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排序方式: 共有382条查询结果,搜索用时 15 毫秒
1.
Marta Teixeira Pinto Ana Sofia Ribeiro Inês Conde Rita Carvalho Joana Paredes 《International journal of molecular sciences》2021,22(1)
The high plasticity of cancer stem-like cells (CSCs) allows them to differentiate and proliferate, specifically when xenotransplanted subcutaneously into immunocompromised mice. CSCs are highly tumorigenic, even when inoculated in small numbers. Thus, in vivo limiting dilution assays (LDA) in mice are the current gold standard method to evaluate CSC enrichment and activity. The chick embryo chorioallantoic membrane (CAM) is a low cost, naturally immune-incompetent and reproducible model widely used to evaluate the spontaneous growth of human tumor cells. Here, we established a CAM-LDA assay able to rapidly reproduce tumor specificities—in particular, the ability of the small population of CSCs to form tumors. We used a panel of organotropic metastatic breast cancer cells, which show an enrichment in a stem cell gene signature, enhanced CD44+/CD24−/low cell surface expression and increased mammosphere-forming efficiency (MFE). The size of CAM-xenografted tumors correlate with the number of inoculated cancer cells, following mice xenograft growth pattern. CAM and mice tumors are histologically comparable, displaying both breast CSC markers CD44 and CD49f. Therefore, we propose a new tool for studying CSC prevalence and function—the chick CAM-LDA—a model with easy handling, accessibility, rapid growth and the absence of ethical and regulatory constraints. 相似文献
2.
Fouto Ana R. Nunes Rita G. Pinto Joana Alves Luísa Calado Sofia Gonçalves Carina Rebolo Margarida Viana-Baptista Miguel Vilela Pedro Figueiredo Patrícia 《Magma (New York, N.Y.)》2022,35(5):779-790
Magnetic Resonance Materials in Physics, Biology and Medicine - Histogram-based metrics extracted from diffusion-tensor imaging (DTI) have been suggested as potential biomarkers for cerebral small... 相似文献
3.
We thoroughly study the behavioural theory of epi, a ??-calculus extended with polyadic synchronisation. We show that the natural contextual equivalence, barbed congruence, coincides with early bisimilarity, which is thus its co-inductive characterisation. Moreover, we relate early bisimilarity with the other usual notions, ground, late and open, obtaining a lattice of equivalence relations that clarifies the relationship among the ??standard?? bisimilarities. Furthermore, we apply the theory developed to obtain an expressiveness result: epi extended with key encryption primitives may be fully abstractly encoded in the original epi calculus. The proposed encoding is sound and complete with respect to barbed congruence; hence, cryptographic epi (crypto-epi) gets behavioural theory for free, which contrasts with other process languages with cryptographic constructs that usually require a big effort to develop such theory. Therefore, it is possible to use crypto-epi to analyse and to verify properties of security protocols using equational reasoning. To illustrate this claim, we prove compliance with symmetric and asymmetric cryptographic system laws, and the correctness of a protocol of secure message exchange. 相似文献
4.
Nelson James Byron; Sanjuan María del Carmen; Vadillo-Ruiz Sandra; Pérez Joana; León Samuel P. 《Canadian Metallurgical Quarterly》2011,37(1):58
Two experiments with human participants are presented that differentiate renewal from other behavioral effects that can produce a response after extinction. Participants played a video game and learned to suppress their behavior when sensor stimuli predicted an attack. Contexts (A, B, & C) were provided by fictitious galaxies where the game play took place. In Experiment 1, participants who received conditioning in A, extinction in B, and testing in A showed some context specificity of conditioning during extinction and a recovery of suppression on test. Experiment 2 demonstrated recovery of extinguished responding when participants were conditioned in A, extinguished in B, and tested in C, a third, neutral context. The experiment also demonstrated that the context of extinction did not control performance by becoming inhibitory. Results are discussed in terms of mechanisms that can produce a response recovery after extinction. The experiments demonstrated a renewal effect: a response recovery that was not attributable to the contexts acting as simple conditioned stimuli and is the first work with human participants to conclusively do so. (PsycINFO Database Record (c) 2010 APA, all rights reserved) 相似文献
5.
