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141.
TB Gon?alves MA Braga FF de Oliveira GM Santiago CB Carvalho PB Cabral Tde M Santiago JS Sousa EB Barros RF Nascimento AT Nagao-Dias 《Phytomedicine》2012,19(11):962-968
We evaluated the antimicrobial activity and some mechanisms used by subinhibitory and inhibitory concentrations of the essential oil, obtained from leaves of Plectranthus amboinicus, against a standard strain of Klebsiella pneumoniae and 5 multiresistant clinical isolates of the bacteria. The minimal inhibitory concentration (MIC) and minimal bactericidal concentration (MBC), the rate of kill and the pH sensitivity of the essential oil were determined by microdilution tests performed in 96-well plates. Subinhibitory and inhibitory concentrations of the essential oil were tested in order to check its action on K. pneumoniae membrane permeability, capsule expression, urease activity and cell morphology. The MIC and MBC of the essential oil were 0.09±0.01%. A complete inhibition of the bacterial growth was observed after 2h of incubation with twice the MIC of the essential oil. A better MIC was found when neutral or alkaline pH broth was used. Alteration in membrane permeability was found by the increase of crystal violet uptake when the bacteria were incubated with twice the MIC levels of the essential oil. The urease activity could be prevented when all the subinhibitory concentrations were tested in comparison to the untreated group (p<0.001). Alteration of the bacterial morphology besides inhibition of the capsule expression was verified by atomic force microscopy, and Anthony's stain method, respectively. Our data allow us to conclude that the essential oil of P. amboinicus can be a good candidate for future research. 相似文献
142.
Aaabstract Hylodinae leptodactylids(sensu Lynch 1971) form a group of diurnal frogs, which is hypothesized on the basis of morphological traits to be the closest relatives
of the dendrobatid frogs. Our study describes ultrastructural characteristics of sperm from three hylodine species(Hylodes phyllodes, Crossodactylus sp. n. andMegaelosia massarti) to reassess the intergeneric relationships within the Hylodinae, as well as the supposed relationship between the Hylodinae
and Dendrobatidae. The ultrastructure of the sperm is very similar among the three species and is indicative of its conserved
nature within the Hylodinae. The structure of the acrosomal complex was very similar to that of other leptodactylid species,
to most of the remaining species included in the Bufonoidea lineage, and also to that observed in the dendrobatid species
examined so far. Since such a structure has been considered a plesiomorphic trait, it contributes little to our understanding
of the relationships between the Hylodinae and Dendrobatidae. The flagellar apparatus ofCrossodactylus sp. n. is very similar to that of most leptodactylids. The sperm ofMegaelosia massarti andHylodes phyllodes display a distinctive condition in their axial and juxtaxonemal fibers. This distinctive flagellar condition expands the
already known variability in sperm structure within the Leptodactylidae. 相似文献
143.
Smetana JH Oliveira CL Jablonka W Aguiar Pertinhez T Carneiro FR Montero-Lomeli M Torriani I Zanchin NI 《Biochimica et biophysica acta》2006,1764(4):724-734
The yeast Tap42 and mammalian alpha4 proteins belong to a highly conserved family of regulators of the type 2A phosphatases, which participate in the rapamycin-sensitive signaling pathway, connecting nutrient availability to cell growth. The mechanism of regulation involves binding of Tap42 to Sit4 and PPH21/22 in yeast and binding of alpha4 to the catalytic subunits of type 2A-related phosphatases PP2A, PP4 and PP6 in mammals. Both recombinant proteins undergo partial proteolysis, generating stable N-terminal fragments. The full-length proteins and alpha4 C-terminal deletion mutants at amino acids 222 (alpha4Delta222), 236 (alpha4Delta236) and 254 (alpha4Delta254) were expressed in E. coli. alpha4Delta254 undergoes proteolysis, producing a fragment similar to the one generated by full-length alpha4, whereas alpha4Delta222 and alpha4Delta236 are highly stable proteins. alpha4 and Tap42 show alpha-helical circular dichroism spectra, as do their respective N-terminal proteolysis resistant products. The cloned truncated proteins alpha4Delta222 and alpha4Delta236, however, possess a higher content of alpha-helix, indicating that the C-terminal region is less structured, which is consistent with its higher sensitivity to proteolysis. In spite of their higher secondary structure content, alpha4Delta222 and alpha4Delta236 showed thermal unfolding kinetics similar to the full-length alpha4. Based on small angle X-ray scattering (SAXS), the calculated radius of gyration for alpha4 and Tap42 were 41.2 +/- 0.8 A and 42.8 +/- 0.7 A and their maximum dimension approximately 142 A and approximately 147 A, respectively. The radii of gyration for alpha4Delta222 and alpha4Delta236 were 21.6 +/- 0.3 A and 25.7 +/- 0.2 A, respectively. Kratky plots show that all studied proteins show variable degree of compactness. Calculation of model structures based on SAXS data showed that alpha4Delta222 and alpha4Delta236 proteins have globular conformation, whereas alpha4 and Tap42 exhibit elongated shapes. 相似文献
144.
