排序方式: 共有184条查询结果,搜索用时 15 毫秒
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Braganhol E Tamajusuku AS Bernardi A Wink MR Battastini AM 《Biochimica et biophysica acta》2007,1770(9):1352-1359
Gliomas are the most malignant of the primary brain tumors. Nucleotides represent an important class of extracellular molecules that are crucial for the normal function of the nervous system. ATP and adenosine can stimulate cell proliferation in different glioma cell lines; the events induced by extracellular adenine nucleotides are controlled by the action of ecto-nucleotidases, which hydrolyze ATP into adenosine in the extracellular space. Recent studies have shown that quercetin has an anti-proliferative effect on the U138MG glioma cell line. Since evidence suggests that purinergic signaling is involved in the growth and progression of glioma and, taking into consideration the anti-proliferative effect elicited by quercetin in this tumor type, the aim of the present study was to better investigate the extracellular metabolism of AMP and evaluate the effect of quercetin on this system in the human U138MG glioma cell line. The adenine products secreted by glioma cells were first characterized; extracellular AMP was efficiently metabolized by the glioma culture, demonstrating a very active ecto-5'-NT/CD73. Quercetin was able to inhibit the ecto-5'-NT/CD73 activity and modulate its expression. In addition, the cell treatment with APCP (alpha,beta-methyleneadenosine-5'-diphosphate), an ecto-5'-NT/CD73 inhibitor, led to a significant reduction in glioma cell proliferation. We suggest that the inhibition of ecto-5'-NT/CD73 may result in a decrease in extracellular adenosine production with a consequent reduction in tumor progression. 相似文献
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Jaroslava Varella Valentova Marco Antonio Corrêa Varella Klára Bártová Zuzana Štěrbová Barnaby James Wyld Dixson 《Evolution and human behavior》2017,38(2):241-248
Recent research has reported that male body and facial hair influence women's mate preferences. However, it is not clear whether such preferences are typical for women or for individuals who prefer males as sexual partners. Here we explored body and facial hair in preferred and actual partners among men and women who prefer men as sexual partners. Including homosexual individuals provides a unique opportunity to investigate whether evolved mating psychologies are specific to the sex of the individual or sex of the partner. Based on an online survey of 1577 participants from Brazil and the Czech Republic, we found that, on average, homosexual men preferred hairier stimuli than heterosexual women, supporting past findings that homosexual men have strong preferences for masculine traits. Preferences for facial and body hair appear to be influenced less by sex of the preferred partner than sex of the individual, pointing to a possible sex-specific mating psychology. Further, Brazilians preferred bigger beards than Czechs, which was positively associated with the self-reported amount of beardedness in Brazil, suggesting that familiarity effects underpin cross-cultural differences in preferences for facial hair. Moreover, homosexual men preferred a self-similar degree of beardedness, and Czech women preferred a similar degree of beardedness as their fathers had during their childhood. However, these effects were not associated with the level of facial hair in their actual partners; in general, mate preferences and actual mate choices for facial and body hair differed. Thus, individual differences in some self-reported characteristics, cultural factors, and aspects of personal experience may modulate differences in preferences for masculine traits. 相似文献
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Andressa Carneiro do Nascimento José Montalva Mariano Lucia Daniel de Paiva Silva 《Journal of Applied Entomology》2023,147(1):23-35
The introduction of exotic species into native ecosystems can be a cause for concern when those species are invasive. Invasive species cause ecological problems and have socio-cultural impacts on human health and the economy; for example, invasive bees may negatively impact their introduced ecosystem by spreading diseases or outcompeting native pollinators. Xylocopa spp. bees are diverse and distributed throughout the Neotropics. However, Xylocopa augusti (Lepeletier, 1841) and Xylocopa splendidula (Lepeletier, 1841) are not native to Mediterranean Chile. This study aimed to evaluate the invasive potential of these exotic species and predict the potential macroecological effects of their invasions. We also aimed to pinpoint possible distributions for these species throughout South America. We correlated biogeographic occurrence data with climatic variables for each species to model their potential distribution in both current and future scenarios. The models provide strong evidence that both species are changing their distributions: their ranges are expanding towards western South America, particularly Bolivia, Chile and Peru. We demonstrate an increase in niche overlap between these species and show there are new geographic areas vulnerable to the establishment of these invasive bees under current and future climate conditions. These data suggest that these bees may adapt their geographic distribution as the climate changes and pose a threat to native pollinators in new geographic areas. 相似文献
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Thaddeus Gregory Blanchette Ana Paula Silva Andressa Raylane Bento 《Dialectical Anthropology》2013,37(2):195-227
