analysis of human blood samples by the proposed method and by using electrothermal atomic absorption spectrometry (ETAAS). The method was subsequently applied for the estimation of background metal blood values in the Brazilian population. In general, the mean concentrations of As, Cd, Cu, Mn, Ni, Pb, and Se in blood were 1.1, 0.4, 890, 9.6, 2.1, 65.4, and 89.3 mg/L, respectively, and are in agreement with other global populations. Influences of age, gender, smoking habits, alcohol consumption, and geographical variation on the values were also considered. Smoking habits influenced the levels of Cd in blood. The levels of Cu, Mn, and Pb were significantly correlated with gender, whereas Cu and Pb were significantly correlated with age. There were also interesting differences in Mn and Se levels in the population living in the north of Brazil compared to the south.
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Pós-graduação em Agronomia (Irrigação e Drenagem) - FCA
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The Brazilian federal government Agency for Health Surveillance detected pesticide residues in fresh food available for consumers all over the country. The current study investigated the effects of a mixture of some of those pesticides (dichlorvos, dicofol, dieldrin, endosulfan, and permethrin) on the reproductive system of Sprague-Dawley (SD), Wistar (WT), and Lewis (LEW) rats. Female rats from each strain were randomized into three experimental groups and were fed a control diet or diets added with pesticides mixture at their respective no-observed-effect level (NOEL)/no-observed-adverse-effect level (NOAEL) (low dose) (mg/kg/d): dichlorvos (0.23), dicofol (0.5), dieldrin (0.025), endosulfan (0.7), permethrin (5), or lowest-observed-effect level (LOEL)/lowest-effect level (LEL)/ lowest-observed-adverse-effect level (LOAEL) (toxically effective dose) (mg/kg/d): dichlorvos (2.3), dicofol (2.1), dieldrin (0.05), endosulfan (3.8), and permethrin (25) as reported in the literature. Euthanasia was performed between wk 10 and 12, during the estrous stage. Decreased body weights gain (SD and WT) and increased liver weights (SD, WT, and LEW) were observed in each strain fed the pesticides mixture at the higher levels. At that dose level, rat strains also varied in their responses regarding the estrous cycle, hormonal levels, and number of developing ovarian follicles. The studied mixture of pesticides was found to interfere with the female reproductive system when individual pesticides were mixed above a certain level, indicating a threshold exists for each of the strains studied.