145.
Alessandra de Santana Braga Barbosa Ribeiro Cláudio Carlos da Silva Flávia de Castro Pereira Aliny Pereira de Lima Cesar Augusto Sam Tiago Vilanova-Costa Simone Santos Aguiar Luiz Alfredo Pavanin Aparecido Divino da Cruz Elisângela de Paula Silveira-Lacerda 《Biological trace element research》2009,130(3):249-261
Chemotherapeutic agents play an important role in cancer treatment mostly due their systemic action on human organism allowing
access to liquid tumors and even metastases. Among these drugs, ruthenium compounds have been showing promising results to
treat tumors and represent an important development of new antitumor therapy. This study presents the evaluation of cis-(dichloro)tetraammineruthenium(III) chloride, cis-[RuCl2(NH3)4]Cl, genotoxic effects using human peripheral blood lymphocytes cultured in vitro. Mitotic index (MI), chromosome aberrations
(CA), and DNA damage using the comet assay were analyzed. MI in human peripheral blood lymphocyte cultures treated with 1,
10, 100, and 1,000 μg mL−1
cis-[RuCl2(NH3)4]Cl were 5.9%, 4.6%, 3.9%, and 0%, respectively. Doxorubicin chloridate was used as the positive control. CA derived from
1, 10, and 100 μg mL−1 concentrations were defined as spontaneous when compared with the negative control, and at the concentration of 1,000 μg
mL−1, the cell cycle was inhibited (IM = 0%). Results obtained for the comet assay using cis-[RuCl2(NH3)4]Cl suggest that this compound has no genotoxic activity against cultured human peripheral blood lymphocytes. 相似文献
146.
Leonardo M. Crema Luisa A. Diehl Ana P. Aguiar Lúcia Almeida Fernanda U. Fontella Letícia Pettenuzzo Deusa Vendite Carla Dalmaz 《Neurochemical research》2010,35(11):1700-1707
Previous studies have shown sex-specific oxidative changes in spinal cord of rats submitted to chronic stress, which may be
due to gonadal hormones. Here, we assessed total radical-trapping potential (TRAP), superoxide dismutase (SOD) and glutathione
peroxidase (GPx) activities and lipid peroxidation (evaluated by the TBARS test) in the spinal cord of ovariectomized (OVX)
female rats. Female rats were subjected to OVX, and half of the animals received estradiol replacement. Animals were subdivided
into controls and chronically stressed (for 40 days). Our findings demonstrate that chronic stress decreased TRAP, and increased
SOD activity in spinal cord homogenates from ovariectomized female rats and had no effect on GPx activity. On the other hand,
groups receiving 17β-estradiol replacement presented a decreased GPx activity, but no alteration in TRAP and in SOD activity.
No differences in the TBARS test were found in any of the groups analyzed. In conclusion, our results support the idea that
chronic stress induces an imbalance between SOD and GPx activities, additionally decreasing TRAP. Estradiol replacement did
not reverse the effects of chronic stress, but induced a decrease in GPx activity. Therefore, estradiol replacement in ovariectomized
chronically stressed rats could make the spinal cord more susceptible to oxidative injury. 相似文献
147.
