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951.
Carlos R. Oliveira Fábio D. Nascimento Marília B. Meneghin Edgar J. Paredes-Gamero Tiago Rodrigues Antonio C.F. Caires Claudia Bincoletto 《Chemico-biological interactions》2009,177(3):181-189
Previous studies reported by our group have introduced a new antitumoural drug called Biphosphinic Palladacycle Complex (BPC). In this paper we show that BPC causes apoptosis in leukaemia cells (HL60 and Jurkat), but not in normal human lymphocytes. IC50 values obtained for both cell lines using the MTT and trypan blue exclusion assays 5 h after BPC treatment were lower than 8.0 μM. Using metachromatic fluorophore, acridine orange, we observed that BPC elicited lysosomal rupture of leukaemic cells. Furthermore, BPC triggered caspase-3 and caspase-6 activation and apoptosis in cell lines, inducing chromatin condensation, apoptotic bodies, and DNA fragmentation. Interestingly, the lysosomal cathepsin B inhibitor CA074 markedly decreased BPC-induced caspase-3 and caspase-6 activation as well as cell death. Lysosomal BPC-induced membrane destabilisation was not dependent on reactive oxygen species generation, which was consistent with the absence of cellular HL60 and Jurkat membrane lipid peroxidation. We conclude that, following BPC treatment, lysosomal membrane rupture precedes cell death and the apoptotic signalling pathway is initiated by the release of cathepsin B in the cytoplasm of leukaemia cells. As no toxic effects for human lymphocytes were observed, we suggest that BPC is more selective for transformed cells, mainly due to their exacerbated lysosome expression. 相似文献
952.
Tiago Canelas Edward Thomsen Basile Kamgang Louise A. Kelly-Hope 《Medical and veterinary entomology》2023,37(1):143-151
Aedes-transmitted arboviruses have spread globally due to the spread of Aedes aegypti and Aedes albopictus. Its distribution is associated with human and physical geography. However, these factors have not been quantified in Cameroon. Therefore, the aim was to develop an Ae. albopictus geo-referenced database to examine the risk factors associated with the vector distribution in Cameroon. Data on the Ae. albopictus presence and absence were collated and mapped from studies in published scientific literature between 2000 and 2020. Publicly available earth observation data were used to assess human geography, land use and climate risk factors related to the vector distribution. A logistic binomial regression was conducted to identify the significant risk factors associated with Ae. albopictus distribution. In total, 111 data points were collated (presence = 87; absence = 24). Different data collection methods and sites hindered the spatiotemporal analysis. An increase of one wet month in a year increased the odds of Ae. albopictus presence by 5.6 times. One unit of peri-urban area increased the odds by 1.3 times. Using publicly available demographic and environmental data to better understand the key determinants of mosquito distributions may facilitate appropriately targeted public health messages and vector control strategies. 相似文献
953.
954.
Lucia Libanez Bessa Campelo Braga Maria Aparecida Alves de Oliveira Maria Helane Rocha Batista Gon?alves Fernando Kennedy Chaves Tiago Gomes da Silva Benigno Adriana Dias Gomes Cícero Igor Sim?es Moura Silva Charles Anacleto Sérgio de Assis Batista Dulciene Maria Magalh?es Queiroz 《Memórias do Instituto Oswaldo Cruz》2014,109(8):1045-1049
Helicobacter pylori infection is one of the most common infections
worldwide and is associated with gastric diseases. Virulence factors such as VacA and
CagA have been shown to increase the risk of these diseases. Studies have suggested a
causal role of CagA EPIYA-C in gastric carcinogenesis and this factor has been shown
to be geographically diverse. We investigated the number of CagA EPIYA motifs and the
vacA i genotypes in H. pylori strains from
asymptomatic children. We included samples from 40 infected children (18 females and
22 males), extracted DNA directly from the gastric mucus/juice (obtained using the
string procedure) and analysed the DNA using polymerase chain reaction and DNA
sequencing. The vacA i1 genotype was present in 30 (75%) samples,
the i2 allele was present in nine (22.5%) samples and both alleles were present in
one (2.5%) sample. The cagA-positive samples showed distinct
patterns in the 3’ variable region of cagA and 18 of the 30 (60%)
strains contained 1 EPIYA-C motif, whereas 12 (40%) strains contained two EPIYA-C
motifs. We confirmed that the studied population was colonised early by the most
virulent H. pylori strains, as demonstrated by the high frequency of
the vacA i1 allele and the high number of EPIYA-C motifs. Therefore,
asymptomatic children from an urban community in Fortaleza in northeastern Brazil are
frequently colonised with the most virulent H. pylori
strains. 相似文献
955.
Jesús Alczar-Trevio Mark Johnson Patricia Arranz Victoria E. Warren Carlos J. Prez-Gonzlez Tiago Marques Peter T. Madsen Natacha Aguilar de Soto 《Proceedings. Biological sciences / The Royal Society》2021,288(1942)
Echolocating animals that forage in social groups can potentially benefit from eavesdropping on other group members, cooperative foraging or social defence, but may also face problems of acoustic interference and intra-group competition for prey. Here, we investigate these potential trade-offs of sociality for extreme deep-diving Blainville′s and Cuvier''s beaked whales. These species perform highly synchronous group dives as a presumed predator-avoidance behaviour, but the benefits and costs of this on foraging have not been investigated. We show that group members could hear their companions for a median of at least 91% of the vocal foraging phase of their dives. This enables whales to coordinate their mean travel direction despite differing individual headings as they pursue prey on a minute-by-minute basis. While beaked whales coordinate their echolocation-based foraging periods tightly, individual click and buzz rates are both independent of the number of whales in the group. Thus, their foraging performance is not affected by intra-group competition or interference from group members, and they do not seem to capitalize directly on eavesdropping on the echoes produced by the echolocation clicks of their companions. We conclude that the close diving and vocal synchronization of beaked whale groups that quantitatively reduces predation risk has little impact on foraging performance. 相似文献
956.