Joana F. B. Barata Paula S. S. Lacerda Maria Graa P. M. S. Neves Jos A. S. Cavaleiro Catarina I. V. Ramos Augusto C. Tom Paulo E. Abreu Alberto A. C. C. Pais 《International journal of molecular sciences》2022,23(21)
Details on the unexpected formation of two new (dimethylamino)methyl corrole isomers from the reaction of 5,10,15-tris(pentafluorophenyl)corrolatogallium(III) with sarcosine and paraformaldehyde are presented. Semi-empirical calculations on possible mechanism pathways seem to indicate that the new compounds are probably formed through a Mannich-type reaction. The extension of the protocol to the free-base 5,10,15-tris(pentafluorophenyl)corrole afforded an unexpected new seven-membered ring corrole derivative, confirming the peculiar behavior of corroles towards known reactions when compared to the well-behaved porphyrin counterparts. 相似文献
6.
Sofia Nogueira Joana Barbosa Juliana Faria Susana I. S Armando Cardoso Raquel Soares Bruno M. Fonseca Sandra Leal 《International journal of molecular sciences》2022,23(18)
The intestinal epithelium is a principal site for environmental agents’ detection. Several inflammation- and stress-related signalling pathways have been identified as key players in these processes. However, it is still unclear how the chronic intake of inadequate nutrients triggers inflammatory signalling pathways in different intestinal regions. We aimed to evaluate the impact of unhealthy dietary patterns, starting at a younger age, and the association with metabolic dysfunction, intestinal inflammatory response, and obesity in adulthood. A rat model was used to evaluate the effects of the consumption of sugary beverages (HSD) and a Western diet (WD), composed of ultra-processed foods. Both diets showed a positive correlation with adiposity index, but a positive correlation was found between the HSD diet and the levels of blood glucose and triglycerides, whereas the WD diet correlated positively with triglyceride levels. Moreover, a distinct inflammatory response was associated with either the WD or HSD diets. The WD induced an increase in TLR2, TLR4, and nuclear factor-kappa B (NF-κB) intestinal gene expression, with higher levels in the colon and overexpression of the inducible nitric oxide synthase. In turn, the HSD diet induced activation of the TLR2-mediated NF-κB signalling pathway in the small intestine. Altogether, these findings support the concept that early intake of unhealthy foods and nutrients are a main exogenous signal for disturbances of intestinal immune mechanisms and in a region-specific manner, ultimately leading to obesity-related disorders in later life. 相似文献
7.
Nuno Vale Mariana Pereira Joana Santos Catarina Moura Lara Marques Diana Duarte 《International journal of molecular sciences》2023,24(1)
Chemotherapy is the main treatment for most early-stage cancers; nevertheless, its efficacy is usually limited by drug resistance, toxicity, and tumor heterogeneity. Cell-penetrating peptides (CPPs) are small peptide sequences that can be used to increase the delivery rate of chemotherapeutic drugs to the tumor site, therefore contributing to overcoming these problems and enhancing the efficacy of chemotherapy. The drug combination is another promising strategy to overcome the aforementioned problems since the combined drugs can synergize through interconnected biological processes and target different pathways simultaneously. Here, we hypothesized that different peptides (P1–P4) could be used to enhance the delivery of chemotherapeutic agents into three different cancer cells (HT-29, MCF-7, and PC-3). In silico studies were performed to simulate the pharmacokinetic (PK) parameters of each peptide and antineoplastic agent to help predict synergistic interactions in vitro. These simulations predicted peptides P2–P4 to have higher bioavailability and lower Tmax, as well as the chemotherapeutic agent 5-fluorouracil (5-FU) to have enhanced permeability properties over other antineoplastic agents, with P3 having prominent accumulation in the colon. In vitro studies were then performed to evaluate the combination of each peptide with the chemotherapeutic agents as well as to assess the nature of drug interactions through the quantification of the Combination Index (CI). Our findings in MCF-7 and PC-3 cancer cells demonstrated that the combination of these peptides with paclitaxel (PTX) and doxorubicin (DOXO), respectively, is not advantageous over a single treatment with the chemotherapeutic agent. In the case of HT-29 colorectal cancer cells, the combination of P2–P4 with 5-FU resulted in synergistic cytotoxic effects, as predicted by the in silico simulations. Taken together, these findings demonstrate that these CPP6-conjugates can be used as adjuvant agents to increase the delivery of 5-FU into HT-29 colorectal cancer cells. Moreover, these results support the use of in silico approaches for the prediction of the interaction between drugs in combination therapy for cancer. 相似文献
8.