Based upon the contradictory definitions of the crime, the Brazilian movement against trafficking in persons situates itself as a “struggle against modern slavery.” Within this moralistic context, the movement has frequently utilized invented statistics and apocalyptic declarations regarding trafficking in order to achieve greater “advocacy value” among members of the Brazilian public. A key component of this discursive formation has been the creation and promulgation of a mythological view of a “typical” trafficking victim’s experience: what we call “The Myth of Maria, an exemplary trafficking victim.” The present article seeks to follow the history of the Myth of Maria, developing an initial chronology mapped out and analyzed by Adriana Piscitelli in 2004 and extending this into the post-2006 period when Brazil established its first national policies and plans to combat trafficking in persons. We then analyze how the myth ignores many of the realities revealed by the past decade of ethnographic research into trafficking in Brazil. Finally, we conclude with a structuralist hypothesis (drawn from the field of feminist anthropology) regarding the Myth’s continuing unabated popularity among almost all actors in the political field of anti-trafficking policy. 相似文献
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Cioato Stefania Giotti Medeiros Liciane Fernandes Lopes Bettega Costa de Souza Andressa Medeiros Helouise Richardt Assumpção José Antônio Fagundes Caumo Wolnei Roesler Rafael Torres Iraci L. S. 《Purinergic signalling》2020,16(4):573-584
This study aimed to evaluate the effect of a single administration of IB-MECA, an A3 adenosine receptor agonist, upon the nociceptive response and central biomarkers of rats submitted to chronic pain models. A total of 136 adult male Wistar rats were divided into two protocols: (1) chronic inflammatory pain (CIP) using complete Freund’s adjuvant and (2) neuropathic pain (NP) by chronic constriction injury of the sciatic nerve. Thermal and mechanical hyperalgesia was measured using von Frey (VF), Randal-Selitto (RS), and hot plate (HP) tests. Rats were treated with a single dose of IB-MECA (0.5 μmol/kg i.p.), a vehicle (dimethyl sulfoxide—DMSO), or positive control (morphine, 5 mg/kg i.p.). Interleukin 1β (IL-1β), brain-derived neurotrophic factor (BDNF), and nerve growth factor (NGF) levels were measured in the brainstem and spinal cord using enzyme-linked immunosorbent assay (ELISA). The establishment of the chronic pain (CIP or NP) model was observed 14 days after induction by a decreased nociceptive threshold in all three tests (GEE, P < 0.05). The antinociceptive effect of a single dose of IB-MECA was observed in both chronic pain models, but this was more effective in NP model. There was an increase in IL-1β levels promoted by CIP. NP model promoted increase in the brainstem BDNF levels, which was reversed by IB-MECA 相似文献
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Klanovicz Natalia Camargo Aline Frumi Stefanski Fábio Spitza Zanivan Jessica Scapini Thamarys Pollon Rafaela Warken Andressa Paliga Letícia Preczeski Karina Paula Ribeiro Anderson André Genro Alves Garda-Buffon Jaqueline Fongaro Gislaine Treichel Helen 《Bioprocess and biosystems engineering》2020,43(2):261-272
Bioprocess and Biosystems Engineering - Enzymes are becoming tools in industrial processes because of several advantages, including activity in mild environmental conditions, and high specificity.... 相似文献
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Ariane Fernanda da Silva Rodrigo Juliano Oliveira Andressa Megumi Niwa Gláucia Fernanda Rocha D’Epiro Lúcia Regina Ribeiro Mário Sérgio Mantovani 《Cytotechnology》2013,65(1):41-48
β-glucan is an important polysaccharide due to its medicinal properties of stimulating the immune system and preventing chronic diseases such as cancer. The aim of the present study was to determine the anticlastogenic effect of β-glucan in cells exposed to ultraviolet radiation (UV). Chromosome aberration assay was performed in drug-metabolizing cells (HTC) and non drug-metabolizing cells (CHO-K1 and repair-deficient CHO-xrs5), using different treatment protocols. Continuous treatment (UV + β-glucan) was not effective in reducing the DNA damage only in CHO-xrs5 cells. However, the pre-treatment protocol (β-glucan before UV exposition) was effective in reducing DNA damage only in CHO-K1 cells. In post-treatment (β-glucan after UV exposition) did not show significative anticlastogenic effects, although there was a tendency toward prevention. The data suggest that β-glucan has more than one action mechanism, being capable of exerting desmutagenic as well as bio-antimutagenic action. The findings also suggest that the presence of the xenobiotic metabolizing system can reduce the chemopreventive capacity of β-glucan. Therefore, these results indicate that β-glucan from Saccharomyces cerevisiae can be used in the prevention and/or reduction of DNA damage. 相似文献
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LITAF is a 161 amino acid cellular protein which includes a proline rich N-terminus and a conserved C-terminal domain known as the simple-like domain. Mutations in LITAF have been identified in Charcot-Marie tooth disease, a disease characterized by protein aggregates. Cells transfected with cellular LITAF reveal that LITAF is localized to late endosomes/lysosomes. Here we investigated the intracellular localization of endogenous LITAF. We demonstrated that endogenous LITAF accumulates at a discrete cytoplasmic site in BGMK cells that we identify as the aggresome. To determine the domain within LITAF that is responsible for the localization of LITAF to aggresomes, we created a construct that contained the C-terminal simple-like domain of LITAF and found that this construct also localizes to aggresomes. These data suggest the simple-like domain is responsible for targeting endogenous LITAF to the aggresome. 相似文献