Pozzi R Rosa JC Eguchi R Oller do Nascimento CM Oyama LM Aguiar O Chaves MD Ribeiro DA 《Cell biochemistry and function》2010,28(8):632-636
The aim of this study was to investigate the effects of acute exercise on genomic damage in an animal model. Male adult Wistar rats were divided into the following groups: control and acute exercised (experimental). For this purpose, 15 animals were accustomed to running on a rodent treadmill for 15 min per day for 5 days (10–20 m min?1; 08 grade). After 4 days at rest, active animals ran on the treadmill (22 m min?1, 58 grade) till exhaustion. Cells from peripheral blood, liver, heart, and brain were collected after 0, 2, and 6 h after exercise. The results showed that acute exercise was able to induce genetic damage in peripheral blood cells after 2 and 6 h of exercise, whereas liver pointed out genetic damage for all periods evaluated. No genetic damage was induced either in brain or in heart cells. In conclusion, our results suggest that acute exercise could contribute to the genetic damage in peripheral blood and liver cells. It seems that liver is a sensitive organ to the genotoxic insult after acute exercise. Copyright © 2010 John Wiley & Sons, Ltd. 相似文献
148.
Isabela Werneck Cunha Katia Candido Carvalho Waleska Keller Martins Sarah Martins Marques Nair Hideko Muto Roberto Falzoni Rafael Malagoli Rocha Samuel Aguiar Ana C.Q. Simoes Lucas Fahham Eduardo Jordão Neves Fernando Augusto Soares Luiz Fernando Lima Reis 《Translational oncology》2010,3(1):23-32
Soft tissue tumors represent a group of neoplasia with different histologic and biological presentations varying from benign, locally confined to very aggressive and metastatic tumors. The molecular mechanisms responsible for such differences are still unknown. The understanding of these molecular alterations mechanism will be critical to discriminate patients who need systemic treatment from those that can be treated only locally and could also guide the development of new drugs'' against this tumors. Using 102 tumor samples representing a large spectrum of these tumors, we performed expression profiling and defined differentially expression genes that are likely to be involved in tumors that are locally aggressive and in tumors with metastatic potential. We described a set of 12 genes (SNRPD3, MEGF9, SPTAN-1, AFAP1L2, ENDOD1, SERPIN5, ZWINTAS, TOP2A, UBE2C, ABCF1, MCM2, and ARL6IP5) showing opposite expression when these two conditions were compared. These genes are mainly related to cell-cell and cell-extracellular matrix interactions and cell proliferation and might represent helpful tools for a more precise classification and diagnosis as well as potential drug targets. 相似文献
149.
Santos LL Magalhães Mde C Januário JN Aguiar MJ Carvalho MR 《Genetics and molecular research : GMR》2006,5(1):33-44
Phenylketonuria (PKU) is one of the few genetic diseases in which mental retardation can be prevented. Hence, diagnosis and treatment must be established early. PKU treatment consists of a phenylalanine-restricted diet supplemented with a phenylalanine-free mixture of amino acids. However, it is difficult to adhere to this diet. In the last decade, a better comprehension of the biochemistry, genetics and molecular basis of the disease, as well as the need for easier treatment, led to the development of several new therapeutic strategies for PKU. In the present study, we evaluated these new therapeutic options in terms of theoretical basis, methodologies, efficacy, and costs. 相似文献
150.
The occurrence of Platycorypha nigrivirga Burckhardt (Hemiptera: Psyllidae, Acizzinae), is reported for the first time, in Brazil. The psyllid was observed causing injuries on leaves and shoots of Tipuana tipu (Benth.), in urban areas of Paraná State. P. nigrivirga are tiny sap-sucking insects that feed on phloem and cause curling, stains and fall of leaves. The excrements of these insects accumulate on the leaves propitiating fungus growth on the leaves, or they fall in great amount on the cars dirtying them as if they were sparkling of white and sticky ink. 相似文献