Bruna R. Kouba Joana Gil-Mohapel Ana Lúcia S. Rodrigues 《International journal of molecular sciences》2023,24(1)
Major depressive disorder (MDD) is a highly prevalent psychiatric disorder, whose pathophysiology has been linked to the neuroinflammatory process. The increased activity of the Nod-like receptor pyrin containing protein 3 (NLRP3) inflammasome, an intracellular multiprotein complex, is intrinsically implicated in neuroinflammation by promoting the maturation and release of proinflammatory cytokines such as interleukin (IL)-1β and IL-18. Interestingly, individuals suffering from MDD have higher expression of NLRP3 inflammasome components and proinflammatory cytokines when compared to healthy individuals. In part, intense activation of the inflammasome may be related to autophagic impairment. Noteworthy, some conventional antidepressants induce autophagy, resulting in less activation of the NLRP3 inflammasome. In addition, the fast-acting antidepressant ketamine, some bioactive compounds and physical exercise have also been shown to have anti-inflammatory properties via inflammasome inhibition. Therefore, it is suggested that modulation of inflammasome-driven pathways may have an antidepressant effect. Here, we review the role of the NLRP3 inflammasome in the pathogenesis of MDD, highlighting that pathways related to its priming and activation are potential therapeutic targets for the treatment of MDD. 相似文献
9.
Joo Neves Joo Monteiro Bruno Sousa Cristiano Soares Susana Pereira Fernanda Fidalgo Jos Pissarra Cludia Pereira 《International journal of molecular sciences》2023,24(1)
Plants must adapt to cope with adverse environmental conditions that affect their growth and development. To overcome these constraints, they can alter their developmental patterns by modulating cellular processes and activating stress-responsive signals. Alongside the activation of the antioxidant (AOX) system, a high number of genes are expressed, and proteins must be distributed to the correct locations within the cell. The endomembrane system and associated vesicles thus play an important role. Several pathways have been associated with adverse environmental conditions, which is the case for the exocyst-positive organelle—EXPO. The present work, using Arabidopsis mutants with T-DNA insertions in the gene EXO70, essential for EXPO vesicles formation, was designed to characterise the anatomical (morphology and root length), biochemical (quantification of stress markers and antioxidant system components), and molecular responses (gene expression) to abiotic stresses (saline, drought, oxidative, and metal-induced toxicity). The results obtained showed that mutant plants behave differently from the wild type (WT) plants. Therefore, in the exo70 mutant, morphological changes were more noticeable in plants under stress, and the non-enzymatic component of the antioxidant system was activated, with no alterations to the enzymatic component. Furthermore, other defence strategies, such as autophagy, did not show important changes. These results confirmed the EXPO as an important structure for tolerance/adaptation to stress. 相似文献
10.
Sónia Soares Joana S. Amaral Maria Beatriz P.P. Oliveira Isabel Mafra 《Comprehensive Reviews in Food Science and Food Safety》2017,16(5):1072-1100
Honey is a highly consumed natural product, not only for its taste and nutritional value, but also for its health benefits. Owing to characteristics that are essentially or exclusively related to the specific region or particular local environment and flora, honey can be classified as a premium product generally perceived as a high‐quality and valued product because of its desirable flavor and taste. Consequently, honey has been a target of adulteration through inappropriate/fraudulent production practices and mislabeling origin. Globally, authentication of honey covers 2 main aspects: the production, with main issues related to sugar syrup addition, filtration, thermal treatment, and water content; and the labeled origin (geographical and/or botanical) and “organic” provenance. This review addresses all those issues, focusing on the approaches to detect the different types of honey adulteration. Due to the complex nature of honey and to the different types of adulteration, its authentication has been challenging and prompted the development of several advanced analytical approaches. Therefore, an updated, critical, and extensive overview on the current and advanced analytical methods targeting markers of adulteration/authenticity, including nontarget fingerprint approaches will be provided. The most recent advances on molecular, chromatographic, and spectroscopic methodologies will be described, emphasizing their pros and cons for the identification of botanical and geographical origins. 相似文献