Tiago Benedito dos Santos Viviane Y. Baba Luiz Gonzaga Esteves Vieira Luiz Filipe Protasio Pereira Douglas Silva Domingues 《Physiology and Molecular Biology of Plants》2021,27(2):203
The high costs of N fertilizers in the coffee production emphasizes the need to optimize fertilization practices and improve nitrogen use efficiency. Urea is widespread in nature, characterizing itself as a significant source of nitrogen for the growth and development of several organisms. Thus, the characterization of genes involved in urea transport in coffee plants is an important research topic for the sustainable production of this valuable cash crop. In the current study, we evaluated the expression of the DUR3 gene under abiotic and biotic stresses in coffee plants. Here, we show that the expression of a high-affinity urea transporter gene (CaDUR3) was up-regulated by N starvation in leaves and roots of two out of three C. arabica cultivars examined. Moreover, the CaDUR3 gene was differentially expressed in coffee plants under different abiotic and biotic stresses. In plants of cv. IAPAR59, CaDUR3 showed an increased expression in leaves after exposure to water deficit and heat stress, while it was downregulated in plants under salinity. Upon infection with H. vastatrix (coffee rust), the CaDUR3 was markedly up-regulated at the beginning of the infection process in the disease susceptible Catuaí Vermelho 99 in comparison with the resistant cultivar. These results indicate that besides urea acquisition and N-remobilization, CaDUR3 gene may be closely involved in the response to various stresses. 相似文献
957.
de Moura e Dias Mariana dos Reis Louzano Sandra Aparecida da Conceição Lisiane Lopes da Conceição Fernandes Rayssa de Oliveira Mendes Tiago Antônio Pereira Solange Silveira de Oliveira Leandro Licursi Gouveia Peluzio Maria do Carmo 《Probiotics and antimicrobial proteins》2021,13(6):1621-1631
Probiotics and Antimicrobial Proteins - The development of adjuvant therapies for obesity treatment is justified by the high prevalence of this disease worldwide, and the relationship between... 相似文献
958.
Manuela da Silva Solc Maiara Reis Arruda Bruna Martins Macedo Leite Tiago Feitosa Mota Miriam Flores Rebouas Matheus Silva de Jesus Leila Denise Alves Ferreira Amorim Valria Matos Borges Jesus Valenzuela Shaden Kamhawi Patrícia Sampaio Tavares Veras Deborah Bittencourt Moth Fraga Claudia Ida Brodskyn 《PLoS neglected tropical diseases》2021,15(2)
BackgroundReports have shown correlations between the immune response to vector saliva and Leishmaniasis outcome. We followed dogs in an endemic area for two years characterizing resistance or susceptibility to canine visceral leishmaniasis (CVL) according to Leishmania infantum diagnosis and clinical development criteria. Then, we aimed to identify a biosignature based on parasite load, serum biological mediators’ interactions, and vector exposure intensity associated with CVL resistance and susceptibility.Methodology/Principal findingsA prospective two-year study was conducted in an area endemic for CVL. Dogs were evaluated at 6-month intervals to determine infection, clinical manifestations, immune profile, and sandfly exposure. CVL resistance or susceptibility was determined upon the conclusion of the study. After two years, 78% of the dogs were infected with L. infantum (53% susceptible and 47% resistant to CVL). Susceptible dogs presented higher splenic parasite load as well as persistence of the parasite during the follow-up, compared to resistant ones. Susceptible dogs also displayed a higher number of correlations among the investigated biological mediators, before and after infection diagnosis. At baseline, anti-saliva antibodies, indicative of exposure to the vector, were detected in 62% of the dogs, reaching 100% in one year. Higher sandfly exposure increased the risk of susceptibility to CVL by 1.6 times (CI: 1.11–2.41). We identified a discriminatory biosignature between the resistant and susceptible dogs assessing splenic parasite load, interaction of biological mediators, PGE2 serum levels and intensity of exposure to sandfly. All these parameters were elevated in susceptible dogs compared to resistant animals.Conclusions/SignificanceThe biosignature identified in our study reinforces the idea that CVL is a complex multifactorial disease that is affected by a set of factors which are correlated and, for a better understanding of CVL, should not be evaluated in an isolated way. 相似文献
959.
Tumor cell plasticity is an event that has been observed in several malignancies. In fact, most of the solid tumors are characterized by cellular heterogeneity and undergo constant changes as the tumor develops. The increased plasticity displayed by these cells allows them to acquire additional properties, enabling epithelial-mesenchymal transitions, dedifferentiation and the acquisition of stem cell-like properties. Here we discuss the particular importance of an inflammatory microenvironment for the bidirectional control of cellular plasticity and the potential for therapeutic intervention. 相似文献
960.
Tiago Villanueva 《CMAJ》2010,182(18):E825-E826